Bug Summary

File:clang/lib/Sema/SemaTemplate.cpp
Warning:line 1395, 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 -debugger-tuning=gdb -ffunction-sections -fdata-sections -fcoverage-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/build-llvm/tools/clang/lib/Sema -resource-dir /usr/lib/llvm-13/lib/clang/13.0.0 -D CLANG_ROUND_TRIP_CC1_ARGS=ON -D _DEBUG -D _GNU_SOURCE -D __STDC_CONSTANT_MACROS -D __STDC_FORMAT_MACROS -D __STDC_LIMIT_MACROS -I /build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/build-llvm/tools/clang/lib/Sema -I /build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema -I /build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/include -I /build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/build-llvm/tools/clang/include -I /build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/build-llvm/include -I /build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/llvm/include -D NDEBUG -U NDEBUG -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/x86_64-linux-gnu/c++/10 -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../include/c++/10/backward -internal-isystem /usr/lib/llvm-13/lib/clang/13.0.0/include -internal-isystem /usr/local/include -internal-isystem /usr/lib/gcc/x86_64-linux-gnu/10/../../../../x86_64-linux-gnu/include -internal-externc-isystem /usr/include/x86_64-linux-gnu -internal-externc-isystem /include -internal-externc-isystem /usr/include -O2 -Wno-unused-parameter -Wwrite-strings -Wno-missing-field-initializers -Wno-long-long -Wno-maybe-uninitialized -Wno-class-memaccess -Wno-redundant-move -Wno-pessimizing-move -Wno-noexcept-type -Wno-comment -std=c++14 -fdeprecated-macro -fdebug-compilation-dir=/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/build-llvm/tools/clang/lib/Sema -fdebug-prefix-map=/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c=. -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 -D__GCC_HAVE_DWARF2_CFI_ASM=1 -o /tmp/scan-build-2021-07-26-235520-9401-1 -x c++ /build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/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!")(static_cast <bool> (getLangOpts().CPlusPlus &&
"No template names in C!") ? void (0) : __assert_fail ("getLangOpts().CPlusPlus && \"No template names in C!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 179, __extension__ __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")(static_cast <bool> (D && "unambiguous result is not a template name"
) ? void (0) : __assert_fail ("D && \"unambiguous result is not a template name\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 273, __extension__ __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) ||(static_cast <bool> (isa<ClassTemplateDecl>(TD) ||
isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl
>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl
>(TD) || isa<ConceptDecl>(TD)) ? void (0) : __assert_fail
("isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD)"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 300, __extension__ __PRETTY_FUNCTION__))
299 isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) ||(static_cast <bool> (isa<ClassTemplateDecl>(TD) ||
isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl
>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl
>(TD) || isa<ConceptDecl>(TD)) ? void (0) : __assert_fail
("isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD)"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 300, __extension__ __PRETTY_FUNCTION__))
300 isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD))(static_cast <bool> (isa<ClassTemplateDecl>(TD) ||
isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl
>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl
>(TD) || isa<ConceptDecl>(TD)) ? void (0) : __assert_fail
("isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) || isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) || isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD)"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 300, __extension__ __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")(static_cast <bool> (SS.isEmpty() && "ObjectType and scope specifier cannot coexist"
) ? void (0) : __assert_fail ("SS.isEmpty() && \"ObjectType and scope specifier cannot coexist\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 393, __extension__ __PRETTY_FUNCTION__))
;
394 LookupCtx = computeDeclContext(ObjectType);
395 IsDependent = !LookupCtx && ObjectType->isDependentType();
396 assert((IsDependent || !ObjectType->isIncompleteType() ||(static_cast <bool> ((IsDependent || !ObjectType->isIncompleteType
() || ObjectType->castAs<TagType>()->isBeingDefined
()) && "Caller should have completed object type") ? void
(0) : __assert_fail ("(IsDependent || !ObjectType->isIncompleteType() || ObjectType->castAs<TagType>()->isBeingDefined()) && \"Caller should have completed object type\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 398, __extension__ __PRETTY_FUNCTION__))
397 ObjectType->castAs<TagType>()->isBeingDefined()) &&(static_cast <bool> ((IsDependent || !ObjectType->isIncompleteType
() || ObjectType->castAs<TagType>()->isBeingDefined
()) && "Caller should have completed object type") ? void
(0) : __assert_fail ("(IsDependent || !ObjectType->isIncompleteType() || ObjectType->castAs<TagType>()->isBeingDefined()) && \"Caller should have completed object type\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 398, __extension__ __PRETTY_FUNCTION__))
398 "Caller should have completed object type")(static_cast <bool> ((IsDependent || !ObjectType->isIncompleteType
() || ObjectType->castAs<TagType>()->isBeingDefined
()) && "Caller should have completed object type") ? void
(0) : __assert_fail ("(IsDependent || !ObjectType->isIncompleteType() || ObjectType->castAs<TagType>()->isBeingDefined()) && \"Caller should have completed object type\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 398, __extension__ __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-13~++20210726100616+dead50d4427c/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) ||(static_cast <bool> (isa<TagDecl>(Instantiation) ||
isa<FunctionDecl>(Instantiation) || isa<VarDecl>
(Instantiation)) ? void (0) : __assert_fail ("isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) || isa<VarDecl>(Instantiation)"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 791, __extension__ __PRETTY_FUNCTION__))
791 isa<VarDecl>(Instantiation))(static_cast <bool> (isa<TagDecl>(Instantiation) ||
isa<FunctionDecl>(Instantiation) || isa<VarDecl>
(Instantiation)) ? void (0) : __assert_fail ("isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) || isa<VarDecl>(Instantiation)"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 791, __extension__ __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!")(static_cast <bool> (isa<TagDecl>(Instantiation) &&
"Must be a TagDecl!") ? void (0) : __assert_fail ("isa<TagDecl>(Instantiation) && \"Must be a TagDecl!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 834, __extension__ __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!")(static_cast <bool> (isa<VarDecl>(Instantiation) &&
"Must be a VarDecl!") ? void (0) : __assert_fail ("isa<VarDecl>(Instantiation) && \"Must be a VarDecl!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 852, __extension__ __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")(static_cast <bool> (PrevDecl->isTemplateParameter()
&& "Not a template parameter") ? void (0) : __assert_fail
("PrevDecl->isTemplateParameter() && \"Not a template parameter\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 883, __extension__ __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 &&(static_cast <bool> (Kind == Template && "Only template template arguments can be pack expansions here"
) ? void (0) : __assert_fail ("Kind == Template && \"Only template template arguments can be pack expansions here\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 910, __extension__ __PRETTY_FUNCTION__))
910 "Only template template arguments can be pack expansions here")(static_cast <bool> (Kind == Template && "Only template template arguments can be pack expansions here"
) ? void (0) : __assert_fail ("Kind == Template && \"Only template template arguments can be pack expansions here\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 910, __extension__ __PRETTY_FUNCTION__))
;
911 assert(getAsTemplate().get().containsUnexpandedParameterPack() &&(static_cast <bool> (getAsTemplate().get().containsUnexpandedParameterPack
() && "Template template argument pack expansion without packs"
) ? void (0) : __assert_fail ("getAsTemplate().get().containsUnexpandedParameterPack() && \"Template template argument pack expansion without packs\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 912, __extension__ __PRETTY_FUNCTION__))
912 "Template template argument pack expansion without packs")(static_cast <bool> (getAsTemplate().get().containsUnexpandedParameterPack
() && "Template template argument pack expansion without packs"
) ? void (0) : __assert_fail ("getAsTemplate().get().containsUnexpandedParameterPack() && \"Template template argument pack expansion without packs\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 912, __extension__ __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-13~++20210726100616+dead50d4427c/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")(static_cast <bool> (TInfo && "template argument with no location"
) ? void (0) : __assert_fail ("TInfo && \"template argument with no location\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 979, __extension__ __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() &&(static_cast <bool> (S->isTemplateParamScope() &&
"Template type parameter not in template parameter scope!") ?
void (0) : __assert_fail ("S->isTemplateParamScope() && \"Template type parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1039, __extension__ __PRETTY_FUNCTION__))
1039 "Template type parameter not in template parameter scope!")(static_cast <bool> (S->isTemplateParamScope() &&
"Template type parameter not in template parameter scope!") ?
void (0) : __assert_fail ("S->isTemplateParamScope() && \"Template type parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1039, __extension__ __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")(static_cast <bool> (DefaultTInfo && "expected source information for type"
) ? void (0) : __assert_fail ("DefaultTInfo && \"expected source information for type\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1074, __extension__ __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 return BuildTypeConstraint(SS, TypeConstr, ConstrainedParameter, EllipsisLoc,
1109 false);
1110}
1111
1112bool Sema::BuildTypeConstraint(const CXXScopeSpec &SS,
1113 TemplateIdAnnotation *TypeConstr,
1114 TemplateTypeParmDecl *ConstrainedParameter,
1115 SourceLocation EllipsisLoc,
1116 bool AllowUnexpandedPack) {
1117 TemplateName TN = TypeConstr->Template.get();
1118 ConceptDecl *CD = cast<ConceptDecl>(TN.getAsTemplateDecl());
1119
1120 // C++2a [temp.param]p4:
1121 // [...] The concept designated by a type-constraint shall be a type
1122 // concept ([temp.concept]).
1123 if (!CD->isTypeConcept()) {
1124 Diag(TypeConstr->TemplateNameLoc,
1125 diag::err_type_constraint_non_type_concept);
1126 return true;
1127 }
1128
1129 bool WereArgsSpecified = TypeConstr->LAngleLoc.isValid();
1130
1131 if (!WereArgsSpecified &&
1132 CD->getTemplateParameters()->getMinRequiredArguments() > 1) {
1133 Diag(TypeConstr->TemplateNameLoc,
1134 diag::err_type_constraint_missing_arguments) << CD;
1135 return true;
1136 }
1137
1138 DeclarationNameInfo ConceptName(DeclarationName(TypeConstr->Name),
1139 TypeConstr->TemplateNameLoc);
1140
1141 TemplateArgumentListInfo TemplateArgs;
1142 if (TypeConstr->LAngleLoc.isValid()) {
1143 TemplateArgs =
1144 makeTemplateArgumentListInfo(*this, *TypeConstr);
1145
1146 if (EllipsisLoc.isInvalid() && !AllowUnexpandedPack) {
1147 for (TemplateArgumentLoc Arg : TemplateArgs.arguments()) {
1148 if (DiagnoseUnexpandedParameterPack(Arg, UPPC_TypeConstraint))
1149 return true;
1150 }
1151 }
1152 }
1153 return AttachTypeConstraint(
1154 SS.isSet() ? SS.getWithLocInContext(Context) : NestedNameSpecifierLoc(),
1155 ConceptName, CD,
1156 TypeConstr->LAngleLoc.isValid() ? &TemplateArgs : nullptr,
1157 ConstrainedParameter, EllipsisLoc);
1158}
1159
1160template<typename ArgumentLocAppender>
1161static ExprResult formImmediatelyDeclaredConstraint(
1162 Sema &S, NestedNameSpecifierLoc NS, DeclarationNameInfo NameInfo,
1163 ConceptDecl *NamedConcept, SourceLocation LAngleLoc,
1164 SourceLocation RAngleLoc, QualType ConstrainedType,
1165 SourceLocation ParamNameLoc, ArgumentLocAppender Appender,
1166 SourceLocation EllipsisLoc) {
1167
1168 TemplateArgumentListInfo ConstraintArgs;
1169 ConstraintArgs.addArgument(
1170 S.getTrivialTemplateArgumentLoc(TemplateArgument(ConstrainedType),
1171 /*NTTPType=*/QualType(), ParamNameLoc));
1172
1173 ConstraintArgs.setRAngleLoc(RAngleLoc);
1174 ConstraintArgs.setLAngleLoc(LAngleLoc);
1175 Appender(ConstraintArgs);
1176
1177 // C++2a [temp.param]p4:
1178 // [...] This constraint-expression E is called the immediately-declared
1179 // constraint of T. [...]
1180 CXXScopeSpec SS;
1181 SS.Adopt(NS);
1182 ExprResult ImmediatelyDeclaredConstraint = S.CheckConceptTemplateId(
1183 SS, /*TemplateKWLoc=*/SourceLocation(), NameInfo,
1184 /*FoundDecl=*/NamedConcept, NamedConcept, &ConstraintArgs);
1185 if (ImmediatelyDeclaredConstraint.isInvalid() || !EllipsisLoc.isValid())
1186 return ImmediatelyDeclaredConstraint;
1187
1188 // C++2a [temp.param]p4:
1189 // [...] If T is not a pack, then E is E', otherwise E is (E' && ...).
1190 //
1191 // We have the following case:
1192 //
1193 // template<typename T> concept C1 = true;
1194 // template<C1... T> struct s1;
1195 //
1196 // The constraint: (C1<T> && ...)
1197 //
1198 // Note that the type of C1<T> is known to be 'bool', so we don't need to do
1199 // any unqualified lookups for 'operator&&' here.
1200 return S.BuildCXXFoldExpr(/*UnqualifiedLookup=*/nullptr,
1201 /*LParenLoc=*/SourceLocation(),
1202 ImmediatelyDeclaredConstraint.get(), BO_LAnd,
1203 EllipsisLoc, /*RHS=*/nullptr,
1204 /*RParenLoc=*/SourceLocation(),
1205 /*NumExpansions=*/None);
1206}
1207
1208/// Attach a type-constraint to a template parameter.
1209/// \returns true if an error occured. This can happen if the
1210/// immediately-declared constraint could not be formed (e.g. incorrect number
1211/// of arguments for the named concept).
1212bool Sema::AttachTypeConstraint(NestedNameSpecifierLoc NS,
1213 DeclarationNameInfo NameInfo,
1214 ConceptDecl *NamedConcept,
1215 const TemplateArgumentListInfo *TemplateArgs,
1216 TemplateTypeParmDecl *ConstrainedParameter,
1217 SourceLocation EllipsisLoc) {
1218 // C++2a [temp.param]p4:
1219 // [...] If Q is of the form C<A1, ..., An>, then let E' be
1220 // C<T, A1, ..., An>. Otherwise, let E' be C<T>. [...]
1221 const ASTTemplateArgumentListInfo *ArgsAsWritten =
1222 TemplateArgs ? ASTTemplateArgumentListInfo::Create(Context,
1223 *TemplateArgs) : nullptr;
1224
1225 QualType ParamAsArgument(ConstrainedParameter->getTypeForDecl(), 0);
1226
1227 ExprResult ImmediatelyDeclaredConstraint =
1228 formImmediatelyDeclaredConstraint(
1229 *this, NS, NameInfo, NamedConcept,
1230 TemplateArgs ? TemplateArgs->getLAngleLoc() : SourceLocation(),
1231 TemplateArgs ? TemplateArgs->getRAngleLoc() : SourceLocation(),
1232 ParamAsArgument, ConstrainedParameter->getLocation(),
1233 [&] (TemplateArgumentListInfo &ConstraintArgs) {
1234 if (TemplateArgs)
1235 for (const auto &ArgLoc : TemplateArgs->arguments())
1236 ConstraintArgs.addArgument(ArgLoc);
1237 }, EllipsisLoc);
1238 if (ImmediatelyDeclaredConstraint.isInvalid())
1239 return true;
1240
1241 ConstrainedParameter->setTypeConstraint(NS, NameInfo,
1242 /*FoundDecl=*/NamedConcept,
1243 NamedConcept, ArgsAsWritten,
1244 ImmediatelyDeclaredConstraint.get());
1245 return false;
1246}
1247
1248bool Sema::AttachTypeConstraint(AutoTypeLoc TL, NonTypeTemplateParmDecl *NTTP,
1249 SourceLocation EllipsisLoc) {
1250 if (NTTP->getType() != TL.getType() ||
1251 TL.getAutoKeyword() != AutoTypeKeyword::Auto) {
1252 Diag(NTTP->getTypeSourceInfo()->getTypeLoc().getBeginLoc(),
1253 diag::err_unsupported_placeholder_constraint)
1254 << NTTP->getTypeSourceInfo()->getTypeLoc().getSourceRange();
1255 return true;
1256 }
1257 // FIXME: Concepts: This should be the type of the placeholder, but this is
1258 // unclear in the wording right now.
1259 DeclRefExpr *Ref =
1260 BuildDeclRefExpr(NTTP, NTTP->getType(), VK_PRValue, NTTP->getLocation());
1261 if (!Ref)
1262 return true;
1263 ExprResult ImmediatelyDeclaredConstraint =
1264 formImmediatelyDeclaredConstraint(
1265 *this, TL.getNestedNameSpecifierLoc(), TL.getConceptNameInfo(),
1266 TL.getNamedConcept(), TL.getLAngleLoc(), TL.getRAngleLoc(),
1267 BuildDecltypeType(Ref, NTTP->getLocation()), NTTP->getLocation(),
1268 [&] (TemplateArgumentListInfo &ConstraintArgs) {
1269 for (unsigned I = 0, C = TL.getNumArgs(); I != C; ++I)
1270 ConstraintArgs.addArgument(TL.getArgLoc(I));
1271 }, EllipsisLoc);
1272 if (ImmediatelyDeclaredConstraint.isInvalid() ||
1273 !ImmediatelyDeclaredConstraint.isUsable())
1274 return true;
1275
1276 NTTP->setPlaceholderTypeConstraint(ImmediatelyDeclaredConstraint.get());
1277 return false;
1278}
1279
1280/// Check that the type of a non-type template parameter is
1281/// well-formed.
1282///
1283/// \returns the (possibly-promoted) parameter type if valid;
1284/// otherwise, produces a diagnostic and returns a NULL type.
1285QualType Sema::CheckNonTypeTemplateParameterType(TypeSourceInfo *&TSI,
1286 SourceLocation Loc) {
1287 if (TSI->getType()->isUndeducedType()) {
1288 // C++17 [temp.dep.expr]p3:
1289 // An id-expression is type-dependent if it contains
1290 // - an identifier associated by name lookup with a non-type
1291 // template-parameter declared with a type that contains a
1292 // placeholder type (7.1.7.4),
1293 TSI = SubstAutoTypeSourceInfo(TSI, Context.DependentTy);
1294 }
1295
1296 return CheckNonTypeTemplateParameterType(TSI->getType(), Loc);
1297}
1298
1299/// Require the given type to be a structural type, and diagnose if it is not.
1300///
1301/// \return \c true if an error was produced.
1302bool Sema::RequireStructuralType(QualType T, SourceLocation Loc) {
1303 if (T->isDependentType())
1304 return false;
1305
1306 if (RequireCompleteType(Loc, T, diag::err_template_nontype_parm_incomplete))
1307 return true;
1308
1309 if (T->isStructuralType())
1310 return false;
1311
1312 // Structural types are required to be object types or lvalue references.
1313 if (T->isRValueReferenceType()) {
1314 Diag(Loc, diag::err_template_nontype_parm_rvalue_ref) << T;
1315 return true;
1316 }
1317
1318 // Don't mention structural types in our diagnostic prior to C++20. Also,
1319 // there's not much more we can say about non-scalar non-class types --
1320 // because we can't see functions or arrays here, those can only be language
1321 // extensions.
1322 if (!getLangOpts().CPlusPlus20 ||
1323 (!T->isScalarType() && !T->isRecordType())) {
1324 Diag(Loc, diag::err_template_nontype_parm_bad_type) << T;
1325 return true;
1326 }
1327
1328 // Structural types are required to be literal types.
1329 if (RequireLiteralType(Loc, T, diag::err_template_nontype_parm_not_literal))
1330 return true;
1331
1332 Diag(Loc, diag::err_template_nontype_parm_not_structural) << T;
1333
1334 // Drill down into the reason why the class is non-structural.
1335 while (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
1336 // All members are required to be public and non-mutable, and can't be of
1337 // rvalue reference type. Check these conditions first to prefer a "local"
1338 // reason over a more distant one.
1339 for (const FieldDecl *FD : RD->fields()) {
1340 if (FD->getAccess() != AS_public) {
1341 Diag(FD->getLocation(), diag::note_not_structural_non_public) << T << 0;
1342 return true;
1343 }
1344 if (FD->isMutable()) {
1345 Diag(FD->getLocation(), diag::note_not_structural_mutable_field) << T;
1346 return true;
1347 }
1348 if (FD->getType()->isRValueReferenceType()) {
1349 Diag(FD->getLocation(), diag::note_not_structural_rvalue_ref_field)
1350 << T;
1351 return true;
1352 }
1353 }
1354
1355 // All bases are required to be public.
1356 for (const auto &BaseSpec : RD->bases()) {
1357 if (BaseSpec.getAccessSpecifier() != AS_public) {
1358 Diag(BaseSpec.getBaseTypeLoc(), diag::note_not_structural_non_public)
1359 << T << 1;
1360 return true;
1361 }
1362 }
1363
1364 // All subobjects are required to be of structural types.
1365 SourceLocation SubLoc;
1366 QualType SubType;
1367 int Kind = -1;
1368
1369 for (const FieldDecl *FD : RD->fields()) {
1370 QualType T = Context.getBaseElementType(FD->getType());
1371 if (!T->isStructuralType()) {
1372 SubLoc = FD->getLocation();
1373 SubType = T;
1374 Kind = 0;
1375 break;
1376 }
1377 }
1378
1379 if (Kind == -1) {
1380 for (const auto &BaseSpec : RD->bases()) {
1381 QualType T = BaseSpec.getType();
1382 if (!T->isStructuralType()) {
1383 SubLoc = BaseSpec.getBaseTypeLoc();
1384 SubType = T;
1385 Kind = 1;
1386 break;
1387 }
1388 }
1389 }
1390
1391 assert(Kind != -1 && "couldn't find reason why type is not structural")(static_cast <bool> (Kind != -1 && "couldn't find reason why type is not structural"
) ? void (0) : __assert_fail ("Kind != -1 && \"couldn't find reason why type is not structural\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1391, __extension__ __PRETTY_FUNCTION__))
;
1392 Diag(SubLoc, diag::note_not_structural_subobject)
1393 << T << Kind << SubType;
1394 T = SubType;
1395 RD = T->getAsCXXRecordDecl();
Value stored to 'RD' is never read
1396 }
1397
1398 return true;
1399}
1400
1401QualType Sema::CheckNonTypeTemplateParameterType(QualType T,
1402 SourceLocation Loc) {
1403 // We don't allow variably-modified types as the type of non-type template
1404 // parameters.
1405 if (T->isVariablyModifiedType()) {
1406 Diag(Loc, diag::err_variably_modified_nontype_template_param)
1407 << T;
1408 return QualType();
1409 }
1410
1411 // C++ [temp.param]p4:
1412 //
1413 // A non-type template-parameter shall have one of the following
1414 // (optionally cv-qualified) types:
1415 //
1416 // -- integral or enumeration type,
1417 if (T->isIntegralOrEnumerationType() ||
1418 // -- pointer to object or pointer to function,
1419 T->isPointerType() ||
1420 // -- lvalue reference to object or lvalue reference to function,
1421 T->isLValueReferenceType() ||
1422 // -- pointer to member,
1423 T->isMemberPointerType() ||
1424 // -- std::nullptr_t, or
1425 T->isNullPtrType() ||
1426 // -- a type that contains a placeholder type.
1427 T->isUndeducedType()) {
1428 // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
1429 // are ignored when determining its type.
1430 return T.getUnqualifiedType();
1431 }
1432
1433 // C++ [temp.param]p8:
1434 //
1435 // A non-type template-parameter of type "array of T" or
1436 // "function returning T" is adjusted to be of type "pointer to
1437 // T" or "pointer to function returning T", respectively.
1438 if (T->isArrayType() || T->isFunctionType())
1439 return Context.getDecayedType(T);
1440
1441 // If T is a dependent type, we can't do the check now, so we
1442 // assume that it is well-formed. Note that stripping off the
1443 // qualifiers here is not really correct if T turns out to be
1444 // an array type, but we'll recompute the type everywhere it's
1445 // used during instantiation, so that should be OK. (Using the
1446 // qualified type is equally wrong.)
1447 if (T->isDependentType())
1448 return T.getUnqualifiedType();
1449
1450 // C++20 [temp.param]p6:
1451 // -- a structural type
1452 if (RequireStructuralType(T, Loc))
1453 return QualType();
1454
1455 if (!getLangOpts().CPlusPlus20) {
1456 // FIXME: Consider allowing structural types as an extension in C++17. (In
1457 // earlier language modes, the template argument evaluation rules are too
1458 // inflexible.)
1459 Diag(Loc, diag::err_template_nontype_parm_bad_structural_type) << T;
1460 return QualType();
1461 }
1462
1463 Diag(Loc, diag::warn_cxx17_compat_template_nontype_parm_type) << T;
1464 return T.getUnqualifiedType();
1465}
1466
1467NamedDecl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
1468 unsigned Depth,
1469 unsigned Position,
1470 SourceLocation EqualLoc,
1471 Expr *Default) {
1472 TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
1473
1474 // Check that we have valid decl-specifiers specified.
1475 auto CheckValidDeclSpecifiers = [this, &D] {
1476 // C++ [temp.param]
1477 // p1
1478 // template-parameter:
1479 // ...
1480 // parameter-declaration
1481 // p2
1482 // ... A storage class shall not be specified in a template-parameter
1483 // declaration.
1484 // [dcl.typedef]p1:
1485 // The typedef specifier [...] shall not be used in the decl-specifier-seq
1486 // of a parameter-declaration
1487 const DeclSpec &DS = D.getDeclSpec();
1488 auto EmitDiag = [this](SourceLocation Loc) {
1489 Diag(Loc, diag::err_invalid_decl_specifier_in_nontype_parm)
1490 << FixItHint::CreateRemoval(Loc);
1491 };
1492 if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified)
1493 EmitDiag(DS.getStorageClassSpecLoc());
1494
1495 if (DS.getThreadStorageClassSpec() != TSCS_unspecified)
1496 EmitDiag(DS.getThreadStorageClassSpecLoc());
1497
1498 // [dcl.inline]p1:
1499 // The inline specifier can be applied only to the declaration or
1500 // definition of a variable or function.
1501
1502 if (DS.isInlineSpecified())
1503 EmitDiag(DS.getInlineSpecLoc());
1504
1505 // [dcl.constexpr]p1:
1506 // The constexpr specifier shall be applied only to the definition of a
1507 // variable or variable template or the declaration of a function or
1508 // function template.
1509
1510 if (DS.hasConstexprSpecifier())
1511 EmitDiag(DS.getConstexprSpecLoc());
1512
1513 // [dcl.fct.spec]p1:
1514 // Function-specifiers can be used only in function declarations.
1515
1516 if (DS.isVirtualSpecified())
1517 EmitDiag(DS.getVirtualSpecLoc());
1518
1519 if (DS.hasExplicitSpecifier())
1520 EmitDiag(DS.getExplicitSpecLoc());
1521
1522 if (DS.isNoreturnSpecified())
1523 EmitDiag(DS.getNoreturnSpecLoc());
1524 };
1525
1526 CheckValidDeclSpecifiers();
1527
1528 if (TInfo->getType()->isUndeducedType()) {
1529 Diag(D.getIdentifierLoc(),
1530 diag::warn_cxx14_compat_template_nontype_parm_auto_type)
1531 << QualType(TInfo->getType()->getContainedAutoType(), 0);
1532 }
1533
1534 assert(S->isTemplateParamScope() &&(static_cast <bool> (S->isTemplateParamScope() &&
"Non-type template parameter not in template parameter scope!"
) ? void (0) : __assert_fail ("S->isTemplateParamScope() && \"Non-type template parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1535, __extension__ __PRETTY_FUNCTION__))
1535 "Non-type template parameter not in template parameter scope!")(static_cast <bool> (S->isTemplateParamScope() &&
"Non-type template parameter not in template parameter scope!"
) ? void (0) : __assert_fail ("S->isTemplateParamScope() && \"Non-type template parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1535, __extension__ __PRETTY_FUNCTION__))
;
1536 bool Invalid = false;
1537
1538 QualType T = CheckNonTypeTemplateParameterType(TInfo, D.getIdentifierLoc());
1539 if (T.isNull()) {
1540 T = Context.IntTy; // Recover with an 'int' type.
1541 Invalid = true;
1542 }
1543
1544 CheckFunctionOrTemplateParamDeclarator(S, D);
1545
1546 IdentifierInfo *ParamName = D.getIdentifier();
1547 bool IsParameterPack = D.hasEllipsis();
1548 NonTypeTemplateParmDecl *Param = NonTypeTemplateParmDecl::Create(
1549 Context, Context.getTranslationUnitDecl(), D.getBeginLoc(),
1550 D.getIdentifierLoc(), Depth, Position, ParamName, T, IsParameterPack,
1551 TInfo);
1552 Param->setAccess(AS_public);
1553
1554 if (AutoTypeLoc TL = TInfo->getTypeLoc().getContainedAutoTypeLoc())
1555 if (TL.isConstrained())
1556 if (AttachTypeConstraint(TL, Param, D.getEllipsisLoc()))
1557 Invalid = true;
1558
1559 if (Invalid)
1560 Param->setInvalidDecl();
1561
1562 if (Param->isParameterPack())
1563 if (auto *LSI = getEnclosingLambda())
1564 LSI->LocalPacks.push_back(Param);
1565
1566 if (ParamName) {
1567 maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(),
1568 ParamName);
1569
1570 // Add the template parameter into the current scope.
1571 S->AddDecl(Param);
1572 IdResolver.AddDecl(Param);
1573 }
1574
1575 // C++0x [temp.param]p9:
1576 // A default template-argument may be specified for any kind of
1577 // template-parameter that is not a template parameter pack.
1578 if (Default && IsParameterPack) {
1579 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1580 Default = nullptr;
1581 }
1582
1583 // Check the well-formedness of the default template argument, if provided.
1584 if (Default) {
1585 // Check for unexpanded parameter packs.
1586 if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
1587 return Param;
1588
1589 TemplateArgument Converted;
1590 ExprResult DefaultRes =
1591 CheckTemplateArgument(Param, Param->getType(), Default, Converted);
1592 if (DefaultRes.isInvalid()) {
1593 Param->setInvalidDecl();
1594 return Param;
1595 }
1596 Default = DefaultRes.get();
1597
1598 Param->setDefaultArgument(Default);
1599 }
1600
1601 return Param;
1602}
1603
1604/// ActOnTemplateTemplateParameter - Called when a C++ template template
1605/// parameter (e.g. T in template <template \<typename> class T> class array)
1606/// has been parsed. S is the current scope.
1607NamedDecl *Sema::ActOnTemplateTemplateParameter(Scope* S,
1608 SourceLocation TmpLoc,
1609 TemplateParameterList *Params,
1610 SourceLocation EllipsisLoc,
1611 IdentifierInfo *Name,
1612 SourceLocation NameLoc,
1613 unsigned Depth,
1614 unsigned Position,
1615 SourceLocation EqualLoc,
1616 ParsedTemplateArgument Default) {
1617 assert(S->isTemplateParamScope() &&(static_cast <bool> (S->isTemplateParamScope() &&
"Template template parameter not in template parameter scope!"
) ? void (0) : __assert_fail ("S->isTemplateParamScope() && \"Template template parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1618, __extension__ __PRETTY_FUNCTION__))
1618 "Template template parameter not in template parameter scope!")(static_cast <bool> (S->isTemplateParamScope() &&
"Template template parameter not in template parameter scope!"
) ? void (0) : __assert_fail ("S->isTemplateParamScope() && \"Template template parameter not in template parameter scope!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1618, __extension__ __PRETTY_FUNCTION__))
;
1619
1620 // Construct the parameter object.
1621 bool IsParameterPack = EllipsisLoc.isValid();
1622 TemplateTemplateParmDecl *Param =
1623 TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
1624 NameLoc.isInvalid()? TmpLoc : NameLoc,
1625 Depth, Position, IsParameterPack,
1626 Name, Params);
1627 Param->setAccess(AS_public);
1628
1629 if (Param->isParameterPack())
1630 if (auto *LSI = getEnclosingLambda())
1631 LSI->LocalPacks.push_back(Param);
1632
1633 // If the template template parameter has a name, then link the identifier
1634 // into the scope and lookup mechanisms.
1635 if (Name) {
1636 maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name);
1637
1638 S->AddDecl(Param);
1639 IdResolver.AddDecl(Param);
1640 }
1641
1642 if (Params->size() == 0) {
1643 Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
1644 << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
1645 Param->setInvalidDecl();
1646 }
1647
1648 // C++0x [temp.param]p9:
1649 // A default template-argument may be specified for any kind of
1650 // template-parameter that is not a template parameter pack.
1651 if (IsParameterPack && !Default.isInvalid()) {
1652 Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1653 Default = ParsedTemplateArgument();
1654 }
1655
1656 if (!Default.isInvalid()) {
1657 // Check only that we have a template template argument. We don't want to
1658 // try to check well-formedness now, because our template template parameter
1659 // might have dependent types in its template parameters, which we wouldn't
1660 // be able to match now.
1661 //
1662 // If none of the template template parameter's template arguments mention
1663 // other template parameters, we could actually perform more checking here.
1664 // However, it isn't worth doing.
1665 TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
1666 if (DefaultArg.getArgument().getAsTemplate().isNull()) {
1667 Diag(DefaultArg.getLocation(), diag::err_template_arg_not_valid_template)
1668 << DefaultArg.getSourceRange();
1669 return Param;
1670 }
1671
1672 // Check for unexpanded parameter packs.
1673 if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(),
1674 DefaultArg.getArgument().getAsTemplate(),
1675 UPPC_DefaultArgument))
1676 return Param;
1677
1678 Param->setDefaultArgument(Context, DefaultArg);
1679 }
1680
1681 return Param;
1682}
1683
1684/// ActOnTemplateParameterList - Builds a TemplateParameterList, optionally
1685/// constrained by RequiresClause, that contains the template parameters in
1686/// Params.
1687TemplateParameterList *
1688Sema::ActOnTemplateParameterList(unsigned Depth,
1689 SourceLocation ExportLoc,
1690 SourceLocation TemplateLoc,
1691 SourceLocation LAngleLoc,
1692 ArrayRef<NamedDecl *> Params,
1693 SourceLocation RAngleLoc,
1694 Expr *RequiresClause) {
1695 if (ExportLoc.isValid())
1696 Diag(ExportLoc, diag::warn_template_export_unsupported);
1697
1698 for (NamedDecl *P : Params)
1699 warnOnReservedIdentifier(P);
1700
1701 return TemplateParameterList::Create(
1702 Context, TemplateLoc, LAngleLoc,
1703 llvm::makeArrayRef(Params.data(), Params.size()),
1704 RAngleLoc, RequiresClause);
1705}
1706
1707static void SetNestedNameSpecifier(Sema &S, TagDecl *T,
1708 const CXXScopeSpec &SS) {
1709 if (SS.isSet())
1710 T->setQualifierInfo(SS.getWithLocInContext(S.Context));
1711}
1712
1713DeclResult Sema::CheckClassTemplate(
1714 Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
1715 CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc,
1716 const ParsedAttributesView &Attr, TemplateParameterList *TemplateParams,
1717 AccessSpecifier AS, SourceLocation ModulePrivateLoc,
1718 SourceLocation FriendLoc, unsigned NumOuterTemplateParamLists,
1719 TemplateParameterList **OuterTemplateParamLists, SkipBodyInfo *SkipBody) {
1720 assert(TemplateParams && TemplateParams->size() > 0 &&(static_cast <bool> (TemplateParams && TemplateParams
->size() > 0 && "No template parameters") ? void
(0) : __assert_fail ("TemplateParams && TemplateParams->size() > 0 && \"No template parameters\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1721, __extension__ __PRETTY_FUNCTION__))
1721 "No template parameters")(static_cast <bool> (TemplateParams && TemplateParams
->size() > 0 && "No template parameters") ? void
(0) : __assert_fail ("TemplateParams && TemplateParams->size() > 0 && \"No template parameters\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1721, __extension__ __PRETTY_FUNCTION__))
;
1722 assert(TUK != TUK_Reference && "Can only declare or define class templates")(static_cast <bool> (TUK != TUK_Reference && "Can only declare or define class templates"
) ? void (0) : __assert_fail ("TUK != TUK_Reference && \"Can only declare or define class templates\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1722, __extension__ __PRETTY_FUNCTION__))
;
1723 bool Invalid = false;
1724
1725 // Check that we can declare a template here.
1726 if (CheckTemplateDeclScope(S, TemplateParams))
1727 return true;
1728
1729 TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
1730 assert(Kind != TTK_Enum && "can't build template of enumerated type")(static_cast <bool> (Kind != TTK_Enum && "can't build template of enumerated type"
) ? void (0) : __assert_fail ("Kind != TTK_Enum && \"can't build template of enumerated type\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1730, __extension__ __PRETTY_FUNCTION__))
;
1731
1732 // There is no such thing as an unnamed class template.
1733 if (!Name) {
1734 Diag(KWLoc, diag::err_template_unnamed_class);
1735 return true;
1736 }
1737
1738 // Find any previous declaration with this name. For a friend with no
1739 // scope explicitly specified, we only look for tag declarations (per
1740 // C++11 [basic.lookup.elab]p2).
1741 DeclContext *SemanticContext;
1742 LookupResult Previous(*this, Name, NameLoc,
1743 (SS.isEmpty() && TUK == TUK_Friend)
1744 ? LookupTagName : LookupOrdinaryName,
1745 forRedeclarationInCurContext());
1746 if (SS.isNotEmpty() && !SS.isInvalid()) {
1747 SemanticContext = computeDeclContext(SS, true);
1748 if (!SemanticContext) {
1749 // FIXME: Horrible, horrible hack! We can't currently represent this
1750 // in the AST, and historically we have just ignored such friend
1751 // class templates, so don't complain here.
1752 Diag(NameLoc, TUK == TUK_Friend
1753 ? diag::warn_template_qualified_friend_ignored
1754 : diag::err_template_qualified_declarator_no_match)
1755 << SS.getScopeRep() << SS.getRange();
1756 return TUK != TUK_Friend;
1757 }
1758
1759 if (RequireCompleteDeclContext(SS, SemanticContext))
1760 return true;
1761
1762 // If we're adding a template to a dependent context, we may need to
1763 // rebuilding some of the types used within the template parameter list,
1764 // now that we know what the current instantiation is.
1765 if (SemanticContext->isDependentContext()) {
1766 ContextRAII SavedContext(*this, SemanticContext);
1767 if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
1768 Invalid = true;
1769 } else if (TUK != TUK_Friend && TUK != TUK_Reference)
1770 diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc, false);
1771
1772 LookupQualifiedName(Previous, SemanticContext);
1773 } else {
1774 SemanticContext = CurContext;
1775
1776 // C++14 [class.mem]p14:
1777 // If T is the name of a class, then each of the following shall have a
1778 // name different from T:
1779 // -- every member template of class T
1780 if (TUK != TUK_Friend &&
1781 DiagnoseClassNameShadow(SemanticContext,
1782 DeclarationNameInfo(Name, NameLoc)))
1783 return true;
1784
1785 LookupName(Previous, S);
1786 }
1787
1788 if (Previous.isAmbiguous())
1789 return true;
1790
1791 NamedDecl *PrevDecl = nullptr;
1792 if (Previous.begin() != Previous.end())
1793 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1794
1795 if (PrevDecl && PrevDecl->isTemplateParameter()) {
1796 // Maybe we will complain about the shadowed template parameter.
1797 DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
1798 // Just pretend that we didn't see the previous declaration.
1799 PrevDecl = nullptr;
1800 }
1801
1802 // If there is a previous declaration with the same name, check
1803 // whether this is a valid redeclaration.
1804 ClassTemplateDecl *PrevClassTemplate =
1805 dyn_cast_or_null<ClassTemplateDecl>(PrevDecl);
1806
1807 // We may have found the injected-class-name of a class template,
1808 // class template partial specialization, or class template specialization.
1809 // In these cases, grab the template that is being defined or specialized.
1810 if (!PrevClassTemplate && PrevDecl && isa<CXXRecordDecl>(PrevDecl) &&
1811 cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()) {
1812 PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext());
1813 PrevClassTemplate
1814 = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate();
1815 if (!PrevClassTemplate && isa<ClassTemplateSpecializationDecl>(PrevDecl)) {
1816 PrevClassTemplate
1817 = cast<ClassTemplateSpecializationDecl>(PrevDecl)
1818 ->getSpecializedTemplate();
1819 }
1820 }
1821
1822 if (TUK == TUK_Friend) {
1823 // C++ [namespace.memdef]p3:
1824 // [...] When looking for a prior declaration of a class or a function
1825 // declared as a friend, and when the name of the friend class or
1826 // function is neither a qualified name nor a template-id, scopes outside
1827 // the innermost enclosing namespace scope are not considered.
1828 if (!SS.isSet()) {
1829 DeclContext *OutermostContext = CurContext;
1830 while (!OutermostContext->isFileContext())
1831 OutermostContext = OutermostContext->getLookupParent();
1832
1833 if (PrevDecl &&
1834 (OutermostContext->Equals(PrevDecl->getDeclContext()) ||
1835 OutermostContext->Encloses(PrevDecl->getDeclContext()))) {
1836 SemanticContext = PrevDecl->getDeclContext();
1837 } else {
1838 // Declarations in outer scopes don't matter. However, the outermost
1839 // context we computed is the semantic context for our new
1840 // declaration.
1841 PrevDecl = PrevClassTemplate = nullptr;
1842 SemanticContext = OutermostContext;
1843
1844 // Check that the chosen semantic context doesn't already contain a
1845 // declaration of this name as a non-tag type.
1846 Previous.clear(LookupOrdinaryName);
1847 DeclContext *LookupContext = SemanticContext;
1848 while (LookupContext->isTransparentContext())
1849 LookupContext = LookupContext->getLookupParent();
1850 LookupQualifiedName(Previous, LookupContext);
1851
1852 if (Previous.isAmbiguous())
1853 return true;
1854
1855 if (Previous.begin() != Previous.end())
1856 PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1857 }
1858 }
1859 } else if (PrevDecl &&
1860 !isDeclInScope(Previous.getRepresentativeDecl(), SemanticContext,
1861 S, SS.isValid()))
1862 PrevDecl = PrevClassTemplate = nullptr;
1863
1864 if (auto *Shadow = dyn_cast_or_null<UsingShadowDecl>(
1865 PrevDecl ? Previous.getRepresentativeDecl() : nullptr)) {
1866 if (SS.isEmpty() &&
1867 !(PrevClassTemplate &&
1868 PrevClassTemplate->getDeclContext()->getRedeclContext()->Equals(
1869 SemanticContext->getRedeclContext()))) {
1870 Diag(KWLoc, diag::err_using_decl_conflict_reverse);
1871 Diag(Shadow->getTargetDecl()->getLocation(),
1872 diag::note_using_decl_target);
1873 Diag(Shadow->getIntroducer()->getLocation(), diag::note_using_decl) << 0;
1874 // Recover by ignoring the old declaration.
1875 PrevDecl = PrevClassTemplate = nullptr;
1876 }
1877 }
1878
1879 if (PrevClassTemplate) {
1880 // Ensure that the template parameter lists are compatible. Skip this check
1881 // for a friend in a dependent context: the template parameter list itself
1882 // could be dependent.
1883 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1884 !TemplateParameterListsAreEqual(TemplateParams,
1885 PrevClassTemplate->getTemplateParameters(),
1886 /*Complain=*/true,
1887 TPL_TemplateMatch))
1888 return true;
1889
1890 // C++ [temp.class]p4:
1891 // In a redeclaration, partial specialization, explicit
1892 // specialization or explicit instantiation of a class template,
1893 // the class-key shall agree in kind with the original class
1894 // template declaration (7.1.5.3).
1895 RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
1896 if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
1897 TUK == TUK_Definition, KWLoc, Name)) {
1898 Diag(KWLoc, diag::err_use_with_wrong_tag)
1899 << Name
1900 << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
1901 Diag(PrevRecordDecl->getLocation(), diag::note_previous_use);
1902 Kind = PrevRecordDecl->getTagKind();
1903 }
1904
1905 // Check for redefinition of this class template.
1906 if (TUK == TUK_Definition) {
1907 if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
1908 // If we have a prior definition that is not visible, treat this as
1909 // simply making that previous definition visible.
1910 NamedDecl *Hidden = nullptr;
1911 if (SkipBody && !hasVisibleDefinition(Def, &Hidden)) {
1912 SkipBody->ShouldSkip = true;
1913 SkipBody->Previous = Def;
1914 auto *Tmpl = cast<CXXRecordDecl>(Hidden)->getDescribedClassTemplate();
1915 assert(Tmpl && "original definition of a class template is not a "(static_cast <bool> (Tmpl && "original definition of a class template is not a "
"class template?") ? void (0) : __assert_fail ("Tmpl && \"original definition of a class template is not a \" \"class template?\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1916, __extension__ __PRETTY_FUNCTION__))
1916 "class template?")(static_cast <bool> (Tmpl && "original definition of a class template is not a "
"class template?") ? void (0) : __assert_fail ("Tmpl && \"original definition of a class template is not a \" \"class template?\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 1916, __extension__ __PRETTY_FUNCTION__))
;
1917 makeMergedDefinitionVisible(Hidden);
1918 makeMergedDefinitionVisible(Tmpl);
1919 } else {
1920 Diag(NameLoc, diag::err_redefinition) << Name;
1921 Diag(Def->getLocation(), diag::note_previous_definition);
1922 // FIXME: Would it make sense to try to "forget" the previous
1923 // definition, as part of error recovery?
1924 return true;
1925 }
1926 }
1927 }
1928 } else if (PrevDecl) {
1929 // C++ [temp]p5:
1930 // A class template shall not have the same name as any other
1931 // template, class, function, object, enumeration, enumerator,
1932 // namespace, or type in the same scope (3.3), except as specified
1933 // in (14.5.4).
1934 Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
1935 Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1936 return true;
1937 }
1938
1939 // Check the template parameter list of this declaration, possibly
1940 // merging in the template parameter list from the previous class
1941 // template declaration. Skip this check for a friend in a dependent
1942 // context, because the template parameter list might be dependent.
1943 if (!(TUK == TUK_Friend && CurContext->isDependentContext()) &&
1944 CheckTemplateParameterList(
1945 TemplateParams,
1946 PrevClassTemplate
1947 ? PrevClassTemplate->getMostRecentDecl()->getTemplateParameters()
1948 : nullptr,
1949 (SS.isSet() && SemanticContext && SemanticContext->isRecord() &&
1950 SemanticContext->isDependentContext())
1951 ? TPC_ClassTemplateMember
1952 : TUK == TUK_Friend ? TPC_FriendClassTemplate : TPC_ClassTemplate,
1953 SkipBody))
1954 Invalid = true;
1955
1956 if (SS.isSet()) {
1957 // If the name of the template was qualified, we must be defining the
1958 // template out-of-line.
1959 if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
1960 Diag(NameLoc, TUK == TUK_Friend ? diag::err_friend_decl_does_not_match
1961 : diag::err_member_decl_does_not_match)
1962 << Name << SemanticContext << /*IsDefinition*/true << SS.getRange();
1963 Invalid = true;
1964 }
1965 }
1966
1967 // If this is a templated friend in a dependent context we should not put it
1968 // on the redecl chain. In some cases, the templated friend can be the most
1969 // recent declaration tricking the template instantiator to make substitutions
1970 // there.
1971 // FIXME: Figure out how to combine with shouldLinkDependentDeclWithPrevious
1972 bool ShouldAddRedecl
1973 = !(TUK == TUK_Friend && CurContext->isDependentContext());
1974
1975 CXXRecordDecl *NewClass =
1976 CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
1977 PrevClassTemplate && ShouldAddRedecl ?
1978 PrevClassTemplate->getTemplatedDecl() : nullptr,
1979 /*DelayTypeCreation=*/true);
1980 SetNestedNameSpecifier(*this, NewClass, SS);
1981 if (NumOuterTemplateParamLists > 0)
1982 NewClass->setTemplateParameterListsInfo(
1983 Context, llvm::makeArrayRef(OuterTemplateParamLists,
1984 NumOuterTemplateParamLists));
1985
1986 // Add alignment attributes if necessary; these attributes are checked when
1987 // the ASTContext lays out the structure.
1988 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip)) {
1989 AddAlignmentAttributesForRecord(NewClass);
1990 AddMsStructLayoutForRecord(NewClass);
1991 }
1992
1993 ClassTemplateDecl *NewTemplate
1994 = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
1995 DeclarationName(Name), TemplateParams,
1996 NewClass);
1997
1998 if (ShouldAddRedecl)
1999 NewTemplate->setPreviousDecl(PrevClassTemplate);
2000
2001 NewClass->setDescribedClassTemplate(NewTemplate);
2002
2003 if (ModulePrivateLoc.isValid())
2004 NewTemplate->setModulePrivate();
2005
2006 // Build the type for the class template declaration now.
2007 QualType T = NewTemplate->getInjectedClassNameSpecialization();
2008 T = Context.getInjectedClassNameType(NewClass, T);
2009 assert(T->isDependentType() && "Class template type is not dependent?")(static_cast <bool> (T->isDependentType() &&
"Class template type is not dependent?") ? void (0) : __assert_fail
("T->isDependentType() && \"Class template type is not dependent?\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2009, __extension__ __PRETTY_FUNCTION__))
;
2010 (void)T;
2011
2012 // If we are providing an explicit specialization of a member that is a
2013 // class template, make a note of that.
2014 if (PrevClassTemplate &&
2015 PrevClassTemplate->getInstantiatedFromMemberTemplate())
2016 PrevClassTemplate->setMemberSpecialization();
2017
2018 // Set the access specifier.
2019 if (!Invalid && TUK != TUK_Friend && NewTemplate->getDeclContext()->isRecord())
2020 SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
2021
2022 // Set the lexical context of these templates
2023 NewClass->setLexicalDeclContext(CurContext);
2024 NewTemplate->setLexicalDeclContext(CurContext);
2025
2026 if (TUK == TUK_Definition && (!SkipBody || !SkipBody->ShouldSkip))
2027 NewClass->startDefinition();
2028
2029 ProcessDeclAttributeList(S, NewClass, Attr);
2030
2031 if (PrevClassTemplate)
2032 mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
2033
2034 AddPushedVisibilityAttribute(NewClass);
2035 inferGslOwnerPointerAttribute(NewClass);
2036
2037 if (TUK != TUK_Friend) {
2038 // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
2039 Scope *Outer = S;
2040 while ((Outer->getFlags() & Scope::TemplateParamScope) != 0)
2041 Outer = Outer->getParent();
2042 PushOnScopeChains(NewTemplate, Outer);
2043 } else {
2044 if (PrevClassTemplate && PrevClassTemplate->getAccess() != AS_none) {
2045 NewTemplate->setAccess(PrevClassTemplate->getAccess());
2046 NewClass->setAccess(PrevClassTemplate->getAccess());
2047 }
2048
2049 NewTemplate->setObjectOfFriendDecl();
2050
2051 // Friend templates are visible in fairly strange ways.
2052 if (!CurContext->isDependentContext()) {
2053 DeclContext *DC = SemanticContext->getRedeclContext();
2054 DC->makeDeclVisibleInContext(NewTemplate);
2055 if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
2056 PushOnScopeChains(NewTemplate, EnclosingScope,
2057 /* AddToContext = */ false);
2058 }
2059
2060 FriendDecl *Friend = FriendDecl::Create(
2061 Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc);
2062 Friend->setAccess(AS_public);
2063 CurContext->addDecl(Friend);
2064 }
2065
2066 if (PrevClassTemplate)
2067 CheckRedeclarationModuleOwnership(NewTemplate, PrevClassTemplate);
2068
2069 if (Invalid) {
2070 NewTemplate->setInvalidDecl();
2071 NewClass->setInvalidDecl();
2072 }
2073
2074 ActOnDocumentableDecl(NewTemplate);
2075
2076 if (SkipBody && SkipBody->ShouldSkip)
2077 return SkipBody->Previous;
2078
2079 return NewTemplate;
2080}
2081
2082namespace {
2083/// Tree transform to "extract" a transformed type from a class template's
2084/// constructor to a deduction guide.
2085class ExtractTypeForDeductionGuide
2086 : public TreeTransform<ExtractTypeForDeductionGuide> {
2087 llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs;
2088
2089public:
2090 typedef TreeTransform<ExtractTypeForDeductionGuide> Base;
2091 ExtractTypeForDeductionGuide(
2092 Sema &SemaRef,
2093 llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs)
2094 : Base(SemaRef), MaterializedTypedefs(MaterializedTypedefs) {}
2095
2096 TypeSourceInfo *transform(TypeSourceInfo *TSI) { return TransformType(TSI); }
2097
2098 QualType TransformTypedefType(TypeLocBuilder &TLB, TypedefTypeLoc TL) {
2099 ASTContext &Context = SemaRef.getASTContext();
2100 TypedefNameDecl *OrigDecl = TL.getTypedefNameDecl();
2101 TypedefNameDecl *Decl = OrigDecl;
2102 // Transform the underlying type of the typedef and clone the Decl only if
2103 // the typedef has a dependent context.
2104 if (OrigDecl->getDeclContext()->isDependentContext()) {
2105 TypeLocBuilder InnerTLB;
2106 QualType Transformed =
2107 TransformType(InnerTLB, OrigDecl->getTypeSourceInfo()->getTypeLoc());
2108 TypeSourceInfo *TSI = InnerTLB.getTypeSourceInfo(Context, Transformed);
2109 if (isa<TypeAliasDecl>(OrigDecl))
2110 Decl = TypeAliasDecl::Create(
2111 Context, Context.getTranslationUnitDecl(), OrigDecl->getBeginLoc(),
2112 OrigDecl->getLocation(), OrigDecl->getIdentifier(), TSI);
2113 else {
2114 assert(isa<TypedefDecl>(OrigDecl) && "Not a Type alias or typedef")(static_cast <bool> (isa<TypedefDecl>(OrigDecl) &&
"Not a Type alias or typedef") ? void (0) : __assert_fail ("isa<TypedefDecl>(OrigDecl) && \"Not a Type alias or typedef\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2114, __extension__ __PRETTY_FUNCTION__))
;
2115 Decl = TypedefDecl::Create(
2116 Context, Context.getTranslationUnitDecl(), OrigDecl->getBeginLoc(),
2117 OrigDecl->getLocation(), OrigDecl->getIdentifier(), TSI);
2118 }
2119 MaterializedTypedefs.push_back(Decl);
2120 }
2121
2122 QualType TDTy = Context.getTypedefType(Decl);
2123 TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(TDTy);
2124 TypedefTL.setNameLoc(TL.getNameLoc());
2125
2126 return TDTy;
2127 }
2128};
2129
2130/// Transform to convert portions of a constructor declaration into the
2131/// corresponding deduction guide, per C++1z [over.match.class.deduct]p1.
2132struct ConvertConstructorToDeductionGuideTransform {
2133 ConvertConstructorToDeductionGuideTransform(Sema &S,
2134 ClassTemplateDecl *Template)
2135 : SemaRef(S), Template(Template) {}
2136
2137 Sema &SemaRef;
2138 ClassTemplateDecl *Template;
2139
2140 DeclContext *DC = Template->getDeclContext();
2141 CXXRecordDecl *Primary = Template->getTemplatedDecl();
2142 DeclarationName DeductionGuideName =
2143 SemaRef.Context.DeclarationNames.getCXXDeductionGuideName(Template);
2144
2145 QualType DeducedType = SemaRef.Context.getTypeDeclType(Primary);
2146
2147 // Index adjustment to apply to convert depth-1 template parameters into
2148 // depth-0 template parameters.
2149 unsigned Depth1IndexAdjustment = Template->getTemplateParameters()->size();
2150
2151 /// Transform a constructor declaration into a deduction guide.
2152 NamedDecl *transformConstructor(FunctionTemplateDecl *FTD,
2153 CXXConstructorDecl *CD) {
2154 SmallVector<TemplateArgument, 16> SubstArgs;
2155
2156 LocalInstantiationScope Scope(SemaRef);
2157
2158 // C++ [over.match.class.deduct]p1:
2159 // -- For each constructor of the class template designated by the
2160 // template-name, a function template with the following properties:
2161
2162 // -- The template parameters are the template parameters of the class
2163 // template followed by the template parameters (including default
2164 // template arguments) of the constructor, if any.
2165 TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2166 if (FTD) {
2167 TemplateParameterList *InnerParams = FTD->getTemplateParameters();
2168 SmallVector<NamedDecl *, 16> AllParams;
2169 AllParams.reserve(TemplateParams->size() + InnerParams->size());
2170 AllParams.insert(AllParams.begin(),
2171 TemplateParams->begin(), TemplateParams->end());
2172 SubstArgs.reserve(InnerParams->size());
2173
2174 // Later template parameters could refer to earlier ones, so build up
2175 // a list of substituted template arguments as we go.
2176 for (NamedDecl *Param : *InnerParams) {
2177 MultiLevelTemplateArgumentList Args;
2178 Args.setKind(TemplateSubstitutionKind::Rewrite);
2179 Args.addOuterTemplateArguments(SubstArgs);
2180 Args.addOuterRetainedLevel();
2181 NamedDecl *NewParam = transformTemplateParameter(Param, Args);
2182 if (!NewParam)
2183 return nullptr;
2184 AllParams.push_back(NewParam);
2185 SubstArgs.push_back(SemaRef.Context.getCanonicalTemplateArgument(
2186 SemaRef.Context.getInjectedTemplateArg(NewParam)));
2187 }
2188 TemplateParams = TemplateParameterList::Create(
2189 SemaRef.Context, InnerParams->getTemplateLoc(),
2190 InnerParams->getLAngleLoc(), AllParams, InnerParams->getRAngleLoc(),
2191 /*FIXME: RequiresClause*/ nullptr);
2192 }
2193
2194 // If we built a new template-parameter-list, track that we need to
2195 // substitute references to the old parameters into references to the
2196 // new ones.
2197 MultiLevelTemplateArgumentList Args;
2198 Args.setKind(TemplateSubstitutionKind::Rewrite);
2199 if (FTD) {
2200 Args.addOuterTemplateArguments(SubstArgs);
2201 Args.addOuterRetainedLevel();
2202 }
2203
2204 FunctionProtoTypeLoc FPTL = CD->getTypeSourceInfo()->getTypeLoc()
2205 .getAsAdjusted<FunctionProtoTypeLoc>();
2206 assert(FPTL && "no prototype for constructor declaration")(static_cast <bool> (FPTL && "no prototype for constructor declaration"
) ? void (0) : __assert_fail ("FPTL && \"no prototype for constructor declaration\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2206, __extension__ __PRETTY_FUNCTION__))
;
2207
2208 // Transform the type of the function, adjusting the return type and
2209 // replacing references to the old parameters with references to the
2210 // new ones.
2211 TypeLocBuilder TLB;
2212 SmallVector<ParmVarDecl*, 8> Params;
2213 SmallVector<TypedefNameDecl *, 4> MaterializedTypedefs;
2214 QualType NewType = transformFunctionProtoType(TLB, FPTL, Params, Args,
2215 MaterializedTypedefs);
2216 if (NewType.isNull())
2217 return nullptr;
2218 TypeSourceInfo *NewTInfo = TLB.getTypeSourceInfo(SemaRef.Context, NewType);
2219
2220 return buildDeductionGuide(TemplateParams, CD, CD->getExplicitSpecifier(),
2221 NewTInfo, CD->getBeginLoc(), CD->getLocation(),
2222 CD->getEndLoc(), MaterializedTypedefs);
2223 }
2224
2225 /// Build a deduction guide with the specified parameter types.
2226 NamedDecl *buildSimpleDeductionGuide(MutableArrayRef<QualType> ParamTypes) {
2227 SourceLocation Loc = Template->getLocation();
2228
2229 // Build the requested type.
2230 FunctionProtoType::ExtProtoInfo EPI;
2231 EPI.HasTrailingReturn = true;
2232 QualType Result = SemaRef.BuildFunctionType(DeducedType, ParamTypes, Loc,
2233 DeductionGuideName, EPI);
2234 TypeSourceInfo *TSI = SemaRef.Context.getTrivialTypeSourceInfo(Result, Loc);
2235
2236 FunctionProtoTypeLoc FPTL =
2237 TSI->getTypeLoc().castAs<FunctionProtoTypeLoc>();
2238
2239 // Build the parameters, needed during deduction / substitution.
2240 SmallVector<ParmVarDecl*, 4> Params;
2241 for (auto T : ParamTypes) {
2242 ParmVarDecl *NewParam = ParmVarDecl::Create(
2243 SemaRef.Context, DC, Loc, Loc, nullptr, T,
2244 SemaRef.Context.getTrivialTypeSourceInfo(T, Loc), SC_None, nullptr);
2245 NewParam->setScopeInfo(0, Params.size());
2246 FPTL.setParam(Params.size(), NewParam);
2247 Params.push_back(NewParam);
2248 }
2249
2250 return buildDeductionGuide(Template->getTemplateParameters(), nullptr,
2251 ExplicitSpecifier(), TSI, Loc, Loc, Loc);
2252 }
2253
2254private:
2255 /// Transform a constructor template parameter into a deduction guide template
2256 /// parameter, rebuilding any internal references to earlier parameters and
2257 /// renumbering as we go.
2258 NamedDecl *transformTemplateParameter(NamedDecl *TemplateParam,
2259 MultiLevelTemplateArgumentList &Args) {
2260 if (auto *TTP = dyn_cast<TemplateTypeParmDecl>(TemplateParam)) {
2261 // TemplateTypeParmDecl's index cannot be changed after creation, so
2262 // substitute it directly.
2263 auto *NewTTP = TemplateTypeParmDecl::Create(
2264 SemaRef.Context, DC, TTP->getBeginLoc(), TTP->getLocation(),
2265 /*Depth*/ 0, Depth1IndexAdjustment + TTP->getIndex(),
2266 TTP->getIdentifier(), TTP->wasDeclaredWithTypename(),
2267 TTP->isParameterPack(), TTP->hasTypeConstraint(),
2268 TTP->isExpandedParameterPack() ?
2269 llvm::Optional<unsigned>(TTP->getNumExpansionParameters()) : None);
2270 if (const auto *TC = TTP->getTypeConstraint()) {
2271 TemplateArgumentListInfo TransformedArgs;
2272 const auto *ArgsAsWritten = TC->getTemplateArgsAsWritten();
2273 if (!ArgsAsWritten ||
2274 SemaRef.Subst(ArgsAsWritten->getTemplateArgs(),
2275 ArgsAsWritten->NumTemplateArgs, TransformedArgs,
2276 Args))
2277 SemaRef.AttachTypeConstraint(
2278 TC->getNestedNameSpecifierLoc(), TC->getConceptNameInfo(),
2279 TC->getNamedConcept(), ArgsAsWritten ? &TransformedArgs : nullptr,
2280 NewTTP,
2281 NewTTP->isParameterPack()
2282 ? cast<CXXFoldExpr>(TC->getImmediatelyDeclaredConstraint())
2283 ->getEllipsisLoc()
2284 : SourceLocation());
2285 }
2286 if (TTP->hasDefaultArgument()) {
2287 TypeSourceInfo *InstantiatedDefaultArg =
2288 SemaRef.SubstType(TTP->getDefaultArgumentInfo(), Args,
2289 TTP->getDefaultArgumentLoc(), TTP->getDeclName());
2290 if (InstantiatedDefaultArg)
2291 NewTTP->setDefaultArgument(InstantiatedDefaultArg);
2292 }
2293 SemaRef.CurrentInstantiationScope->InstantiatedLocal(TemplateParam,
2294 NewTTP);
2295 return NewTTP;
2296 }
2297
2298 if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(TemplateParam))
2299 return transformTemplateParameterImpl(TTP, Args);
2300
2301 return transformTemplateParameterImpl(
2302 cast<NonTypeTemplateParmDecl>(TemplateParam), Args);
2303 }
2304 template<typename TemplateParmDecl>
2305 TemplateParmDecl *
2306 transformTemplateParameterImpl(TemplateParmDecl *OldParam,
2307 MultiLevelTemplateArgumentList &Args) {
2308 // Ask the template instantiator to do the heavy lifting for us, then adjust
2309 // the index of the parameter once it's done.
2310 auto *NewParam =
2311 cast<TemplateParmDecl>(SemaRef.SubstDecl(OldParam, DC, Args));
2312 assert(NewParam->getDepth() == 0 && "unexpected template param depth")(static_cast <bool> (NewParam->getDepth() == 0 &&
"unexpected template param depth") ? void (0) : __assert_fail
("NewParam->getDepth() == 0 && \"unexpected template param depth\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2312, __extension__ __PRETTY_FUNCTION__))
;
2313 NewParam->setPosition(NewParam->getPosition() + Depth1IndexAdjustment);
2314 return NewParam;
2315 }
2316
2317 QualType transformFunctionProtoType(
2318 TypeLocBuilder &TLB, FunctionProtoTypeLoc TL,
2319 SmallVectorImpl<ParmVarDecl *> &Params,
2320 MultiLevelTemplateArgumentList &Args,
2321 SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs) {
2322 SmallVector<QualType, 4> ParamTypes;
2323 const FunctionProtoType *T = TL.getTypePtr();
2324
2325 // -- The types of the function parameters are those of the constructor.
2326 for (auto *OldParam : TL.getParams()) {
2327 ParmVarDecl *NewParam =
2328 transformFunctionTypeParam(OldParam, Args, MaterializedTypedefs);
2329 if (!NewParam)
2330 return QualType();
2331 ParamTypes.push_back(NewParam->getType());
2332 Params.push_back(NewParam);
2333 }
2334
2335 // -- The return type is the class template specialization designated by
2336 // the template-name and template arguments corresponding to the
2337 // template parameters obtained from the class template.
2338 //
2339 // We use the injected-class-name type of the primary template instead.
2340 // This has the convenient property that it is different from any type that
2341 // the user can write in a deduction-guide (because they cannot enter the
2342 // context of the template), so implicit deduction guides can never collide
2343 // with explicit ones.
2344 QualType ReturnType = DeducedType;
2345 TLB.pushTypeSpec(ReturnType).setNameLoc(Primary->getLocation());
2346
2347 // Resolving a wording defect, we also inherit the variadicness of the
2348 // constructor.
2349 FunctionProtoType::ExtProtoInfo EPI;
2350 EPI.Variadic = T->isVariadic();
2351 EPI.HasTrailingReturn = true;
2352
2353 QualType Result = SemaRef.BuildFunctionType(
2354 ReturnType, ParamTypes, TL.getBeginLoc(), DeductionGuideName, EPI);
2355 if (Result.isNull())
2356 return QualType();
2357
2358 FunctionProtoTypeLoc NewTL = TLB.push<FunctionProtoTypeLoc>(Result);
2359 NewTL.setLocalRangeBegin(TL.getLocalRangeBegin());
2360 NewTL.setLParenLoc(TL.getLParenLoc());
2361 NewTL.setRParenLoc(TL.getRParenLoc());
2362 NewTL.setExceptionSpecRange(SourceRange());
2363 NewTL.setLocalRangeEnd(TL.getLocalRangeEnd());
2364 for (unsigned I = 0, E = NewTL.getNumParams(); I != E; ++I)
2365 NewTL.setParam(I, Params[I]);
2366
2367 return Result;
2368 }
2369
2370 ParmVarDecl *transformFunctionTypeParam(
2371 ParmVarDecl *OldParam, MultiLevelTemplateArgumentList &Args,
2372 llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs) {
2373 TypeSourceInfo *OldDI = OldParam->getTypeSourceInfo();
2374 TypeSourceInfo *NewDI;
2375 if (auto PackTL = OldDI->getTypeLoc().getAs<PackExpansionTypeLoc>()) {
2376 // Expand out the one and only element in each inner pack.
2377 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, 0);
2378 NewDI =
2379 SemaRef.SubstType(PackTL.getPatternLoc(), Args,
2380 OldParam->getLocation(), OldParam->getDeclName());
2381 if (!NewDI) return nullptr;
2382 NewDI =
2383 SemaRef.CheckPackExpansion(NewDI, PackTL.getEllipsisLoc(),
2384 PackTL.getTypePtr()->getNumExpansions());
2385 } else
2386 NewDI = SemaRef.SubstType(OldDI, Args, OldParam->getLocation(),
2387 OldParam->getDeclName());
2388 if (!NewDI)
2389 return nullptr;
2390
2391 // Extract the type. This (for instance) replaces references to typedef
2392 // members of the current instantiations with the definitions of those
2393 // typedefs, avoiding triggering instantiation of the deduced type during
2394 // deduction.
2395 NewDI = ExtractTypeForDeductionGuide(SemaRef, MaterializedTypedefs)
2396 .transform(NewDI);
2397
2398 // Resolving a wording defect, we also inherit default arguments from the
2399 // constructor.
2400 ExprResult NewDefArg;
2401 if (OldParam->hasDefaultArg()) {
2402 // We don't care what the value is (we won't use it); just create a
2403 // placeholder to indicate there is a default argument.
2404 QualType ParamTy = NewDI->getType();
2405 NewDefArg = new (SemaRef.Context)
2406 OpaqueValueExpr(OldParam->getDefaultArg()->getBeginLoc(),
2407 ParamTy.getNonLValueExprType(SemaRef.Context),
2408 ParamTy->isLValueReferenceType() ? VK_LValue
2409 : ParamTy->isRValueReferenceType() ? VK_XValue
2410 : VK_PRValue);
2411 }
2412
2413 ParmVarDecl *NewParam = ParmVarDecl::Create(SemaRef.Context, DC,
2414 OldParam->getInnerLocStart(),
2415 OldParam->getLocation(),
2416 OldParam->getIdentifier(),
2417 NewDI->getType(),
2418 NewDI,
2419 OldParam->getStorageClass(),
2420 NewDefArg.get());
2421 NewParam->setScopeInfo(OldParam->getFunctionScopeDepth(),
2422 OldParam->getFunctionScopeIndex());
2423 SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldParam, NewParam);
2424 return NewParam;
2425 }
2426
2427 FunctionTemplateDecl *buildDeductionGuide(
2428 TemplateParameterList *TemplateParams, CXXConstructorDecl *Ctor,
2429 ExplicitSpecifier ES, TypeSourceInfo *TInfo, SourceLocation LocStart,
2430 SourceLocation Loc, SourceLocation LocEnd,
2431 llvm::ArrayRef<TypedefNameDecl *> MaterializedTypedefs = {}) {
2432 DeclarationNameInfo Name(DeductionGuideName, Loc);
2433 ArrayRef<ParmVarDecl *> Params =
2434 TInfo->getTypeLoc().castAs<FunctionProtoTypeLoc>().getParams();
2435
2436 // Build the implicit deduction guide template.
2437 auto *Guide =
2438 CXXDeductionGuideDecl::Create(SemaRef.Context, DC, LocStart, ES, Name,
2439 TInfo->getType(), TInfo, LocEnd, Ctor);
2440 Guide->setImplicit();
2441 Guide->setParams(Params);
2442
2443 for (auto *Param : Params)
2444 Param->setDeclContext(Guide);
2445 for (auto *TD : MaterializedTypedefs)
2446 TD->setDeclContext(Guide);
2447
2448 auto *GuideTemplate = FunctionTemplateDecl::Create(
2449 SemaRef.Context, DC, Loc, DeductionGuideName, TemplateParams, Guide);
2450 GuideTemplate->setImplicit();
2451 Guide->setDescribedFunctionTemplate(GuideTemplate);
2452
2453 if (isa<CXXRecordDecl>(DC)) {
2454 Guide->setAccess(AS_public);
2455 GuideTemplate->setAccess(AS_public);
2456 }
2457
2458 DC->addDecl(GuideTemplate);
2459 return GuideTemplate;
2460 }
2461};
2462}
2463
2464void Sema::DeclareImplicitDeductionGuides(TemplateDecl *Template,
2465 SourceLocation Loc) {
2466 if (CXXRecordDecl *DefRecord =
2467 cast<CXXRecordDecl>(Template->getTemplatedDecl())->getDefinition()) {
2468 TemplateDecl *DescribedTemplate = DefRecord->getDescribedClassTemplate();
2469 Template = DescribedTemplate ? DescribedTemplate : Template;
2470 }
2471
2472 DeclContext *DC = Template->getDeclContext();
2473 if (DC->isDependentContext())
2474 return;
2475
2476 ConvertConstructorToDeductionGuideTransform Transform(
2477 *this, cast<ClassTemplateDecl>(Template));
2478 if (!isCompleteType(Loc, Transform.DeducedType))
2479 return;
2480
2481 // Check whether we've already declared deduction guides for this template.
2482 // FIXME: Consider storing a flag on the template to indicate this.
2483 auto Existing = DC->lookup(Transform.DeductionGuideName);
2484 for (auto *D : Existing)
2485 if (D->isImplicit())
2486 return;
2487
2488 // In case we were expanding a pack when we attempted to declare deduction
2489 // guides, turn off pack expansion for everything we're about to do.
2490 ArgumentPackSubstitutionIndexRAII SubstIndex(*this, -1);
2491 // Create a template instantiation record to track the "instantiation" of
2492 // constructors into deduction guides.
2493 // FIXME: Add a kind for this to give more meaningful diagnostics. But can
2494 // this substitution process actually fail?
2495 InstantiatingTemplate BuildingDeductionGuides(*this, Loc, Template);
2496 if (BuildingDeductionGuides.isInvalid())
2497 return;
2498
2499 // Convert declared constructors into deduction guide templates.
2500 // FIXME: Skip constructors for which deduction must necessarily fail (those
2501 // for which some class template parameter without a default argument never
2502 // appears in a deduced context).
2503 bool AddedAny = false;
2504 for (NamedDecl *D : LookupConstructors(Transform.Primary)) {
2505 D = D->getUnderlyingDecl();
2506 if (D->isInvalidDecl() || D->isImplicit())
2507 continue;
2508 D = cast<NamedDecl>(D->getCanonicalDecl());
2509
2510 auto *FTD = dyn_cast<FunctionTemplateDecl>(D);
2511 auto *CD =
2512 dyn_cast_or_null<CXXConstructorDecl>(FTD ? FTD->getTemplatedDecl() : D);
2513 // Class-scope explicit specializations (MS extension) do not result in
2514 // deduction guides.
2515 if (!CD || (!FTD && CD->isFunctionTemplateSpecialization()))
2516 continue;
2517
2518 // Cannot make a deduction guide when unparsed arguments are present.
2519 if (std::any_of(CD->param_begin(), CD->param_end(), [](ParmVarDecl *P) {
2520 return !P || P->hasUnparsedDefaultArg();
2521 }))
2522 continue;
2523
2524 Transform.transformConstructor(FTD, CD);
2525 AddedAny = true;
2526 }
2527
2528 // C++17 [over.match.class.deduct]
2529 // -- If C is not defined or does not declare any constructors, an
2530 // additional function template derived as above from a hypothetical
2531 // constructor C().
2532 if (!AddedAny)
2533 Transform.buildSimpleDeductionGuide(None);
2534
2535 // -- An additional function template derived as above from a hypothetical
2536 // constructor C(C), called the copy deduction candidate.
2537 cast<CXXDeductionGuideDecl>(
2538 cast<FunctionTemplateDecl>(
2539 Transform.buildSimpleDeductionGuide(Transform.DeducedType))
2540 ->getTemplatedDecl())
2541 ->setIsCopyDeductionCandidate();
2542}
2543
2544/// Diagnose the presence of a default template argument on a
2545/// template parameter, which is ill-formed in certain contexts.
2546///
2547/// \returns true if the default template argument should be dropped.
2548static bool DiagnoseDefaultTemplateArgument(Sema &S,
2549 Sema::TemplateParamListContext TPC,
2550 SourceLocation ParamLoc,
2551 SourceRange DefArgRange) {
2552 switch (TPC) {
2553 case Sema::TPC_ClassTemplate:
2554 case Sema::TPC_VarTemplate:
2555 case Sema::TPC_TypeAliasTemplate:
2556 return false;
2557
2558 case Sema::TPC_FunctionTemplate:
2559 case Sema::TPC_FriendFunctionTemplateDefinition:
2560 // C++ [temp.param]p9:
2561 // A default template-argument shall not be specified in a
2562 // function template declaration or a function template
2563 // definition [...]
2564 // If a friend function template declaration specifies a default
2565 // template-argument, that declaration shall be a definition and shall be
2566 // the only declaration of the function template in the translation unit.
2567 // (C++98/03 doesn't have this wording; see DR226).
2568 S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ?
2569 diag::warn_cxx98_compat_template_parameter_default_in_function_template
2570 : diag::ext_template_parameter_default_in_function_template)
2571 << DefArgRange;
2572 return false;
2573
2574 case Sema::TPC_ClassTemplateMember:
2575 // C++0x [temp.param]p9:
2576 // A default template-argument shall not be specified in the
2577 // template-parameter-lists of the definition of a member of a
2578 // class template that appears outside of the member's class.
2579 S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
2580 << DefArgRange;
2581 return true;
2582
2583 case Sema::TPC_FriendClassTemplate:
2584 case Sema::TPC_FriendFunctionTemplate:
2585 // C++ [temp.param]p9:
2586 // A default template-argument shall not be specified in a
2587 // friend template declaration.
2588 S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
2589 << DefArgRange;
2590 return true;
2591
2592 // FIXME: C++0x [temp.param]p9 allows default template-arguments
2593 // for friend function templates if there is only a single
2594 // declaration (and it is a definition). Strange!
2595 }
2596
2597 llvm_unreachable("Invalid TemplateParamListContext!")::llvm::llvm_unreachable_internal("Invalid TemplateParamListContext!"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2597)
;
2598}
2599
2600/// Check for unexpanded parameter packs within the template parameters
2601/// of a template template parameter, recursively.
2602static bool DiagnoseUnexpandedParameterPacks(Sema &S,
2603 TemplateTemplateParmDecl *TTP) {
2604 // A template template parameter which is a parameter pack is also a pack
2605 // expansion.
2606 if (TTP->isParameterPack())
2607 return false;
2608
2609 TemplateParameterList *Params = TTP->getTemplateParameters();
2610 for (unsigned I = 0, N = Params->size(); I != N; ++I) {
2611 NamedDecl *P = Params->getParam(I);
2612 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(P)) {
2613 if (!TTP->isParameterPack())
2614 if (const TypeConstraint *TC = TTP->getTypeConstraint())
2615 if (TC->hasExplicitTemplateArgs())
2616 for (auto &ArgLoc : TC->getTemplateArgsAsWritten()->arguments())
2617 if (S.DiagnoseUnexpandedParameterPack(ArgLoc,
2618 Sema::UPPC_TypeConstraint))
2619 return true;
2620 continue;
2621 }
2622
2623 if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
2624 if (!NTTP->isParameterPack() &&
2625 S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
2626 NTTP->getTypeSourceInfo(),
2627 Sema::UPPC_NonTypeTemplateParameterType))
2628 return true;
2629
2630 continue;
2631 }
2632
2633 if (TemplateTemplateParmDecl *InnerTTP
2634 = dyn_cast<TemplateTemplateParmDecl>(P))
2635 if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
2636 return true;
2637 }
2638
2639 return false;
2640}
2641
2642/// Checks the validity of a template parameter list, possibly
2643/// considering the template parameter list from a previous
2644/// declaration.
2645///
2646/// If an "old" template parameter list is provided, it must be
2647/// equivalent (per TemplateParameterListsAreEqual) to the "new"
2648/// template parameter list.
2649///
2650/// \param NewParams Template parameter list for a new template
2651/// declaration. This template parameter list will be updated with any
2652/// default arguments that are carried through from the previous
2653/// template parameter list.
2654///
2655/// \param OldParams If provided, template parameter list from a
2656/// previous declaration of the same template. Default template
2657/// arguments will be merged from the old template parameter list to
2658/// the new template parameter list.
2659///
2660/// \param TPC Describes the context in which we are checking the given
2661/// template parameter list.
2662///
2663/// \param SkipBody If we might have already made a prior merged definition
2664/// of this template visible, the corresponding body-skipping information.
2665/// Default argument redefinition is not an error when skipping such a body,
2666/// because (under the ODR) we can assume the default arguments are the same
2667/// as the prior merged definition.
2668///
2669/// \returns true if an error occurred, false otherwise.
2670bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
2671 TemplateParameterList *OldParams,
2672 TemplateParamListContext TPC,
2673 SkipBodyInfo *SkipBody) {
2674 bool Invalid = false;
2675
2676 // C++ [temp.param]p10:
2677 // The set of default template-arguments available for use with a
2678 // template declaration or definition is obtained by merging the
2679 // default arguments from the definition (if in scope) and all
2680 // declarations in scope in the same way default function
2681 // arguments are (8.3.6).
2682 bool SawDefaultArgument = false;
2683 SourceLocation PreviousDefaultArgLoc;
2684
2685 // Dummy initialization to avoid warnings.
2686 TemplateParameterList::iterator OldParam = NewParams->end();
2687 if (OldParams)
2688 OldParam = OldParams->begin();
2689
2690 bool RemoveDefaultArguments = false;
2691 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
2692 NewParamEnd = NewParams->end();
2693 NewParam != NewParamEnd; ++NewParam) {
2694 // Variables used to diagnose redundant default arguments
2695 bool RedundantDefaultArg = false;
2696 SourceLocation OldDefaultLoc;
2697 SourceLocation NewDefaultLoc;
2698
2699 // Variable used to diagnose missing default arguments
2700 bool MissingDefaultArg = false;
2701
2702 // Variable used to diagnose non-final parameter packs
2703 bool SawParameterPack = false;
2704
2705 if (TemplateTypeParmDecl *NewTypeParm
2706 = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
2707 // Check the presence of a default argument here.
2708 if (NewTypeParm->hasDefaultArgument() &&
2709 DiagnoseDefaultTemplateArgument(*this, TPC,
2710 NewTypeParm->getLocation(),
2711 NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
2712 .getSourceRange()))
2713 NewTypeParm->removeDefaultArgument();
2714
2715 // Merge default arguments for template type parameters.
2716 TemplateTypeParmDecl *OldTypeParm
2717 = OldParams? cast<TemplateTypeParmDecl>(*OldParam) : nullptr;
2718 if (NewTypeParm->isParameterPack()) {
2719 assert(!NewTypeParm->hasDefaultArgument() &&(static_cast <bool> (!NewTypeParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2720, __extension__ __PRETTY_FUNCTION__))
2720 "Parameter packs can't have a default argument!")(static_cast <bool> (!NewTypeParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2720, __extension__ __PRETTY_FUNCTION__))
;
2721 SawParameterPack = true;
2722 } else if (OldTypeParm && hasVisibleDefaultArgument(OldTypeParm) &&
2723 NewTypeParm->hasDefaultArgument() &&
2724 (!SkipBody || !SkipBody->ShouldSkip)) {
2725 OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
2726 NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
2727 SawDefaultArgument = true;
2728 RedundantDefaultArg = true;
2729 PreviousDefaultArgLoc = NewDefaultLoc;
2730 } else if (OldTypeParm && OldTypeParm->hasDefaultArgument()) {
2731 // Merge the default argument from the old declaration to the
2732 // new declaration.
2733 NewTypeParm->setInheritedDefaultArgument(Context, OldTypeParm);
2734 PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
2735 } else if (NewTypeParm->hasDefaultArgument()) {
2736 SawDefaultArgument = true;
2737 PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
2738 } else if (SawDefaultArgument)
2739 MissingDefaultArg = true;
2740 } else if (NonTypeTemplateParmDecl *NewNonTypeParm
2741 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
2742 // Check for unexpanded parameter packs.
2743 if (!NewNonTypeParm->isParameterPack() &&
2744 DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
2745 NewNonTypeParm->getTypeSourceInfo(),
2746 UPPC_NonTypeTemplateParameterType)) {
2747 Invalid = true;
2748 continue;
2749 }
2750
2751 // Check the presence of a default argument here.
2752 if (NewNonTypeParm->hasDefaultArgument() &&
2753 DiagnoseDefaultTemplateArgument(*this, TPC,
2754 NewNonTypeParm->getLocation(),
2755 NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
2756 NewNonTypeParm->removeDefaultArgument();
2757 }
2758
2759 // Merge default arguments for non-type template parameters
2760 NonTypeTemplateParmDecl *OldNonTypeParm
2761 = OldParams? cast<NonTypeTemplateParmDecl>(*OldParam) : nullptr;
2762 if (NewNonTypeParm->isParameterPack()) {
2763 assert(!NewNonTypeParm->hasDefaultArgument() &&(static_cast <bool> (!NewNonTypeParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewNonTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2764, __extension__ __PRETTY_FUNCTION__))
2764 "Parameter packs can't have a default argument!")(static_cast <bool> (!NewNonTypeParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewNonTypeParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2764, __extension__ __PRETTY_FUNCTION__))
;
2765 if (!NewNonTypeParm->isPackExpansion())
2766 SawParameterPack = true;
2767 } else if (OldNonTypeParm && hasVisibleDefaultArgument(OldNonTypeParm) &&
2768 NewNonTypeParm->hasDefaultArgument() &&
2769 (!SkipBody || !SkipBody->ShouldSkip)) {
2770 OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
2771 NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
2772 SawDefaultArgument = true;
2773 RedundantDefaultArg = true;
2774 PreviousDefaultArgLoc = NewDefaultLoc;
2775 } else if (OldNonTypeParm && OldNonTypeParm->hasDefaultArgument()) {
2776 // Merge the default argument from the old declaration to the
2777 // new declaration.
2778 NewNonTypeParm->setInheritedDefaultArgument(Context, OldNonTypeParm);
2779 PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
2780 } else if (NewNonTypeParm->hasDefaultArgument()) {
2781 SawDefaultArgument = true;
2782 PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
2783 } else if (SawDefaultArgument)
2784 MissingDefaultArg = true;
2785 } else {
2786 TemplateTemplateParmDecl *NewTemplateParm
2787 = cast<TemplateTemplateParmDecl>(*NewParam);
2788
2789 // Check for unexpanded parameter packs, recursively.
2790 if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
2791 Invalid = true;
2792 continue;
2793 }
2794
2795 // Check the presence of a default argument here.
2796 if (NewTemplateParm->hasDefaultArgument() &&
2797 DiagnoseDefaultTemplateArgument(*this, TPC,
2798 NewTemplateParm->getLocation(),
2799 NewTemplateParm->getDefaultArgument().getSourceRange()))
2800 NewTemplateParm->removeDefaultArgument();
2801
2802 // Merge default arguments for template template parameters
2803 TemplateTemplateParmDecl *OldTemplateParm
2804 = OldParams? cast<TemplateTemplateParmDecl>(*OldParam) : nullptr;
2805 if (NewTemplateParm->isParameterPack()) {
2806 assert(!NewTemplateParm->hasDefaultArgument() &&(static_cast <bool> (!NewTemplateParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewTemplateParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2807, __extension__ __PRETTY_FUNCTION__))
2807 "Parameter packs can't have a default argument!")(static_cast <bool> (!NewTemplateParm->hasDefaultArgument
() && "Parameter packs can't have a default argument!"
) ? void (0) : __assert_fail ("!NewTemplateParm->hasDefaultArgument() && \"Parameter packs can't have a default argument!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 2807, __extension__ __PRETTY_FUNCTION__))
;
2808 if (!NewTemplateParm->isPackExpansion())
2809 SawParameterPack = true;
2810 } else if (OldTemplateParm &&
2811 hasVisibleDefaultArgument(OldTemplateParm) &&
2812 NewTemplateParm->hasDefaultArgument() &&
2813 (!SkipBody || !SkipBody->ShouldSkip)) {
2814 OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
2815 NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
2816 SawDefaultArgument = true;
2817 RedundantDefaultArg = true;
2818 PreviousDefaultArgLoc = NewDefaultLoc;
2819 } else if (OldTemplateParm && OldTemplateParm->hasDefaultArgument()) {
2820 // Merge the default argument from the old declaration to the
2821 // new declaration.
2822 NewTemplateParm->setInheritedDefaultArgument(Context, OldTemplateParm);
2823 PreviousDefaultArgLoc
2824 = OldTemplateParm->getDefaultArgument().getLocation();
2825 } else if (NewTemplateParm->hasDefaultArgument()) {
2826 SawDefaultArgument = true;
2827 PreviousDefaultArgLoc
2828 = NewTemplateParm->getDefaultArgument().getLocation();
2829 } else if (SawDefaultArgument)
2830 MissingDefaultArg = true;
2831 }
2832
2833 // C++11 [temp.param]p11:
2834 // If a template parameter of a primary class template or alias template
2835 // is a template parameter pack, it shall be the last template parameter.
2836 if (SawParameterPack && (NewParam + 1) != NewParamEnd &&
2837 (TPC == TPC_ClassTemplate || TPC == TPC_VarTemplate ||
2838 TPC == TPC_TypeAliasTemplate)) {
2839 Diag((*NewParam)->getLocation(),
2840 diag::err_template_param_pack_must_be_last_template_parameter);
2841 Invalid = true;
2842 }
2843
2844 if (RedundantDefaultArg) {
2845 // C++ [temp.param]p12:
2846 // A template-parameter shall not be given default arguments
2847 // by two different declarations in the same scope.
2848 Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
2849 Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
2850 Invalid = true;
2851 } else if (MissingDefaultArg && TPC != TPC_FunctionTemplate) {
2852 // C++ [temp.param]p11:
2853 // If a template-parameter of a class template has a default
2854 // template-argument, each subsequent template-parameter shall either
2855 // have a default template-argument supplied or be a template parameter
2856 // pack.
2857 Diag((*NewParam)->getLocation(),
2858 diag::err_template_param_default_arg_missing);
2859 Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
2860 Invalid = true;
2861 RemoveDefaultArguments = true;
2862 }
2863
2864 // If we have an old template parameter list that we're merging
2865 // in, move on to the next parameter.
2866 if (OldParams)
2867 ++OldParam;
2868 }
2869
2870 // We were missing some default arguments at the end of the list, so remove
2871 // all of the default arguments.
2872 if (RemoveDefaultArguments) {
2873 for (TemplateParameterList::iterator NewParam = NewParams->begin(),
2874 NewParamEnd = NewParams->end();
2875 NewParam != NewParamEnd; ++NewParam) {
2876 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
2877 TTP->removeDefaultArgument();
2878 else if (NonTypeTemplateParmDecl *NTTP
2879 = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
2880 NTTP->removeDefaultArgument();
2881 else
2882 cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
2883 }
2884 }
2885
2886 return Invalid;
2887}
2888
2889namespace {
2890
2891/// A class which looks for a use of a certain level of template
2892/// parameter.
2893struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
2894 typedef RecursiveASTVisitor<DependencyChecker> super;
2895
2896 unsigned Depth;
2897
2898 // Whether we're looking for a use of a template parameter that makes the
2899 // overall construct type-dependent / a dependent type. This is strictly
2900 // best-effort for now; we may fail to match at all for a dependent type
2901 // in some cases if this is set.
2902 bool IgnoreNonTypeDependent;
2903
2904 bool Match;
2905 SourceLocation MatchLoc;
2906
2907 DependencyChecker(unsigned Depth, bool IgnoreNonTypeDependent)
2908 : Depth(Depth), IgnoreNonTypeDependent(IgnoreNonTypeDependent),
2909 Match(false) {}
2910
2911 DependencyChecker(TemplateParameterList *Params, bool IgnoreNonTypeDependent)
2912 : IgnoreNonTypeDependent(IgnoreNonTypeDependent), Match(false) {
2913 NamedDecl *ND = Params->getParam(0);
2914 if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) {
2915 Depth = PD->getDepth();
2916 } else if (NonTypeTemplateParmDecl *PD =
2917 dyn_cast<NonTypeTemplateParmDecl>(ND)) {
2918 Depth = PD->getDepth();
2919 } else {
2920 Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth();
2921 }
2922 }
2923
2924 bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) {
2925 if (ParmDepth >= Depth) {
2926 Match = true;
2927 MatchLoc = Loc;
2928 return true;
2929 }
2930 return false;
2931 }
2932
2933 bool TraverseStmt(Stmt *S, DataRecursionQueue *Q = nullptr) {
2934 // Prune out non-type-dependent expressions if requested. This can
2935 // sometimes result in us failing to find a template parameter reference
2936 // (if a value-dependent expression creates a dependent type), but this
2937 // mode is best-effort only.
2938 if (auto *E = dyn_cast_or_null<Expr>(S))
2939 if (IgnoreNonTypeDependent && !E->isTypeDependent())
2940 return true;
2941 return super::TraverseStmt(S, Q);
2942 }
2943
2944 bool TraverseTypeLoc(TypeLoc TL) {
2945 if (IgnoreNonTypeDependent && !TL.isNull() &&
2946 !TL.getType()->isDependentType())
2947 return true;
2948 return super::TraverseTypeLoc(TL);
2949 }
2950
2951 bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
2952 return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc());
2953 }
2954
2955 bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
2956 // For a best-effort search, keep looking until we find a location.
2957 return IgnoreNonTypeDependent || !Matches(T->getDepth());
2958 }
2959
2960 bool TraverseTemplateName(TemplateName N) {
2961 if (TemplateTemplateParmDecl *PD =
2962 dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
2963 if (Matches(PD->getDepth()))
2964 return false;
2965 return super::TraverseTemplateName(N);
2966 }
2967
2968 bool VisitDeclRefExpr(DeclRefExpr *E) {
2969 if (NonTypeTemplateParmDecl *PD =
2970 dyn_cast<NonTypeTemplateParmDecl>(E->getDecl()))
2971 if (Matches(PD->getDepth(), E->getExprLoc()))
2972 return false;
2973 return super::VisitDeclRefExpr(E);
2974 }
2975
2976 bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
2977 return TraverseType(T->getReplacementType());
2978 }
2979
2980 bool
2981 VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
2982 return TraverseTemplateArgument(T->getArgumentPack());
2983 }
2984
2985 bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
2986 return TraverseType(T->getInjectedSpecializationType());
2987 }
2988};
2989} // end anonymous namespace
2990
2991/// Determines whether a given type depends on the given parameter
2992/// list.
2993static bool
2994DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
2995 if (!Params->size())
2996 return false;
2997
2998 DependencyChecker Checker(Params, /*IgnoreNonTypeDependent*/false);
2999 Checker.TraverseType(T);
3000 return Checker.Match;
3001}
3002
3003// Find the source range corresponding to the named type in the given
3004// nested-name-specifier, if any.
3005static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
3006 QualType T,
3007 const CXXScopeSpec &SS) {
3008 NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
3009 while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
3010 if (const Type *CurType = NNS->getAsType()) {
3011 if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
3012 return NNSLoc.getTypeLoc().getSourceRange();
3013 } else
3014 break;
3015
3016 NNSLoc = NNSLoc.getPrefix();
3017 }
3018
3019 return SourceRange();
3020}
3021
3022/// Match the given template parameter lists to the given scope
3023/// specifier, returning the template parameter list that applies to the
3024/// name.
3025///
3026/// \param DeclStartLoc the start of the declaration that has a scope
3027/// specifier or a template parameter list.
3028///
3029/// \param DeclLoc The location of the declaration itself.
3030///
3031/// \param SS the scope specifier that will be matched to the given template
3032/// parameter lists. This scope specifier precedes a qualified name that is
3033/// being declared.
3034///
3035/// \param TemplateId The template-id following the scope specifier, if there
3036/// is one. Used to check for a missing 'template<>'.
3037///
3038/// \param ParamLists the template parameter lists, from the outermost to the
3039/// innermost template parameter lists.
3040///
3041/// \param IsFriend Whether to apply the slightly different rules for
3042/// matching template parameters to scope specifiers in friend
3043/// declarations.
3044///
3045/// \param IsMemberSpecialization will be set true if the scope specifier
3046/// denotes a fully-specialized type, and therefore this is a declaration of
3047/// a member specialization.
3048///
3049/// \returns the template parameter list, if any, that corresponds to the
3050/// name that is preceded by the scope specifier @p SS. This template
3051/// parameter list may have template parameters (if we're declaring a
3052/// template) or may have no template parameters (if we're declaring a
3053/// template specialization), or may be NULL (if what we're declaring isn't
3054/// itself a template).
3055TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier(
3056 SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS,
3057 TemplateIdAnnotation *TemplateId,
3058 ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend,
3059 bool &IsMemberSpecialization, bool &Invalid, bool SuppressDiagnostic) {
3060 IsMemberSpecialization = false;
3061 Invalid = false;
3062
3063 // The sequence of nested types to which we will match up the template
3064 // parameter lists. We first build this list by starting with the type named
3065 // by the nested-name-specifier and walking out until we run out of types.
3066 SmallVector<QualType, 4> NestedTypes;
3067 QualType T;
3068 if (SS.getScopeRep()) {
3069 if (CXXRecordDecl *Record
3070 = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
3071 T = Context.getTypeDeclType(Record);
3072 else
3073 T = QualType(SS.getScopeRep()->getAsType(), 0);
3074 }
3075
3076 // If we found an explicit specialization that prevents us from needing
3077 // 'template<>' headers, this will be set to the location of that
3078 // explicit specialization.
3079 SourceLocation ExplicitSpecLoc;
3080
3081 while (!T.isNull()) {
3082 NestedTypes.push_back(T);
3083
3084 // Retrieve the parent of a record type.
3085 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
3086 // If this type is an explicit specialization, we're done.
3087 if (ClassTemplateSpecializationDecl *Spec
3088 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
3089 if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) &&
3090 Spec->getSpecializationKind() == TSK_ExplicitSpecialization) {
3091 ExplicitSpecLoc = Spec->getLocation();
3092 break;
3093 }
3094 } else if (Record->getTemplateSpecializationKind()
3095 == TSK_ExplicitSpecialization) {
3096 ExplicitSpecLoc = Record->getLocation();
3097 break;
3098 }
3099
3100 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
3101 T = Context.getTypeDeclType(Parent);
3102 else
3103 T = QualType();
3104 continue;
3105 }
3106
3107 if (const TemplateSpecializationType *TST
3108 = T->getAs<TemplateSpecializationType>()) {
3109 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
3110 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
3111 T = Context.getTypeDeclType(Parent);
3112 else
3113 T = QualType();
3114 continue;
3115 }
3116 }
3117
3118 // Look one step prior in a dependent template specialization type.
3119 if (const DependentTemplateSpecializationType *DependentTST
3120 = T->getAs<DependentTemplateSpecializationType>()) {
3121 if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
3122 T = QualType(NNS->getAsType(), 0);
3123 else
3124 T = QualType();
3125 continue;
3126 }
3127
3128 // Look one step prior in a dependent name type.
3129 if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
3130 if (NestedNameSpecifier *NNS = DependentName->getQualifier())
3131 T = QualType(NNS->getAsType(), 0);
3132 else
3133 T = QualType();
3134 continue;
3135 }
3136
3137 // Retrieve the parent of an enumeration type.
3138 if (const EnumType *EnumT = T->getAs<EnumType>()) {
3139 // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
3140 // check here.
3141 EnumDecl *Enum = EnumT->getDecl();
3142
3143 // Get to the parent type.
3144 if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
3145 T = Context.getTypeDeclType(Parent);
3146 else
3147 T = QualType();
3148 continue;
3149 }
3150
3151 T = QualType();
3152 }
3153 // Reverse the nested types list, since we want to traverse from the outermost
3154 // to the innermost while checking template-parameter-lists.
3155 std::reverse(NestedTypes.begin(), NestedTypes.end());
3156
3157 // C++0x [temp.expl.spec]p17:
3158 // A member or a member template may be nested within many
3159 // enclosing class templates. In an explicit specialization for
3160 // such a member, the member declaration shall be preceded by a
3161 // template<> for each enclosing class template that is
3162 // explicitly specialized.
3163 bool SawNonEmptyTemplateParameterList = false;
3164
3165 auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) {
3166 if (SawNonEmptyTemplateParameterList) {
3167 if (!SuppressDiagnostic)
3168 Diag(DeclLoc, diag::err_specialize_member_of_template)
3169 << !Recovery << Range;
3170 Invalid = true;
3171 IsMemberSpecialization = false;
3172 return true;
3173 }
3174
3175 return false;
3176 };
3177
3178 auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) {
3179 // Check that we can have an explicit specialization here.
3180 if (CheckExplicitSpecialization(Range, true))
3181 return true;
3182
3183 // We don't have a template header, but we should.
3184 SourceLocation ExpectedTemplateLoc;
3185 if (!ParamLists.empty())
3186 ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
3187 else
3188 ExpectedTemplateLoc = DeclStartLoc;
3189
3190 if (!SuppressDiagnostic)
3191 Diag(DeclLoc, diag::err_template_spec_needs_header)
3192 << Range
3193 << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
3194 return false;
3195 };
3196
3197 unsigned ParamIdx = 0;
3198 for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
3199 ++TypeIdx) {
3200 T = NestedTypes[TypeIdx];
3201
3202 // Whether we expect a 'template<>' header.
3203 bool NeedEmptyTemplateHeader = false;
3204
3205 // Whether we expect a template header with parameters.
3206 bool NeedNonemptyTemplateHeader = false;
3207
3208 // For a dependent type, the set of template parameters that we
3209 // expect to see.
3210 TemplateParameterList *ExpectedTemplateParams = nullptr;
3211
3212 // C++0x [temp.expl.spec]p15:
3213 // A member or a member template may be nested within many enclosing
3214 // class templates. In an explicit specialization for such a member, the
3215 // member declaration shall be preceded by a template<> for each
3216 // enclosing class template that is explicitly specialized.
3217 if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
3218 if (ClassTemplatePartialSpecializationDecl *Partial
3219 = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
3220 ExpectedTemplateParams = Partial->getTemplateParameters();
3221 NeedNonemptyTemplateHeader = true;
3222 } else if (Record->isDependentType()) {
3223 if (Record->getDescribedClassTemplate()) {
3224 ExpectedTemplateParams = Record->getDescribedClassTemplate()
3225 ->getTemplateParameters();
3226 NeedNonemptyTemplateHeader = true;
3227 }
3228 } else if (ClassTemplateSpecializationDecl *Spec
3229 = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
3230 // C++0x [temp.expl.spec]p4:
3231 // Members of an explicitly specialized class template are defined
3232 // in the same manner as members of normal classes, and not using
3233 // the template<> syntax.
3234 if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
3235 NeedEmptyTemplateHeader = true;
3236 else
3237 continue;
3238 } else if (Record->getTemplateSpecializationKind()) {
3239 if (Record->getTemplateSpecializationKind()
3240 != TSK_ExplicitSpecialization &&
3241 TypeIdx == NumTypes - 1)
3242 IsMemberSpecialization = true;
3243
3244 continue;
3245 }
3246 } else if (const TemplateSpecializationType *TST
3247 = T->getAs<TemplateSpecializationType>()) {
3248 if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
3249 ExpectedTemplateParams = Template->getTemplateParameters();
3250 NeedNonemptyTemplateHeader = true;
3251 }
3252 } else if (T->getAs<DependentTemplateSpecializationType>()) {
3253 // FIXME: We actually could/should check the template arguments here
3254 // against the corresponding template parameter list.
3255 NeedNonemptyTemplateHeader = false;
3256 }
3257
3258 // C++ [temp.expl.spec]p16:
3259 // In an explicit specialization declaration for a member of a class
3260 // template or a member template that ap- pears in namespace scope, the
3261 // member template and some of its enclosing class templates may remain
3262 // unspecialized, except that the declaration shall not explicitly
3263 // specialize a class member template if its en- closing class templates
3264 // are not explicitly specialized as well.
3265 if (ParamIdx < ParamLists.size()) {
3266 if (ParamLists[ParamIdx]->size() == 0) {
3267 if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
3268 false))
3269 return nullptr;
3270 } else
3271 SawNonEmptyTemplateParameterList = true;
3272 }
3273
3274 if (NeedEmptyTemplateHeader) {
3275 // If we're on the last of the types, and we need a 'template<>' header
3276 // here, then it's a member specialization.
3277 if (TypeIdx == NumTypes - 1)
3278 IsMemberSpecialization = true;
3279
3280 if (ParamIdx < ParamLists.size()) {
3281 if (ParamLists[ParamIdx]->size() > 0) {
3282 // The header has template parameters when it shouldn't. Complain.
3283 if (!SuppressDiagnostic)
3284 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
3285 diag::err_template_param_list_matches_nontemplate)
3286 << T
3287 << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
3288 ParamLists[ParamIdx]->getRAngleLoc())
3289 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
3290 Invalid = true;
3291 return nullptr;
3292 }
3293
3294 // Consume this template header.
3295 ++ParamIdx;
3296 continue;
3297 }
3298
3299 if (!IsFriend)
3300 if (DiagnoseMissingExplicitSpecialization(
3301 getRangeOfTypeInNestedNameSpecifier(Context, T, SS)))
3302 return nullptr;
3303
3304 continue;
3305 }
3306
3307 if (NeedNonemptyTemplateHeader) {
3308 // In friend declarations we can have template-ids which don't
3309 // depend on the corresponding template parameter lists. But
3310 // assume that empty parameter lists are supposed to match this
3311 // template-id.
3312 if (IsFriend && T->isDependentType()) {
3313 if (ParamIdx < ParamLists.size() &&
3314 DependsOnTemplateParameters(T, ParamLists[ParamIdx]))
3315 ExpectedTemplateParams = nullptr;
3316 else
3317 continue;
3318 }
3319
3320 if (ParamIdx < ParamLists.size()) {
3321 // Check the template parameter list, if we can.
3322 if (ExpectedTemplateParams &&
3323 !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
3324 ExpectedTemplateParams,
3325 !SuppressDiagnostic, TPL_TemplateMatch))
3326 Invalid = true;
3327
3328 if (!Invalid &&
3329 CheckTemplateParameterList(ParamLists[ParamIdx], nullptr,
3330 TPC_ClassTemplateMember))
3331 Invalid = true;
3332
3333 ++ParamIdx;
3334 continue;
3335 }
3336
3337 if (!SuppressDiagnostic)
3338 Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
3339 << T
3340 << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
3341 Invalid = true;
3342 continue;
3343 }
3344 }
3345
3346 // If there were at least as many template-ids as there were template
3347 // parameter lists, then there are no template parameter lists remaining for
3348 // the declaration itself.
3349 if (ParamIdx >= ParamLists.size()) {
3350 if (TemplateId && !IsFriend) {
3351 // We don't have a template header for the declaration itself, but we
3352 // should.
3353 DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc,
3354 TemplateId->RAngleLoc));
3355
3356 // Fabricate an empty template parameter list for the invented header.
3357 return TemplateParameterList::Create(Context, SourceLocation(),
3358 SourceLocation(), None,
3359 SourceLocation(), nullptr);
3360 }
3361
3362 return nullptr;
3363 }
3364
3365 // If there were too many template parameter lists, complain about that now.
3366 if (ParamIdx < ParamLists.size() - 1) {
3367 bool HasAnyExplicitSpecHeader = false;
3368 bool AllExplicitSpecHeaders = true;
3369 for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; ++I) {
3370 if (ParamLists[I]->size() == 0)
3371 HasAnyExplicitSpecHeader = true;
3372 else
3373 AllExplicitSpecHeaders = false;
3374 }
3375
3376 if (!SuppressDiagnostic)
3377 Diag(ParamLists[ParamIdx]->getTemplateLoc(),
3378 AllExplicitSpecHeaders ? diag::warn_template_spec_extra_headers
3379 : diag::err_template_spec_extra_headers)
3380 << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
3381 ParamLists[ParamLists.size() - 2]->getRAngleLoc());
3382
3383 // If there was a specialization somewhere, such that 'template<>' is
3384 // not required, and there were any 'template<>' headers, note where the
3385 // specialization occurred.
3386 if (ExplicitSpecLoc.isValid() && HasAnyExplicitSpecHeader &&
3387 !SuppressDiagnostic)
3388 Diag(ExplicitSpecLoc,
3389 diag::note_explicit_template_spec_does_not_need_header)
3390 << NestedTypes.back();
3391
3392 // We have a template parameter list with no corresponding scope, which
3393 // means that the resulting template declaration can't be instantiated
3394 // properly (we'll end up with dependent nodes when we shouldn't).
3395 if (!AllExplicitSpecHeaders)
3396 Invalid = true;
3397 }
3398
3399 // C++ [temp.expl.spec]p16:
3400 // In an explicit specialization declaration for a member of a class
3401 // template or a member template that ap- pears in namespace scope, the
3402 // member template and some of its enclosing class templates may remain
3403 // unspecialized, except that the declaration shall not explicitly
3404 // specialize a class member template if its en- closing class templates
3405 // are not explicitly specialized as well.
3406 if (ParamLists.back()->size() == 0 &&
3407 CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
3408 false))
3409 return nullptr;
3410
3411 // Return the last template parameter list, which corresponds to the
3412 // entity being declared.
3413 return ParamLists.back();
3414}
3415
3416void Sema::NoteAllFoundTemplates(TemplateName Name) {
3417 if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
3418 Diag(Template->getLocation(), diag::note_template_declared_here)
3419 << (isa<FunctionTemplateDecl>(Template)
3420 ? 0
3421 : isa<ClassTemplateDecl>(Template)
3422 ? 1
3423 : isa<VarTemplateDecl>(Template)
3424 ? 2
3425 : isa<TypeAliasTemplateDecl>(Template) ? 3 : 4)
3426 << Template->getDeclName();
3427 return;
3428 }
3429
3430 if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
3431 for (OverloadedTemplateStorage::iterator I = OST->begin(),
3432 IEnd = OST->end();
3433 I != IEnd; ++I)
3434 Diag((*I)->getLocation(), diag::note_template_declared_here)
3435 << 0 << (*I)->getDeclName();
3436
3437 return;
3438 }
3439}
3440
3441static QualType
3442checkBuiltinTemplateIdType(Sema &SemaRef, BuiltinTemplateDecl *BTD,
3443 const SmallVectorImpl<TemplateArgument> &Converted,
3444 SourceLocation TemplateLoc,
3445 TemplateArgumentListInfo &TemplateArgs) {
3446 ASTContext &Context = SemaRef.getASTContext();
3447 switch (BTD->getBuiltinTemplateKind()) {
3448 case BTK__make_integer_seq: {
3449 // Specializations of __make_integer_seq<S, T, N> are treated like
3450 // S<T, 0, ..., N-1>.
3451
3452 // C++14 [inteseq.intseq]p1:
3453 // T shall be an integer type.
3454 if (!Converted[1].getAsType()->isIntegralType(Context)) {
3455 SemaRef.Diag(TemplateArgs[1].getLocation(),
3456 diag::err_integer_sequence_integral_element_type);
3457 return QualType();
3458 }
3459
3460 // C++14 [inteseq.make]p1:
3461 // If N is negative the program is ill-formed.
3462 TemplateArgument NumArgsArg = Converted[2];
3463 llvm::APSInt NumArgs = NumArgsArg.getAsIntegral();
3464 if (NumArgs < 0) {
3465 SemaRef.Diag(TemplateArgs[2].getLocation(),
3466 diag::err_integer_sequence_negative_length);
3467 return QualType();
3468 }
3469
3470 QualType ArgTy = NumArgsArg.getIntegralType();
3471 TemplateArgumentListInfo SyntheticTemplateArgs;
3472 // The type argument gets reused as the first template argument in the
3473 // synthetic template argument list.
3474 SyntheticTemplateArgs.addArgument(TemplateArgs[1]);
3475 // Expand N into 0 ... N-1.
3476 for (llvm::APSInt I(NumArgs.getBitWidth(), NumArgs.isUnsigned());
3477 I < NumArgs; ++I) {
3478 TemplateArgument TA(Context, I, ArgTy);
3479 SyntheticTemplateArgs.addArgument(SemaRef.getTrivialTemplateArgumentLoc(
3480 TA, ArgTy, TemplateArgs[2].getLocation()));
3481 }
3482 // The first template argument will be reused as the template decl that
3483 // our synthetic template arguments will be applied to.
3484 return SemaRef.CheckTemplateIdType(Converted[0].getAsTemplate(),
3485 TemplateLoc, SyntheticTemplateArgs);
3486 }
3487
3488 case BTK__type_pack_element:
3489 // Specializations of
3490 // __type_pack_element<Index, T_1, ..., T_N>
3491 // are treated like T_Index.
3492 assert(Converted.size() == 2 &&(static_cast <bool> (Converted.size() == 2 && "__type_pack_element should be given an index and a parameter pack"
) ? void (0) : __assert_fail ("Converted.size() == 2 && \"__type_pack_element should be given an index and a parameter pack\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3493, __extension__ __PRETTY_FUNCTION__))
3493 "__type_pack_element should be given an index and a parameter pack")(static_cast <bool> (Converted.size() == 2 && "__type_pack_element should be given an index and a parameter pack"
) ? void (0) : __assert_fail ("Converted.size() == 2 && \"__type_pack_element should be given an index and a parameter pack\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3493, __extension__ __PRETTY_FUNCTION__))
;
3494
3495 // If the Index is out of bounds, the program is ill-formed.
3496 TemplateArgument IndexArg = Converted[0], Ts = Converted[1];
3497 llvm::APSInt Index = IndexArg.getAsIntegral();
3498 assert(Index >= 0 && "the index used with __type_pack_element should be of "(static_cast <bool> (Index >= 0 && "the index used with __type_pack_element should be of "
"type std::size_t, and hence be non-negative") ? void (0) : __assert_fail
("Index >= 0 && \"the index used with __type_pack_element should be of \" \"type std::size_t, and hence be non-negative\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3499, __extension__ __PRETTY_FUNCTION__))
3499 "type std::size_t, and hence be non-negative")(static_cast <bool> (Index >= 0 && "the index used with __type_pack_element should be of "
"type std::size_t, and hence be non-negative") ? void (0) : __assert_fail
("Index >= 0 && \"the index used with __type_pack_element should be of \" \"type std::size_t, and hence be non-negative\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3499, __extension__ __PRETTY_FUNCTION__))
;
3500 if (Index >= Ts.pack_size()) {
3501 SemaRef.Diag(TemplateArgs[0].getLocation(),
3502 diag::err_type_pack_element_out_of_bounds);
3503 return QualType();
3504 }
3505
3506 // We simply return the type at index `Index`.
3507 auto Nth = std::next(Ts.pack_begin(), Index.getExtValue());
3508 return Nth->getAsType();
3509 }
3510 llvm_unreachable("unexpected BuiltinTemplateDecl!")::llvm::llvm_unreachable_internal("unexpected BuiltinTemplateDecl!"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3510)
;
3511}
3512
3513/// Determine whether this alias template is "enable_if_t".
3514static bool isEnableIfAliasTemplate(TypeAliasTemplateDecl *AliasTemplate) {
3515 return AliasTemplate->getName().equals("enable_if_t");
3516}
3517
3518/// Collect all of the separable terms in the given condition, which
3519/// might be a conjunction.
3520///
3521/// FIXME: The right answer is to convert the logical expression into
3522/// disjunctive normal form, so we can find the first failed term
3523/// within each possible clause.
3524static void collectConjunctionTerms(Expr *Clause,
3525 SmallVectorImpl<Expr *> &Terms) {
3526 if (auto BinOp = dyn_cast<BinaryOperator>(Clause->IgnoreParenImpCasts())) {
3527 if (BinOp->getOpcode() == BO_LAnd) {
3528 collectConjunctionTerms(BinOp->getLHS(), Terms);
3529 collectConjunctionTerms(BinOp->getRHS(), Terms);
3530 }
3531
3532 return;
3533 }
3534
3535 Terms.push_back(Clause);
3536}
3537
3538// The ranges-v3 library uses an odd pattern of a top-level "||" with
3539// a left-hand side that is value-dependent but never true. Identify
3540// the idiom and ignore that term.
3541static Expr *lookThroughRangesV3Condition(Preprocessor &PP, Expr *Cond) {
3542 // Top-level '||'.
3543 auto *BinOp = dyn_cast<BinaryOperator>(Cond->IgnoreParenImpCasts());
3544 if (!BinOp) return Cond;
3545
3546 if (BinOp->getOpcode() != BO_LOr) return Cond;
3547
3548 // With an inner '==' that has a literal on the right-hand side.
3549 Expr *LHS = BinOp->getLHS();
3550 auto *InnerBinOp = dyn_cast<BinaryOperator>(LHS->IgnoreParenImpCasts());
3551 if (!InnerBinOp) return Cond;
3552
3553 if (InnerBinOp->getOpcode() != BO_EQ ||
3554 !isa<IntegerLiteral>(InnerBinOp->getRHS()))
3555 return Cond;
3556
3557 // If the inner binary operation came from a macro expansion named
3558 // CONCEPT_REQUIRES or CONCEPT_REQUIRES_, return the right-hand side
3559 // of the '||', which is the real, user-provided condition.
3560 SourceLocation Loc = InnerBinOp->getExprLoc();
3561 if (!Loc.isMacroID()) return Cond;
3562
3563 StringRef MacroName = PP.getImmediateMacroName(Loc);
3564 if (MacroName == "CONCEPT_REQUIRES" || MacroName == "CONCEPT_REQUIRES_")
3565 return BinOp->getRHS();
3566
3567 return Cond;
3568}
3569
3570namespace {
3571
3572// A PrinterHelper that prints more helpful diagnostics for some sub-expressions
3573// within failing boolean expression, such as substituting template parameters
3574// for actual types.
3575class FailedBooleanConditionPrinterHelper : public PrinterHelper {
3576public:
3577 explicit FailedBooleanConditionPrinterHelper(const PrintingPolicy &P)
3578 : Policy(P) {}
3579
3580 bool handledStmt(Stmt *E, raw_ostream &OS) override {
3581 const auto *DR = dyn_cast<DeclRefExpr>(E);
3582 if (DR && DR->getQualifier()) {
3583 // If this is a qualified name, expand the template arguments in nested
3584 // qualifiers.
3585 DR->getQualifier()->print(OS, Policy, true);
3586 // Then print the decl itself.
3587 const ValueDecl *VD = DR->getDecl();
3588 OS << VD->getName();
3589 if (const auto *IV = dyn_cast<VarTemplateSpecializationDecl>(VD)) {
3590 // This is a template variable, print the expanded template arguments.
3591 printTemplateArgumentList(
3592 OS, IV->getTemplateArgs().asArray(), Policy,
3593 IV->getSpecializedTemplate()->getTemplateParameters());
3594 }
3595 return true;
3596 }
3597 return false;
3598 }
3599
3600private:
3601 const PrintingPolicy Policy;
3602};
3603
3604} // end anonymous namespace
3605
3606std::pair<Expr *, std::string>
3607Sema::findFailedBooleanCondition(Expr *Cond) {
3608 Cond = lookThroughRangesV3Condition(PP, Cond);
3609
3610 // Separate out all of the terms in a conjunction.
3611 SmallVector<Expr *, 4> Terms;
3612 collectConjunctionTerms(Cond, Terms);
3613
3614 // Determine which term failed.
3615 Expr *FailedCond = nullptr;
3616 for (Expr *Term : Terms) {
3617 Expr *TermAsWritten = Term->IgnoreParenImpCasts();
3618
3619 // Literals are uninteresting.
3620 if (isa<CXXBoolLiteralExpr>(TermAsWritten) ||
3621 isa<IntegerLiteral>(TermAsWritten))
3622 continue;
3623
3624 // The initialization of the parameter from the argument is
3625 // a constant-evaluated context.
3626 EnterExpressionEvaluationContext ConstantEvaluated(
3627 *this, Sema::ExpressionEvaluationContext::ConstantEvaluated);
3628
3629 bool Succeeded;
3630 if (Term->EvaluateAsBooleanCondition(Succeeded, Context) &&
3631 !Succeeded) {
3632 FailedCond = TermAsWritten;
3633 break;
3634 }
3635 }
3636 if (!FailedCond)
3637 FailedCond = Cond->IgnoreParenImpCasts();
3638
3639 std::string Description;
3640 {
3641 llvm::raw_string_ostream Out(Description);
3642 PrintingPolicy Policy = getPrintingPolicy();
3643 Policy.PrintCanonicalTypes = true;
3644 FailedBooleanConditionPrinterHelper Helper(Policy);
3645 FailedCond->printPretty(Out, &Helper, Policy, 0, "\n", nullptr);
3646 }
3647 return { FailedCond, Description };
3648}
3649
3650QualType Sema::CheckTemplateIdType(TemplateName Name,
3651 SourceLocation TemplateLoc,
3652 TemplateArgumentListInfo &TemplateArgs) {
3653 DependentTemplateName *DTN
3654 = Name.getUnderlying().getAsDependentTemplateName();
3655 if (DTN && DTN->isIdentifier())
3656 // When building a template-id where the template-name is dependent,
3657 // assume the template is a type template. Either our assumption is
3658 // correct, or the code is ill-formed and will be diagnosed when the
3659 // dependent name is substituted.
3660 return Context.getDependentTemplateSpecializationType(ETK_None,
3661 DTN->getQualifier(),
3662 DTN->getIdentifier(),
3663 TemplateArgs);
3664
3665 if (Name.getAsAssumedTemplateName() &&
3666 resolveAssumedTemplateNameAsType(/*Scope*/nullptr, Name, TemplateLoc))
3667 return QualType();
3668
3669 TemplateDecl *Template = Name.getAsTemplateDecl();
3670 if (!Template || isa<FunctionTemplateDecl>(Template) ||
3671 isa<VarTemplateDecl>(Template) || isa<ConceptDecl>(Template)) {
3672 // We might have a substituted template template parameter pack. If so,
3673 // build a template specialization type for it.
3674 if (Name.getAsSubstTemplateTemplateParmPack())
3675 return Context.getTemplateSpecializationType(Name, TemplateArgs);
3676
3677 Diag(TemplateLoc, diag::err_template_id_not_a_type)
3678 << Name;
3679 NoteAllFoundTemplates(Name);
3680 return QualType();
3681 }
3682
3683 // Check that the template argument list is well-formed for this
3684 // template.
3685 SmallVector<TemplateArgument, 4> Converted;
3686 if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
3687 false, Converted,
3688 /*UpdateArgsWithConversion=*/true))
3689 return QualType();
3690
3691 QualType CanonType;
3692
3693 if (TypeAliasTemplateDecl *AliasTemplate =
3694 dyn_cast<TypeAliasTemplateDecl>(Template)) {
3695
3696 // Find the canonical type for this type alias template specialization.
3697 TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
3698 if (Pattern->isInvalidDecl())
3699 return QualType();
3700
3701 TemplateArgumentList StackTemplateArgs(TemplateArgumentList::OnStack,
3702 Converted);
3703
3704 // Only substitute for the innermost template argument list.
3705 MultiLevelTemplateArgumentList TemplateArgLists;
3706 TemplateArgLists.addOuterTemplateArguments(&StackTemplateArgs);
3707 TemplateArgLists.addOuterRetainedLevels(
3708 AliasTemplate->getTemplateParameters()->getDepth());
3709
3710 LocalInstantiationScope Scope(*this);
3711 InstantiatingTemplate Inst(*this, TemplateLoc, Template);
3712 if (Inst.isInvalid())
3713 return QualType();
3714
3715 CanonType = SubstType(Pattern->getUnderlyingType(),
3716 TemplateArgLists, AliasTemplate->getLocation(),
3717 AliasTemplate->getDeclName());
3718 if (CanonType.isNull()) {
3719 // If this was enable_if and we failed to find the nested type
3720 // within enable_if in a SFINAE context, dig out the specific
3721 // enable_if condition that failed and present that instead.
3722 if (isEnableIfAliasTemplate(AliasTemplate)) {
3723 if (auto DeductionInfo = isSFINAEContext()) {
3724 if (*DeductionInfo &&
3725 (*DeductionInfo)->hasSFINAEDiagnostic() &&
3726 (*DeductionInfo)->peekSFINAEDiagnostic().second.getDiagID() ==
3727 diag::err_typename_nested_not_found_enable_if &&
3728 TemplateArgs[0].getArgument().getKind()
3729 == TemplateArgument::Expression) {
3730 Expr *FailedCond;
3731 std::string FailedDescription;
3732 std::tie(FailedCond, FailedDescription) =
3733 findFailedBooleanCondition(TemplateArgs[0].getSourceExpression());
3734
3735 // Remove the old SFINAE diagnostic.
3736 PartialDiagnosticAt OldDiag =
3737 {SourceLocation(), PartialDiagnostic::NullDiagnostic()};
3738 (*DeductionInfo)->takeSFINAEDiagnostic(OldDiag);
3739
3740 // Add a new SFINAE diagnostic specifying which condition
3741 // failed.
3742 (*DeductionInfo)->addSFINAEDiagnostic(
3743 OldDiag.first,
3744 PDiag(diag::err_typename_nested_not_found_requirement)
3745 << FailedDescription
3746 << FailedCond->getSourceRange());
3747 }
3748 }
3749 }
3750
3751 return QualType();
3752 }
3753 } else if (Name.isDependent() ||
3754 TemplateSpecializationType::anyDependentTemplateArguments(
3755 TemplateArgs, Converted)) {
3756 // This class template specialization is a dependent
3757 // type. Therefore, its canonical type is another class template
3758 // specialization type that contains all of the converted
3759 // arguments in canonical form. This ensures that, e.g., A<T> and
3760 // A<T, T> have identical types when A is declared as:
3761 //
3762 // template<typename T, typename U = T> struct A;
3763 CanonType = Context.getCanonicalTemplateSpecializationType(Name, Converted);
3764
3765 // This might work out to be a current instantiation, in which
3766 // case the canonical type needs to be the InjectedClassNameType.
3767 //
3768 // TODO: in theory this could be a simple hashtable lookup; most
3769 // changes to CurContext don't change the set of current
3770 // instantiations.
3771 if (isa<ClassTemplateDecl>(Template)) {
3772 for (DeclContext *Ctx = CurContext; Ctx; Ctx = Ctx->getLookupParent()) {
3773 // If we get out to a namespace, we're done.
3774 if (Ctx->isFileContext()) break;
3775
3776 // If this isn't a record, keep looking.
3777 CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
3778 if (!Record) continue;
3779
3780 // Look for one of the two cases with InjectedClassNameTypes
3781 // and check whether it's the same template.
3782 if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
3783 !Record->getDescribedClassTemplate())
3784 continue;
3785
3786 // Fetch the injected class name type and check whether its
3787 // injected type is equal to the type we just built.
3788 QualType ICNT = Context.getTypeDeclType(Record);
3789 QualType Injected = cast<InjectedClassNameType>(ICNT)
3790 ->getInjectedSpecializationType();
3791
3792 if (CanonType != Injected->getCanonicalTypeInternal())
3793 continue;
3794
3795 // If so, the canonical type of this TST is the injected
3796 // class name type of the record we just found.
3797 assert(ICNT.isCanonical())(static_cast <bool> (ICNT.isCanonical()) ? void (0) : __assert_fail
("ICNT.isCanonical()", "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3797, __extension__ __PRETTY_FUNCTION__))
;
3798 CanonType = ICNT;
3799 break;
3800 }
3801 }
3802 } else if (ClassTemplateDecl *ClassTemplate
3803 = dyn_cast<ClassTemplateDecl>(Template)) {
3804 // Find the class template specialization declaration that
3805 // corresponds to these arguments.
3806 void *InsertPos = nullptr;
3807 ClassTemplateSpecializationDecl *Decl
3808 = ClassTemplate->findSpecialization(Converted, InsertPos);
3809 if (!Decl) {
3810 // This is the first time we have referenced this class template
3811 // specialization. Create the canonical declaration and add it to
3812 // the set of specializations.
3813 Decl = ClassTemplateSpecializationDecl::Create(
3814 Context, ClassTemplate->getTemplatedDecl()->getTagKind(),
3815 ClassTemplate->getDeclContext(),
3816 ClassTemplate->getTemplatedDecl()->getBeginLoc(),
3817 ClassTemplate->getLocation(), ClassTemplate, Converted, nullptr);
3818 ClassTemplate->AddSpecialization(Decl, InsertPos);
3819 if (ClassTemplate->isOutOfLine())
3820 Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext());
3821 }
3822
3823 if (Decl->getSpecializationKind() == TSK_Undeclared &&
3824 ClassTemplate->getTemplatedDecl()->hasAttrs()) {
3825 InstantiatingTemplate Inst(*this, TemplateLoc, Decl);
3826 if (!Inst.isInvalid()) {
3827 MultiLevelTemplateArgumentList TemplateArgLists;
3828 TemplateArgLists.addOuterTemplateArguments(Converted);
3829 InstantiateAttrsForDecl(TemplateArgLists,
3830 ClassTemplate->getTemplatedDecl(), Decl);
3831 }
3832 }
3833
3834 // Diagnose uses of this specialization.
3835 (void)DiagnoseUseOfDecl(Decl, TemplateLoc);
3836
3837 CanonType = Context.getTypeDeclType(Decl);
3838 assert(isa<RecordType>(CanonType) &&(static_cast <bool> (isa<RecordType>(CanonType) &&
"type of non-dependent specialization is not a RecordType") ?
void (0) : __assert_fail ("isa<RecordType>(CanonType) && \"type of non-dependent specialization is not a RecordType\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3839, __extension__ __PRETTY_FUNCTION__))
3839 "type of non-dependent specialization is not a RecordType")(static_cast <bool> (isa<RecordType>(CanonType) &&
"type of non-dependent specialization is not a RecordType") ?
void (0) : __assert_fail ("isa<RecordType>(CanonType) && \"type of non-dependent specialization is not a RecordType\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3839, __extension__ __PRETTY_FUNCTION__))
;
3840 } else if (auto *BTD = dyn_cast<BuiltinTemplateDecl>(Template)) {
3841 CanonType = checkBuiltinTemplateIdType(*this, BTD, Converted, TemplateLoc,
3842 TemplateArgs);
3843 }
3844
3845 // Build the fully-sugared type for this class template
3846 // specialization, which refers back to the class template
3847 // specialization we created or found.
3848 return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
3849}
3850
3851void Sema::ActOnUndeclaredTypeTemplateName(Scope *S, TemplateTy &ParsedName,
3852 TemplateNameKind &TNK,
3853 SourceLocation NameLoc,
3854 IdentifierInfo *&II) {
3855 assert(TNK == TNK_Undeclared_template && "not an undeclared template name")(static_cast <bool> (TNK == TNK_Undeclared_template &&
"not an undeclared template name") ? void (0) : __assert_fail
("TNK == TNK_Undeclared_template && \"not an undeclared template name\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3855, __extension__ __PRETTY_FUNCTION__))
;
3856
3857 TemplateName Name = ParsedName.get();
3858 auto *ATN = Name.getAsAssumedTemplateName();
3859 assert(ATN && "not an assumed template name")(static_cast <bool> (ATN && "not an assumed template name"
) ? void (0) : __assert_fail ("ATN && \"not an assumed template name\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3859, __extension__ __PRETTY_FUNCTION__))
;
3860 II = ATN->getDeclName().getAsIdentifierInfo();
3861
3862 if (!resolveAssumedTemplateNameAsType(S, Name, NameLoc, /*Diagnose*/false)) {
3863 // Resolved to a type template name.
3864 ParsedName = TemplateTy::make(Name);
3865 TNK = TNK_Type_template;
3866 }
3867}
3868
3869bool Sema::resolveAssumedTemplateNameAsType(Scope *S, TemplateName &Name,
3870 SourceLocation NameLoc,
3871 bool Diagnose) {
3872 // We assumed this undeclared identifier to be an (ADL-only) function
3873 // template name, but it was used in a context where a type was required.
3874 // Try to typo-correct it now.
3875 AssumedTemplateStorage *ATN = Name.getAsAssumedTemplateName();
3876 assert(ATN && "not an assumed template name")(static_cast <bool> (ATN && "not an assumed template name"
) ? void (0) : __assert_fail ("ATN && \"not an assumed template name\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 3876, __extension__ __PRETTY_FUNCTION__))
;
3877
3878 LookupResult R(*this, ATN->getDeclName(), NameLoc, LookupOrdinaryName);
3879 struct CandidateCallback : CorrectionCandidateCallback {
3880 bool ValidateCandidate(const TypoCorrection &TC) override {
3881 return TC.getCorrectionDecl() &&
3882 getAsTypeTemplateDecl(TC.getCorrectionDecl());
3883 }
3884 std::unique_ptr<CorrectionCandidateCallback> clone() override {
3885 return std::make_unique<CandidateCallback>(*this);
3886 }
3887 } FilterCCC;
3888
3889 TypoCorrection Corrected =
3890 CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, nullptr,
3891 FilterCCC, CTK_ErrorRecovery);
3892 if (Corrected && Corrected.getFoundDecl()) {
3893 diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest)
3894 << ATN->getDeclName());
3895 Name = TemplateName(Corrected.getCorrectionDeclAs<TemplateDecl>());
3896 return false;
3897 }
3898
3899 if (Diagnose)
3900 Diag(R.getNameLoc(), diag::err_no_template) << R.getLookupName();
3901 return true;
3902}
3903
3904TypeResult Sema::ActOnTemplateIdType(
3905 Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
3906 TemplateTy TemplateD, IdentifierInfo *TemplateII,
3907 SourceLocation TemplateIILoc, SourceLocation LAngleLoc,
3908 ASTTemplateArgsPtr TemplateArgsIn, SourceLocation RAngleLoc,
3909 bool IsCtorOrDtorName, bool IsClassName) {
3910 if (SS.isInvalid())
3911 return true;
3912
3913 if (!IsCtorOrDtorName && !IsClassName && SS.isSet()) {
3914 DeclContext *LookupCtx = computeDeclContext(SS, /*EnteringContext*/false);
3915
3916 // C++ [temp.res]p3:
3917 // A qualified-id that refers to a type and in which the
3918 // nested-name-specifier depends on a template-parameter (14.6.2)
3919 // shall be prefixed by the keyword typename to indicate that the
3920 // qualified-id denotes a type, forming an
3921 // elaborated-type-specifier (7.1.5.3).
3922 if (!LookupCtx && isDependentScopeSpecifier(SS)) {
3923 Diag(SS.getBeginLoc(), diag::err_typename_missing_template)
3924 << SS.getScopeRep() << TemplateII->getName();
3925 // Recover as if 'typename' were specified.
3926 // FIXME: This is not quite correct recovery as we don't transform SS
3927 // into the corresponding dependent form (and we don't diagnose missing
3928 // 'template' keywords within SS as a result).
3929 return ActOnTypenameType(nullptr, SourceLocation(), SS, TemplateKWLoc,
3930 TemplateD, TemplateII, TemplateIILoc, LAngleLoc,
3931 TemplateArgsIn, RAngleLoc);
3932 }
3933
3934 // Per C++ [class.qual]p2, if the template-id was an injected-class-name,
3935 // it's not actually allowed to be used as a type in most cases. Because
3936 // we annotate it before we know whether it's valid, we have to check for
3937 // this case here.
3938 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
3939 if (LookupRD && LookupRD->getIdentifier() == TemplateII) {
3940 Diag(TemplateIILoc,
3941 TemplateKWLoc.isInvalid()
3942 ? diag::err_out_of_line_qualified_id_type_names_constructor
3943 : diag::ext_out_of_line_qualified_id_type_names_constructor)
3944 << TemplateII << 0 /*injected-class-name used as template name*/
3945 << 1 /*if any keyword was present, it was 'template'*/;
3946 }
3947 }
3948
3949 TemplateName Template = TemplateD.get();
3950 if (Template.getAsAssumedTemplateName() &&
3951 resolveAssumedTemplateNameAsType(S, Template, TemplateIILoc))
3952 return true;
3953
3954 // Translate the parser's template argument list in our AST format.
3955 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
3956 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
3957
3958 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
3959 QualType T
3960 = Context.getDependentTemplateSpecializationType(ETK_None,
3961 DTN->getQualifier(),
3962 DTN->getIdentifier(),
3963 TemplateArgs);
3964 // Build type-source information.
3965 TypeLocBuilder TLB;
3966 DependentTemplateSpecializationTypeLoc SpecTL
3967 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
3968 SpecTL.setElaboratedKeywordLoc(SourceLocation());
3969 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
3970 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
3971 SpecTL.setTemplateNameLoc(TemplateIILoc);
3972 SpecTL.setLAngleLoc(LAngleLoc);
3973 SpecTL.setRAngleLoc(RAngleLoc);
3974 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
3975 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
3976 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
3977 }
3978
3979 QualType Result = CheckTemplateIdType(Template, TemplateIILoc, TemplateArgs);
3980 if (Result.isNull())
3981 return true;
3982
3983 // Build type-source information.
3984 TypeLocBuilder TLB;
3985 TemplateSpecializationTypeLoc SpecTL
3986 = TLB.push<TemplateSpecializationTypeLoc>(Result);
3987 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
3988 SpecTL.setTemplateNameLoc(TemplateIILoc);
3989 SpecTL.setLAngleLoc(LAngleLoc);
3990 SpecTL.setRAngleLoc(RAngleLoc);
3991 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
3992 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
3993
3994 // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
3995 // constructor or destructor name (in such a case, the scope specifier
3996 // will be attached to the enclosing Decl or Expr node).
3997 if (SS.isNotEmpty() && !IsCtorOrDtorName) {
3998 // Create an elaborated-type-specifier containing the nested-name-specifier.
3999 Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
4000 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
4001 ElabTL.setElaboratedKeywordLoc(SourceLocation());
4002 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
4003 }
4004
4005 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
4006}
4007
4008TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
4009 TypeSpecifierType TagSpec,
4010 SourceLocation TagLoc,
4011 CXXScopeSpec &SS,
4012 SourceLocation TemplateKWLoc,
4013 TemplateTy TemplateD,
4014 SourceLocation TemplateLoc,
4015 SourceLocation LAngleLoc,
4016 ASTTemplateArgsPtr TemplateArgsIn,
4017 SourceLocation RAngleLoc) {
4018 if (SS.isInvalid())
4019 return TypeResult(true);
4020
4021 TemplateName Template = TemplateD.get();
4022
4023 // Translate the parser's template argument list in our AST format.
4024 TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
4025 translateTemplateArguments(TemplateArgsIn, TemplateArgs);
4026
4027 // Determine the tag kind
4028 TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
4029 ElaboratedTypeKeyword Keyword
4030 = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
4031
4032 if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
4033 QualType T = Context.getDependentTemplateSpecializationType(Keyword,
4034 DTN->getQualifier(),
4035 DTN->getIdentifier(),
4036 TemplateArgs);
4037
4038 // Build type-source information.
4039 TypeLocBuilder TLB;
4040 DependentTemplateSpecializationTypeLoc SpecTL
4041 = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
4042 SpecTL.setElaboratedKeywordLoc(TagLoc);
4043 SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
4044 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4045 SpecTL.setTemplateNameLoc(TemplateLoc);
4046 SpecTL.setLAngleLoc(LAngleLoc);
4047 SpecTL.setRAngleLoc(RAngleLoc);
4048 for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; ++I)
4049 SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
4050 return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
4051 }
4052
4053 if (TypeAliasTemplateDecl *TAT =
4054 dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
4055 // C++0x [dcl.type.elab]p2:
4056 // If the identifier resolves to a typedef-name or the simple-template-id
4057 // resolves to an alias template specialization, the
4058 // elaborated-type-specifier is ill-formed.
4059 Diag(TemplateLoc, diag::err_tag_reference_non_tag)
4060 << TAT << NTK_TypeAliasTemplate << TagKind;
4061 Diag(TAT->getLocation(), diag::note_declared_at);
4062 }
4063
4064 QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
4065 if (Result.isNull())
4066 return TypeResult(true);
4067
4068 // Check the tag kind
4069 if (const RecordType *RT = Result->getAs<RecordType>()) {
4070 RecordDecl *D = RT->getDecl();
4071
4072 IdentifierInfo *Id = D->getIdentifier();
4073 assert(Id && "templated class must have an identifier")(static_cast <bool> (Id && "templated class must have an identifier"
) ? void (0) : __assert_fail ("Id && \"templated class must have an identifier\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 4073, __extension__ __PRETTY_FUNCTION__))
;
4074
4075 if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
4076 TagLoc, Id)) {
4077 Diag(TagLoc, diag::err_use_with_wrong_tag)
4078 << Result
4079 << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
4080 Diag(D->getLocation(), diag::note_previous_use);
4081 }
4082 }
4083
4084 // Provide source-location information for the template specialization.
4085 TypeLocBuilder TLB;
4086 TemplateSpecializationTypeLoc SpecTL
4087 = TLB.push<TemplateSpecializationTypeLoc>(Result);
4088 SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4089 SpecTL.setTemplateNameLoc(TemplateLoc);
4090 SpecTL.setLAngleLoc(LAngleLoc);
4091 SpecTL.setRAngleLoc(RAngleLoc);
4092 for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; ++i)
4093 SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
4094
4095 // Construct an elaborated type containing the nested-name-specifier (if any)
4096 // and tag keyword.
4097 Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
4098 ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
4099 ElabTL.setElaboratedKeywordLoc(TagLoc);
4100 ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
4101 return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
4102}
4103
4104static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized,
4105 NamedDecl *PrevDecl,
4106 SourceLocation Loc,
4107 bool IsPartialSpecialization);
4108
4109static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
4110
4111static bool isTemplateArgumentTemplateParameter(
4112 const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
4113 switch (Arg.getKind()) {
4114 case TemplateArgument::Null:
4115 case TemplateArgument::NullPtr:
4116 case TemplateArgument::Integral:
4117 case TemplateArgument::Declaration:
4118 case TemplateArgument::Pack:
4119 case TemplateArgument::TemplateExpansion:
4120 return false;
4121
4122 case TemplateArgument::Type: {
4123 QualType Type = Arg.getAsType();
4124 const TemplateTypeParmType *TPT =
4125 Arg.getAsType()->getAs<TemplateTypeParmType>();
4126 return TPT && !Type.hasQualifiers() &&
4127 TPT->getDepth() == Depth && TPT->getIndex() == Index;
4128 }
4129
4130 case TemplateArgument::Expression: {
4131 DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
4132 if (!DRE || !DRE->getDecl())
4133 return false;
4134 const NonTypeTemplateParmDecl *NTTP =
4135 dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
4136 return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
4137 }
4138
4139 case TemplateArgument::Template:
4140 const TemplateTemplateParmDecl *TTP =
4141 dyn_cast_or_null<TemplateTemplateParmDecl>(
4142 Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
4143 return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
4144 }
4145 llvm_unreachable("unexpected kind of template argument")::llvm::llvm_unreachable_internal("unexpected kind of template argument"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 4145)
;
4146}
4147
4148static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
4149 ArrayRef<TemplateArgument> Args) {
4150 if (Params->size() != Args.size())
4151 return false;
4152
4153 unsigned Depth = Params->getDepth();
4154
4155 for (unsigned I = 0, N = Args.size(); I != N; ++I) {
4156 TemplateArgument Arg = Args[I];
4157
4158 // If the parameter is a pack expansion, the argument must be a pack
4159 // whose only element is a pack expansion.
4160 if (Params->getParam(I)->isParameterPack()) {
4161 if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
4162 !Arg.pack_begin()->isPackExpansion())
4163 return false;
4164 Arg = Arg.pack_begin()->getPackExpansionPattern();
4165 }
4166
4167 if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
4168 return false;
4169 }
4170
4171 return true;
4172}
4173
4174template<typename PartialSpecDecl>
4175static void checkMoreSpecializedThanPrimary(Sema &S, PartialSpecDecl *Partial) {
4176 if (Partial->getDeclContext()->isDependentContext())
4177 return;
4178
4179 // FIXME: Get the TDK from deduction in order to provide better diagnostics
4180 // for non-substitution-failure issues?
4181 TemplateDeductionInfo Info(Partial->getLocation());
4182 if (S.isMoreSpecializedThanPrimary(Partial, Info))
4183 return;
4184
4185 auto *Template = Partial->getSpecializedTemplate();
4186 S.Diag(Partial->getLocation(),
4187 diag::ext_partial_spec_not_more_specialized_than_primary)
4188 << isa<VarTemplateDecl>(Template);
4189
4190 if (Info.hasSFINAEDiagnostic()) {
4191 PartialDiagnosticAt Diag = {SourceLocation(),
4192 PartialDiagnostic::NullDiagnostic()};
4193 Info.takeSFINAEDiagnostic(Diag);
4194 SmallString<128> SFINAEArgString;
4195 Diag.second.EmitToString(S.getDiagnostics(), SFINAEArgString);
4196 S.Diag(Diag.first,
4197 diag::note_partial_spec_not_more_specialized_than_primary)
4198 << SFINAEArgString;
4199 }
4200
4201 S.Diag(Template->getLocation(), diag::note_template_decl_here);
4202 SmallVector<const Expr *, 3> PartialAC, TemplateAC;
4203 Template->getAssociatedConstraints(TemplateAC);
4204 Partial->getAssociatedConstraints(PartialAC);
4205 S.MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Partial, PartialAC, Template,
4206 TemplateAC);
4207}
4208
4209static void
4210noteNonDeducibleParameters(Sema &S, TemplateParameterList *TemplateParams,
4211 const llvm::SmallBitVector &DeducibleParams) {
4212 for (unsigned I = 0, N = DeducibleParams.size(); I != N; ++I) {
4213 if (!DeducibleParams[I]) {
4214 NamedDecl *Param = TemplateParams->getParam(I);
4215 if (Param->getDeclName())
4216 S.Diag(Param->getLocation(), diag::note_non_deducible_parameter)
4217 << Param->getDeclName();
4218 else
4219 S.Diag(Param->getLocation(), diag::note_non_deducible_parameter)
4220 << "(anonymous)";
4221 }
4222 }
4223}
4224
4225
4226template<typename PartialSpecDecl>
4227static void checkTemplatePartialSpecialization(Sema &S,
4228 PartialSpecDecl *Partial) {
4229 // C++1z [temp.class.spec]p8: (DR1495)
4230 // - The specialization shall be more specialized than the primary
4231 // template (14.5.5.2).
4232 checkMoreSpecializedThanPrimary(S, Partial);
4233
4234 // C++ [temp.class.spec]p8: (DR1315)
4235 // - Each template-parameter shall appear at least once in the
4236 // template-id outside a non-deduced context.
4237 // C++1z [temp.class.spec.match]p3 (P0127R2)
4238 // If the template arguments of a partial specialization cannot be
4239 // deduced because of the structure of its template-parameter-list
4240 // and the template-id, the program is ill-formed.
4241 auto *TemplateParams = Partial->getTemplateParameters();
4242 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4243 S.MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
4244 TemplateParams->getDepth(), DeducibleParams);
4245
4246 if (!DeducibleParams.all()) {
4247 unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4248 S.Diag(Partial->getLocation(), diag::ext_partial_specs_not_deducible)
4249 << isa<VarTemplatePartialSpecializationDecl>(Partial)
4250 << (NumNonDeducible > 1)
4251 << SourceRange(Partial->getLocation(),
4252 Partial->getTemplateArgsAsWritten()->RAngleLoc);
4253 noteNonDeducibleParameters(S, TemplateParams, DeducibleParams);
4254 }
4255}
4256
4257void Sema::CheckTemplatePartialSpecialization(
4258 ClassTemplatePartialSpecializationDecl *Partial) {
4259 checkTemplatePartialSpecialization(*this, Partial);
4260}
4261
4262void Sema::CheckTemplatePartialSpecialization(
4263 VarTemplatePartialSpecializationDecl *Partial) {
4264 checkTemplatePartialSpecialization(*this, Partial);
4265}
4266
4267void Sema::CheckDeductionGuideTemplate(FunctionTemplateDecl *TD) {
4268 // C++1z [temp.param]p11:
4269 // A template parameter of a deduction guide template that does not have a
4270 // default-argument shall be deducible from the parameter-type-list of the
4271 // deduction guide template.
4272 auto *TemplateParams = TD->getTemplateParameters();
4273 llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4274 MarkDeducedTemplateParameters(TD, DeducibleParams);
4275 for (unsigned I = 0; I != TemplateParams->size(); ++I) {
4276 // A parameter pack is deducible (to an empty pack).
4277 auto *Param = TemplateParams->getParam(I);
4278 if (Param->isParameterPack() || hasVisibleDefaultArgument(Param))
4279 DeducibleParams[I] = true;
4280 }
4281
4282 if (!DeducibleParams.all()) {
4283 unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4284 Diag(TD->getLocation(), diag::err_deduction_guide_template_not_deducible)
4285 << (NumNonDeducible > 1);
4286 noteNonDeducibleParameters(*this, TemplateParams, DeducibleParams);
4287 }
4288}
4289
4290DeclResult Sema::ActOnVarTemplateSpecialization(
4291 Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc,
4292 TemplateParameterList *TemplateParams, StorageClass SC,
4293 bool IsPartialSpecialization) {
4294 // D must be variable template id.
4295 assert(D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId &&(static_cast <bool> (D.getName().getKind() == UnqualifiedIdKind
::IK_TemplateId && "Variable template specialization is declared with a template it."
) ? void (0) : __assert_fail ("D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId && \"Variable template specialization is declared with a template it.\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 4296, __extension__ __PRETTY_FUNCTION__))
4296 "Variable template specialization is declared with a template it.")(static_cast <bool> (D.getName().getKind() == UnqualifiedIdKind
::IK_TemplateId && "Variable template specialization is declared with a template it."
) ? void (0) : __assert_fail ("D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId && \"Variable template specialization is declared with a template it.\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 4296, __extension__ __PRETTY_FUNCTION__))
;
4297
4298 TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
4299 TemplateArgumentListInfo TemplateArgs =
4300 makeTemplateArgumentListInfo(*this, *TemplateId);
4301 SourceLocation TemplateNameLoc = D.getIdentifierLoc();
4302 SourceLocation LAngleLoc = TemplateId->LAngleLoc;
4303 SourceLocation RAngleLoc = TemplateId->RAngleLoc;
4304
4305 TemplateName Name = TemplateId->Template.get();
4306
4307 // The template-id must name a variable template.
4308 VarTemplateDecl *VarTemplate =
4309 dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl());
4310 if (!VarTemplate) {
4311 NamedDecl *FnTemplate;
4312 if (auto *OTS = Name.getAsOverloadedTemplate())
4313 FnTemplate = *OTS->begin();
4314 else
4315 FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl());
4316 if (FnTemplate)
4317 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method)
4318 << FnTemplate->getDeclName();
4319 return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template)
4320 << IsPartialSpecialization;
4321 }
4322
4323 // Check for unexpanded parameter packs in any of the template arguments.
4324 for (unsigned I = 0, N = TemplateArgs.size(); I != N; ++I)
4325 if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
4326 UPPC_PartialSpecialization))
4327 return true;
4328
4329 // Check that the template argument list is well-formed for this
4330 // template.
4331 SmallVector<TemplateArgument, 4> Converted;
4332 if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs,
4333 false, Converted,
4334 /*UpdateArgsWithConversion=*/true))
4335 return true;
4336
4337 // Find the variable template (partial) specialization declaration that
4338 // corresponds to these arguments.
4339 if (IsPartialSpecialization) {
4340 if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, VarTemplate,
4341 TemplateArgs.size(), Converted))
4342 return true;
4343
4344 // FIXME: Move these checks to CheckTemplatePartialSpecializationArgs so we
4345 // also do them during instantiation.
4346 if (!Name.isDependent() &&
4347 !TemplateSpecializationType::anyDependentTemplateArguments(TemplateArgs,
4348 Converted)) {
4349 Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
4350 << VarTemplate->getDeclName();
4351 IsPartialSpecialization = false;
4352 }
4353
4354 if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
4355 Converted) &&
4356 (!Context.getLangOpts().CPlusPlus20 ||
4357 !TemplateParams->hasAssociatedConstraints())) {
4358 // C++ [temp.class.spec]p9b3:
4359 //
4360 // -- The argument list of the specialization shall not be identical
4361 // to the implicit argument list of the primary template.
4362 Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
4363 << /*variable template*/ 1
4364 << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
4365 << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
4366 // FIXME: Recover from this by treating the declaration as a redeclaration
4367 // of the primary template.
4368 return true;
4369 }
4370 }
4371
4372 void *InsertPos = nullptr;
4373 VarTemplateSpecializationDecl *PrevDecl = nullptr;
4374
4375 if (IsPartialSpecialization)
4376 PrevDecl = VarTemplate->findPartialSpecialization(Converted, TemplateParams,
4377 InsertPos);
4378 else
4379 PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
4380
4381 VarTemplateSpecializationDecl *Specialization = nullptr;
4382
4383 // Check whether we can declare a variable template specialization in
4384 // the current scope.
4385 if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl,
4386 TemplateNameLoc,
4387 IsPartialSpecialization))
4388 return true;
4389
4390 if (PrevDecl && PrevDecl->getSpecializationKind() == TSK_Undeclared) {
4391 // Since the only prior variable template specialization with these
4392 // arguments was referenced but not declared, reuse that
4393 // declaration node as our own, updating its source location and
4394 // the list of outer template parameters to reflect our new declaration.
4395 Specialization = PrevDecl;
4396 Specialization->setLocation(TemplateNameLoc);
4397 PrevDecl = nullptr;
4398 } else if (IsPartialSpecialization) {
4399 // Create a new class template partial specialization declaration node.
4400 VarTemplatePartialSpecializationDecl *PrevPartial =
4401 cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl);
4402 VarTemplatePartialSpecializationDecl *Partial =
4403 VarTemplatePartialSpecializationDecl::Create(
4404 Context, VarTemplate->getDeclContext(), TemplateKWLoc,
4405 TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC,
4406 Converted, TemplateArgs);
4407
4408 if (!PrevPartial)
4409 VarTemplate->AddPartialSpecialization(Partial, InsertPos);
4410 Specialization = Partial;
4411
4412 // If we are providing an explicit specialization of a member variable
4413 // template specialization, make a note of that.
4414 if (PrevPartial && PrevPartial->getInstantiatedFromMember())
4415 PrevPartial->setMemberSpecialization();
4416
4417 CheckTemplatePartialSpecialization(Partial);
4418 } else {
4419 // Create a new class template specialization declaration node for
4420 // this explicit specialization or friend declaration.
4421 Specialization = VarTemplateSpecializationDecl::Create(
4422 Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc,
4423 VarTemplate, DI->getType(), DI, SC, Converted);
4424 Specialization->setTemplateArgsInfo(TemplateArgs);
4425
4426 if (!PrevDecl)
4427 VarTemplate->AddSpecialization(Specialization, InsertPos);
4428 }
4429
4430 // C++ [temp.expl.spec]p6:
4431 // If a template, a member template or the member of a class template is
4432 // explicitly specialized then that specialization shall be declared
4433 // before the first use of that specialization that would cause an implicit
4434 // instantiation to take place, in every translation unit in which such a
4435 // use occurs; no diagnostic is required.
4436 if (PrevDecl && PrevDecl->getPointOfInstantiation().isValid()) {
4437 bool Okay = false;
4438 for (Decl *Prev = PrevDecl; Prev; Prev = Prev->getPreviousDecl()) {
4439 // Is there any previous explicit specialization declaration?
4440 if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
4441 Okay = true;
4442 break;
4443 }
4444 }
4445
4446 if (!Okay) {
4447 SourceRange Range(TemplateNameLoc, RAngleLoc);
4448 Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
4449 << Name << Range;
4450
4451 Diag(PrevDecl->getPointOfInstantiation(),
4452 diag::note_instantiation_required_here)
4453 << (PrevDecl->getTemplateSpecializationKind() !=
4454 TSK_ImplicitInstantiation);
4455 return true;
4456 }
4457 }
4458
4459 Specialization->setTemplateKeywordLoc(TemplateKWLoc);
4460 Specialization->setLexicalDeclContext(CurContext);
4461
4462 // Add the specialization into its lexical context, so that it can
4463 // be seen when iterating through the list of declarations in that
4464 // context. However, specializations are not found by name lookup.
4465 CurContext->addDecl(Specialization);
4466
4467 // Note that this is an explicit specialization.
4468 Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
4469
4470 if (PrevDecl) {
4471 // Check that this isn't a redefinition of this specialization,
4472 // merging with previous declarations.
4473 LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName,
4474 forRedeclarationInCurContext());
4475 PrevSpec.addDecl(PrevDecl);
4476 D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec));
4477 } else if (Specialization->isStaticDataMember() &&
4478 Specialization->isOutOfLine()) {
4479 Specialization->setAccess(VarTemplate->getAccess());
4480 }
4481
4482 return Specialization;
4483}
4484
4485namespace {
4486/// A partial specialization whose template arguments have matched
4487/// a given template-id.
4488struct PartialSpecMatchResult {
4489 VarTemplatePartialSpecializationDecl *Partial;
4490 TemplateArgumentList *Args;
4491};
4492} // end anonymous namespace
4493
4494DeclResult
4495Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
4496 SourceLocation TemplateNameLoc,
4497 const TemplateArgumentListInfo &TemplateArgs) {
4498 assert(Template && "A variable template id without template?")(static_cast <bool> (Template && "A variable template id without template?"
) ? void (0) : __assert_fail ("Template && \"A variable template id without template?\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 4498, __extension__ __PRETTY_FUNCTION__))
;
4499
4500 // Check that the template argument list is well-formed for this template.
4501 SmallVector<TemplateArgument, 4> Converted;
4502 if (CheckTemplateArgumentList(
4503 Template, TemplateNameLoc,
4504 const_cast<TemplateArgumentListInfo &>(TemplateArgs), false,
4505 Converted, /*UpdateArgsWithConversion=*/true))
4506 return true;
4507
4508 // Produce a placeholder value if the specialization is dependent.
4509 if (Template->getDeclContext()->isDependentContext() ||
4510 TemplateSpecializationType::anyDependentTemplateArguments(TemplateArgs,
4511 Converted))
4512 return DeclResult();
4513
4514 // Find the variable template specialization declaration that
4515 // corresponds to these arguments.
4516 void *InsertPos = nullptr;
4517 if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization(
4518 Converted, InsertPos)) {
4519 checkSpecializationVisibility(TemplateNameLoc, Spec);
4520 // If we already have a variable template specialization, return it.
4521 return Spec;
4522 }
4523
4524 // This is the first time we have referenced this variable template
4525 // specialization. Create the canonical declaration and add it to
4526 // the set of specializations, based on the closest partial specialization
4527 // that it represents. That is,
4528 VarDecl *InstantiationPattern = Template->getTemplatedDecl();
4529 TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
4530 Converted);
4531 TemplateArgumentList *InstantiationArgs = &TemplateArgList;
4532 bool AmbiguousPartialSpec = false;
4533 typedef PartialSpecMatchResult MatchResult;
4534 SmallVector<MatchResult, 4> Matched;
4535 SourceLocation PointOfInstantiation = TemplateNameLoc;
4536 TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation,
4537 /*ForTakingAddress=*/false);
4538
4539 // 1. Attempt to find the closest partial specialization that this
4540 // specializes, if any.
4541 // TODO: Unify with InstantiateClassTemplateSpecialization()?
4542 // Perhaps better after unification of DeduceTemplateArguments() and
4543 // getMoreSpecializedPartialSpecialization().
4544 SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
4545 Template->getPartialSpecializations(PartialSpecs);
4546
4547 for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I) {
4548 VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
4549 TemplateDeductionInfo Info(FailedCandidates.getLocation());
4550
4551 if (TemplateDeductionResult Result =
4552 DeduceTemplateArguments(Partial, TemplateArgList, Info)) {
4553 // Store the failed-deduction information for use in diagnostics, later.
4554 // TODO: Actually use the failed-deduction info?
4555 FailedCandidates.addCandidate().set(
4556 DeclAccessPair::make(Template, AS_public), Partial,
4557 MakeDeductionFailureInfo(Context, Result, Info));
4558 (void)Result;
4559 } else {
4560 Matched.push_back(PartialSpecMatchResult());
4561 Matched.back().Partial = Partial;
4562 Matched.back().Args = Info.take();
4563 }
4564 }
4565
4566 if (Matched.size() >= 1) {
4567 SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
4568 if (Matched.size() == 1) {
4569 // -- If exactly one matching specialization is found, the
4570 // instantiation is generated from that specialization.
4571 // We don't need to do anything for this.
4572 } else {
4573 // -- If more than one matching specialization is found, the
4574 // partial order rules (14.5.4.2) are used to determine
4575 // whether one of the specializations is more specialized
4576 // than the others. If none of the specializations is more
4577 // specialized than all of the other matching
4578 // specializations, then the use of the variable template is
4579 // ambiguous and the program is ill-formed.
4580 for (SmallVector<MatchResult, 4>::iterator P = Best + 1,
4581 PEnd = Matched.end();
4582 P != PEnd; ++P) {
4583 if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial,
4584 PointOfInstantiation) ==
4585 P->Partial)
4586 Best = P;
4587 }
4588
4589 // Determine if the best partial specialization is more specialized than
4590 // the others.
4591 for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
4592 PEnd = Matched.end();
4593 P != PEnd; ++P) {
4594 if (P != Best && getMoreSpecializedPartialSpecialization(
4595 P->Partial, Best->Partial,
4596 PointOfInstantiation) != Best->Partial) {
4597 AmbiguousPartialSpec = true;
4598 break;
4599 }
4600 }
4601 }
4602
4603 // Instantiate using the best variable template partial specialization.
4604 InstantiationPattern = Best->Partial;
4605 InstantiationArgs = Best->Args;
4606 } else {
4607 // -- If no match is found, the instantiation is generated
4608 // from the primary template.
4609 // InstantiationPattern = Template->getTemplatedDecl();
4610 }
4611
4612 // 2. Create the canonical declaration.
4613 // Note that we do not instantiate a definition until we see an odr-use
4614 // in DoMarkVarDeclReferenced().
4615 // FIXME: LateAttrs et al.?
4616 VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation(
4617 Template, InstantiationPattern, *InstantiationArgs, TemplateArgs,
4618 Converted, TemplateNameLoc /*, LateAttrs, StartingScope*/);
4619 if (!Decl)
4620 return true;
4621
4622 if (AmbiguousPartialSpec) {
4623 // Partial ordering did not produce a clear winner. Complain.
4624 Decl->setInvalidDecl();
4625 Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
4626 << Decl;
4627
4628 // Print the matching partial specializations.
4629 for (MatchResult P : Matched)
4630 Diag(P.Partial->getLocation(), diag::note_partial_spec_match)
4631 << getTemplateArgumentBindingsText(P.Partial->getTemplateParameters(),
4632 *P.Args);
4633 return true;
4634 }
4635
4636 if (VarTemplatePartialSpecializationDecl *D =
4637 dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern))
4638 Decl->setInstantiationOf(D, InstantiationArgs);
4639
4640 checkSpecializationVisibility(TemplateNameLoc, Decl);
4641
4642 assert(Decl && "No variable template specialization?")(static_cast <bool> (Decl && "No variable template specialization?"
) ? void (0) : __assert_fail ("Decl && \"No variable template specialization?\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 4642, __extension__ __PRETTY_FUNCTION__))
;
4643 return Decl;
4644}
4645
4646ExprResult
4647Sema::CheckVarTemplateId(const CXXScopeSpec &SS,
4648 const DeclarationNameInfo &NameInfo,
4649 VarTemplateDecl *Template, SourceLocation TemplateLoc,
4650 const TemplateArgumentListInfo *TemplateArgs) {
4651
4652 DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(),
4653 *TemplateArgs);
4654 if (Decl.isInvalid())
4655 return ExprError();
4656
4657 if (!Decl.get())
4658 return ExprResult();
4659
4660 VarDecl *Var = cast<VarDecl>(Decl.get());
4661 if (!Var->getTemplateSpecializationKind())
4662 Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation,
4663 NameInfo.getLoc());
4664
4665 // Build an ordinary singleton decl ref.
4666 return BuildDeclarationNameExpr(SS, NameInfo, Var,
4667 /*FoundD=*/nullptr, TemplateArgs);
4668}
4669
4670void Sema::diagnoseMissingTemplateArguments(TemplateName Name,
4671 SourceLocation Loc) {
4672 Diag(Loc, diag::err_template_missing_args)
4673 << (int)getTemplateNameKindForDiagnostics(Name) << Name;
4674 if (TemplateDecl *TD = Name.getAsTemplateDecl()) {
4675 Diag(TD->getLocation(), diag::note_template_decl_here)
4676 << TD->getTemplateParameters()->getSourceRange();
4677 }
4678}
4679
4680ExprResult
4681Sema::CheckConceptTemplateId(const CXXScopeSpec &SS,
4682 SourceLocation TemplateKWLoc,
4683 const DeclarationNameInfo &ConceptNameInfo,
4684 NamedDecl *FoundDecl,
4685 ConceptDecl *NamedConcept,
4686 const TemplateArgumentListInfo *TemplateArgs) {
4687 assert(NamedConcept && "A concept template id without a template?")(static_cast <bool> (NamedConcept && "A concept template id without a template?"
) ? void (0) : __assert_fail ("NamedConcept && \"A concept template id without a template?\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 4687, __extension__ __PRETTY_FUNCTION__))
;
4688
4689 llvm::SmallVector<TemplateArgument, 4> Converted;
4690 if (CheckTemplateArgumentList(NamedConcept, ConceptNameInfo.getLoc(),
4691 const_cast<TemplateArgumentListInfo&>(*TemplateArgs),
4692 /*PartialTemplateArgs=*/false, Converted,
4693 /*UpdateArgsWithConversion=*/false))
4694 return ExprError();
4695
4696 ConstraintSatisfaction Satisfaction;
4697 bool AreArgsDependent =
4698 TemplateSpecializationType::anyDependentTemplateArguments(*TemplateArgs,
4699 Converted);
4700 if (!AreArgsDependent &&
4701 CheckConstraintSatisfaction(
4702 NamedConcept, {NamedConcept->getConstraintExpr()}, Converted,
4703 SourceRange(SS.isSet() ? SS.getBeginLoc() : ConceptNameInfo.getLoc(),
4704 TemplateArgs->getRAngleLoc()),
4705 Satisfaction))
4706 return ExprError();
4707
4708 return ConceptSpecializationExpr::Create(Context,
4709 SS.isSet() ? SS.getWithLocInContext(Context) : NestedNameSpecifierLoc{},
4710 TemplateKWLoc, ConceptNameInfo, FoundDecl, NamedConcept,
4711 ASTTemplateArgumentListInfo::Create(Context, *TemplateArgs), Converted,
4712 AreArgsDependent ? nullptr : &Satisfaction);
4713}
4714
4715ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
4716 SourceLocation TemplateKWLoc,
4717 LookupResult &R,
4718 bool RequiresADL,
4719 const TemplateArgumentListInfo *TemplateArgs) {
4720 // FIXME: Can we do any checking at this point? I guess we could check the
4721 // template arguments that we have against the template name, if the template
4722 // name refers to a single template. That's not a terribly common case,
4723 // though.
4724 // foo<int> could identify a single function unambiguously
4725 // This approach does NOT work, since f<int>(1);
4726 // gets resolved prior to resorting to overload resolution
4727 // i.e., template<class T> void f(double);
4728 // vs template<class T, class U> void f(U);
4729
4730 // These should be filtered out by our callers.
4731 assert(!R.isAmbiguous() && "ambiguous lookup when building templateid")(static_cast <bool> (!R.isAmbiguous() && "ambiguous lookup when building templateid"
) ? void (0) : __assert_fail ("!R.isAmbiguous() && \"ambiguous lookup when building templateid\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 4731, __extension__ __PRETTY_FUNCTION__))
;
4732
4733 // Non-function templates require a template argument list.
4734 if (auto *TD = R.getAsSingle<TemplateDecl>()) {
4735 if (!TemplateArgs && !isa<FunctionTemplateDecl>(TD)) {
4736 diagnoseMissingTemplateArguments(TemplateName(TD), R.getNameLoc());
4737 return ExprError();
4738 }
4739 }
4740
4741 // In C++1y, check variable template ids.
4742 if (R.getAsSingle<VarTemplateDecl>()) {
4743 ExprResult Res = CheckVarTemplateId(SS, R.getLookupNameInfo(),
4744 R.getAsSingle<VarTemplateDecl>(),
4745 TemplateKWLoc, TemplateArgs);
4746 if (Res.isInvalid() || Res.isUsable())
4747 return Res;
4748 // Result is dependent. Carry on to build an UnresolvedLookupEpxr.
4749 }
4750
4751 if (R.getAsSingle<ConceptDecl>()) {
4752 return CheckConceptTemplateId(SS, TemplateKWLoc, R.getLookupNameInfo(),
4753 R.getFoundDecl(),
4754 R.getAsSingle<ConceptDecl>(), TemplateArgs);
4755 }
4756
4757 // We don't want lookup warnings at this point.
4758 R.suppressDiagnostics();
4759
4760 UnresolvedLookupExpr *ULE
4761 = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
4762 SS.getWithLocInContext(Context),
4763 TemplateKWLoc,
4764 R.getLookupNameInfo(),
4765 RequiresADL, TemplateArgs,
4766 R.begin(), R.end());
4767
4768 return ULE;
4769}
4770
4771// We actually only call this from template instantiation.
4772ExprResult
4773Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
4774 SourceLocation TemplateKWLoc,
4775 const DeclarationNameInfo &NameInfo,
4776 const TemplateArgumentListInfo *TemplateArgs) {
4777
4778 assert(TemplateArgs || TemplateKWLoc.isValid())(static_cast <bool> (TemplateArgs || TemplateKWLoc.isValid
()) ? void (0) : __assert_fail ("TemplateArgs || TemplateKWLoc.isValid()"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 4778, __extension__ __PRETTY_FUNCTION__))
;
4779 DeclContext *DC;
4780 if (!(DC = computeDeclContext(SS, false)) ||
4781 DC->isDependentContext() ||
4782 RequireCompleteDeclContext(SS, DC))
4783 return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
4784
4785 bool MemberOfUnknownSpecialization;
4786 LookupResult R(*this, NameInfo, LookupOrdinaryName);
4787 if (LookupTemplateName(R, (Scope *)nullptr, SS, QualType(),
4788 /*Entering*/false, MemberOfUnknownSpecialization,
4789 TemplateKWLoc))
4790 return ExprError();
4791
4792 if (R.isAmbiguous())
4793 return ExprError();
4794
4795 if (R.empty()) {
4796 Diag(NameInfo.getLoc(), diag::err_no_member)
4797 << NameInfo.getName() << DC << SS.getRange();
4798 return ExprError();
4799 }
4800
4801 if (ClassTemplateDecl *Temp = R.getAsSingle<ClassTemplateDecl>()) {
4802 Diag(NameInfo.getLoc(), diag::err_template_kw_refers_to_class_template)
4803 << SS.getScopeRep()
4804 << NameInfo.getName().getAsString() << SS.getRange();
4805 Diag(Temp->getLocation(), diag::note_referenced_class_template);
4806 return ExprError();
4807 }
4808
4809 return BuildTemplateIdExpr(SS, TemplateKWLoc, R, /*ADL*/ false, TemplateArgs);
4810}
4811
4812/// Form a template name from a name that is syntactically required to name a
4813/// template, either due to use of the 'template' keyword or because a name in
4814/// this syntactic context is assumed to name a template (C++ [temp.names]p2-4).
4815///
4816/// This action forms a template name given the name of the template and its
4817/// optional scope specifier. This is used when the 'template' keyword is used
4818/// or when the parsing context unambiguously treats a following '<' as
4819/// introducing a template argument list. Note that this may produce a
4820/// non-dependent template name if we can perform the lookup now and identify
4821/// the named template.
4822///
4823/// For example, given "x.MetaFun::template apply", the scope specifier
4824/// \p SS will be "MetaFun::", \p TemplateKWLoc contains the location
4825/// of the "template" keyword, and "apply" is the \p Name.
4826TemplateNameKind Sema::ActOnTemplateName(Scope *S,
4827 CXXScopeSpec &SS,
4828 SourceLocation TemplateKWLoc,
4829 const UnqualifiedId &Name,
4830 ParsedType ObjectType,
4831 bool EnteringContext,
4832 TemplateTy &Result,
4833 bool AllowInjectedClassName) {
4834 if (TemplateKWLoc.isValid() && S && !S->getTemplateParamParent())
4835 Diag(TemplateKWLoc,
4836 getLangOpts().CPlusPlus11 ?
4837 diag::warn_cxx98_compat_template_outside_of_template :
4838 diag::ext_template_outside_of_template)
4839 << FixItHint::CreateRemoval(TemplateKWLoc);
4840
4841 if (SS.isInvalid())
4842 return TNK_Non_template;
4843
4844 // Figure out where isTemplateName is going to look.
4845 DeclContext *LookupCtx = nullptr;
4846 if (SS.isNotEmpty())
4847 LookupCtx = computeDeclContext(SS, EnteringContext);
4848 else if (ObjectType)
4849 LookupCtx = computeDeclContext(GetTypeFromParser(ObjectType));
4850
4851 // C++0x [temp.names]p5:
4852 // If a name prefixed by the keyword template is not the name of
4853 // a template, the program is ill-formed. [Note: the keyword
4854 // template may not be applied to non-template members of class
4855 // templates. -end note ] [ Note: as is the case with the
4856 // typename prefix, the template prefix is allowed in cases
4857 // where it is not strictly necessary; i.e., when the
4858 // nested-name-specifier or the expression on the left of the ->
4859 // or . is not dependent on a template-parameter, or the use
4860 // does not appear in the scope of a template. -end note]
4861 //
4862 // Note: C++03 was more strict here, because it banned the use of
4863 // the "template" keyword prior to a template-name that was not a
4864 // dependent name. C++ DR468 relaxed this requirement (the
4865 // "template" keyword is now permitted). We follow the C++0x
4866 // rules, even in C++03 mode with a warning, retroactively applying the DR.
4867 bool MemberOfUnknownSpecialization;
4868 TemplateNameKind TNK = isTemplateName(S, SS, TemplateKWLoc.isValid(), Name,
4869 ObjectType, EnteringContext, Result,
4870 MemberOfUnknownSpecialization);
4871 if (TNK != TNK_Non_template) {
4872 // We resolved this to a (non-dependent) template name. Return it.
4873 auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
4874 if (!AllowInjectedClassName && SS.isNotEmpty() && LookupRD &&
4875 Name.getKind() == UnqualifiedIdKind::IK_Identifier &&
4876 Name.Identifier && LookupRD->getIdentifier() == Name.Identifier) {
4877 // C++14 [class.qual]p2:
4878 // In a lookup in which function names are not ignored and the
4879 // nested-name-specifier nominates a class C, if the name specified
4880 // [...] is the injected-class-name of C, [...] the name is instead
4881 // considered to name the constructor
4882 //
4883 // We don't get here if naming the constructor would be valid, so we
4884 // just reject immediately and recover by treating the
4885 // injected-class-name as naming the template.
4886 Diag(Name.getBeginLoc(),
4887 diag::ext_out_of_line_qualified_id_type_names_constructor)
4888 << Name.Identifier
4889 << 0 /*injected-class-name used as template name*/
4890 << TemplateKWLoc.isValid();
4891 }
4892 return TNK;
4893 }
4894
4895 if (!MemberOfUnknownSpecialization) {
4896 // Didn't find a template name, and the lookup wasn't dependent.
4897 // Do the lookup again to determine if this is a "nothing found" case or
4898 // a "not a template" case. FIXME: Refactor isTemplateName so we don't
4899 // need to do this.
4900 DeclarationNameInfo DNI = GetNameFromUnqualifiedId(Name);
4901 LookupResult R(*this, DNI.getName(), Name.getBeginLoc(),
4902 LookupOrdinaryName);
4903 bool MOUS;
4904 // Tell LookupTemplateName that we require a template so that it diagnoses
4905 // cases where it finds a non-template.
4906 RequiredTemplateKind RTK = TemplateKWLoc.isValid()
4907 ? RequiredTemplateKind(TemplateKWLoc)
4908 : TemplateNameIsRequired;
4909 if (!LookupTemplateName(R, S, SS, ObjectType.get(), EnteringContext, MOUS,
4910 RTK, nullptr, /*AllowTypoCorrection=*/false) &&
4911 !R.isAmbiguous()) {
4912 if (LookupCtx)
4913 Diag(Name.getBeginLoc(), diag::err_no_member)
4914 << DNI.getName() << LookupCtx << SS.getRange();
4915 else
4916 Diag(Name.getBeginLoc(), diag::err_undeclared_use)
4917 << DNI.getName() << SS.getRange();
4918 }
4919 return TNK_Non_template;
4920 }
4921
4922 NestedNameSpecifier *Qualifier = SS.getScopeRep();
4923
4924 switch (Name.getKind()) {
4925 case UnqualifiedIdKind::IK_Identifier:
4926 Result = TemplateTy::make(
4927 Context.getDependentTemplateName(Qualifier, Name.Identifier));
4928 return TNK_Dependent_template_name;
4929
4930 case UnqualifiedIdKind::IK_OperatorFunctionId:
4931 Result = TemplateTy::make(Context.getDependentTemplateName(
4932 Qualifier, Name.OperatorFunctionId.Operator));
4933 return TNK_Function_template;
4934
4935 case UnqualifiedIdKind::IK_LiteralOperatorId:
4936 // This is a kind of template name, but can never occur in a dependent
4937 // scope (literal operators can only be declared at namespace scope).
4938 break;
4939
4940 default:
4941 break;
4942 }
4943
4944 // This name cannot possibly name a dependent template. Diagnose this now
4945 // rather than building a dependent template name that can never be valid.
4946 Diag(Name.getBeginLoc(),
4947 diag::err_template_kw_refers_to_dependent_non_template)
4948 << GetNameFromUnqualifiedId(Name).getName() << Name.getSourceRange()
4949 << TemplateKWLoc.isValid() << TemplateKWLoc;
4950 return TNK_Non_template;
4951}
4952
4953bool Sema::CheckTemplateTypeArgument(TemplateTypeParmDecl *Param,
4954 TemplateArgumentLoc &AL,
4955 SmallVectorImpl<TemplateArgument> &Converted) {
4956 const TemplateArgument &Arg = AL.getArgument();
4957 QualType ArgType;
4958 TypeSourceInfo *TSI = nullptr;
4959
4960 // Check template type parameter.
4961 switch(Arg.getKind()) {
4962 case TemplateArgument::Type:
4963 // C++ [temp.arg.type]p1:
4964 // A template-argument for a template-parameter which is a
4965 // type shall be a type-id.
4966 ArgType = Arg.getAsType();
4967 TSI = AL.getTypeSourceInfo();
4968 break;
4969 case TemplateArgument::Template:
4970 case TemplateArgument::TemplateExpansion: {
4971 // We have a template type parameter but the template argument
4972 // is a template without any arguments.
4973 SourceRange SR = AL.getSourceRange();
4974 TemplateName Name = Arg.getAsTemplateOrTemplatePattern();
4975 diagnoseMissingTemplateArguments(Name, SR.getEnd());
4976 return true;
4977 }
4978 case TemplateArgument::Expression: {
4979 // We have a template type parameter but the template argument is an
4980 // expression; see if maybe it is missing the "typename" keyword.
4981 CXXScopeSpec SS;
4982 DeclarationNameInfo NameInfo;
4983
4984 if (DependentScopeDeclRefExpr *ArgExpr =
4985 dyn_cast<DependentScopeDeclRefExpr>(Arg.getAsExpr())) {
4986 SS.Adopt(ArgExpr->getQualifierLoc());
4987 NameInfo = ArgExpr->getNameInfo();
4988 } else if (CXXDependentScopeMemberExpr *ArgExpr =
4989 dyn_cast<CXXDependentScopeMemberExpr>(Arg.getAsExpr())) {
4990 if (ArgExpr->isImplicitAccess()) {
4991 SS.Adopt(ArgExpr->getQualifierLoc());
4992 NameInfo = ArgExpr->getMemberNameInfo();
4993 }
4994 }
4995
4996 if (auto *II = NameInfo.getName().getAsIdentifierInfo()) {
4997 LookupResult Result(*this, NameInfo, LookupOrdinaryName);
4998 LookupParsedName(Result, CurScope, &SS);
4999
5000 if (Result.getAsSingle<TypeDecl>() ||
5001 Result.getResultKind() ==
5002 LookupResult::NotFoundInCurrentInstantiation) {
5003 assert(SS.getScopeRep() && "dependent scope expr must has a scope!")(static_cast <bool> (SS.getScopeRep() && "dependent scope expr must has a scope!"
) ? void (0) : __assert_fail ("SS.getScopeRep() && \"dependent scope expr must has a scope!\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5003, __extension__ __PRETTY_FUNCTION__))
;
5004 // Suggest that the user add 'typename' before the NNS.
5005 SourceLocation Loc = AL.getSourceRange().getBegin();
5006 Diag(Loc, getLangOpts().MSVCCompat
5007 ? diag::ext_ms_template_type_arg_missing_typename
5008 : diag::err_template_arg_must_be_type_suggest)
5009 << FixItHint::CreateInsertion(Loc, "typename ");
5010 Diag(Param->getLocation(), diag::note_template_param_here);
5011
5012 // Recover by synthesizing a type using the location information that we
5013 // already have.
5014 ArgType =
5015 Context.getDependentNameType(ETK_Typename, SS.getScopeRep(), II);
5016 TypeLocBuilder TLB;
5017 DependentNameTypeLoc TL = TLB.push<DependentNameTypeLoc>(ArgType);
5018 TL.setElaboratedKeywordLoc(SourceLocation(/*synthesized*/));
5019 TL.setQualifierLoc(SS.getWithLocInContext(Context));
5020 TL.setNameLoc(NameInfo.getLoc());
5021 TSI = TLB.getTypeSourceInfo(Context, ArgType);
5022
5023 // Overwrite our input TemplateArgumentLoc so that we can recover
5024 // properly.
5025 AL = TemplateArgumentLoc(TemplateArgument(ArgType),
5026 TemplateArgumentLocInfo(TSI));
5027
5028 break;
5029 }
5030 }
5031 // fallthrough
5032 LLVM_FALLTHROUGH[[gnu::fallthrough]];
5033 }
5034 default: {
5035 // We have a template type parameter but the template argument
5036 // is not a type.
5037 SourceRange SR = AL.getSourceRange();
5038 Diag(SR.getBegin(), diag::err_template_arg_must_be_type) << SR;
5039 Diag(Param->getLocation(), diag::note_template_param_here);
5040
5041 return true;
5042 }
5043 }
5044
5045 if (CheckTemplateArgument(Param, TSI))
5046 return true;
5047
5048 // Add the converted template type argument.
5049 ArgType = Context.getCanonicalType(ArgType);
5050
5051 // Objective-C ARC:
5052 // If an explicitly-specified template argument type is a lifetime type
5053 // with no lifetime qualifier, the __strong lifetime qualifier is inferred.
5054 if (getLangOpts().ObjCAutoRefCount &&
5055 ArgType->isObjCLifetimeType() &&
5056 !ArgType.getObjCLifetime()) {
5057 Qualifiers Qs;
5058 Qs.setObjCLifetime(Qualifiers::OCL_Strong);
5059 ArgType = Context.getQualifiedType(ArgType, Qs);
5060 }
5061
5062 Converted.push_back(TemplateArgument(ArgType));
5063 return false;
5064}
5065
5066/// Substitute template arguments into the default template argument for
5067/// the given template type parameter.
5068///
5069/// \param SemaRef the semantic analysis object for which we are performing
5070/// the substitution.
5071///
5072/// \param Template the template that we are synthesizing template arguments
5073/// for.
5074///
5075/// \param TemplateLoc the location of the template name that started the
5076/// template-id we are checking.
5077///
5078/// \param RAngleLoc the location of the right angle bracket ('>') that
5079/// terminates the template-id.
5080///
5081/// \param Param the template template parameter whose default we are
5082/// substituting into.
5083///
5084/// \param Converted the list of template arguments provided for template
5085/// parameters that precede \p Param in the template parameter list.
5086/// \returns the substituted template argument, or NULL if an error occurred.
5087static TypeSourceInfo *
5088SubstDefaultTemplateArgument(Sema &SemaRef,
5089 TemplateDecl *Template,
5090 SourceLocation TemplateLoc,
5091 SourceLocation RAngleLoc,
5092 TemplateTypeParmDecl *Param,
5093 SmallVectorImpl<TemplateArgument> &Converted) {
5094 TypeSourceInfo *ArgType = Param->getDefaultArgumentInfo();
5095
5096 // If the argument type is dependent, instantiate it now based
5097 // on the previously-computed template arguments.
5098 if (ArgType->getType()->isInstantiationDependentType()) {
5099 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
5100 Param, Template, Converted,
5101 SourceRange(TemplateLoc, RAngleLoc));
5102 if (Inst.isInvalid())
5103 return nullptr;
5104
5105 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5106
5107 // Only substitute for the innermost template argument list.
5108 MultiLevelTemplateArgumentList TemplateArgLists;
5109 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
5110 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
5111 TemplateArgLists.addOuterTemplateArguments(None);
5112
5113 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
5114 ArgType =
5115 SemaRef.SubstType(ArgType, TemplateArgLists,
5116 Param->getDefaultArgumentLoc(), Param->getDeclName());
5117 }
5118
5119 return ArgType;
5120}
5121
5122/// Substitute template arguments into the default template argument for
5123/// the given non-type template parameter.
5124///
5125/// \param SemaRef the semantic analysis object for which we are performing
5126/// the substitution.
5127///
5128/// \param Template the template that we are synthesizing template arguments
5129/// for.
5130///
5131/// \param TemplateLoc the location of the template name that started the
5132/// template-id we are checking.
5133///
5134/// \param RAngleLoc the location of the right angle bracket ('>') that
5135/// terminates the template-id.
5136///
5137/// \param Param the non-type template parameter whose default we are
5138/// substituting into.
5139///
5140/// \param Converted the list of template arguments provided for template
5141/// parameters that precede \p Param in the template parameter list.
5142///
5143/// \returns the substituted template argument, or NULL if an error occurred.
5144static ExprResult
5145SubstDefaultTemplateArgument(Sema &SemaRef,
5146 TemplateDecl *Template,
5147 SourceLocation TemplateLoc,
5148 SourceLocation RAngleLoc,
5149 NonTypeTemplateParmDecl *Param,
5150 SmallVectorImpl<TemplateArgument> &Converted) {
5151 Sema::InstantiatingTemplate Inst(SemaRef, TemplateLoc,
5152 Param, Template, Converted,
5153 SourceRange(TemplateLoc, RAngleLoc));
5154 if (Inst.isInvalid())
5155 return ExprError();
5156
5157 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5158
5159 // Only substitute for the innermost template argument list.
5160 MultiLevelTemplateArgumentList TemplateArgLists;
5161 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
5162 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
5163 TemplateArgLists.addOuterTemplateArguments(None);
5164
5165 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
5166 EnterExpressionEvaluationContext ConstantEvaluated(
5167 SemaRef, Sema::ExpressionEvaluationContext::ConstantEvaluated);
5168 return SemaRef.SubstExpr(Param->getDefaultArgument(), TemplateArgLists);
5169}
5170
5171/// Substitute template arguments into the default template argument for
5172/// the given template template parameter.
5173///
5174/// \param SemaRef the semantic analysis object for which we are performing
5175/// the substitution.
5176///
5177/// \param Template the template that we are synthesizing template arguments
5178/// for.
5179///
5180/// \param TemplateLoc the location of the template name that started the
5181/// template-id we are checking.
5182///
5183/// \param RAngleLoc the location of the right angle bracket ('>') that
5184/// terminates the template-id.
5185///
5186/// \param Param the template template parameter whose default we are
5187/// substituting into.
5188///
5189/// \param Converted the list of template arguments provided for template
5190/// parameters that precede \p Param in the template parameter list.
5191///
5192/// \param QualifierLoc Will be set to the nested-name-specifier (with
5193/// source-location information) that precedes the template name.
5194///
5195/// \returns the substituted template argument, or NULL if an error occurred.
5196static TemplateName
5197SubstDefaultTemplateArgument(Sema &SemaRef,
5198 TemplateDecl *Template,
5199 SourceLocation TemplateLoc,
5200 SourceLocation RAngleLoc,
5201 TemplateTemplateParmDecl *Param,
5202 SmallVectorImpl<TemplateArgument> &Converted,
5203 NestedNameSpecifierLoc &QualifierLoc) {
5204 Sema::InstantiatingTemplate Inst(
5205 SemaRef, TemplateLoc, TemplateParameter(Param), Template, Converted,
5206 SourceRange(TemplateLoc, RAngleLoc));
5207 if (Inst.isInvalid())
5208 return TemplateName();
5209
5210 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5211
5212 // Only substitute for the innermost template argument list.
5213 MultiLevelTemplateArgumentList TemplateArgLists;
5214 TemplateArgLists.addOuterTemplateArguments(&TemplateArgs);
5215 for (unsigned i = 0, e = Param->getDepth(); i != e; ++i)
5216 TemplateArgLists.addOuterTemplateArguments(None);
5217
5218 Sema::ContextRAII SavedContext(SemaRef, Template->getDeclContext());
5219 // Substitute into the nested-name-specifier first,
5220 QualifierLoc = Param->getDefaultArgument().getTemplateQualifierLoc();
5221 if (QualifierLoc) {
5222 QualifierLoc =
5223 SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgLists);
5224 if (!QualifierLoc)
5225 return TemplateName();
5226 }
5227
5228 return SemaRef.SubstTemplateName(
5229 QualifierLoc,
5230 Param->getDefaultArgument().getArgument().getAsTemplate(),
5231 Param->getDefaultArgument().getTemplateNameLoc(),
5232 TemplateArgLists);
5233}
5234
5235/// If the given template parameter has a default template
5236/// argument, substitute into that default template argument and
5237/// return the corresponding template argument.
5238TemplateArgumentLoc
5239Sema::SubstDefaultTemplateArgumentIfAvailable(TemplateDecl *Template,
5240 SourceLocation TemplateLoc,
5241 SourceLocation RAngleLoc,
5242 Decl *Param,
5243 SmallVectorImpl<TemplateArgument>
5244 &Converted,
5245 bool &HasDefaultArg) {
5246 HasDefaultArg = false;
5247
5248 if (TemplateTypeParmDecl *TypeParm = dyn_cast<TemplateTypeParmDecl>(Param)) {
5249 if (!hasVisibleDefaultArgument(TypeParm))
5250 return TemplateArgumentLoc();
5251
5252 HasDefaultArg = true;
5253 TypeSourceInfo *DI = SubstDefaultTemplateArgument(*this, Template,
5254 TemplateLoc,
5255 RAngleLoc,
5256 TypeParm,
5257 Converted);
5258 if (DI)
5259 return TemplateArgumentLoc(TemplateArgument(DI->getType()), DI);
5260
5261 return TemplateArgumentLoc();
5262 }
5263
5264 if (NonTypeTemplateParmDecl *NonTypeParm
5265 = dyn_cast<NonTypeTemplateParmDecl>(Param)) {
5266 if (!hasVisibleDefaultArgument(NonTypeParm))
5267 return TemplateArgumentLoc();
5268
5269 HasDefaultArg = true;
5270 ExprResult Arg = SubstDefaultTemplateArgument(*this, Template,
5271 TemplateLoc,
5272 RAngleLoc,
5273 NonTypeParm,
5274 Converted);
5275 if (Arg.isInvalid())
5276 return TemplateArgumentLoc();
5277
5278 Expr *ArgE = Arg.getAs<Expr>();
5279 return TemplateArgumentLoc(TemplateArgument(ArgE), ArgE);
5280 }
5281
5282 TemplateTemplateParmDecl *TempTempParm
5283 = cast<TemplateTemplateParmDecl>(Param);
5284 if (!hasVisibleDefaultArgument(TempTempParm))
5285 return TemplateArgumentLoc();
5286
5287 HasDefaultArg = true;
5288 NestedNameSpecifierLoc QualifierLoc;
5289 TemplateName TName = SubstDefaultTemplateArgument(*this, Template,
5290 TemplateLoc,
5291 RAngleLoc,
5292 TempTempParm,
5293 Converted,
5294 QualifierLoc);
5295 if (TName.isNull())
5296 return TemplateArgumentLoc();
5297
5298 return TemplateArgumentLoc(
5299 Context, TemplateArgument(TName),
5300 TempTempParm->getDefaultArgument().getTemplateQualifierLoc(),
5301 TempTempParm->getDefaultArgument().getTemplateNameLoc());
5302}
5303
5304/// Convert a template-argument that we parsed as a type into a template, if
5305/// possible. C++ permits injected-class-names to perform dual service as
5306/// template template arguments and as template type arguments.
5307static TemplateArgumentLoc
5308convertTypeTemplateArgumentToTemplate(ASTContext &Context, TypeLoc TLoc) {
5309 // Extract and step over any surrounding nested-name-specifier.
5310 NestedNameSpecifierLoc QualLoc;
5311 if (auto ETLoc = TLoc.getAs<ElaboratedTypeLoc>()) {
5312 if (ETLoc.getTypePtr()->getKeyword() != ETK_None)
5313 return TemplateArgumentLoc();
5314
5315 QualLoc = ETLoc.getQualifierLoc();
5316 TLoc = ETLoc.getNamedTypeLoc();
5317 }
5318 // If this type was written as an injected-class-name, it can be used as a
5319 // template template argument.
5320 if (auto InjLoc = TLoc.getAs<InjectedClassNameTypeLoc>())
5321 return TemplateArgumentLoc(Context, InjLoc.getTypePtr()->getTemplateName(),
5322 QualLoc, InjLoc.getNameLoc());
5323
5324 // If this type was written as an injected-class-name, it may have been
5325 // converted to a RecordType during instantiation. If the RecordType is
5326 // *not* wrapped in a TemplateSpecializationType and denotes a class
5327 // template specialization, it must have come from an injected-class-name.
5328 if (auto RecLoc = TLoc.getAs<RecordTypeLoc>())
5329 if (auto *CTSD =
5330 dyn_cast<ClassTemplateSpecializationDecl>(RecLoc.getDecl()))
5331 return TemplateArgumentLoc(Context,
5332 TemplateName(CTSD->getSpecializedTemplate()),
5333 QualLoc, RecLoc.getNameLoc());
5334
5335 return TemplateArgumentLoc();
5336}
5337
5338/// Check that the given template argument corresponds to the given
5339/// template parameter.
5340///
5341/// \param Param The template parameter against which the argument will be
5342/// checked.
5343///
5344/// \param Arg The template argument, which may be updated due to conversions.
5345///
5346/// \param Template The template in which the template argument resides.
5347///
5348/// \param TemplateLoc The location of the template name for the template
5349/// whose argument list we're matching.
5350///
5351/// \param RAngleLoc The location of the right angle bracket ('>') that closes
5352/// the template argument list.
5353///
5354/// \param ArgumentPackIndex The index into the argument pack where this
5355/// argument will be placed. Only valid if the parameter is a parameter pack.
5356///
5357/// \param Converted The checked, converted argument will be added to the
5358/// end of this small vector.
5359///
5360/// \param CTAK Describes how we arrived at this particular template argument:
5361/// explicitly written, deduced, etc.
5362///
5363/// \returns true on error, false otherwise.
5364bool Sema::CheckTemplateArgument(NamedDecl *Param,
5365 TemplateArgumentLoc &Arg,
5366 NamedDecl *Template,
5367 SourceLocation TemplateLoc,
5368 SourceLocation RAngleLoc,
5369 unsigned ArgumentPackIndex,
5370 SmallVectorImpl<TemplateArgument> &Converted,
5371 CheckTemplateArgumentKind CTAK) {
5372 // Check template type parameters.
5373 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(Param))
5374 return CheckTemplateTypeArgument(TTP, Arg, Converted);
5375
5376 // Check non-type template parameters.
5377 if (NonTypeTemplateParmDecl *NTTP =dyn_cast<NonTypeTemplateParmDecl>(Param)) {
5378 // Do substitution on the type of the non-type template parameter
5379 // with the template arguments we've seen thus far. But if the
5380 // template has a dependent context then we cannot substitute yet.
5381 QualType NTTPType = NTTP->getType();
5382 if (NTTP->isParameterPack() && NTTP->isExpandedParameterPack())
5383 NTTPType = NTTP->getExpansionType(ArgumentPackIndex);
5384
5385 if (NTTPType->isInstantiationDependentType() &&
5386 !isa<TemplateTemplateParmDecl>(Template) &&
5387 !Template->getDeclContext()->isDependentContext()) {
5388 // Do substitution on the type of the non-type template parameter.
5389 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
5390 NTTP, Converted,
5391 SourceRange(TemplateLoc, RAngleLoc));
5392 if (Inst.isInvalid())
5393 return true;
5394
5395 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack,
5396 Converted);
5397
5398 // If the parameter is a pack expansion, expand this slice of the pack.
5399 if (auto *PET = NTTPType->getAs<PackExpansionType>()) {
5400 Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this,
5401 ArgumentPackIndex);
5402 NTTPType = SubstType(PET->getPattern(),
5403 MultiLevelTemplateArgumentList(TemplateArgs),
5404 NTTP->getLocation(),
5405 NTTP->getDeclName());
5406 } else {
5407 NTTPType = SubstType(NTTPType,
5408 MultiLevelTemplateArgumentList(TemplateArgs),
5409 NTTP->getLocation(),
5410 NTTP->getDeclName());
5411 }
5412
5413 // If that worked, check the non-type template parameter type
5414 // for validity.
5415 if (!NTTPType.isNull())
5416 NTTPType = CheckNonTypeTemplateParameterType(NTTPType,
5417 NTTP->getLocation());
5418 if (NTTPType.isNull())
5419 return true;
5420 }
5421
5422 switch (Arg.getArgument().getKind()) {
5423 case TemplateArgument::Null:
5424 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-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5424)
;
5425
5426 case TemplateArgument::Expression: {
5427 TemplateArgument Result;
5428 unsigned CurSFINAEErrors = NumSFINAEErrors;
5429 ExprResult Res =
5430 CheckTemplateArgument(NTTP, NTTPType, Arg.getArgument().getAsExpr(),
5431 Result, CTAK);
5432 if (Res.isInvalid())
5433 return true;
5434 // If the current template argument causes an error, give up now.
5435 if (CurSFINAEErrors < NumSFINAEErrors)
5436 return true;
5437
5438 // If the resulting expression is new, then use it in place of the
5439 // old expression in the template argument.
5440 if (Res.get() != Arg.getArgument().getAsExpr()) {
5441 TemplateArgument TA(Res.get());
5442 Arg = TemplateArgumentLoc(TA, Res.get());
5443 }
5444
5445 Converted.push_back(Result);
5446 break;
5447 }
5448
5449 case TemplateArgument::Declaration:
5450 case TemplateArgument::Integral:
5451 case TemplateArgument::NullPtr:
5452 // We've already checked this template argument, so just copy
5453 // it to the list of converted arguments.
5454 Converted.push_back(Arg.getArgument());
5455 break;
5456
5457 case TemplateArgument::Template:
5458 case TemplateArgument::TemplateExpansion:
5459 // We were given a template template argument. It may not be ill-formed;
5460 // see below.
5461 if (DependentTemplateName *DTN
5462 = Arg.getArgument().getAsTemplateOrTemplatePattern()
5463 .getAsDependentTemplateName()) {
5464 // We have a template argument such as \c T::template X, which we
5465 // parsed as a template template argument. However, since we now
5466 // know that we need a non-type template argument, convert this
5467 // template name into an expression.
5468
5469 DeclarationNameInfo NameInfo(DTN->getIdentifier(),
5470 Arg.getTemplateNameLoc());
5471
5472 CXXScopeSpec SS;
5473 SS.Adopt(Arg.getTemplateQualifierLoc());
5474 // FIXME: the template-template arg was a DependentTemplateName,
5475 // so it was provided with a template keyword. However, its source
5476 // location is not stored in the template argument structure.
5477 SourceLocation TemplateKWLoc;
5478 ExprResult E = DependentScopeDeclRefExpr::Create(
5479 Context, SS.getWithLocInContext(Context), TemplateKWLoc, NameInfo,
5480 nullptr);
5481
5482 // If we parsed the template argument as a pack expansion, create a
5483 // pack expansion expression.
5484 if (Arg.getArgument().getKind() == TemplateArgument::TemplateExpansion){
5485 E = ActOnPackExpansion(E.get(), Arg.getTemplateEllipsisLoc());
5486 if (E.isInvalid())
5487 return true;
5488 }
5489
5490 TemplateArgument Result;
5491 E = CheckTemplateArgument(NTTP, NTTPType, E.get(), Result);
5492 if (E.isInvalid())
5493 return true;
5494
5495 Converted.push_back(Result);
5496 break;
5497 }
5498
5499 // We have a template argument that actually does refer to a class
5500 // template, alias template, or template template parameter, and
5501 // therefore cannot be a non-type template argument.
5502 Diag(Arg.getLocation(), diag::err_template_arg_must_be_expr)
5503 << Arg.getSourceRange();
5504
5505 Diag(Param->getLocation(), diag::note_template_param_here);
5506 return true;
5507
5508 case TemplateArgument::Type: {
5509 // We have a non-type template parameter but the template
5510 // argument is a type.
5511
5512 // C++ [temp.arg]p2:
5513 // In a template-argument, an ambiguity between a type-id and
5514 // an expression is resolved to a type-id, regardless of the
5515 // form of the corresponding template-parameter.
5516 //
5517 // We warn specifically about this case, since it can be rather
5518 // confusing for users.
5519 QualType T = Arg.getArgument().getAsType();
5520 SourceRange SR = Arg.getSourceRange();
5521 if (T->isFunctionType())
5522 Diag(SR.getBegin(), diag::err_template_arg_nontype_ambig) << SR << T;
5523 else
5524 Diag(SR.getBegin(), diag::err_template_arg_must_be_expr) << SR;
5525 Diag(Param->getLocation(), diag::note_template_param_here);
5526 return true;
5527 }
5528
5529 case TemplateArgument::Pack:
5530 llvm_unreachable("Caller must expand template argument packs")::llvm::llvm_unreachable_internal("Caller must expand template argument packs"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5530)
;
5531 }
5532
5533 return false;
5534 }
5535
5536
5537 // Check template template parameters.
5538 TemplateTemplateParmDecl *TempParm = cast<TemplateTemplateParmDecl>(Param);
5539
5540 TemplateParameterList *Params = TempParm->getTemplateParameters();
5541 if (TempParm->isExpandedParameterPack())
5542 Params = TempParm->getExpansionTemplateParameters(ArgumentPackIndex);
5543
5544 // Substitute into the template parameter list of the template
5545 // template parameter, since previously-supplied template arguments
5546 // may appear within the template template parameter.
5547 //
5548 // FIXME: Skip this if the parameters aren't instantiation-dependent.
5549 {
5550 // Set up a template instantiation context.
5551 LocalInstantiationScope Scope(*this);
5552 InstantiatingTemplate Inst(*this, TemplateLoc, Template,
5553 TempParm, Converted,
5554 SourceRange(TemplateLoc, RAngleLoc));
5555 if (Inst.isInvalid())
5556 return true;
5557
5558 TemplateArgumentList TemplateArgs(TemplateArgumentList::OnStack, Converted);
5559 Params = SubstTemplateParams(Params, CurContext,
5560 MultiLevelTemplateArgumentList(TemplateArgs));
5561 if (!Params)
5562 return true;
5563 }
5564
5565 // C++1z [temp.local]p1: (DR1004)
5566 // When [the injected-class-name] is used [...] as a template-argument for
5567 // a template template-parameter [...] it refers to the class template
5568 // itself.
5569 if (Arg.getArgument().getKind() == TemplateArgument::Type) {
5570 TemplateArgumentLoc ConvertedArg = convertTypeTemplateArgumentToTemplate(
5571 Context, Arg.getTypeSourceInfo()->getTypeLoc());
5572 if (!ConvertedArg.getArgument().isNull())
5573 Arg = ConvertedArg;
5574 }
5575
5576 switch (Arg.getArgument().getKind()) {
5577 case TemplateArgument::Null:
5578 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-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5578)
;
5579
5580 case TemplateArgument::Template:
5581 case TemplateArgument::TemplateExpansion:
5582 if (CheckTemplateTemplateArgument(TempParm, Params, Arg))
5583 return true;
5584
5585 Converted.push_back(Arg.getArgument());
5586 break;
5587
5588 case TemplateArgument::Expression:
5589 case TemplateArgument::Type:
5590 // We have a template template parameter but the template
5591 // argument does not refer to a template.
5592 Diag(Arg.getLocation(), diag::err_template_arg_must_be_template)
5593 << getLangOpts().CPlusPlus11;
5594 return true;
5595
5596 case TemplateArgument::Declaration:
5597 llvm_unreachable("Declaration argument with template template parameter")::llvm::llvm_unreachable_internal("Declaration argument with template template parameter"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5597)
;
5598 case TemplateArgument::Integral:
5599 llvm_unreachable("Integral argument with template template parameter")::llvm::llvm_unreachable_internal("Integral argument with template template parameter"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5599)
;
5600 case TemplateArgument::NullPtr:
5601 llvm_unreachable("Null pointer argument with template template parameter")::llvm::llvm_unreachable_internal("Null pointer argument with template template parameter"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5601)
;
5602
5603 case TemplateArgument::Pack:
5604 llvm_unreachable("Caller must expand template argument packs")::llvm::llvm_unreachable_internal("Caller must expand template argument packs"
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5604)
;
5605 }
5606
5607 return false;
5608}
5609
5610/// Diagnose a missing template argument.
5611template<typename TemplateParmDecl>
5612static bool diagnoseMissingArgument(Sema &S, SourceLocation Loc,
5613 TemplateDecl *TD,
5614 const TemplateParmDecl *D,
5615 TemplateArgumentListInfo &Args) {
5616 // Dig out the most recent declaration of the template parameter; there may be
5617 // declarations of the template that are more recent than TD.
5618 D = cast<TemplateParmDecl>(cast<TemplateDecl>(TD->getMostRecentDecl())
5619 ->getTemplateParameters()
5620 ->getParam(D->getIndex()));
5621
5622 // If there's a default argument that's not visible, diagnose that we're
5623 // missing a module import.
5624 llvm::SmallVector<Module*, 8> Modules;
5625 if (D->hasDefaultArgument() && !S.hasVisibleDefaultArgument(D, &Modules)) {
5626 S.diagnoseMissingImport(Loc, cast<NamedDecl>(TD),
5627 D->getDefaultArgumentLoc(), Modules,
5628 Sema::MissingImportKind::DefaultArgument,
5629 /*Recover*/true);
5630 return true;
5631 }
5632
5633 // FIXME: If there's a more recent default argument that *is* visible,
5634 // diagnose that it was declared too late.
5635
5636 TemplateParameterList *Params = TD->getTemplateParameters();
5637
5638 S.Diag(Loc, diag::err_template_arg_list_different_arity)
5639 << /*not enough args*/0
5640 << (int)S.getTemplateNameKindForDiagnostics(TemplateName(TD))
5641 << TD;
5642 S.Diag(TD->getLocation(), diag::note_template_decl_here)
5643 << Params->getSourceRange();
5644 return true;
5645}
5646
5647/// Check that the given template argument list is well-formed
5648/// for specializing the given template.
5649bool Sema::CheckTemplateArgumentList(
5650 TemplateDecl *Template, SourceLocation TemplateLoc,
5651 TemplateArgumentListInfo &TemplateArgs, bool PartialTemplateArgs,
5652 SmallVectorImpl<TemplateArgument> &Converted,
5653 bool UpdateArgsWithConversions, bool *ConstraintsNotSatisfied) {
5654
5655 if (ConstraintsNotSatisfied)
5656 *ConstraintsNotSatisfied = false;
5657
5658 // Make a copy of the template arguments for processing. Only make the
5659 // changes at the end when successful in matching the arguments to the
5660 // template.
5661 TemplateArgumentListInfo NewArgs = TemplateArgs;
5662
5663 // Make sure we get the template parameter list from the most
5664 // recentdeclaration, since that is the only one that has is guaranteed to
5665 // have all the default template argument information.
5666 TemplateParameterList *Params =
5667 cast<TemplateDecl>(Template->getMostRecentDecl())
5668 ->getTemplateParameters();
5669
5670 SourceLocation RAngleLoc = NewArgs.getRAngleLoc();
5671
5672 // C++ [temp.arg]p1:
5673 // [...] The type and form of each template-argument specified in
5674 // a template-id shall match the type and form specified for the
5675 // corresponding parameter declared by the template in its
5676 // template-parameter-list.
5677 bool isTemplateTemplateParameter = isa<TemplateTemplateParmDecl>(Template);
5678 SmallVector<TemplateArgument, 2> ArgumentPack;
5679 unsigned ArgIdx = 0, NumArgs = NewArgs.size();
5680 LocalInstantiationScope InstScope(*this, true);
5681 for (TemplateParameterList::iterator Param = Params->begin(),
5682 ParamEnd = Params->end();
5683 Param != ParamEnd; /* increment in loop */) {
5684 // If we have an expanded parameter pack, make sure we don't have too
5685 // many arguments.
5686 if (Optional<unsigned> Expansions = getExpandedPackSize(*Param)) {
5687 if (*Expansions == ArgumentPack.size()) {
5688 // We're done with this parameter pack. Pack up its arguments and add
5689 // them to the list.
5690 Converted.push_back(
5691 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
5692 ArgumentPack.clear();
5693
5694 // This argument is assigned to the next parameter.
5695 ++Param;
5696 continue;
5697 } else if (ArgIdx == NumArgs && !PartialTemplateArgs) {
5698 // Not enough arguments for this parameter pack.
5699 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
5700 << /*not enough args*/0
5701 << (int)getTemplateNameKindForDiagnostics(TemplateName(Template))
5702 << Template;
5703 Diag(Template->getLocation(), diag::note_template_decl_here)
5704 << Params->getSourceRange();
5705 return true;
5706 }
5707 }
5708
5709 if (ArgIdx < NumArgs) {
5710 // Check the template argument we were given.
5711 if (CheckTemplateArgument(*Param, NewArgs[ArgIdx], Template,
5712 TemplateLoc, RAngleLoc,
5713 ArgumentPack.size(), Converted))
5714 return true;
5715
5716 bool PackExpansionIntoNonPack =
5717 NewArgs[ArgIdx].getArgument().isPackExpansion() &&
5718 (!(*Param)->isTemplateParameterPack() || getExpandedPackSize(*Param));
5719 if (PackExpansionIntoNonPack && (isa<TypeAliasTemplateDecl>(Template) ||
5720 isa<ConceptDecl>(Template))) {
5721 // Core issue 1430: we have a pack expansion as an argument to an
5722 // alias template, and it's not part of a parameter pack. This
5723 // can't be canonicalized, so reject it now.
5724 // As for concepts - we cannot normalize constraints where this
5725 // situation exists.
5726 Diag(NewArgs[ArgIdx].getLocation(),
5727 diag::err_template_expansion_into_fixed_list)
5728 << (isa<ConceptDecl>(Template) ? 1 : 0)
5729 << NewArgs[ArgIdx].getSourceRange();
5730 Diag((*Param)->getLocation(), diag::note_template_param_here);
5731 return true;
5732 }
5733
5734 // We're now done with this argument.
5735 ++ArgIdx;
5736
5737 if ((*Param)->isTemplateParameterPack()) {
5738 // The template parameter was a template parameter pack, so take the
5739 // deduced argument and place it on the argument pack. Note that we
5740 // stay on the same template parameter so that we can deduce more
5741 // arguments.
5742 ArgumentPack.push_back(Converted.pop_back_val());
5743 } else {
5744 // Move to the next template parameter.
5745 ++Param;
5746 }
5747
5748 // If we just saw a pack expansion into a non-pack, then directly convert
5749 // the remaining arguments, because we don't know what parameters they'll
5750 // match up with.
5751 if (PackExpansionIntoNonPack) {
5752 if (!ArgumentPack.empty()) {
5753 // If we were part way through filling in an expanded parameter pack,
5754 // fall back to just producing individual arguments.
5755 Converted.insert(Converted.end(),
5756 ArgumentPack.begin(), ArgumentPack.end());
5757 ArgumentPack.clear();
5758 }
5759
5760 while (ArgIdx < NumArgs) {
5761 Converted.push_back(NewArgs[ArgIdx].getArgument());
5762 ++ArgIdx;
5763 }
5764
5765 return false;
5766 }
5767
5768 continue;
5769 }
5770
5771 // If we're checking a partial template argument list, we're done.
5772 if (PartialTemplateArgs) {
5773 if ((*Param)->isTemplateParameterPack() && !ArgumentPack.empty())
5774 Converted.push_back(
5775 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
5776 return false;
5777 }
5778
5779 // If we have a template parameter pack with no more corresponding
5780 // arguments, just break out now and we'll fill in the argument pack below.
5781 if ((*Param)->isTemplateParameterPack()) {
5782 assert(!getExpandedPackSize(*Param) &&(static_cast <bool> (!getExpandedPackSize(*Param) &&
"Should have dealt with this already") ? void (0) : __assert_fail
("!getExpandedPackSize(*Param) && \"Should have dealt with this already\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5783, __extension__ __PRETTY_FUNCTION__))
5783 "Should have dealt with this already")(static_cast <bool> (!getExpandedPackSize(*Param) &&
"Should have dealt with this already") ? void (0) : __assert_fail
("!getExpandedPackSize(*Param) && \"Should have dealt with this already\""
, "/build/llvm-toolchain-snapshot-13~++20210726100616+dead50d4427c/clang/lib/Sema/SemaTemplate.cpp"
, 5783, __extension__ __PRETTY_FUNCTION__))
;
5784
5785 // A non-expanded parameter pack before the end of the parameter list
5786 // only occurs for an ill-formed template parameter list, unless we've
5787 // got a partial argument list for a function template, so just bail out.
5788 if (Param + 1 != ParamEnd)
5789 return true;
5790
5791 Converted.push_back(
5792 TemplateArgument::CreatePackCopy(Context, ArgumentPack));
5793 ArgumentPack.clear();
5794
5795 ++Param;
5796 continue;
5797 }
5798
5799 // Check whether we have a default argument.
5800 TemplateArgumentLoc Arg;
5801
5802 // Retrieve the default template argument from the template
5803 // parameter. For each kind of template parameter, we substitute the
5804 // template arguments provided thus far and any "outer" template arguments
5805 // (when the template parameter was part of a nested template) into
5806 // the default argument.
5807 if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*Param)) {
5808 if (!hasVisibleDefaultArgument(TTP))
5809 return diagnoseMissingArgument(*this, TemplateLoc, Template, TTP,
5810 NewArgs);
5811
5812 TypeSourceInfo *ArgType = SubstDefaultTemplateArgument(*this,
5813 Template,
5814 TemplateLoc,
5815 RAngleLoc,
5816 TTP,
5817 Converted);
5818 if (!ArgType)
5819 return true;
5820
5821 Arg = TemplateArgumentLoc(TemplateArgument(ArgType->getType()),
5822 ArgType);
5823 } else if (NonTypeTemplateParmDecl *NTTP
5824 = dyn_cast<NonTypeTemplateParmDecl>(*Param)) {
5825 if (!hasVisibleDefaultArgument(NTTP))
5826 return diagnoseMissingArgument(*this, TemplateLoc, Template, NTTP,
5827 NewArgs);
5828
5829 ExprResult E = SubstDefaultTemplateArgument(*this, Template,
5830 TemplateLoc,
5831 RAngleLoc,
5832 NTTP,
5833 Converted);
5834 if (E.isInvalid())
5835 return true;
5836
5837 Expr *Ex = E.getAs<Expr>();
5838 Arg = TemplateArgumentLoc(TemplateArgument(Ex), Ex);
5839 } else {
5840 TemplateTemplateParmDecl *TempParm
5841 = cast<TemplateTemplateParmDecl>(*Param);
5842
5843 if (!hasVisibleDefaultArgument(TempParm))
5844 return diagnoseMissingArgument(*this, TemplateLoc, Template, TempParm,
5845 NewArgs);
5846
5847 NestedNameSpecifierLoc QualifierLoc;
5848 TemplateName Name = SubstDefaultTemplateArgument(*this, Template,
5849 TemplateLoc,
5850 RAngleLoc,
5851 TempParm,
5852 Converted,
5853 QualifierLoc);
5854 if (Name.isNull())
5855 return true;
5856
5857 Arg = TemplateArgumentLoc(
5858 Context, TemplateArgument(Name), QualifierLoc,
5859 TempParm->getDefaultArgument().getTemplateNameLoc());
5860 }
5861
5862 // Introduce an instantiation record that describes where we are using
5863 // the default template argument. We're not actually instantiating a
5864 // template here, we just create this object to put a note into the
5865 // context stack.
5866 InstantiatingTemplate Inst(*this, RAngleLoc, Template, *Param, Converted,
5867 SourceRange(TemplateLoc, RAngleLoc));
5868 if (Inst.isInvalid())
5869 return true;
5870
5871 // Check the default template argument.
5872 if (CheckTemplateArgument(*Param, Arg, Template, TemplateLoc,
5873 RAngleLoc, 0, Converted))
5874 return true;
5875
5876 // Core issue 150 (assumed resolution): if this is a template template
5877 // parameter, keep track of the default template arguments from the
5878 // template definition.
5879 if (isTemplateTemplateParameter)
5880 NewArgs.addArgument(Arg);
5881
5882 // Move to the next template parameter and argument.
5883 ++Param;
5884 ++ArgIdx;
5885 }
5886
5887 // If we're performing a partial argument substitution, allow any trailing
5888 // pack expansions; they might be empty. This can happen even if
5889 // PartialTemplateArgs is false (the list of arguments is complete but
5890 // still dependent).
5891 if (ArgIdx < NumArgs && CurrentInstantiationScope &&
5892 CurrentInstantiationScope->getPartiallySubstitutedPack()) {
5893 while (ArgIdx < NumArgs && NewArgs[ArgIdx].getArgument().isPackExpansion())
5894 Converted.push_back(NewArgs[ArgIdx++].getArgument());
5895 }
5896
5897 // If we have any leftover arguments, then there were too many arguments.
5898 // Complain and fail.
5899 if (ArgIdx < NumArgs) {
5900 Diag(TemplateLoc, diag::err_template_arg_list_different_arity)
5901 << /*too many args*/1
5902 << (int)getTemplateNameKindForDiagnostics(TemplateName(Template))
5903 << Template
5904 << SourceRange(NewArgs[ArgIdx].getLocation(), NewArgs.getRAngleLoc());
5905 Diag(Template->getLocation(), diag::note_template_decl_here)
5906 << Params->getSourceRange();
5907 return true;
5908 }
5909
5910 // No problems found with the new argument list, propagate changes back
5911 // to caller.
5912 if (UpdateArgsWithConversions)
5913 TemplateArgs = std::move(NewArgs);
5914
5915 if (!PartialTemplateArgs &&
5916 EnsureTemplateArgumentListConstraints(
5917 Template, Converted, SourceRange(TemplateLoc,
5918 TemplateArgs.getRAngleLoc()))) {
5919 if (ConstraintsNotSatisfied)
5920 *ConstraintsNotSatisfied = true;
5921 return true;
5922 }
5923
5924 return false;
5925}
5926
5927namespace {
5928 class UnnamedLocalNoLinkageFinder
5929 : public TypeVisitor<UnnamedLocalNoLinkageFinder, bool>
5930 {
5931 Sema &S;
5932 SourceRange SR;
5933
5934 typedef TypeVisitor<UnnamedLocalNoLinkageFinder, bool> inherited;
5935
5936 public:
5937 UnnamedLocalNoLinkageFinder(Sema &S, SourceRange SR) : S(S), SR(SR) { }
5938
5939 bool Visit(QualType T) {
5940 return T.isNull() ? false : inherited::Visit(T.getTypePtr());
5941 }
5942
5943#define TYPE(Class, Parent) \
5944 bool Visit##Class##Type(const Class##Type *);
5945#define ABSTRACT_TYPE(Class, Parent) \
5946 bool Visit##Class##Type(const Class##Type *) { return false; }
5947#define NON_CANONICAL_TYPE(Class, Parent) \
5948 bool Visit##Class##Type(const Class##Type *) { return false; }
5949#include "clang/AST/TypeNodes.inc"
5950
5951 bool VisitTagDecl(const TagDecl *Tag);
5952 bool VisitNestedNameSpecifier(NestedNameSpecifier *NNS);
5953 };
5954} // end anonymous namespace
5955
5956bool UnnamedLocalNoLinkageFinder::VisitBuiltinType(const BuiltinType*) {
5957 return false;
5958}
5959
5960bool UnnamedLocalNoLinkageFinder::VisitComplexType(const ComplexType* T) {
5961 return Visit(T->getElementType());
5962}
5963
5964bool UnnamedLocalNoLinkageFinder::VisitPointerType(const PointerType* T) {
5965 return Visit(T->getPointeeType());
5966}
5967
5968bool UnnamedLocalNoLinkageFinder::VisitBlockPointerType(
5969 const BlockPointerType* T) {
5970 return Visit(T->getPointeeType());
5971}
5972
5973bool UnnamedLocalNoLinkageFinder::VisitLValueReferenceType(
5974 const LValueReferenceType* T) {
5975 return Visit(T->getPointeeType());
5976}
5977
5978bool UnnamedLocalNoLinkageFinder::VisitRValueReferenceType(
5979 const RValueReferenceType* T) {
5980 return Visit(T->getPointeeType());
5981}
5982
5983bool UnnamedLocalNoLinkageFinder::VisitMemberPointerType(
5984 const MemberPointerType* T) {
5985 return Visit(T->getPointeeType()) || Visit(QualType(T->getClass(), 0));
5986}
5987
5988bool UnnamedLocalNoLinkageFinder::VisitConstantArrayType(
5989 const ConstantArrayType* T) {
5990 return Visit(T->getElementType());
5991}
5992
5993bool UnnamedLocalNoLinkageFinder::VisitIncompleteArrayType(
5994 const IncompleteArrayType* T) {
5995 return Visit(T->getElementType());
5996}
5997
5998bool UnnamedLocalNoLinkageFinder::VisitVariableArrayType(
5999 const VariableArrayType* T) {
6000 return Visit(T->getElementType());
6001}
6002
6003bool UnnamedLocalNoLinkageFinder::VisitDependentSizedArrayType(
6004 const DependentSizedArrayType* T) {
6005 return Visit(T->getElementType());
6006}
6007
6008bool UnnamedLocalNoLinkageFinder::VisitDependentSizedExtVectorType(
6009 const DependentSizedExtVectorType* T) {
6010 return Visit(T->getElementType());
6011}
6012
6013bool UnnamedLocalNoLinkageFinder::VisitDependentSizedMatrixType(
6014 const DependentSizedMatrixType *T) {
6015 return Visit(T->getElementType());
6016}
6017
6018bool UnnamedLocalNoLinkageFinder::VisitDependentAddressSpaceType(
6019 const DependentAddressSpaceType *T) {
6020 return Visit(T->getPointeeType());
6021}
6022
6023bool UnnamedLocalNoLinkageFinder::VisitVectorType(const VectorType* T) {
6024 return Visit(T->getElementType());