clang  8.0.0svn
SemaTemplateInstantiateDecl.cpp
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1 //===--- SemaTemplateInstantiateDecl.cpp - C++ Template Decl Instantiation ===/
2 //
3 // The LLVM Compiler Infrastructure
4 //
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
7 //===----------------------------------------------------------------------===/
8 //
9 // This file implements C++ template instantiation for declarations.
10 //
11 //===----------------------------------------------------------------------===/
13 #include "clang/AST/ASTConsumer.h"
14 #include "clang/AST/ASTContext.h"
16 #include "clang/AST/DeclTemplate.h"
17 #include "clang/AST/DeclVisitor.h"
19 #include "clang/AST/Expr.h"
20 #include "clang/AST/ExprCXX.h"
22 #include "clang/AST/TypeLoc.h"
24 #include "clang/Sema/Lookup.h"
25 #include "clang/Sema/Template.h"
27 
28 using namespace clang;
29 
30 static bool isDeclWithinFunction(const Decl *D) {
31  const DeclContext *DC = D->getDeclContext();
32  if (DC->isFunctionOrMethod())
33  return true;
34 
35  if (DC->isRecord())
36  return cast<CXXRecordDecl>(DC)->isLocalClass();
37 
38  return false;
39 }
40 
41 template<typename DeclT>
42 static bool SubstQualifier(Sema &SemaRef, const DeclT *OldDecl, DeclT *NewDecl,
43  const MultiLevelTemplateArgumentList &TemplateArgs) {
44  if (!OldDecl->getQualifierLoc())
45  return false;
46 
47  assert((NewDecl->getFriendObjectKind() ||
48  !OldDecl->getLexicalDeclContext()->isDependentContext()) &&
49  "non-friend with qualified name defined in dependent context");
50  Sema::ContextRAII SavedContext(
51  SemaRef,
52  const_cast<DeclContext *>(NewDecl->getFriendObjectKind()
53  ? NewDecl->getLexicalDeclContext()
54  : OldDecl->getLexicalDeclContext()));
55 
56  NestedNameSpecifierLoc NewQualifierLoc
57  = SemaRef.SubstNestedNameSpecifierLoc(OldDecl->getQualifierLoc(),
58  TemplateArgs);
59 
60  if (!NewQualifierLoc)
61  return true;
62 
63  NewDecl->setQualifierInfo(NewQualifierLoc);
64  return false;
65 }
66 
68  DeclaratorDecl *NewDecl) {
69  return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
70 }
71 
73  TagDecl *NewDecl) {
74  return ::SubstQualifier(SemaRef, OldDecl, NewDecl, TemplateArgs);
75 }
76 
77 // Include attribute instantiation code.
78 #include "clang/Sema/AttrTemplateInstantiate.inc"
79 
81  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
82  const AlignedAttr *Aligned, Decl *New, bool IsPackExpansion) {
83  if (Aligned->isAlignmentExpr()) {
84  // The alignment expression is a constant expression.
87  ExprResult Result = S.SubstExpr(Aligned->getAlignmentExpr(), TemplateArgs);
88  if (!Result.isInvalid())
89  S.AddAlignedAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
90  Aligned->getSpellingListIndex(), IsPackExpansion);
91  } else {
92  TypeSourceInfo *Result = S.SubstType(Aligned->getAlignmentType(),
93  TemplateArgs, Aligned->getLocation(),
94  DeclarationName());
95  if (Result)
96  S.AddAlignedAttr(Aligned->getLocation(), New, Result,
97  Aligned->getSpellingListIndex(), IsPackExpansion);
98  }
99 }
100 
102  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
103  const AlignedAttr *Aligned, Decl *New) {
104  if (!Aligned->isPackExpansion()) {
105  instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
106  return;
107  }
108 
110  if (Aligned->isAlignmentExpr())
111  S.collectUnexpandedParameterPacks(Aligned->getAlignmentExpr(),
112  Unexpanded);
113  else
114  S.collectUnexpandedParameterPacks(Aligned->getAlignmentType()->getTypeLoc(),
115  Unexpanded);
116  assert(!Unexpanded.empty() && "Pack expansion without parameter packs?");
117 
118  // Determine whether we can expand this attribute pack yet.
119  bool Expand = true, RetainExpansion = false;
120  Optional<unsigned> NumExpansions;
121  // FIXME: Use the actual location of the ellipsis.
122  SourceLocation EllipsisLoc = Aligned->getLocation();
123  if (S.CheckParameterPacksForExpansion(EllipsisLoc, Aligned->getRange(),
124  Unexpanded, TemplateArgs, Expand,
125  RetainExpansion, NumExpansions))
126  return;
127 
128  if (!Expand) {
129  Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, -1);
130  instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, true);
131  } else {
132  for (unsigned I = 0; I != *NumExpansions; ++I) {
134  instantiateDependentAlignedAttr(S, TemplateArgs, Aligned, New, false);
135  }
136  }
137 }
138 
140  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
141  const AssumeAlignedAttr *Aligned, Decl *New) {
142  // The alignment expression is a constant expression.
145 
146  Expr *E, *OE = nullptr;
147  ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
148  if (Result.isInvalid())
149  return;
150  E = Result.getAs<Expr>();
151 
152  if (Aligned->getOffset()) {
153  Result = S.SubstExpr(Aligned->getOffset(), TemplateArgs);
154  if (Result.isInvalid())
155  return;
156  OE = Result.getAs<Expr>();
157  }
158 
159  S.AddAssumeAlignedAttr(Aligned->getLocation(), New, E, OE,
160  Aligned->getSpellingListIndex());
161 }
162 
164  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
165  const AlignValueAttr *Aligned, Decl *New) {
166  // The alignment expression is a constant expression.
169  ExprResult Result = S.SubstExpr(Aligned->getAlignment(), TemplateArgs);
170  if (!Result.isInvalid())
171  S.AddAlignValueAttr(Aligned->getLocation(), New, Result.getAs<Expr>(),
172  Aligned->getSpellingListIndex());
173 }
174 
176  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
177  const AllocAlignAttr *Align, Decl *New) {
178  Expr *Param = IntegerLiteral::Create(
179  S.getASTContext(),
180  llvm::APInt(64, Align->getParamIndex().getSourceIndex()),
181  S.getASTContext().UnsignedLongLongTy, Align->getLocation());
182  S.AddAllocAlignAttr(Align->getLocation(), New, Param,
183  Align->getSpellingListIndex());
184 }
185 
187  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
188  const Attr *A, Expr *OldCond, const Decl *Tmpl, FunctionDecl *New) {
189  Expr *Cond = nullptr;
190  {
191  Sema::ContextRAII SwitchContext(S, New);
194  ExprResult Result = S.SubstExpr(OldCond, TemplateArgs);
195  if (Result.isInvalid())
196  return nullptr;
197  Cond = Result.getAs<Expr>();
198  }
199  if (!Cond->isTypeDependent()) {
200  ExprResult Converted = S.PerformContextuallyConvertToBool(Cond);
201  if (Converted.isInvalid())
202  return nullptr;
203  Cond = Converted.get();
204  }
205 
207  if (OldCond->isValueDependent() && !Cond->isValueDependent() &&
208  !Expr::isPotentialConstantExprUnevaluated(Cond, New, Diags)) {
209  S.Diag(A->getLocation(), diag::err_attr_cond_never_constant_expr) << A;
210  for (const auto &P : Diags)
211  S.Diag(P.first, P.second);
212  return nullptr;
213  }
214  return Cond;
215 }
216 
218  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
219  const EnableIfAttr *EIA, const Decl *Tmpl, FunctionDecl *New) {
221  S, TemplateArgs, EIA, EIA->getCond(), Tmpl, New);
222 
223  if (Cond)
224  New->addAttr(new (S.getASTContext()) EnableIfAttr(
225  EIA->getLocation(), S.getASTContext(), Cond, EIA->getMessage(),
226  EIA->getSpellingListIndex()));
227 }
228 
230  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
231  const DiagnoseIfAttr *DIA, const Decl *Tmpl, FunctionDecl *New) {
233  S, TemplateArgs, DIA, DIA->getCond(), Tmpl, New);
234 
235  if (Cond)
236  New->addAttr(new (S.getASTContext()) DiagnoseIfAttr(
237  DIA->getLocation(), S.getASTContext(), Cond, DIA->getMessage(),
238  DIA->getDiagnosticType(), DIA->getArgDependent(), New,
239  DIA->getSpellingListIndex()));
240 }
241 
242 // Constructs and adds to New a new instance of CUDALaunchBoundsAttr using
243 // template A as the base and arguments from TemplateArgs.
245  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
246  const CUDALaunchBoundsAttr &Attr, Decl *New) {
247  // The alignment expression is a constant expression.
250 
251  ExprResult Result = S.SubstExpr(Attr.getMaxThreads(), TemplateArgs);
252  if (Result.isInvalid())
253  return;
254  Expr *MaxThreads = Result.getAs<Expr>();
255 
256  Expr *MinBlocks = nullptr;
257  if (Attr.getMinBlocks()) {
258  Result = S.SubstExpr(Attr.getMinBlocks(), TemplateArgs);
259  if (Result.isInvalid())
260  return;
261  MinBlocks = Result.getAs<Expr>();
262  }
263 
264  S.AddLaunchBoundsAttr(Attr.getLocation(), New, MaxThreads, MinBlocks,
265  Attr.getSpellingListIndex());
266 }
267 
268 static void
270  const MultiLevelTemplateArgumentList &TemplateArgs,
271  const ModeAttr &Attr, Decl *New) {
272  S.AddModeAttr(Attr.getRange(), New, Attr.getMode(),
273  Attr.getSpellingListIndex(), /*InInstantiation=*/true);
274 }
275 
276 /// Instantiation of 'declare simd' attribute and its arguments.
278  Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs,
279  const OMPDeclareSimdDeclAttr &Attr, Decl *New) {
280  // Allow 'this' in clauses with varlists.
281  if (auto *FTD = dyn_cast<FunctionTemplateDecl>(New))
282  New = FTD->getTemplatedDecl();
283  auto *FD = cast<FunctionDecl>(New);
284  auto *ThisContext = dyn_cast_or_null<CXXRecordDecl>(FD->getDeclContext());
285  SmallVector<Expr *, 4> Uniforms, Aligneds, Alignments, Linears, Steps;
286  SmallVector<unsigned, 4> LinModifiers;
287 
288  auto &&Subst = [&](Expr *E) -> ExprResult {
289  if (auto *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParenImpCasts()))
290  if (auto *PVD = dyn_cast<ParmVarDecl>(DRE->getDecl())) {
291  Sema::ContextRAII SavedContext(S, FD);
292  LocalInstantiationScope Local(S);
293  if (FD->getNumParams() > PVD->getFunctionScopeIndex())
294  Local.InstantiatedLocal(
295  PVD, FD->getParamDecl(PVD->getFunctionScopeIndex()));
296  return S.SubstExpr(E, TemplateArgs);
297  }
298  Sema::CXXThisScopeRAII ThisScope(S, ThisContext, /*TypeQuals=*/0,
299  FD->isCXXInstanceMember());
300  return S.SubstExpr(E, TemplateArgs);
301  };
302 
303  ExprResult Simdlen;
304  if (auto *E = Attr.getSimdlen())
305  Simdlen = Subst(E);
306 
307  if (Attr.uniforms_size() > 0) {
308  for(auto *E : Attr.uniforms()) {
309  ExprResult Inst = Subst(E);
310  if (Inst.isInvalid())
311  continue;
312  Uniforms.push_back(Inst.get());
313  }
314  }
315 
316  auto AI = Attr.alignments_begin();
317  for (auto *E : Attr.aligneds()) {
318  ExprResult Inst = Subst(E);
319  if (Inst.isInvalid())
320  continue;
321  Aligneds.push_back(Inst.get());
322  Inst = ExprEmpty();
323  if (*AI)
324  Inst = S.SubstExpr(*AI, TemplateArgs);
325  Alignments.push_back(Inst.get());
326  ++AI;
327  }
328 
329  auto SI = Attr.steps_begin();
330  for (auto *E : Attr.linears()) {
331  ExprResult Inst = Subst(E);
332  if (Inst.isInvalid())
333  continue;
334  Linears.push_back(Inst.get());
335  Inst = ExprEmpty();
336  if (*SI)
337  Inst = S.SubstExpr(*SI, TemplateArgs);
338  Steps.push_back(Inst.get());
339  ++SI;
340  }
341  LinModifiers.append(Attr.modifiers_begin(), Attr.modifiers_end());
343  S.ConvertDeclToDeclGroup(New), Attr.getBranchState(), Simdlen.get(),
344  Uniforms, Aligneds, Alignments, Linears, LinModifiers, Steps,
345  Attr.getRange());
346 }
347 
349  const MultiLevelTemplateArgumentList &TemplateArgs, const Decl *Tmpl,
350  Decl *New, LateInstantiatedAttrVec *LateAttrs,
351  LocalInstantiationScope *OuterMostScope) {
352  if (NamedDecl *ND = dyn_cast<NamedDecl>(New)) {
353  for (const auto *TmplAttr : Tmpl->attrs()) {
354  // FIXME: If any of the special case versions from InstantiateAttrs become
355  // applicable to template declaration, we'll need to add them here.
356  CXXThisScopeRAII ThisScope(
357  *this, dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext()),
358  /*TypeQuals*/ 0, ND->isCXXInstanceMember());
359 
361  TmplAttr, Context, *this, TemplateArgs);
362  if (NewAttr)
363  New->addAttr(NewAttr);
364  }
365  }
366 }
367 
369  const Decl *Tmpl, Decl *New,
370  LateInstantiatedAttrVec *LateAttrs,
371  LocalInstantiationScope *OuterMostScope) {
372  for (const auto *TmplAttr : Tmpl->attrs()) {
373  // FIXME: This should be generalized to more than just the AlignedAttr.
374  const AlignedAttr *Aligned = dyn_cast<AlignedAttr>(TmplAttr);
375  if (Aligned && Aligned->isAlignmentDependent()) {
376  instantiateDependentAlignedAttr(*this, TemplateArgs, Aligned, New);
377  continue;
378  }
379 
380  const AssumeAlignedAttr *AssumeAligned = dyn_cast<AssumeAlignedAttr>(TmplAttr);
381  if (AssumeAligned) {
382  instantiateDependentAssumeAlignedAttr(*this, TemplateArgs, AssumeAligned, New);
383  continue;
384  }
385 
386  const AlignValueAttr *AlignValue = dyn_cast<AlignValueAttr>(TmplAttr);
387  if (AlignValue) {
388  instantiateDependentAlignValueAttr(*this, TemplateArgs, AlignValue, New);
389  continue;
390  }
391 
392  if (const auto *AllocAlign = dyn_cast<AllocAlignAttr>(TmplAttr)) {
393  instantiateDependentAllocAlignAttr(*this, TemplateArgs, AllocAlign, New);
394  continue;
395  }
396 
397 
398  if (const auto *EnableIf = dyn_cast<EnableIfAttr>(TmplAttr)) {
399  instantiateDependentEnableIfAttr(*this, TemplateArgs, EnableIf, Tmpl,
400  cast<FunctionDecl>(New));
401  continue;
402  }
403 
404  if (const auto *DiagnoseIf = dyn_cast<DiagnoseIfAttr>(TmplAttr)) {
405  instantiateDependentDiagnoseIfAttr(*this, TemplateArgs, DiagnoseIf, Tmpl,
406  cast<FunctionDecl>(New));
407  continue;
408  }
409 
410  if (const CUDALaunchBoundsAttr *CUDALaunchBounds =
411  dyn_cast<CUDALaunchBoundsAttr>(TmplAttr)) {
412  instantiateDependentCUDALaunchBoundsAttr(*this, TemplateArgs,
413  *CUDALaunchBounds, New);
414  continue;
415  }
416 
417  if (const ModeAttr *Mode = dyn_cast<ModeAttr>(TmplAttr)) {
418  instantiateDependentModeAttr(*this, TemplateArgs, *Mode, New);
419  continue;
420  }
421 
422  if (const auto *OMPAttr = dyn_cast<OMPDeclareSimdDeclAttr>(TmplAttr)) {
423  instantiateOMPDeclareSimdDeclAttr(*this, TemplateArgs, *OMPAttr, New);
424  continue;
425  }
426 
427  // Existing DLL attribute on the instantiation takes precedence.
428  if (TmplAttr->getKind() == attr::DLLExport ||
429  TmplAttr->getKind() == attr::DLLImport) {
430  if (New->hasAttr<DLLExportAttr>() || New->hasAttr<DLLImportAttr>()) {
431  continue;
432  }
433  }
434 
435  if (auto ABIAttr = dyn_cast<ParameterABIAttr>(TmplAttr)) {
436  AddParameterABIAttr(ABIAttr->getRange(), New, ABIAttr->getABI(),
437  ABIAttr->getSpellingListIndex());
438  continue;
439  }
440 
441  if (isa<NSConsumedAttr>(TmplAttr) || isa<CFConsumedAttr>(TmplAttr)) {
442  AddNSConsumedAttr(TmplAttr->getRange(), New,
443  TmplAttr->getSpellingListIndex(),
444  isa<NSConsumedAttr>(TmplAttr),
445  /*template instantiation*/ true);
446  continue;
447  }
448 
449  assert(!TmplAttr->isPackExpansion());
450  if (TmplAttr->isLateParsed() && LateAttrs) {
451  // Late parsed attributes must be instantiated and attached after the
452  // enclosing class has been instantiated. See Sema::InstantiateClass.
453  LocalInstantiationScope *Saved = nullptr;
454  if (CurrentInstantiationScope)
455  Saved = CurrentInstantiationScope->cloneScopes(OuterMostScope);
456  LateAttrs->push_back(LateInstantiatedAttribute(TmplAttr, Saved, New));
457  } else {
458  // Allow 'this' within late-parsed attributes.
459  NamedDecl *ND = dyn_cast<NamedDecl>(New);
460  CXXRecordDecl *ThisContext =
461  dyn_cast_or_null<CXXRecordDecl>(ND->getDeclContext());
462  CXXThisScopeRAII ThisScope(*this, ThisContext, /*TypeQuals*/0,
463  ND && ND->isCXXInstanceMember());
464 
465  Attr *NewAttr = sema::instantiateTemplateAttribute(TmplAttr, Context,
466  *this, TemplateArgs);
467  if (NewAttr)
468  New->addAttr(NewAttr);
469  }
470  }
471 }
472 
473 /// Get the previous declaration of a declaration for the purposes of template
474 /// instantiation. If this finds a previous declaration, then the previous
475 /// declaration of the instantiation of D should be an instantiation of the
476 /// result of this function.
477 template<typename DeclT>
478 static DeclT *getPreviousDeclForInstantiation(DeclT *D) {
479  DeclT *Result = D->getPreviousDecl();
480 
481  // If the declaration is within a class, and the previous declaration was
482  // merged from a different definition of that class, then we don't have a
483  // previous declaration for the purpose of template instantiation.
484  if (Result && isa<CXXRecordDecl>(D->getDeclContext()) &&
485  D->getLexicalDeclContext() != Result->getLexicalDeclContext())
486  return nullptr;
487 
488  return Result;
489 }
490 
491 Decl *
492 TemplateDeclInstantiator::VisitTranslationUnitDecl(TranslationUnitDecl *D) {
493  llvm_unreachable("Translation units cannot be instantiated");
494 }
495 
496 Decl *
497 TemplateDeclInstantiator::VisitPragmaCommentDecl(PragmaCommentDecl *D) {
498  llvm_unreachable("pragma comment cannot be instantiated");
499 }
500 
501 Decl *TemplateDeclInstantiator::VisitPragmaDetectMismatchDecl(
503  llvm_unreachable("pragma comment cannot be instantiated");
504 }
505 
506 Decl *
507 TemplateDeclInstantiator::VisitExternCContextDecl(ExternCContextDecl *D) {
508  llvm_unreachable("extern \"C\" context cannot be instantiated");
509 }
510 
511 Decl *
512 TemplateDeclInstantiator::VisitLabelDecl(LabelDecl *D) {
513  LabelDecl *Inst = LabelDecl::Create(SemaRef.Context, Owner, D->getLocation(),
514  D->getIdentifier());
515  Owner->addDecl(Inst);
516  return Inst;
517 }
518 
519 Decl *
520 TemplateDeclInstantiator::VisitNamespaceDecl(NamespaceDecl *D) {
521  llvm_unreachable("Namespaces cannot be instantiated");
522 }
523 
524 Decl *
525 TemplateDeclInstantiator::VisitNamespaceAliasDecl(NamespaceAliasDecl *D) {
526  NamespaceAliasDecl *Inst
527  = NamespaceAliasDecl::Create(SemaRef.Context, Owner,
528  D->getNamespaceLoc(),
529  D->getAliasLoc(),
530  D->getIdentifier(),
531  D->getQualifierLoc(),
532  D->getTargetNameLoc(),
533  D->getNamespace());
534  Owner->addDecl(Inst);
535  return Inst;
536 }
537 
539  bool IsTypeAlias) {
540  bool Invalid = false;
542  if (DI->getType()->isInstantiationDependentType() ||
543  DI->getType()->isVariablyModifiedType()) {
544  DI = SemaRef.SubstType(DI, TemplateArgs,
545  D->getLocation(), D->getDeclName());
546  if (!DI) {
547  Invalid = true;
548  DI = SemaRef.Context.getTrivialTypeSourceInfo(SemaRef.Context.IntTy);
549  }
550  } else {
552  }
553 
554  // HACK: g++ has a bug where it gets the value kind of ?: wrong.
555  // libstdc++ relies upon this bug in its implementation of common_type.
556  // If we happen to be processing that implementation, fake up the g++ ?:
557  // semantics. See LWG issue 2141 for more information on the bug.
558  const DecltypeType *DT = DI->getType()->getAs<DecltypeType>();
559  CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D->getDeclContext());
560  if (DT && RD && isa<ConditionalOperator>(DT->getUnderlyingExpr()) &&
561  DT->isReferenceType() &&
562  RD->getEnclosingNamespaceContext() == SemaRef.getStdNamespace() &&
563  RD->getIdentifier() && RD->getIdentifier()->isStr("common_type") &&
564  D->getIdentifier() && D->getIdentifier()->isStr("type") &&
566  // Fold it to the (non-reference) type which g++ would have produced.
567  DI = SemaRef.Context.getTrivialTypeSourceInfo(
568  DI->getType().getNonReferenceType());
569 
570  // Create the new typedef
571  TypedefNameDecl *Typedef;
572  if (IsTypeAlias)
573  Typedef = TypeAliasDecl::Create(SemaRef.Context, Owner, D->getBeginLoc(),
574  D->getLocation(), D->getIdentifier(), DI);
575  else
576  Typedef = TypedefDecl::Create(SemaRef.Context, Owner, D->getBeginLoc(),
577  D->getLocation(), D->getIdentifier(), DI);
578  if (Invalid)
579  Typedef->setInvalidDecl();
580 
581  // If the old typedef was the name for linkage purposes of an anonymous
582  // tag decl, re-establish that relationship for the new typedef.
583  if (const TagType *oldTagType = D->getUnderlyingType()->getAs<TagType>()) {
584  TagDecl *oldTag = oldTagType->getDecl();
585  if (oldTag->getTypedefNameForAnonDecl() == D && !Invalid) {
586  TagDecl *newTag = DI->getType()->castAs<TagType>()->getDecl();
587  assert(!newTag->hasNameForLinkage());
588  newTag->setTypedefNameForAnonDecl(Typedef);
589  }
590  }
591 
593  NamedDecl *InstPrev = SemaRef.FindInstantiatedDecl(D->getLocation(), Prev,
594  TemplateArgs);
595  if (!InstPrev)
596  return nullptr;
597 
598  TypedefNameDecl *InstPrevTypedef = cast<TypedefNameDecl>(InstPrev);
599 
600  // If the typedef types are not identical, reject them.
601  SemaRef.isIncompatibleTypedef(InstPrevTypedef, Typedef);
602 
603  Typedef->setPreviousDecl(InstPrevTypedef);
604  }
605 
606  SemaRef.InstantiateAttrs(TemplateArgs, D, Typedef);
607 
608  Typedef->setAccess(D->getAccess());
609 
610  return Typedef;
611 }
612 
613 Decl *TemplateDeclInstantiator::VisitTypedefDecl(TypedefDecl *D) {
614  Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/false);
615  if (Typedef)
616  Owner->addDecl(Typedef);
617  return Typedef;
618 }
619 
620 Decl *TemplateDeclInstantiator::VisitTypeAliasDecl(TypeAliasDecl *D) {
621  Decl *Typedef = InstantiateTypedefNameDecl(D, /*IsTypeAlias=*/true);
622  if (Typedef)
623  Owner->addDecl(Typedef);
624  return Typedef;
625 }
626 
627 Decl *
628 TemplateDeclInstantiator::VisitTypeAliasTemplateDecl(TypeAliasTemplateDecl *D) {
629  // Create a local instantiation scope for this type alias template, which
630  // will contain the instantiations of the template parameters.
632 
633  TemplateParameterList *TempParams = D->getTemplateParameters();
634  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
635  if (!InstParams)
636  return nullptr;
637 
638  TypeAliasDecl *Pattern = D->getTemplatedDecl();
639 
640  TypeAliasTemplateDecl *PrevAliasTemplate = nullptr;
641  if (getPreviousDeclForInstantiation<TypedefNameDecl>(Pattern)) {
642  DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
643  if (!Found.empty()) {
644  PrevAliasTemplate = dyn_cast<TypeAliasTemplateDecl>(Found.front());
645  }
646  }
647 
648  TypeAliasDecl *AliasInst = cast_or_null<TypeAliasDecl>(
649  InstantiateTypedefNameDecl(Pattern, /*IsTypeAlias=*/true));
650  if (!AliasInst)
651  return nullptr;
652 
654  = TypeAliasTemplateDecl::Create(SemaRef.Context, Owner, D->getLocation(),
655  D->getDeclName(), InstParams, AliasInst);
656  AliasInst->setDescribedAliasTemplate(Inst);
657  if (PrevAliasTemplate)
658  Inst->setPreviousDecl(PrevAliasTemplate);
659 
660  Inst->setAccess(D->getAccess());
661 
662  if (!PrevAliasTemplate)
664 
665  Owner->addDecl(Inst);
666 
667  return Inst;
668 }
669 
670 Decl *TemplateDeclInstantiator::VisitBindingDecl(BindingDecl *D) {
671  auto *NewBD = BindingDecl::Create(SemaRef.Context, Owner, D->getLocation(),
672  D->getIdentifier());
673  NewBD->setReferenced(D->isReferenced());
674  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewBD);
675  return NewBD;
676 }
677 
678 Decl *TemplateDeclInstantiator::VisitDecompositionDecl(DecompositionDecl *D) {
679  // Transform the bindings first.
680  SmallVector<BindingDecl*, 16> NewBindings;
681  for (auto *OldBD : D->bindings())
682  NewBindings.push_back(cast<BindingDecl>(VisitBindingDecl(OldBD)));
683  ArrayRef<BindingDecl*> NewBindingArray = NewBindings;
684 
685  auto *NewDD = cast_or_null<DecompositionDecl>(
686  VisitVarDecl(D, /*InstantiatingVarTemplate=*/false, &NewBindingArray));
687 
688  if (!NewDD || NewDD->isInvalidDecl())
689  for (auto *NewBD : NewBindings)
690  NewBD->setInvalidDecl();
691 
692  return NewDD;
693 }
694 
696  return VisitVarDecl(D, /*InstantiatingVarTemplate=*/false);
697 }
698 
700  bool InstantiatingVarTemplate,
701  ArrayRef<BindingDecl*> *Bindings) {
702 
703  // Do substitution on the type of the declaration
704  TypeSourceInfo *DI = SemaRef.SubstType(
705  D->getTypeSourceInfo(), TemplateArgs, D->getTypeSpecStartLoc(),
706  D->getDeclName(), /*AllowDeducedTST*/true);
707  if (!DI)
708  return nullptr;
709 
710  if (DI->getType()->isFunctionType()) {
711  SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
712  << D->isStaticDataMember() << DI->getType();
713  return nullptr;
714  }
715 
716  DeclContext *DC = Owner;
717  if (D->isLocalExternDecl())
719 
720  // Build the instantiated declaration.
721  VarDecl *Var;
722  if (Bindings)
723  Var = DecompositionDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
724  D->getLocation(), DI->getType(), DI,
725  D->getStorageClass(), *Bindings);
726  else
727  Var = VarDecl::Create(SemaRef.Context, DC, D->getInnerLocStart(),
728  D->getLocation(), D->getIdentifier(), DI->getType(),
729  DI, D->getStorageClass());
730 
731  // In ARC, infer 'retaining' for variables of retainable type.
732  if (SemaRef.getLangOpts().ObjCAutoRefCount &&
733  SemaRef.inferObjCARCLifetime(Var))
734  Var->setInvalidDecl();
735 
736  // Substitute the nested name specifier, if any.
737  if (SubstQualifier(D, Var))
738  return nullptr;
739 
740  SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs, Owner,
741  StartingScope, InstantiatingVarTemplate);
742 
743  if (D->isNRVOVariable()) {
744  QualType ReturnType = cast<FunctionDecl>(DC)->getReturnType();
745  if (SemaRef.isCopyElisionCandidate(ReturnType, Var, Sema::CES_Strict))
746  Var->setNRVOVariable(true);
747  }
748 
749  Var->setImplicit(D->isImplicit());
750 
751  return Var;
752 }
753 
754 Decl *TemplateDeclInstantiator::VisitAccessSpecDecl(AccessSpecDecl *D) {
755  AccessSpecDecl* AD
756  = AccessSpecDecl::Create(SemaRef.Context, D->getAccess(), Owner,
758  Owner->addHiddenDecl(AD);
759  return AD;
760 }
761 
762 Decl *TemplateDeclInstantiator::VisitFieldDecl(FieldDecl *D) {
763  bool Invalid = false;
765  if (DI->getType()->isInstantiationDependentType() ||
766  DI->getType()->isVariablyModifiedType()) {
767  DI = SemaRef.SubstType(DI, TemplateArgs,
768  D->getLocation(), D->getDeclName());
769  if (!DI) {
770  DI = D->getTypeSourceInfo();
771  Invalid = true;
772  } else if (DI->getType()->isFunctionType()) {
773  // C++ [temp.arg.type]p3:
774  // If a declaration acquires a function type through a type
775  // dependent on a template-parameter and this causes a
776  // declaration that does not use the syntactic form of a
777  // function declarator to have function type, the program is
778  // ill-formed.
779  SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
780  << DI->getType();
781  Invalid = true;
782  }
783  } else {
785  }
786 
787  Expr *BitWidth = D->getBitWidth();
788  if (Invalid)
789  BitWidth = nullptr;
790  else if (BitWidth) {
791  // The bit-width expression is a constant expression.
794 
795  ExprResult InstantiatedBitWidth
796  = SemaRef.SubstExpr(BitWidth, TemplateArgs);
797  if (InstantiatedBitWidth.isInvalid()) {
798  Invalid = true;
799  BitWidth = nullptr;
800  } else
801  BitWidth = InstantiatedBitWidth.getAs<Expr>();
802  }
803 
804  FieldDecl *Field = SemaRef.CheckFieldDecl(D->getDeclName(),
805  DI->getType(), DI,
806  cast<RecordDecl>(Owner),
807  D->getLocation(),
808  D->isMutable(),
809  BitWidth,
810  D->getInClassInitStyle(),
811  D->getInnerLocStart(),
812  D->getAccess(),
813  nullptr);
814  if (!Field) {
815  cast<Decl>(Owner)->setInvalidDecl();
816  return nullptr;
817  }
818 
819  SemaRef.InstantiateAttrs(TemplateArgs, D, Field, LateAttrs, StartingScope);
820 
821  if (Field->hasAttrs())
822  SemaRef.CheckAlignasUnderalignment(Field);
823 
824  if (Invalid)
825  Field->setInvalidDecl();
826 
827  if (!Field->getDeclName()) {
828  // Keep track of where this decl came from.
830  }
831  if (CXXRecordDecl *Parent= dyn_cast<CXXRecordDecl>(Field->getDeclContext())) {
832  if (Parent->isAnonymousStructOrUnion() &&
833  Parent->getRedeclContext()->isFunctionOrMethod())
834  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Field);
835  }
836 
837  Field->setImplicit(D->isImplicit());
838  Field->setAccess(D->getAccess());
839  Owner->addDecl(Field);
840 
841  return Field;
842 }
843 
844 Decl *TemplateDeclInstantiator::VisitMSPropertyDecl(MSPropertyDecl *D) {
845  bool Invalid = false;
847 
848  if (DI->getType()->isVariablyModifiedType()) {
849  SemaRef.Diag(D->getLocation(), diag::err_property_is_variably_modified)
850  << D;
851  Invalid = true;
852  } else if (DI->getType()->isInstantiationDependentType()) {
853  DI = SemaRef.SubstType(DI, TemplateArgs,
854  D->getLocation(), D->getDeclName());
855  if (!DI) {
856  DI = D->getTypeSourceInfo();
857  Invalid = true;
858  } else if (DI->getType()->isFunctionType()) {
859  // C++ [temp.arg.type]p3:
860  // If a declaration acquires a function type through a type
861  // dependent on a template-parameter and this causes a
862  // declaration that does not use the syntactic form of a
863  // function declarator to have function type, the program is
864  // ill-formed.
865  SemaRef.Diag(D->getLocation(), diag::err_field_instantiates_to_function)
866  << DI->getType();
867  Invalid = true;
868  }
869  } else {
871  }
872 
874  SemaRef.Context, Owner, D->getLocation(), D->getDeclName(), DI->getType(),
875  DI, D->getBeginLoc(), D->getGetterId(), D->getSetterId());
876 
877  SemaRef.InstantiateAttrs(TemplateArgs, D, Property, LateAttrs,
878  StartingScope);
879 
880  if (Invalid)
881  Property->setInvalidDecl();
882 
883  Property->setAccess(D->getAccess());
884  Owner->addDecl(Property);
885 
886  return Property;
887 }
888 
889 Decl *TemplateDeclInstantiator::VisitIndirectFieldDecl(IndirectFieldDecl *D) {
890  NamedDecl **NamedChain =
891  new (SemaRef.Context)NamedDecl*[D->getChainingSize()];
892 
893  int i = 0;
894  for (auto *PI : D->chain()) {
895  NamedDecl *Next = SemaRef.FindInstantiatedDecl(D->getLocation(), PI,
896  TemplateArgs);
897  if (!Next)
898  return nullptr;
899 
900  NamedChain[i++] = Next;
901  }
902 
903  QualType T = cast<FieldDecl>(NamedChain[i-1])->getType();
905  SemaRef.Context, Owner, D->getLocation(), D->getIdentifier(), T,
906  {NamedChain, D->getChainingSize()});
907 
908  for (const auto *Attr : D->attrs())
909  IndirectField->addAttr(Attr->clone(SemaRef.Context));
910 
911  IndirectField->setImplicit(D->isImplicit());
912  IndirectField->setAccess(D->getAccess());
913  Owner->addDecl(IndirectField);
914  return IndirectField;
915 }
916 
917 Decl *TemplateDeclInstantiator::VisitFriendDecl(FriendDecl *D) {
918  // Handle friend type expressions by simply substituting template
919  // parameters into the pattern type and checking the result.
920  if (TypeSourceInfo *Ty = D->getFriendType()) {
921  TypeSourceInfo *InstTy;
922  // If this is an unsupported friend, don't bother substituting template
923  // arguments into it. The actual type referred to won't be used by any
924  // parts of Clang, and may not be valid for instantiating. Just use the
925  // same info for the instantiated friend.
926  if (D->isUnsupportedFriend()) {
927  InstTy = Ty;
928  } else {
929  InstTy = SemaRef.SubstType(Ty, TemplateArgs,
930  D->getLocation(), DeclarationName());
931  }
932  if (!InstTy)
933  return nullptr;
934 
935  FriendDecl *FD = SemaRef.CheckFriendTypeDecl(D->getBeginLoc(),
936  D->getFriendLoc(), InstTy);
937  if (!FD)
938  return nullptr;
939 
940  FD->setAccess(AS_public);
942  Owner->addDecl(FD);
943  return FD;
944  }
945 
946  NamedDecl *ND = D->getFriendDecl();
947  assert(ND && "friend decl must be a decl or a type!");
948 
949  // All of the Visit implementations for the various potential friend
950  // declarations have to be carefully written to work for friend
951  // objects, with the most important detail being that the target
952  // decl should almost certainly not be placed in Owner.
953  Decl *NewND = Visit(ND);
954  if (!NewND) return nullptr;
955 
956  FriendDecl *FD =
957  FriendDecl::Create(SemaRef.Context, Owner, D->getLocation(),
958  cast<NamedDecl>(NewND), D->getFriendLoc());
959  FD->setAccess(AS_public);
961  Owner->addDecl(FD);
962  return FD;
963 }
964 
965 Decl *TemplateDeclInstantiator::VisitStaticAssertDecl(StaticAssertDecl *D) {
966  Expr *AssertExpr = D->getAssertExpr();
967 
968  // The expression in a static assertion is a constant expression.
971 
972  ExprResult InstantiatedAssertExpr
973  = SemaRef.SubstExpr(AssertExpr, TemplateArgs);
974  if (InstantiatedAssertExpr.isInvalid())
975  return nullptr;
976 
977  return SemaRef.BuildStaticAssertDeclaration(D->getLocation(),
978  InstantiatedAssertExpr.get(),
979  D->getMessage(),
980  D->getRParenLoc(),
981  D->isFailed());
982 }
983 
984 Decl *TemplateDeclInstantiator::VisitEnumDecl(EnumDecl *D) {
985  EnumDecl *PrevDecl = nullptr;
986  if (EnumDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
987  NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
988  PatternPrev,
989  TemplateArgs);
990  if (!Prev) return nullptr;
991  PrevDecl = cast<EnumDecl>(Prev);
992  }
993 
994  EnumDecl *Enum =
995  EnumDecl::Create(SemaRef.Context, Owner, D->getBeginLoc(),
996  D->getLocation(), D->getIdentifier(), PrevDecl,
997  D->isScoped(), D->isScopedUsingClassTag(), D->isFixed());
998  if (D->isFixed()) {
999  if (TypeSourceInfo *TI = D->getIntegerTypeSourceInfo()) {
1000  // If we have type source information for the underlying type, it means it
1001  // has been explicitly set by the user. Perform substitution on it before
1002  // moving on.
1003  SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1004  TypeSourceInfo *NewTI = SemaRef.SubstType(TI, TemplateArgs, UnderlyingLoc,
1005  DeclarationName());
1006  if (!NewTI || SemaRef.CheckEnumUnderlyingType(NewTI))
1007  Enum->setIntegerType(SemaRef.Context.IntTy);
1008  else
1009  Enum->setIntegerTypeSourceInfo(NewTI);
1010  } else {
1011  assert(!D->getIntegerType()->isDependentType()
1012  && "Dependent type without type source info");
1013  Enum->setIntegerType(D->getIntegerType());
1014  }
1015  }
1016 
1017  SemaRef.InstantiateAttrs(TemplateArgs, D, Enum);
1018 
1019  Enum->setInstantiationOfMemberEnum(D, TSK_ImplicitInstantiation);
1020  Enum->setAccess(D->getAccess());
1021  // Forward the mangling number from the template to the instantiated decl.
1022  SemaRef.Context.setManglingNumber(Enum, SemaRef.Context.getManglingNumber(D));
1023  // See if the old tag was defined along with a declarator.
1024  // If it did, mark the new tag as being associated with that declarator.
1026  SemaRef.Context.addDeclaratorForUnnamedTagDecl(Enum, DD);
1027  // See if the old tag was defined along with a typedef.
1028  // If it did, mark the new tag as being associated with that typedef.
1030  SemaRef.Context.addTypedefNameForUnnamedTagDecl(Enum, TND);
1031  if (SubstQualifier(D, Enum)) return nullptr;
1032  Owner->addDecl(Enum);
1033 
1034  EnumDecl *Def = D->getDefinition();
1035  if (Def && Def != D) {
1036  // If this is an out-of-line definition of an enum member template, check
1037  // that the underlying types match in the instantiation of both
1038  // declarations.
1039  if (TypeSourceInfo *TI = Def->getIntegerTypeSourceInfo()) {
1040  SourceLocation UnderlyingLoc = TI->getTypeLoc().getBeginLoc();
1041  QualType DefnUnderlying =
1042  SemaRef.SubstType(TI->getType(), TemplateArgs,
1043  UnderlyingLoc, DeclarationName());
1044  SemaRef.CheckEnumRedeclaration(Def->getLocation(), Def->isScoped(),
1045  DefnUnderlying, /*IsFixed=*/true, Enum);
1046  }
1047  }
1048 
1049  // C++11 [temp.inst]p1: The implicit instantiation of a class template
1050  // specialization causes the implicit instantiation of the declarations, but
1051  // not the definitions of scoped member enumerations.
1052  //
1053  // DR1484 clarifies that enumeration definitions inside of a template
1054  // declaration aren't considered entities that can be separately instantiated
1055  // from the rest of the entity they are declared inside of.
1056  if (isDeclWithinFunction(D) ? D == Def : Def && !Enum->isScoped()) {
1057  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Enum);
1058  InstantiateEnumDefinition(Enum, Def);
1059  }
1060 
1061  return Enum;
1062 }
1063 
1065  EnumDecl *Enum, EnumDecl *Pattern) {
1066  Enum->startDefinition();
1067 
1068  // Update the location to refer to the definition.
1069  Enum->setLocation(Pattern->getLocation());
1070 
1071  SmallVector<Decl*, 4> Enumerators;
1072 
1073  EnumConstantDecl *LastEnumConst = nullptr;
1074  for (auto *EC : Pattern->enumerators()) {
1075  // The specified value for the enumerator.
1076  ExprResult Value((Expr *)nullptr);
1077  if (Expr *UninstValue = EC->getInitExpr()) {
1078  // The enumerator's value expression is a constant expression.
1081 
1082  Value = SemaRef.SubstExpr(UninstValue, TemplateArgs);
1083  }
1084 
1085  // Drop the initial value and continue.
1086  bool isInvalid = false;
1087  if (Value.isInvalid()) {
1088  Value = nullptr;
1089  isInvalid = true;
1090  }
1091 
1092  EnumConstantDecl *EnumConst
1093  = SemaRef.CheckEnumConstant(Enum, LastEnumConst,
1094  EC->getLocation(), EC->getIdentifier(),
1095  Value.get());
1096 
1097  if (isInvalid) {
1098  if (EnumConst)
1099  EnumConst->setInvalidDecl();
1100  Enum->setInvalidDecl();
1101  }
1102 
1103  if (EnumConst) {
1104  SemaRef.InstantiateAttrs(TemplateArgs, EC, EnumConst);
1105 
1106  EnumConst->setAccess(Enum->getAccess());
1107  Enum->addDecl(EnumConst);
1108  Enumerators.push_back(EnumConst);
1109  LastEnumConst = EnumConst;
1110 
1111  if (Pattern->getDeclContext()->isFunctionOrMethod() &&
1112  !Enum->isScoped()) {
1113  // If the enumeration is within a function or method, record the enum
1114  // constant as a local.
1115  SemaRef.CurrentInstantiationScope->InstantiatedLocal(EC, EnumConst);
1116  }
1117  }
1118  }
1119 
1120  SemaRef.ActOnEnumBody(Enum->getLocation(), Enum->getBraceRange(), Enum,
1121  Enumerators, nullptr, ParsedAttributesView());
1122 }
1123 
1124 Decl *TemplateDeclInstantiator::VisitEnumConstantDecl(EnumConstantDecl *D) {
1125  llvm_unreachable("EnumConstantDecls can only occur within EnumDecls.");
1126 }
1127 
1128 Decl *
1129 TemplateDeclInstantiator::VisitBuiltinTemplateDecl(BuiltinTemplateDecl *D) {
1130  llvm_unreachable("BuiltinTemplateDecls cannot be instantiated.");
1131 }
1132 
1133 Decl *TemplateDeclInstantiator::VisitClassTemplateDecl(ClassTemplateDecl *D) {
1134  bool isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1135 
1136  // Create a local instantiation scope for this class template, which
1137  // will contain the instantiations of the template parameters.
1138  LocalInstantiationScope Scope(SemaRef);
1139  TemplateParameterList *TempParams = D->getTemplateParameters();
1140  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1141  if (!InstParams)
1142  return nullptr;
1143 
1144  CXXRecordDecl *Pattern = D->getTemplatedDecl();
1145 
1146  // Instantiate the qualifier. We have to do this first in case
1147  // we're a friend declaration, because if we are then we need to put
1148  // the new declaration in the appropriate context.
1149  NestedNameSpecifierLoc QualifierLoc = Pattern->getQualifierLoc();
1150  if (QualifierLoc) {
1151  QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1152  TemplateArgs);
1153  if (!QualifierLoc)
1154  return nullptr;
1155  }
1156 
1157  CXXRecordDecl *PrevDecl = nullptr;
1158  ClassTemplateDecl *PrevClassTemplate = nullptr;
1159 
1160  if (!isFriend && getPreviousDeclForInstantiation(Pattern)) {
1161  DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1162  if (!Found.empty()) {
1163  PrevClassTemplate = dyn_cast<ClassTemplateDecl>(Found.front());
1164  if (PrevClassTemplate)
1165  PrevDecl = PrevClassTemplate->getTemplatedDecl();
1166  }
1167  }
1168 
1169  // If this isn't a friend, then it's a member template, in which
1170  // case we just want to build the instantiation in the
1171  // specialization. If it is a friend, we want to build it in
1172  // the appropriate context.
1173  DeclContext *DC = Owner;
1174  if (isFriend) {
1175  if (QualifierLoc) {
1176  CXXScopeSpec SS;
1177  SS.Adopt(QualifierLoc);
1178  DC = SemaRef.computeDeclContext(SS);
1179  if (!DC) return nullptr;
1180  } else {
1181  DC = SemaRef.FindInstantiatedContext(Pattern->getLocation(),
1182  Pattern->getDeclContext(),
1183  TemplateArgs);
1184  }
1185 
1186  // Look for a previous declaration of the template in the owning
1187  // context.
1188  LookupResult R(SemaRef, Pattern->getDeclName(), Pattern->getLocation(),
1190  SemaRef.forRedeclarationInCurContext());
1191  SemaRef.LookupQualifiedName(R, DC);
1192 
1193  if (R.isSingleResult()) {
1194  PrevClassTemplate = R.getAsSingle<ClassTemplateDecl>();
1195  if (PrevClassTemplate)
1196  PrevDecl = PrevClassTemplate->getTemplatedDecl();
1197  }
1198 
1199  if (!PrevClassTemplate && QualifierLoc) {
1200  SemaRef.Diag(Pattern->getLocation(), diag::err_not_tag_in_scope)
1201  << D->getTemplatedDecl()->getTagKind() << Pattern->getDeclName() << DC
1202  << QualifierLoc.getSourceRange();
1203  return nullptr;
1204  }
1205 
1206  bool AdoptedPreviousTemplateParams = false;
1207  if (PrevClassTemplate) {
1208  bool Complain = true;
1209 
1210  // HACK: libstdc++ 4.2.1 contains an ill-formed friend class
1211  // template for struct std::tr1::__detail::_Map_base, where the
1212  // template parameters of the friend declaration don't match the
1213  // template parameters of the original declaration. In this one
1214  // case, we don't complain about the ill-formed friend
1215  // declaration.
1216  if (isFriend && Pattern->getIdentifier() &&
1217  Pattern->getIdentifier()->isStr("_Map_base") &&
1218  DC->isNamespace() &&
1219  cast<NamespaceDecl>(DC)->getIdentifier() &&
1220  cast<NamespaceDecl>(DC)->getIdentifier()->isStr("__detail")) {
1221  DeclContext *DCParent = DC->getParent();
1222  if (DCParent->isNamespace() &&
1223  cast<NamespaceDecl>(DCParent)->getIdentifier() &&
1224  cast<NamespaceDecl>(DCParent)->getIdentifier()->isStr("tr1")) {
1225  if (cast<Decl>(DCParent)->isInStdNamespace())
1226  Complain = false;
1227  }
1228  }
1229 
1230  TemplateParameterList *PrevParams
1231  = PrevClassTemplate->getTemplateParameters();
1232 
1233  // Make sure the parameter lists match.
1234  if (!SemaRef.TemplateParameterListsAreEqual(InstParams, PrevParams,
1235  Complain,
1237  if (Complain)
1238  return nullptr;
1239 
1240  AdoptedPreviousTemplateParams = true;
1241  InstParams = PrevParams;
1242  }
1243 
1244  // Do some additional validation, then merge default arguments
1245  // from the existing declarations.
1246  if (!AdoptedPreviousTemplateParams &&
1247  SemaRef.CheckTemplateParameterList(InstParams, PrevParams,
1249  return nullptr;
1250  }
1251  }
1252 
1253  CXXRecordDecl *RecordInst = CXXRecordDecl::Create(
1254  SemaRef.Context, Pattern->getTagKind(), DC, Pattern->getBeginLoc(),
1255  Pattern->getLocation(), Pattern->getIdentifier(), PrevDecl,
1256  /*DelayTypeCreation=*/true);
1257 
1258  if (QualifierLoc)
1259  RecordInst->setQualifierInfo(QualifierLoc);
1260 
1261  ClassTemplateDecl *Inst
1262  = ClassTemplateDecl::Create(SemaRef.Context, DC, D->getLocation(),
1263  D->getIdentifier(), InstParams, RecordInst);
1264  assert(!(isFriend && Owner->isDependentContext()));
1265  Inst->setPreviousDecl(PrevClassTemplate);
1266 
1267  RecordInst->setDescribedClassTemplate(Inst);
1268 
1269  if (isFriend) {
1270  if (PrevClassTemplate)
1271  Inst->setAccess(PrevClassTemplate->getAccess());
1272  else
1273  Inst->setAccess(D->getAccess());
1274 
1275  Inst->setObjectOfFriendDecl();
1276  // TODO: do we want to track the instantiation progeny of this
1277  // friend target decl?
1278  } else {
1279  Inst->setAccess(D->getAccess());
1280  if (!PrevClassTemplate)
1282  }
1283 
1284  // Trigger creation of the type for the instantiation.
1285  SemaRef.Context.getInjectedClassNameType(RecordInst,
1287 
1288  // Finish handling of friends.
1289  if (isFriend) {
1290  DC->makeDeclVisibleInContext(Inst);
1291  Inst->setLexicalDeclContext(Owner);
1292  RecordInst->setLexicalDeclContext(Owner);
1293  return Inst;
1294  }
1295 
1296  if (D->isOutOfLine()) {
1298  RecordInst->setLexicalDeclContext(D->getLexicalDeclContext());
1299  }
1300 
1301  Owner->addDecl(Inst);
1302 
1303  if (!PrevClassTemplate) {
1304  // Queue up any out-of-line partial specializations of this member
1305  // class template; the client will force their instantiation once
1306  // the enclosing class has been instantiated.
1308  D->getPartialSpecializations(PartialSpecs);
1309  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1310  if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1311  OutOfLinePartialSpecs.push_back(std::make_pair(Inst, PartialSpecs[I]));
1312  }
1313 
1314  return Inst;
1315 }
1316 
1317 Decl *
1318 TemplateDeclInstantiator::VisitClassTemplatePartialSpecializationDecl(
1320  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
1321 
1322  // Lookup the already-instantiated declaration in the instantiation
1323  // of the class template and return that.
1325  = Owner->lookup(ClassTemplate->getDeclName());
1326  if (Found.empty())
1327  return nullptr;
1328 
1329  ClassTemplateDecl *InstClassTemplate
1330  = dyn_cast<ClassTemplateDecl>(Found.front());
1331  if (!InstClassTemplate)
1332  return nullptr;
1333 
1335  = InstClassTemplate->findPartialSpecInstantiatedFromMember(D))
1336  return Result;
1337 
1338  return InstantiateClassTemplatePartialSpecialization(InstClassTemplate, D);
1339 }
1340 
1341 Decl *TemplateDeclInstantiator::VisitVarTemplateDecl(VarTemplateDecl *D) {
1342  assert(D->getTemplatedDecl()->isStaticDataMember() &&
1343  "Only static data member templates are allowed.");
1344 
1345  // Create a local instantiation scope for this variable template, which
1346  // will contain the instantiations of the template parameters.
1347  LocalInstantiationScope Scope(SemaRef);
1348  TemplateParameterList *TempParams = D->getTemplateParameters();
1349  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1350  if (!InstParams)
1351  return nullptr;
1352 
1353  VarDecl *Pattern = D->getTemplatedDecl();
1354  VarTemplateDecl *PrevVarTemplate = nullptr;
1355 
1356  if (getPreviousDeclForInstantiation(Pattern)) {
1357  DeclContext::lookup_result Found = Owner->lookup(Pattern->getDeclName());
1358  if (!Found.empty())
1359  PrevVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1360  }
1361 
1362  VarDecl *VarInst =
1363  cast_or_null<VarDecl>(VisitVarDecl(Pattern,
1364  /*InstantiatingVarTemplate=*/true));
1365  if (!VarInst) return nullptr;
1366 
1367  DeclContext *DC = Owner;
1368 
1370  SemaRef.Context, DC, D->getLocation(), D->getIdentifier(), InstParams,
1371  VarInst);
1372  VarInst->setDescribedVarTemplate(Inst);
1373  Inst->setPreviousDecl(PrevVarTemplate);
1374 
1375  Inst->setAccess(D->getAccess());
1376  if (!PrevVarTemplate)
1378 
1379  if (D->isOutOfLine()) {
1382  }
1383 
1384  Owner->addDecl(Inst);
1385 
1386  if (!PrevVarTemplate) {
1387  // Queue up any out-of-line partial specializations of this member
1388  // variable template; the client will force their instantiation once
1389  // the enclosing class has been instantiated.
1391  D->getPartialSpecializations(PartialSpecs);
1392  for (unsigned I = 0, N = PartialSpecs.size(); I != N; ++I)
1393  if (PartialSpecs[I]->getFirstDecl()->isOutOfLine())
1394  OutOfLineVarPartialSpecs.push_back(
1395  std::make_pair(Inst, PartialSpecs[I]));
1396  }
1397 
1398  return Inst;
1399 }
1400 
1401 Decl *TemplateDeclInstantiator::VisitVarTemplatePartialSpecializationDecl(
1403  assert(D->isStaticDataMember() &&
1404  "Only static data member templates are allowed.");
1405 
1406  VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
1407 
1408  // Lookup the already-instantiated declaration and return that.
1409  DeclContext::lookup_result Found = Owner->lookup(VarTemplate->getDeclName());
1410  assert(!Found.empty() && "Instantiation found nothing?");
1411 
1412  VarTemplateDecl *InstVarTemplate = dyn_cast<VarTemplateDecl>(Found.front());
1413  assert(InstVarTemplate && "Instantiation did not find a variable template?");
1414 
1416  InstVarTemplate->findPartialSpecInstantiatedFromMember(D))
1417  return Result;
1418 
1419  return InstantiateVarTemplatePartialSpecialization(InstVarTemplate, D);
1420 }
1421 
1422 Decl *
1423 TemplateDeclInstantiator::VisitFunctionTemplateDecl(FunctionTemplateDecl *D) {
1424  // Create a local instantiation scope for this function template, which
1425  // will contain the instantiations of the template parameters and then get
1426  // merged with the local instantiation scope for the function template
1427  // itself.
1428  LocalInstantiationScope Scope(SemaRef);
1429 
1430  TemplateParameterList *TempParams = D->getTemplateParameters();
1431  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1432  if (!InstParams)
1433  return nullptr;
1434 
1435  FunctionDecl *Instantiated = nullptr;
1436  if (CXXMethodDecl *DMethod = dyn_cast<CXXMethodDecl>(D->getTemplatedDecl()))
1437  Instantiated = cast_or_null<FunctionDecl>(VisitCXXMethodDecl(DMethod,
1438  InstParams));
1439  else
1440  Instantiated = cast_or_null<FunctionDecl>(VisitFunctionDecl(
1441  D->getTemplatedDecl(),
1442  InstParams));
1443 
1444  if (!Instantiated)
1445  return nullptr;
1446 
1447  // Link the instantiated function template declaration to the function
1448  // template from which it was instantiated.
1449  FunctionTemplateDecl *InstTemplate
1450  = Instantiated->getDescribedFunctionTemplate();
1451  InstTemplate->setAccess(D->getAccess());
1452  assert(InstTemplate &&
1453  "VisitFunctionDecl/CXXMethodDecl didn't create a template!");
1454 
1455  bool isFriend = (InstTemplate->getFriendObjectKind() != Decl::FOK_None);
1456 
1457  // Link the instantiation back to the pattern *unless* this is a
1458  // non-definition friend declaration.
1459  if (!InstTemplate->getInstantiatedFromMemberTemplate() &&
1460  !(isFriend && !D->getTemplatedDecl()->isThisDeclarationADefinition()))
1461  InstTemplate->setInstantiatedFromMemberTemplate(D);
1462 
1463  // Make declarations visible in the appropriate context.
1464  if (!isFriend) {
1465  Owner->addDecl(InstTemplate);
1466  } else if (InstTemplate->getDeclContext()->isRecord() &&
1468  SemaRef.CheckFriendAccess(InstTemplate);
1469  }
1470 
1471  return InstTemplate;
1472 }
1473 
1474 Decl *TemplateDeclInstantiator::VisitCXXRecordDecl(CXXRecordDecl *D) {
1475  CXXRecordDecl *PrevDecl = nullptr;
1476  if (D->isInjectedClassName())
1477  PrevDecl = cast<CXXRecordDecl>(Owner);
1478  else if (CXXRecordDecl *PatternPrev = getPreviousDeclForInstantiation(D)) {
1479  NamedDecl *Prev = SemaRef.FindInstantiatedDecl(D->getLocation(),
1480  PatternPrev,
1481  TemplateArgs);
1482  if (!Prev) return nullptr;
1483  PrevDecl = cast<CXXRecordDecl>(Prev);
1484  }
1485 
1487  SemaRef.Context, D->getTagKind(), Owner, D->getBeginLoc(),
1488  D->getLocation(), D->getIdentifier(), PrevDecl);
1489 
1490  // Substitute the nested name specifier, if any.
1491  if (SubstQualifier(D, Record))
1492  return nullptr;
1493 
1494  Record->setImplicit(D->isImplicit());
1495  // FIXME: Check against AS_none is an ugly hack to work around the issue that
1496  // the tag decls introduced by friend class declarations don't have an access
1497  // specifier. Remove once this area of the code gets sorted out.
1498  if (D->getAccess() != AS_none)
1499  Record->setAccess(D->getAccess());
1500  if (!D->isInjectedClassName())
1501  Record->setInstantiationOfMemberClass(D, TSK_ImplicitInstantiation);
1502 
1503  // If the original function was part of a friend declaration,
1504  // inherit its namespace state.
1505  if (D->getFriendObjectKind())
1506  Record->setObjectOfFriendDecl();
1507 
1508  // Make sure that anonymous structs and unions are recorded.
1509  if (D->isAnonymousStructOrUnion())
1510  Record->setAnonymousStructOrUnion(true);
1511 
1512  if (D->isLocalClass())
1513  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Record);
1514 
1515  // Forward the mangling number from the template to the instantiated decl.
1516  SemaRef.Context.setManglingNumber(Record,
1517  SemaRef.Context.getManglingNumber(D));
1518 
1519  // See if the old tag was defined along with a declarator.
1520  // If it did, mark the new tag as being associated with that declarator.
1522  SemaRef.Context.addDeclaratorForUnnamedTagDecl(Record, DD);
1523 
1524  // See if the old tag was defined along with a typedef.
1525  // If it did, mark the new tag as being associated with that typedef.
1527  SemaRef.Context.addTypedefNameForUnnamedTagDecl(Record, TND);
1528 
1529  Owner->addDecl(Record);
1530 
1531  // DR1484 clarifies that the members of a local class are instantiated as part
1532  // of the instantiation of their enclosing entity.
1533  if (D->isCompleteDefinition() && D->isLocalClass()) {
1534  Sema::LocalEagerInstantiationScope LocalInstantiations(SemaRef);
1535 
1536  SemaRef.InstantiateClass(D->getLocation(), Record, D, TemplateArgs,
1538  /*Complain=*/true);
1539 
1540  // For nested local classes, we will instantiate the members when we
1541  // reach the end of the outermost (non-nested) local class.
1542  if (!D->isCXXClassMember())
1543  SemaRef.InstantiateClassMembers(D->getLocation(), Record, TemplateArgs,
1545 
1546  // This class may have local implicit instantiations that need to be
1547  // performed within this scope.
1548  LocalInstantiations.perform();
1549  }
1550 
1551  SemaRef.DiagnoseUnusedNestedTypedefs(Record);
1552 
1553  return Record;
1554 }
1555 
1556 /// Adjust the given function type for an instantiation of the
1557 /// given declaration, to cope with modifications to the function's type that
1558 /// aren't reflected in the type-source information.
1559 ///
1560 /// \param D The declaration we're instantiating.
1561 /// \param TInfo The already-instantiated type.
1563  FunctionDecl *D,
1564  TypeSourceInfo *TInfo) {
1565  const FunctionProtoType *OrigFunc
1566  = D->getType()->castAs<FunctionProtoType>();
1567  const FunctionProtoType *NewFunc
1568  = TInfo->getType()->castAs<FunctionProtoType>();
1569  if (OrigFunc->getExtInfo() == NewFunc->getExtInfo())
1570  return TInfo->getType();
1571 
1572  FunctionProtoType::ExtProtoInfo NewEPI = NewFunc->getExtProtoInfo();
1573  NewEPI.ExtInfo = OrigFunc->getExtInfo();
1574  return Context.getFunctionType(NewFunc->getReturnType(),
1575  NewFunc->getParamTypes(), NewEPI);
1576 }
1577 
1578 /// Normal class members are of more specific types and therefore
1579 /// don't make it here. This function serves three purposes:
1580 /// 1) instantiating function templates
1581 /// 2) substituting friend declarations
1582 /// 3) substituting deduction guide declarations for nested class templates
1584  TemplateParameterList *TemplateParams) {
1585  // Check whether there is already a function template specialization for
1586  // this declaration.
1587  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1588  if (FunctionTemplate && !TemplateParams) {
1589  ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1590 
1591  void *InsertPos = nullptr;
1592  FunctionDecl *SpecFunc
1593  = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1594 
1595  // If we already have a function template specialization, return it.
1596  if (SpecFunc)
1597  return SpecFunc;
1598  }
1599 
1600  bool isFriend;
1601  if (FunctionTemplate)
1602  isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1603  else
1604  isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1605 
1606  bool MergeWithParentScope = (TemplateParams != nullptr) ||
1607  Owner->isFunctionOrMethod() ||
1608  !(isa<Decl>(Owner) &&
1609  cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1610  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1611 
1613  TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1614  if (!TInfo)
1615  return nullptr;
1616  QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1617 
1618  NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1619  if (QualifierLoc) {
1620  QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1621  TemplateArgs);
1622  if (!QualifierLoc)
1623  return nullptr;
1624  }
1625 
1626  // If we're instantiating a local function declaration, put the result
1627  // in the enclosing namespace; otherwise we need to find the instantiated
1628  // context.
1629  DeclContext *DC;
1630  if (D->isLocalExternDecl()) {
1631  DC = Owner;
1632  SemaRef.adjustContextForLocalExternDecl(DC);
1633  } else if (isFriend && QualifierLoc) {
1634  CXXScopeSpec SS;
1635  SS.Adopt(QualifierLoc);
1636  DC = SemaRef.computeDeclContext(SS);
1637  if (!DC) return nullptr;
1638  } else {
1639  DC = SemaRef.FindInstantiatedContext(D->getLocation(), D->getDeclContext(),
1640  TemplateArgs);
1641  }
1642 
1643  DeclarationNameInfo NameInfo
1644  = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1645 
1646  FunctionDecl *Function;
1647  if (auto *DGuide = dyn_cast<CXXDeductionGuideDecl>(D)) {
1648  Function = CXXDeductionGuideDecl::Create(
1649  SemaRef.Context, DC, D->getInnerLocStart(), DGuide->isExplicit(),
1650  NameInfo, T, TInfo, D->getSourceRange().getEnd());
1651  if (DGuide->isCopyDeductionCandidate())
1652  cast<CXXDeductionGuideDecl>(Function)->setIsCopyDeductionCandidate();
1653  Function->setAccess(D->getAccess());
1654  } else {
1655  Function = FunctionDecl::Create(
1656  SemaRef.Context, DC, D->getInnerLocStart(), NameInfo, T, TInfo,
1658  D->hasWrittenPrototype(), D->isConstexpr());
1659  Function->setRangeEnd(D->getSourceRange().getEnd());
1660  }
1661 
1662  if (D->isInlined())
1663  Function->setImplicitlyInline();
1664 
1665  if (QualifierLoc)
1666  Function->setQualifierInfo(QualifierLoc);
1667 
1668  if (D->isLocalExternDecl())
1669  Function->setLocalExternDecl();
1670 
1671  DeclContext *LexicalDC = Owner;
1672  if (!isFriend && D->isOutOfLine() && !D->isLocalExternDecl()) {
1673  assert(D->getDeclContext()->isFileContext());
1674  LexicalDC = D->getDeclContext();
1675  }
1676 
1677  Function->setLexicalDeclContext(LexicalDC);
1678 
1679  // Attach the parameters
1680  for (unsigned P = 0; P < Params.size(); ++P)
1681  if (Params[P])
1682  Params[P]->setOwningFunction(Function);
1683  Function->setParams(Params);
1684 
1685  if (TemplateParams) {
1686  // Our resulting instantiation is actually a function template, since we
1687  // are substituting only the outer template parameters. For example, given
1688  //
1689  // template<typename T>
1690  // struct X {
1691  // template<typename U> friend void f(T, U);
1692  // };
1693  //
1694  // X<int> x;
1695  //
1696  // We are instantiating the friend function template "f" within X<int>,
1697  // which means substituting int for T, but leaving "f" as a friend function
1698  // template.
1699  // Build the function template itself.
1700  FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, DC,
1701  Function->getLocation(),
1702  Function->getDeclName(),
1703  TemplateParams, Function);
1704  Function->setDescribedFunctionTemplate(FunctionTemplate);
1705 
1706  FunctionTemplate->setLexicalDeclContext(LexicalDC);
1707 
1708  if (isFriend && D->isThisDeclarationADefinition()) {
1709  FunctionTemplate->setInstantiatedFromMemberTemplate(
1711  }
1712  } else if (FunctionTemplate) {
1713  // Record this function template specialization.
1714  ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1715  Function->setFunctionTemplateSpecialization(FunctionTemplate,
1717  Innermost),
1718  /*InsertPos=*/nullptr);
1719  } else if (isFriend && D->isThisDeclarationADefinition()) {
1720  // Do not connect the friend to the template unless it's actually a
1721  // definition. We don't want non-template functions to be marked as being
1722  // template instantiations.
1723  Function->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
1724  }
1725 
1726  if (InitFunctionInstantiation(Function, D))
1727  Function->setInvalidDecl();
1728 
1729  bool isExplicitSpecialization = false;
1730 
1732  SemaRef, Function->getDeclName(), SourceLocation(),
1736  : SemaRef.forRedeclarationInCurContext());
1737 
1740  assert(isFriend && "non-friend has dependent specialization info?");
1741 
1742  // This needs to be set now for future sanity.
1743  Function->setObjectOfFriendDecl();
1744 
1745  // Instantiate the explicit template arguments.
1746  TemplateArgumentListInfo ExplicitArgs(Info->getLAngleLoc(),
1747  Info->getRAngleLoc());
1748  if (SemaRef.Subst(Info->getTemplateArgs(), Info->getNumTemplateArgs(),
1749  ExplicitArgs, TemplateArgs))
1750  return nullptr;
1751 
1752  // Map the candidate templates to their instantiations.
1753  for (unsigned I = 0, E = Info->getNumTemplates(); I != E; ++I) {
1754  Decl *Temp = SemaRef.FindInstantiatedDecl(D->getLocation(),
1755  Info->getTemplate(I),
1756  TemplateArgs);
1757  if (!Temp) return nullptr;
1758 
1759  Previous.addDecl(cast<FunctionTemplateDecl>(Temp));
1760  }
1761 
1762  if (SemaRef.CheckFunctionTemplateSpecialization(Function,
1763  &ExplicitArgs,
1764  Previous))
1765  Function->setInvalidDecl();
1766 
1767  isExplicitSpecialization = true;
1768 
1769  } else if (TemplateParams || !FunctionTemplate) {
1770  // Look only into the namespace where the friend would be declared to
1771  // find a previous declaration. This is the innermost enclosing namespace,
1772  // as described in ActOnFriendFunctionDecl.
1773  SemaRef.LookupQualifiedName(Previous, DC);
1774 
1775  // In C++, the previous declaration we find might be a tag type
1776  // (class or enum). In this case, the new declaration will hide the
1777  // tag type. Note that this does does not apply if we're declaring a
1778  // typedef (C++ [dcl.typedef]p4).
1779  if (Previous.isSingleTagDecl())
1780  Previous.clear();
1781  }
1782 
1783  if (isFriend)
1784  Function->setObjectOfFriendDecl();
1785 
1786  SemaRef.CheckFunctionDeclaration(/*Scope*/ nullptr, Function, Previous,
1787  isExplicitSpecialization);
1788 
1789  NamedDecl *PrincipalDecl = (TemplateParams
1790  ? cast<NamedDecl>(FunctionTemplate)
1791  : Function);
1792 
1793  // If the original function was part of a friend declaration,
1794  // inherit its namespace state and add it to the owner.
1795  if (isFriend) {
1796  PrincipalDecl->setObjectOfFriendDecl();
1797  DC->makeDeclVisibleInContext(PrincipalDecl);
1798 
1799  bool QueuedInstantiation = false;
1800 
1801  // C++11 [temp.friend]p4 (DR329):
1802  // When a function is defined in a friend function declaration in a class
1803  // template, the function is instantiated when the function is odr-used.
1804  // The same restrictions on multiple declarations and definitions that
1805  // apply to non-template function declarations and definitions also apply
1806  // to these implicit definitions.
1807  if (D->isThisDeclarationADefinition()) {
1808  SemaRef.CheckForFunctionRedefinition(Function);
1809  if (!Function->isInvalidDecl()) {
1810  for (auto R : Function->redecls()) {
1811  if (R == Function)
1812  continue;
1813 
1814  // If some prior declaration of this function has been used, we need
1815  // to instantiate its definition.
1816  if (!QueuedInstantiation && R->isUsed(false)) {
1817  if (MemberSpecializationInfo *MSInfo =
1818  Function->getMemberSpecializationInfo()) {
1819  if (MSInfo->getPointOfInstantiation().isInvalid()) {
1820  SourceLocation Loc = R->getLocation(); // FIXME
1821  MSInfo->setPointOfInstantiation(Loc);
1822  SemaRef.PendingLocalImplicitInstantiations.push_back(
1823  std::make_pair(Function, Loc));
1824  QueuedInstantiation = true;
1825  }
1826  }
1827  }
1828  }
1829  }
1830  }
1831 
1832  // Check the template parameter list against the previous declaration. The
1833  // goal here is to pick up default arguments added since the friend was
1834  // declared; we know the template parameter lists match, since otherwise
1835  // we would not have picked this template as the previous declaration.
1836  if (TemplateParams && FunctionTemplate->getPreviousDecl()) {
1838  TemplateParams,
1839  FunctionTemplate->getPreviousDecl()->getTemplateParameters(),
1840  Function->isThisDeclarationADefinition()
1843  }
1844  }
1845 
1846  if (Function->isLocalExternDecl() && !Function->getPreviousDecl())
1847  DC->makeDeclVisibleInContext(PrincipalDecl);
1848 
1849  if (Function->isOverloadedOperator() && !DC->isRecord() &&
1851  PrincipalDecl->setNonMemberOperator();
1852 
1853  assert(!D->isDefaulted() && "only methods should be defaulted");
1854  return Function;
1855 }
1856 
1857 Decl *
1859  TemplateParameterList *TemplateParams,
1860  bool IsClassScopeSpecialization) {
1861  FunctionTemplateDecl *FunctionTemplate = D->getDescribedFunctionTemplate();
1862  if (FunctionTemplate && !TemplateParams) {
1863  // We are creating a function template specialization from a function
1864  // template. Check whether there is already a function template
1865  // specialization for this particular set of template arguments.
1866  ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1867 
1868  void *InsertPos = nullptr;
1869  FunctionDecl *SpecFunc
1870  = FunctionTemplate->findSpecialization(Innermost, InsertPos);
1871 
1872  // If we already have a function template specialization, return it.
1873  if (SpecFunc)
1874  return SpecFunc;
1875  }
1876 
1877  bool isFriend;
1878  if (FunctionTemplate)
1879  isFriend = (FunctionTemplate->getFriendObjectKind() != Decl::FOK_None);
1880  else
1881  isFriend = (D->getFriendObjectKind() != Decl::FOK_None);
1882 
1883  bool MergeWithParentScope = (TemplateParams != nullptr) ||
1884  !(isa<Decl>(Owner) &&
1885  cast<Decl>(Owner)->isDefinedOutsideFunctionOrMethod());
1886  LocalInstantiationScope Scope(SemaRef, MergeWithParentScope);
1887 
1888  // Instantiate enclosing template arguments for friends.
1890  unsigned NumTempParamLists = 0;
1891  if (isFriend && (NumTempParamLists = D->getNumTemplateParameterLists())) {
1892  TempParamLists.resize(NumTempParamLists);
1893  for (unsigned I = 0; I != NumTempParamLists; ++I) {
1894  TemplateParameterList *TempParams = D->getTemplateParameterList(I);
1895  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
1896  if (!InstParams)
1897  return nullptr;
1898  TempParamLists[I] = InstParams;
1899  }
1900  }
1901 
1903  TypeSourceInfo *TInfo = SubstFunctionType(D, Params);
1904  if (!TInfo)
1905  return nullptr;
1906  QualType T = adjustFunctionTypeForInstantiation(SemaRef.Context, D, TInfo);
1907 
1908  NestedNameSpecifierLoc QualifierLoc = D->getQualifierLoc();
1909  if (QualifierLoc) {
1910  QualifierLoc = SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc,
1911  TemplateArgs);
1912  if (!QualifierLoc)
1913  return nullptr;
1914  }
1915 
1916  DeclContext *DC = Owner;
1917  if (isFriend) {
1918  if (QualifierLoc) {
1919  CXXScopeSpec SS;
1920  SS.Adopt(QualifierLoc);
1921  DC = SemaRef.computeDeclContext(SS);
1922 
1923  if (DC && SemaRef.RequireCompleteDeclContext(SS, DC))
1924  return nullptr;
1925  } else {
1926  DC = SemaRef.FindInstantiatedContext(D->getLocation(),
1927  D->getDeclContext(),
1928  TemplateArgs);
1929  }
1930  if (!DC) return nullptr;
1931  }
1932 
1933  // Build the instantiated method declaration.
1934  CXXRecordDecl *Record = cast<CXXRecordDecl>(DC);
1935  CXXMethodDecl *Method = nullptr;
1936 
1937  SourceLocation StartLoc = D->getInnerLocStart();
1938  DeclarationNameInfo NameInfo
1939  = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
1940  if (CXXConstructorDecl *Constructor = dyn_cast<CXXConstructorDecl>(D)) {
1941  Method = CXXConstructorDecl::Create(SemaRef.Context, Record,
1942  StartLoc, NameInfo, T, TInfo,
1943  Constructor->isExplicit(),
1944  Constructor->isInlineSpecified(),
1945  false, Constructor->isConstexpr());
1946  Method->setRangeEnd(Constructor->getEndLoc());
1947  } else if (CXXDestructorDecl *Destructor = dyn_cast<CXXDestructorDecl>(D)) {
1948  Method = CXXDestructorDecl::Create(SemaRef.Context, Record,
1949  StartLoc, NameInfo, T, TInfo,
1950  Destructor->isInlineSpecified(),
1951  false);
1952  Method->setRangeEnd(Destructor->getEndLoc());
1953  } else if (CXXConversionDecl *Conversion = dyn_cast<CXXConversionDecl>(D)) {
1954  Method = CXXConversionDecl::Create(
1955  SemaRef.Context, Record, StartLoc, NameInfo, T, TInfo,
1956  Conversion->isInlineSpecified(), Conversion->isExplicit(),
1957  Conversion->isConstexpr(), Conversion->getEndLoc());
1958  } else {
1959  StorageClass SC = D->isStatic() ? SC_Static : SC_None;
1960  Method = CXXMethodDecl::Create(SemaRef.Context, Record, StartLoc, NameInfo,
1961  T, TInfo, SC, D->isInlineSpecified(),
1962  D->isConstexpr(), D->getEndLoc());
1963  }
1964 
1965  if (D->isInlined())
1966  Method->setImplicitlyInline();
1967 
1968  if (QualifierLoc)
1969  Method->setQualifierInfo(QualifierLoc);
1970 
1971  if (TemplateParams) {
1972  // Our resulting instantiation is actually a function template, since we
1973  // are substituting only the outer template parameters. For example, given
1974  //
1975  // template<typename T>
1976  // struct X {
1977  // template<typename U> void f(T, U);
1978  // };
1979  //
1980  // X<int> x;
1981  //
1982  // We are instantiating the member template "f" within X<int>, which means
1983  // substituting int for T, but leaving "f" as a member function template.
1984  // Build the function template itself.
1985  FunctionTemplate = FunctionTemplateDecl::Create(SemaRef.Context, Record,
1986  Method->getLocation(),
1987  Method->getDeclName(),
1988  TemplateParams, Method);
1989  if (isFriend) {
1990  FunctionTemplate->setLexicalDeclContext(Owner);
1991  FunctionTemplate->setObjectOfFriendDecl();
1992  } else if (D->isOutOfLine())
1993  FunctionTemplate->setLexicalDeclContext(D->getLexicalDeclContext());
1994  Method->setDescribedFunctionTemplate(FunctionTemplate);
1995  } else if (FunctionTemplate) {
1996  // Record this function template specialization.
1997  ArrayRef<TemplateArgument> Innermost = TemplateArgs.getInnermost();
1998  Method->setFunctionTemplateSpecialization(FunctionTemplate,
2000  Innermost),
2001  /*InsertPos=*/nullptr);
2002  } else if (!isFriend) {
2003  // Record that this is an instantiation of a member function.
2004  Method->setInstantiationOfMemberFunction(D, TSK_ImplicitInstantiation);
2005  }
2006 
2007  // If we are instantiating a member function defined
2008  // out-of-line, the instantiation will have the same lexical
2009  // context (which will be a namespace scope) as the template.
2010  if (isFriend) {
2011  if (NumTempParamLists)
2012  Method->setTemplateParameterListsInfo(
2013  SemaRef.Context,
2014  llvm::makeArrayRef(TempParamLists.data(), NumTempParamLists));
2015 
2016  Method->setLexicalDeclContext(Owner);
2017  Method->setObjectOfFriendDecl();
2018  } else if (D->isOutOfLine())
2019  Method->setLexicalDeclContext(D->getLexicalDeclContext());
2020 
2021  // Attach the parameters
2022  for (unsigned P = 0; P < Params.size(); ++P)
2023  Params[P]->setOwningFunction(Method);
2024  Method->setParams(Params);
2025 
2026  if (InitMethodInstantiation(Method, D))
2027  Method->setInvalidDecl();
2028 
2029  LookupResult Previous(SemaRef, NameInfo, Sema::LookupOrdinaryName,
2031 
2032  if (!FunctionTemplate || TemplateParams || isFriend) {
2033  SemaRef.LookupQualifiedName(Previous, Record);
2034 
2035  // In C++, the previous declaration we find might be a tag type
2036  // (class or enum). In this case, the new declaration will hide the
2037  // tag type. Note that this does does not apply if we're declaring a
2038  // typedef (C++ [dcl.typedef]p4).
2039  if (Previous.isSingleTagDecl())
2040  Previous.clear();
2041  }
2042 
2043  if (!IsClassScopeSpecialization)
2044  SemaRef.CheckFunctionDeclaration(nullptr, Method, Previous, false);
2045 
2046  if (D->isPure())
2047  SemaRef.CheckPureMethod(Method, SourceRange());
2048 
2049  // Propagate access. For a non-friend declaration, the access is
2050  // whatever we're propagating from. For a friend, it should be the
2051  // previous declaration we just found.
2052  if (isFriend && Method->getPreviousDecl())
2053  Method->setAccess(Method->getPreviousDecl()->getAccess());
2054  else
2055  Method->setAccess(D->getAccess());
2056  if (FunctionTemplate)
2057  FunctionTemplate->setAccess(Method->getAccess());
2058 
2059  SemaRef.CheckOverrideControl(Method);
2060 
2061  // If a function is defined as defaulted or deleted, mark it as such now.
2062  if (D->isExplicitlyDefaulted())
2063  SemaRef.SetDeclDefaulted(Method, Method->getLocation());
2064  if (D->isDeletedAsWritten())
2065  SemaRef.SetDeclDeleted(Method, Method->getLocation());
2066 
2067  // If there's a function template, let our caller handle it.
2068  if (FunctionTemplate) {
2069  // do nothing
2070 
2071  // Don't hide a (potentially) valid declaration with an invalid one.
2072  } else if (Method->isInvalidDecl() && !Previous.empty()) {
2073  // do nothing
2074 
2075  // Otherwise, check access to friends and make them visible.
2076  } else if (isFriend) {
2077  // We only need to re-check access for methods which we didn't
2078  // manage to match during parsing.
2079  if (!D->getPreviousDecl())
2080  SemaRef.CheckFriendAccess(Method);
2081 
2082  Record->makeDeclVisibleInContext(Method);
2083 
2084  // Otherwise, add the declaration. We don't need to do this for
2085  // class-scope specializations because we'll have matched them with
2086  // the appropriate template.
2087  } else if (!IsClassScopeSpecialization) {
2088  Owner->addDecl(Method);
2089  }
2090 
2091  return Method;
2092 }
2093 
2094 Decl *TemplateDeclInstantiator::VisitCXXConstructorDecl(CXXConstructorDecl *D) {
2095  return VisitCXXMethodDecl(D);
2096 }
2097 
2098 Decl *TemplateDeclInstantiator::VisitCXXDestructorDecl(CXXDestructorDecl *D) {
2099  return VisitCXXMethodDecl(D);
2100 }
2101 
2102 Decl *TemplateDeclInstantiator::VisitCXXConversionDecl(CXXConversionDecl *D) {
2103  return VisitCXXMethodDecl(D);
2104 }
2105 
2106 Decl *TemplateDeclInstantiator::VisitParmVarDecl(ParmVarDecl *D) {
2107  return SemaRef.SubstParmVarDecl(D, TemplateArgs, /*indexAdjustment*/ 0, None,
2108  /*ExpectParameterPack=*/ false);
2109 }
2110 
2111 Decl *TemplateDeclInstantiator::VisitTemplateTypeParmDecl(
2112  TemplateTypeParmDecl *D) {
2113  // TODO: don't always clone when decls are refcounted.
2114  assert(D->getTypeForDecl()->isTemplateTypeParmType());
2115 
2117  SemaRef.Context, Owner, D->getBeginLoc(), D->getLocation(),
2118  D->getDepth() - TemplateArgs.getNumSubstitutedLevels(), D->getIndex(),
2120  Inst->setAccess(AS_public);
2121 
2122  if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2123  TypeSourceInfo *InstantiatedDefaultArg =
2124  SemaRef.SubstType(D->getDefaultArgumentInfo(), TemplateArgs,
2125  D->getDefaultArgumentLoc(), D->getDeclName());
2126  if (InstantiatedDefaultArg)
2127  Inst->setDefaultArgument(InstantiatedDefaultArg);
2128  }
2129 
2130  // Introduce this template parameter's instantiation into the instantiation
2131  // scope.
2132  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Inst);
2133 
2134  return Inst;
2135 }
2136 
2137 Decl *TemplateDeclInstantiator::VisitNonTypeTemplateParmDecl(
2139  // Substitute into the type of the non-type template parameter.
2140  TypeLoc TL = D->getTypeSourceInfo()->getTypeLoc();
2141  SmallVector<TypeSourceInfo *, 4> ExpandedParameterPackTypesAsWritten;
2142  SmallVector<QualType, 4> ExpandedParameterPackTypes;
2143  bool IsExpandedParameterPack = false;
2144  TypeSourceInfo *DI;
2145  QualType T;
2146  bool Invalid = false;
2147 
2148  if (D->isExpandedParameterPack()) {
2149  // The non-type template parameter pack is an already-expanded pack
2150  // expansion of types. Substitute into each of the expanded types.
2151  ExpandedParameterPackTypes.reserve(D->getNumExpansionTypes());
2152  ExpandedParameterPackTypesAsWritten.reserve(D->getNumExpansionTypes());
2153  for (unsigned I = 0, N = D->getNumExpansionTypes(); I != N; ++I) {
2154  TypeSourceInfo *NewDI =
2155  SemaRef.SubstType(D->getExpansionTypeSourceInfo(I), TemplateArgs,
2156  D->getLocation(), D->getDeclName());
2157  if (!NewDI)
2158  return nullptr;
2159 
2160  QualType NewT =
2161  SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2162  if (NewT.isNull())
2163  return nullptr;
2164 
2165  ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2166  ExpandedParameterPackTypes.push_back(NewT);
2167  }
2168 
2169  IsExpandedParameterPack = true;
2170  DI = D->getTypeSourceInfo();
2171  T = DI->getType();
2172  } else if (D->isPackExpansion()) {
2173  // The non-type template parameter pack's type is a pack expansion of types.
2174  // Determine whether we need to expand this parameter pack into separate
2175  // types.
2177  TypeLoc Pattern = Expansion.getPatternLoc();
2179  SemaRef.collectUnexpandedParameterPacks(Pattern, Unexpanded);
2180 
2181  // Determine whether the set of unexpanded parameter packs can and should
2182  // be expanded.
2183  bool Expand = true;
2184  bool RetainExpansion = false;
2185  Optional<unsigned> OrigNumExpansions
2186  = Expansion.getTypePtr()->getNumExpansions();
2187  Optional<unsigned> NumExpansions = OrigNumExpansions;
2188  if (SemaRef.CheckParameterPacksForExpansion(Expansion.getEllipsisLoc(),
2189  Pattern.getSourceRange(),
2190  Unexpanded,
2191  TemplateArgs,
2192  Expand, RetainExpansion,
2193  NumExpansions))
2194  return nullptr;
2195 
2196  if (Expand) {
2197  for (unsigned I = 0; I != *NumExpansions; ++I) {
2198  Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2199  TypeSourceInfo *NewDI = SemaRef.SubstType(Pattern, TemplateArgs,
2200  D->getLocation(),
2201  D->getDeclName());
2202  if (!NewDI)
2203  return nullptr;
2204 
2205  QualType NewT =
2206  SemaRef.CheckNonTypeTemplateParameterType(NewDI, D->getLocation());
2207  if (NewT.isNull())
2208  return nullptr;
2209 
2210  ExpandedParameterPackTypesAsWritten.push_back(NewDI);
2211  ExpandedParameterPackTypes.push_back(NewT);
2212  }
2213 
2214  // Note that we have an expanded parameter pack. The "type" of this
2215  // expanded parameter pack is the original expansion type, but callers
2216  // will end up using the expanded parameter pack types for type-checking.
2217  IsExpandedParameterPack = true;
2218  DI = D->getTypeSourceInfo();
2219  T = DI->getType();
2220  } else {
2221  // We cannot fully expand the pack expansion now, so substitute into the
2222  // pattern and create a new pack expansion type.
2223  Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2224  TypeSourceInfo *NewPattern = SemaRef.SubstType(Pattern, TemplateArgs,
2225  D->getLocation(),
2226  D->getDeclName());
2227  if (!NewPattern)
2228  return nullptr;
2229 
2230  SemaRef.CheckNonTypeTemplateParameterType(NewPattern, D->getLocation());
2231  DI = SemaRef.CheckPackExpansion(NewPattern, Expansion.getEllipsisLoc(),
2232  NumExpansions);
2233  if (!DI)
2234  return nullptr;
2235 
2236  T = DI->getType();
2237  }
2238  } else {
2239  // Simple case: substitution into a parameter that is not a parameter pack.
2240  DI = SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
2241  D->getLocation(), D->getDeclName());
2242  if (!DI)
2243  return nullptr;
2244 
2245  // Check that this type is acceptable for a non-type template parameter.
2246  T = SemaRef.CheckNonTypeTemplateParameterType(DI, D->getLocation());
2247  if (T.isNull()) {
2248  T = SemaRef.Context.IntTy;
2249  Invalid = true;
2250  }
2251  }
2252 
2253  NonTypeTemplateParmDecl *Param;
2254  if (IsExpandedParameterPack)
2256  SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2257  D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2258  D->getPosition(), D->getIdentifier(), T, DI, ExpandedParameterPackTypes,
2259  ExpandedParameterPackTypesAsWritten);
2260  else
2262  SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
2263  D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2264  D->getPosition(), D->getIdentifier(), T, D->isParameterPack(), DI);
2265 
2266  Param->setAccess(AS_public);
2267  if (Invalid)
2268  Param->setInvalidDecl();
2269 
2270  if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2271  EnterExpressionEvaluationContext ConstantEvaluated(
2273  ExprResult Value = SemaRef.SubstExpr(D->getDefaultArgument(), TemplateArgs);
2274  if (!Value.isInvalid())
2275  Param->setDefaultArgument(Value.get());
2276  }
2277 
2278  // Introduce this template parameter's instantiation into the instantiation
2279  // scope.
2280  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2281  return Param;
2282 }
2283 
2285  Sema &S,
2286  TemplateParameterList *Params,
2288  for (const auto &P : *Params) {
2289  if (P->isTemplateParameterPack())
2290  continue;
2291  if (NonTypeTemplateParmDecl *NTTP = dyn_cast<NonTypeTemplateParmDecl>(P))
2292  S.collectUnexpandedParameterPacks(NTTP->getTypeSourceInfo()->getTypeLoc(),
2293  Unexpanded);
2294  if (TemplateTemplateParmDecl *TTP = dyn_cast<TemplateTemplateParmDecl>(P))
2295  collectUnexpandedParameterPacks(S, TTP->getTemplateParameters(),
2296  Unexpanded);
2297  }
2298 }
2299 
2300 Decl *
2301 TemplateDeclInstantiator::VisitTemplateTemplateParmDecl(
2303  // Instantiate the template parameter list of the template template parameter.
2304  TemplateParameterList *TempParams = D->getTemplateParameters();
2305  TemplateParameterList *InstParams;
2307 
2308  bool IsExpandedParameterPack = false;
2309 
2310  if (D->isExpandedParameterPack()) {
2311  // The template template parameter pack is an already-expanded pack
2312  // expansion of template parameters. Substitute into each of the expanded
2313  // parameters.
2314  ExpandedParams.reserve(D->getNumExpansionTemplateParameters());
2315  for (unsigned I = 0, N = D->getNumExpansionTemplateParameters();
2316  I != N; ++I) {
2317  LocalInstantiationScope Scope(SemaRef);
2318  TemplateParameterList *Expansion =
2320  if (!Expansion)
2321  return nullptr;
2322  ExpandedParams.push_back(Expansion);
2323  }
2324 
2325  IsExpandedParameterPack = true;
2326  InstParams = TempParams;
2327  } else if (D->isPackExpansion()) {
2328  // The template template parameter pack expands to a pack of template
2329  // template parameters. Determine whether we need to expand this parameter
2330  // pack into separate parameters.
2333  Unexpanded);
2334 
2335  // Determine whether the set of unexpanded parameter packs can and should
2336  // be expanded.
2337  bool Expand = true;
2338  bool RetainExpansion = false;
2339  Optional<unsigned> NumExpansions;
2341  TempParams->getSourceRange(),
2342  Unexpanded,
2343  TemplateArgs,
2344  Expand, RetainExpansion,
2345  NumExpansions))
2346  return nullptr;
2347 
2348  if (Expand) {
2349  for (unsigned I = 0; I != *NumExpansions; ++I) {
2350  Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2351  LocalInstantiationScope Scope(SemaRef);
2352  TemplateParameterList *Expansion = SubstTemplateParams(TempParams);
2353  if (!Expansion)
2354  return nullptr;
2355  ExpandedParams.push_back(Expansion);
2356  }
2357 
2358  // Note that we have an expanded parameter pack. The "type" of this
2359  // expanded parameter pack is the original expansion type, but callers
2360  // will end up using the expanded parameter pack types for type-checking.
2361  IsExpandedParameterPack = true;
2362  InstParams = TempParams;
2363  } else {
2364  // We cannot fully expand the pack expansion now, so just substitute
2365  // into the pattern.
2366  Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2367 
2368  LocalInstantiationScope Scope(SemaRef);
2369  InstParams = SubstTemplateParams(TempParams);
2370  if (!InstParams)
2371  return nullptr;
2372  }
2373  } else {
2374  // Perform the actual substitution of template parameters within a new,
2375  // local instantiation scope.
2376  LocalInstantiationScope Scope(SemaRef);
2377  InstParams = SubstTemplateParams(TempParams);
2378  if (!InstParams)
2379  return nullptr;
2380  }
2381 
2382  // Build the template template parameter.
2383  TemplateTemplateParmDecl *Param;
2384  if (IsExpandedParameterPack)
2386  SemaRef.Context, Owner, D->getLocation(),
2387  D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2388  D->getPosition(), D->getIdentifier(), InstParams, ExpandedParams);
2389  else
2391  SemaRef.Context, Owner, D->getLocation(),
2392  D->getDepth() - TemplateArgs.getNumSubstitutedLevels(),
2393  D->getPosition(), D->isParameterPack(), D->getIdentifier(), InstParams);
2394  if (D->hasDefaultArgument() && !D->defaultArgumentWasInherited()) {
2395  NestedNameSpecifierLoc QualifierLoc =
2397  QualifierLoc =
2398  SemaRef.SubstNestedNameSpecifierLoc(QualifierLoc, TemplateArgs);
2399  TemplateName TName = SemaRef.SubstTemplateName(
2400  QualifierLoc, D->getDefaultArgument().getArgument().getAsTemplate(),
2401  D->getDefaultArgument().getTemplateNameLoc(), TemplateArgs);
2402  if (!TName.isNull())
2403  Param->setDefaultArgument(
2404  SemaRef.Context,
2408  }
2409  Param->setAccess(AS_public);
2410 
2411  // Introduce this template parameter's instantiation into the instantiation
2412  // scope.
2413  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, Param);
2414 
2415  return Param;
2416 }
2417 
2418 Decl *TemplateDeclInstantiator::VisitUsingDirectiveDecl(UsingDirectiveDecl *D) {
2419  // Using directives are never dependent (and never contain any types or
2420  // expressions), so they require no explicit instantiation work.
2421 
2422  UsingDirectiveDecl *Inst
2423  = UsingDirectiveDecl::Create(SemaRef.Context, Owner, D->getLocation(),
2425  D->getQualifierLoc(),
2426  D->getIdentLocation(),
2427  D->getNominatedNamespace(),
2428  D->getCommonAncestor());
2429 
2430  // Add the using directive to its declaration context
2431  // only if this is not a function or method.
2432  if (!Owner->isFunctionOrMethod())
2433  Owner->addDecl(Inst);
2434 
2435  return Inst;
2436 }
2437 
2438 Decl *TemplateDeclInstantiator::VisitUsingDecl(UsingDecl *D) {
2439 
2440  // The nested name specifier may be dependent, for example
2441  // template <typename T> struct t {
2442  // struct s1 { T f1(); };
2443  // struct s2 : s1 { using s1::f1; };
2444  // };
2445  // template struct t<int>;
2446  // Here, in using s1::f1, s1 refers to t<T>::s1;
2447  // we need to substitute for t<int>::s1.
2448  NestedNameSpecifierLoc QualifierLoc
2450  TemplateArgs);
2451  if (!QualifierLoc)
2452  return nullptr;
2453 
2454  // For an inheriting constructor declaration, the name of the using
2455  // declaration is the name of a constructor in this class, not in the
2456  // base class.
2457  DeclarationNameInfo NameInfo = D->getNameInfo();
2459  if (auto *RD = dyn_cast<CXXRecordDecl>(SemaRef.CurContext))
2461  SemaRef.Context.getCanonicalType(SemaRef.Context.getRecordType(RD))));
2462 
2463  // We only need to do redeclaration lookups if we're in a class
2464  // scope (in fact, it's not really even possible in non-class
2465  // scopes).
2466  bool CheckRedeclaration = Owner->isRecord();
2467 
2468  LookupResult Prev(SemaRef, NameInfo, Sema::LookupUsingDeclName,
2470 
2471  UsingDecl *NewUD = UsingDecl::Create(SemaRef.Context, Owner,
2472  D->getUsingLoc(),
2473  QualifierLoc,
2474  NameInfo,
2475  D->hasTypename());
2476 
2477  CXXScopeSpec SS;
2478  SS.Adopt(QualifierLoc);
2479  if (CheckRedeclaration) {
2480  Prev.setHideTags(false);
2481  SemaRef.LookupQualifiedName(Prev, Owner);
2482 
2483  // Check for invalid redeclarations.
2484  if (SemaRef.CheckUsingDeclRedeclaration(D->getUsingLoc(),
2485  D->hasTypename(), SS,
2486  D->getLocation(), Prev))
2487  NewUD->setInvalidDecl();
2488 
2489  }
2490 
2491  if (!NewUD->isInvalidDecl() &&
2492  SemaRef.CheckUsingDeclQualifier(D->getUsingLoc(), D->hasTypename(),
2493  SS, NameInfo, D->getLocation()))
2494  NewUD->setInvalidDecl();
2495 
2496  SemaRef.Context.setInstantiatedFromUsingDecl(NewUD, D);
2497  NewUD->setAccess(D->getAccess());
2498  Owner->addDecl(NewUD);
2499 
2500  // Don't process the shadow decls for an invalid decl.
2501  if (NewUD->isInvalidDecl())
2502  return NewUD;
2503 
2504  if (NameInfo.getName().getNameKind() == DeclarationName::CXXConstructorName)
2505  SemaRef.CheckInheritingConstructorUsingDecl(NewUD);
2506 
2507  bool isFunctionScope = Owner->isFunctionOrMethod();
2508 
2509  // Process the shadow decls.
2510  for (auto *Shadow : D->shadows()) {
2511  // FIXME: UsingShadowDecl doesn't preserve its immediate target, so
2512  // reconstruct it in the case where it matters.
2513  NamedDecl *OldTarget = Shadow->getTargetDecl();
2514  if (auto *CUSD = dyn_cast<ConstructorUsingShadowDecl>(Shadow))
2515  if (auto *BaseShadow = CUSD->getNominatedBaseClassShadowDecl())
2516  OldTarget = BaseShadow;
2517 
2518  NamedDecl *InstTarget =
2519  cast_or_null<NamedDecl>(SemaRef.FindInstantiatedDecl(
2520  Shadow->getLocation(), OldTarget, TemplateArgs));
2521  if (!InstTarget)
2522  return nullptr;
2523 
2524  UsingShadowDecl *PrevDecl = nullptr;
2525  if (CheckRedeclaration) {
2526  if (SemaRef.CheckUsingShadowDecl(NewUD, InstTarget, Prev, PrevDecl))
2527  continue;
2528  } else if (UsingShadowDecl *OldPrev =
2530  PrevDecl = cast_or_null<UsingShadowDecl>(SemaRef.FindInstantiatedDecl(
2531  Shadow->getLocation(), OldPrev, TemplateArgs));
2532  }
2533 
2534  UsingShadowDecl *InstShadow =
2535  SemaRef.BuildUsingShadowDecl(/*Scope*/nullptr, NewUD, InstTarget,
2536  PrevDecl);
2537  SemaRef.Context.setInstantiatedFromUsingShadowDecl(InstShadow, Shadow);
2538 
2539  if (isFunctionScope)
2540  SemaRef.CurrentInstantiationScope->InstantiatedLocal(Shadow, InstShadow);
2541  }
2542 
2543  return NewUD;
2544 }
2545 
2546 Decl *TemplateDeclInstantiator::VisitUsingShadowDecl(UsingShadowDecl *D) {
2547  // Ignore these; we handle them in bulk when processing the UsingDecl.
2548  return nullptr;
2549 }
2550 
2551 Decl *TemplateDeclInstantiator::VisitConstructorUsingShadowDecl(
2553  // Ignore these; we handle them in bulk when processing the UsingDecl.
2554  return nullptr;
2555 }
2556 
2557 template <typename T>
2558 Decl *TemplateDeclInstantiator::instantiateUnresolvedUsingDecl(
2559  T *D, bool InstantiatingPackElement) {
2560  // If this is a pack expansion, expand it now.
2561  if (D->isPackExpansion() && !InstantiatingPackElement) {
2563  SemaRef.collectUnexpandedParameterPacks(D->getQualifierLoc(), Unexpanded);
2564  SemaRef.collectUnexpandedParameterPacks(D->getNameInfo(), Unexpanded);
2565 
2566  // Determine whether the set of unexpanded parameter packs can and should
2567  // be expanded.
2568  bool Expand = true;
2569  bool RetainExpansion = false;
2570  Optional<unsigned> NumExpansions;
2571  if (SemaRef.CheckParameterPacksForExpansion(
2572  D->getEllipsisLoc(), D->getSourceRange(), Unexpanded, TemplateArgs,
2573  Expand, RetainExpansion, NumExpansions))
2574  return nullptr;
2575 
2576  // This declaration cannot appear within a function template signature,
2577  // so we can't have a partial argument list for a parameter pack.
2578  assert(!RetainExpansion &&
2579  "should never need to retain an expansion for UsingPackDecl");
2580 
2581  if (!Expand) {
2582  // We cannot fully expand the pack expansion now, so substitute into the
2583  // pattern and create a new pack expansion.
2584  Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, -1);
2585  return instantiateUnresolvedUsingDecl(D, true);
2586  }
2587 
2588  // Within a function, we don't have any normal way to check for conflicts
2589  // between shadow declarations from different using declarations in the
2590  // same pack expansion, but this is always ill-formed because all expansions
2591  // must produce (conflicting) enumerators.
2592  //
2593  // Sadly we can't just reject this in the template definition because it
2594  // could be valid if the pack is empty or has exactly one expansion.
2595  if (D->getDeclContext()->isFunctionOrMethod() && *NumExpansions > 1) {
2596  SemaRef.Diag(D->getEllipsisLoc(),
2597  diag::err_using_decl_redeclaration_expansion);
2598  return nullptr;
2599  }
2600 
2601  // Instantiate the slices of this pack and build a UsingPackDecl.
2602  SmallVector<NamedDecl*, 8> Expansions;
2603  for (unsigned I = 0; I != *NumExpansions; ++I) {
2604  Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(SemaRef, I);
2605  Decl *Slice = instantiateUnresolvedUsingDecl(D, true);
2606  if (!Slice)
2607  return nullptr;
2608  // Note that we can still get unresolved using declarations here, if we
2609  // had arguments for all packs but the pattern also contained other
2610  // template arguments (this only happens during partial substitution, eg
2611  // into the body of a generic lambda in a function template).
2612  Expansions.push_back(cast<NamedDecl>(Slice));
2613  }
2614 
2615  auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2616  if (isDeclWithinFunction(D))
2617  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2618  return NewD;
2619  }
2620 
2622  SourceLocation TypenameLoc = TD ? TD->getTypenameLoc() : SourceLocation();
2623 
2624  NestedNameSpecifierLoc QualifierLoc
2625  = SemaRef.SubstNestedNameSpecifierLoc(D->getQualifierLoc(),
2626  TemplateArgs);
2627  if (!QualifierLoc)
2628  return nullptr;
2629 
2630  CXXScopeSpec SS;
2631  SS.Adopt(QualifierLoc);
2632 
2633  DeclarationNameInfo NameInfo
2634  = SemaRef.SubstDeclarationNameInfo(D->getNameInfo(), TemplateArgs);
2635 
2636  // Produce a pack expansion only if we're not instantiating a particular
2637  // slice of a pack expansion.
2638  bool InstantiatingSlice = D->getEllipsisLoc().isValid() &&
2639  SemaRef.ArgumentPackSubstitutionIndex != -1;
2640  SourceLocation EllipsisLoc =
2641  InstantiatingSlice ? SourceLocation() : D->getEllipsisLoc();
2642 
2643  NamedDecl *UD = SemaRef.BuildUsingDeclaration(
2644  /*Scope*/ nullptr, D->getAccess(), D->getUsingLoc(),
2645  /*HasTypename*/ TD, TypenameLoc, SS, NameInfo, EllipsisLoc,
2647  /*IsInstantiation*/ true);
2648  if (UD)
2649  SemaRef.Context.setInstantiatedFromUsingDecl(UD, D);
2650 
2651  return UD;
2652 }
2653 
2654 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingTypenameDecl(
2656  return instantiateUnresolvedUsingDecl(D);
2657 }
2658 
2659 Decl *TemplateDeclInstantiator::VisitUnresolvedUsingValueDecl(
2661  return instantiateUnresolvedUsingDecl(D);
2662 }
2663 
2664 Decl *TemplateDeclInstantiator::VisitUsingPackDecl(UsingPackDecl *D) {
2665  SmallVector<NamedDecl*, 8> Expansions;
2666  for (auto *UD : D->expansions()) {
2667  if (NamedDecl *NewUD =
2668  SemaRef.FindInstantiatedDecl(D->getLocation(), UD, TemplateArgs))
2669  Expansions.push_back(NewUD);
2670  else
2671  return nullptr;
2672  }
2673 
2674  auto *NewD = SemaRef.BuildUsingPackDecl(D, Expansions);
2675  if (isDeclWithinFunction(D))
2676  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewD);
2677  return NewD;
2678 }
2679 
2680 Decl *TemplateDeclInstantiator::VisitClassScopeFunctionSpecializationDecl(
2682  CXXMethodDecl *OldFD = Decl->getSpecialization();
2683  CXXMethodDecl *NewFD =
2684  cast_or_null<CXXMethodDecl>(VisitCXXMethodDecl(OldFD, nullptr, true));
2685  if (!NewFD)
2686  return nullptr;
2687 
2690 
2691  TemplateArgumentListInfo TemplateArgs;
2692  TemplateArgumentListInfo *TemplateArgsPtr = nullptr;
2693  if (Decl->hasExplicitTemplateArgs()) {
2694  TemplateArgs = Decl->templateArgs();
2695  TemplateArgsPtr = &TemplateArgs;
2696  }
2697 
2698  SemaRef.LookupQualifiedName(Previous, SemaRef.CurContext);
2699  if (SemaRef.CheckFunctionTemplateSpecialization(NewFD, TemplateArgsPtr,
2700  Previous)) {
2701  NewFD->setInvalidDecl();
2702  return NewFD;
2703  }
2704 
2705  // Associate the specialization with the pattern.
2706  FunctionDecl *Specialization = cast<FunctionDecl>(Previous.getFoundDecl());
2707  assert(Specialization && "Class scope Specialization is null");
2708  SemaRef.Context.setClassScopeSpecializationPattern(Specialization, OldFD);
2709 
2710  // FIXME: If this is a definition, check for redefinition errors!
2711 
2712  return NewFD;
2713 }
2714 
2715 Decl *TemplateDeclInstantiator::VisitOMPThreadPrivateDecl(
2716  OMPThreadPrivateDecl *D) {
2718  for (auto *I : D->varlists()) {
2719  Expr *Var = SemaRef.SubstExpr(I, TemplateArgs).get();
2720  assert(isa<DeclRefExpr>(Var) && "threadprivate arg is not a DeclRefExpr");
2721  Vars.push_back(Var);
2722  }
2723 
2724  OMPThreadPrivateDecl *TD =
2725  SemaRef.CheckOMPThreadPrivateDecl(D->getLocation(), Vars);
2726 
2727  TD->setAccess(AS_public);
2728  Owner->addDecl(TD);
2729 
2730  return TD;
2731 }
2732 
2733 Decl *TemplateDeclInstantiator::VisitOMPDeclareReductionDecl(
2735  // Instantiate type and check if it is allowed.
2736  QualType SubstReductionType = SemaRef.ActOnOpenMPDeclareReductionType(
2737  D->getLocation(),
2738  ParsedType::make(SemaRef.SubstType(D->getType(), TemplateArgs,
2739  D->getLocation(), DeclarationName())));
2740  if (SubstReductionType.isNull())
2741  return nullptr;
2742  bool IsCorrect = !SubstReductionType.isNull();
2743  // Create instantiated copy.
2744  std::pair<QualType, SourceLocation> ReductionTypes[] = {
2745  std::make_pair(SubstReductionType, D->getLocation())};
2746  auto *PrevDeclInScope = D->getPrevDeclInScope();
2747  if (PrevDeclInScope && !PrevDeclInScope->isInvalidDecl()) {
2748  PrevDeclInScope = cast<OMPDeclareReductionDecl>(
2749  SemaRef.CurrentInstantiationScope->findInstantiationOf(PrevDeclInScope)
2750  ->get<Decl *>());
2751  }
2752  auto DRD = SemaRef.ActOnOpenMPDeclareReductionDirectiveStart(
2753  /*S=*/nullptr, Owner, D->getDeclName(), ReductionTypes, D->getAccess(),
2754  PrevDeclInScope);
2755  auto *NewDRD = cast<OMPDeclareReductionDecl>(DRD.get().getSingleDecl());
2756  if (isDeclWithinFunction(NewDRD))
2757  SemaRef.CurrentInstantiationScope->InstantiatedLocal(D, NewDRD);
2758  Expr *SubstCombiner = nullptr;
2759  Expr *SubstInitializer = nullptr;
2760  // Combiners instantiation sequence.
2761  if (D->getCombiner()) {
2763  /*S=*/nullptr, NewDRD);
2764  const char *Names[] = {"omp_in", "omp_out"};
2765  for (auto &Name : Names) {
2766  DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2767  auto OldLookup = D->lookup(DN);
2768  auto Lookup = NewDRD->lookup(DN);
2769  if (!OldLookup.empty() && !Lookup.empty()) {
2770  assert(Lookup.size() == 1 && OldLookup.size() == 1);
2771  SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldLookup.front(),
2772  Lookup.front());
2773  }
2774  }
2775  SubstCombiner = SemaRef.SubstExpr(D->getCombiner(), TemplateArgs).get();
2776  SemaRef.ActOnOpenMPDeclareReductionCombinerEnd(NewDRD, SubstCombiner);
2777  // Initializers instantiation sequence.
2778  if (D->getInitializer()) {
2779  VarDecl *OmpPrivParm =
2781  /*S=*/nullptr, NewDRD);
2782  const char *Names[] = {"omp_orig", "omp_priv"};
2783  for (auto &Name : Names) {
2784  DeclarationName DN(&SemaRef.Context.Idents.get(Name));
2785  auto OldLookup = D->lookup(DN);
2786  auto Lookup = NewDRD->lookup(DN);
2787  if (!OldLookup.empty() && !Lookup.empty()) {
2788  assert(Lookup.size() == 1 && OldLookup.size() == 1);
2789  auto *OldVD = cast<VarDecl>(OldLookup.front());
2790  auto *NewVD = cast<VarDecl>(Lookup.front());
2791  SemaRef.InstantiateVariableInitializer(NewVD, OldVD, TemplateArgs);
2792  SemaRef.CurrentInstantiationScope->InstantiatedLocal(OldVD, NewVD);
2793  }
2794  }
2796  SubstInitializer =
2797  SemaRef.SubstExpr(D->getInitializer(), TemplateArgs).get();
2798  } else {
2799  IsCorrect = IsCorrect && OmpPrivParm->hasInit();
2800  }
2802  NewDRD, SubstInitializer, OmpPrivParm);
2803  }
2804  IsCorrect =
2805  IsCorrect && SubstCombiner &&
2806  (!D->getInitializer() ||
2808  SubstInitializer) ||
2810  !SubstInitializer && !SubstInitializer));
2811  } else
2812  IsCorrect = false;
2813 
2814  (void)SemaRef.ActOnOpenMPDeclareReductionDirectiveEnd(/*S=*/nullptr, DRD,
2815  IsCorrect);
2816 
2817  return NewDRD;
2818 }
2819 
2820 Decl *TemplateDeclInstantiator::VisitOMPCapturedExprDecl(
2821  OMPCapturedExprDecl * /*D*/) {
2822  llvm_unreachable("Should not be met in templates");
2823 }
2824 
2826  return VisitFunctionDecl(D, nullptr);
2827 }
2828 
2829 Decl *
2830 TemplateDeclInstantiator::VisitCXXDeductionGuideDecl(CXXDeductionGuideDecl *D) {
2831  Decl *Inst = VisitFunctionDecl(D, nullptr);
2832  if (Inst && !D->getDescribedFunctionTemplate())
2833  Owner->addDecl(Inst);
2834  return Inst;
2835 }
2836 
2838  return VisitCXXMethodDecl(D, nullptr);
2839 }
2840 
2841 Decl *TemplateDeclInstantiator::VisitRecordDecl(RecordDecl *D) {
2842  llvm_unreachable("There are only CXXRecordDecls in C++");
2843 }
2844 
2845 Decl *
2846 TemplateDeclInstantiator::VisitClassTemplateSpecializationDecl(
2848  // As a MS extension, we permit class-scope explicit specialization
2849  // of member class templates.
2850  ClassTemplateDecl *ClassTemplate = D->getSpecializedTemplate();
2851  assert(ClassTemplate->getDeclContext()->isRecord() &&
2853  "can only instantiate an explicit specialization "
2854  "for a member class template");
2855 
2856  // Lookup the already-instantiated declaration in the instantiation
2857  // of the class template. FIXME: Diagnose or assert if this fails?
2859  = Owner->lookup(ClassTemplate->getDeclName());
2860  if (Found.empty())
2861  return nullptr;
2862  ClassTemplateDecl *InstClassTemplate
2863  = dyn_cast<ClassTemplateDecl>(Found.front());
2864  if (!InstClassTemplate)
2865  return nullptr;
2866 
2867  // Substitute into the template arguments of the class template explicit
2868  // specialization.
2870  castAs<TemplateSpecializationTypeLoc>();
2871  TemplateArgumentListInfo InstTemplateArgs(Loc.getLAngleLoc(),
2872  Loc.getRAngleLoc());
2874  for (unsigned I = 0; I != Loc.getNumArgs(); ++I)
2875  ArgLocs.push_back(Loc.getArgLoc(I));
2876  if (SemaRef.Subst(ArgLocs.data(), ArgLocs.size(),
2877  InstTemplateArgs, TemplateArgs))
2878  return nullptr;
2879 
2880  // Check that the template argument list is well-formed for this
2881  // class template.
2883  if (SemaRef.CheckTemplateArgumentList(InstClassTemplate,
2884  D->getLocation(),
2885  InstTemplateArgs,
2886  false,
2887  Converted))
2888  return nullptr;
2889 
2890  // Figure out where to insert this class template explicit specialization
2891  // in the member template's set of class template explicit specializations.
2892  void *InsertPos = nullptr;
2894  InstClassTemplate->findSpecialization(Converted, InsertPos);
2895 
2896  // Check whether we've already seen a conflicting instantiation of this
2897  // declaration (for instance, if there was a prior implicit instantiation).
2898  bool Ignored;
2899  if (PrevDecl &&
2901  D->getSpecializationKind(),
2902  PrevDecl,
2903  PrevDecl->getSpecializationKind(),
2904  PrevDecl->getPointOfInstantiation(),
2905  Ignored))
2906  return nullptr;
2907 
2908  // If PrevDecl was a definition and D is also a definition, diagnose.
2909  // This happens in cases like:
2910  //
2911  // template<typename T, typename U>
2912  // struct Outer {
2913  // template<typename X> struct Inner;
2914  // template<> struct Inner<T> {};
2915  // template<> struct Inner<U> {};
2916  // };
2917  //
2918  // Outer<int, int> outer; // error: the explicit specializations of Inner
2919  // // have the same signature.
2920  if (PrevDecl && PrevDecl->getDefinition() &&
2922  SemaRef.Diag(D->getLocation(), diag::err_redefinition) << PrevDecl;
2923  SemaRef.Diag(PrevDecl->getDefinition()->getLocation(),
2924  diag::note_previous_definition);
2925  return nullptr;
2926  }
2927 
2928  // Create the class template partial specialization declaration.
2931  SemaRef.Context, D->getTagKind(), Owner, D->getBeginLoc(),
2932  D->getLocation(), InstClassTemplate, Converted, PrevDecl);
2933 
2934  // Add this partial specialization to the set of class template partial
2935  // specializations.
2936  if (!PrevDecl)
2937  InstClassTemplate->AddSpecialization(InstD, InsertPos);
2938 
2939  // Substitute the nested name specifier, if any.
2940  if (SubstQualifier(D, InstD))
2941  return nullptr;
2942 
2943  // Build the canonical type that describes the converted template
2944  // arguments of the class template explicit specialization.
2945  QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
2946  TemplateName(InstClassTemplate), Converted,
2947  SemaRef.Context.getRecordType(InstD));
2948 
2949  // Build the fully-sugared type for this class template
2950  // specialization as the user wrote in the specialization
2951  // itself. This means that we'll pretty-print the type retrieved
2952  // from the specialization's declaration the way that the user
2953  // actually wrote the specialization, rather than formatting the
2954  // name based on the "canonical" representation used to store the
2955  // template arguments in the specialization.
2957  TemplateName(InstClassTemplate), D->getLocation(), InstTemplateArgs,
2958  CanonType);
2959 
2960  InstD->setAccess(D->getAccess());
2963  InstD->setTypeAsWritten(WrittenTy);
2964  InstD->setExternLoc(D->getExternLoc());
2966 
2967  Owner->addDecl(InstD);
2968 
2969  // Instantiate the members of the class-scope explicit specialization eagerly.
2970  // We don't have support for lazy instantiation of an explicit specialization
2971  // yet, and MSVC eagerly instantiates in this case.
2972  if (D->isThisDeclarationADefinition() &&
2973  SemaRef.InstantiateClass(D->getLocation(), InstD, D, TemplateArgs,
2975  /*Complain=*/true))
2976  return nullptr;
2977 
2978  return InstD;
2979 }
2980 
2983 
2984  TemplateArgumentListInfo VarTemplateArgsInfo;
2985  VarTemplateDecl *VarTemplate = D->getSpecializedTemplate();
2986  assert(VarTemplate &&
2987  "A template specialization without specialized template?");
2988 
2989  // Substitute the current template arguments.
2990  const TemplateArgumentListInfo &TemplateArgsInfo = D->getTemplateArgsInfo();
2991  VarTemplateArgsInfo.setLAngleLoc(TemplateArgsInfo.getLAngleLoc());
2992  VarTemplateArgsInfo.setRAngleLoc(TemplateArgsInfo.getRAngleLoc());
2993 
2994  if (SemaRef.Subst(TemplateArgsInfo.getArgumentArray(),
2995  TemplateArgsInfo.size(), VarTemplateArgsInfo, TemplateArgs))
2996  return nullptr;
2997 
2998  // Check that the template argument list is well-formed for this template.
3000  if (SemaRef.CheckTemplateArgumentList(
3001  VarTemplate, VarTemplate->getBeginLoc(),
3002  const_cast<TemplateArgumentListInfo &>(VarTemplateArgsInfo), false,
3003  Converted))
3004  return nullptr;
3005 
3006  // Find the variable template specialization declaration that
3007  // corresponds to these arguments.
3008  void *InsertPos = nullptr;
3009  if (VarTemplateSpecializationDecl *VarSpec = VarTemplate->findSpecialization(
3010  Converted, InsertPos))
3011  // If we already have a variable template specialization, return it.
3012  return VarSpec;
3013 
3014  return VisitVarTemplateSpecializationDecl(VarTemplate, D, InsertPos,
3015  VarTemplateArgsInfo, Converted);
3016 }
3017 
3019  VarTemplateDecl *VarTemplate, VarDecl *D, void *InsertPos,
3020  const TemplateArgumentListInfo &TemplateArgsInfo,
3021  ArrayRef<TemplateArgument> Converted) {
3022 
3023  // Do substitution on the type of the declaration
3024  TypeSourceInfo *DI =
3025  SemaRef.SubstType(D->getTypeSourceInfo(), TemplateArgs,
3026  D->getTypeSpecStartLoc(), D->getDeclName());
3027  if (!DI)
3028  return nullptr;
3029 
3030  if (DI->getType()->isFunctionType()) {
3031  SemaRef.Diag(D->getLocation(), diag::err_variable_instantiates_to_function)
3032  << D->isStaticDataMember() << DI->getType();
3033  return nullptr;
3034  }
3035 
3036  // Build the instantiated declaration
3038  SemaRef.Context, Owner, D->getInnerLocStart(), D->getLocation(),
3039  VarTemplate, DI->getType(), DI, D->getStorageClass(), Converted);
3040  Var->setTemplateArgsInfo(TemplateArgsInfo);
3041  if (InsertPos)
3042  VarTemplate->AddSpecialization(Var, InsertPos);
3043 
3044  // Substitute the nested name specifier, if any.
3045  if (SubstQualifier(D, Var))
3046  return nullptr;
3047 
3048  SemaRef.BuildVariableInstantiation(Var, D, TemplateArgs, LateAttrs,
3049  Owner, StartingScope);
3050 
3051  return Var;
3052 }
3053 
3054 Decl *TemplateDeclInstantiator::VisitObjCAtDefsFieldDecl(ObjCAtDefsFieldDecl *D) {
3055  llvm_unreachable("@defs is not supported in Objective-C++");
3056 }
3057 
3058 Decl *TemplateDeclInstantiator::VisitFriendTemplateDecl(FriendTemplateDecl *D) {
3059  // FIXME: We need to be able to instantiate FriendTemplateDecls.
3060  unsigned DiagID = SemaRef.getDiagnostics().getCustomDiagID(
3062  "cannot instantiate %0 yet");
3063  SemaRef.Diag(D->getLocation(), DiagID)
3064  << D->getDeclKindName();
3065 
3066  return nullptr;
3067 }
3068 
3070  llvm_unreachable("Unexpected decl");
3071 }
3072 
3073 Decl *Sema::SubstDecl(Decl *D, DeclContext *Owner,
3074  const MultiLevelTemplateArgumentList &TemplateArgs) {
3075  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
3076  if (D->isInvalidDecl())
3077  return nullptr;
3078 
3079  return Instantiator.Visit(D);
3080 }
3081 
3082 /// Instantiates a nested template parameter list in the current
3083 /// instantiation context.
3084 ///
3085 /// \param L The parameter list to instantiate
3086 ///
3087 /// \returns NULL if there was an error
3090  // Get errors for all the parameters before bailing out.
3091  bool Invalid = false;
3092 
3093  unsigned N = L->size();
3094  typedef SmallVector<NamedDecl *, 8> ParamVector;
3095  ParamVector Params;
3096  Params.reserve(N);
3097  for (auto &P : *L) {
3098  NamedDecl *D = cast_or_null<NamedDecl>(Visit(P));
3099  Params.push_back(D);
3100  Invalid = Invalid || !D || D->isInvalidDecl();
3101  }
3102 
3103  // Clean up if we had an error.
3104  if (Invalid)
3105  return nullptr;
3106 
3107  // Note: we substitute into associated constraints later
3108  Expr *const UninstantiatedRequiresClause = L->getRequiresClause();
3109 
3110  TemplateParameterList *InstL
3111  = TemplateParameterList::Create(SemaRef.Context, L->getTemplateLoc(),
3112  L->getLAngleLoc(), Params,
3113  L->getRAngleLoc(),
3114  UninstantiatedRequiresClause);
3115  return InstL;
3116 }
3117 
3120  const MultiLevelTemplateArgumentList &TemplateArgs) {
3121  TemplateDeclInstantiator Instantiator(*this, Owner, TemplateArgs);
3122  return Instantiator.SubstTemplateParams(Params);
3123 }
3124 
3125 /// Instantiate the declaration of a class template partial
3126 /// specialization.
3127 ///
3128 /// \param ClassTemplate the (instantiated) class template that is partially
3129 // specialized by the instantiation of \p PartialSpec.
3130 ///
3131 /// \param PartialSpec the (uninstantiated) class template partial
3132 /// specialization that we are instantiating.
3133 ///
3134 /// \returns The instantiated partial specialization, if successful; otherwise,
3135 /// NULL to indicate an error.
3138  ClassTemplateDecl *ClassTemplate,
3140  // Create a local instantiation scope for this class template partial
3141  // specialization, which will contain the instantiations of the template
3142  // parameters.
3143  LocalInstantiationScope Scope(SemaRef);
3144 
3145  // Substitute into the template parameters of the class template partial
3146  // specialization.
3147  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3148  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3149  if (!InstParams)
3150  return nullptr;
3151 
3152  // Substitute into the template arguments of the class template partial
3153  // specialization.
3154  const ASTTemplateArgumentListInfo *TemplArgInfo
3155  = PartialSpec->getTemplateArgsAsWritten();
3156  TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3157  TemplArgInfo->RAngleLoc);
3158  if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3159  TemplArgInfo->NumTemplateArgs,
3160  InstTemplateArgs, TemplateArgs))
3161  return nullptr;
3162 
3163  // Check that the template argument list is well-formed for this
3164  // class template.
3166  if (SemaRef.CheckTemplateArgumentList(ClassTemplate,
3167  PartialSpec->getLocation(),
3168  InstTemplateArgs,
3169  false,
3170  Converted))
3171  return nullptr;
3172 
3173  // Check these arguments are valid for a template partial specialization.
3175  PartialSpec->getLocation(), ClassTemplate, InstTemplateArgs.size(),
3176  Converted))
3177  return nullptr;
3178 
3179  // Figure out where to insert this class template partial specialization
3180  // in the member template's set of class template partial specializations.
3181  void *InsertPos = nullptr;
3183  = ClassTemplate->findPartialSpecialization(Converted, InsertPos);
3184 
3185  // Build the canonical type that describes the converted template
3186  // arguments of the class template partial specialization.
3187  QualType CanonType
3188  = SemaRef.Context.getTemplateSpecializationType(TemplateName(ClassTemplate),
3189  Converted);
3190 
3191  // Build the fully-sugared type for this class template
3192  // specialization as the user wrote in the specialization
3193  // itself. This means that we'll pretty-print the type retrieved
3194  // from the specialization's declaration the way that the user
3195  // actually wrote the specialization, rather than formatting the
3196  // name based on the "canonical" representation used to store the
3197  // template arguments in the specialization.
3198  TypeSourceInfo *WrittenTy
3200  TemplateName(ClassTemplate),
3201  PartialSpec->getLocation(),
3202  InstTemplateArgs,
3203  CanonType);
3204 
3205  if (PrevDecl) {
3206  // We've already seen a partial specialization with the same template
3207  // parameters and template arguments. This can happen, for example, when
3208  // substituting the outer template arguments ends up causing two
3209  // class template partial specializations of a member class template
3210  // to have identical forms, e.g.,
3211  //
3212  // template<typename T, typename U>
3213  // struct Outer {
3214  // template<typename X, typename Y> struct Inner;
3215  // template<typename Y> struct Inner<T, Y>;
3216  // template<typename Y> struct Inner<U, Y>;
3217  // };
3218  //
3219  // Outer<int, int> outer; // error: the partial specializations of Inner
3220  // // have the same signature.
3221  SemaRef.Diag(PartialSpec->getLocation(), diag::err_partial_spec_redeclared)
3222  << WrittenTy->getType();
3223  SemaRef.Diag(PrevDecl->getLocation(), diag::note_prev_partial_spec_here)
3224  << SemaRef.Context.getTypeDeclType(PrevDecl);
3225  return nullptr;
3226  }
3227 
3228 
3229  // Create the class template partial specialization declaration.
3230  ClassTemplatePartialSpecializationDecl *InstPartialSpec =
3232  SemaRef.Context, PartialSpec->getTagKind(), Owner,
3233  PartialSpec->getBeginLoc(), PartialSpec->getLocation(), InstParams,
3234  ClassTemplate, Converted, InstTemplateArgs, CanonType, nullptr);
3235  // Substitute the nested name specifier, if any.
3236  if (SubstQualifier(PartialSpec, InstPartialSpec))
3237  return nullptr;
3238 
3239  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3240  InstPartialSpec->setTypeAsWritten(WrittenTy);
3241 
3242  // Check the completed partial specialization.
3243  SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3244 
3245  // Add this partial specialization to the set of class template partial
3246  // specializations.
3247  ClassTemplate->AddPartialSpecialization(InstPartialSpec,
3248  /*InsertPos=*/nullptr);
3249  return InstPartialSpec;
3250 }
3251 
3252 /// Instantiate the declaration of a variable template partial
3253 /// specialization.
3254 ///
3255 /// \param VarTemplate the (instantiated) variable template that is partially
3256 /// specialized by the instantiation of \p PartialSpec.
3257 ///
3258 /// \param PartialSpec the (uninstantiated) variable template partial
3259 /// specialization that we are instantiating.
3260 ///
3261 /// \returns The instantiated partial specialization, if successful; otherwise,
3262 /// NULL to indicate an error.
3265  VarTemplateDecl *VarTemplate,
3266  VarTemplatePartialSpecializationDecl *PartialSpec) {
3267  // Create a local instantiation scope for this variable template partial
3268  // specialization, which will contain the instantiations of the template
3269  // parameters.
3270  LocalInstantiationScope Scope(SemaRef);
3271 
3272  // Substitute into the template parameters of the variable template partial
3273  // specialization.
3274  TemplateParameterList *TempParams = PartialSpec->getTemplateParameters();
3275  TemplateParameterList *InstParams = SubstTemplateParams(TempParams);
3276  if (!InstParams)
3277  return nullptr;
3278 
3279  // Substitute into the template arguments of the variable template partial
3280  // specialization.
3281  const ASTTemplateArgumentListInfo *TemplArgInfo
3282  = PartialSpec->getTemplateArgsAsWritten();
3283  TemplateArgumentListInfo InstTemplateArgs(TemplArgInfo->LAngleLoc,
3284  TemplArgInfo->RAngleLoc);
3285  if (SemaRef.Subst(TemplArgInfo->getTemplateArgs(),
3286  TemplArgInfo->NumTemplateArgs,
3287  InstTemplateArgs, TemplateArgs))
3288  return nullptr;
3289 
3290  // Check that the template argument list is well-formed for this
3291  // class template.
3293  if (SemaRef.CheckTemplateArgumentList(VarTemplate, PartialSpec->getLocation(),
3294  InstTemplateArgs, false, Converted))
3295  return nullptr;
3296 
3297  // Check these arguments are valid for a template partial specialization.
3299  PartialSpec->getLocation(), VarTemplate, InstTemplateArgs.size(),
3300  Converted))
3301  return nullptr;
3302 
3303  // Figure out where to insert this variable template partial specialization
3304  // in the member template's set of variable template partial specializations.
3305  void *InsertPos = nullptr;
3306  VarTemplateSpecializationDecl *PrevDecl =
3307  VarTemplate->findPartialSpecialization(Converted, InsertPos);
3308 
3309  // Build the canonical type that describes the converted template
3310  // arguments of the variable template partial specialization.
3311  QualType CanonType = SemaRef.Context.getTemplateSpecializationType(
3312  TemplateName(VarTemplate), Converted);
3313 
3314  // Build the fully-sugared type for this variable template
3315  // specialization as the user wrote in the specialization
3316  // itself. This means that we'll pretty-print the type retrieved
3317  // from the specialization's declaration the way that the user
3318  // actually wrote the specialization, rather than formatting the
3319  // name based on the "canonical" representation used to store the
3320  // template arguments in the specialization.
3322  TemplateName(VarTemplate), PartialSpec->getLocation(), InstTemplateArgs,
3323  CanonType);
3324 
3325  if (PrevDecl) {
3326  // We've already seen a partial specialization with the same template
3327  // parameters and template arguments. This can happen, for example, when
3328  // substituting the outer template arguments ends up causing two
3329  // variable template partial specializations of a member variable template
3330  // to have identical forms, e.g.,
3331  //
3332  // template<typename T, typename U>
3333  // struct Outer {
3334  // template<typename X, typename Y> pair<X,Y> p;
3335  // template<typename Y> pair<T, Y> p;
3336  // template<typename Y> pair<U, Y> p;
3337  // };
3338  //
3339  // Outer<int, int> outer; // error: the partial specializations of Inner
3340  // // have the same signature.
3341  SemaRef.Diag(PartialSpec->getLocation(),
3342  diag::err_var_partial_spec_redeclared)
3343  << WrittenTy->getType();
3344  SemaRef.Diag(PrevDecl->getLocation(),
3345  diag::note_var_prev_partial_spec_here);
3346  return nullptr;
3347  }
3348 
3349  // Do substitution on the type of the declaration
3350  TypeSourceInfo *DI = SemaRef.SubstType(
3351  PartialSpec->getTypeSourceInfo(), TemplateArgs,
3352  PartialSpec->getTypeSpecStartLoc(), PartialSpec->getDeclName());
3353  if (!DI)
3354  return nullptr;
3355 
3356  if (DI->getType()->isFunctionType()) {
3357  SemaRef.Diag(PartialSpec->getLocation(),
3358  diag::err_variable_instantiates_to_function)
3359  << PartialSpec->isStaticDataMember() << DI->getType();
3360  return nullptr;
3361  }
3362 
3363  // Create the variable template partial specialization declaration.
3364  VarTemplatePartialSpecializationDecl *InstPartialSpec =
3366  SemaRef.Context, Owner, PartialSpec->getInnerLocStart(),
3367  PartialSpec->getLocation(), InstParams, VarTemplate, DI->getType(),
3368  DI, PartialSpec->getStorageClass(), Converted, InstTemplateArgs);
3369 
3370  // Substitute the nested name specifier, if any.
3371  if (SubstQualifier(PartialSpec, InstPartialSpec))
3372  return nullptr;
3373 
3374  InstPartialSpec->setInstantiatedFromMember(PartialSpec);
3375  InstPartialSpec->setTypeAsWritten(WrittenTy);
3376 
3377  // Check the completed partial specialization.
3378  SemaRef.CheckTemplatePartialSpecialization(InstPartialSpec);
3379 
3380  // Add this partial specialization to the set of variable template partial
3381  // specializations. The instantiation of the initializer is not necessary.
3382  VarTemplate->AddPartialSpecialization(InstPartialSpec, /*InsertPos=*/nullptr);
3383 
3384  SemaRef.BuildVariableInstantiation(InstPartialSpec, PartialSpec, TemplateArgs,
3385  LateAttrs, Owner, StartingScope);
3386 
3387  return InstPartialSpec;
3388 }
3389 
3393  TypeSourceInfo *OldTInfo = D->getTypeSourceInfo();
3394  assert(OldTInfo && "substituting function without type source info");
3395  assert(Params.empty() && "parameter vector is non-empty at start");
3396 
3397  CXXRecordDecl *ThisContext = nullptr;
3398  unsigned ThisTypeQuals = 0;
3399  if (CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(D)) {
3400  ThisContext = cast<CXXRecordDecl>(Owner);
3401  ThisTypeQuals = Method->getTypeQualifiers();
3402  }
3403 
3404  TypeSourceInfo *NewTInfo
3405  = SemaRef.SubstFunctionDeclType(OldTInfo, TemplateArgs,
3406  D->getTypeSpecStartLoc(),
3407  D->getDeclName(),
3408  ThisContext, ThisTypeQuals);
3409  if (!NewTInfo)
3410  return nullptr;
3411 
3412  TypeLoc OldTL = OldTInfo->getTypeLoc().IgnoreParens();
3413  if (FunctionProtoTypeLoc OldProtoLoc = OldTL.getAs<FunctionProtoTypeLoc>()) {
3414  if (NewTInfo != OldTInfo) {
3415  // Get parameters from the new type info.
3416  TypeLoc NewTL = NewTInfo->getTypeLoc().IgnoreParens();
3417  FunctionProtoTypeLoc NewProtoLoc = NewTL.castAs<FunctionProtoTypeLoc>();
3418  unsigned NewIdx = 0;
3419  for (unsigned OldIdx = 0, NumOldParams = OldProtoLoc.getNumParams();
3420  OldIdx != NumOldParams; ++OldIdx) {
3421  ParmVarDecl *OldParam = OldProtoLoc.getParam(OldIdx);
3423 
3424  Optional<unsigned> NumArgumentsInExpansion;
3425  if (OldParam->isParameterPack())
3426  NumArgumentsInExpansion =
3427  SemaRef.getNumArgumentsInExpansion(OldParam->getType(),
3428  TemplateArgs);
3429  if (!NumArgumentsInExpansion) {
3430  // Simple case: normal parameter, or a parameter pack that's
3431  // instantiated to a (still-dependent) parameter pack.
3432  ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3433  Params.push_back(NewParam);
3434  Scope->InstantiatedLocal(OldParam, NewParam);
3435  } else {
3436  // Parameter pack expansion: make the instantiation an argument pack.
3437  Scope->MakeInstantiatedLocalArgPack(OldParam);
3438  for (unsigned I = 0; I != *NumArgumentsInExpansion; ++I) {
3439  ParmVarDecl *NewParam = NewProtoLoc.getParam(NewIdx++);
3440  Params.push_back(NewParam);
3441  Scope->InstantiatedLocalPackArg(OldParam, NewParam);
3442  }
3443  }
3444  }
3445  } else {
3446  // The function type itself was not dependent and therefore no
3447  // substitution occurred. However, we still need to instantiate
3448  // the function parameters themselves.
3449  const FunctionProtoType *OldProto =
3450  cast<FunctionProtoType>(OldProtoLoc.getType());
3451  for (unsigned i = 0, i_end = OldProtoLoc.getNumParams(); i != i_end;
3452  ++i) {
3453  ParmVarDecl *OldParam = OldProtoLoc.getParam(i);
3454  if (!OldParam) {
3455  Params.push_back(SemaRef.BuildParmVarDeclForTypedef(
3456  D, D->getLocation(), OldProto->getParamType(i)));
3457  continue;
3458  }
3459 
3460  ParmVarDecl *Parm =
3461  cast_or_null<ParmVarDecl>(VisitParmVarDecl(OldParam));
3462  if (!Parm)
3463  return nullptr;
3464  Params.push_back(Parm);
3465  }
3466  }
3467  } else {
3468  // If the type of this function, after ignoring parentheses, is not
3469  // *directly* a function type, then we're instantiating a function that
3470  // was declared via a typedef or with attributes, e.g.,
3471  //
3472  // typedef int functype(int, int);
3473  // functype func;
3474  // int __cdecl meth(int, int);
3475  //
3476  // In this case, we'll just go instantiate the ParmVarDecls that we
3477  // synthesized in the method declaration.
3478  SmallVector<QualType, 4> ParamTypes;
3479  Sema::ExtParameterInfoBuilder ExtParamInfos;
3480  if (SemaRef.SubstParmTypes(D->getLocation(), D->parameters(), nullptr,
3481  TemplateArgs, ParamTypes, &Params,
3482  ExtParamInfos))
3483  return nullptr;
3484  }
3485 
3486  return NewTInfo;
3487 }
3488 
3489 /// Introduce the instantiated function parameters into the local
3490 /// instantiation scope, and set the parameter names to those used
3491 /// in the template.
3493  const FunctionDecl *PatternDecl,
3495  const MultiLevelTemplateArgumentList &TemplateArgs) {
3496  unsigned FParamIdx = 0;
3497  for (unsigned I = 0, N = PatternDecl->getNumParams(); I != N; ++I) {
3498  const ParmVarDecl *PatternParam = PatternDecl->getParamDecl(I);
3499  if (!PatternParam->isParameterPack()) {
3500  // Simple case: not a parameter pack.
3501  assert(FParamIdx < Function->getNumParams());
3502  ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3503  FunctionParam->setDeclName(PatternParam->getDeclName());
3504  // If the parameter's type is not dependent, update it to match the type
3505  // in the pattern. They can differ in top-level cv-qualifiers, and we want
3506  // the pattern's type here. If the type is dependent, they can't differ,
3507  // per core issue 1668. Substitute into the type from the pattern, in case
3508  // it's instantiation-dependent.
3509  // FIXME: Updating the type to work around this is at best fragile.
3510  if (!PatternDecl->getType()->isDependentType()) {
3511  QualType T = S.SubstType(PatternParam->getType(), TemplateArgs,
3512  FunctionParam->getLocation(),
3513  FunctionParam->getDeclName());
3514  if (T.isNull())
3515  return true;
3516  FunctionParam->setType(T);
3517  }
3518 
3519  Scope.InstantiatedLocal(PatternParam, FunctionParam);
3520  ++FParamIdx;
3521  continue;
3522  }
3523 
3524  // Expand the parameter pack.
3525  Scope.MakeInstantiatedLocalArgPack(PatternParam);
3526  Optional<unsigned> NumArgumentsInExpansion
3527  = S.getNumArgumentsInExpansion(PatternParam->getType(), TemplateArgs);
3528  assert(NumArgumentsInExpansion &&
3529  "should only be called when all template arguments are known");
3530  QualType PatternType =
3531  PatternParam->getType()->castAs<PackExpansionType>()->getPattern();
3532  for (unsigned Arg = 0; Arg < *NumArgumentsInExpansion; ++Arg) {
3533  ParmVarDecl *FunctionParam = Function->getParamDecl(FParamIdx);
3534  FunctionParam->setDeclName(PatternParam->getDeclName());
3535  if (!PatternDecl->getType()->isDependentType()) {
3536  Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(S, Arg);
3537  QualType T = S.SubstType(PatternType, TemplateArgs,
3538  FunctionParam->getLocation(),
3539  FunctionParam->getDeclName());
3540  if (T.isNull())
3541  return true;
3542  FunctionParam->setType(T);
3543  }
3544 
3545  Scope.InstantiatedLocalPackArg(PatternParam, FunctionParam);
3546  ++FParamIdx;
3547  }
3548  }
3549 
3550  return false;
3551 }
3552 
3554  FunctionDecl *Decl) {
3555  const FunctionProtoType *Proto = Decl->getType()->castAs<FunctionProtoType>();
3556  if (Proto->getExceptionSpecType() != EST_Uninstantiated)
3557  return;
3558 
3559  InstantiatingTemplate Inst(*this, PointOfInstantiation, Decl,
3561  if (Inst.isInvalid()) {
3562  // We hit the instantiation depth limit. Clear the exception specification
3563  // so that our callers don't have to cope with EST_Uninstantiated.
3564  UpdateExceptionSpec(Decl, EST_None);
3565  return;
3566  }
3567  if (Inst.isAlreadyInstantiating()) {
3568  // This exception specification indirectly depends on itself. Reject.
3569  // FIXME: Corresponding rule in the standard?
3570  Diag(PointOfInstantiation, diag::err_exception_spec_cycle) << Decl;
3571  UpdateExceptionSpec(Decl, EST_None);
3572  return;
3573  }
3574 
3575  // Enter the scope of this instantiation. We don't use
3576  // PushDeclContext because we don't have a scope.
3577  Sema::ContextRAII savedContext(*this, Decl);
3579 
3580  MultiLevelTemplateArgumentList TemplateArgs =
3581  getTemplateInstantiationArgs(Decl, nullptr, /*RelativeToPrimary*/true);
3582 
3583  FunctionDecl *Template = Proto->getExceptionSpecTemplate();
3584  if (addInstantiatedParametersToScope(*this, Decl, Template, Scope,
3585  TemplateArgs)) {
3586  UpdateExceptionSpec(Decl, EST_None);
3587  return;
3588  }
3589 
3590  SubstExceptionSpec(Decl, Template->getType()->castAs<FunctionProtoType>(),
3591  TemplateArgs);
3592 }
3593 
3594 /// Initializes the common fields of an instantiation function
3595 /// declaration (New) from the corresponding fields of its template (Tmpl).
3596 ///
3597 /// \returns true if there was an error
3598 bool
3600  FunctionDecl *Tmpl) {
3601  if (Tmpl->isDeleted())
3602  New->setDeletedAsWritten();
3603 
3604  New->setImplicit(Tmpl->isImplicit());
3605 
3606  // Forward the mangling number from the template to the instantiated decl.
3607  SemaRef.Context.setManglingNumber(New,
3608  SemaRef.Context.getManglingNumber(Tmpl));
3609 
3610  // If we are performing substituting explicitly-specified template arguments
3611  // or deduced template arguments into a function template and we reach this
3612  // point, we are now past the point where SFINAE applies and have committed
3613  // to keeping the new function template specialization. We therefore
3614  // convert the active template instantiation for the function template
3615  // into a template instantiation for this specific function template
3616  // specialization, which is not a SFINAE context, so that we diagnose any
3617  // further errors in the declaration itself.
3618  typedef Sema::CodeSynthesisContext ActiveInstType;
3619  ActiveInstType &ActiveInst = SemaRef.CodeSynthesisContexts.back();
3620  if (ActiveInst.Kind == ActiveInstType::ExplicitTemplateArgumentSubstitution ||
3621  ActiveInst.Kind == ActiveInstType::DeducedTemplateArgumentSubstitution) {
3622  if (FunctionTemplateDecl *FunTmpl
3623  = dyn_cast<FunctionTemplateDecl>(ActiveInst.Entity)) {
3624  assert(FunTmpl->getTemplatedDecl() == Tmpl &&
3625  "Deduction from the wrong function template?");
3626  (void) FunTmpl;
3627  atTemplateEnd(SemaRef.TemplateInstCallbacks, SemaRef, ActiveInst);
3628  ActiveInst.Kind = ActiveInstType::TemplateInstantiation;
3629  ActiveInst.Entity = New;
3630  atTemplateBegin(SemaRef.TemplateInstCallbacks, SemaRef, ActiveInst);
3631  }
3632  }
3633 
3634  const FunctionProtoType *Proto = Tmpl->getType()->getAs<FunctionProtoType>();
3635  assert(Proto && "Function template without prototype?");
3636 
3637  if (Proto->hasExceptionSpec() || Proto->getNoReturnAttr()) {
3639 
3640  // DR1330: In C++11, defer instantiation of a non-trivial
3641  // exception specification.
3642  // DR1484: Local classes and their members are instantiated along with the
3643  // containing function.
3644  if (SemaRef.getLangOpts().CPlusPlus11 &&
3645  EPI.ExceptionSpec.Type != EST_None &&
3649  FunctionDecl *ExceptionSpecTemplate = Tmpl;
3651  ExceptionSpecTemplate = EPI.ExceptionSpec.SourceTemplate;
3653  if (EPI.ExceptionSpec.Type == EST_Unevaluated)
3654  NewEST = EST_Unevaluated;
3655 
3656  // Mark the function has having an uninstantiated exception specification.
3657  const FunctionProtoType *NewProto
3658  = New->getType()->getAs<FunctionProtoType>();
3659  assert(NewProto && "Template instantiation without function prototype?");
3660  EPI = NewProto->getExtProtoInfo();
3661  EPI.ExceptionSpec.Type = NewEST;
3662  EPI.ExceptionSpec.SourceDecl = New;
3663  EPI.ExceptionSpec.SourceTemplate = ExceptionSpecTemplate;
3664  New->setType(SemaRef.Context.getFunctionType(
3665  NewProto->getReturnType(), NewProto->getParamTypes(), EPI));
3666  } else {
3667  Sema::ContextRAII SwitchContext(SemaRef, New);
3668  SemaRef.SubstExceptionSpec(New, Proto, TemplateArgs);
3669  }
3670  }
3671 
3672  // Get the definition. Leaves the variable unchanged if undefined.
3673  const FunctionDecl *Definition = Tmpl;
3674  Tmpl->isDefined(Definition);
3675 
3676  SemaRef.InstantiateAttrs(TemplateArgs, Definition, New,
3677  LateAttrs, StartingScope);
3678 
3679  return false;
3680 }
3681 
3682 /// Initializes common fields of an instantiated method
3683 /// declaration (New) from the corresponding fields of its template
3684 /// (Tmpl).
3685 ///
3686 /// \returns true if there was an error
3687 bool
3689  CXXMethodDecl *Tmpl) {
3690  if (InitFunctionInstantiation(New, Tmpl))
3691  return true;
3692 
3693  New->setAccess(Tmpl->getAccess());
3694  if (Tmpl->isVirtualAsWritten())
3695  New->setVirtualAsWritten(true);
3696 
3697  // FIXME: New needs a pointer to Tmpl
3698  return false;
3699 }
3700 
3701 /// Instantiate (or find existing instantiation of) a function template with a
3702 /// given set of template arguments.
3703 ///
3704 /// Usually this should not be used, and template argument deduction should be
3705 /// used in its place.
3706 FunctionDecl *
3708  const TemplateArgumentList *Args,
3709  SourceLocation Loc) {
3710  FunctionDecl *FD = FTD->getTemplatedDecl();
3711 
3712  sema::TemplateDeductionInfo Info(Loc);
3713  InstantiatingTemplate Inst(
3714  *this, Loc, FTD, Args->asArray(),
3715  CodeSynthesisContext::ExplicitTemplateArgumentSubstitution, Info);
3716  if (Inst.isInvalid())
3717  return nullptr;
3718 
3719  ContextRAII SavedContext(*this, FD);
3720  MultiLevelTemplateArgumentList MArgs(*Args);
3721 
3722  return cast_or_null<FunctionDecl>(SubstDecl(FD, FD->getParent(), MArgs));
3723 }
3724 
3725 /// In the MS ABI, we need to instantiate default arguments of dllexported
3726 /// default constructors along with the constructor definition. This allows IR
3727 /// gen to emit a constructor closure which calls the default constructor with
3728 /// its default arguments.
3730  CXXConstructorDecl *Ctor) {
3731  assert(S.Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3732  Ctor->isDefaultConstructor());
3733  unsigned NumParams = Ctor->getNumParams();
3734  if (NumParams == 0)
3735  return;
3736  DLLExportAttr *Attr = Ctor->getAttr<DLLExportAttr>();
3737  if (!Attr)
3738  return;
3739  for (unsigned I = 0; I != NumParams; ++I) {
3740  (void)S.CheckCXXDefaultArgExpr(Attr->getLocation(), Ctor,
3741  Ctor->getParamDecl(I));
3743  }
3744 }
3745 
3746 /// Instantiate the definition of the given function from its
3747 /// template.
3748 ///
3749 /// \param PointOfInstantiation the point at which the instantiation was
3750 /// required. Note that this is not precisely a "point of instantiation"
3751 /// for the function, but it's close.
3752 ///
3753 /// \param Function the already-instantiated declaration of a
3754 /// function template specialization or member function of a class template
3755 /// specialization.
3756 ///
3757 /// \param Recursive if true, recursively instantiates any functions that
3758 /// are required by this instantiation.
3759 ///
3760 /// \param DefinitionRequired if true, then we are performing an explicit
3761 /// instantiation where the body of the function is required. Complain if
3762 /// there is no such body.
3764  FunctionDecl *Function,
3765  bool Recursive,
3766  bool DefinitionRequired,
3767  bool AtEndOfTU) {
3768  if (Function->isInvalidDecl() || Function->isDefined() ||
3769  isa<CXXDeductionGuideDecl>(Function))
3770  return;
3771 
3772  // Never instantiate an explicit specialization except if it is a class scope
3773  // explicit specialization.
3775  if (TSK == TSK_ExplicitSpecialization &&
3777  return;
3778 
3779  // Find the function body that we'll be substituting.
3780  const FunctionDecl *PatternDecl = Function->getTemplateInstantiationPattern();
3781  assert(PatternDecl && "instantiating a non-template");
3782 
3783  const FunctionDecl *PatternDef = PatternDecl->getDefinition();
3784  Stmt *Pattern = nullptr;
3785  if (PatternDef) {
3786  Pattern = PatternDef->getBody(PatternDef);
3787  PatternDecl = PatternDef;
3788  if (PatternDef->willHaveBody())
3789  PatternDef = nullptr;
3790  }
3791 
3792  // FIXME: We need to track the instantiation stack in order to know which
3793  // definitions should be visible within this instantiation.
3794  if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Function,
3796  PatternDecl, PatternDef, TSK,
3797  /*Complain*/DefinitionRequired)) {
3798  if (DefinitionRequired)
3799  Function->setInvalidDecl();
3800  else if (TSK == TSK_ExplicitInstantiationDefinition) {
3801  // Try again at the end of the translation unit (at which point a
3802  // definition will be required).
3803  assert(!Recursive);
3804  Function->setInstantiationIsPending(true);
3805  PendingInstantiations.push_back(
3806  std::make_pair(Function, PointOfInstantiation));
3807  } else if (TSK == TSK_ImplicitInstantiation) {
3808  if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() &&
3809  !getSourceManager().isInSystemHeader(PatternDecl->getBeginLoc())) {
3810  Diag(PointOfInstantiation, diag::warn_func_template_missing)
3811  << Function;
3812  Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
3813  if (getLangOpts().CPlusPlus11)
3814  Diag(PointOfInstantiation, diag::note_inst_declaration_hint)
3815  << Function;
3816  }
3817  }
3818 
3819  return;
3820  }
3821 
3822  // Postpone late parsed template instantiations.
3823  if (PatternDecl->isLateTemplateParsed() &&
3824  !LateTemplateParser) {
3825  Function->setInstantiationIsPending(true);
3826  LateParsedInstantiations.push_back(
3827  std::make_pair(Function, PointOfInstantiation));
3828  return;
3829  }
3830 
3831  // If we're performing recursive template instantiation, create our own
3832  // queue of pending implicit instantiations that we will instantiate later,
3833  // while we're still within our own instantiation context.
3834  // This has to happen before LateTemplateParser below is called, so that
3835  // it marks vtables used in late parsed templates as used.
3836  GlobalEagerInstantiationScope GlobalInstantiations(*this,
3837  /*Enabled=*/Recursive);
3838  LocalEagerInstantiationScope LocalInstantiations(*this);
3839 
3840  // Call the LateTemplateParser callback if there is a need to late parse
3841  // a templated function definition.
3842  if (!Pattern && PatternDecl->isLateTemplateParsed() &&
3843  LateTemplateParser) {
3844  // FIXME: Optimize to allow individual templates to be deserialized.
3845  if (PatternDecl->isFromASTFile())
3846  ExternalSource->ReadLateParsedTemplates(LateParsedTemplateMap);
3847 
3848  auto LPTIter = LateParsedTemplateMap.find(PatternDecl);
3849  assert(LPTIter != LateParsedTemplateMap.end() &&
3850  "missing LateParsedTemplate");
3851  LateTemplateParser(OpaqueParser, *LPTIter->second);
3852  Pattern = PatternDecl->getBody(PatternDecl);
3853  }
3854 
3855  // Note, we should never try to instantiate a deleted function template.
3856  assert((Pattern || PatternDecl->isDefaulted() ||
3857  PatternDecl->hasSkippedBody()) &&
3858  "unexpected kind of function template definition");
3859 
3860  // C++1y [temp.explicit]p10:
3861  // Except for inline functions, declarations with types deduced from their
3862  // initializer or return value, and class template specializations, other
3863  // explicit instantiation declarations have the effect of suppressing the
3864  // implicit instantiation of the entity to which they refer.
3866  !PatternDecl->isInlined() &&
3867  !PatternDecl->getReturnType()->getContainedAutoType())
3868  return;
3869 
3870  if (PatternDecl->isInlined()) {
3871  // Function, and all later redeclarations of it (from imported modules,
3872  // for instance), are now implicitly inline.
3873  for (auto *D = Function->getMostRecentDecl(); /**/;
3874  D = D->getPreviousDecl()) {
3875  D->setImplicitlyInline();
3876  if (D == Function)
3877  break;
3878  }
3879  }
3880 
3881  InstantiatingTemplate Inst(*this, PointOfInstantiation, Function);
3882  if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
3883  return;
3884  PrettyDeclStackTraceEntry CrashInfo(Context, Function, SourceLocation(),
3885  "instantiating function definition");
3886 
3887  // The instantiation is visible here, even if it was first declared in an
3888  // unimported module.
3889  Function->setVisibleDespiteOwningModule();
3890 
3891  // Copy the inner loc start from the pattern.
3892  Function->setInnerLocStart(PatternDecl->getInnerLocStart());
3893 
3896 
3897  // Introduce a new scope where local variable instantiations will be
3898  // recorded, unless we're actually a member function within a local
3899  // class, in which case we need to merge our results with the parent
3900  // scope (of the enclosing function).
3901  bool MergeWithParentScope = false;
3902  if (CXXRecordDecl *Rec = dyn_cast<CXXRecordDecl>(Function->getDeclContext()))
3903  MergeWithParentScope = Rec->isLocalClass();
3904 
3905  LocalInstantiationScope Scope(*this, MergeWithParentScope);
3906 
3907  if (PatternDecl->isDefaulted())
3908  SetDeclDefaulted(Function, PatternDecl->getLocation());
3909  else {
3910  MultiLevelTemplateArgumentList TemplateArgs =
3911  getTemplateInstantiationArgs(Function, nullptr, false, PatternDecl);
3912 
3913  // Substitute into the qualifier; we can get a substitution failure here
3914  // through evil use of alias templates.
3915  // FIXME: Is CurContext correct for this? Should we go to the (instantiation
3916  // of the) lexical context of the pattern?
3917  SubstQualifier(*this, PatternDecl, Function, TemplateArgs);
3918 
3919  ActOnStartOfFunctionDef(nullptr, Function);
3920 
3921  // Enter the scope of this instantiation. We don't use
3922  // PushDeclContext because we don't have a scope.
3923  Sema::ContextRAII savedContext(*this, Function);
3924 
3925  if (addInstantiatedParametersToScope(*this, Function, PatternDecl, Scope,
3926  TemplateArgs))
3927  return;
3928 
3929  StmtResult Body;
3930  if (PatternDecl->hasSkippedBody()) {
3931  ActOnSkippedFunctionBody(Function);
3932  Body = nullptr;
3933  } else {
3934  if (CXXConstructorDecl *Ctor = dyn_cast<CXXConstructorDecl>(Function)) {
3935  // If this is a constructor, instantiate the member initializers.
3936  InstantiateMemInitializers(Ctor, cast<CXXConstructorDecl>(PatternDecl),
3937  TemplateArgs);
3938 
3939  // If this is an MS ABI dllexport default constructor, instantiate any
3940  // default arguments.
3941  if (Context.getTargetInfo().getCXXABI().isMicrosoft() &&
3942  Ctor->isDefaultConstructor()) {
3943  InstantiateDefaultCtorDefaultArgs(*this, Ctor);
3944  }
3945  }
3946 
3947  // Instantiate the function body.
3948  Body = SubstStmt(Pattern, TemplateArgs);
3949 
3950  if (Body.isInvalid())
3951  Function->setInvalidDecl();
3952  }
3953  // FIXME: finishing the function body while in an expression evaluation
3954  // context seems wrong. Investigate more.
3955  ActOnFinishFunctionBody(Function, Body.get(), /*IsInstantiation=*/true);
3956 
3957  PerformDependentDiagnostics(PatternDecl, TemplateArgs);
3958 
3959  if (auto *Listener = getASTMutationListener())
3960  Listener->FunctionDefinitionInstantiated(Function);
3961 
3962  savedContext.pop();
3963  }
3964 
3965  DeclGroupRef DG(Function);
3966  Consumer.HandleTopLevelDecl(DG);
3967 
3968  // This class may have local implicit instantiations that need to be
3969  // instantiation within this scope.
3970  LocalInstantiations.perform();
3971  Scope.Exit();
3972  GlobalInstantiations.perform();
3973 }
3974 
3976  VarTemplateDecl *VarTemplate, VarDecl *FromVar,
3977  const TemplateArgumentList &TemplateArgList,
3978  const TemplateArgumentListInfo &TemplateArgsInfo,
3980  SourceLocation PointOfInstantiation, void *InsertPos,
3981  LateInstantiatedAttrVec *LateAttrs,
3982  LocalInstantiationScope *StartingScope) {
3983  if (FromVar->isInvalidDecl())
3984  return nullptr;
3985 
3986  InstantiatingTemplate Inst(*this, PointOfInstantiation, FromVar);
3987  if (Inst.isInvalid())
3988  return nullptr;
3989 
3990  MultiLevelTemplateArgumentList TemplateArgLists;
3991  TemplateArgLists.addOuterTemplateArguments(&TemplateArgList);
3992 
3993  // Instantiate the first declaration of the variable template: for a partial
3994  // specialization of a static data member template, the first declaration may
3995  // or may not be the declaration in the class; if it's in the class, we want
3996  // to instantiate a member in the class (a declaration), and if it's outside,
3997  // we want to instantiate a definition.
3998  //
3999  // If we're instantiating an explicitly-specialized member template or member
4000  // partial specialization, don't do this. The member specialization completely
4001  // replaces the original declaration in this case.
4002  bool IsMemberSpec = false;
4003  if (VarTemplatePartialSpecializationDecl *PartialSpec =
4004  dyn_cast<VarTemplatePartialSpecializationDecl>(FromVar))
4005  IsMemberSpec = PartialSpec->isMemberSpecialization();
4006  else if (VarTemplateDecl *FromTemplate = FromVar->getDescribedVarTemplate())
4007  IsMemberSpec = FromTemplate->isMemberSpecialization();
4008  if (!IsMemberSpec)
4009  FromVar = FromVar->getFirstDecl();
4010 
4011  MultiLevelTemplateArgumentList MultiLevelList(TemplateArgList);
4012  TemplateDeclInstantiator Instantiator(*this, FromVar->getDeclContext(),
4013  MultiLevelList);
4014 
4015  // TODO: Set LateAttrs and StartingScope ...
4016 
4017  return cast_or_null<VarTemplateSpecializationDecl>(
4018  Instantiator.VisitVarTemplateSpecializationDecl(
4019  VarTemplate, FromVar, InsertPos, TemplateArgsInfo, Converted));
4020 }
4021 
4022 /// Instantiates a variable template specialization by completing it
4023 /// with appropriate type information and initializer.
4025  VarTemplateSpecializationDecl *VarSpec, VarDecl *PatternDecl,
4026  const MultiLevelTemplateArgumentList &TemplateArgs) {
4027  assert(PatternDecl->isThisDeclarationADefinition() &&
4028  "don't have a definition to instantiate from");
4029 
4030  // Do substitution on the type of the declaration
4031  TypeSourceInfo *DI =
4032  SubstType(PatternDecl->getTypeSourceInfo(), TemplateArgs,
4033  PatternDecl->getTypeSpecStartLoc(), PatternDecl->getDeclName());
4034  if (!DI)
4035  return nullptr;
4036 
4037  // Update the type of this variable template specialization.
4038  VarSpec->setType(DI->getType());
4039 
4040  // Convert the declaration into a definition now.
4041  VarSpec->setCompleteDefinition();
4042 
4043  // Instantiate the initializer.
4044  InstantiateVariableInitializer(VarSpec, PatternDecl, TemplateArgs);
4045 
4046  return VarSpec;
4047 }
4048 
4049 /// BuildVariableInstantiation - Used after a new variable has been created.
4050 /// Sets basic variable data and decides whether to postpone the
4051 /// variable instantiation.
4053  VarDecl *NewVar, VarDecl *OldVar,
4054  const MultiLevelTemplateArgumentList &TemplateArgs,
4055  LateInstantiatedAttrVec *LateAttrs, DeclContext *Owner,
4056  LocalInstantiationScope *StartingScope,
4057  bool InstantiatingVarTemplate) {
4058 
4059  // If we are instantiating a local extern declaration, the
4060  // instantiation belongs lexically to the containing function.
4061  // If we are instantiating a static data member defined
4062  // out-of-line, the instantiation will have the same lexical
4063  // context (which will be a namespace scope) as the template.
4064  if (OldVar->isLocalExternDecl()) {
4065  NewVar->setLocalExternDecl();
4066  NewVar->setLexicalDeclContext(Owner);
4067  } else if (OldVar->isOutOfLine())
4068  NewVar->setLexicalDeclContext(OldVar->getLexicalDeclContext());
4069  NewVar->setTSCSpec(OldVar->getTSCSpec());
4070  NewVar->setInitStyle(OldVar->getInitStyle());
4071  NewVar->setCXXForRangeDecl(OldVar->isCXXForRangeDecl());
4072  NewVar->setObjCForDecl(OldVar->isObjCForDecl());
4073  NewVar->setConstexpr(OldVar->isConstexpr());
4074  NewVar->setInitCapture(OldVar->isInitCapture());
4076  OldVar->isPreviousDeclInSameBlockScope());
4077  NewVar->setAccess(OldVar->getAccess());
4078 
4079  if (!OldVar->isStaticDataMember()) {
4080  if (OldVar->isUsed(false))
4081  NewVar->setIsUsed();
4082  NewVar->setReferenced(OldVar->isReferenced());
4083  }
4084 
4085  InstantiateAttrs(TemplateArgs, OldVar, NewVar, LateAttrs, StartingScope);
4086 
4088  *this, NewVar->getDeclName(), NewVar->getLocation(),
4092  : forRedeclarationInCurContext());
4093 
4094  if (NewVar->isLocalExternDecl() && OldVar->getPreviousDecl() &&
4096  OldVar->getPreviousDecl()->getDeclContext()==OldVar->getDeclContext())) {
4097  // We have a previous declaration. Use that one, so we merge with the
4098  // right type.
4099  if (NamedDecl *NewPrev = FindInstantiatedDecl(
4100  NewVar->getLocation(), OldVar->getPreviousDecl(), TemplateArgs))
4101  Previous.addDecl(NewPrev);
4102  } else if (!isa<VarTemplateSpecializationDecl>(NewVar) &&
4103  OldVar->hasLinkage())
4104  LookupQualifiedName(Previous, NewVar->getDeclContext(), false);
4105  CheckVariableDeclaration(NewVar, Previous);
4106 
4107  if (!InstantiatingVarTemplate) {
4108  NewVar->getLexicalDeclContext()->addHiddenDecl(NewVar);
4109  if (!NewVar->isLocalExternDecl() || !NewVar->getPreviousDecl())
4110  NewVar->getDeclContext()->makeDeclVisibleInContext(NewVar);
4111  }
4112 
4113  if (!OldVar->isOutOfLine()) {
4114  if (NewVar->getDeclContext()->isFunctionOrMethod())
4115  CurrentInstantiationScope->InstantiatedLocal(OldVar, NewVar);
4116  }
4117 
4118  // Link instantiations of static data members back to the template from
4119  // which they were instantiated.
4120  if (NewVar->isStaticDataMember() && !InstantiatingVarTemplate)
4121  NewVar->setInstantiationOfStaticDataMember(OldVar,
4123 
4124  // Forward the mangling number from the template to the instantiated decl.
4125  Context.setManglingNumber(NewVar, Context.getManglingNumber(OldVar));
4126  Context.setStaticLocalNumber(NewVar, Context.getStaticLocalNumber(OldVar));
4127 
4128  // Delay instantiation of the initializer for variable templates or inline
4129  // static data members until a definition of the variable is needed. We need
4130  // it right away if the type contains 'auto'.
4131  if ((!isa<VarTemplateSpecializationDecl>(NewVar) &&
4132  !InstantiatingVarTemplate &&
4133  !(OldVar->isInline() && OldVar->isThisDeclarationADefinition() &&
4134  !NewVar->isThisDeclarationADefinition())) ||
4135  NewVar->getType()->isUndeducedType())
4136  InstantiateVariableInitializer(NewVar, OldVar, TemplateArgs);
4137 
4138  // Diagnose unused local variables with dependent types, where the diagnostic
4139  // will have been deferred.
4140  if (!NewVar->isInvalidDecl() &&
4141  NewVar->getDeclContext()->isFunctionOrMethod() &&
4142  OldVar->getType()->isDependentType())
4143  DiagnoseUnusedDecl(NewVar);
4144 }
4145 
4146 /// Instantiate the initializer of a variable.
4148  VarDecl *Var, VarDecl *OldVar,
4149  const MultiLevelTemplateArgumentList &TemplateArgs) {
4150  if (ASTMutationListener *L = getASTContext().getASTMutationListener())
4151  L->VariableDefinitionInstantiated(Var);
4152 
4153  // We propagate the 'inline' flag with the initializer, because it
4154  // would otherwise imply that the variable is a definition for a
4155  // non-static data member.
4156  if (OldVar->isInlineSpecified())
4157  Var->setInlineSpecified();
4158  else if (OldVar->isInline())
4159  Var->setImplicitlyInline();
4160 
4161  if (OldVar->getInit()) {
4164 
4165  // Instantiate the initializer.
4166  ExprResult Init;
4167 
4168  {
4169  ContextRAII SwitchContext(*this, Var->getDeclContext());
4170  Init = SubstInitializer(OldVar->getInit(), TemplateArgs,
4171  OldVar->getInitStyle() == VarDecl::CallInit);
4172  }
4173 
4174  if (!Init.isInvalid()) {
4175  Expr *InitExpr = Init.get();
4176 
4177  if (Var->hasAttr<DLLImportAttr>() &&
4178  (!InitExpr ||
4179  !InitExpr->isConstantInitializer(getASTContext(), false))) {
4180  // Do not dynamically initialize dllimport variables.
4181  } else if (InitExpr) {
4182  bool DirectInit = OldVar->isDirectInit();
4183  AddInitializerToDecl(Var, InitExpr, DirectInit);
4184  } else
4185  ActOnUninitializedDecl(Var);
4186  } else {
4187  // FIXME: Not too happy about invalidating the declaration
4188  // because of a bogus initializer.
4189  Var->setInvalidDecl();
4190  }
4191  } else {
4192  // `inline` variables are a definition and declaration all in one; we won't
4193  // pick up an initializer from anywhere else.
4194  if (Var->isStaticDataMember() && !Var->isInline()) {
4195  if (!Var->isOutOfLine())
4196  return;
4197 
4198  // If the declaration inside the class had an initializer, don't add
4199  // another one to the out-of-line definition.
4200  if (OldVar->getFirstDecl()->hasInit())
4201  return;
4202  }
4203 
4204  // We'll add an initializer to a for-range declaration later.
4205  if (Var->isCXXForRangeDecl() || Var->isObjCForDecl())
4206  return;
4207 
4208  ActOnUninitializedDecl(Var);
4209  }
4210 
4211  if (getLangOpts().CUDA)
4212  checkAllowedCUDAInitializer(Var);
4213 }
4214 
4215 /// Instantiate the definition of the given variable from its
4216 /// template.
4217 ///
4218 /// \param PointOfInstantiation the point at which the instantiation was
4219 /// required. Note that this is not precisely a "point of instantiation"
4220 /// for the variable, but it's close.
4221 ///
4222 /// \param Var the already-instantiated declaration of a templated variable.
4223 ///
4224 /// \param Recursive if true, recursively instantiates any functions that
4225 /// are required by this instantiation.
4226 ///
4227 /// \param DefinitionRequired if true, then we are performing an explicit
4228 /// instantiation where a definition of the variable is required. Complain
4229 /// if there is no such definition.
4231  VarDecl *Var, bool Recursive,
4232  bool DefinitionRequired, bool AtEndOfTU) {
4233  if (Var->isInvalidDecl())
4234  return;
4235 
4237  dyn_cast<VarTemplateSpecializationDecl>(Var);
4238  VarDecl *PatternDecl = nullptr, *Def = nullptr;
4239  MultiLevelTemplateArgumentList TemplateArgs =
4240  getTemplateInstantiationArgs(Var);
4241 
4242  if (VarSpec) {
4243  // If this is a variable template specialization, make sure that it is
4244  // non-dependent, then find its instantiation pattern.
4245  bool InstantiationDependent = false;
4247  VarSpec->getTemplateArgsInfo(), InstantiationDependent) &&
4248  "Only instantiate variable template specializations that are "
4249  "not type-dependent");
4250  (void)InstantiationDependent;
4251 
4252  // Find the variable initialization that we'll be substituting. If the
4253  // pattern was instantiated from a member template, look back further to
4254  // find the real pattern.
4255  assert(VarSpec->getSpecializedTemplate() &&
4256  "Specialization without specialized template?");
4257  llvm::PointerUnion<VarTemplateDecl *,
4258  VarTemplatePartialSpecializationDecl *> PatternPtr =
4260  if (PatternPtr.is<VarTemplatePartialSpecializationDecl *>()) {
4262  PatternPtr.get<VarTemplatePartialSpecializationDecl *>();
4264  Tmpl->getInstantiatedFromMember()) {
4265  if (Tmpl->isMemberSpecialization())
4266  break;
4267 
4268  Tmpl = From;
4269  }
4270  PatternDecl = Tmpl;
4271  } else {
4272  VarTemplateDecl *Tmpl = PatternPtr.get<VarTemplateDecl *>();
4273  while (VarTemplateDecl *From =
4275  if (Tmpl->isMemberSpecialization())
4276  break;
4277 
4278  Tmpl = From;
4279  }
4280  PatternDecl = Tmpl->getTemplatedDecl();
4281  }
4282 
4283  // If this is a static data member template, there might be an
4284  // uninstantiated initializer on the declaration. If so, instantiate
4285  // it now.
4286  //
4287  // FIXME: This largely duplicates what we would do below. The difference
4288  // is that along this path we may instantiate an initializer from an
4289  // in-class declaration of the template and instantiate the definition
4290  // from a separate out-of-class definition.
4291  if (PatternDecl->isStaticDataMember() &&
4292  (PatternDecl = PatternDecl->getFirstDecl())->hasInit() &&
4293  !Var->hasInit()) {
4294  // FIXME: Factor out the duplicated instantiation context setup/tear down
4295  // code here.
4296  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4297  if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4298  return;
4299  PrettyDeclStackTraceEntry CrashInfo(Context, Var, SourceLocation(),
4300  "instantiating variable initializer");
4301 
4302  // The instantiation is visible here, even if it was first declared in an
4303  // unimported module.
4305 
4306  // If we're performing recursive template instantiation, create our own
4307  // queue of pending implicit instantiations that we will instantiate
4308  // later, while we're still within our own instantiation context.
4309  GlobalEagerInstantiationScope GlobalInstantiations(*this,
4310  /*Enabled=*/Recursive);
4311  LocalInstantiationScope Local(*this);
4312  LocalEagerInstantiationScope LocalInstantiations(*this);
4313 
4314  // Enter the scope of this instantiation. We don't use
4315  // PushDeclContext because we don't have a scope.
4316  ContextRAII PreviousContext(*this, Var->getDeclContext());
4317  InstantiateVariableInitializer(Var, PatternDecl, TemplateArgs);
4318  PreviousContext.pop();
4319 
4320  // This variable may have local implicit instantiations that need to be
4321  // instantiated within this scope.
4322  LocalInstantiations.perform();
4323  Local.Exit();
4324  GlobalInstantiations.perform();
4325  }
4326 
4327  // Find actual definition
4328  Def = PatternDecl->getDefinition(getASTContext());
4329  } else {
4330  // If this is a static data member, find its out-of-line definition.
4331  assert(Var->isStaticDataMember() && "not a static data member?");
4332  PatternDecl = Var->getInstantiatedFromStaticDataMember();
4333 
4334  assert(PatternDecl && "data member was not instantiated from a template?");
4335  assert(PatternDecl->isStaticDataMember() && "not a static data member?");
4336  Def = PatternDecl->getDefinition();
4337  }
4338 
4340 
4341  // If we don't have a definition of the variable template, we won't perform
4342  // any instantiation. Rather, we rely on the user to instantiate this
4343  // definition (or provide a specialization for it) in another translation
4344  // unit.
4345  if (!Def && !DefinitionRequired) {
4347  PendingInstantiations.push_back(
4348  std::make_pair(Var, PointOfInstantiation));
4349  } else if (TSK == TSK_ImplicitInstantiation) {
4350  // Warn about missing definition at the end of translation unit.
4351  if (AtEndOfTU && !getDiagnostics().hasErrorOccurred() &&
4352  !getSourceManager().isInSystemHeader(PatternDecl->getBeginLoc())) {
4353  Diag(PointOfInstantiation, diag::warn_var_template_missing)
4354  << Var;
4355  Diag(PatternDecl->getLocation(), diag::note_forward_template_decl);
4356  if (getLangOpts().CPlusPlus11)
4357  Diag(PointOfInstantiation, diag::note_inst_declaration_hint) << Var;
4358  }
4359  return;
4360  }
4361 
4362  }
4363 
4364  // FIXME: We need to track the instantiation stack in order to know which
4365  // definitions should be visible within this instantiation.
4366  // FIXME: Produce diagnostics when Var->getInstantiatedFromStaticDataMember().
4367  if (DiagnoseUninstantiableTemplate(PointOfInstantiation, Var,
4368  /*InstantiatedFromMember*/false,
4369  PatternDecl, Def, TSK,
4370  /*Complain*/DefinitionRequired))
4371  return;
4372 
4373 
4374  // Never instantiate an explicit specialization.
4375  if (TSK == TSK_ExplicitSpecialization)
4376  return;
4377 
4378  // C++11 [temp.explicit]p10:
4379  // Except for inline functions, const variables of literal types, variables
4380  // of reference types, [...] explicit instantiation declarations
4381  // have the effect of suppressing the implicit instantiation of the entity
4382  // to which they refer.
4384  !Var->isUsableInConstantExpressions(getASTContext()))
4385  return;
4386 
4387  // Make sure to pass the instantiated variable to the consumer at the end.
4388  struct PassToConsumerRAII {
4389  ASTConsumer &Consumer;
4390  VarDecl *Var;
4391 
4392  PassToConsumerRAII(ASTConsumer &Consumer, VarDecl *Var)
4393  : Consumer(Consumer), Var(Var) { }
4394 
4395  ~PassToConsumerRAII() {
4397  }
4398  } PassToConsumerRAII(Consumer, Var);
4399 
4400  // If we already have a definition, we're done.
4401  if (VarDecl *Def = Var->getDefinition()) {
4402  // We may be explicitly instantiating something we've already implicitly
4403  // instantiated.
4404  Def->setTemplateSpecializationKind(Var->getTemplateSpecializationKind(),
4405  PointOfInstantiation);
4406  return;
4407  }
4408 
4409  InstantiatingTemplate Inst(*this, PointOfInstantiation, Var);
4410  if (Inst.isInvalid() || Inst.isAlreadyInstantiating())
4411  return;
4412  PrettyDeclStackTraceEntry CrashInfo(Context, Var, SourceLocation(),
4413  "instantiating variable definition");
4414 
4415  // If we're performing recursive template instantiation, create our own
4416  // queue of pending implicit instantiations that we will instantiate later,
4417  // while we're still within our own instantiation context.
4418  GlobalEagerInstantiationScope GlobalInstantiations(*this,
4419  /*Enabled=*/Recursive);
4420 
4421  // Enter the scope of this instantiation. We don't use
4422  // PushDeclContext because we don't have a scope.
4423  ContextRAII PreviousContext(*this, Var->getDeclContext());
4424  LocalInstantiationScope Local(*this);
4425 
4426  LocalEagerInstantiationScope LocalInstantiations(*this);
4427 
4428  VarDecl *OldVar = Var;
4429  if (Def->isStaticDataMember() && !Def->isOutOfLine()) {
4430  // We're instantiating an inline static data member whose definition was
4431  // provided inside the class.
4432  InstantiateVariableInitializer(Var, Def, TemplateArgs);
4433  } else if (!VarSpec) {
4434  Var = cast_or_null<VarDecl>(SubstDecl(Def, Var->getDeclContext(),
4435  TemplateArgs));
4436  } else if (Var->isStaticDataMember() &&
4437  Var->getLexicalDeclContext()->isRecord()) {
4438  // We need to instantiate the definition of a static data member template,
4439  // and all we have is the in-class declaration of it. Instantiate a separate
4440  // declaration of the definition.
4441  TemplateDeclInstantiator Instantiator(*this, Var->getDeclContext(),
4442  TemplateArgs);
4443  Var = cast_or_null<VarDecl>(Instantiator.VisitVarTemplateSpecializationDecl(
4444  VarSpec->getSpecializedTemplate(), Def, nullptr,
4445  VarSpec->getTemplateArgsInfo(), VarSpec->getTemplateArgs().asArray()));
4446  if (Var) {
4447  llvm::PointerUnion<VarTemplateDecl *,
4448  VarTemplatePartialSpecializationDecl *> PatternPtr =
4451  PatternPtr.dyn_cast<VarTemplatePartialSpecializationDecl *>())
4452  cast<VarTemplateSpecializationDecl>(Var)->setInstantiationOf(
4453  Partial, &VarSpec->getTemplateInstantiationArgs());
4454 
4455  // Merge the definition with the declaration.
4456  LookupResult R(*this, Var->getDeclName(), Var->getLocation(),
4457  LookupOrdinaryName, forRedeclarationInCurContext());
4458  R.addDecl(OldVar);
4459  MergeVarDecl(Var, R);
4460 
4461  // Attach the initializer.
4462  InstantiateVariableInitializer(Var, Def, TemplateArgs);
4463  }
4464  } else
4465  // Complete the existing variable's definition with an appropriately
4466  // substituted type and initializer.
4467  Var = CompleteVarTemplateSpecializationDecl(VarSpec, Def, TemplateArgs);
4468 
4469  PreviousContext.pop();
4470 
4471  if (Var) {
4472  PassToConsumerRAII.Var = Var;
4474  OldVar->getPointOfInstantiation());
4475  }
4476 
4477  // This variable may have local implicit instantiations that need to be
4478  // instantiated within this scope.
4479  LocalInstantiations.perform();
4480  Local.Exit();
4481  GlobalInstantiations.perform();
4482 }
4483 
4484 void
4486  const CXXConstructorDecl *Tmpl,
4487  const MultiLevelTemplateArgumentList &TemplateArgs) {
4488 
4490  bool AnyErrors = Tmpl->isInvalidDecl();
4491 
4492  // Instantiate all the initializers.
4493  for (const auto *Init : Tmpl->inits()) {
4494  // Only instantiate written initializers, let Sema re-construct implicit
4495  // ones.
4496  if (!Init->isWritten())
4497  continue;
4498 
4499  SourceLocation EllipsisLoc;
4500 
4501  if (Init->isPackExpansion()) {
4502  // This is a pack expansion. We should expand it now.
4503  TypeLoc BaseTL = Init->getTypeSourceInfo()->getTypeLoc();
4505  collectUnexpandedParameterPacks(BaseTL, Unexpanded);
4506  collectUnexpandedParameterPacks(Init->getInit(), Unexpanded);
4507  bool ShouldExpand = false;
4508  bool RetainExpansion = false;
4509  Optional<unsigned> NumExpansions;
4510  if (CheckParameterPacksForExpansion(Init->getEllipsisLoc(),
4511  BaseTL.getSourceRange(),
4512  Unexpanded,
4513  TemplateArgs, ShouldExpand,
4514  RetainExpansion,
4515  NumExpansions)) {
4516  AnyErrors = true;
4517  New->setInvalidDecl();
4518  continue;
4519  }
4520  assert(ShouldExpand && "Partial instantiation of base initializer?");
4521 
4522  // Loop over all of the arguments in the argument pack(s),
4523  for (unsigned I = 0; I != *NumExpansions; ++I) {
4524  Sema::ArgumentPackSubstitutionIndexRAII SubstIndex(*this, I);
4525 
4526  // Instantiate the initializer.
4527  ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4528  /*CXXDirectInit=*/true);
4529  if (TempInit.isInvalid()) {
4530  AnyErrors = true;
4531  break;
4532  }
4533 
4534  // Instantiate the base type.
4535  TypeSourceInfo *BaseTInfo = SubstType(Init->getTypeSourceInfo(),
4536  TemplateArgs,
4537  Init->getSourceLocation(),
4538  New->getDeclName());
4539  if (!BaseTInfo) {
4540  AnyErrors = true;
4541  break;
4542  }
4543 
4544  // Build the initializer.
4545  MemInitResult NewInit = BuildBaseInitializer(BaseTInfo->getType(),
4546  BaseTInfo, TempInit.get(),
4547  New->getParent(),
4548  SourceLocation());
4549  if (NewInit.isInvalid()) {
4550  AnyErrors = true;
4551  break;
4552  }
4553 
4554  NewInits.push_back(NewInit.get());
4555  }
4556 
4557  continue;
4558  }
4559 
4560  // Instantiate the initializer.
4561  ExprResult TempInit = SubstInitializer(Init->getInit(), TemplateArgs,
4562  /*CXXDirectInit=*/true);
4563  if (TempInit.isInvalid()) {
4564  AnyErrors = true;
4565  continue;
4566  }
4567 
4568  MemInitResult NewInit;
4569  if (Init->isDelegatingInitializer() || Init->isBaseInitializer()) {
4570  TypeSourceInfo *TInfo = SubstType(Init->getTypeSourceInfo(),
4571  TemplateArgs,
4572  Init->getSourceLocation(),
4573  New->getDeclName());
4574  if (!TInfo) {
4575  AnyErrors = true;
4576  New->setInvalidDecl();
4577  continue;
4578  }
4579 
4580  if (Init->isBaseInitializer())
4581  NewInit = BuildBaseInitializer(TInfo->getType(), TInfo, TempInit.get(),
4582  New->getParent(), EllipsisLoc);
4583  else
4584  NewInit = BuildDelegatingInitializer(TInfo, TempInit.get(),
4585  cast<CXXRecordDecl>(CurContext->getParent()));
4586  } else if (Init->isMemberInitializer()) {
4587  FieldDecl *Member = cast_or_null<FieldDecl>(FindInstantiatedDecl(
4588  Init->getMemberLocation(),
4589  Init->getMember(),
4590  TemplateArgs));
4591  if (!Member) {
4592  AnyErrors = true;
4593  New->setInvalidDecl();
4594  continue;
4595  }
4596 
4597  NewInit = BuildMemberInitializer(Member, TempInit.get(),
4598  Init->getSourceLocation());
4599  } else if (Init->isIndirectMemberInitializer()) {
4600  IndirectFieldDecl *IndirectMember =
4601  cast_or_null<IndirectFieldDecl>(FindInstantiatedDecl(
4602  Init->getMemberLocation(),
4603  Init->getIndirectMember(), TemplateArgs));
4604 
4605  if (!IndirectMember) {
4606  AnyErrors = true;
4607  New->setInvalidDecl();
4608  continue;
4609  }
4610 
4611  NewInit = BuildMemberInitializer(IndirectMember, TempInit.get(),
4612  Init->getSourceLocation());
4613  }
4614 
4615  if (NewInit.isInvalid()) {
4616  AnyErrors = true;
4617  New->setInvalidDecl();
4618  } else {
4619  NewInits.push_back(NewInit.get());
4620  }
4621  }
4622 
4623  // Assign all the initializers to the new constructor.
4624  ActOnMemInitializers(New,
4625  /*FIXME: ColonLoc */
4626  SourceLocation(),
4627  NewInits,
4628  AnyErrors);
4629 }
4630 
4631 // TODO: this could be templated if the various decl types used the
4632 // same method name.
4634  ClassTemplateDecl *Instance) {
4635  Pattern = Pattern->getCanonicalDecl();
4636 
4637  do {
4638  Instance = Instance->getCanonicalDecl();
4639  if (Pattern == Instance) return true;
4640  Instance = Instance->getInstantiatedFromMemberTemplate();
4641  } while (Instance);
4642 
4643  return false;
4644 }
4645 
4647  FunctionTemplateDecl *Instance) {
4648  Pattern = Pattern->getCanonicalDecl();
4649 
4650  do {
4651  Instance = Instance->getCanonicalDecl();
4652  if (Pattern == Instance) return true;
4653  Instance = Instance->getInstantiatedFromMemberTemplate();
4654  } while (Instance);
4655 
4656  return false;
4657 }
4658 
4659 static bool
4662  Pattern
4663  = cast<ClassTemplatePartialSpecializationDecl>(Pattern->getCanonicalDecl());
4664  do {
4665  Instance = cast<ClassTemplatePartialSpecializationDecl>(
4666  Instance->getCanonicalDecl());
4667  if (Pattern == Instance)
4668  return true;
4669  Instance = Instance->getInstantiatedFromMember();
4670  } while (Instance);
4671 
4672  return false;
4673 }
4674 
4675 static bool isInstantiationOf(CXXRecordDecl *Pattern,
4676  CXXRecordDecl *Instance) {
4677  Pattern = Pattern->getCanonicalDecl();
4678 
4679  do {
4680  Instance = Instance->getCanonicalDecl();
4681  if (Pattern == Instance) return true;
4682  Instance = Instance->getInstantiatedFromMemberClass();
4683  } while (Instance);
4684 
4685  return false;
4686 }
4687 
4688 static bool isInstantiationOf(FunctionDecl *Pattern,
4689  FunctionDecl *Instance) {
4690  Pattern = Pattern->getCanonicalDecl();
4691 
4692  do {
4693  Instance = Instance->getCanonicalDecl();
4694  if (Pattern == Instance) return true;
4695  Instance = Instance->getInstantiatedFromMemberFunction();
4696  } while (Instance);
4697 
4698  return false;
4699 }
4700 
4701 static bool isInstantiationOf(EnumDecl *Pattern,
4702  EnumDecl *Instance) {
4703  Pattern = Pattern->getCanonicalDecl();
4704 
4705  do {
4706  Instance = Instance->getCanonicalDecl();
4707  if (Pattern == Instance) return true;
4708  Instance = Instance->getInstantiatedFromMemberEnum();
4709  } while (Instance);
4710 
4711  return false;
4712 }
4713 
4714 static bool isInstantiationOf(UsingShadowDecl *Pattern,
4715  UsingShadowDecl *Instance,
4716  ASTContext &C) {
4718  Pattern);
4719 }
4720 
4721 static bool isInstantiationOf(UsingDecl *Pattern, UsingDecl *Instance,
4722  ASTContext &C) {
4723  return declaresSameEntity(C.getInstantiatedFromUsingDecl(Instance), Pattern);
4724 }
4725 
4726 template<typename T>
4727 static bool isInstantiationOfUnresolvedUsingDecl(T *Pattern, Decl *Other,
4728  ASTContext &Ctx) {
4729  // An unresolved using declaration can instantiate to an unresolved using
4730  // declaration, or to a using declaration or a using declaration pack.
4731  //
4732  // Multiple declarations can claim to be instantiated from an unresolved
4733  // using declaration if it's a pack expansion. We want the UsingPackDecl
4734  // in that case, not the individual UsingDecls within the pack.
4735  bool OtherIsPackExpansion;
4736  NamedDecl *OtherFrom;
4737  if (auto *OtherUUD = dyn_cast<T>(Other)) {
4738  OtherIsPackExpansion = OtherUUD->isPackExpansion();
4739  OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUUD);
4740  } else if (auto *OtherUPD = dyn_cast<UsingPackDecl>(Other)) {
4741  OtherIsPackExpansion = true;
4742  OtherFrom = OtherUPD->getInstantiatedFromUsingDecl();
4743  } else if (auto *OtherUD = dyn_cast<UsingDecl>(Other)) {
4744  OtherIsPackExpansion = false;
4745  OtherFrom = Ctx.getInstantiatedFromUsingDecl(OtherUD);
4746  } else {
4747  return false;
4748  }
4749  return Pattern->isPackExpansion() == OtherIsPackExpansion &&
4750  declaresSameEntity(OtherFrom, Pattern);
4751 }
4752 
4754  VarDecl *Instance) {
4755  assert(Instance->isStaticDataMember());
4756 
4757  Pattern = Pattern->getCanonicalDecl();
4758 
4759  do {
4760  Instance = Instance->getCanonicalDecl();
4761  if (Pattern == Instance) return true;
4762  Instance = Instance->getInstantiatedFromStaticDataMember();
4763  } while (Instance);
4764 
4765  return false;
4766 }
4767 
4768 // Other is the prospective instantiation
4769 // D is the prospective pattern
4770 static bool isInstantiationOf(ASTContext &Ctx, NamedDecl *D, Decl *Other) {
4771  if (auto *UUD = dyn_cast<UnresolvedUsingTypenameDecl>(D))
4772  return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4773 
4774  if (auto *UUD = dyn_cast<UnresolvedUsingValueDecl>(D))
4775  return isInstantiationOfUnresolvedUsingDecl(UUD, Other, Ctx);
4776 
4777  if (D->getKind() != Other->getKind())
4778  return false;
4779 
4780  if (auto *Record = dyn_cast<CXXRecordDecl>(Other))
4781  return isInstantiationOf(cast<CXXRecordDecl>(D), Record);
4782 
4783  if (auto *Function = dyn_cast<FunctionDecl>(Other))
4784  return isInstantiationOf(cast<FunctionDecl>(D), Function);
4785 
4786  if (auto *Enum = dyn_cast<EnumDecl>(Other))
4787  return isInstantiationOf(cast<EnumDecl>(D), Enum);
4788 
4789  if (auto *Var = dyn_cast<VarDecl>(Other))
4790  if (Var->isStaticDataMember())
4791  return isInstantiationOfStaticDataMember(cast<VarDecl>(D), Var);
4792 
4793  if (auto *Temp = dyn_cast<ClassTemplateDecl>(Other))
4794  return isInstantiationOf(cast<ClassTemplateDecl>(D), Temp);
4795 
4796  if (auto *Temp = dyn_cast<FunctionTemplateDecl>(Other))
4797  return isInstantiationOf(cast<FunctionTemplateDecl>(D), Temp);
4798 
4799  if (auto *PartialSpec =
4800  dyn_cast<ClassTemplatePartialSpecializationDecl>(Other))
4801  return isInstantiationOf(cast<ClassTemplatePartialSpecializationDecl>(D),
4802  PartialSpec);
4803 
4804  if (auto *Field = dyn_cast<FieldDecl>(Other)) {
4805  if (!Field->getDeclName()) {
4806  // This is an unnamed field.
4808  cast<FieldDecl>(D));
4809  }
4810  }
4811 
4812  if (auto *Using = dyn_cast<UsingDecl>(Other))
4813  return isInstantiationOf(cast<UsingDecl>(D), Using, Ctx);
4814 
4815  if (auto *Shadow = dyn_cast<UsingShadowDecl>(Other))
4816  return isInstantiationOf(cast<UsingShadowDecl>(D), Shadow, Ctx);
4817 
4818  return D->getDeclName() &&
4819  D->getDeclName() == cast<NamedDecl>(Other)->getDeclName();
4820 }
4821 
4822 template<typename ForwardIterator>
4824  NamedDecl *D,
4825  ForwardIterator first,
4826  ForwardIterator last) {
4827  for (; first != last; ++first)
4828  if (isInstantiationOf(Ctx, D, *first))
4829  return cast<NamedDecl>(*first);
4830 
4831  return nullptr;
4832 }
4833 
4834 /// Finds the instantiation of the given declaration context
4835 /// within the current instantiation.
4836 ///
4837 /// \returns NULL if there was an error
4839  const MultiLevelTemplateArgumentList &TemplateArgs) {
4840  if (NamedDecl *D = dyn_cast<NamedDecl>(DC)) {
4841  Decl* ID = FindInstantiatedDecl(Loc, D, TemplateArgs, true);
4842  return cast_or_null<DeclContext>(ID);
4843  } else return DC;
4844 }
4845 
4846 /// Find the instantiation of the given declaration within the
4847 /// current instantiation.
4848 ///
4849 /// This routine is intended to be used when \p D is a declaration
4850 /// referenced from within a template, that needs to mapped into the
4851 /// corresponding declaration within an instantiation. For example,
4852 /// given:
4853 ///
4854 /// \code
4855 /// template<typename T>
4856 /// struct X {
4857 /// enum Kind {
4858 /// KnownValue = sizeof(T)
4859 /// };
4860 ///
4861 /// bool getKind() const { return KnownValue; }
4862 /// };
4863 ///
4864 /// template struct X<int>;
4865 /// \endcode
4866 ///
4867 /// In the instantiation of <tt>X<int>::getKind()</tt>, we need to map the
4868 /// \p EnumConstantDecl for \p KnownValue (which refers to
4869 /// <tt>X<T>::<Kind>::KnownValue</tt>) to its instantiation
4870 /// (<tt>X<int>::<Kind>::KnownValue</tt>). \p FindInstantiatedDecl performs
4871 /// this mapping from within the instantiation of <tt>X<int></tt>.
4873  const MultiLevelTemplateArgumentList &TemplateArgs,
4874  bool FindingInstantiatedContext) {
4875  DeclContext *ParentDC = D->getDeclContext();
4876  // FIXME: Parmeters of pointer to functions (y below) that are themselves
4877  // parameters (p below) can have their ParentDC set to the translation-unit
4878  // - thus we can not consistently check if the ParentDC of such a parameter
4879  // is Dependent or/and a FunctionOrMethod.
4880  // For e.g. this code, during Template argument deduction tries to
4881  // find an instantiated decl for (T y) when the ParentDC for y is
4882  // the translation unit.
4883  // e.g. template <class T> void Foo(auto (*p)(T y) -> decltype(y())) {}
4884  // float baz(float(*)()) { return 0.0; }
4885  // Foo(baz);
4886  // The better fix here is perhaps to ensure that a ParmVarDecl, by the time
4887  // it gets here, always has a FunctionOrMethod as its ParentDC??
4888  // For now:
4889  // - as long as we have a ParmVarDecl whose parent is non-dependent and
4890  // whose type is not instantiation dependent, do nothing to the decl
4891  // - otherwise find its instantiated decl.
4892  if (isa<ParmVarDecl>(D) && !ParentDC->isDependentContext() &&
4893  !cast<ParmVarDecl>(D)->getType()->isInstantiationDependentType())
4894  return D;
4895  if (isa<ParmVarDecl>(D) || isa<NonTypeTemplateParmDecl>(D) ||
4896  isa<TemplateTypeParmDecl>(D) || isa<TemplateTemplateParmDecl>(D) ||
4897  (ParentDC->isFunctionOrMethod() && ParentDC->isDependentContext()) ||
4898  (isa<CXXRecordDecl>(D) && cast<CXXRecordDecl>(D)->isLambda())) {
4899  // D is a local of some kind. Look into the map of local
4900  // declarations to their instantiations.
4901  if (CurrentInstantiationScope) {
4902  if (auto Found = CurrentInstantiationScope->findInstantiationOf(D)) {
4903  if (Decl *FD = Found->dyn_cast<Decl *>())
4904  return cast<NamedDecl>(FD);
4905 
4906  int PackIdx = ArgumentPackSubstitutionIndex;
4907  assert(PackIdx != -1 &&
4908  "found declaration pack but not pack expanding");
4909  typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
4910  return cast<NamedDecl>((*Found->get<DeclArgumentPack *>())[PackIdx]);
4911  }
4912  }
4913 
4914  // If we're performing a partial substitution during template argument
4915  // deduction, we may not have values for template parameters yet. They
4916  // just map to themselves.
4917  if (isa<NonTypeTemplateParmDecl>(D) || isa<TemplateTypeParmDecl>(D) ||
4918  isa<TemplateTemplateParmDecl>(D))
4919  return D;
4920 
4921  if (D->isInvalidDecl())
4922  return nullptr;
4923 
4924  // Normally this function only searches for already instantiated declaration
4925  // however we have to make an exclusion for local types used before
4926  // definition as in the code:
4927  //
4928  // template<typename T> void f1() {
4929  // void g1(struct x1);
4930  // struct x1 {};
4931  // }
4932  //
4933  // In this case instantiation of the type of 'g1' requires definition of
4934  // 'x1', which is defined later. Error recovery may produce an enum used
4935  // before definition. In these cases we need to instantiate relevant
4936  // declarations here.
4937  bool NeedInstantiate = false;
4938  if (CXXRecordDecl *RD = dyn_cast<CXXRecordDecl>(D))
4939  NeedInstantiate = RD->isLocalClass();
4940  else
4941  NeedInstantiate = isa<EnumDecl>(D);
4942  if (NeedInstantiate) {
4943  Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4944  CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4945  return cast<TypeDecl>(Inst);
4946  }
4947 
4948  // If we didn't find the decl, then we must have a label decl that hasn't
4949  // been found yet. Lazily instantiate it and return it now.
4950  assert(isa<LabelDecl>(D));
4951 
4952  Decl *Inst = SubstDecl(D, CurContext, TemplateArgs);
4953  assert(Inst && "Failed to instantiate label??");
4954 
4955  CurrentInstantiationScope->InstantiatedLocal(D, Inst);
4956  return cast<LabelDecl>(Inst);
4957  }
4958 
4959  // For variable template specializations, update those that are still
4960  // type-dependent.
4961  if (VarTemplateSpecializationDecl *VarSpec =
4962  dyn_cast<VarTemplateSpecializationDecl>(D)) {
4963  bool InstantiationDependent = false;
4964  const TemplateArgumentListInfo &VarTemplateArgs =
4965  VarSpec->getTemplateArgsInfo();
4967  VarTemplateArgs, InstantiationDependent))
4968  D = cast<NamedDecl>(
4969  SubstDecl(D, VarSpec->getDeclContext(), TemplateArgs));
4970  return D;
4971  }
4972 
4973  if (CXXRecordDecl *Record = dyn_cast<CXXRecordDecl>(D)) {
4974  if (!Record->isDependentContext())
4975  return D;
4976 
4977  // Determine whether this record is the "templated" declaration describing
4978  // a class template or class template partial specialization.
4979  ClassTemplateDecl *ClassTemplate = Record->getDescribedClassTemplate();
4980  if (ClassTemplate)
4981  ClassTemplate = ClassTemplate->getCanonicalDecl();
4982  else if (ClassTemplatePartialSpecializationDecl *PartialSpec
4983  = dyn_cast<ClassTemplatePartialSpecializationDecl>(Record))
4984  ClassTemplate = PartialSpec->getSpecializedTemplate()->getCanonicalDecl();
4985 
4986  // Walk the current context to find either the record or an instantiation of
4987  // it.
4988  DeclContext *DC = CurContext;
4989  while (!DC->isFileContext()) {
4990  // If we're performing substitution while we're inside the template
4991  // definition, we'll find our own context. We're done.
4992  if (DC->Equals(Record))
4993  return Record;
4994 
4995  if (CXXRecordDecl *InstRecord = dyn_cast<CXXRecordDecl>(DC)) {
4996  // Check whether we're in the process of instantiating a class template
4997  // specialization of the template we're mapping.
4998  if (ClassTemplateSpecializationDecl *InstSpec
4999  = dyn_cast<ClassTemplateSpecializationDecl>(InstRecord)){
5000  ClassTemplateDecl *SpecTemplate = InstSpec->getSpecializedTemplate();
5001  if (ClassTemplate && isInstantiationOf(ClassTemplate, SpecTemplate))
5002  return InstRecord;
5003  }
5004 
5005  // Check whether we're in the process of instantiating a member class.
5006  if (isInstantiationOf(Record, InstRecord))
5007  return InstRecord;
5008  }
5009 
5010  // Move to the outer template scope.
5011  if (FunctionDecl *FD = dyn_cast<FunctionDecl>(DC)) {
5012  if (FD->getFriendObjectKind() && FD->getDeclContext()->isFileContext()){
5013  DC = FD->getLexicalDeclContext();
5014  continue;
5015  }
5016  // An implicit deduction guide acts as if it's within the class template
5017  // specialization described by its name and first N template params.
5018  auto *Guide = dyn_cast<CXXDeductionGuideDecl>(FD);
5019  if (Guide && Guide->isImplicit()) {
5020  TemplateDecl *TD = Guide->getDeducedTemplate();
5021  // Convert the arguments to an "as-written" list.
5022  TemplateArgumentListInfo Args(Loc, Loc);
5023  for (TemplateArgument Arg : TemplateArgs.getInnermost().take_front(
5024  TD->getTemplateParameters()->size())) {
5025  ArrayRef<TemplateArgument> Unpacked(Arg);
5026  if (Arg.getKind() == TemplateArgument::Pack)
5027  Unpacked = Arg.pack_elements();
5028  for (TemplateArgument UnpackedArg : Unpacked)
5029  Args.addArgument(
5030  getTrivialTemplateArgumentLoc(UnpackedArg, QualType(), Loc));
5031  }
5032  QualType T = CheckTemplateIdType(TemplateName(TD), Loc, Args);
5033  if (T.isNull())
5034  return nullptr;
5035  auto *SubstRecord = T->getAsCXXRecordDecl();
5036  assert(SubstRecord && "class template id not a class type?");
5037  // Check that this template-id names the primary template and not a
5038  // partial or explicit specialization. (In the latter cases, it's
5039  // meaningless to attempt to find an instantiation of D within the
5040  // specialization.)
5041  // FIXME: The standard doesn't say what should happen here.
5042  if (FindingInstantiatedContext &&
5043  usesPartialOrExplicitSpecialization(
5044  Loc, cast<ClassTemplateSpecializationDecl>(SubstRecord))) {
5045  Diag(Loc, diag::err_specialization_not_primary_template)
5046  << T << (SubstRecord->getTemplateSpecializationKind() ==
5048  return nullptr;
5049  }
5050  DC = SubstRecord;
5051  continue;
5052  }
5053  }
5054 
5055  DC = DC->getParent();
5056  }
5057 
5058  // Fall through to deal with other dependent record types (e.g.,
5059  // anonymous unions in class templates).
5060  }
5061 
5062  if (!ParentDC->isDependentContext())
5063  return D;
5064 
5065  ParentDC = FindInstantiatedContext(Loc, ParentDC, TemplateArgs);
5066  if (!ParentDC)
5067  return nullptr;
5068 
5069  if (ParentDC != D->getDeclContext()) {
5070  // We performed some kind of instantiation in the parent context,
5071  // so now we need to look into the instantiated parent context to
5072  // find the instantiation of the declaration D.
5073 
5074  // If our context used to be dependent, we may need to instantiate
5075  // it before performing lookup into that context.
5076  bool IsBeingInstantiated = false;
5077  if (CXXRecordDecl *Spec = dyn_cast<CXXRecordDecl>(ParentDC)) {
5078  if (!Spec->isDependentContext()) {
5079  QualType T = Context.getTypeDeclType(Spec);
5080  const RecordType *Tag = T->getAs<RecordType>();
5081  assert(Tag && "type of non-dependent record is not a RecordType");
5082  if (Tag->isBeingDefined())
5083  IsBeingInstantiated = true;
5084  if (!Tag->isBeingDefined() &&
5085  RequireCompleteType(Loc, T, diag::err_incomplete_type))
5086  return nullptr;
5087 
5088  ParentDC = Tag->getDecl();
5089  }
5090  }
5091 
5092  NamedDecl *Result = nullptr;
5093  // FIXME: If the name is a dependent name, this lookup won't necessarily
5094  // find it. Does that ever matter?
5095  if (auto Name = D->getDeclName()) {
5096  DeclarationNameInfo NameInfo(Name, D->getLocation());
5097  Name = SubstDeclarationNameInfo(NameInfo, TemplateArgs).getName();
5098  if (!Name)
5099  return nullptr;
5100  DeclContext::lookup_result Found = ParentDC->lookup(Name);
5101  Result = findInstantiationOf(Context, D, Found.begin(), Found.end());
5102  } else {
5103  // Since we don't have a name for the entity we're looking for,
5104  // our only option is to walk through all of the declarations to
5105  // find that name. This will occur in a few cases:
5106  //
5107  // - anonymous struct/union within a template
5108  // - unnamed class/struct/union/enum within a template
5109  //
5110  // FIXME: Find a better way to find these instantiations!
5111  Result = findInstantiationOf(Context, D,
5112  ParentDC->decls_begin(),
5113  ParentDC->decls_end());
5114  }
5115 
5116  if (!Result) {
5117  if (isa<UsingShadowDecl>(D)) {
5118  // UsingShadowDecls can instantiate to nothing because of using hiding.
5119  } else if (Diags.hasErrorOccurred()) {
5120  // We've already complained about something, so most likely this
5121  // declaration failed to instantiate. There's no point in complaining
5122  // further, since this is normal in invalid code.
5123  } else if (IsBeingInstantiated) {
5124  // The class in which this member exists is currently being
5125  // instantiated, and we haven't gotten around to instantiating this
5126  // member yet. This can happen when the code uses forward declarations
5127  // of member classes, and introduces ordering dependencies via
5128  // template instantiation.
5129  Diag(Loc, diag::err_member_not_yet_instantiated)
5130  << D->getDeclName()
5131  << Context.getTypeDeclType(cast<CXXRecordDecl>(ParentDC));
5132  Diag(D->getLocation(), diag::note_non_instantiated_member_here);
5133  } else if (EnumConstantDecl *ED = dyn_cast<EnumConstantDecl>(D)) {
5134  // This enumeration constant was found when the template was defined,
5135  // but can't be found in the instantiation. This can happen if an
5136  // unscoped enumeration member is explicitly specialized.
5137  EnumDecl *Enum = cast<EnumDecl>(ED->getLexicalDeclContext());
5138  EnumDecl *Spec = cast<EnumDecl>(FindInstantiatedDecl(Loc, Enum,
5139  TemplateArgs));
5140  assert(Spec->getTemplateSpecializationKind() ==
5142  Diag(Loc, diag::err_enumerator_does_not_exist)
5143  << D->getDeclName()
5144  << Context.getTypeDeclType(cast<TypeDecl>(Spec->getDeclContext()));
5145  Diag(Spec->getLocation(), diag::note_enum_specialized_here)
5146  << Context.getTypeDeclType(Spec);
5147  } else {
5148  // We should have found something, but didn't.
5149  llvm_unreachable("Unable to find instantiation of declaration!");
5150  }
5151  }
5152 
5153  D = Result;
5154  }
5155 
5156  return D;
5157 }
5158 
5159 /// Performs template instantiation for all implicit template
5160 /// instantiations we have seen until this point.
5162  while (!PendingLocalImplicitInstantiations.empty() ||
5163  (!LocalOnly && !PendingInstantiations.empty())) {
5165 
5166  if (PendingLocalImplicitInstantiations.empty()) {
5167  Inst = PendingInstantiations.front();
5168  PendingInstantiations.pop_front();
5169  } else {
5170  Inst = PendingLocalImplicitInstantiations.front();
5171  PendingLocalImplicitInstantiations.pop_front();
5172  }
5173 
5174  // Instantiate function definitions
5175  if (FunctionDecl *Function = dyn_cast<FunctionDecl>(Inst.first)) {
5176  bool DefinitionRequired = Function->getTemplateSpecializationKind() ==
5178  if (Function->isMultiVersion()) {
5179  getASTContext().forEachMultiversionedFunctionVersion(
5180  Function, [this, Inst, DefinitionRequired](FunctionDecl *CurFD) {
5181  InstantiateFunctionDefinition(/*FIXME:*/ Inst.second, CurFD, true,
5182  DefinitionRequired, true);
5183  if (CurFD->isDefined())
5184  CurFD->setInstantiationIsPending(false);
5185  });
5186  } else {
5187  InstantiateFunctionDefinition(/*FIXME:*/ Inst.second, Function, true,
5188  DefinitionRequired, true);
5189  if (Function->isDefined())
5190  Function->setInstantiationIsPending(false);
5191  }
5192  continue;
5193  }
5194 
5195  // Instantiate variable definitions
5196  VarDecl *Var = cast<VarDecl>(Inst.first);
5197 
5198  assert((Var->isStaticDataMember() ||
5199  isa<VarTemplateSpecializationDecl>(Var)) &&
5200  "Not a static data member, nor a variable template"
5201  " specialization?");
5202 
5203  // Don't try to instantiate declarations if the most recent redeclaration
5204  // is invalid.
5205  if (Var->getMostRecentDecl()->isInvalidDecl())
5206  continue;
5207 
5208  // Check if the most recent declaration has changed the specialization kind
5209  // and removed the need for implicit instantiation.
5211  case TSK_Undeclared:
5212  llvm_unreachable("Cannot instantitiate an undeclared specialization.");
5215  continue; // No longer need to instantiate this type.
5217  // We only need an instantiation if the pending instantiation *is* the
5218  // explicit instantiation.
5219  if (Var != Var->getMostRecentDecl())
5220  continue;
5221  break;
5223  break;
5224  }
5225 
5226  PrettyDeclStackTraceEntry CrashInfo(Context, Var, SourceLocation(),
5227  "instantiating variable definition");
5228  bool DefinitionRequired = Var->getTemplateSpecializationKind() ==
5230 
5231  // Instantiate static data member definitions or variable template
5232  // specializations.
5233  InstantiateVariableDefinition(/*FIXME:*/ Inst.second, Var, true,
5234  DefinitionRequired, true);
5235  }
5236 }
5237 
5239  const MultiLevelTemplateArgumentList &TemplateArgs) {
5240  for (auto DD : Pattern->ddiags()) {
5241  switch (DD->getKind()) {
5243  HandleDependentAccessCheck(*DD, TemplateArgs);
5244  break;
5245  }
5246  }
5247 }
bool isPackExpansion() const
Whether this parameter pack is a pack expansion.
VarTemplateDecl * getDescribedVarTemplate() const
Retrieves the variable template that is described by this variable declaration.
Definition: Decl.cpp:2426
The lookup results will be used for redeclaration of a name with external linkage; non-visible lookup...
Definition: Sema.h:3071
Defines the clang::ASTContext interface.
FunctionDecl * getDefinition()
Get the definition for this declaration.
Definition: Decl.h:1939
void InstantiateClassMembers(SourceLocation PointOfInstantiation, CXXRecordDecl *Instantiation, const MultiLevelTemplateArgumentList &TemplateArgs, TemplateSpecializationKind TSK)
Instantiates the definitions of all of the member of the given class, which is an instantiation of a ...
static void collectUnexpandedParameterPacks(Sema &S, TemplateParameterList *Params, SmallVectorImpl< UnexpandedParameterPack > &Unexpanded)
The lookup results will be used for redeclaration of a name, if an entity by that name already exists...
Definition: Sema.h:3067
void setImplicit(bool I=true)
Definition: DeclBase.h:561
Represents a function declaration or definition.
Definition: Decl.h:1722
NamespaceDecl * getStdNamespace() const
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
ExprResult PerformContextuallyConvertToBool(Expr *From)
PerformContextuallyConvertToBool - Perform a contextual conversion of the expression From to bool (C+...
no exception specification
virtual void HandleCXXStaticMemberVarInstantiation(VarDecl *D)
HandleCXXStaticMemberVarInstantiation - Tell the consumer that this.
Definition: ASTConsumer.h:112
bool TemplateParameterListsAreEqual(TemplateParameterList *New, TemplateParameterList *Old, bool Complain, TemplateParameterListEqualKind Kind, SourceLocation TemplateArgLoc=SourceLocation())
Determine whether the given template parameter lists are equivalent.
void InstantiateAttrsForDecl(const MultiLevelTemplateArgumentList &TemplateArgs, const Decl *Pattern, Decl *Inst, LateInstantiatedAttrVec *LateAttrs=nullptr, LocalInstantiationScope *OuterMostScope=nullptr)
A (possibly-)qualified type.
Definition: Type.h:641
void ActOnOpenMPDeclareReductionCombinerStart(Scope *S, Decl *D)
Initialize declare reduction construct initializer.
const char * getDeclKindName() const
Definition: DeclBase.cpp:123
void InstantiatedLocal(const Decl *D, Decl *Inst)
bool CheckTemplateParameterList(TemplateParameterList *NewParams, TemplateParameterList *OldParams, TemplateParamListContext TPC)
Checks the validity of a template parameter list, possibly considering the template parameter list fr...
void setTemplateKeywordLoc(SourceLocation Loc)
Sets the location of the template keyword.
Decl * VisitVarDecl(VarDecl *D, bool InstantiatingVarTemplate, ArrayRef< BindingDecl *> *Bindings=nullptr)
bool isOverloadedOperator() const
Whether this function declaration represents an C++ overloaded operator, e.g., "operator+".
Definition: Decl.h:2351
ASTConsumer - This is an abstract interface that should be implemented by clients that read ASTs...
Definition: ASTConsumer.h:34
A stack-allocated class that identifies which local variable declaration instantiations are present i...
Definition: Template.h:228
const TypeClass * getTypePtr() const
Definition: TypeLoc.h:410
void InstantiateExceptionSpec(SourceLocation PointOfInstantiation, FunctionDecl *Function)
std::vector< std::unique_ptr< TemplateInstantiationCallback > > TemplateInstCallbacks
The template instantiation callbacks to trace or track instantiations (objects can be chained)...
Definition: Sema.h:7301
SourceRange getSourceRange() const LLVM_READONLY
Retrieve the source range covering the entirety of this nested-name-specifier.
static TypeAliasTemplateDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation L, DeclarationName Name, TemplateParameterList *Params, NamedDecl *Decl)
Create a function template node.
FunctionDecl * findSpecialization(ArrayRef< TemplateArgument > Args, void *&InsertPos)
Return the specialization with the provided arguments if it exists, otherwise return the insertion po...
Ordinary name lookup, which finds ordinary names (functions, variables, typedefs, etc...
Definition: Sema.h:3016
SourceRange getBraceRange() const
Definition: Decl.h:3124
bool willHaveBody() const
True if this function will eventually have a body, once it&#39;s fully parsed.
Definition: Decl.h:2205
DeclarationName getCXXConstructorName(CanQualType Ty)
getCXXConstructorName - Returns the name of a C++ constructor for the given Type. ...
static void instantiateDependentAllocAlignAttr(Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs, const AllocAlignAttr *Align, Decl *New)
InClassInitStyle getInClassInitStyle() const
Get the kind of (C++11) default member initializer that this field has.
Definition: Decl.h:2682
NestedNameSpecifierLoc getTemplateQualifierLoc() const
Definition: TemplateBase.h:532
void addOuterTemplateArguments(const TemplateArgumentList *TemplateArgs)
Add a new outermost level to the multi-level template argument list.
Definition: Template.h:134
Expr * getUnderlyingExpr() const
Definition: Type.h:4125
static IndirectFieldDecl * Create(ASTContext &C, DeclContext *DC, SourceLocation L, IdentifierInfo *Id, QualType T, llvm::MutableArrayRef< NamedDecl *> CH)
Definition: Decl.cpp:4462
Stmt - This represents one statement.
Definition: Stmt.h:66
Expr * getBitWidth() const
Definition: Decl.h:2643
We are matching the template parameter lists of two templates that might be redeclarations.
Definition: Sema.h:6447
void setPreviousDecl(decl_type *PrevDecl)
Set the previous declaration.
Definition: Decl.h:4264
Provides information about an attempted template argument deduction, whose success or failure was des...
ClassTemplateSpecializationDecl * findSpecialization(ArrayRef< TemplateArgument > Args, void *&InsertPos)
Return the specialization with the provided arguments if it exists, otherwise return the insertion po...
static bool isDeclWithinFunction(const Decl *D)
VarDecl * getTemplatedDecl() const
Get the underlying variable declarations of the template.
bool isOutOfLine() const override
Determine whether this is or was instantiated from an out-of-line definition of a member function...
Definition: Decl.cpp:3576
An instance of this object exists for each enum constant that is defined.
Definition: Decl.h:2761
StorageClass getStorageClass() const
Returns the storage class as written in the source.
Definition: Decl.h:1025
void setTypedefNameForAnonDecl(TypedefNameDecl *TDD)
Definition: Decl.cpp:3830
Represents the declaration of a typedef-name via the &#39;typedef&#39; type specifier.
Definition: Decl.h:2997
bool CheckTemplatePartialSpecializationArgs(SourceLocation Loc, TemplateDecl *PrimaryTemplate, unsigned NumExplicitArgs, ArrayRef< TemplateArgument > Args)
Check the non-type template arguments of a class template partial specialization according to C++ [te...
bool isConstexpr() const
Whether this is a (C++11) constexpr function or constexpr constructor.
Definition: Decl.h:2078
VarTemplateSpecializationDecl * BuildVarTemplateInstantiation(VarTemplateDecl *VarTemplate, VarDecl *FromVar, const TemplateArgumentList &TemplateArgList, const TemplateArgumentListInfo &TemplateArgsInfo, SmallVectorImpl< TemplateArgument > &Converted, SourceLocation PointOfInstantiation, void *InsertPos, LateInstantiatedAttrVec *LateAttrs=nullptr, LocalInstantiationScope *StartingScope=nullptr)
unsigned getNumExpansionTypes() const
Retrieves the number of expansion types in an expanded parameter pack.
static TemplateTemplateParmDecl * Create(const ASTContext &C, DeclContext *DC, SourceLocation L, unsigned D, unsigned P, bool ParameterPack, IdentifierInfo *Id, TemplateParameterList *Params)
bool isSingleTagDecl() const
Asks if the result is a single tag decl.
Definition: Lookup.h:519
NamedDecl * BuildUsingDeclaration(Scope *S, AccessSpecifier AS, SourceLocation UsingLoc, bool HasTypenameKeyword, SourceLocation TypenameLoc, CXXScopeSpec &SS, DeclarationNameInfo NameInfo, SourceLocation EllipsisLoc, const ParsedAttributesView &AttrList, bool IsInstantiation)
Builds a using declaration.
const Type * getTypeForDecl() const
Definition: Decl.h:2873
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
Emit a diagnostic.
Definition: Sema.h:1281
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:86
void setRangeEnd(SourceLocation E)
Definition: Decl.h:1892
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: DeclBase.h:413
static Expr * instantiateDependentFunctionAttrCondition(Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs, const Attr *A, Expr *OldCond, const Decl *Tmpl, FunctionDecl *New)
IdentifierInfo * getGetterId() const
Definition: DeclCXX.h:3936
VarDecl * getDefinition(ASTContext &)
Get the real (not just tentative) definition for this declaration.
Definition: Decl.cpp:2112
ThreadStorageClassSpecifier getTSCSpec() const
Definition: Decl.h:1034
llvm::PointerUnion< Decl *, DeclArgumentPack * > * findInstantiationOf(const Decl *D)
Find the instantiation of the declaration D within the current instantiation scope.
Defines the C++ template declaration subclasses.
StringRef P
bool hasWrittenPrototype() const
Whether this function has a written prototype.
Definition: Decl.h:2056
Decl * InstantiateTypedefNameDecl(TypedefNameDecl *D, bool IsTypeAlias)
SmallVector< CodeSynthesisContext, 16 > CodeSynthesisContexts
List of active code synthesis contexts.
Definition: Sema.h:7244
Not a friend object.
Definition: DeclBase.h:1107
Decl * getPreviousDecl()
Retrieve the previous declaration that declares the same entity as this declaration, or NULL if there is no previous declaration.
Definition: DeclBase.h:966
QualType getNonReferenceType() const
If Type is a reference type (e.g., const int&), returns the type that the reference refers to ("const...
Definition: Type.h:6161
FunctionDecl * InstantiateFunctionDeclaration(FunctionTemplateDecl *FTD, const TemplateArgumentList *Args, SourceLocation Loc)
Instantiate (or find existing instantiation of) a function template with a given set of template argu...
SourceLocation getColonLoc() const
The location of the colon following the access specifier.
Definition: DeclCXX.h:154
bool isCXXForRangeDecl() const
Determine whether this variable is the for-range-declaration in a C++0x for-range statement...
Definition: Decl.h:1340
bool isExpandedParameterPack() const
Whether this parameter is a template template parameter pack that has a known list of different templ...
std::deque< PendingImplicitInstantiation > PendingLocalImplicitInstantiations
The queue of implicit template instantiations that are required and must be performed within the curr...
Definition: Sema.h:7658
Declaration of a variable template.
Represent a C++ namespace.
Definition: Decl.h:514
SourceLocation getEndLoc() const LLVM_READONLY
Definition: DeclBase.h:421
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:698
bool getNoReturnAttr() const
Determine whether this function type includes the GNU noreturn attribute.
Definition: Type.h:3477
A container of type source information.
Definition: Decl.h:86
TemplateParameterList * getTemplateParameters() const
Get the list of template parameters.
std::pair< ValueDecl *, SourceLocation > PendingImplicitInstantiation
An entity for which implicit template instantiation is required.
Definition: Sema.h:7603
FieldDecl * getInstantiatedFromUnnamedFieldDecl(FieldDecl *Field)
TypeSourceInfo * getDefaultArgumentInfo() const
Retrieves the default argument&#39;s source information, if any.
bool isDefined(const FunctionDecl *&Definition) const
Returns true if the function has a definition that does not need to be instantiated.
Definition: Decl.cpp:2683
void setTemplateArgsInfo(const TemplateArgumentListInfo &ArgsInfo)
void setInitStyle(InitializationStyle Style)
Definition: Decl.h:1270
VarTemplatePartialSpecializationDecl * InstantiateVarTemplatePartialSpecialization(VarTemplateDecl *VarTemplate, VarTemplatePartialSpecializationDecl *PartialSpec)
Instantiate the declaration of a variable template partial specialization.
bool CheckTemplateArgumentList(TemplateDecl *Template, SourceLocation TemplateLoc, TemplateArgumentListInfo &TemplateArgs, bool PartialTemplateArgs, SmallVectorImpl< TemplateArgument > &Converted, bool UpdateArgsWithConversions=true)
Check that the given template arguments can be be provided to the given template, converting the argu...
Represents a C++ constructor within a class.
Definition: DeclCXX.h:2483
TemplateName SubstTemplateName(NestedNameSpecifierLoc QualifierLoc, TemplateName Name, SourceLocation Loc, const MultiLevelTemplateArgumentList &TemplateArgs)
bool CheckCXXDefaultArgExpr(SourceLocation CallLoc, FunctionDecl *FD, ParmVarDecl *Param)
Instantiate or parse a C++ default argument expression as necessary.
Definition: SemaExpr.cpp:4551
bool isVirtualAsWritten() const
Whether this function is marked as virtual explicitly.
Definition: Decl.h:1984
void InstantiateVariableDefinition(SourceLocation PointOfInstantiation, VarDecl *Var, bool Recursive=false, bool DefinitionRequired=false, bool AtEndOfTU=false)
Instantiate the definition of the given variable from its template.
static void instantiateDependentEnableIfAttr(Sema &S, const MultiLevelTemplateArgumentList &TemplateArgs, const EnableIfAttr *EIA, const Decl *Tmpl, FunctionDecl *New)
SourceLocation getTargetNameLoc() const
Returns the location of the identifier in the named namespace.
Definition: DeclCXX.h:3115
bool isCompleteDefinition() const
Return true if this decl has its body fully specified.
Definition: Decl.h:3148
bool defaultArgumentWasInherited() const
Determines whether the default argument was inherited from a previous declaration of this template...
TemplateParameterList * getTemplateParameters() const
Get the list of template parameters.
Represents a #pragma comment line.
Definition: Decl.h:139
bool isDefaultConstructor() const
Whether this constructor is a default constructor (C++ [class.ctor]p5), which can be used to default-...
Definition: DeclCXX.cpp:2319
NamedDecl * BuildUsingPackDecl(NamedDecl *InstantiatedFrom, ArrayRef< NamedDecl *> Expansions)
bool isPackExpansion() const
Whether this parameter pack is a pack expansion.
void Adopt(NestedNameSpecifierLoc Other)
Adopt an existing nested-name-specifier (with source-range information).
Definition: DeclSpec.cpp:125
void setRAngleLoc(SourceLocation Loc)
Definition: TemplateBase.h:572
unsigned getDepth() const
Get the nesting depth of the template parameter.