Coverage Report

Created: 2022-07-16 07:03

/Users/buildslave/jenkins/workspace/coverage/llvm-project/clang/lib/Sema/SemaTemplate.cpp
Line
Count
Source (jump to first uncovered line)
1
//===------- SemaTemplate.cpp - Semantic Analysis for C++ Templates -------===//
2
//
3
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4
// See https://llvm.org/LICENSE.txt for license information.
5
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6
//===----------------------------------------------------------------------===//
7
//
8
//  This file implements semantic analysis for C++ templates.
9
//===----------------------------------------------------------------------===//
10
11
#include "TreeTransform.h"
12
#include "clang/AST/ASTConsumer.h"
13
#include "clang/AST/ASTContext.h"
14
#include "clang/AST/Decl.h"
15
#include "clang/AST/DeclFriend.h"
16
#include "clang/AST/DeclTemplate.h"
17
#include "clang/AST/Expr.h"
18
#include "clang/AST/ExprCXX.h"
19
#include "clang/AST/RecursiveASTVisitor.h"
20
#include "clang/AST/TemplateName.h"
21
#include "clang/AST/TypeVisitor.h"
22
#include "clang/Basic/Builtins.h"
23
#include "clang/Basic/LangOptions.h"
24
#include "clang/Basic/PartialDiagnostic.h"
25
#include "clang/Basic/Stack.h"
26
#include "clang/Basic/TargetInfo.h"
27
#include "clang/Sema/DeclSpec.h"
28
#include "clang/Sema/Initialization.h"
29
#include "clang/Sema/Lookup.h"
30
#include "clang/Sema/Overload.h"
31
#include "clang/Sema/ParsedTemplate.h"
32
#include "clang/Sema/Scope.h"
33
#include "clang/Sema/SemaInternal.h"
34
#include "clang/Sema/Template.h"
35
#include "clang/Sema/TemplateDeduction.h"
36
#include "llvm/ADT/SmallBitVector.h"
37
#include "llvm/ADT/SmallString.h"
38
#include "llvm/ADT/StringExtras.h"
39
40
#include <iterator>
41
using namespace clang;
42
using namespace sema;
43
44
// Exported for use by Parser.
45
SourceRange
46
clang::getTemplateParamsRange(TemplateParameterList const * const *Ps,
47
8
                              unsigned N) {
48
8
  if (!N) 
return SourceRange()0
;
49
8
  return SourceRange(Ps[0]->getTemplateLoc(), Ps[N-1]->getRAngleLoc());
50
8
}
51
52
470k
unsigned Sema::getTemplateDepth(Scope *S) const {
53
470k
  unsigned Depth = 0;
54
55
  // Each template parameter scope represents one level of template parameter
56
  // depth.
57
1.13M
  for (Scope *TempParamScope = S->getTemplateParamParent(); TempParamScope;
58
660k
       TempParamScope = TempParamScope->getParent()->getTemplateParamParent()) {
59
660k
    ++Depth;
60
660k
  }
61
62
  // Note that there are template parameters with the given depth.
63
470k
  auto ParamsAtDepth = [&](unsigned D) 
{ Depth = std::max(Depth, D + 1); }0
;
64
65
  // Look for parameters of an enclosing generic lambda. We don't create a
66
  // template parameter scope for these.
67
470k
  for (FunctionScopeInfo *FSI : getFunctionScopes()) {
68
1
    if (auto *LSI = dyn_cast<LambdaScopeInfo>(FSI)) {
69
0
      if (!LSI->TemplateParams.empty()) {
70
0
        ParamsAtDepth(LSI->AutoTemplateParameterDepth);
71
0
        break;
72
0
      }
73
0
      if (LSI->GLTemplateParameterList) {
74
0
        ParamsAtDepth(LSI->GLTemplateParameterList->getDepth());
75
0
        break;
76
0
      }
77
0
    }
78
1
  }
79
80
  // Look for parameters of an enclosing terse function template. We don't
81
  // create a template parameter scope for these either.
82
470k
  for (const InventedTemplateParameterInfo &Info :
83
470k
       getInventedParameterInfos()) {
84
0
    if (!Info.TemplateParams.empty()) {
85
0
      ParamsAtDepth(Info.AutoTemplateParameterDepth);
86
0
      break;
87
0
    }
88
0
  }
89
90
470k
  return Depth;
91
470k
}
92
93
/// \brief Determine whether the declaration found is acceptable as the name
94
/// of a template and, if so, return that template declaration. Otherwise,
95
/// returns null.
96
///
97
/// Note that this may return an UnresolvedUsingValueDecl if AllowDependent
98
/// is true. In all other cases it will return a TemplateDecl (or null).
99
NamedDecl *Sema::getAsTemplateNameDecl(NamedDecl *D,
100
                                       bool AllowFunctionTemplates,
101
9.14M
                                       bool AllowDependent) {
102
9.14M
  D = D->getUnderlyingDecl();
103
104
9.14M
  if (isa<TemplateDecl>(D)) {
105
7.94M
    if (!AllowFunctionTemplates && 
isa<FunctionTemplateDecl>(D)2.12k
)
106
1.52k
      return nullptr;
107
108
7.94M
    return D;
109
7.94M
  }
110
111
1.20M
  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
112
    // C++ [temp.local]p1:
113
    //   Like normal (non-template) classes, class templates have an
114
    //   injected-class-name (Clause 9). The injected-class-name
115
    //   can be used with or without a template-argument-list. When
116
    //   it is used without a template-argument-list, it is
117
    //   equivalent to the injected-class-name followed by the
118
    //   template-parameters of the class template enclosed in
119
    //   <>. When it is used with a template-argument-list, it
120
    //   refers to the specified class template specialization,
121
    //   which could be the current specialization or another
122
    //   specialization.
123
246k
    if (Record->isInjectedClassName()) {
124
236k
      Record = cast<CXXRecordDecl>(Record->getDeclContext());
125
236k
      if (Record->getDescribedClassTemplate())
126
181k
        return Record->getDescribedClassTemplate();
127
128
55.1k
      if (ClassTemplateSpecializationDecl *Spec
129
55.1k
            = dyn_cast<ClassTemplateSpecializationDecl>(Record))
130
53.2k
        return Spec->getSpecializedTemplate();
131
55.1k
    }
132
133
11.7k
    return nullptr;
134
246k
  }
135
136
  // 'using Dependent::foo;' can resolve to a template name.
137
  // 'using typename Dependent::foo;' cannot (not even if 'foo' is an
138
  // injected-class-name).
139
956k
  if (AllowDependent && 
isa<UnresolvedUsingValueDecl>(D)956k
)
140
35
    return D;
141
142
956k
  return nullptr;
143
956k
}
144
145
void Sema::FilterAcceptableTemplateNames(LookupResult &R,
146
                                         bool AllowFunctionTemplates,
147
5.13M
                                         bool AllowDependent) {
148
5.13M
  LookupResult::Filter filter = R.makeFilter();
149
10.7M
  while (filter.hasNext()) {
150
5.63M
    NamedDecl *Orig = filter.next();
151
5.63M
    if (!getAsTemplateNameDecl(Orig, AllowFunctionTemplates, AllowDependent))
152
969k
      filter.erase();
153
5.63M
  }
154
5.13M
  filter.done();
155
5.13M
}
156
157
bool Sema::hasAnyAcceptableTemplateNames(LookupResult &R,
158
                                         bool AllowFunctionTemplates,
159
                                         bool AllowDependent,
160
141
                                         bool AllowNonTemplateFunctions) {
161
283
  for (LookupResult::iterator I = R.begin(), IEnd = R.end(); I != IEnd; 
++I142
) {
162
142
    if (getAsTemplateNameDecl(*I, AllowFunctionTemplates, AllowDependent))
163
0
      return true;
164
142
    if (AllowNonTemplateFunctions &&
165
142
        
isa<FunctionDecl>((*I)->getUnderlyingDecl())3
)
166
0
      return true;
167
142
  }
168
169
141
  return false;
170
141
}
171
172
TemplateNameKind Sema::isTemplateName(Scope *S,
173
                                      CXXScopeSpec &SS,
174
                                      bool hasTemplateKeyword,
175
                                      const UnqualifiedId &Name,
176
                                      ParsedType ObjectTypePtr,
177
                                      bool EnteringContext,
178
                                      TemplateTy &TemplateResult,
179
                                      bool &MemberOfUnknownSpecialization,
180
4.68M
                                      bool Disambiguation) {
181
4.68M
  assert(getLangOpts().CPlusPlus && "No template names in C!");
182
183
0
  DeclarationName TName;
184
4.68M
  MemberOfUnknownSpecialization = false;
185
186
4.68M
  switch (Name.getKind()) {
187
4.67M
  case UnqualifiedIdKind::IK_Identifier:
188
4.67M
    TName = DeclarationName(Name.Identifier);
189
4.67M
    break;
190
191
2.19k
  case UnqualifiedIdKind::IK_OperatorFunctionId:
192
2.19k
    TName = Context.DeclarationNames.getCXXOperatorName(
193
2.19k
                                              Name.OperatorFunctionId.Operator);
194
2.19k
    break;
195
196
4
  case UnqualifiedIdKind::IK_LiteralOperatorId:
197
4
    TName = Context.DeclarationNames.getCXXLiteralOperatorName(Name.Identifier);
198
4
    break;
199
200
0
  default:
201
0
    return TNK_Non_template;
202
4.68M
  }
203
204
4.68M
  QualType ObjectType = ObjectTypePtr.get();
205
206
4.68M
  AssumedTemplateKind AssumedTemplate;
207
4.68M
  LookupResult R(*this, TName, Name.getBeginLoc(), LookupOrdinaryName);
208
4.68M
  if (LookupTemplateName(R, S, SS, ObjectType, EnteringContext,
209
4.68M
                         MemberOfUnknownSpecialization, SourceLocation(),
210
4.68M
                         &AssumedTemplate,
211
4.68M
                         /*AllowTypoCorrection=*/!Disambiguation))
212
232
    return TNK_Non_template;
213
214
4.68M
  if (AssumedTemplate != AssumedTemplateKind::None) {
215
826
    TemplateResult = TemplateTy::make(Context.getAssumedTemplateName(TName));
216
    // Let the parser know whether we found nothing or found functions; if we
217
    // found nothing, we want to more carefully check whether this is actually
218
    // a function template name versus some other kind of undeclared identifier.
219
826
    return AssumedTemplate == AssumedTemplateKind::FoundNothing
220
826
               ? 
TNK_Undeclared_template816
221
826
               : 
TNK_Function_template10
;
222
826
  }
223
224
4.68M
  if (R.empty())
225
1.02M
    return TNK_Non_template;
226
227
3.65M
  NamedDecl *D = nullptr;
228
3.65M
  UsingShadowDecl *FoundUsingShadow = dyn_cast<UsingShadowDecl>(*R.begin());
229
3.65M
  if (R.isAmbiguous()) {
230
    // If we got an ambiguity involving a non-function template, treat this
231
    // as a template name, and pick an arbitrary template for error recovery.
232
12
    bool AnyFunctionTemplates = false;
233
21
    for (NamedDecl *FoundD : R) {
234
21
      if (NamedDecl *FoundTemplate = getAsTemplateNameDecl(FoundD)) {
235
13
        if (isa<FunctionTemplateDecl>(FoundTemplate))
236
5
          AnyFunctionTemplates = true;
237
8
        else {
238
8
          D = FoundTemplate;
239
8
          FoundUsingShadow = dyn_cast<UsingShadowDecl>(FoundD);
240
8
          break;
241
8
        }
242
13
      }
243
21
    }
244
245
    // If we didn't find any templates at all, this isn't a template name.
246
    // Leave the ambiguity for a later lookup to diagnose.
247
12
    if (!D && 
!AnyFunctionTemplates4
) {
248
2
      R.suppressDiagnostics();
249
2
      return TNK_Non_template;
250
2
    }
251
252
    // If the only templates were function templates, filter out the rest.
253
    // We'll diagnose the ambiguity later.
254
10
    if (!D)
255
2
      FilterAcceptableTemplateNames(R);
256
10
  }
257
258
  // At this point, we have either picked a single template name declaration D
259
  // or we have a non-empty set of results R containing either one template name
260
  // declaration or a set of function templates.
261
262
3.65M
  TemplateName Template;
263
3.65M
  TemplateNameKind TemplateKind;
264
265
3.65M
  unsigned ResultCount = R.end() - R.begin();
266
3.65M
  if (!D && 
ResultCount > 13.65M
) {
267
    // We assume that we'll preserve the qualifier from a function
268
    // template name in other ways.
269
140k
    Template = Context.getOverloadedTemplateName(R.begin(), R.end());
270
140k
    TemplateKind = TNK_Function_template;
271
272
    // We'll do this lookup again later.
273
140k
    R.suppressDiagnostics();
274
3.51M
  } else {
275
3.51M
    if (!D) {
276
3.51M
      D = getAsTemplateNameDecl(*R.begin());
277
3.51M
      assert(D && "unambiguous result is not a template name");
278
3.51M
    }
279
280
3.51M
    if (isa<UnresolvedUsingValueDecl>(D)) {
281
      // We don't yet know whether this is a template-name or not.
282
16
      MemberOfUnknownSpecialization = true;
283
16
      return TNK_Non_template;
284
16
    }
285
286
3.51M
    TemplateDecl *TD = cast<TemplateDecl>(D);
287
3.51M
    Template =
288
3.51M
        FoundUsingShadow ? 
TemplateName(FoundUsingShadow)204
:
TemplateName(TD)3.51M
;
289
3.51M
    assert(!FoundUsingShadow || FoundUsingShadow->getTargetDecl() == TD);
290
3.51M
    if (SS.isSet() && 
!SS.isInvalid()296k
) {
291
296k
      NestedNameSpecifier *Qualifier = SS.getScopeRep();
292
296k
      Template = Context.getQualifiedTemplateName(Qualifier, hasTemplateKeyword,
293
296k
                                                  Template);
294
296k
    }
295
296
3.51M
    if (isa<FunctionTemplateDecl>(TD)) {
297
152k
      TemplateKind = TNK_Function_template;
298
299
      // We'll do this lookup again later.
300
152k
      R.suppressDiagnostics();
301
3.36M
    } else {
302
3.36M
      assert(isa<ClassTemplateDecl>(TD) || isa<TemplateTemplateParmDecl>(TD) ||
303
3.36M
             isa<TypeAliasTemplateDecl>(TD) || isa<VarTemplateDecl>(TD) ||
304
3.36M
             isa<BuiltinTemplateDecl>(TD) || isa<ConceptDecl>(TD));
305
0
      TemplateKind =
306
3.36M
          isa<VarTemplateDecl>(TD) ? 
TNK_Var_template6.66k
:
307
3.36M
          
isa<ConceptDecl>(TD)3.35M
?
TNK_Concept_template7.01k
:
308
3.35M
          
TNK_Type_template3.34M
;
309
3.36M
    }
310
3.51M
  }
311
312
3.65M
  TemplateResult = TemplateTy::make(Template);
313
3.65M
  return TemplateKind;
314
3.65M
}
315
316
bool Sema::isDeductionGuideName(Scope *S, const IdentifierInfo &Name,
317
                                SourceLocation NameLoc,
318
141k
                                ParsedTemplateTy *Template) {
319
141k
  CXXScopeSpec SS;
320
141k
  bool MemberOfUnknownSpecialization = false;
321
322
  // We could use redeclaration lookup here, but we don't need to: the
323
  // syntactic form of a deduction guide is enough to identify it even
324
  // if we can't look up the template name at all.
325
141k
  LookupResult R(*this, DeclarationName(&Name), NameLoc, LookupOrdinaryName);
326
141k
  if (LookupTemplateName(R, S, SS, /*ObjectType*/ QualType(),
327
141k
                         /*EnteringContext*/ false,
328
141k
                         MemberOfUnknownSpecialization))
329
0
    return false;
330
331
141k
  if (R.empty()) 
return false130k
;
332
11.5k
  if (R.isAmbiguous()) {
333
    // FIXME: Diagnose an ambiguity if we find at least one template.
334
1
    R.suppressDiagnostics();
335
1
    return false;
336
1
  }
337
338
  // We only treat template-names that name type templates as valid deduction
339
  // guide names.
340
11.5k
  TemplateDecl *TD = R.getAsSingle<TemplateDecl>();
341
11.5k
  if (!TD || 
!getAsTypeTemplateDecl(TD)2.01k
)
342
9.50k
    return false;
343
344
2.01k
  if (Template)
345
907
    *Template = TemplateTy::make(TemplateName(TD));
346
2.01k
  return true;
347
11.5k
}
348
349
bool Sema::DiagnoseUnknownTemplateName(const IdentifierInfo &II,
350
                                       SourceLocation IILoc,
351
                                       Scope *S,
352
                                       const CXXScopeSpec *SS,
353
                                       TemplateTy &SuggestedTemplate,
354
4
                                       TemplateNameKind &SuggestedKind) {
355
  // We can't recover unless there's a dependent scope specifier preceding the
356
  // template name.
357
  // FIXME: Typo correction?
358
4
  if (!SS || !SS->isSet() || 
!isDependentScopeSpecifier(*SS)0
||
359
4
      
computeDeclContext(*SS)0
)
360
4
    return false;
361
362
  // The code is missing a 'template' keyword prior to the dependent template
363
  // name.
364
0
  NestedNameSpecifier *Qualifier = (NestedNameSpecifier*)SS->getScopeRep();
365
0
  Diag(IILoc, diag::err_template_kw_missing)
366
0
    << Qualifier << II.getName()
367
0
    << FixItHint::CreateInsertion(IILoc, "template ");
368
0
  SuggestedTemplate
369
0
    = TemplateTy::make(Context.getDependentTemplateName(Qualifier, &II));
370
0
  SuggestedKind = TNK_Dependent_template_name;
371
0
  return true;
372
4
}
373
374
bool Sema::LookupTemplateName(LookupResult &Found,
375
                              Scope *S, CXXScopeSpec &SS,
376
                              QualType ObjectType,
377
                              bool EnteringContext,
378
                              bool &MemberOfUnknownSpecialization,
379
                              RequiredTemplateKind RequiredTemplate,
380
                              AssumedTemplateKind *ATK,
381
5.13M
                              bool AllowTypoCorrection) {
382
5.13M
  if (ATK)
383
4.95M
    *ATK = AssumedTemplateKind::None;
384
385
5.13M
  if (SS.isInvalid())
386
229
    return true;
387
388
5.13M
  Found.setTemplateNameLookup(true);
389
390
  // Determine where to perform name lookup
391
5.13M
  MemberOfUnknownSpecialization = false;
392
5.13M
  DeclContext *LookupCtx = nullptr;
393
5.13M
  bool IsDependent = false;
394
5.13M
  if (!ObjectType.isNull()) {
395
    // This nested-name-specifier occurs in a member access expression, e.g.,
396
    // x->B::f, and we are looking into the type of the object.
397
29.5k
    assert(SS.isEmpty() && "ObjectType and scope specifier cannot coexist");
398
0
    LookupCtx = computeDeclContext(ObjectType);
399
29.5k
    IsDependent = !LookupCtx && 
ObjectType->isDependentType()5.37k
;
400
29.5k
    assert((IsDependent || !ObjectType->isIncompleteType() ||
401
29.5k
            ObjectType->castAs<TagType>()->isBeingDefined()) &&
402
29.5k
           "Caller should have completed object type");
403
404
    // Template names cannot appear inside an Objective-C class or object type
405
    // or a vector type.
406
    //
407
    // FIXME: This is wrong. For example:
408
    //
409
    //   template<typename T> using Vec = T __attribute__((ext_vector_type(4)));
410
    //   Vec<int> vi;
411
    //   vi.Vec<int>::~Vec<int>();
412
    //
413
    // ... should be accepted but we will not treat 'Vec' as a template name
414
    // here. The right thing to do would be to check if the name is a valid
415
    // vector component name, and look up a template name if not. And similarly
416
    // for lookups into Objective-C class and object types, where the same
417
    // problem can arise.
418
29.5k
    if (ObjectType->isObjCObjectOrInterfaceType() ||
419
29.5k
        
ObjectType->isVectorType()29.5k
) {
420
26
      Found.clear();
421
26
      return false;
422
26
    }
423
5.10M
  } else if (SS.isNotEmpty()) {
424
    // This nested-name-specifier occurs after another nested-name-specifier,
425
    // so long into the context associated with the prior nested-name-specifier.
426
812k
    LookupCtx = computeDeclContext(SS, EnteringContext);
427
812k
    IsDependent = !LookupCtx && 
isDependentScopeSpecifier(SS)209k
;
428
429
    // The declaration context must be complete.
430
812k
    if (LookupCtx && 
RequireCompleteDeclContext(SS, LookupCtx)602k
)
431
6
      return true;
432
812k
  }
433
434
5.13M
  bool ObjectTypeSearchedInScope = false;
435
5.13M
  bool AllowFunctionTemplatesInLookup = true;
436
5.13M
  if (LookupCtx) {
437
    // Perform "qualified" name lookup into the declaration context we
438
    // computed, which is either the type of the base of a member access
439
    // expression or the declaration context associated with a prior
440
    // nested-name-specifier.
441
626k
    LookupQualifiedName(Found, LookupCtx);
442
443
    // FIXME: The C++ standard does not clearly specify what happens in the
444
    // case where the object type is dependent, and implementations vary. In
445
    // Clang, we treat a name after a . or -> as a template-name if lookup
446
    // finds a non-dependent member or member of the current instantiation that
447
    // is a type template, or finds no such members and lookup in the context
448
    // of the postfix-expression finds a type template. In the latter case, the
449
    // name is nonetheless dependent, and we may resolve it to a member of an
450
    // unknown specialization when we come to instantiate the template.
451
626k
    IsDependent |= Found.wasNotFoundInCurrentInstantiation();
452
626k
  }
453
454
5.13M
  if (SS.isEmpty() && 
(4.32M
ObjectType.isNull()4.32M
||
Found.empty()29.5k
)) {
455
    // C++ [basic.lookup.classref]p1:
456
    //   In a class member access expression (5.2.5), if the . or -> token is
457
    //   immediately followed by an identifier followed by a <, the
458
    //   identifier must be looked up to determine whether the < is the
459
    //   beginning of a template argument list (14.2) or a less-than operator.
460
    //   The identifier is first looked up in the class of the object
461
    //   expression. If the identifier is not found, it is then looked up in
462
    //   the context of the entire postfix-expression and shall name a class
463
    //   template.
464
4.29M
    if (S)
465
4.29M
      LookupName(Found, S);
466
467
4.29M
    if (!ObjectType.isNull()) {
468
      //  FIXME: We should filter out all non-type templates here, particularly
469
      //  variable templates and concepts. But the exclusion of alias templates
470
      //  and template template parameters is a wording defect.
471
5.40k
      AllowFunctionTemplatesInLookup = false;
472
5.40k
      ObjectTypeSearchedInScope = true;
473
5.40k
    }
474
475
4.29M
    IsDependent |= Found.wasNotFoundInCurrentInstantiation();
476
4.29M
  }
477
478
5.13M
  if (Found.isAmbiguous())
479
17
    return false;
480
481
5.13M
  if (ATK && 
SS.isEmpty()4.95M
&&
ObjectType.isNull()4.17M
&&
482
5.13M
      
!RequiredTemplate.hasTemplateKeyword()4.15M
) {
483
    // C++2a [temp.names]p2:
484
    //   A name is also considered to refer to a template if it is an
485
    //   unqualified-id followed by a < and name lookup finds either one or more
486
    //   functions or finds nothing.
487
    //
488
    // To keep our behavior consistent, we apply the "finds nothing" part in
489
    // all language modes, and diagnose the empty lookup in ActOnCallExpr if we
490
    // successfully form a call to an undeclared template-id.
491
4.15M
    bool AllFunctions =
492
4.15M
        getLangOpts().CPlusPlus20 && 
llvm::all_of(Found, [](NamedDecl *ND) 87.6k
{
493
87.6k
          return isa<FunctionDecl>(ND->getUnderlyingDecl());
494
87.6k
        });
495
4.15M
    if (AllFunctions || 
(4.15M
Found.empty()4.15M
&&
!IsDependent753
)) {
496
      // If lookup found any functions, or if this is a name that can only be
497
      // used for a function, then strongly assume this is a function
498
      // template-id.
499
877
      *ATK = (Found.empty() && 
Found.getLookupName().isIdentifier()864
)
500
877
                 ? 
AssumedTemplateKind::FoundNothing864
501
877
                 : 
AssumedTemplateKind::FoundFunctions13
;
502
877
      Found.clear();
503
877
      return false;
504
877
    }
505
4.15M
  }
506
507
5.13M
  if (Found.empty() && 
!IsDependent213k
&&
AllowTypoCorrection263
) {
508
    // If we did not find any names, and this is not a disambiguation, attempt
509
    // to correct any typos.
510
227
    DeclarationName Name = Found.getLookupName();
511
227
    Found.clear();
512
    // Simple filter callback that, for keywords, only accepts the C++ *_cast
513
227
    DefaultFilterCCC FilterCCC{};
514
227
    FilterCCC.WantTypeSpecifiers = false;
515
227
    FilterCCC.WantExpressionKeywords = false;
516
227
    FilterCCC.WantRemainingKeywords = false;
517
227
    FilterCCC.WantCXXNamedCasts = true;
518
227
    if (TypoCorrection Corrected =
519
227
            CorrectTypo(Found.getLookupNameInfo(), Found.getLookupKind(), S,
520
227
                        &SS, FilterCCC, CTK_ErrorRecovery, LookupCtx)) {
521
9
      if (auto *ND = Corrected.getFoundDecl())
522
9
        Found.addDecl(ND);
523
9
      FilterAcceptableTemplateNames(Found);
524
9
      if (Found.isAmbiguous()) {
525
0
        Found.clear();
526
9
      } else if (!Found.empty()) {
527
8
        Found.setLookupName(Corrected.getCorrection());
528
8
        if (LookupCtx) {
529
8
          std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
530
8
          bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
531
8
                                  
Name.getAsString() == CorrectedStr4
;
532
8
          diagnoseTypo(Corrected, PDiag(diag::err_no_member_template_suggest)
533
8
                                    << Name << LookupCtx << DroppedSpecifier
534
8
                                    << SS.getRange());
535
8
        } else {
536
0
          diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest) << Name);
537
0
        }
538
8
      }
539
9
    }
540
227
  }
541
542
5.13M
  NamedDecl *ExampleLookupResult =
543
5.13M
      Found.empty() ? 
nullptr213k
:
Found.getRepresentativeDecl()4.92M
;
544
5.13M
  FilterAcceptableTemplateNames(Found, AllowFunctionTemplatesInLookup);
545
5.13M
  if (Found.empty()) {
546
1.15M
    if (IsDependent) {
547
214k
      MemberOfUnknownSpecialization = true;
548
214k
      return false;
549
214k
    }
550
551
    // If a 'template' keyword was used, a lookup that finds only non-template
552
    // names is an error.
553
940k
    if (ExampleLookupResult && 
RequiredTemplate940k
) {
554
40
      Diag(Found.getNameLoc(), diag::err_template_kw_refers_to_non_template)
555
40
          << Found.getLookupName() << SS.getRange()
556
40
          << RequiredTemplate.hasTemplateKeyword()
557
40
          << RequiredTemplate.getTemplateKeywordLoc();
558
40
      Diag(ExampleLookupResult->getUnderlyingDecl()->getLocation(),
559
40
           diag::note_template_kw_refers_to_non_template)
560
40
          << Found.getLookupName();
561
40
      return true;
562
40
    }
563
564
940k
    return false;
565
940k
  }
566
567
3.97M
  if (S && 
!ObjectType.isNull()3.90M
&&
!ObjectTypeSearchedInScope8.93k
&&
568
3.97M
      
!getLangOpts().CPlusPlus118.33k
) {
569
    // C++03 [basic.lookup.classref]p1:
570
    //   [...] If the lookup in the class of the object expression finds a
571
    //   template, the name is also looked up in the context of the entire
572
    //   postfix-expression and [...]
573
    //
574
    // Note: C++11 does not perform this second lookup.
575
87
    LookupResult FoundOuter(*this, Found.getLookupName(), Found.getNameLoc(),
576
87
                            LookupOrdinaryName);
577
87
    FoundOuter.setTemplateNameLookup(true);
578
87
    LookupName(FoundOuter, S);
579
    // FIXME: We silently accept an ambiguous lookup here, in violation of
580
    // [basic.lookup]/1.
581
87
    FilterAcceptableTemplateNames(FoundOuter, /*AllowFunctionTemplates=*/false);
582
583
87
    NamedDecl *OuterTemplate;
584
87
    if (FoundOuter.empty()) {
585
      //   - if the name is not found, the name found in the class of the
586
      //     object expression is used, otherwise
587
77
    } else 
if (10
FoundOuter.isAmbiguous()10
||
!FoundOuter.isSingleResult()10
||
588
10
               !(OuterTemplate =
589
8
                     getAsTemplateNameDecl(FoundOuter.getFoundDecl()))) {
590
      //   - if the name is found in the context of the entire
591
      //     postfix-expression and does not name a class template, the name
592
      //     found in the class of the object expression is used, otherwise
593
2
      FoundOuter.clear();
594
8
    } else if (!Found.isSuppressingDiagnostics()) {
595
      //   - if the name found is a class template, it must refer to the same
596
      //     entity as the one found in the class of the object expression,
597
      //     otherwise the program is ill-formed.
598
8
      if (!Found.isSingleResult() ||
599
8
          getAsTemplateNameDecl(Found.getFoundDecl())->getCanonicalDecl() !=
600
7
              OuterTemplate->getCanonicalDecl()) {
601
2
        Diag(Found.getNameLoc(),
602
2
             diag::ext_nested_name_member_ref_lookup_ambiguous)
603
2
          << Found.getLookupName()
604
2
          << ObjectType;
605
2
        Diag(Found.getRepresentativeDecl()->getLocation(),
606
2
             diag::note_ambig_member_ref_object_type)
607
2
          << ObjectType;
608
2
        Diag(FoundOuter.getFoundDecl()->getLocation(),
609
2
             diag::note_ambig_member_ref_scope);
610
611
        // Recover by taking the template that we found in the object
612
        // expression's type.
613
2
      }
614
8
    }
615
87
  }
616
617
3.97M
  return false;
618
5.13M
}
619
620
void Sema::diagnoseExprIntendedAsTemplateName(Scope *S, ExprResult TemplateName,
621
                                              SourceLocation Less,
622
33
                                              SourceLocation Greater) {
623
33
  if (TemplateName.isInvalid())
624
0
    return;
625
626
33
  DeclarationNameInfo NameInfo;
627
33
  CXXScopeSpec SS;
628
33
  LookupNameKind LookupKind;
629
630
33
  DeclContext *LookupCtx = nullptr;
631
33
  NamedDecl *Found = nullptr;
632
33
  bool MissingTemplateKeyword = false;
633
634
  // Figure out what name we looked up.
635
33
  if (auto *DRE = dyn_cast<DeclRefExpr>(TemplateName.get())) {
636
13
    NameInfo = DRE->getNameInfo();
637
13
    SS.Adopt(DRE->getQualifierLoc());
638
13
    LookupKind = LookupOrdinaryName;
639
13
    Found = DRE->getFoundDecl();
640
20
  } else if (auto *ME = dyn_cast<MemberExpr>(TemplateName.get())) {
641
2
    NameInfo = ME->getMemberNameInfo();
642
2
    SS.Adopt(ME->getQualifierLoc());
643
2
    LookupKind = LookupMemberName;
644
2
    LookupCtx = ME->getBase()->getType()->getAsCXXRecordDecl();
645
2
    Found = ME->getMemberDecl();
646
18
  } else if (auto *DSDRE =
647
18
                 dyn_cast<DependentScopeDeclRefExpr>(TemplateName.get())) {
648
3
    NameInfo = DSDRE->getNameInfo();
649
3
    SS.Adopt(DSDRE->getQualifierLoc());
650
3
    MissingTemplateKeyword = true;
651
15
  } else if (auto *DSME =
652
15
                 dyn_cast<CXXDependentScopeMemberExpr>(TemplateName.get())) {
653
15
    NameInfo = DSME->getMemberNameInfo();
654
15
    SS.Adopt(DSME->getQualifierLoc());
655
15
    MissingTemplateKeyword = true;
656
15
  } else {
657
0
    llvm_unreachable("unexpected kind of potential template name");
658
0
  }
659
660
  // If this is a dependent-scope lookup, diagnose that the 'template' keyword
661
  // was missing.
662
33
  if (MissingTemplateKeyword) {
663
18
    Diag(NameInfo.getBeginLoc(), diag::err_template_kw_missing)
664
18
        << "" << NameInfo.getName().getAsString() << SourceRange(Less, Greater);
665
18
    return;
666
18
  }
667
668
  // Try to correct the name by looking for templates and C++ named casts.
669
15
  struct TemplateCandidateFilter : CorrectionCandidateCallback {
670
15
    Sema &S;
671
15
    TemplateCandidateFilter(Sema &S) : S(S) {
672
15
      WantTypeSpecifiers = false;
673
15
      WantExpressionKeywords = false;
674
15
      WantRemainingKeywords = false;
675
15
      WantCXXNamedCasts = true;
676
15
    };
677
43
    bool ValidateCandidate(const TypoCorrection &Candidate) override {
678
43
      if (auto *ND = Candidate.getCorrectionDecl())
679
43
        return S.getAsTemplateNameDecl(ND);
680
0
      return Candidate.isKeyword();
681
43
    }
682
683
15
    std::unique_ptr<CorrectionCandidateCallback> clone() override {
684
15
      return std::make_unique<TemplateCandidateFilter>(*this);
685
15
    }
686
15
  };
687
688
15
  DeclarationName Name = NameInfo.getName();
689
15
  TemplateCandidateFilter CCC(*this);
690
15
  if (TypoCorrection Corrected = CorrectTypo(NameInfo, LookupKind, S, &SS, CCC,
691
15
                                             CTK_ErrorRecovery, LookupCtx)) {
692
14
    auto *ND = Corrected.getFoundDecl();
693
14
    if (ND)
694
14
      ND = getAsTemplateNameDecl(ND);
695
14
    if (ND || 
Corrected.isKeyword()0
) {
696
14
      if (LookupCtx) {
697
1
        std::string CorrectedStr(Corrected.getAsString(getLangOpts()));
698
1
        bool DroppedSpecifier = Corrected.WillReplaceSpecifier() &&
699
1
                                
Name.getAsString() == CorrectedStr0
;
700
1
        diagnoseTypo(Corrected,
701
1
                     PDiag(diag::err_non_template_in_member_template_id_suggest)
702
1
                         << Name << LookupCtx << DroppedSpecifier
703
1
                         << SS.getRange(), false);
704
13
      } else {
705
13
        diagnoseTypo(Corrected,
706
13
                     PDiag(diag::err_non_template_in_template_id_suggest)
707
13
                         << Name, false);
708
13
      }
709
14
      if (Found)
710
14
        Diag(Found->getLocation(),
711
14
             diag::note_non_template_in_template_id_found);
712
14
      return;
713
14
    }
714
14
  }
715
716
1
  Diag(NameInfo.getLoc(), diag::err_non_template_in_template_id)
717
1
    << Name << SourceRange(Less, Greater);
718
1
  if (Found)
719
1
    Diag(Found->getLocation(), diag::note_non_template_in_template_id_found);
720
1
}
721
722
/// ActOnDependentIdExpression - Handle a dependent id-expression that
723
/// was just parsed.  This is only possible with an explicit scope
724
/// specifier naming a dependent type.
725
ExprResult
726
Sema::ActOnDependentIdExpression(const CXXScopeSpec &SS,
727
                                 SourceLocation TemplateKWLoc,
728
                                 const DeclarationNameInfo &NameInfo,
729
                                 bool isAddressOfOperand,
730
852k
                           const TemplateArgumentListInfo *TemplateArgs) {
731
852k
  DeclContext *DC = getFunctionLevelDeclContext();
732
733
  // C++11 [expr.prim.general]p12:
734
  //   An id-expression that denotes a non-static data member or non-static
735
  //   member function of a class can only be used:
736
  //   (...)
737
  //   - if that id-expression denotes a non-static data member and it
738
  //     appears in an unevaluated operand.
739
  //
740
  // If this might be the case, form a DependentScopeDeclRefExpr instead of a
741
  // CXXDependentScopeMemberExpr. The former can instantiate to either
742
  // DeclRefExpr or MemberExpr depending on lookup results, while the latter is
743
  // always a MemberExpr.
744
852k
  bool MightBeCxx11UnevalField =
745
852k
      getLangOpts().CPlusPlus11 && 
isUnevaluatedContext()852k
;
746
747
  // Check if the nested name specifier is an enum type.
748
852k
  bool IsEnum = false;
749
852k
  if (NestedNameSpecifier *NNS = SS.getScopeRep())
750
852k
    IsEnum = isa_and_nonnull<EnumType>(NNS->getAsType());
751
752
852k
  if (!MightBeCxx11UnevalField && 
!isAddressOfOperand848k
&&
!IsEnum848k
&&
753
852k
      
isa<CXXMethodDecl>(DC)848k
&&
cast<CXXMethodDecl>(DC)->isInstance()174k
) {
754
141k
    QualType ThisType = cast<CXXMethodDecl>(DC)->getThisType();
755
756
    // Since the 'this' expression is synthesized, we don't need to
757
    // perform the double-lookup check.
758
141k
    NamedDecl *FirstQualifierInScope = nullptr;
759
760
141k
    return CXXDependentScopeMemberExpr::Create(
761
141k
        Context, /*This*/ nullptr, ThisType, /*IsArrow*/ true,
762
141k
        /*Op*/ SourceLocation(), SS.getWithLocInContext(Context), TemplateKWLoc,
763
141k
        FirstQualifierInScope, NameInfo, TemplateArgs);
764
141k
  }
765
766
711k
  return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
767
852k
}
768
769
ExprResult
770
Sema::BuildDependentDeclRefExpr(const CXXScopeSpec &SS,
771
                                SourceLocation TemplateKWLoc,
772
                                const DeclarationNameInfo &NameInfo,
773
1.18M
                                const TemplateArgumentListInfo *TemplateArgs) {
774
  // DependentScopeDeclRefExpr::Create requires a valid QualifierLoc
775
1.18M
  NestedNameSpecifierLoc QualifierLoc = SS.getWithLocInContext(Context);
776
1.18M
  if (!QualifierLoc)
777
1
    return ExprError();
778
779
1.18M
  return DependentScopeDeclRefExpr::Create(
780
1.18M
      Context, QualifierLoc, TemplateKWLoc, NameInfo, TemplateArgs);
781
1.18M
}
782
783
784
/// Determine whether we would be unable to instantiate this template (because
785
/// it either has no definition, or is in the process of being instantiated).
786
bool Sema::DiagnoseUninstantiableTemplate(SourceLocation PointOfInstantiation,
787
                                          NamedDecl *Instantiation,
788
                                          bool InstantiatedFromMember,
789
                                          const NamedDecl *Pattern,
790
                                          const NamedDecl *PatternDef,
791
                                          TemplateSpecializationKind TSK,
792
1.99M
                                          bool Complain /*= true*/) {
793
1.99M
  assert(isa<TagDecl>(Instantiation) || isa<FunctionDecl>(Instantiation) ||
794
1.99M
         isa<VarDecl>(Instantiation));
795
796
0
  bool IsEntityBeingDefined = false;
797
1.99M
  if (const TagDecl *TD = dyn_cast_or_null<TagDecl>(PatternDef))
798
931k
    IsEntityBeingDefined = TD->isBeingDefined();
799
800
1.99M
  if (PatternDef && 
!IsEntityBeingDefined1.94M
) {
801
1.94M
    NamedDecl *SuggestedDef = nullptr;
802
1.94M
    if (!hasReachableDefinition(const_cast<NamedDecl *>(PatternDef),
803
1.94M
                                &SuggestedDef,
804
1.94M
                                /*OnlyNeedComplete*/ false)) {
805
      // If we're allowed to diagnose this and recover, do so.
806
23
      bool Recover = Complain && 
!isSFINAEContext()16
;
807
23
      if (Complain)
808
16
        diagnoseMissingImport(PointOfInstantiation, SuggestedDef,
809
16
                              Sema::MissingImportKind::Definition, Recover);
810
23
      return !Recover;
811
23
    }
812
1.94M
    return false;
813
1.94M
  }
814
815
51.3k
  if (!Complain || 
(641
PatternDef641
&&
PatternDef->isInvalidDecl()3
))
816
50.6k
    return true;
817
818
641
  llvm::Optional<unsigned> Note;
819
641
  QualType InstantiationTy;
820
641
  if (TagDecl *TD = dyn_cast<TagDecl>(Instantiation))
821
596
    InstantiationTy = Context.getTypeDeclType(TD);
822
641
  if (PatternDef) {
823
3
    Diag(PointOfInstantiation,
824
3
         diag::err_template_instantiate_within_definition)
825
3
      << /*implicit|explicit*/(TSK != TSK_ImplicitInstantiation)
826
3
      << InstantiationTy;
827
    // Not much point in noting the template declaration here, since
828
    // we're lexically inside it.
829
3
    Instantiation->setInvalidDecl();
830
638
  } else if (InstantiatedFromMember) {
831
16
    if (isa<FunctionDecl>(Instantiation)) {
832
2
      Diag(PointOfInstantiation,
833
2
           diag::err_explicit_instantiation_undefined_member)
834
2
        << /*member function*/ 1 << Instantiation->getDeclName()
835
2
        << Instantiation->getDeclContext();
836
2
      Note = diag::note_explicit_instantiation_here;
837
14
    } else {
838
14
      assert(isa<TagDecl>(Instantiation) && "Must be a TagDecl!");
839
0
      Diag(PointOfInstantiation,
840
14
           diag::err_implicit_instantiate_member_undefined)
841
14
        << InstantiationTy;
842
14
      Note = diag::note_member_declared_at;
843
14
    }
844
622
  } else {
845
622
    if (isa<FunctionDecl>(Instantiation)) {
846
9
      Diag(PointOfInstantiation,
847
9
           diag::err_explicit_instantiation_undefined_func_template)
848
9
        << Pattern;
849
9
      Note = diag::note_explicit_instantiation_here;
850
613
    } else if (isa<TagDecl>(Instantiation)) {
851
579
      Diag(PointOfInstantiation, diag::err_template_instantiate_undefined)
852
579
        << (TSK != TSK_ImplicitInstantiation)
853
579
        << InstantiationTy;
854
579
      Note = diag::note_template_decl_here;
855
579
    } else {
856
34
      assert(isa<VarDecl>(Instantiation) && "Must be a VarDecl!");
857
34
      if (isa<VarTemplateSpecializationDecl>(Instantiation)) {
858
30
        Diag(PointOfInstantiation,
859
30
             diag::err_explicit_instantiation_undefined_var_template)
860
30
          << Instantiation;
861
30
        Instantiation->setInvalidDecl();
862
30
      } else
863
4
        Diag(PointOfInstantiation,
864
4
             diag::err_explicit_instantiation_undefined_member)
865
4
          << /*static data member*/ 2 << Instantiation->getDeclName()
866
4
          << Instantiation->getDeclContext();
867
34
      Note = diag::note_explicit_instantiation_here;
868
34
    }
869
622
  }
870
641
  if (Note) // Diagnostics were emitted.
871
638
    Diag(Pattern->getLocation(), *Note);
872
873
  // In general, Instantiation isn't marked invalid to get more than one
874
  // error for multiple undefined instantiations. But the code that does
875
  // explicit declaration -> explicit definition conversion can't handle
876
  // invalid declarations, so mark as invalid in that case.
877
641
  if (TSK == TSK_ExplicitInstantiationDeclaration)
878
3
    Instantiation->setInvalidDecl();
879
641
  return true;
880
51.3k
}
881
882
/// DiagnoseTemplateParameterShadow - Produce a diagnostic complaining
883
/// that the template parameter 'PrevDecl' is being shadowed by a new
884
/// declaration at location Loc. Returns true to indicate that this is
885
/// an error, and false otherwise.
886
93
void Sema::DiagnoseTemplateParameterShadow(SourceLocation Loc, Decl *PrevDecl) {
887
93
  assert(PrevDecl->isTemplateParameter() && "Not a template parameter");
888
889
  // C++ [temp.local]p4:
890
  //   A template-parameter shall not be redeclared within its
891
  //   scope (including nested scopes).
892
  //
893
  // Make this a warning when MSVC compatibility is requested.
894
93
  unsigned DiagId = getLangOpts().MSVCCompat ? 
diag::ext_template_param_shadow11
895
93
                                             : 
diag::err_template_param_shadow82
;
896
93
  Diag(Loc, DiagId) << cast<NamedDecl>(PrevDecl)->getDeclName();
897
93
  Diag(PrevDecl->getLocation(), diag::note_template_param_here);
898
93
}
899
900
/// AdjustDeclIfTemplate - If the given decl happens to be a template, reset
901
/// the parameter D to reference the templated declaration and return a pointer
902
/// to the template declaration. Otherwise, do nothing to D and return null.
903
7.19M
TemplateDecl *Sema::AdjustDeclIfTemplate(Decl *&D) {
904
7.19M
  if (TemplateDecl *Temp = dyn_cast_or_null<TemplateDecl>(D)) {
905
1.61M
    D = Temp->getTemplatedDecl();
906
1.61M
    return Temp;
907
1.61M
  }
908
5.58M
  return nullptr;
909
7.19M
}
910
911
ParsedTemplateArgument ParsedTemplateArgument::getTemplatePackExpansion(
912
24
                                             SourceLocation EllipsisLoc) const {
913
24
  assert(Kind == Template &&
914
24
         "Only template template arguments can be pack expansions here");
915
0
  assert(getAsTemplate().get().containsUnexpandedParameterPack() &&
916
24
         "Template template argument pack expansion without packs");
917
0
  ParsedTemplateArgument Result(*this);
918
24
  Result.EllipsisLoc = EllipsisLoc;
919
24
  return Result;
920
24
}
921
922
static TemplateArgumentLoc translateTemplateArgument(Sema &SemaRef,
923
5.78M
                                            const ParsedTemplateArgument &Arg) {
924
925
5.78M
  switch (Arg.getKind()) {
926
4.91M
  case ParsedTemplateArgument::Type: {
927
4.91M
    TypeSourceInfo *DI;
928
4.91M
    QualType T = SemaRef.GetTypeFromParser(Arg.getAsType(), &DI);
929
4.91M
    if (!DI)
930
0
      DI = SemaRef.Context.getTrivialTypeSourceInfo(T, Arg.getLocation());
931
4.91M
    return TemplateArgumentLoc(TemplateArgument(T), DI);
932
0
  }
933
934
851k
  case ParsedTemplateArgument::NonType: {
935
851k
    Expr *E = static_cast<Expr *>(Arg.getAsExpr());
936
851k
    return TemplateArgumentLoc(TemplateArgument(E), E);
937
0
  }
938
939
21.9k
  case ParsedTemplateArgument::Template: {
940
21.9k
    TemplateName Template = Arg.getAsTemplate().get();
941
21.9k
    TemplateArgument TArg;
942
21.9k
    if (Arg.getEllipsisLoc().isValid())
943
24
      TArg = TemplateArgument(Template, Optional<unsigned int>());
944
21.9k
    else
945
21.9k
      TArg = Template;
946
21.9k
    return TemplateArgumentLoc(
947
21.9k
        SemaRef.Context, TArg,
948
21.9k
        Arg.getScopeSpec().getWithLocInContext(SemaRef.Context),
949
21.9k
        Arg.getLocation(), Arg.getEllipsisLoc());
950
0
  }
951
5.78M
  }
952
953
0
  llvm_unreachable("Unhandled parsed template argument");
954
0
}
955
956
/// Translates template arguments as provided by the parser
957
/// into template arguments used by semantic analysis.
958
void Sema::translateTemplateArguments(const ASTTemplateArgsPtr &TemplateArgsIn,
959
3.61M
                                      TemplateArgumentListInfo &TemplateArgs) {
960
9.39M
 for (unsigned I = 0, Last = TemplateArgsIn.size(); I != Last; 
++I5.77M
)
961
5.77M
   TemplateArgs.addArgument(translateTemplateArgument(*this,
962
5.77M
                                                      TemplateArgsIn[I]));
963
3.61M
}
964
965
static void maybeDiagnoseTemplateParameterShadow(Sema &SemaRef, Scope *S,
966
                                                 SourceLocation Loc,
967
2.71M
                                                 IdentifierInfo *Name) {
968
2.71M
  NamedDecl *PrevDecl = SemaRef.LookupSingleName(
969
2.71M
      S, Name, Loc, Sema::LookupOrdinaryName, Sema::ForVisibleRedeclaration);
970
2.71M
  if (PrevDecl && 
PrevDecl->isTemplateParameter()9.43k
)
971
24
    SemaRef.DiagnoseTemplateParameterShadow(Loc, PrevDecl);
972
2.71M
}
973
974
/// Convert a parsed type into a parsed template argument. This is mostly
975
/// trivial, except that we may have parsed a C++17 deduced class template
976
/// specialization type, in which case we should form a template template
977
/// argument instead of a type template argument.
978
4.91M
ParsedTemplateArgument Sema::ActOnTemplateTypeArgument(TypeResult ParsedType) {
979
4.91M
  TypeSourceInfo *TInfo;
980
4.91M
  QualType T = GetTypeFromParser(ParsedType.get(), &TInfo);
981
4.91M
  if (T.isNull())
982
235
    return ParsedTemplateArgument();
983
4.91M
  assert(TInfo && "template argument with no location");
984
985
  // If we might have formed a deduced template specialization type, convert
986
  // it to a template template argument.
987
4.91M
  if (getLangOpts().CPlusPlus17) {
988
398k
    TypeLoc TL = TInfo->getTypeLoc();
989
398k
    SourceLocation EllipsisLoc;
990
398k
    if (auto PET = TL.getAs<PackExpansionTypeLoc>()) {
991
0
      EllipsisLoc = PET.getEllipsisLoc();
992
0
      TL = PET.getPatternLoc();
993
0
    }
994
995
398k
    CXXScopeSpec SS;
996
398k
    if (auto ET = TL.getAs<ElaboratedTypeLoc>()) {
997
17.0k
      SS.Adopt(ET.getQualifierLoc());
998
17.0k
      TL = ET.getNamedTypeLoc();
999
17.0k
    }
1000
1001
398k
    if (auto DTST = TL.getAs<DeducedTemplateSpecializationTypeLoc>()) {
1002
772
      TemplateName Name = DTST.getTypePtr()->getTemplateName();
1003
772
      if (SS.isSet())
1004
19
        Name = Context.getQualifiedTemplateName(SS.getScopeRep(),
1005
19
                                                /*HasTemplateKeyword=*/false,
1006
19
                                                Name);
1007
772
      ParsedTemplateArgument Result(SS, TemplateTy::make(Name),
1008
772
                                    DTST.getTemplateNameLoc());
1009
772
      if (EllipsisLoc.isValid())
1010
0
        Result = Result.getTemplatePackExpansion(EllipsisLoc);
1011
772
      return Result;
1012
772
    }
1013
398k
  }
1014
1015
  // This is a normal type template argument. Note, if the type template
1016
  // argument is an injected-class-name for a template, it has a dual nature
1017
  // and can be used as either a type or a template. We handle that in
1018
  // convertTypeTemplateArgumentToTemplate.
1019
4.91M
  return ParsedTemplateArgument(ParsedTemplateArgument::Type,
1020
4.91M
                                ParsedType.get().getAsOpaquePtr(),
1021
4.91M
                                TInfo->getTypeLoc().getBeginLoc());
1022
4.91M
}
1023
1024
/// ActOnTypeParameter - Called when a C++ template type parameter
1025
/// (e.g., "typename T") has been parsed. Typename specifies whether
1026
/// the keyword "typename" was used to declare the type parameter
1027
/// (otherwise, "class" was used), and KeyLoc is the location of the
1028
/// "class" or "typename" keyword. ParamName is the name of the
1029
/// parameter (NULL indicates an unnamed template parameter) and
1030
/// ParamNameLoc is the location of the parameter name (if any).
1031
/// If the type parameter has a default argument, it will be added
1032
/// later via ActOnTypeParameterDefault.
1033
NamedDecl *Sema::ActOnTypeParameter(Scope *S, bool Typename,
1034
                                    SourceLocation EllipsisLoc,
1035
                                    SourceLocation KeyLoc,
1036
                                    IdentifierInfo *ParamName,
1037
                                    SourceLocation ParamNameLoc,
1038
                                    unsigned Depth, unsigned Position,
1039
                                    SourceLocation EqualLoc,
1040
                                    ParsedType DefaultArg,
1041
2.65M
                                    bool HasTypeConstraint) {
1042
2.65M
  assert(S->isTemplateParamScope() &&
1043
2.65M
         "Template type parameter not in template parameter scope!");
1044
1045
0
  bool IsParameterPack = EllipsisLoc.isValid();
1046
2.65M
  TemplateTypeParmDecl *Param
1047
2.65M
    = TemplateTypeParmDecl::Create(Context, Context.getTranslationUnitDecl(),
1048
2.65M
                                   KeyLoc, ParamNameLoc, Depth, Position,
1049
2.65M
                                   ParamName, Typename, IsParameterPack,
1050
2.65M
                                   HasTypeConstraint);
1051
2.65M
  Param->setAccess(AS_public);
1052
1053
2.65M
  if (Param->isParameterPack())
1054
167k
    if (auto *LSI = getEnclosingLambda())
1055
13
      LSI->LocalPacks.push_back(Param);
1056
1057
2.65M
  if (ParamName) {
1058
2.50M
    maybeDiagnoseTemplateParameterShadow(*this, S, ParamNameLoc, ParamName);
1059
1060
    // Add the template parameter into the current scope.
1061
2.50M
    S->AddDecl(Param);
1062
2.50M
    IdResolver.AddDecl(Param);
1063
2.50M
  }
1064
1065
  // C++0x [temp.param]p9:
1066
  //   A default template-argument may be specified for any kind of
1067
  //   template-parameter that is not a template parameter pack.
1068
2.65M
  if (DefaultArg && 
IsParameterPack128k
) {
1069
1
    Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1070
1
    DefaultArg = nullptr;
1071
1
  }
1072
1073
  // Handle the default argument, if provided.
1074
2.65M
  if (DefaultArg) {
1075
128k
    TypeSourceInfo *DefaultTInfo;
1076
128k
    GetTypeFromParser(DefaultArg, &DefaultTInfo);
1077
1078
128k
    assert(DefaultTInfo && "expected source information for type");
1079
1080
    // Check for unexpanded parameter packs.
1081
128k
    if (DiagnoseUnexpandedParameterPack(ParamNameLoc, DefaultTInfo,
1082
128k
                                        UPPC_DefaultArgument))
1083
2
      return Param;
1084
1085
    // Check the template argument itself.
1086
128k
    if (CheckTemplateArgument(DefaultTInfo)) {
1087
0
      Param->setInvalidDecl();
1088
0
      return Param;
1089
0
    }
1090
1091
128k
    Param->setDefaultArgument(DefaultTInfo);
1092
128k
  }
1093
1094
2.65M
  return Param;
1095
2.65M
}
1096
1097
/// Convert the parser's template argument list representation into our form.
1098
static TemplateArgumentListInfo
1099
277k
makeTemplateArgumentListInfo(Sema &S, TemplateIdAnnotation &TemplateId) {
1100
277k
  TemplateArgumentListInfo TemplateArgs(TemplateId.LAngleLoc,
1101
277k
                                        TemplateId.RAngleLoc);
1102
277k
  ASTTemplateArgsPtr TemplateArgsPtr(TemplateId.getTemplateArgs(),
1103
277k
                                     TemplateId.NumArgs);
1104
277k
  S.translateTemplateArguments(TemplateArgsPtr, TemplateArgs);
1105
277k
  return TemplateArgs;
1106
277k
}
1107
1108
bool Sema::ActOnTypeConstraint(const CXXScopeSpec &SS,
1109
                               TemplateIdAnnotation *TypeConstr,
1110
                               TemplateTypeParmDecl *ConstrainedParameter,
1111
2.74k
                               SourceLocation EllipsisLoc) {
1112
2.74k
  return BuildTypeConstraint(SS, TypeConstr, ConstrainedParameter, EllipsisLoc,
1113
2.74k
                             false);
1114
2.74k
}
1115
1116
bool Sema::BuildTypeConstraint(const CXXScopeSpec &SS,
1117
                               TemplateIdAnnotation *TypeConstr,
1118
                               TemplateTypeParmDecl *ConstrainedParameter,
1119
                               SourceLocation EllipsisLoc,
1120
3.19k
                               bool AllowUnexpandedPack) {
1121
3.19k
  TemplateName TN = TypeConstr->Template.get();
1122
3.19k
  ConceptDecl *CD = cast<ConceptDecl>(TN.getAsTemplateDecl());
1123
1124
  // C++2a [temp.param]p4:
1125
  //     [...] The concept designated by a type-constraint shall be a type
1126
  //     concept ([temp.concept]).
1127
3.19k
  if (!CD->isTypeConcept()) {
1128
5
    Diag(TypeConstr->TemplateNameLoc,
1129
5
         diag::err_type_constraint_non_type_concept);
1130
5
    return true;
1131
5
  }
1132
1133
3.19k
  bool WereArgsSpecified = TypeConstr->LAngleLoc.isValid();
1134
1135
3.19k
  if (!WereArgsSpecified &&
1136
3.19k
      
CD->getTemplateParameters()->getMinRequiredArguments() > 11.91k
) {
1137
4
    Diag(TypeConstr->TemplateNameLoc,
1138
4
         diag::err_type_constraint_missing_arguments) << CD;
1139
4
    return true;
1140
4
  }
1141
1142
3.18k
  DeclarationNameInfo ConceptName(DeclarationName(TypeConstr->Name),
1143
3.18k
                                  TypeConstr->TemplateNameLoc);
1144
1145
3.18k
  TemplateArgumentListInfo TemplateArgs;
1146
3.18k
  if (TypeConstr->LAngleLoc.isValid()) {
1147
1.27k
    TemplateArgs =
1148
1.27k
        makeTemplateArgumentListInfo(*this, *TypeConstr);
1149
1150
1.27k
    if (EllipsisLoc.isInvalid() && 
!AllowUnexpandedPack1.26k
) {
1151
1.05k
      for (TemplateArgumentLoc Arg : TemplateArgs.arguments()) {
1152
1.05k
        if (DiagnoseUnexpandedParameterPack(Arg, UPPC_TypeConstraint))
1153
2
          return true;
1154
1.05k
      }
1155
994
    }
1156
1.27k
  }
1157
3.18k
  return AttachTypeConstraint(
1158
3.18k
      SS.isSet() ? 
SS.getWithLocInContext(Context)76
:
NestedNameSpecifierLoc()3.10k
,
1159
3.18k
      ConceptName, CD,
1160
3.18k
      TypeConstr->LAngleLoc.isValid() ? 
&TemplateArgs1.26k
:
nullptr1.91k
,
1161
3.18k
      ConstrainedParameter, EllipsisLoc);
1162
3.18k
}
1163
1164
template<typename ArgumentLocAppender>
1165
static ExprResult formImmediatelyDeclaredConstraint(
1166
    Sema &S, NestedNameSpecifierLoc NS, DeclarationNameInfo NameInfo,
1167
    ConceptDecl *NamedConcept, SourceLocation LAngleLoc,
1168
    SourceLocation RAngleLoc, QualType ConstrainedType,
1169
    SourceLocation ParamNameLoc, ArgumentLocAppender Appender,
1170
5.47k
    SourceLocation EllipsisLoc) {
1171
1172
5.47k
  TemplateArgumentListInfo ConstraintArgs;
1173
5.47k
  ConstraintArgs.addArgument(
1174
5.47k
    S.getTrivialTemplateArgumentLoc(TemplateArgument(ConstrainedType),
1175
5.47k
                                    /*NTTPType=*/QualType(), ParamNameLoc));
1176
1177
5.47k
  ConstraintArgs.setRAngleLoc(RAngleLoc);
1178
5.47k
  ConstraintArgs.setLAngleLoc(LAngleLoc);
1179
5.47k
  Appender(ConstraintArgs);
1180
1181
  // C++2a [temp.param]p4:
1182
  //     [...] This constraint-expression E is called the immediately-declared
1183
  //     constraint of T. [...]
1184
5.47k
  CXXScopeSpec SS;
1185
5.47k
  SS.Adopt(NS);
1186
5.47k
  ExprResult ImmediatelyDeclaredConstraint = S.CheckConceptTemplateId(
1187
5.47k
      SS, /*TemplateKWLoc=*/SourceLocation(), NameInfo,
1188
5.47k
      /*FoundDecl=*/NamedConcept, NamedConcept, &ConstraintArgs);
1189
5.47k
  if (ImmediatelyDeclaredConstraint.isInvalid() || !EllipsisLoc.isValid())
1190
5.44k
    return ImmediatelyDeclaredConstraint;
1191
1192
  // C++2a [temp.param]p4:
1193
  //     [...] If T is not a pack, then E is E', otherwise E is (E' && ...).
1194
  //
1195
  // We have the following case:
1196
  //
1197
  // template<typename T> concept C1 = true;
1198
  // template<C1... T> struct s1;
1199
  //
1200
  // The constraint: (C1<T> && ...)
1201
  //
1202
  // Note that the type of C1<T> is known to be 'bool', so we don't need to do
1203
  // any unqualified lookups for 'operator&&' here.
1204
29
  return S.BuildCXXFoldExpr(/*UnqualifiedLookup=*/nullptr,
1205
29
                            /*LParenLoc=*/SourceLocation(),
1206
29
                            ImmediatelyDeclaredConstraint.get(), BO_LAnd,
1207
29
                            EllipsisLoc, /*RHS=*/nullptr,
1208
29
                            /*RParenLoc=*/SourceLocation(),
1209
29
                            /*NumExpansions=*/None);
1210
5.47k
}
SemaTemplate.cpp:clang::ActionResult<clang::Expr*, true> formImmediatelyDeclaredConstraint<clang::Sema::AttachTypeConstraint(clang::NestedNameSpecifierLoc, clang::DeclarationNameInfo, clang::ConceptDecl*, clang::TemplateArgumentListInfo const*, clang::TemplateTypeParmDecl*, clang::SourceLocation)::$_2>(clang::Sema&, clang::NestedNameSpecifierLoc, clang::DeclarationNameInfo, clang::ConceptDecl*, clang::SourceLocation, clang::SourceLocation, clang::QualType, clang::SourceLocation, clang::Sema::AttachTypeConstraint(clang::NestedNameSpecifierLoc, clang::DeclarationNameInfo, clang::ConceptDecl*, clang::TemplateArgumentListInfo const*, clang::TemplateTypeParmDecl*, clang::SourceLocation)::$_2, clang::SourceLocation)
Line
Count
Source
1170
5.47k
    SourceLocation EllipsisLoc) {
1171
1172
5.47k
  TemplateArgumentListInfo ConstraintArgs;
1173
5.47k
  ConstraintArgs.addArgument(
1174
5.47k
    S.getTrivialTemplateArgumentLoc(TemplateArgument(ConstrainedType),
1175
5.47k
                                    /*NTTPType=*/QualType(), ParamNameLoc));
1176
1177
5.47k
  ConstraintArgs.setRAngleLoc(RAngleLoc);
1178
5.47k
  ConstraintArgs.setLAngleLoc(LAngleLoc);
1179
5.47k
  Appender(ConstraintArgs);
1180
1181
  // C++2a [temp.param]p4:
1182
  //     [...] This constraint-expression E is called the immediately-declared
1183
  //     constraint of T. [...]
1184
5.47k
  CXXScopeSpec SS;
1185
5.47k
  SS.Adopt(NS);
1186
5.47k
  ExprResult ImmediatelyDeclaredConstraint = S.CheckConceptTemplateId(
1187
5.47k
      SS, /*TemplateKWLoc=*/SourceLocation(), NameInfo,
1188
5.47k
      /*FoundDecl=*/NamedConcept, NamedConcept, &ConstraintArgs);
1189
5.47k
  if (ImmediatelyDeclaredConstraint.isInvalid() || !EllipsisLoc.isValid())
1190
5.44k
    return ImmediatelyDeclaredConstraint;
1191
1192
  // C++2a [temp.param]p4:
1193
  //     [...] If T is not a pack, then E is E', otherwise E is (E' && ...).
1194
  //
1195
  // We have the following case:
1196
  //
1197
  // template<typename T> concept C1 = true;
1198
  // template<C1... T> struct s1;
1199
  //
1200
  // The constraint: (C1<T> && ...)
1201
  //
1202
  // Note that the type of C1<T> is known to be 'bool', so we don't need to do
1203
  // any unqualified lookups for 'operator&&' here.
1204
28
  return S.BuildCXXFoldExpr(/*UnqualifiedLookup=*/nullptr,
1205
28
                            /*LParenLoc=*/SourceLocation(),
1206
28
                            ImmediatelyDeclaredConstraint.get(), BO_LAnd,
1207
28
                            EllipsisLoc, /*RHS=*/nullptr,
1208
28
                            /*RParenLoc=*/SourceLocation(),
1209
28
                            /*NumExpansions=*/None);
1210
5.47k
}
SemaTemplate.cpp:clang::ActionResult<clang::Expr*, true> formImmediatelyDeclaredConstraint<clang::Sema::AttachTypeConstraint(clang::AutoTypeLoc, clang::NonTypeTemplateParmDecl*, clang::SourceLocation)::$_3>(clang::Sema&, clang::NestedNameSpecifierLoc, clang::DeclarationNameInfo, clang::ConceptDecl*, clang::SourceLocation, clang::SourceLocation, clang::QualType, clang::SourceLocation, clang::Sema::AttachTypeConstraint(clang::AutoTypeLoc, clang::NonTypeTemplateParmDecl*, clang::SourceLocation)::$_3, clang::SourceLocation)
Line
Count
Source
1170
2
    SourceLocation EllipsisLoc) {
1171
1172
2
  TemplateArgumentListInfo ConstraintArgs;
1173
2
  ConstraintArgs.addArgument(
1174
2
    S.getTrivialTemplateArgumentLoc(TemplateArgument(ConstrainedType),
1175
2
                                    /*NTTPType=*/QualType(), ParamNameLoc));
1176
1177
2
  ConstraintArgs.setRAngleLoc(RAngleLoc);
1178
2
  ConstraintArgs.setLAngleLoc(LAngleLoc);
1179
2
  Appender(ConstraintArgs);
1180
1181
  // C++2a [temp.param]p4:
1182
  //     [...] This constraint-expression E is called the immediately-declared
1183
  //     constraint of T. [...]
1184
2
  CXXScopeSpec SS;
1185
2
  SS.Adopt(NS);
1186
2
  ExprResult ImmediatelyDeclaredConstraint = S.CheckConceptTemplateId(
1187
2
      SS, /*TemplateKWLoc=*/SourceLocation(), NameInfo,
1188
2
      /*FoundDecl=*/NamedConcept, NamedConcept, &ConstraintArgs);
1189
2
  if (ImmediatelyDeclaredConstraint.isInvalid() || !EllipsisLoc.isValid())
1190
1
    return ImmediatelyDeclaredConstraint;
1191
1192
  // C++2a [temp.param]p4:
1193
  //     [...] If T is not a pack, then E is E', otherwise E is (E' && ...).
1194
  //
1195
  // We have the following case:
1196
  //
1197
  // template<typename T> concept C1 = true;
1198
  // template<C1... T> struct s1;
1199
  //
1200
  // The constraint: (C1<T> && ...)
1201
  //
1202
  // Note that the type of C1<T> is known to be 'bool', so we don't need to do
1203
  // any unqualified lookups for 'operator&&' here.
1204
1
  return S.BuildCXXFoldExpr(/*UnqualifiedLookup=*/nullptr,
1205
1
                            /*LParenLoc=*/SourceLocation(),
1206
1
                            ImmediatelyDeclaredConstraint.get(), BO_LAnd,
1207
1
                            EllipsisLoc, /*RHS=*/nullptr,
1208
1
                            /*RParenLoc=*/SourceLocation(),
1209
1
                            /*NumExpansions=*/None);
1210
2
}
1211
1212
/// Attach a type-constraint to a template parameter.
1213
/// \returns true if an error occurred. This can happen if the
1214
/// immediately-declared constraint could not be formed (e.g. incorrect number
1215
/// of arguments for the named concept).
1216
bool Sema::AttachTypeConstraint(NestedNameSpecifierLoc NS,
1217
                                DeclarationNameInfo NameInfo,
1218
                                ConceptDecl *NamedConcept,
1219
                                const TemplateArgumentListInfo *TemplateArgs,
1220
                                TemplateTypeParmDecl *ConstrainedParameter,
1221
5.47k
                                SourceLocation EllipsisLoc) {
1222
  // C++2a [temp.param]p4:
1223
  //     [...] If Q is of the form C<A1, ..., An>, then let E' be
1224
  //     C<T, A1, ..., An>. Otherwise, let E' be C<T>. [...]
1225
5.47k
  const ASTTemplateArgumentListInfo *ArgsAsWritten =
1226
5.47k
    TemplateArgs ? ASTTemplateArgumentListInfo::Create(Context,
1227
3.50k
                                                       *TemplateArgs) : 
nullptr1.96k
;
1228
1229
5.47k
  QualType ParamAsArgument(ConstrainedParameter->getTypeForDecl(), 0);
1230
1231
5.47k
  ExprResult ImmediatelyDeclaredConstraint =
1232
5.47k
      formImmediatelyDeclaredConstraint(
1233
5.47k
          *this, NS, NameInfo, NamedConcept,
1234
5.47k
          TemplateArgs ? 
TemplateArgs->getLAngleLoc()3.50k
:
SourceLocation()1.96k
,
1235
5.47k
          TemplateArgs ? 
TemplateArgs->getRAngleLoc()3.50k
:
SourceLocation()1.96k
,
1236
5.47k
          ParamAsArgument, ConstrainedParameter->getLocation(),
1237
5.47k
          [&] (TemplateArgumentListInfo &ConstraintArgs) {
1238
5.47k
            if (TemplateArgs)
1239
3.50k
              for (const auto &ArgLoc : TemplateArgs->arguments())
1240
2.68k
                ConstraintArgs.addArgument(ArgLoc);
1241
5.47k
          }, EllipsisLoc);
1242
5.47k
  if (ImmediatelyDeclaredConstraint.isInvalid())
1243
0
    return true;
1244
1245
5.47k
  ConstrainedParameter->setTypeConstraint(NS, NameInfo,
1246
5.47k
                                          /*FoundDecl=*/NamedConcept,
1247
5.47k
                                          NamedConcept, ArgsAsWritten,
1248
5.47k
                                          ImmediatelyDeclaredConstraint.get());
1249
5.47k
  return false;
1250
5.47k
}
1251
1252
bool Sema::AttachTypeConstraint(AutoTypeLoc TL, NonTypeTemplateParmDecl *NTTP,
1253
3
                                SourceLocation EllipsisLoc) {
1254
3
  if (NTTP->getType() != TL.getType() ||
1255
3
      
TL.getAutoKeyword() != AutoTypeKeyword::Auto2
) {
1256
1
    Diag(NTTP->getTypeSourceInfo()->getTypeLoc().getBeginLoc(),
1257
1
         diag::err_unsupported_placeholder_constraint)
1258
1
       << NTTP->getTypeSourceInfo()->getTypeLoc().getSourceRange();
1259
1
    return true;
1260
1
  }
1261
  // FIXME: Concepts: This should be the type of the placeholder, but this is
1262
  // unclear in the wording right now.
1263
2
  DeclRefExpr *Ref =
1264
2
      BuildDeclRefExpr(NTTP, NTTP->getType(), VK_PRValue, NTTP->getLocation());
1265
2
  if (!Ref)
1266
0
    return true;
1267
2
  ExprResult ImmediatelyDeclaredConstraint = formImmediatelyDeclaredConstraint(
1268
2
      *this, TL.getNestedNameSpecifierLoc(), TL.getConceptNameInfo(),
1269
2
      TL.getNamedConcept(), TL.getLAngleLoc(), TL.getRAngleLoc(),
1270
2
      BuildDecltypeType(Ref), NTTP->getLocation(),
1271
2
      [&](TemplateArgumentListInfo &ConstraintArgs) {
1272
6
        for (unsigned I = 0, C = TL.getNumArgs(); I != C; 
++I4
)
1273
4
          ConstraintArgs.addArgument(TL.getArgLoc(I));
1274
2
      },
1275
2
      EllipsisLoc);
1276
2
  if (ImmediatelyDeclaredConstraint.isInvalid() ||
1277
2
     !ImmediatelyDeclaredConstraint.isUsable())
1278
0
    return true;
1279
1280
2
  NTTP->setPlaceholderTypeConstraint(ImmediatelyDeclaredConstraint.get());
1281
2
  return false;
1282
2
}
1283
1284
/// Check that the type of a non-type template parameter is
1285
/// well-formed.
1286
///
1287
/// \returns the (possibly-promoted) parameter type if valid;
1288
/// otherwise, produces a diagnostic and returns a NULL type.
1289
QualType Sema::CheckNonTypeTemplateParameterType(TypeSourceInfo *&TSI,
1290
414k
                                                 SourceLocation Loc) {
1291
414k
  if (TSI->getType()->isUndeducedType()) {
1292
    // C++17 [temp.dep.expr]p3:
1293
    //   An id-expression is type-dependent if it contains
1294
    //    - an identifier associated by name lookup with a non-type
1295
    //      template-parameter declared with a type that contains a
1296
    //      placeholder type (7.1.7.4),
1297
228
    TSI = SubstAutoTypeSourceInfoDependent(TSI);
1298
228
  }
1299
1300
414k
  return CheckNonTypeTemplateParameterType(TSI->getType(), Loc);
1301
414k
}
1302
1303
/// Require the given type to be a structural type, and diagnose if it is not.
1304
///
1305
/// \return \c true if an error was produced.
1306
373
bool Sema::RequireStructuralType(QualType T, SourceLocation Loc) {
1307
373
  if (T->isDependentType())
1308
0
    return false;
1309
1310
373
  if (RequireCompleteType(Loc, T, diag::err_template_nontype_parm_incomplete))
1311
8
    return true;
1312
1313
365
  if (T->isStructuralType())
1314
315
    return false;
1315
1316
  // Structural types are required to be object types or lvalue references.
1317
50
  if (T->isRValueReferenceType()) {
1318
4
    Diag(Loc, diag::err_template_nontype_parm_rvalue_ref) << T;
1319
4
    return true;
1320
4
  }
1321
1322
  // Don't mention structural types in our diagnostic prior to C++20. Also,
1323
  // there's not much more we can say about non-scalar non-class types --
1324
  // because we can't see functions or arrays here, those can only be language
1325
  // extensions.
1326
46
  if (!getLangOpts().CPlusPlus20 ||
1327
46
      
(15
!T->isScalarType()15
&&
!T->isRecordType()15
)) {
1328
33
    Diag(Loc, diag::err_template_nontype_parm_bad_type) << T;
1329
33
    return true;
1330
33
  }
1331
1332
  // Structural types are required to be literal types.
1333
13
  if (RequireLiteralType(Loc, T, diag::err_template_nontype_parm_not_literal))
1334
0
    return true;
1335
1336
13
  Diag(Loc, diag::err_template_nontype_parm_not_structural) << T;
1337
1338
  // Drill down into the reason why the class is non-structural.
1339
18
  while (const CXXRecordDecl *RD = T->getAsCXXRecordDecl()) {
1340
    // All members are required to be public and non-mutable, and can't be of
1341
    // rvalue reference type. Check these conditions first to prefer a "local"
1342
    // reason over a more distant one.
1343
16
    for (const FieldDecl *FD : RD->fields()) {
1344
12
      if (FD->getAccess() != AS_public) {
1345
3
        Diag(FD->getLocation(), diag::note_not_structural_non_public) << T << 0;
1346
3
        return true;
1347
3
      }
1348
9
      if (FD->isMutable()) {
1349
1
        Diag(FD->getLocation(), diag::note_not_structural_mutable_field) << T;
1350
1
        return true;
1351
1
      }
1352
8
      if (FD->getType()->isRValueReferenceType()) {
1353
4
        Diag(FD->getLocation(), diag::note_not_structural_rvalue_ref_field)
1354
4
            << T;
1355
4
        return true;
1356
4
      }
1357
8
    }
1358
1359
    // All bases are required to be public.
1360
8
    for (const auto &BaseSpec : RD->bases()) {
1361
4
      if (BaseSpec.getAccessSpecifier() != AS_public) {
1362
3
        Diag(BaseSpec.getBaseTypeLoc(), diag::note_not_structural_non_public)
1363
3
            << T << 1;
1364
3
        return true;
1365
3
      }
1366
4
    }
1367
1368
    // All subobjects are required to be of structural types.
1369
5
    SourceLocation SubLoc;
1370
5
    QualType SubType;
1371
5
    int Kind = -1;
1372
1373
5
    for (const FieldDecl *FD : RD->fields()) {
1374
4
      QualType T = Context.getBaseElementType(FD->getType());
1375
4
      if (!T->isStructuralType()) {
1376
4
        SubLoc = FD->getLocation();
1377
4
        SubType = T;
1378
4
        Kind = 0;
1379
4
        break;
1380
4
      }
1381
4
    }
1382
1383
5
    if (Kind == -1) {
1384
1
      for (const auto &BaseSpec : RD->bases()) {
1385
1
        QualType T = BaseSpec.getType();
1386
1
        if (!T->isStructuralType()) {
1387
1
          SubLoc = BaseSpec.getBaseTypeLoc();
1388
1
          SubType = T;
1389
1
          Kind = 1;
1390
1
          break;
1391
1
        }
1392
1
      }
1393
1
    }
1394
1395
5
    assert(Kind != -1 && "couldn't find reason why type is not structural");
1396
0
    Diag(SubLoc, diag::note_not_structural_subobject)
1397
5
        << T << Kind << SubType;
1398
5
    T = SubType;
1399
5
    RD = T->getAsCXXRecordDecl();
1400
5
  }
1401
1402
2
  return true;
1403
13
}
1404
1405
QualType Sema::CheckNonTypeTemplateParameterType(QualType T,
1406
971k
                                                 SourceLocation Loc) {
1407
  // We don't allow variably-modified types as the type of non-type template
1408
  // parameters.
1409
971k
  if (T->isVariablyModifiedType()) {
1410
1
    Diag(Loc, diag::err_variably_modified_nontype_template_param)
1411
1
      << T;
1412
1
    return QualType();
1413
1
  }
1414
1415
  // C++ [temp.param]p4:
1416
  //
1417
  // A non-type template-parameter shall have one of the following
1418
  // (optionally cv-qualified) types:
1419
  //
1420
  //       -- integral or enumeration type,
1421
971k
  if (T->isIntegralOrEnumerationType() ||
1422
      //   -- pointer to object or pointer to function,
1423
971k
      
T->isPointerType()226k
||
1424
      //   -- lvalue reference to object or lvalue reference to function,
1425
971k
      
T->isLValueReferenceType()165k
||
1426
      //   -- pointer to member,
1427
971k
      
T->isMemberPointerType()160k
||
1428
      //   -- std::nullptr_t, or
1429
971k
      
T->isNullPtrType()160k
||
1430
      //   -- a type that contains a placeholder type.
1431
971k
      
T->isUndeducedType()160k
) {
1432
    // C++ [temp.param]p5: The top-level cv-qualifiers on the template-parameter
1433
    // are ignored when determining its type.
1434
811k
    return T.getUnqualifiedType();
1435
811k
  }
1436
1437
  // C++ [temp.param]p8:
1438
  //
1439
  //   A non-type template-parameter of type "array of T" or
1440
  //   "function returning T" is adjusted to be of type "pointer to
1441
  //   T" or "pointer to function returning T", respectively.
1442
159k
  if (T->isArrayType() || 
T->isFunctionType()159k
)
1443
99
    return Context.getDecayedType(T);
1444
1445
  // If T is a dependent type, we can't do the check now, so we
1446
  // assume that it is well-formed. Note that stripping off the
1447
  // qualifiers here is not really correct if T turns out to be
1448
  // an array type, but we'll recompute the type everywhere it's
1449
  // used during instantiation, so that should be OK. (Using the
1450
  // qualified type is equally wrong.)
1451
159k
  if (T->isDependentType())
1452
158k
    return T.getUnqualifiedType();
1453
1454
  // C++20 [temp.param]p6:
1455
  //   -- a structural type
1456
373
  if (RequireStructuralType(T, Loc))
1457
58
    return QualType();
1458
1459
315
  if (!getLangOpts().CPlusPlus20) {
1460
    // FIXME: Consider allowing structural types as an extension in C++17. (In
1461
    // earlier language modes, the template argument evaluation rules are too
1462
    // inflexible.)
1463
30
    Diag(Loc, diag::err_template_nontype_parm_bad_structural_type) << T;
1464
30
    return QualType();
1465
30
  }
1466
1467
285
  Diag(Loc, diag::warn_cxx17_compat_template_nontype_parm_type) << T;
1468
285
  return T.getUnqualifiedType();
1469
315
}
1470
1471
NamedDecl *Sema::ActOnNonTypeTemplateParameter(Scope *S, Declarator &D,
1472
                                          unsigned Depth,
1473
                                          unsigned Position,
1474
                                          SourceLocation EqualLoc,
1475
267k
                                          Expr *Default) {
1476
267k
  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
1477
1478
  // Check that we have valid decl-specifiers specified.
1479
267k
  auto CheckValidDeclSpecifiers = [this, &D] {
1480
    // C++ [temp.param]
1481
    // p1
1482
    //   template-parameter:
1483
    //     ...
1484
    //     parameter-declaration
1485
    // p2
1486
    //   ... A storage class shall not be specified in a template-parameter
1487
    //   declaration.
1488
    // [dcl.typedef]p1:
1489
    //   The typedef specifier [...] shall not be used in the decl-specifier-seq
1490
    //   of a parameter-declaration
1491
267k
    const DeclSpec &DS = D.getDeclSpec();
1492
267k
    auto EmitDiag = [this](SourceLocation Loc) {
1493
35
      Diag(Loc, diag::err_invalid_decl_specifier_in_nontype_parm)
1494
35
          << FixItHint::CreateRemoval(Loc);
1495
35
    };
1496
267k
    if (DS.getStorageClassSpec() != DeclSpec::SCS_unspecified)
1497
18
      EmitDiag(DS.getStorageClassSpecLoc());
1498
1499
267k
    if (DS.getThreadStorageClassSpec() != TSCS_unspecified)
1500
1
      EmitDiag(DS.getThreadStorageClassSpecLoc());
1501
1502
    // [dcl.inline]p1:
1503
    //   The inline specifier can be applied only to the declaration or
1504
    //   definition of a variable or function.
1505
1506
267k
    if (DS.isInlineSpecified())
1507
6
      EmitDiag(DS.getInlineSpecLoc());
1508
1509
    // [dcl.constexpr]p1:
1510
    //   The constexpr specifier shall be applied only to the definition of a
1511
    //   variable or variable template or the declaration of a function or
1512
    //   function template.
1513
1514
267k
    if (DS.hasConstexprSpecifier())
1515
1
      EmitDiag(DS.getConstexprSpecLoc());
1516
1517
    // [dcl.fct.spec]p1:
1518
    //   Function-specifiers can be used only in function declarations.
1519
1520
267k
    if (DS.isVirtualSpecified())
1521
3
      EmitDiag(DS.getVirtualSpecLoc());
1522
1523
267k
    if (DS.hasExplicitSpecifier())
1524
6
      EmitDiag(DS.getExplicitSpecLoc());
1525
1526
267k
    if (DS.isNoreturnSpecified())
1527
0
      EmitDiag(DS.getNoreturnSpecLoc());
1528
267k
  };
1529
1530
267k
  CheckValidDeclSpecifiers();
1531
1532
267k
  if (TInfo->getType()->isUndeducedType()) {
1533
208
    Diag(D.getIdentifierLoc(),
1534
208
         diag::warn_cxx14_compat_template_nontype_parm_auto_type)
1535
208
      << QualType(TInfo->getType()->getContainedAutoType(), 0);
1536
208
  }
1537
1538
267k
  assert(S->isTemplateParamScope() &&
1539
267k
         "Non-type template parameter not in template parameter scope!");
1540
0
  bool Invalid = false;
1541
1542
267k
  QualType T = CheckNonTypeTemplateParameterType(TInfo, D.getIdentifierLoc());
1543
267k
  if (T.isNull()) {
1544
73
    T = Context.IntTy; // Recover with an 'int' type.
1545
73
    Invalid = true;
1546
73
  }
1547
1548
267k
  CheckFunctionOrTemplateParamDeclarator(S, D);
1549
1550
267k
  IdentifierInfo *ParamName = D.getIdentifier();
1551
267k
  bool IsParameterPack = D.hasEllipsis();
1552
267k
  NonTypeTemplateParmDecl *Param = NonTypeTemplateParmDecl::Create(
1553
267k
      Context, Context.getTranslationUnitDecl(), D.getBeginLoc(),
1554
267k
      D.getIdentifierLoc(), Depth, Position, ParamName, T, IsParameterPack,
1555
267k
      TInfo);
1556
267k
  Param->setAccess(AS_public);
1557
1558
267k
  if (AutoTypeLoc TL = TInfo->getTypeLoc().getContainedAutoTypeLoc())
1559
192
    if (TL.isConstrained())
1560
3
      if (AttachTypeConstraint(TL, Param, D.getEllipsisLoc()))
1561
1
        Invalid = true;
1562
1563
267k
  if (Invalid)
1564
74
    Param->setInvalidDecl();
1565
1566
267k
  if (Param->isParameterPack())
1567
14.8k
    if (auto *LSI = getEnclosingLambda())
1568
12
      LSI->LocalPacks.push_back(Param);
1569
1570
267k
  if (ParamName) {
1571
194k
    maybeDiagnoseTemplateParameterShadow(*this, S, D.getIdentifierLoc(),
1572
194k
                                         ParamName);
1573
1574
    // Add the template parameter into the current scope.
1575
194k
    S->AddDecl(Param);
1576
194k
    IdResolver.AddDecl(Param);
1577
194k
  }
1578
1579
  // C++0x [temp.param]p9:
1580
  //   A default template-argument may be specified for any kind of
1581
  //   template-parameter that is not a template parameter pack.
1582
267k
  if (Default && 
IsParameterPack78.2k
) {
1583
1
    Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1584
1
    Default = nullptr;
1585
1
  }
1586
1587
  // Check the well-formedness of the default template argument, if provided.
1588
267k
  if (Default) {
1589
    // Check for unexpanded parameter packs.
1590
78.2k
    if (DiagnoseUnexpandedParameterPack(Default, UPPC_DefaultArgument))
1591
1
      return Param;
1592
1593
78.2k
    TemplateArgument Converted;
1594
78.2k
    ExprResult DefaultRes =
1595
78.2k
        CheckTemplateArgument(Param, Param->getType(), Default, Converted);
1596
78.2k
    if (DefaultRes.isInvalid()) {
1597
2
      Param->setInvalidDecl();
1598
2
      return Param;
1599
2
    }
1600
78.2k
    Default = DefaultRes.get();
1601
1602
78.2k
    Param->setDefaultArgument(Default);
1603
78.2k
  }
1604
1605
267k
  return Param;
1606
267k
}
1607
1608
/// ActOnTemplateTemplateParameter - Called when a C++ template template
1609
/// parameter (e.g. T in template <template \<typename> class T> class array)
1610
/// has been parsed. S is the current scope.
1611
NamedDecl *Sema::ActOnTemplateTemplateParameter(Scope* S,
1612
                                           SourceLocation TmpLoc,
1613
                                           TemplateParameterList *Params,
1614
                                           SourceLocation EllipsisLoc,
1615
                                           IdentifierInfo *Name,
1616
                                           SourceLocation NameLoc,
1617
                                           unsigned Depth,
1618
                                           unsigned Position,
1619
                                           SourceLocation EqualLoc,
1620
19.7k
                                           ParsedTemplateArgument Default) {
1621
19.7k
  assert(S->isTemplateParamScope() &&
1622
19.7k
         "Template template parameter not in template parameter scope!");
1623
1624
  // Construct the parameter object.
1625
0
  bool IsParameterPack = EllipsisLoc.isValid();
1626
19.7k
  TemplateTemplateParmDecl *Param =
1627
19.7k
    TemplateTemplateParmDecl::Create(Context, Context.getTranslationUnitDecl(),
1628
19.7k
                                     NameLoc.isInvalid()? 
TmpLoc0
: NameLoc,
1629
19.7k
                                     Depth, Position, IsParameterPack,
1630
19.7k
                                     Name, Params);
1631
19.7k
  Param->setAccess(AS_public);
1632
1633
19.7k
  if (Param->isParameterPack())
1634
106
    if (auto *LSI = getEnclosingLambda())
1635
10
      LSI->LocalPacks.push_back(Param);
1636
1637
  // If the template template parameter has a name, then link the identifier
1638
  // into the scope and lookup mechanisms.
1639
19.7k
  if (Name) {
1640
18.0k
    maybeDiagnoseTemplateParameterShadow(*this, S, NameLoc, Name);
1641
1642
18.0k
    S->AddDecl(Param);
1643
18.0k
    IdResolver.AddDecl(Param);
1644
18.0k
  }
1645
1646
19.7k
  if (Params->size() == 0) {
1647
1
    Diag(Param->getLocation(), diag::err_template_template_parm_no_parms)
1648
1
    << SourceRange(Params->getLAngleLoc(), Params->getRAngleLoc());
1649
1
    Param->setInvalidDecl();
1650
1
  }
1651
1652
  // C++0x [temp.param]p9:
1653
  //   A default template-argument may be specified for any kind of
1654
  //   template-parameter that is not a template parameter pack.
1655
19.7k
  if (IsParameterPack && 
!Default.isInvalid()106
) {
1656
1
    Diag(EqualLoc, diag::err_template_param_pack_default_arg);
1657
1
    Default = ParsedTemplateArgument();
1658
1
  }
1659
1660
19.7k
  if (!Default.isInvalid()) {
1661
    // Check only that we have a template template argument. We don't want to
1662
    // try to check well-formedness now, because our template template parameter
1663
    // might have dependent types in its template parameters, which we wouldn't
1664
    // be able to match now.
1665
    //
1666
    // If none of the template template parameter's template arguments mention
1667
    // other template parameters, we could actually perform more checking here.
1668
    // However, it isn't worth doing.
1669
9.34k
    TemplateArgumentLoc DefaultArg = translateTemplateArgument(*this, Default);
1670
9.34k
    if (DefaultArg.getArgument().getAsTemplate().isNull()) {
1671
0
      Diag(DefaultArg.getLocation(), diag::err_template_arg_not_valid_template)
1672
0
        << DefaultArg.getSourceRange();
1673
0
      return Param;
1674
0
    }
1675
1676
    // Check for unexpanded parameter packs.
1677
9.34k
    if (DiagnoseUnexpandedParameterPack(DefaultArg.getLocation(),
1678
9.34k
                                        DefaultArg.getArgument().getAsTemplate(),
1679
9.34k
                                        UPPC_DefaultArgument))
1680
1
      return Param;
1681
1682
9.34k
    Param->setDefaultArgument(Context, DefaultArg);
1683
9.34k
  }
1684
1685
19.7k
  return Param;
1686
19.7k
}
1687
1688
/// ActOnTemplateParameterList - Builds a TemplateParameterList, optionally
1689
/// constrained by RequiresClause, that contains the template parameters in
1690
/// Params.
1691
TemplateParameterList *
1692
Sema::ActOnTemplateParameterList(unsigned Depth,
1693
                                 SourceLocation ExportLoc,
1694
                                 SourceLocation TemplateLoc,
1695
                                 SourceLocation LAngleLoc,
1696
                                 ArrayRef<NamedDecl *> Params,
1697
                                 SourceLocation RAngleLoc,
1698
1.63M
                                 Expr *RequiresClause) {
1699
1.63M
  if (ExportLoc.isValid())
1700
3
    Diag(ExportLoc, diag::warn_template_export_unsupported);
1701
1702
1.63M
  for (NamedDecl *P : Params)
1703
2.93M
    warnOnReservedIdentifier(P);
1704
1705
1.63M
  return TemplateParameterList::Create(
1706
1.63M
      Context, TemplateLoc, LAngleLoc,
1707
1.63M
      llvm::makeArrayRef(Params.data(), Params.size()),
1708
1.63M
      RAngleLoc, RequiresClause);
1709
1.63M
}
1710
1711
static void SetNestedNameSpecifier(Sema &S, TagDecl *T,
1712
593k
                                   const CXXScopeSpec &SS) {
1713
593k
  if (SS.isSet())
1714
626
    T->setQualifierInfo(SS.getWithLocInContext(S.Context));
1715
593k
}
1716
1717
DeclResult Sema::CheckClassTemplate(
1718
    Scope *S, unsigned TagSpec, TagUseKind TUK, SourceLocation KWLoc,
1719
    CXXScopeSpec &SS, IdentifierInfo *Name, SourceLocation NameLoc,
1720
    const ParsedAttributesView &Attr, TemplateParameterList *TemplateParams,
1721
    AccessSpecifier AS, SourceLocation ModulePrivateLoc,
1722
    SourceLocation FriendLoc, unsigned NumOuterTemplateParamLists,
1723
328k
    TemplateParameterList **OuterTemplateParamLists, SkipBodyInfo *SkipBody) {
1724
328k
  assert(TemplateParams && TemplateParams->size() > 0 &&
1725
328k
         "No template parameters");
1726
0
  assert(TUK != TUK_Reference && "Can only declare or define class templates");
1727
0
  bool Invalid = false;
1728
1729
  // Check that we can declare a template here.
1730
328k
  if (CheckTemplateDeclScope(S, TemplateParams))
1731
7
    return true;
1732
1733
328k
  TagTypeKind Kind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
1734
328k
  assert(Kind != TTK_Enum && "can't build template of enumerated type");
1735
1736
  // There is no such thing as an unnamed class template.
1737
328k
  if (!Name) {
1738
0
    Diag(KWLoc, diag::err_template_unnamed_class);
1739
0
    return true;
1740
0
  }
1741
1742
  // Find any previous declaration with this name. For a friend with no
1743
  // scope explicitly specified, we only look for tag declarations (per
1744
  // C++11 [basic.lookup.elab]p2).
1745
328k
  DeclContext *SemanticContext;
1746
328k
  LookupResult Previous(*this, Name, NameLoc,
1747
328k
                        (SS.isEmpty() && 
TUK == TUK_Friend328k
)
1748
328k
                          ? 
LookupTagName18.8k
:
LookupOrdinaryName309k
,
1749
328k
                        forRedeclarationInCurContext());
1750
328k
  if (SS.isNotEmpty() && 
!SS.isInvalid()149
) {
1751
149
    SemanticContext = computeDeclContext(SS, true);
1752
149
    if (!SemanticContext) {
1753
      // FIXME: Horrible, horrible hack! We can't currently represent this
1754
      // in the AST, and historically we have just ignored such friend
1755
      // class templates, so don't complain here.
1756
2
      Diag(NameLoc, TUK == TUK_Friend
1757
2
                        ? 
diag::warn_template_qualified_friend_ignored1
1758
2
                        : 
diag::err_template_qualified_declarator_no_match1
)
1759
2
          << SS.getScopeRep() << SS.getRange();
1760
2
      return TUK != TUK_Friend;
1761
2
    }
1762
1763
147
    if (RequireCompleteDeclContext(SS, SemanticContext))
1764
0
      return true;
1765
1766
    // If we're adding a template to a dependent context, we may need to
1767
    // rebuilding some of the types used within the template parameter list,
1768
    // now that we know what the current instantiation is.
1769
147
    if (SemanticContext->isDependentContext()) {
1770
41
      ContextRAII SavedContext(*this, SemanticContext);
1771
41
      if (RebuildTemplateParamsInCurrentInstantiation(TemplateParams))
1772
0
        Invalid = true;
1773
106
    } else if (TUK != TUK_Friend && 
TUK != TUK_Reference87
)
1774
87
      diagnoseQualifiedDeclaration(SS, SemanticContext, Name, NameLoc, false);
1775
1776
147
    LookupQualifiedName(Previous, SemanticContext);
1777
328k
  } else {
1778
328k
    SemanticContext = CurContext;
1779
1780
    // C++14 [class.mem]p14:
1781
    //   If T is the name of a class, then each of the following shall have a
1782
    //   name different from T:
1783
    //    -- every member template of class T
1784
328k
    if (TUK != TUK_Friend &&
1785
328k
        DiagnoseClassNameShadow(SemanticContext,
1786
309k
                                DeclarationNameInfo(Name, NameLoc)))
1787
6
      return true;
1788
1789
328k
    LookupName(Previous, S);
1790
328k
  }
1791
1792
328k
  if (Previous.isAmbiguous())
1793
0
    return true;
1794
1795
328k
  NamedDecl *PrevDecl = nullptr;
1796
328k
  if (Previous.begin() != Previous.end())
1797
42.0k
    PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1798
1799
328k
  if (PrevDecl && 
PrevDecl->isTemplateParameter()42.0k
) {
1800
    // Maybe we will complain about the shadowed template parameter.
1801
7
    DiagnoseTemplateParameterShadow(NameLoc, PrevDecl);
1802
    // Just pretend that we didn't see the previous declaration.
1803
7
    PrevDecl = nullptr;
1804
7
  }
1805
1806
  // If there is a previous declaration with the same name, check
1807
  // whether this is a valid redeclaration.
1808
328k
  ClassTemplateDecl *PrevClassTemplate =
1809
328k
      dyn_cast_or_null<ClassTemplateDecl>(PrevDecl);
1810
1811
  // We may have found the injected-class-name of a class template,
1812
  // class template partial specialization, or class template specialization.
1813
  // In these cases, grab the template that is being defined or specialized.
1814
328k
  if (!PrevClassTemplate && 
PrevDecl289k
&&
isa<CXXRecordDecl>(PrevDecl)3.03k
&&
1815
328k
      
cast<CXXRecordDecl>(PrevDecl)->isInjectedClassName()3.02k
) {
1816
3.01k
    PrevDecl = cast<CXXRecordDecl>(PrevDecl->getDeclContext());
1817
3.01k
    PrevClassTemplate
1818
3.01k
      = cast<CXXRecordDecl>(PrevDecl)->getDescribedClassTemplate();
1819
3.01k
    if (!PrevClassTemplate && 
isa<ClassTemplateSpecializationDecl>(PrevDecl)25
) {
1820
25
      PrevClassTemplate
1821
25
        = cast<ClassTemplateSpecializationDecl>(PrevDecl)
1822
25
            ->getSpecializedTemplate();
1823
25
    }
1824
3.01k
  }
1825
1826
328k
  if (TUK == TUK_Friend) {
1827
    // C++ [namespace.memdef]p3:
1828
    //   [...] When looking for a prior declaration of a class or a function
1829
    //   declared as a friend, and when the name of the friend class or
1830
    //   function is neither a qualified name nor a template-id, scopes outside
1831
    //   the innermost enclosing namespace scope are not considered.
1832
18.8k
    if (!SS.isSet()) {
1833
18.8k
      DeclContext *OutermostContext = CurContext;
1834
37.7k
      while (!OutermostContext->isFileContext())
1835
18.9k
        OutermostContext = OutermostContext->getLookupParent();
1836
1837
18.8k
      if (PrevDecl &&
1838
18.8k
          
(14.5k
OutermostContext->Equals(PrevDecl->getDeclContext())14.5k
||
1839
14.5k
           
OutermostContext->Encloses(PrevDecl->getDeclContext())15
)) {
1840
14.5k
        SemanticContext = PrevDecl->getDeclContext();
1841
14.5k
      } else {
1842
        // Declarations in outer scopes don't matter. However, the outermost
1843
        // context we computed is the semantic context for our new
1844
        // declaration.
1845
4.27k
        PrevDecl = PrevClassTemplate = nullptr;
1846
4.27k
        SemanticContext = OutermostContext;
1847
1848
        // Check that the chosen semantic context doesn't already contain a
1849
        // declaration of this name as a non-tag type.
1850
4.27k
        Previous.clear(LookupOrdinaryName);
1851
4.27k
        DeclContext *LookupContext = SemanticContext;
1852
4.27k
        while (LookupContext->isTransparentContext())
1853
0
          LookupContext = LookupContext->getLookupParent();
1854
4.27k
        LookupQualifiedName(Previous, LookupContext);
1855
1856
4.27k
        if (Previous.isAmbiguous())
1857
0
          return true;
1858
1859
4.27k
        if (Previous.begin() != Previous.end())
1860
1
          PrevDecl = (*Previous.begin())->getUnderlyingDecl();
1861
4.27k
      }
1862
18.8k
    }
1863
309k
  } else if (PrevDecl &&
1864
309k
             !isDeclInScope(Previous.getRepresentativeDecl(), SemanticContext,
1865
27.3k
                            S, SS.isValid()))
1866
49
    PrevDecl = PrevClassTemplate = nullptr;
1867
1868
328k
  if (auto *Shadow = dyn_cast_or_null<UsingShadowDecl>(
1869
328k
          PrevDecl ? Previous.getRepresentativeDecl() : nullptr)) {
1870
3
    if (SS.isEmpty() &&
1871
3
        !(PrevClassTemplate &&
1872
3
          PrevClassTemplate->getDeclContext()->getRedeclContext()->Equals(
1873
3
              SemanticContext->getRedeclContext()))) {
1874
2
      Diag(KWLoc, diag::err_using_decl_conflict_reverse);
1875
2
      Diag(Shadow->getTargetDecl()->getLocation(),
1876
2
           diag::note_using_decl_target);
1877
2
      Diag(Shadow->getIntroducer()->getLocation(), diag::note_using_decl) << 0;
1878
      // Recover by ignoring the old declaration.
1879
2
      PrevDecl = PrevClassTemplate = nullptr;
1880
2
    }
1881
3
  }
1882
1883
328k
  if (PrevClassTemplate) {
1884
    // Ensure that the template parameter lists are compatible. Skip this check
1885
    // for a friend in a dependent context: the template parameter list itself
1886
    // could be dependent.
1887
41.9k
    if (!(TUK == TUK_Friend && 
CurContext->isDependentContext()14.6k
) &&
1888
41.9k
        !TemplateParameterListsAreEqual(TemplateParams,
1889
27.6k
                                   PrevClassTemplate->getTemplateParameters(),
1890
27.6k
                                        /*Complain=*/true,
1891
27.6k
                                        TPL_TemplateMatch))
1892
34
      return true;
1893
1894
    // C++ [temp.class]p4:
1895
    //   In a redeclaration, partial specialization, explicit
1896
    //   specialization or explicit instantiation of a class template,
1897
    //   the class-key shall agree in kind with the original class
1898
    //   template declaration (7.1.5.3).
1899
41.9k
    RecordDecl *PrevRecordDecl = PrevClassTemplate->getTemplatedDecl();
1900
41.9k
    if (!isAcceptableTagRedeclaration(PrevRecordDecl, Kind,
1901
41.9k
                                      TUK == TUK_Definition,  KWLoc, Name)) {
1902
0
      Diag(KWLoc, diag::err_use_with_wrong_tag)
1903
0
        << Name
1904
0
        << FixItHint::CreateReplacement(KWLoc, PrevRecordDecl->getKindName());
1905
0
      Diag(PrevRecordDecl->getLocation(), diag::note_previous_use);
1906
0
      Kind = PrevRecordDecl->getTagKind();
1907
0
    }
1908
1909
    // Check for redefinition of this class template.
1910
41.9k
    if (TUK == TUK_Definition) {
1911
17.5k
      if (TagDecl *Def = PrevRecordDecl->getDefinition()) {
1912
        // If we have a prior definition that is not visible, treat this as
1913
        // simply making that previous definition visible.
1914
114
        NamedDecl *Hidden = nullptr;
1915
114
        if (SkipBody && 
!hasVisibleDefinition(Def, &Hidden)113
) {
1916
111
          SkipBody->ShouldSkip = true;
1917
111
          SkipBody->Previous = Def;
1918
111
          auto *Tmpl = cast<CXXRecordDecl>(Hidden)->getDescribedClassTemplate();
1919
111
          assert(Tmpl && "original definition of a class template is not a "
1920
111
                         "class template?");
1921
0
          makeMergedDefinitionVisible(Hidden);
1922
111
          makeMergedDefinitionVisible(Tmpl);
1923
111
        } else {
1924
3
          Diag(NameLoc, diag::err_redefinition) << Name;
1925
3
          Diag(Def->getLocation(), diag::note_previous_definition);
1926
          // FIXME: Would it make sense to try to "forget" the previous
1927
          // definition, as part of error recovery?
1928
3
          return true;
1929
3
        }
1930
114
      }
1931
17.5k
    }
1932
286k
  } else if (PrevDecl) {
1933
    // C++ [temp]p5:
1934
    //   A class template shall not have the same name as any other
1935
    //   template, class, function, object, enumeration, enumerator,
1936
    //   namespace, or type in the same scope (3.3), except as specified
1937
    //   in (14.5.4).
1938
6
    Diag(NameLoc, diag::err_redefinition_different_kind) << Name;
1939
6
    Diag(PrevDecl->getLocation(), diag::note_previous_definition);
1940
6
    return true;
1941
6
  }
1942
1943
  // Check the template parameter list of this declaration, possibly
1944
  // merging in the template parameter list from the previous class
1945
  // template declaration. Skip this check for a friend in a dependent
1946
  // context, because the template parameter list might be dependent.
1947
328k
  if (!(TUK == TUK_Friend && 
CurContext->isDependentContext()18.8k
) &&
1948
328k
      CheckTemplateParameterList(
1949
309k
          TemplateParams,
1950
309k
          PrevClassTemplate
1951
309k
              ? 
PrevClassTemplate->getMostRecentDecl()->getTemplateParameters()27.5k
1952
309k
              : 
nullptr281k
,
1953
309k
          (SS.isSet() && 
SemanticContext130
&&
SemanticContext->isRecord()130
&&
1954
309k
           
SemanticContext->isDependentContext()112
)
1955
309k
              ? 
TPC_ClassTemplateMember33
1956
309k
              : 
TUK == TUK_Friend309k
?
TPC_FriendClassTemplate349
:
TPC_ClassTemplate309k
,
1957
309k
          SkipBody))
1958
22
    Invalid = true;
1959
1960
328k
  if (SS.isSet()) {
1961
    // If the name of the template was qualified, we must be defining the
1962
    // template out-of-line.
1963
144
    if (!SS.isInvalid() && !Invalid && !PrevClassTemplate) {
1964
3
      Diag(NameLoc, TUK == TUK_Friend ? 
diag::err_friend_decl_does_not_match1
1965
3
                                      : 
diag::err_member_decl_does_not_match2
)
1966
3
        << Name << SemanticContext << /*IsDefinition*/true << SS.getRange();
1967
3
      Invalid = true;
1968
3
    }
1969
144
  }
1970
1971
  // If this is a templated friend in a dependent context we should not put it
1972
  // on the redecl chain. In some cases, the templated friend can be the most
1973
  // recent declaration tricking the template instantiator to make substitutions
1974
  // there.
1975
  // FIXME: Figure out how to combine with shouldLinkDependentDeclWithPrevious
1976
328k
  bool ShouldAddRedecl
1977
328k
    = !(TUK == TUK_Friend && 
CurContext->isDependentContext()18.8k
);
1978
1979
328k
  CXXRecordDecl *NewClass =
1980
328k
    CXXRecordDecl::Create(Context, Kind, SemanticContext, KWLoc, NameLoc, Name,
1981
328k
                          PrevClassTemplate && 
ShouldAddRedecl41.9k
?
1982
300k
                            
PrevClassTemplate->getTemplatedDecl()27.5k
: nullptr,
1983
328k
                          /*DelayTypeCreation=*/true);
1984
328k
  SetNestedNameSpecifier(*this, NewClass, SS);
1985
328k
  if (NumOuterTemplateParamLists > 0)
1986
76
    NewClass->setTemplateParameterListsInfo(
1987
76
        Context, llvm::makeArrayRef(OuterTemplateParamLists,
1988
76
                                    NumOuterTemplateParamLists));
1989
1990
  // Add alignment attributes if necessary; these attributes are checked when
1991
  // the ASTContext lays out the structure.
1992
328k
  if (TUK == TUK_Definition && 
(250k
!SkipBody250k
||
!SkipBody->ShouldSkip250k
)) {
1993
250k
    AddAlignmentAttributesForRecord(NewClass);
1994
250k
    AddMsStructLayoutForRecord(NewClass);
1995
250k
  }
1996
1997
328k
  ClassTemplateDecl *NewTemplate
1998
328k
    = ClassTemplateDecl::Create(Context, SemanticContext, NameLoc,
1999
328k
                                DeclarationName(Name), TemplateParams,
2000
328k
                                NewClass);
2001
2002
328k
  if (ShouldAddRedecl)
2003
309k
    NewTemplate->setPreviousDecl(PrevClassTemplate);
2004
2005
328k
  NewClass->setDescribedClassTemplate(NewTemplate);
2006
2007
328k
  if (ModulePrivateLoc.isValid())
2008
3
    NewTemplate->setModulePrivate();
2009
2010
  // Build the type for the class template declaration now.
2011
328k
  QualType T = NewTemplate->getInjectedClassNameSpecialization();
2012
328k
  T = Context.getInjectedClassNameType(NewClass, T);
2013
328k
  assert(T->isDependentType() && "Class template type is not dependent?");
2014
0
  (void)T;
2015
2016
  // If we are providing an explicit specialization of a member that is a
2017
  // class template, make a note of that.
2018
328k
  if (PrevClassTemplate &&
2019
328k
      
PrevClassTemplate->getInstantiatedFromMemberTemplate()41.9k
)
2020
39
    PrevClassTemplate->setMemberSpecialization();
2021
2022
  // Set the access specifier.
2023
328k
  if (!Invalid && 
TUK != TUK_Friend328k
&&
NewTemplate->getDeclContext()->isRecord()309k
)
2024
11.1k
    SetMemberAccessSpecifier(NewTemplate, PrevClassTemplate, AS);
2025
2026
  // Set the lexical context of these templates
2027
328k
  NewClass->setLexicalDeclContext(CurContext);
2028
328k
  NewTemplate->setLexicalDeclContext(CurContext);
2029
2030
328k
  if (TUK == TUK_Definition && 
(250k
!SkipBody250k
||
!SkipBody->ShouldSkip250k
))
2031
250k
    NewClass->startDefinition();
2032
2033
328k
  ProcessDeclAttributeList(S, NewClass, Attr);
2034
2035
328k
  if (PrevClassTemplate)
2036
41.9k
    mergeDeclAttributes(NewClass, PrevClassTemplate->getTemplatedDecl());
2037
2038
328k
  AddPushedVisibilityAttribute(NewClass);
2039
328k
  inferGslOwnerPointerAttribute(NewClass);
2040
2041
328k
  if (TUK != TUK_Friend) {
2042
    // Per C++ [basic.scope.temp]p2, skip the template parameter scopes.
2043
309k
    Scope *Outer = S;
2044
618k
    while ((Outer->getFlags() & Scope::TemplateParamScope) != 0)
2045
309k
      Outer = Outer->getParent();
2046
309k
    PushOnScopeChains(NewTemplate, Outer);
2047
309k
  } else {
2048
18.8k
    if (PrevClassTemplate && 
PrevClassTemplate->getAccess() != AS_none14.6k
) {
2049
27
      NewTemplate->setAccess(PrevClassTemplate->getAccess());
2050
27
      NewClass->setAccess(PrevClassTemplate->getAccess());
2051
27
    }
2052
2053
18.8k
    NewTemplate->setObjectOfFriendDecl();
2054
2055
    // Friend templates are visible in fairly strange ways.
2056
18.8k
    if (!CurContext->isDependentContext()) {
2057
349
      DeclContext *DC = SemanticContext->getRedeclContext();
2058
349
      DC->makeDeclVisibleInContext(NewTemplate);
2059
349
      if (Scope *EnclosingScope = getScopeForDeclContext(S, DC))
2060
338
        PushOnScopeChains(NewTemplate, EnclosingScope,
2061
338
                          /* AddToContext = */ false);
2062
349
    }
2063
2064
18.8k
    FriendDecl *Friend = FriendDecl::Create(
2065
18.8k
        Context, CurContext, NewClass->getLocation(), NewTemplate, FriendLoc);
2066
18.8k
    Friend->setAccess(AS_public);
2067
18.8k
    CurContext->addDecl(Friend);
2068
18.8k
  }
2069
2070
328k
  if (PrevClassTemplate)
2071
41.9k
    CheckRedeclarationInModule(NewTemplate, PrevClassTemplate);
2072
2073
328k
  if (Invalid) {
2074
25
    NewTemplate->setInvalidDecl();
2075
25
    NewClass->setInvalidDecl();
2076
25
  }
2077
2078
328k
  ActOnDocumentableDecl(NewTemplate);
2079
2080
328k
  if (SkipBody && 
SkipBody->ShouldSkip309k
)
2081
111
    return SkipBody->Previous;
2082
2083
328k
  return NewTemplate;
2084
328k
}
2085
2086
namespace {
2087
/// Tree transform to "extract" a transformed type from a class template's
2088
/// constructor to a deduction guide.
2089
class ExtractTypeForDeductionGuide
2090
  : public TreeTransform<ExtractTypeForDeductionGuide> {
2091
  llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs;
2092
2093
public:
2094
  typedef TreeTransform<ExtractTypeForDeductionGuide> Base;
2095
  ExtractTypeForDeductionGuide(
2096
      Sema &SemaRef,
2097
      llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs)
2098
6.08k
      : Base(SemaRef), MaterializedTypedefs(MaterializedTypedefs) {}
2099
2100
6.08k
  TypeSourceInfo *transform(TypeSourceInfo *TSI) { return TransformType(TSI); }
2101
2102
10.6k
  QualType TransformTypedefType(TypeLocBuilder &TLB, TypedefTypeLoc TL) {
2103
10.6k
    ASTContext &Context = SemaRef.getASTContext();
2104
10.6k
    TypedefNameDecl *OrigDecl = TL.getTypedefNameDecl();
2105
10.6k
    TypedefNameDecl *Decl = OrigDecl;
2106
    // Transform the underlying type of the typedef and clone the Decl only if
2107
    // the typedef has a dependent context.
2108
10.6k
    if (OrigDecl->getDeclContext()->isDependentContext()) {
2109
10.6k
      TypeLocBuilder InnerTLB;
2110
10.6k
      QualType Transformed =
2111
10.6k
          TransformType(InnerTLB, OrigDecl->getTypeSourceInfo()->getTypeLoc());
2112
10.6k
      TypeSourceInfo *TSI = InnerTLB.getTypeSourceInfo(Context, Transformed);
2113
10.6k
      if (isa<TypeAliasDecl>(OrigDecl))
2114
15
        Decl = TypeAliasDecl::Create(
2115
15
            Context, Context.getTranslationUnitDecl(), OrigDecl->getBeginLoc(),
2116
15
            OrigDecl->getLocation(), OrigDecl->getIdentifier(), TSI);
2117
10.5k
      else {
2118
10.5k
        assert(isa<TypedefDecl>(OrigDecl) && "Not a Type alias or typedef");
2119
0
        Decl = TypedefDecl::Create(
2120
10.5k
            Context, Context.getTranslationUnitDecl(), OrigDecl->getBeginLoc(),
2121
10.5k
            OrigDecl->getLocation(), OrigDecl->getIdentifier(), TSI);
2122
10.5k
      }
2123
0
      MaterializedTypedefs.push_back(Decl);
2124
10.6k
    }
2125
2126
0
    QualType TDTy = Context.getTypedefType(Decl);
2127
10.6k
    TypedefTypeLoc TypedefTL = TLB.push<TypedefTypeLoc>(TDTy);
2128
10.6k
    TypedefTL.setNameLoc(TL.getNameLoc());
2129
2130
10.6k
    return TDTy;
2131
10.6k
  }
2132
};
2133
2134
/// Transform to convert portions of a constructor declaration into the
2135
/// corresponding deduction guide, per C++1z [over.match.class.deduct]p1.
2136
struct ConvertConstructorToDeductionGuideTransform {
2137
  ConvertConstructorToDeductionGuideTransform(Sema &S,
2138
                                              ClassTemplateDecl *Template)
2139
2.00k
      : SemaRef(S), Template(Template) {}
2140
2141
  Sema &SemaRef;
2142
  ClassTemplateDecl *Template;
2143
2144
  DeclContext *DC = Template->getDeclContext();
2145
  CXXRecordDecl *Primary = Template->getTemplatedDecl();
2146
  DeclarationName DeductionGuideName =
2147
      SemaRef.Context.DeclarationNames.getCXXDeductionGuideName(Template);
2148
2149
  QualType DeducedType = SemaRef.Context.getTypeDeclType(Primary);
2150
2151
  // Index adjustment to apply to convert depth-1 template parameters into
2152
  // depth-0 template parameters.
2153
  unsigned Depth1IndexAdjustment = Template->getTemplateParameters()->size();
2154
2155
  /// Transform a constructor declaration into a deduction guide.
2156
  NamedDecl *transformConstructor(FunctionTemplateDecl *FTD,
2157
3.12k
                                  CXXConstructorDecl *CD) {
2158
3.12k
    SmallVector<TemplateArgument, 16> SubstArgs;
2159
2160
3.12k
    LocalInstantiationScope Scope(SemaRef);
2161
2162
    // C++ [over.match.class.deduct]p1:
2163
    // -- For each constructor of the class template designated by the
2164
    //    template-name, a function template with the following properties:
2165
2166
    //    -- The template parameters are the template parameters of the class
2167
    //       template followed by the template parameters (including default
2168
    //       template arguments) of the constructor, if any.
2169
3.12k
    TemplateParameterList *TemplateParams = Template->getTemplateParameters();
2170
3.12k
    if (FTD) {
2171
1.50k
      TemplateParameterList *InnerParams = FTD->getTemplateParameters();
2172
1.50k
      SmallVector<NamedDecl *, 16> AllParams;
2173
1.50k
      AllParams.reserve(TemplateParams->size() + InnerParams->size());
2174
1.50k
      AllParams.insert(AllParams.begin(),
2175
1.50k
                       TemplateParams->begin(), TemplateParams->end());
2176
1.50k
      SubstArgs.reserve(InnerParams->size());
2177
2178
      // Later template parameters could refer to earlier ones, so build up
2179
      // a list of substituted template arguments as we go.
2180
3.16k
      for (NamedDecl *Param : *InnerParams) {
2181
3.16k
        MultiLevelTemplateArgumentList Args;
2182
3.16k
        Args.setKind(TemplateSubstitutionKind::Rewrite);
2183
3.16k
        Args.addOuterTemplateArguments(SubstArgs);
2184
3.16k
        Args.addOuterRetainedLevel();
2185
3.16k
        NamedDecl *NewParam = transformTemplateParameter(Param, Args);
2186
3.16k
        if (!NewParam)
2187
0
          return nullptr;
2188
3.16k
        AllParams.push_back(NewParam);
2189
3.16k
        SubstArgs.push_back(SemaRef.Context.getCanonicalTemplateArgument(
2190
3.16k
            SemaRef.Context.getInjectedTemplateArg(NewParam)));
2191
3.16k
      }
2192
2193
      // Substitute new template parameters into requires-clause if present.
2194
1.50k
      Expr *RequiresClause = nullptr;
2195
1.50k
      if (Expr *InnerRC = InnerParams->getRequiresClause()) {
2196
35
        MultiLevelTemplateArgumentList Args;
2197
35
        Args.setKind(TemplateSubstitutionKind::Rewrite);
2198
35
        Args.addOuterTemplateArguments(SubstArgs);
2199
35
        Args.addOuterRetainedLevel();
2200
35
        ExprResult E = SemaRef.SubstExpr(InnerRC, Args);
2201
35
        if (E.isInvalid())
2202
0
          return nullptr;
2203
35
        RequiresClause = E.getAs<Expr>();
2204
35
      }
2205
2206
1.50k
      TemplateParams = TemplateParameterList::Create(
2207
1.50k
          SemaRef.Context, InnerParams->getTemplateLoc(),
2208
1.50k
          InnerParams->getLAngleLoc(), AllParams, InnerParams->getRAngleLoc(),
2209
1.50k
          RequiresClause);
2210
1.50k
    }
2211
2212
    // If we built a new template-parameter-list, track that we need to
2213
    // substitute references to the old parameters into references to the
2214
    // new ones.
2215
3.12k
    MultiLevelTemplateArgumentList Args;
2216
3.12k
    Args.setKind(TemplateSubstitutionKind::Rewrite);
2217
3.12k
    if (FTD) {
2218
1.50k
      Args.addOuterTemplateArguments(SubstArgs);
2219
1.50k
      Args.addOuterRetainedLevel();
2220
1.50k
    }
2221
2222
3.12k
    FunctionProtoTypeLoc FPTL = CD->getTypeSourceInfo()->getTypeLoc()
2223
3.12k
                                   .getAsAdjusted<FunctionProtoTypeLoc>();
2224
3.12k
    assert(FPTL && "no prototype for constructor declaration");
2225
2226
    // Transform the type of the function, adjusting the return type and
2227
    // replacing references to the old parameters with references to the
2228
    // new ones.
2229
0
    TypeLocBuilder TLB;
2230
3.12k
    SmallVector<ParmVarDecl*, 8> Params;
2231
3.12k
    SmallVector<TypedefNameDecl *, 4> MaterializedTypedefs;
2232
3.12k
    QualType NewType = transformFunctionProtoType(TLB, FPTL, Params, Args,
2233
3.12k
                                                  MaterializedTypedefs);
2234
3.12k
    if (NewType.isNull())
2235
0
      return nullptr;
2236
3.12k
    TypeSourceInfo *NewTInfo = TLB.getTypeSourceInfo(SemaRef.Context, NewType);
2237
2238
3.12k
    return buildDeductionGuide(TemplateParams, CD, CD->getExplicitSpecifier(),
2239
3.12k
                               NewTInfo, CD->getBeginLoc(), CD->getLocation(),
2240
3.12k
                               CD->getEndLoc(), MaterializedTypedefs);
2241
3.12k
  }
2242
2243
  /// Build a deduction guide with the specified parameter types.
2244
547
  NamedDecl *buildSimpleDeductionGuide(MutableArrayRef<QualType> ParamTypes) {
2245
547
    SourceLocation Loc = Template->getLocation();
2246
2247
    // Build the requested type.
2248
547
    FunctionProtoType::ExtProtoInfo EPI;
2249
547
    EPI.HasTrailingReturn = true;
2250
547
    QualType Result = SemaRef.BuildFunctionType(DeducedType, ParamTypes, Loc,
2251
547
                                                DeductionGuideName, EPI);
2252
547
    TypeSourceInfo *TSI = SemaRef.Context.getTrivialTypeSourceInfo(Result, Loc);
2253
2254
547
    FunctionProtoTypeLoc FPTL =
2255
547
        TSI->getTypeLoc().castAs<FunctionProtoTypeLoc>();
2256
2257
    // Build the parameters, needed during deduction / substitution.
2258
547
    SmallVector<ParmVarDecl*, 4> Params;
2259
547
    for (auto T : ParamTypes) {
2260
468
      ParmVarDecl *NewParam = ParmVarDecl::Create(
2261
468
          SemaRef.Context, DC, Loc, Loc, nullptr, T,
2262
468
          SemaRef.Context.getTrivialTypeSourceInfo(T, Loc), SC_None, nullptr);
2263
468
      NewParam->setScopeInfo(0, Params.size());
2264
468
      FPTL.setParam(Params.size(), NewParam);
2265
468
      Params.push_back(NewParam);
2266
468
    }
2267
2268
547
    return buildDeductionGuide(Template->getTemplateParameters(), nullptr,
2269
547
                               ExplicitSpecifier(), TSI, Loc, Loc, Loc);
2270
547
  }
2271
2272
private:
2273
  /// Transform a constructor template parameter into a deduction guide template
2274
  /// parameter, rebuilding any internal references to earlier parameters and
2275
  /// renumbering as we go.
2276
  NamedDecl *transformTemplateParameter(NamedDecl *TemplateParam,
2277
3.16k
                                        MultiLevelTemplateArgumentList &Args) {
2278
3.16k
    if (auto *TTP = dyn_cast<TemplateTypeParmDecl>(TemplateParam)) {
2279
      // TemplateTypeParmDecl's index cannot be changed after creation, so
2280
      // substitute it directly.
2281
2.11k
      auto *NewTTP = TemplateTypeParmDecl::Create(
2282
2.11k
          SemaRef.Context, DC, TTP->getBeginLoc(), TTP->getLocation(),
2283
2.11k
          /*Depth*/ 0, Depth1IndexAdjustment + TTP->getIndex(),
2284
2.11k
          TTP->getIdentifier(), TTP->wasDeclaredWithTypename(),
2285
2.11k
          TTP->isParameterPack(), TTP->hasTypeConstraint(),
2286
2.11k
          TTP->isExpandedParameterPack() ?
2287
2.11k
          
llvm::Optional<unsigned>(TTP->getNumExpansionParameters())0
: None);
2288
2.11k
      if (const auto *TC = TTP->getTypeConstraint())
2289
73
        SemaRef.SubstTypeConstraint(NewTTP, TC, Args);
2290
2.11k
      if (TTP->hasDefaultArgument()) {
2291
313
        TypeSourceInfo *InstantiatedDefaultArg =
2292
313
            SemaRef.SubstType(TTP->getDefaultArgumentInfo(), Args,
2293
313
                              TTP->getDefaultArgumentLoc(), TTP->getDeclName());
2294
313
        if (InstantiatedDefaultArg)
2295
313
          NewTTP->setDefaultArgument(InstantiatedDefaultArg);
2296
313
      }
2297
2.11k
      SemaRef.CurrentInstantiationScope->InstantiatedLocal(TemplateParam,
2298
2.11k
                                                           NewTTP);
2299
2.11k
      return NewTTP;
2300
2.11k
    }
2301
2302
1.04k
    if (auto *TTP = dyn_cast<TemplateTemplateParmDecl>(TemplateParam))
2303
284
      return transformTemplateParameterImpl(TTP, Args);
2304
2305
764
    return transformTemplateParameterImpl(
2306
764
        cast<NonTypeTemplateParmDecl>(TemplateParam), Args);
2307
1.04k
  }
2308
  template<typename TemplateParmDecl>
2309
  TemplateParmDecl *
2310
  transformTemplateParameterImpl(TemplateParmDecl *OldParam,
2311
1.04k
                                 MultiLevelTemplateArgumentList &Args) {
2312
    // Ask the template instantiator to do the heavy lifting for us, then adjust
2313
    // the index of the parameter once it's done.
2314
1.04k
    auto *NewParam =
2315
1.04k
        cast<TemplateParmDecl>(SemaRef.SubstDecl(OldParam, DC, Args));
2316
1.04k
    assert(NewParam->getDepth() == 0 && "unexpected template param depth");
2317
0
    NewParam->setPosition(NewParam->getPosition() + Depth1IndexAdjustment);
2318
1.04k
    return NewParam;
2319
1.04k
  }
SemaTemplate.cpp:clang::TemplateTemplateParmDecl* (anonymous namespace)::ConvertConstructorToDeductionGuideTransform::transformTemplateParameterImpl<clang::TemplateTemplateParmDecl>(clang::TemplateTemplateParmDecl*, clang::MultiLevelTemplateArgumentList&)
Line
Count
Source
2311
284
                                 MultiLevelTemplateArgumentList &Args) {
2312
    // Ask the template instantiator to do the heavy lifting for us, then adjust
2313
    // the index of the parameter once it's done.
2314
284
    auto *NewParam =
2315
284
        cast<TemplateParmDecl>(SemaRef.SubstDecl(OldParam, DC, Args));
2316
284
    assert(NewParam->getDepth() == 0 && "unexpected template param depth");
2317
0
    NewParam->setPosition(NewParam->getPosition() + Depth1IndexAdjustment);
2318
284
    return NewParam;
2319
284
  }
SemaTemplate.cpp:clang::NonTypeTemplateParmDecl* (anonymous namespace)::ConvertConstructorToDeductionGuideTransform::transformTemplateParameterImpl<clang::NonTypeTemplateParmDecl>(clang::NonTypeTemplateParmDecl*, clang::MultiLevelTemplateArgumentList&)
Line
Count
Source
2311
764
                                 MultiLevelTemplateArgumentList &Args) {
2312
    // Ask the template instantiator to do the heavy lifting for us, then adjust
2313
    // the index of the parameter once it's done.
2314
764
    auto *NewParam =
2315
764
        cast<TemplateParmDecl>(SemaRef.SubstDecl(OldParam, DC, Args));
2316
764
    assert(NewParam->getDepth() == 0 && "unexpected template param depth");
2317
0
    NewParam->setPosition(NewParam->getPosition() + Depth1IndexAdjustment);
2318
764
    return NewParam;
2319
764
  }
2320
2321
  QualType transformFunctionProtoType(
2322
      TypeLocBuilder &TLB, FunctionProtoTypeLoc TL,
2323
      SmallVectorImpl<ParmVarDecl *> &Params,
2324
      MultiLevelTemplateArgumentList &Args,
2325
3.12k
      SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs) {
2326
3.12k
    SmallVector<QualType, 4> ParamTypes;
2327
3.12k
    const FunctionProtoType *T = TL.getTypePtr();
2328
2329
    //    -- The types of the function parameters are those of the constructor.
2330
6.08k
    for (auto *OldParam : TL.getParams()) {
2331
6.08k
      ParmVarDecl *NewParam =
2332
6.08k
          transformFunctionTypeParam(OldParam, Args, MaterializedTypedefs);
2333
6.08k
      if (!NewParam)
2334
0
        return QualType();
2335
6.08k
      ParamTypes.push_back(NewParam->getType());
2336
6.08k
      Params.push_back(NewParam);
2337
6.08k
    }
2338
2339
    //    -- The return type is the class template specialization designated by
2340
    //       the template-name and template arguments corresponding to the
2341
    //       template parameters obtained from the class template.
2342
    //
2343
    // We use the injected-class-name type of the primary template instead.
2344
    // This has the convenient property that it is different from any type that
2345
    // the user can write in a deduction-guide (because they cannot enter the
2346
    // context of the template), so implicit deduction guides can never collide
2347
    // with explicit ones.
2348
3.12k
    QualType ReturnType = DeducedType;
2349
3.12k
    TLB.pushTypeSpec(ReturnType).setNameLoc(Primary->getLocation());
2350
2351
    // Resolving a wording defect, we also inherit the variadicness of the
2352
    // constructor.
2353
3.12k
    FunctionProtoType::ExtProtoInfo EPI;
2354
3.12k
    EPI.Variadic = T->isVariadic();
2355
3.12k
    EPI.HasTrailingReturn = true;
2356
2357
3.12k
    QualType Result = SemaRef.BuildFunctionType(
2358
3.12k
        ReturnType, ParamTypes, TL.getBeginLoc(), DeductionGuideName, EPI);
2359
3.12k
    if (Result.isNull())
2360
0
      return QualType();
2361
2362
3.12k
    FunctionProtoTypeLoc NewTL = TLB.push<FunctionProtoTypeLoc>(Result);
2363
3.12k
    NewTL.setLocalRangeBegin(TL.getLocalRangeBegin());
2364
3.12k
    NewTL.setLParenLoc(TL.getLParenLoc());
2365
3.12k
    NewTL.setRParenLoc(TL.getRParenLoc());
2366
3.12k
    NewTL.setExceptionSpecRange(SourceRange());
2367
3.12k
    NewTL.setLocalRangeEnd(TL.getLocalRangeEnd());
2368
9.21k
    for (unsigned I = 0, E = NewTL.getNumParams(); I != E; 
++I6.08k
)
2369
6.08k
      NewTL.setParam(I, Params[I]);
2370
2371
3.12k
    return Result;
2372
3.12k
  }
2373
2374
  ParmVarDecl *transformFunctionTypeParam(
2375
      ParmVarDecl *OldParam, MultiLevelTemplateArgumentList &Args,
2376
6.08k
      llvm::SmallVectorImpl<TypedefNameDecl *> &MaterializedTypedefs) {
2377
6.08k
    TypeSourceInfo *OldDI = OldParam->getTypeSourceInfo();
2378
6.08k
    TypeSourceInfo *NewDI;
2379
6.08k
    if (auto PackTL = OldDI->getTypeLoc().getAs<PackExpansionTypeLoc>()) {
2380
      // Expand out the one and only element in each inner pack.
2381
150
      Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, 0);
2382
150
      NewDI =
2383
150
          SemaRef.SubstType(PackTL.getPatternLoc(), Args,
2384
150
                            OldParam->getLocation(), OldParam->getDeclName());
2385
150
      if (!NewDI) 
return nullptr0
;
2386
150
      NewDI =
2387
150
          SemaRef.CheckPackExpansion(NewDI, PackTL.getEllipsisLoc(),
2388
150
                                     PackTL.getTypePtr()->getNumExpansions());
2389
150
    } else
2390
5.93k
      NewDI = SemaRef.SubstType(OldDI, Args, OldParam->getLocation(),
2391
5.93k
                                OldParam->getDeclName());
2392
6.08k
    if (!NewDI)
2393
0
      return nullptr;
2394
2395
    // Extract the type. This (for instance) replaces references to typedef
2396
    // members of the current instantiations with the definitions of those
2397
    // typedefs, avoiding triggering instantiation of the deduced type during
2398
    // deduction.
2399
6.08k
    NewDI = ExtractTypeForDeductionGuide(SemaRef, MaterializedTypedefs)
2400
6.08k
                .transform(NewDI);
2401
2402
    // Resolving a wording defect, we also inherit default arguments from the
2403
    // constructor.
2404
6.08k
    ExprResult NewDefArg;
2405
6.08k
    if (OldParam->hasDefaultArg()) {
2406
      // We don't care what the value is (we won't use it); just create a
2407
      // placeholder to indicate there is a default argument.
2408
463
      QualType ParamTy = NewDI->getType();
2409
463
      NewDefArg = new (SemaRef.Context)
2410
463
          OpaqueValueExpr(OldParam->getDefaultArg()->getBeginLoc(),
2411
463
                          ParamTy.getNonLValueExprType(SemaRef.Context),
2412
463
                          ParamTy->isLValueReferenceType()   ? 
VK_LValue264
2413
463
                          : 
ParamTy->isRValueReferenceType()199
?
VK_XValue0
2414
199
                                                             : VK_PRValue);
2415
463
    }
2416
2417
6.08k
    ParmVarDecl *NewParam = ParmVarDecl::Create(SemaRef.Context, DC,
2418
6.08k
                                                OldParam->getInnerLocStart(),
2419
6.08k
                                                OldParam->getLocation(),
2420
6.08k
                                                OldParam->getIdentifier(),
2421
6.08k
                                                NewDI->getType(),
2422
6.08k
                                                NewDI,
2423
6.08k
                                                OldParam->getStorageClass(),
2424
6.08k
                                                NewDefArg.get());
2425
6.08k
    NewParam->setScopeInfo(OldParam->getFunctionScopeDepth(),
2426
6.08k
                           OldParam->getFunctionScopeIndex());
2427
6.08k
    SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldParam, NewParam);
2428
6.08k
    return NewParam;
2429
6.08k
  }
2430
2431
  FunctionTemplateDecl *buildDeductionGuide(
2432
      TemplateParameterList *TemplateParams, CXXConstructorDecl *Ctor,
2433
      ExplicitSpecifier ES, TypeSourceInfo *TInfo, SourceLocation LocStart,
2434
      SourceLocation Loc, SourceLocation LocEnd,
2435
3.67k
      llvm::ArrayRef<TypedefNameDecl *> MaterializedTypedefs = {}) {
2436
3.67k
    DeclarationNameInfo Name(DeductionGuideName, Loc);
2437
3.67k
    ArrayRef<ParmVarDecl *> Params =
2438
3.67k
        TInfo->getTypeLoc().castAs<FunctionProtoTypeLoc>().getParams();
2439
2440
    // Build the implicit deduction guide template.
2441
3.67k
    auto *Guide =
2442
3.67k
        CXXDeductionGuideDecl::Create(SemaRef.Context, DC, LocStart, ES, Name,
2443
3.67k
                                      TInfo->getType(), TInfo, LocEnd, Ctor);
2444
3.67k
    Guide->setImplicit();
2445
3.67k
    Guide->setParams(Params);
2446
2447
3.67k
    for (auto *Param : Params)
2448
6.55k
      Param->setDeclContext(Guide);
2449
3.67k
    for (auto *TD : MaterializedTypedefs)
2450
10.6k
      TD->setDeclContext(Guide);
2451
2452
3.67k
    auto *GuideTemplate = FunctionTemplateDecl::Create(
2453
3.67k
        SemaRef.Context, DC, Loc, DeductionGuideName, TemplateParams, Guide);
2454
3.67k
    GuideTemplate->setImplicit();
2455
3.67k
    Guide->setDescribedFunctionTemplate(GuideTemplate);
2456
2457
3.67k
    if (isa<CXXRecordDecl>(DC)) {
2458
30
      Guide->setAccess(AS_public);
2459
30
      GuideTemplate->setAccess(AS_public);
2460
30
    }
2461
2462
3.67k
    DC->addDecl(GuideTemplate);
2463
3.67k
    return GuideTemplate;
2464
3.67k
  }
2465
};
2466
}
2467
2468
void Sema::DeclareImplicitDeductionGuides(TemplateDecl *Template,
2469
2.00k
                                          SourceLocation Loc) {
2470
2.00k
  if (CXXRecordDecl *DefRecord =
2471
2.00k
          cast<CXXRecordDecl>(Template->getTemplatedDecl())->getDefinition()) {
2472
1.93k
    TemplateDecl *DescribedTemplate = DefRecord->getDescribedClassTemplate();
2473
1.93k
    Template = DescribedTemplate ? DescribedTemplate : 
Template0
;
2474
1.93k
  }
2475
2476
2.00k
  DeclContext *DC = Template->getDeclContext();
2477
2.00k
  if (DC->isDependentContext())
2478
4
    return;
2479
2480
2.00k
  ConvertConstructorToDeductionGuideTransform Transform(
2481
2.00k
      *this, cast<ClassTemplateDecl>(Template));
2482
2.00k
  if (!isCompleteType(Loc, Transform.DeducedType))
2483
0
    return;
2484
2485
  // Check whether we've already declared deduction guides for this template.
2486
  // FIXME: Consider storing a flag on the template to indicate this.
2487
2.00k
  auto Existing = DC->lookup(Transform.DeductionGuideName);
2488
2.00k
  for (auto *D : Existing)
2489
1.53k
    if (D->isImplicit())
2490
1.53k
      return;
2491
2492
  // In case we were expanding a pack when we attempted to declare deduction
2493
  // guides, turn off pack expansion for everything we're about to do.
2494
469
  ArgumentPackSubstitutionIndexRAII SubstIndex(*this, -1);
2495
  // Create a template instantiation record to track the "instantiation" of
2496
  // constructors into deduction guides.
2497
  // FIXME: Add a kind for this to give more meaningful diagnostics. But can
2498
  // this substitution process actually fail?
2499
469
  InstantiatingTemplate BuildingDeductionGuides(*this, Loc, Template);
2500
469
  if (BuildingDeductionGuides.isInvalid())
2501
1
    return;
2502
2503
  // Convert declared constructors into deduction guide templates.
2504
  // FIXME: Skip constructors for which deduction must necessarily fail (those
2505
  // for which some class template parameter without a default argument never
2506
  // appears in a deduced context).
2507
468
  bool AddedAny = false;
2508
3.13k
  for (NamedDecl *D : LookupConstructors(Transform.Primary)) {
2509
3.13k
    D = D->getUnderlyingDecl();
2510
3.13k
    if (D->isInvalidDecl() || 
D->isImplicit()3.13k
)
2511
1
      continue;
2512
3.13k
    D = cast<NamedDecl>(D->getCanonicalDecl());
2513
2514
3.13k
    auto *FTD = dyn_cast<FunctionTemplateDecl>(D);
2515
3.13k
    auto *CD =
2516
3.13k
        dyn_cast_or_null<CXXConstructorDecl>(FTD ? 
FTD->getTemplatedDecl()1.50k
:
D1.62k
);
2517
    // Class-scope explicit specializations (MS extension) do not result in
2518
    // deduction guides.
2519
3.13k
    if (!CD || (!FTD && 
CD->isFunctionTemplateSpecialization()1.62k
))
2520
0
      continue;
2521
2522
    // Cannot make a deduction guide when unparsed arguments are present.
2523
6.08k
    
if (3.13k
std::any_of(CD->param_begin(), CD->param_end(), [](ParmVarDecl *P) 3.13k
{
2524
6.08k
          return !P || P->hasUnparsedDefaultArg();
2525
6.08k
        }))
2526
1
      continue;
2527
2528
3.12k
    Transform.transformConstructor(FTD, CD);
2529
3.12k
    AddedAny = true;
2530
3.12k
  }
2531
2532
  // C++17 [over.match.class.deduct]
2533
  //    --  If C is not defined or does not declare any constructors, an
2534
  //    additional function template derived as above from a hypothetical
2535
  //    constructor C().
2536
468
  if (!AddedAny)
2537
79
    Transform.buildSimpleDeductionGuide(None);
2538
2539
  //    -- An additional function template derived as above from a hypothetical
2540
  //    constructor C(C), called the copy deduction candidate.
2541
468
  cast<CXXDeductionGuideDecl>(
2542
468
      cast<FunctionTemplateDecl>(
2543
468
          Transform.buildSimpleDeductionGuide(Transform.DeducedType))
2544
468
          ->getTemplatedDecl())
2545
468
      ->setIsCopyDeductionCandidate();
2546
468
}
2547
2548
/// Diagnose the presence of a default template argument on a
2549
/// template parameter, which is ill-formed in certain contexts.
2550
///
2551
/// \returns true if the default template argument should be dropped.
2552
static bool DiagnoseDefaultTemplateArgument(Sema &S,
2553
                                            Sema::TemplateParamListContext TPC,
2554
                                            SourceLocation ParamLoc,
2555
216k
                                            SourceRange DefArgRange) {
2556
216k
  switch (TPC) {
2557
85.5k
  case Sema::TPC_ClassTemplate:
2558
85.6k
  case Sema::TPC_VarTemplate:
2559
99.6k
  case Sema::TPC_TypeAliasTemplate:
2560
99.6k
    return false;
2561
2562
116k
  case Sema::TPC_FunctionTemplate:
2563
116k
  case Sema::TPC_FriendFunctionTemplateDefinition:
2564
    // C++ [temp.param]p9:
2565
    //   A default template-argument shall not be specified in a
2566
    //   function template declaration or a function template
2567
    //   definition [...]
2568
    //   If a friend function template declaration specifies a default
2569
    //   template-argument, that declaration shall be a definition and shall be
2570
    //   the only declaration of the function template in the translation unit.
2571
    // (C++98/03 doesn't have this wording; see DR226).
2572
116k
    S.Diag(ParamLoc, S.getLangOpts().CPlusPlus11 ?
2573
116k
         diag::warn_cxx98_compat_template_parameter_default_in_function_template
2574
116k
           : 
diag::ext_template_parameter_default_in_function_template39
)
2575
116k
      << DefArgRange;
2576
116k
    return false;
2577
2578
14
  case Sema::TPC_ClassTemplateMember:
2579
    // C++0x [temp.param]p9:
2580
    //   A default template-argument shall not be specified in the
2581
    //   template-parameter-lists of the definition of a member of a
2582
    //   class template that appears outside of the member's class.
2583
14
    S.Diag(ParamLoc, diag::err_template_parameter_default_template_member)
2584
14
      << DefArgRange;
2585
14
    return true;
2586
2587
8
  case Sema::TPC_FriendClassTemplate:
2588
10
  case Sema::TPC_FriendFunctionTemplate:
2589
    // C++ [temp.param]p9:
2590
    //   A default template-argument shall not be specified in a
2591
    //   friend template declaration.
2592
10
    S.Diag(ParamLoc, diag::err_template_parameter_default_friend_template)
2593
10
      << DefArgRange;
2594
10
    return true;
2595
2596
    // FIXME: C++0x [temp.param]p9 allows default template-arguments
2597
    // for friend function templates if there is only a single
2598
    // declaration (and it is a definition). Strange!
2599
216k
  }
2600
2601
0
  llvm_unreachable("Invalid TemplateParamListContext!");
2602
0
}
2603
2604
/// Check for unexpanded parameter packs within the template parameters
2605
/// of a template template parameter, recursively.
2606
static bool DiagnoseUnexpandedParameterPacks(Sema &S,
2607
15.6k
                                             TemplateTemplateParmDecl *TTP) {
2608
  // A template template parameter which is a parameter pack is also a pack
2609
  // expansion.
2610
15.6k
  if (TTP->isParameterPack())
2611
89
    return false;
2612
2613
15.5k
  TemplateParameterList *Params = TTP->getTemplateParameters();
2614
32.2k
  for (unsigned I = 0, N = Params->size(); I != N; 
++I16.6k
) {
2615
16.6k
    NamedDecl *P = Params->getParam(I);
2616
16.6k
    if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(P)) {
2617
15.9k
      if (!TTP->isParameterPack())
2618
1.84k
        if (const TypeConstraint *TC = TTP->getTypeConstraint())
2619
1
          if (TC->hasExplicitTemplateArgs())
2620
0
            for (auto &ArgLoc : TC->getTemplateArgsAsWritten()->arguments())
2621
0
              if (S.DiagnoseUnexpandedParameterPack(ArgLoc,
2622
0
                                                    Sema::UPPC_TypeConstraint))
2623
0
                return true;
2624
15.9k
      continue;
2625
15.9k
    }
2626
2627
742
    if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P)) {
2628
715
      if (!NTTP->isParameterPack() &&
2629
715
          S.DiagnoseUnexpandedParameterPack(NTTP->getLocation(),
2630
243
                                            NTTP->getTypeSourceInfo(),
2631
243
                                      Sema::UPPC_NonTypeTemplateParameterType))
2632
0
        return true;
2633
2634
715
      continue;
2635
715
    }
2636
2637
27
    if (TemplateTemplateParmDecl *InnerTTP
2638
27
                                        = dyn_cast<TemplateTemplateParmDecl>(P))
2639
27
      if (DiagnoseUnexpandedParameterPacks(S, InnerTTP))
2640
0
        return true;
2641
27
  }
2642
2643
15.5k
  return false;
2644
15.5k
}
2645
2646
/// Checks the validity of a template parameter list, possibly
2647
/// considering the template parameter list from a previous
2648
/// declaration.
2649
///
2650
/// If an "old" template parameter list is provided, it must be
2651
/// equivalent (per TemplateParameterListsAreEqual) to the "new"
2652
/// template parameter list.
2653
///
2654
/// \param NewParams Template parameter list for a new template
2655
/// declaration. This template parameter list will be updated with any
2656
/// default arguments that are carried through from the previous
2657
/// template parameter list.
2658
///
2659
/// \param OldParams If provided, template parameter list from a
2660
/// previous declaration of the same template. Default template
2661
/// arguments will be merged from the old template parameter list to
2662
/// the new template parameter list.
2663
///
2664
/// \param TPC Describes the context in which we are checking the given
2665
/// template parameter list.
2666
///
2667
/// \param SkipBody If we might have already made a prior merged definition
2668
/// of this template visible, the corresponding body-skipping information.
2669
/// Default argument redefinition is not an error when skipping such a body,
2670
/// because (under the ODR) we can assume the default arguments are the same
2671
/// as the prior merged definition.
2672
///
2673
/// \returns true if an error occurred, false otherwise.
2674
bool Sema::CheckTemplateParameterList(TemplateParameterList *NewParams,
2675
                                      TemplateParameterList *OldParams,
2676
                                      TemplateParamListContext TPC,
2677
1.53M
                                      SkipBodyInfo *SkipBody) {
2678
1.53M
  bool Invalid = false;
2679
2680
  // C++ [temp.param]p10:
2681
  //   The set of default template-arguments available for use with a
2682
  //   template declaration or definition is obtained by merging the
2683
  //   default arguments from the definition (if in scope) and all
2684
  //   declarations in scope in the same way default function
2685
  //   arguments are (8.3.6).
2686
1.53M
  bool SawDefaultArgument = false;
2687
1.53M
  SourceLocation PreviousDefaultArgLoc;
2688
2689
  // Dummy initialization to avoid warnings.
2690
1.53M
  TemplateParameterList::iterator OldParam = NewParams->end();
2691
1.53M
  if (OldParams)
2692
99.4k
    OldParam = OldParams->begin();
2693
2694
1.53M
  bool RemoveDefaultArguments = false;
2695
1.53M
  for (TemplateParameterList::iterator NewParam = NewParams->begin(),
2696
1.53M
                                    NewParamEnd = NewParams->end();
2697
4.56M
       NewParam != NewParamEnd; 
++NewParam3.02M
) {
2698
    // Whether we've seen a duplicate default argument in the same translation
2699
    // unit.
2700
3.02M
    bool RedundantDefaultArg = false;
2701
    // Whether we've found inconsis inconsitent default arguments in different
2702
    // translation unit.
2703
3.02M
    bool InconsistentDefaultArg = false;
2704
    // The name of the module which contains the inconsistent default argument.
2705
3.02M
    std::string PrevModuleName;
2706
2707
3.02M
    SourceLocation OldDefaultLoc;
2708
3.02M
    SourceLocation NewDefaultLoc;
2709
2710
    // Variable used to diagnose missing default arguments
2711
3.02M
    bool MissingDefaultArg = false;
2712
2713
    // Variable used to diagnose non-final parameter packs
2714
3.02M
    bool SawParameterPack = false;
2715
2716
3.02M
    if (TemplateTypeParmDecl *NewTypeParm
2717
3.02M
          = dyn_cast<TemplateTypeParmDecl>(*NewParam)) {
2718
      // Check the presence of a default argument here.
2719
2.77M
      if (NewTypeParm->hasDefaultArgument() &&
2720
2.77M
          DiagnoseDefaultTemplateArgument(*this, TPC,
2721
128k
                                          NewTypeParm->getLocation(),
2722
128k
               NewTypeParm->getDefaultArgumentInfo()->getTypeLoc()
2723
128k
                                                       .getSourceRange()))
2724
22
        NewTypeParm->removeDefaultArgument();
2725
2726
      // Merge default arguments for template type parameters.
2727
2.77M
      TemplateTypeParmDecl *OldTypeParm
2728
2.77M
          = OldParams? 
cast<TemplateTypeParmDecl>(*OldParam)146k
:
nullptr2.63M
;
2729
2.77M
      if (NewTypeParm->isParameterPack()) {
2730
120k
        assert(!NewTypeParm->hasDefaultArgument() &&
2731
120k
               "Parameter packs can't have a default argument!");
2732
0
        SawParameterPack = true;
2733
2.65M
      } else if (OldTypeParm && 
hasVisibleDefaultArgument(OldTypeParm)137k
&&
2734
2.65M
                 
NewTypeParm->hasDefaultArgument()19.4k
&&
2735
2.65M
                 
(5
!SkipBody5
||
!SkipBody->ShouldSkip3
)) {
2736
3
        OldDefaultLoc = OldTypeParm->getDefaultArgumentLoc();
2737
3
        NewDefaultLoc = NewTypeParm->getDefaultArgumentLoc();
2738
3
        SawDefaultArgument = true;
2739
2740
3
        if (!OldTypeParm->getOwningModule() ||
2741
3
            
isModuleUnitOfCurrentTU(OldTypeParm->getOwningModule())2
)
2742
1
          RedundantDefaultArg = true;
2743
2
        else if (!getASTContext().isSameDefaultTemplateArgument(OldTypeParm,
2744
2
                                                                NewTypeParm)) {
2745
1
          InconsistentDefaultArg = true;
2746
1
          PrevModuleName =
2747
1
              OldTypeParm->getImportedOwningModule()->getFullModuleName();
2748
1
        }
2749
3
        PreviousDefaultArgLoc = NewDefaultLoc;
2750
2.65M
      } else if (OldTypeParm && 
OldTypeParm->hasDefaultArgument()137k
) {
2751
        // Merge the default argument from the old declaration to the
2752
        // new declaration.
2753
19.6k
        NewTypeParm->setInheritedDefaultArgument(Context, OldTypeParm);
2754
19.6k
        PreviousDefaultArgLoc = OldTypeParm->getDefaultArgumentLoc();
2755
2.63M
      } else if (NewTypeParm->hasDefaultArgument()) {
2756
128k
        SawDefaultArgument = true;
2757
128k
        PreviousDefaultArgLoc = NewTypeParm->getDefaultArgumentLoc();
2758
2.51M
      } else if (SawDefaultArgument)
2759
213
        MissingDefaultArg = true;
2760
2.77M
    } else 
if (NonTypeTemplateParmDecl *249k
NewNonTypeParm249k
2761
249k
               = dyn_cast<NonTypeTemplateParmDecl>(*NewParam)) {
2762
      // Check for unexpanded parameter packs.
2763
233k
      if (!NewNonTypeParm->isParameterPack() &&
2764
233k
          DiagnoseUnexpandedParameterPack(NewNonTypeParm->getLocation(),
2765
223k
                                          NewNonTypeParm->getTypeSourceInfo(),
2766
223k
                                          UPPC_NonTypeTemplateParameterType)) {
2767
1
        Invalid = true;
2768
1
        continue;
2769
1
      }
2770
2771
      // Check the presence of a default argument here.
2772
233k
      if (NewNonTypeParm->hasDefaultArgument() &&
2773
233k
          DiagnoseDefaultTemplateArgument(*this, TPC,
2774
78.2k
                                          NewNonTypeParm->getLocation(),
2775
78.2k
                    NewNonTypeParm->getDefaultArgument()->getSourceRange())) {
2776
1
        NewNonTypeParm->removeDefaultArgument();
2777
1
      }
2778
2779
      // Merge default arguments for non-type template parameters
2780
233k
      NonTypeTemplateParmDecl *OldNonTypeParm
2781
233k
        = OldParams? 
cast<NonTypeTemplateParmDecl>(*OldParam)21.0k
:
nullptr212k
;
2782
233k
      if (NewNonTypeParm->isParameterPack()) {
2783
10.6k
        assert(!NewNonTypeParm->hasDefaultArgument() &&
2784
10.6k
               "Parameter packs can't have a default argument!");
2785
10.6k
        if (!NewNonTypeParm->isPackExpansion())
2786
10.5k
          SawParameterPack = true;
2787
223k
      } else if (OldNonTypeParm && 
hasVisibleDefaultArgument(OldNonTypeParm)20.0k
&&
2788
223k
                 
NewNonTypeParm->hasDefaultArgument()1.02k
&&
2789
223k
                 
(15
!SkipBody15
||
!SkipBody->ShouldSkip1
)) {
2790
15
        OldDefaultLoc = OldNonTypeParm->getDefaultArgumentLoc();
2791
15
        NewDefaultLoc = NewNonTypeParm->getDefaultArgumentLoc();
2792
15
        SawDefaultArgument = true;
2793
15
        if (!OldNonTypeParm->getOwningModule() ||
2794
15
            
isModuleUnitOfCurrentTU(OldNonTypeParm->getOwningModule())14
)
2795
1
          RedundantDefaultArg = true;
2796
14
        else if (!getASTContext().isSameDefaultTemplateArgument(
2797
14
                     OldNonTypeParm, NewNonTypeParm)) {
2798
7
          InconsistentDefaultArg = true;
2799
7
          PrevModuleName =
2800
7
              OldNonTypeParm->getImportedOwningModule()->getFullModuleName();
2801
7
        }
2802
15
        PreviousDefaultArgLoc = NewDefaultLoc;
2803
223k
      } else if (OldNonTypeParm && 
OldNonTypeParm->hasDefaultArgument()20.0k
) {
2804
        // Merge the default argument from the old declaration to the
2805
        // new declaration.
2806
1.03k
        NewNonTypeParm->setInheritedDefaultArgument(Context, OldNonTypeParm);
2807
1.03k
        PreviousDefaultArgLoc = OldNonTypeParm->getDefaultArgumentLoc();
2808
222k
      } else if (NewNonTypeParm->hasDefaultArgument()) {
2809
78.2k
        SawDefaultArgument = true;
2810
78.2k
        PreviousDefaultArgLoc = NewNonTypeParm->getDefaultArgumentLoc();
2811
143k
      } else if (SawDefaultArgument)
2812
7
        MissingDefaultArg = true;
2813
233k
    } else {
2814
15.6k
      TemplateTemplateParmDecl *NewTemplateParm
2815
15.6k
        = cast<TemplateTemplateParmDecl>(*NewParam);
2816
2817
      // Check for unexpanded parameter packs, recursively.
2818
15.6k
      if (::DiagnoseUnexpandedParameterPacks(*this, NewTemplateParm)) {
2819
0
        Invalid = true;
2820
0
        continue;
2821
0
      }
2822
2823
      // Check the presence of a default argument here.
2824
15.6k
      if (NewTemplateParm->hasDefaultArgument() &&
2825
15.6k
          DiagnoseDefaultTemplateArgument(*this, TPC,
2826
9.33k
                                          NewTemplateParm->getLocation(),
2827
9.33k
                     NewTemplateParm->getDefaultArgument().getSourceRange()))
2828
1
        NewTemplateParm->removeDefaultArgument();
2829
2830
      // Merge default arguments for template template parameters
2831
15.6k
      TemplateTemplateParmDecl *OldTemplateParm
2832
15.6k
        = OldParams? 
cast<TemplateTemplateParmDecl>(*OldParam)78
:
nullptr15.5k
;
2833
15.6k
      if (NewTemplateParm->isParameterPack()) {
2834
89
        assert(!NewTemplateParm->hasDefaultArgument() &&
2835
89
               "Parameter packs can't have a default argument!");
2836
89
        if (!NewTemplateParm->isPackExpansion())
2837
80
          SawParameterPack = true;
2838
15.5k
      } else if (OldTemplateParm &&
2839
15.5k
                 
hasVisibleDefaultArgument(OldTemplateParm)78
&&
2840
15.5k
                 
NewTemplateParm->hasDefaultArgument()32
&&
2841
15.5k
                 
(3
!SkipBody3
||
!SkipBody->ShouldSkip1
)) {
2842
3
        OldDefaultLoc = OldTemplateParm->getDefaultArgument().getLocation();
2843
3
        NewDefaultLoc = NewTemplateParm->getDefaultArgument().getLocation();
2844
3
        SawDefaultArgument = true;
2845
3
        if (!OldTemplateParm->getOwningModule() ||
2846
3
            
isModuleUnitOfCurrentTU(OldTemplateParm->getOwningModule())2
)
2847
1
          RedundantDefaultArg = true;
2848
2
        else if (!getASTContext().isSameDefaultTemplateArgument(
2849
2
                     OldTemplateParm, NewTemplateParm)) {
2850
1
          InconsistentDefaultArg = true;
2851
1
          PrevModuleName =
2852
1
              OldTemplateParm->getImportedOwningModule()->getFullModuleName();
2853
1
        }
2854
3
        PreviousDefaultArgLoc = NewDefaultLoc;
2855
15.5k
      } else if (OldTemplateParm && 
OldTemplateParm->hasDefaultArgument()75
) {
2856
        // Merge the default argument from the old declaration to the
2857
        // new declaration.
2858
56
        NewTemplateParm->setInheritedDefaultArgument(Context, OldTemplateParm);
2859
56
        PreviousDefaultArgLoc
2860
56
          = OldTemplateParm->getDefaultArgument().getLocation();
2861
15.5k
      } else if (NewTemplateParm->hasDefaultArgument()) {
2862
9.30k
        SawDefaultArgument = true;
2863
9.30k
        PreviousDefaultArgLoc
2864
9.30k
          = NewTemplateParm->getDefaultArgument().getLocation();
2865
9.30k
      } else 
if (6.19k
SawDefaultArgument6.19k
)
2866
5
        MissingDefaultArg = true;
2867
15.6k
    }
2868
2869
    // C++11 [temp.param]p11:
2870
    //   If a template parameter of a primary class template or alias template
2871
    //   is a template parameter pack, it shall be the last template parameter.
2872
3.02M
    if (SawParameterPack && 
(NewParam + 1) != NewParamEnd130k
&&
2873
3.02M
        
(26.9k
TPC == TPC_ClassTemplate26.9k
||
TPC == TPC_VarTemplate26.8k
||
2874
26.9k
         
TPC == TPC_TypeAliasTemplate26.8k
)) {
2875
7
      Diag((*NewParam)->getLocation(),
2876
7
           diag::err_template_param_pack_must_be_last_template_parameter);
2877
7
      Invalid = true;
2878
7
    }
2879
2880
    // [basic.def.odr]/13:
2881
    //     There can be more than one definition of a
2882
    //     ...
2883
    //     default template argument
2884
    //     ...
2885
    //     in a program provided that each definition appears in a different
2886
    //     translation unit and the definitions satisfy the [same-meaning
2887
    //     criteria of the ODR].
2888
    //
2889
    // Simply, the design of modules allows the definition of template default
2890
    // argument to be repeated across translation unit. Note that the ODR is
2891
    // checked elsewhere. But it is still not allowed to repeat template default
2892
    // argument in the same translation unit.
2893
3.02M
    if (RedundantDefaultArg) {
2894
3
      Diag(NewDefaultLoc, diag::err_template_param_default_arg_redefinition);
2895
3
      Diag(OldDefaultLoc, diag::note_template_param_prev_default_arg);
2896
3
      Invalid = true;
2897
3.02M
    } else if (InconsistentDefaultArg) {
2898
      // We could only diagnose about the case that the OldParam is imported.
2899
      // The case NewParam is imported should be handled in ASTReader.
2900
9
      Diag(NewDefaultLoc,
2901
9
           diag::err_template_param_default_arg_inconsistent_redefinition);
2902
9
      Diag(OldDefaultLoc,
2903
9
           diag::note_template_param_prev_default_arg_in_other_module)
2904
9
          << PrevModuleName;
2905
9
      Invalid = true;
2906
3.02M
    } else if (MissingDefaultArg && 
TPC != TPC_FunctionTemplate225
) {
2907
      // C++ [temp.param]p11:
2908
      //   If a template-parameter of a class template has a default
2909
      //   template-argument, each subsequent template-parameter shall either
2910
      //   have a default template-argument supplied or be a template parameter
2911
      //   pack.
2912
17
      Diag((*NewParam)->getLocation(),
2913
17
           diag::err_template_param_default_arg_missing);
2914
17
      Diag(PreviousDefaultArgLoc, diag::note_template_param_prev_default_arg);
2915
17
      Invalid = true;
2916
17
      RemoveDefaultArguments = true;
2917
17
    }
2918
2919
    // If we have an old template parameter list that we're merging
2920
    // in, move on to the next parameter.
2921
3.02M
    if (OldParams)
2922
167k
      ++OldParam;
2923
3.02M
  }
2924
2925
  // We were missing some default arguments at the end of the list, so remove
2926
  // all of the default arguments.
2927
1.53M
  if (RemoveDefaultArguments) {
2928
17
    for (TemplateParameterList::iterator NewParam = NewParams->begin(),
2929
17
                                      NewParamEnd = NewParams->end();
2930
55
         NewParam != NewParamEnd; 
++NewParam38
) {
2931
38
      if (TemplateTypeParmDecl *TTP = dyn_cast<TemplateTypeParmDecl>(*NewParam))
2932
24
        TTP->removeDefaultArgument();
2933
14
      else if (NonTypeTemplateParmDecl *NTTP
2934
14
                                = dyn_cast<NonTypeTemplateParmDecl>(*NewParam))
2935
8
        NTTP->removeDefaultArgument();
2936
6
      else
2937
6
        cast<TemplateTemplateParmDecl>(*NewParam)->removeDefaultArgument();
2938
38
    }
2939
17
  }
2940
2941
1.53M
  return Invalid;
2942
1.53M
}
2943
2944
namespace {
2945
2946
/// A class which looks for a use of a certain level of template
2947
/// parameter.
2948
struct DependencyChecker : RecursiveASTVisitor<DependencyChecker> {
2949
  typedef RecursiveASTVisitor<DependencyChecker> super;
2950
2951
  unsigned Depth;
2952
2953
  // Whether we're looking for a use of a template parameter that makes the
2954
  // overall construct type-dependent / a dependent type. This is strictly
2955
  // best-effort for now; we may fail to match at all for a dependent type
2956
  // in some cases if this is set.
2957
  bool IgnoreNonTypeDependent;
2958
2959
  bool Match;
2960
  SourceLocation MatchLoc;
2961
2962
  DependencyChecker(unsigned Depth, bool IgnoreNonTypeDependent)
2963
      : Depth(Depth), IgnoreNonTypeDependent(IgnoreNonTypeDependent),
2964
18
        Match(false) {}
2965
2966
  DependencyChecker(TemplateParameterList *Params, bool IgnoreNonTypeDependent)
2967
48
      : IgnoreNonTypeDependent(IgnoreNonTypeDependent), Match(false) {
2968
48
    NamedDecl *ND = Params->getParam(0);
2969
48
    if (TemplateTypeParmDecl *PD = dyn_cast<TemplateTypeParmDecl>(ND)) {
2970
41
      Depth = PD->getDepth();
2971
41
    } else 
if (NonTypeTemplateParmDecl *7
PD7
=
2972
7
                 dyn_cast<NonTypeTemplateParmDecl>(ND)) {
2973
5
      Depth = PD->getDepth();
2974
5
    } else {
2975
2
      Depth = cast<TemplateTemplateParmDecl>(ND)->getDepth();
2976
2
    }
2977
48
  }
2978
2979
64
  bool Matches(unsigned ParmDepth, SourceLocation Loc = SourceLocation()) {
2980
64
    if (ParmDepth >= Depth) {
2981
52
      Match = true;
2982
52
      MatchLoc = Loc;
2983
52
      return true;
2984
52
    }
2985
12
    return false;
2986
64
  }
2987
2988
35
  bool TraverseStmt(Stmt *S, DataRecursionQueue *Q = nullptr) {
2989
    // Prune out non-type-dependent expressions if requested. This can
2990
    // sometimes result in us failing to find a template parameter reference
2991
    // (if a value-dependent expression creates a dependent type), but this
2992
    // mode is best-effort only.
2993
35
    if (auto *E = dyn_cast_or_null<Expr>(S))
2994
35
      if (IgnoreNonTypeDependent && 
!E->isTypeDependent()34
)
2995
16
        return true;
2996
19
    return super::TraverseStmt(S, Q);
2997
35
  }
2998
2999
36
  bool TraverseTypeLoc(TypeLoc TL) {
3000
36
    if (IgnoreNonTypeDependent && !TL.isNull() &&
3001
36
        !TL.getType()->isDependentType())
3002
6
      return true;
3003
30
    return super::TraverseTypeLoc(TL);
3004
36
  }
3005
3006
11
  bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
3007
11
    return !Matches(TL.getTypePtr()->getDepth(), TL.getNameLoc());
3008
11
  }
3009
3010
50
  bool VisitTemplateTypeParmType(const TemplateTypeParmType *T) {
3011
    // For a best-effort search, keep looking until we find a location.
3012
50
    return IgnoreNonTypeDependent || !Matches(T->getDepth());
3013
50
  }
3014
3015
50
  bool TraverseTemplateName(TemplateName N) {
3016
50
    if (TemplateTemplateParmDecl *PD =
3017
50
          dyn_cast_or_null<TemplateTemplateParmDecl>(N.getAsTemplateDecl()))
3018
1
      if (Matches(PD->getDepth()))
3019
1
        return false;
3020
49
    return super::TraverseTemplateName(N);
3021
50
  }
3022
3023
2
  bool VisitDeclRefExpr(DeclRefExpr *E) {
3024
2
    if (NonTypeTemplateParmDecl *PD =
3025
2
          dyn_cast<NonTypeTemplateParmDecl>(E->getDecl()))
3026
2
      if (Matches(PD->getDepth(), E->getExprLoc()))
3027
1
        return false;
3028
1
    return super::VisitDeclRefExpr(E);
3029
2
  }
3030
3031
0
  bool VisitSubstTemplateTypeParmType(const SubstTemplateTypeParmType *T) {
3032
0
    return TraverseType(T->getReplacementType());
3033
0
  }
3034
3035
  bool
3036
0
  VisitSubstTemplateTypeParmPackType(const SubstTemplateTypeParmPackType *T) {
3037
0
    return TraverseTemplateArgument(T->getArgumentPack());
3038
0
  }
3039
3040
43
  bool TraverseInjectedClassNameType(const InjectedClassNameType *T) {
3041
43
    return TraverseType(T->getInjectedSpecializationType());
3042
43
  }
3043
};
3044
} // end anonymous namespace
3045
3046
/// Determines whether a given type depends on the given parameter
3047
/// list.
3048
static bool
3049
48
DependsOnTemplateParameters(QualType T, TemplateParameterList *Params) {
3050
48
  if (!Params->size())
3051
0
    return false;
3052
3053
48
  DependencyChecker Checker(Params, /*IgnoreNonTypeDependent*/false);
3054
48
  Checker.TraverseType(T);
3055
48
  return Checker.Match;
3056
48
}
3057
3058
// Find the source range corresponding to the named type in the given
3059
// nested-name-specifier, if any.
3060
static SourceRange getRangeOfTypeInNestedNameSpecifier(ASTContext &Context,
3061
                                                       QualType T,
3062
56
                                                       const CXXScopeSpec &SS) {
3063
56
  NestedNameSpecifierLoc NNSLoc(SS.getScopeRep(), SS.location_data());
3064
66
  while (NestedNameSpecifier *NNS = NNSLoc.getNestedNameSpecifier()) {
3065
65
    if (const Type *CurType = NNS->getAsType()) {
3066
65
      if (Context.hasSameUnqualifiedType(T, QualType(CurType, 0)))
3067
55
        return NNSLoc.getTypeLoc().getSourceRange();
3068
65
    } else
3069
0
      break;
3070
3071
10
    NNSLoc = NNSLoc.getPrefix();
3072
10
  }
3073
3074
1
  return SourceRange();
3075
56
}
3076
3077
/// Match the given template parameter lists to the given scope
3078
/// specifier, returning the template parameter list that applies to the
3079
/// name.
3080
///
3081
/// \param DeclStartLoc the start of the declaration that has a scope
3082
/// specifier or a template parameter list.
3083
///
3084
/// \param DeclLoc The location of the declaration itself.
3085
///
3086
/// \param SS the scope specifier that will be matched to the given template
3087
/// parameter lists. This scope specifier precedes a qualified name that is
3088
/// being declared.
3089
///
3090
/// \param TemplateId The template-id following the scope specifier, if there
3091
/// is one. Used to check for a missing 'template<>'.
3092
///
3093
/// \param ParamLists the template parameter lists, from the outermost to the
3094
/// innermost template parameter lists.
3095
///
3096
/// \param IsFriend Whether to apply the slightly different rules for
3097
/// matching template parameters to scope specifiers in friend
3098
/// declarations.
3099
///
3100
/// \param IsMemberSpecialization will be set true if the scope specifier
3101
/// denotes a fully-specialized type, and therefore this is a declaration of
3102
/// a member specialization.
3103
///
3104
/// \returns the template parameter list, if any, that corresponds to the
3105
/// name that is preceded by the scope specifier @p SS. This template
3106
/// parameter list may have template parameters (if we're declaring a
3107
/// template) or may have no template parameters (if we're declaring a
3108
/// template specialization), or may be NULL (if what we're declaring isn't
3109
/// itself a template).
3110
TemplateParameterList *Sema::MatchTemplateParametersToScopeSpecifier(
3111
    SourceLocation DeclStartLoc, SourceLocation DeclLoc, const CXXScopeSpec &SS,
3112
    TemplateIdAnnotation *TemplateId,
3113
    ArrayRef<TemplateParameterList *> ParamLists, bool IsFriend,
3114
13.9M
    bool &IsMemberSpecialization, bool &Invalid, bool SuppressDiagnostic) {
3115
13.9M
  IsMemberSpecialization = false;
3116
13.9M
  Invalid = false;
3117
3118
  // The sequence of nested types to which we will match up the template
3119
  // parameter lists. We first build this list by starting with the type named
3120
  // by the nested-name-specifier and walking out until we run out of types.
3121
13.9M
  SmallVector<QualType, 4> NestedTypes;
3122
13.9M
  QualType T;
3123
13.9M
  if (SS.getScopeRep()) {
3124
470k
    if (CXXRecordDecl *Record
3125
470k
              = dyn_cast_or_null<CXXRecordDecl>(computeDeclContext(SS, true)))
3126
469k
      T = Context.getTypeDeclType(Record);
3127
1.66k
    else
3128
1.66k
      T = QualType(SS.getScopeRep()->getAsType(), 0);
3129
470k
  }
3130
3131
  // If we found an explicit specialization that prevents us from needing
3132
  // 'template<>' headers, this will be set to the location of that
3133
  // explicit specialization.
3134
13.9M
  SourceLocation ExplicitSpecLoc;
3135
3136
14.4M
  while (!T.isNull()) {
3137
471k
    NestedTypes.push_back(T);
3138
3139
    // Retrieve the parent of a record type.
3140
471k
    if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
3141
      // If this type is an explicit specialization, we're done.
3142
471k
      if (ClassTemplateSpecializationDecl *Spec
3143
471k
          = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
3144
108k
        if (!isa<ClassTemplatePartialSpecializationDecl>(Spec) &&
3145
108k
            
Spec->getSpecializationKind() == TSK_ExplicitSpecialization10.9k
) {
3146
4.29k
          ExplicitSpecLoc = Spec->getLocation();
3147
4.29k
          break;
3148
4.29k
        }
3149
362k
      } else if (Record->getTemplateSpecializationKind()
3150
362k
                                                == TSK_ExplicitSpecialization) {
3151
8
        ExplicitSpecLoc = Record->getLocation();
3152
8
        break;
3153
8
      }
3154
3155
466k
      if (TypeDecl *Parent = dyn_cast<TypeDecl>(Record->getParent()))
3156
2.00k
        T = Context.getTypeDeclType(Parent);
3157
464k
      else
3158
464k
        T = QualType();
3159
466k
      continue;
3160
471k
    }
3161
3162
58
    if (const TemplateSpecializationType *TST
3163
58
                                     = T->getAs<TemplateSpecializationType>()) {
3164
29
      if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
3165
29
        if (TypeDecl *Parent = dyn_cast<TypeDecl>(Template->getDeclContext()))
3166
16
          T = Context.getTypeDeclType(Parent);
3167
13
        else
3168
13
          T = QualType();
3169
29
        continue;
3170
29
      }
3171
29
    }
3172
3173
    // Look one step prior in a dependent template specialization type.
3174
29
    if (const DependentTemplateSpecializationType *DependentTST
3175
29
                          = T->getAs<DependentTemplateSpecializationType>()) {
3176
0
      if (NestedNameSpecifier *NNS = DependentTST->getQualifier())
3177
0
        T = QualType(NNS->getAsType(), 0);
3178
0
      else
3179
0
        T = QualType();
3180
0
      continue;
3181
0
    }
3182
3183
    // Look one step prior in a dependent name type.
3184
29
    if (const DependentNameType *DependentName = T->getAs<DependentNameType>()){
3185
0
      if (NestedNameSpecifier *NNS = DependentName->getQualifier())
3186
0
        T = QualType(NNS->getAsType(), 0);
3187
0
      else
3188
0
        T = QualType();
3189
0
      continue;
3190
0
    }
3191
3192
    // Retrieve the parent of an enumeration type.
3193
29
    if (const EnumType *EnumT = T->getAs<EnumType>()) {
3194
      // FIXME: Forward-declared enums require a TSK_ExplicitSpecialization
3195
      // check here.
3196
8
      EnumDecl *Enum = EnumT->getDecl();
3197
3198
      // Get to the parent type.
3199
8
      if (TypeDecl *Parent = dyn_cast<TypeDecl>(Enum->getParent()))
3200
0
        T = Context.getTypeDeclType(Parent);
3201
8
      else
3202
8
        T = QualType();
3203
8
      continue;
3204
8
    }
3205
3206
21
    T = QualType();
3207
21
  }
3208
  // Reverse the nested types list, since we want to traverse from the outermost
3209
  // to the innermost while checking template-parameter-lists.
3210
13.9M
  std::reverse(NestedTypes.begin(), NestedTypes.end());
3211
3212
  // C++0x [temp.expl.spec]p17:
3213
  //   A member or a member template may be nested within many
3214
  //   enclosing class templates. In an explicit specialization for
3215
  //   such a member, the member declaration shall be preceded by a
3216
  //   template<> for each enclosing class template that is
3217
  //   explicitly specialized.
3218
13.9M
  bool SawNonEmptyTemplateParameterList = false;
3219
3220
13.9M
  auto CheckExplicitSpecialization = [&](SourceRange Range, bool Recovery) {
3221
86.7k
    if (SawNonEmptyTemplateParameterList) {
3222
19
      if (!SuppressDiagnostic)
3223
4
        Diag(DeclLoc, diag::err_specialize_member_of_template)
3224
4
          << !Recovery << Range;
3225
19
      Invalid = true;
3226
19
      IsMemberSpecialization = false;
3227
19
      return true;
3228
19
    }
3229
3230
86.7k
    return false;
3231
86.7k
  };
3232
3233
13.9M
  auto DiagnoseMissingExplicitSpecialization = [&] (SourceRange Range) {
3234
    // Check that we can have an explicit specialization here.
3235
62
    if (CheckExplicitSpecialization(Range, true))
3236
3
      return true;
3237
3238
    // We don't have a template header, but we should.
3239
59
    SourceLocation ExpectedTemplateLoc;
3240
59
    if (!ParamLists.empty())
3241
10
      ExpectedTemplateLoc = ParamLists[0]->getTemplateLoc();
3242
49
    else
3243
49
      ExpectedTemplateLoc = DeclStartLoc;
3244
3245
59
    if (!SuppressDiagnostic)
3246
54
      Diag(DeclLoc, diag::err_template_spec_needs_header)
3247
54
        << Range
3248
54
        << FixItHint::CreateInsertion(ExpectedTemplateLoc, "template<> ");
3249
59
    return false;
3250
62
  };
3251
3252
13.9M
  unsigned ParamIdx = 0;
3253
14.4M
  for (unsigned TypeIdx = 0, NumTypes = NestedTypes.size(); TypeIdx != NumTypes;
3254
13.9M
       
++TypeIdx471k
) {
3255
471k
    T = NestedTypes[TypeIdx];
3256
3257
    // Whether we expect a 'template<>' header.
3258
471k
    bool NeedEmptyTemplateHeader = false;
3259
3260
    // Whether we expect a template header with parameters.
3261
471k
    bool NeedNonemptyTemplateHeader = false;
3262
3263
    // For a dependent type, the set of template parameters that we
3264
    // expect to see.
3265
471k
    TemplateParameterList *ExpectedTemplateParams = nullptr;
3266
3267
    // C++0x [temp.expl.spec]p15:
3268
    //   A member or a member template may be nested within many enclosing
3269
    //   class templates. In an explicit specialization for such a member, the
3270
    //   member declaration shall be preceded by a template<> for each
3271
    //   enclosing class template that is explicitly specialized.
3272
471k
    if (CXXRecordDecl *Record = T->getAsCXXRecordDecl()) {
3273
471k
      if (ClassTemplatePartialSpecializationDecl *Partial
3274
471k
            = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record)) {
3275
97.6k
        ExpectedTemplateParams = Partial->getTemplateParameters();
3276
97.6k
        NeedNonemptyTemplateHeader = true;
3277
373k
      } else if (Record->isDependentType()) {
3278
344k
        if (Record->getDescribedClassTemplate()) {
3279
343k
          ExpectedTemplateParams = Record->getDescribedClassTemplate()
3280
343k
                                                      ->getTemplateParameters();
3281
343k
          NeedNonemptyTemplateHeader = true;
3282
343k
        }
3283
344k
      } else 
if (ClassTemplateSpecializationDecl *28.9k
Spec28.9k
3284
28.9k
                     = dyn_cast<ClassTemplateSpecializationDecl>(Record)) {
3285
        // C++0x [temp.expl.spec]p4:
3286
        //   Members of an explicitly specialized class template are defined
3287
        //   in the same manner as members of normal classes, and not using
3288
        //   the template<> syntax.
3289
10.9k
        if (Spec->getSpecializationKind() != TSK_ExplicitSpecialization)
3290
6.66k
          NeedEmptyTemplateHeader = true;
3291
4.29k
        else
3292
4.29k
          continue;
3293
18.0k
      } else if (Record->getTemplateSpecializationKind()) {
3294
9
        if (Record->getTemplateSpecializationKind()
3295
9
                                                != TSK_ExplicitSpecialization &&
3296
9
            
TypeIdx == NumTypes - 11
)
3297
1
          IsMemberSpecialization = true;
3298
3299
9
        continue;
3300
9
      }
3301
471k
    } else 
if (const TemplateSpecializationType *58
TST58
3302
58
                                     = T->getAs<TemplateSpecializationType>()) {
3303
29
      if (TemplateDecl *Template = TST->getTemplateName().getAsTemplateDecl()) {
3304
29
        ExpectedTemplateParams = Template->getTemplateParameters();
3305
29
        NeedNonemptyTemplateHeader = true;
3306
29
      }
3307
29
    } else if (T->getAs<DependentTemplateSpecializationType>()) {
3308
      // FIXME:  We actually could/should check the template arguments here
3309
      // against the corresponding template parameter list.
3310
0
      NeedNonemptyTemplateHeader = false;
3311
0
    }
3312
3313
    // C++ [temp.expl.spec]p16:
3314
    //   In an explicit specialization declaration for a member of a class
3315
    //   template or a member template that ap- pears in namespace scope, the
3316
    //   member template and some of its enclosing class templates may remain
3317
    //   unspecialized, except that the declaration shall not explicitly
3318
    //   specialize a class member template if its en- closing class templates
3319
    //   are not explicitly specialized as well.
3320
467k
    if (ParamIdx < ParamLists.size()) {
3321
455k
      if (ParamLists[ParamIdx]->size() == 0) {
3322
7.66k
        if (CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
3323
7.66k
                                        false))
3324
14
          return nullptr;
3325
7.66k
      } else
3326
447k
        SawNonEmptyTemplateParameterList = true;
3327
455k
    }
3328
3329
467k
    if (NeedEmptyTemplateHeader) {
3330
      // If we're on the last of the types, and we need a 'template<>' header
3331
      // here, then it's a member specialization.
3332
6.66k
      if (TypeIdx == NumTypes - 1)
3333
6.54k
        IsMemberSpecialization = true;
3334
3335
6.66k
      if (ParamIdx < ParamLists.size()) {
3336
6.58k
        if (ParamLists[ParamIdx]->size() > 0) {
3337
          // The header has template parameters when it shouldn't. Complain.
3338
39
          if (!SuppressDiagnostic)
3339
22
            Diag(ParamLists[ParamIdx]->getTemplateLoc(),
3340
22
                 diag::err_template_param_list_matches_nontemplate)
3341
22
              << T
3342
22
              << SourceRange(ParamLists[ParamIdx]->getLAngleLoc(),
3343
22
                             ParamLists[ParamIdx]->getRAngleLoc())
3344
22
              << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
3345
39
          Invalid = true;
3346
39
          return nullptr;
3347
39
        }
3348
3349
        // Consume this template header.
3350
6.55k
        ++ParamIdx;
3351
6.55k
        continue;
3352
6.58k
      }
3353
3354
75
      if (!IsFriend)
3355
33
        if (DiagnoseMissingExplicitSpecialization(
3356
33
                getRangeOfTypeInNestedNameSpecifier(Context, T, SS)))
3357
0
          return nullptr;
3358
3359
75
      continue;
3360
75
    }
3361
3362
460k
    if (NeedNonemptyTemplateHeader) {
3363
      // In friend declarations we can have template-ids which don't
3364
      // depend on the corresponding template parameter lists.  But
3365
      // assume that empty parameter lists are supposed to match this
3366
      // template-id.
3367
440k
      if (IsFriend && 
T->isDependentType()60
) {
3368
60
        if (ParamIdx < ParamLists.size() &&
3369
60
            
DependsOnTemplateParameters(T, ParamLists[ParamIdx])48
)
3370
40
          ExpectedTemplateParams = nullptr;
3371
20
        else
3372
20
          continue;
3373
60
      }
3374
3375
440k
      if (ParamIdx < ParamLists.size()) {
3376
        // Check the template parameter list, if we can.
3377
440k
        if (ExpectedTemplateParams &&
3378
440k
            !TemplateParameterListsAreEqual(ParamLists[ParamIdx],
3379
440k
                                            ExpectedTemplateParams,
3380
440k
                                            !SuppressDiagnostic, TPL_TemplateMatch))
3381
4
          Invalid = true;
3382
3383
440k
        if (!Invalid &&
3384
440k
            CheckTemplateParameterList(ParamLists[ParamIdx], nullptr,
3385
440k
                                       TPC_ClassTemplateMember))
3386
0
          Invalid = true;
3387
3388
440k
        ++ParamIdx;
3389
440k
        continue;
3390
440k
      }
3391
3392
3
      if (!SuppressDiagnostic)
3393
1
        Diag(DeclLoc, diag::err_template_spec_needs_template_parameters)
3394
1
          << T
3395
1
          << getRangeOfTypeInNestedNameSpecifier(Context, T, SS);
3396
3
      Invalid = true;
3397
3
      continue;
3398
440k
    }
3399
460k
  }
3400
3401
  // If there were at least as many template-ids as there were template
3402
  // parameter lists, then there are no template parameter lists remaining for
3403
  // the declaration itself.
3404
13.9M
  if (ParamIdx >= ParamLists.size()) {
3405
11.9M
    if (TemplateId && 
!IsFriend1.72k
) {
3406
      // We don't have a template header for the declaration itself, but we
3407
      // should.
3408
29
      DiagnoseMissingExplicitSpecialization(SourceRange(TemplateId->LAngleLoc,
3409
29
                                                        TemplateId->RAngleLoc));
3410
3411
      // Fabricate an empty template parameter list for the invented header.
3412
29
      return TemplateParameterList::Create(Context, SourceLocation(),
3413
29
                                           SourceLocation(), None,
3414
29
                                           SourceLocation(), nullptr);
3415
29
    }
3416
3417
11.9M
    return nullptr;
3418
11.9M
  }
3419
3420
  // If there were too many template parameter lists, complain about that now.
3421
2.01M
  if (ParamIdx < ParamLists.size() - 1) {
3422
20
    bool HasAnyExplicitSpecHeader = false;
3423
20
    bool AllExplicitSpecHeaders = true;
3424
40
    for (unsigned I = ParamIdx, E = ParamLists.size() - 1; I != E; 
++I20
) {
3425
20
      if (ParamLists[I]->size() == 0)
3426
15
        HasAnyExplicitSpecHeader = true;
3427
5
      else
3428
5
        AllExplicitSpecHeaders = false;
3429
20
    }
3430
3431
20
    if (!SuppressDiagnostic)
3432
14
      Diag(ParamLists[ParamIdx]->getTemplateLoc(),
3433
14
           AllExplicitSpecHeaders ? 
diag::warn_template_spec_extra_headers11
3434
14
                                  : 
diag::err_template_spec_extra_headers3
)
3435
14
          << SourceRange(ParamLists[ParamIdx]->getTemplateLoc(),
3436
14
                         ParamLists[ParamLists.size() - 2]->getRAngleLoc());
3437
3438
    // If there was a specialization somewhere, such that 'template<>' is
3439
    // not required, and there were any 'template<>' headers, note where the
3440
    // specialization occurred.
3441
20
    if (ExplicitSpecLoc.isValid() && 
HasAnyExplicitSpecHeader15
&&
3442
20
        
!SuppressDiagnostic15
)
3443
11
      Diag(ExplicitSpecLoc,
3444
11
           diag::note_explicit_template_spec_does_not_need_header)
3445
11
        << NestedTypes.back();
3446
3447
    // We have a template parameter list with no corresponding scope, which
3448
    // means that the resulting template declaration can't be instantiated
3449
    // properly (we'll end up with dependent nodes when we shouldn't).
3450
20
    if (!AllExplicitSpecHeaders)
3451
5
      Invalid = true;
3452
20
  }
3453
3454
  // C++ [temp.expl.spec]p16:
3455
  //   In an explicit specialization declaration for a member of a class
3456
  //   template or a member template that ap- pears in namespace scope, the
3457
  //   member template and some of its enclosing class templates may remain
3458
  //   unspecialized, except that the declaration shall not explicitly
3459
  //   specialize a class member template if its en- closing class templates
3460
  //   are not explicitly specialized as well.
3461
2.01M
  if (ParamLists.back()->size() == 0 &&
3462
2.01M
      CheckExplicitSpecialization(ParamLists[ParamIdx]->getSourceRange(),
3463
79.0k
                                  false))
3464
2
    return nullptr;
3465
3466
  // Return the last template parameter list, which corresponds to the
3467
  // entity being declared.
3468
2.01M
  return ParamLists.back();
3469
2.01M
}
3470
3471
43
void Sema::NoteAllFoundTemplates(TemplateName Name) {
3472
43
  if (TemplateDecl *Template = Name.getAsTemplateDecl()) {
3473
28
    Diag(Template->getLocation(), diag::note_template_declared_here)
3474
28
        << (isa<FunctionTemplateDecl>(Template)
3475
28
                ? 
06
3476
28
                : 
isa<ClassTemplateDecl>(Template)22
3477
22
                      ? 
10
3478
22
                      : isa<VarTemplateDecl>(Template)
3479
22
                            ? 
220
3480
22
                            : 
isa<TypeAliasTemplateDecl>(Template)2
?
32
:
40
)
3481
28
        << Template->getDeclName();
3482
28
    return;
3483
28
  }
3484
3485
15
  if (OverloadedTemplateStorage *OST = Name.getAsOverloadedTemplate()) {
3486
3
    for (OverloadedTemplateStorage::iterator I = OST->begin(),
3487
3
                                          IEnd = OST->end();
3488
9
         I != IEnd; 
++I6
)
3489
6
      Diag((*I)->getLocation(), diag::note_template_declared_here)
3490
6
        << 0 << (*I)->getDeclName();
3491
3492
3
    return;
3493
3
  }
3494
15
}
3495
3496
static QualType
3497
checkBuiltinTemplateIdType(Sema &SemaRef, BuiltinTemplateDecl *BTD,
3498
                           const SmallVectorImpl<TemplateArgument> &Converted,
3499
                           SourceLocation TemplateLoc,
3500
1.89k
                           TemplateArgumentListInfo &TemplateArgs) {
3501
1.89k
  ASTContext &Context = SemaRef.getASTContext();
3502
1.89k
  switch (BTD->getBuiltinTemplateKind()) {
3503
1.17k
  case BTK__make_integer_seq: {
3504
    // Specializations of __make_integer_seq<S, T, N> are treated like
3505
    // S<T, 0, ..., N-1>.
3506
3507
    // C++14 [inteseq.intseq]p1:
3508
    //   T shall be an integer type.
3509
1.17k
    if (!Converted[1].getAsType()->isIntegralType(Context)) {
3510
1
      SemaRef.Diag(TemplateArgs[1].getLocation(),
3511
1
                   diag::err_integer_sequence_integral_element_type);
3512
1
      return QualType();
3513
1
    }
3514
3515
    // C++14 [inteseq.make]p1:
3516
    //   If N is negative the program is ill-formed.
3517
1.17k
    TemplateArgument NumArgsArg = Converted[2];
3518
1.17k
    llvm::APSInt NumArgs = NumArgsArg.getAsIntegral();
3519
1.17k
    if (NumArgs < 0) {
3520
1
      SemaRef.Diag(TemplateArgs[2].getLocation(),
3521
1
                   diag::err_integer_sequence_negative_length);
3522
1
      return QualType();
3523
1
    }
3524
3525
1.17k
    QualType ArgTy = NumArgsArg.getIntegralType();
3526
1.17k
    TemplateArgumentListInfo SyntheticTemplateArgs;
3527
    // The type argument gets reused as the first template argument in the
3528
    // synthetic template argument list.
3529
1.17k
    SyntheticTemplateArgs.addArgument(TemplateArgs[1]);
3530
    // Expand N into 0 ... N-1.
3531
1.17k
    for (llvm::APSInt I(NumArgs.getBitWidth(), NumArgs.isUnsigned());
3532
19.2k
         I < NumArgs; 
++I18.0k
) {
3533
18.0k
      TemplateArgument TA(Context, I, ArgTy);
3534
18.0k
      SyntheticTemplateArgs.addArgument(SemaRef.getTrivialTemplateArgumentLoc(
3535
18.0k
          TA, ArgTy, TemplateArgs[2].getLocation()));
3536
18.0k
    }
3537
    // The first template argument will be reused as the template decl that
3538
    // our synthetic template arguments will be applied to.
3539
1.17k
    return SemaRef.CheckTemplateIdType(Converted[0].getAsTemplate(),
3540
1.17k
                                       TemplateLoc, SyntheticTemplateArgs);
3541
1.17k
  }
3542
3543
716
  case BTK__type_pack_element:
3544
    // Specializations of
3545
    //    __type_pack_element<Index, T_1, ..., T_N>
3546
    // are treated like T_Index.
3547
716
    assert(Converted.size() == 2 &&
3548
716
      "__type_pack_element should be given an index and a parameter pack");
3549
3550
    // If the Index is out of bounds, the program is ill-formed.
3551
0
    TemplateArgument IndexArg = Converted[0], Ts = Converted[1];
3552
716
    llvm::APSInt Index = IndexArg.getAsIntegral();
3553
716
    assert(Index >= 0 && "the index used with __type_pack_element should be of "
3554
716
                         "type std::size_t, and hence be non-negative");
3555
716
    if (Index >= Ts.pack_size()) {
3556
1
      SemaRef.Diag(TemplateArgs[0].getLocation(),
3557
1
                   diag::err_type_pack_element_out_of_bounds);
3558
1
      return QualType();
3559
1
    }
3560
3561
    // We simply return the type at index `Index`.
3562
715
    auto Nth = std::next(Ts.pack_begin(), Index.getExtValue());
3563
715
    return Nth->getAsType();
3564
1.89k
  }
3565
0
  llvm_unreachable("unexpected BuiltinTemplateDecl!");
3566
0
}
3567
3568
/// Determine whether this alias template is "enable_if_t".
3569
/// libc++ >=14 uses "__enable_if_t" in C++11 mode.
3570
56.7k
static bool isEnableIfAliasTemplate(TypeAliasTemplateDecl *AliasTemplate) {
3571
56.7k
  return AliasTemplate->getName().equals("enable_if_t") ||
3572
56.7k
         
AliasTemplate->getName().equals("__enable_if_t")56.0k
;
3573
56.7k
}
3574
3575
/// Collect all of the separable terms in the given condition, which
3576
/// might be a conjunction.
3577
///
3578
/// FIXME: The right answer is to convert the logical expression into
3579
/// disjunctive normal form, so we can find the first failed term
3580
/// within each possible clause.
3581
static void collectConjunctionTerms(Expr *Clause,
3582
205k
                                    SmallVectorImpl<Expr *> &Terms) {
3583
205k
  if (auto BinOp = dyn_cast<BinaryOperator>(Clause->IgnoreParenImpCasts())) {
3584
49.1k
    if (BinOp->getOpcode() == BO_LAnd) {
3585
41.8k
      collectConjunctionTerms(BinOp->getLHS(), Terms);
3586
41.8k
      collectConjunctionTerms(BinOp->getRHS(), Terms);
3587
41.8k
    }
3588
3589
49.1k
    return;
3590
49.1k
  }
3591
3592
155k
  Terms.push_back(Clause);
3593
155k
}
3594
3595
// The ranges-v3 library uses an odd pattern of a top-level "||" with
3596
// a left-hand side that is value-dependent but never true. Identify
3597
// the idiom and ignore that term.
3598
121k
static Expr *lookThroughRangesV3Condition(Preprocessor &PP, Expr *Cond) {
3599
  // Top-level '||'.
3600
121k
  auto *BinOp = dyn_cast<BinaryOperator>(Cond->IgnoreParenImpCasts());
3601
121k
  if (!BinOp) 
return Cond90.3k
;
3602
3603
31.1k
  if (BinOp->getOpcode() != BO_LOr) 
return Cond31.0k
;
3604
3605
  // With an inner '==' that has a literal on the right-hand side.
3606
47
  Expr *LHS = BinOp->getLHS();
3607
47
  auto *InnerBinOp = dyn_cast<BinaryOperator>(LHS->IgnoreParenImpCasts());
3608
47
  if (!InnerBinOp) 
return Cond1
;
3609
3610
46
  if (InnerBinOp->getOpcode() != BO_EQ ||
3611
46
      
!isa<IntegerLiteral>(InnerBinOp->getRHS())6
)
3612
40
    return Cond;
3613
3614
  // If the inner binary operation came from a macro expansion named
3615
  // CONCEPT_REQUIRES or CONCEPT_REQUIRES_, return the right-hand side
3616
  // of the '||', which is the real, user-provided condition.
3617
6
  SourceLocation Loc = InnerBinOp->getExprLoc();
3618
6
  if (!Loc.isMacroID()) 
return Cond3
;
3619
3620
3
  StringRef MacroName = PP.getImmediateMacroName(Loc);
3621
3
  if (MacroName == "CONCEPT_REQUIRES" || MacroName == "CONCEPT_REQUIRES_")
3622
3
    return BinOp->getRHS();
3623
3624
0
  return Cond;
3625
3
}
3626
3627
namespace {
3628
3629
// A PrinterHelper that prints more helpful diagnostics for some sub-expressions
3630
// within failing boolean expression, such as substituting template parameters
3631
// for actual types.
3632
class FailedBooleanConditionPrinterHelper : public PrinterHelper {
3633
public:
3634
  explicit FailedBooleanConditionPrinterHelper(const PrintingPolicy &P)
3635
121k
      : Policy(P) {}
3636
3637
252k
  bool handledStmt(Stmt *E, raw_ostream &OS) override {
3638
252k
    const auto *DR = dyn_cast<DeclRefExpr>(E);
3639
252k
    if (DR && 
DR->getQualifier()125k
) {
3640
      // If this is a qualified name, expand the template arguments in nested
3641
      // qualifiers.
3642
124k
      DR->getQualifier()->print(OS, Policy, true);
3643
      // Then print the decl itself.
3644
124k
      const ValueDecl *VD = DR->getDecl();
3645
124k
      OS << VD->getName();
3646
124k
      if (const auto *IV = dyn_cast<VarTemplateSpecializationDecl>(VD)) {
3647
        // This is a template variable, print the expanded template arguments.
3648
6
        printTemplateArgumentList(
3649
6
            OS, IV->getTemplateArgs().asArray(), Policy,
3650
6
            IV->getSpecializedTemplate()->getTemplateParameters());
3651
6
      }
3652
124k
      return true;
3653
124k
    }
3654
128k
    return false;
3655
252k
  }
3656
3657
private:
3658
  const PrintingPolicy Policy;
3659
};
3660
3661
} // end anonymous namespace
3662
3663
std::pair<Expr *, std::string>
3664
121k
Sema::findFailedBooleanCondition(Expr *Cond) {
3665
121k
  Cond = lookThroughRangesV3Condition(PP, Cond);
3666
3667
  // Separate out all of the terms in a conjunction.
3668
121k
  SmallVector<Expr *, 4> Terms;
3669
121k
  collectConjunctionTerms(Cond, Terms);
3670
3671
  // Determine which term failed.
3672
121k
  Expr *FailedCond = nullptr;
3673
130k
  for (Expr *Term : Terms) {
3674
130k
    Expr *TermAsWritten = Term->IgnoreParenImpCasts();
3675
3676
    // Literals are uninteresting.
3677
130k
    if (isa<CXXBoolLiteralExpr>(TermAsWritten) ||
3678
130k
        
isa<IntegerLiteral>(TermAsWritten)130k
)
3679
42
      continue;
3680
3681
    // The initialization of the parameter from the argument is
3682
    // a constant-evaluated context.
3683
130k
    EnterExpressionEvaluationContext ConstantEvaluated(
3684
130k
      *this, Sema::ExpressionEvaluationContext::ConstantEvaluated);
3685
3686
130k
    bool Succeeded;
3687
130k
    if (Term->EvaluateAsBooleanCondition(Succeeded, Context) &&
3688
130k
        !Succeeded) {
3689
120k
      FailedCond = TermAsWritten;
3690
120k
      break;
3691
120k
    }
3692
130k
  }
3693
121k
  if (!FailedCond)
3694
512
    FailedCond = Cond->IgnoreParenImpCasts();
3695
3696
121k
  std::string Description;
3697
121k
  {
3698
121k
    llvm::raw_string_ostream Out(Description);
3699
121k
    PrintingPolicy Policy = getPrintingPolicy();
3700
121k
    Policy.PrintCanonicalTypes = true;
3701
121k
    FailedBooleanConditionPrinterHelper Helper(Policy);
3702
121k
    FailedCond->printPretty(Out, &Helper, Policy, 0, "\n", nullptr);
3703
121k
  }
3704
121k
  return { FailedCond, Description };
3705
121k
}
3706
3707
QualType Sema::CheckTemplateIdType(TemplateName Name,
3708
                                   SourceLocation TemplateLoc,
3709
8.13M
                                   TemplateArgumentListInfo &TemplateArgs) {
3710
8.13M
  DependentTemplateName *DTN
3711
8.13M
    = Name.getUnderlying().getAsDependentTemplateName();
3712
8.13M
  if (DTN && 
DTN->isIdentifier()10
)
3713
    // When building a template-id where the template-name is dependent,
3714
    // assume the template is a type template. Either our assumption is
3715
    // correct, or the code is ill-formed and will be diagnosed when the
3716
    // dependent name is substituted.
3717
10
    return Context.getDependentTemplateSpecializationType(ETK_None,
3718
10
                                                          DTN->getQualifier(),
3719
10
                                                          DTN->getIdentifier(),
3720
10
                                                          TemplateArgs);
3721
3722
8.13M
  if (Name.getAsAssumedTemplateName() &&
3723
8.13M
      
resolveAssumedTemplateNameAsType(/*Scope*/nullptr, Name, TemplateLoc)0
)
3724
0
    return QualType();
3725
3726
8.13M
  TemplateDecl *Template = Name.getAsTemplateDecl();
3727
8.13M
  if (!Template || 
isa<FunctionTemplateDecl>(Template)8.13M
||
3728
8.13M
      
isa<VarTemplateDecl>(Template)8.13M
||
isa<ConceptDecl>(Template)8.13M
) {
3729
    // We might have a substituted template template parameter pack. If so,
3730
    // build a template specialization type for it.
3731
22
    if (Name.getAsSubstTemplateTemplateParmPack())
3732
2
      return Context.getTemplateSpecializationType(Name, TemplateArgs);
3733
3734
20
    Diag(TemplateLoc, diag::err_template_id_not_a_type)
3735
20
      << Name;
3736
20
    NoteAllFoundTemplates(Name);
3737
20
    return QualType();
3738
22
  }
3739
3740
  // Check that the template argument list is well-formed for this
3741
  // template.
3742
8.13M
  SmallVector<TemplateArgument, 4> Converted;
3743
8.13M
  if (CheckTemplateArgumentList(Template, TemplateLoc, TemplateArgs,
3744
8.13M
                                false, Converted,
3745
8.13M
                                /*UpdateArgsWithConversions=*/true))
3746
2.96k
    return QualType();
3747
3748
8.12M
  QualType CanonType;
3749
3750
8.12M
  if (TypeAliasTemplateDecl *AliasTemplate =
3751
8.12M
          dyn_cast<TypeAliasTemplateDecl>(Template)) {
3752
3753
    // Find the canonical type for this type alias template specialization.
3754
1.10M
    TypeAliasDecl *Pattern = AliasTemplate->getTemplatedDecl();
3755
1.10M
    if (Pattern->isInvalidDecl())
3756
1
      return QualType();
3757
3758
1.10M
    TemplateArgumentList StackTemplateArgs(TemplateArgumentList::OnStack,
3759
1.10M
                                           Converted);
3760
3761
    // Only substitute for the innermost template argument list.
3762
1.10M
    MultiLevelTemplateArgumentList TemplateArgLists;
3763
1.10M
    TemplateArgLists.addOuterTemplateArguments(&StackTemplateArgs);
3764
1.10M
    TemplateArgLists.addOuterRetainedLevels(
3765
1.10M
        AliasTemplate->getTemplateParameters()->getDepth());
3766
3767
1.10M
    LocalInstantiationScope Scope(*this);
3768
1.10M
    InstantiatingTemplate Inst(*this, TemplateLoc, Template);
3769
1.10M
    if (Inst.isInvalid())
3770
212
      return QualType();
3771
3772
1.10M
    CanonType = SubstType(Pattern->getUnderlyingType(),
3773
1.10M
                          TemplateArgLists, AliasTemplate->getLocation(),
3774
1.10M
                          AliasTemplate->getDeclName());
3775
1.10M
    if (CanonType.isNull()) {
3776
      // If this was enable_if and we failed to find the nested type
3777
      // within enable_if in a SFINAE context, dig out the specific
3778
      // enable_if condition that failed and present that instead.
3779
56.7k
      if (isEnableIfAliasTemplate(AliasTemplate)) {
3780
50.5k
        if (auto DeductionInfo = isSFINAEContext()) {
3781
50.5k
          if (*DeductionInfo &&
3782
50.5k
              (*DeductionInfo)->hasSFINAEDiagnostic() &&
3783
50.5k
              (*DeductionInfo)->peekSFINAEDiagnostic().second.getDiagID() ==
3784
50.5k
                diag::err_typename_nested_not_found_enable_if &&
3785
50.5k
              TemplateArgs[0].getArgument().getKind()
3786
50.5k
                == TemplateArgument::Expression) {
3787
50.5k
            Expr *FailedCond;
3788
50.5k
            std::string FailedDescription;
3789
50.5k
            std::tie(FailedCond, FailedDescription) =
3790
50.5k
              findFailedBooleanCondition(TemplateArgs[0].getSourceExpression());
3791
3792
            // Remove the old SFINAE diagnostic.
3793
50.5k
            PartialDiagnosticAt OldDiag =
3794
50.5k
              {SourceLocation(), PartialDiagnostic::NullDiagnostic()};
3795
50.5k
            (*DeductionInfo)->takeSFINAEDiagnostic(OldDiag);
3796
3797
            // Add a new SFINAE diagnostic specifying which condition
3798
            // failed.
3799
50.5k
            (*DeductionInfo)->addSFINAEDiagnostic(
3800
50.5k
              OldDiag.first,
3801
50.5k
              PDiag(diag::err_typename_nested_not_found_requirement)
3802
50.5k
                << FailedDescription
3803
50.5k
                << FailedCond->getSourceRange());
3804
50.5k
          }
3805
50.5k
        }
3806
50.5k
      }
3807
3808
56.7k
      return QualType();
3809
56.7k
    }
3810
7.02M
  } else if (Name.isDependent() ||
3811
7.02M
             TemplateSpecializationType::anyDependentTemplateArguments(
3812
6.93M
                 TemplateArgs, Converted)) {
3813
    // This class template specialization is a dependent
3814
    // type. Therefore, its canonical type is another class template
3815
    // specialization type that contains all of the converted
3816
    // arguments in canonical form. This ensures that, e.g., A<T> and
3817
    // A<T, T> have identical types when A is declared as:
3818
    //
3819
    //   template<typename T, typename U = T> struct A;
3820
4.27M
    CanonType = Context.getCanonicalTemplateSpecializationType(Name, Converted);
3821
3822
    // This might work out to be a current instantiation, in which
3823
    // case the canonical type needs to be the InjectedClassNameType.
3824
    //
3825
    // TODO: in theory this could be a simple hashtable lookup; most
3826
    // changes to CurContext don't change the set of current
3827
    // instantiations.
3828
4.27M
    if (isa<ClassTemplateDecl>(Template)) {
3829
7.02M
      for (DeclContext *Ctx = CurContext; Ctx; 
Ctx = Ctx->getLookupParent()2.79M
) {
3830
        // If we get out to a namespace, we're done.
3831
7.02M
        if (Ctx->isFileContext()) 
break3.86M
;
3832
3833
        // If this isn't a record, keep looking.
3834
3.16M
        CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(Ctx);
3835
3.16M
        if (!Record) 
continue580k
;
3836
3837
        // Look for one of the two cases with InjectedClassNameTypes
3838
        // and check whether it's the same template.
3839
2.58M
        if (!isa<ClassTemplatePartialSpecializationDecl>(Record) &&
3840
2.58M
            
!Record->getDescribedClassTemplate()2.16M
)
3841
677k
          continue;
3842
3843
        // Fetch the injected class name type and check whether its
3844
        // injected type is equal to the type we just built.
3845
1.91M
        QualType ICNT = Context.getTypeDeclType(Record);
3846
1.91M
        QualType Injected = cast<InjectedClassNameType>(ICNT)
3847
1.91M
          ->getInjectedSpecializationType();
3848
3849
1.91M
        if (CanonType != Injected->getCanonicalTypeInternal())
3850
1.53M
          continue;
3851
3852
        // If so, the canonical type of this TST is the injected
3853
        // class name type of the record we just found.
3854
374k
        assert(ICNT.isCanonical());
3855
0
        CanonType = ICNT;
3856
374k
        break;
3857
1.91M
      }
3858
4.23M
    }
3859
4.27M
  } else 
if (ClassTemplateDecl *2.75M
ClassTemplate2.75M
3860
2.75M
               = dyn_cast<ClassTemplateDecl>(Template)) {
3861
    // Find the class template specialization declaration that
3862
    // corresponds to these arguments.
3863
2.74M
    void *InsertPos = nullptr;
3864
2.74M
    ClassTemplateSpecializationDecl *Decl
3865
2.74M
      = ClassTemplate->findSpecialization(Converted, InsertPos);
3866
2.74M
    if (!Decl) {
3867
      // This is the first time we have referenced this class template
3868
      // specialization. Create the canonical declaration and add it to
3869
      // the set of specializations.
3870
1.00M
      Decl = ClassTemplateSpecializationDecl::Create(
3871
1.00M
          Context, ClassTemplate->getTemplatedDecl()->getTagKind(),
3872
1.00M
          ClassTemplate->getDeclContext(),
3873
1.00M
          ClassTemplate->getTemplatedDecl()->getBeginLoc(),
3874
1.00M
          ClassTemplate->getLocation(), ClassTemplate, Converted, nullptr);
3875
1.00M
      ClassTemplate->AddSpecialization(Decl, InsertPos);
3876
1.00M
      if (ClassTemplate->isOutOfLine())
3877
52
        Decl->setLexicalDeclContext(ClassTemplate->getLexicalDeclContext());
3878
1.00M
    }
3879
3880
2.74M
    if (Decl->getSpecializationKind() == TSK_Undeclared &&
3881
2.74M
        
ClassTemplate->getTemplatedDecl()->hasAttrs()1.10M
) {
3882
637k
      InstantiatingTemplate Inst(*this, TemplateLoc, Decl);
3883
637k
      if (!Inst.isInvalid()) {
3884
637k
        MultiLevelTemplateArgumentList TemplateArgLists;
3885
637k
        TemplateArgLists.addOuterTemplateArguments(Converted);
3886
637k
        InstantiateAttrsForDecl(TemplateArgLists,
3887
637k
                                ClassTemplate->getTemplatedDecl(), Decl);
3888
637k
      }
3889
637k
    }
3890
3891
    // Diagnose uses of this specialization.
3892
2.74M
    (void)DiagnoseUseOfDecl(Decl, TemplateLoc);
3893
3894
2.74M
    CanonType = Context.getTypeDeclType(Decl);
3895
2.74M
    assert(isa<RecordType>(CanonType) &&
3896
2.74M
           "type of non-dependent specialization is not a RecordType");
3897
2.74M
  } else 
if (auto *1.89k
BTD1.89k
= dyn_cast<BuiltinTemplateDecl>(Template)) {
3898
1.89k
    CanonType = checkBuiltinTemplateIdType(*this, BTD, Converted, TemplateLoc,
3899
1.89k
                                           TemplateArgs);
3900
1.89k
  }
3901
3902
  // Build the fully-sugared type for this class template
3903
  // specialization, which refers back to the class template
3904
  // specialization we created or found.
3905
8.07M
  return Context.getTemplateSpecializationType(Name, TemplateArgs, CanonType);
3906
8.12M
}
3907
3908
void Sema::ActOnUndeclaredTypeTemplateName(Scope *S, TemplateTy &ParsedName,
3909
                                           TemplateNameKind &TNK,
3910
                                           SourceLocation NameLoc,
3911
20
                                           IdentifierInfo *&II) {
3912
20
  assert(TNK == TNK_Undeclared_template && "not an undeclared template name");
3913
3914
0
  TemplateName Name = ParsedName.get();
3915
20
  auto *ATN = Name.getAsAssumedTemplateName();
3916
20
  assert(ATN && "not an assumed template name");
3917
0
  II = ATN->getDeclName().getAsIdentifierInfo();
3918
3919
20
  if (!resolveAssumedTemplateNameAsType(S, Name, NameLoc, /*Diagnose*/false)) {
3920
    // Resolved to a type template name.
3921
3
    ParsedName = TemplateTy::make(Name);
3922
3
    TNK = TNK_Type_template;
3923
3
  }
3924
20
}
3925
3926
bool Sema::resolveAssumedTemplateNameAsType(Scope *S, TemplateName &Name,
3927
                                            SourceLocation NameLoc,
3928
191
                                            bool Diagnose) {
3929
  // We assumed this undeclared identifier to be an (ADL-only) function
3930
  // template name, but it was used in a context where a type was required.
3931
  // Try to typo-correct it now.
3932
191
  AssumedTemplateStorage *ATN = Name.getAsAssumedTemplateName();
3933
191
  assert(ATN && "not an assumed template name");
3934
3935
0
  LookupResult R(*this, ATN->getDeclName(), NameLoc, LookupOrdinaryName);
3936
191
  struct CandidateCallback : CorrectionCandidateCallback {
3937
191
    bool ValidateCandidate(const TypoCorrection &TC) override {
3938
48
      return TC.getCorrectionDecl() &&
3939
48
             
getAsTypeTemplateDecl(TC.getCorrectionDecl())47
;
3940
48
    }
3941
191
    std::unique_ptr<CorrectionCandidateCallback> clone() override {
3942
140
      return std::make_unique<CandidateCallback>(*this);
3943
140
    }
3944
191
  } FilterCCC;
3945
3946
191
  TypoCorrection Corrected =
3947
191
      CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, nullptr,
3948
191
                  FilterCCC, CTK_ErrorRecovery);
3949
191
  if (Corrected && 
Corrected.getFoundDecl()36
) {
3950
36
    diagnoseTypo(Corrected, PDiag(diag::err_no_template_suggest)
3951
36
                                << ATN->getDeclName());
3952
36
    Name = TemplateName(Corrected.getCorrectionDeclAs<TemplateDecl>());
3953
36
    return false;
3954
36
  }
3955
3956
155
  if (Diagnose)
3957
138
    Diag(R.getNameLoc(), diag::err_no_template) << R.getLookupName();
3958
155
  return true;
3959
191
}
3960
3961
TypeResult Sema::ActOnTemplateIdType(
3962
    Scope *S, CXXScopeSpec &SS, SourceLocation TemplateKWLoc,
3963
    TemplateTy TemplateD, IdentifierInfo *TemplateII,
3964
    SourceLocation TemplateIILoc, SourceLocation LAngleLoc,
3965
    ASTTemplateArgsPtr TemplateArgsIn, SourceLocation RAngleLoc,
3966
1.55M
    bool IsCtorOrDtorName, bool IsClassName) {
3967
1.55M
  if (SS.isInvalid())
3968
0
    return true;
3969
3970
1.55M
  if (!IsCtorOrDtorName && 
!IsClassName1.55M
&&
SS.isSet()1.40M
) {
3971
57.3k
    DeclContext *LookupCtx = computeDeclContext(SS, /*EnteringContext*/false);
3972
3973
    // C++ [temp.res]p3:
3974
    //   A qualified-id that refers to a type and in which the
3975
    //   nested-name-specifier depends on a template-parameter (14.6.2)
3976
    //   shall be prefixed by the keyword typename to indicate that the
3977
    //   qualified-id denotes a type, forming an
3978
    //   elaborated-type-specifier (7.1.5.3).
3979
57.3k
    if (!LookupCtx && 
isDependentScopeSpecifier(SS)7
) {
3980
7
      Diag(SS.getBeginLoc(), diag::err_typename_missing_template)
3981
7
        << SS.getScopeRep() << TemplateII->getName();
3982
      // Recover as if 'typename' were specified.
3983
      // FIXME: This is not quite correct recovery as we don't transform SS
3984
      // into the corresponding dependent form (and we don't diagnose missing
3985
      // 'template' keywords within SS as a result).
3986
7
      return ActOnTypenameType(nullptr, SourceLocation(), SS, TemplateKWLoc,
3987
7
                               TemplateD, TemplateII, TemplateIILoc, LAngleLoc,
3988
7
                               TemplateArgsIn, RAngleLoc);
3989
7
    }
3990
3991
    // Per C++ [class.qual]p2, if the template-id was an injected-class-name,
3992
    // it's not actually allowed to be used as a type in most cases. Because
3993
    // we annotate it before we know whether it's valid, we have to check for
3994
    // this case here.
3995
57.3k
    auto *LookupRD = dyn_cast_or_null<CXXRecordDecl>(LookupCtx);
3996
57.3k
    if (LookupRD && 
LookupRD->getIdentifier() == TemplateII500
) {
3997
16
      Diag(TemplateIILoc,
3998
16
           TemplateKWLoc.isInvalid()
3999
16
               ? 
diag::err_out_of_line_qualified_id_type_names_constructor12
4000
16
               : 
diag::ext_out_of_line_qualified_id_type_names_constructor4
)
4001
16
        << TemplateII << 0 /*injected-class-name used as template name*/
4002
16
        << 1 /*if any keyword was present, it was 'template'*/;
4003
16
    }
4004
57.3k
  }
4005
4006
1.55M
  TemplateName Template = TemplateD.get();
4007
1.55M
  if (Template.getAsAssumedTemplateName() &&
4008
1.55M
      
resolveAssumedTemplateNameAsType(S, Template, TemplateIILoc)148
)
4009
118
    return true;
4010
4011
  // Translate the parser's template argument list in our AST format.
4012
1.55M
  TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
4013
1.55M
  translateTemplateArguments(TemplateArgsIn, TemplateArgs);
4014
4015
1.55M
  if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
4016
60
    QualType T
4017
60
      = Context.getDependentTemplateSpecializationType(ETK_None,
4018
60
                                                       DTN->getQualifier(),
4019
60
                                                       DTN->getIdentifier(),
4020
60
                                                       TemplateArgs);
4021
    // Build type-source information.
4022
60
    TypeLocBuilder TLB;
4023
60
    DependentTemplateSpecializationTypeLoc SpecTL
4024
60
      = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
4025
60
    SpecTL.setElaboratedKeywordLoc(SourceLocation());
4026
60
    SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
4027
60
    SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4028
60
    SpecTL.setTemplateNameLoc(TemplateIILoc);
4029
60
    SpecTL.setLAngleLoc(LAngleLoc);
4030
60
    SpecTL.setRAngleLoc(RAngleLoc);
4031
120
    for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; 
++I60
)
4032
60
      SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
4033
60
    return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
4034
60
  }
4035
4036
1.55M
  QualType Result = CheckTemplateIdType(Template, TemplateIILoc, TemplateArgs);
4037
1.55M
  if (Result.isNull())
4038
1.27k
    return true;
4039
4040
  // Build type-source information.
4041
1.55M
  TypeLocBuilder TLB;
4042
1.55M
  TemplateSpecializationTypeLoc SpecTL
4043
1.55M
    = TLB.push<TemplateSpecializationTypeLoc>(Result);
4044
1.55M
  SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4045
1.55M
  SpecTL.setTemplateNameLoc(TemplateIILoc);
4046
1.55M
  SpecTL.setLAngleLoc(LAngleLoc);
4047
1.55M
  SpecTL.setRAngleLoc(RAngleLoc);
4048
4.05M
  for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; 
++i2.49M
)
4049
2.49M
    SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
4050
4051
  // NOTE: avoid constructing an ElaboratedTypeLoc if this is a
4052
  // constructor or destructor name (in such a case, the scope specifier
4053
  // will be attached to the enclosing Decl or Expr node).
4054
1.55M
  if (SS.isNotEmpty() && 
!IsCtorOrDtorName60.7k
) {
4055
    // Create an elaborated-type-specifier containing the nested-name-specifier.
4056
60.7k
    Result = Context.getElaboratedType(ETK_None, SS.getScopeRep(), Result);
4057
60.7k
    ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
4058
60.7k
    ElabTL.setElaboratedKeywordLoc(SourceLocation());
4059
60.7k
    ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
4060
60.7k
  }
4061
4062
1.55M
  return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
4063
1.55M
}
4064
4065
TypeResult Sema::ActOnTagTemplateIdType(TagUseKind TUK,
4066
                                        TypeSpecifierType TagSpec,
4067
                                        SourceLocation TagLoc,
4068
                                        CXXScopeSpec &SS,
4069
                                        SourceLocation TemplateKWLoc,
4070
                                        TemplateTy TemplateD,
4071
                                        SourceLocation TemplateLoc,
4072
                                        SourceLocation LAngleLoc,
4073
                                        ASTTemplateArgsPtr TemplateArgsIn,
4074
7.15k
                                        SourceLocation RAngleLoc) {
4075
7.15k
  if (SS.isInvalid())
4076
0
    return TypeResult(true);
4077
4078
7.15k
  TemplateName Template = TemplateD.get();
4079
4080
  // Translate the parser's template argument list in our AST format.
4081
7.15k
  TemplateArgumentListInfo TemplateArgs(LAngleLoc, RAngleLoc);
4082
7.15k
  translateTemplateArguments(TemplateArgsIn, TemplateArgs);
4083
4084
  // Determine the tag kind
4085
7.15k
  TagTypeKind TagKind = TypeWithKeyword::getTagTypeKindForTypeSpec(TagSpec);
4086
7.15k
  ElaboratedTypeKeyword Keyword
4087
7.15k
    = TypeWithKeyword::getKeywordForTagTypeKind(TagKind);
4088
4089
7.15k
  if (DependentTemplateName *DTN = Template.getAsDependentTemplateName()) {
4090
5
    QualType T = Context.getDependentTemplateSpecializationType(Keyword,
4091
5
                                                          DTN->getQualifier(),
4092
5
                                                          DTN->getIdentifier(),
4093
5
                                                                TemplateArgs);
4094
4095
    // Build type-source information.
4096
5
    TypeLocBuilder TLB;
4097
5
    DependentTemplateSpecializationTypeLoc SpecTL
4098
5
      = TLB.push<DependentTemplateSpecializationTypeLoc>(T);
4099
5
    SpecTL.setElaboratedKeywordLoc(TagLoc);
4100
5
    SpecTL.setQualifierLoc(SS.getWithLocInContext(Context));
4101
5
    SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4102
5
    SpecTL.setTemplateNameLoc(TemplateLoc);
4103
5
    SpecTL.setLAngleLoc(LAngleLoc);
4104
5
    SpecTL.setRAngleLoc(RAngleLoc);
4105
10
    for (unsigned I = 0, N = SpecTL.getNumArgs(); I != N; 
++I5
)
4106
5
      SpecTL.setArgLocInfo(I, TemplateArgs[I].getLocInfo());
4107
5
    return CreateParsedType(T, TLB.getTypeSourceInfo(Context, T));
4108
5
  }
4109
4110
7.15k
  if (TypeAliasTemplateDecl *TAT =
4111
7.15k
        dyn_cast_or_null<TypeAliasTemplateDecl>(Template.getAsTemplateDecl())) {
4112
    // C++0x [dcl.type.elab]p2:
4113
    //   If the identifier resolves to a typedef-name or the simple-template-id
4114
    //   resolves to an alias template specialization, the
4115
    //   elaborated-type-specifier is ill-formed.
4116
2
    Diag(TemplateLoc, diag::err_tag_reference_non_tag)
4117
2
        << TAT << NTK_TypeAliasTemplate << TagKind;
4118
2
    Diag(TAT->getLocation(), diag::note_declared_at);
4119
2
  }
4120
4121
7.15k
  QualType Result = CheckTemplateIdType(Template, TemplateLoc, TemplateArgs);
4122
7.15k
  if (Result.isNull())
4123
15
    return TypeResult(true);
4124
4125
  // Check the tag kind
4126
7.13k
  if (const RecordType *RT = Result->getAs<RecordType>()) {
4127
1.02k
    RecordDecl *D = RT->getDecl();
4128
4129
1.02k
    IdentifierInfo *Id = D->getIdentifier();
4130
1.02k
    assert(Id && "templated class must have an identifier");
4131
4132
1.02k
    if (!isAcceptableTagRedeclaration(D, TagKind, TUK == TUK_Definition,
4133
1.02k
                                      TagLoc, Id)) {
4134
4
      Diag(TagLoc, diag::err_use_with_wrong_tag)
4135
4
        << Result
4136
4
        << FixItHint::CreateReplacement(SourceRange(TagLoc), D->getKindName());
4137
4
      Diag(D->getLocation(), diag::note_previous_use);
4138
4
    }
4139
1.02k
  }
4140
4141
  // Provide source-location information for the template specialization.
4142
0
  TypeLocBuilder TLB;
4143
7.13k
  TemplateSpecializationTypeLoc SpecTL
4144
7.13k
    = TLB.push<TemplateSpecializationTypeLoc>(Result);
4145
7.13k
  SpecTL.setTemplateKeywordLoc(TemplateKWLoc);
4146
7.13k
  SpecTL.setTemplateNameLoc(TemplateLoc);
4147
7.13k
  SpecTL.setLAngleLoc(LAngleLoc);
4148
7.13k
  SpecTL.setRAngleLoc(RAngleLoc);
4149
16.9k
  for (unsigned i = 0, e = SpecTL.getNumArgs(); i != e; 
++i9.81k
)
4150
9.81k
    SpecTL.setArgLocInfo(i, TemplateArgs[i].getLocInfo());
4151
4152
  // Construct an elaborated type containing the nested-name-specifier (if any)
4153
  // and tag keyword.
4154
7.13k
  Result = Context.getElaboratedType(Keyword, SS.getScopeRep(), Result);
4155
7.13k
  ElaboratedTypeLoc ElabTL = TLB.push<ElaboratedTypeLoc>(Result);
4156
7.13k
  ElabTL.setElaboratedKeywordLoc(TagLoc);
4157
7.13k
  ElabTL.setQualifierLoc(SS.getWithLocInContext(Context));
4158
7.13k
  return CreateParsedType(Result, TLB.getTypeSourceInfo(Context, Result));
4159
7.15k
}
4160
4161
static bool CheckTemplateSpecializationScope(Sema &S, NamedDecl *Specialized,
4162
                                             NamedDecl *PrevDecl,
4163
                                             SourceLocation Loc,
4164
                                             bool IsPartialSpecialization);
4165
4166
static TemplateSpecializationKind getTemplateSpecializationKind(Decl *D);
4167
4168
static bool isTemplateArgumentTemplateParameter(
4169
538
    const TemplateArgument &Arg, unsigned Depth, unsigned Index) {
4170
538
  switch (Arg.getKind()) {
4171
0
  case TemplateArgument::Null:
4172
0
  case TemplateArgument::NullPtr:
4173
10
  case TemplateArgument::Integral:
4174
10
  case TemplateArgument::Declaration:
4175
10
  case TemplateArgument::Pack:
4176
10
  case TemplateArgument::TemplateExpansion:
4177
10
    return false;
4178
4179
518
  case TemplateArgument::Type: {
4180
518
    QualType Type = Arg.getAsType();
4181
518
    const TemplateTypeParmType *TPT =
4182
518
        Arg.getAsType()->getAs<TemplateTypeParmType>();
4183
518
    return TPT && 
!Type.hasQualifiers()162
&&
4184
518
           
TPT->getDepth() == Depth162
&&
TPT->getIndex() == Index160
;
4185
10
  }
4186
4187
8
  case TemplateArgument::Expression: {
4188
8
    DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(Arg.getAsExpr());
4189
8
    if (!DRE || !DRE->getDecl())
4190
0
      return false;
4191
8
    const NonTypeTemplateParmDecl *NTTP =
4192
8
        dyn_cast<NonTypeTemplateParmDecl>(DRE->getDecl());
4193
8
    return NTTP && NTTP->getDepth() == Depth && NTTP->getIndex() == Index;
4194
8
  }
4195
4196
2
  case TemplateArgument::Template:
4197
2
    const TemplateTemplateParmDecl *TTP =
4198
2
        dyn_cast_or_null<TemplateTemplateParmDecl>(
4199
2
            Arg.getAsTemplateOrTemplatePattern().getAsTemplateDecl());
4200
2
    return TTP && TTP->getDepth() == Depth && TTP->getIndex() == Index;
4201
538
  }
4202
0
  llvm_unreachable("unexpected kind of template argument");
4203
0
}
4204
4205
static bool isSameAsPrimaryTemplate(TemplateParameterList *Params,
4206
441
                                    ArrayRef<TemplateArgument> Args) {
4207
441
  if (Params->size() != Args.size())
4208
6
    return false;
4209
4210
435
  unsigned Depth = Params->getDepth();
4211
4212
571
  for (unsigned I = 0, N = Args.size(); I != N; 
++I136
) {
4213
540
    TemplateArgument Arg = Args[I];
4214
4215
    // If the parameter is a pack expansion, the argument must be a pack
4216
    // whose only element is a pack expansion.
4217
540
    if (Params->getParam(I)->isParameterPack()) {
4218
5
      if (Arg.getKind() != TemplateArgument::Pack || Arg.pack_size() != 1 ||
4219
5
          !Arg.pack_begin()->isPackExpansion())
4220
2
        return false;
4221
3
      Arg = Arg.pack_begin()->getPackExpansionPattern();
4222
3
    }
4223
4224
538
    if (!isTemplateArgumentTemplateParameter(Arg, Depth, I))
4225
402
      return false;
4226
538
  }
4227
4228
31
  return true;
4229
435
}
4230
4231
template<typename PartialSpecDecl>
4232
193k
static void checkMoreSpecializedThanPrimary(Sema &S, PartialSpecDecl *Partial) {
4233
193k
  if (Partial->getDeclContext()->isDependentContext())
4234
5.41k
    return;
4235
4236
  // FIXME: Get the TDK from deduction in order to provide better diagnostics
4237
  // for non-substitution-failure issues?
4238
187k
  TemplateDeductionInfo Info(Partial->getLocation());
4239
187k
  if (S.isMoreSpecializedThanPrimary(Partial, Info))
4240
187k
    return;
4241
4242
342
  auto *Template = Partial->getSpecializedTemplate();
4243
342
  S.Diag(Partial->getLocation(),
4244
342
         diag::ext_partial_spec_not_more_specialized_than_primary)
4245
342
      << isa<VarTemplateDecl>(Template);
4246
4247
342
  if (Info.hasSFINAEDiagnostic()) {
4248
3
    PartialDiagnosticAt Diag = {SourceLocation(),
4249
3
                                PartialDiagnostic::NullDiagnostic()};
4250
3
    Info.takeSFINAEDiagnostic(Diag);
4251
3
    SmallString<128> SFINAEArgString;
4252
3
    Diag.second.EmitToString(S.getDiagnostics(), SFINAEArgString);
4253
3
    S.Diag(Diag.first,
4254
3
           diag::note_partial_spec_not_more_specialized_than_primary)
4255
3
      << SFINAEArgString;
4256
3
  }
4257
4258
342
  S.Diag(Template->getLocation(), diag::note_template_decl_here);
4259
342
  SmallVector<const Expr *, 3> PartialAC, TemplateAC;
4260
342
  Template->getAssociatedConstraints(TemplateAC);
4261
342
  Partial->getAssociatedConstraints(PartialAC);
4262
342
  S.MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Partial, PartialAC, Template,
4263
342
                                                  TemplateAC);
4264
342
}
SemaTemplate.cpp:void checkMoreSpecializedThanPrimary<clang::ClassTemplatePartialSpecializationDecl>(clang::Sema&, clang::ClassTemplatePartialSpecializationDecl*)
Line
Count
Source
4232
192k
static void checkMoreSpecializedThanPrimary(Sema &S, PartialSpecDecl *Partial) {
4233
192k
  if (Partial->getDeclContext()->isDependentContext())
4234
5.34k
    return;
4235
4236
  // FIXME: Get the TDK from deduction in order to provide better diagnostics
4237
  // for non-substitution-failure issues?
4238
187k
  TemplateDeductionInfo Info(Partial->getLocation());
4239
187k
  if (S.isMoreSpecializedThanPrimary(Partial, Info))
4240
186k
    return;
4241
4242
332
  auto *Template = Partial->getSpecializedTemplate();
4243
332
  S.Diag(Partial->getLocation(),
4244
332
         diag::ext_partial_spec_not_more_specialized_than_primary)
4245
332
      << isa<VarTemplateDecl>(Template);
4246
4247
332
  if (Info.hasSFINAEDiagnostic()) {
4248
3
    PartialDiagnosticAt Diag = {SourceLocation(),
4249
3
                                PartialDiagnostic::NullDiagnostic()};
4250
3
    Info.takeSFINAEDiagnostic(Diag);
4251
3
    SmallString<128> SFINAEArgString;
4252
3
    Diag.second.EmitToString(S.getDiagnostics(), SFINAEArgString);
4253
3
    S.Diag(Diag.first,
4254
3
           diag::note_partial_spec_not_more_specialized_than_primary)
4255
3
      << SFINAEArgString;
4256
3
  }
4257
4258
332
  S.Diag(Template->getLocation(), diag::note_template_decl_here);
4259
332
  SmallVector<const Expr *, 3> PartialAC, TemplateAC;
4260
332
  Template->getAssociatedConstraints(TemplateAC);
4261
332
  Partial->getAssociatedConstraints(PartialAC);
4262
332
  S.MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Partial, PartialAC, Template,
4263
332
                                                  TemplateAC);
4264
332
}
SemaTemplate.cpp:void checkMoreSpecializedThanPrimary<clang::VarTemplatePartialSpecializationDecl>(clang::Sema&, clang::VarTemplatePartialSpecializationDecl*)
Line
Count
Source
4232
471
static void checkMoreSpecializedThanPrimary(Sema &S, PartialSpecDecl *Partial) {
4233
471
  if (Partial->getDeclContext()->isDependentContext())
4234
69
    return;
4235
4236
  // FIXME: Get the TDK from deduction in order to provide better diagnostics
4237
  // for non-substitution-failure issues?
4238
402
  TemplateDeductionInfo Info(Partial->getLocation());
4239
402
  if (S.isMoreSpecializedThanPrimary(Partial, Info))
4240
392
    return;
4241
4242
10
  auto *Template = Partial->getSpecializedTemplate();
4243
10
  S.Diag(Partial->getLocation(),
4244
10
         diag::ext_partial_spec_not_more_specialized_than_primary)
4245
10
      << isa<VarTemplateDecl>(Template);
4246
4247
10
  if (Info.hasSFINAEDiagnostic()) {
4248
0
    PartialDiagnosticAt Diag = {SourceLocation(),
4249
0
                                PartialDiagnostic::NullDiagnostic()};
4250
0
    Info.takeSFINAEDiagnostic(Diag);
4251
0
    SmallString<128> SFINAEArgString;
4252
0
    Diag.second.EmitToString(S.getDiagnostics(), SFINAEArgString);
4253
0
    S.Diag(Diag.first,
4254
0
           diag::note_partial_spec_not_more_specialized_than_primary)
4255
0
      << SFINAEArgString;
4256
0
  }
4257
4258
10
  S.Diag(Template->getLocation(), diag::note_template_decl_here);
4259
10
  SmallVector<const Expr *, 3> PartialAC, TemplateAC;
4260
10
  Template->getAssociatedConstraints(TemplateAC);
4261
10
  Partial->getAssociatedConstraints(PartialAC);
4262
10
  S.MaybeEmitAmbiguousAtomicConstraintsDiagnostic(Partial, PartialAC, Template,
4263
10
                                                  TemplateAC);
4264
10
}
4265
4266
static void
4267
noteNonDeducibleParameters(Sema &S, TemplateParameterList *TemplateParams,
4268
26
                           const llvm::SmallBitVector &DeducibleParams) {
4269
60
  for (unsigned I = 0, N = DeducibleParams.size(); I != N; 
++I34
) {
4270
34
    if (!DeducibleParams[I]) {
4271
28
      NamedDecl *Param = TemplateParams->getParam(I);
4272
28
      if (Param->getDeclName())
4273
27
        S.Diag(Param->getLocation(), diag::note_non_deducible_parameter)
4274
27
            << Param->getDeclName();
4275
1
      else
4276
1
        S.Diag(Param->getLocation(), diag::note_non_deducible_parameter)
4277
1
            << "(anonymous)";
4278
28
    }
4279
34
  }
4280
26
}
4281
4282
4283
template<typename PartialSpecDecl>
4284
static void checkTemplatePartialSpecialization(Sema &S,
4285
193k
                                               PartialSpecDecl *Partial) {
4286
  // C++1z [temp.class.spec]p8: (DR1495)
4287
  //   - The specialization shall be more specialized than the primary
4288
  //     template (14.5.5.2).
4289
193k
  checkMoreSpecializedThanPrimary(S, Partial);
4290
4291
  // C++ [temp.class.spec]p8: (DR1315)
4292
  //   - Each template-parameter shall appear at least once in the
4293
  //     template-id outside a non-deduced context.
4294
  // C++1z [temp.class.spec.match]p3 (P0127R2)
4295
  //   If the template arguments of a partial specialization cannot be
4296
  //   deduced because of the structure of its template-parameter-list
4297
  //   and the template-id, the program is ill-formed.
4298
193k
  auto *TemplateParams = Partial->getTemplateParameters();
4299
193k
  llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4300
193k
  S.MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
4301
193k
                               TemplateParams->getDepth(), DeducibleParams);
4302
4303
193k
  if (!DeducibleParams.all()) {
4304
21
    unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4305
21
    S.Diag(Partial->getLocation(), diag::ext_partial_specs_not_deducible)
4306
21
      << isa<VarTemplatePartialSpecializationDecl>(Partial)
4307
21
      << (NumNonDeducible > 1)
4308
21
      << SourceRange(Partial->getLocation(),
4309
21
                     Partial->getTemplateArgsAsWritten()->RAngleLoc);
4310
21
    noteNonDeducibleParameters(S, TemplateParams, DeducibleParams);
4311
21
  }
4312
193k
}
SemaTemplate.cpp:void checkTemplatePartialSpecialization<clang::ClassTemplatePartialSpecializationDecl>(clang::Sema&, clang::ClassTemplatePartialSpecializationDecl*)
Line
Count
Source
4285
192k
                                               PartialSpecDecl *Partial) {
4286
  // C++1z [temp.class.spec]p8: (DR1495)
4287
  //   - The specialization shall be more specialized than the primary
4288
  //     template (14.5.5.2).
4289
192k
  checkMoreSpecializedThanPrimary(S, Partial);
4290
4291
  // C++ [temp.class.spec]p8: (DR1315)
4292
  //   - Each template-parameter shall appear at least once in the
4293
  //     template-id outside a non-deduced context.
4294
  // C++1z [temp.class.spec.match]p3 (P0127R2)
4295
  //   If the template arguments of a partial specialization cannot be
4296
  //   deduced because of the structure of its template-parameter-list
4297
  //   and the template-id, the program is ill-formed.
4298
192k
  auto *TemplateParams = Partial->getTemplateParameters();
4299
192k
  llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4300
192k
  S.MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
4301
192k
                               TemplateParams->getDepth(), DeducibleParams);
4302
4303
192k
  if (!DeducibleParams.all()) {
4304
16
    unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4305
16
    S.Diag(Partial->getLocation(), diag::ext_partial_specs_not_deducible)
4306
16
      << isa<VarTemplatePartialSpecializationDecl>(Partial)
4307
16
      << (NumNonDeducible > 1)
4308
16
      << SourceRange(Partial->getLocation(),
4309
16
                     Partial->getTemplateArgsAsWritten()->RAngleLoc);
4310
16
    noteNonDeducibleParameters(S, TemplateParams, DeducibleParams);
4311
16
  }
4312
192k
}
SemaTemplate.cpp:void checkTemplatePartialSpecialization<clang::VarTemplatePartialSpecializationDecl>(clang::Sema&, clang::VarTemplatePartialSpecializationDecl*)
Line
Count
Source
4285
471
                                               PartialSpecDecl *Partial) {
4286
  // C++1z [temp.class.spec]p8: (DR1495)
4287
  //   - The specialization shall be more specialized than the primary
4288
  //     template (14.5.5.2).
4289
471
  checkMoreSpecializedThanPrimary(S, Partial);
4290
4291
  // C++ [temp.class.spec]p8: (DR1315)
4292
  //   - Each template-parameter shall appear at least once in the
4293
  //     template-id outside a non-deduced context.
4294
  // C++1z [temp.class.spec.match]p3 (P0127R2)
4295
  //   If the template arguments of a partial specialization cannot be
4296
  //   deduced because of the structure of its template-parameter-list
4297
  //   and the template-id, the program is ill-formed.
4298
471
  auto *TemplateParams = Partial->getTemplateParameters();
4299
471
  llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4300
471
  S.MarkUsedTemplateParameters(Partial->getTemplateArgs(), true,
4301
471
                               TemplateParams->getDepth(), DeducibleParams);
4302
4303
471
  if (!DeducibleParams.all()) {
4304
5
    unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4305
5
    S.Diag(Partial->getLocation(), diag::ext_partial_specs_not_deducible)
4306
5
      << isa<VarTemplatePartialSpecializationDecl>(Partial)
4307
5
      << (NumNonDeducible > 1)
4308
5
      << SourceRange(Partial->getLocation(),
4309
5
                     Partial->getTemplateArgsAsWritten()->RAngleLoc);
4310
5
    noteNonDeducibleParameters(S, TemplateParams, DeducibleParams);
4311
5
  }
4312
471
}
4313
4314
void Sema::CheckTemplatePartialSpecialization(
4315
192k
    ClassTemplatePartialSpecializationDecl *Partial) {
4316
192k
  checkTemplatePartialSpecialization(*this, Partial);
4317
192k
}
4318
4319
void Sema::CheckTemplatePartialSpecialization(
4320
471
    VarTemplatePartialSpecializationDecl *Partial) {
4321
471
  checkTemplatePartialSpecialization(*this, Partial);
4322
471
}
4323
4324
767
void Sema::CheckDeductionGuideTemplate(FunctionTemplateDecl *TD) {
4325
  // C++1z [temp.param]p11:
4326
  //   A template parameter of a deduction guide template that does not have a
4327
  //   default-argument shall be deducible from the parameter-type-list of the
4328
  //   deduction guide template.
4329
767
  auto *TemplateParams = TD->getTemplateParameters();
4330
767
  llvm::SmallBitVector DeducibleParams(TemplateParams->size());
4331
767
  MarkDeducedTemplateParameters(TD, DeducibleParams);
4332
3.61k
  for (unsigned I = 0; I != TemplateParams->size(); 
++I2.84k
) {
4333
    // A parameter pack is deducible (to an empty pack).
4334
2.84k
    auto *Param = TemplateParams->getParam(I);
4335
2.84k
    if (Param->isParameterPack() || 
hasVisibleDefaultArgument(Param)2.77k
)
4336
1.50k
      DeducibleParams[I] = true;
4337
2.84k
  }
4338
4339
767
  if (!DeducibleParams.all()) {
4340
5
    unsigned NumNonDeducible = DeducibleParams.size() - DeducibleParams.count();
4341
5
    Diag(TD->getLocation(), diag::err_deduction_guide_template_not_deducible)
4342
5
      << (NumNonDeducible > 1);
4343
5
    noteNonDeducibleParameters(*this, TemplateParams, DeducibleParams);
4344
5
  }
4345
767
}
4346
4347
DeclResult Sema::ActOnVarTemplateSpecialization(
4348
    Scope *S, Declarator &D, TypeSourceInfo *DI, SourceLocation TemplateKWLoc,
4349
    TemplateParameterList *TemplateParams, StorageClass SC,
4350
1.02k
    bool IsPartialSpecialization) {
4351
  // D must be variable template id.
4352
1.02k
  assert(D.getName().getKind() == UnqualifiedIdKind::IK_TemplateId &&
4353
1.02k
         "Variable template specialization is declared with a template id.");
4354
4355
0
  TemplateIdAnnotation *TemplateId = D.getName().TemplateId;
4356
1.02k
  TemplateArgumentListInfo TemplateArgs =
4357
1.02k
      makeTemplateArgumentListInfo(*this, *TemplateId);
4358
1.02k
  SourceLocation TemplateNameLoc = D.getIdentifierLoc();
4359
1.02k
  SourceLocation LAngleLoc = TemplateId->LAngleLoc;
4360
1.02k
  SourceLocation RAngleLoc = TemplateId->RAngleLoc;
4361
4362
1.02k
  TemplateName Name = TemplateId->Template.get();
4363
4364
  // The template-id must name a variable template.
4365
1.02k
  VarTemplateDecl *VarTemplate =
4366
1.02k
      dyn_cast_or_null<VarTemplateDecl>(Name.getAsTemplateDecl());
4367
1.02k
  if (!VarTemplate) {
4368
9
    NamedDecl *FnTemplate;
4369
9
    if (auto *OTS = Name.getAsOverloadedTemplate())
4370
3
      FnTemplate = *OTS->begin();
4371
6
    else
4372
6
      FnTemplate = dyn_cast_or_null<FunctionTemplateDecl>(Name.getAsTemplateDecl());
4373
9
    if (FnTemplate)
4374
6
      return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template_but_method)
4375
6
               << FnTemplate->getDeclName();
4376
3
    return Diag(D.getIdentifierLoc(), diag::err_var_spec_no_template)
4377
3
             << IsPartialSpecialization;
4378
9
  }
4379
4380
  // Check for unexpanded parameter packs in any of the template arguments.
4381
2.19k
  
for (unsigned I = 0, N = TemplateArgs.size(); 1.01k
I != N;
++I1.18k
)
4382
1.18k
    if (DiagnoseUnexpandedParameterPack(TemplateArgs[I],
4383
1.18k
                                        UPPC_PartialSpecialization))
4384
0
      return true;
4385
4386
  // Check that the template argument list is well-formed for this
4387
  // template.
4388
1.01k
  SmallVector<TemplateArgument, 4> Converted;
4389
1.01k
  if (CheckTemplateArgumentList(VarTemplate, TemplateNameLoc, TemplateArgs,
4390
1.01k
                                false, Converted,
4391
1.01k
                                /*UpdateArgsWithConversions=*/true))
4392
0
    return true;
4393
4394
  // Find the variable template (partial) specialization declaration that
4395
  // corresponds to these arguments.
4396
1.01k
  if (IsPartialSpecialization) {
4397
441
    if (CheckTemplatePartialSpecializationArgs(TemplateNameLoc, VarTemplate,
4398
441
                                               TemplateArgs.size(), Converted))
4399
0
      return true;
4400
4401
    // FIXME: Move these checks to CheckTemplatePartialSpecializationArgs so we
4402
    // also do them during instantiation.
4403
441
    if (!Name.isDependent() &&
4404
441
        !TemplateSpecializationType::anyDependentTemplateArguments(TemplateArgs,
4405
370
                                                                   Converted)) {
4406
0
      Diag(TemplateNameLoc, diag::err_partial_spec_fully_specialized)
4407
0
          << VarTemplate->getDeclName();
4408
0
      IsPartialSpecialization = false;
4409
0
    }
4410
4411
441
    if (isSameAsPrimaryTemplate(VarTemplate->getTemplateParameters(),
4412
441
                                Converted) &&
4413
441
        
(31
!Context.getLangOpts().CPlusPlus2031
||
4414
31
         
!TemplateParams->hasAssociatedConstraints()24
)) {
4415
      // C++ [temp.class.spec]p9b3:
4416
      //
4417
      //   -- The argument list of the specialization shall not be identical
4418
      //      to the implicit argument list of the primary template.
4419
9
      Diag(TemplateNameLoc, diag::err_partial_spec_args_match_primary_template)
4420
9
        << /*variable template*/ 1
4421
9
        << /*is definition*/(SC != SC_Extern && !CurContext->isRecord())
4422
9
        << FixItHint::CreateRemoval(SourceRange(LAngleLoc, RAngleLoc));
4423
      // FIXME: Recover from this by treating the declaration as a redeclaration
4424
      // of the primary template.
4425
9
      return true;
4426
9
    }
4427
441
  }
4428
4429
1.00k
  void *InsertPos = nullptr;
4430
1.00k
  VarTemplateSpecializationDecl *PrevDecl = nullptr;
4431
4432
1.00k
  if (IsPartialSpecialization)
4433
432
    PrevDecl = VarTemplate->findPartialSpecialization(Converted, TemplateParams,
4434
432
                                                      InsertPos);
4435
573
  else
4436
573
    PrevDecl = VarTemplate->findSpecialization(Converted, InsertPos);
4437
4438
1.00k
  VarTemplateSpecializationDecl *Specialization = nullptr;
4439
4440
  // Check whether we can declare a variable template specialization in
4441
  // the current scope.
4442
1.00k
  if (CheckTemplateSpecializationScope(*this, VarTemplate, PrevDecl,
4443
1.00k
                                       TemplateNameLoc,
4444
1.00k
                                       IsPartialSpecialization))
4445
20
    return true;
4446
4447
985
  if (PrevDecl && 
PrevDecl->getSpecializationKind() == TSK_Undeclared118
) {
4448
    // Since the only prior variable template specialization with these
4449
    // arguments was referenced but not declared,  reuse that
4450
    // declaration node as our own, updating its source location and
4451
    // the list of outer template parameters to reflect our new declaration.
4452
0
    Specialization = PrevDecl;
4453
0
    Specialization->setLocation(TemplateNameLoc);
4454
0
    PrevDecl = nullptr;
4455
985
  } else if (IsPartialSpecialization) {
4456
    // Create a new class template partial specialization declaration node.
4457
422
    VarTemplatePartialSpecializationDecl *PrevPartial =
4458
422
        cast_or_null<VarTemplatePartialSpecializationDecl>(PrevDecl);
4459
422
    VarTemplatePartialSpecializationDecl *Partial =
4460
422
        VarTemplatePartialSpecializationDecl::Create(
4461
422
            Context, VarTemplate->getDeclContext(), TemplateKWLoc,
4462
422
            TemplateNameLoc, TemplateParams, VarTemplate, DI->getType(), DI, SC,
4463
422
            Converted, TemplateArgs);
4464
4465
422
    if (!PrevPartial)
4466
357
      VarTemplate->AddPartialSpecialization(Partial, InsertPos);
4467
422
    Specialization = Partial;
4468
4469
    // If we are providing an explicit specialization of a member variable
4470
    // template specialization, make a note of that.
4471
422
    if (PrevPartial && 
PrevPartial->getInstantiatedFromMember()65
)
4472
21
      PrevPartial->setMemberSpecialization();
4473
4474
422
    CheckTemplatePartialSpecialization(Partial);
4475
563
  } else {
4476
    // Create a new class template specialization declaration node for
4477
    // this explicit specialization or friend declaration.
4478
563
    Specialization = VarTemplateSpecializationDecl::Create(
4479
563
        Context, VarTemplate->getDeclContext(), TemplateKWLoc, TemplateNameLoc,
4480
563
        VarTemplate, DI->getType(), DI, SC, Converted);
4481
563
    Specialization->setTemplateArgsInfo(TemplateArgs);
4482
4483
563
    if (!PrevDecl)
4484
510
      VarTemplate->AddSpecialization(Specialization, InsertPos);
4485
563
  }
4486
4487
  // C++ [temp.expl.spec]p6:
4488
  //   If a template, a member template or the member of a class template is
4489
  //   explicitly specialized then that specialization shall be declared
4490
  //   before the first use of that specialization that would cause an implicit
4491
  //   instantiation to take place, in every translation unit in which such a
4492
  //   use occurs; no diagnostic is required.
4493
985
  if (PrevDecl && 
PrevDecl->getPointOfInstantiation().isValid()118
) {
4494
6
    bool Okay = false;
4495
12
    for (Decl *Prev = PrevDecl; Prev; 
Prev = Prev->getPreviousDecl()6
) {
4496
      // Is there any previous explicit specialization declaration?
4497
6
      if (getTemplateSpecializationKind(Prev) == TSK_ExplicitSpecialization) {
4498
0
        Okay = true;
4499
0
        break;
4500
0
      }
4501
6
    }
4502
4503
6
    if (!Okay) {
4504
6
      SourceRange Range(TemplateNameLoc, RAngleLoc);
4505
6
      Diag(TemplateNameLoc, diag::err_specialization_after_instantiation)
4506
6
          << Name << Range;
4507
4508
6
      Diag(PrevDecl->getPointOfInstantiation(),
4509
6
           diag::note_instantiation_required_here)
4510
6
          << (PrevDecl->getTemplateSpecializationKind() !=
4511
6
              TSK_ImplicitInstantiation);
4512
6
      return true;
4513
6
    }
4514
6
  }
4515
4516
979
  Specialization->setTemplateKeywordLoc(TemplateKWLoc);
4517
979
  Specialization->setLexicalDeclContext(CurContext);
4518
4519
  // Add the specialization into its lexical context, so that it can
4520
  // be seen when iterating through the list of declarations in that
4521
  // context. However, specializations are not found by name lookup.
4522
979
  CurContext->addDecl(Specialization);
4523
4524
  // Note that this is an explicit specialization.
4525
979
  Specialization->setSpecializationKind(TSK_ExplicitSpecialization);
4526
4527
979
  if (PrevDecl) {
4528
    // Check that this isn't a redefinition of this specialization,
4529
    // merging with previous declarations.
4530
112
    LookupResult PrevSpec(*this, GetNameForDeclarator(D), LookupOrdinaryName,
4531
112
                          forRedeclarationInCurContext());
4532
112
    PrevSpec.addDecl(PrevDecl);
4533
112
    D.setRedeclaration(CheckVariableDeclaration(Specialization, PrevSpec));
4534
867
  } else if (Specialization->isStaticDataMember() &&
4535
867
             
Specialization->isOutOfLine()328
) {
4536
163
    Specialization->setAccess(VarTemplate->getAccess());
4537
163
  }
4538
4539
979
  return Specialization;
4540
985
}
4541
4542
namespace {
4543
/// A partial specialization whose template arguments have matched
4544
/// a given template-id.
4545
struct PartialSpecMatchResult {
4546
  VarTemplatePartialSpecializationDecl *Partial;
4547
  TemplateArgumentList *Args;
4548
};
4549
} // end anonymous namespace
4550
4551
DeclResult
4552
Sema::CheckVarTemplateId(VarTemplateDecl *Template, SourceLocation TemplateLoc,
4553
                         SourceLocation TemplateNameLoc,
4554
10.6k
                         const TemplateArgumentListInfo &TemplateArgs) {
4555
10.6k
  assert(Template && "A variable template id without template?");
4556
4557
  // Check that the template argument list is well-formed for this template.
4558
0
  SmallVector<TemplateArgument, 4> Converted;
4559
10.6k
  if (CheckTemplateArgumentList(
4560
10.6k
          Template, TemplateNameLoc,
4561
10.6k
          const_cast<TemplateArgumentListInfo &>(TemplateArgs), false,
4562
10.6k
          Converted, /*UpdateArgsWithConversions=*/true))
4563
14
    return true;
4564
4565
  // Produce a placeholder value if the specialization is dependent.
4566
10.6k
  if (Template->getDeclContext()->isDependentContext() ||
4567
10.6k
      TemplateSpecializationType::anyDependentTemplateArguments(TemplateArgs,
4568
10.6k
                                                                Converted))
4569
4.27k
    return DeclResult();
4570
4571
  // Find the variable template specialization declaration that
4572
  // corresponds to these arguments.
4573
6.35k
  void *InsertPos = nullptr;
4574
6.35k
  if (VarTemplateSpecializationDecl *Spec = Template->findSpecialization(
4575
6.35k
          Converted, InsertPos)) {
4576
2.13k
    checkSpecializationVisibility(TemplateNameLoc, Spec);
4577
    // If we already have a variable template specialization, return it.
4578
2.13k
    return Spec;
4579
2.13k
  }
4580
4581
  // This is the first time we have referenced this variable template
4582
  // specialization. Create the canonical declaration and add it to
4583
  // the set of specializations, based on the closest partial specialization
4584
  // that it represents. That is,
4585
4.21k
  VarDecl *InstantiationPattern = Template->getTemplatedDecl();
4586
4.21k
  TemplateArgumentList TemplateArgList(TemplateArgumentList::OnStack,
4587
4.21k
                                       Converted);
4588
4.21k
  TemplateArgumentList *InstantiationArgs = &TemplateArgList;
4589
4.21k
  bool AmbiguousPartialSpec = false;
4590
4.21k
  typedef PartialSpecMatchResult MatchResult;
4591
4.21k
  SmallVector<MatchResult, 4> Matched;
4592
4.21k
  SourceLocation PointOfInstantiation = TemplateNameLoc;
4593
4.21k
  TemplateSpecCandidateSet FailedCandidates(PointOfInstantiation,
4594
4.21k
                                            /*ForTakingAddress=*/false);
4595
4596
  // 1. Attempt to find the closest partial specialization that this
4597
  // specializes, if any.
4598
  // TODO: Unify with InstantiateClassTemplateSpecialization()?
4599
  //       Perhaps better after unification of DeduceTemplateArguments() and
4600
  //       getMoreSpecializedPartialSpecialization().
4601
4.21k
  SmallVector<VarTemplatePartialSpecializationDecl *, 4> PartialSpecs;
4602
4.21k
  Template->getPartialSpecializations(PartialSpecs);
4603
4604
5.35k
  for (unsigned I = 0, N = PartialSpecs.size(); I != N; 
++I1.13k
) {
4605
1.13k
    VarTemplatePartialSpecializationDecl *Partial = PartialSpecs[I];
4606
1.13k
    TemplateDeductionInfo Info(FailedCandidates.getLocation());
4607
4608
1.13k
    if (TemplateDeductionResult Result =
4609
1.13k
            DeduceTemplateArguments(Partial, TemplateArgList, Info)) {
4610
      // Store the failed-deduction information for use in diagnostics, later.
4611
      // TODO: Actually use the failed-deduction info?
4612
287
      FailedCandidates.addCandidate().set(
4613
287
          DeclAccessPair::make(Template, AS_public), Partial,
4614
287
          MakeDeductionFailureInfo(Context, Result, Info));
4615
287
      (void)Result;
4616
850
    } else {
4617
850
      Matched.push_back(PartialSpecMatchResult());
4618
850
      Matched.back().Partial = Partial;
4619
850
      Matched.back().Args = Info.take();
4620
850
    }
4621
1.13k
  }
4622
4623
4.21k
  if (Matched.size() >= 1) {
4624
838
    SmallVector<MatchResult, 4>::iterator Best = Matched.begin();
4625
838
    if (Matched.size() == 1) {
4626
      //   -- If exactly one matching specialization is found, the
4627
      //      instantiation is generated from that specialization.
4628
      // We don't need to do anything for this.
4629
826
    } else {
4630
      //   -- If more than one matching specialization is found, the
4631
      //      partial order rules (14.5.4.2) are used to determine
4632
      //      whether one of the specializations is more specialized
4633
      //      than the others. If none of the specializations is more
4634
      //      specialized than all of the other matching
4635
      //      specializations, then the use of the variable template is
4636
      //      ambiguous and the program is ill-formed.
4637
12
      for (SmallVector<MatchResult, 4>::iterator P = Best + 1,
4638
12
                                                 PEnd = Matched.end();
4639
24
           P != PEnd; 
++P12
) {
4640
12
        if (getMoreSpecializedPartialSpecialization(P->Partial, Best->Partial,
4641
12
                                                    PointOfInstantiation) ==
4642
12
            P->Partial)
4643
8
          Best = P;
4644
12
      }
4645
4646
      // Determine if the best partial specialization is more specialized than
4647
      // the others.
4648
12
      for (SmallVector<MatchResult, 4>::iterator P = Matched.begin(),
4649
12
                                                 PEnd = Matched.end();
4650
33
           P != PEnd; 
++P21
) {
4651
24
        if (P != Best && getMoreSpecializedPartialSpecialization(
4652
12
                             P->Partial, Best->Partial,
4653
12
                             PointOfInstantiation) != Best->Partial) {
4654
3
          AmbiguousPartialSpec = true;
4655
3
          break;
4656
3
        }
4657
24
      }
4658
12
    }
4659
4660
    // Instantiate using the best variable template partial specialization.
4661
838
    InstantiationPattern = Best->Partial;
4662
838
    InstantiationArgs = Best->Args;
4663
3.37k
  } else {
4664
    //   -- If no match is found, the instantiation is generated
4665
    //      from the primary template.
4666
    // InstantiationPattern = Template->getTemplatedDecl();
4667
3.37k
  }
4668
4669
  // 2. Create the canonical declaration.
4670
  // Note that we do not instantiate a definition until we see an odr-use
4671
  // in DoMarkVarDeclReferenced().
4672
  // FIXME: LateAttrs et al.?
4673
4.21k
  VarTemplateSpecializationDecl *Decl = BuildVarTemplateInstantiation(
4674
4.21k
      Template, InstantiationPattern, *InstantiationArgs, TemplateArgs,
4675
4.21k
      Converted, TemplateNameLoc /*, LateAttrs, StartingScope*/);
4676
4.21k
  if (!Decl)
4677
0
    return true;
4678
4679
4.21k
  if (AmbiguousPartialSpec) {
4680
    // Partial ordering did not produce a clear winner. Complain.
4681
3
    Decl->setInvalidDecl();
4682
3
    Diag(PointOfInstantiation, diag::err_partial_spec_ordering_ambiguous)
4683
3
        << Decl;
4684
4685
    // Print the matching partial specializations.
4686
3
    for (MatchResult P : Matched)
4687
6
      Diag(P.Partial->getLocation(), diag::note_partial_spec_match)
4688
6
          << getTemplateArgumentBindingsText(P.Partial->getTemplateParameters(),
4689
6
                                             *P.Args);
4690
3
    return true;
4691
3
  }
4692
4693
4.21k
  if (VarTemplatePartialSpecializationDecl *D =
4694
4.21k
          dyn_cast<VarTemplatePartialSpecializationDecl>(InstantiationPattern))
4695
835
    Decl->setInstantiationOf(D, InstantiationArgs);
4696
4697
4.21k
  checkSpecializationVisibility(TemplateNameLoc, Decl);
4698
4699
4.21k
  assert(Decl && "No variable template specialization?");
4700
0
  return Decl;
4701
4.21k
}
4702
4703
ExprResult
4704
Sema::CheckVarTemplateId(const CXXScopeSpec &SS,
4705
                         const DeclarationNameInfo &NameInfo,
4706
                         VarTemplateDecl *Template, SourceLocation TemplateLoc,
4707
9.92k
                         const TemplateArgumentListInfo *TemplateArgs) {
4708
4709
9.92k
  DeclResult Decl = CheckVarTemplateId(Template, TemplateLoc, NameInfo.getLoc(),
4710
9.92k
                                       *TemplateArgs);
4711
9.92k
  if (Decl.isInvalid())
4712
16
    return ExprError();
4713
4714
9.91k
  if (!Decl.get())
4715
4.27k
    return ExprResult();
4716
4717
5.64k
  VarDecl *Var = cast<VarDecl>(Decl.get());
4718
5.64k
  if (!Var->getTemplateSpecializationKind())
4719
3.61k
    Var->setTemplateSpecializationKind(TSK_ImplicitInstantiation,
4720
3.61k
                                       NameInfo.getLoc());
4721
4722
  // Build an ordinary singleton decl ref.
4723
5.64k
  return BuildDeclarationNameExpr(SS, NameInfo, Var,
4724
5.64k
                                  /*FoundD=*/nullptr, TemplateArgs);
4725
9.91k
}
4726
4727
void Sema::diagnoseMissingTemplateArguments(TemplateName Name,
4728
90
                                            SourceLocation Loc) {
4729
90
  Diag(Loc, diag::err_template_missing_args)
4730
90
    << (int)getTemplateNameKindForDiagnostics(Name) << Name;
4731
90
  if (TemplateDecl *TD = Name.getAsTemplateDecl()) {
4732
90
    Diag(TD->getLocation(), diag::note_template_decl_here)
4733
90
      << TD->getTemplateParameters()->getSourceRange();
4734
90
  }
4735
90
}
4736
4737
ExprResult
4738
Sema::CheckConceptTemplateId(const CXXScopeSpec &SS,
4739
                             SourceLocation TemplateKWLoc,
4740
                             const DeclarationNameInfo &ConceptNameInfo,
4741
                             NamedDecl *FoundDecl,
4742
                             ConceptDecl *NamedConcept,
4743
19.3k
                             const TemplateArgumentListInfo *TemplateArgs) {
4744
19.3k
  assert(NamedConcept && "A concept template id without a template?");
4745
4746
0
  llvm::SmallVector<TemplateArgument, 4> Converted;
4747
19.3k
  if (CheckTemplateArgumentList(NamedConcept, ConceptNameInfo.getLoc(),
4748
19.3k
                           const_cast<TemplateArgumentListInfo&>(*TemplateArgs),
4749
19.3k
                                /*PartialTemplateArgs=*/false, Converted,
4750
19.3k
                                /*UpdateArgsWithConversions=*/false))
4751
3
    return ExprError();
4752
4753
19.3k
  ConstraintSatisfaction Satisfaction;
4754
19.3k
  bool AreArgsDependent =
4755
19.3k
      TemplateSpecializationType::anyDependentTemplateArguments(*TemplateArgs,
4756
19.3k
                                                                Converted);
4757
19.3k
  if (!AreArgsDependent &&
4758
19.3k
      CheckConstraintSatisfaction(
4759
9.80k
          NamedConcept, {NamedConcept->getConstraintExpr()}, Converted,
4760
9.80k
          SourceRange(SS.isSet() ? 
SS.getBeginLoc()177
:
ConceptNameInfo.getLoc()9.62k
,
4761
9.80k
                      TemplateArgs->getRAngleLoc()),
4762
9.80k
          Satisfaction))
4763
6
    return ExprError();
4764
4765
19.3k
  return ConceptSpecializationExpr::Create(Context,
4766
19.3k
      SS.isSet() ? 
SS.getWithLocInContext(Context)314
:
NestedNameSpecifierLoc{}19.0k
,
4767
19.3k
      TemplateKWLoc, ConceptNameInfo, FoundDecl, NamedConcept,
4768
19.3k
      ASTTemplateArgumentListInfo::Create(Context, *TemplateArgs), Converted,
4769
19.3k
      AreArgsDependent ? 
nullptr9.52k
:
&Satisfaction9.79k
);
4770
19.3k
}
4771
4772
ExprResult Sema::BuildTemplateIdExpr(const CXXScopeSpec &SS,
4773
                                     SourceLocation TemplateKWLoc,
4774
                                     LookupResult &R,
4775
                                     bool RequiresADL,
4776
546k
                                 const TemplateArgumentListInfo *TemplateArgs) {
4777
  // FIXME: Can we do any checking at this point? I guess we could check the
4778
  // template arguments that we have against the template name, if the template
4779
  // name refers to a single template. That's not a terribly common case,
4780
  // though.
4781
  // foo<int> could identify a single function unambiguously
4782
  // This approach does NOT work, since f<int>(1);
4783
  // gets resolved prior to resorting to overload resolution
4784
  // i.e., template<class T> void f(double);
4785
  //       vs template<class T, class U> void f(U);
4786
4787
  // These should be filtered out by our callers.
4788
546k
  assert(!R.isAmbiguous() && "ambiguous lookup when building templateid");
4789
4790
  // Non-function templates require a template argument list.
4791
546k
  if (auto *TD = R.getAsSingle<TemplateDecl>()) {
4792
13.5k
    if (!TemplateArgs && 
!isa<FunctionTemplateDecl>(TD)9
) {
4793
9
      diagnoseMissingTemplateArguments(TemplateName(TD), R.getNameLoc());
4794
9
      return ExprError();
4795
9
    }
4796
13.5k
  }
4797
4798
  // In C++1y, check variable template ids.
4799
546k
  if (R.getAsSingle<VarTemplateDecl>()) {
4800
9.92k
    ExprResult Res = CheckVarTemplateId(SS, R.getLookupNameInfo(),
4801
9.92k
                                        R.getAsSingle<VarTemplateDecl>(),
4802
9.92k
                                        TemplateKWLoc, TemplateArgs);
4803
9.92k
    if (Res.isInvalid() || 
Res.isUsable()9.91k
)
4804
5.65k
      return Res;
4805
    // Result is dependent. Carry on to build an UnresolvedLookupEpxr.
4806
9.92k
  }
4807
4808
540k
  if (R.getAsSingle<ConceptDecl>()) {
4809
3.65k
    return CheckConceptTemplateId(SS, TemplateKWLoc, R.getLookupNameInfo(),
4810
3.65k
                                  R.getFoundDecl(),
4811
3.65k
                                  R.getAsSingle<ConceptDecl>(), TemplateArgs);
4812
3.65k
  }
4813
4814
  // We don't want lookup warnings at this point.
4815
537k
  R.suppressDiagnostics();
4816
4817
537k
  UnresolvedLookupExpr *ULE
4818
537k
    = UnresolvedLookupExpr::Create(Context, R.getNamingClass(),
4819
537k
                                   SS.getWithLocInContext(Context),
4820
537k
                                   TemplateKWLoc,
4821
537k
                                   R.getLookupNameInfo(),
4822
537k
                                   RequiresADL, TemplateArgs,
4823
537k
                                   R.begin(), R.end());
4824
4825
537k
  return ULE;
4826
540k
}
4827
4828
// We actually only call this from template instantiation.
4829
ExprResult
4830
Sema::BuildQualifiedTemplateIdExpr(CXXScopeSpec &SS,
4831
                                   SourceLocation TemplateKWLoc,
4832
                                   const DeclarationNameInfo &NameInfo,
4833
47.3k
                             const TemplateArgumentListInfo *TemplateArgs) {
4834
4835
47.3k
  assert(TemplateArgs || TemplateKWLoc.isValid());
4836
0
  DeclContext *DC;
4837
47.3k
  if (!(DC = computeDeclContext(SS, false)) ||
4838
47.3k
      
DC->isDependentContext()29.4k
||
4839
47.3k
      
RequireCompleteDeclContext(SS, DC)29.4k
)
4840
17.8k
    return BuildDependentDeclRefExpr(SS, TemplateKWLoc, NameInfo, TemplateArgs);
4841
4842
29.4k
  bool MemberOfUnknownSpecialization;
4843
29.4k
  LookupResult R(*this, NameInfo, LookupOrdinaryName);
4844
29.4k
  if (LookupTemplateName(R, (Scope *)nullptr, SS, QualType(),
4845
29.4k
                         /*Entering*/false, MemberOfUnknownSpecialization,
4846
29.4k
                         TemplateKWLoc))
4847
3
    return ExprError();
4848
4849
29.4k
  if (R.isAmbiguous())
4850
0
    return ExprError();
4851
4852
29.4k
  if (R.empty()) {
4853
42
    Diag(NameInfo.getLoc(), diag::err_no_member)
4854
42
      << NameInfo.getName() << DC <<