Bug Summary

File:build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/clang/lib/Sema/SemaTemplate.cpp
Warning:line 1402, column 5
Value stored to 'RD' is never read

Annotated Source Code

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clang -cc1 -cc1 -triple x86_64-pc-linux-gnu -analyze -disable-free -clear-ast-before-backend -disable-llvm-verifier -discard-value-names -main-file-name SemaTemplate.cpp -analyzer-store=region -analyzer-opt-analyze-nested-blocks -analyzer-checker=core -analyzer-checker=apiModeling -analyzer-checker=unix -analyzer-checker=deadcode -analyzer-checker=cplusplus -analyzer-checker=security.insecureAPI.UncheckedReturn -analyzer-checker=security.insecureAPI.getpw -analyzer-checker=security.insecureAPI.gets -analyzer-checker=security.insecureAPI.mktemp -analyzer-checker=security.insecureAPI.mkstemp -analyzer-checker=security.insecureAPI.vfork -analyzer-checker=nullability.NullPassedToNonnull -analyzer-checker=nullability.NullReturnedFromNonnull -analyzer-output plist -w -setup-static-analyzer -analyzer-config-compatibility-mode=true -mrelocation-model pic -pic-level 2 -mframe-pointer=none -relaxed-aliasing -fmath-errno -ffp-contract=on -fno-rounding-math -mconstructor-aliases -funwind-tables=2 -target-cpu x86-64 -tune-cpu generic -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm -resource-dir /usr/lib/llvm-15/lib/clang/15.0.0 -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/clang/lib/Sema -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/clang/include -I tools/clang/include -I include -I /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/llvm/include -D _FORTIFY_SOURCE=2 -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-15/lib/clang/15.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm=build-llvm -fmacro-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm=build-llvm -fcoverage-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -O3 -Wno-unused-command-line-argument -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/build-llvm=build-llvm -fdebug-prefix-map=/build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/= -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -fcolor-diagnostics -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2022-04-20-140412-16051-1 -x c++ /build/llvm-toolchain-snapshot-15~++20220420111733+e13d2efed663/clang/lib/Sema/SemaTemplate.cpp
1//===------- SemaTemplate.cpp - Semantic Analysis for C++ Templates -------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//===----------------------------------------------------------------------===//
7//
8// This file implements semantic analysis for C++ templates.
9//===----------------------------------------------------------------------===//
10
11#include "TreeTransform.h"
12#include "clang/AST/ASTConsumer.h"
13#include "clang/AST/ASTContext.h"
14#include "clang/AST/Decl.h"
15#include "clang/AST/DeclFriend.h"
16#include "clang/AST/DeclTemplate.h"
17#include "clang/AST/Expr.h"
18#include "clang/AST/ExprCXX.h"
19#include "clang/AST/RecursiveASTVisitor.h"
20#include "clang/AST/TemplateName.h"
21#include "clang/AST/TypeVisitor.h"
22#include "clang/Basic/Builtins.h"
23#include "clang/Basic/LangOptions.h"
24#include "clang/Basic/PartialDiagnostic.h"
25#include "clang/Basic/Stack.h"
26#include "clang/Basic/TargetInfo.h"
27#include "clang/Sema/DeclSpec.h"
28#include "clang/Sema/Initialization.h"
29#include "clang/Sema/Lookup.h"
30#include "clang/Sema/Overload.h"
31#include "clang/Sema/ParsedTemplate.h"
32#include "clang/Sema/Scope.h"
33#include "clang/Sema/SemaInternal.h"
34#include "clang/Sema/Template.h"
35#include "clang/Sema/TemplateDeduction.h"
36#include "llvm/ADT/SmallBitVector.h"
37#include "llvm/ADT/SmallString.h"
38#include "llvm/ADT/StringExtras.h"
39
40#include <iterator>
41using namespace clang;
42using namespace sema;
43
44// Exported for use by Parser.
45SourceRange
46clang::getTemplateParamsRange(TemplateParameterList const * const *Ps,
47 unsigned N) {
48 if (!N) return SourceRange();
49 return SourceRange(Ps[0]->getTemplateLoc(), Ps[N-1]->getRAngleLoc());
50}
51
52unsigned Sema::getTemplateDepth(Scope *S) const {
53 unsigned Depth = 0;
54
55 // Each template parameter scope represents one level of template parameter
56 // depth.
57 for (Scope *TempParamScope = S->getTemplateParamParent(); TempParamScope;
58 TempParamScope = TempParamScope->getParent()->getTemplateParamParent()) {
59 ++Depth;
60 }
61
62 // Note that there are template parameters with the given depth.
63 auto ParamsAtDepth = [&](unsigned D) { Depth = std::max(Depth, D + 1); };
64
65 // Look for parameters of an enclosing generic lambda. We don't create a
66 // template parameter scope for these.
67 for (FunctionScopeInfo *FSI : getFunctionScopes()) {
68 if (auto *LSI = dyn_cast<LambdaScopeInfo>(FSI)) {
69 if (!LSI->TemplateParams.empty()) {
70 ParamsAtDepth(LSI->AutoTemplateParameterDepth);
71 break;
72 }
73 if (LSI->GLTemplateParameterList) {
74 ParamsAtDepth(LSI->GLTemplateParameterList->getDepth());
75 break;
76 }
77 }
78 }
79
80 // Look for parameters of an enclosing terse function template. We don't
81 // create a template parameter scope for these either.
82 for (const InventedTemplateParameterInfo &Info :
83 getInventedParameterInfos()) {
84 if (!Info.TemplateParams.empty()) {
85 ParamsAtDepth(Info.AutoTemplateParameterDepth);
86 break;
87 }
88 }
89
90 return Depth;
91}
92
93/// \brief Determine whether the declaration found is acceptable as the name
94/// of a template and, if so, return that template declaration. Otherwise,
95/// returns null.
96///
97/// Note that this may return an UnresolvedUsingValueDecl if AllowDependent
98/// is true. In all other cases it will return a TemplateDecl (or null).
99NamedDecl *Sema::getAsTemplateNameDecl(NamedDecl *D,
100 bool AllowFunctionTemplates,
101 bool AllowDependent) {
102 D = D->getUnderlyingDecl();
103
104 if (isa<TemplateDecl>(D)) {
105 if (!AllowFunctionTemplates && isa<FunctionTemplateDecl>(D))
106 return nullptr;
107
108 return D;
109 }
110
111 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
112 // C++ [temp.local]p1:
113 // Like normal (non-template) classes, class templates have an
114 // injected-class-name (Clause 9). The injected-class-name
115 // can be used with or without a template-argument-list. When
116 // it is used without a template-argument-list, it is
117 // equivalent to the injected-class-name followed by the
118 // template-parameters of the class template enclosed in
119 // <>. When it is used with a template-argument-list, it
120 // refers to the specified class template specialization,
121 // which could be the current specialization or another
122 // specialization.
123 if (Record->isInjectedClassName()) {
124 Record = cast<CXXRecordDecl>(Record->getDeclContext());
125 if (Record->getDescribedClassTemplate())
126 return Record->getDescribedClassTemplate();
127
128 if (ClassTemplateSpecializationDecl *Spec
129 = dyn_cast<ClassTemplateSpecializationDecl>(Record))
130 return Spec->getSpecializedTemplate();
131 }
132
133 return nullptr;
134 }
135
136 // 'using Dependent::foo;' can resolve to a template name.
137 // 'using typename Dependent::foo;' cannot (not even if 'foo' is an
138 // injected-class-name).
139 if (AllowDependent && isa<UnresolvedUsingValueDecl>(D))
140 return D;
141
142 return nullptr;
143}
144
145void Sema::FilterAcceptableTemplateNames(LookupResult &R,
146 bool AllowFunctionTemplates,
147 bool AllowDependent) {
148 LookupResult::Filter filter = R.makeFilter();
149 while (filter.hasNext()) {
150 NamedDecl *Orig = filter.next();
151 if (!getAsTemplateNameDecl(Orig, AllowFunctionTemplates, AllowDependent))
152 filter.erase();
153 }
154 filter.done();
155}
156
157bool Sema::hasAnyAcceptableTemplateNames(LookupResult &R,
158 bool AllowFunctionTemplates,
159 bool AllowDependent,
160 bool AllowNonTemplateFunctions) {
161 for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) {
162 if (getAsTemplateNameDecl(*I, AllowFunctionTemplates, AllowDependent))
163 return true;
164 if (AllowNonTemplateFunctions &&
165 isa<FunctionDecl>((*I)->getUnderlyingDecl()))
166 return true;
167 }
168
169 return false;
170}
171
172TemplateNameKind Sema::isTemplateName(Scope *S,
173 CXXScopeSpec &SS,
174 bool hasTemplateKeyword,
175 const UnqualifiedId &Name,
176 ParsedType ObjectTypePtr,
177 bool EnteringContext,
178 TemplateTy &TemplateResult,
179 bool &MemberOfUnknownSpecialization,
180 bool Disambiguation) {
181 assert(getLangOpts().CPlusPlus && "No template names in C!")(static_cast <bool> (getLangOpts().CPlusPlus &&
"No template names in C!") ? void (0) : __assert_fail ("getLangOpts().CPlusPlus && \"No template names in C!\""
, "clang/lib/Sema/SemaTemplate.cpp", 181, __extension__ __PRETTY_FUNCTION__
))
;
182
183 DeclarationName TName;
184 MemberOfUnknownSpecialization = false;
185
186 switch (Name.getKind()) {
187 case UnqualifiedIdKind::IK_Identifier:
188 TName = DeclarationName(Name.Identifier);
189 break;
190
191 case UnqualifiedIdKind::IK_OperatorFunctionId:
192 TName = Context.DeclarationNames.getCXXOperatorName(
193 Name.OperatorFunctionId.Operator);
194 break;
195
196 case UnqualifiedIdKind::IK_LiteralOperatorId:
197 TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier);
198 break;
199
200 default:
201 return TNK_Non_template;
202 }
203
204 QualType ObjectType = ObjectTypePtr.get();
205
206 AssumedTemplateKind AssumedTemplate;
207 LookupResult R(*this, TName, Name.getBeginLoc(), LookupOrdinaryName);
208 if (LookupTemplateName(R, S, SS, ObjectType, EnteringContext,
209 MemberOfUnknownSpecialization, SourceLocation(),
210 &AssumedTemplate,
211 /*AllowTypoCorrection=*/!Disambiguation))
212 return TNK_Non_template;
213
214 if (AssumedTemplate != AssumedTemplateKind::None) {
215 TemplateResult = TemplateTy::make(Context.getAssumedTemplateName(TName));
216 // Let the parser know whether we found nothing or found functions; if we
217 // found nothing, we want to more carefully check whether this is actually
218 // a function template name versus some other kind of undeclared identifier.
219 return AssumedTemplate == AssumedTemplateKind::FoundNothing
220 ? TNK_Undeclared_template
221 : TNK_Function_template;
222 }
223
224 if (R.empty())
225 return TNK_Non_template;
226
227 NamedDecl *D = nullptr;
228 UsingShadowDecl *FoundUsingShadow = dyn_cast<UsingShadowDecl>(*R.begin());
229 if (R.isAmbiguous()) {
230 // If we got an ambiguity involving a non-function template, treat this
231 // as a template name, and pick an arbitrary template for error recovery.
232 bool AnyFunctionTemplates = false;
233 for (NamedDecl *FoundD : R) {
234 if (NamedDecl *FoundTemplate = getAsTemplateNameDecl(FoundD)) {
235 if (isa<FunctionTemplateDecl>(FoundTemplate))
236 AnyFunctionTemplates = true;
237 else {
238 D = FoundTemplate;
239 FoundUsingShadow = dyn_cast<UsingShadowDecl>(FoundD);
240 break;
241 }
242 }
243 }
244
245 // If we didn't find any templates at all, this isn't a template name.
246 // Leave the ambiguity for a later lookup to diagnose.
247 if (!D && !AnyFunctionTemplates) {
248 R.suppressDiagnostics();
249 return TNK_Non_template;
250 }
251
252 // If the only templates were function templates, filter out the rest.
253 // We'll diagnose the ambiguity later.
254 if (!D)
255 FilterAcceptableTemplateNames(R);
256 }
257
258 // At this point, we have either picked a single template name declaration D
259 // or we have a non-empty set of results R containing either one template name
260 // declaration or a set of function templates.
261
262 TemplateName Template;
263 TemplateNameKind TemplateKind;
264
265 unsigned ResultCount = R.end() - R.begin();
266 if (!D && ResultCount > 1) {
267 // We assume that we'll preserve the qualifier from a function
268 // template name in other ways.
269 Template = Context.getOverloadedTemplateName(R.begin(), R.end());
270 TemplateKind = TNK_Function_template;
271
272 // We'll do this lookup again later.
273 R.suppressDiagnostics();
274 } else {
275 if (!D) {
276 D = getAsTemplateNameDecl(*R.begin());
277 assert(D && "unambiguous result is not a template name")(static_cast <bool> (D && "unambiguous result is not a template name"
) ? void (0) : __assert_fail ("D && \"unambiguous result is not a template name\""
, "clang/lib/Sema/SemaTemplate.cpp", 277, __extension__ __PRETTY_FUNCTION__
))
;
278 }
279
280 if (isa<UnresolvedUsingValueDecl>(D)) {
281 // We don't yet know whether this is a template-name or not.
282 MemberOfUnknownSpecialization = true;
283 return TNK_Non_template;
284 }
285
286 TemplateDecl *TD = cast<TemplateDecl>(D);
287
288 if (SS.isSet() && !SS.isInvalid()) {
289 NestedNameSpecifier *Qualifier = SS.getScopeRep();
290 // FIXME: store the using TemplateName in QualifiedTemplateName if
291 // the TD is referred via a using-declaration.
292 Template =
293 Context.getQualifiedTemplateName(Qualifier, hasTemplateKeyword, TD);
294 } else {
295 Template =
296 FoundUsingShadow ? TemplateName(FoundUsingShadow) : TemplateName(TD);
297 assert(!FoundUsingShadow || FoundUsingShadow->getTargetDecl() == TD)(static_cast <bool> (!FoundUsingShadow || FoundUsingShadow
->getTargetDecl() == TD) ? void (0) : __assert_fail ("!FoundUsingShadow || FoundUsingShadow->getTargetDecl() == TD"
, "clang/lib/Sema/SemaTemplate.cpp", 297, __extension__ __PRETTY_FUNCTION__
))
;
298 }
299
300 if (isa<FunctionTemplateDecl>(TD)) {
301 TemplateKind = TNK_Function_template;
302
303 // We'll do this lookup again later.
304 R.suppressDiagnostics();
305 } else {
306 assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) ||(static_cast <bool> (isa<ClassTemplateDecl>(TD) ||
isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl
>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl
>(TD) || isa<ConceptDecl>(TD)) ? void (0) : __assert_fail
("isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD)"
, "clang/lib/Sema/SemaTemplate.cpp", 308, __extension__ __PRETTY_FUNCTION__
))
307 isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) ||(static_cast <bool> (isa<ClassTemplateDecl>(TD) ||
isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl
>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl
>(TD) || isa<ConceptDecl>(TD)) ? void (0) : __assert_fail
("isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD)"
, "clang/lib/Sema/SemaTemplate.cpp", 308, __extension__ __PRETTY_FUNCTION__
))
308 isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD))(static_cast <bool> (isa<ClassTemplateDecl>(TD) ||
isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl
>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl
>(TD) || isa<ConceptDecl>(TD)) ? void (0) : __assert_fail
("isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD)"
, "clang/lib/Sema/SemaTemplate.cpp", 308, __extension__ __PRETTY_FUNCTION__
))
;
309 TemplateKind =
310 isa<VarTemplateDecl>(TD) ? TNK_Var_template :
311 isa<ConceptDecl>(TD) ? TNK_Concept_template :
312 TNK_Type_template;
313 }
314 }
315
316 TemplateResult = TemplateTy::make(Template);
317 return TemplateKind;
318}
319
320bool Sema::isDeductionGuideName(Scope *S, const IdentifierInfo &Name,
321 SourceLocation NameLoc,
322 ParsedTemplateTy *Template) {
323 CXXScopeSpec SS;
324 bool MemberOfUnknownSpecialization = false;
325
326 // We could use redeclaration lookup here, but we don't need to: the
327 // syntactic form of a deduction guide is enough to identify it even
328 // if we can't look up the template name at all.
329 LookupResult R(*this, DeclarationName(&Name), NameLoc, LookupOrdinaryName);
330 if (LookupTemplateName(R, S, SS, /*ObjectType*/ QualType(),
331 /*EnteringContext*/ false,
332 MemberOfUnknownSpecialization))
333 return false;
334
335 if (R.empty()) return false;
336 if (R.isAmbiguous()) {
337 // FIXME: Diagnose an ambiguity if we find at least one template.
338 R.suppressDiagnostics();
339 return false;
340 }
341
342 // We only treat template-names that name type templates as valid deduction
343 // guide names.
344 TemplateDecl *TD = R.getAsSingle<TemplateDecl>();
345 if (!TD || !getAsTypeTemplateDecl(TD))
346 return false;
347
348 if (Template)
349 *Template = TemplateTy::make(TemplateName(TD));
350 return true;
351}
352
353bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II,
354 SourceLocation IILoc,
355 Scope *S,
356 const CXXScopeSpec *SS,
357 TemplateTy &SuggestedTemplate,
358 TemplateNameKind &SuggestedKind) {
359 // We can't recover unless there's a dependent scope specifier preceding the
360 // template name.
361 // FIXME: Typo correction?
362 if (!SS || !SS->isSet() || !isDependentScopeSpecifier(*SS) ||
363 computeDeclContext(*SS))
364 return false;
365
366 // The code is missing a 'template' keyword prior to the dependent template
367 // name.
368 NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep();
369 Diag(IILoc, diag::err_template_kw_missing)
370 << Qualifier << II.getName()
371 << FixItHint::CreateInsertion(IILoc, "template ");
372 SuggestedTemplate
373 = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II));
374 SuggestedKind = TNK_Dependent_template_name;
375 return true;
376}
377
378bool Sema::LookupTemplateName(LookupResult &Found,
379 Scope *S, CXXScopeSpec &SS,
380 QualType ObjectType,
381 bool EnteringContext,
382 bool &MemberOfUnknownSpecialization,
383 RequiredTemplateKind RequiredTemplate,
384 AssumedTemplateKind *ATK,
385 bool AllowTypoCorrection) {
386 if (ATK)
387 *ATK = AssumedTemplateKind::None;
388
389 if (SS.isInvalid())
390 return true;
391
392 Found.setTemplateNameLookup(true);
393
394 // Determine where to perform name lookup
395 MemberOfUnknownSpecialization = false;
396 DeclContext *LookupCtx = nullptr;
397 bool IsDependent = false;
398 if (!ObjectType.isNull()) {
399 // This nested-name-specifier occurs in a member access expression, e.g.,
400 // x->B::f, and we are looking into the type of the object.
401 assert(SS.isEmpty() && "ObjectType and scope specifier cannot coexist")(static_cast <bool> (SS.isEmpty() && "ObjectType and scope specifier cannot coexist"
) ? void (0) : __assert_fail ("SS.isEmpty() && \"ObjectType and scope specifier cannot coexist\""
, "clang/lib/Sema/SemaTemplate.cpp", 401, __extension__ __PRETTY_FUNCTION__
))
;
402 LookupCtx = computeDeclContext(ObjectType);
403 IsDependent = !LookupCtx && ObjectType->isDependentType();
404 assert((IsDependent || !ObjectType->isIncompleteType() ||(static_cast <bool> ((IsDependent || !ObjectType->isIncompleteType
() || ObjectType->castAs<TagType>()->isBeingDefined
()) && "Caller should have completed object type") ? void
(0) : __assert_fail ("(IsDependent || !ObjectType->isIncompleteType() || ObjectType->castAs<TagType>()->isBeingDefined()) && \"Caller should have completed object type\""
, "clang/lib/Sema/SemaTemplate.cpp", 406, __extension__ __PRETTY_FUNCTION__
))
405 ObjectType->castAs<TagType>()->isBeingDefined()) &&(static_cast <bool> ((IsDependent || !ObjectType->isIncompleteType
() || ObjectType->castAs<TagType>()->isBeingDefined
()) && "Caller should have completed object type") ? void
(0) : __assert_fail ("(IsDependent || !ObjectType->isIncompleteType() || ObjectType->castAs<TagType>()->isBeingDefined()) && \"Caller should have completed object type\""
, "clang/lib/Sema/SemaTemplate.cpp", 406, __extension__ __PRETTY_FUNCTION__
))
406 "Caller should have completed object type")(static_cast <bool> ((IsDependent || !ObjectType->isIncompleteType
() || ObjectType->castAs<TagType>()->isBeingDefined
()) && "Caller should have completed object type") ? void
(0) : __assert_fail ("(IsDependent || !ObjectType->isIncompleteType() || ObjectType->castAs<TagType>()->isBeingDefined()) && \"Caller should have completed object type\""
, "clang/lib/Sema/SemaTemplate.cpp", 406, __extension__ __PRETTY_FUNCTION__
))
;
407
408 // Template names cannot appear inside an Objective-C class or object type
409 // or a vector type.
410 //
411 // FIXME: This is wrong. For example:
412 //
413 // template<typename T> using Vec = T __attribute__((ext_vector_type(4)));
414 // Vec<int> vi;
415 // vi.Vec<int>::~Vec<int>();
416 //
417 // ... should be accepted but we will not treat 'Vec' as a template name
418 // here. The right thing to do would be to check if the name is a valid
419 // vector component name, and look up a template name if not. And similarly
420 // for lookups into Objective-C class and object types, where the same
421 // problem can arise.
422 if (ObjectType->isObjCObjectOrInterfaceType() ||
423 ObjectType->isVectorType()) {
424 Found.clear();
425 return false;
426 }
427 } else if (SS.isNotEmpty()) {
428 // This nested-name-specifier occurs after another nested-name-specifier,
429 // so long into the context associated with the prior nested-name-specifier.
430 LookupCtx = computeDeclContext(SS, EnteringContext);
431 IsDependent = !LookupCtx && isDependentScopeSpecifier(SS);
432
433 // The declaration context must be complete.
434 if (LookupCtx && RequireCompleteDeclContext(SS, LookupCtx))
435 return true;
436 }
437
438 bool ObjectTypeSearchedInScope = false;
439 bool AllowFunctionTemplatesInLookup = true;
440 if (LookupCtx) {
441 // Perform "qualified" name lookup into the declaration context we
442 // computed, which is either the type of the base of a member access
443 // expression or the declaration context associated with a prior
444 // nested-name-specifier.
445 LookupQualifiedName(Found, LookupCtx);
446
447 // FIXME: The C++ standard does not clearly specify what happens in the
448 // case where the object type is dependent, and implementations vary. In
449 // Clang, we treat a name after a . or -> as a template-name if lookup
450 // finds a non-dependent member or member of the current instantiation that
451 // is a type template, or finds no such members and lookup in the context
452 // of the postfix-expression finds a type template. In the latter case, the
453 // name is nonetheless dependent, and we may resolve it to a member of an
454 // unknown specialization when we come to instantiate the template.
455 IsDependent |= Found.wasNotFoundInCurrentInstantiation();
456 }
457
458 if (SS.isEmpty() && (ObjectType.isNull() || Found.empty())) {
459 // C++ [basic.lookup.classref]p1:
460 // In a class member access expression (5.2.5), if the . or -> token is
461 // immediately followed by an identifier followed by a <, the
462 // identifier must be looked up to determine whether the < is the
463 // beginning of a template argument list (14.2) or a less-than operator.
464 // The identifier is first looked up in the class of the object
465 // expression. If the identifier is not found, it is then looked up in
466 // the context of the entire postfix-expression and shall name a class
467 // template.
468 if (S)
469 LookupName(Found, S);
470
471 if (!ObjectType.isNull()) {
472 // FIXME: We should filter out all non-type templates here, particularly
473 // variable templates and concepts. But the exclusion of alias templates
474 // and template template parameters is a wording defect.
475 AllowFunctionTemplatesInLookup = false;
476 ObjectTypeSearchedInScope = true;
477 }
478
479 IsDependent |= Found.wasNotFoundInCurrentInstantiation();
480 }
481
482 if (Found.isAmbiguous())
483 return false;
484
485 if (ATK && SS.isEmpty() && ObjectType.isNull() &&
486 !RequiredTemplate.hasTemplateKeyword()) {
487 // C++2a [temp.names]p2:
488 // A name is also considered to refer to a template if it is an
489 // unqualified-id followed by a < and name lookup finds either one or more
490 // functions or finds nothing.
491 //
492 // To keep our behavior consistent, we apply the "finds nothing" part in
493 // all language modes, and diagnose the empty lookup in ActOnCallExpr if we
494 // successfully form a call to an undeclared template-id.
495 bool AllFunctions =
496 getLangOpts().CPlusPlus20 && llvm::all_of(Found, [](NamedDecl *ND) {
497 return isa<FunctionDecl>(ND->getUnderlyingDecl());
498 });
499 if (AllFunctions || (Found.empty() && !IsDependent)) {
500 // If lookup found any functions, or if this is a name that can only be
501 // used for a function, then strongly assume this is a function
502 // template-id.
503 *ATK = (Found.empty() && Found.getLookupName().isIdentifier())
504 ? AssumedTemplateKind::FoundNothing
505 : AssumedTemplateKind::FoundFunctions;
506 Found.clear();
507 return false;
508 }
509 }
510
511 if (Found.empty() && !IsDependent && AllowTypoCorrection) {
512 // If we did not find any names, and this is not a disambiguation, attempt
513 // to correct any typos.
514 DeclarationName Name = Found.getLookupName();
515 Found.clear();
516 // Simple filter callback that, for keywords, only accepts the C++ *_cast
517 DefaultFilterCCC FilterCCC{};
518 FilterCCC.WantTypeSpecifiers = false;
519 FilterCCC.WantExpressionKeywords = false;
520 FilterCCC.WantRemainingKeywords = false;
521 FilterCCC.WantCXXNamedCasts = true;
522 if (TypoCorrection Corrected =
523 CorrectTypo(Found.getLookupNameInfo(), Found.getLookupKind(), S,
524 &SS, FilterCCC, CTK_ErrorRecovery, LookupCtx)) {
525 if (auto *ND = Corrected.getFoundDecl())
526 Found.addDecl(ND);
527 FilterAcceptableTemplateNames(Found);
528 if (Found.isAmbiguous()) {
529 Found.clear();
530 } else if (!Found.empty()) {
531 Found.setLookupName(Corrected.getCorrection());
532 if (LookupCtx) {
533 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
534 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
535 Name.getAsString() == CorrectedStr;
536 diagnoseTypo(Corrected, PDiag(diag::err_no_member_template_suggest)
537 << Name << LookupCtx << DroppedSpecifier
538 << SS.getRange());
539 } else {
540 diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest) << Name);
541 }
542 }
543 }
544 }
545
546 NamedDecl *ExampleLookupResult =
547 Found.empty() ? nullptr : Found.getRepresentativeDecl();
548 FilterAcceptableTemplateNames(Found, AllowFunctionTemplatesInLookup);
549 if (Found.empty()) {
550 if (IsDependent) {
551 MemberOfUnknownSpecialization = true;
552 return false;
553 }
554
555 // If a 'template' keyword was used, a lookup that finds only non-template
556 // names is an error.
557 if (ExampleLookupResult && RequiredTemplate) {
558 Diag(Found.getNameLoc(), diag::err_template_kw_refers_to_non_template)
559 << Found.getLookupName() << SS.getRange()
560 << RequiredTemplate.hasTemplateKeyword()
561 << RequiredTemplate.getTemplateKeywordLoc();
562 Diag(ExampleLookupResult->getUnderlyingDecl()->getLocation(),
563 diag::note_template_kw_refers_to_non_template)
564 << Found.getLookupName();
565 return true;
566 }
567
568 return false;
569 }
570
571 if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope &&
572 !getLangOpts().CPlusPlus11) {
573 // C++03 [basic.lookup.classref]p1:
574 // [...] If the lookup in the class of the object expression finds a
575 // template, the name is also looked up in the context of the entire
576 // postfix-expression and [...]
577 //
578 // Note: C++11 does not perform this second lookup.
579 LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(),
580 LookupOrdinaryName);
581 FoundOuter.setTemplateNameLookup(true);
582 LookupName(FoundOuter, S);
583 // FIXME: We silently accept an ambiguous lookup here, in violation of
584 // [basic.lookup]/1.
585 FilterAcceptableTemplateNames(FoundOuter, /*AllowFunctionTemplates=*/false);
586
587 NamedDecl *OuterTemplate;
588 if (FoundOuter.empty()) {
589 // - if the name is not found, the name found in the class of the
590 // object expression is used, otherwise
591 } else if (FoundOuter.isAmbiguous() || !FoundOuter.isSingleResult() ||
592 !(OuterTemplate =
593 getAsTemplateNameDecl(FoundOuter.getFoundDecl()))) {
594 // - if the name is found in the context of the entire
595 // postfix-expression and does not name a class template, the name
596 // found in the class of the object expression is used, otherwise
597 FoundOuter.clear();
598 } else if (!Found.isSuppressingDiagnostics()) {
599 // - if the name found is a class template, it must refer to the same
600 // entity as the one found in the class of the object expression,
601 // otherwise the program is ill-formed.
602 if (!Found.isSingleResult() ||
603 getAsTemplateNameDecl(Found.getFoundDecl())->getCanonicalDecl() !=
604 OuterTemplate->getCanonicalDecl()) {
605 Diag(Found.getNameLoc(),
606 diag::ext_nested_name_member_ref_lookup_ambiguous)
607 << Found.getLookupName()
608 << ObjectType;
609 Diag(Found.getRepresentativeDecl()->getLocation(),
610 diag::note_ambig_member_ref_object_type)
611 << ObjectType;
612 Diag(FoundOuter.getFoundDecl()->getLocation(),
613 diag::note_ambig_member_ref_scope);
614
615 // Recover by taking the template that we found in the object
616 // expression's type.
617 }
618 }
619 }
620
621 return false;
622}
623
624void Sema::diagnoseExprIntendedAsTemplateName(Scope *S, ExprResult TemplateName,
625 SourceLocation Less,
626 SourceLocation Greater) {
627 if (TemplateName.isInvalid())
628 return;
629
630 DeclarationNameInfo NameInfo;
631 CXXScopeSpec SS;
632 LookupNameKind LookupKind;
633
634 DeclContext *LookupCtx = nullptr;
635 NamedDecl *Found = nullptr;
636 bool MissingTemplateKeyword = false;
637
638 // Figure out what name we looked up.
639 if (auto *DRE = dyn_cast<DeclRefExpr>(TemplateName.get())) {
640 NameInfo = DRE->getNameInfo();
641 SS.Adopt(DRE->getQualifierLoc());
642 LookupKind = LookupOrdinaryName;
643 Found = DRE->getFoundDecl();
644 } else if (auto *ME = dyn_cast<MemberExpr>(TemplateName.get())) {
645 NameInfo = ME->getMemberNameInfo();
646 SS.Adopt(ME->getQualifierLoc());
647 LookupKind = LookupMemberName;
648 LookupCtx = ME->getBase()->getType()->getAsCXXRecordDecl();
649 Found = ME->getMemberDecl();
650 } else if (auto *DSDRE =
651 dyn_cast<DependentScopeDeclRefExpr>(TemplateName.get())) {
652 NameInfo = DSDRE->getNameInfo();
653 SS.Adopt(DSDRE->getQualifierLoc());
654 MissingTemplateKeyword = true;
655 } else if (auto *DSME =
656 dyn_cast<CXXDependentScopeMemberExpr>(TemplateName.get())) {
657 NameInfo = DSME->getMemberNameInfo();
658 SS.Adopt(DSME->getQualifierLoc());
659 MissingTemplateKeyword = true;
660 } else {
661 llvm_unreachable("unexpected kind of potential template name")::llvm::llvm_unreachable_internal("unexpected kind of potential template name"
, "clang/lib/Sema/SemaTemplate.cpp", 661)
;
662 }
663
664 // If this is a dependent-scope lookup, diagnose that the 'template' keyword
665 // was missing.
666 if (MissingTemplateKeyword) {
667 Diag(NameInfo.getBeginLoc(), diag::err_template_kw_missing)
668 << "" << NameInfo.getName().getAsString() << SourceRange(Less, Greater);
669 return;
670 }
671
672 // Try to correct the name by looking for templates and C++ named casts.
673 struct TemplateCandidateFilter : CorrectionCandidateCallback {
674 Sema &S;
675 TemplateCandidateFilter(Sema &S) : S(S) {
676 WantTypeSpecifiers = false;
677 WantExpressionKeywords = false;
678 WantRemainingKeywords = false;
679 WantCXXNamedCasts = true;
680 };
681 bool ValidateCandidate(const TypoCorrection &Candidate) override {
682 if (auto *ND = Candidate.getCorrectionDecl())
683 return S.getAsTemplateNameDecl(ND);
684 return Candidate.isKeyword();
685 }
686
687 std::unique_ptr<CorrectionCandidateCallback> clone() override {
688 return std::make_unique<TemplateCandidateFilter>(*this);
689 }
690 };
691
692 DeclarationName Name = NameInfo.getName();
693 TemplateCandidateFilter CCC(*this);
694 if (TypoCorrection Corrected = CorrectTypo(NameInfo, LookupKind, S, &SS, CCC,
695 CTK_ErrorRecovery, LookupCtx)) {
696 auto *ND = Corrected.getFoundDecl();
697 if (ND)
698 ND = getAsTemplateNameDecl(ND);
699 if (ND || Corrected.isKeyword()) {
700 if (LookupCtx) {
701 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
702 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
703 Name.getAsString() == CorrectedStr;
704 diagnoseTypo(Corrected,
705 PDiag(diag::err_non_template_in_member_template_id_suggest)
706 << Name << LookupCtx << DroppedSpecifier
707 << SS.getRange(), false);
708 } else {
709 diagnoseTypo(Corrected,
710 PDiag(diag::err_non_template_in_template_id_suggest)
711 << Name, false);
712 }
713 if (Found)
714 Diag(Found->getLocation(),
715 diag::note_non_template_in_template_id_found);
716 return;
717 }
718 }
719
720 Diag(NameInfo.getLoc(), diag::err_non_template_in_template_id)
721 << Name << SourceRange(Less, Greater);
722 if (Found)
723 Diag(Found->getLocation(), diag::note_non_template_in_template_id_found);
724}
725
726/// ActOnDependentIdExpression - Handle a dependent id-expression that
727/// was just parsed. This is only possible with an explicit scope
728/// specifier naming a dependent type.
729ExprResult
730Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS,
731 SourceLocation TemplateKWLoc,
732 const DeclarationNameInfo &NameInfo,
733 bool isAddressOfOperand,
734 const TemplateArgumentListInfo *TemplateArgs) {
735 DeclContext *DC = getFunctionLevelDeclContext();
736
737 // C++11 [expr.prim.general]p12:
738 // An id-expression that denotes a non-static data member or non-static
739 // member function of a class can only be used:
740 // (...)
741 // - if that id-expression denotes a non-static data member and it
742 // appears in an unevaluated operand.
743 //
744 // If this might be the case, form a DependentScopeDeclRefExpr instead of a
745 // CXXDependentScopeMemberExpr. The former can instantiate to either
746 // DeclRefExpr or MemberExpr depending on lookup results, while the latter is
747 // always a MemberExpr.
748 bool MightBeCxx11UnevalField =
749 getLangOpts().CPlusPlus11 && isUnevaluatedContext();
750
751 // Check if the nested name specifier is an enum type.
752 bool IsEnum = false;
753 if (NestedNameSpecifier *NNS = SS.getScopeRep())
754 IsEnum = isa_and_nonnull<EnumType>(NNS->getAsType());
755
756 if (!MightBeCxx11UnevalField && !isAddressOfOperand && !IsEnum &&
757 isa<CXXMethodDecl>(DC) && cast<CXXMethodDecl>(DC)->isInstance()) {
758 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType();
759
760 // Since the 'this' expression is synthesized, we don't need to
761 // perform the double-lookup check.
762 NamedDecl *FirstQualifierInScope = nullptr;
763
764 return CXXDependentScopeMemberExpr::Create(
765 Context, /*This*/ nullptr, ThisType, /*IsArrow*/ true,
766 /*Op*/ SourceLocation(), SS.getWithLocInContext(Context), TemplateKWLoc,
767 FirstQualifierInScope, NameInfo, TemplateArgs);
768 }
769
770 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
771}
772
773ExprResult
774Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
775 SourceLocation TemplateKWLoc,
776 const DeclarationNameInfo &NameInfo,
777 const TemplateArgumentListInfo *TemplateArgs) {
778 // DependentScopeDeclRefExpr::Create requires a valid QualifierLoc
779 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
780 if (!QualifierLoc)
781 return ExprError();
782
783 return DependentScopeDeclRefExpr::Create(
784 Context, QualifierLoc, TemplateKWLoc, NameInfo, TemplateArgs);
785}
786
787
788/// Determine whether we would be unable to instantiate this template (because
789/// it either has no definition, or is in the process of being instantiated).
790bool Sema::DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation,
791 NamedDecl *Instantiation,
792 bool InstantiatedFromMember,
793 const NamedDecl *Pattern,
794 const NamedDecl *PatternDef,
795 TemplateSpecializationKind TSK,
796 bool Complain /*= true*/) {
797 assert(isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) ||(static_cast <bool> (isa<TagDecl>(Instantiation) ||
isa<FunctionDecl>(Instantiation) || isa<VarDecl>
(Instantiation)) ? void (0) : __assert_fail ("isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) || isa<VarDecl>(Instantiation)"
, "clang/lib/Sema/SemaTemplate.cpp", 798, __extension__ __PRETTY_FUNCTION__
))
798 isa<VarDecl>(Instantiation))(static_cast <bool> (isa<TagDecl>(Instantiation) ||
isa<FunctionDecl>(Instantiation) || isa<VarDecl>
(Instantiation)) ? void (0) : __assert_fail ("isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) || isa<VarDecl>(Instantiation)"
, "clang/lib/Sema/SemaTemplate.cpp", 798, __extension__ __PRETTY_FUNCTION__
))
;
799
800 bool IsEntityBeingDefined = false;
801 if (const TagDecl *TD = dyn_cast_or_null<TagDecl>(PatternDef))
802 IsEntityBeingDefined = TD->isBeingDefined();
803
804 if (PatternDef && !IsEntityBeingDefined) {
805 NamedDecl *SuggestedDef = nullptr;
806 if (!hasVisibleDefinition(const_cast<NamedDecl*>(PatternDef), &SuggestedDef,
807 /*OnlyNeedComplete*/false)) {
808 // If we're allowed to diagnose this and recover, do so.
809 bool Recover = Complain && !isSFINAEContext();
810 if (Complain)
811 diagnoseMissingImport(PointOfInstantiation, SuggestedDef,
812 Sema::MissingImportKind::Definition, Recover);
813 return !Recover;
814 }
815 return false;
816 }
817
818 if (!Complain || (PatternDef && PatternDef->isInvalidDecl()))
819 return true;
820
821 llvm::Optional<unsigned> Note;
822 QualType InstantiationTy;
823 if (TagDecl *TD = dyn_cast<TagDecl>(Instantiation))
824 InstantiationTy = Context.getTypeDeclType(TD);
825 if (PatternDef) {
826 Diag(PointOfInstantiation,
827 diag::err_template_instantiate_within_definition)
828 << /*implicit|explicit*/(TSK != TSK_ImplicitInstantiation)
829 << InstantiationTy;
830 // Not much point in noting the template declaration here, since
831 // we're lexically inside it.
832 Instantiation->setInvalidDecl();
833 } else if (InstantiatedFromMember) {
834 if (isa<FunctionDecl>(Instantiation)) {
835 Diag(PointOfInstantiation,
836 diag::err_explicit_instantiation_undefined_member)
837 << /*member function*/ 1 << Instantiation->getDeclName()
838 << Instantiation->getDeclContext();
839 Note = diag::note_explicit_instantiation_here;
840 } else {
841 assert(isa<TagDecl>(Instantiation) && "Must be a TagDecl!")(static_cast <bool> (isa<TagDecl>(Instantiation) &&
"Must be a TagDecl!") ? void (0) : __assert_fail ("isa<TagDecl>(Instantiation) && \"Must be a TagDecl!\""
, "clang/lib/Sema/SemaTemplate.cpp", 841, __extension__ __PRETTY_FUNCTION__
))
;
842 Diag(PointOfInstantiation,
843 diag::err_implicit_instantiate_member_undefined)
844 << InstantiationTy;
845 Note = diag::note_member_declared_at;
846 }
847 } else {
848 if (isa<FunctionDecl>(Instantiation)) {
849 Diag(PointOfInstantiation,
850 diag::err_explicit_instantiation_undefined_func_template)
851 << Pattern;
852 Note = diag::note_explicit_instantiation_here;
853 } else if (isa<TagDecl>(Instantiation)) {
854 Diag(PointOfInstantiation, diag::err_template_instantiate_undefined)
855 << (TSK != TSK_ImplicitInstantiation)
856 << InstantiationTy;
857 Note = diag::note_template_decl_here;
858 } else {
859 assert(isa<VarDecl>(Instantiation) && "Must be a VarDecl!")(static_cast <bool> (isa<VarDecl>(Instantiation) &&
"Must be a VarDecl!") ? void (0) : __assert_fail ("isa<VarDecl>(Instantiation) && \"Must be a VarDecl!\""
, "clang/lib/Sema/SemaTemplate.cpp", 859, __extension__ __PRETTY_FUNCTION__
))
;
860 if (isa<VarTemplateSpecializationDecl>(Instantiation)) {
861 Diag(PointOfInstantiation,
862 diag::err_explicit_instantiation_undefined_var_template)
863 << Instantiation;
864 Instantiation->setInvalidDecl();
865 } else
866 Diag(PointOfInstantiation,
867 diag::err_explicit_instantiation_undefined_member)
868 << /*static data member*/ 2 << Instantiation->getDeclName()
869 << Instantiation->getDeclContext();
870 Note = diag::note_explicit_instantiation_here;
871 }
872 }
873 if (Note) // Diagnostics were emitted.
874 Diag(Pattern->getLocation(), Note.getValue());
875
876 // In general, Instantiation isn't marked invalid to get more than one
877 // error for multiple undefined instantiations. But the code that does
878 // explicit declaration -> explicit definition conversion can't handle
879 // invalid declarations, so mark as invalid in that case.
880 if (TSK == TSK_ExplicitInstantiationDeclaration)
881 Instantiation->setInvalidDecl();
882 return true;
883}
884
885/// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
886/// that the template parameter 'PrevDecl' is being shadowed by a new
887/// declaration at location Loc. Returns true to indicate that this is
888/// an error, and false otherwise.
889void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) {
890 assert(PrevDecl->isTemplateParameter() && "Not a template parameter")(static_cast <bool> (PrevDecl->isTemplateParameter()
&& "Not a template parameter") ? void (0) : __assert_fail
("PrevDecl->isTemplateParameter() && \"Not a template parameter\""
, "clang/lib/Sema/SemaTemplate.cpp", 890, __extension__ __PRETTY_FUNCTION__
))
;
891
892 // C++ [temp.local]p4:
893 // A template-parameter shall not be redeclared within its
894 // scope (including nested scopes).
895 //
896 // Make this a warning when MSVC compatibility is requested.
897 unsigned DiagId = getLangOpts().MSVCCompat ? diag::ext_template_param_shadow
898 : diag::err_template_param_shadow;
899 Diag(Loc, DiagId) << cast<NamedDecl>(PrevDecl)->getDeclName();
900 Diag(PrevDecl->getLocation(), diag::note_template_param_here);
901}
902
903/// AdjustDeclIfTemplate - If the given decl happens to be a template, reset
904/// the parameter D to reference the templated declaration and return a pointer
905/// to the template declaration. Otherwise, do nothing to D and return null.
906TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) {
907 if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) {
908 D = Temp->getTemplatedDecl();
909 return Temp;
910 }
911 return nullptr;
912}
913
914ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion(
915 SourceLocation EllipsisLoc) const {
916 assert(Kind == Template &&(static_cast <bool> (Kind == Template && "Only template template arguments can be pack expansions here"
) ? void (0) : __assert_fail ("Kind == Template && \"Only template template arguments can be pack expansions here\""
, "clang/lib/Sema/SemaTemplate.cpp", 917, __extension__ __PRETTY_FUNCTION__
))
917 "Only template template arguments can be pack expansions here")(static_cast <bool> (Kind == Template && "Only template template arguments can be pack expansions here"
) ? void (0) : __assert_fail ("Kind == Template && \"Only template template arguments can be pack expansions here\""
, "clang/lib/Sema/SemaTemplate.cpp", 917, __extension__ __PRETTY_FUNCTION__
))
;
918 assert(getAsTemplate().get().containsUnexpandedParameterPack() &&(static_cast <bool> (getAsTemplate().get().containsUnexpandedParameterPack
() && "Template template argument pack expansion without packs"
) ? void (0) : __assert_fail ("getAsTemplate().get().containsUnexpandedParameterPack() && \"Template template argument pack expansion without packs\""
, "clang/lib/Sema/SemaTemplate.cpp", 919, __extension__ __PRETTY_FUNCTION__
))
919 "Template template argument pack expansion without packs")(static_cast <bool> (getAsTemplate().get().containsUnexpandedParameterPack
() && "Template template argument pack expansion without packs"
) ? void (0) : __assert_fail ("getAsTemplate().get().containsUnexpandedParameterPack() && \"Template template argument pack expansion without packs\""
, "clang/lib/Sema/SemaTemplate.cpp", 919, __extension__ __PRETTY_FUNCTION__
))
;
920 ParsedTemplateArgument Result(*this);
921 Result.EllipsisLoc = EllipsisLoc;
922 return Result;
923}
924
925static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef,
926 const ParsedTemplateArgument &Arg) {
927
928 switch (Arg.getKind()) {
929 case ParsedTemplateArgument::Type: {
930 TypeSourceInfo *DI;
931 QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI);
932 if (!DI)
933 DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation());
934 return TemplateArgumentLoc(TemplateArgument(T), DI);
935 }
936
937 case ParsedTemplateArgument::NonType: {
938 Expr *E = static_cast<Expr *>(Arg.getAsExpr());
939 return TemplateArgumentLoc(TemplateArgument(E), E);
940 }
941
942 case ParsedTemplateArgument::Template: {
943 TemplateName Template = Arg.getAsTemplate().get();
944 TemplateArgument TArg;
945 if (Arg.getEllipsisLoc().isValid())
946 TArg = TemplateArgument(Template, Optional<unsigned int>());
947 else
948 TArg = Template;
949 return TemplateArgumentLoc(
950 SemaRef.Context, TArg,
951 Arg.getScopeSpec().getWithLocInContext(SemaRef.Context),
952 Arg.getLocation(), Arg.getEllipsisLoc());
953 }
954 }
955
956 llvm_unreachable("Unhandled parsed template argument")::llvm::llvm_unreachable_internal("Unhandled parsed template argument"
, "clang/lib/Sema/SemaTemplate.cpp", 956)
;
957}
958
959/// Translates template arguments as provided by the parser
960/// into template arguments used by semantic analysis.
961void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn,
962 TemplateArgumentListInfo &TemplateArgs) {
963 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I)
964 TemplateArgs.addArgument(translateTemplateArgument(*this,
965 TemplateArgsIn[I]));
966}
967
968static void maybeDiagnoseTemplateParameterShadow(Sema &SemaRef, Scope *S,
969 SourceLocation Loc,
970 IdentifierInfo *Name) {
971 NamedDecl *PrevDecl = SemaRef.LookupSingleName(
972 S, Name, Loc, Sema::LookupOrdinaryName, Sema::ForVisibleRedeclaration);
973 if (PrevDecl && PrevDecl->isTemplateParameter())
974 SemaRef.DiagnoseTemplateParameterShadow(Loc, PrevDecl);
975}
976
977/// Convert a parsed type into a parsed template argument. This is mostly
978/// trivial, except that we may have parsed a C++17 deduced class template
979/// specialization type, in which case we should form a template template
980/// argument instead of a type template argument.
981ParsedTemplateArgument Sema::ActOnTemplateTypeArgument(TypeResult ParsedType) {
982 TypeSourceInfo *TInfo;
983 QualType T = GetTypeFromParser(ParsedType.get(), &TInfo);
984 if (T.isNull())
985 return ParsedTemplateArgument();
986 assert(TInfo && "template argument with no location")(static_cast <bool> (TInfo && "template argument with no location"
) ? void (0) : __assert_fail ("TInfo && \"template argument with no location\""
, "clang/lib/Sema/SemaTemplate.cpp", 986, __extension__ __PRETTY_FUNCTION__
))
;
987
988 // If we might have formed a deduced template specialization type, convert
989 // it to a template template argument.
990 if (getLangOpts().CPlusPlus17) {
991 TypeLoc TL = TInfo->getTypeLoc();
992 SourceLocation EllipsisLoc;
993 if (auto PET = TL.getAs<PackExpansionTypeLoc>()) {
994 EllipsisLoc = PET.getEllipsisLoc();
995 TL = PET.getPatternLoc();
996 }
997
998 CXXScopeSpec SS;
999 if (auto ET = TL.getAs<ElaboratedTypeLoc>()) {
1000 SS.Adopt(ET.getQualifierLoc());
1001 TL = ET.getNamedTypeLoc();
1002 }
1003
1004 if (auto DTST = TL.getAs<DeducedTemplateSpecializationTypeLoc>()) {
1005 TemplateName Name = DTST.getTypePtr()->getTemplateName();
1006 if (SS.isSet())
1007 Name = Context.getQualifiedTemplateName(SS.getScopeRep(),
1008 /*HasTemplateKeyword*/ false,
1009 Name.getAsTemplateDecl());
1010 ParsedTemplateArgument Result(SS, TemplateTy::make(Name),
1011 DTST.getTemplateNameLoc());
1012 if (EllipsisLoc.isValid())
1013 Result = Result.getTemplatePackExpansion(EllipsisLoc);
1014 return Result;
1015 }
1016 }
1017
1018 // This is a normal type template argument. Note, if the type template
1019 // argument is an injected-class-name for a template, it has a dual nature
1020 // and can be used as either a type or a template. We handle that in
1021 // convertTypeTemplateArgumentToTemplate.
1022 return ParsedTemplateArgument(ParsedTemplateArgument::Type,
1023 ParsedType.get().getAsOpaquePtr(),
1024 TInfo->getTypeLoc().getBeginLoc());
1025}
1026
1027/// ActOnTypeParameter - Called when a C++ template type parameter
1028/// (e.g., "typename T") has been parsed. Typename specifies whether
1029/// the keyword "typename" was used to declare the type parameter
1030/// (otherwise, "class" was used), and KeyLoc is the location of the
1031/// "class" or "typename" keyword. ParamName is the name of the
1032/// parameter (NULL indicates an unnamed template parameter) and
1033/// ParamNameLoc is the location of the parameter name (if any).
1034/// If the type parameter has a default argument, it will be added
1035/// later via ActOnTypeParameterDefault.
1036NamedDecl *Sema::ActOnTypeParameter(Scope *S, bool Typename,
1037 SourceLocation EllipsisLoc,
1038 SourceLocation KeyLoc,
1039 IdentifierInfo *ParamName,
1040 SourceLocation ParamNameLoc,
1041 unsigned Depth, unsigned Position,
1042 SourceLocation EqualLoc,
1043 ParsedType DefaultArg,
1044 bool HasTypeConstraint) {
1045 assert(S->isTemplateParamScope() &&(static_cast <bool> (S->isTemplateParamScope() &&
"Template type parameter not in template parameter scope!") ?
void (0) : __assert_fail ("S->isTemplateParamScope() && \"Template type parameter not in template parameter scope!\""
, "clang/lib/Sema/SemaTemplate.cpp", 1046, __extension__ __PRETTY_FUNCTION__
))
1046 "Template type parameter not in template parameter scope!")(static_cast <bool> (S->isTemplateParamScope() &&
"Template type parameter not in template parameter scope!") ?
void (0) : __assert_fail ("S->isTemplateParamScope() && \"Template type parameter not in template parameter scope!\""
, "clang/lib/Sema/SemaTemplate.cpp", 1046, __extension__ __PRETTY_FUNCTION__
))
;
1047
1048 bool IsParameterPack = EllipsisLoc.isValid();
1049 TemplateTypeParmDecl *Param
1050 = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(),
1051 KeyLoc, ParamNameLoc, Depth, Position,
1052 ParamName, Typename, IsParameterPack,
1053 HasTypeConstraint);
1054 Param->setAccess(AS_public);
1055
1056 if (Param->isParameterPack())
1057 if (auto *LSI = getEnclosingLambda())
1058 LSI->LocalPacks.push_back(Param);
1059
1060 if (ParamName) {
1061 maybeDiagnoseTemplateParameterShadow(*this, S, ParamNameLoc, ParamName);
1062
1063 // Add the template parameter into the current scope.
1064 S->AddDecl(Param);
1065 IdResolver.AddDecl(Param);
1066 }
1067
1068 // C++0x [temp.param]p9:
1069 // A default template-argument may be specified for any kind of
1070 // template-parameter that is not a template parameter pack.
1071 if (DefaultArg && IsParameterPack) {
1072 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1073 DefaultArg = nullptr;
1074 }
1075
1076 // Handle the default argument, if provided.
1077 if (DefaultArg) {
1078 TypeSourceInfo *DefaultTInfo;
1079 GetTypeFromParser(DefaultArg, &DefaultTInfo);
1080
1081 assert(DefaultTInfo && "expected source information for type")(static_cast <bool> (DefaultTInfo && "expected source information for type"
) ? void (0) : __assert_fail ("DefaultTInfo && \"expected source information for type\""
, "clang/lib/Sema/SemaTemplate.cpp", 1081, __extension__ __PRETTY_FUNCTION__
))
;
1082
1083 // Check for unexpanded parameter packs.
1084 if (DiagnoseUnexpandedParameterPack(ParamNameLoc, DefaultTInfo,
1085 UPPC_DefaultArgument))
1086 return Param;
1087
1088 // Check the template argument itself.
1089 if (CheckTemplateArgument(DefaultTInfo)) {
1090 Param->setInvalidDecl();
1091 return Param;
1092 }
1093
1094 Param->setDefaultArgument(DefaultTInfo);
1095 }
1096
1097 return Param;
1098}
1099
1100/// Convert the parser's template argument list representation into our form.
1101static TemplateArgumentListInfo
1102makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) {
1103 TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc,
1104 TemplateId.RAngleLoc);
1105 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(),
1106 TemplateId.NumArgs);
1107 S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
1108 return TemplateArgs;
1109}
1110
1111bool Sema::ActOnTypeConstraint(const CXXScopeSpec &SS,
1112 TemplateIdAnnotation *TypeConstr,
1113 TemplateTypeParmDecl *ConstrainedParameter,
1114 SourceLocation EllipsisLoc) {
1115 return BuildTypeConstraint(SS, TypeConstr, ConstrainedParameter, EllipsisLoc,
1116 false);
1117}
1118
1119bool Sema::BuildTypeConstraint(const CXXScopeSpec &SS,
1120 TemplateIdAnnotation *TypeConstr,
1121 TemplateTypeParmDecl *ConstrainedParameter,
1122 SourceLocation EllipsisLoc,
1123 bool AllowUnexpandedPack) {
1124 TemplateName TN = TypeConstr->Template.get();
1125 ConceptDecl *CD = cast<ConceptDecl>(TN.getAsTemplateDecl());
1126
1127 // C++2a [temp.param]p4:
1128 // [...] The concept designated by a type-constraint shall be a type
1129 // concept ([temp.concept]).
1130 if (!CD->isTypeConcept()) {
1131 Diag(TypeConstr->TemplateNameLoc,
1132 diag::err_type_constraint_non_type_concept);
1133 return true;
1134 }
1135
1136 bool WereArgsSpecified = TypeConstr->LAngleLoc.isValid();
1137
1138 if (!WereArgsSpecified &&
1139 CD->getTemplateParameters()->getMinRequiredArguments() > 1) {
1140 Diag(TypeConstr->TemplateNameLoc,
1141 diag::err_type_constraint_missing_arguments) << CD;
1142 return true;
1143 }
1144
1145 DeclarationNameInfo ConceptName(DeclarationName(TypeConstr->Name),
1146 TypeConstr->TemplateNameLoc);
1147
1148 TemplateArgumentListInfo TemplateArgs;
1149 if (TypeConstr->LAngleLoc.isValid()) {
1150 TemplateArgs =
1151 makeTemplateArgumentListInfo(*this, *TypeConstr);
1152
1153 if (EllipsisLoc.isInvalid() && !AllowUnexpandedPack) {
1154 for (TemplateArgumentLoc Arg : TemplateArgs.arguments()) {
1155 if (DiagnoseUnexpandedParameterPack(Arg, UPPC_TypeConstraint))
1156 return true;
1157 }
1158 }
1159 }
1160 return AttachTypeConstraint(
1161 SS.isSet() ? SS.getWithLocInContext(Context) : NestedNameSpecifierLoc(),
1162 ConceptName, CD,
1163 TypeConstr->LAngleLoc.isValid() ? &TemplateArgs : nullptr,
1164 ConstrainedParameter, EllipsisLoc);
1165}
1166
1167template<typename ArgumentLocAppender>
1168static ExprResult formImmediatelyDeclaredConstraint(
1169 Sema &S, NestedNameSpecifierLoc NS, DeclarationNameInfo NameInfo,
1170 ConceptDecl *NamedConcept, SourceLocation LAngleLoc,
1171 SourceLocation RAngleLoc, QualType ConstrainedType,
1172 SourceLocation ParamNameLoc, ArgumentLocAppender Appender,
1173 SourceLocation EllipsisLoc) {
1174
1175 TemplateArgumentListInfo ConstraintArgs;
1176 ConstraintArgs.addArgument(
1177 S.getTrivialTemplateArgumentLoc(TemplateArgument(ConstrainedType),
1178 /*NTTPType=*/QualType(), ParamNameLoc));
1179
1180 ConstraintArgs.setRAngleLoc(RAngleLoc);
1181 ConstraintArgs.setLAngleLoc(LAngleLoc);
1182 Appender(ConstraintArgs);
1183
1184 // C++2a [temp.param]p4:
1185 // [...] This constraint-expression E is called the immediately-declared
1186 // constraint of T. [...]
1187 CXXScopeSpec SS;
1188 SS.Adopt(NS);
1189 ExprResult ImmediatelyDeclaredConstraint = S.CheckConceptTemplateId(
1190 SS, /*TemplateKWLoc=*/SourceLocation(), NameInfo,
1191 /*FoundDecl=*/NamedConcept, NamedConcept, &ConstraintArgs);
1192 if (ImmediatelyDeclaredConstraint.isInvalid() || !EllipsisLoc.isValid())
1193 return ImmediatelyDeclaredConstraint;
1194
1195 // C++2a [temp.param]p4:
1196 // [...] If T is not a pack, then E is E', otherwise E is (E' && ...).
1197 //
1198 // We have the following case:
1199 //
1200 // template<typename T> concept C1 = true;
1201 // template<C1... T> struct s1;
1202 //
1203 // The constraint: (C1<T> && ...)
1204 //
1205 // Note that the type of C1<T> is known to be 'bool', so we don't need to do
1206 // any unqualified lookups for 'operator&&' here.
1207 return S.BuildCXXFoldExpr(/*UnqualifiedLookup=*/nullptr,
1208 /*LParenLoc=*/SourceLocation(),
1209 ImmediatelyDeclaredConstraint.get(), BO_LAnd,
1210 EllipsisLoc, /*RHS=*/nullptr,
1211 /*RParenLoc=*/SourceLocation(),
1212 /*NumExpansions=*/None);
1213}
1214
1215/// Attach a type-constraint to a template parameter.
1216/// \returns true if an error occurred. This can happen if the
1217/// immediately-declared constraint could not be formed (e.g. incorrect number
1218/// of arguments for the named concept).
1219bool Sema::AttachTypeConstraint(NestedNameSpecifierLoc NS,
1220 DeclarationNameInfo NameInfo,
1221 ConceptDecl *NamedConcept,
1222 const TemplateArgumentListInfo *TemplateArgs,
1223 TemplateTypeParmDecl *ConstrainedParameter,
1224 SourceLocation EllipsisLoc) {
1225 // C++2a [temp.param]p4:
1226 // [...] If Q is of the form C<A1, ..., An>, then let E' be
1227 // C<T, A1, ..., An>. Otherwise, let E' be C<T>. [...]
1228 const ASTTemplateArgumentListInfo *ArgsAsWritten =
1229 TemplateArgs ? ASTTemplateArgumentListInfo::Create(Context,
1230 *TemplateArgs) : nullptr;
1231
1232 QualType ParamAsArgument(ConstrainedParameter->getTypeForDecl(), 0);
1233
1234 ExprResult ImmediatelyDeclaredConstraint =
1235 formImmediatelyDeclaredConstraint(
1236 *this, NS, NameInfo, NamedConcept,
1237 TemplateArgs ? TemplateArgs->getLAngleLoc() : SourceLocation(),
1238 TemplateArgs ? TemplateArgs->getRAngleLoc() : SourceLocation(),
1239 ParamAsArgument, ConstrainedParameter->getLocation(),
1240 [&] (TemplateArgumentListInfo &ConstraintArgs) {
1241 if (TemplateArgs)
1242 for (const auto &ArgLoc : TemplateArgs->arguments())
1243 ConstraintArgs.addArgument(ArgLoc);
1244 }, EllipsisLoc);
1245 if (ImmediatelyDeclaredConstraint.isInvalid())
1246 return true;
1247
1248 ConstrainedParameter->setTypeConstraint(NS, NameInfo,
1249 /*FoundDecl=*/NamedConcept,
1250 NamedConcept, ArgsAsWritten,
1251 ImmediatelyDeclaredConstraint.get());
1252 return false;
1253}
1254
1255bool Sema::AttachTypeConstraint(AutoTypeLoc TL, NonTypeTemplateParmDecl *NTTP,
1256 SourceLocation EllipsisLoc) {
1257 if (NTTP->getType() != TL.getType() ||
1258 TL.getAutoKeyword() != AutoTypeKeyword::Auto) {
1259 Diag(NTTP->getTypeSourceInfo()->getTypeLoc().getBeginLoc(),
1260 diag::err_unsupported_placeholder_constraint)
1261 << NTTP->getTypeSourceInfo()->getTypeLoc().getSourceRange();
1262 return true;
1263 }
1264 // FIXME: Concepts: This should be the type of the placeholder, but this is
1265 // unclear in the wording right now.
1266 DeclRefExpr *Ref =
1267 BuildDeclRefExpr(NTTP, NTTP->getType(), VK_PRValue, NTTP->getLocation());
1268 if (!Ref)
1269 return true;
1270 ExprResult ImmediatelyDeclaredConstraint = formImmediatelyDeclaredConstraint(
1271 *this, TL.getNestedNameSpecifierLoc(), TL.getConceptNameInfo(),
1272 TL.getNamedConcept(), TL.getLAngleLoc(), TL.getRAngleLoc(),
1273 BuildDecltypeType(Ref), NTTP->getLocation(),
1274 [&](TemplateArgumentListInfo &ConstraintArgs) {
1275 for (unsigned I = 0, C = TL.getNumArgs(); I != C; ++I)
1276 ConstraintArgs.addArgument(TL.getArgLoc(I));
1277 },
1278 EllipsisLoc);
1279 if (ImmediatelyDeclaredConstraint.isInvalid() ||
1280 !ImmediatelyDeclaredConstraint.isUsable())
1281 return true;
1282
1283 NTTP->setPlaceholderTypeConstraint(ImmediatelyDeclaredConstraint.get());
1284 return false;
1285}
1286
1287/// Check that the type of a non-type template parameter is
1288/// well-formed.
1289///
1290/// \returns the (possibly-promoted) parameter type if valid;
1291/// otherwise, produces a diagnostic and returns a NULL type.
1292QualType Sema::CheckNonTypeTemplateParameterType(TypeSourceInfo *&TSI,
1293 SourceLocation Loc) {
1294 if (TSI->getType()->isUndeducedType()) {
1295 // C++17 [temp.dep.expr]p3:
1296 // An id-expression is type-dependent if it contains
1297 // - an identifier associated by name lookup with a non-type
1298 // template-parameter declared with a type that contains a
1299 // placeholder type (7.1.7.4),
1300 TSI = SubstAutoTypeSourceInfoDependent(TSI);
1301 }
1302
1303 return CheckNonTypeTemplateParameterType(TSI->getType(), Loc);
1304}
1305
1306/// Require the given type to be a structural type, and diagnose if it is not.
1307///
1308/// \return \c true if an error was produced.
1309bool Sema::RequireStructuralType(QualType T, SourceLocation Loc) {
1310 if (T->isDependentType())
1311 return false;
1312
1313 if (RequireCompleteType(Loc, T, diag::err_template_nontype_parm_incomplete))
1314 return true;
1315
1316 if (T->isStructuralType())
1317 return false;
1318
1319 // Structural types are required to be object types or lvalue references.
1320 if (T->isRValueReferenceType()) {
1321 Diag(Loc, diag::err_template_nontype_parm_rvalue_ref) << T;
1322 return true;
1323 }
1324
1325 // Don't mention structural types in our diagnostic prior to C++20. Also,
1326 // there's not much more we can say about non-scalar non-class types --
1327 // because we can't see functions or arrays here, those can only be language
1328 // extensions.
1329 if (!getLangOpts().CPlusPlus20 ||
1330 (!T->isScalarType() && !T->isRecordType())) {
1331 Diag(Loc, diag::err_template_nontype_parm_bad_type) << T;
1332 return true;
1333 }
1334
1335 // Structural types are required to be literal types.
1336 if (RequireLiteralType(Loc, T, diag::err_template_nontype_parm_not_literal))
1337 return true;
1338
1339 Diag(Loc, diag::err_template_nontype_parm_not_structural) << T;
1340
1341 // Drill down into the reason why the class is non-structural.
1342 while (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
1343 // All members are required to be public and non-mutable, and can't be of
1344 // rvalue reference type. Check these conditions first to prefer a "local"
1345 // reason over a more distant one.
1346 for (const FieldDecl *FD : RD->fields()) {
1347 if (FD->getAccess() != AS_public) {
1348 Diag(FD->getLocation(), diag::note_not_structural_non_public) << T << 0;
1349 return true;
1350 }
1351 if (FD->isMutable()) {
1352 Diag(FD->getLocation(), diag::note_not_structural_mutable_field) << T;
1353 return true;
1354 }
1355 if (FD->getType()->isRValueReferenceType()) {
1356 Diag(FD->getLocation(), diag::note_not_structural_rvalue_ref_field)
1357 << T;
1358 return true;
1359 }
1360 }
1361
1362 // All bases are required to be public.
1363 for (const auto &BaseSpec : RD->bases()) {
1364 if (BaseSpec.getAccessSpecifier() != AS_public) {
1365 Diag(BaseSpec.getBaseTypeLoc(), diag::note_not_structural_non_public)
1366 << T << 1;
1367 return true;
1368 }
1369 }
1370
1371 // All subobjects are required to be of structural types.
1372 SourceLocation SubLoc;
1373 QualType SubType;
1374 int Kind = -1;
1375
1376 for (const FieldDecl *FD : RD->fields()) {
1377 QualType T = Context.getBaseElementType(FD->getType());
1378 if (!T->isStructuralType()) {
1379 SubLoc = FD->getLocation();
1380 SubType = T;
1381 Kind = 0;
1382 break;
1383 }
1384 }
1385
1386 if (Kind == -1) {
1387 for (const auto &BaseSpec : RD->bases()) {
1388 QualType T = BaseSpec.getType();
1389 if (!T->isStructuralType()) {
1390 SubLoc = BaseSpec.getBaseTypeLoc();
1391 SubType = T;
1392 Kind = 1;
1393 break;
1394 }
1395 }
1396 }
1397
1398 assert(Kind != -1 && "couldn't find reason why type is not structural")(static_cast <bool> (Kind != -1 && "couldn't find reason why type is not structural"
) ? void (0) : __assert_fail ("Kind != -1 && \"couldn't find reason why type is not structural\""
, "clang/lib/Sema/SemaTemplate.cpp", 1398, __extension__ __PRETTY_FUNCTION__
))
;
1399 Diag(SubLoc, diag::note_not_structural_subobject)
1400 << T << Kind << SubType;
1401 T = SubType;
1402 RD = T->getAsCXXRecordDecl();
Value stored to 'RD' is never read
1403 }
1404
1405 return true;
1406}
1407
1408QualType Sema::CheckNonTypeTemplateParameterType(QualType T,
1409 SourceLocation Loc) {
1410 // We don't allow variably-modified types as the type of non-type template
1411 // parameters.
1412 if (T->isVariablyModifiedType()) {
1413 Diag(Loc, diag::err_variably_modified_nontype_template_param)
1414 << T;
1415 return QualType();
1416 }
1417
1418 // C++ [temp.param]p4:
1419 //
1420 // A non-type template-parameter shall have one of the following
1421 // (optionally cv-qualified) types:
1422 //
1423 // -- integral or enumeration type,
1424 if (T->isIntegralOrEnumerationType() ||
1425 // -- pointer to object or pointer to function,
1426 T->isPointerType() ||
1427 // -- lvalue reference to object or lvalue reference to function,
1428 T->isLValueReferenceType() ||
1429 // -- pointer to member,
1430 T->isMemberPointerType() ||
1431 // -- std::nullptr_t, or
1432 T->isNullPtrType() ||
1433 // -- a type that contains a placeholder type.
1434 T->isUndeducedType()) {
1435 // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
1436 // are ignored when determining its type.
1437 return T.getUnqualifiedType();
1438 }
1439
1440 // C++ [temp.param]p8:
1441 //
1442 // A non-type template-parameter of type "array of T" or
1443 // "function returning T" is adjusted to be of type "pointer to
1444 // T" or "pointer to function returning T", respectively.
1445 if (T->isArrayType() || T->isFunctionType())
1446 return Context.getDecayedType(T);
1447
1448 // If T is a dependent type, we can't do the check now, so we
1449 // assume that it is well-formed. Note that stripping off the
1450 // qualifiers here is not really correct if T turns out to be
1451 // an array type, but we'll recompute the type everywhere it's
1452 // used during instantiation, so that should be OK. (Using the
1453 // qualified type is equally wrong.)
1454 if (T->isDependentType())
1455 return T.getUnqualifiedType();
1456
1457 // C++20 [temp.param]p6:
1458 // -- a structural type
1459 if (RequireStructuralType(T, Loc))
1460 return QualType();
1461
1462 if (!getLangOpts().CPlusPlus20) {
1463 // FIXME: Consider allowing structural types as an extension in C++17. (In
1464 // earlier language modes, the template argument evaluation rules are too
1465 // inflexible.)
1466 Diag(Loc, diag::err_template_nontype_parm_bad_structural_type) << T;
1467 return QualType();
1468 }
1469
1470 Diag(Loc, diag::warn_cxx17_compat_template_nontype_parm_type) << T;
1471 return T.getUnqualifiedType();
1472}
1473
1474NamedDecl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
1475 unsigned Depth,
1476 unsigned Position,
1477 SourceLocation EqualLoc,
1478 Expr *Default) {
1479 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
1480
1481 // Check that we have valid decl-specifiers specified.
1482 auto CheckValidDeclSpecifiers = [this, &D] {
1483 // C++ [temp.param]
1484 // p1
1485 // template-parameter:
1486 // ...
1487 // parameter-declaration
1488 // p2
1489 // ... A storage class shall not be specified in a template-parameter
1490 // declaration.
1491 // [dcl.typedef]p1:
1492 // The typedef specifier [...] shall not be used in the decl-specifier-seq
1493 // of a parameter-declaration
1494 const DeclSpec &DS = D.getDeclSpec();
1495 auto EmitDiag = [this](SourceLocation Loc) {
1496 Diag(Loc, diag::err_invalid_decl_specifier_in_nontype_parm)
1497 << FixItHint::CreateRemoval(Loc);
1498 };
1499 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified)
1500 EmitDiag(DS.getStorageClassSpecLoc());
1501
1502 if (DS.getThreadStorageClassSpec() != TSCS_unspecified)
1503 EmitDiag(DS.getThreadStorageClassSpecLoc());
1504
1505 // [dcl.inline]p1:
1506 // The inline specifier can be applied only to the declaration or
1507 // definition of a variable or function.
1508
1509 if (DS.isInlineSpecified())
1510 EmitDiag(DS.getInlineSpecLoc());
1511
1512 // [dcl.constexpr]p1:
1513 // The constexpr specifier shall be applied only to the definition of a
1514 // variable or variable template or the declaration of a function or
1515 // function template.
1516
1517 if (DS.hasConstexprSpecifier())
1518 EmitDiag(DS.getConstexprSpecLoc());
1519
1520 // [dcl.fct.spec]p1:
1521 // Function-specifiers can be used only in function declarations.
1522
1523 if (DS.isVirtualSpecified())
1524 EmitDiag(DS.getVirtualSpecLoc());
1525
1526 if (DS.hasExplicitSpecifier())
1527 EmitDiag(DS.getExplicitSpecLoc());
1528
1529 if (DS.isNoreturnSpecified())
1530 EmitDiag(DS.getNoreturnSpecLoc());
1531 };
1532
1533 CheckValidDeclSpecifiers();
1534
1535 if (TInfo->getType()->isUndeducedType()) {
1536 Diag(D.getIdentifierLoc(),
1537 diag::warn_cxx14_compat_template_nontype_parm_auto_type)
1538 << QualType(TInfo->getType()->getContainedAutoType(), 0);
1539 }
1540
1541 assert(S->isTemplateParamScope() &&(static_cast <bool> (S->isTemplateParamScope() &&
"Non-type template parameter not in template parameter scope!"
) ? void (0) : __assert_fail ("S->isTemplateParamScope() && \"Non-type template parameter not in template parameter scope!\""
, "clang/lib/Sema/SemaTemplate.cpp", 1542, __extension__ __PRETTY_FUNCTION__
))
1542 "Non-type template parameter not in template parameter scope!")(static_cast <bool> (S->isTemplateParamScope() &&
"Non-type template parameter not in template parameter scope!"
) ? void (0) : __assert_fail ("S->isTemplateParamScope() && \"Non-type template parameter not in template parameter scope!\""
, "clang/lib/Sema/SemaTemplate.cpp", 1542, __extension__ __PRETTY_FUNCTION__
))
;
1543 bool Invalid = false;
1544
1545 QualType T = CheckNonTypeTemplateParameterType(TInfo, D.getIdentifierLoc());
1546 if (T.isNull()) {
1547 T = Context.IntTy; // Recover with an 'int' type.
1548 Invalid = true;
1549 }
1550
1551 CheckFunctionOrTemplateParamDeclarator(S, D);
1552
1553 IdentifierInfo *ParamName = D.getIdentifier();
1554 bool IsParameterPack = D.hasEllipsis();
1555 NonTypeTemplateParmDecl *Param = NonTypeTemplateParmDecl::Create(
1556 Context, Context.getTranslationUnitDecl(), D.getBeginLoc(),
1557 D.getIdentifierLoc(), Depth, Position, ParamName, T, IsParameterPack,
1558 TInfo);
1559 Param->setAccess(AS_public);
1560
1561 if (AutoTypeLoc TL = TInfo->getTypeLoc().getContainedAutoTypeLoc())
1562 if (TL.isConstrained())
1563 if (AttachTypeConstraint(TL, Param, D.getEllipsisLoc()))
1564 Invalid = true;
1565
1566 if (Invalid)
1567 Param->setInvalidDecl();
1568
1569 if (Param->isParameterPack())
1570 if (auto *LSI = getEnclosingLambda())
1571 LSI->LocalPacks.push_back(Param);
1572
1573 if (ParamName) {
1574 maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(),
1575 ParamName);
1576
1577 // Add the template parameter into the current scope.
1578 S->AddDecl(Param);
1579 IdResolver.AddDecl(Param);
1580 }
1581
1582 // C++0x [temp.param]p9:
1583 // A default template-argument may be specified for any kind of
1584 // template-parameter that is not a template parameter pack.
1585 if (Default && IsParameterPack) {
1586 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1587 Default = nullptr;
1588 }
1589
1590 // Check the well-formedness of the default template argument, if provided.
1591 if (Default) {
1592 // Check for unexpanded parameter packs.
1593 if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
1594 return Param;
1595
1596 TemplateArgument Converted;
1597 ExprResult DefaultRes =
1598 CheckTemplateArgument(Param, Param->getType(), Default, Converted);
1599 if (DefaultRes.isInvalid()) {
1600 Param->setInvalidDecl();
1601 return Param;
1602 }
1603 Default = DefaultRes.get();
1604
1605 Param->setDefaultArgument(Default);
1606 }
1607
1608 return Param;
1609}
1610
1611/// ActOnTemplateTemplateParameter - Called when a C++ template template
1612/// parameter (e.g. T in template <template \<typename> class T> class array)
1613/// has been parsed. S is the current scope.
1614NamedDecl *Sema::ActOnTemplateTemplateParameter(Scope* S,
1615 SourceLocation TmpLoc,
1616 TemplateParameterList *Params,
1617 SourceLocation EllipsisLoc,
1618 IdentifierInfo *Name,
1619 SourceLocation NameLoc,
1620 unsigned Depth,
1621 unsigned Position,
1622 SourceLocation EqualLoc,
1623 ParsedTemplateArgument Default) {
1624 assert(S->isTemplateParamScope() &&(static_cast <bool> (S->isTemplateParamScope() &&
"Template template parameter not in template parameter scope!"
) ? void (0) : __assert_fail ("S->isTemplateParamScope() && \"Template template parameter not in template parameter scope!\""
, "clang/lib/Sema/SemaTemplate.cpp", 1625, __extension__ __PRETTY_FUNCTION__
))
1625 "Template template parameter not in template parameter scope!")(static_cast <bool> (S->isTemplateParamScope() &&
"Template template parameter not in template parameter scope!"
) ? void (0) : __assert_fail ("S->isTemplateParamScope() && \"Template template parameter not in template parameter scope!\""
, "clang/lib/Sema/SemaTemplate.cpp", 1625, __extension__ __PRETTY_FUNCTION__
))
;
1626
1627 // Construct the parameter object.
1628 bool IsParameterPack = EllipsisLoc.isValid();
1629 TemplateTemplateParmDecl *Param =
1630 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
1631 NameLoc.isInvalid()? TmpLoc : NameLoc,
1632 Depth, Position, IsParameterPack,
1633 Name, Params);
1634 Param->setAccess(AS_public);
1635
1636 if (Param->isParameterPack())
1637 if (auto *LSI = getEnclosingLambda())
1638 LSI->LocalPacks.push_back(Param);
1639
1640 // If the template template parameter has a name, then link the identifier
1641 // into the scope and lookup mechanisms.
1642 if (Name) {
1643 maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name);
1644
1645 S->AddDecl(Param);
1646 IdResolver.AddDecl(Param);
1647 }
1648
1649 if (Params->size() == 0) {
1650 Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
1651 << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
1652 Param->setInvalidDecl();
1653 }
1654
1655 // C++0x [temp.param]p9:
1656 // A default template-argument may be specified for any kind of
1657 // template-parameter that is not a template parameter pack.
1658 if (IsParameterPack && !Default.isInvalid()) {
1659 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1660 Default = ParsedTemplateArgument();
1661 }
1662
1663 if (!Default.isInvalid()) {
1664 // Check only that we have a template template argument. We don't want to
1665 // try to check well-formedness now, because our template template parameter
1666 // might have dependent types in its template parameters, which we wouldn't
1667 // be able to match now.
1668 //
1669 // If none of the template template parameter's template arguments mention
1670 // other template parameters, we could actually perform more checking here.
1671 // However, it isn't worth doing.
1672 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
1673 if (DefaultArg.getArgument().getAsTemplate().isNull()) {
1674 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_valid_template)
1675 << DefaultArg.getSourceRange();
1676 return Param;
1677 }
1678
1679 // Check for unexpanded parameter packs.
1680 if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(),
1681 DefaultArg.getArgument().getAsTemplate(),
1682 UPPC_DefaultArgument))
1683 return Param;
1684
1685 Param->setDefaultArgument(Context, DefaultArg);
1686 }
1687
1688 return Param;
1689}
1690
1691/// ActOnTemplateParameterList - Builds a TemplateParameterList, optionally
1692/// constrained by RequiresClause, that contains the template parameters in
1693/// Params.
1694TemplateParameterList *
1695Sema::ActOnTemplateParameterList(unsigned Depth,
1696 SourceLocation ExportLoc,
1697 SourceLocation TemplateLoc,
1698 SourceLocation LAngleLoc,
1699 ArrayRef<NamedDecl *> Params,
1700 SourceLocation RAngleLoc,
1701 Expr *RequiresClause) {
1702 if (ExportLoc.isValid())
1703 Diag(ExportLoc, diag::warn_template_export_unsupported);
1704
1705 for (NamedDecl *P : Params)
1706 warnOnReservedIdentifier(P);
1707
1708 return TemplateParameterList::Create(
1709 Context, TemplateLoc, LAngleLoc,
1710 llvm::makeArrayRef(Params.data(), Params.size()),
1711 RAngleLoc, RequiresClause);
1712}
1713
1714static void SetNestedNameSpecifier(Sema &S, TagDecl *T,
1715 const CXXScopeSpec &SS) {
1716 if (SS.isSet())
1717 T->setQualifierInfo(SS.getWithLocInContext(S.Context));
1718}
1719
1720DeclResult Sema::CheckClassTemplate(
1721 Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
1722 CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc,
1723 const ParsedAttributesView &Attr, TemplateParameterList *TemplateParams,
1724 AccessSpecifier AS, SourceLocation ModulePrivateLoc,
1725 SourceLocation FriendLoc, unsigned NumOuterTemplateParamLists,
1726 TemplateParameterList **OuterTemplateParamLists, SkipBodyInfo *SkipBody) {
1727 assert(TemplateParams && TemplateParams->size() > 0 &&(static_cast <bool> (TemplateParams && TemplateParams
->size() > 0 && "No template parameters") ? void
(0) : __assert_fail ("TemplateParams && TemplateParams->size() > 0 && \"No template parameters\""
, "clang/lib/Sema/SemaTemplate.cpp", 1728, __extension__ __PRETTY_FUNCTION__
))
1728 "No template parameters")(static_cast <bool> (TemplateParams && TemplateParams
->size() > 0 && "No template parameters") ? void
(0) : __assert_fail ("TemplateParams && TemplateParams->size() > 0 && \"No template parameters\""
, "clang/lib/Sema/SemaTemplate.cpp", 1728, __extension__ __PRETTY_FUNCTION__
))
;
1729 assert(TUK != TUK_Reference && "Can only declare or define class templates")(static_cast <bool> (TUK != TUK_Reference && "Can only declare or define class templates"
) ? void (0) : __assert_fail ("TUK != TUK_Reference && \"Can only declare or define class templates\""
, "clang/lib/Sema/SemaTemplate.cpp", 1729, __extension__ __PRETTY_FUNCTION__
))
;
1730 bool Invalid = false;
1731
1732 // Check that we can declare a template here.
1733 if (CheckTemplateDeclScope(S, TemplateParams))
1734 return true;
1735
1736 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
1737 assert(Kind != TTK_Enum && "can't build template of enumerated type")(static_cast <bool> (Kind != TTK_Enum && "can't build template of enumerated type"
) ? void (0) : __assert_fail ("Kind != TTK_Enum && \"can't build template of enumerated type\""
, "clang/lib/Sema/SemaTemplate.cpp", 1737, __extension__ __PRETTY_FUNCTION__
))
;
1738
1739 // There is no such thing as an unnamed class template.
1740 if (!Name) {
1741 Diag(KWLoc, diag::err_template_unnamed_class);
1742 return true;
1743 }
1744
1745 // Find any previous declaration with this name. For a friend with no
1746 // scope explicitly specified, we only look for tag declarations (per
1747 // C++11 [basic.lookup.elab]p2).
1748 DeclContext *SemanticContext;
1749 LookupResult Previous(*this, Name, NameLoc,
1750 (SS.isEmpty() && TUK == TUK_Friend)
1751 ? LookupTagName : LookupOrdinaryName,
1752 forRedeclarationInCurContext());
1753 if (SS.isNotEmpty() && !SS.isInvalid()) {
1754 SemanticContext = computeDeclContext(SS, true);
1755 if (!SemanticContext) {
1756 // FIXME: Horrible, horrible hack! We can't currently represent this
1757 // in the AST, and historically we have just ignored such friend
1758 // class templates, so don't complain here.
1759 Diag(NameLoc, TUK == TUK_Friend
1760 ? diag::warn_template_qualified_friend_ignored
1761 : diag::err_template_qualified_declarator_no_match)
1762 << SS.getScopeRep() << SS.getRange();
1763 return TUK != TUK_Friend;
1764 }
1765
1766 if (RequireCompleteDeclContext(SS, SemanticContext))
1767 return true;
1768
1769 // If we're adding a template to a dependent context, we may need to
1770 // rebuilding some of the types used within the template parameter list,
1771 // now that we know what the current instantiation is.
1772 if (SemanticContext->isDependentContext()) {
1773 ContextRAII SavedContext(*this, SemanticContext);
1774 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
1775 Invalid = true;
1776 } else if (TUK != TUK_Friend && TUK != TUK_Reference)
1777 diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc, false);
1778
1779 LookupQualifiedName(Previous, SemanticContext);
1780 } else {
1781 SemanticContext = CurContext;
1782
1783 // C++14 [class.mem]p14:
1784 // If T is the name of a class, then each of the following shall have a
1785 // name different from T:
1786 // -- every member template of class T
1787 if (TUK != TUK_Friend &&
1788 DiagnoseClassNameShadow(SemanticContext,
1789 DeclarationNameInfo(Name, NameLoc)))
1790 return true;
1791
1792 LookupName(Previous, S);
1793 }
1794
1795 if (Previous.isAmbiguous())
1796 return true;
1797
1798 NamedDecl *PrevDecl = nullptr;
1799 if (Previous.begin() != Previous.end())
1800 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1801
1802 if (PrevDecl && PrevDecl->isTemplateParameter()) {
1803 // Maybe we will complain about the shadowed template parameter.
1804 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
1805 // Just pretend that we didn't see the previous declaration.
1806 PrevDecl = nullptr;
1807 }
1808
1809 // If there is a previous declaration with the same name, check
1810 // whether this is a valid redeclaration.
1811 ClassTemplateDecl *PrevClassTemplate =
1812 dyn_cast_or_null<ClassTemplateDecl>(PrevDecl);
1813
1814 // We may have found the injected-class-name of a class template,
1815 // class template partial specialization, or class template specialization.
1816 // In these cases, grab the template that is being defined or specialized.
1817 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) &&
1818 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) {
1819 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext());
1820 PrevClassTemplate
1821 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate();
1822 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) {
1823 PrevClassTemplate
1824 = cast<ClassTemplateSpecializationDecl>(PrevDecl)
1825 ->getSpecializedTemplate();
1826 }
1827 }
1828
1829 if (TUK == TUK_Friend) {
1830 // C++ [namespace.memdef]p3:
1831 // [...] When looking for a prior declaration of a class or a function
1832 // declared as a friend, and when the name of the friend class or
1833 // function is neither a qualified name nor a template-id, scopes outside
1834 // the innermost enclosing namespace scope are not considered.
1835 if (!SS.isSet()) {
1836 DeclContext *OutermostContext = CurContext;
1837 while (!OutermostContext->isFileContext())
1838 OutermostContext = OutermostContext->getLookupParent();
1839
1840 if (PrevDecl &&
1841 (OutermostContext->Equals(PrevDecl->getDeclContext()) ||
1842 OutermostContext->Encloses(PrevDecl->getDeclContext()))) {
1843 SemanticContext = PrevDecl->getDeclContext();
1844 } else {
1845 // Declarations in outer scopes don't matter. However, the outermost
1846 // context we computed is the semantic context for our new
1847 // declaration.
1848 PrevDecl = PrevClassTemplate = nullptr;
1849 SemanticContext = OutermostContext;
1850
1851 // Check that the chosen semantic context doesn't already contain a
1852 // declaration of this name as a non-tag type.
1853 Previous.clear(LookupOrdinaryName);
1854 DeclContext *LookupContext = SemanticContext;
1855 while (LookupContext->isTransparentContext())
1856 LookupContext = LookupContext->getLookupParent();
1857 LookupQualifiedName(Previous, LookupContext);
1858
1859 if (Previous.isAmbiguous())
1860 return true;
1861
1862 if (Previous.begin() != Previous.end())
1863 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1864 }
1865 }
1866 } else if (PrevDecl &&
1867 !isDeclInScope(Previous.getRepresentativeDecl(), SemanticContext,
1868 S, SS.isValid()))
1869 PrevDecl = PrevClassTemplate = nullptr;
1870
1871 if (auto *Shadow = dyn_cast_or_null<UsingShadowDecl>(
1872 PrevDecl ? Previous.getRepresentativeDecl() : nullptr)) {
1873 if (SS.isEmpty() &&
1874 !(PrevClassTemplate &&
1875 PrevClassTemplate->getDeclContext()->getRedeclContext()->Equals(
1876 SemanticContext->getRedeclContext()))) {
1877 Diag(KWLoc, diag::err_using_decl_conflict_reverse);
1878 Diag(Shadow->getTargetDecl()->getLocation(),
1879 diag::note_using_decl_target);
1880 Diag(Shadow->getIntroducer()->getLocation(), diag::note_using_decl) << 0;
1881 // Recover by ignoring the old declaration.
1882 PrevDecl = PrevClassTemplate = nullptr;
1883 }
1884 }
1885
1886 if (PrevClassTemplate) {
1887 // Ensure that the template parameter lists are compatible. Skip this check
1888 // for a friend in a dependent context: the template parameter list itself
1889 // could be dependent.
1890 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1891 !TemplateParameterListsAreEqual(TemplateParams,
1892 PrevClassTemplate->getTemplateParameters(),
1893 /*Complain=*/true,
1894 TPL_TemplateMatch))
1895 return true;
1896
1897 // C++ [temp.class]p4:
1898 // In a redeclaration, partial specialization, explicit
1899 // specialization or explicit instantiation of a class template,
1900 // the class-key shall agree in kind with the original class
1901 // template declaration (7.1.5.3).
1902 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
1903 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
1904 TUK == TUK_Definition, KWLoc, Name)) {
1905 Diag(KWLoc, diag::err_use_with_wrong_tag)
1906 << Name
1907 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
1908 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use);
1909 Kind = PrevRecordDecl->getTagKind();
1910 }
1911
1912 // Check for redefinition of this class template.
1913 if (TUK == TUK_Definition) {
1914 if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
1915 // If we have a prior definition that is not visible, treat this as
1916 // simply making that previous definition visible.
1917 NamedDecl *Hidden = nullptr;
1918 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
1919 SkipBody->ShouldSkip = true;
1920 SkipBody->Previous = Def;
1921 auto *Tmpl = cast<CXXRecordDecl>(Hidden)->getDescribedClassTemplate();
1922 assert(Tmpl && "original definition of a class template is not a "(static_cast <bool> (Tmpl && "original definition of a class template is not a "
"class template?") ? void (0) : __assert_fail ("Tmpl && \"original definition of a class template is not a \" \"class template?\""
, "clang/lib/Sema/SemaTemplate.cpp", 1923, __extension__ __PRETTY_FUNCTION__
))
1923 "class template?")(static_cast <bool> (Tmpl && "original definition of a class template is not a "
"class template?") ? void (0) : __assert_fail ("Tmpl && \"original definition of a class template is not a \" \"class template?\""
, "clang/lib/Sema/SemaTemplate.cpp", 1923, __extension__ __PRETTY_FUNCTION__
))
;
1924 makeMergedDefinitionVisible(Hidden);
1925 makeMergedDefinitionVisible(Tmpl);
1926 } else {
1927 Diag(NameLoc, diag::err_redefinition) << Name;
1928 Diag(Def->getLocation(), diag::note_previous_definition);
1929 // FIXME: Would it make sense to try to "forget" the previous
1930 // definition, as part of error recovery?
1931 return true;
1932 }
1933 }
1934 }
1935 } else if (PrevDecl) {
1936 // C++ [temp]p5:
1937 // A class template shall not have the same name as any other
1938 // template, class, function, object, enumeration, enumerator,
1939 // namespace, or type in the same scope (3.3), except as specified
1940 // in (14.5.4).
1941 Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
1942 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1943 return true;
1944 }
1945
1946 // Check the template parameter list of this declaration, possibly
1947 // merging in the template parameter list from the previous class
1948 // template declaration. Skip this check for a friend in a dependent
1949 // context, because the template parameter list might be dependent.
1950 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1951 CheckTemplateParameterList(
1952 TemplateParams,
1953 PrevClassTemplate
1954 ? PrevClassTemplate->getMostRecentDecl()->getTemplateParameters()
1955 : nullptr,
1956 (SS.isSet() && SemanticContext && SemanticContext->isRecord() &&
1957 SemanticContext->isDependentContext())
1958 ? TPC_ClassTemplateMember
1959 : TUK == TUK_Friend ? TPC_FriendClassTemplate : TPC_ClassTemplate,
1960 SkipBody))
1961 Invalid = true;
1962
1963 if (SS.isSet()) {
1964 // If the name of the template was qualified, we must be defining the
1965 // template out-of-line.
1966 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
1967 Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match
1968 : diag::err_member_decl_does_not_match)
1969 << Name << SemanticContext << /*IsDefinition*/true << SS.getRange();
1970 Invalid = true;
1971 }
1972 }
1973
1974 // If this is a templated friend in a dependent context we should not put it
1975 // on the redecl chain. In some cases, the templated friend can be the most
1976 // recent declaration tricking the template instantiator to make substitutions
1977 // there.
1978 // FIXME: Figure out how to combine with shouldLinkDependentDeclWithPrevious
1979 bool ShouldAddRedecl
1980 = !(TUK == TUK_Friend && CurContext->isDependentContext());
1981
1982 CXXRecordDecl *NewClass =
1983 CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
1984 PrevClassTemplate && ShouldAddRedecl ?
1985 PrevClassTemplate->getTemplatedDecl() : nullptr,
1986 /*DelayTypeCreation=*/true);
1987 SetNestedNameSpecifier(*this, NewClass, SS);
1988 if (NumOuterTemplateParamLists > 0)
1989 NewClass->setTemplateParameterListsInfo(
1990 Context, llvm::makeArrayRef(OuterTemplateParamLists,
1991 NumOuterTemplateParamLists));
1992
1993 // Add alignment attributes if necessary; these attributes are checked when
1994 // the ASTContext lays out the structure.
1995 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) {
1996 AddAlignmentAttributesForRecord(NewClass);
1997 AddMsStructLayoutForRecord(NewClass);
1998 }
1999
2000 ClassTemplateDecl *NewTemplate
2001 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
2002 DeclarationName(Name), TemplateParams,
2003 NewClass);
2004
2005 if (ShouldAddRedecl)
2006 NewTemplate->setPreviousDecl(PrevClassTemplate);
2007
2008 NewClass->setDescribedClassTemplate(NewTemplate);
2009
2010 if (ModulePrivateLoc.isValid())
2011 NewTemplate->setModulePrivate();
2012
2013 // Build the type for the class template declaration now.
2014 QualType T = NewTemplate->getInjectedClassNameSpecialization();
2015 T = Context.getInjectedClassNameType(NewClass, T);
2016 assert(T->isDependentType() && "Class template type is not dependent?")(static_cast <bool> (T->isDependentType() &&
"Class template type is not dependent?") ? void (0) : __assert_fail
("T->isDependentType() && \"Class template type is not dependent?\""
, "clang/lib/Sema/SemaTemplate.cpp", 2016, __extension__ __PRETTY_FUNCTION__
))
;
2017 (void)T;
2018
2019 // If we are providing an explicit specialization of a member that is a
2020 // class template, make a note of that.
2021 if (PrevClassTemplate &&
2022 PrevClassTemplate->getInstantiatedFromMemberTemplate())
2023 PrevClassTemplate->setMemberSpecialization();
2024
2025 // Set the access specifier.
2026 if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord())
2027 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
2028
2029 // Set the lexical context of these templates
2030 NewClass->setLexicalDeclContext(CurContext);
2031 NewTemplate->setLexicalDeclContext(CurContext);
2032
2033 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip))
2034 NewClass->startDefinition();
2035
2036 ProcessDeclAttributeList(S, NewClass, Attr);
2037
2038 if (PrevClassTemplate)
2039 mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
2040
2041 AddPushedVisibilityAttribute(NewClass);
2042 inferGslOwnerPointerAttribute(NewClass);
2043
2044 if (TUK != TUK_Friend) {
2045 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
2046 Scope *Outer = S;
2047 while ((Outer->getFlags() & Scope::TemplateParamScope) != 0)
2048 Outer = Outer->getParent();
2049 PushOnScopeChains(NewTemplate, Outer);
2050 } else {
2051 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) {
2052 NewTemplate->setAccess(PrevClassTemplate->getAccess());
2053 NewClass->setAccess(PrevClassTemplate->getAccess());
2054 }
2055
2056 NewTemplate->setObjectOfFriendDecl();
2057
2058 // Friend templates are visible in fairly strange ways.
2059 if (!CurContext->isDependentContext()) {
2060 DeclContext *DC = SemanticContext->getRedeclContext();
2061 DC->makeDeclVisibleInContext(NewTemplate);
2062 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
2063 PushOnScopeChains(NewTemplate, EnclosingScope,
2064 /* AddToContext = */ false);
2065 }
2066
2067 FriendDecl *Friend = FriendDecl::Create(
2068 Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc);
2069 Friend->setAccess(AS_public);
2070 CurContext->addDecl(Friend);
2071 }
2072
2073 if (PrevClassTemplate)
2074 CheckRedeclarationInModule(NewTemplate, PrevClassTemplate);
2075
2076 if (Invalid) {
2077 NewTemplate->setInvalidDecl();
2078 NewClass->setInvalidDecl();
2079 }
2080
2081 ActOnDocumentableDecl(NewTemplate);
2082
2083 if (SkipBody && SkipBody->ShouldSkip)
2084 return SkipBody->Previous;
2085
2086 return NewTemplate;
2087}
2088
2089namespace {
2090/// Tree transform to "extract" a transformed type from a class template's
2091/// constructor to a deduction guide.
2092class ExtractTypeForDeductionGuide
2093 : public TreeTransform<ExtractTypeForDeductionGuide> {
2094 llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs;
2095
2096public:
2097 typedef TreeTransform<ExtractTypeForDeductionGuide> Base;
2098 ExtractTypeForDeductionGuide(
2099 Sema &SemaRef,
2100 llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs)
2101 : Base(SemaRef), MaterializedTypedefs(MaterializedTypedefs) {}
2102
2103 TypeSourceInfo *transform(TypeSourceInfo *TSI) { return TransformType(TSI); }
2104
2105 QualType TransformTypedefType(TypeLocBuilder &TLB, TypedefTypeLoc TL) {
2106 ASTContext &Context = SemaRef.getASTContext();
2107 TypedefNameDecl *OrigDecl = TL.getTypedefNameDecl();
2108 TypedefNameDecl *Decl = OrigDecl;
2109 // Transform the underlying type of the typedef and clone the Decl only if
2110 // the typedef has a dependent context.
2111 if (OrigDecl->getDeclContext()->isDependentContext()) {
2112 TypeLocBuilder InnerTLB;
2113 QualType Transformed =
2114 TransformType(InnerTLB, OrigDecl->getTypeSourceInfo()->getTypeLoc());
2115 TypeSourceInfo *TSI = InnerTLB.getTypeSourceInfo(Context, Transformed);
2116 if (isa<TypeAliasDecl>(OrigDecl))
2117 Decl = TypeAliasDecl::Create(
2118 Context, Context.getTranslationUnitDecl(), OrigDecl->getBeginLoc(),
2119 OrigDecl->getLocation(), OrigDecl->getIdentifier(), TSI);
2120 else {
2121 assert(isa<TypedefDecl>(OrigDecl) && "Not a Type alias or typedef")(static_cast <bool> (isa<TypedefDecl>(OrigDecl) &&
"Not a Type alias or typedef") ? void (0) : __assert_fail ("isa<TypedefDecl>(OrigDecl) && \"Not a Type alias or typedef\""
, "clang/lib/Sema/SemaTemplate.cpp", 2121, __extension__ __PRETTY_FUNCTION__
))
;
2122 Decl = TypedefDecl::Create(
2123 Context, Context.getTranslationUnitDecl(), OrigDecl->getBeginLoc(),
2124 OrigDecl->getLocation(), OrigDecl->getIdentifier(), TSI);
2125 }
2126 MaterializedTypedefs.push_back(Decl);
2127 }
2128
2129 QualType TDTy = Context.getTypedefType(Decl);
2130 TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(TDTy);
2131 TypedefTL.setNameLoc(TL.getNameLoc());
2132
2133 return TDTy;
2134 }
2135};
2136
2137/// Transform to convert portions of a constructor declaration into the
2138/// corresponding deduction guide, per C++1z [over.match.class.deduct]p1.
2139struct ConvertConstructorToDeductionGuideTransform {
2140 ConvertConstructorToDeductionGuideTransform(Sema &S,
2141 ClassTemplateDecl *Template)
2142 : SemaRef(S), Template(Template) {}
2143
2144 Sema &SemaRef;
2145 ClassTemplateDecl *Template;
2146
2147 DeclContext *DC = Template->getDeclContext();
2148 CXXRecordDecl *Primary = Template->getTemplatedDecl();
2149 DeclarationName DeductionGuideName =
2150 SemaRef.Context.DeclarationNames.getCXXDeductionGuideName(Template);
2151
2152 QualType DeducedType = SemaRef.Context.getTypeDeclType(Primary);
2153
2154 // Index adjustment to apply to convert depth-1 template parameters into
2155 // depth-0 template parameters.
2156 unsigned Depth1IndexAdjustment = Template->getTemplateParameters()->size();
2157
2158 /// Transform a constructor declaration into a deduction guide.
2159 NamedDecl *transformConstructor(FunctionTemplateDecl *FTD,
2160 CXXConstructorDecl *CD) {
2161 SmallVector<TemplateArgument, 16> SubstArgs;
2162
2163 LocalInstantiationScope Scope(SemaRef);
2164
2165 // C++ [over.match.class.deduct]p1:
2166 // -- For each constructor of the class template designated by the
2167 // template-name, a function template with the following properties:
2168
2169 // -- The template parameters are the template parameters of the class
2170 // template followed by the template parameters (including default
2171 // template arguments) of the constructor, if any.
2172 TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2173 if (FTD) {
2174 TemplateParameterList *InnerParams = FTD->getTemplateParameters();
2175 SmallVector<NamedDecl *, 16> AllParams;
2176 AllParams.reserve(TemplateParams->size() + InnerParams->size());
2177 AllParams.insert(AllParams.begin(),
2178 TemplateParams->begin(), TemplateParams->end());
2179 SubstArgs.reserve(InnerParams->size());
2180
2181 // Later template parameters could refer to earlier ones, so build up
2182 // a list of substituted template arguments as we go.
2183 for (NamedDecl *Param : *InnerParams) {
2184 MultiLevelTemplateArgumentList Args;
2185 Args.setKind(TemplateSubstitutionKind::Rewrite);
2186 Args.addOuterTemplateArguments(SubstArgs);
2187 Args.addOuterRetainedLevel();
2188 NamedDecl *NewParam = transformTemplateParameter(Param, Args);
2189 if (!NewParam)
2190 return nullptr;
2191 AllParams.push_back(NewParam);
2192 SubstArgs.push_back(SemaRef.Context.getCanonicalTemplateArgument(
2193 SemaRef.Context.getInjectedTemplateArg(NewParam)));
2194 }
2195
2196 // Substitute new template parameters into requires-clause if present.
2197 Expr *RequiresClause = nullptr;
2198 if (Expr *InnerRC = InnerParams->getRequiresClause()) {
2199 MultiLevelTemplateArgumentList Args;
2200 Args.setKind(TemplateSubstitutionKind::Rewrite);
2201 Args.addOuterTemplateArguments(SubstArgs);
2202 Args.addOuterRetainedLevel();
2203 ExprResult E = SemaRef.SubstExpr(InnerRC, Args);
2204 if (E.isInvalid())
2205 return nullptr;
2206 RequiresClause = E.getAs<Expr>();
2207 }
2208
2209 TemplateParams = TemplateParameterList::Create(
2210 SemaRef.Context, InnerParams->getTemplateLoc(),
2211 InnerParams->getLAngleLoc(), AllParams, InnerParams->getRAngleLoc(),
2212 RequiresClause);
2213 }
2214
2215 // If we built a new template-parameter-list, track that we need to
2216 // substitute references to the old parameters into references to the
2217 // new ones.
2218 MultiLevelTemplateArgumentList Args;
2219 Args.setKind(TemplateSubstitutionKind::Rewrite);
2220 if (FTD) {
2221 Args.addOuterTemplateArguments(SubstArgs);
2222 Args.addOuterRetainedLevel();
2223 }
2224
2225 FunctionProtoTypeLoc FPTL = CD->getTypeSourceInfo()->getTypeLoc()
2226 .getAsAdjusted<FunctionProtoTypeLoc>();
2227 assert(FPTL && "no prototype for constructor declaration")(static_cast <bool> (FPTL && "no prototype for constructor declaration"
) ? void (0) : __assert_fail ("FPTL && \"no prototype for constructor declaration\""
, "clang/lib/Sema/SemaTemplate.cpp", 2227, __extension__ __PRETTY_FUNCTION__
))
;
2228
2229 // Transform the type of the function, adjusting the return type and
2230 // replacing references to the old parameters with references to the
2231 // new ones.
2232 TypeLocBuilder TLB;
2233 SmallVector<ParmVarDecl*, 8> Params;
2234 SmallVector<TypedefNameDecl *, 4> MaterializedTypedefs;
2235 QualType NewType = transformFunctionProtoType(TLB, FPTL, Params, Args,
2236 MaterializedTypedefs);
2237 if (NewType.isNull())
2238 return nullptr;
2239 TypeSourceInfo *NewTInfo = TLB.getTypeSourceInfo(SemaRef.Context, NewType);
2240
2241 return buildDeductionGuide(TemplateParams, CD, CD->getExplicitSpecifier(),
2242 NewTInfo, CD->getBeginLoc(), CD->getLocation(),
2243 CD->getEndLoc(), MaterializedTypedefs);
2244 }
2245
2246 /// Build a deduction guide with the specified parameter types.
2247 NamedDecl *buildSimpleDeductionGuide(MutableArrayRef<QualType> ParamTypes) {
2248 SourceLocation Loc = Template->getLocation();
2249
2250 // Build the requested type.
2251 FunctionProtoType::ExtProtoInfo EPI;
2252 EPI.HasTrailingReturn = true;
2253 QualType Result = SemaRef.BuildFunctionType(DeducedType, ParamTypes, Loc,
2254 DeductionGuideName, EPI);
2255 TypeSourceInfo *TSI = SemaRef.Context.getTrivialTypeSourceInfo(Result, Loc);
2256
2257 FunctionProtoTypeLoc FPTL =
2258 TSI->getTypeLoc().castAs<FunctionProtoTypeLoc>();
2259
2260 // Build the parameters, needed during deduction / substitution.
2261 SmallVector<ParmVarDecl*, 4> Params;
2262 for (auto T : ParamTypes) {
2263 ParmVarDecl *NewParam = ParmVarDecl::Create(
2264 SemaRef.Context, DC, Loc, Loc, nullptr, T,
2265 SemaRef.Context.getTrivialTypeSourceInfo(T, Loc), SC_None, nullptr);
2266 NewParam->setScopeInfo(0, Params.size());
2267 FPTL.setParam(Params.size(), NewParam);
2268 Params.push_back(NewParam);
2269 }
2270
2271 return buildDeductionGuide(Template->getTemplateParameters(), nullptr,
2272 ExplicitSpecifier(), TSI, Loc, Loc, Loc);
2273 }
2274
2275private:
2276 /// Transform a constructor template parameter into a deduction guide template
2277 /// parameter, rebuilding any internal references to earlier parameters and
2278 /// renumbering as we go.
2279 NamedDecl *transformTemplateParameter(NamedDecl *TemplateParam,
2280 MultiLevelTemplateArgumentList &Args) {
2281 if (auto *TTP = dyn_cast<TemplateTypeParmDecl>(TemplateParam)) {
2282 // TemplateTypeParmDecl's index cannot be changed after creation, so
2283 // substitute it directly.
2284 auto *NewTTP = TemplateTypeParmDecl::Create(
2285 SemaRef.Context, DC, TTP->getBeginLoc(), TTP->getLocation(),
2286 /*Depth*/ 0, Depth1IndexAdjustment + TTP->getIndex(),
2287 TTP->getIdentifier(), TTP->wasDeclaredWithTypename(),
2288 TTP->isParameterPack(), TTP->hasTypeConstraint(),
2289 TTP->isExpandedParameterPack() ?
2290 llvm::Optional<unsigned>(TTP->getNumExpansionParameters()) : None);
2291 if (const auto *TC = TTP->getTypeConstraint())
2292 SemaRef.SubstTypeConstraint(NewTTP, TC, Args);
2293 if (TTP->hasDefaultArgument()) {
2294 TypeSourceInfo *InstantiatedDefaultArg =
2295 SemaRef.SubstType(TTP->getDefaultArgumentInfo(), Args,
2296 TTP->getDefaultArgumentLoc(), TTP->getDeclName());
2297 if (InstantiatedDefaultArg)
2298 NewTTP->setDefaultArgument(InstantiatedDefaultArg);
2299 }
2300 SemaRef.CurrentInstantiationScope->InstantiatedLocal(TemplateParam,
2301 NewTTP);
2302 return NewTTP;
2303 }
2304
2305 if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(TemplateParam))
2306 return transformTemplateParameterImpl(TTP, Args);
2307
2308 return transformTemplateParameterImpl(
2309 cast<NonTypeTemplateParmDecl>(TemplateParam), Args);
2310 }
2311 template<typename TemplateParmDecl>
2312 TemplateParmDecl *
2313 transformTemplateParameterImpl(TemplateParmDecl *OldParam,
2314 MultiLevelTemplateArgumentList &Args) {
2315 // Ask the template instantiator to do the heavy lifting for us, then adjust
2316 // the index of the parameter once it's done.
2317 auto *NewParam =
2318 cast<TemplateParmDecl>(SemaRef.SubstDecl(OldParam, DC, Args));
2319 assert(NewParam->getDepth() == 0 && "unexpected template param depth")(static_cast <bool> (NewParam->getDepth() == 0 &&
"unexpected template param depth") ? void (0) : __assert_fail
("NewParam->getDepth() == 0 && \"unexpected template param depth\""
, "clang/lib/Sema/SemaTemplate.cpp", 2319, __extension__ __PRETTY_FUNCTION__
))
;
2320 NewParam->setPosition(NewParam->getPosition() + Depth1IndexAdjustment);
2321 return NewParam;
2322 }
2323
2324 QualType transformFunctionProtoType(
2325 TypeLocBuilder &TLB, FunctionProtoTypeLoc TL,
2326 SmallVectorImpl<ParmVarDecl *> &Params,
2327 MultiLevelTemplateArgumentList &Args,
2328 SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs) {
2329 SmallVector<QualType, 4> ParamTypes;
2330 const FunctionProtoType *T = TL.getTypePtr();
2331
2332 // -- The types of the function parameters are those of the constructor.
2333 for (auto *OldParam : TL.getParams()) {
2334 ParmVarDecl *NewParam =
2335 transformFunctionTypeParam(OldParam, Args, MaterializedTypedefs);
2336 if (!NewParam)
2337 return QualType();
2338 ParamTypes.push_back(NewParam->getType());
2339 Params.push_back(NewParam);
2340 }
2341
2342 // -- The return type is the class template specialization designated by
2343 // the template-name and template arguments corresponding to the
2344 // template parameters obtained from the class template.
2345 //
2346 // We use the injected-class-name type of the primary template instead.
2347 // This has the convenient property that it is different from any type that
2348 // the user can write in a deduction-guide (because they cannot enter the
2349 // context of the template), so implicit deduction guides can never collide
2350 // with explicit ones.
2351 QualType ReturnType = DeducedType;
2352 TLB.pushTypeSpec(ReturnType).setNameLoc(Primary->getLocation());
2353
2354 // Resolving a wording defect, we also inherit the variadicness of the
2355 // constructor.
2356 FunctionProtoType::ExtProtoInfo EPI;
2357 EPI.Variadic = T->isVariadic();
2358 EPI.HasTrailingReturn = true;
2359
2360 QualType Result = SemaRef.BuildFunctionType(
2361 ReturnType, ParamTypes, TL.getBeginLoc(), DeductionGuideName, EPI);
2362 if (Result.isNull())
2363 return QualType();
2364
2365 FunctionProtoTypeLoc NewTL = TLB.push<FunctionProtoTypeLoc>(Result);
2366 NewTL.setLocalRangeBegin(TL.getLocalRangeBegin());
2367 NewTL.setLParenLoc(TL.getLParenLoc());
2368 NewTL.setRParenLoc(TL.getRParenLoc());
2369 NewTL.setExceptionSpecRange(SourceRange());
2370 NewTL.setLocalRangeEnd(TL.getLocalRangeEnd());
2371 for (unsigned I = 0, E = NewTL.getNumParams(); I != E; ++I)
2372 NewTL.setParam(I, Params[I]);
2373
2374 return Result;
2375 }
2376
2377 ParmVarDecl *transformFunctionTypeParam(
2378 ParmVarDecl *OldParam, MultiLevelTemplateArgumentList &Args,
2379 llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs) {
2380 TypeSourceInfo *OldDI = OldParam->getTypeSourceInfo();
2381 TypeSourceInfo *NewDI;
2382 if (auto PackTL = OldDI->getTypeLoc().getAs<PackExpansionTypeLoc>()) {
2383 // Expand out the one and only element in each inner pack.
2384 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, 0);
2385 NewDI =
2386 SemaRef.SubstType(PackTL.getPatternLoc(), Args,
2387 OldParam->getLocation(), OldParam->getDeclName());
2388 if (!NewDI) return nullptr;
2389 NewDI =
2390 SemaRef.CheckPackExpansion(NewDI, PackTL.getEllipsisLoc(),
2391 PackTL.getTypePtr()->getNumExpansions());
2392 } else
2393 NewDI = SemaRef.SubstType(OldDI, Args, OldParam->getLocation(),
2394 OldParam->getDeclName());
2395 if (!NewDI)
2396 return nullptr;
2397
2398 // Extract the type. This (for instance) replaces references to typedef
2399 // members of the current instantiations with the definitions of those
2400 // typedefs, avoiding triggering instantiation of the deduced type during
2401 // deduction.
2402 NewDI = ExtractTypeForDeductionGuide(SemaRef, MaterializedTypedefs)
2403 .transform(NewDI);
2404
2405 // Resolving a wording defect, we also inherit default arguments from the
2406 // constructor.
2407 ExprResult NewDefArg;
2408 if (OldParam->hasDefaultArg()) {
2409 // We don't care what the value is (we won't use it); just create a
2410 // placeholder to indicate there is a default argument.
2411 QualType ParamTy = NewDI->getType();
2412 NewDefArg = new (SemaRef.Context)
2413 OpaqueValueExpr(OldParam->getDefaultArg()->getBeginLoc(),
2414 ParamTy.getNonLValueExprType(SemaRef.Context),
2415 ParamTy->isLValueReferenceType() ? VK_LValue
2416 : ParamTy->isRValueReferenceType() ? VK_XValue
2417 : VK_PRValue);
2418 }
2419
2420 ParmVarDecl *NewParam = ParmVarDecl::Create(SemaRef.Context, DC,
2421 OldParam->getInnerLocStart(),
2422 OldParam->getLocation(),
2423 OldParam->getIdentifier(),
2424 NewDI->getType(),
2425 NewDI,
2426 OldParam->getStorageClass(),
2427 NewDefArg.get());
2428 NewParam->setScopeInfo(OldParam->getFunctionScopeDepth(),
2429 OldParam->getFunctionScopeIndex());
2430 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldParam, NewParam);
2431 return NewParam;
2432 }
2433
2434 FunctionTemplateDecl *buildDeductionGuide(
2435 TemplateParameterList *TemplateParams, CXXConstructorDecl *Ctor,
2436 ExplicitSpecifier ES, TypeSourceInfo *TInfo, SourceLocation LocStart,
2437 SourceLocation Loc, SourceLocation LocEnd,
2438 llvm::ArrayRef<TypedefNameDecl *> MaterializedTypedefs = {}) {
2439 DeclarationNameInfo Name(DeductionGuideName, Loc);
2440 ArrayRef<ParmVarDecl *> Params =
2441 TInfo->getTypeLoc().castAs<FunctionProtoTypeLoc>().getParams();
2442
2443 // Build the implicit deduction guide template.
2444 auto *Guide =
2445 CXXDeductionGuideDecl::Create(SemaRef.Context, DC, LocStart, ES, Name,
2446 TInfo->getType(), TInfo, LocEnd, Ctor);
2447 Guide->setImplicit();
2448 Guide->setParams(Params);
2449
2450 for (auto *Param : Params)
2451 Param->setDeclContext(Guide);
2452 for (auto *TD : MaterializedTypedefs)
2453 TD->setDeclContext(Guide);
2454
2455 auto *GuideTemplate = FunctionTemplateDecl::Create(
2456 SemaRef.Context, DC, Loc, DeductionGuideName, TemplateParams, Guide);
2457 GuideTemplate->setImplicit();
2458 Guide->setDescribedFunctionTemplate(GuideTemplate);
2459
2460 if (isa<CXXRecordDecl>(DC)) {
2461 Guide->setAccess(AS_public);
2462 GuideTemplate->setAccess(AS_public);
2463 }
2464
2465 DC->addDecl(GuideTemplate);
2466 return GuideTemplate;
2467 }
2468};
2469}
2470
2471void Sema::DeclareImplicitDeductionGuides(TemplateDecl *Template,
2472 SourceLocation Loc) {
2473 if (CXXRecordDecl *DefRecord =
2474 cast<CXXRecordDecl>(Template->getTemplatedDecl())->getDefinition()) {
2475 TemplateDecl *DescribedTemplate = DefRecord->getDescribedClassTemplate();
2476 Template = DescribedTemplate ? DescribedTemplate : Template;
2477 }
2478
2479 DeclContext *DC = Template->getDeclContext();
2480 if (DC->isDependentContext())
2481 return;
2482
2483 ConvertConstructorToDeductionGuideTransform Transform(
2484 *this, cast<ClassTemplateDecl>(Template));
2485 if (!isCompleteType(Loc, Transform.DeducedType))
2486 return;
2487
2488 // Check whether we've already declared deduction guides for this template.
2489 // FIXME: Consider storing a flag on the template to indicate this.
2490 auto Existing = DC->lookup(Transform.DeductionGuideName);
2491 for (auto *D : Existing)
2492 if (D->isImplicit())
2493 return;
2494
2495 // In case we were expanding a pack when we attempted to declare deduction
2496 // guides, turn off pack expansion for everything we're about to do.
2497 ArgumentPackSubstitutionIndexRAII SubstIndex(*this, -1);
2498 // Create a template instantiation record to track the "instantiation" of
2499 // constructors into deduction guides.
2500 // FIXME: Add a kind for this to give more meaningful diagnostics. But can
2501 // this substitution process actually fail?
2502 InstantiatingTemplate BuildingDeductionGuides(*this, Loc, Template);
2503 if (BuildingDeductionGuides.isInvalid())
2504 return;
2505
2506 // Convert declared constructors into deduction guide templates.
2507 // FIXME: Skip constructors for which deduction must necessarily fail (those
2508 // for which some class template parameter without a default argument never
2509 // appears in a deduced context).
2510 bool AddedAny = false;
2511 for (NamedDecl *D : LookupConstructors(Transform.Primary)) {
2512 D = D->getUnderlyingDecl();
2513 if (D->isInvalidDecl() || D->isImplicit())
2514 continue;
2515 D = cast<NamedDecl>(D->getCanonicalDecl());
2516
2517 auto *FTD = dyn_cast<FunctionTemplateDecl>(D);
2518 auto *CD =
2519 dyn_cast_or_null<CXXConstructorDecl>(FTD ? FTD->getTemplatedDecl() : D);
2520 // Class-scope explicit specializations (MS extension) do not result in
2521 // deduction guides.
2522 if (!CD || (!FTD && CD->isFunctionTemplateSpecialization()))
2523 continue;
2524
2525 // Cannot make a deduction guide when unparsed arguments are present.
2526 if (std::any_of(CD->param_begin(), CD->param_end(), [](ParmVarDecl *P) {
2527 return !P || P->hasUnparsedDefaultArg();
2528 }))
2529 continue;
2530
2531 Transform.transformConstructor(FTD, CD);
2532 AddedAny = true;
2533 }
2534
2535 // C++17 [over.match.class.deduct]
2536 // -- If C is not defined or does not declare any constructors, an
2537 // additional function template derived as above from a hypothetical
2538 // constructor C().
2539 if (!AddedAny)
2540 Transform.buildSimpleDeductionGuide(None);
2541
2542 // -- An additional function template derived as above from a hypothetical
2543 // constructor C(C), called the copy deduction candidate.
2544 cast<CXXDeductionGuideDecl>(
2545 cast<FunctionTemplateDecl>(
2546 Transform.buildSimpleDeductionGuide(Transform.DeducedType))
2547 ->getTemplatedDecl())
2548 ->setIsCopyDeductionCandidate();
2549}
2550
2551/// Diagnose the presence of a default template argument on a
2552/// template parameter, which is ill-formed in certain contexts.
2553///
2554/// \returns true if the default template argument should be dropped.
2555static bool DiagnoseDefaultTemplateArgument(Sema &S,
2556 Sema::TemplateParamListContext TPC,
2557 SourceLocation ParamLoc,
2558 SourceRange DefArgRange) {
2559 switch (TPC) {
2560 case Sema::TPC_ClassTemplate:
2561 case Sema::TPC_VarTemplate:
2562 case Sema::TPC_TypeAliasTemplate:
2563 return false;
2564
2565 case Sema::TPC_FunctionTemplate:
2566 case Sema::TPC_FriendFunctionTemplateDefinition:
2567 // C++ [temp.param]p9:
2568 // A default template-argument shall not be specified in a
2569 // function template declaration or a function template
2570 // definition [...]
2571 // If a friend function template declaration specifies a default
2572 // template-argument, that declaration shall be a definition and shall be
2573 // the only declaration of the function template in the translation unit.
2574 // (C++98/03 doesn't have this wording; see DR226).
2575 S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ?
2576 diag::warn_cxx98_compat_template_parameter_default_in_function_template
2577 : diag::ext_template_parameter_default_in_function_template)
2578 << DefArgRange;
2579 return false;
2580
2581 case Sema::TPC_ClassTemplateMember:
2582 // C++0x [temp.param]p9:
2583 // A default template-argument shall not be specified in the
2584 // template-parameter-lists of the definition of a member of a
2585 // class template that appears outside of the member's class.
2586 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
2587 << DefArgRange;
2588 return true;
2589
2590 case Sema::TPC_FriendClassTemplate:
2591 case Sema::TPC_FriendFunctionTemplate:
2592 // C++ [temp.param]p9:
2593 // A default template-argument shall not be specified in a
2594 // friend template declaration.
2595 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
2596 << DefArgRange;
2597 return true;
2598
2599 // FIXME: C++0x [temp.param]p9 allows default template-arguments
2600 // for friend function templates if there is only a single
2601 // declaration (and it is a definition). Strange!
2602 }
2603
2604 llvm_unreachable("Invalid TemplateParamListContext!")::llvm::llvm_unreachable_internal("Invalid TemplateParamListContext!"
, "clang/lib/Sema/SemaTemplate.cpp", 2604)
;
2605}
2606
2607/// Check for unexpanded parameter packs within the template parameters
2608/// of a template template parameter, recursively.
2609static bool DiagnoseUnexpandedParameterPacks(Sema &S,
2610 TemplateTemplateParmDecl *TTP) {
2611 // A template template parameter which is a parameter pack is also a pack
2612 // expansion.
2613 if (TTP->isParameterPack())
2614 return false;
2615
2616 TemplateParameterList *Params = TTP->getTemplateParameters();
2617 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
2618 NamedDecl *P = Params->getParam(I);
2619 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(P)) {
2620 if (!TTP->isParameterPack())
2621 if (const TypeConstraint *TC = TTP->getTypeConstraint())
2622 if (TC->hasExplicitTemplateArgs())
2623 for (auto &ArgLoc : TC->getTemplateArgsAsWritten()->arguments())
2624 if (S.DiagnoseUnexpandedParameterPack(ArgLoc,
2625 Sema::UPPC_TypeConstraint))
2626 return true;
2627 continue;
2628 }
2629
2630 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
2631 if (!NTTP->isParameterPack() &&
2632 S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
2633 NTTP->getTypeSourceInfo(),
2634 Sema::UPPC_NonTypeTemplateParameterType))
2635 return true;
2636
2637 continue;
2638 }
2639
2640 if (TemplateTemplateParmDecl *InnerTTP
2641 = dyn_cast<TemplateTemplateParmDecl>(P))
2642 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
2643 return true;
2644 }
2645
2646 return false;
2647}
2648
2649/// Checks the validity of a template parameter list, possibly
2650/// considering the template parameter list from a previous
2651/// declaration.
2652///
2653/// If an "old" template parameter list is provided, it must be
2654/// equivalent (per TemplateParameterListsAreEqual) to the "new"
2655/// template parameter list.
2656///
2657/// \param NewParams Template parameter list for a new template
2658/// declaration. This template parameter list will be updated with any
2659/// default arguments that are carried through from the previous
2660/// template parameter list.
2661///
2662/// \param OldParams If provided, template parameter list from a
2663/// previous declaration of the same template. Default template
2664/// arguments will be merged from the old template parameter list to
2665/// the new template parameter list.
2666///
2667/// \param TPC Describes the context in which we are checking the given
2668/// template parameter list.
2669///
2670/// \param SkipBody If we might have already made a prior merged definition
2671/// of this template visible, the corresponding body-skipping information.
2672/// Default argument redefinition is not an error when skipping such a body,
2673/// because (under the ODR) we can assume the default arguments are the same
2674/// as the prior merged definition.
2675///
2676/// \returns true if an error occurred, false otherwise.
2677bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
2678 TemplateParameterList *OldParams,
2679 TemplateParamListContext TPC,
2680 SkipBodyInfo *SkipBody) {
2681 bool Invalid = false;
2682
2683 // C++ [temp.param]p10:
2684 // The set of default template-arguments available for use with a
2685 // template declaration or definition is obtained by merging the
2686 // default arguments from the definition (if in scope) and all
2687 // declarations in scope in the same way default function
2688 // arguments are (8.3.6).
2689 bool SawDefaultArgument = false;
2690 SourceLocation PreviousDefaultArgLoc;
2691
2692 // Dummy initialization to avoid warnings.
2693 TemplateParameterList::iterator OldParam = NewParams->end();
2694 if (OldParams)
2695 OldParam = OldParams->begin();
2696
2697 bool RemoveDefaultArguments = false;
2698 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
2699 NewParamEnd = NewParams->end();
2700 NewParam != NewParamEnd; ++NewParam) {
2701 // Variables used to diagnose redundant default arguments
2702 bool RedundantDefaultArg = false;
2703 SourceLocation OldDefaultLoc;
2704 SourceLocation NewDefaultLoc;
2705
2706 // Variable used to diagnose missing default arguments
2707 bool MissingDefaultArg = false;
2708
2709 // Variable used to diagnose non-final parameter packs
2710 bool SawParameterPack = false;
2711
2712 if (TemplateTypeParmDecl *NewTypeParm
2713 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
2714 // Check the presence of a default argument here.
2715 if (NewTypeParm->hasDefaultArgument() &&
2716 DiagnoseDefaultTemplateArgument(*this, TPC,
2717 NewTypeParm->getLocation(),
2718 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
2719 .getSourceRange()))
2720 NewTypeParm->removeDefaultArgument();
2721
2722 // Merge default arguments for template type parameters.
2723 TemplateTypeParmDecl *OldTypeParm
2724 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr;
2725 if (NewTypeParm->isParameterPack()) {
2726 assert(!NewTypeParm->hasDefaultArgument() &&(static_cast <bool> (!NewTypeParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "clang/lib/Sema/SemaTemplate.cpp", 2727, __extension__ __PRETTY_FUNCTION__
))
2727 "Parameter packs can't have a default argument!")(static_cast <bool> (!NewTypeParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "clang/lib/Sema/SemaTemplate.cpp", 2727, __extension__ __PRETTY_FUNCTION__
))
;
2728 SawParameterPack = true;
2729 } else if (OldTypeParm && hasVisibleDefaultArgument(OldTypeParm) &&
2730 NewTypeParm->hasDefaultArgument() &&
2731 (!SkipBody || !SkipBody->ShouldSkip)) {
2732 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
2733 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
2734 SawDefaultArgument = true;
2735 RedundantDefaultArg = true;
2736 PreviousDefaultArgLoc = NewDefaultLoc;
2737 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) {
2738 // Merge the default argument from the old declaration to the
2739 // new declaration.
2740 NewTypeParm->setInheritedDefaultArgument(Context, OldTypeParm);
2741 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
2742 } else if (NewTypeParm->hasDefaultArgument()) {
2743 SawDefaultArgument = true;
2744 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
2745 } else if (SawDefaultArgument)
2746 MissingDefaultArg = true;
2747 } else if (NonTypeTemplateParmDecl *NewNonTypeParm
2748 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
2749 // Check for unexpanded parameter packs.
2750 if (!NewNonTypeParm->isParameterPack() &&
2751 DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
2752 NewNonTypeParm->getTypeSourceInfo(),
2753 UPPC_NonTypeTemplateParameterType)) {
2754 Invalid = true;
2755 continue;
2756 }
2757
2758 // Check the presence of a default argument here.
2759 if (NewNonTypeParm->hasDefaultArgument() &&
2760 DiagnoseDefaultTemplateArgument(*this, TPC,
2761 NewNonTypeParm->getLocation(),
2762 NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
2763 NewNonTypeParm->removeDefaultArgument();
2764 }
2765
2766 // Merge default arguments for non-type template parameters
2767 NonTypeTemplateParmDecl *OldNonTypeParm
2768 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr;
2769 if (NewNonTypeParm->isParameterPack()) {
2770 assert(!NewNonTypeParm->hasDefaultArgument() &&(static_cast <bool> (!NewNonTypeParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewNonTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "clang/lib/Sema/SemaTemplate.cpp", 2771, __extension__ __PRETTY_FUNCTION__
))
2771 "Parameter packs can't have a default argument!")(static_cast <bool> (!NewNonTypeParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewNonTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "clang/lib/Sema/SemaTemplate.cpp", 2771, __extension__ __PRETTY_FUNCTION__
))
;
2772 if (!NewNonTypeParm->isPackExpansion())
2773 SawParameterPack = true;
2774 } else if (OldNonTypeParm && hasVisibleDefaultArgument(OldNonTypeParm) &&
2775 NewNonTypeParm->hasDefaultArgument() &&
2776 (!SkipBody || !SkipBody->ShouldSkip)) {
2777 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
2778 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
2779 SawDefaultArgument = true;
2780 RedundantDefaultArg = true;
2781 PreviousDefaultArgLoc = NewDefaultLoc;
2782 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) {
2783 // Merge the default argument from the old declaration to the
2784 // new declaration.
2785 NewNonTypeParm->setInheritedDefaultArgument(Context, OldNonTypeParm);
2786 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
2787 } else if (NewNonTypeParm->hasDefaultArgument()) {
2788 SawDefaultArgument = true;
2789 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
2790 } else if (SawDefaultArgument)
2791 MissingDefaultArg = true;
2792 } else {
2793 TemplateTemplateParmDecl *NewTemplateParm
2794 = cast<TemplateTemplateParmDecl>(*NewParam);
2795
2796 // Check for unexpanded parameter packs, recursively.
2797 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
2798 Invalid = true;
2799 continue;
2800 }
2801
2802 // Check the presence of a default argument here.
2803 if (NewTemplateParm->hasDefaultArgument() &&
2804 DiagnoseDefaultTemplateArgument(*this, TPC,
2805 NewTemplateParm->getLocation(),
2806 NewTemplateParm->getDefaultArgument().getSourceRange()))
2807 NewTemplateParm->removeDefaultArgument();
2808
2809 // Merge default arguments for template template parameters
2810 TemplateTemplateParmDecl *OldTemplateParm
2811 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr;
2812 if (NewTemplateParm->isParameterPack()) {
2813 assert(!NewTemplateParm->hasDefaultArgument() &&(static_cast <bool> (!NewTemplateParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewTemplateParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "clang/lib/Sema/SemaTemplate.cpp", 2814, __extension__ __PRETTY_FUNCTION__
))
2814 "Parameter packs can't have a default argument!")(static_cast <bool> (!NewTemplateParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewTemplateParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "clang/lib/Sema/SemaTemplate.cpp", 2814, __extension__ __PRETTY_FUNCTION__
))
;
2815 if (!NewTemplateParm->isPackExpansion())
2816 SawParameterPack = true;
2817 } else if (OldTemplateParm &&
2818 hasVisibleDefaultArgument(OldTemplateParm) &&
2819 NewTemplateParm->hasDefaultArgument() &&
2820 (!SkipBody || !SkipBody->ShouldSkip)) {
2821 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
2822 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
2823 SawDefaultArgument = true;
2824 RedundantDefaultArg = true;
2825 PreviousDefaultArgLoc = NewDefaultLoc;
2826 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) {
2827 // Merge the default argument from the old declaration to the
2828 // new declaration.
2829 NewTemplateParm->setInheritedDefaultArgument(Context, OldTemplateParm);
2830 PreviousDefaultArgLoc
2831 = OldTemplateParm->getDefaultArgument().getLocation();
2832 } else if (NewTemplateParm->hasDefaultArgument()) {
2833 SawDefaultArgument = true;
2834 PreviousDefaultArgLoc
2835 = NewTemplateParm->getDefaultArgument().getLocation();
2836 } else if (SawDefaultArgument)
2837 MissingDefaultArg = true;
2838 }
2839
2840 // C++11 [temp.param]p11:
2841 // If a template parameter of a primary class template or alias template
2842 // is a template parameter pack, it shall be the last template parameter.
2843 if (SawParameterPack && (NewParam + 1) != NewParamEnd &&
2844 (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate ||
2845 TPC == TPC_TypeAliasTemplate)) {
2846 Diag((*NewParam)->getLocation(),
2847 diag::err_template_param_pack_must_be_last_template_parameter);
2848 Invalid = true;
2849 }
2850
2851 if (RedundantDefaultArg) {
2852 // C++ [temp.param]p12:
2853 // A template-parameter shall not be given default arguments
2854 // by two different declarations in the same scope.
2855 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
2856 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
2857 Invalid = true;
2858 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) {
2859 // C++ [temp.param]p11:
2860 // If a template-parameter of a class template has a default
2861 // template-argument, each subsequent template-parameter shall either
2862 // have a default template-argument supplied or be a template parameter
2863 // pack.
2864 Diag((*NewParam)->getLocation(),
2865 diag::err_template_param_default_arg_missing);
2866 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
2867 Invalid = true;
2868 RemoveDefaultArguments = true;
2869 }
2870
2871 // If we have an old template parameter list that we're merging
2872 // in, move on to the next parameter.
2873 if (OldParams)
2874 ++OldParam;
2875 }
2876
2877 // We were missing some default arguments at the end of the list, so remove
2878 // all of the default arguments.
2879 if (RemoveDefaultArguments) {
2880 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
2881 NewParamEnd = NewParams->end();
2882 NewParam != NewParamEnd; ++NewParam) {
2883 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
2884 TTP->removeDefaultArgument();
2885 else if (NonTypeTemplateParmDecl *NTTP
2886 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
2887 NTTP->removeDefaultArgument();
2888 else
2889 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
2890 }
2891 }
2892
2893 return Invalid;
2894}
2895
2896namespace {
2897
2898/// A class which looks for a use of a certain level of template
2899/// parameter.
2900struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
2901 typedef RecursiveASTVisitor<DependencyChecker> super;
2902
2903 unsigned Depth;
2904
2905 // Whether we're looking for a use of a template parameter that makes the
2906 // overall construct type-dependent / a dependent type. This is strictly
2907 // best-effort for now; we may fail to match at all for a dependent type
2908 // in some cases if this is set.
2909 bool IgnoreNonTypeDependent;
2910
2911 bool Match;
2912 SourceLocation MatchLoc;
2913
2914 DependencyChecker(unsigned Depth, bool IgnoreNonTypeDependent)
2915 : Depth(Depth), IgnoreNonTypeDependent(IgnoreNonTypeDependent),
2916 Match(false) {}
2917
2918 DependencyChecker(TemplateParameterList *Params, bool IgnoreNonTypeDependent)
2919 : IgnoreNonTypeDependent(IgnoreNonTypeDependent), Match(false) {
2920 NamedDecl *ND = Params->getParam(0);
2921 if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) {
2922 Depth = PD->getDepth();
2923 } else if (NonTypeTemplateParmDecl *PD =
2924 dyn_cast<NonTypeTemplateParmDecl>(ND)) {
2925 Depth = PD->getDepth();
2926 } else {
2927 Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth();
2928 }
2929 }
2930
2931 bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) {
2932 if (ParmDepth >= Depth) {
2933 Match = true;
2934 MatchLoc = Loc;
2935 return true;
2936 }
2937 return false;
2938 }
2939
2940 bool TraverseStmt(Stmt *S, DataRecursionQueue *Q = nullptr) {
2941 // Prune out non-type-dependent expressions if requested. This can
2942 // sometimes result in us failing to find a template parameter reference
2943 // (if a value-dependent expression creates a dependent type), but this
2944 // mode is best-effort only.
2945 if (auto *E = dyn_cast_or_null<Expr>(S))
2946 if (IgnoreNonTypeDependent && !E->isTypeDependent())
2947 return true;
2948 return super::TraverseStmt(S, Q);
2949 }
2950
2951 bool TraverseTypeLoc(TypeLoc TL) {
2952 if (IgnoreNonTypeDependent && !TL.isNull() &&
2953 !TL.getType()->isDependentType())
2954 return true;
2955 return super::TraverseTypeLoc(TL);
2956 }
2957
2958 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
2959 return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc());
2960 }
2961
2962 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
2963 // For a best-effort search, keep looking until we find a location.
2964 return IgnoreNonTypeDependent || !Matches(T->getDepth());
2965 }
2966
2967 bool TraverseTemplateName(TemplateName N) {
2968 if (TemplateTemplateParmDecl *PD =
2969 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
2970 if (Matches(PD->getDepth()))
2971 return false;
2972 return super::TraverseTemplateName(N);
2973 }
2974
2975 bool VisitDeclRefExpr(DeclRefExpr *E) {
2976 if (NonTypeTemplateParmDecl *PD =
2977 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl()))
2978 if (Matches(PD->getDepth(), E->getExprLoc()))
2979 return false;
2980 return super::VisitDeclRefExpr(E);
2981 }
2982
2983 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
2984 return TraverseType(T->getReplacementType());
2985 }
2986
2987 bool
2988 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
2989 return TraverseTemplateArgument(T->getArgumentPack());
2990 }
2991
2992 bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
2993 return TraverseType(T->getInjectedSpecializationType());
2994 }
2995};
2996} // end anonymous namespace
2997
2998/// Determines whether a given type depends on the given parameter
2999/// list.
3000static bool
3001DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
3002 if (!Params->size())
3003 return false;
3004
3005 DependencyChecker Checker(Params, /*IgnoreNonTypeDependent*/false);
3006 Checker.TraverseType(T);
3007 return Checker.Match;
3008}
3009
3010// Find the source range corresponding to the named type in the given
3011// nested-name-specifier, if any.
3012static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
3013 QualType T,
3014 const CXXScopeSpec &SS) {
3015 NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
3016 while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
3017 if (const Type *CurType = NNS->getAsType()) {
3018 if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
3019 return NNSLoc.getTypeLoc().getSourceRange();
3020 } else
3021 break;
3022
3023 NNSLoc = NNSLoc.getPrefix();
3024 }
3025
3026 return SourceRange();
3027}
3028
3029/// Match the given template parameter lists to the given scope
3030/// specifier, returning the template parameter list that applies to the
3031/// name.
3032///
3033/// \param DeclStartLoc the start of the declaration that has a scope
3034/// specifier or a template parameter list.
3035///
3036/// \param DeclLoc The location of the declaration itself.
3037///
3038/// \param SS the scope specifier that will be matched to the given template
3039/// parameter lists. This scope specifier precedes a qualified name that is
3040/// being declared.
3041///
3042/// \param TemplateId The template-id following the scope specifier, if there
3043/// is one. Used to check for a missing 'template<>'.
3044///
3045/// \param ParamLists the template parameter lists, from the outermost to the
3046/// innermost template parameter lists.
3047///
3048/// \param IsFriend Whether to apply the slightly different rules for
3049/// matching template parameters to scope specifiers in friend
3050/// declarations.
3051///
3052/// \param IsMemberSpecialization will be set true if the scope specifier
3053/// denotes a fully-specialized type, and therefore this is a declaration of
3054/// a member specialization.
3055///
3056/// \returns the template parameter list, if any, that corresponds to the
3057/// name that is preceded by the scope specifier @p SS. This template
3058/// parameter list may have template parameters (if we're declaring a
3059/// template) or may have no template parameters (if we're declaring a
3060/// template specialization), or may be NULL (if what we're declaring isn't
3061/// itself a template).
3062TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier(
3063 SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS,
3064 TemplateIdAnnotation *TemplateId,
3065 ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend,
3066 bool &IsMemberSpecialization, bool &Invalid, bool SuppressDiagnostic) {
3067 IsMemberSpecialization = false;
3068 Invalid = false;
3069
3070 // The sequence of nested types to which we will match up the template
3071 // parameter lists. We first build this list by starting with the type named
3072 // by the nested-name-specifier and walking out until we run out of types.
3073 SmallVector<QualType, 4> NestedTypes;
3074 QualType T;
3075 if (SS.getScopeRep()) {
3076 if (CXXRecordDecl *Record
3077 = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
3078 T = Context.getTypeDeclType(Record);
3079 else
3080 T = QualType(SS.getScopeRep()->getAsType(), 0);
3081 }
3082
3083 // If we found an explicit specialization that prevents us from needing
3084 // 'template<>' headers, this will be set to the location of that
3085 // explicit specialization.
3086 SourceLocation ExplicitSpecLoc;
3087
3088 while (!T.isNull()) {
3089 NestedTypes.push_back(T);
3090
3091 // Retrieve the parent of a record type.
3092 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
3093 // If this type is an explicit specialization, we're done.
3094 if (ClassTemplateSpecializationDecl *Spec
3095 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
3096 if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) &&
3097 Spec->getSpecializationKind() == TSK_ExplicitSpecialization) {
3098 ExplicitSpecLoc = Spec->getLocation();
3099 break;
3100 }
3101 } else if (Record->getTemplateSpecializationKind()
3102 == TSK_ExplicitSpecialization) {
3103 ExplicitSpecLoc = Record->getLocation();
3104 break;
3105 }
3106
3107 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
3108 T = Context.getTypeDeclType(Parent);
3109 else
3110 T = QualType();
3111 continue;
3112 }
3113
3114 if (const TemplateSpecializationType *TST
3115 = T->getAs<TemplateSpecializationType>()) {
3116 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
3117 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
3118 T = Context.getTypeDeclType(Parent);
3119 else
3120 T = QualType();
3121 continue;
3122 }
3123 }
3124
3125 // Look one step prior in a dependent template specialization type.
3126 if (const DependentTemplateSpecializationType *DependentTST
3127 = T->getAs<DependentTemplateSpecializationType>()) {
3128 if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
3129 T = QualType(NNS->getAsType(), 0);
3130 else
3131 T = QualType();
3132 continue;
3133 }
3134
3135 // Look one step prior in a dependent name type.
3136 if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
3137 if (NestedNameSpecifier *NNS = DependentName->getQualifier())
3138 T = QualType(NNS->getAsType(), 0);
3139 else
3140 T = QualType();
3141 continue;
3142 }
3143
3144 // Retrieve the parent of an enumeration type.
3145 if (const EnumType *EnumT = T->getAs<EnumType>()) {
3146 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
3147 // check here.
3148 EnumDecl *Enum = EnumT->getDecl();
3149
3150 // Get to the parent type.
3151 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
3152 T = Context.getTypeDeclType(Parent);
3153 else
3154 T = QualType();
3155 continue;
3156 }
3157
3158 T = QualType();
3159 }
3160 // Reverse the nested types list, since we want to traverse from the outermost
3161 // to the innermost while checking template-parameter-lists.
3162 std::reverse(NestedTypes.begin(), NestedTypes.end());
3163
3164 // C++0x [temp.expl.spec]p17:
3165 // A member or a member template may be nested within many
3166 // enclosing class templates. In an explicit specialization for
3167 // such a member, the member declaration shall be preceded by a
3168 // template<> for each enclosing class template that is
3169 // explicitly specialized.
3170 bool SawNonEmptyTemplateParameterList = false;
3171
3172 auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) {
3173 if (SawNonEmptyTemplateParameterList) {
3174 if (!SuppressDiagnostic)
3175 Diag(DeclLoc, diag::err_specialize_member_of_template)
3176 << !Recovery << Range;
3177 Invalid = true;
3178 IsMemberSpecialization = false;
3179 return true;
3180 }
3181
3182 return false;
3183 };
3184
3185 auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) {
3186 // Check that we can have an explicit specialization here.
3187 if (CheckExplicitSpecialization(Range, true))
3188 return true;
3189
3190 // We don't have a template header, but we should.
3191 SourceLocation ExpectedTemplateLoc;
3192 if (!ParamLists.empty())
3193 ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
3194 else
3195 ExpectedTemplateLoc = DeclStartLoc;
3196
3197 if (!SuppressDiagnostic)
3198 Diag(DeclLoc, diag::err_template_spec_needs_header)
3199 << Range
3200 << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
3201 return false;
3202 };
3203
3204 unsigned ParamIdx = 0;
3205 for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
3206 ++TypeIdx) {
3207 T = NestedTypes[TypeIdx];
3208
3209 // Whether we expect a 'template<>' header.
3210 bool NeedEmptyTemplateHeader = false;
3211
3212 // Whether we expect a template header with parameters.
3213 bool NeedNonemptyTemplateHeader = false;
3214
3215 // For a dependent type, the set of template parameters that we
3216 // expect to see.
3217 TemplateParameterList *ExpectedTemplateParams = nullptr;
3218
3219 // C++0x [temp.expl.spec]p15:
3220 // A member or a member template may be nested within many enclosing
3221 // class templates. In an explicit specialization for such a member, the
3222 // member declaration shall be preceded by a template<> for each
3223 // enclosing class template that is explicitly specialized.
3224 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
3225 if (ClassTemplatePartialSpecializationDecl *Partial
3226 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
3227 ExpectedTemplateParams = Partial->getTemplateParameters();
3228 NeedNonemptyTemplateHeader = true;
3229 } else if (Record->isDependentType()) {
3230 if (Record->getDescribedClassTemplate()) {
3231 ExpectedTemplateParams = Record->getDescribedClassTemplate()
3232 ->getTemplateParameters();
3233 NeedNonemptyTemplateHeader = true;
3234 }
3235 } else if (ClassTemplateSpecializationDecl *Spec
3236 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
3237 // C++0x [temp.expl.spec]p4:
3238 // Members of an explicitly specialized class template are defined
3239 // in the same manner as members of normal classes, and not using
3240 // the template<> syntax.
3241 if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
3242 NeedEmptyTemplateHeader = true;
3243 else
3244 continue;
3245 } else if (Record->getTemplateSpecializationKind()) {
3246 if (Record->getTemplateSpecializationKind()
3247 != TSK_ExplicitSpecialization &&
3248 TypeIdx == NumTypes - 1)
3249 IsMemberSpecialization = true;
3250
3251 continue;
3252 }
3253 } else if (const TemplateSpecializationType *TST
3254 = T->getAs<TemplateSpecializationType>()) {
3255 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
3256 ExpectedTemplateParams = Template->getTemplateParameters();
3257 NeedNonemptyTemplateHeader = true;
3258 }
3259 } else if (T->getAs<DependentTemplateSpecializationType>()) {
3260 // FIXME: We actually could/should check the template arguments here
3261 // against the corresponding template parameter list.
3262 NeedNonemptyTemplateHeader = false;
3263 }
3264
3265 // C++ [temp.expl.spec]p16:
3266 // In an explicit specialization declaration for a member of a class
3267 // template or a member template that ap- pears in namespace scope, the
3268 // member template and some of its enclosing class templates may remain
3269 // unspecialized, except that the declaration shall not explicitly
3270 // specialize a class member template if its en- closing class templates
3271 // are not explicitly specialized as well.
3272 if (ParamIdx < ParamLists.size()) {
3273 if (ParamLists[ParamIdx]->size() == 0) {
3274 if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
3275 false))
3276 return nullptr;
3277 } else
3278 SawNonEmptyTemplateParameterList = true;
3279 }
3280
3281 if (NeedEmptyTemplateHeader) {
3282 // If we're on the last of the types, and we need a 'template<>' header
3283 // here, then it's a member specialization.
3284 if (TypeIdx == NumTypes - 1)
3285 IsMemberSpecialization = true;
3286
3287 if (ParamIdx < ParamLists.size()) {
3288 if (ParamLists[ParamIdx]->size() > 0) {
3289 // The header has template parameters when it shouldn't. Complain.
3290 if (!SuppressDiagnostic)
3291 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
3292 diag::err_template_param_list_matches_nontemplate)
3293 << T
3294 << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
3295 ParamLists[ParamIdx]->getRAngleLoc())
3296 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
3297 Invalid = true;
3298 return nullptr;
3299 }
3300
3301 // Consume this template header.
3302 ++ParamIdx;
3303 continue;
3304 }
3305
3306 if (!IsFriend)
3307 if (DiagnoseMissingExplicitSpecialization(
3308 getRangeOfTypeInNestedNameSpecifier(Context, T, SS)))
3309 return nullptr;
3310
3311 continue;
3312 }
3313
3314 if (NeedNonemptyTemplateHeader) {
3315 // In friend declarations we can have template-ids which don't
3316 // depend on the corresponding template parameter lists. But
3317 // assume that empty parameter lists are supposed to match this
3318 // template-id.
3319 if (IsFriend && T->isDependentType()) {
3320 if (ParamIdx < ParamLists.size() &&
3321 DependsOnTemplateParameters(T, ParamLists[ParamIdx]))
3322 ExpectedTemplateParams = nullptr;
3323 else
3324 continue;
3325 }
3326
3327 if (ParamIdx < ParamLists.size()) {
3328 // Check the template parameter list, if we can.
3329 if (ExpectedTemplateParams &&
3330 !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
3331 ExpectedTemplateParams,
3332 !SuppressDiagnostic, TPL_TemplateMatch))
3333 Invalid = true;
3334
3335 if (!Invalid &&
3336 CheckTemplateParameterList(ParamLists[ParamIdx], nullptr,
3337 TPC_ClassTemplateMember))
3338 Invalid = true;
3339
3340 ++ParamIdx;
3341 continue;
3342 }
3343
3344 if (!SuppressDiagnostic)
3345 Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
3346 << T
3347 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
3348 Invalid = true;
3349 continue;
3350 }
3351 }
3352
3353 // If there were at least as many template-ids as there were template
3354 // parameter lists, then there are no template parameter lists remaining for
3355 // the declaration itself.
3356 if (ParamIdx >= ParamLists.size()) {
3357 if (TemplateId && !IsFriend) {
3358 // We don't have a template header for the declaration itself, but we
3359 // should.
3360 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc,
3361 TemplateId->RAngleLoc));
3362
3363 // Fabricate an empty template parameter list for the invented header.
3364 return TemplateParameterList::Create(Context, SourceLocation(),
3365 SourceLocation(), None,
3366 SourceLocation(), nullptr);
3367 }
3368
3369 return nullptr;
3370 }
3371
3372 // If there were too many template parameter lists, complain about that now.
3373 if (ParamIdx < ParamLists.size() - 1) {
3374 bool HasAnyExplicitSpecHeader = false;
3375 bool AllExplicitSpecHeaders = true;
3376 for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) {
3377 if (ParamLists[I]->size() == 0)
3378 HasAnyExplicitSpecHeader = true;
3379 else
3380 AllExplicitSpecHeaders = false;
3381 }
3382
3383 if (!SuppressDiagnostic)
3384 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
3385 AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers
3386 : diag::err_template_spec_extra_headers)
3387 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
3388 ParamLists[ParamLists.size() - 2]->getRAngleLoc());
3389
3390 // If there was a specialization somewhere, such that 'template<>' is
3391 // not required, and there were any 'template<>' headers, note where the
3392 // specialization occurred.
3393 if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader &&
3394 !SuppressDiagnostic)
3395 Diag(ExplicitSpecLoc,
3396 diag::note_explicit_template_spec_does_not_need_header)
3397 << NestedTypes.back();
3398
3399 // We have a template parameter list with no corresponding scope, which
3400 // means that the resulting template declaration can't be instantiated
3401 // properly (we'll end up with dependent nodes when we shouldn't).
3402 if (!AllExplicitSpecHeaders)
3403 Invalid = true;
3404 }
3405
3406 // C++ [temp.expl.spec]p16:
3407 // In an explicit specialization declaration for a member of a class
3408 // template or a member template that ap- pears in namespace scope, the
3409 // member template and some of its enclosing class templates may remain
3410 // unspecialized, except that the declaration shall not explicitly
3411 // specialize a class member template if its en- closing class templates
3412 // are not explicitly specialized as well.
3413 if (ParamLists.back()->size() == 0 &&
3414 CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
3415 false))
3416 return nullptr;
3417
3418 // Return the last template parameter list, which corresponds to the
3419 // entity being declared.
3420 return ParamLists.back();
3421}
3422
3423void Sema::NoteAllFoundTemplates(TemplateName Name) {
3424 if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
3425 Diag(Template->getLocation(), diag::note_template_declared_here)
3426 << (isa<FunctionTemplateDecl>(Template)
3427 ? 0
3428 : isa<ClassTemplateDecl>(Template)
3429 ? 1
3430 : isa<VarTemplateDecl>(Template)
3431 ? 2
3432 : isa<TypeAliasTemplateDecl>(Template) ? 3 : 4)
3433 << Template->getDeclName();
3434 return;
3435 }
3436
3437 if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
3438 for (OverloadedTemplateStorage::iterator I = OST->begin(),
3439 IEnd = OST->end();
3440 I != IEnd; ++I)
3441 Diag((*I)->getLocation(), diag::note_template_declared_here)
3442 << 0 << (*I)->getDeclName();
3443
3444 return;
3445 }
3446}
3447
3448static QualType
3449checkBuiltinTemplateIdType(Sema &SemaRef, BuiltinTemplateDecl *BTD,
3450 const SmallVectorImpl<TemplateArgument> &Converted,
3451 SourceLocation TemplateLoc,
3452 TemplateArgumentListInfo &TemplateArgs) {
3453 ASTContext &Context = SemaRef.getASTContext();
3454 switch (BTD->getBuiltinTemplateKind()) {
3455 case BTK__make_integer_seq: {
3456 // Specializations of __make_integer_seq<S, T, N> are treated like
3457 // S<T, 0, ..., N-1>.
3458
3459 // C++14 [inteseq.intseq]p1:
3460 // T shall be an integer type.
3461 if (!Converted[1].getAsType()->isIntegralType(Context)) {
3462 SemaRef.Diag(TemplateArgs[1].getLocation(),
3463 diag::err_integer_sequence_integral_element_type);
3464 return QualType();
3465 }
3466
3467 // C++14 [inteseq.make]p1:
3468 // If N is negative the program is ill-formed.
3469 TemplateArgument NumArgsArg = Converted[2];
3470 llvm::APSInt NumArgs = NumArgsArg.getAsIntegral();
3471 if (NumArgs < 0) {
3472 SemaRef.Diag(TemplateArgs[2].getLocation(),
3473 diag::err_integer_sequence_negative_length);
3474 return QualType();
3475 }
3476
3477 QualType ArgTy = NumArgsArg.getIntegralType();
3478 TemplateArgumentListInfo SyntheticTemplateArgs;
3479 // The type argument gets reused as the first template argument in the
3480 // synthetic template argument list.
3481 SyntheticTemplateArgs.addArgument(TemplateArgs[1]);
3482 // Expand N into 0 ... N-1.
3483 for (llvm::APSInt I(NumArgs.getBitWidth(), NumArgs.isUnsigned());
3484 I < NumArgs; ++I) {
3485 TemplateArgument TA(Context, I, ArgTy);
3486 SyntheticTemplateArgs.addArgument(SemaRef.getTrivialTemplateArgumentLoc(
3487 TA, ArgTy, TemplateArgs[2].getLocation()));
3488 }
3489 // The first template argument will be reused as the template decl that
3490 // our synthetic template arguments will be applied to.
3491 return SemaRef.CheckTemplateIdType(Converted[0].getAsTemplate(),
3492 TemplateLoc, SyntheticTemplateArgs);
3493 }
3494
3495 case BTK__type_pack_element:
3496 // Specializations of
3497 // __type_pack_element<Index, T_1, ..., T_N>
3498 // are treated like T_Index.
3499 assert(Converted.size() == 2 &&(static_cast <bool> (Converted.size() == 2 && "__type_pack_element should be given an index and a parameter pack"
) ? void (0) : __assert_fail ("Converted.size() == 2 && \"__type_pack_element should be given an index and a parameter pack\""
, "clang/lib/Sema/SemaTemplate.cpp", 3500, __extension__ __PRETTY_FUNCTION__
))
3500 "__type_pack_element should be given an index and a parameter pack")(static_cast <bool> (Converted.size() == 2 && "__type_pack_element should be given an index and a parameter pack"
) ? void (0) : __assert_fail ("Converted.size() == 2 && \"__type_pack_element should be given an index and a parameter pack\""
, "clang/lib/Sema/SemaTemplate.cpp", 3500, __extension__ __PRETTY_FUNCTION__
))
;
3501
3502 // If the Index is out of bounds, the program is ill-formed.
3503 TemplateArgument IndexArg = Converted[0], Ts = Converted[1];
3504 llvm::APSInt Index = IndexArg.getAsIntegral();
3505 assert(Index >= 0 && "the index used with __type_pack_element should be of "(static_cast <bool> (Index >= 0 && "the index used with __type_pack_element should be of "
"type std::size_t, and hence be non-negative") ? void (0) : __assert_fail
("Index >= 0 && \"the index used with __type_pack_element should be of \" \"type std::size_t, and hence be non-negative\""
, "clang/lib/Sema/SemaTemplate.cpp", 3506, __extension__ __PRETTY_FUNCTION__
))
3506 "type std::size_t, and hence be non-negative")(static_cast <bool> (Index >= 0 && "the index used with __type_pack_element should be of "
"type std::size_t, and hence be non-negative") ? void (0) : __assert_fail
("Index >= 0 && \"the index used with __type_pack_element should be of \" \"type std::size_t, and hence be non-negative\""
, "clang/lib/Sema/SemaTemplate.cpp", 3506, __extension__ __PRETTY_FUNCTION__
))
;
3507 if (Index >= Ts.pack_size()) {
3508 SemaRef.Diag(TemplateArgs[0].getLocation(),
3509 diag::err_type_pack_element_out_of_bounds);
3510 return QualType();
3511 }
3512
3513 // We simply return the type at index `Index`.
3514 auto Nth = std::next(Ts.pack_begin(), Index.getExtValue());
3515 return Nth->getAsType();
3516 }
3517 llvm_unreachable("unexpected BuiltinTemplateDecl!")::llvm::llvm_unreachable_internal("unexpected BuiltinTemplateDecl!"
, "clang/lib/Sema/SemaTemplate.cpp", 3517)
;
3518}
3519
3520/// Determine whether this alias template is "enable_if_t".
3521/// libc++ >=14 uses "__enable_if_t" in C++11 mode.
3522static bool isEnableIfAliasTemplate(TypeAliasTemplateDecl *AliasTemplate) {
3523 return AliasTemplate->getName().equals("enable_if_t") ||
3524 AliasTemplate->getName().equals("__enable_if_t");
3525}
3526
3527/// Collect all of the separable terms in the given condition, which
3528/// might be a conjunction.
3529///
3530/// FIXME: The right answer is to convert the logical expression into
3531/// disjunctive normal form, so we can find the first failed term
3532/// within each possible clause.
3533static void collectConjunctionTerms(Expr *Clause,
3534 SmallVectorImpl<Expr *> &Terms) {
3535 if (auto BinOp = dyn_cast<BinaryOperator>(Clause->IgnoreParenImpCasts())) {
3536 if (BinOp->getOpcode() == BO_LAnd) {
3537 collectConjunctionTerms(BinOp->getLHS(), Terms);
3538 collectConjunctionTerms(BinOp->getRHS(), Terms);
3539 }
3540
3541 return;
3542 }
3543
3544 Terms.push_back(Clause);
3545}
3546
3547// The ranges-v3 library uses an odd pattern of a top-level "||" with
3548// a left-hand side that is value-dependent but never true. Identify
3549// the idiom and ignore that term.
3550static Expr *lookThroughRangesV3Condition(Preprocessor &PP, Expr *Cond) {
3551 // Top-level '||'.
3552 auto *BinOp = dyn_cast<BinaryOperator>(Cond->IgnoreParenImpCasts());
3553 if (!BinOp) return Cond;
3554
3555 if (BinOp->getOpcode() != BO_LOr) return Cond;
3556
3557 // With an inner '==' that has a literal on the right-hand side.
3558 Expr *LHS = BinOp->getLHS();
3559 auto *InnerBinOp = dyn_cast<BinaryOperator>(LHS->IgnoreParenImpCasts());
3560 if (!InnerBinOp) return Cond;
3561
3562 if (InnerBinOp->getOpcode() != BO_EQ ||
3563 !isa<IntegerLiteral>(InnerBinOp->getRHS()))
3564 return Cond;
3565
3566 // If the inner binary operation came from a macro expansion named
3567 // CONCEPT_REQUIRES or CONCEPT_REQUIRES_, return the right-hand side
3568 // of the '||', which is the real, user-provided condition.
3569 SourceLocation Loc = InnerBinOp->getExprLoc();
3570 if (!Loc.isMacroID()) return Cond;
3571
3572 StringRef MacroName = PP.getImmediateMacroName(Loc);
3573 if (MacroName == "CONCEPT_REQUIRES" || MacroName == "CONCEPT_REQUIRES_")
3574 return BinOp->getRHS();
3575
3576 return Cond;
3577}
3578
3579namespace {
3580
3581// A PrinterHelper that prints more helpful diagnostics for some sub-expressions
3582// within failing boolean expression, such as substituting template parameters
3583// for actual types.
3584class FailedBooleanConditionPrinterHelper : public PrinterHelper {
3585public:
3586 explicit FailedBooleanConditionPrinterHelper(const PrintingPolicy &P)
3587 : Policy(P) {}
3588
3589 bool handledStmt(Stmt *E, raw_ostream &OS) override {
3590 const auto *DR = dyn_cast<DeclRefExpr>(E);
3591 if (DR && DR->getQualifier()) {
3592 // If this is a qualified name, expand the template arguments in nested
3593 // qualifiers.
3594 DR->getQualifier()->print(OS, Policy, true);
3595 // Then print the decl itself.
3596 const ValueDecl *VD = DR->getDecl();
3597 OS << VD->getName();
3598 if (const auto *IV = dyn_cast<VarTemplateSpecializationDecl>(VD)) {
3599 // This is a template variable, print the expanded template arguments.
3600 printTemplateArgumentList(
3601 OS, IV->getTemplateArgs().asArray(), Policy,
3602 IV->getSpecializedTemplate()->getTemplateParameters());
3603 }
3604 return true;
3605 }
3606 return false;
3607 }
3608
3609private:
3610 const PrintingPolicy Policy;
3611};
3612
3613} // end anonymous namespace
3614
3615std::pair<Expr *, std::string>
3616Sema::findFailedBooleanCondition(Expr *Cond) {
3617 Cond = lookThroughRangesV3Condition(PP, Cond);
3618
3619 // Separate out all of the terms in a conjunction.
3620 SmallVector<Expr *, 4> Terms;
3621 collectConjunctionTerms(Cond, Terms);
3622
3623 // Determine which term failed.
3624 Expr *FailedCond = nullptr;
3625 for (Expr *Term : Terms) {
3626 Expr *TermAsWritten = Term->IgnoreParenImpCasts();
3627
3628 // Literals are uninteresting.
3629 if (isa<CXXBoolLiteralExpr>(TermAsWritten) ||
3630 isa<IntegerLiteral>(TermAsWritten))
3631 continue;
3632
3633 // The initialization of the parameter from the argument is
3634 // a constant-evaluated context.
3635 EnterExpressionEvaluationContext ConstantEvaluated(
3636 *this, Sema::ExpressionEvaluationContext::ConstantEvaluated);
3637
3638 bool Succeeded;
3639 if (Term->EvaluateAsBooleanCondition(Succeeded, Context) &&
3640 !Succeeded) {
3641 FailedCond = TermAsWritten;
3642 break;
3643 }
3644 }
3645 if (!FailedCond)
3646 FailedCond = Cond->IgnoreParenImpCasts();
3647
3648 std::string Description;
3649 {
3650 llvm::raw_string_ostream Out(Description);
3651 PrintingPolicy Policy = getPrintingPolicy();
3652 Policy.PrintCanonicalTypes = true;
3653 FailedBooleanConditionPrinterHelper Helper(Policy);
3654 FailedCond->printPretty(Out, &Helper, Policy, 0, "\n", nullptr);
3655 }
3656 return { FailedCond, Description };
3657}
3658
3659QualType Sema::CheckTemplateIdType(TemplateName Name,
3660 SourceLocation TemplateLoc,
3661 TemplateArgumentListInfo &TemplateArgs) {
3662 DependentTemplateName *DTN
3663 = Name.getUnderlying().getAsDependentTemplateName();
3664 if (DTN && DTN->isIdentifier())
3665 // When building a template-id where the template-name is dependent,
3666 // assume the template is a type template. Either our assumption is
3667 // correct, or the code is ill-formed and will be diagnosed when the
3668 // dependent name is substituted.
3669 return Context.getDependentTemplateSpecializationType(ETK_None,
3670 DTN->getQualifier(),
3671 DTN->getIdentifier(),
3672 TemplateArgs);
3673
3674 if (Name.getAsAssumedTemplateName() &&
3675 resolveAssumedTemplateNameAsType(/*Scope*/nullptr, Name, TemplateLoc))
3676 return QualType();
3677
3678 TemplateDecl *Template = Name.getAsTemplateDecl();
3679 if (!Template || isa<FunctionTemplateDecl>(Template) ||
3680 isa<VarTemplateDecl>(Template) || isa<ConceptDecl>(Template)) {
3681 // We might have a substituted template template parameter pack. If so,
3682 // build a template specialization type for it.
3683 if (Name.getAsSubstTemplateTemplateParmPack())
3684 return Context.getTemplateSpecializationType(Name, TemplateArgs);
3685
3686 Diag(TemplateLoc, diag::err_template_id_not_a_type)
3687 << Name;
3688 NoteAllFoundTemplates(Name);
3689 return QualType();
3690 }
3691
3692 // Check that the template argument list is well-formed for this
3693 // template.
3694 SmallVector<TemplateArgument, 4> Converted;
3695 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
3696 false, Converted,
3697 /*UpdateArgsWithConversions=*/true))
3698 return QualType();
3699
3700 QualType CanonType;
3701
3702 if (TypeAliasTemplateDecl *AliasTemplate =
3703 dyn_cast<TypeAliasTemplateDecl>(Template)) {
3704
3705 // Find the canonical type for this type alias template specialization.
3706 TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
3707 if (Pattern->isInvalidDecl())
3708 return QualType();
3709
3710 TemplateArgumentList StackTemplateArgs(TemplateArgumentList::OnStack,
3711 Converted);
3712
3713 // Only substitute for the innermost template argument list.
3714 MultiLevelTemplateArgumentList TemplateArgLists;
3715 TemplateArgLists.addOuterTemplateArguments(&StackTemplateArgs);
3716 TemplateArgLists.addOuterRetainedLevels(
3717 AliasTemplate->getTemplateParameters()->getDepth());
3718
3719 LocalInstantiationScope Scope(*this);
3720 InstantiatingTemplate Inst(*this, TemplateLoc, Template);
3721 if (Inst.isInvalid())
3722 return QualType();
3723
3724 CanonType = SubstType(Pattern->getUnderlyingType(),
3725 TemplateArgLists, AliasTemplate->getLocation(),
3726 AliasTemplate->getDeclName());
3727 if (CanonType.isNull()) {
3728 // If this was enable_if and we failed to find the nested type
3729 // within enable_if in a SFINAE context, dig out the specific
3730 // enable_if condition that failed and present that instead.
3731 if (isEnableIfAliasTemplate(AliasTemplate)) {
3732 if (auto DeductionInfo = isSFINAEContext()) {
3733 if (*DeductionInfo &&
3734 (*DeductionInfo)->hasSFINAEDiagnostic() &&
3735 (*DeductionInfo)->peekSFINAEDiagnostic().second.getDiagID() ==
3736 diag::err_typename_nested_not_found_enable_if &&
3737 TemplateArgs[0].getArgument().getKind()
3738 == TemplateArgument::Expression) {
3739 Expr *FailedCond;
3740 std::string FailedDescription;
3741 std::tie(FailedCond, FailedDescription) =
3742 findFailedBooleanCondition(TemplateArgs[0].getSourceExpression());
3743
3744 // Remove the old SFINAE diagnostic.
3745 PartialDiagnosticAt OldDiag =
3746 {SourceLocation(), PartialDiagnostic::NullDiagnostic()};
3747 (*DeductionInfo)->takeSFINAEDiagnostic(OldDiag);
3748
3749 // Add a new SFINAE diagnostic specifying which condition
3750 // failed.
3751 (*DeductionInfo)->addSFINAEDiagnostic(
3752 OldDiag.first,
3753 PDiag(diag::err_typename_nested_not_found_requirement)
3754 << FailedDescription
3755 << FailedCond->getSourceRange());
3756 }
3757 }
3758 }
3759
3760 return QualType();
3761 }
3762 } else if (Name.isDependent() ||
3763 TemplateSpecializationType::anyDependentTemplateArguments(
3764 TemplateArgs, Converted)) {
3765 // This class template specialization is a dependent
3766 // type. Therefore, its canonical type is another class template
3767 // specialization type that contains all of the converted
3768 // arguments in canonical form. This ensures that, e.g., A<T> and
3769 // A<T, T> have identical types when A is declared as:
3770 //
3771 // template<typename T, typename U = T> struct A;
3772 CanonType = Context.getCanonicalTemplateSpecializationType(Name, Converted);
3773
3774 // This might work out to be a current instantiation, in which
3775 // case the canonical type needs to be the InjectedClassNameType.
3776 //
3777 // TODO: in theory this could be a simple hashtable lookup; most
3778 // changes to CurContext don't change the set of current
3779 // instantiations.
3780 if (isa<ClassTemplateDecl>(Template)) {
3781 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) {
3782 // If we get out to a namespace, we're done.
3783 if (Ctx->isFileContext()) break;
3784
3785 // If this isn't a record, keep looking.
3786 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
3787 if (!Record) continue;
3788
3789 // Look for one of the two cases with InjectedClassNameTypes
3790 // and check whether it's the same template.
3791 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
3792 !Record->getDescribedClassTemplate())
3793 continue;
3794
3795 // Fetch the injected class name type and check whether its
3796 // injected type is equal to the type we just built.
3797 QualType ICNT = Context.getTypeDeclType(Record);
3798 QualType Injected = cast<InjectedClassNameType>(ICNT)
3799 ->getInjectedSpecializationType();
3800
3801 if (CanonType != Injected->getCanonicalTypeInternal())
3802 continue;
3803
3804 // If so, the canonical type of this TST is the injected
3805 // class name type of the record we just found.
3806 assert(ICNT.isCanonical())(static_cast <bool> (ICNT.isCanonical()) ? void (0) : __assert_fail
("ICNT.isCanonical()", "clang/lib/Sema/SemaTemplate.cpp", 3806
, __extension__ __PRETTY_FUNCTION__))
;
3807 CanonType = ICNT;
3808 break;
3809 }
3810 }
3811 } else if (ClassTemplateDecl *ClassTemplate
3812 = dyn_cast<ClassTemplateDecl>(Template)) {
3813 // Find the class template specialization declaration that
3814 // corresponds to these arguments.
3815 void *InsertPos = nullptr;
3816 ClassTemplateSpecializationDecl *Decl
3817 = ClassTemplate->findSpecialization(Converted, InsertPos);
3818 if (!Decl) {
3819 // This is the first time we have referenced this class template
3820 // specialization. Create the canonical declaration and add it to
3821 // the set of specializations.
3822 Decl = ClassTemplateSpecializationDecl::Create(
3823 Context, ClassTemplate->getTemplatedDecl()->getTagKind(),
3824 ClassTemplate->getDeclContext(),
3825 ClassTemplate->getTemplatedDecl()->getBeginLoc(),
3826 ClassTemplate->getLocation(), ClassTemplate, Converted, nullptr);
3827 ClassTemplate->AddSpecialization(Decl, InsertPos);
3828 if (ClassTemplate->isOutOfLine())
3829 Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext());
3830 }
3831
3832 if (Decl->getSpecializationKind() == TSK_Undeclared &&
3833 ClassTemplate->getTemplatedDecl()->hasAttrs()) {
3834 InstantiatingTemplate Inst(*this, TemplateLoc, Decl);
3835 if (!Inst.isInvalid()) {
3836 MultiLevelTemplateArgumentList TemplateArgLists;
3837 TemplateArgLists.addOuterTemplateArguments(Converted);
3838 InstantiateAttrsForDecl(TemplateArgLists,
3839 ClassTemplate->getTemplatedDecl(), Decl);
3840 }
3841 }
3842
3843 // Diagnose uses of this specialization.
3844 (void)DiagnoseUseOfDecl(Decl, TemplateLoc);
3845
3846 CanonType = Context.getTypeDeclType(Decl);
3847 assert(isa<RecordType>(CanonType) &&(static_cast <bool> (isa<RecordType>(CanonType) &&
"type of non-dependent specialization is not a RecordType") ?
void (0) : __assert_fail ("isa<RecordType>(CanonType) && \"type of non-dependent specialization is not a RecordType\""
, "clang/lib/Sema/SemaTemplate.cpp", 3848, __extension__ __PRETTY_FUNCTION__
))
3848 "type of non-dependent specialization is not a RecordType")(static_cast <bool> (isa<RecordType>(CanonType) &&
"type of non-dependent specialization is not a RecordType") ?
void (0) : __assert_fail ("isa<RecordType>(CanonType) && \"type of non-dependent specialization is not a RecordType\""
, "clang/lib/Sema/SemaTemplate.cpp", 3848, __extension__ __PRETTY_FUNCTION__
))
;
3849 } else if (auto *BTD = dyn_cast<BuiltinTemplateDecl>(Template)) {
3850 CanonType = checkBuiltinTemplateIdType(*this, BTD, Converted, TemplateLoc,
3851 TemplateArgs);
3852 }
3853
3854 // Build the fully-sugared type for this class template
3855 // specialization, which refers back to the class template
3856 // specialization we created or found.
3857 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
3858}
3859
3860void Sema::ActOnUndeclaredTypeTemplateName(Scope *S, TemplateTy &ParsedName,
3861 TemplateNameKind &TNK,
3862 SourceLocation NameLoc,
3863 IdentifierInfo *&II) {
3864 assert(TNK == TNK_Undeclared_template && "not an undeclared template name")(static_cast <bool> (TNK == TNK_Undeclared_template &&
"not an undeclared template name") ? void (0) : __assert_fail
("TNK == TNK_Undeclared_template && \"not an undeclared template name\""
, "clang/lib/Sema/SemaTemplate.cpp", 3864, __extension__ __PRETTY_FUNCTION__
))
;
3865
3866 TemplateName Name = ParsedName.get();
3867 auto *ATN = Name.getAsAssumedTemplateName();
3868 assert(ATN && "not an assumed template name")(static_cast <bool> (ATN && "not an assumed template name"
) ? void (0) : __assert_fail ("ATN && \"not an assumed template name\""
, "clang/lib/Sema/SemaTemplate.cpp", 3868, __extension__ __PRETTY_FUNCTION__
))
;
3869 II = ATN->getDeclName().getAsIdentifierInfo();
3870
3871 if (!resolveAssumedTemplateNameAsType(S, Name, NameLoc, /*Diagnose*/false)) {
3872 // Resolved to a type template name.
3873 ParsedName = TemplateTy::make(Name);
3874 TNK = TNK_Type_template;
3875 }
3876}
3877
3878bool Sema::resolveAssumedTemplateNameAsType(Scope *S, TemplateName &Name,
3879 SourceLocation NameLoc,
3880 bool Diagnose) {
3881 // We assumed this undeclared identifier to be an (ADL-only) function
3882 // template name, but it was used in a context where a type was required.
3883 // Try to typo-correct it now.
3884 AssumedTemplateStorage *ATN = Name.getAsAssumedTemplateName();
3885 assert(ATN && "not an assumed template name")(static_cast <bool> (ATN && "not an assumed template name"
) ? void (0) : __assert_fail ("ATN && \"not an assumed template name\""
, "clang/lib/Sema/SemaTemplate.cpp", 3885, __extension__ __PRETTY_FUNCTION__
))
;
3886
3887 LookupResult R(*this, ATN->getDeclName(), NameLoc, LookupOrdinaryName);
3888 struct CandidateCallback : CorrectionCandidateCallback {
3889 bool ValidateCandidate(const TypoCorrection &TC) override {
3890 return TC.getCorrectionDecl() &&
3891 getAsTypeTemplateDecl(TC.getCorrectionDecl());
3892 }
3893 std::unique_ptr<CorrectionCandidateCallback> clone() override {
3894 return std::make_unique<CandidateCallback>(*this);
3895 }
3896 } FilterCCC;
3897
3898 TypoCorrection Corrected =
3899 CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, nullptr,
3900 FilterCCC, CTK_ErrorRecovery);
3901 if (Corrected && Corrected.getFoundDecl()) {
3902 diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest)
3903 << ATN->getDeclName());
3904 Name = TemplateName(Corrected.getCorrectionDeclAs<TemplateDecl>());
3905 return false;
3906 }
3907
3908 if (Diagnose)
3909 Diag(R.getNameLoc(), diag::err_no_template) << R.getLookupName();
3910 return true;
3911}
3912
3913TypeResult Sema::ActOnTemplateIdType(
3914 Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
3915 TemplateTy TemplateD, IdentifierInfo *TemplateII,
3916 SourceLocation TemplateIILoc, SourceLocation LAngleLoc,
3917 ASTTemplateArgsPtr TemplateArgsIn, SourceLocation RAngleLoc,
3918 bool IsCtorOrDtorName, bool IsClassName) {
3919 if (SS.isInvalid())
3920 return true;
3921
3922 if (!IsCtorOrDtorName && !IsClassName && SS.isSet()) {
3923 DeclContext *LookupCtx = computeDeclContext(SS, /*EnteringContext*/false);
3924
3925 // C++ [temp.res]p3:
3926 // A qualified-id that refers to a type and in which the
3927 // nested-name-specifier depends on a template-parameter (14.6.2)
3928 // shall be prefixed by the keyword typename to indicate that the
3929 // qualified-id denotes a type, forming an
3930 // elaborated-type-specifier (7.1.5.3).
3931 if (!LookupCtx && isDependentScopeSpecifier(SS)) {
3932 Diag(SS.getBeginLoc(), diag::err_typename_missing_template)
3933 << SS.getScopeRep() << TemplateII->getName();
3934 // Recover as if 'typename' were specified.
3935 // FIXME: This is not quite correct recovery as we don't transform SS
3936 // into the corresponding dependent form (and we don't diagnose missing
3937 // 'template' keywords within SS as a result).
3938 return ActOnTypenameType(nullptr, SourceLocation(), SS, TemplateKWLoc,
3939 TemplateD, TemplateII, TemplateIILoc, LAngleLoc,
3940 TemplateArgsIn, RAngleLoc);
3941 }
3942
3943 // Per C++ [class.qual]p2, if the template-id was an injected-class-name,
3944 // it's not actually allowed to be used as a type in most cases. Because
3945 // we annotate it before we know whether it's valid, we have to check for
3946 // this case here.
3947 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
3948 if (LookupRD && LookupRD->getIdentifier() == TemplateII) {
3949 Diag(TemplateIILoc,
3950 TemplateKWLoc.isInvalid()
3951 ? diag::err_out_of_line_qualified_id_type_names_constructor
3952 : diag::ext_out_of_line_qualified_id_type_names_constructor)
3953 << TemplateII << 0 /*injected-class-name used as template name*/
3954 << 1 /*if any keyword was present, it was 'template'*/;
3955 }
3956 }
3957
3958 TemplateName Template = TemplateD.get();
3959 if (Template.getAsAssumedTemplateName() &&
3960 resolveAssumedTemplateNameAsType(S, Template, TemplateIILoc))
3961 return true;
3962
3963 // Translate the parser's template argument list in our AST format.
3964 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
3965 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
3966
3967 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
3968 QualType T
3969 = Context.getDependentTemplateSpecializationType(ETK_None,
3970 DTN->getQualifier(),
3971 DTN->getIdentifier(),
3972 TemplateArgs);
3973 // Build type-source information.
3974 TypeLocBuilder TLB;
3975 DependentTemplateSpecializationTypeLoc SpecTL
3976 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
3977 SpecTL.setElaboratedKeywordLoc(SourceLocation());
3978 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
3979 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
3980 SpecTL.setTemplateNameLoc(TemplateIILoc);
3981 SpecTL.setLAngleLoc(LAngleLoc);
3982 SpecTL.setRAngleLoc(RAngleLoc);
3983 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
3984 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
3985 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
3986 }
3987
3988 QualType Result = CheckTemplateIdType(Template, TemplateIILoc, TemplateArgs);
3989 if (Result.isNull())
3990 return true;
3991
3992 // Build type-source information.
3993 TypeLocBuilder TLB;
3994 TemplateSpecializationTypeLoc SpecTL
3995 = TLB.push<TemplateSpecializationTypeLoc>(Result);
3996 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
3997 SpecTL.setTemplateNameLoc(TemplateIILoc);
3998 SpecTL.setLAngleLoc(LAngleLoc);
3999 SpecTL.setRAngleLoc(RAngleLoc);
4000 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
4001 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
4002
4003 // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
4004 // constructor or destructor name (in such a case, the scope specifier
4005 // will be attached to the enclosing Decl or Expr node).
4006 if (SS.isNotEmpty() && !IsCtorOrDtorName) {
4007 // Create an elaborated-type-specifier containing the nested-name-specifier.
4008 Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
4009 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
4010 ElabTL.setElaboratedKeywordLoc(SourceLocation());
4011 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
4012 }
4013
4014 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
4015}
4016
4017TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
4018 TypeSpecifierType TagSpec,
4019 SourceLocation TagLoc,
4020 CXXScopeSpec &SS,
4021 SourceLocation TemplateKWLoc,
4022 TemplateTy TemplateD,
4023 SourceLocation TemplateLoc,
4024 SourceLocation LAngleLoc,
4025 ASTTemplateArgsPtr TemplateArgsIn,
4026 SourceLocation RAngleLoc) {
4027 if (SS.isInvalid())
4028 return TypeResult(true);
4029
4030 TemplateName Template = TemplateD.get();
4031
4032 // Translate the parser's template argument list in our AST format.
4033 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
4034 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
4035
4036 // Determine the tag kind
4037 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
4038 ElaboratedTypeKeyword Keyword
4039 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
4040
4041 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
4042 QualType T = Context.getDependentTemplateSpecializationType(Keyword,
4043 DTN->getQualifier(),
4044 DTN->getIdentifier(),
4045 TemplateArgs);
4046
4047 // Build type-source information.
4048 TypeLocBuilder TLB;
4049 DependentTemplateSpecializationTypeLoc SpecTL
4050 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
4051 SpecTL.setElaboratedKeywordLoc(TagLoc);
4052 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
4053 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4054 SpecTL.setTemplateNameLoc(TemplateLoc);
4055 SpecTL.setLAngleLoc(LAngleLoc);
4056 SpecTL.setRAngleLoc(RAngleLoc);
4057 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
4058 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
4059 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
4060 }
4061
4062 if (TypeAliasTemplateDecl *TAT =
4063 dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
4064 // C++0x [dcl.type.elab]p2:
4065 // If the identifier resolves to a typedef-name or the simple-template-id
4066 // resolves to an alias template specialization, the
4067 // elaborated-type-specifier is ill-formed.
4068 Diag(TemplateLoc, diag::err_tag_reference_non_tag)
4069 << TAT << NTK_TypeAliasTemplate << TagKind;
4070 Diag(TAT->getLocation(), diag::note_declared_at);
4071 }
4072
4073 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
4074 if (Result.isNull())
4075 return TypeResult(true);
4076
4077 // Check the tag kind
4078 if (const RecordType *RT = Result->getAs<RecordType>()) {
4079 RecordDecl *D = RT->getDecl();
4080
4081 IdentifierInfo *Id = D->getIdentifier();
4082 assert(Id && "templated class must have an identifier")(static_cast <bool> (Id && "templated class must have an identifier"
) ? void (0) : __assert_fail ("Id && \"templated class must have an identifier\""
, "clang/lib/Sema/SemaTemplate.cpp", 4082, __extension__ __PRETTY_FUNCTION__
))
;
4083
4084 if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
4085 TagLoc, Id)) {
4086 Diag(TagLoc, diag::err_use_with_wrong_tag)
4087 << Result
4088 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
4089 Diag(D->getLocation(), diag::note_previous_use);
4090 }
4091 }
4092
4093 // Provide source-location information for the template specialization.
4094 TypeLocBuilder TLB;
4095 TemplateSpecializationTypeLoc SpecTL
4096 = TLB.push<TemplateSpecializationTypeLoc>(Result);
4097 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4098 SpecTL.setTemplateNameLoc(TemplateLoc);
4099 SpecTL.setLAngleLoc(LAngleLoc);
4100 SpecTL.setRAngleLoc(RAngleLoc);
4101 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
4102 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
4103
4104 // Construct an elaborated type containing the nested-name-specifier (if any)
4105 // and tag keyword.
4106 Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
4107 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
4108 ElabTL.setElaboratedKeywordLoc(TagLoc);
4109 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
4110 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
4111}
4112
4113static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized,
4114 NamedDecl *PrevDecl,
4115 SourceLocation Loc,
4116 bool IsPartialSpecialization);
4117
4118static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
4119
4120static bool isTemplateArgumentTemplateParameter(
4121 const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
4122 switch (Arg.getKind()) {
4123 case TemplateArgument::Null:
4124 case TemplateArgument::NullPtr:
4125 case TemplateArgument::Integral:
4126 case TemplateArgument::Declaration:
4127 case TemplateArgument::Pack:
4128 case TemplateArgument::TemplateExpansion:
4129 return false;
4130
4131 case TemplateArgument::Type: {
4132 QualType Type = Arg.getAsType();
4133 const TemplateTypeParmType *TPT =
4134 Arg.getAsType()->getAs<TemplateTypeParmType>();
4135 return TPT && !Type.hasQualifiers() &&
4136 TPT->getDepth() == Depth && TPT->getIndex() == Index;
4137 }
4138
4139 case TemplateArgument::Expression: {
4140 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
4141 if (!DRE || !DRE->getDecl())
4142 return false;
4143 const NonTypeTemplateParmDecl *NTTP =
4144 dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
4145 return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
4146 }
4147
4148 case TemplateArgument::Template:
4149 const TemplateTemplateParmDecl *TTP =
4150 dyn_cast_or_null<TemplateTemplateParmDecl>(
4151 Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
4152 return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
4153 }
4154 llvm_unreachable("unexpected kind of template argument")::llvm::llvm_unreachable_internal("unexpected kind of template argument"
, "clang/lib/Sema/SemaTemplate.cpp", 4154)
;
4155}
4156
4157static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
4158 ArrayRef<TemplateArgument> Args) {
4159 if (Params->size() != Args.size())
4160 return false;
4161
4162 unsigned Depth = Params->getDepth();
4163
4164 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
4165 TemplateArgument Arg = Args[I];
4166
4167 // If the parameter is a pack expansion, the argument must be a pack
4168 // whose only element is a pack expansion.
4169 if (Params->getParam(I)->isParameterPack()) {
4170 if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
4171 !Arg.pack_begin()->isPackExpansion())
4172 return false;
4173 Arg = Arg.pack_begin()->getPackExpansionPattern();
4174 }
4175
4176 if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
4177 return false;
4178 }
4179
4180 return true;
4181}
4182
4183template<typename PartialSpecDecl>
4184static void checkMoreSpecializedThanPrimary(Sema &S, PartialSpecDecl *Partial) {
4185 if (Partial->getDeclContext()->isDependentContext())
4186 return;
4187
4188 // FIXME: Get the TDK from deduction in order to provide better diagnostics
4189 // for non-substitution-failure issues?
4190 TemplateDeductionInfo Info(Partial->getLocation());
4191 if (S.isMoreSpecializedThanPrimary(Partial, Info))
4192 return;
4193
4194 auto *Template = Partial->getSpecializedTemplate();
4195 S.Diag(Partial->getLocation(),
4196 diag::ext_partial_spec_not_more_specialized_than_primary)
4197 << isa<VarTemplateDecl>(Template);
4198
4199 if (Info.hasSFINAEDiagnostic()) {
4200 PartialDiagnosticAt Diag = {SourceLocation(),
4201 PartialDiagnostic::NullDiagnostic()};
4202 Info.takeSFINAEDiagnostic(Diag);
4203 SmallString<128> SFINAEArgString;
4204 Diag.second.EmitToString(S.getDiagnostics(), SFINAEArgString);
4205 S.Diag(Diag.first,
4206 diag::note_partial_spec_not_more_specialized_than_primary)
4207 << SFINAEArgString;
4208 }
4209
4210 S.Diag(Template->getLocation(), diag::note_template_decl_here);
4211 SmallVector<const Expr *, 3> PartialAC, TemplateAC;
4212 Template->getAssociatedConstraints(TemplateAC);
4213 Partial->getAssociatedConstraints(PartialAC);
4214 S.MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Partial, PartialAC, Template,
4215 TemplateAC);
4216}
4217
4218static void
4219noteNonDeducibleParameters(Sema &S, TemplateParameterList *TemplateParams,
4220 const llvm::SmallBitVector &DeducibleParams) {
4221 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
4222 if (!DeducibleParams[I]) {
4223 NamedDecl *Param = TemplateParams->getParam(I);
4224 if (Param->getDeclName())
4225 S.Diag(Param->getLocation(), diag::note_non_deducible_parameter)
4226 << Param->getDeclName();
4227 else
4228 S.Diag(Param->getLocation(), diag::note_non_deducible_parameter)
4229 << "(anonymous)";
4230 }
4231 }
4232}
4233
4234
4235template<typename PartialSpecDecl>
4236static void checkTemplatePartialSpecialization(Sema &S,
4237 PartialSpecDecl *Partial) {
4238 // C++1z [temp.class.spec]p8: (DR1495)
4239 // - The specialization shall be more specialized than the primary
4240 // template (14.5.5.2).
4241 checkMoreSpecializedThanPrimary(S, Partial);
4242
4243 // C++ [temp.class.spec]p8: (DR1315)
4244 // - Each template-parameter shall appear at least once in the
4245 // template-id outside a non-deduced context.
4246 // C++1z [temp.class.spec.match]p3 (P0127R2)
4247 // If the template arguments of a partial specialization cannot be
4248 // deduced because of the structure of its template-parameter-list
4249 // and the template-id, the program is ill-formed.
4250 auto *TemplateParams = Partial->getTemplateParameters();
4251 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4252 S.MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
4253 TemplateParams->getDepth(), DeducibleParams);
4254
4255 if (!DeducibleParams.all()) {
4256 unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4257 S.Diag(Partial->getLocation(), diag::ext_partial_specs_not_deducible)
4258 << isa<VarTemplatePartialSpecializationDecl>(Partial)
4259 << (NumNonDeducible > 1)
4260 << SourceRange(Partial->getLocation(),
4261 Partial->getTemplateArgsAsWritten()->RAngleLoc);
4262 noteNonDeducibleParameters(S, TemplateParams, DeducibleParams);
4263 }
4264}
4265
4266void Sema::CheckTemplatePartialSpecialization(
4267 ClassTemplatePartialSpecializationDecl *Partial) {
4268 checkTemplatePartialSpecialization(*this, Partial);
4269}
4270
4271void Sema::CheckTemplatePartialSpecialization(
4272 VarTemplatePartialSpecializationDecl *Partial) {
4273 checkTemplatePartialSpecialization(*this, Partial);
4274}
4275
4276void Sema::CheckDeductionGuideTemplate(FunctionTemplateDecl *TD) {
4277 // C++1z [temp.param]p11:
4278 // A template parameter of a deduction guide template that does not have a
4279 // default-argument shall be deducible from the parameter-type-list of the
4280 // deduction guide template.
4281 auto *TemplateParams = TD->getTemplateParameters();
4282 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4283 MarkDeducedTemplateParameters(TD, DeducibleParams);
4284 for (unsigned I = 0; I != TemplateParams->size(); ++I) {
4285 // A parameter pack is deducible (to an empty pack).
4286 auto *Param = TemplateParams->getParam(I);
4287 if (Param->isParameterPack() || hasVisibleDefaultArgument(Param))
4288 DeducibleParams[I] = true;
4289 }
4290
4291 if (!DeducibleParams.all()) {
4292 unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4293 Diag(TD->getLocation(), diag::err_deduction_guide_template_not_deducible)
4294 << (NumNonDeducible > 1);
4295 noteNonDeducibleParameters(*this, TemplateParams, DeducibleParams);
4296 }
4297}
4298
4299DeclResult Sema::ActOnVarTemplateSpecialization(
4300 Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc,
4301 TemplateParameterList *TemplateParams, StorageClass SC,
4302 bool IsPartialSpecialization) {
4303 // D must be variable template id.
4304 assert(D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId &&(static_cast <bool> (D.getName().getKind() == UnqualifiedIdKind
::IK_TemplateId && "Variable template specialization is declared with a template id."
) ? void (0) : __assert_fail ("D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId && \"Variable template specialization is declared with a template id.\""
, "clang/lib/Sema/SemaTemplate.cpp", 4305, __extension__ __PRETTY_FUNCTION__
))
4305 "Variable template specialization is declared with a template id.")(static_cast <bool> (D.getName().getKind() == UnqualifiedIdKind
::IK_TemplateId && "Variable template specialization is declared with a template id."
) ? void (0) : __assert_fail ("D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId && \"Variable template specialization is declared with a template id.\""
, "clang/lib/Sema/SemaTemplate.cpp", 4305, __extension__ __PRETTY_FUNCTION__
))
;
4306
4307 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
4308 TemplateArgumentListInfo TemplateArgs =
4309 makeTemplateArgumentListInfo(*this, *TemplateId);
4310 SourceLocation TemplateNameLoc = D.getIdentifierLoc();
4311 SourceLocation LAngleLoc = TemplateId->LAngleLoc;
4312 SourceLocation RAngleLoc = TemplateId->RAngleLoc;
4313
4314 TemplateName Name = TemplateId->Template.get();
4315
4316 // The template-id must name a variable template.
4317 VarTemplateDecl *VarTemplate =
4318 dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl());
4319 if (!VarTemplate) {
4320 NamedDecl *FnTemplate;
4321 if (auto *OTS = Name.getAsOverloadedTemplate())
4322 FnTemplate = *OTS->begin();
4323 else
4324 FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl());
4325 if (FnTemplate)
4326 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method)
4327 << FnTemplate->getDeclName();
4328 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template)
4329 << IsPartialSpecialization;
4330 }
4331
4332 // Check for unexpanded parameter packs in any of the template arguments.
4333 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
4334 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
4335 UPPC_PartialSpecialization))
4336 return true;
4337
4338 // Check that the template argument list is well-formed for this
4339 // template.
4340 SmallVector<TemplateArgument, 4> Converted;
4341 if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs,
4342 false, Converted,
4343 /*UpdateArgsWithConversions=*/true))
4344 return true;
4345
4346 // Find the variable template (partial) specialization declaration that
4347 // corresponds to these arguments.
4348 if (IsPartialSpecialization) {
4349 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, VarTemplate,
4350 TemplateArgs.size(), Converted))
4351 return true;
4352
4353 // FIXME: Move these checks to CheckTemplatePartialSpecializationArgs so we
4354 // also do them during instantiation.
4355 if (!Name.isDependent() &&
4356 !TemplateSpecializationType::anyDependentTemplateArguments(TemplateArgs,
4357 Converted)) {
4358 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
4359 << VarTemplate->getDeclName();
4360 IsPartialSpecialization = false;
4361 }
4362
4363 if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
4364 Converted) &&
4365 (!Context.getLangOpts().CPlusPlus20 ||
4366 !TemplateParams->hasAssociatedConstraints())) {
4367 // C++ [temp.class.spec]p9b3:
4368 //
4369 // -- The argument list of the specialization shall not be identical
4370 // to the implicit argument list of the primary template.
4371 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
4372 << /*variable template*/ 1
4373 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
4374 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
4375 // FIXME: Recover from this by treating the declaration as a redeclaration
4376 // of the primary template.
4377 return true;
4378 }
4379 }
4380
4381 void *InsertPos = nullptr;
4382 VarTemplateSpecializationDecl *PrevDecl = nullptr;
4383
4384 if (IsPartialSpecialization)
4385 PrevDecl = VarTemplate->findPartialSpecialization(Converted, TemplateParams,
4386 InsertPos);
4387 else
4388 PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
4389
4390 VarTemplateSpecializationDecl *Specialization = nullptr;
4391
4392 // Check whether we can declare a variable template specialization in
4393 // the current scope.
4394 if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl,
4395 TemplateNameLoc,
4396 IsPartialSpecialization))
4397 return true;
4398
4399 if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) {
4400 // Since the only prior variable template specialization with these
4401 // arguments was referenced but not declared, reuse that
4402 // declaration node as our own, updating its source location and
4403 // the list of outer template parameters to reflect our new declaration.
4404 Specialization = PrevDecl;
4405 Specialization->setLocation(TemplateNameLoc);
4406 PrevDecl = nullptr;
4407 } else if (IsPartialSpecialization) {
4408 // Create a new class template partial specialization declaration node.
4409 VarTemplatePartialSpecializationDecl *PrevPartial =
4410 cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl);
4411 VarTemplatePartialSpecializationDecl *Partial =
4412 VarTemplatePartialSpecializationDecl::Create(
4413 Context, VarTemplate->getDeclContext(), TemplateKWLoc,
4414 TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC,
4415 Converted, TemplateArgs);
4416
4417 if (!PrevPartial)
4418 VarTemplate->AddPartialSpecialization(Partial, InsertPos);
4419 Specialization = Partial;
4420
4421 // If we are providing an explicit specialization of a member variable
4422 // template specialization, make a note of that.
4423 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
4424 PrevPartial->setMemberSpecialization();
4425
4426 CheckTemplatePartialSpecialization(Partial);
4427 } else {
4428 // Create a new class template specialization declaration node for
4429 // this explicit specialization or friend declaration.
4430 Specialization = VarTemplateSpecializationDecl::Create(
4431 Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc,
4432 VarTemplate, DI->getType(), DI, SC, Converted);
4433 Specialization->setTemplateArgsInfo(TemplateArgs);
4434
4435 if (!PrevDecl)
4436 VarTemplate->AddSpecialization(Specialization, InsertPos);
4437 }
4438
4439 // C++ [temp.expl.spec]p6:
4440 // If a template, a member template or the member of a class template is
4441 // explicitly specialized then that specialization shall be declared
4442 // before the first use of that specialization that would cause an implicit
4443 // instantiation to take place, in every translation unit in which such a
4444 // use occurs; no diagnostic is required.
4445 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
4446 bool Okay = false;
4447 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
4448 // Is there any previous explicit specialization declaration?
4449 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
4450 Okay = true;
4451 break;
4452 }
4453 }
4454
4455 if (!Okay) {
4456 SourceRange Range(TemplateNameLoc, RAngleLoc);
4457 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
4458 << Name << Range;
4459
4460 Diag(PrevDecl->getPointOfInstantiation(),
4461 diag::note_instantiation_required_here)
4462 << (PrevDecl->getTemplateSpecializationKind() !=
4463 TSK_ImplicitInstantiation);
4464 return true;
4465 }
4466 }
4467
4468 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
4469 Specialization->setLexicalDeclContext(CurContext);
4470
4471 // Add the specialization into its lexical context, so that it can
4472 // be seen when iterating through the list of declarations in that
4473 // context. However, specializations are not found by name lookup.
4474 CurContext->addDecl(Specialization);
4475
4476 // Note that this is an explicit specialization.
4477 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
4478
4479 if (PrevDecl) {
4480 // Check that this isn't a redefinition of this specialization,
4481 // merging with previous declarations.
4482 LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName,
4483 forRedeclarationInCurContext());
4484 PrevSpec.addDecl(PrevDecl);
4485 D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec));
4486 } else if (Specialization->isStaticDataMember() &&
4487 Specialization->isOutOfLine()) {
4488 Specialization->setAccess(VarTemplate->getAccess());
4489 }
4490
4491 return Specialization;
4492}
4493
4494namespace {
4495/// A partial specialization whose template arguments have matched
4496/// a given template-id.
4497struct PartialSpecMatchResult {
4498 VarTemplatePartialSpecializationDecl *Partial;
4499 TemplateArgumentList *Args;
4500};
4501} // end anonymous namespace
4502
4503DeclResult
4504Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
4505 SourceLocation TemplateNameLoc,
4506 const TemplateArgumentListInfo &TemplateArgs) {
4507 assert(Template && "A variable template id without template?")(static_cast <bool> (Template && "A variable template id without template?"
) ? void (0) : __assert_fail ("Template && \"A variable template id without template?\""
, "clang/lib/Sema/SemaTemplate.cpp", 4507, __extension__ __PRETTY_FUNCTION__
))
;
4508
4509 // Check that the template argument list is well-formed for this template.
4510 SmallVector<TemplateArgument, 4> Converted;
4511 if (CheckTemplateArgumentList(
4512 Template, TemplateNameLoc,
4513 const_cast<TemplateArgumentListInfo &>(TemplateArgs), false,
4514 Converted, /*UpdateArgsWithConversions=*/true))
4515 return true;
4516
4517 // Produce a placeholder value if the specialization is dependent.
4518 if (Template->getDeclContext()->isDependentContext() ||
4519 TemplateSpecializationType::anyDependentTemplateArguments(TemplateArgs,
4520 Converted))
4521 return DeclResult();
4522
4523 // Find the variable template specialization declaration that
4524 // corresponds to these arguments.
4525 void *InsertPos = nullptr;
4526 if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization(
4527 Converted, InsertPos)) {
4528 checkSpecializationVisibility(TemplateNameLoc, Spec);
4529 // If we already have a variable template specialization, return it.
4530 return Spec;
4531 }
4532
4533 // This is the first time we have referenced this variable template
4534 // specialization. Create the canonical declaration and add it to
4535 // the set of specializations, based on the closest partial specialization
4536 // that it represents. That is,
4537 VarDecl *InstantiationPattern = Template->getTemplatedDecl();
4538 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
4539 Converted);
4540 TemplateArgumentList *InstantiationArgs = &TemplateArgList;
4541 bool AmbiguousPartialSpec = false;
4542 typedef PartialSpecMatchResult MatchResult;
4543 SmallVector<MatchResult, 4> Matched;
4544 SourceLocation PointOfInstantiation = TemplateNameLoc;
4545 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation,
4546 /*ForTakingAddress=*/false);
4547
4548 // 1. Attempt to find the closest partial specialization that this
4549 // specializes, if any.
4550 // TODO: Unify with InstantiateClassTemplateSpecialization()?
4551 // Perhaps better after unification of DeduceTemplateArguments() and
4552 // getMoreSpecializedPartialSpecialization().
4553 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
4554 Template->getPartialSpecializations(PartialSpecs);
4555
4556 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
4557 VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
4558 TemplateDeductionInfo Info(FailedCandidates.getLocation());
4559
4560 if (TemplateDeductionResult Result =
4561 DeduceTemplateArguments(Partial, TemplateArgList, Info)) {
4562 // Store the failed-deduction information for use in diagnostics, later.
4563 // TODO: Actually use the failed-deduction info?
4564 FailedCandidates.addCandidate().set(
4565 DeclAccessPair::make(Template, AS_public), Partial,
4566 MakeDeductionFailureInfo(Context, Result, Info));
4567 (void)Result;
4568 } else {
4569 Matched.push_back(PartialSpecMatchResult());
4570 Matched.back().Partial = Partial;
4571 Matched.back().Args = Info.take();
4572 }
4573 }
4574
4575 if (Matched.size() >= 1) {
4576 SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
4577 if (Matched.size() == 1) {
4578 // -- If exactly one matching specialization is found, the
4579 // instantiation is generated from that specialization.
4580 // We don't need to do anything for this.
4581 } else {
4582 // -- If more than one matching specialization is found, the
4583 // partial order rules (14.5.4.2) are used to determine
4584 // whether one of the specializations is more specialized
4585 // than the others. If none of the specializations is more
4586 // specialized than all of the other matching
4587 // specializations, then the use of the variable template is
4588 // ambiguous and the program is ill-formed.
4589 for (SmallVector<MatchResult, 4>::iterator P = Best + 1,
4590 PEnd = Matched.end();
4591 P != PEnd; ++P) {
4592 if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial,
4593 PointOfInstantiation) ==
4594 P->Partial)
4595 Best = P;
4596 }
4597
4598 // Determine if the best partial specialization is more specialized than
4599 // the others.
4600 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
4601 PEnd = Matched.end();
4602 P != PEnd; ++P) {
4603 if (P != Best && getMoreSpecializedPartialSpecialization(
4604 P->Partial, Best->Partial,
4605 PointOfInstantiation) != Best->Partial) {
4606 AmbiguousPartialSpec = true;
4607 break;
4608 }
4609 }
4610 }
4611
4612 // Instantiate using the best variable template partial specialization.
4613 InstantiationPattern = Best->Partial;
4614 InstantiationArgs = Best->Args;
4615 } else {
4616 // -- If no match is found, the instantiation is generated
4617 // from the primary template.
4618 // InstantiationPattern = Template->getTemplatedDecl();
4619 }
4620
4621 // 2. Create the canonical declaration.
4622 // Note that we do not instantiate a definition until we see an odr-use
4623 // in DoMarkVarDeclReferenced().
4624 // FIXME: LateAttrs et al.?
4625 VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation(
4626 Template, InstantiationPattern, *InstantiationArgs, TemplateArgs,
4627 Converted, TemplateNameLoc /*, LateAttrs, StartingScope*/);
4628 if (!Decl)
4629 return true;
4630
4631 if (AmbiguousPartialSpec) {
4632 // Partial ordering did not produce a clear winner. Complain.
4633 Decl->setInvalidDecl();
4634 Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
4635 << Decl;
4636
4637 // Print the matching partial specializations.
4638 for (MatchResult P : Matched)
4639 Diag(P.Partial->getLocation(), diag::note_partial_spec_match)
4640 << getTemplateArgumentBindingsText(P.Partial->getTemplateParameters(),
4641 *P.Args);
4642 return true;
4643 }
4644
4645 if (VarTemplatePartialSpecializationDecl *D =
4646 dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern))
4647 Decl->setInstantiationOf(D, InstantiationArgs);
4648
4649 checkSpecializationVisibility(TemplateNameLoc, Decl);
4650
4651 assert(Decl && "No variable template specialization?")(static_cast <bool> (Decl && "No variable template specialization?"
) ? void (0) : __assert_fail ("Decl && \"No variable template specialization?\""
, "clang/lib/Sema/SemaTemplate.cpp", 4651, __extension__ __PRETTY_FUNCTION__
))
;
4652 return Decl;
4653}
4654
4655ExprResult
4656Sema::CheckVarTemplateId(const CXXScopeSpec &SS,
4657 const DeclarationNameInfo &NameInfo,
4658 VarTemplateDecl *Template, SourceLocation TemplateLoc,
4659 const TemplateArgumentListInfo *TemplateArgs) {
4660
4661 DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(),
4662 *TemplateArgs);
4663 if (Decl.isInvalid())
4664 return ExprError();
4665
4666 if (!Decl.get())
4667 return ExprResult();
4668
4669 VarDecl *Var = cast<VarDecl>(Decl.get());
4670 if (!Var->getTemplateSpecializationKind())
4671 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation,
4672 NameInfo.getLoc());
4673
4674 // Build an ordinary singleton decl ref.
4675 return BuildDeclarationNameExpr(SS, NameInfo, Var,
4676 /*FoundD=*/nullptr, TemplateArgs);
4677}
4678
4679void Sema::diagnoseMissingTemplateArguments(TemplateName Name,
4680 SourceLocation Loc) {
4681 Diag(Loc, diag::err_template_missing_args)
4682 << (int)getTemplateNameKindForDiagnostics(Name) << Name;
4683 if (TemplateDecl *TD = Name.getAsTemplateDecl()) {
4684 Diag(TD->getLocation(), diag::note_template_decl_here)
4685 << TD->getTemplateParameters()->getSourceRange();
4686 }
4687}
4688
4689ExprResult
4690Sema::CheckConceptTemplateId(const CXXScopeSpec &SS,
4691 SourceLocation TemplateKWLoc,
4692 const DeclarationNameInfo &ConceptNameInfo,
4693 NamedDecl *FoundDecl,
4694 ConceptDecl *NamedConcept,
4695 const TemplateArgumentListInfo *TemplateArgs) {
4696 assert(NamedConcept && "A concept template id without a template?")(static_cast <bool> (NamedConcept && "A concept template id without a template?"
) ? void (0) : __assert_fail ("NamedConcept && \"A concept template id without a template?\""
, "clang/lib/Sema/SemaTemplate.cpp", 4696, __extension__ __PRETTY_FUNCTION__
))
;
4697
4698 llvm::SmallVector<TemplateArgument, 4> Converted;
4699 if (CheckTemplateArgumentList(NamedConcept, ConceptNameInfo.getLoc(),
4700 const_cast<TemplateArgumentListInfo&>(*TemplateArgs),
4701 /*PartialTemplateArgs=*/false, Converted,
4702 /*UpdateArgsWithConversions=*/false))
4703 return ExprError();
4704
4705 ConstraintSatisfaction Satisfaction;
4706 bool AreArgsDependent =
4707 TemplateSpecializationType::anyDependentTemplateArguments(*TemplateArgs,
4708 Converted);
4709 if (!AreArgsDependent &&
4710 CheckConstraintSatisfaction(
4711 NamedConcept, {NamedConcept->getConstraintExpr()}, Converted,
4712 SourceRange(SS.isSet() ? SS.getBeginLoc() : ConceptNameInfo.getLoc(),
4713 TemplateArgs->getRAngleLoc()),
4714 Satisfaction))
4715 return ExprError();
4716
4717 return ConceptSpecializationExpr::Create(Context,
4718 SS.isSet() ? SS.getWithLocInContext(Context) : NestedNameSpecifierLoc{},
4719 TemplateKWLoc, ConceptNameInfo, FoundDecl, NamedConcept,
4720 ASTTemplateArgumentListInfo::Create(Context, *TemplateArgs), Converted,
4721 AreArgsDependent ? nullptr : &Satisfaction);
4722}
4723
4724ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
4725 SourceLocation TemplateKWLoc,
4726 LookupResult &R,
4727 bool RequiresADL,
4728 const TemplateArgumentListInfo *TemplateArgs) {
4729 // FIXME: Can we do any checking at this point? I guess we could check the
4730 // template arguments that we have against the template name, if the template
4731 // name refers to a single template. That's not a terribly common case,
4732 // though.
4733 // foo<int> could identify a single function unambiguously
4734 // This approach does NOT work, since f<int>(1);
4735 // gets resolved prior to resorting to overload resolution
4736 // i.e., template<class T> void f(double);
4737 // vs template<class T, class U> void f(U);
4738
4739 // These should be filtered out by our callers.
4740 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid")(static_cast <bool> (!R.isAmbiguous() && "ambiguous lookup when building templateid"
) ? void (0) : __assert_fail ("!R.isAmbiguous() && \"ambiguous lookup when building templateid\""
, "clang/lib/Sema/SemaTemplate.cpp", 4740, __extension__ __PRETTY_FUNCTION__
))
;
4741
4742 // Non-function templates require a template argument list.
4743 if (auto *TD = R.getAsSingle<TemplateDecl>()) {
4744 if (!TemplateArgs && !isa<FunctionTemplateDecl>(TD)) {
4745 diagnoseMissingTemplateArguments(TemplateName(TD), R.getNameLoc());
4746 return ExprError();
4747 }
4748 }
4749
4750 // In C++1y, check variable template ids.
4751 if (R.getAsSingle<VarTemplateDecl>()) {
4752 ExprResult Res = CheckVarTemplateId(SS, R.getLookupNameInfo(),
4753 R.getAsSingle<VarTemplateDecl>(),
4754 TemplateKWLoc, TemplateArgs);
4755 if (Res.isInvalid() || Res.isUsable())
4756 return Res;
4757 // Result is dependent. Carry on to build an UnresolvedLookupEpxr.
4758 }
4759
4760 if (R.getAsSingle<ConceptDecl>()) {
4761 return CheckConceptTemplateId(SS, TemplateKWLoc, R.getLookupNameInfo(),
4762 R.getFoundDecl(),
4763 R.getAsSingle<ConceptDecl>(), TemplateArgs);
4764 }
4765
4766 // We don't want lookup warnings at this point.
4767 R.suppressDiagnostics();
4768
4769 UnresolvedLookupExpr *ULE
4770 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
4771 SS.getWithLocInContext(Context),
4772 TemplateKWLoc,
4773 R.getLookupNameInfo(),
4774 RequiresADL, TemplateArgs,
4775 R.begin(), R.end());
4776
4777 return ULE;
4778}
4779
4780// We actually only call this from template instantiation.
4781ExprResult
4782Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
4783 SourceLocation TemplateKWLoc,
4784 const DeclarationNameInfo &NameInfo,
4785 const TemplateArgumentListInfo *TemplateArgs) {
4786
4787 assert(TemplateArgs || TemplateKWLoc.isValid())(static_cast <bool> (TemplateArgs || TemplateKWLoc.isValid
()) ? void (0) : __assert_fail ("TemplateArgs || TemplateKWLoc.isValid()"
, "clang/lib/Sema/SemaTemplate.cpp", 4787, __extension__ __PRETTY_FUNCTION__
))
;
4788 DeclContext *DC;
4789 if (!(DC = computeDeclContext(SS, false)) ||
4790 DC->isDependentContext() ||
4791 RequireCompleteDeclContext(SS, DC))
4792 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
4793
4794 bool MemberOfUnknownSpecialization;
4795 LookupResult R(*this, NameInfo, LookupOrdinaryName);
4796 if (LookupTemplateName(R, (Scope *)nullptr, SS, QualType(),
4797 /*Entering*/false, MemberOfUnknownSpecialization,
4798 TemplateKWLoc))
4799 return ExprError();
4800
4801 if (R.isAmbiguous())
4802 return ExprError();
4803
4804 if (R.empty()) {
4805 Diag(NameInfo.getLoc(), diag::err_no_member)
4806 << NameInfo.getName() << DC << SS.getRange();
4807 return ExprError();
4808 }
4809
4810 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) {
4811 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template)
4812 << SS.getScopeRep()
4813 << NameInfo.getName().getAsString() << SS.getRange();
4814 Diag(Temp->getLocation(), diag::note_referenced_class_template);
4815 return ExprError();
4816 }
4817
4818 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs);
4819}
4820
4821/// Form a template name from a name that is syntactically required to name a
4822/// template, either due to use of the 'template' keyword or because a name in
4823/// this syntactic context is assumed to name a template (C++ [temp.names]p2-4).
4824///
4825/// This action forms a template name given the name of the template and its
4826/// optional scope specifier. This is used when the 'template' keyword is used
4827/// or when the parsing context unambiguously treats a following '<' as
4828/// introducing a template argument list. Note that this may produce a
4829/// non-dependent template name if we can perform the lookup now and identify
4830/// the named template.
4831///
4832/// For example, given "x.MetaFun::template apply", the scope specifier
4833/// \p SS will be "MetaFun::", \p TemplateKWLoc contains the location
4834/// of the "template" keyword, and "apply" is the \p Name.
4835TemplateNameKind Sema::ActOnTemplateName(Scope *S,
4836 CXXScopeSpec &SS,
4837 SourceLocation TemplateKWLoc,
4838 const UnqualifiedId &Name,
4839 ParsedType ObjectType,
4840 bool EnteringContext,
4841 TemplateTy &Result,
4842 bool AllowInjectedClassName) {
4843 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent())
4844 Diag(TemplateKWLoc,
4845 getLangOpts().CPlusPlus11 ?
4846 diag::warn_cxx98_compat_template_outside_of_template :
4847 diag::ext_template_outside_of_template)
4848 << FixItHint::CreateRemoval(TemplateKWLoc);
4849
4850 if (SS.isInvalid())
4851 return TNK_Non_template;
4852
4853 // Figure out where isTemplateName is going to look.
4854 DeclContext *LookupCtx = nullptr;
4855 if (SS.isNotEmpty())
4856 LookupCtx = computeDeclContext(SS, EnteringContext);
4857 else if (ObjectType)
4858 LookupCtx = computeDeclContext(GetTypeFromParser(ObjectType));
4859
4860 // C++0x [temp.names]p5:
4861 // If a name prefixed by the keyword template is not the name of
4862 // a template, the program is ill-formed. [Note: the keyword
4863 // template may not be applied to non-template members of class
4864 // templates. -end note ] [ Note: as is the case with the
4865 // typename prefix, the template prefix is allowed in cases
4866 // where it is not strictly necessary; i.e., when the
4867 // nested-name-specifier or the expression on the left of the ->
4868 // or . is not dependent on a template-parameter, or the use
4869 // does not appear in the scope of a template. -end note]
4870 //
4871 // Note: C++03 was more strict here, because it banned the use of
4872 // the "template" keyword prior to a template-name that was not a
4873 // dependent name. C++ DR468 relaxed this requirement (the
4874 // "template" keyword is now permitted). We follow the C++0x
4875 // rules, even in C++03 mode with a warning, retroactively applying the DR.
4876 bool MemberOfUnknownSpecialization;
4877 TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name,
4878 ObjectType, EnteringContext, Result,
4879 MemberOfUnknownSpecialization);
4880 if (TNK != TNK_Non_template) {
4881 // We resolved this to a (non-dependent) template name. Return it.
4882 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
4883 if (!AllowInjectedClassName && SS.isNotEmpty() && LookupRD &&
4884 Name.getKind() == UnqualifiedIdKind::IK_Identifier &&
4885 Name.Identifier && LookupRD->getIdentifier() == Name.Identifier) {
4886 // C++14 [class.qual]p2:
4887 // In a lookup in which function names are not ignored and the
4888 // nested-name-specifier nominates a class C, if the name specified
4889 // [...] is the injected-class-name of C, [...] the name is instead
4890 // considered to name the constructor
4891 //
4892 // We don't get here if naming the constructor would be valid, so we
4893 // just reject immediately and recover by treating the
4894 // injected-class-name as naming the template.
4895 Diag(Name.getBeginLoc(),
4896 diag::ext_out_of_line_qualified_id_type_names_constructor)
4897 << Name.Identifier
4898 << 0 /*injected-class-name used as template name*/
4899 << TemplateKWLoc.isValid();
4900 }
4901 return TNK;
4902 }
4903
4904 if (!MemberOfUnknownSpecialization) {
4905 // Didn't find a template name, and the lookup wasn't dependent.
4906 // Do the lookup again to determine if this is a "nothing found" case or
4907 // a "not a template" case. FIXME: Refactor isTemplateName so we don't
4908 // need to do this.
4909 DeclarationNameInfo DNI = GetNameFromUnqualifiedId(Name);
4910 LookupResult R(*this, DNI.getName(), Name.getBeginLoc(),
4911 LookupOrdinaryName);
4912 bool MOUS;
4913 // Tell LookupTemplateName that we require a template so that it diagnoses
4914 // cases where it finds a non-template.
4915 RequiredTemplateKind RTK = TemplateKWLoc.isValid()
4916 ? RequiredTemplateKind(TemplateKWLoc)
4917 : TemplateNameIsRequired;
4918 if (!LookupTemplateName(R, S, SS, ObjectType.get(), EnteringContext, MOUS,
4919 RTK, nullptr, /*AllowTypoCorrection=*/false) &&
4920 !R.isAmbiguous()) {
4921 if (LookupCtx)
4922 Diag(Name.getBeginLoc(), diag::err_no_member)
4923 << DNI.getName() << LookupCtx << SS.getRange();
4924 else
4925 Diag(Name.getBeginLoc(), diag::err_undeclared_use)
4926 << DNI.getName() << SS.getRange();
4927 }
4928 return TNK_Non_template;
4929 }
4930
4931 NestedNameSpecifier *Qualifier = SS.getScopeRep();
4932
4933 switch (Name.getKind()) {
4934 case UnqualifiedIdKind::IK_Identifier:
4935 Result = TemplateTy::make(
4936 Context.getDependentTemplateName(Qualifier, Name.Identifier));
4937 return TNK_Dependent_template_name;
4938
4939 case UnqualifiedIdKind::IK_OperatorFunctionId:
4940 Result = TemplateTy::make(Context.getDependentTemplateName(
4941 Qualifier, Name.OperatorFunctionId.Operator));
4942 return TNK_Function_template;
4943
4944 case UnqualifiedIdKind::IK_LiteralOperatorId:
4945 // This is a kind of template name, but can never occur in a dependent
4946 // scope (literal operators can only be declared at namespace scope).
4947 break;
4948
4949 default:
4950 break;
4951 }
4952
4953 // This name cannot possibly name a dependent template. Diagnose this now
4954 // rather than building a dependent template name that can never be valid.
4955 Diag(Name.getBeginLoc(),
4956 diag::err_template_kw_refers_to_dependent_non_template)
4957 << GetNameFromUnqualifiedId(Name).getName() << Name.getSourceRange()
4958 << TemplateKWLoc.isValid() << TemplateKWLoc;
4959 return TNK_Non_template;
4960}
4961
4962bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
4963 TemplateArgumentLoc &AL,
4964 SmallVectorImpl<TemplateArgument> &Converted) {
4965 const TemplateArgument &Arg = AL.getArgument();
4966 QualType ArgType;
4967 TypeSourceInfo *TSI = nullptr;
4968
4969 // Check template type parameter.
4970 switch(Arg.getKind()) {
4971 case TemplateArgument::Type:
4972 // C++ [temp.arg.type]p1:
4973 // A template-argument for a template-parameter which is a
4974 // type shall be a type-id.
4975 ArgType = Arg.getAsType();
4976 TSI = AL.getTypeSourceInfo();
4977 break;
4978 case TemplateArgument::Template:
4979 case TemplateArgument::TemplateExpansion: {
4980 // We have a template type parameter but the template argument
4981 // is a template without any arguments.
4982 SourceRange SR = AL.getSourceRange();
4983 TemplateName Name = Arg.getAsTemplateOrTemplatePattern();
4984 diagnoseMissingTemplateArguments(Name, SR.getEnd());
4985 return true;
4986 }
4987 case TemplateArgument::Expression: {
4988 // We have a template type parameter but the template argument is an
4989 // expression; see if maybe it is missing the "typename" keyword.
4990 CXXScopeSpec SS;
4991 DeclarationNameInfo NameInfo;
4992
4993 if (DependentScopeDeclRefExpr *ArgExpr =
4994 dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) {
4995 SS.Adopt(ArgExpr->getQualifierLoc());
4996 NameInfo = ArgExpr->getNameInfo();
4997 } else if (CXXDependentScopeMemberExpr *ArgExpr =
4998 dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) {
4999 if (ArgExpr->isImplicitAccess()) {
5000 SS.Adopt(ArgExpr->getQualifierLoc());
5001 NameInfo = ArgExpr->getMemberNameInfo();
5002 }
5003 }
5004
5005 if (auto *II = NameInfo.getName().getAsIdentifierInfo()) {
5006 LookupResult Result(*this, NameInfo, LookupOrdinaryName);
5007 LookupParsedName(Result, CurScope, &SS);
5008
5009 if (Result.getAsSingle<TypeDecl>() ||
5010 Result.getResultKind() ==
5011 LookupResult::NotFoundInCurrentInstantiation) {
5012 assert(SS.getScopeRep() && "dependent scope expr must has a scope!")(static_cast <bool> (SS.getScopeRep() && "dependent scope expr must has a scope!"
) ? void (0) : __assert_fail ("SS.getScopeRep() && \"dependent scope expr must has a scope!\""
, "clang/lib/Sema/SemaTemplate.cpp", 5012, __extension__ __PRETTY_FUNCTION__
))
;
5013 // Suggest that the user add 'typename' before the NNS.
5014 SourceLocation Loc = AL.getSourceRange().getBegin();
5015 Diag(Loc, getLangOpts().MSVCCompat
5016 ? diag::ext_ms_template_type_arg_missing_typename
5017 : diag::err_template_arg_must_be_type_suggest)
5018 << FixItHint::CreateInsertion(Loc, "typename ");
5019 Diag(Param->getLocation(), diag::note_template_param_here);
5020
5021 // Recover by synthesizing a type using the location information that we
5022 // already have.
5023 ArgType =
5024 Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II);
5025 TypeLocBuilder TLB;
5026 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(ArgType);
5027 TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/));
5028 TL.setQualifierLoc(SS.getWithLocInContext(Context));
5029 TL.setNameLoc(NameInfo.getLoc());
5030 TSI = TLB.getTypeSourceInfo(Context, ArgType);
5031
5032 // Overwrite our input TemplateArgumentLoc so that we can recover
5033 // properly.
5034 AL = TemplateArgumentLoc(TemplateArgument(ArgType),
5035 TemplateArgumentLocInfo(TSI));
5036
5037 break;
5038 }
5039 }
5040 // fallthrough
5041 LLVM_FALLTHROUGH[[gnu::fallthrough]];
5042 }
5043 default: {
5044 // We have a template type parameter but the template argument
5045 // is not a type.
5046 SourceRange SR = AL.getSourceRange();
5047 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR;
5048 Diag(Param->getLocation(), diag::note_template_param_here);
5049
5050 return true;
5051 }
5052 }
5053
5054 if (CheckTemplateArgument(TSI))
5055 return true;
5056
5057 // Add the converted template type argument.
5058 ArgType = Context.getCanonicalType(ArgType);
5059
5060 // Objective-C ARC:
5061 // If an explicitly-specified template argument type is a lifetime type
5062 // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
5063 if (getLangOpts().ObjCAutoRefCount &&
5064 ArgType->isObjCLifetimeType() &&
5065 !ArgType.getObjCLifetime()) {
5066 Qualifiers Qs;
5067 Qs.setObjCLifetime(Qualifiers::OCL_Strong);
5068 ArgType = Context.getQualifiedType(ArgType, Qs);
5069 }
5070
5071 Converted.push_back(TemplateArgument(ArgType));
5072 return false;
5073}
5074
5075/// Substitute template arguments into the default template argument for
5076/// the given template type parameter.
5077///
5078/// \param SemaRef the semantic analysis object for which we are performing
5079/// the substitution.
5080///
5081/// \param Template the template that we are synthesizing template arguments
5082/// for.
5083///
5084/// \param TemplateLoc the location of the template name that started the
5085/// template-id we are checking.
5086///
5087/// \param RAngleLoc the location of the right angle bracket ('>') that
5088/// terminates the template-id.
5089///
5090/// \param Param the template template parameter whose default we are
5091/// substituting into.
5092///
5093/// \param Converted the list of template arguments provided for template
5094/// parameters that precede \p Param in the template parameter list.
5095/// \returns the substituted template argument, or NULL if an error occurred.
5096static TypeSourceInfo *
5097SubstDefaultTemplateArgument(Sema &SemaRef,
5098 TemplateDecl *Template,
5099 SourceLocation TemplateLoc,
5100 SourceLocation RAngleLoc,
5101 TemplateTypeParmDecl *Param,
5102 SmallVectorImpl<TemplateArgument> &Converted) {
5103 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo();
5104
5105 // If the argument type is dependent, instantiate it now based
5106 // on the previously-computed template arguments.
5107 if (ArgType->getType()->isInstantiationDependentType()) {
5108 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
5109 Param, Template, Converted,
5110 SourceRange(TemplateLoc, RAngleLoc));
5111 if (Inst.isInvalid())
5112 return nullptr;
5113
5114 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5115
5116 // Only substitute for the innermost template argument list.
5117 MultiLevelTemplateArgumentList TemplateArgLists;
5118 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
5119 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
5120 TemplateArgLists.addOuterTemplateArguments(None);
5121
5122 bool ForLambdaCallOperator = false;
5123 if (const auto *Rec = dyn_cast<CXXRecordDecl>(Template->getDeclContext()))
5124 ForLambdaCallOperator = Rec->isLambda();
5125 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext(),
5126 !ForLambdaCallOperator);
5127 ArgType =
5128 SemaRef.SubstType(ArgType, TemplateArgLists,
5129 Param->getDefaultArgumentLoc(), Param->getDeclName());
5130 }
5131
5132 return ArgType;
5133}
5134
5135/// Substitute template arguments into the default template argument for
5136/// the given non-type template parameter.
5137///
5138/// \param SemaRef the semantic analysis object for which we are performing
5139/// the substitution.
5140///
5141/// \param Template the template that we are synthesizing template arguments
5142/// for.
5143///
5144/// \param TemplateLoc the location of the template name that started the
5145/// template-id we are checking.
5146///
5147/// \param RAngleLoc the location of the right angle bracket ('>') that
5148/// terminates the template-id.
5149///
5150/// \param Param the non-type template parameter whose default we are
5151/// substituting into.
5152///
5153/// \param Converted the list of template arguments provided for template
5154/// parameters that precede \p Param in the template parameter list.
5155///
5156/// \returns the substituted template argument, or NULL if an error occurred.
5157static ExprResult
5158SubstDefaultTemplateArgument(Sema &SemaRef,
5159 TemplateDecl *Template,
5160 SourceLocation TemplateLoc,
5161 SourceLocation RAngleLoc,
5162 NonTypeTemplateParmDecl *Param,
5163 SmallVectorImpl<TemplateArgument> &Converted) {
5164 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
5165 Param, Template, Converted,
5166 SourceRange(TemplateLoc, RAngleLoc));
5167 if (Inst.isInvalid())
5168 return ExprError();
5169
5170 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5171
5172 // Only substitute for the innermost template argument list.
5173 MultiLevelTemplateArgumentList TemplateArgLists;
5174 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
5175 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
5176 TemplateArgLists.addOuterTemplateArguments(None);
5177
5178 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
5179 EnterExpressionEvaluationContext ConstantEvaluated(
5180 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
5181 return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
5182}
5183
5184/// Substitute template arguments into the default template argument for
5185/// the given template template parameter.
5186///
5187/// \param SemaRef the semantic analysis object for which we are performing
5188/// the substitution.
5189///
5190/// \param Template the template that we are synthesizing template arguments
5191/// for.
5192///
5193/// \param TemplateLoc the location of the template name that started the
5194/// template-id we are checking.
5195///
5196/// \param RAngleLoc the location of the right angle bracket ('>') that
5197/// terminates the template-id.
5198///
5199/// \param Param the template template parameter whose default we are
5200/// substituting into.
5201///
5202/// \param Converted the list of template arguments provided for template
5203/// parameters that precede \p Param in the template parameter list.
5204///
5205/// \param QualifierLoc Will be set to the nested-name-specifier (with
5206/// source-location information) that precedes the template name.
5207///
5208/// \returns the substituted template argument, or NULL if an error occurred.
5209static TemplateName
5210SubstDefaultTemplateArgument(Sema &SemaRef,
5211 TemplateDecl *Template,
5212 SourceLocation TemplateLoc,
5213 SourceLocation RAngleLoc,
5214 TemplateTemplateParmDecl *Param,
5215 SmallVectorImpl<TemplateArgument> &Converted,
5216 NestedNameSpecifierLoc &QualifierLoc) {
5217 Sema::InstantiatingTemplate Inst(
5218 SemaRef, TemplateLoc, TemplateParameter(Param), Template, Converted,
5219 SourceRange(TemplateLoc, RAngleLoc));
5220 if (Inst.isInvalid())
5221 return TemplateName();
5222
5223 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5224
5225 // Only substitute for the innermost template argument list.
5226 MultiLevelTemplateArgumentList TemplateArgLists;
5227 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
5228 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
5229 TemplateArgLists.addOuterTemplateArguments(None);
5230
5231 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
5232 // Substitute into the nested-name-specifier first,
5233 QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
5234 if (QualifierLoc) {
5235 QualifierLoc =
5236 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists);
5237 if (!QualifierLoc)
5238 return TemplateName();
5239 }
5240
5241 return SemaRef.SubstTemplateName(
5242 QualifierLoc,
5243 Param->getDefaultArgument().getArgument().getAsTemplate(),
5244 Param->getDefaultArgument().getTemplateNameLoc(),
5245 TemplateArgLists);
5246}
5247
5248/// If the given template parameter has a default template
5249/// argument, substitute into that default template argument and
5250/// return the corresponding template argument.
5251TemplateArgumentLoc
5252Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
5253 SourceLocation TemplateLoc,
5254 SourceLocation RAngleLoc,
5255 Decl *Param,
5256 SmallVectorImpl<TemplateArgument>
5257 &Converted,
5258 bool &HasDefaultArg) {
5259 HasDefaultArg = false;
5260
5261 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) {
5262 if (!hasVisibleDefaultArgument(TypeParm))
5263 return TemplateArgumentLoc();
5264
5265 HasDefaultArg = true;
5266 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template,
5267 TemplateLoc,
5268 RAngleLoc,
5269 TypeParm,
5270 Converted);
5271 if (DI)
5272 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI);
5273
5274 return TemplateArgumentLoc();
5275 }
5276
5277 if (NonTypeTemplateParmDecl *NonTypeParm
5278 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
5279 if (!hasVisibleDefaultArgument(NonTypeParm))
5280 return TemplateArgumentLoc();
5281
5282 HasDefaultArg = true;
5283 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template,
5284 TemplateLoc,
5285 RAngleLoc,
5286 NonTypeParm,
5287 Converted);
5288 if (Arg.isInvalid())
5289 return TemplateArgumentLoc();
5290
5291 Expr *ArgE = Arg.getAs<Expr>();
5292 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE);
5293 }
5294
5295 TemplateTemplateParmDecl *TempTempParm
5296 = cast<TemplateTemplateParmDecl>(Param);
5297 if (!hasVisibleDefaultArgument(TempTempParm))
5298 return TemplateArgumentLoc();
5299
5300 HasDefaultArg = true;
5301 NestedNameSpecifierLoc QualifierLoc;
5302 TemplateName TName = SubstDefaultTemplateArgument(*this, Template,
5303 TemplateLoc,
5304 RAngleLoc,
5305 TempTempParm,
5306 Converted,
5307 QualifierLoc);
5308 if (TName.isNull())
5309 return TemplateArgumentLoc();
5310
5311 return TemplateArgumentLoc(
5312 Context, TemplateArgument(TName),
5313 TempTempParm->getDefaultArgument().getTemplateQualifierLoc(),
5314 TempTempParm->getDefaultArgument().getTemplateNameLoc());
5315}
5316
5317/// Convert a template-argument that we parsed as a type into a template, if
5318/// possible. C++ permits injected-class-names to perform dual service as
5319/// template template arguments and as template type arguments.
5320static TemplateArgumentLoc
5321convertTypeTemplateArgumentToTemplate(ASTContext &Context, TypeLoc TLoc) {
5322 // Extract and step over any surrounding nested-name-specifier.
5323 NestedNameSpecifierLoc QualLoc;
5324 if (auto ETLoc = TLoc.getAs<ElaboratedTypeLoc>()) {
5325 if (ETLoc.getTypePtr()->getKeyword() != ETK_None)
5326 return TemplateArgumentLoc();
5327
5328 QualLoc = ETLoc.getQualifierLoc();
5329 TLoc = ETLoc.getNamedTypeLoc();
5330 }
5331 // If this type was written as an injected-class-name, it can be used as a
5332 // template template argument.
5333 if (auto InjLoc = TLoc.getAs<InjectedClassNameTypeLoc>())
5334 return TemplateArgumentLoc(Context, InjLoc.getTypePtr()->getTemplateName(),
5335 QualLoc, InjLoc.getNameLoc());
5336
5337 // If this type was written as an injected-class-name, it may have been
5338 // converted to a RecordType during instantiation. If the RecordType is
5339 // *not* wrapped in a TemplateSpecializationType and denotes a class
5340 // template specialization, it must have come from an injected-class-name.
5341 if (auto RecLoc = TLoc.getAs<RecordTypeLoc>())
5342 if (auto *CTSD =
5343 dyn_cast<ClassTemplateSpecializationDecl>(RecLoc.getDecl()))
5344 return TemplateArgumentLoc(Context,
5345 TemplateName(CTSD->getSpecializedTemplate()),
5346 QualLoc, RecLoc.getNameLoc());
5347
5348 return TemplateArgumentLoc();
5349}
5350
5351/// Check that the given template argument corresponds to the given
5352/// template parameter.
5353///
5354/// \param Param The template parameter against which the argument will be
5355/// checked.
5356///
5357/// \param Arg The template argument, which may be updated due to conversions.
5358///
5359/// \param Template The template in which the template argument resides.
5360///
5361/// \param TemplateLoc The location of the template name for the template
5362/// whose argument list we're matching.
5363///
5364/// \param RAngleLoc The location of the right angle bracket ('>') that closes
5365/// the template argument list.
5366///
5367/// \param ArgumentPackIndex The index into the argument pack where this
5368/// argument will be placed. Only valid if the parameter is a parameter pack.
5369///
5370/// \param Converted The checked, converted argument will be added to the
5371/// end of this small vector.
5372///
5373/// \param CTAK Describes how we arrived at this particular template argument:
5374/// explicitly written, deduced, etc.
5375///
5376/// \returns true on error, false otherwise.
5377bool Sema::CheckTemplateArgument(NamedDecl *Param,
5378 TemplateArgumentLoc &Arg,
5379 NamedDecl *Template,
5380 SourceLocation TemplateLoc,
5381 SourceLocation RAngleLoc,
5382 unsigned ArgumentPackIndex,
5383 SmallVectorImpl<TemplateArgument> &Converted,
5384 CheckTemplateArgumentKind CTAK) {
5385 // Check template type parameters.
5386 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
5387 return CheckTemplateTypeArgument(TTP, Arg, Converted);
5388
5389 // Check non-type template parameters.
5390 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) {
5391 // Do substitution on the type of the non-type template parameter
5392 // with the template arguments we've seen thus far. But if the
5393 // template has a dependent context then we cannot substitute yet.
5394 QualType NTTPType = NTTP->getType();
5395 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack())
5396 NTTPType = NTTP->getExpansionType(ArgumentPackIndex);
5397
5398 if (NTTPType->isInstantiationDependentType() &&
5399 !isa<TemplateTemplateParmDecl>(Template) &&
5400 !Template->getDeclContext()->isDependentContext()) {
5401 // Do substitution on the type of the non-type template parameter.
5402 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
5403 NTTP, Converted,
5404 SourceRange(TemplateLoc, RAngleLoc));
5405 if (Inst.isInvalid())
5406 return true;
5407
5408 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
5409 Converted);
5410
5411 // If the parameter is a pack expansion, expand this slice of the pack.
5412 if (auto *PET = NTTPType->getAs<PackExpansionType>()) {
5413 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this,
5414 ArgumentPackIndex);
5415 NTTPType = SubstType(PET->getPattern(),
5416 MultiLevelTemplateArgumentList(TemplateArgs),
5417 NTTP->getLocation(),
5418 NTTP->getDeclName());
5419 } else {
5420 NTTPType = SubstType(NTTPType,
5421 MultiLevelTemplateArgumentList(TemplateArgs),
5422 NTTP->getLocation(),
5423 NTTP->getDeclName());
5424 }
5425
5426 // If that worked, check the non-type template parameter type
5427 // for validity.
5428 if (!NTTPType.isNull())
5429 NTTPType = CheckNonTypeTemplateParameterType(NTTPType,
5430 NTTP->getLocation());
5431 if (NTTPType.isNull())
5432 return true;
5433 }
5434
5435 switch (Arg.getArgument().getKind()) {
5436 case TemplateArgument::Null:
5437 llvm_unreachable("Should never see a NULL template argument here")::llvm::llvm_unreachable_internal("Should never see a NULL template argument here"
, "clang/lib/Sema/SemaTemplate.cpp", 5437)
;
5438
5439 case TemplateArgument::Expression: {
5440 TemplateArgument Result;
5441 unsigned CurSFINAEErrors = NumSFINAEErrors;
5442 ExprResult Res =
5443 CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(),
5444 Result, CTAK);
5445 if (Res.isInvalid())
5446 return true;
5447 // If the current template argument causes an error, give up now.
5448 if (CurSFINAEErrors < NumSFINAEErrors)
5449 return true;
5450
5451 // If the resulting expression is new, then use it in place of the
5452 // old expression in the template argument.
5453 if (Res.get() != Arg.getArgument().getAsExpr()) {
5454 TemplateArgument TA(Res.get());
5455 Arg = TemplateArgumentLoc(TA, Res.get());
5456 }
5457
5458 Converted.push_back(Result);
5459 break;
5460 }
5461
5462 case TemplateArgument::Declaration:
5463 case TemplateArgument::Integral:
5464 case TemplateArgument::NullPtr:
5465 // We've already checked this template argument, so just copy
5466 // it to the list of converted arguments.
5467 Converted.push_back(Arg.getArgument());
5468 break;
5469
5470 case TemplateArgument::Template:
5471 case TemplateArgument::TemplateExpansion:
5472 // We were given a template template argument. It may not be ill-formed;
5473 // see below.
5474 if (DependentTemplateName *DTN
5475 = Arg.getArgument().getAsTemplateOrTemplatePattern()
5476 .getAsDependentTemplateName()) {
5477 // We have a template argument such as \c T::template X, which we
5478 // parsed as a template template argument. However, since we now
5479 // know that we need a non-type template argument, convert this
5480 // template name into an expression.
5481
5482 DeclarationNameInfo NameInfo(DTN->getIdentifier(),
5483 Arg.getTemplateNameLoc());
5484
5485 CXXScopeSpec SS;
5486 SS.Adopt(Arg.getTemplateQualifierLoc());
5487 // FIXME: the template-template arg was a DependentTemplateName,
5488 // so it was provided with a template keyword. However, its source
5489 // location is not stored in the template argument structure.
5490 SourceLocation TemplateKWLoc;
5491 ExprResult E = DependentScopeDeclRefExpr::Create(
5492 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
5493 nullptr);
5494
5495 // If we parsed the template argument as a pack expansion, create a
5496 // pack expansion expression.
5497 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){
5498 E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc());
5499 if (E.isInvalid())
5500 return true;
5501 }
5502
5503 TemplateArgument Result;
5504 E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result);
5505 if (E.isInvalid())
5506 return true;
5507
5508 Converted.push_back(Result);
5509 break;
5510 }
5511
5512 // We have a template argument that actually does refer to a class
5513 // template, alias template, or template template parameter, and
5514 // therefore cannot be a non-type template argument.
5515 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr)
5516 << Arg.getSourceRange();
5517
5518 Diag(Param->getLocation(), diag::note_template_param_here);
5519 return true;
5520
5521 case TemplateArgument::Type: {
5522 // We have a non-type template parameter but the template
5523 // argument is a type.
5524
5525 // C++ [temp.arg]p2:
5526 // In a template-argument, an ambiguity between a type-id and
5527 // an expression is resolved to a type-id, regardless of the
5528 // form of the corresponding template-parameter.
5529 //
5530 // We warn specifically about this case, since it can be rather
5531 // confusing for users.
5532 QualType T = Arg.getArgument().getAsType();
5533 SourceRange SR = Arg.getSourceRange();
5534 if (T->isFunctionType())
5535 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T;
5536 else
5537 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR;
5538 Diag(Param->getLocation(), diag::note_template_param_here);
5539 return true;
5540 }
5541
5542 case TemplateArgument::Pack:
5543 llvm_unreachable("Caller must expand template argument packs")::llvm::llvm_unreachable_internal("Caller must expand template argument packs"
, "clang/lib/Sema/SemaTemplate.cpp", 5543)
;
5544 }
5545
5546 return false;
5547 }
5548
5549
5550 // Check template template parameters.
5551 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param);
5552
5553 TemplateParameterList *Params = TempParm->getTemplateParameters();
5554 if (TempParm->isExpandedParameterPack())
5555 Params = TempParm->getExpansionTemplateParameters(ArgumentPackIndex);
5556
5557 // Substitute into the template parameter list of the template
5558 // template parameter, since previously-supplied template arguments
5559 // may appear within the template template parameter.
5560 //
5561 // FIXME: Skip this if the parameters aren't instantiation-dependent.
5562 {
5563 // Set up a template instantiation context.
5564 LocalInstantiationScope Scope(*this);
5565 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
5566 TempParm, Converted,
5567 SourceRange(TemplateLoc, RAngleLoc));
5568 if (Inst.isInvalid())
5569 return true;
5570
5571 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5572 Params = SubstTemplateParams(Params, CurContext,
5573 MultiLevelTemplateArgumentList(TemplateArgs));
5574 if (!Params)
5575 return true;
5576 }
5577
5578 // C++1z [temp.local]p1: (DR1004)
5579 // When [the injected-class-name] is used [...] as a template-argument for
5580 // a template template-parameter [...] it refers to the class template
5581 // itself.
5582 if (Arg.getArgument().getKind() == TemplateArgument::Type) {
5583 TemplateArgumentLoc ConvertedArg = convertTypeTemplateArgumentToTemplate(
5584 Context, Arg.getTypeSourceInfo()->getTypeLoc());
5585 if (!ConvertedArg.getArgument().isNull())
5586 Arg = ConvertedArg;
5587 }
5588
5589 switch (Arg.getArgument().getKind()) {
5590 case TemplateArgument::Null:
5591 llvm_unreachable("Should never see a NULL template argument here")::llvm::llvm_unreachable_internal("Should never see a NULL template argument here"
, "clang/lib/Sema/SemaTemplate.cpp", 5591)
;
5592
5593 case TemplateArgument::Template:
5594 case TemplateArgument::TemplateExpansion:
5595 if (CheckTemplateTemplateArgument(TempParm, Params, Arg))
5596 return true;
5597
5598 Converted.push_back(Arg.getArgument());
5599 break;
5600
5601 case TemplateArgument::Expression:
5602 case TemplateArgument::Type:
5603 // We have a template template parameter but the template
5604 // argument does not refer to a template.
5605 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template)
5606 << getLangOpts().CPlusPlus11;
5607 return true;
5608
5609 case TemplateArgument::Declaration:
5610 llvm_unreachable("Declaration argument with template template parameter")::llvm::llvm_unreachable_internal("Declaration argument with template template parameter"
, "clang/lib/Sema/SemaTemplate.cpp", 5610)
;
5611 case TemplateArgument::Integral:
5612 llvm_unreachable("Integral argument with template template parameter")::llvm::llvm_unreachable_internal("Integral argument with template template parameter"
, "clang/lib/Sema/SemaTemplate.cpp", 5612)
;
5613 case TemplateArgument::NullPtr:
5614 llvm_unreachable("Null pointer argument with template template parameter")::llvm::llvm_unreachable_internal("Null pointer argument with template template parameter"
, "clang/lib/Sema/SemaTemplate.cpp", 5614)
;
5615
5616 case TemplateArgument::Pack:
5617 llvm_unreachable("Caller must expand template argument packs")::llvm::llvm_unreachable_internal("Caller must expand template argument packs"
, "clang/lib/Sema/SemaTemplate.cpp", 5617)
;
5618 }
5619
5620 return false;
5621}
5622
5623/// Diagnose a missing template argument.
5624template<typename TemplateParmDecl>
5625static bool diagnoseMissingArgument(Sema &S, SourceLocation Loc,
5626 TemplateDecl *TD,
5627 const TemplateParmDecl *D,
5628 TemplateArgumentListInfo &Args) {
5629 // Dig out the most recent declaration of the template parameter; there may be
5630 // declarations of the template that are more recent than TD.
5631 D = cast<TemplateParmDecl>(cast<TemplateDecl>(TD->getMostRecentDecl())
5632 ->getTemplateParameters()
5633 ->getParam(D->getIndex()));
5634
5635 // If there's a default argument that's not visible, diagnose that we're
5636 // missing a module import.
5637 llvm::SmallVector<Module*, 8> Modules;
5638 if (D->hasDefaultArgument() && !S.hasVisibleDefaultArgument(D, &Modules)) {
5639 S.diagnoseMissingImport(Loc, cast<NamedDecl>(TD),
5640 D->getDefaultArgumentLoc(), Modules,
5641 Sema::MissingImportKind::DefaultArgument,
5642 /*Recover*/true);
5643 return true;
5644 }
5645
5646 // FIXME: If there's a more recent default argument that *is* visible,
5647 // diagnose that it was declared too late.
5648
5649 TemplateParameterList *Params = TD->getTemplateParameters();
5650
5651 S.Diag(Loc, diag::err_template_arg_list_different_arity)
5652 << /*not enough args*/0
5653 << (int)S.getTemplateNameKindForDiagnostics(TemplateName(TD))
5654 << TD;
5655 S.Diag(TD->getLocation(), diag::note_template_decl_here)
5656 << Params->getSourceRange();
5657 return true;
5658}
5659
5660/// Check that the given template argument list is well-formed
5661/// for specializing the given template.
5662bool Sema::CheckTemplateArgumentList(
5663 TemplateDecl *Template, SourceLocation TemplateLoc,
5664 TemplateArgumentListInfo &TemplateArgs, bool PartialTemplateArgs,
5665 SmallVectorImpl<TemplateArgument> &Converted,
5666 bool UpdateArgsWithConversions, bool *ConstraintsNotSatisfied) {
5667
5668 if (ConstraintsNotSatisfied)
5669 *ConstraintsNotSatisfied = false;
5670
5671 // Make a copy of the template arguments for processing. Only make the
5672 // changes at the end when successful in matching the arguments to the
5673 // template.
5674 TemplateArgumentListInfo NewArgs = TemplateArgs;
5675
5676 // Make sure we get the template parameter list from the most
5677 // recent declaration, since that is the only one that is guaranteed to
5678 // have all the default template argument information.
5679 TemplateParameterList *Params =
5680 cast<TemplateDecl>(Template->getMostRecentDecl())
5681 ->getTemplateParameters();
5682
5683 SourceLocation RAngleLoc = NewArgs.getRAngleLoc();
5684
5685 // C++ [temp.arg]p1:
5686 // [...] The type and form of each template-argument specified in
5687 // a template-id shall match the type and form specified for the
5688 // corresponding parameter declared by the template in its
5689 // template-parameter-list.
5690 bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template);
5691 SmallVector<TemplateArgument, 2> ArgumentPack;
5692 unsigned ArgIdx = 0, NumArgs = NewArgs.size();
5693 LocalInstantiationScope InstScope(*this, true);
5694 for (TemplateParameterList::iterator Param = Params->begin(),
5695 ParamEnd = Params->end();
5696 Param != ParamEnd; /* increment in loop */) {
5697 // If we have an expanded parameter pack, make sure we don't have too
5698 // many arguments.
5699 if (Optional<unsigned> Expansions = getExpandedPackSize(*Param)) {
5700 if (*Expansions == ArgumentPack.size()) {
5701 // We're done with this parameter pack. Pack up its arguments and add
5702 // them to the list.
5703 Converted.push_back(
5704 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
5705 ArgumentPack.clear();
5706
5707 // This argument is assigned to the next parameter.
5708 ++Param;
5709 continue;
5710 } else if (ArgIdx == NumArgs && !PartialTemplateArgs) {
5711 // Not enough arguments for this parameter pack.
5712 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
5713 << /*not enough args*/0
5714 << (int)getTemplateNameKindForDiagnostics(TemplateName(Template))
5715 << Template;
5716 Diag(Template->getLocation(), diag::note_template_decl_here)
5717 << Params->getSourceRange();
5718 return true;
5719 }
5720 }
5721
5722 if (ArgIdx < NumArgs) {
5723 // Check the template argument we were given.
5724 if (CheckTemplateArgument(*Param, NewArgs[ArgIdx], Template,
5725 TemplateLoc, RAngleLoc,
5726 ArgumentPack.size(), Converted))
5727 return true;
5728
5729 bool PackExpansionIntoNonPack =
5730 NewArgs[ArgIdx].getArgument().isPackExpansion() &&
5731 (!(*Param)->isTemplateParameterPack() || getExpandedPackSize(*Param));
5732 if (PackExpansionIntoNonPack && (isa<TypeAliasTemplateDecl>(Template) ||
5733 isa<ConceptDecl>(Template))) {
5734 // Core issue 1430: we have a pack expansion as an argument to an
5735 // alias template, and it's not part of a parameter pack. This
5736 // can't be canonicalized, so reject it now.
5737 // As for concepts - we cannot normalize constraints where this
5738 // situation exists.
5739 Diag(NewArgs[ArgIdx].getLocation(),
5740 diag::err_template_expansion_into_fixed_list)
5741 << (isa<ConceptDecl>(Template) ? 1 : 0)
5742 << NewArgs[ArgIdx].getSourceRange();
5743 Diag((*Param)->getLocation(), diag::note_template_param_here);
5744 return true;
5745 }
5746
5747 // We're now done with this argument.
5748 ++ArgIdx;
5749
5750 if ((*Param)->isTemplateParameterPack()) {
5751 // The template parameter was a template parameter pack, so take the
5752 // deduced argument and place it on the argument pack. Note that we
5753 // stay on the same template parameter so that we can deduce more
5754 // arguments.
5755 ArgumentPack.push_back(Converted.pop_back_val());
5756 } else {
5757 // Move to the next template parameter.
5758 ++Param;
5759 }
5760
5761 // If we just saw a pack expansion into a non-pack, then directly convert
5762 // the remaining arguments, because we don't know what parameters they'll
5763 // match up with.
5764 if (PackExpansionIntoNonPack) {
5765 if (!ArgumentPack.empty()) {
5766 // If we were part way through filling in an expanded parameter pack,
5767 // fall back to just producing individual arguments.
5768 Converted.insert(Converted.end(),
5769 ArgumentPack.begin(), ArgumentPack.end());
5770 ArgumentPack.clear();
5771 }
5772
5773 while (ArgIdx < NumArgs) {
5774 Converted.push_back(NewArgs[ArgIdx].getArgument());
5775 ++ArgIdx;
5776 }
5777
5778 return false;
5779 }
5780
5781 continue;
5782 }
5783
5784 // If we're checking a partial template argument list, we're done.
5785 if (PartialTemplateArgs) {
5786 if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty())
5787 Converted.push_back(
5788 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
5789 return false;
5790 }
5791
5792 // If we have a template parameter pack with no more corresponding
5793 // arguments, just break out now and we'll fill in the argument pack below.
5794 if ((*Param)->isTemplateParameterPack()) {
5795 assert(!getExpandedPackSize(*Param) &&(static_cast <bool> (!getExpandedPackSize(*Param) &&
"Should have dealt with this already") ? void (0) : __assert_fail
("!getExpandedPackSize(*Param) && \"Should have dealt with this already\""
, "clang/lib/Sema/SemaTemplate.cpp", 5796, __extension__ __PRETTY_FUNCTION__
))
5796 "Should have dealt with this already")(static_cast <bool> (!getExpandedPackSize(*Param) &&
"Should have dealt with this already") ? void (0) : __assert_fail
("!getExpandedPackSize(*Param) && \"Should have dealt with this already\""
, "clang/lib/Sema/SemaTemplate.cpp", 5796, __extension__ __PRETTY_FUNCTION__
))
;
5797
5798 // A non-expanded parameter pack before the end of the parameter list
5799 // only occurs for an ill-formed template parameter list, unless we've
5800 // got a partial argument list for a function template, so just bail out.
5801 if (Param + 1 != ParamEnd)
5802 return true;
5803
5804 Converted.push_back(
5805 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
5806 ArgumentPack.clear();
5807
5808 ++Param;
5809 continue;
5810 }
5811
5812 // Check whether we have a default argument.
5813 TemplateArgumentLoc Arg;
5814
5815 // Retrieve the default template argument from the template
5816 // parameter. For each kind of template parameter, we substitute the
5817 // template arguments provided thus far and any "outer" template arguments
5818 // (when the template parameter was part of a nested template) into
5819 // the default argument.
5820 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) {
5821 if (!hasVisibleDefaultArgument(TTP))
5822 return diagnoseMissingArgument(*this, TemplateLoc, Template, TTP,
5823 NewArgs);
5824
5825 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this,
5826 Template,
5827 TemplateLoc,
5828 RAngleLoc,
5829 TTP,
5830 Converted);
5831 if (!ArgType)
5832 return true;
5833
5834 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()),
5835 ArgType);
5836 } else if (NonTypeTemplateParmDecl *NTTP
5837 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
5838 if (!hasVisibleDefaultArgument(NTTP))
5839 return diagnoseMissingArgument(*this, TemplateLoc, Template, NTTP,
5840 NewArgs);
5841
5842 ExprResult E = SubstDefaultTemplateArgument(*this, Template,
5843 TemplateLoc,
5844 RAngleLoc,
5845 NTTP,
5846 Converted);
5847 if (E.isInvalid())
5848 return true;
5849
5850 Expr *Ex = E.getAs<Expr>();
5851 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex);
5852 } else {
5853 TemplateTemplateParmDecl *TempParm
5854 = cast<TemplateTemplateParmDecl>(*Param);
5855
5856 if (!hasVisibleDefaultArgument(TempParm))
5857 return diagnoseMissingArgument(*this, TemplateLoc, Template, TempParm,
5858 NewArgs);
5859
5860 NestedNameSpecifierLoc QualifierLoc;
5861 TemplateName Name = SubstDefaultTemplateArgument(*this, Template,
5862 TemplateLoc,
5863 RAngleLoc,
5864 TempParm,
5865 Converted,
5866 QualifierLoc);
5867 if (Name.isNull())
5868 return true;
5869
5870 Arg = TemplateArgumentLoc(
5871 Context, TemplateArgument(Name), QualifierLoc,
5872 TempParm->getDefaultArgument().getTemplateNameLoc());
5873 }
5874
5875 // Introduce an instantiation record that describes where we are using
5876 // the default template argument. We're not actually instantiating a
5877 // template here, we just create this object to put a note into the
5878 // context stack.
5879 InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted,
5880 SourceRange(TemplateLoc, RAngleLoc));
5881 if (Inst.isInvalid())
5882 return true;
5883
5884 // Check the default template argument.
5885 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
5886 RAngleLoc, 0, Converted))
5887 return true;
5888
5889 // Core issue 150 (assumed resolution): if this is a template template
5890 // parameter, keep track of the default template arguments from the
5891 // template definition.
5892 if (isTemplateTemplateParameter)
5893 NewArgs.addArgument(Arg);
5894
5895 // Move to the next template parameter and argument.
5896 ++Param;
5897 ++ArgIdx;
5898 }
5899
5900 // If we're performing a partial argument substitution, allow any trailing
5901 // pack expansions; they might be empty. This can happen even if
5902 // PartialTemplateArgs is false (the list of arguments is complete but
5903 // still dependent).
5904 if (ArgIdx < NumArgs && CurrentInstantiationScope &&
5905 CurrentInstantiationScope->getPartiallySubstitutedPack()) {
5906 while (ArgIdx < NumArgs && NewArgs[ArgIdx].getArgument().isPackExpansion())
5907 Converted.push_back(NewArgs[ArgIdx++].getArgument());
5908 }
5909
5910 // If we have any leftover arguments, then there were too many arguments.
5911 // Complain and fail.
5912 if (ArgIdx < NumArgs) {
5913 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
5914 << /*too many args*/1
5915 << (int)getTemplateNameKindForDiagnostics(TemplateName(Template))
5916 << Template
5917 << SourceRange(NewArgs[ArgIdx].getLocation(), NewArgs.getRAngleLoc());
5918 Diag(Template->getLocation(), diag::note_template_decl_here)
5919 << Params->getSourceRange();
5920 return true;
5921 }
5922
5923 // No problems found with the new argument list, propagate changes back
5924 // to caller.
5925 if (UpdateArgsWithConversions)
5926 TemplateArgs = std::move(NewArgs);
5927
5928 if (!PartialTemplateArgs &&
5929 EnsureTemplateArgumentListConstraints(
5930 Template, Converted, SourceRange(TemplateLoc,
5931 TemplateArgs.getRAngleLoc()))) {
5932 if (ConstraintsNotSatisfied)
5933 *ConstraintsNotSatisfied = true;
5934 return true;
5935 }
5936
5937 return false;
5938}
5939
5940namespace {
5941 class UnnamedLocalNoLinkageFinder
5942 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool>
5943 {
5944 Sema &S;
5945 SourceRange SR;
5946
5947 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited;
5948
5949 public:
5950 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { }
5951
5952 bool Visit(QualType T) {
5953 return T.isNull() ? false : inherited::Visit(T.getTypePtr());
5954 }
5955
5956#define TYPE(Class, Parent) \
5957 bool Visit##Class##Type(const Class##Type *);
5958#define ABSTRACT_TYPE(Class, Parent) \
5959 bool Visit##Class##Type(const Class##Type *) { return false; }
5960#define NON_CANONICAL_TYPE(Class, Parent) \
5961 bool Visit##Class##Type(const Class##Type *) { return false; }
5962#include "clang/AST/TypeNodes.inc"
5963
5964 bool VisitTagDecl(const TagDecl *Tag);
5965 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS);
5966 };
5967} // end anonymous namespace
5968
5969bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) {
5970 return false;
5971}
5972
5973bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) {
5974 return Visit(T->getElementType());
5975}
5976
5977bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) {
5978 return Visit(T->getPointeeType());
5979}
5980
5981bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
5982 const BlockPointerType* T) {
5983 return Visit(T->getPointeeType());
5984}
5985
5986bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
5987 const LValueReferenceType* T) {
5988 return Visit(T->getPointeeType());
5989}
5990
5991bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
5992 const RValueReferenceType* T) {
5993 return Visit(T->getPointeeType());
5994}
5995
5996bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
5997 const MemberPointerType* T) {
5998 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0));
5999}
6000
6001bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
6002 const ConstantArrayType* T) {
6003 return Visit(T->getElementType());
6004}
6005
6006bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
6007 const IncompleteArrayType* T) {
6008 return Visit(T->getElementType());
6009}
6010
6011bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
6012 const VariableArrayType* T) {
6013 return Visit(T->getElementType());
6014}
6015
6016bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
6017 const DependentSizedArrayType* T) {
6018 return Visit(T->getElementType());
6019}
6020
6021bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
6022 const DependentSizedExtVectorType* T) {
6023 return Visit(T->getElementType());
6024}
6025
6026bool UnnamedLocalNoLinkageFinder::VisitDependentSizedMatrixType(
6027 const DependentSizedMatrixType *T) {
6028 return Visit(T->getElementType());
6029}
6030
6031bool UnnamedLocalNoLinkageFinder::VisitDependentAddressSpaceType(
6032 const DependentAddressSpaceType *T) {
6033 return Visit(T->getPointeeType());
6034}
6035
6036bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) {
6037 return Visit(T->getElementType());
6038}
6039
6040bool UnnamedLocalNoLinkageFinder::VisitDependentVectorType(
6041 const DependentVectorType *T) {
6042 return Visit(T->getElementType());
6043}
6044
6045bool UnnamedLocalNoLinkageFinder::VisitExtVectorType(const ExtVectorType* T) {
6046 return Visit(T->getElementType());
6047}
6048
6049bool UnnamedLocalNoLinkageFinder::VisitConstantMatrixType(
6050 const ConstantMatrixType *T) {
6051 return Visit(T->getElementType());
6052}
6053
6054bool UnnamedLocalNoLinkageFinder::VisitFunctionProtoType(
6055 const FunctionProtoType* T) {
6056 for (const auto &A : T->param_types()) {
6057 if (Visit(A))
6058 return true;
6059 }
6060
6061 return Visit(T->getReturnType());
6062}
6063
6064bool UnnamedLocalNoLinkageFinder::VisitFunctionNoProtoType(
6065 const FunctionNoProtoType* T) {
6066 return Visit(T->getReturnType());
6067}
6068
6069bool UnnamedLocalNoLinkageFinder::VisitUnresolvedUsingType(
6070 const UnresolvedUsingType*) {
6071 return false;
6072}
6073
6074bool UnnamedLocalNoLinkageFinder::VisitTypeOfExprType(const TypeOfExprType*) {
6075 return false;
6076}
6077
6078bool UnnamedLocalNoLinkageFinder::VisitTypeOfType(const TypeOfType* T) {
6079 return Visit(T->getUnderlyingType());
6080}
6081
6082bool UnnamedLocalNoLinkageFinder::VisitDecltypeType(const DecltypeType*) {
6083 return false;
6084}
6085
6086bool UnnamedLocalNoLinkageFinder::VisitUnaryTransformType(
6087 const UnaryTransformType*) {
6088 return false;
6089}
6090
6091bool UnnamedLocalNoLinkageFinder::VisitAutoType(const AutoType *T) {
6092 return Visit(T->getDeducedType());
6093}
6094
6095bool UnnamedLocalNoLinkageFinder::VisitDeducedTemplateSpecializationType(
6096 const DeducedTemplateSpecializationType *T) {
6097 return Visit(T->getDeducedType());
6098}
6099
6100bool UnnamedLocalNoLinkageFinder::VisitRecordType(const RecordType* T) {
6101 return VisitTagDecl(T->getDecl());
6102}
6103
6104bool UnnamedLocalNoLinkageFinder::VisitEnumType(const EnumType* T) {
6105 return VisitTagDecl(T->getDecl());
6106}
6107
6108bool UnnamedLocalNoLinkageFinder::VisitTemplateTypeParmType(
6109 const TemplateTypeParmType*) {
6110 return false;
6111}
6112
6113bool UnnamedLocalNoLinkageFinder::VisitSubstTemplateTypeParmPackType(
6114 const SubstTemplateTypeParmPackType *) {
6115 return false;
6116}
6117
6118bool UnnamedLocalNoLinkageFinder::VisitTemplateSpecializationType(
6119 const TemplateSpecializationType*) {
6120 return false;
6121}
6122
6123bool UnnamedLocalNoLinkageFinder::VisitInjectedClassNameType(
6124 const InjectedClassNameType* T) {
6125 return VisitTagDecl(T->getDecl());
6126}
6127
6128bool UnnamedLocalNoLinkageFinder::VisitDependentNameType(
6129 const DependentNameType* T) {
6130 return VisitNestedNameSpecifier(T->getQualifier());
6131}
6132
6133bool UnnamedLocalNoLinkageFinder::VisitDependentTemplateSpecializationType(
6134 const DependentTemplateSpecializationType* T) {
6135 if (auto *Q = T->getQualifier())
6136 return VisitNestedNameSpecifier(Q);
6137 return false;
6138}
6139
6140bool UnnamedLocalNoLinkageFinder::VisitPackExpansionType(
6141 const PackExpansionType* T) {
6142 return Visit(T->getPattern());
6143}
6144
6145bool UnnamedLocalNoLinkageFinder::VisitObjCObjectType(const ObjCObjectType *) {
6146 return false;
6147}
6148
6149bool UnnamedLocalNoLinkageFinder::VisitObjCInterfaceType(
6150 const ObjCInterfaceType *) {
6151 return false;
6152}
6153
6154bool UnnamedLocalNoLinkageFinder::VisitObjCObjectPointerType(
6155 const ObjCObjectPointerType *) {
6156 return false;
6157}
6158
6159bool UnnamedLocalNoLinkageFinder::VisitAtomicType(const AtomicType* T) {
6160 return Visit(T->getValueType());
6161}
6162
6163bool UnnamedLocalNoLinkageFinder::VisitPipeType(const PipeType* T) {
6164 return false;
6165}
6166
6167bool UnnamedLocalNoLinkageFinder::VisitBitIntType(const BitIntType *T) {
6168 return false;
6169}
6170
6171bool UnnamedLocalNoLinkageFinder::VisitDependentBitIntType(
6172 const DependentBitIntType *T) {
6173 return false;
6174}
6175
6176bool UnnamedLocalNoLinkageFinder::VisitTagDecl(const TagDecl *Tag) {
6177 if (Tag->getDeclContext()->isFunctionOrMethod()) {
6178 S.Diag(SR.getBegin(),
6179 S.getLangOpts().CPlusPlus11 ?
6180 diag::warn_cxx98_compat_template_arg_local_type :
6181 diag::ext_template_arg_local_type)
6182 << S.Context.getTypeDeclType(Tag) << SR;
6183 return true;
6184 }
6185
6186 if (!Tag->hasNameForLinkage()) {
6187 S.Diag(SR.getBegin(),
6188 S.getLangOpts().CPlusPlus11 ?
6189 diag::warn_cxx98_compat_template_arg_unnamed_type :
6190 diag::ext_template_arg_unnamed_type) << SR;
6191 S.Diag(Tag->getLocation(), diag::note_template_unnamed_type_here);
6192 return true;
6193 }
6194
6195 return false;
6196}
6197
6198bool UnnamedLocalNoLinkageFinder::VisitNestedNameSpecifier(
6199 NestedNameSpecifier *NNS) {
6200 assert(NNS)(static_cast <bool> (NNS) ? void (0) : __assert_fail ("NNS"
, "clang/lib/Sema/SemaTemplate.cpp", 6200, __extension__ __PRETTY_FUNCTION__
))
;
6201 if (NNS->getPrefix() && VisitNestedNameSpecifier(NNS->getPrefix()))
6202 return true;
6203
6204 switch (NNS->getKind()) {
6205 case NestedNameSpecifier::Identifier:
6206 case NestedNameSpecifier::Namespace:
6207 case NestedNameSpecifier::NamespaceAlias:
6208 case NestedNameSpecifier::Global:
6209 case NestedNameSpecifier::Super:
6210 return false;
6211
6212 case NestedNameSpecifier::TypeSpec:
6213 case NestedNameSpecifier::TypeSpecWithTemplate:
6214 return Visit(QualType(NNS->getAsType(), 0));
6215 }
6216 llvm_unreachable("Invalid NestedNameSpecifier::Kind!")::llvm::llvm_unreachable_internal("Invalid NestedNameSpecifier::Kind!"
, "clang/lib/Sema/SemaTemplate.cpp", 6216)
;
6217}
6218
6219/// Check a template argument against its corresponding
6220/// template type parameter.
6221///
6222/// This routine implements the semantics of C++ [temp.arg.type]. It
6223/// returns true if an error occurred, and false otherwise.
6224bool Sema::CheckTemplateArgument(TypeSourceInfo *ArgInfo) {
6225 assert(ArgInfo && "invalid TypeSourceInfo")(static_cast <bool> (ArgInfo && "invalid TypeSourceInfo"
) ? void (0) : __assert_fail ("ArgInfo && \"invalid TypeSourceInfo\""
, "clang/lib/Sema/SemaTemplate.cpp", 6225, __extension__ __PRETTY_FUNCTION__
))
;
6226 QualType Arg = ArgInfo->getType();
6227 SourceRange SR = ArgInfo->getTypeLoc().getSourceRange();
6228
6229 if (Arg->isVariablyModifiedType()) {
6230 return Diag(SR.getBegin(), diag::err_variably_modified_template_arg) << Arg;
6231 } else if (Context.hasSameUnqualifiedType(Arg, Context.OverloadTy)) {
6232 return Diag(SR.getBegin(), diag::err_template_arg_overload_type) << SR;
6233 }
6234
6235 // C++03 [temp.arg.type]p2:
6236 // A local type, a type with no linkage, an unnamed type or a type
6237 // compounded from any of these types shall not be used as a
6238 // template-argument for a template type-parameter.
6239 //
6240 // C++11 allows these, and even in C++03 we allow them as an extension with
6241 // a warning.
6242 if (LangOpts.CPlusPlus11 || Arg->hasUnnamedOrLocalType()) {
6243 UnnamedLocalNoLinkageFinder Finder(*this, SR);
6244 (void)Finder.Visit(Context.getCanonicalType(Arg));
6245 }
6246
6247 return false;
6248}
6249
6250enum NullPointerValueKind {
6251 NPV_NotNullPointer,
6252 NPV_NullPointer,
6253 NPV_Error
6254};
6255
6256/// Determine whether the given template argument is a null pointer
6257/// value of the appropriate type.
6258static NullPointerValueKind
6259isNullPointerValueTemplateArgument(Sema &S, NonTypeTemplateParmDecl *Param,
6260 QualType ParamType, Expr *Arg,
6261 Decl *Entity = nullptr) {
6262 if (Arg->isValueDependent() || Arg->isTypeDependent())
6263 return NPV_NotNullPointer;
6264
6265 // dllimport'd entities aren't constant but are available inside of template
6266 // arguments.
6267 if (Entity && Entity->hasAttr<DLLImportAttr>())
6268 return NPV_NotNullPointer;
6269
6270 if (!S.isCompleteType(Arg->getExprLoc(), ParamType))
6271 llvm_unreachable(::llvm::llvm_unreachable_internal("Incomplete parameter type in isNullPointerValueTemplateArgument!"
, "clang/lib/Sema/SemaTemplate.cpp", 6272)
6272 "Incomplete parameter type in isNullPointerValueTemplateArgument!")::llvm::llvm_unreachable_internal("Incomplete parameter type in isNullPointerValueTemplateArgument!"
, "clang/lib/Sema/SemaTemplate.cpp", 6272)
;
6273
6274 if (!S.getLangOpts().CPlusPlus11)
6275 return NPV_NotNullPointer;
6276
6277 // Determine whether we have a constant expression.
6278 ExprResult ArgRV = S.DefaultFunctionArrayConversion(Arg);
6279 if (ArgRV.isInvalid())
6280 return NPV_Error;
6281 Arg = ArgRV.get();
6282
6283 Expr::EvalResult EvalResult;
6284 SmallVector<PartialDiagnosticAt, 8> Notes;
6285 EvalResult.Diag = &Notes;
6286 if (!Arg->EvaluateAsRValue(EvalResult, S.Context) ||
6287 EvalResult.HasSideEffects) {
6288 SourceLocation DiagLoc = Arg->getExprLoc();
6289
6290 // If our only note is the usual "invalid subexpression" note, just point
6291 // the caret at its location rather than producing an essentially
6292 // redundant note.
6293 if (Notes.size() == 1 && Notes[0].second.getDiagID() ==
6294 diag::note_invalid_subexpr_in_const_expr) {
6295 DiagLoc = Notes[0].first;
6296 Notes.clear();
6297 }
6298
6299 S.Diag(DiagLoc, diag::err_template_arg_not_address_constant)
6300 << Arg->getType() << Arg->getSourceRange();
6301 for (unsigned I = 0, N = Notes.size(); I != N; ++I)
6302 S.Diag(Notes[I].first, Notes[I].second);
6303
6304 S.Diag(Param->getLocation(), diag::note_template_param_here);
6305 return NPV_Error;
6306 }
6307
6308 // C++11 [temp.arg.nontype]p1:
6309 // - an address constant expression of type std::nullptr_t
6310 if (Arg->getType()->isNullPtrType())
6311 return NPV_NullPointer;
6312
6313 // - a constant expression that evaluates to a null pointer value (4.10); or
6314 // - a constant expression that evaluates to a null member pointer value
6315 // (4.11); or
6316 if ((EvalResult.Val.isLValue() && !EvalResult.Val.getLValueBase()) ||
6317 (EvalResult.Val.isMemberPointer() &&
6318 !EvalResult.Val.getMemberPointerDecl())) {
6319 // If our expression has an appropriate type, we've succeeded.
6320 bool ObjCLifetimeConversion;
6321 if (S.Context.hasSameUnqualifiedType(Arg->getType(), ParamType) ||
6322 S.IsQualificationConversion(Arg->getType(), ParamType, false,
6323 ObjCLifetimeConversion))
6324 return NPV_NullPointer;
6325
6326 // The types didn't match, but we know we got a null pointer; complain,
6327 // then recover as if the types were correct.
6328 S.Diag(Arg->getExprLoc(), diag::err_template_arg_wrongtype_null_constant)
6329 << Arg->getType() << ParamType << Arg->getSourceRange();
6330 S.Diag(Param->getLocation(), diag::note_template_param_here);
6331 return NPV_NullPointer;
6332 }
6333
6334 // If we don't have a null pointer value, but we do have a NULL pointer
6335 // constant, suggest a cast to the appropriate type.
6336 if (Arg->isNullPointerConstant(S.Context, Expr::NPC_NeverValueDependent)) {
6337 std::string Code = "static_cast<" + ParamType.getAsString() + ">(";
6338 S.Diag(Arg->getExprLoc(), diag::err_template_arg_untyped_null_constant)
6339 << ParamType << FixItHint::CreateInsertion(Arg->getBeginLoc(), Code)
6340 << FixItHint::CreateInsertion(S.getLocForEndOfToken(Arg->getEndLoc()),
6341 ")");
6342 S.Diag(Param->getLocation(), diag::note_template_param_here);
6343 return NPV_NullPointer;
6344 }
6345
6346 // FIXME: If we ever want to support general, address-constant expressions
6347 // as non-type template arguments, we should return the ExprResult here to
6348 // be interpreted by the caller.
6349 return NPV_NotNullPointer;
6350}
6351
6352/// Checks whether the given template argument is compatible with its
6353/// template parameter.
6354static bool CheckTemplateArgumentIsCompatibleWithParameter(
6355 Sema &S, NonTypeTemplateParmDecl *Param, QualType ParamType, Expr *ArgIn,
6356 Expr *Arg, QualType ArgType) {
6357 bool ObjCLifetimeConversion;
6358 if (ParamType->isPointerType() &&
6359 !ParamType->castAs<PointerType>()->getPointeeType()->isFunctionType() &&
6360 S.IsQualificationConversion(ArgType, ParamType, false,
6361 ObjCLifetimeConversion)) {
6362 // For pointer-to-object types, qualification conversions are
6363 // permitted.
6364 } else {
6365 if (const ReferenceType *ParamRef = ParamType->getAs<ReferenceType>()) {
6366 if (!ParamRef->getPointeeType()->isFunctionType()) {
6367 // C++ [temp.arg.nontype]p5b3:
6368 // For a non-type template-parameter of type reference to
6369 // object, no conversions apply. The type referred to by the
6370 // reference may be more cv-qualified than the (otherwise
6371 // identical) type of the template- argument. The
6372 // template-parameter is bound directly to the
6373 // template-argument, which shall be an lvalue.
6374
6375 // FIXME: Other qualifiers?
6376 unsigned ParamQuals = ParamRef->getPointeeType().getCVRQualifiers();
6377 unsigned ArgQuals = ArgType.getCVRQualifiers();
6378
6379 if ((ParamQuals | ArgQuals) != ParamQuals) {
6380 S.Diag(Arg->getBeginLoc(),
6381 diag::err_template_arg_ref_bind_ignores_quals)
6382 << ParamType << Arg->getType() << Arg->getSourceRange();
6383 S.Diag(Param->getLocation(), diag::note_template_param_here);
6384 return true;
6385 }
6386 }
6387 }
6388
6389 // At this point, the template argument refers to an object or
6390 // function with external linkage. We now need to check whether the
6391 // argument and parameter types are compatible.
6392 if (!S.Context.hasSameUnqualifiedType(ArgType,
6393 ParamType.getNonReferenceType())) {
6394 // We can't perform this conversion or binding.
6395 if (ParamType->isReferenceType())
6396 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_no_ref_bind)
6397 << ParamType << ArgIn->getType() << Arg->getSourceRange();
6398 else
6399 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_not_convertible)
6400 << ArgIn->getType() << ParamType << Arg->getSourceRange();
6401 S.Diag(Param->getLocation(), diag::note_template_param_here);
6402 return true;
6403 }
6404 }
6405
6406 return false;
6407}
6408
6409/// Checks whether the given template argument is the address
6410/// of an object or function according to C++ [temp.arg.nontype]p1.
6411static bool
6412CheckTemplateArgumentAddressOfObjectOrFunction(Sema &S,
6413 NonTypeTemplateParmDecl *Param,
6414 QualType ParamType,
6415 Expr *ArgIn,
6416 TemplateArgument &Converted) {
6417 bool Invalid = false;
6418 Expr *Arg = ArgIn;
6419 QualType ArgType = Arg->getType();
6420
6421 bool AddressTaken = false;
6422 SourceLocation AddrOpLoc;
6423 if (S.getLangOpts().MicrosoftExt) {
6424 // Microsoft Visual C++ strips all casts, allows an arbitrary number of
6425 // dereference and address-of operators.
6426 Arg = Arg->IgnoreParenCasts();
6427
6428 bool ExtWarnMSTemplateArg = false;
6429 UnaryOperatorKind FirstOpKind;
6430 SourceLocation FirstOpLoc;
6431 while (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
6432 UnaryOperatorKind UnOpKind = UnOp->getOpcode();
6433 if (UnOpKind == UO_Deref)
6434 ExtWarnMSTemplateArg = true;
6435 if (UnOpKind == UO_AddrOf || UnOpKind == UO_Deref) {
6436 Arg = UnOp->getSubExpr()->IgnoreParenCasts();
6437 if (!AddrOpLoc.isValid()) {
6438 FirstOpKind = UnOpKind;
6439 FirstOpLoc = UnOp->getOperatorLoc();
6440 }
6441 } else
6442 break;
6443 }
6444 if (FirstOpLoc.isValid()) {
6445 if (ExtWarnMSTemplateArg)
6446 S.Diag(ArgIn->getBeginLoc(), diag::ext_ms_deref_template_argument)
6447 << ArgIn->getSourceRange();
6448
6449 if (FirstOpKind == UO_AddrOf)
6450 AddressTaken = true;
6451 else if (Arg->getType()->isPointerType()) {
6452 // We cannot let pointers get dereferenced here, that is obviously not a
6453 // constant expression.
6454 assert(FirstOpKind == UO_Deref)(static_cast <bool> (FirstOpKind == UO_Deref) ? void (0
) : __assert_fail ("FirstOpKind == UO_Deref", "clang/lib/Sema/SemaTemplate.cpp"
, 6454, __extension__ __PRETTY_FUNCTION__))
;
6455 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_not_decl_ref)
6456 << Arg->getSourceRange();
6457 }
6458 }
6459 } else {
6460 // See through any implicit casts we added to fix the type.
6461 Arg = Arg->IgnoreImpCasts();
6462
6463 // C++ [temp.arg.nontype]p1:
6464 //
6465 // A template-argument for a non-type, non-template
6466 // template-parameter shall be one of: [...]
6467 //
6468 // -- the address of an object or function with external
6469 // linkage, including function templates and function
6470 // template-ids but excluding non-static class members,
6471 // expressed as & id-expression where the & is optional if
6472 // the name refers to a function or array, or if the
6473 // corresponding template-parameter is a reference; or
6474
6475 // In C++98/03 mode, give an extension warning on any extra parentheses.
6476 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
6477 bool ExtraParens = false;
6478 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
6479 if (!Invalid && !ExtraParens) {
6480 S.Diag(Arg->getBeginLoc(),
6481 S.getLangOpts().CPlusPlus11
6482 ? diag::warn_cxx98_compat_template_arg_extra_parens
6483 : diag::ext_template_arg_extra_parens)
6484 << Arg->getSourceRange();
6485 ExtraParens = true;
6486 }
6487
6488 Arg = Parens->getSubExpr();
6489 }
6490
6491 while (SubstNonTypeTemplateParmExpr *subst =
6492 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
6493 Arg = subst->getReplacement()->IgnoreImpCasts();
6494
6495 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
6496 if (UnOp->getOpcode() == UO_AddrOf) {
6497 Arg = UnOp->getSubExpr();
6498 AddressTaken = true;
6499 AddrOpLoc = UnOp->getOperatorLoc();
6500 }
6501 }
6502
6503 while (SubstNonTypeTemplateParmExpr *subst =
6504 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
6505 Arg = subst->getReplacement()->IgnoreImpCasts();
6506 }
6507
6508 ValueDecl *Entity = nullptr;
6509 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg))
6510 Entity = DRE->getDecl();
6511 else if (CXXUuidofExpr *CUE = dyn_cast<CXXUuidofExpr>(Arg))
6512 Entity = CUE->getGuidDecl();
6513
6514 // If our parameter has pointer type, check for a null template value.
6515 if (ParamType->isPointerType() || ParamType->isNullPtrType()) {
6516 switch (isNullPointerValueTemplateArgument(S, Param, ParamType, ArgIn,
6517 Entity)) {
6518 case NPV_NullPointer:
6519 S.Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
6520 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
6521 /*isNullPtr=*/true);
6522 return false;
6523
6524 case NPV_Error:
6525 return true;
6526
6527 case NPV_NotNullPointer:
6528 break;
6529 }
6530 }
6531
6532 // Stop checking the precise nature of the argument if it is value dependent,
6533 // it should be checked when instantiated.
6534 if (Arg->isValueDependent()) {
6535 Converted = TemplateArgument(ArgIn);
6536 return false;
6537 }
6538
6539 if (!Entity) {
6540 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_not_decl_ref)
6541 << Arg->getSourceRange();
6542 S.Diag(Param->getLocation(), diag::note_template_param_here);
6543 return true;
6544 }
6545
6546 // Cannot refer to non-static data members
6547 if (isa<FieldDecl>(Entity) || isa<IndirectFieldDecl>(Entity)) {
6548 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_field)
6549 << Entity << Arg->getSourceRange();
6550 S.Diag(Param->getLocation(), diag::note_template_param_here);
6551 return true;
6552 }
6553
6554 // Cannot refer to non-static member functions
6555 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Entity)) {
6556 if (!Method->isStatic()) {
6557 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_method)
6558 << Method << Arg->getSourceRange();
6559 S.Diag(Param->getLocation(), diag::note_template_param_here);
6560 return true;
6561 }
6562 }
6563
6564 FunctionDecl *Func = dyn_cast<FunctionDecl>(Entity);
6565 VarDecl *Var = dyn_cast<VarDecl>(Entity);
6566 MSGuidDecl *Guid = dyn_cast<MSGuidDecl>(Entity);
6567
6568 // A non-type template argument must refer to an object or function.
6569 if (!Func && !Var && !Guid) {
6570 // We found something, but we don't know specifically what it is.
6571 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_not_object_or_func)
6572 << Arg->getSourceRange();
6573 S.Diag(Entity->getLocation(), diag::note_template_arg_refers_here);
6574 return true;
6575 }
6576
6577 // Address / reference template args must have external linkage in C++98.
6578 if (Entity->getFormalLinkage() == InternalLinkage) {
6579 S.Diag(Arg->getBeginLoc(),
6580 S.getLangOpts().CPlusPlus11
6581 ? diag::warn_cxx98_compat_template_arg_object_internal
6582 : diag::ext_template_arg_object_internal)
6583 << !Func << Entity << Arg->getSourceRange();
6584 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
6585 << !Func;
6586 } else if (!Entity->hasLinkage()) {
6587 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_object_no_linkage)
6588 << !Func << Entity << Arg->getSourceRange();
6589 S.Diag(Entity->getLocation(), diag::note_template_arg_internal_object)
6590 << !Func;
6591 return true;
6592 }
6593
6594 if (Var) {
6595 // A value of reference type is not an object.
6596 if (Var->getType()->isReferenceType()) {
6597 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_reference_var)
6598 << Var->getType() << Arg->getSourceRange();
6599 S.Diag(Param->getLocation(), diag::note_template_param_here);
6600 return true;
6601 }
6602
6603 // A template argument must have static storage duration.
6604 if (Var->getTLSKind()) {
6605 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_thread_local)
6606 << Arg->getSourceRange();
6607 S.Diag(Var->getLocation(), diag::note_template_arg_refers_here);
6608 return true;
6609 }
6610 }
6611
6612 if (AddressTaken && ParamType->isReferenceType()) {
6613 // If we originally had an address-of operator, but the
6614 // parameter has reference type, complain and (if things look
6615 // like they will work) drop the address-of operator.
6616 if (!S.Context.hasSameUnqualifiedType(Entity->getType(),
6617 ParamType.getNonReferenceType())) {
6618 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
6619 << ParamType;
6620 S.Diag(Param->getLocation(), diag::note_template_param_here);
6621 return true;
6622 }
6623
6624 S.Diag(AddrOpLoc, diag::err_template_arg_address_of_non_pointer)
6625 << ParamType
6626 << FixItHint::CreateRemoval(AddrOpLoc);
6627 S.Diag(Param->getLocation(), diag::note_template_param_here);
6628
6629 ArgType = Entity->getType();
6630 }
6631
6632 // If the template parameter has pointer type, either we must have taken the
6633 // address or the argument must decay to a pointer.
6634 if (!AddressTaken && ParamType->isPointerType()) {
6635 if (Func) {
6636 // Function-to-pointer decay.
6637 ArgType = S.Context.getPointerType(Func->getType());
6638 } else if (Entity->getType()->isArrayType()) {
6639 // Array-to-pointer decay.
6640 ArgType = S.Context.getArrayDecayedType(Entity->getType());
6641 } else {
6642 // If the template parameter has pointer type but the address of
6643 // this object was not taken, complain and (possibly) recover by
6644 // taking the address of the entity.
6645 ArgType = S.Context.getPointerType(Entity->getType());
6646 if (!S.Context.hasSameUnqualifiedType(ArgType, ParamType)) {
6647 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_not_address_of)
6648 << ParamType;
6649 S.Diag(Param->getLocation(), diag::note_template_param_here);
6650 return true;
6651 }
6652
6653 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_not_address_of)
6654 << ParamType << FixItHint::CreateInsertion(Arg->getBeginLoc(), "&");
6655
6656 S.Diag(Param->getLocation(), diag::note_template_param_here);
6657 }
6658 }
6659
6660 if (CheckTemplateArgumentIsCompatibleWithParameter(S, Param, ParamType, ArgIn,
6661 Arg, ArgType))
6662 return true;
6663
6664 // Create the template argument.
6665 Converted = TemplateArgument(cast<ValueDecl>(Entity->getCanonicalDecl()),
6666 S.Context.getCanonicalType(ParamType));
6667 S.MarkAnyDeclReferenced(Arg->getBeginLoc(), Entity, false);
6668 return false;
6669}
6670
6671/// Checks whether the given template argument is a pointer to
6672/// member constant according to C++ [temp.arg.nontype]p1.
6673static bool CheckTemplateArgumentPointerToMember(Sema &S,
6674 NonTypeTemplateParmDecl *Param,
6675 QualType ParamType,
6676 Expr *&ResultArg,
6677 TemplateArgument &Converted) {
6678 bool Invalid = false;
6679
6680 Expr *Arg = ResultArg;
6681 bool ObjCLifetimeConversion;
6682
6683 // C++ [temp.arg.nontype]p1:
6684 //
6685 // A template-argument for a non-type, non-template
6686 // template-parameter shall be one of: [...]
6687 //
6688 // -- a pointer to member expressed as described in 5.3.1.
6689 DeclRefExpr *DRE = nullptr;
6690
6691 // In C++98/03 mode, give an extension warning on any extra parentheses.
6692 // See http://www.open-std.org/jtc1/sc22/wg21/docs/cwg_defects.html#773
6693 bool ExtraParens = false;
6694 while (ParenExpr *Parens = dyn_cast<ParenExpr>(Arg)) {
6695 if (!Invalid && !ExtraParens) {
6696 S.Diag(Arg->getBeginLoc(),
6697 S.getLangOpts().CPlusPlus11
6698 ? diag::warn_cxx98_compat_template_arg_extra_parens
6699 : diag::ext_template_arg_extra_parens)
6700 << Arg->getSourceRange();
6701 ExtraParens = true;
6702 }
6703
6704 Arg = Parens->getSubExpr();
6705 }
6706
6707 while (SubstNonTypeTemplateParmExpr *subst =
6708 dyn_cast<SubstNonTypeTemplateParmExpr>(Arg))
6709 Arg = subst->getReplacement()->IgnoreImpCasts();
6710
6711 // A pointer-to-member constant written &Class::member.
6712 if (UnaryOperator *UnOp = dyn_cast<UnaryOperator>(Arg)) {
6713 if (UnOp->getOpcode() == UO_AddrOf) {
6714 DRE = dyn_cast<DeclRefExpr>(UnOp->getSubExpr());
6715 if (DRE && !DRE->getQualifier())
6716 DRE = nullptr;
6717 }
6718 }
6719 // A constant of pointer-to-member type.
6720 else if ((DRE = dyn_cast<DeclRefExpr>(Arg))) {
6721 ValueDecl *VD = DRE->getDecl();
6722 if (VD->getType()->isMemberPointerType()) {
6723 if (isa<NonTypeTemplateParmDecl>(VD)) {
6724 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
6725 Converted = TemplateArgument(Arg);
6726 } else {
6727 VD = cast<ValueDecl>(VD->getCanonicalDecl());
6728 Converted = TemplateArgument(VD, ParamType);
6729 }
6730 return Invalid;
6731 }
6732 }
6733
6734 DRE = nullptr;
6735 }
6736
6737 ValueDecl *Entity = DRE ? DRE->getDecl() : nullptr;
6738
6739 // Check for a null pointer value.
6740 switch (isNullPointerValueTemplateArgument(S, Param, ParamType, ResultArg,
6741 Entity)) {
6742 case NPV_Error:
6743 return true;
6744 case NPV_NullPointer:
6745 S.Diag(ResultArg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
6746 Converted = TemplateArgument(S.Context.getCanonicalType(ParamType),
6747 /*isNullPtr*/true);
6748 return false;
6749 case NPV_NotNullPointer:
6750 break;
6751 }
6752
6753 if (S.IsQualificationConversion(ResultArg->getType(),
6754 ParamType.getNonReferenceType(), false,
6755 ObjCLifetimeConversion)) {
6756 ResultArg = S.ImpCastExprToType(ResultArg, ParamType, CK_NoOp,
6757 ResultArg->getValueKind())
6758 .get();
6759 } else if (!S.Context.hasSameUnqualifiedType(
6760 ResultArg->getType(), ParamType.getNonReferenceType())) {
6761 // We can't perform this conversion.
6762 S.Diag(ResultArg->getBeginLoc(), diag::err_template_arg_not_convertible)
6763 << ResultArg->getType() << ParamType << ResultArg->getSourceRange();
6764 S.Diag(Param->getLocation(), diag::note_template_param_here);
6765 return true;
6766 }
6767
6768 if (!DRE)
6769 return S.Diag(Arg->getBeginLoc(),
6770 diag::err_template_arg_not_pointer_to_member_form)
6771 << Arg->getSourceRange();
6772
6773 if (isa<FieldDecl>(DRE->getDecl()) ||
6774 isa<IndirectFieldDecl>(DRE->getDecl()) ||
6775 isa<CXXMethodDecl>(DRE->getDecl())) {
6776 assert((isa<FieldDecl>(DRE->getDecl()) ||(static_cast <bool> ((isa<FieldDecl>(DRE->getDecl
()) || isa<IndirectFieldDecl>(DRE->getDecl()) || !cast
<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
"Only non-static member pointers can make it here") ? void (
0) : __assert_fail ("(isa<FieldDecl>(DRE->getDecl()) || isa<IndirectFieldDecl>(DRE->getDecl()) || !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) && \"Only non-static member pointers can make it here\""
, "clang/lib/Sema/SemaTemplate.cpp", 6779, __extension__ __PRETTY_FUNCTION__
))
6777 isa<IndirectFieldDecl>(DRE->getDecl()) ||(static_cast <bool> ((isa<FieldDecl>(DRE->getDecl
()) || isa<IndirectFieldDecl>(DRE->getDecl()) || !cast
<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
"Only non-static member pointers can make it here") ? void (
0) : __assert_fail ("(isa<FieldDecl>(DRE->getDecl()) || isa<IndirectFieldDecl>(DRE->getDecl()) || !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) && \"Only non-static member pointers can make it here\""
, "clang/lib/Sema/SemaTemplate.cpp", 6779, __extension__ __PRETTY_FUNCTION__
))
6778 !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&(static_cast <bool> ((isa<FieldDecl>(DRE->getDecl
()) || isa<IndirectFieldDecl>(DRE->getDecl()) || !cast
<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
"Only non-static member pointers can make it here") ? void (
0) : __assert_fail ("(isa<FieldDecl>(DRE->getDecl()) || isa<IndirectFieldDecl>(DRE->getDecl()) || !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) && \"Only non-static member pointers can make it here\""
, "clang/lib/Sema/SemaTemplate.cpp", 6779, __extension__ __PRETTY_FUNCTION__
))
6779 "Only non-static member pointers can make it here")(static_cast <bool> ((isa<FieldDecl>(DRE->getDecl
()) || isa<IndirectFieldDecl>(DRE->getDecl()) || !cast
<CXXMethodDecl>(DRE->getDecl())->isStatic()) &&
"Only non-static member pointers can make it here") ? void (
0) : __assert_fail ("(isa<FieldDecl>(DRE->getDecl()) || isa<IndirectFieldDecl>(DRE->getDecl()) || !cast<CXXMethodDecl>(DRE->getDecl())->isStatic()) && \"Only non-static member pointers can make it here\""
, "clang/lib/Sema/SemaTemplate.cpp", 6779, __extension__ __PRETTY_FUNCTION__
))
;
6780
6781 // Okay: this is the address of a non-static member, and therefore
6782 // a member pointer constant.
6783 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
6784 Converted = TemplateArgument(Arg);
6785 } else {
6786 ValueDecl *D = cast<ValueDecl>(DRE->getDecl()->getCanonicalDecl());
6787 Converted = TemplateArgument(D, S.Context.getCanonicalType(ParamType));
6788 }
6789 return Invalid;
6790 }
6791
6792 // We found something else, but we don't know specifically what it is.
6793 S.Diag(Arg->getBeginLoc(), diag::err_template_arg_not_pointer_to_member_form)
6794 << Arg->getSourceRange();
6795 S.Diag(DRE->getDecl()->getLocation(), diag::note_template_arg_refers_here);
6796 return true;
6797}
6798
6799/// Check a template argument against its corresponding
6800/// non-type template parameter.
6801///
6802/// This routine implements the semantics of C++ [temp.arg.nontype].
6803/// If an error occurred, it returns ExprError(); otherwise, it
6804/// returns the converted template argument. \p ParamType is the
6805/// type of the non-type template parameter after it has been instantiated.
6806ExprResult Sema::CheckTemplateArgument(NonTypeTemplateParmDecl *Param,
6807 QualType ParamType, Expr *Arg,
6808 TemplateArgument &Converted,
6809 CheckTemplateArgumentKind CTAK) {
6810 SourceLocation StartLoc = Arg->getBeginLoc();
6811
6812 // If the parameter type somehow involves auto, deduce the type now.
6813 DeducedType *DeducedT = ParamType->getContainedDeducedType();
6814 if (getLangOpts().CPlusPlus17 && DeducedT && !DeducedT->isDeduced()) {
6815 // During template argument deduction, we allow 'decltype(auto)' to
6816 // match an arbitrary dependent argument.
6817 // FIXME: The language rules don't say what happens in this case.
6818 // FIXME: We get an opaque dependent type out of decltype(auto) if the
6819 // expression is merely instantiation-dependent; is this enough?
6820 if (CTAK == CTAK_Deduced && Arg->isTypeDependent()) {
6821 auto *AT = dyn_cast<AutoType>(DeducedT);
6822 if (AT && AT->isDecltypeAuto()) {
6823 Converted = TemplateArgument(Arg);
6824 return Arg;
6825 }
6826 }
6827
6828 // When checking a deduced template argument, deduce from its type even if
6829 // the type is dependent, in order to check the types of non-type template
6830 // arguments line up properly in partial ordering.
6831 Optional<unsigned> Depth = Param->getDepth() + 1;
6832 Expr *DeductionArg = Arg;
6833 if (auto *PE = dyn_cast<PackExpansionExpr>(DeductionArg))
6834 DeductionArg = PE->getPattern();
6835 TypeSourceInfo *TSI =
6836 Context.getTrivialTypeSourceInfo(ParamType, Param->getLocation());
6837 if (isa<DeducedTemplateSpecializationType>(DeducedT)) {
6838 InitializedEntity Entity =
6839 InitializedEntity::InitializeTemplateParameter(ParamType, Param);
6840 InitializationKind Kind = InitializationKind::CreateForInit(
6841 DeductionArg->getBeginLoc(), /*DirectInit*/false, DeductionArg);
6842 Expr *Inits[1] = {DeductionArg};
6843 ParamType =
6844 DeduceTemplateSpecializationFromInitializer(TSI, Entity, Kind, Inits);
6845 if (ParamType.isNull())
6846 return ExprError();
6847 } else if (DeduceAutoType(
6848 TSI, DeductionArg, ParamType, Depth,
6849 // We do not check constraints right now because the
6850 // immediately-declared constraint of the auto type is also
6851 // an associated constraint, and will be checked along with
6852 // the other associated constraints after checking the
6853 // template argument list.
6854 /*IgnoreConstraints=*/true) == DAR_Failed) {
6855 Diag(Arg->getExprLoc(),
6856 diag::err_non_type_template_parm_type_deduction_failure)
6857 << Param->getDeclName() << Param->getType() << Arg->getType()
6858 << Arg->getSourceRange();
6859 Diag(Param->getLocation(), diag::note_template_param_here);
6860 return ExprError();
6861 }
6862 // CheckNonTypeTemplateParameterType will produce a diagnostic if there's
6863 // an error. The error message normally references the parameter
6864 // declaration, but here we'll pass the argument location because that's
6865 // where the parameter type is deduced.
6866 ParamType = CheckNonTypeTemplateParameterType(ParamType, Arg->getExprLoc());
6867 if (ParamType.isNull()) {
6868 Diag(Param->getLocation(), diag::note_template_param_here);
6869 return ExprError();
6870 }
6871 }
6872
6873 // We should have already dropped all cv-qualifiers by now.
6874 assert(!ParamType.hasQualifiers() &&(static_cast <bool> (!ParamType.hasQualifiers() &&
"non-type template parameter type cannot be qualified") ? void
(0) : __assert_fail ("!ParamType.hasQualifiers() && \"non-type template parameter type cannot be qualified\""
, "clang/lib/Sema/SemaTemplate.cpp", 6875, __extension__ __PRETTY_FUNCTION__
))
6875 "non-type template parameter type cannot be qualified")(static_cast <bool> (!ParamType.hasQualifiers() &&
"non-type template parameter type cannot be qualified") ? void
(0) : __assert_fail ("!ParamType.hasQualifiers() && \"non-type template parameter type cannot be qualified\""
, "clang/lib/Sema/SemaTemplate.cpp", 6875, __extension__ __PRETTY_FUNCTION__
))
;
6876
6877 // FIXME: When Param is a reference, should we check that Arg is an lvalue?
6878 if (CTAK == CTAK_Deduced &&
6879 (ParamType->isReferenceType()
6880 ? !Context.hasSameType(ParamType.getNonReferenceType(),
6881 Arg->getType())
6882 : !Context.hasSameUnqualifiedType(ParamType, Arg->getType()))) {
6883 // FIXME: If either type is dependent, we skip the check. This isn't
6884 // correct, since during deduction we're supposed to have replaced each
6885 // template parameter with some unique (non-dependent) placeholder.
6886 // FIXME: If the argument type contains 'auto', we carry on and fail the
6887 // type check in order to force specific types to be more specialized than
6888 // 'auto'. It's not clear how partial ordering with 'auto' is supposed to
6889 // work. Similarly for CTAD, when comparing 'A<x>' against 'A'.
6890 if ((ParamType->isDependentType() || Arg->isTypeDependent()) &&
6891 !Arg->getType()->getContainedDeducedType()) {
6892 Converted = TemplateArgument(Arg);
6893 return Arg;
6894 }
6895 // FIXME: This attempts to implement C++ [temp.deduct.type]p17. Per DR1770,
6896 // we should actually be checking the type of the template argument in P,
6897 // not the type of the template argument deduced from A, against the
6898 // template parameter type.
6899 Diag(StartLoc, diag::err_deduced_non_type_template_arg_type_mismatch)
6900 << Arg->getType()
6901 << ParamType.getUnqualifiedType();
6902 Diag(Param->getLocation(), diag::note_template_param_here);
6903 return ExprError();
6904 }
6905
6906 // If either the parameter has a dependent type or the argument is
6907 // type-dependent, there's nothing we can check now. The argument only
6908 // contains an unexpanded pack during partial ordering, and there's
6909 // nothing more we can check in that case.
6910 if (ParamType->isDependentType() || Arg->isTypeDependent() ||
6911 Arg->containsUnexpandedParameterPack()) {
6912 // Force the argument to the type of the parameter to maintain invariants.
6913 auto *PE = dyn_cast<PackExpansionExpr>(Arg);
6914 if (PE)
6915 Arg = PE->getPattern();
6916 ExprResult E = ImpCastExprToType(
6917 Arg, ParamType.getNonLValueExprType(Context), CK_Dependent,
6918 ParamType->isLValueReferenceType() ? VK_LValue
6919 : ParamType->isRValueReferenceType() ? VK_XValue
6920 : VK_PRValue);
6921 if (E.isInvalid())
6922 return ExprError();
6923 if (PE) {
6924 // Recreate a pack expansion if we unwrapped one.
6925 E = new (Context)
6926 PackExpansionExpr(E.get()->getType(), E.get(), PE->getEllipsisLoc(),
6927 PE->getNumExpansions());
6928 }
6929 Converted = TemplateArgument(E.get());
6930 return E;
6931 }
6932
6933 // The initialization of the parameter from the argument is
6934 // a constant-evaluated context.
6935 EnterExpressionEvaluationContext ConstantEvaluated(
6936 *this, Sema::ExpressionEvaluationContext::ConstantEvaluated);
6937
6938 if (getLangOpts().CPlusPlus17) {
6939 QualType CanonParamType = Context.getCanonicalType(ParamType);
6940
6941 // Avoid making a copy when initializing a template parameter of class type
6942 // from a template parameter object of the same type. This is going beyond
6943 // the standard, but is required for soundness: in
6944 // template<A a> struct X { X *p; X<a> *q; };
6945 // ... we need p and q to have the same type.
6946 //
6947 // Similarly, don't inject a call to a copy constructor when initializing
6948 // from a template parameter of the same type.
6949 Expr *InnerArg = Arg->IgnoreParenImpCasts();
6950 if (ParamType->isRecordType() && isa<DeclRefExpr>(InnerArg) &&
6951 Context.hasSameUnqualifiedType(ParamType, InnerArg->getType())) {
6952 NamedDecl *ND = cast<DeclRefExpr>(InnerArg)->getDecl();
6953 if (auto *TPO = dyn_cast<TemplateParamObjectDecl>(ND)) {
6954 Converted = TemplateArgument(TPO, CanonParamType);
6955 return Arg;
6956 }
6957 if (isa<NonTypeTemplateParmDecl>(ND)) {
6958 Converted = TemplateArgument(Arg);
6959 return Arg;
6960 }
6961 }
6962
6963 // C++17 [temp.arg.nontype]p1:
6964 // A template-argument for a non-type template parameter shall be
6965 // a converted constant expression of the type of the template-parameter.
6966 APValue Value;
6967 ExprResult ArgResult = CheckConvertedConstantExpression(
6968 Arg, ParamType, Value, CCEK_TemplateArg, Param);
6969 if (ArgResult.isInvalid())
6970 return ExprError();
6971
6972 // For a value-dependent argument, CheckConvertedConstantExpression is
6973 // permitted (and expected) to be unable to determine a value.
6974 if (ArgResult.get()->isValueDependent()) {
6975 Converted = TemplateArgument(ArgResult.get());
6976 return ArgResult;
6977 }
6978
6979 // Convert the APValue to a TemplateArgument.
6980 switch (Value.getKind()) {
6981 case APValue::None:
6982 assert(ParamType->isNullPtrType())(static_cast <bool> (ParamType->isNullPtrType()) ? void
(0) : __assert_fail ("ParamType->isNullPtrType()", "clang/lib/Sema/SemaTemplate.cpp"
, 6982, __extension__ __PRETTY_FUNCTION__))
;
6983 Converted = TemplateArgument(CanonParamType, /*isNullPtr*/true);
6984 break;
6985 case APValue::Indeterminate:
6986 llvm_unreachable("result of constant evaluation should be initialized")::llvm::llvm_unreachable_internal("result of constant evaluation should be initialized"
, "clang/lib/Sema/SemaTemplate.cpp", 6986)
;
6987 break;
6988 case APValue::Int:
6989 assert(ParamType->isIntegralOrEnumerationType())(static_cast <bool> (ParamType->isIntegralOrEnumerationType
()) ? void (0) : __assert_fail ("ParamType->isIntegralOrEnumerationType()"
, "clang/lib/Sema/SemaTemplate.cpp", 6989, __extension__ __PRETTY_FUNCTION__
))
;
6990 Converted = TemplateArgument(Context, Value.getInt(), CanonParamType);
6991 break;
6992 case APValue::MemberPointer: {
6993 assert(ParamType->isMemberPointerType())(static_cast <bool> (ParamType->isMemberPointerType(
)) ? void (0) : __assert_fail ("ParamType->isMemberPointerType()"
, "clang/lib/Sema/SemaTemplate.cpp", 6993, __extension__ __PRETTY_FUNCTION__
))
;
6994
6995 // FIXME: We need TemplateArgument representation and mangling for these.
6996 if (!Value.getMemberPointerPath().empty()) {
6997 Diag(Arg->getBeginLoc(),
6998 diag::err_template_arg_member_ptr_base_derived_not_supported)
6999 << Value.getMemberPointerDecl() << ParamType
7000 << Arg->getSourceRange();
7001 return ExprError();
7002 }
7003
7004 auto *VD = const_cast<ValueDecl*>(Value.getMemberPointerDecl());
7005 Converted = VD ? TemplateArgument(VD, CanonParamType)
7006 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
7007 break;
7008 }
7009 case APValue::LValue: {
7010 // For a non-type template-parameter of pointer or reference type,
7011 // the value of the constant expression shall not refer to
7012 assert(ParamType->isPointerType() || ParamType->isReferenceType() ||(static_cast <bool> (ParamType->isPointerType() || ParamType
->isReferenceType() || ParamType->isNullPtrType()) ? void
(0) : __assert_fail ("ParamType->isPointerType() || ParamType->isReferenceType() || ParamType->isNullPtrType()"
, "clang/lib/Sema/SemaTemplate.cpp", 7013, __extension__ __PRETTY_FUNCTION__
))
7013 ParamType->isNullPtrType())(static_cast <bool> (ParamType->isPointerType() || ParamType
->isReferenceType() || ParamType->isNullPtrType()) ? void
(0) : __assert_fail ("ParamType->isPointerType() || ParamType->isReferenceType() || ParamType->isNullPtrType()"
, "clang/lib/Sema/SemaTemplate.cpp", 7013, __extension__ __PRETTY_FUNCTION__
))
;
7014 // -- a temporary object
7015 // -- a string literal
7016 // -- the result of a typeid expression, or
7017 // -- a predefined __func__ variable
7018 APValue::LValueBase Base = Value.getLValueBase();
7019 auto *VD = const_cast<ValueDecl *>(Base.dyn_cast<const ValueDecl *>());
7020 if (Base &&
7021 (!VD ||
7022 isa<LifetimeExtendedTemporaryDecl, UnnamedGlobalConstantDecl>(VD))) {
7023 Diag(Arg->getBeginLoc(), diag::err_template_arg_not_decl_ref)
7024 << Arg->getSourceRange();
7025 return ExprError();
7026 }
7027 // -- a subobject
7028 // FIXME: Until C++20
7029 if (Value.hasLValuePath() && Value.getLValuePath().size() == 1 &&
7030 VD && VD->getType()->isArrayType() &&
7031 Value.getLValuePath()[0].getAsArrayIndex() == 0 &&
7032 !Value.isLValueOnePastTheEnd() && ParamType->isPointerType()) {
7033 // Per defect report (no number yet):
7034 // ... other than a pointer to the first element of a complete array
7035 // object.
7036 } else if (!Value.hasLValuePath() || Value.getLValuePath().size() ||
7037 Value.isLValueOnePastTheEnd()) {
7038 Diag(StartLoc, diag::err_non_type_template_arg_subobject)
7039 << Value.getAsString(Context, ParamType);
7040 return ExprError();
7041 }
7042 assert((VD || !ParamType->isReferenceType()) &&(static_cast <bool> ((VD || !ParamType->isReferenceType
()) && "null reference should not be a constant expression"
) ? void (0) : __assert_fail ("(VD || !ParamType->isReferenceType()) && \"null reference should not be a constant expression\""
, "clang/lib/Sema/SemaTemplate.cpp", 7043, __extension__ __PRETTY_FUNCTION__
))
7043 "null reference should not be a constant expression")(static_cast <bool> ((VD || !ParamType->isReferenceType
()) && "null reference should not be a constant expression"
) ? void (0) : __assert_fail ("(VD || !ParamType->isReferenceType()) && \"null reference should not be a constant expression\""
, "clang/lib/Sema/SemaTemplate.cpp", 7043, __extension__ __PRETTY_FUNCTION__
))
;
7044 assert((!VD || !ParamType->isNullPtrType()) &&(static_cast <bool> ((!VD || !ParamType->isNullPtrType
()) && "non-null value of type nullptr_t?") ? void (0
) : __assert_fail ("(!VD || !ParamType->isNullPtrType()) && \"non-null value of type nullptr_t?\""
, "clang/lib/Sema/SemaTemplate.cpp", 7045, __extension__ __PRETTY_FUNCTION__
))
7045 "non-null value of type nullptr_t?")(static_cast <bool> ((!VD || !ParamType->isNullPtrType
()) && "non-null value of type nullptr_t?") ? void (0
) : __assert_fail ("(!VD || !ParamType->isNullPtrType()) && \"non-null value of type nullptr_t?\""
, "clang/lib/Sema/SemaTemplate.cpp", 7045, __extension__ __PRETTY_FUNCTION__
))
;
7046 Converted = VD ? TemplateArgument(VD, CanonParamType)
7047 : TemplateArgument(CanonParamType, /*isNullPtr*/true);
7048 break;
7049 }
7050 case APValue::Struct:
7051 case APValue::Union:
7052 // Get or create the corresponding template parameter object.
7053 Converted = TemplateArgument(
7054 Context.getTemplateParamObjectDecl(CanonParamType, Value),
7055 CanonParamType);
7056 break;
7057 case APValue::AddrLabelDiff:
7058 return Diag(StartLoc, diag::err_non_type_template_arg_addr_label_diff);
7059 case APValue::FixedPoint:
7060 case APValue::Float:
7061 case APValue::ComplexInt:
7062 case APValue::ComplexFloat:
7063 case APValue::Vector:
7064 case APValue::Array:
7065 return Diag(StartLoc, diag::err_non_type_template_arg_unsupported)
7066 << ParamType;
7067 }
7068
7069 return ArgResult.get();
7070 }
7071
7072 // C++ [temp.arg.nontype]p5:
7073 // The following conversions are performed on each expression used
7074 // as a non-type template-argument. If a non-type
7075 // template-argument cannot be converted to the type of the
7076 // corresponding template-parameter then the program is
7077 // ill-formed.
7078 if (ParamType->isIntegralOrEnumerationType()) {
7079 // C++11:
7080 // -- for a non-type template-parameter of integral or
7081 // enumeration type, conversions permitted in a converted
7082 // constant expression are applied.
7083 //
7084 // C++98:
7085 // -- for a non-type template-parameter of integral or
7086 // enumeration type, integral promotions (4.5) and integral
7087 // conversions (4.7) are applied.
7088
7089 if (getLangOpts().CPlusPlus11) {
7090 // C++ [temp.arg.nontype]p1:
7091 // A template-argument for a non-type, non-template template-parameter
7092 // shall be one of:
7093 //
7094 // -- for a non-type template-parameter of integral or enumeration
7095 // type, a converted constant expression of the type of the
7096 // template-parameter; or
7097 llvm::APSInt Value;
7098 ExprResult ArgResult =
7099 CheckConvertedConstantExpression(Arg, ParamType, Value,
7100 CCEK_TemplateArg);
7101 if (ArgResult.isInvalid())
7102 return ExprError();
7103
7104 // We can't check arbitrary value-dependent arguments.
7105 if (ArgResult.get()->isValueDependent()) {
7106 Converted = TemplateArgument(ArgResult.get());
7107 return ArgResult;
7108 }
7109
7110 // Widen the argument value to sizeof(parameter type). This is almost
7111 // always a no-op, except when the parameter type is bool. In
7112 // that case, this may extend the argument from 1 bit to 8 bits.
7113 QualType IntegerType = ParamType;
7114 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
7115 IntegerType = Enum->getDecl()->getIntegerType();
7116 Value = Value.extOrTrunc(IntegerType->isBitIntType()
7117 ? Context.getIntWidth(IntegerType)
7118 : Context.getTypeSize(IntegerType));
7119
7120 Converted = TemplateArgument(Context, Value,
7121 Context.getCanonicalType(ParamType));
7122 return ArgResult;
7123 }
7124
7125 ExprResult ArgResult = DefaultLvalueConversion(Arg);
7126 if (ArgResult.isInvalid())
7127 return ExprError();
7128 Arg = ArgResult.get();
7129
7130 QualType ArgType = Arg->getType();
7131
7132 // C++ [temp.arg.nontype]p1:
7133 // A template-argument for a non-type, non-template
7134 // template-parameter shall be one of:
7135 //
7136 // -- an integral constant-expression of integral or enumeration
7137 // type; or
7138 // -- the name of a non-type template-parameter; or
7139 llvm::APSInt Value;
7140 if (!ArgType->isIntegralOrEnumerationType()) {
7141 Diag(Arg->getBeginLoc(), diag::err_template_arg_not_integral_or_enumeral)
7142 << ArgType << Arg->getSourceRange();
7143 Diag(Param->getLocation(), diag::note_template_param_here);
7144 return ExprError();
7145 } else if (!Arg->isValueDependent()) {
7146 class TmplArgICEDiagnoser : public VerifyICEDiagnoser {
7147 QualType T;
7148
7149 public:
7150 TmplArgICEDiagnoser(QualType T) : T(T) { }
7151
7152 SemaDiagnosticBuilder diagnoseNotICE(Sema &S,
7153 SourceLocation Loc) override {
7154 return S.Diag(Loc, diag::err_template_arg_not_ice) << T;
7155 }
7156 } Diagnoser(ArgType);
7157
7158 Arg = VerifyIntegerConstantExpression(Arg, &Value, Diagnoser).get();
7159 if (!Arg)
7160 return ExprError();
7161 }
7162
7163 // From here on out, all we care about is the unqualified form
7164 // of the argument type.
7165 ArgType = ArgType.getUnqualifiedType();
7166
7167 // Try to convert the argument to the parameter's type.
7168 if (Context.hasSameType(ParamType, ArgType)) {
7169 // Okay: no conversion necessary
7170 } else if (ParamType->isBooleanType()) {
7171 // This is an integral-to-boolean conversion.
7172 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralToBoolean).get();
7173 } else if (IsIntegralPromotion(Arg, ArgType, ParamType) ||
7174 !ParamType->isEnumeralType()) {
7175 // This is an integral promotion or conversion.
7176 Arg = ImpCastExprToType(Arg, ParamType, CK_IntegralCast).get();
7177 } else {
7178 // We can't perform this conversion.
7179 Diag(Arg->getBeginLoc(), diag::err_template_arg_not_convertible)
7180 << Arg->getType() << ParamType << Arg->getSourceRange();
7181 Diag(Param->getLocation(), diag::note_template_param_here);
7182 return ExprError();
7183 }
7184
7185 // Add the value of this argument to the list of converted
7186 // arguments. We use the bitwidth and signedness of the template
7187 // parameter.
7188 if (Arg->isValueDependent()) {
7189 // The argument is value-dependent. Create a new
7190 // TemplateArgument with the converted expression.
7191 Converted = TemplateArgument(Arg);
7192 return Arg;
7193 }
7194
7195 QualType IntegerType = Context.getCanonicalType(ParamType);
7196 if (const EnumType *Enum = IntegerType->getAs<EnumType>())
7197 IntegerType = Context.getCanonicalType(Enum->getDecl()->getIntegerType());
7198
7199 if (ParamType->isBooleanType()) {
7200 // Value must be zero or one.
7201 Value = Value != 0;
7202 unsigned AllowedBits = Context.getTypeSize(IntegerType);
7203 if (Value.getBitWidth() != AllowedBits)
7204 Value = Value.extOrTrunc(AllowedBits);
7205 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
7206 } else {
7207 llvm::APSInt OldValue = Value;
7208
7209 // Coerce the template argument's value to the value it will have
7210 // based on the template parameter's type.
7211 unsigned AllowedBits = IntegerType->isBitIntType()
7212 ? Context.getIntWidth(IntegerType)
7213 : Context.getTypeSize(IntegerType);
7214 if (Value.getBitWidth() != AllowedBits)
7215 Value = Value.extOrTrunc(AllowedBits);
7216 Value.setIsSigned(IntegerType->isSignedIntegerOrEnumerationType());
7217
7218 // Complain if an unsigned parameter received a negative value.
7219 if (IntegerType->isUnsignedIntegerOrEnumerationType() &&
7220 (OldValue.isSigned() && OldValue.isNegative())) {
7221 Diag(Arg->getBeginLoc(), diag::warn_template_arg_negative)
7222 << toString(OldValue, 10) << toString(Value, 10) << Param->getType()
7223 << Arg->getSourceRange();
7224 Diag(Param->getLocation(), diag::note_template_param_here);
7225 }
7226
7227 // Complain if we overflowed the template parameter's type.
7228 unsigned RequiredBits;
7229 if (IntegerType->isUnsignedIntegerOrEnumerationType())
7230 RequiredBits = OldValue.getActiveBits();
7231 else if (OldValue.isUnsigned())
7232 RequiredBits = OldValue.getActiveBits() + 1;
7233 else
7234 RequiredBits = OldValue.getMinSignedBits();
7235 if (RequiredBits > AllowedBits) {
7236 Diag(Arg->getBeginLoc(), diag::warn_template_arg_too_large)
7237 << toString(OldValue, 10) << toString(Value, 10) << Param->getType()
7238 << Arg->getSourceRange();
7239 Diag(Param->getLocation(), diag::note_template_param_here);
7240 }
7241 }
7242
7243 Converted = TemplateArgument(Context, Value,
7244 ParamType->isEnumeralType()
7245 ? Context.getCanonicalType(ParamType)
7246 : IntegerType);
7247 return Arg;
7248 }
7249
7250 QualType ArgType = Arg->getType();
7251 DeclAccessPair FoundResult; // temporary for ResolveOverloadedFunction
7252
7253 // Handle pointer-to-function, reference-to-function, and
7254 // pointer-to-member-function all in (roughly) the same way.
7255 if (// -- For a non-type template-parameter of type pointer to
7256 // function, only the function-to-pointer conversion (4.3) is
7257 // applied. If the template-argument represents a set of
7258 // overloaded functions (or a pointer to such), the matching
7259 // function is selected from the set (13.4).
7260 (ParamType->isPointerType() &&
7261 ParamType->castAs<PointerType>()->getPointeeType()->isFunctionType()) ||
7262 // -- For a non-type template-parameter of type reference to
7263 // function, no conversions apply. If the template-argument
7264 // represents a set of overloaded functions, the matching
7265 // function is selected from the set (13.4).
7266 (ParamType->isReferenceType() &&
7267 ParamType->castAs<ReferenceType>()->getPointeeType()->isFunctionType()) ||
7268 // -- For a non-type template-parameter of type pointer to
7269 // member function, no conversions apply. If the
7270 // template-argument represents a set of overloaded member
7271 // functions, the matching member function is selected from
7272 // the set (13.4).
7273 (ParamType->isMemberPointerType() &&
7274 ParamType->castAs<MemberPointerType>()->getPointeeType()
7275 ->isFunctionType())) {
7276
7277 if (Arg->getType() == Context.OverloadTy) {
7278 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg, ParamType,
7279 true,
7280 FoundResult)) {
7281 if (DiagnoseUseOfDecl(Fn, Arg->getBeginLoc()))
7282 return ExprError();
7283
7284 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
7285 ArgType = Arg->getType();
7286 } else
7287 return ExprError();
7288 }
7289
7290 if (!ParamType->isMemberPointerType()) {
7291 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
7292 ParamType,
7293 Arg, Converted))
7294 return ExprError();
7295 return Arg;
7296 }
7297
7298 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
7299 Converted))
7300 return ExprError();
7301 return Arg;
7302 }
7303
7304 if (ParamType->isPointerType()) {
7305 // -- for a non-type template-parameter of type pointer to
7306 // object, qualification conversions (4.4) and the
7307 // array-to-pointer conversion (4.2) are applied.
7308 // C++0x also allows a value of std::nullptr_t.
7309 assert(ParamType->getPointeeType()->isIncompleteOrObjectType() &&(static_cast <bool> (ParamType->getPointeeType()->
isIncompleteOrObjectType() && "Only object pointers allowed here"
) ? void (0) : __assert_fail ("ParamType->getPointeeType()->isIncompleteOrObjectType() && \"Only object pointers allowed here\""
, "clang/lib/Sema/SemaTemplate.cpp", 7310, __extension__ __PRETTY_FUNCTION__
))
7310 "Only object pointers allowed here")(static_cast <bool> (ParamType->getPointeeType()->
isIncompleteOrObjectType() && "Only object pointers allowed here"
) ? void (0) : __assert_fail ("ParamType->getPointeeType()->isIncompleteOrObjectType() && \"Only object pointers allowed here\""
, "clang/lib/Sema/SemaTemplate.cpp", 7310, __extension__ __PRETTY_FUNCTION__
))
;
7311
7312 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
7313 ParamType,
7314 Arg, Converted))
7315 return ExprError();
7316 return Arg;
7317 }
7318
7319 if (const ReferenceType *ParamRefType = ParamType->getAs<ReferenceType>()) {
7320 // -- For a non-type template-parameter of type reference to
7321 // object, no conversions apply. The type referred to by the
7322 // reference may be more cv-qualified than the (otherwise
7323 // identical) type of the template-argument. The
7324 // template-parameter is bound directly to the
7325 // template-argument, which must be an lvalue.
7326 assert(ParamRefType->getPointeeType()->isIncompleteOrObjectType() &&(static_cast <bool> (ParamRefType->getPointeeType()->
isIncompleteOrObjectType() && "Only object references allowed here"
) ? void (0) : __assert_fail ("ParamRefType->getPointeeType()->isIncompleteOrObjectType() && \"Only object references allowed here\""
, "clang/lib/Sema/SemaTemplate.cpp", 7327, __extension__ __PRETTY_FUNCTION__
))
7327 "Only object references allowed here")(static_cast <bool> (ParamRefType->getPointeeType()->
isIncompleteOrObjectType() && "Only object references allowed here"
) ? void (0) : __assert_fail ("ParamRefType->getPointeeType()->isIncompleteOrObjectType() && \"Only object references allowed here\""
, "clang/lib/Sema/SemaTemplate.cpp", 7327, __extension__ __PRETTY_FUNCTION__
))
;
7328
7329 if (Arg->getType() == Context.OverloadTy) {
7330 if (FunctionDecl *Fn = ResolveAddressOfOverloadedFunction(Arg,
7331 ParamRefType->getPointeeType(),
7332 true,
7333 FoundResult)) {
7334 if (DiagnoseUseOfDecl(Fn, Arg->getBeginLoc()))
7335 return ExprError();
7336
7337 Arg = FixOverloadedFunctionReference(Arg, FoundResult, Fn);
7338 ArgType = Arg->getType();
7339 } else
7340 return ExprError();
7341 }
7342
7343 if (CheckTemplateArgumentAddressOfObjectOrFunction(*this, Param,
7344 ParamType,
7345 Arg, Converted))
7346 return ExprError();
7347 return Arg;
7348 }
7349
7350 // Deal with parameters of type std::nullptr_t.
7351 if (ParamType->isNullPtrType()) {
7352 if (Arg->isTypeDependent() || Arg->isValueDependent()) {
7353 Converted = TemplateArgument(Arg);
7354 return Arg;
7355 }
7356
7357 switch (isNullPointerValueTemplateArgument(*this, Param, ParamType, Arg)) {
7358 case NPV_NotNullPointer:
7359 Diag(Arg->getExprLoc(), diag::err_template_arg_not_convertible)
7360 << Arg->getType() << ParamType;
7361 Diag(Param->getLocation(), diag::note_template_param_here);
7362 return ExprError();
7363
7364 case NPV_Error:
7365 return ExprError();
7366
7367 case NPV_NullPointer:
7368 Diag(Arg->getExprLoc(), diag::warn_cxx98_compat_template_arg_null);
7369 Converted = TemplateArgument(Context.getCanonicalType(ParamType),
7370 /*isNullPtr*/true);
7371 return Arg;
7372 }
7373 }
7374
7375 // -- For a non-type template-parameter of type pointer to data
7376 // member, qualification conversions (4.4) are applied.
7377 assert(ParamType->isMemberPointerType() && "Only pointers to members remain")(static_cast <bool> (ParamType->isMemberPointerType(
) && "Only pointers to members remain") ? void (0) : __assert_fail
("ParamType->isMemberPointerType() && \"Only pointers to members remain\""
, "clang/lib/Sema/SemaTemplate.cpp", 7377, __extension__ __PRETTY_FUNCTION__
))
;
7378
7379 if (CheckTemplateArgumentPointerToMember(*this, Param, ParamType, Arg,
7380 Converted))
7381 return ExprError();
7382 return Arg;
7383}
7384
7385static void DiagnoseTemplateParameterListArityMismatch(
7386 Sema &S, TemplateParameterList *New, TemplateParameterList *Old,
7387 Sema::TemplateParameterListEqualKind Kind, SourceLocation TemplateArgLoc);
7388
7389/// Check a template argument against its corresponding
7390/// template template parameter.
7391///
7392/// This routine implements the semantics of C++ [temp.arg.template].
7393/// It returns true if an error occurred, and false otherwise.
7394bool Sema::CheckTemplateTemplateArgument(TemplateTemplateParmDecl *Param,
7395 TemplateParameterList *Params,
7396 TemplateArgumentLoc &Arg) {
7397 TemplateName Name = Arg.getArgument().getAsTemplateOrTemplatePattern();
7398 TemplateDecl *Template = Name.getAsTemplateDecl();
7399 if (!Template) {
7400 // Any dependent template name is fine.
7401 assert(Name.isDependent() && "Non-dependent template isn't a declaration?")(static_cast <bool> (Name.isDependent() && "Non-dependent template isn't a declaration?"
) ? void (0) : __assert_fail ("Name.isDependent() && \"Non-dependent template isn't a declaration?\""
, "clang/lib/Sema/SemaTemplate.cpp", 7401, __extension__ __PRETTY_FUNCTION__
))
;
7402 return false;
7403 }
7404
7405 if (Template->isInvalidDecl())
7406 return true;
7407
7408 // C++0x [temp.arg.template]p1:
7409 // A template-argument for a template template-parameter shall be
7410 // the name of a class template or an alias template, expressed as an
7411 // id-expression. When the template-argument names a class template, only
7412 // primary class templates are considered when matching the
7413 // template template argument with the corresponding parameter;
7414 // partial specializations are not considered even if their
7415 // parameter lists match that of the template template parameter.
7416 //
7417 // Note that we also allow template template parameters here, which
7418 // will happen when we are dealing with, e.g., class template
7419 // partial specializations.
7420 if (!isa<ClassTemplateDecl>(Template) &&
7421 !isa<TemplateTemplateParmDecl>(Template) &&
7422 !isa<TypeAliasTemplateDecl>(Template) &&
7423 !isa<BuiltinTemplateDecl>(Template)) {
7424 assert(isa<FunctionTemplateDecl>(Template) &&(static_cast <bool> (isa<FunctionTemplateDecl>(Template
) && "Only function templates are possible here") ? void
(0) : __assert_fail ("isa<FunctionTemplateDecl>(Template) && \"Only function templates are possible here\""
, "clang/lib/Sema/SemaTemplate.cpp", 7425, __extension__ __PRETTY_FUNCTION__
))
7425 "Only function templates are possible here")(static_cast <bool> (isa<FunctionTemplateDecl>(Template
) && "Only function templates are possible here") ? void
(0) : __assert_fail ("isa<FunctionTemplateDecl>(Template) && \"Only function templates are possible here\""
, "clang/lib/Sema/SemaTemplate.cpp", 7425, __extension__ __PRETTY_FUNCTION__
))
;
7426 Diag(Arg.getLocation(), diag::err_template_arg_not_valid_template);
7427 Diag(Template->getLocation(), diag::note_template_arg_refers_here_func)
7428 << Template;
7429 }
7430
7431 // C++1z [temp.arg.template]p3: (DR 150)
7432 // A template-argument matches a template template-parameter P when P
7433 // is at least as specialized as the template-argument A.
7434 // FIXME: We should enable RelaxedTemplateTemplateArgs by default as it is a
7435 // defect report resolution from C++17 and shouldn't be introduced by
7436 // concepts.
7437 if (getLangOpts().RelaxedTemplateTemplateArgs) {
7438 // Quick check for the common case:
7439 // If P contains a parameter pack, then A [...] matches P if each of A's
7440 // template parameters matches the corresponding template parameter in
7441 // the template-parameter-list of P.
7442 if (TemplateParameterListsAreEqual(
7443 Template->getTemplateParameters(), Params, false,
7444 TPL_TemplateTemplateArgumentMatch, Arg.getLocation()) &&
7445 // If the argument has no associated constraints, then the parameter is
7446 // definitely at least as specialized as the argument.
7447 // Otherwise - we need a more thorough check.
7448 !Template->hasAssociatedConstraints())
7449 return false;
7450
7451 if (isTemplateTemplateParameterAtLeastAsSpecializedAs(Params, Template,
7452 Arg.getLocation())) {
7453 // C++2a[temp.func.order]p2
7454 // [...] If both deductions succeed, the partial ordering selects the
7455 // more constrained template as described by the rules in
7456 // [temp.constr.order].
7457 SmallVector<const Expr *, 3> ParamsAC, TemplateAC;
7458 Params->getAssociatedConstraints(ParamsAC);
7459 // C++2a[temp.arg.template]p3
7460 // [...] In this comparison, if P is unconstrained, the constraints on A
7461 // are not considered.
7462 if (ParamsAC.empty())
7463 return false;
7464 Template->getAssociatedConstraints(TemplateAC);
7465 bool IsParamAtLeastAsConstrained;
7466 if (IsAtLeastAsConstrained(Param, ParamsAC, Template, TemplateAC,
7467 IsParamAtLeastAsConstrained))
7468 return true;
7469 if (!IsParamAtLeastAsConstrained) {
7470 Diag(Arg.getLocation(),
7471 diag::err_template_template_parameter_not_at_least_as_constrained)
7472 << Template << Param << Arg.getSourceRange();
7473 Diag(Param->getLocation(), diag::note_entity_declared_at) << Param;
7474 Diag(Template->getLocation(), diag::note_entity_declared_at)
7475 << Template;
7476 MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Param, ParamsAC, Template,
7477 TemplateAC);
7478 return true;
7479 }
7480 return false;
7481 }
7482 // FIXME: Produce better diagnostics for deduction failures.
7483 }
7484
7485 return !TemplateParameterListsAreEqual(Template->getTemplateParameters(),
7486 Params,
7487 true,
7488 TPL_TemplateTemplateArgumentMatch,
7489 Arg.getLocation());
7490}
7491
7492/// Given a non-type template argument that refers to a
7493/// declaration and the type of its corresponding non-type template
7494/// parameter, produce an expression that properly refers to that
7495/// declaration.
7496ExprResult
7497Sema::BuildExpressionFromDeclTemplateArgument(const TemplateArgument &Arg,
7498 QualType ParamType,
7499 SourceLocation Loc) {
7500 // C++ [temp.param]p8:
7501 //
7502 // A non-type template-parameter of type "array of T" or
7503 // "function returning T" is adjusted to be of type "pointer to
7504 // T" or "pointer to function returning T", respectively.
7505 if (ParamType->isArrayType())
7506 ParamType = Context.getArrayDecayedType(ParamType);
7507 else if (ParamType->isFunctionType())
7508 ParamType = Context.getPointerType(ParamType);
7509
7510 // For a NULL non-type template argument, return nullptr casted to the
7511 // parameter's type.
7512 if (Arg.getKind() == TemplateArgument::NullPtr) {
7513 return ImpCastExprToType(
7514 new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc),
7515 ParamType,
7516 ParamType->getAs<MemberPointerType>()
7517 ? CK_NullToMemberPointer
7518 : CK_NullToPointer);
7519 }
7520 assert(Arg.getKind() == TemplateArgument::Declaration &&(static_cast <bool> (Arg.getKind() == TemplateArgument::
Declaration && "Only declaration template arguments permitted here"
) ? void (0) : __assert_fail ("Arg.getKind() == TemplateArgument::Declaration && \"Only declaration template arguments permitted here\""
, "clang/lib/Sema/SemaTemplate.cpp", 7521, __extension__ __PRETTY_FUNCTION__
))
7521 "Only declaration template arguments permitted here")(static_cast <bool> (Arg.getKind() == TemplateArgument::
Declaration && "Only declaration template arguments permitted here"
) ? void (0) : __assert_fail ("Arg.getKind() == TemplateArgument::Declaration && \"Only declaration template arguments permitted here\""
, "clang/lib/Sema/SemaTemplate.cpp", 7521, __extension__ __PRETTY_FUNCTION__
))
;
7522
7523 ValueDecl *VD = Arg.getAsDecl();
7524
7525 CXXScopeSpec SS;
7526 if (ParamType->isMemberPointerType()) {
7527 // If this is a pointer to member, we need to use a qualified name to
7528 // form a suitable pointer-to-member constant.
7529 assert(VD->getDeclContext()->isRecord() &&(static_cast <bool> (VD->getDeclContext()->isRecord
() && (isa<CXXMethodDecl>(VD) || isa<FieldDecl
>(VD) || isa<IndirectFieldDecl>(VD))) ? void (0) : __assert_fail
("VD->getDeclContext()->isRecord() && (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) || isa<IndirectFieldDecl>(VD))"
, "clang/lib/Sema/SemaTemplate.cpp", 7531, __extension__ __PRETTY_FUNCTION__
))
7530 (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) ||(static_cast <bool> (VD->getDeclContext()->isRecord
() && (isa<CXXMethodDecl>(VD) || isa<FieldDecl
>(VD) || isa<IndirectFieldDecl>(VD))) ? void (0) : __assert_fail
("VD->getDeclContext()->isRecord() && (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) || isa<IndirectFieldDecl>(VD))"
, "clang/lib/Sema/SemaTemplate.cpp", 7531, __extension__ __PRETTY_FUNCTION__
))
7531 isa<IndirectFieldDecl>(VD)))(static_cast <bool> (VD->getDeclContext()->isRecord
() && (isa<CXXMethodDecl>(VD) || isa<FieldDecl
>(VD) || isa<IndirectFieldDecl>(VD))) ? void (0) : __assert_fail
("VD->getDeclContext()->isRecord() && (isa<CXXMethodDecl>(VD) || isa<FieldDecl>(VD) || isa<IndirectFieldDecl>(VD))"
, "clang/lib/Sema/SemaTemplate.cpp", 7531, __extension__ __PRETTY_FUNCTION__
))
;
7532 QualType ClassType
7533 = Context.getTypeDeclType(cast<RecordDecl>(VD->getDeclContext()));
7534 NestedNameSpecifier *Qualifier
7535 = NestedNameSpecifier::Create(Context, nullptr, false,
7536 ClassType.getTypePtr());
7537 SS.MakeTrivial(Context, Qualifier, Loc);
7538 }
7539
7540 ExprResult RefExpr = BuildDeclarationNameExpr(
7541 SS, DeclarationNameInfo(VD->getDeclName(), Loc), VD);
7542 if (RefExpr.isInvalid())
7543 return ExprError();
7544
7545 // For a pointer, the argument declaration is the pointee. Take its address.
7546 QualType ElemT(RefExpr.get()->getType()->getArrayElementTypeNoTypeQual(), 0);
7547 if (ParamType->isPointerType() && !ElemT.isNull() &&
7548 Context.hasSimilarType(ElemT, ParamType->getPointeeType())) {
7549 // Decay an array argument if we want a pointer to its first element.
7550 RefExpr = DefaultFunctionArrayConversion(RefExpr.get());
7551 if (RefExpr.isInvalid())
7552 return ExprError();
7553 } else if (ParamType->isPointerType() || ParamType->isMemberPointerType()) {
7554 // For any other pointer, take the address (or form a pointer-to-member).
7555 RefExpr = CreateBuiltinUnaryOp(Loc, UO_AddrOf, RefExpr.get());
7556 if (RefExpr.isInvalid())
7557 return ExprError();
7558 } else if (ParamType->isRecordType()) {
7559 assert(isa<TemplateParamObjectDecl>(VD) &&(static_cast <bool> (isa<TemplateParamObjectDecl>
(VD) && "arg for class template param not a template parameter object"
) ? void (0) : __assert_fail ("isa<TemplateParamObjectDecl>(VD) && \"arg for class template param not a template parameter object\""
, "clang/lib/Sema/SemaTemplate.cpp", 7560, __extension__ __PRETTY_FUNCTION__
))
7560 "arg for class template param not a template parameter object")(static_cast <bool> (isa<TemplateParamObjectDecl>
(VD) && "arg for class template param not a template parameter object"
) ? void (0) : __assert_fail ("isa<TemplateParamObjectDecl>(VD) && \"arg for class template param not a template parameter object\""
, "clang/lib/Sema/SemaTemplate.cpp", 7560, __extension__ __PRETTY_FUNCTION__
))
;
7561 // No conversions apply in this case.
7562 return RefExpr;
7563 } else {
7564 assert(ParamType->isReferenceType() &&(static_cast <bool> (ParamType->isReferenceType() &&
"unexpected type for decl template argument") ? void (0) : __assert_fail
("ParamType->isReferenceType() && \"unexpected type for decl template argument\""
, "clang/lib/Sema/SemaTemplate.cpp", 7565, __extension__ __PRETTY_FUNCTION__
))
7565 "unexpected type for decl template argument")(static_cast <bool> (ParamType->isReferenceType() &&
"unexpected type for decl template argument") ? void (0) : __assert_fail
("ParamType->isReferenceType() && \"unexpected type for decl template argument\""
, "clang/lib/Sema/SemaTemplate.cpp", 7565, __extension__ __PRETTY_FUNCTION__
))
;
7566 }
7567
7568 // At this point we should have the right value category.
7569 assert(ParamType->isReferenceType() == RefExpr.get()->isLValue() &&(static_cast <bool> (ParamType->isReferenceType() ==
RefExpr.get()->isLValue() && "value kind mismatch for non-type template argument"
) ? void (0) : __assert_fail ("ParamType->isReferenceType() == RefExpr.get()->isLValue() && \"value kind mismatch for non-type template argument\""
, "clang/lib/Sema/SemaTemplate.cpp", 7570, __extension__ __PRETTY_FUNCTION__
))
7570 "value kind mismatch for non-type template argument")(static_cast <bool> (ParamType->isReferenceType() ==
RefExpr.get()->isLValue() && "value kind mismatch for non-type template argument"
) ? void (0) : __assert_fail ("ParamType->isReferenceType() == RefExpr.get()->isLValue() && \"value kind mismatch for non-type template argument\""
, "clang/lib/Sema/SemaTemplate.cpp", 7570, __extension__ __PRETTY_FUNCTION__
))
;
7571
7572 // The type of the template parameter can differ from the type of the
7573 // argument in various ways; convert it now if necessary.
7574 QualType DestExprType = ParamType.getNonLValueExprType(Context);
7575 if (!Context.hasSameType(RefExpr.get()->getType(), DestExprType)) {
7576 CastKind CK;
7577 QualType Ignored;
7578 if (Context.hasSimilarType(RefExpr.get()->getType(), DestExprType) ||
7579 IsFunctionConversion(RefExpr.get()->getType(), DestExprType, Ignored)) {
7580 CK = CK_NoOp;
7581 } else if (ParamType->isVoidPointerType() &&
7582 RefExpr.get()->getType()->isPointerType()) {
7583 CK = CK_BitCast;
7584 } else {
7585 // FIXME: Pointers to members can need conversion derived-to-base or
7586 // base-to-derived conversions. We currently don't retain enough
7587 // information to convert properly (we need to track a cast path or
7588 // subobject number in the template argument).
7589 llvm_unreachable(::llvm::llvm_unreachable_internal("unexpected conversion required for non-type template argument"
, "clang/lib/Sema/SemaTemplate.cpp", 7590)
7590 "unexpected conversion required for non-type template argument")::llvm::llvm_unreachable_internal("unexpected conversion required for non-type template argument"
, "clang/lib/Sema/SemaTemplate.cpp", 7590)
;
7591 }
7592 RefExpr = ImpCastExprToType(RefExpr.get(), DestExprType, CK,
7593 RefExpr.get()->getValueKind());
7594 }
7595
7596 return RefExpr;
7597}
7598
7599/// Construct a new expression that refers to the given
7600/// integral template argument with the given source-location
7601/// information.
7602///
7603/// This routine takes care of the mapping from an integral template
7604/// argument (which may have any integral type) to the appropriate
7605/// literal value.
7606ExprResult
7607Sema::BuildExpressionFromIntegralTemplateArgument(const TemplateArgument &Arg,
7608 SourceLocation Loc) {
7609 assert(Arg.getKind() == TemplateArgument::Integral &&(static_cast <bool> (Arg.getKind() == TemplateArgument::
Integral && "Operation is only valid for integral template arguments"
) ? void (0) : __assert_fail ("Arg.getKind() == TemplateArgument::Integral && \"Operation is only valid for integral template arguments\""
, "clang/lib/Sema/SemaTemplate.cpp", 7610, __extension__ __PRETTY_FUNCTION__
))
7610 "Operation is only valid for integral template arguments")(static_cast <bool> (Arg.getKind() == TemplateArgument::
Integral && "Operation is only valid for integral template arguments"
) ? void (0) : __assert_fail ("Arg.getKind() == TemplateArgument::Integral && \"Operation is only valid for integral template arguments\""
, "clang/lib/Sema/SemaTemplate.cpp", 7610, __extension__ __PRETTY_FUNCTION__
))
;
7611 QualType OrigT = Arg.getIntegralType();
7612
7613 // If this is an enum type that we're instantiating, we need to use an integer
7614 // type the same size as the enumerator. We don't want to build an
7615 // IntegerLiteral with enum type. The integer type of an enum type can be of
7616 // any integral type with C++11 enum classes, make sure we create the right
7617 // type of literal for it.
7618 QualType T = OrigT;
7619 if (const EnumType *ET = OrigT->getAs<EnumType>())
7620 T = ET->getDecl()->getIntegerType();
7621
7622 Expr *E;
7623 if (T->isAnyCharacterType()) {
7624 CharacterLiteral::CharacterKind Kind;
7625 if (T->isWideCharType())
7626 Kind = CharacterLiteral::Wide;
7627 else if (T->isChar8Type() && getLangOpts().Char8)
7628 Kind = CharacterLiteral::UTF8;
7629 else if (T->isChar16Type())
7630 Kind = CharacterLiteral::UTF16;
7631 else if (T->isChar32Type())
7632 Kind = CharacterLiteral::UTF32;
7633 else
7634 Kind = CharacterLiteral::Ascii;
7635
7636 E = new (Context) CharacterLiteral(Arg.getAsIntegral().getZExtValue(),
7637 Kind, T, Loc);
7638 } else if (T->isBooleanType()) {
7639 E = new (Context) CXXBoolLiteralExpr(Arg.getAsIntegral().getBoolValue(),
7640 T, Loc);
7641 } else if (T->isNullPtrType()) {
7642 E = new (Context) CXXNullPtrLiteralExpr(Context.NullPtrTy, Loc);
7643 } else {
7644 E = IntegerLiteral::Create(Context, Arg.getAsIntegral(), T, Loc);
7645 }
7646
7647 if (OrigT->isEnumeralType()) {
7648 // FIXME: This is a hack. We need a better way to handle substituted
7649 // non-type template parameters.
7650 E = CStyleCastExpr::Create(Context, OrigT, VK_PRValue, CK_IntegralCast, E,
7651 nullptr, CurFPFeatureOverrides(),
7652 Context.getTrivialTypeSourceInfo(OrigT, Loc),
7653 Loc, Loc);
7654 }
7655
7656 return E;
7657}
7658
7659/// Match two template parameters within template parameter lists.
7660static bool MatchTemplateParameterKind(Sema &S, NamedDecl *New, NamedDecl *Old,
7661 bool Complain,
7662 Sema::TemplateParameterListEqualKind Kind,
7663 SourceLocation TemplateArgLoc) {
7664 // Check the actual kind (type, non-type, template).
7665 if (Old->getKind() != New->getKind()) {
7666 if (Complain) {
7667 unsigned NextDiag = diag::err_template_param_different_kind;
7668 if (TemplateArgLoc.isValid()) {
7669 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
7670 NextDiag = diag::note_template_param_different_kind;
7671 }
7672 S.Diag(New->getLocation(), NextDiag)
7673 << (Kind != Sema::TPL_TemplateMatch);
7674 S.Diag(Old->getLocation(), diag::note_template_prev_declaration)
7675 << (Kind != Sema::TPL_TemplateMatch);
7676 }
7677
7678 return false;
7679 }
7680
7681 // Check that both are parameter packs or neither are parameter packs.
7682 // However, if we are matching a template template argument to a
7683 // template template parameter, the template template parameter can have
7684 // a parameter pack where the template template argument does not.
7685 if (Old->isTemplateParameterPack() != New->isTemplateParameterPack() &&
7686 !(Kind == Sema::TPL_TemplateTemplateArgumentMatch &&
7687 Old->isTemplateParameterPack())) {
7688 if (Complain) {
7689 unsigned NextDiag = diag::err_template_parameter_pack_non_pack;
7690 if (TemplateArgLoc.isValid()) {
7691 S.Diag(TemplateArgLoc,
7692 diag::err_template_arg_template_params_mismatch);
7693 NextDiag = diag::note_template_parameter_pack_non_pack;
7694 }
7695
7696 unsigned ParamKind = isa<TemplateTypeParmDecl>(New)? 0
7697 : isa<NonTypeTemplateParmDecl>(New)? 1
7698 : 2;
7699 S.Diag(New->getLocation(), NextDiag)
7700 << ParamKind << New->isParameterPack();
7701 S.Diag(Old->getLocation(), diag::note_template_parameter_pack_here)
7702 << ParamKind << Old->isParameterPack();
7703 }
7704
7705 return false;
7706 }
7707
7708 // For non-type template parameters, check the type of the parameter.
7709 if (NonTypeTemplateParmDecl *OldNTTP
7710 = dyn_cast<NonTypeTemplateParmDecl>(Old)) {
7711 NonTypeTemplateParmDecl *NewNTTP = cast<NonTypeTemplateParmDecl>(New);
7712
7713 // If we are matching a template template argument to a template
7714 // template parameter and one of the non-type template parameter types
7715 // is dependent, then we must wait until template instantiation time
7716 // to actually compare the arguments.
7717 if (Kind != Sema::TPL_TemplateTemplateArgumentMatch ||
7718 (!OldNTTP->getType()->isDependentType() &&
7719 !NewNTTP->getType()->isDependentType()))
7720 if (!S.Context.hasSameType(OldNTTP->getType(), NewNTTP->getType())) {
7721 if (Complain) {
7722 unsigned NextDiag = diag::err_template_nontype_parm_different_type;
7723 if (TemplateArgLoc.isValid()) {
7724 S.Diag(TemplateArgLoc,
7725 diag::err_template_arg_template_params_mismatch);
7726 NextDiag = diag::note_template_nontype_parm_different_type;
7727 }
7728 S.Diag(NewNTTP->getLocation(), NextDiag)
7729 << NewNTTP->getType()
7730 << (Kind != Sema::TPL_TemplateMatch);
7731 S.Diag(OldNTTP->getLocation(),
7732 diag::note_template_nontype_parm_prev_declaration)
7733 << OldNTTP->getType();
7734 }
7735
7736 return false;
7737 }
7738 }
7739 // For template template parameters, check the template parameter types.
7740 // The template parameter lists of template template
7741 // parameters must agree.
7742 else if (TemplateTemplateParmDecl *OldTTP
7743 = dyn_cast<TemplateTemplateParmDecl>(Old)) {
7744 TemplateTemplateParmDecl *NewTTP = cast<TemplateTemplateParmDecl>(New);
7745 if (!S.TemplateParameterListsAreEqual(NewTTP->getTemplateParameters(),
7746 OldTTP->getTemplateParameters(),
7747 Complain,
7748 (Kind == Sema::TPL_TemplateMatch
7749 ? Sema::TPL_TemplateTemplateParmMatch
7750 : Kind),
7751 TemplateArgLoc))
7752 return false;
7753 } else if (Kind != Sema::TPL_TemplateTemplateArgumentMatch) {
7754 const Expr *NewC = nullptr, *OldC = nullptr;
7755 if (const auto *TC = cast<TemplateTypeParmDecl>(New)->getTypeConstraint())
7756 NewC = TC->getImmediatelyDeclaredConstraint();
7757 if (const auto *TC = cast<TemplateTypeParmDecl>(Old)->getTypeConstraint())
7758 OldC = TC->getImmediatelyDeclaredConstraint();
7759
7760 auto Diagnose = [&] {
7761 S.Diag(NewC ? NewC->getBeginLoc() : New->getBeginLoc(),
7762 diag::err_template_different_type_constraint);
7763 S.Diag(OldC ? OldC->getBeginLoc() : Old->getBeginLoc(),
7764 diag::note_template_prev_declaration) << /*declaration*/0;
7765 };
7766
7767 if (!NewC != !OldC) {
7768 if (Complain)
7769 Diagnose();
7770 return false;
7771 }
7772
7773 if (NewC) {
7774 llvm::FoldingSetNodeID OldCID, NewCID;
7775 OldC->Profile(OldCID, S.Context, /*Canonical=*/true);
7776 NewC->Profile(NewCID, S.Context, /*Canonical=*/true);
7777 if (OldCID != NewCID) {
7778 if (Complain)
7779 Diagnose();
7780 return false;
7781 }
7782 }
7783 }
7784
7785 return true;
7786}
7787
7788/// Diagnose a known arity mismatch when comparing template argument
7789/// lists.
7790static
7791void DiagnoseTemplateParameterListArityMismatch(Sema &S,
7792 TemplateParameterList *New,
7793 TemplateParameterList *Old,
7794 Sema::TemplateParameterListEqualKind Kind,
7795 SourceLocation TemplateArgLoc) {
7796 unsigned NextDiag = diag::err_template_param_list_different_arity;
7797 if (TemplateArgLoc.isValid()) {
7798 S.Diag(TemplateArgLoc, diag::err_template_arg_template_params_mismatch);
7799 NextDiag = diag::note_template_param_list_different_arity;
7800 }
7801 S.Diag(New->getTemplateLoc(), NextDiag)
7802 << (New->size() > Old->size())
7803 << (Kind != Sema::TPL_TemplateMatch)
7804 << SourceRange(New->getTemplateLoc(), New->getRAngleLoc());
7805 S.Diag(Old->getTemplateLoc(), diag::note_template_prev_declaration)
7806 << (Kind != Sema::TPL_TemplateMatch)
7807 << SourceRange(Old->getTemplateLoc(), Old->getRAngleLoc());
7808}
7809
7810/// Determine whether the given template parameter lists are
7811/// equivalent.
7812///
7813/// \param New The new template parameter list, typically written in the
7814/// source code as part of a new template declaration.
7815///
7816/// \param Old The old template parameter list, typically found via
7817/// name lookup of the template declared with this template parameter
7818/// list.
7819///
7820/// \param Complain If true, this routine will produce a diagnostic if
7821/// the template parameter lists are not equivalent.
7822///
7823/// \param Kind describes how we are to match the template parameter lists.
7824///
7825/// \param TemplateArgLoc If this source location is valid, then we
7826/// are actually checking the template parameter list of a template
7827/// argument (New) against the template parameter list of its
7828/// corresponding template template parameter (Old). We produce
7829/// slightly different diagnostics in this scenario.
7830///
7831/// \returns True if the template parameter lists are equal, false
7832/// otherwise.
7833bool
7834Sema::TemplateParameterListsAreEqual(TemplateParameterList *New,
7835 TemplateParameterList *Old,
7836 bool Complain,
7837 TemplateParameterListEqualKind Kind,
7838 SourceLocation TemplateArgLoc) {
7839 if (Old->size() != New->size() && Kind != TPL_TemplateTemplateArgumentMatch) {
7840 if (Complain)
7841 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
7842 TemplateArgLoc);
7843
7844 return false;
7845 }
7846
7847 // C++0x [temp.arg.template]p3:
7848 // A template-argument matches a template template-parameter (call it P)
7849 // when each of the template parameters in the template-parameter-list of
7850 // the template-argument's corresponding class template or alias template
7851 // (call it A) matches the corresponding template parameter in the
7852 // template-parameter-list of P. [...]
7853 TemplateParameterList::iterator NewParm = New->begin();
7854 TemplateParameterList::iterator NewParmEnd = New->end();
7855 for (TemplateParameterList::iterator OldParm = Old->begin(),
7856 OldParmEnd = Old->end();
7857 OldParm != OldParmEnd; ++OldParm) {
7858 if (Kind != TPL_TemplateTemplateArgumentMatch ||
7859 !(*OldParm)->isTemplateParameterPack()) {
7860 if (NewParm == NewParmEnd) {
7861 if (Complain)
7862 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
7863 TemplateArgLoc);
7864
7865 return false;
7866 }
7867
7868 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
7869 Kind, TemplateArgLoc))
7870 return false;
7871
7872 ++NewParm;
7873 continue;
7874 }
7875
7876 // C++0x [temp.arg.template]p3:
7877 // [...] When P's template- parameter-list contains a template parameter
7878 // pack (14.5.3), the template parameter pack will match zero or more
7879 // template parameters or template parameter packs in the
7880 // template-parameter-list of A with the same type and form as the
7881 // template parameter pack in P (ignoring whether those template
7882 // parameters are template parameter packs).
7883 for (; NewParm != NewParmEnd; ++NewParm) {
7884 if (!MatchTemplateParameterKind(*this, *NewParm, *OldParm, Complain,
7885 Kind, TemplateArgLoc))
7886 return false;
7887 }
7888 }
7889
7890 // Make sure we exhausted all of the arguments.
7891 if (NewParm != NewParmEnd) {
7892 if (Complain)
7893 DiagnoseTemplateParameterListArityMismatch(*this, New, Old, Kind,
7894 TemplateArgLoc);
7895
7896 return false;
7897 }
7898
7899 if (Kind != TPL_TemplateTemplateArgumentMatch) {
7900 const Expr *NewRC = New->getRequiresClause();
7901 const Expr *OldRC = Old->getRequiresClause();
7902
7903 auto Diagnose = [&] {
7904 Diag(NewRC ? NewRC->getBeginLoc() : New->getTemplateLoc(),
7905 diag::err_template_different_requires_clause);
7906 Diag(OldRC ? OldRC->getBeginLoc() : Old->getTemplateLoc(),
7907 diag::note_template_prev_declaration) << /*declaration*/0;
7908 };
7909
7910 if (!NewRC != !OldRC) {
7911 if (Complain)
7912 Diagnose();
7913 return false;
7914 }
7915
7916 if (NewRC) {
7917 llvm::FoldingSetNodeID OldRCID, NewRCID;
7918 OldRC->Profile(OldRCID, Context, /*Canonical=*/true);
7919 NewRC->Profile(NewRCID, Context, /*Canonical=*/true);
7920 if (OldRCID != NewRCID) {
7921 if (Complain)
7922 Diagnose();
7923 return false;
7924 }
7925 }
7926 }
7927
7928 return true;
7929}
7930
7931/// Check whether a template can be declared within this scope.
7932///
7933/// If the template declaration is valid in this scope, returns
7934/// false. Otherwise, issues a diagnostic and returns true.
7935bool
7936Sema::CheckTemplateDeclScope(Scope *S, TemplateParameterList *TemplateParams) {
7937 if (!S)
7938 return false;
7939
7940 // Find the nearest enclosing declaration scope.
7941 while ((S->getFlags() & Scope::DeclScope) == 0 ||
7942 (S->getFlags() & Scope::TemplateParamScope) != 0)
7943 S = S->getParent();
7944
7945 // C++ [temp.pre]p6: [P2096]
7946 // A template, explicit specialization, or partial specialization shall not
7947 // have C linkage.
7948 DeclContext *Ctx = S->getEntity();
7949 if (Ctx && Ctx->isExternCContext()) {
7950 Diag(TemplateParams->getTemplateLoc(), diag::err_template_linkage)
7951 << TemplateParams->getSourceRange();
7952 if (const LinkageSpecDecl *LSD = Ctx->getExternCContext())
7953 Diag(LSD->getExternLoc(), diag::note_extern_c_begins_here);
7954 return true;
7955 }
7956 Ctx = Ctx ? Ctx->getRedeclContext() : nullptr;
7957
7958 // C++ [temp]p2:
7959 // A template-declaration can appear only as a namespace scope or
7960 // class scope declaration.
7961 // C++ [temp.expl.spec]p3:
7962 // An explicit specialization may be declared in any scope in which the
7963 // corresponding primary template may be defined.
7964 // C++ [temp.class.spec]p6: [P2096]
7965 // A partial specialization may be declared in any scope in which the
7966 // corresponding primary template may be defined.
7967 if (Ctx) {
7968 if (Ctx->isFileContext())
7969 return false;
7970 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(Ctx)) {
7971 // C++ [temp.mem]p2:
7972 // A local class shall not have member templates.
7973 if (RD->isLocalClass())
7974 return Diag(TemplateParams->getTemplateLoc(),
7975 diag::err_template_inside_local_class)
7976 << TemplateParams->getSourceRange();
7977 else
7978 return false;
7979 }
7980 }
7981
7982 return Diag(TemplateParams->getTemplateLoc(),
7983 diag::err_template_outside_namespace_or_class_scope)
7984 << TemplateParams->getSourceRange();
7985}
7986
7987/// Determine what kind of template specialization the given declaration
7988/// is.
7989static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D) {
7990 if (!D)
7991 return TSK_Undeclared;
7992
7993 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D))
7994 return Record->getTemplateSpecializationKind();
7995 if (FunctionDecl *Function = dyn_cast<FunctionDecl>(D))
7996 return Function->getTemplateSpecializationKind();
7997 if (VarDecl *Var = dyn_cast<VarDecl>(D))
7998 return Var->getTemplateSpecializationKind();
7999
8000 return TSK_Undeclared;
8001}
8002
8003/// Check whether a specialization is well-formed in the current
8004/// context.
8005///
8006/// This routine determines whether a template specialization can be declared
8007/// in the current context (C++ [temp.expl.spec]p2).
8008///
8009/// \param S the semantic analysis object for which this check is being
8010/// performed.
8011///
8012/// \param Specialized the entity being specialized or instantiated, which
8013/// may be a kind of template (class template, function template, etc.) or
8014/// a member of a class template (member function, static data member,
8015/// member class).
8016///
8017/// \param PrevDecl the previous declaration of this entity, if any.
8018///
8019/// \param Loc the location of the explicit specialization or instantiation of
8020/// this entity.
8021///
8022/// \param IsPartialSpecialization whether this is a partial specialization of
8023/// a class template.
8024///
8025/// \returns true if there was an error that we cannot recover from, false
8026/// otherwise.
8027static bool CheckTemplateSpecializationScope(Sema &S,
8028 NamedDecl *Specialized,
8029 NamedDecl *PrevDecl,
8030 SourceLocation Loc,
8031 bool IsPartialSpecialization) {
8032 // Keep these "kind" numbers in sync with the %select statements in the
8033 // various diagnostics emitted by this routine.
8034 int EntityKind = 0;
8035 if (isa<ClassTemplateDecl>(Specialized))
8036 EntityKind = IsPartialSpecialization? 1 : 0;
8037 else if (isa<VarTemplateDecl>(Specialized))
8038 EntityKind = IsPartialSpecialization ? 3 : 2;
8039 else if (isa<FunctionTemplateDecl>(Specialized))
8040 EntityKind = 4;
8041 else if (isa<CXXMethodDecl>(Specialized))
8042 EntityKind = 5;
8043 else if (isa<VarDecl>(Specialized))
8044 EntityKind = 6;
8045 else if (isa<RecordDecl>(Specialized))
8046 EntityKind = 7;
8047 else if (isa<EnumDecl>(Specialized) && S.getLangOpts().CPlusPlus11)
8048 EntityKind = 8;
8049 else {
8050 S.Diag(Loc, diag::err_template_spec_unknown_kind)
8051 << S.getLangOpts().CPlusPlus11;
8052 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
8053 return true;
8054 }
8055
8056 // C++ [temp.expl.spec]p2:
8057 // An explicit specialization may be declared in any scope in which
8058 // the corresponding primary template may be defined.
8059 if (S.CurContext->getRedeclContext()->isFunctionOrMethod()) {
8060 S.Diag(Loc, diag::err_template_spec_decl_function_scope)
8061 << Specialized;
8062 return true;
8063 }
8064
8065 // C++ [temp.class.spec]p6:
8066 // A class template partial specialization may be declared in any
8067 // scope in which the primary template may be defined.
8068 DeclContext *SpecializedContext =
8069 Specialized->getDeclContext()->getRedeclContext();
8070 DeclContext *DC = S.CurContext->getRedeclContext();
8071
8072 // Make sure that this redeclaration (or definition) occurs in the same
8073 // scope or an enclosing namespace.
8074 if (!(DC->isFileContext() ? DC->Encloses(SpecializedContext)
8075 : DC->Equals(SpecializedContext))) {
8076 if (isa<TranslationUnitDecl>(SpecializedContext))
8077 S.Diag(Loc, diag::err_template_spec_redecl_global_scope)
8078 << EntityKind << Specialized;
8079 else {
8080 auto *ND = cast<NamedDecl>(SpecializedContext);
8081 int Diag = diag::err_template_spec_redecl_out_of_scope;
8082 if (S.getLangOpts().MicrosoftExt && !DC->isRecord())
8083 Diag = diag::ext_ms_template_spec_redecl_out_of_scope;
8084 S.Diag(Loc, Diag) << EntityKind << Specialized
8085 << ND << isa<CXXRecordDecl>(ND);
8086 }
8087
8088 S.Diag(Specialized->getLocation(), diag::note_specialized_entity);
8089
8090 // Don't allow specializing in the wrong class during error recovery.
8091 // Otherwise, things can go horribly wrong.
8092 if (DC->isRecord())
8093 return true;
8094 }
8095
8096 return false;
8097}
8098
8099static SourceRange findTemplateParameterInType(unsigned Depth, Expr *E) {
8100 if (!E->isTypeDependent())
8101 return SourceLocation();
8102 DependencyChecker Checker(Depth, /*IgnoreNonTypeDependent*/true);
8103 Checker.TraverseStmt(E);
8104 if (Checker.MatchLoc.isInvalid())
8105 return E->getSourceRange();
8106 return Checker.MatchLoc;
8107}
8108
8109static SourceRange findTemplateParameter(unsigned Depth, TypeLoc TL) {
8110 if (!TL.getType()->isDependentType())
8111 return SourceLocation();
8112 DependencyChecker Checker(Depth, /*IgnoreNonTypeDependent*/true);
8113 Checker.TraverseTypeLoc(TL);
8114 if (Checker.MatchLoc.isInvalid())
8115 return TL.getSourceRange();
8116 return Checker.MatchLoc;
8117}
8118
8119/// Subroutine of Sema::CheckTemplatePartialSpecializationArgs
8120/// that checks non-type template partial specialization arguments.
8121static bool CheckNonTypeTemplatePartialSpecializationArgs(
8122 Sema &S, SourceLocation TemplateNameLoc, NonTypeTemplateParmDecl *Param,
8123 const TemplateArgument *Args, unsigned NumArgs, bool IsDefaultArgument) {
8124 for (unsigned I = 0; I != NumArgs; ++I) {
8125 if (Args[I].getKind() == TemplateArgument::Pack) {
8126 if (CheckNonTypeTemplatePartialSpecializationArgs(
8127 S, TemplateNameLoc, Param, Args[I].pack_begin(),
8128 Args[I].pack_size(), IsDefaultArgument))
8129 return true;
8130
8131 continue;
8132 }
8133
8134 if (Args[I].getKind() != TemplateArgument::Expression)
8135 continue;
8136
8137 Expr *ArgExpr = Args[I].getAsExpr();
8138
8139 // We can have a pack expansion of any of the bullets below.
8140 if (PackExpansionExpr *Expansion = dyn_cast<PackExpansionExpr>(ArgExpr))
8141 ArgExpr = Expansion->getPattern();
8142
8143 // Strip off any implicit casts we added as part of type checking.
8144 while (ImplicitCastExpr *ICE = dyn_cast<ImplicitCastExpr>(ArgExpr))
8145 ArgExpr = ICE->getSubExpr();
8146
8147 // C++ [temp.class.spec]p8:
8148 // A non-type argument is non-specialized if it is the name of a
8149 // non-type parameter. All other non-type arguments are
8150 // specialized.
8151 //
8152 // Below, we check the two conditions that only apply to
8153 // specialized non-type arguments, so skip any non-specialized
8154 // arguments.
8155 if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(ArgExpr))
8156 if (isa<NonTypeTemplateParmDecl>(DRE->getDecl()))
8157 continue;
8158
8159 // C++ [temp.class.spec]p9:
8160 // Within the argument list of a class template partial
8161 // specialization, the following restrictions apply:
8162 // -- A partially specialized non-type argument expression
8163 // shall not involve a template parameter of the partial
8164 // specialization except when the argument expression is a
8165 // simple identifier.
8166 // -- The type of a template parameter corresponding to a
8167 // specialized non-type argument shall not be dependent on a
8168 // parameter of the specialization.
8169 // DR1315 removes the first bullet, leaving an incoherent set of rules.
8170 // We implement a compromise between the original rules and DR1315:
8171 // -- A specialized non-type template argument shall not be
8172 // type-dependent and the corresponding template parameter
8173 // shall have a non-dependent type.
8174 SourceRange ParamUseRange =
8175 findTemplateParameterInType(Param->getDepth(), ArgExpr);
8176 if (ParamUseRange.isValid()) {
8177 if (IsDefaultArgument) {
8178 S.Diag(TemplateNameLoc,
8179 diag::err_dependent_non_type_arg_in_partial_spec);
8180 S.Diag(ParamUseRange.getBegin(),
8181 diag::note_dependent_non_type_default_arg_in_partial_spec)
8182 << ParamUseRange;
8183 } else {
8184 S.Diag(ParamUseRange.getBegin(),
8185 diag::err_dependent_non_type_arg_in_partial_spec)
8186 << ParamUseRange;
8187 }
8188 return true;
8189 }
8190
8191 ParamUseRange = findTemplateParameter(
8192 Param->getDepth(), Param->getTypeSourceInfo()->getTypeLoc());
8193 if (ParamUseRange.isValid()) {
8194 S.Diag(IsDefaultArgument ? TemplateNameLoc : ArgExpr->getBeginLoc(),
8195 diag::err_dependent_typed_non_type_arg_in_partial_spec)
8196 << Param->getType();
8197 S.Diag(Param->getLocation(), diag::note_template_param_here)
8198 << (IsDefaultArgument ? ParamUseRange : SourceRange())
8199 << ParamUseRange;
8200 return true;
8201 }
8202 }
8203
8204 return false;
8205}
8206
8207/// Check the non-type template arguments of a class template
8208/// partial specialization according to C++ [temp.class.spec]p9.
8209///
8210/// \param TemplateNameLoc the location of the template name.
8211/// \param PrimaryTemplate the template parameters of the primary class
8212/// template.
8213/// \param NumExplicit the number of explicitly-specified template arguments.
8214/// \param TemplateArgs the template arguments of the class template
8215/// partial specialization.
8216///
8217/// \returns \c true if there was an error, \c false otherwise.
8218bool Sema::CheckTemplatePartialSpecializationArgs(
8219 SourceLocation TemplateNameLoc, TemplateDecl *PrimaryTemplate,
8220 unsigned NumExplicit, ArrayRef<TemplateArgument> TemplateArgs) {
8221 // We have to be conservative when checking a template in a dependent
8222 // context.
8223 if (PrimaryTemplate->getDeclContext()->isDependentContext())
8224 return false;
8225
8226 TemplateParameterList *TemplateParams =
8227 PrimaryTemplate->getTemplateParameters();
8228 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
8229 NonTypeTemplateParmDecl *Param
8230 = dyn_cast<NonTypeTemplateParmDecl>(TemplateParams->getParam(I));
8231 if (!Param)
8232 continue;
8233
8234 if (CheckNonTypeTemplatePartialSpecializationArgs(*this, TemplateNameLoc,
8235 Param, &TemplateArgs[I],
8236 1, I >= NumExplicit))
8237 return true;
8238 }
8239
8240 return false;
8241}
8242
8243DeclResult Sema::ActOnClassTemplateSpecialization(
8244 Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
8245 SourceLocation ModulePrivateLoc, CXXScopeSpec &SS,
8246 TemplateIdAnnotation &TemplateId, const ParsedAttributesView &Attr,
8247 MultiTemplateParamsArg TemplateParameterLists, SkipBodyInfo *SkipBody) {
8248 assert(TUK != TUK_Reference && "References are not specializations")(static_cast <bool> (TUK != TUK_Reference && "References are not specializations"
) ? void (0) : __assert_fail ("TUK != TUK_Reference && \"References are not specializations\""
, "clang/lib/Sema/SemaTemplate.cpp", 8248, __extension__ __PRETTY_FUNCTION__
))
;
8249
8250 // NOTE: KWLoc is the location of the tag keyword. This will instead
8251 // store the location of the outermost template keyword in the declaration.
8252 SourceLocation TemplateKWLoc = TemplateParameterLists.size() > 0
8253 ? TemplateParameterLists[0]->getTemplateLoc() : KWLoc;
8254 SourceLocation TemplateNameLoc = TemplateId.TemplateNameLoc;
8255 SourceLocation LAngleLoc = TemplateId.LAngleLoc;
8256 SourceLocation RAngleLoc = TemplateId.RAngleLoc;
8257
8258 // Find the class template we're specializing
8259 TemplateName Name = TemplateId.Template.get();
8260 ClassTemplateDecl *ClassTemplate
8261 = dyn_cast_or_null<ClassTemplateDecl>(Name.getAsTemplateDecl());
8262
8263 if (!ClassTemplate) {
8264 Diag(TemplateNameLoc, diag::err_not_class_template_specialization)
8265 << (Name.getAsTemplateDecl() &&
8266 isa<TemplateTemplateParmDecl>(Name.getAsTemplateDecl()));
8267 return true;
8268 }
8269
8270 bool isMemberSpecialization = false;
8271 bool isPartialSpecialization = false;
8272
8273 // Check the validity of the template headers that introduce this
8274 // template.
8275 // FIXME: We probably shouldn't complain about these headers for
8276 // friend declarations.
8277 bool Invalid = false;
8278 TemplateParameterList *TemplateParams =
8279 MatchTemplateParametersToScopeSpecifier(
8280 KWLoc, TemplateNameLoc, SS, &TemplateId,
8281 TemplateParameterLists, TUK == TUK_Friend, isMemberSpecialization,
8282 Invalid);
8283 if (Invalid)
8284 return true;
8285
8286 // Check that we can declare a template specialization here.
8287 if (TemplateParams && CheckTemplateDeclScope(S, TemplateParams))
8288 return true;
8289
8290 if (TemplateParams && TemplateParams->size() > 0) {
8291 isPartialSpecialization = true;
8292
8293 if (TUK == TUK_Friend) {
8294 Diag(KWLoc, diag::err_partial_specialization_friend)
8295 << SourceRange(LAngleLoc, RAngleLoc);
8296 return true;
8297 }
8298
8299 // C++ [temp.class.spec]p10:
8300 // The template parameter list of a specialization shall not
8301 // contain default template argument values.
8302 for (unsigned I = 0, N = TemplateParams->size(); I != N; ++I) {
8303 Decl *Param = TemplateParams->getParam(I);
8304 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param)) {
8305 if (TTP->hasDefaultArgument()) {
8306 Diag(TTP->getDefaultArgumentLoc(),
8307 diag::err_default_arg_in_partial_spec);
8308 TTP->removeDefaultArgument();
8309 }
8310 } else if (NonTypeTemplateParmDecl *NTTP
8311 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
8312 if (Expr *DefArg = NTTP->getDefaultArgument()) {
8313 Diag(NTTP->getDefaultArgumentLoc(),
8314 diag::err_default_arg_in_partial_spec)
8315 << DefArg->getSourceRange();
8316 NTTP->removeDefaultArgument();
8317 }
8318 } else {
8319 TemplateTemplateParmDecl *TTP = cast<TemplateTemplateParmDecl>(Param);
8320 if (TTP->hasDefaultArgument()) {
8321 Diag(TTP->getDefaultArgument().getLocation(),
8322 diag::err_default_arg_in_partial_spec)
8323 << TTP->getDefaultArgument().getSourceRange();
8324 TTP->removeDefaultArgument();
8325 }
8326 }
8327 }
8328 } else if (TemplateParams) {
8329 if (TUK == TUK_Friend)
8330 Diag(KWLoc, diag::err_template_spec_friend)
8331 << FixItHint::CreateRemoval(
8332 SourceRange(TemplateParams->getTemplateLoc(),
8333 TemplateParams->getRAngleLoc()))
8334 << SourceRange(LAngleLoc, RAngleLoc);
8335 } else {
8336 assert(TUK == TUK_Friend && "should have a 'template<>' for this decl")(static_cast <bool> (TUK == TUK_Friend && "should have a 'template<>' for this decl"
) ? void (0) : __assert_fail ("TUK == TUK_Friend && \"should have a 'template<>' for this decl\""
, "clang/lib/Sema/SemaTemplate.cpp", 8336, __extension__ __PRETTY_FUNCTION__
))
;
8337 }
8338
8339 // Check that the specialization uses the same tag kind as the
8340 // original template.
8341 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
8342 assert(Kind != TTK_Enum && "Invalid enum tag in class template spec!")(static_cast <bool> (Kind != TTK_Enum && "Invalid enum tag in class template spec!"
) ? void (0) : __assert_fail ("Kind != TTK_Enum && \"Invalid enum tag in class template spec!\""
, "clang/lib/Sema/SemaTemplate.cpp", 8342, __extension__ __PRETTY_FUNCTION__
))
;
8343 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
8344 Kind, TUK == TUK_Definition, KWLoc,
8345 ClassTemplate->getIdentifier())) {
8346 Diag(KWLoc, diag::err_use_with_wrong_tag)
8347 << ClassTemplate
8348 << FixItHint::CreateReplacement(KWLoc,
8349 ClassTemplate->getTemplatedDecl()->getKindName());
8350 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
8351 diag::note_previous_use);
8352 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
8353 }
8354
8355 // Translate the parser's template argument list in our AST format.
8356 TemplateArgumentListInfo TemplateArgs =
8357 makeTemplateArgumentListInfo(*this, TemplateId);
8358
8359 // Check for unexpanded parameter packs in any of the template arguments.
8360 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
8361 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
8362 UPPC_PartialSpecialization))
8363 return true;
8364
8365 // Check that the template argument list is well-formed for this
8366 // template.
8367 SmallVector<TemplateArgument, 4> Converted;
8368 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
8369 TemplateArgs, false, Converted,
8370 /*UpdateArgsWithConversions=*/true))
8371 return true;
8372
8373 // Find the class template (partial) specialization declaration that
8374 // corresponds to these arguments.
8375 if (isPartialSpecialization) {
8376 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, ClassTemplate,
8377 TemplateArgs.size(), Converted))
8378 return true;
8379
8380 // FIXME: Move this to CheckTemplatePartialSpecializationArgs so we
8381 // also do it during instantiation.
8382 if (!Name.isDependent() &&
8383 !TemplateSpecializationType::anyDependentTemplateArguments(TemplateArgs,
8384 Converted)) {
8385 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
8386 << ClassTemplate->getDeclName();
8387 isPartialSpecialization = false;
8388 }
8389 }
8390
8391 void *InsertPos = nullptr;
8392 ClassTemplateSpecializationDecl *PrevDecl = nullptr;
8393
8394 if (isPartialSpecialization)
8395 PrevDecl = ClassTemplate->findPartialSpecialization(Converted,
8396 TemplateParams,
8397 InsertPos);
8398 else
8399 PrevDecl = ClassTemplate->findSpecialization(Converted, InsertPos);
8400
8401 ClassTemplateSpecializationDecl *Specialization = nullptr;
8402
8403 // Check whether we can declare a class template specialization in
8404 // the current scope.
8405 if (TUK != TUK_Friend &&
8406 CheckTemplateSpecializationScope(*this, ClassTemplate, PrevDecl,
8407 TemplateNameLoc,
8408 isPartialSpecialization))
8409 return true;
8410
8411 // The canonical type
8412 QualType CanonType;
8413 if (isPartialSpecialization) {
8414 // Build the canonical type that describes the converted template
8415 // arguments of the class template partial specialization.
8416 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
8417 CanonType = Context.getTemplateSpecializationType(CanonTemplate,
8418 Converted);
8419
8420 if (Context.hasSameType(CanonType,
8421 ClassTemplate->getInjectedClassNameSpecialization()) &&
8422 (!Context.getLangOpts().CPlusPlus20 ||
8423 !TemplateParams->hasAssociatedConstraints())) {
8424 // C++ [temp.class.spec]p9b3:
8425 //
8426 // -- The argument list of the specialization shall not be identical
8427 // to the implicit argument list of the primary template.
8428 //
8429 // This rule has since been removed, because it's redundant given DR1495,
8430 // but we keep it because it produces better diagnostics and recovery.
8431 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
8432 << /*class template*/0 << (TUK == TUK_Definition)
8433 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
8434 return CheckClassTemplate(S, TagSpec, TUK, KWLoc, SS,
8435 ClassTemplate->getIdentifier(),
8436 TemplateNameLoc,
8437 Attr,
8438 TemplateParams,
8439 AS_none, /*ModulePrivateLoc=*/SourceLocation(),
8440 /*FriendLoc*/SourceLocation(),
8441 TemplateParameterLists.size() - 1,
8442 TemplateParameterLists.data());
8443 }
8444
8445 // Create a new class template partial specialization declaration node.
8446 ClassTemplatePartialSpecializationDecl *PrevPartial
8447 = cast_or_null<ClassTemplatePartialSpecializationDecl>(PrevDecl);
8448 ClassTemplatePartialSpecializationDecl *Partial
8449 = ClassTemplatePartialSpecializationDecl::Create(Context, Kind,
8450 ClassTemplate->getDeclContext(),
8451 KWLoc, TemplateNameLoc,
8452 TemplateParams,
8453 ClassTemplate,
8454 Converted,
8455 TemplateArgs,
8456 CanonType,
8457 PrevPartial);
8458 SetNestedNameSpecifier(*this, Partial, SS);
8459 if (TemplateParameterLists.size() > 1 && SS.isSet()) {
8460 Partial->setTemplateParameterListsInfo(
8461 Context, TemplateParameterLists.drop_back(1));
8462 }
8463
8464 if (!PrevPartial)
8465 ClassTemplate->AddPartialSpecialization(Partial, InsertPos);
8466 Specialization = Partial;
8467
8468 // If we are providing an explicit specialization of a member class
8469 // template specialization, make a note of that.
8470 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
8471 PrevPartial->setMemberSpecialization();
8472
8473 CheckTemplatePartialSpecialization(Partial);
8474 } else {
8475 // Create a new class template specialization declaration node for
8476 // this explicit specialization or friend declaration.
8477 Specialization
8478 = ClassTemplateSpecializationDecl::Create(Context, Kind,
8479 ClassTemplate->getDeclContext(),
8480 KWLoc, TemplateNameLoc,
8481 ClassTemplate,
8482 Converted,
8483 PrevDecl);
8484 SetNestedNameSpecifier(*this, Specialization, SS);
8485 if (TemplateParameterLists.size() > 0) {
8486 Specialization->setTemplateParameterListsInfo(Context,
8487 TemplateParameterLists);
8488 }
8489
8490 if (!PrevDecl)
8491 ClassTemplate->AddSpecialization(Specialization, InsertPos);
8492
8493 if (CurContext->isDependentContext()) {
8494 TemplateName CanonTemplate = Context.getCanonicalTemplateName(Name);
8495 CanonType = Context.getTemplateSpecializationType(
8496 CanonTemplate, Converted);
8497 } else {
8498 CanonType = Context.getTypeDeclType(Specialization);
8499 }
8500 }
8501
8502 // C++ [temp.expl.spec]p6:
8503 // If a template, a member template or the member of a class template is
8504 // explicitly specialized then that specialization shall be declared
8505 // before the first use of that specialization that would cause an implicit
8506 // instantiation to take place, in every translation unit in which such a
8507 // use occurs; no diagnostic is required.
8508 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
8509 bool Okay = false;
8510 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
8511 // Is there any previous explicit specialization declaration?
8512 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
8513 Okay = true;
8514 break;
8515 }
8516 }
8517
8518 if (!Okay) {
8519 SourceRange Range(TemplateNameLoc, RAngleLoc);
8520 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
8521 << Context.getTypeDeclType(Specialization) << Range;
8522
8523 Diag(PrevDecl->getPointOfInstantiation(),
8524 diag::note_instantiation_required_here)
8525 << (PrevDecl->getTemplateSpecializationKind()
8526 != TSK_ImplicitInstantiation);
8527 return true;
8528 }
8529 }
8530
8531 // If this is not a friend, note that this is an explicit specialization.
8532 if (TUK != TUK_Friend)
8533 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
8534
8535 // Check that this isn't a redefinition of this specialization.
8536 if (TUK == TUK_Definition) {
8537 RecordDecl *Def = Specialization->getDefinition();
8538 NamedDecl *Hidden = nullptr;
8539 if (Def && SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
8540 SkipBody->ShouldSkip = true;
8541 SkipBody->Previous = Def;
8542 makeMergedDefinitionVisible(Hidden);
8543 } else if (Def) {
8544 SourceRange Range(TemplateNameLoc, RAngleLoc);
8545 Diag(TemplateNameLoc, diag::err_redefinition) << Specialization << Range;
8546 Diag(Def->getLocation(), diag::note_previous_definition);
8547 Specialization->setInvalidDecl();
8548 return true;
8549 }
8550 }
8551
8552 ProcessDeclAttributeList(S, Specialization, Attr);
8553
8554 // Add alignment attributes if necessary; these attributes are checked when
8555 // the ASTContext lays out the structure.
8556 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) {
8557 AddAlignmentAttributesForRecord(Specialization);
8558 AddMsStructLayoutForRecord(Specialization);
8559 }
8560
8561 if (ModulePrivateLoc.isValid())
8562 Diag(Specialization->getLocation(), diag::err_module_private_specialization)
8563 << (isPartialSpecialization? 1 : 0)
8564 << FixItHint::CreateRemoval(ModulePrivateLoc);
8565
8566 // Build the fully-sugared type for this class template
8567 // specialization as the user wrote in the specialization
8568 // itself. This means that we'll pretty-print the type retrieved
8569 // from the specialization's declaration the way that the user
8570 // actually wrote the specialization, rather than formatting the
8571 // name based on the "canonical" representation used to store the
8572 // template arguments in the specialization.
8573 TypeSourceInfo *WrittenTy
8574 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
8575 TemplateArgs, CanonType);
8576 if (TUK != TUK_Friend) {
8577 Specialization->setTypeAsWritten(WrittenTy);
8578 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
8579 }
8580
8581 // C++ [temp.expl.spec]p9:
8582 // A template explicit specialization is in the scope of the
8583 // namespace in which the template was defined.
8584 //
8585 // We actually implement this paragraph where we set the semantic
8586 // context (in the creation of the ClassTemplateSpecializationDecl),
8587 // but we also maintain the lexical context where the actual
8588 // definition occurs.
8589 Specialization->setLexicalDeclContext(CurContext);
8590
8591 // We may be starting the definition of this specialization.
8592 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip))
8593 Specialization->startDefinition();
8594
8595 if (TUK == TUK_Friend) {
8596 FriendDecl *Friend = FriendDecl::Create(Context, CurContext,
8597 TemplateNameLoc,
8598 WrittenTy,
8599 /*FIXME:*/KWLoc);
8600 Friend->setAccess(AS_public);
8601 CurContext->addDecl(Friend);
8602 } else {
8603 // Add the specialization into its lexical context, so that it can
8604 // be seen when iterating through the list of declarations in that
8605 // context. However, specializations are not found by name lookup.
8606 CurContext->addDecl(Specialization);
8607 }
8608
8609 if (SkipBody && SkipBody->ShouldSkip)
8610 return SkipBody->Previous;
8611
8612 return Specialization;
8613}
8614
8615Decl *Sema::ActOnTemplateDeclarator(Scope *S,
8616 MultiTemplateParamsArg TemplateParameterLists,
8617 Declarator &D) {
8618 Decl *NewDecl = HandleDeclarator(S, D, TemplateParameterLists);
8619 ActOnDocumentableDecl(NewDecl);
8620 return NewDecl;
8621}
8622
8623Decl *Sema::ActOnConceptDefinition(Scope *S,
8624 MultiTemplateParamsArg TemplateParameterLists,
8625 IdentifierInfo *Name, SourceLocation NameLoc,
8626 Expr *ConstraintExpr) {
8627 DeclContext *DC = CurContext;
8628
8629 if (!DC->getRedeclContext()->isFileContext()) {
8630 Diag(NameLoc,
8631 diag::err_concept_decls_may_only_appear_in_global_namespace_scope);
8632 return nullptr;
8633 }
8634
8635 if (TemplateParameterLists.size() > 1) {
8636 Diag(NameLoc, diag::err_concept_extra_headers);
8637 return nullptr;
8638 }
8639
8640 if (TemplateParameterLists.front()->size() == 0) {
8641 Diag(NameLoc, diag::err_concept_no_parameters);
8642 return nullptr;
8643 }
8644
8645 if (DiagnoseUnexpandedParameterPack(ConstraintExpr))
8646 return nullptr;
8647
8648 ConceptDecl *NewDecl = ConceptDecl::Create(Context, DC, NameLoc, Name,
8649 TemplateParameterLists.front(),
8650 ConstraintExpr);
8651
8652 if (NewDecl->hasAssociatedConstraints()) {
8653 // C++2a [temp.concept]p4:
8654 // A concept shall not have associated constraints.
8655 Diag(NameLoc, diag::err_concept_no_associated_constraints);
8656 NewDecl->setInvalidDecl();
8657 }
8658
8659 // Check for conflicting previous declaration.
8660 DeclarationNameInfo NameInfo(NewDecl->getDeclName(), NameLoc);
8661 LookupResult Previous(*this, NameInfo, LookupOrdinaryName,
8662 ForVisibleRedeclaration);
8663 LookupName(Previous, S);
8664
8665 FilterLookupForScope(Previous, DC, S, /*ConsiderLinkage=*/false,
8666 /*AllowInlineNamespace*/false);
8667 if (!Previous.empty()) {
8668 auto *Old = Previous.getRepresentativeDecl();
8669 Diag(NameLoc, isa<ConceptDecl>(Old) ? diag::err_redefinition :
8670 diag::err_redefinition_different_kind) << NewDecl->getDeclName();
8671 Diag(Old->getLocation(), diag::note_previous_definition);
8672 }
8673
8674 ActOnDocumentableDecl(NewDecl);
8675 PushOnScopeChains(NewDecl, S);
8676 return NewDecl;
8677}
8678
8679/// \brief Strips various properties off an implicit instantiation
8680/// that has just been explicitly specialized.
8681static void StripImplicitInstantiation(NamedDecl *D) {
8682 D->dropAttr<DLLImportAttr>();
8683 D->dropAttr<DLLExportAttr>();
8684
8685 if (FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
8686 FD->setInlineSpecified(false);
8687}
8688
8689/// Compute the diagnostic location for an explicit instantiation
8690// declaration or definition.
8691static SourceLocation DiagLocForExplicitInstantiation(
8692 NamedDecl* D, SourceLocation PointOfInstantiation) {
8693 // Explicit instantiations following a specialization have no effect and
8694 // hence no PointOfInstantiation. In that case, walk decl backwards
8695 // until a valid name loc is found.
8696 SourceLocation PrevDiagLoc = PointOfInstantiation;
8697 for (Decl *Prev = D; Prev && !PrevDiagLoc.isValid();
8698 Prev = Prev->getPreviousDecl()) {
8699 PrevDiagLoc = Prev->getLocation();
8700 }
8701 assert(PrevDiagLoc.isValid() &&(static_cast <bool> (PrevDiagLoc.isValid() && "Explicit instantiation without point of instantiation?"
) ? void (0) : __assert_fail ("PrevDiagLoc.isValid() && \"Explicit instantiation without point of instantiation?\""
, "clang/lib/Sema/SemaTemplate.cpp", 8702, __extension__ __PRETTY_FUNCTION__
))
8702 "Explicit instantiation without point of instantiation?")(static_cast <bool> (PrevDiagLoc.isValid() && "Explicit instantiation without point of instantiation?"
) ? void (0) : __assert_fail ("PrevDiagLoc.isValid() && \"Explicit instantiation without point of instantiation?\""
, "clang/lib/Sema/SemaTemplate.cpp", 8702, __extension__ __PRETTY_FUNCTION__
))
;
8703 return PrevDiagLoc;
8704}
8705
8706/// Diagnose cases where we have an explicit template specialization
8707/// before/after an explicit template instantiation, producing diagnostics
8708/// for those cases where they are required and determining whether the
8709/// new specialization/instantiation will have any effect.
8710///
8711/// \param NewLoc the location of the new explicit specialization or
8712/// instantiation.
8713///
8714/// \param NewTSK the kind of the new explicit specialization or instantiation.
8715///
8716/// \param PrevDecl the previous declaration of the entity.
8717///
8718/// \param PrevTSK the kind of the old explicit specialization or instantiatin.
8719///
8720/// \param PrevPointOfInstantiation if valid, indicates where the previous
8721/// declaration was instantiated (either implicitly or explicitly).
8722///
8723/// \param HasNoEffect will be set to true to indicate that the new
8724/// specialization or instantiation has no effect and should be ignored.
8725///
8726/// \returns true if there was an error that should prevent the introduction of
8727/// the new declaration into the AST, false otherwise.
8728bool
8729Sema::CheckSpecializationInstantiationRedecl(SourceLocation NewLoc,
8730 TemplateSpecializationKind NewTSK,
8731 NamedDecl *PrevDecl,
8732 TemplateSpecializationKind PrevTSK,
8733 SourceLocation PrevPointOfInstantiation,
8734 bool &HasNoEffect) {
8735 HasNoEffect = false;
8736
8737 switch (NewTSK) {
8738 case TSK_Undeclared:
8739 case TSK_ImplicitInstantiation:
8740 assert((static_cast <bool> ((PrevTSK == TSK_Undeclared || PrevTSK
== TSK_ImplicitInstantiation) && "previous declaration must be implicit!"
) ? void (0) : __assert_fail ("(PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) && \"previous declaration must be implicit!\""
, "clang/lib/Sema/SemaTemplate.cpp", 8742, __extension__ __PRETTY_FUNCTION__
))
8741 (PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) &&(static_cast <bool> ((PrevTSK == TSK_Undeclared || PrevTSK
== TSK_ImplicitInstantiation) && "previous declaration must be implicit!"
) ? void (0) : __assert_fail ("(PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) && \"previous declaration must be implicit!\""
, "clang/lib/Sema/SemaTemplate.cpp", 8742, __extension__ __PRETTY_FUNCTION__
))
8742 "previous declaration must be implicit!")(static_cast <bool> ((PrevTSK == TSK_Undeclared || PrevTSK
== TSK_ImplicitInstantiation) && "previous declaration must be implicit!"
) ? void (0) : __assert_fail ("(PrevTSK == TSK_Undeclared || PrevTSK == TSK_ImplicitInstantiation) && \"previous declaration must be implicit!\""
, "clang/lib/Sema/SemaTemplate.cpp", 8742, __extension__ __PRETTY_FUNCTION__
))
;
8743 return false;
8744
8745 case TSK_ExplicitSpecialization:
8746 switch (PrevTSK) {
8747 case TSK_Undeclared:
8748 case TSK_ExplicitSpecialization:
8749 // Okay, we're just specializing something that is either already
8750 // explicitly specialized or has merely been mentioned without any
8751 // instantiation.
8752 return false;
8753
8754 case TSK_ImplicitInstantiation:
8755 if (PrevPointOfInstantiation.isInvalid()) {
8756 // The declaration itself has not actually been instantiated, so it is
8757 // still okay to specialize it.
8758 StripImplicitInstantiation(PrevDecl);
8759 return false;
8760 }
8761 // Fall through
8762 LLVM_FALLTHROUGH[[gnu::fallthrough]];
8763
8764 case TSK_ExplicitInstantiationDeclaration:
8765 case TSK_ExplicitInstantiationDefinition:
8766 assert((PrevTSK == TSK_ImplicitInstantiation ||(static_cast <bool> ((PrevTSK == TSK_ImplicitInstantiation
|| PrevPointOfInstantiation.isValid()) && "Explicit instantiation without point of instantiation?"
) ? void (0) : __assert_fail ("(PrevTSK == TSK_ImplicitInstantiation || PrevPointOfInstantiation.isValid()) && \"Explicit instantiation without point of instantiation?\""
, "clang/lib/Sema/SemaTemplate.cpp", 8768, __extension__ __PRETTY_FUNCTION__
))
8767 PrevPointOfInstantiation.isValid()) &&(static_cast <bool> ((PrevTSK == TSK_ImplicitInstantiation
|| PrevPointOfInstantiation.isValid()) && "Explicit instantiation without point of instantiation?"
) ? void (0) : __assert_fail ("(PrevTSK == TSK_ImplicitInstantiation || PrevPointOfInstantiation.isValid()) && \"Explicit instantiation without point of instantiation?\""
, "clang/lib/Sema/SemaTemplate.cpp", 8768, __extension__ __PRETTY_FUNCTION__
))
8768 "Explicit instantiation without point of instantiation?")(static_cast <bool> ((PrevTSK == TSK_ImplicitInstantiation
|| PrevPointOfInstantiation.isValid()) && "Explicit instantiation without point of instantiation?"
) ? void (0) : __assert_fail ("(PrevTSK == TSK_ImplicitInstantiation || PrevPointOfInstantiation.isValid()) && \"Explicit instantiation without point of instantiation?\""
, "clang/lib/Sema/SemaTemplate.cpp", 8768, __extension__ __PRETTY_FUNCTION__
))
;
8769
8770 // C++ [temp.expl.spec]p6:
8771 // If a template, a member template or the member of a class template
8772 // is explicitly specialized then that specialization shall be declared
8773 // before the first use of that specialization that would cause an
8774 // implicit instantiation to take place, in every translation unit in
8775 // which such a use occurs; no diagnostic is required.
8776 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
8777 // Is there any previous explicit specialization declaration?
8778 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization)
8779 return false;
8780 }
8781
8782 Diag(NewLoc, diag::err_specialization_after_instantiation)
8783 << PrevDecl;
8784 Diag(PrevPointOfInstantiation, diag::note_instantiation_required_here)
8785 << (PrevTSK != TSK_ImplicitInstantiation);
8786
8787 return true;
8788 }
8789 llvm_unreachable("The switch over PrevTSK must be exhaustive.")::llvm::llvm_unreachable_internal("The switch over PrevTSK must be exhaustive."
, "clang/lib/Sema/SemaTemplate.cpp", 8789)
;
8790
8791 case TSK_ExplicitInstantiationDeclaration:
8792 switch (PrevTSK) {
8793 case TSK_ExplicitInstantiationDeclaration:
8794 // This explicit instantiation declaration is redundant (that's okay).
8795 HasNoEffect = true;
8796 return false;
8797
8798 case TSK_Undeclared:
8799 case TSK_ImplicitInstantiation:
8800 // We're explicitly instantiating something that may have already been
8801 // implicitly instantiated; that's fine.
8802 return false;
8803
8804 case TSK_ExplicitSpecialization:
8805 // C++0x [temp.explicit]p4:
8806 // For a given set of template parameters, if an explicit instantiation
8807 // of a template appears after a declaration of an explicit
8808 // specialization for that template, the explicit instantiation has no
8809 // effect.
8810 HasNoEffect = true;
8811 return false;
8812
8813 case TSK_ExplicitInstantiationDefinition:
8814 // C++0x [temp.explicit]p10:
8815 // If an entity is the subject of both an explicit instantiation
8816 // declaration and an explicit instantiation definition in the same
8817 // translation unit, the definition shall follow the declaration.
8818 Diag(NewLoc,
8819 diag::err_explicit_instantiation_declaration_after_definition);
8820
8821 // Explicit instantiations following a specialization have no effect and
8822 // hence no PrevPointOfInstantiation. In that case, walk decl backwards
8823 // until a valid name loc is found.
8824 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
8825 diag::note_explicit_instantiation_definition_here);
8826 HasNoEffect = true;
8827 return false;
8828 }
8829 llvm_unreachable("Unexpected TemplateSpecializationKind!")::llvm::llvm_unreachable_internal("Unexpected TemplateSpecializationKind!"
, "clang/lib/Sema/SemaTemplate.cpp", 8829)
;
8830
8831 case TSK_ExplicitInstantiationDefinition:
8832 switch (PrevTSK) {
8833 case TSK_Undeclared:
8834 case TSK_ImplicitInstantiation:
8835 // We're explicitly instantiating something that may have already been
8836 // implicitly instantiated; that's fine.
8837 return false;
8838
8839 case TSK_ExplicitSpecialization:
8840 // C++ DR 259, C++0x [temp.explicit]p4:
8841 // For a given set of template parameters, if an explicit
8842 // instantiation of a template appears after a declaration of
8843 // an explicit specialization for that template, the explicit
8844 // instantiation has no effect.
8845 Diag(NewLoc, diag::warn_explicit_instantiation_after_specialization)
8846 << PrevDecl;
8847 Diag(PrevDecl->getLocation(),
8848 diag::note_previous_template_specialization);
8849 HasNoEffect = true;
8850 return false;
8851
8852 case TSK_ExplicitInstantiationDeclaration:
8853 // We're explicitly instantiating a definition for something for which we
8854 // were previously asked to suppress instantiations. That's fine.
8855
8856 // C++0x [temp.explicit]p4:
8857 // For a given set of template parameters, if an explicit instantiation
8858 // of a template appears after a declaration of an explicit
8859 // specialization for that template, the explicit instantiation has no
8860 // effect.
8861 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
8862 // Is there any previous explicit specialization declaration?
8863 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
8864 HasNoEffect = true;
8865 break;
8866 }
8867 }
8868
8869 return false;
8870
8871 case TSK_ExplicitInstantiationDefinition:
8872 // C++0x [temp.spec]p5:
8873 // For a given template and a given set of template-arguments,
8874 // - an explicit instantiation definition shall appear at most once
8875 // in a program,
8876
8877 // MSVCCompat: MSVC silently ignores duplicate explicit instantiations.
8878 Diag(NewLoc, (getLangOpts().MSVCCompat)
8879 ? diag::ext_explicit_instantiation_duplicate
8880 : diag::err_explicit_instantiation_duplicate)
8881 << PrevDecl;
8882 Diag(DiagLocForExplicitInstantiation(PrevDecl, PrevPointOfInstantiation),
8883 diag::note_previous_explicit_instantiation);
8884 HasNoEffect = true;
8885 return false;
8886 }
8887 }
8888
8889 llvm_unreachable("Missing specialization/instantiation case?")::llvm::llvm_unreachable_internal("Missing specialization/instantiation case?"
, "clang/lib/Sema/SemaTemplate.cpp", 8889)
;
8890}
8891
8892/// Perform semantic analysis for the given dependent function
8893/// template specialization.
8894///
8895/// The only possible way to get a dependent function template specialization
8896/// is with a friend declaration, like so:
8897///
8898/// \code
8899/// template \<class T> void foo(T);
8900/// template \<class T> class A {
8901/// friend void foo<>(T);
8902/// };
8903/// \endcode
8904///
8905/// There really isn't any useful analysis we can do here, so we
8906/// just store the information.
8907bool
8908Sema::CheckDependentFunctionTemplateSpecialization(FunctionDecl *FD,
8909 const TemplateArgumentListInfo &ExplicitTemplateArgs,
8910 LookupResult &Previous) {
8911 // Remove anything from Previous that isn't a function template in
8912 // the correct context.
8913 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
8914 LookupResult::Filter F = Previous.makeFilter();
8915 enum DiscardReason { NotAFunctionTemplate, NotAMemberOfEnclosing };
8916 SmallVector<std::pair<DiscardReason, Decl *>, 8> DiscardedCandidates;
8917 while (F.hasNext()) {
8918 NamedDecl *D = F.next()->getUnderlyingDecl();
8919 if (!isa<FunctionTemplateDecl>(D)) {
8920 F.erase();
8921 DiscardedCandidates.push_back(std::make_pair(NotAFunctionTemplate, D));
8922 continue;
8923 }
8924
8925 if (!FDLookupContext->InEnclosingNamespaceSetOf(
8926 D->getDeclContext()->getRedeclContext())) {
8927 F.erase();
8928 DiscardedCandidates.push_back(std::make_pair(NotAMemberOfEnclosing, D));
8929 continue;
8930 }
8931 }
8932 F.done();
8933
8934 if (Previous.empty()) {
8935 Diag(FD->getLocation(),
8936 diag::err_dependent_function_template_spec_no_match);
8937 for (auto &P : DiscardedCandidates)
8938 Diag(P.second->getLocation(),
8939 diag::note_dependent_function_template_spec_discard_reason)
8940 << P.first;
8941 return true;
8942 }
8943
8944 FD->setDependentTemplateSpecialization(Context, Previous.asUnresolvedSet(),
8945 ExplicitTemplateArgs);
8946 return false;
8947}
8948
8949/// Perform semantic analysis for the given function template
8950/// specialization.
8951///
8952/// This routine performs all of the semantic analysis required for an
8953/// explicit function template specialization. On successful completion,
8954/// the function declaration \p FD will become a function template
8955/// specialization.
8956///
8957/// \param FD the function declaration, which will be updated to become a
8958/// function template specialization.
8959///
8960/// \param ExplicitTemplateArgs the explicitly-provided template arguments,
8961/// if any. Note that this may be valid info even when 0 arguments are
8962/// explicitly provided as in, e.g., \c void sort<>(char*, char*);
8963/// as it anyway contains info on the angle brackets locations.
8964///
8965/// \param Previous the set of declarations that may be specialized by
8966/// this function specialization.
8967///
8968/// \param QualifiedFriend whether this is a lookup for a qualified friend
8969/// declaration with no explicit template argument list that might be
8970/// befriending a function template specialization.
8971bool Sema::CheckFunctionTemplateSpecialization(
8972 FunctionDecl *FD, TemplateArgumentListInfo *ExplicitTemplateArgs,
8973 LookupResult &Previous, bool QualifiedFriend) {
8974 // The set of function template specializations that could match this
8975 // explicit function template specialization.
8976 UnresolvedSet<8> Candidates;
8977 TemplateSpecCandidateSet FailedCandidates(FD->getLocation(),
8978 /*ForTakingAddress=*/false);
8979
8980 llvm::SmallDenseMap<FunctionDecl *, TemplateArgumentListInfo, 8>
8981 ConvertedTemplateArgs;
8982
8983 DeclContext *FDLookupContext = FD->getDeclContext()->getRedeclContext();
8984 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
8985 I != E; ++I) {
8986 NamedDecl *Ovl = (*I)->getUnderlyingDecl();
8987 if (FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Ovl)) {
8988 // Only consider templates found within the same semantic lookup scope as
8989 // FD.
8990 if (!FDLookupContext->InEnclosingNamespaceSetOf(
8991 Ovl->getDeclContext()->getRedeclContext()))
8992 continue;
8993
8994 // When matching a constexpr member function template specialization
8995 // against the primary template, we don't yet know whether the
8996 // specialization has an implicit 'const' (because we don't know whether
8997 // it will be a static member function until we know which template it
8998 // specializes), so adjust it now assuming it specializes this template.
8999 QualType FT = FD->getType();
9000 if (FD->isConstexpr()) {
9001 CXXMethodDecl *OldMD =
9002 dyn_cast<CXXMethodDecl>(FunTmpl->getTemplatedDecl());
9003 if (OldMD && OldMD->isConst()) {
9004 const FunctionProtoType *FPT = FT->castAs<FunctionProtoType>();
9005 FunctionProtoType::ExtProtoInfo EPI = FPT->getExtProtoInfo();
9006 EPI.TypeQuals.addConst();
9007 FT = Context.getFunctionType(FPT->getReturnType(),
9008 FPT->getParamTypes(), EPI);
9009 }
9010 }
9011
9012 TemplateArgumentListInfo Args;
9013 if (ExplicitTemplateArgs)
9014 Args = *ExplicitTemplateArgs;
9015
9016 // C++ [temp.expl.spec]p11:
9017 // A trailing template-argument can be left unspecified in the
9018 // template-id naming an explicit function template specialization
9019 // provided it can be deduced from the function argument type.
9020 // Perform template argument deduction to determine whether we may be
9021 // specializing this template.
9022 // FIXME: It is somewhat wasteful to build
9023 TemplateDeductionInfo Info(FailedCandidates.getLocation());
9024 FunctionDecl *Specialization = nullptr;
9025 if (TemplateDeductionResult TDK = DeduceTemplateArguments(
9026 cast<FunctionTemplateDecl>(FunTmpl->getFirstDecl()),
9027 ExplicitTemplateArgs ? &Args : nullptr, FT, Specialization,
9028 Info)) {
9029 // Template argument deduction failed; record why it failed, so
9030 // that we can provide nifty diagnostics.
9031 FailedCandidates.addCandidate().set(
9032 I.getPair(), FunTmpl->getTemplatedDecl(),
9033 MakeDeductionFailureInfo(Context, TDK, Info));
9034 (void)TDK;
9035 continue;
9036 }
9037
9038 // Target attributes are part of the cuda function signature, so
9039 // the deduced template's cuda target must match that of the
9040 // specialization. Given that C++ template deduction does not
9041 // take target attributes into account, we reject candidates
9042 // here that have a different target.
9043 if (LangOpts.CUDA &&
9044 IdentifyCUDATarget(Specialization,
9045 /* IgnoreImplicitHDAttr = */ true) !=
9046 IdentifyCUDATarget(FD, /* IgnoreImplicitHDAttr = */ true)) {
9047 FailedCandidates.addCandidate().set(
9048 I.getPair(), FunTmpl->getTemplatedDecl(),
9049 MakeDeductionFailureInfo(Context, TDK_CUDATargetMismatch, Info));
9050 continue;
9051 }
9052
9053 // Record this candidate.
9054 if (ExplicitTemplateArgs)
9055 ConvertedTemplateArgs[Specialization] = std::move(Args);
9056 Candidates.addDecl(Specialization, I.getAccess());
9057 }
9058 }
9059
9060 // For a qualified friend declaration (with no explicit marker to indicate
9061 // that a template specialization was intended), note all (template and
9062 // non-template) candidates.
9063 if (QualifiedFriend && Candidates.empty()) {
9064 Diag(FD->getLocation(), diag::err_qualified_friend_no_match)
9065 << FD->getDeclName() << FDLookupContext;
9066 // FIXME: We should form a single candidate list and diagnose all
9067 // candidates at once, to get proper sorting and limiting.
9068 for (auto *OldND : Previous) {
9069 if (auto *OldFD = dyn_cast<FunctionDecl>(OldND->getUnderlyingDecl()))
9070 NoteOverloadCandidate(OldND, OldFD, CRK_None, FD->getType(), false);
9071 }
9072 FailedCandidates.NoteCandidates(*this, FD->getLocation());
9073 return true;
9074 }
9075
9076 // Find the most specialized function template.
9077 UnresolvedSetIterator Result = getMostSpecialized(
9078 Candidates.begin(), Candidates.end(), FailedCandidates, FD->getLocation(),
9079 PDiag(diag::err_function_template_spec_no_match) << FD->getDeclName(),
9080 PDiag(diag::err_function_template_spec_ambiguous)
9081 << FD->getDeclName() << (ExplicitTemplateArgs != nullptr),
9082 PDiag(diag::note_function_template_spec_matched));
9083
9084 if (Result == Candidates.end())
9085 return true;
9086
9087 // Ignore access information; it doesn't figure into redeclaration checking.
9088 FunctionDecl *Specialization = cast<FunctionDecl>(*Result);
9089
9090 FunctionTemplateSpecializationInfo *SpecInfo
9091 = Specialization->getTemplateSpecializationInfo();
9092 assert(SpecInfo && "Function template specialization info missing?")(static_cast <bool> (SpecInfo && "Function template specialization info missing?"
) ? void (0) : __assert_fail ("SpecInfo && \"Function template specialization info missing?\""
, "clang/lib/Sema/SemaTemplate.cpp", 9092, __extension__ __PRETTY_FUNCTION__
))
;
9093
9094 // Note: do not overwrite location info if previous template
9095 // specialization kind was explicit.
9096 TemplateSpecializationKind TSK = SpecInfo->getTemplateSpecializationKind();
9097 if (TSK == TSK_Undeclared || TSK == TSK_ImplicitInstantiation) {
9098 Specialization->setLocation(FD->getLocation());
9099 Specialization->setLexicalDeclContext(FD->getLexicalDeclContext());
9100 // C++11 [dcl.constexpr]p1: An explicit specialization of a constexpr
9101 // function can differ from the template declaration with respect to
9102 // the constexpr specifier.
9103 // FIXME: We need an update record for this AST mutation.
9104 // FIXME: What if there are multiple such prior declarations (for instance,
9105 // from different modules)?
9106 Specialization->setConstexprKind(FD->getConstexprKind());
9107 }
9108
9109 // FIXME: Check if the prior specialization has a point of instantiation.
9110 // If so, we have run afoul of .
9111
9112 // If this is a friend declaration, then we're not really declaring
9113 // an explicit specialization.
9114 bool isFriend = (FD->getFriendObjectKind() != Decl::FOK_None);
9115
9116 // Check the scope of this explicit specialization.
9117 if (!isFriend &&
9118 CheckTemplateSpecializationScope(*this,
9119 Specialization->getPrimaryTemplate(),
9120 Specialization, FD->getLocation(),
9121 false))
9122 return true;
9123
9124 // C++ [temp.expl.spec]p6:
9125 // If a template, a member template or the member of a class template is
9126 // explicitly specialized then that specialization shall be declared
9127 // before the first use of that specialization that would cause an implicit
9128 // instantiation to take place, in every translation unit in which such a
9129 // use occurs; no diagnostic is required.
9130 bool HasNoEffect = false;
9131 if (!isFriend &&
9132 CheckSpecializationInstantiationRedecl(FD->getLocation(),
9133 TSK_ExplicitSpecialization,
9134 Specialization,
9135 SpecInfo->getTemplateSpecializationKind(),
9136 SpecInfo->getPointOfInstantiation(),
9137 HasNoEffect))
9138 return true;
9139
9140 // Mark the prior declaration as an explicit specialization, so that later
9141 // clients know that this is an explicit specialization.
9142 if (!isFriend) {
9143 // Since explicit specializations do not inherit '=delete' from their
9144 // primary function template - check if the 'specialization' that was
9145 // implicitly generated (during template argument deduction for partial
9146 // ordering) from the most specialized of all the function templates that
9147 // 'FD' could have been specializing, has a 'deleted' definition. If so,
9148 // first check that it was implicitly generated during template argument
9149 // deduction by making sure it wasn't referenced, and then reset the deleted
9150 // flag to not-deleted, so that we can inherit that information from 'FD'.
9151 if (Specialization->isDeleted() && !SpecInfo->isExplicitSpecialization() &&
9152 !Specialization->getCanonicalDecl()->isReferenced()) {
9153 // FIXME: This assert will not hold in the presence of modules.
9154 assert((static_cast <bool> (Specialization->getCanonicalDecl
() == Specialization && "This must be the only existing declaration of this specialization"
) ? void (0) : __assert_fail ("Specialization->getCanonicalDecl() == Specialization && \"This must be the only existing declaration of this specialization\""
, "clang/lib/Sema/SemaTemplate.cpp", 9156, __extension__ __PRETTY_FUNCTION__
))
9155 Specialization->getCanonicalDecl() == Specialization &&(static_cast <bool> (Specialization->getCanonicalDecl
() == Specialization && "This must be the only existing declaration of this specialization"
) ? void (0) : __assert_fail ("Specialization->getCanonicalDecl() == Specialization && \"This must be the only existing declaration of this specialization\""
, "clang/lib/Sema/SemaTemplate.cpp", 9156, __extension__ __PRETTY_FUNCTION__
))
9156 "This must be the only existing declaration of this specialization")(static_cast <bool> (Specialization->getCanonicalDecl
() == Specialization && "This must be the only existing declaration of this specialization"
) ? void (0) : __assert_fail ("Specialization->getCanonicalDecl() == Specialization && \"This must be the only existing declaration of this specialization\""
, "clang/lib/Sema/SemaTemplate.cpp", 9156, __extension__ __PRETTY_FUNCTION__
))
;
9157 // FIXME: We need an update record for this AST mutation.
9158 Specialization->setDeletedAsWritten(false);
9159 }
9160 // FIXME: We need an update record for this AST mutation.
9161 SpecInfo->setTemplateSpecializationKind(TSK_ExplicitSpecialization);
9162 MarkUnusedFileScopedDecl(Specialization);
9163 }
9164
9165 // Turn the given function declaration into a function template
9166 // specialization, with the template arguments from the previous
9167 // specialization.
9168 // Take copies of (semantic and syntactic) template argument lists.
9169 const TemplateArgumentList* TemplArgs = new (Context)
9170 TemplateArgumentList(Specialization->getTemplateSpecializationArgs());
9171 FD->setFunctionTemplateSpecialization(
9172 Specialization->getPrimaryTemplate(), TemplArgs, /*InsertPos=*/nullptr,
9173 SpecInfo->getTemplateSpecializationKind(),
9174 ExplicitTemplateArgs ? &ConvertedTemplateArgs[Specialization] : nullptr);
9175
9176 // A function template specialization inherits the target attributes
9177 // of its template. (We require the attributes explicitly in the
9178 // code to match, but a template may have implicit attributes by
9179 // virtue e.g. of being constexpr, and it passes these implicit
9180 // attributes on to its specializations.)
9181 if (LangOpts.CUDA)
9182 inheritCUDATargetAttrs(FD, *Specialization->getPrimaryTemplate());
9183
9184 // The "previous declaration" for this function template specialization is
9185 // the prior function template specialization.
9186 Previous.clear();
9187 Previous.addDecl(Specialization);
9188 return false;
9189}
9190
9191/// Perform semantic analysis for the given non-template member
9192/// specialization.
9193///
9194/// This routine performs all of the semantic analysis required for an
9195/// explicit member function specialization. On successful completion,
9196/// the function declaration \p FD will become a member function
9197/// specialization.
9198///
9199/// \param Member the member declaration, which will be updated to become a
9200/// specialization.
9201///
9202/// \param Previous the set of declarations, one of which may be specialized
9203/// by this function specialization; the set will be modified to contain the
9204/// redeclared member.
9205bool
9206Sema::CheckMemberSpecialization(NamedDecl *Member, LookupResult &Previous) {
9207 assert(!isa<TemplateDecl>(Member) && "Only for non-template members")(static_cast <bool> (!isa<TemplateDecl>(Member) &&
"Only for non-template members") ? void (0) : __assert_fail (
"!isa<TemplateDecl>(Member) && \"Only for non-template members\""
, "clang/lib/Sema/SemaTemplate.cpp", 9207, __extension__ __PRETTY_FUNCTION__
))
;
9208
9209 // Try to find the member we are instantiating.
9210 NamedDecl *FoundInstantiation = nullptr;
9211 NamedDecl *Instantiation = nullptr;
9212 NamedDecl *InstantiatedFrom = nullptr;
9213 MemberSpecializationInfo *MSInfo = nullptr;
9214
9215 if (Previous.empty()) {
9216 // Nowhere to look anyway.
9217 } else if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Member)) {
9218 for (LookupResult::iterator I = Previous.begin(), E = Previous.end();
9219 I != E; ++I) {
9220 NamedDecl *D = (*I)->getUnderlyingDecl();
9221 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
9222 QualType Adjusted = Function->getType();
9223 if (!hasExplicitCallingConv(Adjusted))
9224 Adjusted = adjustCCAndNoReturn(Adjusted, Method->getType());
9225 // This doesn't handle deduced return types, but both function
9226 // declarations should be undeduced at this point.
9227 if (Context.hasSameType(Adjusted, Method->getType())) {
9228 FoundInstantiation = *I;
9229 Instantiation = Method;
9230 InstantiatedFrom = Method->getInstantiatedFromMemberFunction();
9231 MSInfo = Method->getMemberSpecializationInfo();
9232 break;
9233 }
9234 }
9235 }
9236 } else if (isa<VarDecl>(Member)) {
9237 VarDecl *PrevVar;
9238 if (Previous.isSingleResult() &&
9239 (PrevVar = dyn_cast<VarDecl>(Previous.getFoundDecl())))
9240 if (PrevVar->isStaticDataMember()) {
9241 FoundInstantiation = Previous.getRepresentativeDecl();
9242 Instantiation = PrevVar;
9243 InstantiatedFrom = PrevVar->getInstantiatedFromStaticDataMember();
9244 MSInfo = PrevVar->getMemberSpecializationInfo();
9245 }
9246 } else if (isa<RecordDecl>(Member)) {
9247 CXXRecordDecl *PrevRecord;
9248 if (Previous.isSingleResult() &&
9249 (PrevRecord = dyn_cast<CXXRecordDecl>(Previous.getFoundDecl()))) {
9250 FoundInstantiation = Previous.getRepresentativeDecl();
9251 Instantiation = PrevRecord;
9252 InstantiatedFrom = PrevRecord->getInstantiatedFromMemberClass();
9253 MSInfo = PrevRecord->getMemberSpecializationInfo();
9254 }
9255 } else if (isa<EnumDecl>(Member)) {
9256 EnumDecl *PrevEnum;
9257 if (Previous.isSingleResult() &&
9258 (PrevEnum = dyn_cast<EnumDecl>(Previous.getFoundDecl()))) {
9259 FoundInstantiation = Previous.getRepresentativeDecl();
9260 Instantiation = PrevEnum;
9261 InstantiatedFrom = PrevEnum->getInstantiatedFromMemberEnum();
9262 MSInfo = PrevEnum->getMemberSpecializationInfo();
9263 }
9264 }
9265
9266 if (!Instantiation) {
9267 // There is no previous declaration that matches. Since member
9268 // specializations are always out-of-line, the caller will complain about
9269 // this mismatch later.
9270 return false;
9271 }
9272
9273 // A member specialization in a friend declaration isn't really declaring
9274 // an explicit specialization, just identifying a specific (possibly implicit)
9275 // specialization. Don't change the template specialization kind.
9276 //
9277 // FIXME: Is this really valid? Other compilers reject.
9278 if (Member->getFriendObjectKind() != Decl::FOK_None) {
9279 // Preserve instantiation information.
9280 if (InstantiatedFrom && isa<CXXMethodDecl>(Member)) {
9281 cast<CXXMethodDecl>(Member)->setInstantiationOfMemberFunction(
9282 cast<CXXMethodDecl>(InstantiatedFrom),
9283 cast<CXXMethodDecl>(Instantiation)->getTemplateSpecializationKind());
9284 } else if (InstantiatedFrom && isa<CXXRecordDecl>(Member)) {
9285 cast<CXXRecordDecl>(Member)->setInstantiationOfMemberClass(
9286 cast<CXXRecordDecl>(InstantiatedFrom),
9287 cast<CXXRecordDecl>(Instantiation)->getTemplateSpecializationKind());
9288 }
9289
9290 Previous.clear();
9291 Previous.addDecl(FoundInstantiation);
9292 return false;
9293 }
9294
9295 // Make sure that this is a specialization of a member.
9296 if (!InstantiatedFrom) {
9297 Diag(Member->getLocation(), diag::err_spec_member_not_instantiated)
9298 << Member;
9299 Diag(Instantiation->getLocation(), diag::note_specialized_decl);
9300 return true;
9301 }
9302
9303 // C++ [temp.expl.spec]p6:
9304 // If a template, a member template or the member of a class template is
9305 // explicitly specialized then that specialization shall be declared
9306 // before the first use of that specialization that would cause an implicit
9307 // instantiation to take place, in every translation unit in which such a
9308 // use occurs; no diagnostic is required.
9309 assert(MSInfo && "Member specialization info missing?")(static_cast <bool> (MSInfo && "Member specialization info missing?"
) ? void (0) : __assert_fail ("MSInfo && \"Member specialization info missing?\""
, "clang/lib/Sema/SemaTemplate.cpp", 9309, __extension__ __PRETTY_FUNCTION__
))
;
9310
9311 bool HasNoEffect = false;
9312 if (CheckSpecializationInstantiationRedecl(Member->getLocation(),
9313 TSK_ExplicitSpecialization,
9314 Instantiation,
9315 MSInfo->getTemplateSpecializationKind(),
9316 MSInfo->getPointOfInstantiation(),
9317 HasNoEffect))
9318 return true;
9319
9320 // Check the scope of this explicit specialization.
9321 if (CheckTemplateSpecializationScope(*this,
9322 InstantiatedFrom,
9323 Instantiation, Member->getLocation(),
9324 false))
9325 return true;
9326
9327 // Note that this member specialization is an "instantiation of" the
9328 // corresponding member of the original template.
9329 if (auto *MemberFunction = dyn_cast<FunctionDecl>(Member)) {
9330 FunctionDecl *InstantiationFunction = cast<FunctionDecl>(Instantiation);
9331 if (InstantiationFunction->getTemplateSpecializationKind() ==
9332 TSK_ImplicitInstantiation) {
9333 // Explicit specializations of member functions of class templates do not
9334 // inherit '=delete' from the member function they are specializing.
9335 if (InstantiationFunction->isDeleted()) {
9336 // FIXME: This assert will not hold in the presence of modules.
9337 assert(InstantiationFunction->getCanonicalDecl() ==(static_cast <bool> (InstantiationFunction->getCanonicalDecl
() == InstantiationFunction) ? void (0) : __assert_fail ("InstantiationFunction->getCanonicalDecl() == InstantiationFunction"
, "clang/lib/Sema/SemaTemplate.cpp", 9338, __extension__ __PRETTY_FUNCTION__
))
9338 InstantiationFunction)(static_cast <bool> (InstantiationFunction->getCanonicalDecl
() == InstantiationFunction) ? void (0) : __assert_fail ("InstantiationFunction->getCanonicalDecl() == InstantiationFunction"
, "clang/lib/Sema/SemaTemplate.cpp", 9338, __extension__ __PRETTY_FUNCTION__
))
;
9339 // FIXME: We need an update record for this AST mutation.
9340 InstantiationFunction->setDeletedAsWritten(false);
9341 }
9342 }
9343
9344 MemberFunction->setInstantiationOfMemberFunction(
9345 cast<CXXMethodDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
9346 } else if (auto *MemberVar = dyn_cast<VarDecl>(Member)) {
9347 MemberVar->setInstantiationOfStaticDataMember(
9348 cast<VarDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
9349 } else if (auto *MemberClass = dyn_cast<CXXRecordDecl>(Member)) {
9350 MemberClass->setInstantiationOfMemberClass(
9351 cast<CXXRecordDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
9352 } else if (auto *MemberEnum = dyn_cast<EnumDecl>(Member)) {
9353 MemberEnum->setInstantiationOfMemberEnum(
9354 cast<EnumDecl>(InstantiatedFrom), TSK_ExplicitSpecialization);
9355 } else {
9356 llvm_unreachable("unknown member specialization kind")::llvm::llvm_unreachable_internal("unknown member specialization kind"
, "clang/lib/Sema/SemaTemplate.cpp", 9356)
;
9357 }
9358
9359 // Save the caller the trouble of having to figure out which declaration
9360 // this specialization matches.
9361 Previous.clear();
9362 Previous.addDecl(FoundInstantiation);
9363 return false;
9364}
9365
9366/// Complete the explicit specialization of a member of a class template by
9367/// updating the instantiated member to be marked as an explicit specialization.
9368///
9369/// \param OrigD The member declaration instantiated from the template.
9370/// \param Loc The location of the explicit specialization of the member.
9371template<typename DeclT>
9372static void completeMemberSpecializationImpl(Sema &S, DeclT *OrigD,
9373 SourceLocation Loc) {
9374 if (OrigD->getTemplateSpecializationKind() != TSK_ImplicitInstantiation)
9375 return;
9376
9377 // FIXME: Inform AST mutation listeners of this AST mutation.
9378 // FIXME: If there are multiple in-class declarations of the member (from
9379 // multiple modules, or a declaration and later definition of a member type),
9380 // should we update all of them?
9381 OrigD->setTemplateSpecializationKind(TSK_ExplicitSpecialization);
9382 OrigD->setLocation(Loc);
9383}
9384
9385void Sema::CompleteMemberSpecialization(NamedDecl *Member,
9386 LookupResult &Previous) {
9387 NamedDecl *Instantiation = cast<NamedDecl>(Member->getCanonicalDecl());
9388 if (Instantiation == Member)
9389 return;
9390
9391 if (auto *Function = dyn_cast<CXXMethodDecl>(Instantiation))
9392 completeMemberSpecializationImpl(*this, Function, Member->getLocation());
9393 else if (auto *Var = dyn_cast<VarDecl>(Instantiation))
9394 completeMemberSpecializationImpl(*this, Var, Member->getLocation());
9395 else if (auto *Record = dyn_cast<CXXRecordDecl>(Instantiation))
9396 completeMemberSpecializationImpl(*this, Record, Member->getLocation());
9397 else if (auto *Enum = dyn_cast<EnumDecl>(Instantiation))
9398 completeMemberSpecializationImpl(*this, Enum, Member->getLocation());
9399 else
9400 llvm_unreachable("unknown member specialization kind")::llvm::llvm_unreachable_internal("unknown member specialization kind"
, "clang/lib/Sema/SemaTemplate.cpp", 9400)
;
9401}
9402
9403/// Check the scope of an explicit instantiation.
9404///
9405/// \returns true if a serious error occurs, false otherwise.
9406static bool CheckExplicitInstantiationScope(Sema &S, NamedDecl *D,
9407 SourceLocation InstLoc,
9408 bool WasQualifiedName) {
9409 DeclContext *OrigContext= D->getDeclContext()->getEnclosingNamespaceContext();
9410 DeclContext *CurContext = S.CurContext->getRedeclContext();
9411
9412 if (CurContext->isRecord()) {
9413 S.Diag(InstLoc, diag::err_explicit_instantiation_in_class)
9414 << D;
9415 return true;
9416 }
9417
9418 // C++11 [temp.explicit]p3:
9419 // An explicit instantiation shall appear in an enclosing namespace of its
9420 // template. If the name declared in the explicit instantiation is an
9421 // unqualified name, the explicit instantiation shall appear in the
9422 // namespace where its template is declared or, if that namespace is inline
9423 // (7.3.1), any namespace from its enclosing namespace set.
9424 //
9425 // This is DR275, which we do not retroactively apply to C++98/03.
9426 if (WasQualifiedName) {
9427 if (CurContext->Encloses(OrigContext))
9428 return false;
9429 } else {
9430 if (CurContext->InEnclosingNamespaceSetOf(OrigContext))
9431 return false;
9432 }
9433
9434 if (NamespaceDecl *NS = dyn_cast<NamespaceDecl>(OrigContext)) {
9435 if (WasQualifiedName)
9436 S.Diag(InstLoc,
9437 S.getLangOpts().CPlusPlus11?
9438 diag::err_explicit_instantiation_out_of_scope :
9439 diag::warn_explicit_instantiation_out_of_scope_0x)
9440 << D << NS;
9441 else
9442 S.Diag(InstLoc,
9443 S.getLangOpts().CPlusPlus11?
9444 diag::err_explicit_instantiation_unqualified_wrong_namespace :
9445 diag::warn_explicit_instantiation_unqualified_wrong_namespace_0x)
9446 << D << NS;
9447 } else
9448 S.Diag(InstLoc,
9449 S.getLangOpts().CPlusPlus11?
9450 diag::err_explicit_instantiation_must_be_global :
9451 diag::warn_explicit_instantiation_must_be_global_0x)
9452 << D;
9453 S.Diag(D->getLocation(), diag::note_explicit_instantiation_here);
9454 return false;
9455}
9456
9457/// Common checks for whether an explicit instantiation of \p D is valid.
9458static bool CheckExplicitInstantiation(Sema &S, NamedDecl *D,
9459 SourceLocation InstLoc,
9460 bool WasQualifiedName,
9461 TemplateSpecializationKind TSK) {
9462 // C++ [temp.explicit]p13:
9463 // An explicit instantiation declaration shall not name a specialization of
9464 // a template with internal linkage.
9465 if (TSK == TSK_ExplicitInstantiationDeclaration &&
9466 D->getFormalLinkage() == InternalLinkage) {
9467 S.Diag(InstLoc, diag::err_explicit_instantiation_internal_linkage) << D;
9468 return true;
9469 }
9470
9471 // C++11 [temp.explicit]p3: [DR 275]
9472 // An explicit instantiation shall appear in an enclosing namespace of its
9473 // template.
9474 if (CheckExplicitInstantiationScope(S, D, InstLoc, WasQualifiedName))
9475 return true;
9476
9477 return false;
9478}
9479
9480/// Determine whether the given scope specifier has a template-id in it.
9481static bool ScopeSpecifierHasTemplateId(const CXXScopeSpec &SS) {
9482 if (!SS.isSet())
9483 return false;
9484
9485 // C++11 [temp.explicit]p3:
9486 // If the explicit instantiation is for a member function, a member class
9487 // or a static data member of a class template specialization, the name of
9488 // the class template specialization in the qualified-id for the member
9489 // name shall be a simple-template-id.
9490 //
9491 // C++98 has the same restriction, just worded differently.
9492 for (NestedNameSpecifier *NNS = SS.getScopeRep(); NNS;
9493 NNS = NNS->getPrefix())
9494 if (const Type *T = NNS->getAsType())
9495 if (isa<TemplateSpecializationType>(T))
9496 return true;
9497
9498 return false;
9499}
9500
9501/// Make a dllexport or dllimport attr on a class template specialization take
9502/// effect.
9503static void dllExportImportClassTemplateSpecialization(
9504 Sema &S, ClassTemplateSpecializationDecl *Def) {
9505 auto *A = cast_or_null<InheritableAttr>(getDLLAttr(Def));
9506 assert(A && "dllExportImportClassTemplateSpecialization called "(static_cast <bool> (A && "dllExportImportClassTemplateSpecialization called "
"on Def without dllexport or dllimport") ? void (0) : __assert_fail
("A && \"dllExportImportClassTemplateSpecialization called \" \"on Def without dllexport or dllimport\""
, "clang/lib/Sema/SemaTemplate.cpp", 9507, __extension__ __PRETTY_FUNCTION__
))
9507 "on Def without dllexport or dllimport")(static_cast <bool> (A && "dllExportImportClassTemplateSpecialization called "
"on Def without dllexport or dllimport") ? void (0) : __assert_fail
("A && \"dllExportImportClassTemplateSpecialization called \" \"on Def without dllexport or dllimport\""
, "clang/lib/Sema/SemaTemplate.cpp", 9507, __extension__ __PRETTY_FUNCTION__
))
;
9508
9509 // We reject explicit instantiations in class scope, so there should
9510 // never be any delayed exported classes to worry about.
9511 assert(S.DelayedDllExportClasses.empty() &&(static_cast <bool> (S.DelayedDllExportClasses.empty() &&
"delayed exports present at explicit instantiation") ? void (
0) : __assert_fail ("S.DelayedDllExportClasses.empty() && \"delayed exports present at explicit instantiation\""
, "clang/lib/Sema/SemaTemplate.cpp", 9512, __extension__ __PRETTY_FUNCTION__
))
9512 "delayed exports present at explicit instantiation")(static_cast <bool> (S.DelayedDllExportClasses.empty() &&
"delayed exports present at explicit instantiation") ? void (
0) : __assert_fail ("S.DelayedDllExportClasses.empty() && \"delayed exports present at explicit instantiation\""
, "clang/lib/Sema/SemaTemplate.cpp", 9512, __extension__ __PRETTY_FUNCTION__
))
;
9513 S.checkClassLevelDLLAttribute(Def);
9514
9515 // Propagate attribute to base class templates.
9516 for (auto &B : Def->bases()) {
9517 if (auto *BT = dyn_cast_or_null<ClassTemplateSpecializationDecl>(
9518 B.getType()->getAsCXXRecordDecl()))
9519 S.propagateDLLAttrToBaseClassTemplate(Def, A, BT, B.getBeginLoc());
9520 }
9521
9522 S.referenceDLLExportedClassMethods();
9523}
9524
9525// Explicit instantiation of a class template specialization
9526DeclResult Sema::ActOnExplicitInstantiation(
9527 Scope *S, SourceLocation ExternLoc, SourceLocation TemplateLoc,
9528 unsigned TagSpec, SourceLocation KWLoc, const CXXScopeSpec &SS,
9529 TemplateTy TemplateD, SourceLocation TemplateNameLoc,
9530 SourceLocation LAngleLoc, ASTTemplateArgsPtr TemplateArgsIn,
9531 SourceLocation RAngleLoc, const ParsedAttributesView &Attr) {
9532 // Find the class template we're specializing
9533 TemplateName Name = TemplateD.get();
9534 TemplateDecl *TD = Name.getAsTemplateDecl();
9535 // Check that the specialization uses the same tag kind as the
9536 // original template.
9537 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
9538 assert(Kind != TTK_Enum &&(static_cast <bool> (Kind != TTK_Enum && "Invalid enum tag in class template explicit instantiation!"
) ? void (0) : __assert_fail ("Kind != TTK_Enum && \"Invalid enum tag in class template explicit instantiation!\""
, "clang/lib/Sema/SemaTemplate.cpp", 9539, __extension__ __PRETTY_FUNCTION__
))
9539 "Invalid enum tag in class template explicit instantiation!")(static_cast <bool> (Kind != TTK_Enum && "Invalid enum tag in class template explicit instantiation!"
) ? void (0) : __assert_fail ("Kind != TTK_Enum && \"Invalid enum tag in class template explicit instantiation!\""
, "clang/lib/Sema/SemaTemplate.cpp", 9539, __extension__ __PRETTY_FUNCTION__
))
;
9540
9541 ClassTemplateDecl *ClassTemplate = dyn_cast<ClassTemplateDecl>(TD);
9542
9543 if (!ClassTemplate) {
9544 NonTagKind NTK = getNonTagTypeDeclKind(TD, Kind);
9545 Diag(TemplateNameLoc, diag::err_tag_reference_non_tag) << TD << NTK << Kind;
9546 Diag(TD->getLocation(), diag::note_previous_use);
9547 return true;
9548 }
9549
9550 if (!isAcceptableTagRedeclaration(ClassTemplate->getTemplatedDecl(),
9551 Kind, /*isDefinition*/false, KWLoc,
9552 ClassTemplate->getIdentifier())) {
9553 Diag(KWLoc, diag::err_use_with_wrong_tag)
9554 << ClassTemplate
9555 << FixItHint::CreateReplacement(KWLoc,
9556 ClassTemplate->getTemplatedDecl()->getKindName());
9557 Diag(ClassTemplate->getTemplatedDecl()->getLocation(),
9558 diag::note_previous_use);
9559 Kind = ClassTemplate->getTemplatedDecl()->getTagKind();
9560 }
9561
9562 // C++0x [temp.explicit]p2:
9563 // There are two forms of explicit instantiation: an explicit instantiation
9564 // definition and an explicit instantiation declaration. An explicit
9565 // instantiation declaration begins with the extern keyword. [...]
9566 TemplateSpecializationKind TSK = ExternLoc.isInvalid()
9567 ? TSK_ExplicitInstantiationDefinition
9568 : TSK_ExplicitInstantiationDeclaration;
9569
9570 if (TSK == TSK_ExplicitInstantiationDeclaration &&
9571 !Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
9572 // Check for dllexport class template instantiation declarations,
9573 // except for MinGW mode.
9574 for (const ParsedAttr &AL : Attr) {
9575 if (AL.getKind() == ParsedAttr::AT_DLLExport) {
9576 Diag(ExternLoc,
9577 diag::warn_attribute_dllexport_explicit_instantiation_decl);
9578 Diag(AL.getLoc(), diag::note_attribute);
9579 break;
9580 }
9581 }
9582
9583 if (auto *A = ClassTemplate->getTemplatedDecl()->getAttr<DLLExportAttr>()) {
9584 Diag(ExternLoc,
9585 diag::warn_attribute_dllexport_explicit_instantiation_decl);
9586 Diag(A->getLocation(), diag::note_attribute);
9587 }
9588 }
9589
9590 // In MSVC mode, dllimported explicit instantiation definitions are treated as
9591 // instantiation declarations for most purposes.
9592 bool DLLImportExplicitInstantiationDef = false;
9593 if (TSK == TSK_ExplicitInstantiationDefinition &&
9594 Context.getTargetInfo().getCXXABI().isMicrosoft()) {
9595 // Check for dllimport class template instantiation definitions.
9596 bool DLLImport =
9597 ClassTemplate->getTemplatedDecl()->getAttr<DLLImportAttr>();
9598 for (const ParsedAttr &AL : Attr) {
9599 if (AL.getKind() == ParsedAttr::AT_DLLImport)
9600 DLLImport = true;
9601 if (AL.getKind() == ParsedAttr::AT_DLLExport) {
9602 // dllexport trumps dllimport here.
9603 DLLImport = false;
9604 break;
9605 }
9606 }
9607 if (DLLImport) {
9608 TSK = TSK_ExplicitInstantiationDeclaration;
9609 DLLImportExplicitInstantiationDef = true;
9610 }
9611 }
9612
9613 // Translate the parser's template argument list in our AST format.
9614 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
9615 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
9616
9617 // Check that the template argument list is well-formed for this
9618 // template.
9619 SmallVector<TemplateArgument, 4> Converted;
9620 if (CheckTemplateArgumentList(ClassTemplate, TemplateNameLoc,
9621 TemplateArgs, false, Converted,
9622 /*UpdateArgsWithConversions=*/true))
9623 return true;
9624
9625 // Find the class template specialization declaration that
9626 // corresponds to these arguments.
9627 void *InsertPos = nullptr;
9628 ClassTemplateSpecializationDecl *PrevDecl
9629 = ClassTemplate->findSpecialization(Converted, InsertPos);
9630
9631 TemplateSpecializationKind PrevDecl_TSK
9632 = PrevDecl ? PrevDecl->getTemplateSpecializationKind() : TSK_Undeclared;
9633
9634 if (TSK == TSK_ExplicitInstantiationDefinition && PrevDecl != nullptr &&
9635 Context.getTargetInfo().getTriple().isWindowsGNUEnvironment()) {
9636 // Check for dllexport class template instantiation definitions in MinGW
9637 // mode, if a previous declaration of the instantiation was seen.
9638 for (const ParsedAttr &AL : Attr) {
9639 if (AL.getKind() == ParsedAttr::AT_DLLExport) {
9640 Diag(AL.getLoc(),
9641 diag::warn_attribute_dllexport_explicit_instantiation_def);
9642 break;
9643 }
9644 }
9645 }
9646
9647 if (CheckExplicitInstantiation(*this, ClassTemplate, TemplateNameLoc,
9648 SS.isSet(), TSK))
9649 return true;
9650
9651 ClassTemplateSpecializationDecl *Specialization = nullptr;
9652
9653 bool HasNoEffect = false;
9654 if (PrevDecl) {
9655 if (CheckSpecializationInstantiationRedecl(TemplateNameLoc, TSK,
9656 PrevDecl, PrevDecl_TSK,
9657 PrevDecl->getPointOfInstantiation(),
9658 HasNoEffect))
9659 return PrevDecl;
9660
9661 // Even though HasNoEffect == true means that this explicit instantiation
9662 // has no effect on semantics, we go on to put its syntax in the AST.
9663
9664 if (PrevDecl_TSK == TSK_ImplicitInstantiation ||
9665 PrevDecl_TSK == TSK_Undeclared) {
9666 // Since the only prior class template specialization with these
9667 // arguments was referenced but not declared, reuse that
9668 // declaration node as our own, updating the source location
9669 // for the template name to reflect our new declaration.
9670 // (Other source locations will be updated later.)
9671 Specialization = PrevDecl;
9672 Specialization->setLocation(TemplateNameLoc);
9673 PrevDecl = nullptr;
9674 }
9675
9676 if (PrevDecl_TSK == TSK_ExplicitInstantiationDeclaration &&
9677 DLLImportExplicitInstantiationDef) {
9678 // The new specialization might add a dllimport attribute.
9679 HasNoEffect = false;
9680 }
9681 }
9682
9683 if (!Specialization) {
9684 // Create a new class template specialization declaration node for
9685 // this explicit specialization.
9686 Specialization
9687 = ClassTemplateSpecializationDecl::Create(Context, Kind,
9688 ClassTemplate->getDeclContext(),
9689 KWLoc, TemplateNameLoc,
9690 ClassTemplate,
9691 Converted,
9692 PrevDecl);
9693 SetNestedNameSpecifier(*this, Specialization, SS);
9694
9695 if (!HasNoEffect && !PrevDecl) {
9696 // Insert the new specialization.
9697 ClassTemplate->AddSpecialization(Specialization, InsertPos);
9698 }
9699 }
9700
9701 // Build the fully-sugared type for this explicit instantiation as
9702 // the user wrote in the explicit instantiation itself. This means
9703 // that we'll pretty-print the type retrieved from the
9704 // specialization's declaration the way that the user actually wrote
9705 // the explicit instantiation, rather than formatting the name based
9706 // on the "canonical" representation used to store the template
9707 // arguments in the specialization.
9708 TypeSourceInfo *WrittenTy
9709 = Context.getTemplateSpecializationTypeInfo(Name, TemplateNameLoc,
9710 TemplateArgs,
9711 Context.getTypeDeclType(Specialization));
9712 Specialization->setTypeAsWritten(WrittenTy);
9713
9714 // Set source locations for keywords.
9715 Specialization->setExternLoc(ExternLoc);
9716 Specialization->setTemplateKeywordLoc(TemplateLoc);
9717 Specialization->setBraceRange(SourceRange());
9718
9719 bool PreviouslyDLLExported = Specialization->hasAttr<DLLExportAttr>();
9720 ProcessDeclAttributeList(S, Specialization, Attr);
9721
9722 // Add the explicit instantiation into its lexical context. However,
9723 // since explicit instantiations are never found by name lookup, we
9724 // just put it into the declaration context directly.
9725 Specialization->setLexicalDeclContext(CurContext);
9726 CurContext->addDecl(Specialization);
9727
9728 // Syntax is now OK, so return if it has no other effect on semantics.
9729 if (HasNoEffect) {
9730 // Set the template specialization kind.
9731 Specialization->setTemplateSpecializationKind(TSK);
9732 return Specialization;
9733 }
9734
9735 // C++ [temp.explicit]p3:
9736 // A definition of a class template or class member template
9737 // shall be in scope at the point of the explicit instantiation of
9738 // the class template or class member template.
9739 //
9740 // This check comes when we actually try to perform the
9741 // instantiation.
9742 ClassTemplateSpecializationDecl *Def
9743 = cast_or_null<ClassTemplateSpecializationDecl>(
9744 Specialization->getDefinition());
9745 if (!Def)
9746 InstantiateClassTemplateSpecialization(TemplateNameLoc, Specialization, TSK);
9747 else if (TSK == TSK_ExplicitInstantiationDefinition) {
9748 MarkVTableUsed(TemplateNameLoc, Specialization, true);
9749 Specialization->setPointOfInstantiation(Def->getPointOfInstantiation());
9750 }
9751
9752 // Instantiate the members of this class template specialization.
9753 Def = cast_or_null<ClassTemplateSpecializationDecl>(
9754 Specialization->getDefinition());
9755 if (Def) {
9756 TemplateSpecializationKind Old_TSK = Def->getTemplateSpecializationKind();
9757 // Fix a TSK_ExplicitInstantiationDeclaration followed by a
9758 // TSK_ExplicitInstantiationDefinition
9759 if (Old_TSK == TSK_ExplicitInstantiationDeclaration &&
9760 (TSK == TSK_ExplicitInstantiationDefinition ||
9761 DLLImportExplicitInstantiationDef)) {
9762 // FIXME: Need to notify the ASTMutationListener that we did this.
9763 Def->setTemplateSpecializationKind(TSK);
9764
9765 if (!getDLLAttr(Def) && getDLLAttr(Specialization) &&
9766 (Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
9767 !Context.getTargetInfo().getTriple().isPS4())) {
9768 // An explicit instantiation definition can add a dll attribute to a
9769 // template with a previous instantiation declaration. MinGW doesn't
9770 // allow this.
9771 auto *A = cast<InheritableAttr>(
9772 getDLLAttr(Specialization)->clone(getASTContext()));
9773 A->setInherited(true);
9774 Def->addAttr(A);
9775 dllExportImportClassTemplateSpecialization(*this, Def);
9776 }
9777 }
9778
9779 // Fix a TSK_ImplicitInstantiation followed by a
9780 // TSK_ExplicitInstantiationDefinition
9781 bool NewlyDLLExported =
9782 !PreviouslyDLLExported && Specialization->hasAttr<DLLExportAttr>();
9783 if (Old_TSK == TSK_ImplicitInstantiation && NewlyDLLExported &&
9784 (Context.getTargetInfo().shouldDLLImportComdatSymbols() &&
9785 !Context.getTargetInfo().getTriple().isPS4())) {
9786 // An explicit instantiation definition can add a dll attribute to a
9787 // template with a previous implicit instantiation. MinGW doesn't allow
9788 // this. We limit clang to only adding dllexport, to avoid potentially
9789 // strange codegen behavior. For example, if we extend this conditional
9790 // to dllimport, and we have a source file calling a method on an
9791 // implicitly instantiated template class instance and then declaring a
9792 // dllimport explicit instantiation definition for the same template
9793 // class, the codegen for the method call will not respect the dllimport,
9794 // while it will with cl. The Def will already have the DLL attribute,
9795 // since the Def and Specialization will be the same in the case of
9796 // Old_TSK == TSK_ImplicitInstantiation, and we already added the
9797 // attribute to the Specialization; we just need to make it take effect.
9798 assert(Def == Specialization &&(static_cast <bool> (Def == Specialization && "Def and Specialization should match for implicit instantiation"
) ? void (0) : __assert_fail ("Def == Specialization && \"Def and Specialization should match for implicit instantiation\""
, "clang/lib/Sema/SemaTemplate.cpp", 9799, __extension__ __PRETTY_FUNCTION__
))
9799 "Def and Specialization should match for implicit instantiation")(static_cast <bool> (Def == Specialization && "Def and Specialization should match for implicit instantiation"
) ? void (0) : __assert_fail ("Def == Specialization && \"Def and Specialization should match for implicit instantiation\""
, "clang/lib/Sema/SemaTemplate.cpp", 9799, __extension__ __PRETTY_FUNCTION__
))
;
9800 dllExportImportClassTemplateSpecialization(*this, Def);
9801 }
9802
9803 // In MinGW mode, export the template instantiation if the declaration
9804 // was marked dllexport.
9805 if (PrevDecl_TSK == TSK_ExplicitInstantiationDeclaration &&
9806 Context.getTargetInfo().getTriple().isWindowsGNUEnvironment() &&
9807 PrevDecl->hasAttr<DLLExportAttr>()) {
9808 dllExportImportClassTemplateSpecialization(*this, Def);
9809 }
9810
9811 if (Def->hasAttr<MSInheritanceAttr>()) {
9812 Specialization->addAttr(Def->getAttr<MSInheritanceAttr>());
9813 Consumer.AssignInheritanceModel(Specialization);
9814 }
9815
9816 // Set the template specialization kind. Make sure it is set before
9817 // instantiating the members which will trigger ASTConsumer callbacks.
9818 Specialization->setTemplateSpecializationKind(TSK);
9819 InstantiateClassTemplateSpecializationMembers(TemplateNameLoc, Def, TSK);
9820 } else {
9821
9822 // Set the template specialization kind.
9823 Specialization->setTemplateSpecializationKind(TSK);
9824 }
9825
9826 return Specialization;
9827}
9828
9829// Explicit instantiation of a member class of a class template.
9830DeclResult
9831Sema::ActOnExplicitInstantiation(Scope *S, SourceLocation ExternLoc,
9832 SourceLocation TemplateLoc, unsigned TagSpec,
9833 SourceLocation KWLoc, CXXScopeSpec &SS,
9834 IdentifierInfo *Name, SourceLocation NameLoc,
9835 const ParsedAttributesView &Attr) {
9836
9837 bool Owned = false;
9838 bool IsDependent = false;
9839 Decl *TagD = ActOnTag(S, TagSpec, Sema::TUK_Reference,
9840 KWLoc, SS, Name, NameLoc, Attr, AS_none,
9841 /*ModulePrivateLoc=*/SourceLocation(),
9842 MultiTemplateParamsArg(), Owned, IsDependent,
9843 SourceLocation(), false, TypeResult(),
9844 /*IsTypeSpecifier*/false,
9845 /*IsTemplateParamOrArg*/false);
9846 assert(!IsDependent && "explicit instantiation of dependent name not yet handled")(static_cast <bool> (!IsDependent && "explicit instantiation of dependent name not yet handled"
) ? void (0) : __assert_fail ("!IsDependent && \"explicit instantiation of dependent name not yet handled\""
, "clang/lib/Sema/SemaTemplate.cpp", 9846, __extension__ __PRETTY_FUNCTION__
))
;
9847
9848 if (!TagD)
9849 return true;
9850
9851 TagDecl *Tag = cast<TagDecl>(TagD);
9852 assert(!Tag->isEnum() && "shouldn't see enumerations here")(static_cast <bool> (!Tag->isEnum() && "shouldn't see enumerations here"
) ? void (0) : __assert_fail ("!Tag->isEnum() && \"shouldn't see enumerations here\""
, "clang/lib/Sema/SemaTemplate.cpp", 9852, __extension__ __PRETTY_FUNCTION__
))
;
9853
9854 if (Tag->isInvalidDecl())
9855 return true;
9856
9857 CXXRecordDecl *Record = cast<CXXRecordDecl>(Tag);
9858 CXXRecordDecl *Pattern = Record->getInstantiatedFromMemberClass();
9859 if (!Pattern) {
9860 Diag(TemplateLoc, diag::err_explicit_instantiation_nontemplate_type)
9861 << Context.getTypeDeclType(Record);
9862 Diag(Record->getLocation(), diag::note_nontemplate_decl_here);
9863 return true;
9864 }
9865
9866 // C++0x [temp.explicit]p2:
9867 // If the explicit instantiation is for a class or member class, the
9868 // elaborated-type-specifier in the declaration shall include a
9869 // simple-template-id.
9870 //
9871 // C++98 has the same restriction, just worded differently.
9872 if (!ScopeSpecifierHasTemplateId(SS))
9873 Diag(TemplateLoc, diag::ext_explicit_instantiation_without_qualified_id)
9874 << Record << SS.getRange();
9875
9876 // C++0x [temp.explicit]p2:
9877 // There are two forms of explicit instantiation: an explicit instantiation
9878 // definition and an explicit instantiation declaration. An explicit
9879 // instantiation declaration begins with the extern keyword. [...]
9880 TemplateSpecializationKind TSK
9881 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
9882 : TSK_ExplicitInstantiationDeclaration;
9883
9884 CheckExplicitInstantiation(*this, Record, NameLoc, true, TSK);
9885
9886 // Verify that it is okay to explicitly instantiate here.
9887 CXXRecordDecl *PrevDecl
9888 = cast_or_null<CXXRecordDecl>(Record->getPreviousDecl());
9889 if (!PrevDecl && Record->getDefinition())
9890 PrevDecl = Record;
9891 if (PrevDecl) {
9892 MemberSpecializationInfo *MSInfo = PrevDecl->getMemberSpecializationInfo();
9893 bool HasNoEffect = false;
9894 assert(MSInfo && "No member specialization information?")(static_cast <bool> (MSInfo && "No member specialization information?"
) ? void (0) : __assert_fail ("MSInfo && \"No member specialization information?\""
, "clang/lib/Sema/SemaTemplate.cpp", 9894, __extension__ __PRETTY_FUNCTION__
))
;
9895 if (CheckSpecializationInstantiationRedecl(TemplateLoc, TSK,
9896 PrevDecl,
9897 MSInfo->getTemplateSpecializationKind(),
9898 MSInfo->getPointOfInstantiation(),
9899 HasNoEffect))
9900 return true;
9901 if (HasNoEffect)
9902 return TagD;
9903 }
9904
9905 CXXRecordDecl *RecordDef
9906 = cast_or_null<CXXRecordDecl>(Record->getDefinition());
9907 if (!RecordDef) {
9908 // C++ [temp.explicit]p3:
9909 // A definition of a member class of a class template shall be in scope
9910 // at the point of an explicit instantiation of the member class.
9911 CXXRecordDecl *Def
9912 = cast_or_null<CXXRecordDecl>(Pattern->getDefinition());
9913 if (!Def) {
9914 Diag(TemplateLoc, diag::err_explicit_instantiation_undefined_member)
9915 << 0 << Record->getDeclName() << Record->getDeclContext();
9916 Diag(Pattern->getLocation(), diag::note_forward_declaration)
9917 << Pattern;
9918 return true;
9919 } else {
9920 if (InstantiateClass(NameLoc, Record, Def,
9921 getTemplateInstantiationArgs(Record),
9922 TSK))
9923 return true;
9924
9925 RecordDef = cast_or_null<CXXRecordDecl>(Record->getDefinition());
9926 if (!RecordDef)
9927 return true;
9928 }
9929 }
9930
9931 // Instantiate all of the members of the class.
9932 InstantiateClassMembers(NameLoc, RecordDef,
9933 getTemplateInstantiationArgs(Record), TSK);
9934
9935 if (TSK == TSK_ExplicitInstantiationDefinition)
9936 MarkVTableUsed(NameLoc, RecordDef, true);
9937
9938 // FIXME: We don't have any representation for explicit instantiations of
9939 // member classes. Such a representation is not needed for compilation, but it
9940 // should be available for clients that want to see all of the declarations in
9941 // the source code.
9942 return TagD;
9943}
9944
9945DeclResult Sema::ActOnExplicitInstantiation(Scope *S,
9946 SourceLocation ExternLoc,
9947 SourceLocation TemplateLoc,
9948 Declarator &D) {
9949 // Explicit instantiations always require a name.
9950 // TODO: check if/when DNInfo should replace Name.
9951 DeclarationNameInfo NameInfo = GetNameForDeclarator(D);
9952 DeclarationName Name = NameInfo.getName();
9953 if (!Name) {
9954 if (!D.isInvalidType())
9955 Diag(D.getDeclSpec().getBeginLoc(),
9956 diag::err_explicit_instantiation_requires_name)
9957 << D.getDeclSpec().getSourceRange() << D.getSourceRange();
9958
9959 return true;
9960 }
9961
9962 // The scope passed in may not be a decl scope. Zip up the scope tree until
9963 // we find one that is.
9964 while ((S->getFlags() & Scope::DeclScope) == 0 ||
9965 (S->getFlags() & Scope::TemplateParamScope) != 0)
9966 S = S->getParent();
9967
9968 // Determine the type of the declaration.
9969 TypeSourceInfo *T = GetTypeForDeclarator(D, S);
9970 QualType R = T->getType();
9971 if (R.isNull())
9972 return true;
9973
9974 // C++ [dcl.stc]p1:
9975 // A storage-class-specifier shall not be specified in [...] an explicit
9976 // instantiation (14.7.2) directive.
9977 if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef) {
9978 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_of_typedef)
9979 << Name;
9980 return true;
9981 } else if (D.getDeclSpec().getStorageClassSpec()
9982 != DeclSpec::SCS_unspecified) {
9983 // Complain about then remove the storage class specifier.
9984 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_storage_class)
9985 << FixItHint::CreateRemoval(D.getDeclSpec().getStorageClassSpecLoc());
9986
9987 D.getMutableDeclSpec().ClearStorageClassSpecs();
9988 }
9989
9990 // C++0x [temp.explicit]p1:
9991 // [...] An explicit instantiation of a function template shall not use the
9992 // inline or constexpr specifiers.
9993 // Presumably, this also applies to member functions of class templates as
9994 // well.
9995 if (D.getDeclSpec().isInlineSpecified())
9996 Diag(D.getDeclSpec().getInlineSpecLoc(),
9997 getLangOpts().CPlusPlus11 ?
9998 diag::err_explicit_instantiation_inline :
9999 diag::warn_explicit_instantiation_inline_0x)
10000 << FixItHint::CreateRemoval(D.getDeclSpec().getInlineSpecLoc());
10001 if (D.getDeclSpec().hasConstexprSpecifier() && R->isFunctionType())
10002 // FIXME: Add a fix-it to remove the 'constexpr' and add a 'const' if one is
10003 // not already specified.
10004 Diag(D.getDeclSpec().getConstexprSpecLoc(),
10005 diag::err_explicit_instantiation_constexpr);
10006
10007 // A deduction guide is not on the list of entities that can be explicitly
10008 // instantiated.
10009 if (Name.getNameKind() == DeclarationName::CXXDeductionGuideName) {
10010 Diag(D.getDeclSpec().getBeginLoc(), diag::err_deduction_guide_specialized)
10011 << /*explicit instantiation*/ 0;
10012 return true;
10013 }
10014
10015 // C++0x [temp.explicit]p2:
10016 // There are two forms of explicit instantiation: an explicit instantiation
10017 // definition and an explicit instantiation declaration. An explicit
10018 // instantiation declaration begins with the extern keyword. [...]
10019 TemplateSpecializationKind TSK
10020 = ExternLoc.isInvalid()? TSK_ExplicitInstantiationDefinition
10021 : TSK_ExplicitInstantiationDeclaration;
10022
10023 LookupResult Previous(*this, NameInfo, LookupOrdinaryName);
10024 LookupParsedName(Previous, S, &D.getCXXScopeSpec());
10025
10026 if (!R->isFunctionType()) {
10027 // C++ [temp.explicit]p1:
10028 // A [...] static data member of a class template can be explicitly
10029 // instantiated from the member definition associated with its class
10030 // template.
10031 // C++1y [temp.explicit]p1:
10032 // A [...] variable [...] template specialization can be explicitly
10033 // instantiated from its template.
10034 if (Previous.isAmbiguous())
10035 return true;
10036
10037 VarDecl *Prev = Previous.getAsSingle<VarDecl>();
10038 VarTemplateDecl *PrevTemplate = Previous.getAsSingle<VarTemplateDecl>();
10039
10040 if (!PrevTemplate) {
10041 if (!Prev || !Prev->isStaticDataMember()) {
10042 // We expect to see a static data member here.
10043 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_not_known)
10044 << Name;
10045 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
10046 P != PEnd; ++P)
10047 Diag((*P)->getLocation(), diag::note_explicit_instantiation_here);
10048 return true;
10049 }
10050
10051 if (!Prev->getInstantiatedFromStaticDataMember()) {
10052 // FIXME: Check for explicit specialization?
10053 Diag(D.getIdentifierLoc(),
10054 diag::err_explicit_instantiation_data_member_not_instantiated)
10055 << Prev;
10056 Diag(Prev->getLocation(), diag::note_explicit_instantiation_here);
10057 // FIXME: Can we provide a note showing where this was declared?
10058 return true;
10059 }
10060 } else {
10061 // Explicitly instantiate a variable template.
10062
10063 // C++1y [dcl.spec.auto]p6:
10064 // ... A program that uses auto or decltype(auto) in a context not
10065 // explicitly allowed in this section is ill-formed.
10066 //
10067 // This includes auto-typed variable template instantiations.
10068 if (R->isUndeducedType()) {
10069 Diag(T->getTypeLoc().getBeginLoc(),
10070 diag::err_auto_not_allowed_var_inst);
10071 return true;
10072 }
10073
10074 if (D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId) {
10075 // C++1y [temp.explicit]p3:
10076 // If the explicit instantiation is for a variable, the unqualified-id
10077 // in the declaration shall be a template-id.
10078 Diag(D.getIdentifierLoc(),
10079 diag::err_explicit_instantiation_without_template_id)
10080 << PrevTemplate;
10081 Diag(PrevTemplate->getLocation(),
10082 diag::note_explicit_instantiation_here);
10083 return true;
10084 }
10085
10086 // Translate the parser's template argument list into our AST format.
10087 TemplateArgumentListInfo TemplateArgs =
10088 makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
10089
10090 DeclResult Res = CheckVarTemplateId(PrevTemplate, TemplateLoc,
10091 D.getIdentifierLoc(), TemplateArgs);
10092 if (Res.isInvalid())
10093 return true;
10094
10095 if (!Res.isUsable()) {
10096 // We somehow specified dependent template arguments in an explicit
10097 // instantiation. This should probably only happen during error
10098 // recovery.
10099 Diag(D.getIdentifierLoc(), diag::err_explicit_instantiation_dependent);
10100 return true;
10101 }
10102
10103 // Ignore access control bits, we don't need them for redeclaration
10104 // checking.
10105 Prev = cast<VarDecl>(Res.get());
10106 }
10107
10108 // C++0x [temp.explicit]p2:
10109 // If the explicit instantiation is for a member function, a member class
10110 // or a static data member of a class template specialization, the name of
10111 // the class template specialization in the qualified-id for the member
10112 // name shall be a simple-template-id.
10113 //
10114 // C++98 has the same restriction, just worded differently.
10115 //
10116 // This does not apply to variable template specializations, where the
10117 // template-id is in the unqualified-id instead.
10118 if (!ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()) && !PrevTemplate)
10119 Diag(D.getIdentifierLoc(),
10120 diag::ext_explicit_instantiation_without_qualified_id)
10121 << Prev << D.getCXXScopeSpec().getRange();
10122
10123 CheckExplicitInstantiation(*this, Prev, D.getIdentifierLoc(), true, TSK);
10124
10125 // Verify that it is okay to explicitly instantiate here.
10126 TemplateSpecializationKind PrevTSK = Prev->getTemplateSpecializationKind();
10127 SourceLocation POI = Prev->getPointOfInstantiation();
10128 bool HasNoEffect = false;
10129 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK, Prev,
10130 PrevTSK, POI, HasNoEffect))
10131 return true;
10132
10133 if (!HasNoEffect) {
10134 // Instantiate static data member or variable template.
10135 Prev->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
10136 // Merge attributes.
10137 ProcessDeclAttributeList(S, Prev, D.getDeclSpec().getAttributes());
10138 if (TSK == TSK_ExplicitInstantiationDefinition)
10139 InstantiateVariableDefinition(D.getIdentifierLoc(), Prev);
10140 }
10141
10142 // Check the new variable specialization against the parsed input.
10143 if (PrevTemplate && !Context.hasSameType(Prev->getType(), R)) {
10144 Diag(T->getTypeLoc().getBeginLoc(),
10145 diag::err_invalid_var_template_spec_type)
10146 << 0 << PrevTemplate << R << Prev->getType();
10147 Diag(PrevTemplate->getLocation(), diag::note_template_declared_here)
10148 << 2 << PrevTemplate->getDeclName();
10149 return true;
10150 }
10151
10152 // FIXME: Create an ExplicitInstantiation node?
10153 return (Decl*) nullptr;
10154 }
10155
10156 // If the declarator is a template-id, translate the parser's template
10157 // argument list into our AST format.
10158 bool HasExplicitTemplateArgs = false;
10159 TemplateArgumentListInfo TemplateArgs;
10160 if (D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId) {
10161 TemplateArgs = makeTemplateArgumentListInfo(*this, *D.getName().TemplateId);
10162 HasExplicitTemplateArgs = true;
10163 }
10164
10165 // C++ [temp.explicit]p1:
10166 // A [...] function [...] can be explicitly instantiated from its template.
10167 // A member function [...] of a class template can be explicitly
10168 // instantiated from the member definition associated with its class
10169 // template.
10170 UnresolvedSet<8> TemplateMatches;
10171 FunctionDecl *NonTemplateMatch = nullptr;
10172 TemplateSpecCandidateSet FailedCandidates(D.getIdentifierLoc());
10173 for (LookupResult::iterator P = Previous.begin(), PEnd = Previous.end();
10174 P != PEnd; ++P) {
10175 NamedDecl *Prev = *P;
10176 if (!HasExplicitTemplateArgs) {
10177 if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(Prev)) {
10178 QualType Adjusted = adjustCCAndNoReturn(R, Method->getType(),
10179 /*AdjustExceptionSpec*/true);
10180 if (Context.hasSameUnqualifiedType(Method->getType(), Adjusted)) {
10181 if (Method->getPrimaryTemplate()) {
10182 TemplateMatches.addDecl(Method, P.getAccess());
10183 } else {
10184 // FIXME: Can this assert ever happen? Needs a test.
10185 assert(!NonTemplateMatch && "Multiple NonTemplateMatches")(static_cast <bool> (!NonTemplateMatch && "Multiple NonTemplateMatches"
) ? void (0) : __assert_fail ("!NonTemplateMatch && \"Multiple NonTemplateMatches\""
, "clang/lib/Sema/SemaTemplate.cpp", 10185, __extension__ __PRETTY_FUNCTION__
))
;
10186 NonTemplateMatch = Method;
10187 }
10188 }
10189 }
10190 }
10191
10192 FunctionTemplateDecl *FunTmpl = dyn_cast<FunctionTemplateDecl>(Prev);
10193 if (!FunTmpl)
10194 continue;
10195
10196 TemplateDeductionInfo Info(FailedCandidates.getLocation());
10197 FunctionDecl *Specialization = nullptr;
10198 if (TemplateDeductionResult TDK
10199 = DeduceTemplateArguments(FunTmpl,
10200 (HasExplicitTemplateArgs ? &TemplateArgs
10201 : nullptr),
10202 R, Specialization, Info)) {
10203 // Keep track of almost-matches.
10204 FailedCandidates.addCandidate()
10205 .set(P.getPair(), FunTmpl->getTemplatedDecl(),
10206 MakeDeductionFailureInfo(Context, TDK, Info));
10207 (void)TDK;
10208 continue;
10209 }
10210
10211 // Target attributes are part of the cuda function signature, so
10212 // the cuda target of the instantiated function must match that of its
10213 // template. Given that C++ template deduction does not take
10214 // target attributes into account, we reject candidates here that
10215 // have a different target.
10216 if (LangOpts.CUDA &&
10217 IdentifyCUDATarget(Specialization,
10218 /* IgnoreImplicitHDAttr = */ true) !=
10219 IdentifyCUDATarget(D.getDeclSpec().getAttributes())) {
10220 FailedCandidates.addCandidate().set(
10221 P.getPair(), FunTmpl->getTemplatedDecl(),
10222 MakeDeductionFailureInfo(Context, TDK_CUDATargetMismatch, Info));
10223 continue;
10224 }
10225
10226 TemplateMatches.addDecl(Specialization, P.getAccess());
10227 }
10228
10229 FunctionDecl *Specialization = NonTemplateMatch;
10230 if (!Specialization) {
10231 // Find the most specialized function template specialization.
10232 UnresolvedSetIterator Result = getMostSpecialized(
10233 TemplateMatches.begin(), TemplateMatches.end(), FailedCandidates,
10234 D.getIdentifierLoc(),
10235 PDiag(diag::err_explicit_instantiation_not_known) << Name,
10236 PDiag(diag::err_explicit_instantiation_ambiguous) << Name,
10237 PDiag(diag::note_explicit_instantiation_candidate));
10238
10239 if (Result == TemplateMatches.end())
10240 return true;
10241
10242 // Ignore access control bits, we don't need them for redeclaration checking.
10243 Specialization = cast<FunctionDecl>(*Result);
10244 }
10245
10246 // C++11 [except.spec]p4
10247 // In an explicit instantiation an exception-specification may be specified,
10248 // but is not required.
10249 // If an exception-specification is specified in an explicit instantiation
10250 // directive, it shall be compatible with the exception-specifications of
10251 // other declarations of that function.
10252 if (auto *FPT = R->getAs<FunctionProtoType>())
10253 if (FPT->hasExceptionSpec()) {
10254 unsigned DiagID =
10255 diag::err_mismatched_exception_spec_explicit_instantiation;
10256 if (getLangOpts().MicrosoftExt)
10257 DiagID = diag::ext_mismatched_exception_spec_explicit_instantiation;
10258 bool Result = CheckEquivalentExceptionSpec(
10259 PDiag(DiagID) << Specialization->getType(),
10260 PDiag(diag::note_explicit_instantiation_here),
10261 Specialization->getType()->getAs<FunctionProtoType>(),
10262 Specialization->getLocation(), FPT, D.getBeginLoc());
10263 // In Microsoft mode, mismatching exception specifications just cause a
10264 // warning.
10265 if (!getLangOpts().MicrosoftExt && Result)
10266 return true;
10267 }
10268
10269 if (Specialization->getTemplateSpecializationKind() == TSK_Undeclared) {
10270 Diag(D.getIdentifierLoc(),
10271 diag::err_explicit_instantiation_member_function_not_instantiated)
10272 << Specialization
10273 << (Specialization->getTemplateSpecializationKind() ==
10274 TSK_ExplicitSpecialization);
10275 Diag(Specialization->getLocation(), diag::note_explicit_instantiation_here);
10276 return true;
10277 }
10278
10279 FunctionDecl *PrevDecl = Specialization->getPreviousDecl();
10280 if (!PrevDecl && Specialization->isThisDeclarationADefinition())
10281 PrevDecl = Specialization;
10282
10283 if (PrevDecl) {
10284 bool HasNoEffect = false;
10285 if (CheckSpecializationInstantiationRedecl(D.getIdentifierLoc(), TSK,
10286 PrevDecl,
10287 PrevDecl->getTemplateSpecializationKind(),
10288 PrevDecl->getPointOfInstantiation(),
10289 HasNoEffect))
10290 return true;
10291
10292 // FIXME: We may still want to build some representation of this
10293 // explicit specialization.
10294 if (HasNoEffect)
10295 return (Decl*) nullptr;
10296 }
10297
10298 // HACK: libc++ has a bug where it attempts to explicitly instantiate the
10299 // functions
10300 // valarray<size_t>::valarray(size_t) and
10301 // valarray<size_t>::~valarray()
10302 // that it declared to have internal linkage with the internal_linkage
10303 // attribute. Ignore the explicit instantiation declaration in this case.
10304 if (Specialization->hasAttr<InternalLinkageAttr>() &&
10305 TSK == TSK_ExplicitInstantiationDeclaration) {
10306 if (auto *RD = dyn_cast<CXXRecordDecl>(Specialization->getDeclContext()))
10307 if (RD->getIdentifier() && RD->getIdentifier()->isStr("valarray") &&
10308 RD->isInStdNamespace())
10309 return (Decl*) nullptr;
10310 }
10311
10312 ProcessDeclAttributeList(S, Specialization, D.getDeclSpec().getAttributes());
10313
10314 // In MSVC mode, dllimported explicit instantiation definitions are treated as
10315 // instantiation declarations.
10316 if (TSK == TSK_ExplicitInstantiationDefinition &&
10317 Specialization->hasAttr<DLLImportAttr>() &&
10318 Context.getTargetInfo().getCXXABI().isMicrosoft())
10319 TSK = TSK_ExplicitInstantiationDeclaration;
10320
10321 Specialization->setTemplateSpecializationKind(TSK, D.getIdentifierLoc());
10322
10323 if (Specialization->isDefined()) {
10324 // Let the ASTConsumer know that this function has been explicitly
10325 // instantiated now, and its linkage might have changed.
10326 Consumer.HandleTopLevelDecl(DeclGroupRef(Specialization));
10327 } else if (TSK == TSK_ExplicitInstantiationDefinition)
10328 InstantiateFunctionDefinition(D.getIdentifierLoc(), Specialization);
10329
10330 // C++0x [temp.explicit]p2:
10331 // If the explicit instantiation is for a member function, a member class
10332 // or a static data member of a class template specialization, the name of
10333 // the class template specialization in the qualified-id for the member
10334 // name shall be a simple-template-id.
10335 //
10336 // C++98 has the same restriction, just worded differently.
10337 FunctionTemplateDecl *FunTmpl = Specialization->getPrimaryTemplate();
10338 if (D.getName().getKind() != UnqualifiedIdKind::IK_TemplateId && !FunTmpl &&
10339 D.getCXXScopeSpec().isSet() &&
10340 !ScopeSpecifierHasTemplateId(D.getCXXScopeSpec()))
10341 Diag(D.getIdentifierLoc(),
10342 diag::ext_explicit_instantiation_without_qualified_id)
10343 << Specialization << D.getCXXScopeSpec().getRange();
10344
10345 CheckExplicitInstantiation(
10346 *this,
10347 FunTmpl ? (NamedDecl *)FunTmpl
10348 : Specialization->getInstantiatedFromMemberFunction(),
10349 D.getIdentifierLoc(), D.getCXXScopeSpec().isSet(), TSK);
10350
10351 // FIXME: Create some kind of ExplicitInstantiationDecl here.
10352 return (Decl*) nullptr;
10353}
10354
10355TypeResult
10356Sema::ActOnDependentTag(Scope *S, unsigned TagSpec, TagUseKind TUK,
10357 const CXXScopeSpec &SS, IdentifierInfo *Name,
10358 SourceLocation TagLoc, SourceLocation NameLoc) {
10359 // This has to hold, because SS is expected to be defined.
10360 assert(Name && "Expected a name in a dependent tag")(static_cast <bool> (Name && "Expected a name in a dependent tag"
) ? void (0) : __assert_fail ("Name && \"Expected a name in a dependent tag\""
, "clang/lib/Sema/SemaTemplate.cpp", 10360, __extension__ __PRETTY_FUNCTION__
))
;
10361
10362 NestedNameSpecifier *NNS = SS.getScopeRep();
10363 if (!NNS)
10364 return true;
10365
10366 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
10367
10368 if (TUK == TUK_Declaration || TUK == TUK_Definition) {
10369 Diag(NameLoc, diag::err_dependent_tag_decl)
10370 << (TUK == TUK_Definition) << Kind << SS.getRange();
10371 return true;
10372 }
10373
10374 // Create the resulting type.
10375 ElaboratedTypeKeyword Kwd = TypeWithKeyword::getKeywordForTagTypeKind(Kind);
10376 QualType Result = Context.getDependentNameType(Kwd, NNS, Name);
10377
10378 // Create type-source location information for this type.
10379 TypeLocBuilder TLB;
10380 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(Result);
10381 TL.setElaboratedKeywordLoc(TagLoc);
10382 TL.setQualifierLoc(SS.getWithLocInContext(Context));
10383 TL.setNameLoc(NameLoc);
10384 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
10385}
10386
10387TypeResult
10388Sema::ActOnTypenameType(Scope *S, SourceLocation TypenameLoc,
10389 const CXXScopeSpec &SS, const IdentifierInfo &II,
10390 SourceLocation IdLoc) {
10391 if (SS.isInvalid())
10392 return true;
10393
10394 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
10395 Diag(TypenameLoc,
10396 getLangOpts().CPlusPlus11 ?
10397 diag::warn_cxx98_compat_typename_outside_of_template :
10398 diag::ext_typename_outside_of_template)
10399 << FixItHint::CreateRemoval(TypenameLoc);
10400
10401 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
10402 TypeSourceInfo *TSI = nullptr;
10403 QualType T = CheckTypenameType(TypenameLoc.isValid()? ETK_Typename : ETK_None,
10404 TypenameLoc, QualifierLoc, II, IdLoc, &TSI,
10405 /*DeducedTSTContext=*/true);
10406 if (T.isNull())
10407 return true;
10408 return CreateParsedType(T, TSI);
10409}
10410
10411TypeResult
10412Sema::ActOnTypenameType(Scope *S,
10413 SourceLocation TypenameLoc,
10414 const CXXScopeSpec &SS,
10415 SourceLocation TemplateKWLoc,
10416 TemplateTy TemplateIn,
10417 IdentifierInfo *TemplateII,
10418 SourceLocation TemplateIILoc,
10419 SourceLocation LAngleLoc,
10420 ASTTemplateArgsPtr TemplateArgsIn,
10421 SourceLocation RAngleLoc) {
10422 if (TypenameLoc.isValid() && S && !S->getTemplateParamParent())
10423 Diag(TypenameLoc,
10424 getLangOpts().CPlusPlus11 ?
10425 diag::warn_cxx98_compat_typename_outside_of_template :
10426 diag::ext_typename_outside_of_template)
10427 << FixItHint::CreateRemoval(TypenameLoc);
10428
10429 // Strangely, non-type results are not ignored by this lookup, so the
10430 // program is ill-formed if it finds an injected-class-name.
10431 if (TypenameLoc.isValid()) {
10432 auto *LookupRD =
10433 dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, false));
10434 if (LookupRD && LookupRD->getIdentifier() == TemplateII) {
10435 Diag(TemplateIILoc,
10436 diag::ext_out_of_line_qualified_id_type_names_constructor)
10437 << TemplateII << 0 /*injected-class-name used as template name*/
10438 << (TemplateKWLoc.isValid() ? 1 : 0 /*'template'/'typename' keyword*/);
10439 }
10440 }
10441
10442 // Translate the parser's template argument list in our AST format.
10443 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
10444 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
10445
10446 TemplateName Template = TemplateIn.get();
10447 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
10448 // Construct a dependent template specialization type.
10449 assert(DTN && "dependent template has non-dependent name?")(static_cast <bool> (DTN && "dependent template has non-dependent name?"
) ? void (0) : __assert_fail ("DTN && \"dependent template has non-dependent name?\""
, "clang/lib/Sema/SemaTemplate.cpp", 10449, __extension__ __PRETTY_FUNCTION__
))
;
10450 assert(DTN->getQualifier() == SS.getScopeRep())(static_cast <bool> (DTN->getQualifier() == SS.getScopeRep
()) ? void (0) : __assert_fail ("DTN->getQualifier() == SS.getScopeRep()"
, "clang/lib/Sema/SemaTemplate.cpp", 10450, __extension__ __PRETTY_FUNCTION__
))
;
10451 QualType T = Context.getDependentTemplateSpecializationType(ETK_Typename,
10452 DTN->getQualifier(),
10453 DTN->getIdentifier(),
10454 TemplateArgs);
10455
10456 // Create source-location information for this type.
10457 TypeLocBuilder Builder;
10458 DependentTemplateSpecializationTypeLoc SpecTL
10459 = Builder.push<DependentTemplateSpecializationTypeLoc>(T);
10460 SpecTL.setElaboratedKeywordLoc(TypenameLoc);
10461 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
10462 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
10463 SpecTL.setTemplateNameLoc(TemplateIILoc);
10464 SpecTL.setLAngleLoc(LAngleLoc);
10465 SpecTL.setRAngleLoc(RAngleLoc);
10466 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
10467 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
10468 return CreateParsedType(T, Builder.getTypeSourceInfo(Context, T));
10469 }
10470
10471 QualType T = CheckTemplateIdType(Template, TemplateIILoc, TemplateArgs);
10472 if (T.isNull())
10473 return true;
10474
10475 // Provide source-location information for the template specialization type.
10476 TypeLocBuilder Builder;
10477 TemplateSpecializationTypeLoc SpecTL
10478 = Builder.push<TemplateSpecializationTypeLoc>(T);
10479 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
10480 SpecTL.setTemplateNameLoc(TemplateIILoc);
10481 SpecTL.setLAngleLoc(LAngleLoc);
10482 SpecTL.setRAngleLoc(RAngleLoc);
10483 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
10484 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
10485
10486 T = Context.getElaboratedType(ETK_Typename, SS.getScopeRep(), T);
10487 ElaboratedTypeLoc TL = Builder.push<ElaboratedTypeLoc>(T);
10488 TL.setElaboratedKeywordLoc(TypenameLoc);
10489 TL.setQualifierLoc(SS.getWithLocInContext(Context));
10490
10491 TypeSourceInfo *TSI = Builder.getTypeSourceInfo(Context, T);
10492 return CreateParsedType(T, TSI);
10493}
10494
10495
10496/// Determine whether this failed name lookup should be treated as being
10497/// disabled by a usage of std::enable_if.
10498static bool isEnableIf(NestedNameSpecifierLoc NNS, const IdentifierInfo &II,
10499 SourceRange &CondRange, Expr *&Cond) {
10500 // We must be looking for a ::type...
10501 if (!II.isStr("type"))
10502 return false;
10503
10504 // ... within an explicitly-written template specialization...
10505 if (!NNS || !NNS.getNestedNameSpecifier()->getAsType())
10506 return false;
10507 TypeLoc EnableIfTy = NNS.getTypeLoc();
10508 TemplateSpecializationTypeLoc EnableIfTSTLoc =
10509 EnableIfTy.getAs<TemplateSpecializationTypeLoc>();
10510 if (!EnableIfTSTLoc || EnableIfTSTLoc.getNumArgs() == 0)
10511 return false;
10512 const TemplateSpecializationType *EnableIfTST = EnableIfTSTLoc.getTypePtr();
10513
10514 // ... which names a complete class template declaration...
10515 const TemplateDecl *EnableIfDecl =
10516 EnableIfTST->getTemplateName().getAsTemplateDecl();
10517 if (!EnableIfDecl || EnableIfTST->isIncompleteType())
10518 return false;
10519
10520 // ... called "enable_if".
10521 const IdentifierInfo *EnableIfII =
10522 EnableIfDecl->getDeclName().getAsIdentifierInfo();
10523 if (!EnableIfII || !EnableIfII->isStr("enable_if"))
10524 return false;
10525
10526 // Assume the first template argument is the condition.
10527 CondRange = EnableIfTSTLoc.getArgLoc(0).getSourceRange();
10528
10529 // Dig out the condition.
10530 Cond = nullptr;
10531 if (EnableIfTSTLoc.getArgLoc(0).getArgument().getKind()
10532 != TemplateArgument::Expression)
10533 return true;
10534
10535 Cond = EnableIfTSTLoc.getArgLoc(0).getSourceExpression();
10536
10537 // Ignore Boolean literals; they add no value.
10538 if (isa<CXXBoolLiteralExpr>(Cond->IgnoreParenCasts()))
10539 Cond = nullptr;
10540
10541 return true;
10542}
10543
10544QualType
10545Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
10546 SourceLocation KeywordLoc,
10547 NestedNameSpecifierLoc QualifierLoc,
10548 const IdentifierInfo &II,
10549 SourceLocation IILoc,
10550 TypeSourceInfo **TSI,
10551 bool DeducedTSTContext) {
10552 QualType T = CheckTypenameType(Keyword, KeywordLoc, QualifierLoc, II, IILoc,
10553 DeducedTSTContext);
10554 if (T.isNull())
10555 return QualType();
10556
10557 *TSI = Context.CreateTypeSourceInfo(T);
10558 if (isa<DependentNameType>(T)) {
10559 DependentNameTypeLoc TL =
10560 (*TSI)->getTypeLoc().castAs<DependentNameTypeLoc>();
10561 TL.setElaboratedKeywordLoc(KeywordLoc);
10562 TL.setQualifierLoc(QualifierLoc);
10563 TL.setNameLoc(IILoc);
10564 } else {
10565 ElaboratedTypeLoc TL = (*TSI)->getTypeLoc().castAs<ElaboratedTypeLoc>();
10566 TL.setElaboratedKeywordLoc(KeywordLoc);
10567 TL.setQualifierLoc(QualifierLoc);
10568 TL.getNamedTypeLoc().castAs<TypeSpecTypeLoc>().setNameLoc(IILoc);
10569 }
10570 return T;
10571}
10572
10573/// Build the type that describes a C++ typename specifier,
10574/// e.g., "typename T::type".
10575QualType
10576Sema::CheckTypenameType(ElaboratedTypeKeyword Keyword,
10577 SourceLocation KeywordLoc,
10578 NestedNameSpecifierLoc QualifierLoc,
10579 const IdentifierInfo &II,
10580 SourceLocation IILoc, bool DeducedTSTContext) {
10581 CXXScopeSpec SS;
10582 SS.Adopt(QualifierLoc);
10583
10584 DeclContext *Ctx = nullptr;
10585 if (QualifierLoc) {
10586 Ctx = computeDeclContext(SS);
10587 if (!Ctx) {
10588 // If the nested-name-specifier is dependent and couldn't be
10589 // resolved to a type, build a typename type.
10590 assert(QualifierLoc.getNestedNameSpecifier()->isDependent())(static_cast <bool> (QualifierLoc.getNestedNameSpecifier
()->isDependent()) ? void (0) : __assert_fail ("QualifierLoc.getNestedNameSpecifier()->isDependent()"
, "clang/lib/Sema/SemaTemplate.cpp", 10590, __extension__ __PRETTY_FUNCTION__
))
;
10591 return Context.getDependentNameType(Keyword,
10592 QualifierLoc.getNestedNameSpecifier(),
10593 &II);
10594 }
10595
10596 // If the nested-name-specifier refers to the current instantiation,
10597 // the "typename" keyword itself is superfluous. In C++03, the
10598 // program is actually ill-formed. However, DR 382 (in C++0x CD1)
10599 // allows such extraneous "typename" keywords, and we retroactively
10600 // apply this DR to C++03 code with only a warning. In any case we continue.
10601
10602 if (RequireCompleteDeclContext(SS, Ctx))
10603 return QualType();
10604 }
10605
10606 DeclarationName Name(&II);
10607 LookupResult Result(*this, Name, IILoc, LookupOrdinaryName);
10608 if (Ctx)
10609 LookupQualifiedName(Result, Ctx, SS);
10610 else
10611 LookupName(Result, CurScope);
10612 unsigned DiagID = 0;
10613 Decl *Referenced = nullptr;
10614 switch (Result.getResultKind()) {
10615 case LookupResult::NotFound: {
10616 // If we're looking up 'type' within a template named 'enable_if', produce
10617 // a more specific diagnostic.
10618 SourceRange CondRange;
10619 Expr *Cond = nullptr;
10620 if (Ctx && isEnableIf(QualifierLoc, II, CondRange, Cond)) {
10621 // If we have a condition, narrow it down to the specific failed
10622 // condition.
10623 if (Cond) {
10624 Expr *FailedCond;
10625 std::string FailedDescription;
10626 std::tie(FailedCond, FailedDescription) =
10627 findFailedBooleanCondition(Cond);
10628
10629 Diag(FailedCond->getExprLoc(),
10630 diag::err_typename_nested_not_found_requirement)
10631 << FailedDescription
10632 << FailedCond->getSourceRange();
10633 return QualType();
10634 }
10635
10636 Diag(CondRange.getBegin(),
10637 diag::err_typename_nested_not_found_enable_if)
10638 << Ctx << CondRange;
10639 return QualType();
10640 }
10641
10642 DiagID = Ctx ? diag::err_typename_nested_not_found
10643 : diag::err_unknown_typename;
10644 break;
10645 }
10646
10647 case LookupResult::FoundUnresolvedValue: {
10648 // We found a using declaration that is a value. Most likely, the using
10649 // declaration itself is meant to have the 'typename' keyword.
10650 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
10651 IILoc);
10652 Diag(IILoc, diag::err_typename_refers_to_using_value_decl)
10653 << Name << Ctx << FullRange;
10654 if (UnresolvedUsingValueDecl *Using
10655 = dyn_cast<UnresolvedUsingValueDecl>(Result.getRepresentativeDecl())){
10656 SourceLocation Loc = Using->getQualifierLoc().getBeginLoc();
10657 Diag(Loc, diag::note_using_value_decl_missing_typename)
10658 << FixItHint::CreateInsertion(Loc, "typename ");
10659 }
10660 }
10661 // Fall through to create a dependent typename type, from which we can recover
10662 // better.
10663 LLVM_FALLTHROUGH[[gnu::fallthrough]];
10664
10665 case LookupResult::NotFoundInCurrentInstantiation:
10666 // Okay, it's a member of an unknown instantiation.
10667 return Context.getDependentNameType(Keyword,
10668 QualifierLoc.getNestedNameSpecifier(),
10669 &II);
10670
10671 case LookupResult::Found:
10672 if (TypeDecl *Type = dyn_cast<TypeDecl>(Result.getFoundDecl())) {
10673 // C++ [class.qual]p2:
10674 // In a lookup in which function names are not ignored and the
10675 // nested-name-specifier nominates a class C, if the name specified
10676 // after the nested-name-specifier, when looked up in C, is the
10677 // injected-class-name of C [...] then the name is instead considered
10678 // to name the constructor of class C.
10679 //
10680 // Unlike in an elaborated-type-specifier, function names are not ignored
10681 // in typename-specifier lookup. However, they are ignored in all the
10682 // contexts where we form a typename type with no keyword (that is, in
10683 // mem-initializer-ids, base-specifiers, and elaborated-type-specifiers).
10684 //
10685 // FIXME: That's not strictly true: mem-initializer-id lookup does not
10686 // ignore functions, but that appears to be an oversight.
10687 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(Ctx);
10688 auto *FoundRD = dyn_cast<CXXRecordDecl>(Type);
10689 if (Keyword == ETK_Typename && LookupRD && FoundRD &&
10690 FoundRD->isInjectedClassName() &&
10691 declaresSameEntity(LookupRD, cast<Decl>(FoundRD->getParent())))
10692 Diag(IILoc, diag::ext_out_of_line_qualified_id_type_names_constructor)
10693 << &II << 1 << 0 /*'typename' keyword used*/;
10694
10695 // We found a type. Build an ElaboratedType, since the
10696 // typename-specifier was just sugar.
10697 MarkAnyDeclReferenced(Type->getLocation(), Type, /*OdrUse=*/false);
10698 return Context.getElaboratedType(Keyword,
10699 QualifierLoc.getNestedNameSpecifier(),
10700 Context.getTypeDeclType(Type));
10701 }
10702
10703 // C++ [dcl.type.simple]p2:
10704 // A type-specifier of the form
10705 // typename[opt] nested-name-specifier[opt] template-name
10706 // is a placeholder for a deduced class type [...].
10707 if (getLangOpts().CPlusPlus17) {
10708 if (auto *TD = getAsTypeTemplateDecl(Result.getFoundDecl())) {
10709 if (!DeducedTSTContext) {
10710 QualType T(QualifierLoc
10711 ? QualifierLoc.getNestedNameSpecifier()->getAsType()
10712 : nullptr, 0);
10713 if (!T.isNull())
10714 Diag(IILoc, diag::err_dependent_deduced_tst)
10715 << (int)getTemplateNameKindForDiagnostics(TemplateName(TD)) << T;
10716 else
10717 Diag(IILoc, diag::err_deduced_tst)
10718 << (int)getTemplateNameKindForDiagnostics(TemplateName(TD));
10719 Diag(TD->getLocation(), diag::note_template_decl_here);
10720 return QualType();
10721 }
10722 return Context.getElaboratedType(
10723 Keyword, QualifierLoc.getNestedNameSpecifier(),
10724 Context.getDeducedTemplateSpecializationType(TemplateName(TD),
10725 QualType(), false));
10726 }
10727 }
10728
10729 DiagID = Ctx ? diag::err_typename_nested_not_type
10730 : diag::err_typename_not_type;
10731 Referenced = Result.getFoundDecl();
10732 break;
10733
10734 case LookupResult::FoundOverloaded:
10735 DiagID = Ctx ? diag::err_typename_nested_not_type
10736 : diag::err_typename_not_type;
10737 Referenced = *Result.begin();
10738 break;
10739
10740 case LookupResult::Ambiguous:
10741 return QualType();
10742 }
10743
10744 // If we get here, it's because name lookup did not find a
10745 // type. Emit an appropriate diagnostic and return an error.
10746 SourceRange FullRange(KeywordLoc.isValid() ? KeywordLoc : SS.getBeginLoc(),
10747 IILoc);
10748 if (Ctx)
10749 Diag(IILoc, DiagID) << FullRange << Name << Ctx;
10750 else
10751 Diag(IILoc, DiagID) << FullRange << Name;
10752 if (Referenced)
10753 Diag(Referenced->getLocation(),
10754 Ctx ? diag::note_typename_member_refers_here
10755 : diag::note_typename_refers_here)
10756 << Name;
10757 return QualType();
10758}
10759
10760namespace {
10761 // See Sema::RebuildTypeInCurrentInstantiation
10762 class CurrentInstantiationRebuilder
10763 : public TreeTransform<CurrentInstantiationRebuilder> {
10764 SourceLocation Loc;
10765 DeclarationName Entity;
10766
10767 public:
10768 typedef TreeTransform<CurrentInstantiationRebuilder> inherited;
10769
10770 CurrentInstantiationRebuilder(Sema &SemaRef,
10771 SourceLocation Loc,
10772 DeclarationName Entity)
10773 : TreeTransform<CurrentInstantiationRebuilder>(SemaRef),
10774 Loc(Loc), Entity(Entity) { }
10775
10776 /// Determine whether the given type \p T has already been
10777 /// transformed.
10778 ///
10779 /// For the purposes of type reconstruction, a type has already been
10780 /// transformed if it is NULL or if it is not dependent.
10781 bool AlreadyTransformed(QualType T) {
10782 return T.isNull() || !T->isInstantiationDependentType();
10783 }
10784
10785 /// Returns the location of the entity whose type is being
10786 /// rebuilt.
10787 SourceLocation getBaseLocation() { return Loc; }
10788
10789 /// Returns the name of the entity whose type is being rebuilt.
10790 DeclarationName getBaseEntity() { return Entity; }
10791
10792 /// Sets the "base" location and entity when that
10793 /// information is known based on another transformation.
10794 void setBase(SourceLocation Loc, DeclarationName Entity) {
10795 this->Loc = Loc;
10796 this->Entity = Entity;
10797 }
10798
10799 ExprResult TransformLambdaExpr(LambdaExpr *E) {
10800 // Lambdas never need to be transformed.
10801 return E;
10802 }
10803 };
10804} // end anonymous namespace
10805
10806/// Rebuilds a type within the context of the current instantiation.
10807///
10808/// The type \p T is part of the type of an out-of-line member definition of
10809/// a class template (or class template partial specialization) that was parsed
10810/// and constructed before we entered the scope of the class template (or
10811/// partial specialization thereof). This routine will rebuild that type now
10812/// that we have entered the declarator's scope, which may produce different
10813/// canonical types, e.g.,
10814///
10815/// \code
10816/// template<typename T>
10817/// struct X {
10818/// typedef T* pointer;
10819/// pointer data();
10820/// };
10821///
10822/// template<typename T>
10823/// typename X<T>::pointer X<T>::data() { ... }
10824/// \endcode
10825///
10826/// Here, the type "typename X<T>::pointer" will be created as a DependentNameType,
10827/// since we do not know that we can look into X<T> when we parsed the type.
10828/// This function will rebuild the type, performing the lookup of "pointer"
10829/// in X<T> and returning an ElaboratedType whose canonical type is the same
10830/// as the canonical type of T*, allowing the return types of the out-of-line
10831/// definition and the declaration to match.
10832TypeSourceInfo *Sema::RebuildTypeInCurrentInstantiation(TypeSourceInfo *T,
10833 SourceLocation Loc,
10834 DeclarationName Name) {
10835 if (!T || !T->getType()->isInstantiationDependentType())
10836 return T;
10837
10838 CurrentInstantiationRebuilder Rebuilder(*this, Loc, Name);
10839 return Rebuilder.TransformType(T);
10840}
10841
10842ExprResult Sema::RebuildExprInCurrentInstantiation(Expr *E) {
10843 CurrentInstantiationRebuilder Rebuilder(*this, E->getExprLoc(),
10844 DeclarationName());
10845 return Rebuilder.TransformExpr(E);
10846}
10847
10848bool Sema::RebuildNestedNameSpecifierInCurrentInstantiation(CXXScopeSpec &SS) {
10849 if (SS.isInvalid())
10850 return true;
10851
10852 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
10853 CurrentInstantiationRebuilder Rebuilder(*this, SS.getRange().getBegin(),
10854 DeclarationName());
10855 NestedNameSpecifierLoc Rebuilt
10856 = Rebuilder.TransformNestedNameSpecifierLoc(QualifierLoc);
10857 if (!Rebuilt)
10858 return true;
10859
10860 SS.Adopt(Rebuilt);
10861 return false;
10862}
10863
10864/// Rebuild the template parameters now that we know we're in a current
10865/// instantiation.
10866bool Sema::RebuildTemplateParamsInCurrentInstantiation(
10867 TemplateParameterList *Params) {
10868 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
10869 Decl *Param = Params->getParam(I);
10870
10871 // There is nothing to rebuild in a type parameter.
10872 if (isa<TemplateTypeParmDecl>(Param))
10873 continue;
10874
10875 // Rebuild the template parameter list of a template template parameter.
10876 if (TemplateTemplateParmDecl *TTP
10877 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
10878 if (RebuildTemplateParamsInCurrentInstantiation(
10879 TTP->getTemplateParameters()))
10880 return true;
10881
10882 continue;
10883 }
10884
10885 // Rebuild the type of a non-type template parameter.
10886 NonTypeTemplateParmDecl *NTTP = cast<NonTypeTemplateParmDecl>(Param);
10887 TypeSourceInfo *NewTSI
10888 = RebuildTypeInCurrentInstantiation(NTTP->getTypeSourceInfo(),
10889 NTTP->getLocation(),
10890 NTTP->getDeclName());
10891 if (!NewTSI)
10892 return true;
10893
10894 if (NewTSI->getType()->isUndeducedType()) {
10895 // C++17 [temp.dep.expr]p3:
10896 // An id-expression is type-dependent if it contains
10897 // - an identifier associated by name lookup with a non-type
10898 // template-parameter declared with a type that contains a
10899 // placeholder type (7.1.7.4),
10900 NewTSI = SubstAutoTypeSourceInfoDependent(NewTSI);
10901 }
10902
10903 if (NewTSI != NTTP->getTypeSourceInfo()) {
10904 NTTP->setTypeSourceInfo(NewTSI);
10905 NTTP->setType(NewTSI->getType());
10906 }
10907 }
10908
10909 return false;
10910}
10911
10912/// Produces a formatted string that describes the binding of
10913/// template parameters to template arguments.
10914std::string
10915Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
10916 const TemplateArgumentList &Args) {
10917 return getTemplateArgumentBindingsText(Params, Args.data(), Args.size());
10918}
10919
10920std::string
10921Sema::getTemplateArgumentBindingsText(const TemplateParameterList *Params,
10922 const TemplateArgument *Args,
10923 unsigned NumArgs) {
10924 SmallString<128> Str;
10925 llvm::raw_svector_ostream Out(Str);
10926
10927 if (!Params || Params->size() == 0 || NumArgs == 0)
10928 return std::string();
10929
10930 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
10931 if (I >= NumArgs)
10932 break;
10933
10934 if (I == 0)
10935 Out << "[with ";
10936 else
10937 Out << ", ";
10938
10939 if (const IdentifierInfo *Id = Params->getParam(I)->getIdentifier()) {
10940 Out << Id->getName();
10941 } else {
10942 Out << '$' << I;
10943 }
10944
10945 Out << " = ";
10946 Args[I].print(getPrintingPolicy(), Out,
10947 TemplateParameterList::shouldIncludeTypeForArgument(
10948 getPrintingPolicy(), Params, I));
10949 }
10950
10951 Out << ']';
10952 return std::string(Out.str());
10953}
10954
10955void Sema::MarkAsLateParsedTemplate(FunctionDecl *FD, Decl *FnD,
10956 CachedTokens &Toks) {
10957 if (!FD)
10958 return;
10959
10960 auto LPT = std::make_unique<LateParsedTemplate>();
10961
10962 // Take tokens to avoid allocations
10963 LPT->Toks.swap(Toks);
10964 LPT->D = FnD;
10965 LateParsedTemplateMap.insert(std::make_pair(FD, std::move(LPT)));
10966
10967 FD->setLateTemplateParsed(true);
10968}
10969
10970void Sema::UnmarkAsLateParsedTemplate(FunctionDecl *FD) {
10971 if (!FD)
10972 return;
10973 FD->setLateTemplateParsed(false);
10974}
10975
10976bool Sema::IsInsideALocalClassWithinATemplateFunction() {
10977 DeclContext *DC = CurContext;
10978
10979 while (DC) {
10980 if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(CurContext)) {
10981 const FunctionDecl *FD = RD->isLocalClass();
10982 return (FD && FD->getTemplatedKind() != FunctionDecl::TK_NonTemplate);
10983 } else if (DC->isTranslationUnit() || DC->isNamespace())
10984 return false;
10985
10986 DC = DC->getParent();
10987 }
10988 return false;
10989}
10990
10991namespace {
10992/// Walk the path from which a declaration was instantiated, and check
10993/// that every explicit specialization along that path is visible. This enforces
10994/// C++ [temp.expl.spec]/6:
10995///
10996/// If a template, a member template or a member of a class template is
10997/// explicitly specialized then that specialization shall be declared before
10998/// the first use of that specialization that would cause an implicit
10999/// instantiation to take place, in every translation unit in which such a
11000/// use occurs; no diagnostic is required.
11001///
11002/// and also C++ [temp.class.spec]/1:
11003///
11004/// A partial specialization shall be declared before the first use of a
11005/// class template specialization that would make use of the partial
11006/// specialization as the result of an implicit or explicit instantiation
11007/// in every translation unit in which such a use occurs; no diagnostic is
11008/// required.
11009class ExplicitSpecializationVisibilityChecker {
11010 Sema &S;
11011 SourceLocation Loc;
11012 llvm::SmallVector<Module *, 8> Modules;
11013
11014public:
11015 ExplicitSpecializationVisibilityChecker(Sema &S, SourceLocation Loc)
11016 : S(S), Loc(Loc) {}
11017
11018 void check(NamedDecl *ND) {
11019 if (auto *FD = dyn_cast<FunctionDecl>(ND))
11020 return checkImpl(FD);
11021 if (auto *RD = dyn_cast<CXXRecordDecl>(ND))
11022 return checkImpl(RD);
11023 if (auto *VD = dyn_cast<VarDecl>(ND))
11024 return checkImpl(VD);
11025 if (auto *ED = dyn_cast<EnumDecl>(ND))
11026 return checkImpl(ED);
11027 }
11028
11029private:
11030 void diagnose(NamedDecl *D, bool IsPartialSpec) {
11031 auto Kind = IsPartialSpec ? Sema::MissingImportKind::PartialSpecialization
11032 : Sema::MissingImportKind::ExplicitSpecialization;
11033 const bool Recover = true;
11034
11035 // If we got a custom set of modules (because only a subset of the
11036 // declarations are interesting), use them, otherwise let
11037 // diagnoseMissingImport intelligently pick some.
11038 if (Modules.empty())
11039 S.diagnoseMissingImport(Loc, D, Kind, Recover);
11040 else
11041 S.diagnoseMissingImport(Loc, D, D->getLocation(), Modules, Kind, Recover);
11042 }
11043
11044 // Check a specific declaration. There are three problematic cases:
11045 //
11046 // 1) The declaration is an explicit specialization of a template
11047 // specialization.
11048 // 2) The declaration is an explicit specialization of a member of an
11049 // templated class.
11050 // 3) The declaration is an instantiation of a template, and that template
11051 // is an explicit specialization of a member of a templated class.
11052 //
11053 // We don't need to go any deeper than that, as the instantiation of the
11054 // surrounding class / etc is not triggered by whatever triggered this
11055 // instantiation, and thus should be checked elsewhere.
11056 template<typename SpecDecl>
11057 void checkImpl(SpecDecl *Spec) {
11058 bool IsHiddenExplicitSpecialization = false;
11059 if (Spec->getTemplateSpecializationKind() == TSK_ExplicitSpecialization) {
11060 IsHiddenExplicitSpecialization =
11061 Spec->getMemberSpecializationInfo()
11062 ? !S.hasVisibleMemberSpecialization(Spec, &Modules)
11063 : !S.hasVisibleExplicitSpecialization(Spec, &Modules);
11064 } else {
11065 checkInstantiated(Spec);
11066 }
11067
11068 if (IsHiddenExplicitSpecialization)
11069 diagnose(Spec->getMostRecentDecl(), false);
11070 }
11071
11072 void checkInstantiated(FunctionDecl *FD) {
11073 if (auto *TD = FD->getPrimaryTemplate())
11074 checkTemplate(TD);
11075 }
11076
11077 void checkInstantiated(CXXRecordDecl *RD) {
11078 auto *SD = dyn_cast<ClassTemplateSpecializationDecl>(RD);
11079 if (!SD)
11080 return;
11081
11082 auto From = SD->getSpecializedTemplateOrPartial();
11083 if (auto *TD = From.dyn_cast<ClassTemplateDecl *>())
11084 checkTemplate(TD);
11085 else if (auto *TD =
11086 From.dyn_cast<ClassTemplatePartialSpecializationDecl *>()) {
11087 if (!S.hasVisibleDeclaration(TD))
11088 diagnose(TD, true);
11089 checkTemplate(TD);
11090 }
11091 }
11092
11093 void checkInstantiated(VarDecl *RD) {
11094 auto *SD = dyn_cast<VarTemplateSpecializationDecl>(RD);
11095 if (!SD)
11096 return;
11097
11098 auto From = SD->getSpecializedTemplateOrPartial();
11099 if (auto *TD = From.dyn_cast<VarTemplateDecl *>())
11100 checkTemplate(TD);
11101 else if (auto *TD =
11102 From.dyn_cast<VarTemplatePartialSpecializationDecl *>()) {
11103 if (!S.hasVisibleDeclaration(TD))
11104 diagnose(TD, true);
11105 checkTemplate(TD);
11106 }
11107 }
11108
11109 void checkInstantiated(EnumDecl *FD) {}
11110
11111 template<typename TemplDecl>
11112 void checkTemplate(TemplDecl *TD) {
11113 if (TD->isMemberSpecialization()) {
11114 if (!S.hasVisibleMemberSpecialization(TD, &Modules))
11115 diagnose(TD->getMostRecentDecl(), false);
11116 }
11117 }
11118};
11119} // end anonymous namespace
11120
11121void Sema::checkSpecializationVisibility(SourceLocation Loc, NamedDecl *Spec) {
11122 if (!getLangOpts().Modules)
11123 return;
11124
11125 ExplicitSpecializationVisibilityChecker(*this, Loc).check(Spec);
11126}