clang  9.0.0svn
SemaTemplateVariadic.cpp
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1 //===------- SemaTemplateVariadic.cpp - C++ Variadic Templates ------------===/
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //===----------------------------------------------------------------------===/
7 //
8 // This file implements semantic analysis for C++0x variadic templates.
9 //===----------------------------------------------------------------------===/
10 
11 #include "clang/Sema/Sema.h"
12 #include "TypeLocBuilder.h"
13 #include "clang/AST/Expr.h"
15 #include "clang/AST/TypeLoc.h"
16 #include "clang/Sema/Lookup.h"
18 #include "clang/Sema/ScopeInfo.h"
20 #include "clang/Sema/Template.h"
21 
22 using namespace clang;
23 
24 //----------------------------------------------------------------------------
25 // Visitor that collects unexpanded parameter packs
26 //----------------------------------------------------------------------------
27 
28 namespace {
29  /// A class that collects unexpanded parameter packs.
30  class CollectUnexpandedParameterPacksVisitor :
31  public RecursiveASTVisitor<CollectUnexpandedParameterPacksVisitor>
32  {
34  inherited;
35 
37 
38  bool InLambda = false;
39  unsigned DepthLimit = (unsigned)-1;
40 
41  void addUnexpanded(NamedDecl *ND, SourceLocation Loc = SourceLocation()) {
42  if (auto *VD = dyn_cast<VarDecl>(ND)) {
43  // For now, the only problematic case is a generic lambda's templated
44  // call operator, so we don't need to look for all the other ways we
45  // could have reached a dependent parameter pack.
46  auto *FD = dyn_cast<FunctionDecl>(VD->getDeclContext());
47  auto *FTD = FD ? FD->getDescribedFunctionTemplate() : nullptr;
48  if (FTD && FTD->getTemplateParameters()->getDepth() >= DepthLimit)
49  return;
50  } else if (getDepthAndIndex(ND).first >= DepthLimit)
51  return;
52 
53  Unexpanded.push_back({ND, Loc});
54  }
55  void addUnexpanded(const TemplateTypeParmType *T,
57  if (T->getDepth() < DepthLimit)
58  Unexpanded.push_back({T, Loc});
59  }
60 
61  public:
62  explicit CollectUnexpandedParameterPacksVisitor(
64  : Unexpanded(Unexpanded) {}
65 
66  bool shouldWalkTypesOfTypeLocs() const { return false; }
67 
68  //------------------------------------------------------------------------
69  // Recording occurrences of (unexpanded) parameter packs.
70  //------------------------------------------------------------------------
71 
72  /// Record occurrences of template type parameter packs.
73  bool VisitTemplateTypeParmTypeLoc(TemplateTypeParmTypeLoc TL) {
74  if (TL.getTypePtr()->isParameterPack())
75  addUnexpanded(TL.getTypePtr(), TL.getNameLoc());
76  return true;
77  }
78 
79  /// Record occurrences of template type parameter packs
80  /// when we don't have proper source-location information for
81  /// them.
82  ///
83  /// Ideally, this routine would never be used.
84  bool VisitTemplateTypeParmType(TemplateTypeParmType *T) {
85  if (T->isParameterPack())
86  addUnexpanded(T);
87 
88  return true;
89  }
90 
91  /// Record occurrences of function and non-type template
92  /// parameter packs in an expression.
93  bool VisitDeclRefExpr(DeclRefExpr *E) {
94  if (E->getDecl()->isParameterPack())
95  addUnexpanded(E->getDecl(), E->getLocation());
96 
97  return true;
98  }
99 
100  /// Record occurrences of template template parameter packs.
101  bool TraverseTemplateName(TemplateName Template) {
102  if (auto *TTP = dyn_cast_or_null<TemplateTemplateParmDecl>(
103  Template.getAsTemplateDecl())) {
104  if (TTP->isParameterPack())
105  addUnexpanded(TTP);
106  }
107 
108  return inherited::TraverseTemplateName(Template);
109  }
110 
111  /// Suppress traversal into Objective-C container literal
112  /// elements that are pack expansions.
113  bool TraverseObjCDictionaryLiteral(ObjCDictionaryLiteral *E) {
115  return true;
116 
117  for (unsigned I = 0, N = E->getNumElements(); I != N; ++I) {
119  if (Element.isPackExpansion())
120  continue;
121 
122  TraverseStmt(Element.Key);
123  TraverseStmt(Element.Value);
124  }
125  return true;
126  }
127  //------------------------------------------------------------------------
128  // Pruning the search for unexpanded parameter packs.
129  //------------------------------------------------------------------------
130 
131  /// Suppress traversal into statements and expressions that
132  /// do not contain unexpanded parameter packs.
133  bool TraverseStmt(Stmt *S) {
134  Expr *E = dyn_cast_or_null<Expr>(S);
135  if ((E && E->containsUnexpandedParameterPack()) || InLambda)
136  return inherited::TraverseStmt(S);
137 
138  return true;
139  }
140 
141  /// Suppress traversal into types that do not contain
142  /// unexpanded parameter packs.
143  bool TraverseType(QualType T) {
144  if ((!T.isNull() && T->containsUnexpandedParameterPack()) || InLambda)
145  return inherited::TraverseType(T);
146 
147  return true;
148  }
149 
150  /// Suppress traversal into types with location information
151  /// that do not contain unexpanded parameter packs.
152  bool TraverseTypeLoc(TypeLoc TL) {
153  if ((!TL.getType().isNull() &&
155  InLambda)
156  return inherited::TraverseTypeLoc(TL);
157 
158  return true;
159  }
160 
161  /// Suppress traversal of parameter packs.
162  bool TraverseDecl(Decl *D) {
163  // A function parameter pack is a pack expansion, so cannot contain
164  // an unexpanded parameter pack. Likewise for a template parameter
165  // pack that contains any references to other packs.
166  if (D && D->isParameterPack())
167  return true;
168 
169  return inherited::TraverseDecl(D);
170  }
171 
172  /// Suppress traversal of pack-expanded attributes.
173  bool TraverseAttr(Attr *A) {
174  if (A->isPackExpansion())
175  return true;
176 
177  return inherited::TraverseAttr(A);
178  }
179 
180  /// Suppress traversal of pack expansion expressions and types.
181  ///@{
182  bool TraversePackExpansionType(PackExpansionType *T) { return true; }
183  bool TraversePackExpansionTypeLoc(PackExpansionTypeLoc TL) { return true; }
184  bool TraversePackExpansionExpr(PackExpansionExpr *E) { return true; }
185  bool TraverseCXXFoldExpr(CXXFoldExpr *E) { return true; }
186 
187  ///@}
188 
189  /// Suppress traversal of using-declaration pack expansion.
190  bool TraverseUnresolvedUsingValueDecl(UnresolvedUsingValueDecl *D) {
191  if (D->isPackExpansion())
192  return true;
193 
194  return inherited::TraverseUnresolvedUsingValueDecl(D);
195  }
196 
197  /// Suppress traversal of using-declaration pack expansion.
198  bool TraverseUnresolvedUsingTypenameDecl(UnresolvedUsingTypenameDecl *D) {
199  if (D->isPackExpansion())
200  return true;
201 
202  return inherited::TraverseUnresolvedUsingTypenameDecl(D);
203  }
204 
205  /// Suppress traversal of template argument pack expansions.
206  bool TraverseTemplateArgument(const TemplateArgument &Arg) {
207  if (Arg.isPackExpansion())
208  return true;
209 
210  return inherited::TraverseTemplateArgument(Arg);
211  }
212 
213  /// Suppress traversal of template argument pack expansions.
214  bool TraverseTemplateArgumentLoc(const TemplateArgumentLoc &ArgLoc) {
215  if (ArgLoc.getArgument().isPackExpansion())
216  return true;
217 
218  return inherited::TraverseTemplateArgumentLoc(ArgLoc);
219  }
220 
221  /// Suppress traversal of base specifier pack expansions.
222  bool TraverseCXXBaseSpecifier(const CXXBaseSpecifier &Base) {
223  if (Base.isPackExpansion())
224  return true;
225 
226  return inherited::TraverseCXXBaseSpecifier(Base);
227  }
228 
229  /// Suppress traversal of mem-initializer pack expansions.
230  bool TraverseConstructorInitializer(CXXCtorInitializer *Init) {
231  if (Init->isPackExpansion())
232  return true;
233 
234  return inherited::TraverseConstructorInitializer(Init);
235  }
236 
237  /// Note whether we're traversing a lambda containing an unexpanded
238  /// parameter pack. In this case, the unexpanded pack can occur anywhere,
239  /// including all the places where we normally wouldn't look. Within a
240  /// lambda, we don't propagate the 'contains unexpanded parameter pack' bit
241  /// outside an expression.
242  bool TraverseLambdaExpr(LambdaExpr *Lambda) {
243  // The ContainsUnexpandedParameterPack bit on a lambda is always correct,
244  // even if it's contained within another lambda.
245  if (!Lambda->containsUnexpandedParameterPack())
246  return true;
247 
248  bool WasInLambda = InLambda;
249  unsigned OldDepthLimit = DepthLimit;
250 
251  InLambda = true;
252  if (auto *TPL = Lambda->getTemplateParameterList())
253  DepthLimit = TPL->getDepth();
254 
255  inherited::TraverseLambdaExpr(Lambda);
256 
257  InLambda = WasInLambda;
258  DepthLimit = OldDepthLimit;
259  return true;
260  }
261 
262  /// Suppress traversal within pack expansions in lambda captures.
263  bool TraverseLambdaCapture(LambdaExpr *Lambda, const LambdaCapture *C,
264  Expr *Init) {
265  if (C->isPackExpansion())
266  return true;
267 
268  return inherited::TraverseLambdaCapture(Lambda, C, Init);
269  }
270  };
271 }
272 
273 /// Determine whether it's possible for an unexpanded parameter pack to
274 /// be valid in this location. This only happens when we're in a declaration
275 /// that is nested within an expression that could be expanded, such as a
276 /// lambda-expression within a function call.
277 ///
278 /// This is conservatively correct, but may claim that some unexpanded packs are
279 /// permitted when they are not.
281  for (auto *SI : FunctionScopes)
282  if (isa<sema::LambdaScopeInfo>(SI))
283  return true;
284  return false;
285 }
286 
287 /// Diagnose all of the unexpanded parameter packs in the given
288 /// vector.
289 bool
293  if (Unexpanded.empty())
294  return false;
295 
296  // If we are within a lambda expression and referencing a pack that is not
297  // a parameter of the lambda itself, that lambda contains an unexpanded
298  // parameter pack, and we are done.
299  // FIXME: Store 'Unexpanded' on the lambda so we don't need to recompute it
300  // later.
301  SmallVector<UnexpandedParameterPack, 4> LambdaParamPackReferences;
302  for (unsigned N = FunctionScopes.size(); N; --N) {
303  sema::FunctionScopeInfo *Func = FunctionScopes[N-1];
304  // We do not permit pack expansion that would duplicate a statement
305  // expression, not even within a lambda.
306  // FIXME: We could probably support this for statement expressions that do
307  // not contain labels, and for pack expansions that expand both the stmt
308  // expr and the enclosing lambda.
309  if (std::any_of(
310  Func->CompoundScopes.begin(), Func->CompoundScopes.end(),
311  [](sema::CompoundScopeInfo &CSI) { return CSI.IsStmtExpr; }))
312  break;
313 
314  if (auto *LSI = dyn_cast<sema::LambdaScopeInfo>(Func)) {
315  if (N == FunctionScopes.size()) {
316  for (auto &Pack : Unexpanded) {
317  auto *VD = dyn_cast_or_null<VarDecl>(
318  Pack.first.dyn_cast<NamedDecl *>());
319  if (VD && VD->getDeclContext() == LSI->CallOperator)
320  LambdaParamPackReferences.push_back(Pack);
321  }
322  }
323 
324  // If we have references to a parameter pack of the innermost enclosing
325  // lambda, only diagnose those ones. We don't know whether any other
326  // unexpanded parameters referenced herein are actually unexpanded;
327  // they might be expanded at an outer level.
328  if (!LambdaParamPackReferences.empty()) {
329  Unexpanded = LambdaParamPackReferences;
330  break;
331  }
332 
333  LSI->ContainsUnexpandedParameterPack = true;
334  return false;
335  }
336  }
337 
340  llvm::SmallPtrSet<IdentifierInfo *, 4> NamesKnown;
341 
342  for (unsigned I = 0, N = Unexpanded.size(); I != N; ++I) {
343  IdentifierInfo *Name = nullptr;
344  if (const TemplateTypeParmType *TTP
345  = Unexpanded[I].first.dyn_cast<const TemplateTypeParmType *>())
346  Name = TTP->getIdentifier();
347  else
348  Name = Unexpanded[I].first.get<NamedDecl *>()->getIdentifier();
349 
350  if (Name && NamesKnown.insert(Name).second)
351  Names.push_back(Name);
352 
353  if (Unexpanded[I].second.isValid())
354  Locations.push_back(Unexpanded[I].second);
355  }
356 
357  DiagnosticBuilder DB = Diag(Loc, diag::err_unexpanded_parameter_pack)
358  << (int)UPPC << (int)Names.size();
359  for (size_t I = 0, E = std::min(Names.size(), (size_t)2); I != E; ++I)
360  DB << Names[I];
361 
362  for (unsigned I = 0, N = Locations.size(); I != N; ++I)
363  DB << SourceRange(Locations[I]);
364  return true;
365 }
366 
368  TypeSourceInfo *T,
370  // C++0x [temp.variadic]p5:
371  // An appearance of a name of a parameter pack that is not expanded is
372  // ill-formed.
374  return false;
375 
377  CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseTypeLoc(
378  T->getTypeLoc());
379  assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs");
380  return DiagnoseUnexpandedParameterPacks(Loc, UPPC, Unexpanded);
381 }
382 
385  // C++0x [temp.variadic]p5:
386  // An appearance of a name of a parameter pack that is not expanded is
387  // ill-formed.
389  return false;
390 
392  CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseStmt(E);
393  assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs");
394  return DiagnoseUnexpandedParameterPacks(E->getBeginLoc(), UPPC, Unexpanded);
395 }
396 
399  // C++0x [temp.variadic]p5:
400  // An appearance of a name of a parameter pack that is not expanded is
401  // ill-formed.
402  if (!SS.getScopeRep() ||
404  return false;
405 
407  CollectUnexpandedParameterPacksVisitor(Unexpanded)
408  .TraverseNestedNameSpecifier(SS.getScopeRep());
409  assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs");
411  UPPC, Unexpanded);
412 }
413 
416  // C++0x [temp.variadic]p5:
417  // An appearance of a name of a parameter pack that is not expanded is
418  // ill-formed.
419  switch (NameInfo.getName().getNameKind()) {
428  return false;
429 
433  // FIXME: We shouldn't need this null check!
434  if (TypeSourceInfo *TSInfo = NameInfo.getNamedTypeInfo())
435  return DiagnoseUnexpandedParameterPack(NameInfo.getLoc(), TSInfo, UPPC);
436 
438  return false;
439 
440  break;
441  }
442 
444  CollectUnexpandedParameterPacksVisitor(Unexpanded)
445  .TraverseType(NameInfo.getName().getCXXNameType());
446  assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs");
447  return DiagnoseUnexpandedParameterPacks(NameInfo.getLoc(), UPPC, Unexpanded);
448 }
449 
451  TemplateName Template,
453 
454  if (Template.isNull() || !Template.containsUnexpandedParameterPack())
455  return false;
456 
458  CollectUnexpandedParameterPacksVisitor(Unexpanded)
459  .TraverseTemplateName(Template);
460  assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs");
461  return DiagnoseUnexpandedParameterPacks(Loc, UPPC, Unexpanded);
462 }
463 
466  if (Arg.getArgument().isNull() ||
468  return false;
469 
471  CollectUnexpandedParameterPacksVisitor(Unexpanded)
472  .TraverseTemplateArgumentLoc(Arg);
473  assert(!Unexpanded.empty() && "Unable to find unexpanded parameter packs");
474  return DiagnoseUnexpandedParameterPacks(Arg.getLocation(), UPPC, Unexpanded);
475 }
476 
479  CollectUnexpandedParameterPacksVisitor(Unexpanded)
480  .TraverseTemplateArgument(Arg);
481 }
482 
485  CollectUnexpandedParameterPacksVisitor(Unexpanded)
486  .TraverseTemplateArgumentLoc(Arg);
487 }
488 
491  CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseType(T);
492 }
493 
496  CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseTypeLoc(TL);
497 }
498 
502  CollectUnexpandedParameterPacksVisitor(Unexpanded)
503  .TraverseNestedNameSpecifierLoc(NNS);
504 }
505 
507  const DeclarationNameInfo &NameInfo,
509  CollectUnexpandedParameterPacksVisitor(Unexpanded)
510  .TraverseDeclarationNameInfo(NameInfo);
511 }
512 
513 
516  SourceLocation EllipsisLoc) {
517  if (Arg.isInvalid())
518  return Arg;
519 
520  switch (Arg.getKind()) {
522  TypeResult Result = ActOnPackExpansion(Arg.getAsType(), EllipsisLoc);
523  if (Result.isInvalid())
524  return ParsedTemplateArgument();
525 
526  return ParsedTemplateArgument(Arg.getKind(), Result.get().getAsOpaquePtr(),
527  Arg.getLocation());
528  }
529 
531  ExprResult Result = ActOnPackExpansion(Arg.getAsExpr(), EllipsisLoc);
532  if (Result.isInvalid())
533  return ParsedTemplateArgument();
534 
535  return ParsedTemplateArgument(Arg.getKind(), Result.get(),
536  Arg.getLocation());
537  }
538 
541  SourceRange R(Arg.getLocation());
542  if (Arg.getScopeSpec().isValid())
543  R.setBegin(Arg.getScopeSpec().getBeginLoc());
544  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
545  << R;
546  return ParsedTemplateArgument();
547  }
548 
549  return Arg.getTemplatePackExpansion(EllipsisLoc);
550  }
551  llvm_unreachable("Unhandled template argument kind?");
552 }
553 
555  SourceLocation EllipsisLoc) {
556  TypeSourceInfo *TSInfo;
557  GetTypeFromParser(Type, &TSInfo);
558  if (!TSInfo)
559  return true;
560 
561  TypeSourceInfo *TSResult = CheckPackExpansion(TSInfo, EllipsisLoc, None);
562  if (!TSResult)
563  return true;
564 
565  return CreateParsedType(TSResult->getType(), TSResult);
566 }
567 
570  Optional<unsigned> NumExpansions) {
571  // Create the pack expansion type and source-location information.
572  QualType Result = CheckPackExpansion(Pattern->getType(),
573  Pattern->getTypeLoc().getSourceRange(),
574  EllipsisLoc, NumExpansions);
575  if (Result.isNull())
576  return nullptr;
577 
578  TypeLocBuilder TLB;
579  TLB.pushFullCopy(Pattern->getTypeLoc());
581  TL.setEllipsisLoc(EllipsisLoc);
582 
583  return TLB.getTypeSourceInfo(Context, Result);
584 }
585 
587  SourceLocation EllipsisLoc,
588  Optional<unsigned> NumExpansions) {
589  // C++11 [temp.variadic]p5:
590  // The pattern of a pack expansion shall name one or more
591  // parameter packs that are not expanded by a nested pack
592  // expansion.
593  //
594  // A pattern containing a deduced type can't occur "naturally" but arises in
595  // the desugaring of an init-capture pack.
596  if (!Pattern->containsUnexpandedParameterPack() &&
597  !Pattern->getContainedDeducedType()) {
598  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
599  << PatternRange;
600  return QualType();
601  }
602 
603  return Context.getPackExpansionType(Pattern, NumExpansions);
604 }
605 
607  return CheckPackExpansion(Pattern, EllipsisLoc, None);
608 }
609 
611  Optional<unsigned> NumExpansions) {
612  if (!Pattern)
613  return ExprError();
614 
615  // C++0x [temp.variadic]p5:
616  // The pattern of a pack expansion shall name one or more
617  // parameter packs that are not expanded by a nested pack
618  // expansion.
619  if (!Pattern->containsUnexpandedParameterPack()) {
620  Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
621  << Pattern->getSourceRange();
622  return ExprError();
623  }
624 
625  // Create the pack expansion expression and source-location information.
626  return new (Context)
627  PackExpansionExpr(Context.DependentTy, Pattern, EllipsisLoc, NumExpansions);
628 }
629 
631  SourceLocation EllipsisLoc, SourceRange PatternRange,
633  const MultiLevelTemplateArgumentList &TemplateArgs, bool &ShouldExpand,
634  bool &RetainExpansion, Optional<unsigned> &NumExpansions) {
635  ShouldExpand = true;
636  RetainExpansion = false;
637  std::pair<IdentifierInfo *, SourceLocation> FirstPack;
638  bool HaveFirstPack = false;
639  Optional<unsigned> NumPartialExpansions;
640  SourceLocation PartiallySubstitutedPackLoc;
641 
642  for (ArrayRef<UnexpandedParameterPack>::iterator i = Unexpanded.begin(),
643  end = Unexpanded.end();
644  i != end; ++i) {
645  // Compute the depth and index for this parameter pack.
646  unsigned Depth = 0, Index = 0;
647  IdentifierInfo *Name;
648  bool IsVarDeclPack = false;
649 
650  if (const TemplateTypeParmType *TTP
651  = i->first.dyn_cast<const TemplateTypeParmType *>()) {
652  Depth = TTP->getDepth();
653  Index = TTP->getIndex();
654  Name = TTP->getIdentifier();
655  } else {
656  NamedDecl *ND = i->first.get<NamedDecl *>();
657  if (isa<VarDecl>(ND))
658  IsVarDeclPack = true;
659  else
660  std::tie(Depth, Index) = getDepthAndIndex(ND);
661 
662  Name = ND->getIdentifier();
663  }
664 
665  // Determine the size of this argument pack.
666  unsigned NewPackSize;
667  if (IsVarDeclPack) {
668  // Figure out whether we're instantiating to an argument pack or not.
669  typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
670 
671  llvm::PointerUnion<Decl *, DeclArgumentPack *> *Instantiation
672  = CurrentInstantiationScope->findInstantiationOf(
673  i->first.get<NamedDecl *>());
674  if (Instantiation->is<DeclArgumentPack *>()) {
675  // We could expand this function parameter pack.
676  NewPackSize = Instantiation->get<DeclArgumentPack *>()->size();
677  } else {
678  // We can't expand this function parameter pack, so we can't expand
679  // the pack expansion.
680  ShouldExpand = false;
681  continue;
682  }
683  } else {
684  // If we don't have a template argument at this depth/index, then we
685  // cannot expand the pack expansion. Make a note of this, but we still
686  // want to check any parameter packs we *do* have arguments for.
687  if (Depth >= TemplateArgs.getNumLevels() ||
688  !TemplateArgs.hasTemplateArgument(Depth, Index)) {
689  ShouldExpand = false;
690  continue;
691  }
692 
693  // Determine the size of the argument pack.
694  NewPackSize = TemplateArgs(Depth, Index).pack_size();
695  }
696 
697  // C++0x [temp.arg.explicit]p9:
698  // Template argument deduction can extend the sequence of template
699  // arguments corresponding to a template parameter pack, even when the
700  // sequence contains explicitly specified template arguments.
701  if (!IsVarDeclPack && CurrentInstantiationScope) {
702  if (NamedDecl *PartialPack
703  = CurrentInstantiationScope->getPartiallySubstitutedPack()){
704  unsigned PartialDepth, PartialIndex;
705  std::tie(PartialDepth, PartialIndex) = getDepthAndIndex(PartialPack);
706  if (PartialDepth == Depth && PartialIndex == Index) {
707  RetainExpansion = true;
708  // We don't actually know the new pack size yet.
709  NumPartialExpansions = NewPackSize;
710  PartiallySubstitutedPackLoc = i->second;
711  continue;
712  }
713  }
714  }
715 
716  if (!NumExpansions) {
717  // The is the first pack we've seen for which we have an argument.
718  // Record it.
719  NumExpansions = NewPackSize;
720  FirstPack.first = Name;
721  FirstPack.second = i->second;
722  HaveFirstPack = true;
723  continue;
724  }
725 
726  if (NewPackSize != *NumExpansions) {
727  // C++0x [temp.variadic]p5:
728  // All of the parameter packs expanded by a pack expansion shall have
729  // the same number of arguments specified.
730  if (HaveFirstPack)
731  Diag(EllipsisLoc, diag::err_pack_expansion_length_conflict)
732  << FirstPack.first << Name << *NumExpansions << NewPackSize
733  << SourceRange(FirstPack.second) << SourceRange(i->second);
734  else
735  Diag(EllipsisLoc, diag::err_pack_expansion_length_conflict_multilevel)
736  << Name << *NumExpansions << NewPackSize
737  << SourceRange(i->second);
738  return true;
739  }
740  }
741 
742  // If we're performing a partial expansion but we also have a full expansion,
743  // expand to the number of common arguments. For example, given:
744  //
745  // template<typename ...T> struct A {
746  // template<typename ...U> void f(pair<T, U>...);
747  // };
748  //
749  // ... a call to 'A<int, int>().f<int>' should expand the pack once and
750  // retain an expansion.
751  if (NumPartialExpansions) {
752  if (NumExpansions && *NumExpansions < *NumPartialExpansions) {
753  NamedDecl *PartialPack =
754  CurrentInstantiationScope->getPartiallySubstitutedPack();
755  Diag(EllipsisLoc, diag::err_pack_expansion_length_conflict_partial)
756  << PartialPack << *NumPartialExpansions << *NumExpansions
757  << SourceRange(PartiallySubstitutedPackLoc);
758  return true;
759  }
760 
761  NumExpansions = NumPartialExpansions;
762  }
763 
764  return false;
765 }
766 
768  const MultiLevelTemplateArgumentList &TemplateArgs) {
769  QualType Pattern = cast<PackExpansionType>(T)->getPattern();
771  CollectUnexpandedParameterPacksVisitor(Unexpanded).TraverseType(Pattern);
772 
774  for (unsigned I = 0, N = Unexpanded.size(); I != N; ++I) {
775  // Compute the depth and index for this parameter pack.
776  unsigned Depth;
777  unsigned Index;
778 
779  if (const TemplateTypeParmType *TTP
780  = Unexpanded[I].first.dyn_cast<const TemplateTypeParmType *>()) {
781  Depth = TTP->getDepth();
782  Index = TTP->getIndex();
783  } else {
784  NamedDecl *ND = Unexpanded[I].first.get<NamedDecl *>();
785  if (isa<VarDecl>(ND)) {
786  // Function parameter pack or init-capture pack.
787  typedef LocalInstantiationScope::DeclArgumentPack DeclArgumentPack;
788 
789  llvm::PointerUnion<Decl *, DeclArgumentPack *> *Instantiation
790  = CurrentInstantiationScope->findInstantiationOf(
791  Unexpanded[I].first.get<NamedDecl *>());
792  if (Instantiation->is<Decl*>())
793  // The pattern refers to an unexpanded pack. We're not ready to expand
794  // this pack yet.
795  return None;
796 
797  unsigned Size = Instantiation->get<DeclArgumentPack *>()->size();
798  assert((!Result || *Result == Size) && "inconsistent pack sizes");
799  Result = Size;
800  continue;
801  }
802 
803  std::tie(Depth, Index) = getDepthAndIndex(ND);
804  }
805  if (Depth >= TemplateArgs.getNumLevels() ||
806  !TemplateArgs.hasTemplateArgument(Depth, Index))
807  // The pattern refers to an unknown template argument. We're not ready to
808  // expand this pack yet.
809  return None;
810 
811  // Determine the size of the argument pack.
812  unsigned Size = TemplateArgs(Depth, Index).pack_size();
813  assert((!Result || *Result == Size) && "inconsistent pack sizes");
814  Result = Size;
815  }
816 
817  return Result;
818 }
819 
821  const DeclSpec &DS = D.getDeclSpec();
822  switch (DS.getTypeSpecType()) {
823  case TST_typename:
824  case TST_typeofType:
825  case TST_underlyingType:
826  case TST_atomic: {
827  QualType T = DS.getRepAsType().get();
828  if (!T.isNull() && T->containsUnexpandedParameterPack())
829  return true;
830  break;
831  }
832 
833  case TST_typeofExpr:
834  case TST_decltype:
835  if (DS.getRepAsExpr() &&
837  return true;
838  break;
839 
840  case TST_unspecified:
841  case TST_void:
842  case TST_char:
843  case TST_wchar:
844  case TST_char8:
845  case TST_char16:
846  case TST_char32:
847  case TST_int:
848  case TST_int128:
849  case TST_half:
850  case TST_float:
851  case TST_double:
852  case TST_Accum:
853  case TST_Fract:
854  case TST_Float16:
855  case TST_float128:
856  case TST_bool:
857  case TST_decimal32:
858  case TST_decimal64:
859  case TST_decimal128:
860  case TST_enum:
861  case TST_union:
862  case TST_struct:
863  case TST_interface:
864  case TST_class:
865  case TST_auto:
866  case TST_auto_type:
867  case TST_decltype_auto:
868 #define GENERIC_IMAGE_TYPE(ImgType, Id) case TST_##ImgType##_t:
869 #include "clang/Basic/OpenCLImageTypes.def"
870  case TST_unknown_anytype:
871  case TST_error:
872  break;
873  }
874 
875  for (unsigned I = 0, N = D.getNumTypeObjects(); I != N; ++I) {
876  const DeclaratorChunk &Chunk = D.getTypeObject(I);
877  switch (Chunk.Kind) {
883  // These declarator chunks cannot contain any parameter packs.
884  break;
885 
887  if (Chunk.Arr.NumElts &&
889  return true;
890  break;
892  for (unsigned i = 0, e = Chunk.Fun.NumParams; i != e; ++i) {
893  ParmVarDecl *Param = cast<ParmVarDecl>(Chunk.Fun.Params[i].Param);
894  QualType ParamTy = Param->getType();
895  assert(!ParamTy.isNull() && "Couldn't parse type?");
896  if (ParamTy->containsUnexpandedParameterPack()) return true;
897  }
898 
899  if (Chunk.Fun.getExceptionSpecType() == EST_Dynamic) {
900  for (unsigned i = 0; i != Chunk.Fun.getNumExceptions(); ++i) {
901  if (Chunk.Fun.Exceptions[i]
902  .Ty.get()
904  return true;
905  }
906  } else if (isComputedNoexcept(Chunk.Fun.getExceptionSpecType()) &&
908  return true;
909 
910  if (Chunk.Fun.hasTrailingReturnType()) {
911  QualType T = Chunk.Fun.getTrailingReturnType().get();
912  if (!T.isNull() && T->containsUnexpandedParameterPack())
913  return true;
914  }
915  break;
916 
918  if (Chunk.Mem.Scope().getScopeRep() &&
920  return true;
921  break;
922  }
923  }
924 
925  return false;
926 }
927 
928 namespace {
929 
930 // Callback to only accept typo corrections that refer to parameter packs.
931 class ParameterPackValidatorCCC final : public CorrectionCandidateCallback {
932  public:
933  bool ValidateCandidate(const TypoCorrection &candidate) override {
934  NamedDecl *ND = candidate.getCorrectionDecl();
935  return ND && ND->isParameterPack();
936  }
937 
938  std::unique_ptr<CorrectionCandidateCallback> clone() override {
939  return llvm::make_unique<ParameterPackValidatorCCC>(*this);
940  }
941 };
942 
943 }
944 
945 /// Called when an expression computing the size of a parameter pack
946 /// is parsed.
947 ///
948 /// \code
949 /// template<typename ...Types> struct count {
950 /// static const unsigned value = sizeof...(Types);
951 /// };
952 /// \endcode
953 ///
954 //
955 /// \param OpLoc The location of the "sizeof" keyword.
956 /// \param Name The name of the parameter pack whose size will be determined.
957 /// \param NameLoc The source location of the name of the parameter pack.
958 /// \param RParenLoc The location of the closing parentheses.
960  SourceLocation OpLoc,
961  IdentifierInfo &Name,
962  SourceLocation NameLoc,
963  SourceLocation RParenLoc) {
964  // C++0x [expr.sizeof]p5:
965  // The identifier in a sizeof... expression shall name a parameter pack.
966  LookupResult R(*this, &Name, NameLoc, LookupOrdinaryName);
967  LookupName(R, S);
968 
969  NamedDecl *ParameterPack = nullptr;
970  switch (R.getResultKind()) {
971  case LookupResult::Found:
972  ParameterPack = R.getFoundDecl();
973  break;
974 
977  ParameterPackValidatorCCC CCC{};
978  if (TypoCorrection Corrected =
979  CorrectTypo(R.getLookupNameInfo(), R.getLookupKind(), S, nullptr,
980  CCC, CTK_ErrorRecovery)) {
981  diagnoseTypo(Corrected,
982  PDiag(diag::err_sizeof_pack_no_pack_name_suggest) << &Name,
983  PDiag(diag::note_parameter_pack_here));
984  ParameterPack = Corrected.getCorrectionDecl();
985  }
986  break;
987  }
990  break;
991 
993  DiagnoseAmbiguousLookup(R);
994  return ExprError();
995  }
996 
997  if (!ParameterPack || !ParameterPack->isParameterPack()) {
998  Diag(NameLoc, diag::err_sizeof_pack_no_pack_name)
999  << &Name;
1000  return ExprError();
1001  }
1002 
1003  MarkAnyDeclReferenced(OpLoc, ParameterPack, true);
1004 
1005  return SizeOfPackExpr::Create(Context, OpLoc, ParameterPack, NameLoc,
1006  RParenLoc);
1007 }
1008 
1011  TemplateArgumentLoc OrigLoc,
1012  SourceLocation &Ellipsis, Optional<unsigned> &NumExpansions) const {
1013  const TemplateArgument &Argument = OrigLoc.getArgument();
1014  assert(Argument.isPackExpansion());
1015  switch (Argument.getKind()) {
1016  case TemplateArgument::Type: {
1017  // FIXME: We shouldn't ever have to worry about missing
1018  // type-source info!
1019  TypeSourceInfo *ExpansionTSInfo = OrigLoc.getTypeSourceInfo();
1020  if (!ExpansionTSInfo)
1021  ExpansionTSInfo = Context.getTrivialTypeSourceInfo(Argument.getAsType(),
1022  Ellipsis);
1023  PackExpansionTypeLoc Expansion =
1024  ExpansionTSInfo->getTypeLoc().castAs<PackExpansionTypeLoc>();
1025  Ellipsis = Expansion.getEllipsisLoc();
1026 
1027  TypeLoc Pattern = Expansion.getPatternLoc();
1028  NumExpansions = Expansion.getTypePtr()->getNumExpansions();
1029 
1030  // We need to copy the TypeLoc because TemplateArgumentLocs store a
1031  // TypeSourceInfo.
1032  // FIXME: Find some way to avoid the copy?
1033  TypeLocBuilder TLB;
1034  TLB.pushFullCopy(Pattern);
1035  TypeSourceInfo *PatternTSInfo =
1036  TLB.getTypeSourceInfo(Context, Pattern.getType());
1037  return TemplateArgumentLoc(TemplateArgument(Pattern.getType()),
1038  PatternTSInfo);
1039  }
1040 
1042  PackExpansionExpr *Expansion
1043  = cast<PackExpansionExpr>(Argument.getAsExpr());
1044  Expr *Pattern = Expansion->getPattern();
1045  Ellipsis = Expansion->getEllipsisLoc();
1046  NumExpansions = Expansion->getNumExpansions();
1047  return TemplateArgumentLoc(Pattern, Pattern);
1048  }
1049 
1051  Ellipsis = OrigLoc.getTemplateEllipsisLoc();
1052  NumExpansions = Argument.getNumTemplateExpansions();
1053  return TemplateArgumentLoc(Argument.getPackExpansionPattern(),
1054  OrigLoc.getTemplateQualifierLoc(),
1055  OrigLoc.getTemplateNameLoc());
1056 
1063  return TemplateArgumentLoc();
1064  }
1065 
1066  llvm_unreachable("Invalid TemplateArgument Kind!");
1067 }
1068 
1070  assert(Arg.containsUnexpandedParameterPack());
1071 
1072  // If this is a substituted pack, grab that pack. If not, we don't know
1073  // the size yet.
1074  // FIXME: We could find a size in more cases by looking for a substituted
1075  // pack anywhere within this argument, but that's not necessary in the common
1076  // case for 'sizeof...(A)' handling.
1077  TemplateArgument Pack;
1078  switch (Arg.getKind()) {
1080  if (auto *Subst = Arg.getAsType()->getAs<SubstTemplateTypeParmPackType>())
1081  Pack = Subst->getArgumentPack();
1082  else
1083  return None;
1084  break;
1085 
1087  if (auto *Subst =
1088  dyn_cast<SubstNonTypeTemplateParmPackExpr>(Arg.getAsExpr()))
1089  Pack = Subst->getArgumentPack();
1090  else if (auto *Subst = dyn_cast<FunctionParmPackExpr>(Arg.getAsExpr())) {
1091  for (VarDecl *PD : *Subst)
1092  if (PD->isParameterPack())
1093  return None;
1094  return Subst->getNumExpansions();
1095  } else
1096  return None;
1097  break;
1098 
1102  Pack = Subst->getArgumentPack();
1103  else
1104  return None;
1105  break;
1106 
1113  return None;
1114  }
1115 
1116  // Check that no argument in the pack is itself a pack expansion.
1117  for (TemplateArgument Elem : Pack.pack_elements()) {
1118  // There's no point recursing in this case; we would have already
1119  // expanded this pack expansion into the enclosing pack if we could.
1120  if (Elem.isPackExpansion())
1121  return None;
1122  }
1123  return Pack.pack_size();
1124 }
1125 
1126 static void CheckFoldOperand(Sema &S, Expr *E) {
1127  if (!E)
1128  return;
1129 
1130  E = E->IgnoreImpCasts();
1131  auto *OCE = dyn_cast<CXXOperatorCallExpr>(E);
1132  if ((OCE && OCE->isInfixBinaryOp()) || isa<BinaryOperator>(E) ||
1133  isa<AbstractConditionalOperator>(E)) {
1134  S.Diag(E->getExprLoc(), diag::err_fold_expression_bad_operand)
1135  << E->getSourceRange()
1137  << FixItHint::CreateInsertion(E->getEndLoc(), ")");
1138  }
1139 }
1140 
1142  tok::TokenKind Operator,
1143  SourceLocation EllipsisLoc, Expr *RHS,
1144  SourceLocation RParenLoc) {
1145  // LHS and RHS must be cast-expressions. We allow an arbitrary expression
1146  // in the parser and reduce down to just cast-expressions here.
1147  CheckFoldOperand(*this, LHS);
1148  CheckFoldOperand(*this, RHS);
1149 
1150  auto DiscardOperands = [&] {
1151  CorrectDelayedTyposInExpr(LHS);
1152  CorrectDelayedTyposInExpr(RHS);
1153  };
1154 
1155  // [expr.prim.fold]p3:
1156  // In a binary fold, op1 and op2 shall be the same fold-operator, and
1157  // either e1 shall contain an unexpanded parameter pack or e2 shall contain
1158  // an unexpanded parameter pack, but not both.
1159  if (LHS && RHS &&
1162  DiscardOperands();
1163  return Diag(EllipsisLoc,
1165  ? diag::err_fold_expression_packs_both_sides
1166  : diag::err_pack_expansion_without_parameter_packs)
1167  << LHS->getSourceRange() << RHS->getSourceRange();
1168  }
1169 
1170  // [expr.prim.fold]p2:
1171  // In a unary fold, the cast-expression shall contain an unexpanded
1172  // parameter pack.
1173  if (!LHS || !RHS) {
1174  Expr *Pack = LHS ? LHS : RHS;
1175  assert(Pack && "fold expression with neither LHS nor RHS");
1176  DiscardOperands();
1177  if (!Pack->containsUnexpandedParameterPack())
1178  return Diag(EllipsisLoc, diag::err_pack_expansion_without_parameter_packs)
1179  << Pack->getSourceRange();
1180  }
1181 
1182  BinaryOperatorKind Opc = ConvertTokenKindToBinaryOpcode(Operator);
1183  return BuildCXXFoldExpr(LParenLoc, LHS, Opc, EllipsisLoc, RHS, RParenLoc,
1184  None);
1185 }
1186 
1188  BinaryOperatorKind Operator,
1189  SourceLocation EllipsisLoc, Expr *RHS,
1190  SourceLocation RParenLoc,
1191  Optional<unsigned> NumExpansions) {
1192  return new (Context) CXXFoldExpr(Context.DependentTy, LParenLoc, LHS,
1193  Operator, EllipsisLoc, RHS, RParenLoc,
1194  NumExpansions);
1195 }
1196 
1198  BinaryOperatorKind Operator) {
1199  // [temp.variadic]p9:
1200  // If N is zero for a unary fold-expression, the value of the expression is
1201  // && -> true
1202  // || -> false
1203  // , -> void()
1204  // if the operator is not listed [above], the instantiation is ill-formed.
1205  //
1206  // Note that we need to use something like int() here, not merely 0, to
1207  // prevent the result from being a null pointer constant.
1208  QualType ScalarType;
1209  switch (Operator) {
1210  case BO_LOr:
1211  return ActOnCXXBoolLiteral(EllipsisLoc, tok::kw_false);
1212  case BO_LAnd:
1213  return ActOnCXXBoolLiteral(EllipsisLoc, tok::kw_true);
1214  case BO_Comma:
1215  ScalarType = Context.VoidTy;
1216  break;
1217 
1218  default:
1219  return Diag(EllipsisLoc, diag::err_fold_expression_empty)
1220  << BinaryOperator::getOpcodeStr(Operator);
1221  }
1222 
1223  return new (Context) CXXScalarValueInitExpr(
1224  ScalarType, Context.getTrivialTypeSourceInfo(ScalarType, EllipsisLoc),
1225  EllipsisLoc);
1226 }
ParsedType getTrailingReturnType() const
Get the trailing-return-type for this function declarator.
Definition: DeclSpec.h:1490
A call to an overloaded operator written using operator syntax.
Definition: ExprCXX.h:77
SourceLocation getLoc() const
getLoc - Returns the main location of the declaration name.
Represents a function declaration or definition.
Definition: Decl.h:1748
Name lookup found a set of overloaded functions that met the criteria.
Definition: Lookup.h:63
UnexpandedParameterPackContext
The context in which an unexpanded parameter pack is being diagnosed.
Definition: Sema.h:6827
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.
ObjCDictionaryElement getKeyValueElement(unsigned Index) const
Definition: ExprObjC.h:360
const TypeClass * getTypePtr() const
Definition: TypeLoc.h:498
PtrTy get() const
Definition: Ownership.h:80
A (possibly-)qualified type.
Definition: Type.h:643
Simple class containing the result of Sema::CorrectTypo.
const TypeClass * getTypePtr() const
Definition: TypeLoc.h:405
const DeclaratorChunk & getTypeObject(unsigned i) const
Return the specified TypeInfo from this declarator.
Definition: DeclSpec.h:2189
NestedNameSpecifierLoc getTemplateQualifierLoc() const
Definition: TemplateBase.h:531
Stmt - This represents one statement.
Definition: Stmt.h:66
The template argument is an expression, and we&#39;ve not resolved it to one of the other forms yet...
Definition: TemplateBase.h:86
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
Emit a diagnostic.
Definition: Sema.h:1362
Decl - This represents one declaration (or definition), e.g.
Definition: DeclBase.h:88
Expr * getAsExpr() const
Retrieve the non-type template argument&#39;s expression.
bool isPackExpansion() const
Determine whether this is a pack expansion.
Definition: DeclCXX.h:3843
The base class of the type hierarchy.
Definition: Type.h:1418
One instance of this struct is used for each type in a declarator that is parsed. ...
Definition: DeclSpec.h:1158
The template argument is a declaration that was provided for a pointer, reference, or pointer to member non-type template parameter.
Definition: TemplateBase.h:63
A container of type source information.
Definition: Decl.h:86
bool isPackExpansion() const
Determine whether this capture is a pack expansion, which captures a function parameter pack...
Describes the capture of a variable or of this, or of a C++1y init-capture.
Definition: LambdaCapture.h:25
bool isPackExpansion() const
Determine whether this initializer is a pack expansion.
Definition: DeclCXX.h:2440
Retains information about a function, method, or block that is currently being parsed.
Definition: ScopeInfo.h:97
Represents a variable declaration or definition.
Definition: Decl.h:812
Information about one declarator, including the parsed type information and the identifier.
Definition: DeclSpec.h:1775
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6818
Represents an empty template argument, e.g., one that has not been deduced.
Definition: TemplateBase.h:56
void setBegin(SourceLocation b)
bool isParameterPack() const
Whether this declaration is a parameter pack.
Definition: DeclBase.cpp:210
unsigned getNumExceptions() const
Get the number of dynamic exception specifications.
Definition: DeclSpec.h:1473
Represents a parameter to a function.
Definition: Decl.h:1564
long i
Definition: xmmintrin.h:1456
enum clang::DeclaratorChunk::@217 Kind
IdentifierInfo * getIdentifier() const
Get the identifier that names this declaration, if there is one.
Definition: Decl.h:269
Base wrapper for a particular "section" of type source info.
Definition: TypeLoc.h:56
Expr * NoexceptExpr
Pointer to the expression in the noexcept-specifier of this function, if it has one.
Definition: DeclSpec.h:1339
ExprResult BuildCXXFoldExpr(SourceLocation LParenLoc, Expr *LHS, BinaryOperatorKind Operator, SourceLocation EllipsisLoc, Expr *RHS, SourceLocation RParenLoc, Optional< unsigned > NumExpansions)
One of these records is kept for each identifier that is lexed.
Name lookup results in an ambiguity; use getAmbiguityKind to figure out what kind of ambiguity we hav...
Definition: Lookup.h:73
TemplateArgument getPackExpansionPattern() const
When the template argument is a pack expansion, returns the pattern of the pack expansion.
An element in an Objective-C dictionary literal.
Definition: ExprObjC.h:261
Expr * getAsExpr() const
Retrieve the template argument as an expression.
Definition: TemplateBase.h:329
A C++ nested-name-specifier augmented with source location information.
TypeSourceInfo * getTypeSourceInfo() const
Definition: TemplateBase.h:506
The template argument is an integral value stored in an llvm::APSInt that was provided for an integra...
Definition: TemplateBase.h:71
TemplateDecl * getAsTemplateDecl() const
Retrieve the underlying template declaration that this template name refers to, if known...
Base class for callback objects used by Sema::CorrectTypo to check the validity of a potential typo c...
TypeSourceInfo * getTypeSourceInfo(ASTContext &Context, QualType T)
Creates a TypeSourceInfo for the given type.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:263
NameKind getNameKind() const
Determine what kind of name this is.
SubstTemplateTemplateParmPackStorage * getAsSubstTemplateTemplateParmPack() const
Retrieve the substituted template template parameter pack, if known.
SourceLocation getLocation() const
Retrieve the location of the template argument.
SourceLocation getLocation() const
Definition: TemplateBase.h:487
const DeclarationNameInfo & getLookupNameInfo() const
Gets the name info to look up.
Definition: Lookup.h:233
Optional< unsigned > getNumTemplateExpansions() const
Retrieve the number of expansions that a template template argument expansion will produce...
Represents the result of substituting a set of types for a template type parameter pack...
Definition: Type.h:4712
__SIZE_TYPE__ size_t
The unsigned integer type of the result of the sizeof operator.
Definition: opencl-c-base.h:40
A non-type template parameter, stored as an expression.
bool CheckParameterPacksForExpansion(SourceLocation EllipsisLoc, SourceRange PatternRange, ArrayRef< UnexpandedParameterPack > Unexpanded, const MultiLevelTemplateArgumentList &TemplateArgs, bool &ShouldExpand, bool &RetainExpansion, Optional< unsigned > &NumExpansions)
Determine whether we could expand a pack expansion with the given set of parameter packs into separat...
LookupResultKind getResultKind() const
Definition: Lookup.h:321
ParsedType getAsType() const
Retrieve the template type argument&#39;s type.
No entity found met the criteria within the current instantiation,, but there were dependent base cla...
Definition: Lookup.h:55
StringRef getOpcodeStr() const
Definition: Expr.h:3461
BinaryOperatorKind
Represents the results of name lookup.
Definition: Lookup.h:46
PtrTy get() const
Definition: Ownership.h:170
bool DiagnoseUnexpandedParameterPacks(SourceLocation Loc, UnexpandedParameterPackContext UPPC, ArrayRef< UnexpandedParameterPack > Unexpanded)
Diagnose unexpanded parameter packs.
ArrayTypeInfo Arr
Definition: DeclSpec.h:1529
FunctionTemplateDecl * getDescribedFunctionTemplate() const
Retrieves the function template that is described by this function declaration.
Definition: Decl.cpp:3443
unsigned getNumTypeObjects() const
Return the number of types applied to this declarator.
Definition: DeclSpec.h:2185
bool containsUnexpandedParameterPack() const
Whether this type is or contains an unexpanded parameter pack, used to support C++0x variadic templat...
Definition: Type.h:1844
SourceLocation getTemplateEllipsisLoc() const
Definition: TemplateBase.h:545
ExprResult ActOnCXXFoldExpr(SourceLocation LParenLoc, Expr *LHS, tok::TokenKind Operator, SourceLocation EllipsisLoc, Expr *RHS, SourceLocation RParenLoc)
Handle a C++1z fold-expression: ( expr op ... op expr ).
Scope - A scope is a transient data structure that is used while parsing the program.
Definition: Scope.h:40
Represents a C++ nested-name-specifier or a global scope specifier.
Definition: DeclSpec.h:63
Optional< unsigned > getFullyPackExpandedSize(TemplateArgument Arg)
Given a template argument that contains an unexpanded parameter pack, but which has already been subs...
Expr * Key
The key for the dictionary element.
Definition: ExprObjC.h:263
A C++ lambda expression, which produces a function object (of unspecified type) that can be invoked l...
Definition: ExprCXX.h:1722
A class that does preorder or postorder depth-first traversal on the entire Clang AST and visits each...
Expr * IgnoreImpCasts() LLVM_READONLY
Skip past any implicit casts which might surround this expression until reaching a fixed point...
Definition: Expr.cpp:2925
Contains information about the compound statement currently being parsed.
Definition: ScopeInfo.h:67
TyLocType push(QualType T)
Pushes space for a new TypeLoc of the given type.
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:328
bool containsUnexpandedParameterPack() const
Determines whether this template name contains an unexpanded parameter pack (for C++0x variadic templ...
A little helper class used to produce diagnostics.
Definition: Diagnostic.h:1044
std::pair< unsigned, unsigned > getDepthAndIndex(NamedDecl *ND)
Retrieve the depth and index of a template parameter.
Definition: SemaInternal.h:65
unsigned NumParams
NumParams - This is the number of formal parameters specified by the declarator.
Definition: DeclSpec.h:1298
SourceLocation getLocation() const
Definition: Expr.h:1225
SourceRange getRange() const
Definition: DeclSpec.h:68
TypeSourceInfo * getTrivialTypeSourceInfo(QualType T, SourceLocation Loc=SourceLocation()) const
Allocate a TypeSourceInfo where all locations have been initialized to a given location, which defaults to the empty location.
TST getTypeSpecType() const
Definition: DeclSpec.h:473
An expression "T()" which creates a value-initialized rvalue of type T, which is a non-class type...
Definition: ExprCXX.h:1953
TypeSourceInfo * CheckPackExpansion(TypeSourceInfo *Pattern, SourceLocation EllipsisLoc, Optional< unsigned > NumExpansions)
Construct a pack expansion type from the pattern of the pack expansion.
QualType getCXXNameType() const
If this name is one of the C++ names (of a constructor, destructor, or conversion function)...
This represents one expression.
Definition: Expr.h:108
bool containsUnexpandedParameterPacks(Declarator &D)
Determine whether the given declarator contains any unexpanded parameter packs.
bool isPackExpansion() const
Definition: Attr.h:105
The template argument is a null pointer or null pointer to member that was provided for a non-type te...
Definition: TemplateBase.h:67
bool isPackExpansion() const
Determine whether this is a pack expansion.
Definition: DeclCXX.h:3753
ObjCDictionaryLiteral - AST node to represent objective-c dictionary literals; as in:"name" : NSUserN...
Definition: ExprObjC.h:304
SourceLocation getBeginLoc() const
Definition: DeclSpec.h:72
SourceLocation getEllipsisLoc() const
Definition: TypeLoc.h:2211
TypeSourceInfo * getNamedTypeInfo() const
getNamedTypeInfo - Returns the source type info associated to the name.
Represents a C++ template name within the type system.
Definition: TemplateName.h:187
Defines the clang::TypeLoc interface and its subclasses.
int Depth
Definition: ASTDiff.cpp:190
void setEllipsisLoc(SourceLocation Loc)
Definition: TypeLoc.h:2215
Represents a folding of a pack over an operator.
Definition: ExprCXX.h:4439
Data structure that captures multiple levels of template argument lists for use in template instantia...
Definition: Template.h:64
bool isInvalid() const
Definition: Ownership.h:166
bool isPackExpansion() const
Determine whether this template argument is a pack expansion.
ValueDecl * getDecl()
Definition: Expr.h:1217
The result type of a method or function.
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:708
ParsedTemplateArgument ActOnPackExpansion(const ParsedTemplateArgument &Arg, SourceLocation EllipsisLoc)
Invoked when parsing a template argument followed by an ellipsis, which creates a pack expansion...
static StringRef getIdentifier(const Token &Tok)
SourceLocation getEndLoc() const LLVM_READONLY
Definition: Stmt.cpp:276
TypeAndRange * Exceptions
Pointer to a new[]&#39;d array of TypeAndRange objects that contain the types in the function&#39;s dynamic e...
Definition: DeclSpec.h:1335
NestedNameSpecifier * getScopeRep() const
Retrieve the representation of the nested-name-specifier.
Definition: DeclSpec.h:76
QualType getPackExpansionType(QualType Pattern, Optional< unsigned > NumExpansions)
const CXXScopeSpec & getScopeSpec() const
Retrieve the nested-name-specifier that precedes the template name in a template template argument...
bool isComputedNoexcept(ExceptionSpecificationType ESpecType)
static bool DiagnoseUnexpandedParameterPacks(Sema &S, TemplateTemplateParmDecl *TTP)
Check for unexpanded parameter packs within the template parameters of a template template parameter...
bool containsUnexpandedParameterPack() const
Whether this nested-name-specifier contains an unexpanded parameter pack (for C++11 variadic template...
TypeLoc getPatternLoc() const
Definition: TypeLoc.h:2227
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:153
Represents the parsed form of a C++ template argument.
Encodes a location in the source.
A structure for storing an already-substituted template template parameter pack.
Definition: TemplateName.h:130
unsigned getNumElements() const
getNumElements - Return number of elements of objective-c dictionary literal.
Definition: ExprObjC.h:358
DeclarationName getName() const
getName - Returns the embedded declaration name.
SourceLocation getEllipsisLoc() const
Retrieve the location of the ellipsis that describes this pack expansion.
Definition: ExprCXX.h:3952
static SizeOfPackExpr * Create(ASTContext &Context, SourceLocation OperatorLoc, NamedDecl *Pack, SourceLocation PackLoc, SourceLocation RParenLoc, Optional< unsigned > Length=None, ArrayRef< TemplateArgument > PartialArgs=None)
Definition: ExprCXX.cpp:1511
FunctionTypeInfo Fun
Definition: DeclSpec.h:1530
Represents a dependent using declaration which was not marked with typename.
Definition: DeclCXX.h:3699
KindType getKind() const
Determine what kind of template argument we have.
bool isPackExpansion() const
Determine whether this base specifier is a pack expansion.
Definition: DeclCXX.h:252
bool isParameterPack() const
Definition: Type.h:4620
Name lookup found an unresolvable value declaration and cannot yet complete.
Definition: Lookup.h:68
MemberPointerTypeInfo Mem
Definition: DeclSpec.h:1532
CanQualType VoidTy
Definition: ASTContext.h:1014
TokenKind
Provides a simple uniform namespace for tokens from all C languages.
Definition: TokenKinds.h:24
bool hasTrailingReturnType() const
Determine whether this function declarator had a trailing-return-type.
Definition: DeclSpec.h:1487
No entity found met the criteria.
Definition: Lookup.h:50
A template type parameter, stored as a type.
bool hasTemplateArgument(unsigned Depth, unsigned Index) const
Determine whether there is a non-NULL template argument at the given depth and index.
Definition: Template.h:109
Optional< unsigned > getNumExpansions() const
Retrieve the number of expansions that this pack expansion will generate, if known.
Definition: Type.h:5435
SourceLocation getExprLoc() const LLVM_READONLY
getExprLoc - Return the preferred location for the arrow when diagnosing a problem with a generic exp...
Definition: Expr.cpp:215
Expr * Value
The value of the dictionary element.
Definition: ExprObjC.h:266
Represents a pack expansion of types.
Definition: Type.h:5410
ArrayRef< TemplateArgument > pack_elements() const
Iterator range referencing all of the elements of a template argument pack.
Definition: TemplateBase.h:353
Represents a template argument.
Definition: TemplateBase.h:50
void collectUnexpandedParameterPacks(TemplateArgument Arg, SmallVectorImpl< UnexpandedParameterPack > &Unexpanded)
Collect the set of unexpanded parameter packs within the given template argument. ...
bool isNull() const
Determine whether this template name is NULL.
Dataflow Directional Tag Classes.
bool containsUnexpandedParameterPack() const
Whether this template argument contains an unexpanded parameter pack.
ParsedTemplateTy getAsTemplate() const
Retrieve the template template argument&#39;s template name.
DeducedType * getContainedDeducedType() const
Get the DeducedType whose type will be deduced for a variable with an initializer of this type...
Definition: Type.cpp:1754
const TemplateArgument & getArgument() const
Definition: TemplateBase.h:498
QualType getType() const
Get the type for which this source info wrapper provides information.
Definition: TypeLoc.h:130
The template argument is a pack expansion of a template name that was provided for a template templat...
Definition: TemplateBase.h:79
bool isInvalid() const
Determine whether the given template argument is invalid.
Represents a dependent using declaration which was marked with typename.
Definition: DeclCXX.h:3795
NamedDecl * getCorrectionDecl() const
Gets the pointer to the declaration of the typo correction.
NamedDecl * getFoundDecl() const
Fetch the unique decl found by this lookup.
Definition: Lookup.h:517
Represents a C++11 pack expansion that produces a sequence of expressions.
Definition: ExprCXX.h:3916
static void CheckFoldOperand(Sema &S, Expr *E)
DeclarationNameInfo - A collector data type for bundling together a DeclarationName and the correspnd...
TemplateParameterList * getTemplateParameterList() const
If this is a generic lambda expression, retrieve the template parameter list associated with it...
Definition: ExprCXX.cpp:1208
ExprResult BuildEmptyCXXFoldExpr(SourceLocation EllipsisLoc, BinaryOperatorKind Operator)
bool isNull() const
Determine whether this template argument has no value.
Definition: TemplateBase.h:237
bool isValid() const
A scope specifier is present, and it refers to a real scope.
Definition: DeclSpec.h:196
SourceRange getSourceRange() const LLVM_READONLY
Get the full source range.
Definition: TypeLoc.h:150
Name lookup found a single declaration that met the criteria.
Definition: Lookup.h:59
Location wrapper for a TemplateArgument.
Definition: TemplateBase.h:449
ParsedTemplateArgument getTemplatePackExpansion(SourceLocation EllipsisLoc) const
Retrieve a pack expansion of the given template template argument.
Represents a C++ base or member initializer.
Definition: DeclCXX.h:2338
CanQualType DependentTy
Definition: ASTContext.h:1043
unsigned getNumLevels() const
Determine the number of levels in this template argument list.
Definition: Template.h:88
The template argument is a type.
Definition: TemplateBase.h:59
static FixItHint CreateInsertion(SourceLocation InsertionLoc, StringRef Code, bool BeforePreviousInsertions=false)
Create a code modification hint that inserts the given code string at a specific location.
Definition: Diagnostic.h:91
ExceptionSpecificationType getExceptionSpecType() const
Get the type of exception specification this function has.
Definition: DeclSpec.h:1468
Sema::LookupNameKind getLookupKind() const
Gets the kind of lookup to perform.
Definition: Lookup.h:253
The template argument is actually a parameter pack.
Definition: TemplateBase.h:90
Represents a base class of a C++ class.
Definition: DeclCXX.h:192
bool isUnexpandedParameterPackPermitted()
Determine whether an unexpanded parameter pack might be permitted in this location.
TypeLoc getTypeLoc() const
Return the TypeLoc wrapper for the type source info.
Definition: TypeLoc.h:240
ArgKind getKind() const
Return the kind of stored template argument.
Definition: TemplateBase.h:234
unsigned getDepth() const
Definition: Type.h:4618
bool DiagnoseUnexpandedParameterPack(SourceLocation Loc, TypeSourceInfo *T, UnexpandedParameterPackContext UPPC)
If the given type contains an unexpanded parameter pack, diagnose the error.
Captures information about "declaration specifiers".
Definition: DeclSpec.h:228
The template argument is a template name that was provided for a template template parameter...
Definition: TemplateBase.h:75
Expr * NumElts
This is the size of the array, or null if [] or [*] was specified.
Definition: DeclSpec.h:1222
bool isPackExpansion() const
Determines whether this dictionary element is a pack expansion.
Definition: ExprObjC.h:276
const DeclSpec & getDeclSpec() const
getDeclSpec - Return the declaration-specifier that this declarator was declared with.
Definition: DeclSpec.h:1864
bool containsUnexpandedParameterPack() const
Whether this expression contains an unexpanded parameter pack (for C++11 variadic templates)...
Definition: Expr.h:223
Optional< unsigned > getNumExpansions() const
Determine the number of expansions that will be produced when this pack expansion is instantiated...
Definition: ExprCXX.h:3956
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:251
ParsedType getRepAsType() const
Definition: DeclSpec.h:482
SourceLocation getNameLoc() const
Definition: TypeLoc.h:519
Expr * getPattern()
Retrieve the pattern of the pack expansion.
Definition: ExprCXX.h:3945
ExprResult ExprError()
Definition: Ownership.h:279
QualType getAsType() const
Retrieve the type for a type template argument.
Definition: TemplateBase.h:256
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1141
Optional< unsigned > getNumArgumentsInExpansion(QualType T, const MultiLevelTemplateArgumentList &TemplateArgs)
Determine the number of arguments in the given pack expansion type.
__DEVICE__ int min(int __a, int __b)
SourceLocation getTemplateNameLoc() const
Definition: TemplateBase.h:538
SmallVector< CompoundScopeInfo, 4 > CompoundScopes
The stack of currently active compound stamement scopes in the function.
Definition: ScopeInfo.h:204
QualType getType() const
Definition: Decl.h:647
TemplateArgumentLoc getTemplateArgumentPackExpansionPattern(TemplateArgumentLoc OrigLoc, SourceLocation &Ellipsis, Optional< unsigned > &NumExpansions) const
Returns the pattern of the pack expansion for a template argument.
Wrapper for template type parameters.
Definition: TypeLoc.h:734
A trivial tuple used to represent a source range.
This represents a decl that may have a name.
Definition: Decl.h:248
Expr * getRepAsExpr() const
Definition: DeclSpec.h:490
T castAs() const
Convert to the specified TypeLoc type, asserting that this TypeLoc is of the desired type...
Definition: TypeLoc.h:75
A template template argument, stored as a template name.
TemplateName getAsTemplate() const
Retrieve the template name for a template name argument.
Definition: TemplateBase.h:280
void pushFullCopy(TypeLoc L)
Pushes a copy of the given TypeLoc onto this builder.
ExprResult ActOnSizeofParameterPackExpr(Scope *S, SourceLocation OpLoc, IdentifierInfo &Name, SourceLocation NameLoc, SourceLocation RParenLoc)
Called when an expression computing the size of a parameter pack is parsed.
SourceLocation getBegin() const
ParamInfo * Params
Params - This is a pointer to a new[]&#39;d array of ParamInfo objects that describe the parameters speci...
Definition: DeclSpec.h:1323
Attr - This represents one attribute.
Definition: Attr.h:43
QualType getType() const
Return the type wrapped by this type source info.
Definition: Decl.h:97