Bug Summary

File:clang/lib/Sema/SemaTemplate.cpp
Warning:line 1377, 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 -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 -fno-rounding-math -mconstructor-aliases -munwind-tables -target-cpu x86-64 -tune-cpu generic -fno-split-dwarf-inlining -debugger-tuning=gdb -ffunction-sections -fdata-sections -resource-dir /usr/lib/llvm-12/lib/clang/12.0.0 -D CLANG_VENDOR="Debian " -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema -I /build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/include -I /build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/build-llvm/include -I /build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/llvm/include -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/x86_64-linux-gnu/c++/6.3.0 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/6.3.0/../../../../include/c++/6.3.0/backward -internal-isystem /usr/local/include -internal-isystem /usr/lib/llvm-12/lib/clang/12.0.0/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir /build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875=. -ferror-limit 19 -fvisibility-inlines-hidden -stack-protector 2 -fgnuc-version=4.2.1 -vectorize-loops -vectorize-slp -analyzer-output=html -analyzer-config stable-report-filename=true -faddrsig -o /tmp/scan-build-2020-10-30-042338-28487-1 -x c++ /build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/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/DeclFriend.h"
15#include "clang/AST/DeclTemplate.h"
16#include "clang/AST/Expr.h"
17#include "clang/AST/ExprCXX.h"
18#include "clang/AST/RecursiveASTVisitor.h"
19#include "clang/AST/TypeVisitor.h"
20#include "clang/Basic/Builtins.h"
21#include "clang/Basic/LangOptions.h"
22#include "clang/Basic/PartialDiagnostic.h"
23#include "clang/Basic/Stack.h"
24#include "clang/Basic/TargetInfo.h"
25#include "clang/Sema/DeclSpec.h"
26#include "clang/Sema/Initialization.h"
27#include "clang/Sema/Lookup.h"
28#include "clang/Sema/Overload.h"
29#include "clang/Sema/ParsedTemplate.h"
30#include "clang/Sema/Scope.h"
31#include "clang/Sema/SemaInternal.h"
32#include "clang/Sema/Template.h"
33#include "clang/Sema/TemplateDeduction.h"
34#include "llvm/ADT/SmallBitVector.h"
35#include "llvm/ADT/SmallString.h"
36#include "llvm/ADT/StringExtras.h"
37
38#include <iterator>
39using namespace clang;
40using namespace sema;
41
42// Exported for use by Parser.
43SourceRange
44clang::getTemplateParamsRange(TemplateParameterList const * const *Ps,
45 unsigned N) {
46 if (!N) return SourceRange();
47 return SourceRange(Ps[0]->getTemplateLoc(), Ps[N-1]->getRAngleLoc());
48}
49
50unsigned Sema::getTemplateDepth(Scope *S) const {
51 unsigned Depth = 0;
52
53 // Each template parameter scope represents one level of template parameter
54 // depth.
55 for (Scope *TempParamScope = S->getTemplateParamParent(); TempParamScope;
56 TempParamScope = TempParamScope->getParent()->getTemplateParamParent()) {
57 ++Depth;
58 }
59
60 // Note that there are template parameters with the given depth.
61 auto ParamsAtDepth = [&](unsigned D) { Depth = std::max(Depth, D + 1); };
62
63 // Look for parameters of an enclosing generic lambda. We don't create a
64 // template parameter scope for these.
65 for (FunctionScopeInfo *FSI : getFunctionScopes()) {
66 if (auto *LSI = dyn_cast<LambdaScopeInfo>(FSI)) {
67 if (!LSI->TemplateParams.empty()) {
68 ParamsAtDepth(LSI->AutoTemplateParameterDepth);
69 break;
70 }
71 if (LSI->GLTemplateParameterList) {
72 ParamsAtDepth(LSI->GLTemplateParameterList->getDepth());
73 break;
74 }
75 }
76 }
77
78 // Look for parameters of an enclosing terse function template. We don't
79 // create a template parameter scope for these either.
80 for (const InventedTemplateParameterInfo &Info :
81 getInventedParameterInfos()) {
82 if (!Info.TemplateParams.empty()) {
83 ParamsAtDepth(Info.AutoTemplateParameterDepth);
84 break;
85 }
86 }
87
88 return Depth;
89}
90
91/// \brief Determine whether the declaration found is acceptable as the name
92/// of a template and, if so, return that template declaration. Otherwise,
93/// returns null.
94///
95/// Note that this may return an UnresolvedUsingValueDecl if AllowDependent
96/// is true. In all other cases it will return a TemplateDecl (or null).
97NamedDecl *Sema::getAsTemplateNameDecl(NamedDecl *D,
98 bool AllowFunctionTemplates,
99 bool AllowDependent) {
100 D = D->getUnderlyingDecl();
101
102 if (isa<TemplateDecl>(D)) {
103 if (!AllowFunctionTemplates && isa<FunctionTemplateDecl>(D))
104 return nullptr;
105
106 return D;
107 }
108
109 if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
110 // C++ [temp.local]p1:
111 // Like normal (non-template) classes, class templates have an
112 // injected-class-name (Clause 9). The injected-class-name
113 // can be used with or without a template-argument-list. When
114 // it is used without a template-argument-list, it is
115 // equivalent to the injected-class-name followed by the
116 // template-parameters of the class template enclosed in
117 // <>. When it is used with a template-argument-list, it
118 // refers to the specified class template specialization,
119 // which could be the current specialization or another
120 // specialization.
121 if (Record->isInjectedClassName()) {
122 Record = cast<CXXRecordDecl>(Record->getDeclContext());
123 if (Record->getDescribedClassTemplate())
124 return Record->getDescribedClassTemplate();
125
126 if (ClassTemplateSpecializationDecl *Spec
127 = dyn_cast<ClassTemplateSpecializationDecl>(Record))
128 return Spec->getSpecializedTemplate();
129 }
130
131 return nullptr;
132 }
133
134 // 'using Dependent::foo;' can resolve to a template name.
135 // 'using typename Dependent::foo;' cannot (not even if 'foo' is an
136 // injected-class-name).
137 if (AllowDependent && isa<UnresolvedUsingValueDecl>(D))
138 return D;
139
140 return nullptr;
141}
142
143void Sema::FilterAcceptableTemplateNames(LookupResult &R,
144 bool AllowFunctionTemplates,
145 bool AllowDependent) {
146 LookupResult::Filter filter = R.makeFilter();
147 while (filter.hasNext()) {
148 NamedDecl *Orig = filter.next();
149 if (!getAsTemplateNameDecl(Orig, AllowFunctionTemplates, AllowDependent))
150 filter.erase();
151 }
152 filter.done();
153}
154
155bool Sema::hasAnyAcceptableTemplateNames(LookupResult &R,
156 bool AllowFunctionTemplates,
157 bool AllowDependent,
158 bool AllowNonTemplateFunctions) {
159 for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; ++I) {
160 if (getAsTemplateNameDecl(*I, AllowFunctionTemplates, AllowDependent))
161 return true;
162 if (AllowNonTemplateFunctions &&
163 isa<FunctionDecl>((*I)->getUnderlyingDecl()))
164 return true;
165 }
166
167 return false;
168}
169
170TemplateNameKind Sema::isTemplateName(Scope *S,
171 CXXScopeSpec &SS,
172 bool hasTemplateKeyword,
173 const UnqualifiedId &Name,
174 ParsedType ObjectTypePtr,
175 bool EnteringContext,
176 TemplateTy &TemplateResult,
177 bool &MemberOfUnknownSpecialization,
178 bool Disambiguation) {
179 assert(getLangOpts().CPlusPlus && "No template names in C!")((getLangOpts().CPlusPlus && "No template names in C!"
) ? static_cast<void> (0) : __assert_fail ("getLangOpts().CPlusPlus && \"No template names in C!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 179, __PRETTY_FUNCTION__))
;
180
181 DeclarationName TName;
182 MemberOfUnknownSpecialization = false;
183
184 switch (Name.getKind()) {
185 case UnqualifiedIdKind::IK_Identifier:
186 TName = DeclarationName(Name.Identifier);
187 break;
188
189 case UnqualifiedIdKind::IK_OperatorFunctionId:
190 TName = Context.DeclarationNames.getCXXOperatorName(
191 Name.OperatorFunctionId.Operator);
192 break;
193
194 case UnqualifiedIdKind::IK_LiteralOperatorId:
195 TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier);
196 break;
197
198 default:
199 return TNK_Non_template;
200 }
201
202 QualType ObjectType = ObjectTypePtr.get();
203
204 AssumedTemplateKind AssumedTemplate;
205 LookupResult R(*this, TName, Name.getBeginLoc(), LookupOrdinaryName);
206 if (LookupTemplateName(R, S, SS, ObjectType, EnteringContext,
207 MemberOfUnknownSpecialization, SourceLocation(),
208 &AssumedTemplate,
209 /*AllowTypoCorrection=*/!Disambiguation))
210 return TNK_Non_template;
211
212 if (AssumedTemplate != AssumedTemplateKind::None) {
213 TemplateResult = TemplateTy::make(Context.getAssumedTemplateName(TName));
214 // Let the parser know whether we found nothing or found functions; if we
215 // found nothing, we want to more carefully check whether this is actually
216 // a function template name versus some other kind of undeclared identifier.
217 return AssumedTemplate == AssumedTemplateKind::FoundNothing
218 ? TNK_Undeclared_template
219 : TNK_Function_template;
220 }
221
222 if (R.empty())
223 return TNK_Non_template;
224
225 NamedDecl *D = nullptr;
226 if (R.isAmbiguous()) {
227 // If we got an ambiguity involving a non-function template, treat this
228 // as a template name, and pick an arbitrary template for error recovery.
229 bool AnyFunctionTemplates = false;
230 for (NamedDecl *FoundD : R) {
231 if (NamedDecl *FoundTemplate = getAsTemplateNameDecl(FoundD)) {
232 if (isa<FunctionTemplateDecl>(FoundTemplate))
233 AnyFunctionTemplates = true;
234 else {
235 D = FoundTemplate;
236 break;
237 }
238 }
239 }
240
241 // If we didn't find any templates at all, this isn't a template name.
242 // Leave the ambiguity for a later lookup to diagnose.
243 if (!D && !AnyFunctionTemplates) {
244 R.suppressDiagnostics();
245 return TNK_Non_template;
246 }
247
248 // If the only templates were function templates, filter out the rest.
249 // We'll diagnose the ambiguity later.
250 if (!D)
251 FilterAcceptableTemplateNames(R);
252 }
253
254 // At this point, we have either picked a single template name declaration D
255 // or we have a non-empty set of results R containing either one template name
256 // declaration or a set of function templates.
257
258 TemplateName Template;
259 TemplateNameKind TemplateKind;
260
261 unsigned ResultCount = R.end() - R.begin();
262 if (!D && ResultCount > 1) {
263 // We assume that we'll preserve the qualifier from a function
264 // template name in other ways.
265 Template = Context.getOverloadedTemplateName(R.begin(), R.end());
266 TemplateKind = TNK_Function_template;
267
268 // We'll do this lookup again later.
269 R.suppressDiagnostics();
270 } else {
271 if (!D) {
272 D = getAsTemplateNameDecl(*R.begin());
273 assert(D && "unambiguous result is not a template name")((D && "unambiguous result is not a template name") ?
static_cast<void> (0) : __assert_fail ("D && \"unambiguous result is not a template name\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 273, __PRETTY_FUNCTION__))
;
274 }
275
276 if (isa<UnresolvedUsingValueDecl>(D)) {
277 // We don't yet know whether this is a template-name or not.
278 MemberOfUnknownSpecialization = true;
279 return TNK_Non_template;
280 }
281
282 TemplateDecl *TD = cast<TemplateDecl>(D);
283
284 if (SS.isSet() && !SS.isInvalid()) {
285 NestedNameSpecifier *Qualifier = SS.getScopeRep();
286 Template = Context.getQualifiedTemplateName(Qualifier,
287 hasTemplateKeyword, TD);
288 } else {
289 Template = TemplateName(TD);
290 }
291
292 if (isa<FunctionTemplateDecl>(TD)) {
293 TemplateKind = TNK_Function_template;
294
295 // We'll do this lookup again later.
296 R.suppressDiagnostics();
297 } else {
298 assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) ||((isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl
>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl
>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl
>(TD)) ? static_cast<void> (0) : __assert_fail ("isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD)"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 300, __PRETTY_FUNCTION__))
299 isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) ||((isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl
>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl
>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl
>(TD)) ? static_cast<void> (0) : __assert_fail ("isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD)"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 300, __PRETTY_FUNCTION__))
300 isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD))((isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl
>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl
>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl
>(TD)) ? static_cast<void> (0) : __assert_fail ("isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD)"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 300, __PRETTY_FUNCTION__))
;
301 TemplateKind =
302 isa<VarTemplateDecl>(TD) ? TNK_Var_template :
303 isa<ConceptDecl>(TD) ? TNK_Concept_template :
304 TNK_Type_template;
305 }
306 }
307
308 TemplateResult = TemplateTy::make(Template);
309 return TemplateKind;
310}
311
312bool Sema::isDeductionGuideName(Scope *S, const IdentifierInfo &Name,
313 SourceLocation NameLoc,
314 ParsedTemplateTy *Template) {
315 CXXScopeSpec SS;
316 bool MemberOfUnknownSpecialization = false;
317
318 // We could use redeclaration lookup here, but we don't need to: the
319 // syntactic form of a deduction guide is enough to identify it even
320 // if we can't look up the template name at all.
321 LookupResult R(*this, DeclarationName(&Name), NameLoc, LookupOrdinaryName);
322 if (LookupTemplateName(R, S, SS, /*ObjectType*/ QualType(),
323 /*EnteringContext*/ false,
324 MemberOfUnknownSpecialization))
325 return false;
326
327 if (R.empty()) return false;
328 if (R.isAmbiguous()) {
329 // FIXME: Diagnose an ambiguity if we find at least one template.
330 R.suppressDiagnostics();
331 return false;
332 }
333
334 // We only treat template-names that name type templates as valid deduction
335 // guide names.
336 TemplateDecl *TD = R.getAsSingle<TemplateDecl>();
337 if (!TD || !getAsTypeTemplateDecl(TD))
338 return false;
339
340 if (Template)
341 *Template = TemplateTy::make(TemplateName(TD));
342 return true;
343}
344
345bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II,
346 SourceLocation IILoc,
347 Scope *S,
348 const CXXScopeSpec *SS,
349 TemplateTy &SuggestedTemplate,
350 TemplateNameKind &SuggestedKind) {
351 // We can't recover unless there's a dependent scope specifier preceding the
352 // template name.
353 // FIXME: Typo correction?
354 if (!SS || !SS->isSet() || !isDependentScopeSpecifier(*SS) ||
355 computeDeclContext(*SS))
356 return false;
357
358 // The code is missing a 'template' keyword prior to the dependent template
359 // name.
360 NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep();
361 Diag(IILoc, diag::err_template_kw_missing)
362 << Qualifier << II.getName()
363 << FixItHint::CreateInsertion(IILoc, "template ");
364 SuggestedTemplate
365 = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II));
366 SuggestedKind = TNK_Dependent_template_name;
367 return true;
368}
369
370bool Sema::LookupTemplateName(LookupResult &Found,
371 Scope *S, CXXScopeSpec &SS,
372 QualType ObjectType,
373 bool EnteringContext,
374 bool &MemberOfUnknownSpecialization,
375 RequiredTemplateKind RequiredTemplate,
376 AssumedTemplateKind *ATK,
377 bool AllowTypoCorrection) {
378 if (ATK)
379 *ATK = AssumedTemplateKind::None;
380
381 if (SS.isInvalid())
382 return true;
383
384 Found.setTemplateNameLookup(true);
385
386 // Determine where to perform name lookup
387 MemberOfUnknownSpecialization = false;
388 DeclContext *LookupCtx = nullptr;
389 bool IsDependent = false;
390 if (!ObjectType.isNull()) {
391 // This nested-name-specifier occurs in a member access expression, e.g.,
392 // x->B::f, and we are looking into the type of the object.
393 assert(SS.isEmpty() && "ObjectType and scope specifier cannot coexist")((SS.isEmpty() && "ObjectType and scope specifier cannot coexist"
) ? static_cast<void> (0) : __assert_fail ("SS.isEmpty() && \"ObjectType and scope specifier cannot coexist\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 393, __PRETTY_FUNCTION__))
;
394 LookupCtx = computeDeclContext(ObjectType);
395 IsDependent = !LookupCtx && ObjectType->isDependentType();
396 assert((IsDependent || !ObjectType->isIncompleteType() ||(((IsDependent || !ObjectType->isIncompleteType() || ObjectType
->castAs<TagType>()->isBeingDefined()) &&
"Caller should have completed object type") ? static_cast<
void> (0) : __assert_fail ("(IsDependent || !ObjectType->isIncompleteType() || ObjectType->castAs<TagType>()->isBeingDefined()) && \"Caller should have completed object type\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 398, __PRETTY_FUNCTION__))
397 ObjectType->castAs<TagType>()->isBeingDefined()) &&(((IsDependent || !ObjectType->isIncompleteType() || ObjectType
->castAs<TagType>()->isBeingDefined()) &&
"Caller should have completed object type") ? static_cast<
void> (0) : __assert_fail ("(IsDependent || !ObjectType->isIncompleteType() || ObjectType->castAs<TagType>()->isBeingDefined()) && \"Caller should have completed object type\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 398, __PRETTY_FUNCTION__))
398 "Caller should have completed object type")(((IsDependent || !ObjectType->isIncompleteType() || ObjectType
->castAs<TagType>()->isBeingDefined()) &&
"Caller should have completed object type") ? static_cast<
void> (0) : __assert_fail ("(IsDependent || !ObjectType->isIncompleteType() || ObjectType->castAs<TagType>()->isBeingDefined()) && \"Caller should have completed object type\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 398, __PRETTY_FUNCTION__))
;
399
400 // Template names cannot appear inside an Objective-C class or object type
401 // or a vector type.
402 //
403 // FIXME: This is wrong. For example:
404 //
405 // template<typename T> using Vec = T __attribute__((ext_vector_type(4)));
406 // Vec<int> vi;
407 // vi.Vec<int>::~Vec<int>();
408 //
409 // ... should be accepted but we will not treat 'Vec' as a template name
410 // here. The right thing to do would be to check if the name is a valid
411 // vector component name, and look up a template name if not. And similarly
412 // for lookups into Objective-C class and object types, where the same
413 // problem can arise.
414 if (ObjectType->isObjCObjectOrInterfaceType() ||
415 ObjectType->isVectorType()) {
416 Found.clear();
417 return false;
418 }
419 } else if (SS.isNotEmpty()) {
420 // This nested-name-specifier occurs after another nested-name-specifier,
421 // so long into the context associated with the prior nested-name-specifier.
422 LookupCtx = computeDeclContext(SS, EnteringContext);
423 IsDependent = !LookupCtx && isDependentScopeSpecifier(SS);
424
425 // The declaration context must be complete.
426 if (LookupCtx && RequireCompleteDeclContext(SS, LookupCtx))
427 return true;
428 }
429
430 bool ObjectTypeSearchedInScope = false;
431 bool AllowFunctionTemplatesInLookup = true;
432 if (LookupCtx) {
433 // Perform "qualified" name lookup into the declaration context we
434 // computed, which is either the type of the base of a member access
435 // expression or the declaration context associated with a prior
436 // nested-name-specifier.
437 LookupQualifiedName(Found, LookupCtx);
438
439 // FIXME: The C++ standard does not clearly specify what happens in the
440 // case where the object type is dependent, and implementations vary. In
441 // Clang, we treat a name after a . or -> as a template-name if lookup
442 // finds a non-dependent member or member of the current instantiation that
443 // is a type template, or finds no such members and lookup in the context
444 // of the postfix-expression finds a type template. In the latter case, the
445 // name is nonetheless dependent, and we may resolve it to a member of an
446 // unknown specialization when we come to instantiate the template.
447 IsDependent |= Found.wasNotFoundInCurrentInstantiation();
448 }
449
450 if (SS.isEmpty() && (ObjectType.isNull() || Found.empty())) {
451 // C++ [basic.lookup.classref]p1:
452 // In a class member access expression (5.2.5), if the . or -> token is
453 // immediately followed by an identifier followed by a <, the
454 // identifier must be looked up to determine whether the < is the
455 // beginning of a template argument list (14.2) or a less-than operator.
456 // The identifier is first looked up in the class of the object
457 // expression. If the identifier is not found, it is then looked up in
458 // the context of the entire postfix-expression and shall name a class
459 // template.
460 if (S)
461 LookupName(Found, S);
462
463 if (!ObjectType.isNull()) {
464 // FIXME: We should filter out all non-type templates here, particularly
465 // variable templates and concepts. But the exclusion of alias templates
466 // and template template parameters is a wording defect.
467 AllowFunctionTemplatesInLookup = false;
468 ObjectTypeSearchedInScope = true;
469 }
470
471 IsDependent |= Found.wasNotFoundInCurrentInstantiation();
472 }
473
474 if (Found.isAmbiguous())
475 return false;
476
477 if (ATK && SS.isEmpty() && ObjectType.isNull() &&
478 !RequiredTemplate.hasTemplateKeyword()) {
479 // C++2a [temp.names]p2:
480 // A name is also considered to refer to a template if it is an
481 // unqualified-id followed by a < and name lookup finds either one or more
482 // functions or finds nothing.
483 //
484 // To keep our behavior consistent, we apply the "finds nothing" part in
485 // all language modes, and diagnose the empty lookup in ActOnCallExpr if we
486 // successfully form a call to an undeclared template-id.
487 bool AllFunctions =
488 getLangOpts().CPlusPlus20 &&
489 std::all_of(Found.begin(), Found.end(), [](NamedDecl *ND) {
490 return isa<FunctionDecl>(ND->getUnderlyingDecl());
491 });
492 if (AllFunctions || (Found.empty() && !IsDependent)) {
493 // If lookup found any functions, or if this is a name that can only be
494 // used for a function, then strongly assume this is a function
495 // template-id.
496 *ATK = (Found.empty() && Found.getLookupName().isIdentifier())
497 ? AssumedTemplateKind::FoundNothing
498 : AssumedTemplateKind::FoundFunctions;
499 Found.clear();
500 return false;
501 }
502 }
503
504 if (Found.empty() && !IsDependent && AllowTypoCorrection) {
505 // If we did not find any names, and this is not a disambiguation, attempt
506 // to correct any typos.
507 DeclarationName Name = Found.getLookupName();
508 Found.clear();
509 // Simple filter callback that, for keywords, only accepts the C++ *_cast
510 DefaultFilterCCC FilterCCC{};
511 FilterCCC.WantTypeSpecifiers = false;
512 FilterCCC.WantExpressionKeywords = false;
513 FilterCCC.WantRemainingKeywords = false;
514 FilterCCC.WantCXXNamedCasts = true;
515 if (TypoCorrection Corrected =
516 CorrectTypo(Found.getLookupNameInfo(), Found.getLookupKind(), S,
517 &SS, FilterCCC, CTK_ErrorRecovery, LookupCtx)) {
518 if (auto *ND = Corrected.getFoundDecl())
519 Found.addDecl(ND);
520 FilterAcceptableTemplateNames(Found);
521 if (Found.isAmbiguous()) {
522 Found.clear();
523 } else if (!Found.empty()) {
524 Found.setLookupName(Corrected.getCorrection());
525 if (LookupCtx) {
526 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
527 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
528 Name.getAsString() == CorrectedStr;
529 diagnoseTypo(Corrected, PDiag(diag::err_no_member_template_suggest)
530 << Name << LookupCtx << DroppedSpecifier
531 << SS.getRange());
532 } else {
533 diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest) << Name);
534 }
535 }
536 }
537 }
538
539 NamedDecl *ExampleLookupResult =
540 Found.empty() ? nullptr : Found.getRepresentativeDecl();
541 FilterAcceptableTemplateNames(Found, AllowFunctionTemplatesInLookup);
542 if (Found.empty()) {
543 if (IsDependent) {
544 MemberOfUnknownSpecialization = true;
545 return false;
546 }
547
548 // If a 'template' keyword was used, a lookup that finds only non-template
549 // names is an error.
550 if (ExampleLookupResult && RequiredTemplate) {
551 Diag(Found.getNameLoc(), diag::err_template_kw_refers_to_non_template)
552 << Found.getLookupName() << SS.getRange()
553 << RequiredTemplate.hasTemplateKeyword()
554 << RequiredTemplate.getTemplateKeywordLoc();
555 Diag(ExampleLookupResult->getUnderlyingDecl()->getLocation(),
556 diag::note_template_kw_refers_to_non_template)
557 << Found.getLookupName();
558 return true;
559 }
560
561 return false;
562 }
563
564 if (S && !ObjectType.isNull() && !ObjectTypeSearchedInScope &&
565 !getLangOpts().CPlusPlus11) {
566 // C++03 [basic.lookup.classref]p1:
567 // [...] If the lookup in the class of the object expression finds a
568 // template, the name is also looked up in the context of the entire
569 // postfix-expression and [...]
570 //
571 // Note: C++11 does not perform this second lookup.
572 LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(),
573 LookupOrdinaryName);
574 FoundOuter.setTemplateNameLookup(true);
575 LookupName(FoundOuter, S);
576 // FIXME: We silently accept an ambiguous lookup here, in violation of
577 // [basic.lookup]/1.
578 FilterAcceptableTemplateNames(FoundOuter, /*AllowFunctionTemplates=*/false);
579
580 NamedDecl *OuterTemplate;
581 if (FoundOuter.empty()) {
582 // - if the name is not found, the name found in the class of the
583 // object expression is used, otherwise
584 } else if (FoundOuter.isAmbiguous() || !FoundOuter.isSingleResult() ||
585 !(OuterTemplate =
586 getAsTemplateNameDecl(FoundOuter.getFoundDecl()))) {
587 // - if the name is found in the context of the entire
588 // postfix-expression and does not name a class template, the name
589 // found in the class of the object expression is used, otherwise
590 FoundOuter.clear();
591 } else if (!Found.isSuppressingDiagnostics()) {
592 // - if the name found is a class template, it must refer to the same
593 // entity as the one found in the class of the object expression,
594 // otherwise the program is ill-formed.
595 if (!Found.isSingleResult() ||
596 getAsTemplateNameDecl(Found.getFoundDecl())->getCanonicalDecl() !=
597 OuterTemplate->getCanonicalDecl()) {
598 Diag(Found.getNameLoc(),
599 diag::ext_nested_name_member_ref_lookup_ambiguous)
600 << Found.getLookupName()
601 << ObjectType;
602 Diag(Found.getRepresentativeDecl()->getLocation(),
603 diag::note_ambig_member_ref_object_type)
604 << ObjectType;
605 Diag(FoundOuter.getFoundDecl()->getLocation(),
606 diag::note_ambig_member_ref_scope);
607
608 // Recover by taking the template that we found in the object
609 // expression's type.
610 }
611 }
612 }
613
614 return false;
615}
616
617void Sema::diagnoseExprIntendedAsTemplateName(Scope *S, ExprResult TemplateName,
618 SourceLocation Less,
619 SourceLocation Greater) {
620 if (TemplateName.isInvalid())
621 return;
622
623 DeclarationNameInfo NameInfo;
624 CXXScopeSpec SS;
625 LookupNameKind LookupKind;
626
627 DeclContext *LookupCtx = nullptr;
628 NamedDecl *Found = nullptr;
629 bool MissingTemplateKeyword = false;
630
631 // Figure out what name we looked up.
632 if (auto *DRE = dyn_cast<DeclRefExpr>(TemplateName.get())) {
633 NameInfo = DRE->getNameInfo();
634 SS.Adopt(DRE->getQualifierLoc());
635 LookupKind = LookupOrdinaryName;
636 Found = DRE->getFoundDecl();
637 } else if (auto *ME = dyn_cast<MemberExpr>(TemplateName.get())) {
638 NameInfo = ME->getMemberNameInfo();
639 SS.Adopt(ME->getQualifierLoc());
640 LookupKind = LookupMemberName;
641 LookupCtx = ME->getBase()->getType()->getAsCXXRecordDecl();
642 Found = ME->getMemberDecl();
643 } else if (auto *DSDRE =
644 dyn_cast<DependentScopeDeclRefExpr>(TemplateName.get())) {
645 NameInfo = DSDRE->getNameInfo();
646 SS.Adopt(DSDRE->getQualifierLoc());
647 MissingTemplateKeyword = true;
648 } else if (auto *DSME =
649 dyn_cast<CXXDependentScopeMemberExpr>(TemplateName.get())) {
650 NameInfo = DSME->getMemberNameInfo();
651 SS.Adopt(DSME->getQualifierLoc());
652 MissingTemplateKeyword = true;
653 } else {
654 llvm_unreachable("unexpected kind of potential template name")::llvm::llvm_unreachable_internal("unexpected kind of potential template name"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 654)
;
655 }
656
657 // If this is a dependent-scope lookup, diagnose that the 'template' keyword
658 // was missing.
659 if (MissingTemplateKeyword) {
660 Diag(NameInfo.getBeginLoc(), diag::err_template_kw_missing)
661 << "" << NameInfo.getName().getAsString() << SourceRange(Less, Greater);
662 return;
663 }
664
665 // Try to correct the name by looking for templates and C++ named casts.
666 struct TemplateCandidateFilter : CorrectionCandidateCallback {
667 Sema &S;
668 TemplateCandidateFilter(Sema &S) : S(S) {
669 WantTypeSpecifiers = false;
670 WantExpressionKeywords = false;
671 WantRemainingKeywords = false;
672 WantCXXNamedCasts = true;
673 };
674 bool ValidateCandidate(const TypoCorrection &Candidate) override {
675 if (auto *ND = Candidate.getCorrectionDecl())
676 return S.getAsTemplateNameDecl(ND);
677 return Candidate.isKeyword();
678 }
679
680 std::unique_ptr<CorrectionCandidateCallback> clone() override {
681 return std::make_unique<TemplateCandidateFilter>(*this);
682 }
683 };
684
685 DeclarationName Name = NameInfo.getName();
686 TemplateCandidateFilter CCC(*this);
687 if (TypoCorrection Corrected = CorrectTypo(NameInfo, LookupKind, S, &SS, CCC,
688 CTK_ErrorRecovery, LookupCtx)) {
689 auto *ND = Corrected.getFoundDecl();
690 if (ND)
691 ND = getAsTemplateNameDecl(ND);
692 if (ND || Corrected.isKeyword()) {
693 if (LookupCtx) {
694 std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
695 bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
696 Name.getAsString() == CorrectedStr;
697 diagnoseTypo(Corrected,
698 PDiag(diag::err_non_template_in_member_template_id_suggest)
699 << Name << LookupCtx << DroppedSpecifier
700 << SS.getRange(), false);
701 } else {
702 diagnoseTypo(Corrected,
703 PDiag(diag::err_non_template_in_template_id_suggest)
704 << Name, false);
705 }
706 if (Found)
707 Diag(Found->getLocation(),
708 diag::note_non_template_in_template_id_found);
709 return;
710 }
711 }
712
713 Diag(NameInfo.getLoc(), diag::err_non_template_in_template_id)
714 << Name << SourceRange(Less, Greater);
715 if (Found)
716 Diag(Found->getLocation(), diag::note_non_template_in_template_id_found);
717}
718
719/// ActOnDependentIdExpression - Handle a dependent id-expression that
720/// was just parsed. This is only possible with an explicit scope
721/// specifier naming a dependent type.
722ExprResult
723Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS,
724 SourceLocation TemplateKWLoc,
725 const DeclarationNameInfo &NameInfo,
726 bool isAddressOfOperand,
727 const TemplateArgumentListInfo *TemplateArgs) {
728 DeclContext *DC = getFunctionLevelDeclContext();
729
730 // C++11 [expr.prim.general]p12:
731 // An id-expression that denotes a non-static data member or non-static
732 // member function of a class can only be used:
733 // (...)
734 // - if that id-expression denotes a non-static data member and it
735 // appears in an unevaluated operand.
736 //
737 // If this might be the case, form a DependentScopeDeclRefExpr instead of a
738 // CXXDependentScopeMemberExpr. The former can instantiate to either
739 // DeclRefExpr or MemberExpr depending on lookup results, while the latter is
740 // always a MemberExpr.
741 bool MightBeCxx11UnevalField =
742 getLangOpts().CPlusPlus11 && isUnevaluatedContext();
743
744 // Check if the nested name specifier is an enum type.
745 bool IsEnum = false;
746 if (NestedNameSpecifier *NNS = SS.getScopeRep())
747 IsEnum = dyn_cast_or_null<EnumType>(NNS->getAsType());
748
749 if (!MightBeCxx11UnevalField && !isAddressOfOperand && !IsEnum &&
750 isa<CXXMethodDecl>(DC) && cast<CXXMethodDecl>(DC)->isInstance()) {
751 QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType();
752
753 // Since the 'this' expression is synthesized, we don't need to
754 // perform the double-lookup check.
755 NamedDecl *FirstQualifierInScope = nullptr;
756
757 return CXXDependentScopeMemberExpr::Create(
758 Context, /*This*/ nullptr, ThisType, /*IsArrow*/ true,
759 /*Op*/ SourceLocation(), SS.getWithLocInContext(Context), TemplateKWLoc,
760 FirstQualifierInScope, NameInfo, TemplateArgs);
761 }
762
763 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
764}
765
766ExprResult
767Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
768 SourceLocation TemplateKWLoc,
769 const DeclarationNameInfo &NameInfo,
770 const TemplateArgumentListInfo *TemplateArgs) {
771 // DependentScopeDeclRefExpr::Create requires a valid QualifierLoc
772 NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
773 if (!QualifierLoc)
774 return ExprError();
775
776 return DependentScopeDeclRefExpr::Create(
777 Context, QualifierLoc, TemplateKWLoc, NameInfo, TemplateArgs);
778}
779
780
781/// Determine whether we would be unable to instantiate this template (because
782/// it either has no definition, or is in the process of being instantiated).
783bool Sema::DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation,
784 NamedDecl *Instantiation,
785 bool InstantiatedFromMember,
786 const NamedDecl *Pattern,
787 const NamedDecl *PatternDef,
788 TemplateSpecializationKind TSK,
789 bool Complain /*= true*/) {
790 assert(isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) ||((isa<TagDecl>(Instantiation) || isa<FunctionDecl>
(Instantiation) || isa<VarDecl>(Instantiation)) ? static_cast
<void> (0) : __assert_fail ("isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) || isa<VarDecl>(Instantiation)"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 791, __PRETTY_FUNCTION__))
791 isa<VarDecl>(Instantiation))((isa<TagDecl>(Instantiation) || isa<FunctionDecl>
(Instantiation) || isa<VarDecl>(Instantiation)) ? static_cast
<void> (0) : __assert_fail ("isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) || isa<VarDecl>(Instantiation)"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 791, __PRETTY_FUNCTION__))
;
792
793 bool IsEntityBeingDefined = false;
794 if (const TagDecl *TD = dyn_cast_or_null<TagDecl>(PatternDef))
795 IsEntityBeingDefined = TD->isBeingDefined();
796
797 if (PatternDef && !IsEntityBeingDefined) {
798 NamedDecl *SuggestedDef = nullptr;
799 if (!hasVisibleDefinition(const_cast<NamedDecl*>(PatternDef), &SuggestedDef,
800 /*OnlyNeedComplete*/false)) {
801 // If we're allowed to diagnose this and recover, do so.
802 bool Recover = Complain && !isSFINAEContext();
803 if (Complain)
804 diagnoseMissingImport(PointOfInstantiation, SuggestedDef,
805 Sema::MissingImportKind::Definition, Recover);
806 return !Recover;
807 }
808 return false;
809 }
810
811 if (!Complain || (PatternDef && PatternDef->isInvalidDecl()))
812 return true;
813
814 llvm::Optional<unsigned> Note;
815 QualType InstantiationTy;
816 if (TagDecl *TD = dyn_cast<TagDecl>(Instantiation))
817 InstantiationTy = Context.getTypeDeclType(TD);
818 if (PatternDef) {
819 Diag(PointOfInstantiation,
820 diag::err_template_instantiate_within_definition)
821 << /*implicit|explicit*/(TSK != TSK_ImplicitInstantiation)
822 << InstantiationTy;
823 // Not much point in noting the template declaration here, since
824 // we're lexically inside it.
825 Instantiation->setInvalidDecl();
826 } else if (InstantiatedFromMember) {
827 if (isa<FunctionDecl>(Instantiation)) {
828 Diag(PointOfInstantiation,
829 diag::err_explicit_instantiation_undefined_member)
830 << /*member function*/ 1 << Instantiation->getDeclName()
831 << Instantiation->getDeclContext();
832 Note = diag::note_explicit_instantiation_here;
833 } else {
834 assert(isa<TagDecl>(Instantiation) && "Must be a TagDecl!")((isa<TagDecl>(Instantiation) && "Must be a TagDecl!"
) ? static_cast<void> (0) : __assert_fail ("isa<TagDecl>(Instantiation) && \"Must be a TagDecl!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 834, __PRETTY_FUNCTION__))
;
835 Diag(PointOfInstantiation,
836 diag::err_implicit_instantiate_member_undefined)
837 << InstantiationTy;
838 Note = diag::note_member_declared_at;
839 }
840 } else {
841 if (isa<FunctionDecl>(Instantiation)) {
842 Diag(PointOfInstantiation,
843 diag::err_explicit_instantiation_undefined_func_template)
844 << Pattern;
845 Note = diag::note_explicit_instantiation_here;
846 } else if (isa<TagDecl>(Instantiation)) {
847 Diag(PointOfInstantiation, diag::err_template_instantiate_undefined)
848 << (TSK != TSK_ImplicitInstantiation)
849 << InstantiationTy;
850 Note = diag::note_template_decl_here;
851 } else {
852 assert(isa<VarDecl>(Instantiation) && "Must be a VarDecl!")((isa<VarDecl>(Instantiation) && "Must be a VarDecl!"
) ? static_cast<void> (0) : __assert_fail ("isa<VarDecl>(Instantiation) && \"Must be a VarDecl!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 852, __PRETTY_FUNCTION__))
;
853 if (isa<VarTemplateSpecializationDecl>(Instantiation)) {
854 Diag(PointOfInstantiation,
855 diag::err_explicit_instantiation_undefined_var_template)
856 << Instantiation;
857 Instantiation->setInvalidDecl();
858 } else
859 Diag(PointOfInstantiation,
860 diag::err_explicit_instantiation_undefined_member)
861 << /*static data member*/ 2 << Instantiation->getDeclName()
862 << Instantiation->getDeclContext();
863 Note = diag::note_explicit_instantiation_here;
864 }
865 }
866 if (Note) // Diagnostics were emitted.
867 Diag(Pattern->getLocation(), Note.getValue());
868
869 // In general, Instantiation isn't marked invalid to get more than one
870 // error for multiple undefined instantiations. But the code that does
871 // explicit declaration -> explicit definition conversion can't handle
872 // invalid declarations, so mark as invalid in that case.
873 if (TSK == TSK_ExplicitInstantiationDeclaration)
874 Instantiation->setInvalidDecl();
875 return true;
876}
877
878/// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
879/// that the template parameter 'PrevDecl' is being shadowed by a new
880/// declaration at location Loc. Returns true to indicate that this is
881/// an error, and false otherwise.
882void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) {
883 assert(PrevDecl->isTemplateParameter() && "Not a template parameter")((PrevDecl->isTemplateParameter() && "Not a template parameter"
) ? static_cast<void> (0) : __assert_fail ("PrevDecl->isTemplateParameter() && \"Not a template parameter\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 883, __PRETTY_FUNCTION__))
;
884
885 // C++ [temp.local]p4:
886 // A template-parameter shall not be redeclared within its
887 // scope (including nested scopes).
888 //
889 // Make this a warning when MSVC compatibility is requested.
890 unsigned DiagId = getLangOpts().MSVCCompat ? diag::ext_template_param_shadow
891 : diag::err_template_param_shadow;
892 Diag(Loc, DiagId) << cast<NamedDecl>(PrevDecl)->getDeclName();
893 Diag(PrevDecl->getLocation(), diag::note_template_param_here);
894}
895
896/// AdjustDeclIfTemplate - If the given decl happens to be a template, reset
897/// the parameter D to reference the templated declaration and return a pointer
898/// to the template declaration. Otherwise, do nothing to D and return null.
899TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) {
900 if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) {
901 D = Temp->getTemplatedDecl();
902 return Temp;
903 }
904 return nullptr;
905}
906
907ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion(
908 SourceLocation EllipsisLoc) const {
909 assert(Kind == Template &&((Kind == Template && "Only template template arguments can be pack expansions here"
) ? static_cast<void> (0) : __assert_fail ("Kind == Template && \"Only template template arguments can be pack expansions here\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 910, __PRETTY_FUNCTION__))
910 "Only template template arguments can be pack expansions here")((Kind == Template && "Only template template arguments can be pack expansions here"
) ? static_cast<void> (0) : __assert_fail ("Kind == Template && \"Only template template arguments can be pack expansions here\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 910, __PRETTY_FUNCTION__))
;
911 assert(getAsTemplate().get().containsUnexpandedParameterPack() &&((getAsTemplate().get().containsUnexpandedParameterPack() &&
"Template template argument pack expansion without packs") ?
static_cast<void> (0) : __assert_fail ("getAsTemplate().get().containsUnexpandedParameterPack() && \"Template template argument pack expansion without packs\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 912, __PRETTY_FUNCTION__))
912 "Template template argument pack expansion without packs")((getAsTemplate().get().containsUnexpandedParameterPack() &&
"Template template argument pack expansion without packs") ?
static_cast<void> (0) : __assert_fail ("getAsTemplate().get().containsUnexpandedParameterPack() && \"Template template argument pack expansion without packs\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 912, __PRETTY_FUNCTION__))
;
913 ParsedTemplateArgument Result(*this);
914 Result.EllipsisLoc = EllipsisLoc;
915 return Result;
916}
917
918static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef,
919 const ParsedTemplateArgument &Arg) {
920
921 switch (Arg.getKind()) {
922 case ParsedTemplateArgument::Type: {
923 TypeSourceInfo *DI;
924 QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI);
925 if (!DI)
926 DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation());
927 return TemplateArgumentLoc(TemplateArgument(T), DI);
928 }
929
930 case ParsedTemplateArgument::NonType: {
931 Expr *E = static_cast<Expr *>(Arg.getAsExpr());
932 return TemplateArgumentLoc(TemplateArgument(E), E);
933 }
934
935 case ParsedTemplateArgument::Template: {
936 TemplateName Template = Arg.getAsTemplate().get();
937 TemplateArgument TArg;
938 if (Arg.getEllipsisLoc().isValid())
939 TArg = TemplateArgument(Template, Optional<unsigned int>());
940 else
941 TArg = Template;
942 return TemplateArgumentLoc(
943 SemaRef.Context, TArg,
944 Arg.getScopeSpec().getWithLocInContext(SemaRef.Context),
945 Arg.getLocation(), Arg.getEllipsisLoc());
946 }
947 }
948
949 llvm_unreachable("Unhandled parsed template argument")::llvm::llvm_unreachable_internal("Unhandled parsed template argument"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 949)
;
950}
951
952/// Translates template arguments as provided by the parser
953/// into template arguments used by semantic analysis.
954void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn,
955 TemplateArgumentListInfo &TemplateArgs) {
956 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; ++I)
957 TemplateArgs.addArgument(translateTemplateArgument(*this,
958 TemplateArgsIn[I]));
959}
960
961static void maybeDiagnoseTemplateParameterShadow(Sema &SemaRef, Scope *S,
962 SourceLocation Loc,
963 IdentifierInfo *Name) {
964 NamedDecl *PrevDecl = SemaRef.LookupSingleName(
965 S, Name, Loc, Sema::LookupOrdinaryName, Sema::ForVisibleRedeclaration);
966 if (PrevDecl && PrevDecl->isTemplateParameter())
967 SemaRef.DiagnoseTemplateParameterShadow(Loc, PrevDecl);
968}
969
970/// Convert a parsed type into a parsed template argument. This is mostly
971/// trivial, except that we may have parsed a C++17 deduced class template
972/// specialization type, in which case we should form a template template
973/// argument instead of a type template argument.
974ParsedTemplateArgument Sema::ActOnTemplateTypeArgument(TypeResult ParsedType) {
975 TypeSourceInfo *TInfo;
976 QualType T = GetTypeFromParser(ParsedType.get(), &TInfo);
977 if (T.isNull())
978 return ParsedTemplateArgument();
979 assert(TInfo && "template argument with no location")((TInfo && "template argument with no location") ? static_cast
<void> (0) : __assert_fail ("TInfo && \"template argument with no location\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 979, __PRETTY_FUNCTION__))
;
980
981 // If we might have formed a deduced template specialization type, convert
982 // it to a template template argument.
983 if (getLangOpts().CPlusPlus17) {
984 TypeLoc TL = TInfo->getTypeLoc();
985 SourceLocation EllipsisLoc;
986 if (auto PET = TL.getAs<PackExpansionTypeLoc>()) {
987 EllipsisLoc = PET.getEllipsisLoc();
988 TL = PET.getPatternLoc();
989 }
990
991 CXXScopeSpec SS;
992 if (auto ET = TL.getAs<ElaboratedTypeLoc>()) {
993 SS.Adopt(ET.getQualifierLoc());
994 TL = ET.getNamedTypeLoc();
995 }
996
997 if (auto DTST = TL.getAs<DeducedTemplateSpecializationTypeLoc>()) {
998 TemplateName Name = DTST.getTypePtr()->getTemplateName();
999 if (SS.isSet())
1000 Name = Context.getQualifiedTemplateName(SS.getScopeRep(),
1001 /*HasTemplateKeyword*/ false,
1002 Name.getAsTemplateDecl());
1003 ParsedTemplateArgument Result(SS, TemplateTy::make(Name),
1004 DTST.getTemplateNameLoc());
1005 if (EllipsisLoc.isValid())
1006 Result = Result.getTemplatePackExpansion(EllipsisLoc);
1007 return Result;
1008 }
1009 }
1010
1011 // This is a normal type template argument. Note, if the type template
1012 // argument is an injected-class-name for a template, it has a dual nature
1013 // and can be used as either a type or a template. We handle that in
1014 // convertTypeTemplateArgumentToTemplate.
1015 return ParsedTemplateArgument(ParsedTemplateArgument::Type,
1016 ParsedType.get().getAsOpaquePtr(),
1017 TInfo->getTypeLoc().getBeginLoc());
1018}
1019
1020/// ActOnTypeParameter - Called when a C++ template type parameter
1021/// (e.g., "typename T") has been parsed. Typename specifies whether
1022/// the keyword "typename" was used to declare the type parameter
1023/// (otherwise, "class" was used), and KeyLoc is the location of the
1024/// "class" or "typename" keyword. ParamName is the name of the
1025/// parameter (NULL indicates an unnamed template parameter) and
1026/// ParamNameLoc is the location of the parameter name (if any).
1027/// If the type parameter has a default argument, it will be added
1028/// later via ActOnTypeParameterDefault.
1029NamedDecl *Sema::ActOnTypeParameter(Scope *S, bool Typename,
1030 SourceLocation EllipsisLoc,
1031 SourceLocation KeyLoc,
1032 IdentifierInfo *ParamName,
1033 SourceLocation ParamNameLoc,
1034 unsigned Depth, unsigned Position,
1035 SourceLocation EqualLoc,
1036 ParsedType DefaultArg,
1037 bool HasTypeConstraint) {
1038 assert(S->isTemplateParamScope() &&((S->isTemplateParamScope() && "Template type parameter not in template parameter scope!"
) ? static_cast<void> (0) : __assert_fail ("S->isTemplateParamScope() && \"Template type parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1039, __PRETTY_FUNCTION__))
1039 "Template type parameter not in template parameter scope!")((S->isTemplateParamScope() && "Template type parameter not in template parameter scope!"
) ? static_cast<void> (0) : __assert_fail ("S->isTemplateParamScope() && \"Template type parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1039, __PRETTY_FUNCTION__))
;
1040
1041 bool IsParameterPack = EllipsisLoc.isValid();
1042 TemplateTypeParmDecl *Param
1043 = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(),
1044 KeyLoc, ParamNameLoc, Depth, Position,
1045 ParamName, Typename, IsParameterPack,
1046 HasTypeConstraint);
1047 Param->setAccess(AS_public);
1048
1049 if (Param->isParameterPack())
1050 if (auto *LSI = getEnclosingLambda())
1051 LSI->LocalPacks.push_back(Param);
1052
1053 if (ParamName) {
1054 maybeDiagnoseTemplateParameterShadow(*this, S, ParamNameLoc, ParamName);
1055
1056 // Add the template parameter into the current scope.
1057 S->AddDecl(Param);
1058 IdResolver.AddDecl(Param);
1059 }
1060
1061 // C++0x [temp.param]p9:
1062 // A default template-argument may be specified for any kind of
1063 // template-parameter that is not a template parameter pack.
1064 if (DefaultArg && IsParameterPack) {
1065 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1066 DefaultArg = nullptr;
1067 }
1068
1069 // Handle the default argument, if provided.
1070 if (DefaultArg) {
1071 TypeSourceInfo *DefaultTInfo;
1072 GetTypeFromParser(DefaultArg, &DefaultTInfo);
1073
1074 assert(DefaultTInfo && "expected source information for type")((DefaultTInfo && "expected source information for type"
) ? static_cast<void> (0) : __assert_fail ("DefaultTInfo && \"expected source information for type\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1074, __PRETTY_FUNCTION__))
;
1075
1076 // Check for unexpanded parameter packs.
1077 if (DiagnoseUnexpandedParameterPack(ParamNameLoc, DefaultTInfo,
1078 UPPC_DefaultArgument))
1079 return Param;
1080
1081 // Check the template argument itself.
1082 if (CheckTemplateArgument(Param, DefaultTInfo)) {
1083 Param->setInvalidDecl();
1084 return Param;
1085 }
1086
1087 Param->setDefaultArgument(DefaultTInfo);
1088 }
1089
1090 return Param;
1091}
1092
1093/// Convert the parser's template argument list representation into our form.
1094static TemplateArgumentListInfo
1095makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) {
1096 TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc,
1097 TemplateId.RAngleLoc);
1098 ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(),
1099 TemplateId.NumArgs);
1100 S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
1101 return TemplateArgs;
1102}
1103
1104bool Sema::ActOnTypeConstraint(const CXXScopeSpec &SS,
1105 TemplateIdAnnotation *TypeConstr,
1106 TemplateTypeParmDecl *ConstrainedParameter,
1107 SourceLocation EllipsisLoc) {
1108 ConceptDecl *CD =
1109 cast<ConceptDecl>(TypeConstr->Template.get().getAsTemplateDecl());
1110
1111 // C++2a [temp.param]p4:
1112 // [...] The concept designated by a type-constraint shall be a type
1113 // concept ([temp.concept]).
1114 if (!CD->isTypeConcept()) {
1115 Diag(TypeConstr->TemplateNameLoc,
1116 diag::err_type_constraint_non_type_concept);
1117 return true;
1118 }
1119
1120 bool WereArgsSpecified = TypeConstr->LAngleLoc.isValid();
1121
1122 if (!WereArgsSpecified &&
1123 CD->getTemplateParameters()->getMinRequiredArguments() > 1) {
1124 Diag(TypeConstr->TemplateNameLoc,
1125 diag::err_type_constraint_missing_arguments) << CD;
1126 return true;
1127 }
1128
1129 TemplateArgumentListInfo TemplateArgs;
1130 if (TypeConstr->LAngleLoc.isValid()) {
1131 TemplateArgs =
1132 makeTemplateArgumentListInfo(*this, *TypeConstr);
1133 }
1134 return AttachTypeConstraint(
1135 SS.isSet() ? SS.getWithLocInContext(Context) : NestedNameSpecifierLoc(),
1136 DeclarationNameInfo(DeclarationName(TypeConstr->Name),
1137 TypeConstr->TemplateNameLoc), CD,
1138 TypeConstr->LAngleLoc.isValid() ? &TemplateArgs : nullptr,
1139 ConstrainedParameter, EllipsisLoc);
1140}
1141
1142template<typename ArgumentLocAppender>
1143static ExprResult formImmediatelyDeclaredConstraint(
1144 Sema &S, NestedNameSpecifierLoc NS, DeclarationNameInfo NameInfo,
1145 ConceptDecl *NamedConcept, SourceLocation LAngleLoc,
1146 SourceLocation RAngleLoc, QualType ConstrainedType,
1147 SourceLocation ParamNameLoc, ArgumentLocAppender Appender,
1148 SourceLocation EllipsisLoc) {
1149
1150 TemplateArgumentListInfo ConstraintArgs;
1151 ConstraintArgs.addArgument(
1152 S.getTrivialTemplateArgumentLoc(TemplateArgument(ConstrainedType),
1153 /*NTTPType=*/QualType(), ParamNameLoc));
1154
1155 ConstraintArgs.setRAngleLoc(RAngleLoc);
1156 ConstraintArgs.setLAngleLoc(LAngleLoc);
1157 Appender(ConstraintArgs);
1158
1159 // C++2a [temp.param]p4:
1160 // [...] This constraint-expression E is called the immediately-declared
1161 // constraint of T. [...]
1162 CXXScopeSpec SS;
1163 SS.Adopt(NS);
1164 ExprResult ImmediatelyDeclaredConstraint = S.CheckConceptTemplateId(
1165 SS, /*TemplateKWLoc=*/SourceLocation(), NameInfo,
1166 /*FoundDecl=*/NamedConcept, NamedConcept, &ConstraintArgs);
1167 if (ImmediatelyDeclaredConstraint.isInvalid() || !EllipsisLoc.isValid())
1168 return ImmediatelyDeclaredConstraint;
1169
1170 // C++2a [temp.param]p4:
1171 // [...] If T is not a pack, then E is E', otherwise E is (E' && ...).
1172 //
1173 // We have the following case:
1174 //
1175 // template<typename T> concept C1 = true;
1176 // template<C1... T> struct s1;
1177 //
1178 // The constraint: (C1<T> && ...)
1179 //
1180 // Note that the type of C1<T> is known to be 'bool', so we don't need to do
1181 // any unqualified lookups for 'operator&&' here.
1182 return S.BuildCXXFoldExpr(/*UnqualifiedLookup=*/nullptr,
1183 /*LParenLoc=*/SourceLocation(),
1184 ImmediatelyDeclaredConstraint.get(), BO_LAnd,
1185 EllipsisLoc, /*RHS=*/nullptr,
1186 /*RParenLoc=*/SourceLocation(),
1187 /*NumExpansions=*/None);
1188}
1189
1190/// Attach a type-constraint to a template parameter.
1191/// \returns true if an error occured. This can happen if the
1192/// immediately-declared constraint could not be formed (e.g. incorrect number
1193/// of arguments for the named concept).
1194bool Sema::AttachTypeConstraint(NestedNameSpecifierLoc NS,
1195 DeclarationNameInfo NameInfo,
1196 ConceptDecl *NamedConcept,
1197 const TemplateArgumentListInfo *TemplateArgs,
1198 TemplateTypeParmDecl *ConstrainedParameter,
1199 SourceLocation EllipsisLoc) {
1200 // C++2a [temp.param]p4:
1201 // [...] If Q is of the form C<A1, ..., An>, then let E' be
1202 // C<T, A1, ..., An>. Otherwise, let E' be C<T>. [...]
1203 const ASTTemplateArgumentListInfo *ArgsAsWritten =
1204 TemplateArgs ? ASTTemplateArgumentListInfo::Create(Context,
1205 *TemplateArgs) : nullptr;
1206
1207 QualType ParamAsArgument(ConstrainedParameter->getTypeForDecl(), 0);
1208
1209 ExprResult ImmediatelyDeclaredConstraint =
1210 formImmediatelyDeclaredConstraint(
1211 *this, NS, NameInfo, NamedConcept,
1212 TemplateArgs ? TemplateArgs->getLAngleLoc() : SourceLocation(),
1213 TemplateArgs ? TemplateArgs->getRAngleLoc() : SourceLocation(),
1214 ParamAsArgument, ConstrainedParameter->getLocation(),
1215 [&] (TemplateArgumentListInfo &ConstraintArgs) {
1216 if (TemplateArgs)
1217 for (const auto &ArgLoc : TemplateArgs->arguments())
1218 ConstraintArgs.addArgument(ArgLoc);
1219 }, EllipsisLoc);
1220 if (ImmediatelyDeclaredConstraint.isInvalid())
1221 return true;
1222
1223 ConstrainedParameter->setTypeConstraint(NS, NameInfo,
1224 /*FoundDecl=*/NamedConcept,
1225 NamedConcept, ArgsAsWritten,
1226 ImmediatelyDeclaredConstraint.get());
1227 return false;
1228}
1229
1230bool Sema::AttachTypeConstraint(AutoTypeLoc TL, NonTypeTemplateParmDecl *NTTP,
1231 SourceLocation EllipsisLoc) {
1232 if (NTTP->getType() != TL.getType() ||
1233 TL.getAutoKeyword() != AutoTypeKeyword::Auto) {
1234 Diag(NTTP->getTypeSourceInfo()->getTypeLoc().getBeginLoc(),
1235 diag::err_unsupported_placeholder_constraint)
1236 << NTTP->getTypeSourceInfo()->getTypeLoc().getSourceRange();
1237 return true;
1238 }
1239 // FIXME: Concepts: This should be the type of the placeholder, but this is
1240 // unclear in the wording right now.
1241 DeclRefExpr *Ref = BuildDeclRefExpr(NTTP, NTTP->getType(), VK_RValue,
1242 NTTP->getLocation());
1243 if (!Ref)
1244 return true;
1245 ExprResult ImmediatelyDeclaredConstraint =
1246 formImmediatelyDeclaredConstraint(
1247 *this, TL.getNestedNameSpecifierLoc(), TL.getConceptNameInfo(),
1248 TL.getNamedConcept(), TL.getLAngleLoc(), TL.getRAngleLoc(),
1249 BuildDecltypeType(Ref, NTTP->getLocation()), NTTP->getLocation(),
1250 [&] (TemplateArgumentListInfo &ConstraintArgs) {
1251 for (unsigned I = 0, C = TL.getNumArgs(); I != C; ++I)
1252 ConstraintArgs.addArgument(TL.getArgLoc(I));
1253 }, EllipsisLoc);
1254 if (ImmediatelyDeclaredConstraint.isInvalid() ||
1255 !ImmediatelyDeclaredConstraint.isUsable())
1256 return true;
1257
1258 NTTP->setPlaceholderTypeConstraint(ImmediatelyDeclaredConstraint.get());
1259 return false;
1260}
1261
1262/// Check that the type of a non-type template parameter is
1263/// well-formed.
1264///
1265/// \returns the (possibly-promoted) parameter type if valid;
1266/// otherwise, produces a diagnostic and returns a NULL type.
1267QualType Sema::CheckNonTypeTemplateParameterType(TypeSourceInfo *&TSI,
1268 SourceLocation Loc) {
1269 if (TSI->getType()->isUndeducedType()) {
1270 // C++17 [temp.dep.expr]p3:
1271 // An id-expression is type-dependent if it contains
1272 // - an identifier associated by name lookup with a non-type
1273 // template-parameter declared with a type that contains a
1274 // placeholder type (7.1.7.4),
1275 TSI = SubstAutoTypeSourceInfo(TSI, Context.DependentTy);
1276 }
1277
1278 return CheckNonTypeTemplateParameterType(TSI->getType(), Loc);
1279}
1280
1281/// Require the given type to be a structural type, and diagnose if it is not.
1282///
1283/// \return \c true if an error was produced.
1284bool Sema::RequireStructuralType(QualType T, SourceLocation Loc) {
1285 if (T->isDependentType())
1286 return false;
1287
1288 if (RequireCompleteType(Loc, T, diag::err_template_nontype_parm_incomplete))
1289 return true;
1290
1291 if (T->isStructuralType())
1292 return false;
1293
1294 // Structural types are required to be object types or lvalue references.
1295 if (T->isRValueReferenceType()) {
1296 Diag(Loc, diag::err_template_nontype_parm_rvalue_ref) << T;
1297 return true;
1298 }
1299
1300 // Don't mention structural types in our diagnostic prior to C++20. Also,
1301 // there's not much more we can say about non-scalar non-class types --
1302 // because we can't see functions or arrays here, those can only be language
1303 // extensions.
1304 if (!getLangOpts().CPlusPlus20 ||
1305 (!T->isScalarType() && !T->isRecordType())) {
1306 Diag(Loc, diag::err_template_nontype_parm_bad_type) << T;
1307 return true;
1308 }
1309
1310 // Structural types are required to be literal types.
1311 if (RequireLiteralType(Loc, T, diag::err_template_nontype_parm_not_literal))
1312 return true;
1313
1314 Diag(Loc, diag::err_template_nontype_parm_not_structural) << T;
1315
1316 // Drill down into the reason why the class is non-structural.
1317 while (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
1318 // All members are required to be public and non-mutable, and can't be of
1319 // rvalue reference type. Check these conditions first to prefer a "local"
1320 // reason over a more distant one.
1321 for (const FieldDecl *FD : RD->fields()) {
1322 if (FD->getAccess() != AS_public) {
1323 Diag(FD->getLocation(), diag::note_not_structural_non_public) << T << 0;
1324 return true;
1325 }
1326 if (FD->isMutable()) {
1327 Diag(FD->getLocation(), diag::note_not_structural_mutable_field) << T;
1328 return true;
1329 }
1330 if (FD->getType()->isRValueReferenceType()) {
1331 Diag(FD->getLocation(), diag::note_not_structural_rvalue_ref_field)
1332 << T;
1333 return true;
1334 }
1335 }
1336
1337 // All bases are required to be public.
1338 for (const auto &BaseSpec : RD->bases()) {
1339 if (BaseSpec.getAccessSpecifier() != AS_public) {
1340 Diag(BaseSpec.getBaseTypeLoc(), diag::note_not_structural_non_public)
1341 << T << 1;
1342 return true;
1343 }
1344 }
1345
1346 // All subobjects are required to be of structural types.
1347 SourceLocation SubLoc;
1348 QualType SubType;
1349 int Kind = -1;
1350
1351 for (const FieldDecl *FD : RD->fields()) {
1352 QualType T = Context.getBaseElementType(FD->getType());
1353 if (!T->isStructuralType()) {
1354 SubLoc = FD->getLocation();
1355 SubType = T;
1356 Kind = 0;
1357 break;
1358 }
1359 }
1360
1361 if (Kind == -1) {
1362 for (const auto &BaseSpec : RD->bases()) {
1363 QualType T = BaseSpec.getType();
1364 if (!T->isStructuralType()) {
1365 SubLoc = BaseSpec.getBaseTypeLoc();
1366 SubType = T;
1367 Kind = 1;
1368 break;
1369 }
1370 }
1371 }
1372
1373 assert(Kind != -1 && "couldn't find reason why type is not structural")((Kind != -1 && "couldn't find reason why type is not structural"
) ? static_cast<void> (0) : __assert_fail ("Kind != -1 && \"couldn't find reason why type is not structural\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1373, __PRETTY_FUNCTION__))
;
1374 Diag(SubLoc, diag::note_not_structural_subobject)
1375 << T << Kind << SubType;
1376 T = SubType;
1377 RD = T->getAsCXXRecordDecl();
Value stored to 'RD' is never read
1378 }
1379
1380 return true;
1381}
1382
1383QualType Sema::CheckNonTypeTemplateParameterType(QualType T,
1384 SourceLocation Loc) {
1385 // We don't allow variably-modified types as the type of non-type template
1386 // parameters.
1387 if (T->isVariablyModifiedType()) {
1388 Diag(Loc, diag::err_variably_modified_nontype_template_param)
1389 << T;
1390 return QualType();
1391 }
1392
1393 // C++ [temp.param]p4:
1394 //
1395 // A non-type template-parameter shall have one of the following
1396 // (optionally cv-qualified) types:
1397 //
1398 // -- integral or enumeration type,
1399 if (T->isIntegralOrEnumerationType() ||
1400 // -- pointer to object or pointer to function,
1401 T->isPointerType() ||
1402 // -- lvalue reference to object or lvalue reference to function,
1403 T->isLValueReferenceType() ||
1404 // -- pointer to member,
1405 T->isMemberPointerType() ||
1406 // -- std::nullptr_t, or
1407 T->isNullPtrType() ||
1408 // -- a type that contains a placeholder type.
1409 T->isUndeducedType()) {
1410 // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
1411 // are ignored when determining its type.
1412 return T.getUnqualifiedType();
1413 }
1414
1415 // C++ [temp.param]p8:
1416 //
1417 // A non-type template-parameter of type "array of T" or
1418 // "function returning T" is adjusted to be of type "pointer to
1419 // T" or "pointer to function returning T", respectively.
1420 if (T->isArrayType() || T->isFunctionType())
1421 return Context.getDecayedType(T);
1422
1423 // If T is a dependent type, we can't do the check now, so we
1424 // assume that it is well-formed. Note that stripping off the
1425 // qualifiers here is not really correct if T turns out to be
1426 // an array type, but we'll recompute the type everywhere it's
1427 // used during instantiation, so that should be OK. (Using the
1428 // qualified type is equally wrong.)
1429 if (T->isDependentType())
1430 return T.getUnqualifiedType();
1431
1432 // C++20 [temp.param]p6:
1433 // -- a structural type
1434 if (RequireStructuralType(T, Loc))
1435 return QualType();
1436
1437 if (!getLangOpts().CPlusPlus20) {
1438 // FIXME: Consider allowing structural types as an extension in C++17. (In
1439 // earlier language modes, the template argument evaluation rules are too
1440 // inflexible.)
1441 Diag(Loc, diag::err_template_nontype_parm_bad_structural_type) << T;
1442 return QualType();
1443 }
1444
1445 Diag(Loc, diag::warn_cxx17_compat_template_nontype_parm_type) << T;
1446 return T.getUnqualifiedType();
1447}
1448
1449NamedDecl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
1450 unsigned Depth,
1451 unsigned Position,
1452 SourceLocation EqualLoc,
1453 Expr *Default) {
1454 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
1455
1456 // Check that we have valid decl-specifiers specified.
1457 auto CheckValidDeclSpecifiers = [this, &D] {
1458 // C++ [temp.param]
1459 // p1
1460 // template-parameter:
1461 // ...
1462 // parameter-declaration
1463 // p2
1464 // ... A storage class shall not be specified in a template-parameter
1465 // declaration.
1466 // [dcl.typedef]p1:
1467 // The typedef specifier [...] shall not be used in the decl-specifier-seq
1468 // of a parameter-declaration
1469 const DeclSpec &DS = D.getDeclSpec();
1470 auto EmitDiag = [this](SourceLocation Loc) {
1471 Diag(Loc, diag::err_invalid_decl_specifier_in_nontype_parm)
1472 << FixItHint::CreateRemoval(Loc);
1473 };
1474 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified)
1475 EmitDiag(DS.getStorageClassSpecLoc());
1476
1477 if (DS.getThreadStorageClassSpec() != TSCS_unspecified)
1478 EmitDiag(DS.getThreadStorageClassSpecLoc());
1479
1480 // [dcl.inline]p1:
1481 // The inline specifier can be applied only to the declaration or
1482 // definition of a variable or function.
1483
1484 if (DS.isInlineSpecified())
1485 EmitDiag(DS.getInlineSpecLoc());
1486
1487 // [dcl.constexpr]p1:
1488 // The constexpr specifier shall be applied only to the definition of a
1489 // variable or variable template or the declaration of a function or
1490 // function template.
1491
1492 if (DS.hasConstexprSpecifier())
1493 EmitDiag(DS.getConstexprSpecLoc());
1494
1495 // [dcl.fct.spec]p1:
1496 // Function-specifiers can be used only in function declarations.
1497
1498 if (DS.isVirtualSpecified())
1499 EmitDiag(DS.getVirtualSpecLoc());
1500
1501 if (DS.hasExplicitSpecifier())
1502 EmitDiag(DS.getExplicitSpecLoc());
1503
1504 if (DS.isNoreturnSpecified())
1505 EmitDiag(DS.getNoreturnSpecLoc());
1506 };
1507
1508 CheckValidDeclSpecifiers();
1509
1510 if (TInfo->getType()->isUndeducedType()) {
1511 Diag(D.getIdentifierLoc(),
1512 diag::warn_cxx14_compat_template_nontype_parm_auto_type)
1513 << QualType(TInfo->getType()->getContainedAutoType(), 0);
1514 }
1515
1516 assert(S->isTemplateParamScope() &&((S->isTemplateParamScope() && "Non-type template parameter not in template parameter scope!"
) ? static_cast<void> (0) : __assert_fail ("S->isTemplateParamScope() && \"Non-type template parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1517, __PRETTY_FUNCTION__))
1517 "Non-type template parameter not in template parameter scope!")((S->isTemplateParamScope() && "Non-type template parameter not in template parameter scope!"
) ? static_cast<void> (0) : __assert_fail ("S->isTemplateParamScope() && \"Non-type template parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1517, __PRETTY_FUNCTION__))
;
1518 bool Invalid = false;
1519
1520 QualType T = CheckNonTypeTemplateParameterType(TInfo, D.getIdentifierLoc());
1521 if (T.isNull()) {
1522 T = Context.IntTy; // Recover with an 'int' type.
1523 Invalid = true;
1524 }
1525
1526 CheckFunctionOrTemplateParamDeclarator(S, D);
1527
1528 IdentifierInfo *ParamName = D.getIdentifier();
1529 bool IsParameterPack = D.hasEllipsis();
1530 NonTypeTemplateParmDecl *Param = NonTypeTemplateParmDecl::Create(
1531 Context, Context.getTranslationUnitDecl(), D.getBeginLoc(),
1532 D.getIdentifierLoc(), Depth, Position, ParamName, T, IsParameterPack,
1533 TInfo);
1534 Param->setAccess(AS_public);
1535
1536 if (AutoTypeLoc TL = TInfo->getTypeLoc().getContainedAutoTypeLoc())
1537 if (TL.isConstrained())
1538 if (AttachTypeConstraint(TL, Param, D.getEllipsisLoc()))
1539 Invalid = true;
1540
1541 if (Invalid)
1542 Param->setInvalidDecl();
1543
1544 if (Param->isParameterPack())
1545 if (auto *LSI = getEnclosingLambda())
1546 LSI->LocalPacks.push_back(Param);
1547
1548 if (ParamName) {
1549 maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(),
1550 ParamName);
1551
1552 // Add the template parameter into the current scope.
1553 S->AddDecl(Param);
1554 IdResolver.AddDecl(Param);
1555 }
1556
1557 // C++0x [temp.param]p9:
1558 // A default template-argument may be specified for any kind of
1559 // template-parameter that is not a template parameter pack.
1560 if (Default && IsParameterPack) {
1561 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1562 Default = nullptr;
1563 }
1564
1565 // Check the well-formedness of the default template argument, if provided.
1566 if (Default) {
1567 // Check for unexpanded parameter packs.
1568 if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
1569 return Param;
1570
1571 TemplateArgument Converted;
1572 ExprResult DefaultRes =
1573 CheckTemplateArgument(Param, Param->getType(), Default, Converted);
1574 if (DefaultRes.isInvalid()) {
1575 Param->setInvalidDecl();
1576 return Param;
1577 }
1578 Default = DefaultRes.get();
1579
1580 Param->setDefaultArgument(Default);
1581 }
1582
1583 return Param;
1584}
1585
1586/// ActOnTemplateTemplateParameter - Called when a C++ template template
1587/// parameter (e.g. T in template <template \<typename> class T> class array)
1588/// has been parsed. S is the current scope.
1589NamedDecl *Sema::ActOnTemplateTemplateParameter(Scope* S,
1590 SourceLocation TmpLoc,
1591 TemplateParameterList *Params,
1592 SourceLocation EllipsisLoc,
1593 IdentifierInfo *Name,
1594 SourceLocation NameLoc,
1595 unsigned Depth,
1596 unsigned Position,
1597 SourceLocation EqualLoc,
1598 ParsedTemplateArgument Default) {
1599 assert(S->isTemplateParamScope() &&((S->isTemplateParamScope() && "Template template parameter not in template parameter scope!"
) ? static_cast<void> (0) : __assert_fail ("S->isTemplateParamScope() && \"Template template parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1600, __PRETTY_FUNCTION__))
1600 "Template template parameter not in template parameter scope!")((S->isTemplateParamScope() && "Template template parameter not in template parameter scope!"
) ? static_cast<void> (0) : __assert_fail ("S->isTemplateParamScope() && \"Template template parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1600, __PRETTY_FUNCTION__))
;
1601
1602 // Construct the parameter object.
1603 bool IsParameterPack = EllipsisLoc.isValid();
1604 TemplateTemplateParmDecl *Param =
1605 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
1606 NameLoc.isInvalid()? TmpLoc : NameLoc,
1607 Depth, Position, IsParameterPack,
1608 Name, Params);
1609 Param->setAccess(AS_public);
1610
1611 if (Param->isParameterPack())
1612 if (auto *LSI = getEnclosingLambda())
1613 LSI->LocalPacks.push_back(Param);
1614
1615 // If the template template parameter has a name, then link the identifier
1616 // into the scope and lookup mechanisms.
1617 if (Name) {
1618 maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name);
1619
1620 S->AddDecl(Param);
1621 IdResolver.AddDecl(Param);
1622 }
1623
1624 if (Params->size() == 0) {
1625 Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
1626 << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
1627 Param->setInvalidDecl();
1628 }
1629
1630 // C++0x [temp.param]p9:
1631 // A default template-argument may be specified for any kind of
1632 // template-parameter that is not a template parameter pack.
1633 if (IsParameterPack && !Default.isInvalid()) {
1634 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1635 Default = ParsedTemplateArgument();
1636 }
1637
1638 if (!Default.isInvalid()) {
1639 // Check only that we have a template template argument. We don't want to
1640 // try to check well-formedness now, because our template template parameter
1641 // might have dependent types in its template parameters, which we wouldn't
1642 // be able to match now.
1643 //
1644 // If none of the template template parameter's template arguments mention
1645 // other template parameters, we could actually perform more checking here.
1646 // However, it isn't worth doing.
1647 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
1648 if (DefaultArg.getArgument().getAsTemplate().isNull()) {
1649 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_valid_template)
1650 << DefaultArg.getSourceRange();
1651 return Param;
1652 }
1653
1654 // Check for unexpanded parameter packs.
1655 if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(),
1656 DefaultArg.getArgument().getAsTemplate(),
1657 UPPC_DefaultArgument))
1658 return Param;
1659
1660 Param->setDefaultArgument(Context, DefaultArg);
1661 }
1662
1663 return Param;
1664}
1665
1666/// ActOnTemplateParameterList - Builds a TemplateParameterList, optionally
1667/// constrained by RequiresClause, that contains the template parameters in
1668/// Params.
1669TemplateParameterList *
1670Sema::ActOnTemplateParameterList(unsigned Depth,
1671 SourceLocation ExportLoc,
1672 SourceLocation TemplateLoc,
1673 SourceLocation LAngleLoc,
1674 ArrayRef<NamedDecl *> Params,
1675 SourceLocation RAngleLoc,
1676 Expr *RequiresClause) {
1677 if (ExportLoc.isValid())
1678 Diag(ExportLoc, diag::warn_template_export_unsupported);
1679
1680 return TemplateParameterList::Create(
1681 Context, TemplateLoc, LAngleLoc,
1682 llvm::makeArrayRef(Params.data(), Params.size()),
1683 RAngleLoc, RequiresClause);
1684}
1685
1686static void SetNestedNameSpecifier(Sema &S, TagDecl *T,
1687 const CXXScopeSpec &SS) {
1688 if (SS.isSet())
1689 T->setQualifierInfo(SS.getWithLocInContext(S.Context));
1690}
1691
1692DeclResult Sema::CheckClassTemplate(
1693 Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
1694 CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc,
1695 const ParsedAttributesView &Attr, TemplateParameterList *TemplateParams,
1696 AccessSpecifier AS, SourceLocation ModulePrivateLoc,
1697 SourceLocation FriendLoc, unsigned NumOuterTemplateParamLists,
1698 TemplateParameterList **OuterTemplateParamLists, SkipBodyInfo *SkipBody) {
1699 assert(TemplateParams && TemplateParams->size() > 0 &&((TemplateParams && TemplateParams->size() > 0 &&
"No template parameters") ? static_cast<void> (0) : __assert_fail
("TemplateParams && TemplateParams->size() > 0 && \"No template parameters\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1700, __PRETTY_FUNCTION__))
1700 "No template parameters")((TemplateParams && TemplateParams->size() > 0 &&
"No template parameters") ? static_cast<void> (0) : __assert_fail
("TemplateParams && TemplateParams->size() > 0 && \"No template parameters\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1700, __PRETTY_FUNCTION__))
;
1701 assert(TUK != TUK_Reference && "Can only declare or define class templates")((TUK != TUK_Reference && "Can only declare or define class templates"
) ? static_cast<void> (0) : __assert_fail ("TUK != TUK_Reference && \"Can only declare or define class templates\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1701, __PRETTY_FUNCTION__))
;
1702 bool Invalid = false;
1703
1704 // Check that we can declare a template here.
1705 if (CheckTemplateDeclScope(S, TemplateParams))
1706 return true;
1707
1708 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
1709 assert(Kind != TTK_Enum && "can't build template of enumerated type")((Kind != TTK_Enum && "can't build template of enumerated type"
) ? static_cast<void> (0) : __assert_fail ("Kind != TTK_Enum && \"can't build template of enumerated type\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1709, __PRETTY_FUNCTION__))
;
1710
1711 // There is no such thing as an unnamed class template.
1712 if (!Name) {
1713 Diag(KWLoc, diag::err_template_unnamed_class);
1714 return true;
1715 }
1716
1717 // Find any previous declaration with this name. For a friend with no
1718 // scope explicitly specified, we only look for tag declarations (per
1719 // C++11 [basic.lookup.elab]p2).
1720 DeclContext *SemanticContext;
1721 LookupResult Previous(*this, Name, NameLoc,
1722 (SS.isEmpty() && TUK == TUK_Friend)
1723 ? LookupTagName : LookupOrdinaryName,
1724 forRedeclarationInCurContext());
1725 if (SS.isNotEmpty() && !SS.isInvalid()) {
1726 SemanticContext = computeDeclContext(SS, true);
1727 if (!SemanticContext) {
1728 // FIXME: Horrible, horrible hack! We can't currently represent this
1729 // in the AST, and historically we have just ignored such friend
1730 // class templates, so don't complain here.
1731 Diag(NameLoc, TUK == TUK_Friend
1732 ? diag::warn_template_qualified_friend_ignored
1733 : diag::err_template_qualified_declarator_no_match)
1734 << SS.getScopeRep() << SS.getRange();
1735 return TUK != TUK_Friend;
1736 }
1737
1738 if (RequireCompleteDeclContext(SS, SemanticContext))
1739 return true;
1740
1741 // If we're adding a template to a dependent context, we may need to
1742 // rebuilding some of the types used within the template parameter list,
1743 // now that we know what the current instantiation is.
1744 if (SemanticContext->isDependentContext()) {
1745 ContextRAII SavedContext(*this, SemanticContext);
1746 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
1747 Invalid = true;
1748 } else if (TUK != TUK_Friend && TUK != TUK_Reference)
1749 diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc, false);
1750
1751 LookupQualifiedName(Previous, SemanticContext);
1752 } else {
1753 SemanticContext = CurContext;
1754
1755 // C++14 [class.mem]p14:
1756 // If T is the name of a class, then each of the following shall have a
1757 // name different from T:
1758 // -- every member template of class T
1759 if (TUK != TUK_Friend &&
1760 DiagnoseClassNameShadow(SemanticContext,
1761 DeclarationNameInfo(Name, NameLoc)))
1762 return true;
1763
1764 LookupName(Previous, S);
1765 }
1766
1767 if (Previous.isAmbiguous())
1768 return true;
1769
1770 NamedDecl *PrevDecl = nullptr;
1771 if (Previous.begin() != Previous.end())
1772 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1773
1774 if (PrevDecl && PrevDecl->isTemplateParameter()) {
1775 // Maybe we will complain about the shadowed template parameter.
1776 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
1777 // Just pretend that we didn't see the previous declaration.
1778 PrevDecl = nullptr;
1779 }
1780
1781 // If there is a previous declaration with the same name, check
1782 // whether this is a valid redeclaration.
1783 ClassTemplateDecl *PrevClassTemplate =
1784 dyn_cast_or_null<ClassTemplateDecl>(PrevDecl);
1785
1786 // We may have found the injected-class-name of a class template,
1787 // class template partial specialization, or class template specialization.
1788 // In these cases, grab the template that is being defined or specialized.
1789 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) &&
1790 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) {
1791 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext());
1792 PrevClassTemplate
1793 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate();
1794 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) {
1795 PrevClassTemplate
1796 = cast<ClassTemplateSpecializationDecl>(PrevDecl)
1797 ->getSpecializedTemplate();
1798 }
1799 }
1800
1801 if (TUK == TUK_Friend) {
1802 // C++ [namespace.memdef]p3:
1803 // [...] When looking for a prior declaration of a class or a function
1804 // declared as a friend, and when the name of the friend class or
1805 // function is neither a qualified name nor a template-id, scopes outside
1806 // the innermost enclosing namespace scope are not considered.
1807 if (!SS.isSet()) {
1808 DeclContext *OutermostContext = CurContext;
1809 while (!OutermostContext->isFileContext())
1810 OutermostContext = OutermostContext->getLookupParent();
1811
1812 if (PrevDecl &&
1813 (OutermostContext->Equals(PrevDecl->getDeclContext()) ||
1814 OutermostContext->Encloses(PrevDecl->getDeclContext()))) {
1815 SemanticContext = PrevDecl->getDeclContext();
1816 } else {
1817 // Declarations in outer scopes don't matter. However, the outermost
1818 // context we computed is the semantic context for our new
1819 // declaration.
1820 PrevDecl = PrevClassTemplate = nullptr;
1821 SemanticContext = OutermostContext;
1822
1823 // Check that the chosen semantic context doesn't already contain a
1824 // declaration of this name as a non-tag type.
1825 Previous.clear(LookupOrdinaryName);
1826 DeclContext *LookupContext = SemanticContext;
1827 while (LookupContext->isTransparentContext())
1828 LookupContext = LookupContext->getLookupParent();
1829 LookupQualifiedName(Previous, LookupContext);
1830
1831 if (Previous.isAmbiguous())
1832 return true;
1833
1834 if (Previous.begin() != Previous.end())
1835 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1836 }
1837 }
1838 } else if (PrevDecl &&
1839 !isDeclInScope(Previous.getRepresentativeDecl(), SemanticContext,
1840 S, SS.isValid()))
1841 PrevDecl = PrevClassTemplate = nullptr;
1842
1843 if (auto *Shadow = dyn_cast_or_null<UsingShadowDecl>(
1844 PrevDecl ? Previous.getRepresentativeDecl() : nullptr)) {
1845 if (SS.isEmpty() &&
1846 !(PrevClassTemplate &&
1847 PrevClassTemplate->getDeclContext()->getRedeclContext()->Equals(
1848 SemanticContext->getRedeclContext()))) {
1849 Diag(KWLoc, diag::err_using_decl_conflict_reverse);
1850 Diag(Shadow->getTargetDecl()->getLocation(),
1851 diag::note_using_decl_target);
1852 Diag(Shadow->getUsingDecl()->getLocation(), diag::note_using_decl) << 0;
1853 // Recover by ignoring the old declaration.
1854 PrevDecl = PrevClassTemplate = nullptr;
1855 }
1856 }
1857
1858 if (PrevClassTemplate) {
1859 // Ensure that the template parameter lists are compatible. Skip this check
1860 // for a friend in a dependent context: the template parameter list itself
1861 // could be dependent.
1862 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1863 !TemplateParameterListsAreEqual(TemplateParams,
1864 PrevClassTemplate->getTemplateParameters(),
1865 /*Complain=*/true,
1866 TPL_TemplateMatch))
1867 return true;
1868
1869 // C++ [temp.class]p4:
1870 // In a redeclaration, partial specialization, explicit
1871 // specialization or explicit instantiation of a class template,
1872 // the class-key shall agree in kind with the original class
1873 // template declaration (7.1.5.3).
1874 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
1875 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
1876 TUK == TUK_Definition, KWLoc, Name)) {
1877 Diag(KWLoc, diag::err_use_with_wrong_tag)
1878 << Name
1879 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
1880 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use);
1881 Kind = PrevRecordDecl->getTagKind();
1882 }
1883
1884 // Check for redefinition of this class template.
1885 if (TUK == TUK_Definition) {
1886 if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
1887 // If we have a prior definition that is not visible, treat this as
1888 // simply making that previous definition visible.
1889 NamedDecl *Hidden = nullptr;
1890 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
1891 SkipBody->ShouldSkip = true;
1892 SkipBody->Previous = Def;
1893 auto *Tmpl = cast<CXXRecordDecl>(Hidden)->getDescribedClassTemplate();
1894 assert(Tmpl && "original definition of a class template is not a "((Tmpl && "original definition of a class template is not a "
"class template?") ? static_cast<void> (0) : __assert_fail
("Tmpl && \"original definition of a class template is not a \" \"class template?\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1895, __PRETTY_FUNCTION__))
1895 "class template?")((Tmpl && "original definition of a class template is not a "
"class template?") ? static_cast<void> (0) : __assert_fail
("Tmpl && \"original definition of a class template is not a \" \"class template?\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1895, __PRETTY_FUNCTION__))
;
1896 makeMergedDefinitionVisible(Hidden);
1897 makeMergedDefinitionVisible(Tmpl);
1898 } else {
1899 Diag(NameLoc, diag::err_redefinition) << Name;
1900 Diag(Def->getLocation(), diag::note_previous_definition);
1901 // FIXME: Would it make sense to try to "forget" the previous
1902 // definition, as part of error recovery?
1903 return true;
1904 }
1905 }
1906 }
1907 } else if (PrevDecl) {
1908 // C++ [temp]p5:
1909 // A class template shall not have the same name as any other
1910 // template, class, function, object, enumeration, enumerator,
1911 // namespace, or type in the same scope (3.3), except as specified
1912 // in (14.5.4).
1913 Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
1914 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1915 return true;
1916 }
1917
1918 // Check the template parameter list of this declaration, possibly
1919 // merging in the template parameter list from the previous class
1920 // template declaration. Skip this check for a friend in a dependent
1921 // context, because the template parameter list might be dependent.
1922 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1923 CheckTemplateParameterList(
1924 TemplateParams,
1925 PrevClassTemplate
1926 ? PrevClassTemplate->getMostRecentDecl()->getTemplateParameters()
1927 : nullptr,
1928 (SS.isSet() && SemanticContext && SemanticContext->isRecord() &&
1929 SemanticContext->isDependentContext())
1930 ? TPC_ClassTemplateMember
1931 : TUK == TUK_Friend ? TPC_FriendClassTemplate : TPC_ClassTemplate,
1932 SkipBody))
1933 Invalid = true;
1934
1935 if (SS.isSet()) {
1936 // If the name of the template was qualified, we must be defining the
1937 // template out-of-line.
1938 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
1939 Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match
1940 : diag::err_member_decl_does_not_match)
1941 << Name << SemanticContext << /*IsDefinition*/true << SS.getRange();
1942 Invalid = true;
1943 }
1944 }
1945
1946 // If this is a templated friend in a dependent context we should not put it
1947 // on the redecl chain. In some cases, the templated friend can be the most
1948 // recent declaration tricking the template instantiator to make substitutions
1949 // there.
1950 // FIXME: Figure out how to combine with shouldLinkDependentDeclWithPrevious
1951 bool ShouldAddRedecl
1952 = !(TUK == TUK_Friend && CurContext->isDependentContext());
1953
1954 CXXRecordDecl *NewClass =
1955 CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
1956 PrevClassTemplate && ShouldAddRedecl ?
1957 PrevClassTemplate->getTemplatedDecl() : nullptr,
1958 /*DelayTypeCreation=*/true);
1959 SetNestedNameSpecifier(*this, NewClass, SS);
1960 if (NumOuterTemplateParamLists > 0)
1961 NewClass->setTemplateParameterListsInfo(
1962 Context, llvm::makeArrayRef(OuterTemplateParamLists,
1963 NumOuterTemplateParamLists));
1964
1965 // Add alignment attributes if necessary; these attributes are checked when
1966 // the ASTContext lays out the structure.
1967 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) {
1968 AddAlignmentAttributesForRecord(NewClass);
1969 AddMsStructLayoutForRecord(NewClass);
1970 }
1971
1972 ClassTemplateDecl *NewTemplate
1973 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
1974 DeclarationName(Name), TemplateParams,
1975 NewClass);
1976
1977 if (ShouldAddRedecl)
1978 NewTemplate->setPreviousDecl(PrevClassTemplate);
1979
1980 NewClass->setDescribedClassTemplate(NewTemplate);
1981
1982 if (ModulePrivateLoc.isValid())
1983 NewTemplate->setModulePrivate();
1984
1985 // Build the type for the class template declaration now.
1986 QualType T = NewTemplate->getInjectedClassNameSpecialization();
1987 T = Context.getInjectedClassNameType(NewClass, T);
1988 assert(T->isDependentType() && "Class template type is not dependent?")((T->isDependentType() && "Class template type is not dependent?"
) ? static_cast<void> (0) : __assert_fail ("T->isDependentType() && \"Class template type is not dependent?\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 1988, __PRETTY_FUNCTION__))
;
1989 (void)T;
1990
1991 // If we are providing an explicit specialization of a member that is a
1992 // class template, make a note of that.
1993 if (PrevClassTemplate &&
1994 PrevClassTemplate->getInstantiatedFromMemberTemplate())
1995 PrevClassTemplate->setMemberSpecialization();
1996
1997 // Set the access specifier.
1998 if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord())
1999 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
2000
2001 // Set the lexical context of these templates
2002 NewClass->setLexicalDeclContext(CurContext);
2003 NewTemplate->setLexicalDeclContext(CurContext);
2004
2005 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip))
2006 NewClass->startDefinition();
2007
2008 ProcessDeclAttributeList(S, NewClass, Attr);
2009
2010 if (PrevClassTemplate)
2011 mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
2012
2013 AddPushedVisibilityAttribute(NewClass);
2014 inferGslOwnerPointerAttribute(NewClass);
2015
2016 if (TUK != TUK_Friend) {
2017 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
2018 Scope *Outer = S;
2019 while ((Outer->getFlags() & Scope::TemplateParamScope) != 0)
2020 Outer = Outer->getParent();
2021 PushOnScopeChains(NewTemplate, Outer);
2022 } else {
2023 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) {
2024 NewTemplate->setAccess(PrevClassTemplate->getAccess());
2025 NewClass->setAccess(PrevClassTemplate->getAccess());
2026 }
2027
2028 NewTemplate->setObjectOfFriendDecl();
2029
2030 // Friend templates are visible in fairly strange ways.
2031 if (!CurContext->isDependentContext()) {
2032 DeclContext *DC = SemanticContext->getRedeclContext();
2033 DC->makeDeclVisibleInContext(NewTemplate);
2034 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
2035 PushOnScopeChains(NewTemplate, EnclosingScope,
2036 /* AddToContext = */ false);
2037 }
2038
2039 FriendDecl *Friend = FriendDecl::Create(
2040 Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc);
2041 Friend->setAccess(AS_public);
2042 CurContext->addDecl(Friend);
2043 }
2044
2045 if (PrevClassTemplate)
2046 CheckRedeclarationModuleOwnership(NewTemplate, PrevClassTemplate);
2047
2048 if (Invalid) {
2049 NewTemplate->setInvalidDecl();
2050 NewClass->setInvalidDecl();
2051 }
2052
2053 ActOnDocumentableDecl(NewTemplate);
2054
2055 if (SkipBody && SkipBody->ShouldSkip)
2056 return SkipBody->Previous;
2057
2058 return NewTemplate;
2059}
2060
2061namespace {
2062/// Tree transform to "extract" a transformed type from a class template's
2063/// constructor to a deduction guide.
2064class ExtractTypeForDeductionGuide
2065 : public TreeTransform<ExtractTypeForDeductionGuide> {
2066 llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs;
2067
2068public:
2069 typedef TreeTransform<ExtractTypeForDeductionGuide> Base;
2070 ExtractTypeForDeductionGuide(
2071 Sema &SemaRef,
2072 llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs)
2073 : Base(SemaRef), MaterializedTypedefs(MaterializedTypedefs) {}
2074
2075 TypeSourceInfo *transform(TypeSourceInfo *TSI) { return TransformType(TSI); }
2076
2077 QualType TransformTypedefType(TypeLocBuilder &TLB, TypedefTypeLoc TL) {
2078 ASTContext &Context = SemaRef.getASTContext();
2079 TypedefNameDecl *OrigDecl = TL.getTypedefNameDecl();
2080 TypeLocBuilder InnerTLB;
2081 QualType Transformed =
2082 TransformType(InnerTLB, OrigDecl->getTypeSourceInfo()->getTypeLoc());
2083 TypeSourceInfo *TSI =
2084 TransformType(InnerTLB.getTypeSourceInfo(Context, Transformed));
2085
2086 TypedefNameDecl *Decl = nullptr;
2087
2088 if (isa<TypeAliasDecl>(OrigDecl))
2089 Decl = TypeAliasDecl::Create(
2090 Context, Context.getTranslationUnitDecl(), OrigDecl->getBeginLoc(),
2091 OrigDecl->getLocation(), OrigDecl->getIdentifier(), TSI);
2092 else {
2093 assert(isa<TypedefDecl>(OrigDecl) && "Not a Type alias or typedef")((isa<TypedefDecl>(OrigDecl) && "Not a Type alias or typedef"
) ? static_cast<void> (0) : __assert_fail ("isa<TypedefDecl>(OrigDecl) && \"Not a Type alias or typedef\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2093, __PRETTY_FUNCTION__))
;
2094 Decl = TypedefDecl::Create(
2095 Context, Context.getTranslationUnitDecl(), OrigDecl->getBeginLoc(),
2096 OrigDecl->getLocation(), OrigDecl->getIdentifier(), TSI);
2097 }
2098
2099 MaterializedTypedefs.push_back(Decl);
2100
2101 QualType TDTy = Context.getTypedefType(Decl);
2102 TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(TDTy);
2103 TypedefTL.setNameLoc(TL.getNameLoc());
2104
2105 return TDTy;
2106 }
2107};
2108
2109/// Transform to convert portions of a constructor declaration into the
2110/// corresponding deduction guide, per C++1z [over.match.class.deduct]p1.
2111struct ConvertConstructorToDeductionGuideTransform {
2112 ConvertConstructorToDeductionGuideTransform(Sema &S,
2113 ClassTemplateDecl *Template)
2114 : SemaRef(S), Template(Template) {}
2115
2116 Sema &SemaRef;
2117 ClassTemplateDecl *Template;
2118
2119 DeclContext *DC = Template->getDeclContext();
2120 CXXRecordDecl *Primary = Template->getTemplatedDecl();
2121 DeclarationName DeductionGuideName =
2122 SemaRef.Context.DeclarationNames.getCXXDeductionGuideName(Template);
2123
2124 QualType DeducedType = SemaRef.Context.getTypeDeclType(Primary);
2125
2126 // Index adjustment to apply to convert depth-1 template parameters into
2127 // depth-0 template parameters.
2128 unsigned Depth1IndexAdjustment = Template->getTemplateParameters()->size();
2129
2130 /// Transform a constructor declaration into a deduction guide.
2131 NamedDecl *transformConstructor(FunctionTemplateDecl *FTD,
2132 CXXConstructorDecl *CD) {
2133 SmallVector<TemplateArgument, 16> SubstArgs;
2134
2135 LocalInstantiationScope Scope(SemaRef);
2136
2137 // C++ [over.match.class.deduct]p1:
2138 // -- For each constructor of the class template designated by the
2139 // template-name, a function template with the following properties:
2140
2141 // -- The template parameters are the template parameters of the class
2142 // template followed by the template parameters (including default
2143 // template arguments) of the constructor, if any.
2144 TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2145 if (FTD) {
2146 TemplateParameterList *InnerParams = FTD->getTemplateParameters();
2147 SmallVector<NamedDecl *, 16> AllParams;
2148 AllParams.reserve(TemplateParams->size() + InnerParams->size());
2149 AllParams.insert(AllParams.begin(),
2150 TemplateParams->begin(), TemplateParams->end());
2151 SubstArgs.reserve(InnerParams->size());
2152
2153 // Later template parameters could refer to earlier ones, so build up
2154 // a list of substituted template arguments as we go.
2155 for (NamedDecl *Param : *InnerParams) {
2156 MultiLevelTemplateArgumentList Args;
2157 Args.setKind(TemplateSubstitutionKind::Rewrite);
2158 Args.addOuterTemplateArguments(SubstArgs);
2159 Args.addOuterRetainedLevel();
2160 NamedDecl *NewParam = transformTemplateParameter(Param, Args);
2161 if (!NewParam)
2162 return nullptr;
2163 AllParams.push_back(NewParam);
2164 SubstArgs.push_back(SemaRef.Context.getCanonicalTemplateArgument(
2165 SemaRef.Context.getInjectedTemplateArg(NewParam)));
2166 }
2167 TemplateParams = TemplateParameterList::Create(
2168 SemaRef.Context, InnerParams->getTemplateLoc(),
2169 InnerParams->getLAngleLoc(), AllParams, InnerParams->getRAngleLoc(),
2170 /*FIXME: RequiresClause*/ nullptr);
2171 }
2172
2173 // If we built a new template-parameter-list, track that we need to
2174 // substitute references to the old parameters into references to the
2175 // new ones.
2176 MultiLevelTemplateArgumentList Args;
2177 Args.setKind(TemplateSubstitutionKind::Rewrite);
2178 if (FTD) {
2179 Args.addOuterTemplateArguments(SubstArgs);
2180 Args.addOuterRetainedLevel();
2181 }
2182
2183 FunctionProtoTypeLoc FPTL = CD->getTypeSourceInfo()->getTypeLoc()
2184 .getAsAdjusted<FunctionProtoTypeLoc>();
2185 assert(FPTL && "no prototype for constructor declaration")((FPTL && "no prototype for constructor declaration")
? static_cast<void> (0) : __assert_fail ("FPTL && \"no prototype for constructor declaration\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2185, __PRETTY_FUNCTION__))
;
2186
2187 // Transform the type of the function, adjusting the return type and
2188 // replacing references to the old parameters with references to the
2189 // new ones.
2190 TypeLocBuilder TLB;
2191 SmallVector<ParmVarDecl*, 8> Params;
2192 SmallVector<TypedefNameDecl *, 4> MaterializedTypedefs;
2193 QualType NewType = transformFunctionProtoType(TLB, FPTL, Params, Args,
2194 MaterializedTypedefs);
2195 if (NewType.isNull())
2196 return nullptr;
2197 TypeSourceInfo *NewTInfo = TLB.getTypeSourceInfo(SemaRef.Context, NewType);
2198
2199 return buildDeductionGuide(TemplateParams, CD->getExplicitSpecifier(),
2200 NewTInfo, CD->getBeginLoc(), CD->getLocation(),
2201 CD->getEndLoc(), MaterializedTypedefs);
2202 }
2203
2204 /// Build a deduction guide with the specified parameter types.
2205 NamedDecl *buildSimpleDeductionGuide(MutableArrayRef<QualType> ParamTypes) {
2206 SourceLocation Loc = Template->getLocation();
2207
2208 // Build the requested type.
2209 FunctionProtoType::ExtProtoInfo EPI;
2210 EPI.HasTrailingReturn = true;
2211 QualType Result = SemaRef.BuildFunctionType(DeducedType, ParamTypes, Loc,
2212 DeductionGuideName, EPI);
2213 TypeSourceInfo *TSI = SemaRef.Context.getTrivialTypeSourceInfo(Result, Loc);
2214
2215 FunctionProtoTypeLoc FPTL =
2216 TSI->getTypeLoc().castAs<FunctionProtoTypeLoc>();
2217
2218 // Build the parameters, needed during deduction / substitution.
2219 SmallVector<ParmVarDecl*, 4> Params;
2220 for (auto T : ParamTypes) {
2221 ParmVarDecl *NewParam = ParmVarDecl::Create(
2222 SemaRef.Context, DC, Loc, Loc, nullptr, T,
2223 SemaRef.Context.getTrivialTypeSourceInfo(T, Loc), SC_None, nullptr);
2224 NewParam->setScopeInfo(0, Params.size());
2225 FPTL.setParam(Params.size(), NewParam);
2226 Params.push_back(NewParam);
2227 }
2228
2229 return buildDeductionGuide(Template->getTemplateParameters(),
2230 ExplicitSpecifier(), TSI, Loc, Loc, Loc);
2231 }
2232
2233private:
2234 /// Transform a constructor template parameter into a deduction guide template
2235 /// parameter, rebuilding any internal references to earlier parameters and
2236 /// renumbering as we go.
2237 NamedDecl *transformTemplateParameter(NamedDecl *TemplateParam,
2238 MultiLevelTemplateArgumentList &Args) {
2239 if (auto *TTP = dyn_cast<TemplateTypeParmDecl>(TemplateParam)) {
2240 // TemplateTypeParmDecl's index cannot be changed after creation, so
2241 // substitute it directly.
2242 auto *NewTTP = TemplateTypeParmDecl::Create(
2243 SemaRef.Context, DC, TTP->getBeginLoc(), TTP->getLocation(),
2244 /*Depth*/ 0, Depth1IndexAdjustment + TTP->getIndex(),
2245 TTP->getIdentifier(), TTP->wasDeclaredWithTypename(),
2246 TTP->isParameterPack(), TTP->hasTypeConstraint(),
2247 TTP->isExpandedParameterPack() ?
2248 llvm::Optional<unsigned>(TTP->getNumExpansionParameters()) : None);
2249 if (const auto *TC = TTP->getTypeConstraint()) {
2250 TemplateArgumentListInfo TransformedArgs;
2251 const auto *ArgsAsWritten = TC->getTemplateArgsAsWritten();
2252 if (!ArgsAsWritten ||
2253 SemaRef.Subst(ArgsAsWritten->getTemplateArgs(),
2254 ArgsAsWritten->NumTemplateArgs, TransformedArgs,
2255 Args))
2256 SemaRef.AttachTypeConstraint(
2257 TC->getNestedNameSpecifierLoc(), TC->getConceptNameInfo(),
2258 TC->getNamedConcept(), ArgsAsWritten ? &TransformedArgs : nullptr,
2259 NewTTP,
2260 NewTTP->isParameterPack()
2261 ? cast<CXXFoldExpr>(TC->getImmediatelyDeclaredConstraint())
2262 ->getEllipsisLoc()
2263 : SourceLocation());
2264 }
2265 if (TTP->hasDefaultArgument()) {
2266 TypeSourceInfo *InstantiatedDefaultArg =
2267 SemaRef.SubstType(TTP->getDefaultArgumentInfo(), Args,
2268 TTP->getDefaultArgumentLoc(), TTP->getDeclName());
2269 if (InstantiatedDefaultArg)
2270 NewTTP->setDefaultArgument(InstantiatedDefaultArg);
2271 }
2272 SemaRef.CurrentInstantiationScope->InstantiatedLocal(TemplateParam,
2273 NewTTP);
2274 return NewTTP;
2275 }
2276
2277 if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(TemplateParam))
2278 return transformTemplateParameterImpl(TTP, Args);
2279
2280 return transformTemplateParameterImpl(
2281 cast<NonTypeTemplateParmDecl>(TemplateParam), Args);
2282 }
2283 template<typename TemplateParmDecl>
2284 TemplateParmDecl *
2285 transformTemplateParameterImpl(TemplateParmDecl *OldParam,
2286 MultiLevelTemplateArgumentList &Args) {
2287 // Ask the template instantiator to do the heavy lifting for us, then adjust
2288 // the index of the parameter once it's done.
2289 auto *NewParam =
2290 cast<TemplateParmDecl>(SemaRef.SubstDecl(OldParam, DC, Args));
2291 assert(NewParam->getDepth() == 0 && "unexpected template param depth")((NewParam->getDepth() == 0 && "unexpected template param depth"
) ? static_cast<void> (0) : __assert_fail ("NewParam->getDepth() == 0 && \"unexpected template param depth\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2291, __PRETTY_FUNCTION__))
;
2292 NewParam->setPosition(NewParam->getPosition() + Depth1IndexAdjustment);
2293 return NewParam;
2294 }
2295
2296 QualType transformFunctionProtoType(
2297 TypeLocBuilder &TLB, FunctionProtoTypeLoc TL,
2298 SmallVectorImpl<ParmVarDecl *> &Params,
2299 MultiLevelTemplateArgumentList &Args,
2300 SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs) {
2301 SmallVector<QualType, 4> ParamTypes;
2302 const FunctionProtoType *T = TL.getTypePtr();
2303
2304 // -- The types of the function parameters are those of the constructor.
2305 for (auto *OldParam : TL.getParams()) {
2306 ParmVarDecl *NewParam =
2307 transformFunctionTypeParam(OldParam, Args, MaterializedTypedefs);
2308 if (!NewParam)
2309 return QualType();
2310 ParamTypes.push_back(NewParam->getType());
2311 Params.push_back(NewParam);
2312 }
2313
2314 // -- The return type is the class template specialization designated by
2315 // the template-name and template arguments corresponding to the
2316 // template parameters obtained from the class template.
2317 //
2318 // We use the injected-class-name type of the primary template instead.
2319 // This has the convenient property that it is different from any type that
2320 // the user can write in a deduction-guide (because they cannot enter the
2321 // context of the template), so implicit deduction guides can never collide
2322 // with explicit ones.
2323 QualType ReturnType = DeducedType;
2324 TLB.pushTypeSpec(ReturnType).setNameLoc(Primary->getLocation());
2325
2326 // Resolving a wording defect, we also inherit the variadicness of the
2327 // constructor.
2328 FunctionProtoType::ExtProtoInfo EPI;
2329 EPI.Variadic = T->isVariadic();
2330 EPI.HasTrailingReturn = true;
2331
2332 QualType Result = SemaRef.BuildFunctionType(
2333 ReturnType, ParamTypes, TL.getBeginLoc(), DeductionGuideName, EPI);
2334 if (Result.isNull())
2335 return QualType();
2336
2337 FunctionProtoTypeLoc NewTL = TLB.push<FunctionProtoTypeLoc>(Result);
2338 NewTL.setLocalRangeBegin(TL.getLocalRangeBegin());
2339 NewTL.setLParenLoc(TL.getLParenLoc());
2340 NewTL.setRParenLoc(TL.getRParenLoc());
2341 NewTL.setExceptionSpecRange(SourceRange());
2342 NewTL.setLocalRangeEnd(TL.getLocalRangeEnd());
2343 for (unsigned I = 0, E = NewTL.getNumParams(); I != E; ++I)
2344 NewTL.setParam(I, Params[I]);
2345
2346 return Result;
2347 }
2348
2349 ParmVarDecl *transformFunctionTypeParam(
2350 ParmVarDecl *OldParam, MultiLevelTemplateArgumentList &Args,
2351 llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs) {
2352 TypeSourceInfo *OldDI = OldParam->getTypeSourceInfo();
2353 TypeSourceInfo *NewDI;
2354 if (auto PackTL = OldDI->getTypeLoc().getAs<PackExpansionTypeLoc>()) {
2355 // Expand out the one and only element in each inner pack.
2356 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, 0);
2357 NewDI =
2358 SemaRef.SubstType(PackTL.getPatternLoc(), Args,
2359 OldParam->getLocation(), OldParam->getDeclName());
2360 if (!NewDI) return nullptr;
2361 NewDI =
2362 SemaRef.CheckPackExpansion(NewDI, PackTL.getEllipsisLoc(),
2363 PackTL.getTypePtr()->getNumExpansions());
2364 } else
2365 NewDI = SemaRef.SubstType(OldDI, Args, OldParam->getLocation(),
2366 OldParam->getDeclName());
2367 if (!NewDI)
2368 return nullptr;
2369
2370 // Extract the type. This (for instance) replaces references to typedef
2371 // members of the current instantiations with the definitions of those
2372 // typedefs, avoiding triggering instantiation of the deduced type during
2373 // deduction.
2374 NewDI = ExtractTypeForDeductionGuide(SemaRef, MaterializedTypedefs)
2375 .transform(NewDI);
2376
2377 // Resolving a wording defect, we also inherit default arguments from the
2378 // constructor.
2379 ExprResult NewDefArg;
2380 if (OldParam->hasDefaultArg()) {
2381 // We don't care what the value is (we won't use it); just create a
2382 // placeholder to indicate there is a default argument.
2383 QualType ParamTy = NewDI->getType();
2384 NewDefArg = new (SemaRef.Context)
2385 OpaqueValueExpr(OldParam->getDefaultArg()->getBeginLoc(),
2386 ParamTy.getNonLValueExprType(SemaRef.Context),
2387 ParamTy->isLValueReferenceType() ? VK_LValue :
2388 ParamTy->isRValueReferenceType() ? VK_XValue :
2389 VK_RValue);
2390 }
2391
2392 ParmVarDecl *NewParam = ParmVarDecl::Create(SemaRef.Context, DC,
2393 OldParam->getInnerLocStart(),
2394 OldParam->getLocation(),
2395 OldParam->getIdentifier(),
2396 NewDI->getType(),
2397 NewDI,
2398 OldParam->getStorageClass(),
2399 NewDefArg.get());
2400 NewParam->setScopeInfo(OldParam->getFunctionScopeDepth(),
2401 OldParam->getFunctionScopeIndex());
2402 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldParam, NewParam);
2403 return NewParam;
2404 }
2405
2406 FunctionTemplateDecl *buildDeductionGuide(
2407 TemplateParameterList *TemplateParams, ExplicitSpecifier ES,
2408 TypeSourceInfo *TInfo, SourceLocation LocStart, SourceLocation Loc,
2409 SourceLocation LocEnd,
2410 llvm::ArrayRef<TypedefNameDecl *> MaterializedTypedefs = {}) {
2411 DeclarationNameInfo Name(DeductionGuideName, Loc);
2412 ArrayRef<ParmVarDecl *> Params =
2413 TInfo->getTypeLoc().castAs<FunctionProtoTypeLoc>().getParams();
2414
2415 // Build the implicit deduction guide template.
2416 auto *Guide =
2417 CXXDeductionGuideDecl::Create(SemaRef.Context, DC, LocStart, ES, Name,
2418 TInfo->getType(), TInfo, LocEnd);
2419 Guide->setImplicit();
2420 Guide->setParams(Params);
2421
2422 for (auto *Param : Params)
2423 Param->setDeclContext(Guide);
2424 for (auto *TD : MaterializedTypedefs)
2425 TD->setDeclContext(Guide);
2426
2427 auto *GuideTemplate = FunctionTemplateDecl::Create(
2428 SemaRef.Context, DC, Loc, DeductionGuideName, TemplateParams, Guide);
2429 GuideTemplate->setImplicit();
2430 Guide->setDescribedFunctionTemplate(GuideTemplate);
2431
2432 if (isa<CXXRecordDecl>(DC)) {
2433 Guide->setAccess(AS_public);
2434 GuideTemplate->setAccess(AS_public);
2435 }
2436
2437 DC->addDecl(GuideTemplate);
2438 return GuideTemplate;
2439 }
2440};
2441}
2442
2443void Sema::DeclareImplicitDeductionGuides(TemplateDecl *Template,
2444 SourceLocation Loc) {
2445 if (CXXRecordDecl *DefRecord =
2446 cast<CXXRecordDecl>(Template->getTemplatedDecl())->getDefinition()) {
2447 TemplateDecl *DescribedTemplate = DefRecord->getDescribedClassTemplate();
2448 Template = DescribedTemplate ? DescribedTemplate : Template;
2449 }
2450
2451 DeclContext *DC = Template->getDeclContext();
2452 if (DC->isDependentContext())
2453 return;
2454
2455 ConvertConstructorToDeductionGuideTransform Transform(
2456 *this, cast<ClassTemplateDecl>(Template));
2457 if (!isCompleteType(Loc, Transform.DeducedType))
2458 return;
2459
2460 // Check whether we've already declared deduction guides for this template.
2461 // FIXME: Consider storing a flag on the template to indicate this.
2462 auto Existing = DC->lookup(Transform.DeductionGuideName);
2463 for (auto *D : Existing)
2464 if (D->isImplicit())
2465 return;
2466
2467 // In case we were expanding a pack when we attempted to declare deduction
2468 // guides, turn off pack expansion for everything we're about to do.
2469 ArgumentPackSubstitutionIndexRAII SubstIndex(*this, -1);
2470 // Create a template instantiation record to track the "instantiation" of
2471 // constructors into deduction guides.
2472 // FIXME: Add a kind for this to give more meaningful diagnostics. But can
2473 // this substitution process actually fail?
2474 InstantiatingTemplate BuildingDeductionGuides(*this, Loc, Template);
2475 if (BuildingDeductionGuides.isInvalid())
2476 return;
2477
2478 // Convert declared constructors into deduction guide templates.
2479 // FIXME: Skip constructors for which deduction must necessarily fail (those
2480 // for which some class template parameter without a default argument never
2481 // appears in a deduced context).
2482 bool AddedAny = false;
2483 for (NamedDecl *D : LookupConstructors(Transform.Primary)) {
2484 D = D->getUnderlyingDecl();
2485 if (D->isInvalidDecl() || D->isImplicit())
2486 continue;
2487 D = cast<NamedDecl>(D->getCanonicalDecl());
2488
2489 auto *FTD = dyn_cast<FunctionTemplateDecl>(D);
2490 auto *CD =
2491 dyn_cast_or_null<CXXConstructorDecl>(FTD ? FTD->getTemplatedDecl() : D);
2492 // Class-scope explicit specializations (MS extension) do not result in
2493 // deduction guides.
2494 if (!CD || (!FTD && CD->isFunctionTemplateSpecialization()))
2495 continue;
2496
2497 Transform.transformConstructor(FTD, CD);
2498 AddedAny = true;
2499 }
2500
2501 // C++17 [over.match.class.deduct]
2502 // -- If C is not defined or does not declare any constructors, an
2503 // additional function template derived as above from a hypothetical
2504 // constructor C().
2505 if (!AddedAny)
2506 Transform.buildSimpleDeductionGuide(None);
2507
2508 // -- An additional function template derived as above from a hypothetical
2509 // constructor C(C), called the copy deduction candidate.
2510 cast<CXXDeductionGuideDecl>(
2511 cast<FunctionTemplateDecl>(
2512 Transform.buildSimpleDeductionGuide(Transform.DeducedType))
2513 ->getTemplatedDecl())
2514 ->setIsCopyDeductionCandidate();
2515}
2516
2517/// Diagnose the presence of a default template argument on a
2518/// template parameter, which is ill-formed in certain contexts.
2519///
2520/// \returns true if the default template argument should be dropped.
2521static bool DiagnoseDefaultTemplateArgument(Sema &S,
2522 Sema::TemplateParamListContext TPC,
2523 SourceLocation ParamLoc,
2524 SourceRange DefArgRange) {
2525 switch (TPC) {
2526 case Sema::TPC_ClassTemplate:
2527 case Sema::TPC_VarTemplate:
2528 case Sema::TPC_TypeAliasTemplate:
2529 return false;
2530
2531 case Sema::TPC_FunctionTemplate:
2532 case Sema::TPC_FriendFunctionTemplateDefinition:
2533 // C++ [temp.param]p9:
2534 // A default template-argument shall not be specified in a
2535 // function template declaration or a function template
2536 // definition [...]
2537 // If a friend function template declaration specifies a default
2538 // template-argument, that declaration shall be a definition and shall be
2539 // the only declaration of the function template in the translation unit.
2540 // (C++98/03 doesn't have this wording; see DR226).
2541 S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ?
2542 diag::warn_cxx98_compat_template_parameter_default_in_function_template
2543 : diag::ext_template_parameter_default_in_function_template)
2544 << DefArgRange;
2545 return false;
2546
2547 case Sema::TPC_ClassTemplateMember:
2548 // C++0x [temp.param]p9:
2549 // A default template-argument shall not be specified in the
2550 // template-parameter-lists of the definition of a member of a
2551 // class template that appears outside of the member's class.
2552 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
2553 << DefArgRange;
2554 return true;
2555
2556 case Sema::TPC_FriendClassTemplate:
2557 case Sema::TPC_FriendFunctionTemplate:
2558 // C++ [temp.param]p9:
2559 // A default template-argument shall not be specified in a
2560 // friend template declaration.
2561 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
2562 << DefArgRange;
2563 return true;
2564
2565 // FIXME: C++0x [temp.param]p9 allows default template-arguments
2566 // for friend function templates if there is only a single
2567 // declaration (and it is a definition). Strange!
2568 }
2569
2570 llvm_unreachable("Invalid TemplateParamListContext!")::llvm::llvm_unreachable_internal("Invalid TemplateParamListContext!"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2570)
;
2571}
2572
2573/// Check for unexpanded parameter packs within the template parameters
2574/// of a template template parameter, recursively.
2575static bool DiagnoseUnexpandedParameterPacks(Sema &S,
2576 TemplateTemplateParmDecl *TTP) {
2577 // A template template parameter which is a parameter pack is also a pack
2578 // expansion.
2579 if (TTP->isParameterPack())
2580 return false;
2581
2582 TemplateParameterList *Params = TTP->getTemplateParameters();
2583 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
2584 NamedDecl *P = Params->getParam(I);
2585 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(P)) {
2586 if (!TTP->isParameterPack())
2587 if (const TypeConstraint *TC = TTP->getTypeConstraint())
2588 if (TC->hasExplicitTemplateArgs())
2589 for (auto &ArgLoc : TC->getTemplateArgsAsWritten()->arguments())
2590 if (S.DiagnoseUnexpandedParameterPack(ArgLoc,
2591 Sema::UPPC_TypeConstraint))
2592 return true;
2593 continue;
2594 }
2595
2596 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
2597 if (!NTTP->isParameterPack() &&
2598 S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
2599 NTTP->getTypeSourceInfo(),
2600 Sema::UPPC_NonTypeTemplateParameterType))
2601 return true;
2602
2603 continue;
2604 }
2605
2606 if (TemplateTemplateParmDecl *InnerTTP
2607 = dyn_cast<TemplateTemplateParmDecl>(P))
2608 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
2609 return true;
2610 }
2611
2612 return false;
2613}
2614
2615/// Checks the validity of a template parameter list, possibly
2616/// considering the template parameter list from a previous
2617/// declaration.
2618///
2619/// If an "old" template parameter list is provided, it must be
2620/// equivalent (per TemplateParameterListsAreEqual) to the "new"
2621/// template parameter list.
2622///
2623/// \param NewParams Template parameter list for a new template
2624/// declaration. This template parameter list will be updated with any
2625/// default arguments that are carried through from the previous
2626/// template parameter list.
2627///
2628/// \param OldParams If provided, template parameter list from a
2629/// previous declaration of the same template. Default template
2630/// arguments will be merged from the old template parameter list to
2631/// the new template parameter list.
2632///
2633/// \param TPC Describes the context in which we are checking the given
2634/// template parameter list.
2635///
2636/// \param SkipBody If we might have already made a prior merged definition
2637/// of this template visible, the corresponding body-skipping information.
2638/// Default argument redefinition is not an error when skipping such a body,
2639/// because (under the ODR) we can assume the default arguments are the same
2640/// as the prior merged definition.
2641///
2642/// \returns true if an error occurred, false otherwise.
2643bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
2644 TemplateParameterList *OldParams,
2645 TemplateParamListContext TPC,
2646 SkipBodyInfo *SkipBody) {
2647 bool Invalid = false;
2648
2649 // C++ [temp.param]p10:
2650 // The set of default template-arguments available for use with a
2651 // template declaration or definition is obtained by merging the
2652 // default arguments from the definition (if in scope) and all
2653 // declarations in scope in the same way default function
2654 // arguments are (8.3.6).
2655 bool SawDefaultArgument = false;
2656 SourceLocation PreviousDefaultArgLoc;
2657
2658 // Dummy initialization to avoid warnings.
2659 TemplateParameterList::iterator OldParam = NewParams->end();
2660 if (OldParams)
2661 OldParam = OldParams->begin();
2662
2663 bool RemoveDefaultArguments = false;
2664 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
2665 NewParamEnd = NewParams->end();
2666 NewParam != NewParamEnd; ++NewParam) {
2667 // Variables used to diagnose redundant default arguments
2668 bool RedundantDefaultArg = false;
2669 SourceLocation OldDefaultLoc;
2670 SourceLocation NewDefaultLoc;
2671
2672 // Variable used to diagnose missing default arguments
2673 bool MissingDefaultArg = false;
2674
2675 // Variable used to diagnose non-final parameter packs
2676 bool SawParameterPack = false;
2677
2678 if (TemplateTypeParmDecl *NewTypeParm
2679 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
2680 // Check the presence of a default argument here.
2681 if (NewTypeParm->hasDefaultArgument() &&
2682 DiagnoseDefaultTemplateArgument(*this, TPC,
2683 NewTypeParm->getLocation(),
2684 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
2685 .getSourceRange()))
2686 NewTypeParm->removeDefaultArgument();
2687
2688 // Merge default arguments for template type parameters.
2689 TemplateTypeParmDecl *OldTypeParm
2690 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr;
2691 if (NewTypeParm->isParameterPack()) {
2692 assert(!NewTypeParm->hasDefaultArgument() &&((!NewTypeParm->hasDefaultArgument() && "Parameter packs can't have a default argument!"
) ? static_cast<void> (0) : __assert_fail ("!NewTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2693, __PRETTY_FUNCTION__))
2693 "Parameter packs can't have a default argument!")((!NewTypeParm->hasDefaultArgument() && "Parameter packs can't have a default argument!"
) ? static_cast<void> (0) : __assert_fail ("!NewTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2693, __PRETTY_FUNCTION__))
;
2694 SawParameterPack = true;
2695 } else if (OldTypeParm && hasVisibleDefaultArgument(OldTypeParm) &&
2696 NewTypeParm->hasDefaultArgument() &&
2697 (!SkipBody || !SkipBody->ShouldSkip)) {
2698 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
2699 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
2700 SawDefaultArgument = true;
2701 RedundantDefaultArg = true;
2702 PreviousDefaultArgLoc = NewDefaultLoc;
2703 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) {
2704 // Merge the default argument from the old declaration to the
2705 // new declaration.
2706 NewTypeParm->setInheritedDefaultArgument(Context, OldTypeParm);
2707 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
2708 } else if (NewTypeParm->hasDefaultArgument()) {
2709 SawDefaultArgument = true;
2710 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
2711 } else if (SawDefaultArgument)
2712 MissingDefaultArg = true;
2713 } else if (NonTypeTemplateParmDecl *NewNonTypeParm
2714 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
2715 // Check for unexpanded parameter packs.
2716 if (!NewNonTypeParm->isParameterPack() &&
2717 DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
2718 NewNonTypeParm->getTypeSourceInfo(),
2719 UPPC_NonTypeTemplateParameterType)) {
2720 Invalid = true;
2721 continue;
2722 }
2723
2724 // Check the presence of a default argument here.
2725 if (NewNonTypeParm->hasDefaultArgument() &&
2726 DiagnoseDefaultTemplateArgument(*this, TPC,
2727 NewNonTypeParm->getLocation(),
2728 NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
2729 NewNonTypeParm->removeDefaultArgument();
2730 }
2731
2732 // Merge default arguments for non-type template parameters
2733 NonTypeTemplateParmDecl *OldNonTypeParm
2734 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr;
2735 if (NewNonTypeParm->isParameterPack()) {
2736 assert(!NewNonTypeParm->hasDefaultArgument() &&((!NewNonTypeParm->hasDefaultArgument() && "Parameter packs can't have a default argument!"
) ? static_cast<void> (0) : __assert_fail ("!NewNonTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2737, __PRETTY_FUNCTION__))
2737 "Parameter packs can't have a default argument!")((!NewNonTypeParm->hasDefaultArgument() && "Parameter packs can't have a default argument!"
) ? static_cast<void> (0) : __assert_fail ("!NewNonTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2737, __PRETTY_FUNCTION__))
;
2738 if (!NewNonTypeParm->isPackExpansion())
2739 SawParameterPack = true;
2740 } else if (OldNonTypeParm && hasVisibleDefaultArgument(OldNonTypeParm) &&
2741 NewNonTypeParm->hasDefaultArgument() &&
2742 (!SkipBody || !SkipBody->ShouldSkip)) {
2743 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
2744 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
2745 SawDefaultArgument = true;
2746 RedundantDefaultArg = true;
2747 PreviousDefaultArgLoc = NewDefaultLoc;
2748 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) {
2749 // Merge the default argument from the old declaration to the
2750 // new declaration.
2751 NewNonTypeParm->setInheritedDefaultArgument(Context, OldNonTypeParm);
2752 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
2753 } else if (NewNonTypeParm->hasDefaultArgument()) {
2754 SawDefaultArgument = true;
2755 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
2756 } else if (SawDefaultArgument)
2757 MissingDefaultArg = true;
2758 } else {
2759 TemplateTemplateParmDecl *NewTemplateParm
2760 = cast<TemplateTemplateParmDecl>(*NewParam);
2761
2762 // Check for unexpanded parameter packs, recursively.
2763 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
2764 Invalid = true;
2765 continue;
2766 }
2767
2768 // Check the presence of a default argument here.
2769 if (NewTemplateParm->hasDefaultArgument() &&
2770 DiagnoseDefaultTemplateArgument(*this, TPC,
2771 NewTemplateParm->getLocation(),
2772 NewTemplateParm->getDefaultArgument().getSourceRange()))
2773 NewTemplateParm->removeDefaultArgument();
2774
2775 // Merge default arguments for template template parameters
2776 TemplateTemplateParmDecl *OldTemplateParm
2777 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr;
2778 if (NewTemplateParm->isParameterPack()) {
2779 assert(!NewTemplateParm->hasDefaultArgument() &&((!NewTemplateParm->hasDefaultArgument() && "Parameter packs can't have a default argument!"
) ? static_cast<void> (0) : __assert_fail ("!NewTemplateParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2780, __PRETTY_FUNCTION__))
2780 "Parameter packs can't have a default argument!")((!NewTemplateParm->hasDefaultArgument() && "Parameter packs can't have a default argument!"
) ? static_cast<void> (0) : __assert_fail ("!NewTemplateParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 2780, __PRETTY_FUNCTION__))
;
2781 if (!NewTemplateParm->isPackExpansion())
2782 SawParameterPack = true;
2783 } else if (OldTemplateParm &&
2784 hasVisibleDefaultArgument(OldTemplateParm) &&
2785 NewTemplateParm->hasDefaultArgument() &&
2786 (!SkipBody || !SkipBody->ShouldSkip)) {
2787 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
2788 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
2789 SawDefaultArgument = true;
2790 RedundantDefaultArg = true;
2791 PreviousDefaultArgLoc = NewDefaultLoc;
2792 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) {
2793 // Merge the default argument from the old declaration to the
2794 // new declaration.
2795 NewTemplateParm->setInheritedDefaultArgument(Context, OldTemplateParm);
2796 PreviousDefaultArgLoc
2797 = OldTemplateParm->getDefaultArgument().getLocation();
2798 } else if (NewTemplateParm->hasDefaultArgument()) {
2799 SawDefaultArgument = true;
2800 PreviousDefaultArgLoc
2801 = NewTemplateParm->getDefaultArgument().getLocation();
2802 } else if (SawDefaultArgument)
2803 MissingDefaultArg = true;
2804 }
2805
2806 // C++11 [temp.param]p11:
2807 // If a template parameter of a primary class template or alias template
2808 // is a template parameter pack, it shall be the last template parameter.
2809 if (SawParameterPack && (NewParam + 1) != NewParamEnd &&
2810 (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate ||
2811 TPC == TPC_TypeAliasTemplate)) {
2812 Diag((*NewParam)->getLocation(),
2813 diag::err_template_param_pack_must_be_last_template_parameter);
2814 Invalid = true;
2815 }
2816
2817 if (RedundantDefaultArg) {
2818 // C++ [temp.param]p12:
2819 // A template-parameter shall not be given default arguments
2820 // by two different declarations in the same scope.
2821 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
2822 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
2823 Invalid = true;
2824 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) {
2825 // C++ [temp.param]p11:
2826 // If a template-parameter of a class template has a default
2827 // template-argument, each subsequent template-parameter shall either
2828 // have a default template-argument supplied or be a template parameter
2829 // pack.
2830 Diag((*NewParam)->getLocation(),
2831 diag::err_template_param_default_arg_missing);
2832 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
2833 Invalid = true;
2834 RemoveDefaultArguments = true;
2835 }
2836
2837 // If we have an old template parameter list that we're merging
2838 // in, move on to the next parameter.
2839 if (OldParams)
2840 ++OldParam;
2841 }
2842
2843 // We were missing some default arguments at the end of the list, so remove
2844 // all of the default arguments.
2845 if (RemoveDefaultArguments) {
2846 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
2847 NewParamEnd = NewParams->end();
2848 NewParam != NewParamEnd; ++NewParam) {
2849 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
2850 TTP->removeDefaultArgument();
2851 else if (NonTypeTemplateParmDecl *NTTP
2852 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
2853 NTTP->removeDefaultArgument();
2854 else
2855 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
2856 }
2857 }
2858
2859 return Invalid;
2860}
2861
2862namespace {
2863
2864/// A class which looks for a use of a certain level of template
2865/// parameter.
2866struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
2867 typedef RecursiveASTVisitor<DependencyChecker> super;
2868
2869 unsigned Depth;
2870
2871 // Whether we're looking for a use of a template parameter that makes the
2872 // overall construct type-dependent / a dependent type. This is strictly
2873 // best-effort for now; we may fail to match at all for a dependent type
2874 // in some cases if this is set.
2875 bool IgnoreNonTypeDependent;
2876
2877 bool Match;
2878 SourceLocation MatchLoc;
2879
2880 DependencyChecker(unsigned Depth, bool IgnoreNonTypeDependent)
2881 : Depth(Depth), IgnoreNonTypeDependent(IgnoreNonTypeDependent),
2882 Match(false) {}
2883
2884 DependencyChecker(TemplateParameterList *Params, bool IgnoreNonTypeDependent)
2885 : IgnoreNonTypeDependent(IgnoreNonTypeDependent), Match(false) {
2886 NamedDecl *ND = Params->getParam(0);
2887 if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) {
2888 Depth = PD->getDepth();
2889 } else if (NonTypeTemplateParmDecl *PD =
2890 dyn_cast<NonTypeTemplateParmDecl>(ND)) {
2891 Depth = PD->getDepth();
2892 } else {
2893 Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth();
2894 }
2895 }
2896
2897 bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) {
2898 if (ParmDepth >= Depth) {
2899 Match = true;
2900 MatchLoc = Loc;
2901 return true;
2902 }
2903 return false;
2904 }
2905
2906 bool TraverseStmt(Stmt *S, DataRecursionQueue *Q = nullptr) {
2907 // Prune out non-type-dependent expressions if requested. This can
2908 // sometimes result in us failing to find a template parameter reference
2909 // (if a value-dependent expression creates a dependent type), but this
2910 // mode is best-effort only.
2911 if (auto *E = dyn_cast_or_null<Expr>(S))
2912 if (IgnoreNonTypeDependent && !E->isTypeDependent())
2913 return true;
2914 return super::TraverseStmt(S, Q);
2915 }
2916
2917 bool TraverseTypeLoc(TypeLoc TL) {
2918 if (IgnoreNonTypeDependent && !TL.isNull() &&
2919 !TL.getType()->isDependentType())
2920 return true;
2921 return super::TraverseTypeLoc(TL);
2922 }
2923
2924 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
2925 return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc());
2926 }
2927
2928 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
2929 // For a best-effort search, keep looking until we find a location.
2930 return IgnoreNonTypeDependent || !Matches(T->getDepth());
2931 }
2932
2933 bool TraverseTemplateName(TemplateName N) {
2934 if (TemplateTemplateParmDecl *PD =
2935 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
2936 if (Matches(PD->getDepth()))
2937 return false;
2938 return super::TraverseTemplateName(N);
2939 }
2940
2941 bool VisitDeclRefExpr(DeclRefExpr *E) {
2942 if (NonTypeTemplateParmDecl *PD =
2943 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl()))
2944 if (Matches(PD->getDepth(), E->getExprLoc()))
2945 return false;
2946 return super::VisitDeclRefExpr(E);
2947 }
2948
2949 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
2950 return TraverseType(T->getReplacementType());
2951 }
2952
2953 bool
2954 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
2955 return TraverseTemplateArgument(T->getArgumentPack());
2956 }
2957
2958 bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
2959 return TraverseType(T->getInjectedSpecializationType());
2960 }
2961};
2962} // end anonymous namespace
2963
2964/// Determines whether a given type depends on the given parameter
2965/// list.
2966static bool
2967DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
2968 if (!Params->size())
2969 return false;
2970
2971 DependencyChecker Checker(Params, /*IgnoreNonTypeDependent*/false);
2972 Checker.TraverseType(T);
2973 return Checker.Match;
2974}
2975
2976// Find the source range corresponding to the named type in the given
2977// nested-name-specifier, if any.
2978static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
2979 QualType T,
2980 const CXXScopeSpec &SS) {
2981 NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
2982 while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
2983 if (const Type *CurType = NNS->getAsType()) {
2984 if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
2985 return NNSLoc.getTypeLoc().getSourceRange();
2986 } else
2987 break;
2988
2989 NNSLoc = NNSLoc.getPrefix();
2990 }
2991
2992 return SourceRange();
2993}
2994
2995/// Match the given template parameter lists to the given scope
2996/// specifier, returning the template parameter list that applies to the
2997/// name.
2998///
2999/// \param DeclStartLoc the start of the declaration that has a scope
3000/// specifier or a template parameter list.
3001///
3002/// \param DeclLoc The location of the declaration itself.
3003///
3004/// \param SS the scope specifier that will be matched to the given template
3005/// parameter lists. This scope specifier precedes a qualified name that is
3006/// being declared.
3007///
3008/// \param TemplateId The template-id following the scope specifier, if there
3009/// is one. Used to check for a missing 'template<>'.
3010///
3011/// \param ParamLists the template parameter lists, from the outermost to the
3012/// innermost template parameter lists.
3013///
3014/// \param IsFriend Whether to apply the slightly different rules for
3015/// matching template parameters to scope specifiers in friend
3016/// declarations.
3017///
3018/// \param IsMemberSpecialization will be set true if the scope specifier
3019/// denotes a fully-specialized type, and therefore this is a declaration of
3020/// a member specialization.
3021///
3022/// \returns the template parameter list, if any, that corresponds to the
3023/// name that is preceded by the scope specifier @p SS. This template
3024/// parameter list may have template parameters (if we're declaring a
3025/// template) or may have no template parameters (if we're declaring a
3026/// template specialization), or may be NULL (if what we're declaring isn't
3027/// itself a template).
3028TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier(
3029 SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS,
3030 TemplateIdAnnotation *TemplateId,
3031 ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend,
3032 bool &IsMemberSpecialization, bool &Invalid, bool SuppressDiagnostic) {
3033 IsMemberSpecialization = false;
3034 Invalid = false;
3035
3036 // The sequence of nested types to which we will match up the template
3037 // parameter lists. We first build this list by starting with the type named
3038 // by the nested-name-specifier and walking out until we run out of types.
3039 SmallVector<QualType, 4> NestedTypes;
3040 QualType T;
3041 if (SS.getScopeRep()) {
3042 if (CXXRecordDecl *Record
3043 = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
3044 T = Context.getTypeDeclType(Record);
3045 else
3046 T = QualType(SS.getScopeRep()->getAsType(), 0);
3047 }
3048
3049 // If we found an explicit specialization that prevents us from needing
3050 // 'template<>' headers, this will be set to the location of that
3051 // explicit specialization.
3052 SourceLocation ExplicitSpecLoc;
3053
3054 while (!T.isNull()) {
3055 NestedTypes.push_back(T);
3056
3057 // Retrieve the parent of a record type.
3058 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
3059 // If this type is an explicit specialization, we're done.
3060 if (ClassTemplateSpecializationDecl *Spec
3061 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
3062 if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) &&
3063 Spec->getSpecializationKind() == TSK_ExplicitSpecialization) {
3064 ExplicitSpecLoc = Spec->getLocation();
3065 break;
3066 }
3067 } else if (Record->getTemplateSpecializationKind()
3068 == TSK_ExplicitSpecialization) {
3069 ExplicitSpecLoc = Record->getLocation();
3070 break;
3071 }
3072
3073 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
3074 T = Context.getTypeDeclType(Parent);
3075 else
3076 T = QualType();
3077 continue;
3078 }
3079
3080 if (const TemplateSpecializationType *TST
3081 = T->getAs<TemplateSpecializationType>()) {
3082 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
3083 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
3084 T = Context.getTypeDeclType(Parent);
3085 else
3086 T = QualType();
3087 continue;
3088 }
3089 }
3090
3091 // Look one step prior in a dependent template specialization type.
3092 if (const DependentTemplateSpecializationType *DependentTST
3093 = T->getAs<DependentTemplateSpecializationType>()) {
3094 if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
3095 T = QualType(NNS->getAsType(), 0);
3096 else
3097 T = QualType();
3098 continue;
3099 }
3100
3101 // Look one step prior in a dependent name type.
3102 if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
3103 if (NestedNameSpecifier *NNS = DependentName->getQualifier())
3104 T = QualType(NNS->getAsType(), 0);
3105 else
3106 T = QualType();
3107 continue;
3108 }
3109
3110 // Retrieve the parent of an enumeration type.
3111 if (const EnumType *EnumT = T->getAs<EnumType>()) {
3112 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
3113 // check here.
3114 EnumDecl *Enum = EnumT->getDecl();
3115
3116 // Get to the parent type.
3117 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
3118 T = Context.getTypeDeclType(Parent);
3119 else
3120 T = QualType();
3121 continue;
3122 }
3123
3124 T = QualType();
3125 }
3126 // Reverse the nested types list, since we want to traverse from the outermost
3127 // to the innermost while checking template-parameter-lists.
3128 std::reverse(NestedTypes.begin(), NestedTypes.end());
3129
3130 // C++0x [temp.expl.spec]p17:
3131 // A member or a member template may be nested within many
3132 // enclosing class templates. In an explicit specialization for
3133 // such a member, the member declaration shall be preceded by a
3134 // template<> for each enclosing class template that is
3135 // explicitly specialized.
3136 bool SawNonEmptyTemplateParameterList = false;
3137
3138 auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) {
3139 if (SawNonEmptyTemplateParameterList) {
3140 if (!SuppressDiagnostic)
3141 Diag(DeclLoc, diag::err_specialize_member_of_template)
3142 << !Recovery << Range;
3143 Invalid = true;
3144 IsMemberSpecialization = false;
3145 return true;
3146 }
3147
3148 return false;
3149 };
3150
3151 auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) {
3152 // Check that we can have an explicit specialization here.
3153 if (CheckExplicitSpecialization(Range, true))
3154 return true;
3155
3156 // We don't have a template header, but we should.
3157 SourceLocation ExpectedTemplateLoc;
3158 if (!ParamLists.empty())
3159 ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
3160 else
3161 ExpectedTemplateLoc = DeclStartLoc;
3162
3163 if (!SuppressDiagnostic)
3164 Diag(DeclLoc, diag::err_template_spec_needs_header)
3165 << Range
3166 << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
3167 return false;
3168 };
3169
3170 unsigned ParamIdx = 0;
3171 for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
3172 ++TypeIdx) {
3173 T = NestedTypes[TypeIdx];
3174
3175 // Whether we expect a 'template<>' header.
3176 bool NeedEmptyTemplateHeader = false;
3177
3178 // Whether we expect a template header with parameters.
3179 bool NeedNonemptyTemplateHeader = false;
3180
3181 // For a dependent type, the set of template parameters that we
3182 // expect to see.
3183 TemplateParameterList *ExpectedTemplateParams = nullptr;
3184
3185 // C++0x [temp.expl.spec]p15:
3186 // A member or a member template may be nested within many enclosing
3187 // class templates. In an explicit specialization for such a member, the
3188 // member declaration shall be preceded by a template<> for each
3189 // enclosing class template that is explicitly specialized.
3190 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
3191 if (ClassTemplatePartialSpecializationDecl *Partial
3192 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
3193 ExpectedTemplateParams = Partial->getTemplateParameters();
3194 NeedNonemptyTemplateHeader = true;
3195 } else if (Record->isDependentType()) {
3196 if (Record->getDescribedClassTemplate()) {
3197 ExpectedTemplateParams = Record->getDescribedClassTemplate()
3198 ->getTemplateParameters();
3199 NeedNonemptyTemplateHeader = true;
3200 }
3201 } else if (ClassTemplateSpecializationDecl *Spec
3202 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
3203 // C++0x [temp.expl.spec]p4:
3204 // Members of an explicitly specialized class template are defined
3205 // in the same manner as members of normal classes, and not using
3206 // the template<> syntax.
3207 if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
3208 NeedEmptyTemplateHeader = true;
3209 else
3210 continue;
3211 } else if (Record->getTemplateSpecializationKind()) {
3212 if (Record->getTemplateSpecializationKind()
3213 != TSK_ExplicitSpecialization &&
3214 TypeIdx == NumTypes - 1)
3215 IsMemberSpecialization = true;
3216
3217 continue;
3218 }
3219 } else if (const TemplateSpecializationType *TST
3220 = T->getAs<TemplateSpecializationType>()) {
3221 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
3222 ExpectedTemplateParams = Template->getTemplateParameters();
3223 NeedNonemptyTemplateHeader = true;
3224 }
3225 } else if (T->getAs<DependentTemplateSpecializationType>()) {
3226 // FIXME: We actually could/should check the template arguments here
3227 // against the corresponding template parameter list.
3228 NeedNonemptyTemplateHeader = false;
3229 }
3230
3231 // C++ [temp.expl.spec]p16:
3232 // In an explicit specialization declaration for a member of a class
3233 // template or a member template that ap- pears in namespace scope, the
3234 // member template and some of its enclosing class templates may remain
3235 // unspecialized, except that the declaration shall not explicitly
3236 // specialize a class member template if its en- closing class templates
3237 // are not explicitly specialized as well.
3238 if (ParamIdx < ParamLists.size()) {
3239 if (ParamLists[ParamIdx]->size() == 0) {
3240 if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
3241 false))
3242 return nullptr;
3243 } else
3244 SawNonEmptyTemplateParameterList = true;
3245 }
3246
3247 if (NeedEmptyTemplateHeader) {
3248 // If we're on the last of the types, and we need a 'template<>' header
3249 // here, then it's a member specialization.
3250 if (TypeIdx == NumTypes - 1)
3251 IsMemberSpecialization = true;
3252
3253 if (ParamIdx < ParamLists.size()) {
3254 if (ParamLists[ParamIdx]->size() > 0) {
3255 // The header has template parameters when it shouldn't. Complain.
3256 if (!SuppressDiagnostic)
3257 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
3258 diag::err_template_param_list_matches_nontemplate)
3259 << T
3260 << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
3261 ParamLists[ParamIdx]->getRAngleLoc())
3262 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
3263 Invalid = true;
3264 return nullptr;
3265 }
3266
3267 // Consume this template header.
3268 ++ParamIdx;
3269 continue;
3270 }
3271
3272 if (!IsFriend)
3273 if (DiagnoseMissingExplicitSpecialization(
3274 getRangeOfTypeInNestedNameSpecifier(Context, T, SS)))
3275 return nullptr;
3276
3277 continue;
3278 }
3279
3280 if (NeedNonemptyTemplateHeader) {
3281 // In friend declarations we can have template-ids which don't
3282 // depend on the corresponding template parameter lists. But
3283 // assume that empty parameter lists are supposed to match this
3284 // template-id.
3285 if (IsFriend && T->isDependentType()) {
3286 if (ParamIdx < ParamLists.size() &&
3287 DependsOnTemplateParameters(T, ParamLists[ParamIdx]))
3288 ExpectedTemplateParams = nullptr;
3289 else
3290 continue;
3291 }
3292
3293 if (ParamIdx < ParamLists.size()) {
3294 // Check the template parameter list, if we can.
3295 if (ExpectedTemplateParams &&
3296 !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
3297 ExpectedTemplateParams,
3298 !SuppressDiagnostic, TPL_TemplateMatch))
3299 Invalid = true;
3300
3301 if (!Invalid &&
3302 CheckTemplateParameterList(ParamLists[ParamIdx], nullptr,
3303 TPC_ClassTemplateMember))
3304 Invalid = true;
3305
3306 ++ParamIdx;
3307 continue;
3308 }
3309
3310 if (!SuppressDiagnostic)
3311 Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
3312 << T
3313 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
3314 Invalid = true;
3315 continue;
3316 }
3317 }
3318
3319 // If there were at least as many template-ids as there were template
3320 // parameter lists, then there are no template parameter lists remaining for
3321 // the declaration itself.
3322 if (ParamIdx >= ParamLists.size()) {
3323 if (TemplateId && !IsFriend) {
3324 // We don't have a template header for the declaration itself, but we
3325 // should.
3326 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc,
3327 TemplateId->RAngleLoc));
3328
3329 // Fabricate an empty template parameter list for the invented header.
3330 return TemplateParameterList::Create(Context, SourceLocation(),
3331 SourceLocation(), None,
3332 SourceLocation(), nullptr);
3333 }
3334
3335 return nullptr;
3336 }
3337
3338 // If there were too many template parameter lists, complain about that now.
3339 if (ParamIdx < ParamLists.size() - 1) {
3340 bool HasAnyExplicitSpecHeader = false;
3341 bool AllExplicitSpecHeaders = true;
3342 for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) {
3343 if (ParamLists[I]->size() == 0)
3344 HasAnyExplicitSpecHeader = true;
3345 else
3346 AllExplicitSpecHeaders = false;
3347 }
3348
3349 if (!SuppressDiagnostic)
3350 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
3351 AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers
3352 : diag::err_template_spec_extra_headers)
3353 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
3354 ParamLists[ParamLists.size() - 2]->getRAngleLoc());
3355
3356 // If there was a specialization somewhere, such that 'template<>' is
3357 // not required, and there were any 'template<>' headers, note where the
3358 // specialization occurred.
3359 if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader &&
3360 !SuppressDiagnostic)
3361 Diag(ExplicitSpecLoc,
3362 diag::note_explicit_template_spec_does_not_need_header)
3363 << NestedTypes.back();
3364
3365 // We have a template parameter list with no corresponding scope, which
3366 // means that the resulting template declaration can't be instantiated
3367 // properly (we'll end up with dependent nodes when we shouldn't).
3368 if (!AllExplicitSpecHeaders)
3369 Invalid = true;
3370 }
3371
3372 // C++ [temp.expl.spec]p16:
3373 // In an explicit specialization declaration for a member of a class
3374 // template or a member template that ap- pears in namespace scope, the
3375 // member template and some of its enclosing class templates may remain
3376 // unspecialized, except that the declaration shall not explicitly
3377 // specialize a class member template if its en- closing class templates
3378 // are not explicitly specialized as well.
3379 if (ParamLists.back()->size() == 0 &&
3380 CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
3381 false))
3382 return nullptr;
3383
3384 // Return the last template parameter list, which corresponds to the
3385 // entity being declared.
3386 return ParamLists.back();
3387}
3388
3389void Sema::NoteAllFoundTemplates(TemplateName Name) {
3390 if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
3391 Diag(Template->getLocation(), diag::note_template_declared_here)
3392 << (isa<FunctionTemplateDecl>(Template)
3393 ? 0
3394 : isa<ClassTemplateDecl>(Template)
3395 ? 1
3396 : isa<VarTemplateDecl>(Template)
3397 ? 2
3398 : isa<TypeAliasTemplateDecl>(Template) ? 3 : 4)
3399 << Template->getDeclName();
3400 return;
3401 }
3402
3403 if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
3404 for (OverloadedTemplateStorage::iterator I = OST->begin(),
3405 IEnd = OST->end();
3406 I != IEnd; ++I)
3407 Diag((*I)->getLocation(), diag::note_template_declared_here)
3408 << 0 << (*I)->getDeclName();
3409
3410 return;
3411 }
3412}
3413
3414static QualType
3415checkBuiltinTemplateIdType(Sema &SemaRef, BuiltinTemplateDecl *BTD,
3416 const SmallVectorImpl<TemplateArgument> &Converted,
3417 SourceLocation TemplateLoc,
3418 TemplateArgumentListInfo &TemplateArgs) {
3419 ASTContext &Context = SemaRef.getASTContext();
3420 switch (BTD->getBuiltinTemplateKind()) {
3421 case BTK__make_integer_seq: {
3422 // Specializations of __make_integer_seq<S, T, N> are treated like
3423 // S<T, 0, ..., N-1>.
3424
3425 // C++14 [inteseq.intseq]p1:
3426 // T shall be an integer type.
3427 if (!Converted[1].getAsType()->isIntegralType(Context)) {
3428 SemaRef.Diag(TemplateArgs[1].getLocation(),
3429 diag::err_integer_sequence_integral_element_type);
3430 return QualType();
3431 }
3432
3433 // C++14 [inteseq.make]p1:
3434 // If N is negative the program is ill-formed.
3435 TemplateArgument NumArgsArg = Converted[2];
3436 llvm::APSInt NumArgs = NumArgsArg.getAsIntegral();
3437 if (NumArgs < 0) {
3438 SemaRef.Diag(TemplateArgs[2].getLocation(),
3439 diag::err_integer_sequence_negative_length);
3440 return QualType();
3441 }
3442
3443 QualType ArgTy = NumArgsArg.getIntegralType();
3444 TemplateArgumentListInfo SyntheticTemplateArgs;
3445 // The type argument gets reused as the first template argument in the
3446 // synthetic template argument list.
3447 SyntheticTemplateArgs.addArgument(TemplateArgs[1]);
3448 // Expand N into 0 ... N-1.
3449 for (llvm::APSInt I(NumArgs.getBitWidth(), NumArgs.isUnsigned());
3450 I < NumArgs; ++I) {
3451 TemplateArgument TA(Context, I, ArgTy);
3452 SyntheticTemplateArgs.addArgument(SemaRef.getTrivialTemplateArgumentLoc(
3453 TA, ArgTy, TemplateArgs[2].getLocation()));
3454 }
3455 // The first template argument will be reused as the template decl that
3456 // our synthetic template arguments will be applied to.
3457 return SemaRef.CheckTemplateIdType(Converted[0].getAsTemplate(),
3458 TemplateLoc, SyntheticTemplateArgs);
3459 }
3460
3461 case BTK__type_pack_element:
3462 // Specializations of
3463 // __type_pack_element<Index, T_1, ..., T_N>
3464 // are treated like T_Index.
3465 assert(Converted.size() == 2 &&((Converted.size() == 2 && "__type_pack_element should be given an index and a parameter pack"
) ? static_cast<void> (0) : __assert_fail ("Converted.size() == 2 && \"__type_pack_element should be given an index and a parameter pack\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3466, __PRETTY_FUNCTION__))
3466 "__type_pack_element should be given an index and a parameter pack")((Converted.size() == 2 && "__type_pack_element should be given an index and a parameter pack"
) ? static_cast<void> (0) : __assert_fail ("Converted.size() == 2 && \"__type_pack_element should be given an index and a parameter pack\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3466, __PRETTY_FUNCTION__))
;
3467
3468 // If the Index is out of bounds, the program is ill-formed.
3469 TemplateArgument IndexArg = Converted[0], Ts = Converted[1];
3470 llvm::APSInt Index = IndexArg.getAsIntegral();
3471 assert(Index >= 0 && "the index used with __type_pack_element should be of "((Index >= 0 && "the index used with __type_pack_element should be of "
"type std::size_t, and hence be non-negative") ? static_cast
<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\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3472, __PRETTY_FUNCTION__))
3472 "type std::size_t, and hence be non-negative")((Index >= 0 && "the index used with __type_pack_element should be of "
"type std::size_t, and hence be non-negative") ? static_cast
<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\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3472, __PRETTY_FUNCTION__))
;
3473 if (Index >= Ts.pack_size()) {
3474 SemaRef.Diag(TemplateArgs[0].getLocation(),
3475 diag::err_type_pack_element_out_of_bounds);
3476 return QualType();
3477 }
3478
3479 // We simply return the type at index `Index`.
3480 auto Nth = std::next(Ts.pack_begin(), Index.getExtValue());
3481 return Nth->getAsType();
3482 }
3483 llvm_unreachable("unexpected BuiltinTemplateDecl!")::llvm::llvm_unreachable_internal("unexpected BuiltinTemplateDecl!"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3483)
;
3484}
3485
3486/// Determine whether this alias template is "enable_if_t".
3487static bool isEnableIfAliasTemplate(TypeAliasTemplateDecl *AliasTemplate) {
3488 return AliasTemplate->getName().equals("enable_if_t");
3489}
3490
3491/// Collect all of the separable terms in the given condition, which
3492/// might be a conjunction.
3493///
3494/// FIXME: The right answer is to convert the logical expression into
3495/// disjunctive normal form, so we can find the first failed term
3496/// within each possible clause.
3497static void collectConjunctionTerms(Expr *Clause,
3498 SmallVectorImpl<Expr *> &Terms) {
3499 if (auto BinOp = dyn_cast<BinaryOperator>(Clause->IgnoreParenImpCasts())) {
3500 if (BinOp->getOpcode() == BO_LAnd) {
3501 collectConjunctionTerms(BinOp->getLHS(), Terms);
3502 collectConjunctionTerms(BinOp->getRHS(), Terms);
3503 }
3504
3505 return;
3506 }
3507
3508 Terms.push_back(Clause);
3509}
3510
3511// The ranges-v3 library uses an odd pattern of a top-level "||" with
3512// a left-hand side that is value-dependent but never true. Identify
3513// the idiom and ignore that term.
3514static Expr *lookThroughRangesV3Condition(Preprocessor &PP, Expr *Cond) {
3515 // Top-level '||'.
3516 auto *BinOp = dyn_cast<BinaryOperator>(Cond->IgnoreParenImpCasts());
3517 if (!BinOp) return Cond;
3518
3519 if (BinOp->getOpcode() != BO_LOr) return Cond;
3520
3521 // With an inner '==' that has a literal on the right-hand side.
3522 Expr *LHS = BinOp->getLHS();
3523 auto *InnerBinOp = dyn_cast<BinaryOperator>(LHS->IgnoreParenImpCasts());
3524 if (!InnerBinOp) return Cond;
3525
3526 if (InnerBinOp->getOpcode() != BO_EQ ||
3527 !isa<IntegerLiteral>(InnerBinOp->getRHS()))
3528 return Cond;
3529
3530 // If the inner binary operation came from a macro expansion named
3531 // CONCEPT_REQUIRES or CONCEPT_REQUIRES_, return the right-hand side
3532 // of the '||', which is the real, user-provided condition.
3533 SourceLocation Loc = InnerBinOp->getExprLoc();
3534 if (!Loc.isMacroID()) return Cond;
3535
3536 StringRef MacroName = PP.getImmediateMacroName(Loc);
3537 if (MacroName == "CONCEPT_REQUIRES" || MacroName == "CONCEPT_REQUIRES_")
3538 return BinOp->getRHS();
3539
3540 return Cond;
3541}
3542
3543namespace {
3544
3545// A PrinterHelper that prints more helpful diagnostics for some sub-expressions
3546// within failing boolean expression, such as substituting template parameters
3547// for actual types.
3548class FailedBooleanConditionPrinterHelper : public PrinterHelper {
3549public:
3550 explicit FailedBooleanConditionPrinterHelper(const PrintingPolicy &P)
3551 : Policy(P) {}
3552
3553 bool handledStmt(Stmt *E, raw_ostream &OS) override {
3554 const auto *DR = dyn_cast<DeclRefExpr>(E);
3555 if (DR && DR->getQualifier()) {
3556 // If this is a qualified name, expand the template arguments in nested
3557 // qualifiers.
3558 DR->getQualifier()->print(OS, Policy, true);
3559 // Then print the decl itself.
3560 const ValueDecl *VD = DR->getDecl();
3561 OS << VD->getName();
3562 if (const auto *IV = dyn_cast<VarTemplateSpecializationDecl>(VD)) {
3563 // This is a template variable, print the expanded template arguments.
3564 printTemplateArgumentList(OS, IV->getTemplateArgs().asArray(), Policy);
3565 }
3566 return true;
3567 }
3568 return false;
3569 }
3570
3571private:
3572 const PrintingPolicy Policy;
3573};
3574
3575} // end anonymous namespace
3576
3577std::pair<Expr *, std::string>
3578Sema::findFailedBooleanCondition(Expr *Cond) {
3579 Cond = lookThroughRangesV3Condition(PP, Cond);
3580
3581 // Separate out all of the terms in a conjunction.
3582 SmallVector<Expr *, 4> Terms;
3583 collectConjunctionTerms(Cond, Terms);
3584
3585 // Determine which term failed.
3586 Expr *FailedCond = nullptr;
3587 for (Expr *Term : Terms) {
3588 Expr *TermAsWritten = Term->IgnoreParenImpCasts();
3589
3590 // Literals are uninteresting.
3591 if (isa<CXXBoolLiteralExpr>(TermAsWritten) ||
3592 isa<IntegerLiteral>(TermAsWritten))
3593 continue;
3594
3595 // The initialization of the parameter from the argument is
3596 // a constant-evaluated context.
3597 EnterExpressionEvaluationContext ConstantEvaluated(
3598 *this, Sema::ExpressionEvaluationContext::ConstantEvaluated);
3599
3600 bool Succeeded;
3601 if (Term->EvaluateAsBooleanCondition(Succeeded, Context) &&
3602 !Succeeded) {
3603 FailedCond = TermAsWritten;
3604 break;
3605 }
3606 }
3607 if (!FailedCond)
3608 FailedCond = Cond->IgnoreParenImpCasts();
3609
3610 std::string Description;
3611 {
3612 llvm::raw_string_ostream Out(Description);
3613 PrintingPolicy Policy = getPrintingPolicy();
3614 Policy.PrintCanonicalTypes = true;
3615 FailedBooleanConditionPrinterHelper Helper(Policy);
3616 FailedCond->printPretty(Out, &Helper, Policy, 0, "\n", nullptr);
3617 }
3618 return { FailedCond, Description };
3619}
3620
3621QualType Sema::CheckTemplateIdType(TemplateName Name,
3622 SourceLocation TemplateLoc,
3623 TemplateArgumentListInfo &TemplateArgs) {
3624 DependentTemplateName *DTN
3625 = Name.getUnderlying().getAsDependentTemplateName();
3626 if (DTN && DTN->isIdentifier())
3627 // When building a template-id where the template-name is dependent,
3628 // assume the template is a type template. Either our assumption is
3629 // correct, or the code is ill-formed and will be diagnosed when the
3630 // dependent name is substituted.
3631 return Context.getDependentTemplateSpecializationType(ETK_None,
3632 DTN->getQualifier(),
3633 DTN->getIdentifier(),
3634 TemplateArgs);
3635
3636 if (Name.getAsAssumedTemplateName() &&
3637 resolveAssumedTemplateNameAsType(/*Scope*/nullptr, Name, TemplateLoc))
3638 return QualType();
3639
3640 TemplateDecl *Template = Name.getAsTemplateDecl();
3641 if (!Template || isa<FunctionTemplateDecl>(Template) ||
3642 isa<VarTemplateDecl>(Template) || isa<ConceptDecl>(Template)) {
3643 // We might have a substituted template template parameter pack. If so,
3644 // build a template specialization type for it.
3645 if (Name.getAsSubstTemplateTemplateParmPack())
3646 return Context.getTemplateSpecializationType(Name, TemplateArgs);
3647
3648 Diag(TemplateLoc, diag::err_template_id_not_a_type)
3649 << Name;
3650 NoteAllFoundTemplates(Name);
3651 return QualType();
3652 }
3653
3654 // Check that the template argument list is well-formed for this
3655 // template.
3656 SmallVector<TemplateArgument, 4> Converted;
3657 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
3658 false, Converted,
3659 /*UpdateArgsWithConversion=*/true))
3660 return QualType();
3661
3662 QualType CanonType;
3663
3664 bool InstantiationDependent = false;
3665 if (TypeAliasTemplateDecl *AliasTemplate =
3666 dyn_cast<TypeAliasTemplateDecl>(Template)) {
3667
3668 // Find the canonical type for this type alias template specialization.
3669 TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
3670 if (Pattern->isInvalidDecl())
3671 return QualType();
3672
3673 TemplateArgumentList StackTemplateArgs(TemplateArgumentList::OnStack,
3674 Converted);
3675
3676 // Only substitute for the innermost template argument list.
3677 MultiLevelTemplateArgumentList TemplateArgLists;
3678 TemplateArgLists.addOuterTemplateArguments(&StackTemplateArgs);
3679 TemplateArgLists.addOuterRetainedLevels(
3680 AliasTemplate->getTemplateParameters()->getDepth());
3681
3682 LocalInstantiationScope Scope(*this);
3683 InstantiatingTemplate Inst(*this, TemplateLoc, Template);
3684 if (Inst.isInvalid())
3685 return QualType();
3686
3687 CanonType = SubstType(Pattern->getUnderlyingType(),
3688 TemplateArgLists, AliasTemplate->getLocation(),
3689 AliasTemplate->getDeclName());
3690 if (CanonType.isNull()) {
3691 // If this was enable_if and we failed to find the nested type
3692 // within enable_if in a SFINAE context, dig out the specific
3693 // enable_if condition that failed and present that instead.
3694 if (isEnableIfAliasTemplate(AliasTemplate)) {
3695 if (auto DeductionInfo = isSFINAEContext()) {
3696 if (*DeductionInfo &&
3697 (*DeductionInfo)->hasSFINAEDiagnostic() &&
3698 (*DeductionInfo)->peekSFINAEDiagnostic().second.getDiagID() ==
3699 diag::err_typename_nested_not_found_enable_if &&
3700 TemplateArgs[0].getArgument().getKind()
3701 == TemplateArgument::Expression) {
3702 Expr *FailedCond;
3703 std::string FailedDescription;
3704 std::tie(FailedCond, FailedDescription) =
3705 findFailedBooleanCondition(TemplateArgs[0].getSourceExpression());
3706
3707 // Remove the old SFINAE diagnostic.
3708 PartialDiagnosticAt OldDiag =
3709 {SourceLocation(), PartialDiagnostic::NullDiagnostic()};
3710 (*DeductionInfo)->takeSFINAEDiagnostic(OldDiag);
3711
3712 // Add a new SFINAE diagnostic specifying which condition
3713 // failed.
3714 (*DeductionInfo)->addSFINAEDiagnostic(
3715 OldDiag.first,
3716 PDiag(diag::err_typename_nested_not_found_requirement)
3717 << FailedDescription
3718 << FailedCond->getSourceRange());
3719 }
3720 }
3721 }
3722
3723 return QualType();
3724 }
3725 } else if (Name.isDependent() ||
3726 TemplateSpecializationType::anyDependentTemplateArguments(
3727 TemplateArgs, InstantiationDependent)) {
3728 // This class template specialization is a dependent
3729 // type. Therefore, its canonical type is another class template
3730 // specialization type that contains all of the converted
3731 // arguments in canonical form. This ensures that, e.g., A<T> and
3732 // A<T, T> have identical types when A is declared as:
3733 //
3734 // template<typename T, typename U = T> struct A;
3735 CanonType = Context.getCanonicalTemplateSpecializationType(Name, Converted);
3736
3737 // This might work out to be a current instantiation, in which
3738 // case the canonical type needs to be the InjectedClassNameType.
3739 //
3740 // TODO: in theory this could be a simple hashtable lookup; most
3741 // changes to CurContext don't change the set of current
3742 // instantiations.
3743 if (isa<ClassTemplateDecl>(Template)) {
3744 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) {
3745 // If we get out to a namespace, we're done.
3746 if (Ctx->isFileContext()) break;
3747
3748 // If this isn't a record, keep looking.
3749 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
3750 if (!Record) continue;
3751
3752 // Look for one of the two cases with InjectedClassNameTypes
3753 // and check whether it's the same template.
3754 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
3755 !Record->getDescribedClassTemplate())
3756 continue;
3757
3758 // Fetch the injected class name type and check whether its
3759 // injected type is equal to the type we just built.
3760 QualType ICNT = Context.getTypeDeclType(Record);
3761 QualType Injected = cast<InjectedClassNameType>(ICNT)
3762 ->getInjectedSpecializationType();
3763
3764 if (CanonType != Injected->getCanonicalTypeInternal())
3765 continue;
3766
3767 // If so, the canonical type of this TST is the injected
3768 // class name type of the record we just found.
3769 assert(ICNT.isCanonical())((ICNT.isCanonical()) ? static_cast<void> (0) : __assert_fail
("ICNT.isCanonical()", "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3769, __PRETTY_FUNCTION__))
;
3770 CanonType = ICNT;
3771 break;
3772 }
3773 }
3774 } else if (ClassTemplateDecl *ClassTemplate
3775 = dyn_cast<ClassTemplateDecl>(Template)) {
3776 // Find the class template specialization declaration that
3777 // corresponds to these arguments.
3778 void *InsertPos = nullptr;
3779 ClassTemplateSpecializationDecl *Decl
3780 = ClassTemplate->findSpecialization(Converted, InsertPos);
3781 if (!Decl) {
3782 // This is the first time we have referenced this class template
3783 // specialization. Create the canonical declaration and add it to
3784 // the set of specializations.
3785 Decl = ClassTemplateSpecializationDecl::Create(
3786 Context, ClassTemplate->getTemplatedDecl()->getTagKind(),
3787 ClassTemplate->getDeclContext(),
3788 ClassTemplate->getTemplatedDecl()->getBeginLoc(),
3789 ClassTemplate->getLocation(), ClassTemplate, Converted, nullptr);
3790 ClassTemplate->AddSpecialization(Decl, InsertPos);
3791 if (ClassTemplate->isOutOfLine())
3792 Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext());
3793 }
3794
3795 if (Decl->getSpecializationKind() == TSK_Undeclared) {
3796 MultiLevelTemplateArgumentList TemplateArgLists;
3797 TemplateArgLists.addOuterTemplateArguments(Converted);
3798 InstantiateAttrsForDecl(TemplateArgLists, ClassTemplate->getTemplatedDecl(),
3799 Decl);
3800 }
3801
3802 // Diagnose uses of this specialization.
3803 (void)DiagnoseUseOfDecl(Decl, TemplateLoc);
3804
3805 CanonType = Context.getTypeDeclType(Decl);
3806 assert(isa<RecordType>(CanonType) &&((isa<RecordType>(CanonType) && "type of non-dependent specialization is not a RecordType"
) ? static_cast<void> (0) : __assert_fail ("isa<RecordType>(CanonType) && \"type of non-dependent specialization is not a RecordType\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3807, __PRETTY_FUNCTION__))
3807 "type of non-dependent specialization is not a RecordType")((isa<RecordType>(CanonType) && "type of non-dependent specialization is not a RecordType"
) ? static_cast<void> (0) : __assert_fail ("isa<RecordType>(CanonType) && \"type of non-dependent specialization is not a RecordType\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3807, __PRETTY_FUNCTION__))
;
3808 } else if (auto *BTD = dyn_cast<BuiltinTemplateDecl>(Template)) {
3809 CanonType = checkBuiltinTemplateIdType(*this, BTD, Converted, TemplateLoc,
3810 TemplateArgs);
3811 }
3812
3813 // Build the fully-sugared type for this class template
3814 // specialization, which refers back to the class template
3815 // specialization we created or found.
3816 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
3817}
3818
3819void Sema::ActOnUndeclaredTypeTemplateName(Scope *S, TemplateTy &ParsedName,
3820 TemplateNameKind &TNK,
3821 SourceLocation NameLoc,
3822 IdentifierInfo *&II) {
3823 assert(TNK == TNK_Undeclared_template && "not an undeclared template name")((TNK == TNK_Undeclared_template && "not an undeclared template name"
) ? static_cast<void> (0) : __assert_fail ("TNK == TNK_Undeclared_template && \"not an undeclared template name\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3823, __PRETTY_FUNCTION__))
;
3824
3825 TemplateName Name = ParsedName.get();
3826 auto *ATN = Name.getAsAssumedTemplateName();
3827 assert(ATN && "not an assumed template name")((ATN && "not an assumed template name") ? static_cast
<void> (0) : __assert_fail ("ATN && \"not an assumed template name\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3827, __PRETTY_FUNCTION__))
;
3828 II = ATN->getDeclName().getAsIdentifierInfo();
3829
3830 if (!resolveAssumedTemplateNameAsType(S, Name, NameLoc, /*Diagnose*/false)) {
3831 // Resolved to a type template name.
3832 ParsedName = TemplateTy::make(Name);
3833 TNK = TNK_Type_template;
3834 }
3835}
3836
3837bool Sema::resolveAssumedTemplateNameAsType(Scope *S, TemplateName &Name,
3838 SourceLocation NameLoc,
3839 bool Diagnose) {
3840 // We assumed this undeclared identifier to be an (ADL-only) function
3841 // template name, but it was used in a context where a type was required.
3842 // Try to typo-correct it now.
3843 AssumedTemplateStorage *ATN = Name.getAsAssumedTemplateName();
3844 assert(ATN && "not an assumed template name")((ATN && "not an assumed template name") ? static_cast
<void> (0) : __assert_fail ("ATN && \"not an assumed template name\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 3844, __PRETTY_FUNCTION__))
;
3845
3846 LookupResult R(*this, ATN->getDeclName(), NameLoc, LookupOrdinaryName);
3847 struct CandidateCallback : CorrectionCandidateCallback {
3848 bool ValidateCandidate(const TypoCorrection &TC) override {
3849 return TC.getCorrectionDecl() &&
3850 getAsTypeTemplateDecl(TC.getCorrectionDecl());
3851 }
3852 std::unique_ptr<CorrectionCandidateCallback> clone() override {
3853 return std::make_unique<CandidateCallback>(*this);
3854 }
3855 } FilterCCC;
3856
3857 TypoCorrection Corrected =
3858 CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, nullptr,
3859 FilterCCC, CTK_ErrorRecovery);
3860 if (Corrected && Corrected.getFoundDecl()) {
3861 diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest)
3862 << ATN->getDeclName());
3863 Name = TemplateName(Corrected.getCorrectionDeclAs<TemplateDecl>());
3864 return false;
3865 }
3866
3867 if (Diagnose)
3868 Diag(R.getNameLoc(), diag::err_no_template) << R.getLookupName();
3869 return true;
3870}
3871
3872TypeResult Sema::ActOnTemplateIdType(
3873 Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
3874 TemplateTy TemplateD, IdentifierInfo *TemplateII,
3875 SourceLocation TemplateIILoc, SourceLocation LAngleLoc,
3876 ASTTemplateArgsPtr TemplateArgsIn, SourceLocation RAngleLoc,
3877 bool IsCtorOrDtorName, bool IsClassName) {
3878 if (SS.isInvalid())
3879 return true;
3880
3881 if (!IsCtorOrDtorName && !IsClassName && SS.isSet()) {
3882 DeclContext *LookupCtx = computeDeclContext(SS, /*EnteringContext*/false);
3883
3884 // C++ [temp.res]p3:
3885 // A qualified-id that refers to a type and in which the
3886 // nested-name-specifier depends on a template-parameter (14.6.2)
3887 // shall be prefixed by the keyword typename to indicate that the
3888 // qualified-id denotes a type, forming an
3889 // elaborated-type-specifier (7.1.5.3).
3890 if (!LookupCtx && isDependentScopeSpecifier(SS)) {
3891 Diag(SS.getBeginLoc(), diag::err_typename_missing_template)
3892 << SS.getScopeRep() << TemplateII->getName();
3893 // Recover as if 'typename' were specified.
3894 // FIXME: This is not quite correct recovery as we don't transform SS
3895 // into the corresponding dependent form (and we don't diagnose missing
3896 // 'template' keywords within SS as a result).
3897 return ActOnTypenameType(nullptr, SourceLocation(), SS, TemplateKWLoc,
3898 TemplateD, TemplateII, TemplateIILoc, LAngleLoc,
3899 TemplateArgsIn, RAngleLoc);
3900 }
3901
3902 // Per C++ [class.qual]p2, if the template-id was an injected-class-name,
3903 // it's not actually allowed to be used as a type in most cases. Because
3904 // we annotate it before we know whether it's valid, we have to check for
3905 // this case here.
3906 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
3907 if (LookupRD && LookupRD->getIdentifier() == TemplateII) {
3908 Diag(TemplateIILoc,
3909 TemplateKWLoc.isInvalid()
3910 ? diag::err_out_of_line_qualified_id_type_names_constructor
3911 : diag::ext_out_of_line_qualified_id_type_names_constructor)
3912 << TemplateII << 0 /*injected-class-name used as template name*/
3913 << 1 /*if any keyword was present, it was 'template'*/;
3914 }
3915 }
3916
3917 TemplateName Template = TemplateD.get();
3918 if (Template.getAsAssumedTemplateName() &&
3919 resolveAssumedTemplateNameAsType(S, Template, TemplateIILoc))
3920 return true;
3921
3922 // Translate the parser's template argument list in our AST format.
3923 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
3924 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
3925
3926 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
3927 QualType T
3928 = Context.getDependentTemplateSpecializationType(ETK_None,
3929 DTN->getQualifier(),
3930 DTN->getIdentifier(),
3931 TemplateArgs);
3932 // Build type-source information.
3933 TypeLocBuilder TLB;
3934 DependentTemplateSpecializationTypeLoc SpecTL
3935 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
3936 SpecTL.setElaboratedKeywordLoc(SourceLocation());
3937 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
3938 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
3939 SpecTL.setTemplateNameLoc(TemplateIILoc);
3940 SpecTL.setLAngleLoc(LAngleLoc);
3941 SpecTL.setRAngleLoc(RAngleLoc);
3942 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
3943 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
3944 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
3945 }
3946
3947 QualType Result = CheckTemplateIdType(Template, TemplateIILoc, TemplateArgs);
3948 if (Result.isNull())
3949 return true;
3950
3951 // Build type-source information.
3952 TypeLocBuilder TLB;
3953 TemplateSpecializationTypeLoc SpecTL
3954 = TLB.push<TemplateSpecializationTypeLoc>(Result);
3955 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
3956 SpecTL.setTemplateNameLoc(TemplateIILoc);
3957 SpecTL.setLAngleLoc(LAngleLoc);
3958 SpecTL.setRAngleLoc(RAngleLoc);
3959 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
3960 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
3961
3962 // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
3963 // constructor or destructor name (in such a case, the scope specifier
3964 // will be attached to the enclosing Decl or Expr node).
3965 if (SS.isNotEmpty() && !IsCtorOrDtorName) {
3966 // Create an elaborated-type-specifier containing the nested-name-specifier.
3967 Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
3968 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
3969 ElabTL.setElaboratedKeywordLoc(SourceLocation());
3970 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
3971 }
3972
3973 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
3974}
3975
3976TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
3977 TypeSpecifierType TagSpec,
3978 SourceLocation TagLoc,
3979 CXXScopeSpec &SS,
3980 SourceLocation TemplateKWLoc,
3981 TemplateTy TemplateD,
3982 SourceLocation TemplateLoc,
3983 SourceLocation LAngleLoc,
3984 ASTTemplateArgsPtr TemplateArgsIn,
3985 SourceLocation RAngleLoc) {
3986 if (SS.isInvalid())
3987 return TypeResult(true);
3988
3989 TemplateName Template = TemplateD.get();
3990
3991 // Translate the parser's template argument list in our AST format.
3992 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
3993 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
3994
3995 // Determine the tag kind
3996 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
3997 ElaboratedTypeKeyword Keyword
3998 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
3999
4000 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
4001 QualType T = Context.getDependentTemplateSpecializationType(Keyword,
4002 DTN->getQualifier(),
4003 DTN->getIdentifier(),
4004 TemplateArgs);
4005
4006 // Build type-source information.
4007 TypeLocBuilder TLB;
4008 DependentTemplateSpecializationTypeLoc SpecTL
4009 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
4010 SpecTL.setElaboratedKeywordLoc(TagLoc);
4011 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
4012 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4013 SpecTL.setTemplateNameLoc(TemplateLoc);
4014 SpecTL.setLAngleLoc(LAngleLoc);
4015 SpecTL.setRAngleLoc(RAngleLoc);
4016 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
4017 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
4018 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
4019 }
4020
4021 if (TypeAliasTemplateDecl *TAT =
4022 dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
4023 // C++0x [dcl.type.elab]p2:
4024 // If the identifier resolves to a typedef-name or the simple-template-id
4025 // resolves to an alias template specialization, the
4026 // elaborated-type-specifier is ill-formed.
4027 Diag(TemplateLoc, diag::err_tag_reference_non_tag)
4028 << TAT << NTK_TypeAliasTemplate << TagKind;
4029 Diag(TAT->getLocation(), diag::note_declared_at);
4030 }
4031
4032 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
4033 if (Result.isNull())
4034 return TypeResult(true);
4035
4036 // Check the tag kind
4037 if (const RecordType *RT = Result->getAs<RecordType>()) {
4038 RecordDecl *D = RT->getDecl();
4039
4040 IdentifierInfo *Id = D->getIdentifier();
4041 assert(Id && "templated class must have an identifier")((Id && "templated class must have an identifier") ? static_cast
<void> (0) : __assert_fail ("Id && \"templated class must have an identifier\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4041, __PRETTY_FUNCTION__))
;
4042
4043 if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
4044 TagLoc, Id)) {
4045 Diag(TagLoc, diag::err_use_with_wrong_tag)
4046 << Result
4047 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
4048 Diag(D->getLocation(), diag::note_previous_use);
4049 }
4050 }
4051
4052 // Provide source-location information for the template specialization.
4053 TypeLocBuilder TLB;
4054 TemplateSpecializationTypeLoc SpecTL
4055 = TLB.push<TemplateSpecializationTypeLoc>(Result);
4056 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4057 SpecTL.setTemplateNameLoc(TemplateLoc);
4058 SpecTL.setLAngleLoc(LAngleLoc);
4059 SpecTL.setRAngleLoc(RAngleLoc);
4060 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
4061 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
4062
4063 // Construct an elaborated type containing the nested-name-specifier (if any)
4064 // and tag keyword.
4065 Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
4066 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
4067 ElabTL.setElaboratedKeywordLoc(TagLoc);
4068 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
4069 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
4070}
4071
4072static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized,
4073 NamedDecl *PrevDecl,
4074 SourceLocation Loc,
4075 bool IsPartialSpecialization);
4076
4077static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
4078
4079static bool isTemplateArgumentTemplateParameter(
4080 const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
4081 switch (Arg.getKind()) {
4082 case TemplateArgument::Null:
4083 case TemplateArgument::NullPtr:
4084 case TemplateArgument::Integral:
4085 case TemplateArgument::Declaration:
4086 case TemplateArgument::Pack:
4087 case TemplateArgument::TemplateExpansion:
4088 return false;
4089
4090 case TemplateArgument::Type: {
4091 QualType Type = Arg.getAsType();
4092 const TemplateTypeParmType *TPT =
4093 Arg.getAsType()->getAs<TemplateTypeParmType>();
4094 return TPT && !Type.hasQualifiers() &&
4095 TPT->getDepth() == Depth && TPT->getIndex() == Index;
4096 }
4097
4098 case TemplateArgument::Expression: {
4099 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
4100 if (!DRE || !DRE->getDecl())
4101 return false;
4102 const NonTypeTemplateParmDecl *NTTP =
4103 dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
4104 return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
4105 }
4106
4107 case TemplateArgument::Template:
4108 const TemplateTemplateParmDecl *TTP =
4109 dyn_cast_or_null<TemplateTemplateParmDecl>(
4110 Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
4111 return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
4112 }
4113 llvm_unreachable("unexpected kind of template argument")::llvm::llvm_unreachable_internal("unexpected kind of template argument"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4113)
;
4114}
4115
4116static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
4117 ArrayRef<TemplateArgument> Args) {
4118 if (Params->size() != Args.size())
4119 return false;
4120
4121 unsigned Depth = Params->getDepth();
4122
4123 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
4124 TemplateArgument Arg = Args[I];
4125
4126 // If the parameter is a pack expansion, the argument must be a pack
4127 // whose only element is a pack expansion.
4128 if (Params->getParam(I)->isParameterPack()) {
4129 if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
4130 !Arg.pack_begin()->isPackExpansion())
4131 return false;
4132 Arg = Arg.pack_begin()->getPackExpansionPattern();
4133 }
4134
4135 if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
4136 return false;
4137 }
4138
4139 return true;
4140}
4141
4142template<typename PartialSpecDecl>
4143static void checkMoreSpecializedThanPrimary(Sema &S, PartialSpecDecl *Partial) {
4144 if (Partial->getDeclContext()->isDependentContext())
4145 return;
4146
4147 // FIXME: Get the TDK from deduction in order to provide better diagnostics
4148 // for non-substitution-failure issues?
4149 TemplateDeductionInfo Info(Partial->getLocation());
4150 if (S.isMoreSpecializedThanPrimary(Partial, Info))
4151 return;
4152
4153 auto *Template = Partial->getSpecializedTemplate();
4154 S.Diag(Partial->getLocation(),
4155 diag::ext_partial_spec_not_more_specialized_than_primary)
4156 << isa<VarTemplateDecl>(Template);
4157
4158 if (Info.hasSFINAEDiagnostic()) {
4159 PartialDiagnosticAt Diag = {SourceLocation(),
4160 PartialDiagnostic::NullDiagnostic()};
4161 Info.takeSFINAEDiagnostic(Diag);
4162 SmallString<128> SFINAEArgString;
4163 Diag.second.EmitToString(S.getDiagnostics(), SFINAEArgString);
4164 S.Diag(Diag.first,
4165 diag::note_partial_spec_not_more_specialized_than_primary)
4166 << SFINAEArgString;
4167 }
4168
4169 S.Diag(Template->getLocation(), diag::note_template_decl_here);
4170 SmallVector<const Expr *, 3> PartialAC, TemplateAC;
4171 Template->getAssociatedConstraints(TemplateAC);
4172 Partial->getAssociatedConstraints(PartialAC);
4173 S.MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Partial, PartialAC, Template,
4174 TemplateAC);
4175}
4176
4177static void
4178noteNonDeducibleParameters(Sema &S, TemplateParameterList *TemplateParams,
4179 const llvm::SmallBitVector &DeducibleParams) {
4180 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
4181 if (!DeducibleParams[I]) {
4182 NamedDecl *Param = TemplateParams->getParam(I);
4183 if (Param->getDeclName())
4184 S.Diag(Param->getLocation(), diag::note_non_deducible_parameter)
4185 << Param->getDeclName();
4186 else
4187 S.Diag(Param->getLocation(), diag::note_non_deducible_parameter)
4188 << "(anonymous)";
4189 }
4190 }
4191}
4192
4193
4194template<typename PartialSpecDecl>
4195static void checkTemplatePartialSpecialization(Sema &S,
4196 PartialSpecDecl *Partial) {
4197 // C++1z [temp.class.spec]p8: (DR1495)
4198 // - The specialization shall be more specialized than the primary
4199 // template (14.5.5.2).
4200 checkMoreSpecializedThanPrimary(S, Partial);
4201
4202 // C++ [temp.class.spec]p8: (DR1315)
4203 // - Each template-parameter shall appear at least once in the
4204 // template-id outside a non-deduced context.
4205 // C++1z [temp.class.spec.match]p3 (P0127R2)
4206 // If the template arguments of a partial specialization cannot be
4207 // deduced because of the structure of its template-parameter-list
4208 // and the template-id, the program is ill-formed.
4209 auto *TemplateParams = Partial->getTemplateParameters();
4210 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4211 S.MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
4212 TemplateParams->getDepth(), DeducibleParams);
4213
4214 if (!DeducibleParams.all()) {
4215 unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4216 S.Diag(Partial->getLocation(), diag::ext_partial_specs_not_deducible)
4217 << isa<VarTemplatePartialSpecializationDecl>(Partial)
4218 << (NumNonDeducible > 1)
4219 << SourceRange(Partial->getLocation(),
4220 Partial->getTemplateArgsAsWritten()->RAngleLoc);
4221 noteNonDeducibleParameters(S, TemplateParams, DeducibleParams);
4222 }
4223}
4224
4225void Sema::CheckTemplatePartialSpecialization(
4226 ClassTemplatePartialSpecializationDecl *Partial) {
4227 checkTemplatePartialSpecialization(*this, Partial);
4228}
4229
4230void Sema::CheckTemplatePartialSpecialization(
4231 VarTemplatePartialSpecializationDecl *Partial) {
4232 checkTemplatePartialSpecialization(*this, Partial);
4233}
4234
4235void Sema::CheckDeductionGuideTemplate(FunctionTemplateDecl *TD) {
4236 // C++1z [temp.param]p11:
4237 // A template parameter of a deduction guide template that does not have a
4238 // default-argument shall be deducible from the parameter-type-list of the
4239 // deduction guide template.
4240 auto *TemplateParams = TD->getTemplateParameters();
4241 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4242 MarkDeducedTemplateParameters(TD, DeducibleParams);
4243 for (unsigned I = 0; I != TemplateParams->size(); ++I) {
4244 // A parameter pack is deducible (to an empty pack).
4245 auto *Param = TemplateParams->getParam(I);
4246 if (Param->isParameterPack() || hasVisibleDefaultArgument(Param))
4247 DeducibleParams[I] = true;
4248 }
4249
4250 if (!DeducibleParams.all()) {
4251 unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4252 Diag(TD->getLocation(), diag::err_deduction_guide_template_not_deducible)
4253 << (NumNonDeducible > 1);
4254 noteNonDeducibleParameters(*this, TemplateParams, DeducibleParams);
4255 }
4256}
4257
4258DeclResult Sema::ActOnVarTemplateSpecialization(
4259 Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc,
4260 TemplateParameterList *TemplateParams, StorageClass SC,
4261 bool IsPartialSpecialization) {
4262 // D must be variable template id.
4263 assert(D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId &&((D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId &&
"Variable template specialization is declared with a template it."
) ? static_cast<void> (0) : __assert_fail ("D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId && \"Variable template specialization is declared with a template it.\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4264, __PRETTY_FUNCTION__))
4264 "Variable template specialization is declared with a template it.")((D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId &&
"Variable template specialization is declared with a template it."
) ? static_cast<void> (0) : __assert_fail ("D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId && \"Variable template specialization is declared with a template it.\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4264, __PRETTY_FUNCTION__))
;
4265
4266 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
4267 TemplateArgumentListInfo TemplateArgs =
4268 makeTemplateArgumentListInfo(*this, *TemplateId);
4269 SourceLocation TemplateNameLoc = D.getIdentifierLoc();
4270 SourceLocation LAngleLoc = TemplateId->LAngleLoc;
4271 SourceLocation RAngleLoc = TemplateId->RAngleLoc;
4272
4273 TemplateName Name = TemplateId->Template.get();
4274
4275 // The template-id must name a variable template.
4276 VarTemplateDecl *VarTemplate =
4277 dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl());
4278 if (!VarTemplate) {
4279 NamedDecl *FnTemplate;
4280 if (auto *OTS = Name.getAsOverloadedTemplate())
4281 FnTemplate = *OTS->begin();
4282 else
4283 FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl());
4284 if (FnTemplate)
4285 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method)
4286 << FnTemplate->getDeclName();
4287 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template)
4288 << IsPartialSpecialization;
4289 }
4290
4291 // Check for unexpanded parameter packs in any of the template arguments.
4292 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
4293 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
4294 UPPC_PartialSpecialization))
4295 return true;
4296
4297 // Check that the template argument list is well-formed for this
4298 // template.
4299 SmallVector<TemplateArgument, 4> Converted;
4300 if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs,
4301 false, Converted,
4302 /*UpdateArgsWithConversion=*/true))
4303 return true;
4304
4305 // Find the variable template (partial) specialization declaration that
4306 // corresponds to these arguments.
4307 if (IsPartialSpecialization) {
4308 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, VarTemplate,
4309 TemplateArgs.size(), Converted))
4310 return true;
4311
4312 // FIXME: Move these checks to CheckTemplatePartialSpecializationArgs so we
4313 // also do them during instantiation.
4314 bool InstantiationDependent;
4315 if (!Name.isDependent() &&
4316 !TemplateSpecializationType::anyDependentTemplateArguments(
4317 TemplateArgs.arguments(),
4318 InstantiationDependent)) {
4319 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
4320 << VarTemplate->getDeclName();
4321 IsPartialSpecialization = false;
4322 }
4323
4324 if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
4325 Converted) &&
4326 (!Context.getLangOpts().CPlusPlus20 ||
4327 !TemplateParams->hasAssociatedConstraints())) {
4328 // C++ [temp.class.spec]p9b3:
4329 //
4330 // -- The argument list of the specialization shall not be identical
4331 // to the implicit argument list of the primary template.
4332 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
4333 << /*variable template*/ 1
4334 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
4335 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
4336 // FIXME: Recover from this by treating the declaration as a redeclaration
4337 // of the primary template.
4338 return true;
4339 }
4340 }
4341
4342 void *InsertPos = nullptr;
4343 VarTemplateSpecializationDecl *PrevDecl = nullptr;
4344
4345 if (IsPartialSpecialization)
4346 PrevDecl = VarTemplate->findPartialSpecialization(Converted, TemplateParams,
4347 InsertPos);
4348 else
4349 PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
4350
4351 VarTemplateSpecializationDecl *Specialization = nullptr;
4352
4353 // Check whether we can declare a variable template specialization in
4354 // the current scope.
4355 if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl,
4356 TemplateNameLoc,
4357 IsPartialSpecialization))
4358 return true;
4359
4360 if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) {
4361 // Since the only prior variable template specialization with these
4362 // arguments was referenced but not declared, reuse that
4363 // declaration node as our own, updating its source location and
4364 // the list of outer template parameters to reflect our new declaration.
4365 Specialization = PrevDecl;
4366 Specialization->setLocation(TemplateNameLoc);
4367 PrevDecl = nullptr;
4368 } else if (IsPartialSpecialization) {
4369 // Create a new class template partial specialization declaration node.
4370 VarTemplatePartialSpecializationDecl *PrevPartial =
4371 cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl);
4372 VarTemplatePartialSpecializationDecl *Partial =
4373 VarTemplatePartialSpecializationDecl::Create(
4374 Context, VarTemplate->getDeclContext(), TemplateKWLoc,
4375 TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC,
4376 Converted, TemplateArgs);
4377
4378 if (!PrevPartial)
4379 VarTemplate->AddPartialSpecialization(Partial, InsertPos);
4380 Specialization = Partial;
4381
4382 // If we are providing an explicit specialization of a member variable
4383 // template specialization, make a note of that.
4384 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
4385 PrevPartial->setMemberSpecialization();
4386
4387 CheckTemplatePartialSpecialization(Partial);
4388 } else {
4389 // Create a new class template specialization declaration node for
4390 // this explicit specialization or friend declaration.
4391 Specialization = VarTemplateSpecializationDecl::Create(
4392 Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc,
4393 VarTemplate, DI->getType(), DI, SC, Converted);
4394 Specialization->setTemplateArgsInfo(TemplateArgs);
4395
4396 if (!PrevDecl)
4397 VarTemplate->AddSpecialization(Specialization, InsertPos);
4398 }
4399
4400 // C++ [temp.expl.spec]p6:
4401 // If a template, a member template or the member of a class template is
4402 // explicitly specialized then that specialization shall be declared
4403 // before the first use of that specialization that would cause an implicit
4404 // instantiation to take place, in every translation unit in which such a
4405 // use occurs; no diagnostic is required.
4406 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
4407 bool Okay = false;
4408 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
4409 // Is there any previous explicit specialization declaration?
4410 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
4411 Okay = true;
4412 break;
4413 }
4414 }
4415
4416 if (!Okay) {
4417 SourceRange Range(TemplateNameLoc, RAngleLoc);
4418 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
4419 << Name << Range;
4420
4421 Diag(PrevDecl->getPointOfInstantiation(),
4422 diag::note_instantiation_required_here)
4423 << (PrevDecl->getTemplateSpecializationKind() !=
4424 TSK_ImplicitInstantiation);
4425 return true;
4426 }
4427 }
4428
4429 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
4430 Specialization->setLexicalDeclContext(CurContext);
4431
4432 // Add the specialization into its lexical context, so that it can
4433 // be seen when iterating through the list of declarations in that
4434 // context. However, specializations are not found by name lookup.
4435 CurContext->addDecl(Specialization);
4436
4437 // Note that this is an explicit specialization.
4438 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
4439
4440 if (PrevDecl) {
4441 // Check that this isn't a redefinition of this specialization,
4442 // merging with previous declarations.
4443 LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName,
4444 forRedeclarationInCurContext());
4445 PrevSpec.addDecl(PrevDecl);
4446 D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec));
4447 } else if (Specialization->isStaticDataMember() &&
4448 Specialization->isOutOfLine()) {
4449 Specialization->setAccess(VarTemplate->getAccess());
4450 }
4451
4452 return Specialization;
4453}
4454
4455namespace {
4456/// A partial specialization whose template arguments have matched
4457/// a given template-id.
4458struct PartialSpecMatchResult {
4459 VarTemplatePartialSpecializationDecl *Partial;
4460 TemplateArgumentList *Args;
4461};
4462} // end anonymous namespace
4463
4464DeclResult
4465Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
4466 SourceLocation TemplateNameLoc,
4467 const TemplateArgumentListInfo &TemplateArgs) {
4468 assert(Template && "A variable template id without template?")((Template && "A variable template id without template?"
) ? static_cast<void> (0) : __assert_fail ("Template && \"A variable template id without template?\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4468, __PRETTY_FUNCTION__))
;
4469
4470 // Check that the template argument list is well-formed for this template.
4471 SmallVector<TemplateArgument, 4> Converted;
4472 if (CheckTemplateArgumentList(
4473 Template, TemplateNameLoc,
4474 const_cast<TemplateArgumentListInfo &>(TemplateArgs), false,
4475 Converted, /*UpdateArgsWithConversion=*/true))
4476 return true;
4477
4478 // Produce a placeholder value if the specialization is dependent.
4479 bool InstantiationDependent = false;
4480 if (Template->getDeclContext()->isDependentContext() ||
4481 TemplateSpecializationType::anyDependentTemplateArguments(
4482 TemplateArgs, InstantiationDependent))
4483 return DeclResult();
4484
4485 // Find the variable template specialization declaration that
4486 // corresponds to these arguments.
4487 void *InsertPos = nullptr;
4488 if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization(
4489 Converted, InsertPos)) {
4490 checkSpecializationVisibility(TemplateNameLoc, Spec);
4491 // If we already have a variable template specialization, return it.
4492 return Spec;
4493 }
4494
4495 // This is the first time we have referenced this variable template
4496 // specialization. Create the canonical declaration and add it to
4497 // the set of specializations, based on the closest partial specialization
4498 // that it represents. That is,
4499 VarDecl *InstantiationPattern = Template->getTemplatedDecl();
4500 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
4501 Converted);
4502 TemplateArgumentList *InstantiationArgs = &TemplateArgList;
4503 bool AmbiguousPartialSpec = false;
4504 typedef PartialSpecMatchResult MatchResult;
4505 SmallVector<MatchResult, 4> Matched;
4506 SourceLocation PointOfInstantiation = TemplateNameLoc;
4507 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation,
4508 /*ForTakingAddress=*/false);
4509
4510 // 1. Attempt to find the closest partial specialization that this
4511 // specializes, if any.
4512 // TODO: Unify with InstantiateClassTemplateSpecialization()?
4513 // Perhaps better after unification of DeduceTemplateArguments() and
4514 // getMoreSpecializedPartialSpecialization().
4515 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
4516 Template->getPartialSpecializations(PartialSpecs);
4517
4518 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
4519 VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
4520 TemplateDeductionInfo Info(FailedCandidates.getLocation());
4521
4522 if (TemplateDeductionResult Result =
4523 DeduceTemplateArguments(Partial, TemplateArgList, Info)) {
4524 // Store the failed-deduction information for use in diagnostics, later.
4525 // TODO: Actually use the failed-deduction info?
4526 FailedCandidates.addCandidate().set(
4527 DeclAccessPair::make(Template, AS_public), Partial,
4528 MakeDeductionFailureInfo(Context, Result, Info));
4529 (void)Result;
4530 } else {
4531 Matched.push_back(PartialSpecMatchResult());
4532 Matched.back().Partial = Partial;
4533 Matched.back().Args = Info.take();
4534 }
4535 }
4536
4537 if (Matched.size() >= 1) {
4538 SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
4539 if (Matched.size() == 1) {
4540 // -- If exactly one matching specialization is found, the
4541 // instantiation is generated from that specialization.
4542 // We don't need to do anything for this.
4543 } else {
4544 // -- If more than one matching specialization is found, the
4545 // partial order rules (14.5.4.2) are used to determine
4546 // whether one of the specializations is more specialized
4547 // than the others. If none of the specializations is more
4548 // specialized than all of the other matching
4549 // specializations, then the use of the variable template is
4550 // ambiguous and the program is ill-formed.
4551 for (SmallVector<MatchResult, 4>::iterator P = Best + 1,
4552 PEnd = Matched.end();
4553 P != PEnd; ++P) {
4554 if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial,
4555 PointOfInstantiation) ==
4556 P->Partial)
4557 Best = P;
4558 }
4559
4560 // Determine if the best partial specialization is more specialized than
4561 // the others.
4562 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
4563 PEnd = Matched.end();
4564 P != PEnd; ++P) {
4565 if (P != Best && getMoreSpecializedPartialSpecialization(
4566 P->Partial, Best->Partial,
4567 PointOfInstantiation) != Best->Partial) {
4568 AmbiguousPartialSpec = true;
4569 break;
4570 }
4571 }
4572 }
4573
4574 // Instantiate using the best variable template partial specialization.
4575 InstantiationPattern = Best->Partial;
4576 InstantiationArgs = Best->Args;
4577 } else {
4578 // -- If no match is found, the instantiation is generated
4579 // from the primary template.
4580 // InstantiationPattern = Template->getTemplatedDecl();
4581 }
4582
4583 // 2. Create the canonical declaration.
4584 // Note that we do not instantiate a definition until we see an odr-use
4585 // in DoMarkVarDeclReferenced().
4586 // FIXME: LateAttrs et al.?
4587 VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation(
4588 Template, InstantiationPattern, *InstantiationArgs, TemplateArgs,
4589 Converted, TemplateNameLoc /*, LateAttrs, StartingScope*/);
4590 if (!Decl)
4591 return true;
4592
4593 if (AmbiguousPartialSpec) {
4594 // Partial ordering did not produce a clear winner. Complain.
4595 Decl->setInvalidDecl();
4596 Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
4597 << Decl;
4598
4599 // Print the matching partial specializations.
4600 for (MatchResult P : Matched)
4601 Diag(P.Partial->getLocation(), diag::note_partial_spec_match)
4602 << getTemplateArgumentBindingsText(P.Partial->getTemplateParameters(),
4603 *P.Args);
4604 return true;
4605 }
4606
4607 if (VarTemplatePartialSpecializationDecl *D =
4608 dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern))
4609 Decl->setInstantiationOf(D, InstantiationArgs);
4610
4611 checkSpecializationVisibility(TemplateNameLoc, Decl);
4612
4613 assert(Decl && "No variable template specialization?")((Decl && "No variable template specialization?") ? static_cast
<void> (0) : __assert_fail ("Decl && \"No variable template specialization?\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4613, __PRETTY_FUNCTION__))
;
4614 return Decl;
4615}
4616
4617ExprResult
4618Sema::CheckVarTemplateId(const CXXScopeSpec &SS,
4619 const DeclarationNameInfo &NameInfo,
4620 VarTemplateDecl *Template, SourceLocation TemplateLoc,
4621 const TemplateArgumentListInfo *TemplateArgs) {
4622
4623 DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(),
4624 *TemplateArgs);
4625 if (Decl.isInvalid())
4626 return ExprError();
4627
4628 if (!Decl.get())
4629 return ExprResult();
4630
4631 VarDecl *Var = cast<VarDecl>(Decl.get());
4632 if (!Var->getTemplateSpecializationKind())
4633 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation,
4634 NameInfo.getLoc());
4635
4636 // Build an ordinary singleton decl ref.
4637 return BuildDeclarationNameExpr(SS, NameInfo, Var,
4638 /*FoundD=*/nullptr, TemplateArgs);
4639}
4640
4641void Sema::diagnoseMissingTemplateArguments(TemplateName Name,
4642 SourceLocation Loc) {
4643 Diag(Loc, diag::err_template_missing_args)
4644 << (int)getTemplateNameKindForDiagnostics(Name) << Name;
4645 if (TemplateDecl *TD = Name.getAsTemplateDecl()) {
4646 Diag(TD->getLocation(), diag::note_template_decl_here)
4647 << TD->getTemplateParameters()->getSourceRange();
4648 }
4649}
4650
4651ExprResult
4652Sema::CheckConceptTemplateId(const CXXScopeSpec &SS,
4653 SourceLocation TemplateKWLoc,
4654 const DeclarationNameInfo &ConceptNameInfo,
4655 NamedDecl *FoundDecl,
4656 ConceptDecl *NamedConcept,
4657 const TemplateArgumentListInfo *TemplateArgs) {
4658 assert(NamedConcept && "A concept template id without a template?")((NamedConcept && "A concept template id without a template?"
) ? static_cast<void> (0) : __assert_fail ("NamedConcept && \"A concept template id without a template?\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4658, __PRETTY_FUNCTION__))
;
4659
4660 llvm::SmallVector<TemplateArgument, 4> Converted;
4661 if (CheckTemplateArgumentList(NamedConcept, ConceptNameInfo.getLoc(),
4662 const_cast<TemplateArgumentListInfo&>(*TemplateArgs),
4663 /*PartialTemplateArgs=*/false, Converted,
4664 /*UpdateArgsWithConversion=*/false))
4665 return ExprError();
4666
4667 ConstraintSatisfaction Satisfaction;
4668 bool AreArgsDependent = false;
4669 for (TemplateArgument &Arg : Converted) {
4670 if (Arg.isDependent()) {
4671 AreArgsDependent = true;
4672 break;
4673 }
4674 }
4675 if (!AreArgsDependent &&
4676 CheckConstraintSatisfaction(NamedConcept,
4677 {NamedConcept->getConstraintExpr()},
4678 Converted,
4679 SourceRange(SS.isSet() ? SS.getBeginLoc() :
4680 ConceptNameInfo.getLoc(),
4681 TemplateArgs->getRAngleLoc()),
4682 Satisfaction))
4683 return ExprError();
4684
4685 return ConceptSpecializationExpr::Create(Context,
4686 SS.isSet() ? SS.getWithLocInContext(Context) : NestedNameSpecifierLoc{},
4687 TemplateKWLoc, ConceptNameInfo, FoundDecl, NamedConcept,
4688 ASTTemplateArgumentListInfo::Create(Context, *TemplateArgs), Converted,
4689 AreArgsDependent ? nullptr : &Satisfaction);
4690}
4691
4692ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
4693 SourceLocation TemplateKWLoc,
4694 LookupResult &R,
4695 bool RequiresADL,
4696 const TemplateArgumentListInfo *TemplateArgs) {
4697 // FIXME: Can we do any checking at this point? I guess we could check the
4698 // template arguments that we have against the template name, if the template
4699 // name refers to a single template. That's not a terribly common case,
4700 // though.
4701 // foo<int> could identify a single function unambiguously
4702 // This approach does NOT work, since f<int>(1);
4703 // gets resolved prior to resorting to overload resolution
4704 // i.e., template<class T> void f(double);
4705 // vs template<class T, class U> void f(U);
4706
4707 // These should be filtered out by our callers.
4708 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid")((!R.isAmbiguous() && "ambiguous lookup when building templateid"
) ? static_cast<void> (0) : __assert_fail ("!R.isAmbiguous() && \"ambiguous lookup when building templateid\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4708, __PRETTY_FUNCTION__))
;
4709
4710 // Non-function templates require a template argument list.
4711 if (auto *TD = R.getAsSingle<TemplateDecl>()) {
4712 if (!TemplateArgs && !isa<FunctionTemplateDecl>(TD)) {
4713 diagnoseMissingTemplateArguments(TemplateName(TD), R.getNameLoc());
4714 return ExprError();
4715 }
4716 }
4717
4718 // In C++1y, check variable template ids.
4719 if (R.getAsSingle<VarTemplateDecl>()) {
4720 ExprResult Res = CheckVarTemplateId(SS, R.getLookupNameInfo(),
4721 R.getAsSingle<VarTemplateDecl>(),
4722 TemplateKWLoc, TemplateArgs);
4723 if (Res.isInvalid() || Res.isUsable())
4724 return Res;
4725 // Result is dependent. Carry on to build an UnresolvedLookupEpxr.
4726 }
4727
4728 if (R.getAsSingle<ConceptDecl>()) {
4729 return CheckConceptTemplateId(SS, TemplateKWLoc, R.getLookupNameInfo(),
4730 R.getFoundDecl(),
4731 R.getAsSingle<ConceptDecl>(), TemplateArgs);
4732 }
4733
4734 // We don't want lookup warnings at this point.
4735 R.suppressDiagnostics();
4736
4737 UnresolvedLookupExpr *ULE
4738 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
4739 SS.getWithLocInContext(Context),
4740 TemplateKWLoc,
4741 R.getLookupNameInfo(),
4742 RequiresADL, TemplateArgs,
4743 R.begin(), R.end());
4744
4745 return ULE;
4746}
4747
4748// We actually only call this from template instantiation.
4749ExprResult
4750Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
4751 SourceLocation TemplateKWLoc,
4752 const DeclarationNameInfo &NameInfo,
4753 const TemplateArgumentListInfo *TemplateArgs) {
4754
4755 assert(TemplateArgs || TemplateKWLoc.isValid())((TemplateArgs || TemplateKWLoc.isValid()) ? static_cast<void
> (0) : __assert_fail ("TemplateArgs || TemplateKWLoc.isValid()"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4755, __PRETTY_FUNCTION__))
;
4756 DeclContext *DC;
4757 if (!(DC = computeDeclContext(SS, false)) ||
4758 DC->isDependentContext() ||
4759 RequireCompleteDeclContext(SS, DC))
4760 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
4761
4762 bool MemberOfUnknownSpecialization;
4763 LookupResult R(*this, NameInfo, LookupOrdinaryName);
4764 if (LookupTemplateName(R, (Scope *)nullptr, SS, QualType(),
4765 /*Entering*/false, MemberOfUnknownSpecialization,
4766 TemplateKWLoc))
4767 return ExprError();
4768
4769 if (R.isAmbiguous())
4770 return ExprError();
4771
4772 if (R.empty()) {
4773 Diag(NameInfo.getLoc(), diag::err_no_member)
4774 << NameInfo.getName() << DC << SS.getRange();
4775 return ExprError();
4776 }
4777
4778 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) {
4779 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template)
4780 << SS.getScopeRep()
4781 << NameInfo.getName().getAsString() << SS.getRange();
4782 Diag(Temp->getLocation(), diag::note_referenced_class_template);
4783 return ExprError();
4784 }
4785
4786 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs);
4787}
4788
4789/// Form a template name from a name that is syntactically required to name a
4790/// template, either due to use of the 'template' keyword or because a name in
4791/// this syntactic context is assumed to name a template (C++ [temp.names]p2-4).
4792///
4793/// This action forms a template name given the name of the template and its
4794/// optional scope specifier. This is used when the 'template' keyword is used
4795/// or when the parsing context unambiguously treats a following '<' as
4796/// introducing a template argument list. Note that this may produce a
4797/// non-dependent template name if we can perform the lookup now and identify
4798/// the named template.
4799///
4800/// For example, given "x.MetaFun::template apply", the scope specifier
4801/// \p SS will be "MetaFun::", \p TemplateKWLoc contains the location
4802/// of the "template" keyword, and "apply" is the \p Name.
4803TemplateNameKind Sema::ActOnTemplateName(Scope *S,
4804 CXXScopeSpec &SS,
4805 SourceLocation TemplateKWLoc,
4806 const UnqualifiedId &Name,
4807 ParsedType ObjectType,
4808 bool EnteringContext,
4809 TemplateTy &Result,
4810 bool AllowInjectedClassName) {
4811 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent())
4812 Diag(TemplateKWLoc,
4813 getLangOpts().CPlusPlus11 ?
4814 diag::warn_cxx98_compat_template_outside_of_template :
4815 diag::ext_template_outside_of_template)
4816 << FixItHint::CreateRemoval(TemplateKWLoc);
4817
4818 if (SS.isInvalid())
4819 return TNK_Non_template;
4820
4821 // Figure out where isTemplateName is going to look.
4822 DeclContext *LookupCtx = nullptr;
4823 if (SS.isNotEmpty())
4824 LookupCtx = computeDeclContext(SS, EnteringContext);
4825 else if (ObjectType)
4826 LookupCtx = computeDeclContext(GetTypeFromParser(ObjectType));
4827
4828 // C++0x [temp.names]p5:
4829 // If a name prefixed by the keyword template is not the name of
4830 // a template, the program is ill-formed. [Note: the keyword
4831 // template may not be applied to non-template members of class
4832 // templates. -end note ] [ Note: as is the case with the
4833 // typename prefix, the template prefix is allowed in cases
4834 // where it is not strictly necessary; i.e., when the
4835 // nested-name-specifier or the expression on the left of the ->
4836 // or . is not dependent on a template-parameter, or the use
4837 // does not appear in the scope of a template. -end note]
4838 //
4839 // Note: C++03 was more strict here, because it banned the use of
4840 // the "template" keyword prior to a template-name that was not a
4841 // dependent name. C++ DR468 relaxed this requirement (the
4842 // "template" keyword is now permitted). We follow the C++0x
4843 // rules, even in C++03 mode with a warning, retroactively applying the DR.
4844 bool MemberOfUnknownSpecialization;
4845 TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name,
4846 ObjectType, EnteringContext, Result,
4847 MemberOfUnknownSpecialization);
4848 if (TNK != TNK_Non_template) {
4849 // We resolved this to a (non-dependent) template name. Return it.
4850 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
4851 if (!AllowInjectedClassName && SS.isNotEmpty() && LookupRD &&
4852 Name.getKind() == UnqualifiedIdKind::IK_Identifier &&
4853 Name.Identifier && LookupRD->getIdentifier() == Name.Identifier) {
4854 // C++14 [class.qual]p2:
4855 // In a lookup in which function names are not ignored and the
4856 // nested-name-specifier nominates a class C, if the name specified
4857 // [...] is the injected-class-name of C, [...] the name is instead
4858 // considered to name the constructor
4859 //
4860 // We don't get here if naming the constructor would be valid, so we
4861 // just reject immediately and recover by treating the
4862 // injected-class-name as naming the template.
4863 Diag(Name.getBeginLoc(),
4864 diag::ext_out_of_line_qualified_id_type_names_constructor)
4865 << Name.Identifier
4866 << 0 /*injected-class-name used as template name*/
4867 << TemplateKWLoc.isValid();
4868 }
4869 return TNK;
4870 }
4871
4872 if (!MemberOfUnknownSpecialization) {
4873 // Didn't find a template name, and the lookup wasn't dependent.
4874 // Do the lookup again to determine if this is a "nothing found" case or
4875 // a "not a template" case. FIXME: Refactor isTemplateName so we don't
4876 // need to do this.
4877 DeclarationNameInfo DNI = GetNameFromUnqualifiedId(Name);
4878 LookupResult R(*this, DNI.getName(), Name.getBeginLoc(),
4879 LookupOrdinaryName);
4880 bool MOUS;
4881 // Tell LookupTemplateName that we require a template so that it diagnoses
4882 // cases where it finds a non-template.
4883 RequiredTemplateKind RTK = TemplateKWLoc.isValid()
4884 ? RequiredTemplateKind(TemplateKWLoc)
4885 : TemplateNameIsRequired;
4886 if (!LookupTemplateName(R, S, SS, ObjectType.get(), EnteringContext, MOUS,
4887 RTK, nullptr, /*AllowTypoCorrection=*/false) &&
4888 !R.isAmbiguous()) {
4889 if (LookupCtx)
4890 Diag(Name.getBeginLoc(), diag::err_no_member)
4891 << DNI.getName() << LookupCtx << SS.getRange();
4892 else
4893 Diag(Name.getBeginLoc(), diag::err_undeclared_use)
4894 << DNI.getName() << SS.getRange();
4895 }
4896 return TNK_Non_template;
4897 }
4898
4899 NestedNameSpecifier *Qualifier = SS.getScopeRep();
4900
4901 switch (Name.getKind()) {
4902 case UnqualifiedIdKind::IK_Identifier:
4903 Result = TemplateTy::make(
4904 Context.getDependentTemplateName(Qualifier, Name.Identifier));
4905 return TNK_Dependent_template_name;
4906
4907 case UnqualifiedIdKind::IK_OperatorFunctionId:
4908 Result = TemplateTy::make(Context.getDependentTemplateName(
4909 Qualifier, Name.OperatorFunctionId.Operator));
4910 return TNK_Function_template;
4911
4912 case UnqualifiedIdKind::IK_LiteralOperatorId:
4913 // This is a kind of template name, but can never occur in a dependent
4914 // scope (literal operators can only be declared at namespace scope).
4915 break;
4916
4917 default:
4918 break;
4919 }
4920
4921 // This name cannot possibly name a dependent template. Diagnose this now
4922 // rather than building a dependent template name that can never be valid.
4923 Diag(Name.getBeginLoc(),
4924 diag::err_template_kw_refers_to_dependent_non_template)
4925 << GetNameFromUnqualifiedId(Name).getName() << Name.getSourceRange()
4926 << TemplateKWLoc.isValid() << TemplateKWLoc;
4927 return TNK_Non_template;
4928}
4929
4930bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
4931 TemplateArgumentLoc &AL,
4932 SmallVectorImpl<TemplateArgument> &Converted) {
4933 const TemplateArgument &Arg = AL.getArgument();
4934 QualType ArgType;
4935 TypeSourceInfo *TSI = nullptr;
4936
4937 // Check template type parameter.
4938 switch(Arg.getKind()) {
4939 case TemplateArgument::Type:
4940 // C++ [temp.arg.type]p1:
4941 // A template-argument for a template-parameter which is a
4942 // type shall be a type-id.
4943 ArgType = Arg.getAsType();
4944 TSI = AL.getTypeSourceInfo();
4945 break;
4946 case TemplateArgument::Template:
4947 case TemplateArgument::TemplateExpansion: {
4948 // We have a template type parameter but the template argument
4949 // is a template without any arguments.
4950 SourceRange SR = AL.getSourceRange();
4951 TemplateName Name = Arg.getAsTemplateOrTemplatePattern();
4952 diagnoseMissingTemplateArguments(Name, SR.getEnd());
4953 return true;
4954 }
4955 case TemplateArgument::Expression: {
4956 // We have a template type parameter but the template argument is an
4957 // expression; see if maybe it is missing the "typename" keyword.
4958 CXXScopeSpec SS;
4959 DeclarationNameInfo NameInfo;
4960
4961 if (DependentScopeDeclRefExpr *ArgExpr =
4962 dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) {
4963 SS.Adopt(ArgExpr->getQualifierLoc());
4964 NameInfo = ArgExpr->getNameInfo();
4965 } else if (CXXDependentScopeMemberExpr *ArgExpr =
4966 dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) {
4967 if (ArgExpr->isImplicitAccess()) {
4968 SS.Adopt(ArgExpr->getQualifierLoc());
4969 NameInfo = ArgExpr->getMemberNameInfo();
4970 }
4971 }
4972
4973 if (auto *II = NameInfo.getName().getAsIdentifierInfo()) {
4974 LookupResult Result(*this, NameInfo, LookupOrdinaryName);
4975 LookupParsedName(Result, CurScope, &SS);
4976
4977 if (Result.getAsSingle<TypeDecl>() ||
4978 Result.getResultKind() ==
4979 LookupResult::NotFoundInCurrentInstantiation) {
4980 assert(SS.getScopeRep() && "dependent scope expr must has a scope!")((SS.getScopeRep() && "dependent scope expr must has a scope!"
) ? static_cast<void> (0) : __assert_fail ("SS.getScopeRep() && \"dependent scope expr must has a scope!\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 4980, __PRETTY_FUNCTION__))
;
4981 // Suggest that the user add 'typename' before the NNS.
4982 SourceLocation Loc = AL.getSourceRange().getBegin();
4983 Diag(Loc, getLangOpts().MSVCCompat
4984 ? diag::ext_ms_template_type_arg_missing_typename
4985 : diag::err_template_arg_must_be_type_suggest)
4986 << FixItHint::CreateInsertion(Loc, "typename ");
4987 Diag(Param->getLocation(), diag::note_template_param_here);
4988
4989 // Recover by synthesizing a type using the location information that we
4990 // already have.
4991 ArgType =
4992 Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II);
4993 TypeLocBuilder TLB;
4994 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(ArgType);
4995 TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/));
4996 TL.setQualifierLoc(SS.getWithLocInContext(Context));
4997 TL.setNameLoc(NameInfo.getLoc());
4998 TSI = TLB.getTypeSourceInfo(Context, ArgType);
4999
5000 // Overwrite our input TemplateArgumentLoc so that we can recover
5001 // properly.
5002 AL = TemplateArgumentLoc(TemplateArgument(ArgType),
5003 TemplateArgumentLocInfo(TSI));
5004
5005 break;
5006 }
5007 }
5008 // fallthrough
5009 LLVM_FALLTHROUGH[[gnu::fallthrough]];
5010 }
5011 default: {
5012 // We have a template type parameter but the template argument
5013 // is not a type.
5014 SourceRange SR = AL.getSourceRange();
5015 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR;
5016 Diag(Param->getLocation(), diag::note_template_param_here);
5017
5018 return true;
5019 }
5020 }
5021
5022 if (CheckTemplateArgument(Param, TSI))
5023 return true;
5024
5025 // Add the converted template type argument.
5026 ArgType = Context.getCanonicalType(ArgType);
5027
5028 // Objective-C ARC:
5029 // If an explicitly-specified template argument type is a lifetime type
5030 // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
5031 if (getLangOpts().ObjCAutoRefCount &&
5032 ArgType->isObjCLifetimeType() &&
5033 !ArgType.getObjCLifetime()) {
5034 Qualifiers Qs;
5035 Qs.setObjCLifetime(Qualifiers::OCL_Strong);
5036 ArgType = Context.getQualifiedType(ArgType, Qs);
5037 }
5038
5039 Converted.push_back(TemplateArgument(ArgType));
5040 return false;
5041}
5042
5043/// Substitute template arguments into the default template argument for
5044/// the given template type parameter.
5045///
5046/// \param SemaRef the semantic analysis object for which we are performing
5047/// the substitution.
5048///
5049/// \param Template the template that we are synthesizing template arguments
5050/// for.
5051///
5052/// \param TemplateLoc the location of the template name that started the
5053/// template-id we are checking.
5054///
5055/// \param RAngleLoc the location of the right angle bracket ('>') that
5056/// terminates the template-id.
5057///
5058/// \param Param the template template parameter whose default we are
5059/// substituting into.
5060///
5061/// \param Converted the list of template arguments provided for template
5062/// parameters that precede \p Param in the template parameter list.
5063/// \returns the substituted template argument, or NULL if an error occurred.
5064static TypeSourceInfo *
5065SubstDefaultTemplateArgument(Sema &SemaRef,
5066 TemplateDecl *Template,
5067 SourceLocation TemplateLoc,
5068 SourceLocation RAngleLoc,
5069 TemplateTypeParmDecl *Param,
5070 SmallVectorImpl<TemplateArgument> &Converted) {
5071 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo();
5072
5073 // If the argument type is dependent, instantiate it now based
5074 // on the previously-computed template arguments.
5075 if (ArgType->getType()->isInstantiationDependentType()) {
5076 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
5077 Param, Template, Converted,
5078 SourceRange(TemplateLoc, RAngleLoc));
5079 if (Inst.isInvalid())
5080 return nullptr;
5081
5082 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5083
5084 // Only substitute for the innermost template argument list.
5085 MultiLevelTemplateArgumentList TemplateArgLists;
5086 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
5087 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
5088 TemplateArgLists.addOuterTemplateArguments(None);
5089
5090 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
5091 ArgType =
5092 SemaRef.SubstType(ArgType, TemplateArgLists,
5093 Param->getDefaultArgumentLoc(), Param->getDeclName());
5094 }
5095
5096 return ArgType;
5097}
5098
5099/// Substitute template arguments into the default template argument for
5100/// the given non-type template parameter.
5101///
5102/// \param SemaRef the semantic analysis object for which we are performing
5103/// the substitution.
5104///
5105/// \param Template the template that we are synthesizing template arguments
5106/// for.
5107///
5108/// \param TemplateLoc the location of the template name that started the
5109/// template-id we are checking.
5110///
5111/// \param RAngleLoc the location of the right angle bracket ('>') that
5112/// terminates the template-id.
5113///
5114/// \param Param the non-type template parameter whose default we are
5115/// substituting into.
5116///
5117/// \param Converted the list of template arguments provided for template
5118/// parameters that precede \p Param in the template parameter list.
5119///
5120/// \returns the substituted template argument, or NULL if an error occurred.
5121static ExprResult
5122SubstDefaultTemplateArgument(Sema &SemaRef,
5123 TemplateDecl *Template,
5124 SourceLocation TemplateLoc,
5125 SourceLocation RAngleLoc,
5126 NonTypeTemplateParmDecl *Param,
5127 SmallVectorImpl<TemplateArgument> &Converted) {
5128 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
5129 Param, Template, Converted,
5130 SourceRange(TemplateLoc, RAngleLoc));
5131 if (Inst.isInvalid())
5132 return ExprError();
5133
5134 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5135
5136 // Only substitute for the innermost template argument list.
5137 MultiLevelTemplateArgumentList TemplateArgLists;
5138 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
5139 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
5140 TemplateArgLists.addOuterTemplateArguments(None);
5141
5142 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
5143 EnterExpressionEvaluationContext ConstantEvaluated(
5144 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
5145 return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
5146}
5147
5148/// Substitute template arguments into the default template argument for
5149/// the given template template parameter.
5150///
5151/// \param SemaRef the semantic analysis object for which we are performing
5152/// the substitution.
5153///
5154/// \param Template the template that we are synthesizing template arguments
5155/// for.
5156///
5157/// \param TemplateLoc the location of the template name that started the
5158/// template-id we are checking.
5159///
5160/// \param RAngleLoc the location of the right angle bracket ('>') that
5161/// terminates the template-id.
5162///
5163/// \param Param the template template parameter whose default we are
5164/// substituting into.
5165///
5166/// \param Converted the list of template arguments provided for template
5167/// parameters that precede \p Param in the template parameter list.
5168///
5169/// \param QualifierLoc Will be set to the nested-name-specifier (with
5170/// source-location information) that precedes the template name.
5171///
5172/// \returns the substituted template argument, or NULL if an error occurred.
5173static TemplateName
5174SubstDefaultTemplateArgument(Sema &SemaRef,
5175 TemplateDecl *Template,
5176 SourceLocation TemplateLoc,
5177 SourceLocation RAngleLoc,
5178 TemplateTemplateParmDecl *Param,
5179 SmallVectorImpl<TemplateArgument> &Converted,
5180 NestedNameSpecifierLoc &QualifierLoc) {
5181 Sema::InstantiatingTemplate Inst(
5182 SemaRef, TemplateLoc, TemplateParameter(Param), Template, Converted,
5183 SourceRange(TemplateLoc, RAngleLoc));
5184 if (Inst.isInvalid())
5185 return TemplateName();
5186
5187 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5188
5189 // Only substitute for the innermost template argument list.
5190 MultiLevelTemplateArgumentList TemplateArgLists;
5191 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
5192 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
5193 TemplateArgLists.addOuterTemplateArguments(None);
5194
5195 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
5196 // Substitute into the nested-name-specifier first,
5197 QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
5198 if (QualifierLoc) {
5199 QualifierLoc =
5200 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists);
5201 if (!QualifierLoc)
5202 return TemplateName();
5203 }
5204
5205 return SemaRef.SubstTemplateName(
5206 QualifierLoc,
5207 Param->getDefaultArgument().getArgument().getAsTemplate(),
5208 Param->getDefaultArgument().getTemplateNameLoc(),
5209 TemplateArgLists);
5210}
5211
5212/// If the given template parameter has a default template
5213/// argument, substitute into that default template argument and
5214/// return the corresponding template argument.
5215TemplateArgumentLoc
5216Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
5217 SourceLocation TemplateLoc,
5218 SourceLocation RAngleLoc,
5219 Decl *Param,
5220 SmallVectorImpl<TemplateArgument>
5221 &Converted,
5222 bool &HasDefaultArg) {
5223 HasDefaultArg = false;
5224
5225 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) {
5226 if (!hasVisibleDefaultArgument(TypeParm))
5227 return TemplateArgumentLoc();
5228
5229 HasDefaultArg = true;
5230 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template,
5231 TemplateLoc,
5232 RAngleLoc,
5233 TypeParm,
5234 Converted);
5235 if (DI)
5236 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI);
5237
5238 return TemplateArgumentLoc();
5239 }
5240
5241 if (NonTypeTemplateParmDecl *NonTypeParm
5242 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
5243 if (!hasVisibleDefaultArgument(NonTypeParm))
5244 return TemplateArgumentLoc();
5245
5246 HasDefaultArg = true;
5247 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template,
5248 TemplateLoc,
5249 RAngleLoc,
5250 NonTypeParm,
5251 Converted);
5252 if (Arg.isInvalid())
5253 return TemplateArgumentLoc();
5254
5255 Expr *ArgE = Arg.getAs<Expr>();
5256 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE);
5257 }
5258
5259 TemplateTemplateParmDecl *TempTempParm
5260 = cast<TemplateTemplateParmDecl>(Param);
5261 if (!hasVisibleDefaultArgument(TempTempParm))
5262 return TemplateArgumentLoc();
5263
5264 HasDefaultArg = true;
5265 NestedNameSpecifierLoc QualifierLoc;
5266 TemplateName TName = SubstDefaultTemplateArgument(*this, Template,
5267 TemplateLoc,
5268 RAngleLoc,
5269 TempTempParm,
5270 Converted,
5271 QualifierLoc);
5272 if (TName.isNull())
5273 return TemplateArgumentLoc();
5274
5275 return TemplateArgumentLoc(
5276 Context, TemplateArgument(TName),
5277 TempTempParm->getDefaultArgument().getTemplateQualifierLoc(),
5278 TempTempParm->getDefaultArgument().getTemplateNameLoc());
5279}
5280
5281/// Convert a template-argument that we parsed as a type into a template, if
5282/// possible. C++ permits injected-class-names to perform dual service as
5283/// template template arguments and as template type arguments.
5284static TemplateArgumentLoc
5285convertTypeTemplateArgumentToTemplate(ASTContext &Context, TypeLoc TLoc) {
5286 // Extract and step over any surrounding nested-name-specifier.
5287 NestedNameSpecifierLoc QualLoc;
5288 if (auto ETLoc = TLoc.getAs<ElaboratedTypeLoc>()) {
5289 if (ETLoc.getTypePtr()->getKeyword() != ETK_None)
5290 return TemplateArgumentLoc();
5291
5292 QualLoc = ETLoc.getQualifierLoc();
5293 TLoc = ETLoc.getNamedTypeLoc();
5294 }
5295 // If this type was written as an injected-class-name, it can be used as a
5296 // template template argument.
5297 if (auto InjLoc = TLoc.getAs<InjectedClassNameTypeLoc>())
5298 return TemplateArgumentLoc(Context, InjLoc.getTypePtr()->getTemplateName(),
5299 QualLoc, InjLoc.getNameLoc());
5300
5301 // If this type was written as an injected-class-name, it may have been
5302 // converted to a RecordType during instantiation. If the RecordType is
5303 // *not* wrapped in a TemplateSpecializationType and denotes a class
5304 // template specialization, it must have come from an injected-class-name.
5305 if (auto RecLoc = TLoc.getAs<RecordTypeLoc>())
5306 if (auto *CTSD =
5307 dyn_cast<ClassTemplateSpecializationDecl>(RecLoc.getDecl()))
5308 return TemplateArgumentLoc(Context,
5309 TemplateName(CTSD->getSpecializedTemplate()),
5310 QualLoc, RecLoc.getNameLoc());
5311
5312 return TemplateArgumentLoc();
5313}
5314
5315/// Check that the given template argument corresponds to the given
5316/// template parameter.
5317///
5318/// \param Param The template parameter against which the argument will be
5319/// checked.
5320///
5321/// \param Arg The template argument, which may be updated due to conversions.
5322///
5323/// \param Template The template in which the template argument resides.
5324///
5325/// \param TemplateLoc The location of the template name for the template
5326/// whose argument list we're matching.
5327///
5328/// \param RAngleLoc The location of the right angle bracket ('>') that closes
5329/// the template argument list.
5330///
5331/// \param ArgumentPackIndex The index into the argument pack where this
5332/// argument will be placed. Only valid if the parameter is a parameter pack.
5333///
5334/// \param Converted The checked, converted argument will be added to the
5335/// end of this small vector.
5336///
5337/// \param CTAK Describes how we arrived at this particular template argument:
5338/// explicitly written, deduced, etc.
5339///
5340/// \returns true on error, false otherwise.
5341bool Sema::CheckTemplateArgument(NamedDecl *Param,
5342 TemplateArgumentLoc &Arg,
5343 NamedDecl *Template,
5344 SourceLocation TemplateLoc,
5345 SourceLocation RAngleLoc,
5346 unsigned ArgumentPackIndex,
5347 SmallVectorImpl<TemplateArgument> &Converted,
5348 CheckTemplateArgumentKind CTAK) {
5349 // Check template type parameters.
5350 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
5351 return CheckTemplateTypeArgument(TTP, Arg, Converted);
5352
5353 // Check non-type template parameters.
5354 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) {
5355 // Do substitution on the type of the non-type template parameter
5356 // with the template arguments we've seen thus far. But if the
5357 // template has a dependent context then we cannot substitute yet.
5358 QualType NTTPType = NTTP->getType();
5359 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack())
5360 NTTPType = NTTP->getExpansionType(ArgumentPackIndex);
5361
5362 if (NTTPType->isInstantiationDependentType() &&
5363 !isa<TemplateTemplateParmDecl>(Template) &&
5364 !Template->getDeclContext()->isDependentContext()) {
5365 // Do substitution on the type of the non-type template parameter.
5366 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
5367 NTTP, Converted,
5368 SourceRange(TemplateLoc, RAngleLoc));
5369 if (Inst.isInvalid())
5370 return true;
5371
5372 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
5373 Converted);
5374
5375 // If the parameter is a pack expansion, expand this slice of the pack.
5376 if (auto *PET = NTTPType->getAs<PackExpansionType>()) {
5377 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this,
5378 ArgumentPackIndex);
5379 NTTPType = SubstType(PET->getPattern(),
5380 MultiLevelTemplateArgumentList(TemplateArgs),
5381 NTTP->getLocation(),
5382 NTTP->getDeclName());
5383 } else {
5384 NTTPType = SubstType(NTTPType,
5385 MultiLevelTemplateArgumentList(TemplateArgs),
5386 NTTP->getLocation(),
5387 NTTP->getDeclName());
5388 }
5389
5390 // If that worked, check the non-type template parameter type
5391 // for validity.
5392 if (!NTTPType.isNull())
5393 NTTPType = CheckNonTypeTemplateParameterType(NTTPType,
5394 NTTP->getLocation());
5395 if (NTTPType.isNull())
5396 return true;
5397 }
5398
5399 switch (Arg.getArgument().getKind()) {
5400 case TemplateArgument::Null:
5401 llvm_unreachable("Should never see a NULL template argument here")::llvm::llvm_unreachable_internal("Should never see a NULL template argument here"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 5401)
;
5402
5403 case TemplateArgument::Expression: {
5404 TemplateArgument Result;
5405 unsigned CurSFINAEErrors = NumSFINAEErrors;
5406 ExprResult Res =
5407 CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(),
5408 Result, CTAK);
5409 if (Res.isInvalid())
5410 return true;
5411 // If the current template argument causes an error, give up now.
5412 if (CurSFINAEErrors < NumSFINAEErrors)
5413 return true;
5414
5415 // If the resulting expression is new, then use it in place of the
5416 // old expression in the template argument.
5417 if (Res.get() != Arg.getArgument().getAsExpr()) {
5418 TemplateArgument TA(Res.get());
5419 Arg = TemplateArgumentLoc(TA, Res.get());
5420 }
5421
5422 Converted.push_back(Result);
5423 break;
5424 }
5425
5426 case TemplateArgument::Declaration:
5427 case TemplateArgument::Integral:
5428 case TemplateArgument::NullPtr:
5429 // We've already checked this template argument, so just copy
5430 // it to the list of converted arguments.
5431 Converted.push_back(Arg.getArgument());
5432 break;
5433
5434 case TemplateArgument::Template:
5435 case TemplateArgument::TemplateExpansion:
5436 // We were given a template template argument. It may not be ill-formed;
5437 // see below.
5438 if (DependentTemplateName *DTN
5439 = Arg.getArgument().getAsTemplateOrTemplatePattern()
5440 .getAsDependentTemplateName()) {
5441 // We have a template argument such as \c T::template X, which we
5442 // parsed as a template template argument. However, since we now
5443 // know that we need a non-type template argument, convert this
5444 // template name into an expression.
5445
5446 DeclarationNameInfo NameInfo(DTN->getIdentifier(),
5447 Arg.getTemplateNameLoc());
5448
5449 CXXScopeSpec SS;
5450 SS.Adopt(Arg.getTemplateQualifierLoc());
5451 // FIXME: the template-template arg was a DependentTemplateName,
5452 // so it was provided with a template keyword. However, its source
5453 // location is not stored in the template argument structure.
5454 SourceLocation TemplateKWLoc;
5455 ExprResult E = DependentScopeDeclRefExpr::Create(
5456 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
5457 nullptr);
5458
5459 // If we parsed the template argument as a pack expansion, create a
5460 // pack expansion expression.
5461 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){
5462 E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc());
5463 if (E.isInvalid())
5464 return true;
5465 }
5466
5467 TemplateArgument Result;
5468 E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result);
5469 if (E.isInvalid())
5470 return true;
5471
5472 Converted.push_back(Result);
5473 break;
5474 }
5475
5476 // We have a template argument that actually does refer to a class
5477 // template, alias template, or template template parameter, and
5478 // therefore cannot be a non-type template argument.
5479 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr)
5480 << Arg.getSourceRange();
5481
5482 Diag(Param->getLocation(), diag::note_template_param_here);
5483 return true;
5484
5485 case TemplateArgument::Type: {
5486 // We have a non-type template parameter but the template
5487 // argument is a type.
5488
5489 // C++ [temp.arg]p2:
5490 // In a template-argument, an ambiguity between a type-id and
5491 // an expression is resolved to a type-id, regardless of the
5492 // form of the corresponding template-parameter.
5493 //
5494 // We warn specifically about this case, since it can be rather
5495 // confusing for users.
5496 QualType T = Arg.getArgument().getAsType();
5497 SourceRange SR = Arg.getSourceRange();
5498 if (T->isFunctionType())
5499 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T;
5500 else
5501 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR;
5502 Diag(Param->getLocation(), diag::note_template_param_here);
5503 return true;
5504 }
5505
5506 case TemplateArgument::Pack:
5507 llvm_unreachable("Caller must expand template argument packs")::llvm::llvm_unreachable_internal("Caller must expand template argument packs"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 5507)
;
5508 }
5509
5510 return false;
5511 }
5512
5513
5514 // Check template template parameters.
5515 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param);
5516
5517 TemplateParameterList *Params = TempParm->getTemplateParameters();
5518 if (TempParm->isExpandedParameterPack())
5519 Params = TempParm->getExpansionTemplateParameters(ArgumentPackIndex);
5520
5521 // Substitute into the template parameter list of the template
5522 // template parameter, since previously-supplied template arguments
5523 // may appear within the template template parameter.
5524 //
5525 // FIXME: Skip this if the parameters aren't instantiation-dependent.
5526 {
5527 // Set up a template instantiation context.
5528 LocalInstantiationScope Scope(*this);
5529 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
5530 TempParm, Converted,
5531 SourceRange(TemplateLoc, RAngleLoc));
5532 if (Inst.isInvalid())
5533 return true;
5534
5535 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5536 Params = SubstTemplateParams(Params, CurContext,
5537 MultiLevelTemplateArgumentList(TemplateArgs));
5538 if (!Params)
5539 return true;
5540 }
5541
5542 // C++1z [temp.local]p1: (DR1004)
5543 // When [the injected-class-name] is used [...] as a template-argument for
5544 // a template template-parameter [...] it refers to the class template
5545 // itself.
5546 if (Arg.getArgument().getKind() == TemplateArgument::Type) {
5547 TemplateArgumentLoc ConvertedArg = convertTypeTemplateArgumentToTemplate(
5548 Context, Arg.getTypeSourceInfo()->getTypeLoc());
5549 if (!ConvertedArg.getArgument().isNull())
5550 Arg = ConvertedArg;
5551 }
5552
5553 switch (Arg.getArgument().getKind()) {
5554 case TemplateArgument::Null:
5555 llvm_unreachable("Should never see a NULL template argument here")::llvm::llvm_unreachable_internal("Should never see a NULL template argument here"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 5555)
;
5556
5557 case TemplateArgument::Template:
5558 case TemplateArgument::TemplateExpansion:
5559 if (CheckTemplateTemplateArgument(TempParm, Params, Arg))
5560 return true;
5561
5562 Converted.push_back(Arg.getArgument());
5563 break;
5564
5565 case TemplateArgument::Expression:
5566 case TemplateArgument::Type:
5567 // We have a template template parameter but the template
5568 // argument does not refer to a template.
5569 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template)
5570 << getLangOpts().CPlusPlus11;
5571 return true;
5572
5573 case TemplateArgument::Declaration:
5574 llvm_unreachable("Declaration argument with template template parameter")::llvm::llvm_unreachable_internal("Declaration argument with template template parameter"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 5574)
;
5575 case TemplateArgument::Integral:
5576 llvm_unreachable("Integral argument with template template parameter")::llvm::llvm_unreachable_internal("Integral argument with template template parameter"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 5576)
;
5577 case TemplateArgument::NullPtr:
5578 llvm_unreachable("Null pointer argument with template template parameter")::llvm::llvm_unreachable_internal("Null pointer argument with template template parameter"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 5578)
;
5579
5580 case TemplateArgument::Pack:
5581 llvm_unreachable("Caller must expand template argument packs")::llvm::llvm_unreachable_internal("Caller must expand template argument packs"
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 5581)
;
5582 }
5583
5584 return false;
5585}
5586
5587/// Check whether the template parameter is a pack expansion, and if so,
5588/// determine the number of parameters produced by that expansion. For instance:
5589///
5590/// \code
5591/// template<typename ...Ts> struct A {
5592/// template<Ts ...NTs, template<Ts> class ...TTs, typename ...Us> struct B;
5593/// };
5594/// \endcode
5595///
5596/// In \c A<int,int>::B, \c NTs and \c TTs have expanded pack size 2, and \c Us
5597/// is not a pack expansion, so returns an empty Optional.
5598static Optional<unsigned> getExpandedPackSize(NamedDecl *Param) {
5599 if (TemplateTypeParmDecl *TTP
5600 = dyn_cast<TemplateTypeParmDecl>(Param)) {
5601 if (TTP->isExpandedParameterPack())
5602 return TTP->getNumExpansionParameters();
5603 }
5604
5605 if (NonTypeTemplateParmDecl *NTTP
5606 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
5607 if (NTTP->isExpandedParameterPack())
5608 return NTTP->getNumExpansionTypes();
5609 }
5610
5611 if (TemplateTemplateParmDecl *TTP
5612 = dyn_cast<TemplateTemplateParmDecl>(Param)) {
5613 if (TTP->isExpandedParameterPack())
5614 return TTP->getNumExpansionTemplateParameters();
5615 }
5616
5617 return None;
5618}
5619
5620/// Diagnose a missing template argument.
5621template<typename TemplateParmDecl>
5622static bool diagnoseMissingArgument(Sema &S, SourceLocation Loc,
5623 TemplateDecl *TD,
5624 const TemplateParmDecl *D,
5625 TemplateArgumentListInfo &Args) {
5626 // Dig out the most recent declaration of the template parameter; there may be
5627 // declarations of the template that are more recent than TD.
5628 D = cast<TemplateParmDecl>(cast<TemplateDecl>(TD->getMostRecentDecl())
5629 ->getTemplateParameters()
5630 ->getParam(D->getIndex()));
5631
5632 // If there's a default argument that's not visible, diagnose that we're
5633 // missing a module import.
5634 llvm::SmallVector<Module*, 8> Modules;
5635 if (D->hasDefaultArgument() && !S.hasVisibleDefaultArgument(D, &Modules)) {
5636 S.diagnoseMissingImport(Loc, cast<NamedDecl>(TD),
5637 D->getDefaultArgumentLoc(), Modules,
5638 Sema::MissingImportKind::DefaultArgument,
5639 /*Recover*/true);
5640 return true;
5641 }
5642
5643 // FIXME: If there's a more recent default argument that *is* visible,
5644 // diagnose that it was declared too late.
5645
5646 TemplateParameterList *Params = TD->getTemplateParameters();
5647
5648 S.Diag(Loc, diag::err_template_arg_list_different_arity)
5649 << /*not enough args*/0
5650 << (int)S.getTemplateNameKindForDiagnostics(TemplateName(TD))
5651 << TD;
5652 S.Diag(TD->getLocation(), diag::note_template_decl_here)
5653 << Params->getSourceRange();
5654 return true;
5655}
5656
5657/// Check that the given template argument list is well-formed
5658/// for specializing the given template.
5659bool Sema::CheckTemplateArgumentList(
5660 TemplateDecl *Template, SourceLocation TemplateLoc,
5661 TemplateArgumentListInfo &TemplateArgs, bool PartialTemplateArgs,
5662 SmallVectorImpl<TemplateArgument> &Converted,
5663 bool UpdateArgsWithConversions, bool *ConstraintsNotSatisfied) {
5664
5665 if (ConstraintsNotSatisfied)
5666 *ConstraintsNotSatisfied = false;
5667
5668 // Make a copy of the template arguments for processing. Only make the
5669 // changes at the end when successful in matching the arguments to the
5670 // template.
5671 TemplateArgumentListInfo NewArgs = TemplateArgs;
5672
5673 // Make sure we get the template parameter list from the most
5674 // recentdeclaration, since that is the only one that has is guaranteed to
5675 // have all the default template argument information.
5676 TemplateParameterList *Params =
5677 cast<TemplateDecl>(Template->getMostRecentDecl())
5678 ->getTemplateParameters();
5679
5680 SourceLocation RAngleLoc = NewArgs.getRAngleLoc();
5681
5682 // C++ [temp.arg]p1:
5683 // [...] The type and form of each template-argument specified in
5684 // a template-id shall match the type and form specified for the
5685 // corresponding parameter declared by the template in its
5686 // template-parameter-list.
5687 bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template);
5688 SmallVector<TemplateArgument, 2> ArgumentPack;
5689 unsigned ArgIdx = 0, NumArgs = NewArgs.size();
5690 LocalInstantiationScope InstScope(*this, true);
5691 for (TemplateParameterList::iterator Param = Params->begin(),
5692 ParamEnd = Params->end();
5693 Param != ParamEnd; /* increment in loop */) {
5694 // If we have an expanded parameter pack, make sure we don't have too
5695 // many arguments.
5696 if (Optional<unsigned> Expansions = getExpandedPackSize(*Param)) {
5697 if (*Expansions == ArgumentPack.size()) {
5698 // We're done with this parameter pack. Pack up its arguments and add
5699 // them to the list.
5700 Converted.push_back(
5701 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
5702 ArgumentPack.clear();
5703
5704 // This argument is assigned to the next parameter.
5705 ++Param;
5706 continue;
5707 } else if (ArgIdx == NumArgs && !PartialTemplateArgs) {
5708 // Not enough arguments for this parameter pack.
5709 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
5710 << /*not enough args*/0
5711 << (int)getTemplateNameKindForDiagnostics(TemplateName(Template))
5712 << Template;
5713 Diag(Template->getLocation(), diag::note_template_decl_here)
5714 << Params->getSourceRange();
5715 return true;
5716 }
5717 }
5718
5719 if (ArgIdx < NumArgs) {
5720 // Check the template argument we were given.
5721 if (CheckTemplateArgument(*Param, NewArgs[ArgIdx], Template,
5722 TemplateLoc, RAngleLoc,
5723 ArgumentPack.size(), Converted))
5724 return true;
5725
5726 bool PackExpansionIntoNonPack =
5727 NewArgs[ArgIdx].getArgument().isPackExpansion() &&
5728 (!(*Param)->isTemplateParameterPack() || getExpandedPackSize(*Param));
5729 if (PackExpansionIntoNonPack && (isa<TypeAliasTemplateDecl>(Template) ||
5730 isa<ConceptDecl>(Template))) {
5731 // Core issue 1430: we have a pack expansion as an argument to an
5732 // alias template, and it's not part of a parameter pack. This
5733 // can't be canonicalized, so reject it now.
5734 // As for concepts - we cannot normalize constraints where this
5735 // situation exists.
5736 Diag(NewArgs[ArgIdx].getLocation(),
5737 diag::err_template_expansion_into_fixed_list)
5738 << (isa<ConceptDecl>(Template) ? 1 : 0)
5739 << NewArgs[ArgIdx].getSourceRange();
5740 Diag((*Param)->getLocation(), diag::note_template_param_here);
5741 return true;
5742 }
5743
5744 // We're now done with this argument.
5745 ++ArgIdx;
5746
5747 if ((*Param)->isTemplateParameterPack()) {
5748 // The template parameter was a template parameter pack, so take the
5749 // deduced argument and place it on the argument pack. Note that we
5750 // stay on the same template parameter so that we can deduce more
5751 // arguments.
5752 ArgumentPack.push_back(Converted.pop_back_val());
5753 } else {
5754 // Move to the next template parameter.
5755 ++Param;
5756 }
5757
5758 // If we just saw a pack expansion into a non-pack, then directly convert
5759 // the remaining arguments, because we don't know what parameters they'll
5760 // match up with.
5761 if (PackExpansionIntoNonPack) {
5762 if (!ArgumentPack.empty()) {
5763 // If we were part way through filling in an expanded parameter pack,
5764 // fall back to just producing individual arguments.
5765 Converted.insert(Converted.end(),
5766 ArgumentPack.begin(), ArgumentPack.end());
5767 ArgumentPack.clear();
5768 }
5769
5770 while (ArgIdx < NumArgs) {
5771 Converted.push_back(NewArgs[ArgIdx].getArgument());
5772 ++ArgIdx;
5773 }
5774
5775 return false;
5776 }
5777
5778 continue;
5779 }
5780
5781 // If we're checking a partial template argument list, we're done.
5782 if (PartialTemplateArgs) {
5783 if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty())
5784 Converted.push_back(
5785 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
5786 return false;
5787 }
5788
5789 // If we have a template parameter pack with no more corresponding
5790 // arguments, just break out now and we'll fill in the argument pack below.
5791 if ((*Param)->isTemplateParameterPack()) {
5792 assert(!getExpandedPackSize(*Param) &&((!getExpandedPackSize(*Param) && "Should have dealt with this already"
) ? static_cast<void> (0) : __assert_fail ("!getExpandedPackSize(*Param) && \"Should have dealt with this already\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 5793, __PRETTY_FUNCTION__))
5793 "Should have dealt with this already")((!getExpandedPackSize(*Param) && "Should have dealt with this already"
) ? static_cast<void> (0) : __assert_fail ("!getExpandedPackSize(*Param) && \"Should have dealt with this already\""
, "/build/llvm-toolchain-snapshot-12~++20201029100616+6c2ad4cf875/clang/lib/Sema/SemaTemplate.cpp"
, 5793, __PRETTY_FUNCTION__))
;
5794
5795 // A non-expanded parameter pack before the end of the parameter list
5796 // only occurs for an ill-formed template parameter list, unless we've
5797 // got a partial argument list for a function template, so just bail out.
5798 if (Param + 1 != ParamEnd)
5799 return true;
5800
5801 Converted.push_back(
5802 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
5803 ArgumentPack.clear();
5804
5805 ++Param;
5806 continue;
5807 }
5808
5809 // Check whether we have a default argument.
5810 TemplateArgumentLoc Arg;
5811
5812 // Retrieve the default template argument from the template
5813 // parameter. For each kind of template parameter, we substitute the
5814 // template arguments provided thus far and any "outer" template arguments
5815 // (when the template parameter was part of a nested template) into
5816 // the default argument.
5817 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) {
5818 if (!hasVisibleDefaultArgument(TTP))
5819 return diagnoseMissingArgument(*this, TemplateLoc, Template, TTP,
5820 NewArgs);
5821
5822 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this,
5823 Template,
5824 TemplateLoc,
5825 RAngleLoc,
5826 TTP,
5827 Converted);
5828 if (!ArgType)
5829 return true;
5830
5831 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()),
5832 ArgType);
5833 } else if (NonTypeTemplateParmDecl *NTTP
5834 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
5835 if (!hasVisibleDefaultArgument(NTTP))
5836 return diagnoseMissingArgument(*this, TemplateLoc, Template, NTTP,
5837 NewArgs);
5838
5839 ExprResult E = SubstDefaultTemplateArgument(*this, Template,
5840 TemplateLoc,
5841 RAngleLoc,
5842 NTTP,
5843 Converted);
5844 if (E.isInvalid())
5845 return true;
5846
5847 Expr *Ex = E.getAs<Expr>();
5848 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex);
5849 } else {
5850 TemplateTemplateParmDecl *TempParm
5851 = cast<TemplateTemplateParmDecl>(*Param);
5852
5853 if (!hasVisibleDefaultArgument(TempParm))
5854 return diagnoseMissingArgument(*this, TemplateLoc, Template, TempParm,
5855 NewArgs);
5856
5857 NestedNameSpecifierLoc QualifierLoc;
5858 TemplateName Name = SubstDefaultTemplateArgument(*this, Template,
5859 TemplateLoc,
5860 RAngleLoc,
5861 TempParm,
5862 Converted,
5863 QualifierLoc);
5864 if (Name.isNull())
5865 return true;
5866
5867 Arg = TemplateArgumentLoc(
5868 Context, TemplateArgument(Name), QualifierLoc,
5869 TempParm->getDefaultArgument().getTemplateNameLoc());
5870 }
5871
5872 // Introduce an instantiation record that describes where we are using
5873 // the default template argument. We're not actually instantiating a
5874 // template here, we just create this object to put a note into the
5875 // context stack.
5876 InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted,
5877 SourceRange(TemplateLoc, RAngleLoc));
5878 if (Inst.isInvalid())
5879 return true;
5880
5881 // Check the default template argument.
5882 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
5883 RAngleLoc, 0, Converted))
5884 return true;
5885
5886 // Core issue 150 (assumed resolution): if this is a template template
5887 // parameter, keep track of the default template arguments from the
5888 // template definition.
5889 if (isTemplateTemplateParameter)
5890 NewArgs.addArgument(Arg);
5891
5892 // Move to the next template parameter and argument.
5893 ++Param;
5894 ++ArgIdx;
5895 }
5896
5897 // If we're performing a partial argument substitution, allow any trailing
5898 // pack expansions; they might be empty. This can happen even if
5899 // PartialTemplateArgs is false (the list of arguments is complete but
5900 // still dependent).
5901 if (ArgIdx < NumArgs && CurrentInstantiationScope &&
5902 CurrentInstantiationScope->getPartiallySubstitutedPack()) {
5903 while (ArgIdx < NumArgs && NewArgs[ArgIdx].getArgument().isPackExpansion())
5904 Converted.push_back(NewArgs[ArgIdx++].getArgument());
5905 }
5906
5907 // If we have any leftover arguments, then there were too many arguments.
5908 // Complain and fail.
5909 if (ArgIdx < NumArgs) {
5910 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
5911 << /*too many args*/1
5912 << (int)getTemplateNameKindForDiagnostics(TemplateName(Template))
5913 << Template
5914 << SourceRange(NewArgs[ArgIdx].getLocation(), NewArgs.getRAngleLoc());
5915 Diag(Template->getLocation(), diag::note_template_decl_here)
5916 << Params->getSourceRange();
5917 return true;
5918 }
5919
5920 // No problems found with the new argument list, propagate changes back
5921 // to caller.
5922 if (UpdateArgsWithConversions)
5923 TemplateArgs = std::move(NewArgs);
5924
5925 if (!PartialTemplateArgs &&
5926 EnsureTemplateArgumentListConstraints(
5927 Template, Converted, SourceRange(TemplateLoc,
5928 TemplateArgs.getRAngleLoc()))) {
5929 if (ConstraintsNotSatisfied)
5930 *ConstraintsNotSatisfied = true;
5931 return true;
5932 }
5933
5934 return false;
5935}
5936
5937namespace {
5938 class UnnamedLocalNoLinkageFinder
5939 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool>
5940 {
5941 Sema &S;
5942 SourceRange SR;
5943
5944 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited;
5945
5946 public:
5947 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { }
5948
5949 bool Visit(QualType T) {
5950 return T.isNull() ? false : inherited::Visit(T.getTypePtr());
5951 }
5952
5953#define TYPE(Class, Parent) \
5954 bool Visit##Class##Type(const Class##Type *);
5955#define ABSTRACT_TYPE(Class, Parent) \
5956 bool Visit##Class##Type(const Class##Type *) { return false; }
5957#define NON_CANONICAL_TYPE(Class, Parent) \
5958 bool Visit##Class##Type(const Class##Type *) { return false; }
5959#include "clang/AST/TypeNodes.inc"
5960
5961 bool VisitTagDecl(const TagDecl *Tag);
5962 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS);
5963 };
5964} // end anonymous namespace
5965
5966bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) {
5967 return false;
5968}
5969
5970bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) {
5971 return Visit(T->getElementType());
5972}
5973
5974bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) {
5975 return Visit(T->getPointeeType());
5976}
5977
5978bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
5979 const BlockPointerType* T) {
5980 return Visit(T->getPointeeType());
5981}
5982
5983bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
5984 const LValueReferenceType* T) {
5985 return Visit(T->getPointeeType());
5986}
5987
5988bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
5989 const RValueReferenceType* T) {
5990 return Visit(T->getPointeeType());
5991}
5992
5993bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
5994 const MemberPointerType* T) {
5995 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0));
5996}
5997
5998bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
5999 const ConstantArrayType* T) {
6000 return Visit(T->getElementType());
6001}
6002
6003bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
6004 const IncompleteArrayType* T) {
6005 return Visit(T->getElementType());
6006}
6007
6008bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
6009 const VariableArrayType* T) {
6010 return Visit(T->getElementType());
6011}
6012
6013bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
6014 const DependentSizedArrayType* T) {
6015 return Visit(T->getElementType());
6016}
6017
6018bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
6019 const DependentSizedExtVectorType* T) {
6020 return Visit(T->getElementType());
6021}
6022
6023bool UnnamedLocalNoLinkageFinder::VisitDependentSizedMatrixType(
6024 const DependentSizedMatrixType *T) {
6025 return Visit(T->getElementType());
6026}
6027
6028bool UnnamedLocalNoLinkageFinder::VisitDependentAddressSpaceType(
6029 const DependentAddressSpaceType *T) {
6030 return Visit(T->getPointeeType());
6031}
6032
6033bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) {
6034 return Visit(T->getElementType());
6035}
6036
6037bool<