clang  10.0.0svn
SemaType.cpp
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1 //===--- SemaType.cpp - Semantic Analysis for Types -----------------------===//
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 //
9 // This file implements type-related semantic analysis.
10 //
11 //===----------------------------------------------------------------------===//
12 
13 #include "TypeLocBuilder.h"
14 #include "clang/AST/ASTConsumer.h"
15 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/DeclObjC.h"
20 #include "clang/AST/DeclTemplate.h"
21 #include "clang/AST/Expr.h"
22 #include "clang/AST/TypeLoc.h"
25 #include "clang/Basic/TargetInfo.h"
26 #include "clang/Lex/Preprocessor.h"
27 #include "clang/Sema/DeclSpec.h"
29 #include "clang/Sema/Lookup.h"
30 #include "clang/Sema/ScopeInfo.h"
32 #include "clang/Sema/Template.h"
34 #include "llvm/ADT/SmallPtrSet.h"
35 #include "llvm/ADT/SmallString.h"
36 #include "llvm/ADT/StringSwitch.h"
37 #include "llvm/Support/ErrorHandling.h"
38 
39 using namespace clang;
40 
45 };
46 
47 /// isOmittedBlockReturnType - Return true if this declarator is missing a
48 /// return type because this is a omitted return type on a block literal.
49 static bool isOmittedBlockReturnType(const Declarator &D) {
52  return false;
53 
54  if (D.getNumTypeObjects() == 0)
55  return true; // ^{ ... }
56 
57  if (D.getNumTypeObjects() == 1 &&
59  return true; // ^(int X, float Y) { ... }
60 
61  return false;
62 }
63 
64 /// diagnoseBadTypeAttribute - Diagnoses a type attribute which
65 /// doesn't apply to the given type.
66 static void diagnoseBadTypeAttribute(Sema &S, const ParsedAttr &attr,
67  QualType type) {
68  TypeDiagSelector WhichType;
69  bool useExpansionLoc = true;
70  switch (attr.getKind()) {
71  case ParsedAttr::AT_ObjCGC:
72  WhichType = TDS_Pointer;
73  break;
74  case ParsedAttr::AT_ObjCOwnership:
75  WhichType = TDS_ObjCObjOrBlock;
76  break;
77  default:
78  // Assume everything else was a function attribute.
79  WhichType = TDS_Function;
80  useExpansionLoc = false;
81  break;
82  }
83 
84  SourceLocation loc = attr.getLoc();
85  StringRef name = attr.getAttrName()->getName();
86 
87  // The GC attributes are usually written with macros; special-case them.
88  IdentifierInfo *II = attr.isArgIdent(0) ? attr.getArgAsIdent(0)->Ident
89  : nullptr;
90  if (useExpansionLoc && loc.isMacroID() && II) {
91  if (II->isStr("strong")) {
92  if (S.findMacroSpelling(loc, "__strong")) name = "__strong";
93  } else if (II->isStr("weak")) {
94  if (S.findMacroSpelling(loc, "__weak")) name = "__weak";
95  }
96  }
97 
98  S.Diag(loc, diag::warn_type_attribute_wrong_type) << name << WhichType
99  << type;
100 }
101 
102 // objc_gc applies to Objective-C pointers or, otherwise, to the
103 // smallest available pointer type (i.e. 'void*' in 'void**').
104 #define OBJC_POINTER_TYPE_ATTRS_CASELIST \
105  case ParsedAttr::AT_ObjCGC: \
106  case ParsedAttr::AT_ObjCOwnership
107 
108 // Calling convention attributes.
109 #define CALLING_CONV_ATTRS_CASELIST \
110  case ParsedAttr::AT_CDecl: \
111  case ParsedAttr::AT_FastCall: \
112  case ParsedAttr::AT_StdCall: \
113  case ParsedAttr::AT_ThisCall: \
114  case ParsedAttr::AT_RegCall: \
115  case ParsedAttr::AT_Pascal: \
116  case ParsedAttr::AT_SwiftCall: \
117  case ParsedAttr::AT_VectorCall: \
118  case ParsedAttr::AT_AArch64VectorPcs: \
119  case ParsedAttr::AT_MSABI: \
120  case ParsedAttr::AT_SysVABI: \
121  case ParsedAttr::AT_Pcs: \
122  case ParsedAttr::AT_IntelOclBicc: \
123  case ParsedAttr::AT_PreserveMost: \
124  case ParsedAttr::AT_PreserveAll
125 
126 // Function type attributes.
127 #define FUNCTION_TYPE_ATTRS_CASELIST \
128  case ParsedAttr::AT_NSReturnsRetained: \
129  case ParsedAttr::AT_NoReturn: \
130  case ParsedAttr::AT_Regparm: \
131  case ParsedAttr::AT_AnyX86NoCallerSavedRegisters: \
132  case ParsedAttr::AT_AnyX86NoCfCheck: \
133  CALLING_CONV_ATTRS_CASELIST
134 
135 // Microsoft-specific type qualifiers.
136 #define MS_TYPE_ATTRS_CASELIST \
137  case ParsedAttr::AT_Ptr32: \
138  case ParsedAttr::AT_Ptr64: \
139  case ParsedAttr::AT_SPtr: \
140  case ParsedAttr::AT_UPtr
141 
142 // Nullability qualifiers.
143 #define NULLABILITY_TYPE_ATTRS_CASELIST \
144  case ParsedAttr::AT_TypeNonNull: \
145  case ParsedAttr::AT_TypeNullable: \
146  case ParsedAttr::AT_TypeNullUnspecified
147 
148 namespace {
149  /// An object which stores processing state for the entire
150  /// GetTypeForDeclarator process.
151  class TypeProcessingState {
152  Sema &sema;
153 
154  /// The declarator being processed.
155  Declarator &declarator;
156 
157  /// The index of the declarator chunk we're currently processing.
158  /// May be the total number of valid chunks, indicating the
159  /// DeclSpec.
160  unsigned chunkIndex;
161 
162  /// Whether there are non-trivial modifications to the decl spec.
163  bool trivial;
164 
165  /// Whether we saved the attributes in the decl spec.
166  bool hasSavedAttrs;
167 
168  /// The original set of attributes on the DeclSpec.
169  SmallVector<ParsedAttr *, 2> savedAttrs;
170 
171  /// A list of attributes to diagnose the uselessness of when the
172  /// processing is complete.
173  SmallVector<ParsedAttr *, 2> ignoredTypeAttrs;
174 
175  /// Attributes corresponding to AttributedTypeLocs that we have not yet
176  /// populated.
177  // FIXME: The two-phase mechanism by which we construct Types and fill
178  // their TypeLocs makes it hard to correctly assign these. We keep the
179  // attributes in creation order as an attempt to make them line up
180  // properly.
181  using TypeAttrPair = std::pair<const AttributedType*, const Attr*>;
182  SmallVector<TypeAttrPair, 8> AttrsForTypes;
183  bool AttrsForTypesSorted = true;
184 
185  /// MacroQualifiedTypes mapping to macro expansion locations that will be
186  /// stored in a MacroQualifiedTypeLoc.
187  llvm::DenseMap<const MacroQualifiedType *, SourceLocation> LocsForMacros;
188 
189  /// Flag to indicate we parsed a noderef attribute. This is used for
190  /// validating that noderef was used on a pointer or array.
191  bool parsedNoDeref;
192 
193  public:
194  TypeProcessingState(Sema &sema, Declarator &declarator)
195  : sema(sema), declarator(declarator),
196  chunkIndex(declarator.getNumTypeObjects()), trivial(true),
197  hasSavedAttrs(false), parsedNoDeref(false) {}
198 
199  Sema &getSema() const {
200  return sema;
201  }
202 
203  Declarator &getDeclarator() const {
204  return declarator;
205  }
206 
207  bool isProcessingDeclSpec() const {
208  return chunkIndex == declarator.getNumTypeObjects();
209  }
210 
211  unsigned getCurrentChunkIndex() const {
212  return chunkIndex;
213  }
214 
215  void setCurrentChunkIndex(unsigned idx) {
216  assert(idx <= declarator.getNumTypeObjects());
217  chunkIndex = idx;
218  }
219 
220  ParsedAttributesView &getCurrentAttributes() const {
221  if (isProcessingDeclSpec())
222  return getMutableDeclSpec().getAttributes();
223  return declarator.getTypeObject(chunkIndex).getAttrs();
224  }
225 
226  /// Save the current set of attributes on the DeclSpec.
227  void saveDeclSpecAttrs() {
228  // Don't try to save them multiple times.
229  if (hasSavedAttrs) return;
230 
231  DeclSpec &spec = getMutableDeclSpec();
232  for (ParsedAttr &AL : spec.getAttributes())
233  savedAttrs.push_back(&AL);
234  trivial &= savedAttrs.empty();
235  hasSavedAttrs = true;
236  }
237 
238  /// Record that we had nowhere to put the given type attribute.
239  /// We will diagnose such attributes later.
240  void addIgnoredTypeAttr(ParsedAttr &attr) {
241  ignoredTypeAttrs.push_back(&attr);
242  }
243 
244  /// Diagnose all the ignored type attributes, given that the
245  /// declarator worked out to the given type.
246  void diagnoseIgnoredTypeAttrs(QualType type) const {
247  for (auto *Attr : ignoredTypeAttrs)
248  diagnoseBadTypeAttribute(getSema(), *Attr, type);
249  }
250 
251  /// Get an attributed type for the given attribute, and remember the Attr
252  /// object so that we can attach it to the AttributedTypeLoc.
253  QualType getAttributedType(Attr *A, QualType ModifiedType,
254  QualType EquivType) {
255  QualType T =
256  sema.Context.getAttributedType(A->getKind(), ModifiedType, EquivType);
257  AttrsForTypes.push_back({cast<AttributedType>(T.getTypePtr()), A});
258  AttrsForTypesSorted = false;
259  return T;
260  }
261 
262  /// Completely replace the \c auto in \p TypeWithAuto by
263  /// \p Replacement. Also replace \p TypeWithAuto in \c TypeAttrPair if
264  /// necessary.
265  QualType ReplaceAutoType(QualType TypeWithAuto, QualType Replacement) {
266  QualType T = sema.ReplaceAutoType(TypeWithAuto, Replacement);
267  if (auto *AttrTy = TypeWithAuto->getAs<AttributedType>()) {
268  // Attributed type still should be an attributed type after replacement.
269  auto *NewAttrTy = cast<AttributedType>(T.getTypePtr());
270  for (TypeAttrPair &A : AttrsForTypes) {
271  if (A.first == AttrTy)
272  A.first = NewAttrTy;
273  }
274  AttrsForTypesSorted = false;
275  }
276  return T;
277  }
278 
279  /// Extract and remove the Attr* for a given attributed type.
280  const Attr *takeAttrForAttributedType(const AttributedType *AT) {
281  if (!AttrsForTypesSorted) {
282  llvm::stable_sort(AttrsForTypes, llvm::less_first());
283  AttrsForTypesSorted = true;
284  }
285 
286  // FIXME: This is quadratic if we have lots of reuses of the same
287  // attributed type.
288  for (auto It = std::partition_point(
289  AttrsForTypes.begin(), AttrsForTypes.end(),
290  [=](const TypeAttrPair &A) { return A.first < AT; });
291  It != AttrsForTypes.end() && It->first == AT; ++It) {
292  if (It->second) {
293  const Attr *Result = It->second;
294  It->second = nullptr;
295  return Result;
296  }
297  }
298 
299  llvm_unreachable("no Attr* for AttributedType*");
300  }
301 
303  getExpansionLocForMacroQualifiedType(const MacroQualifiedType *MQT) const {
304  auto FoundLoc = LocsForMacros.find(MQT);
305  assert(FoundLoc != LocsForMacros.end() &&
306  "Unable to find macro expansion location for MacroQualifedType");
307  return FoundLoc->second;
308  }
309 
310  void setExpansionLocForMacroQualifiedType(const MacroQualifiedType *MQT,
311  SourceLocation Loc) {
312  LocsForMacros[MQT] = Loc;
313  }
314 
315  void setParsedNoDeref(bool parsed) { parsedNoDeref = parsed; }
316 
317  bool didParseNoDeref() const { return parsedNoDeref; }
318 
319  ~TypeProcessingState() {
320  if (trivial) return;
321 
322  restoreDeclSpecAttrs();
323  }
324 
325  private:
326  DeclSpec &getMutableDeclSpec() const {
327  return const_cast<DeclSpec&>(declarator.getDeclSpec());
328  }
329 
330  void restoreDeclSpecAttrs() {
331  assert(hasSavedAttrs);
332 
333  getMutableDeclSpec().getAttributes().clearListOnly();
334  for (ParsedAttr *AL : savedAttrs)
335  getMutableDeclSpec().getAttributes().addAtEnd(AL);
336  }
337  };
338 } // end anonymous namespace
339 
341  ParsedAttributesView &fromList,
342  ParsedAttributesView &toList) {
343  fromList.remove(&attr);
344  toList.addAtEnd(&attr);
345 }
346 
347 /// The location of a type attribute.
349  /// The attribute is in the decl-specifier-seq.
351  /// The attribute is part of a DeclaratorChunk.
353  /// The attribute is immediately after the declaration's name.
355 };
356 
357 static void processTypeAttrs(TypeProcessingState &state, QualType &type,
359 
360 static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
361  QualType &type);
362 
363 static bool handleMSPointerTypeQualifierAttr(TypeProcessingState &state,
364  ParsedAttr &attr, QualType &type);
365 
366 static bool handleObjCGCTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
367  QualType &type);
368 
369 static bool handleObjCOwnershipTypeAttr(TypeProcessingState &state,
370  ParsedAttr &attr, QualType &type);
371 
372 static bool handleObjCPointerTypeAttr(TypeProcessingState &state,
373  ParsedAttr &attr, QualType &type) {
374  if (attr.getKind() == ParsedAttr::AT_ObjCGC)
375  return handleObjCGCTypeAttr(state, attr, type);
376  assert(attr.getKind() == ParsedAttr::AT_ObjCOwnership);
377  return handleObjCOwnershipTypeAttr(state, attr, type);
378 }
379 
380 /// Given the index of a declarator chunk, check whether that chunk
381 /// directly specifies the return type of a function and, if so, find
382 /// an appropriate place for it.
383 ///
384 /// \param i - a notional index which the search will start
385 /// immediately inside
386 ///
387 /// \param onlyBlockPointers Whether we should only look into block
388 /// pointer types (vs. all pointer types).
390  unsigned i,
391  bool onlyBlockPointers) {
392  assert(i <= declarator.getNumTypeObjects());
393 
394  DeclaratorChunk *result = nullptr;
395 
396  // First, look inwards past parens for a function declarator.
397  for (; i != 0; --i) {
398  DeclaratorChunk &fnChunk = declarator.getTypeObject(i-1);
399  switch (fnChunk.Kind) {
401  continue;
402 
403  // If we find anything except a function, bail out.
410  return result;
411 
412  // If we do find a function declarator, scan inwards from that,
413  // looking for a (block-)pointer declarator.
415  for (--i; i != 0; --i) {
416  DeclaratorChunk &ptrChunk = declarator.getTypeObject(i-1);
417  switch (ptrChunk.Kind) {
423  continue;
424 
427  if (onlyBlockPointers)
428  continue;
429 
430  LLVM_FALLTHROUGH;
431 
433  result = &ptrChunk;
434  goto continue_outer;
435  }
436  llvm_unreachable("bad declarator chunk kind");
437  }
438 
439  // If we run out of declarators doing that, we're done.
440  return result;
441  }
442  llvm_unreachable("bad declarator chunk kind");
443 
444  // Okay, reconsider from our new point.
445  continue_outer: ;
446  }
447 
448  // Ran out of chunks, bail out.
449  return result;
450 }
451 
452 /// Given that an objc_gc attribute was written somewhere on a
453 /// declaration *other* than on the declarator itself (for which, use
454 /// distributeObjCPointerTypeAttrFromDeclarator), and given that it
455 /// didn't apply in whatever position it was written in, try to move
456 /// it to a more appropriate position.
457 static void distributeObjCPointerTypeAttr(TypeProcessingState &state,
458  ParsedAttr &attr, QualType type) {
459  Declarator &declarator = state.getDeclarator();
460 
461  // Move it to the outermost normal or block pointer declarator.
462  for (unsigned i = state.getCurrentChunkIndex(); i != 0; --i) {
463  DeclaratorChunk &chunk = declarator.getTypeObject(i-1);
464  switch (chunk.Kind) {
467  // But don't move an ARC ownership attribute to the return type
468  // of a block.
469  DeclaratorChunk *destChunk = nullptr;
470  if (state.isProcessingDeclSpec() &&
471  attr.getKind() == ParsedAttr::AT_ObjCOwnership)
472  destChunk = maybeMovePastReturnType(declarator, i - 1,
473  /*onlyBlockPointers=*/true);
474  if (!destChunk) destChunk = &chunk;
475 
476  moveAttrFromListToList(attr, state.getCurrentAttributes(),
477  destChunk->getAttrs());
478  return;
479  }
480 
483  continue;
484 
485  // We may be starting at the return type of a block.
487  if (state.isProcessingDeclSpec() &&
488  attr.getKind() == ParsedAttr::AT_ObjCOwnership) {
490  declarator, i,
491  /*onlyBlockPointers=*/true)) {
492  moveAttrFromListToList(attr, state.getCurrentAttributes(),
493  dest->getAttrs());
494  return;
495  }
496  }
497  goto error;
498 
499  // Don't walk through these.
503  goto error;
504  }
505  }
506  error:
507 
508  diagnoseBadTypeAttribute(state.getSema(), attr, type);
509 }
510 
511 /// Distribute an objc_gc type attribute that was written on the
512 /// declarator.
514  TypeProcessingState &state, ParsedAttr &attr, QualType &declSpecType) {
515  Declarator &declarator = state.getDeclarator();
516 
517  // objc_gc goes on the innermost pointer to something that's not a
518  // pointer.
519  unsigned innermost = -1U;
520  bool considerDeclSpec = true;
521  for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
522  DeclaratorChunk &chunk = declarator.getTypeObject(i);
523  switch (chunk.Kind) {
526  innermost = i;
527  continue;
528 
534  continue;
535 
537  considerDeclSpec = false;
538  goto done;
539  }
540  }
541  done:
542 
543  // That might actually be the decl spec if we weren't blocked by
544  // anything in the declarator.
545  if (considerDeclSpec) {
546  if (handleObjCPointerTypeAttr(state, attr, declSpecType)) {
547  // Splice the attribute into the decl spec. Prevents the
548  // attribute from being applied multiple times and gives
549  // the source-location-filler something to work with.
550  state.saveDeclSpecAttrs();
552  declarator.getAttributes(), &attr);
553  return;
554  }
555  }
556 
557  // Otherwise, if we found an appropriate chunk, splice the attribute
558  // into it.
559  if (innermost != -1U) {
560  moveAttrFromListToList(attr, declarator.getAttributes(),
561  declarator.getTypeObject(innermost).getAttrs());
562  return;
563  }
564 
565  // Otherwise, diagnose when we're done building the type.
566  declarator.getAttributes().remove(&attr);
567  state.addIgnoredTypeAttr(attr);
568 }
569 
570 /// A function type attribute was written somewhere in a declaration
571 /// *other* than on the declarator itself or in the decl spec. Given
572 /// that it didn't apply in whatever position it was written in, try
573 /// to move it to a more appropriate position.
574 static void distributeFunctionTypeAttr(TypeProcessingState &state,
575  ParsedAttr &attr, QualType type) {
576  Declarator &declarator = state.getDeclarator();
577 
578  // Try to push the attribute from the return type of a function to
579  // the function itself.
580  for (unsigned i = state.getCurrentChunkIndex(); i != 0; --i) {
581  DeclaratorChunk &chunk = declarator.getTypeObject(i-1);
582  switch (chunk.Kind) {
584  moveAttrFromListToList(attr, state.getCurrentAttributes(),
585  chunk.getAttrs());
586  return;
587 
595  continue;
596  }
597  }
598 
599  diagnoseBadTypeAttribute(state.getSema(), attr, type);
600 }
601 
602 /// Try to distribute a function type attribute to the innermost
603 /// function chunk or type. Returns true if the attribute was
604 /// distributed, false if no location was found.
606  TypeProcessingState &state, ParsedAttr &attr,
607  ParsedAttributesView &attrList, QualType &declSpecType) {
608  Declarator &declarator = state.getDeclarator();
609 
610  // Put it on the innermost function chunk, if there is one.
611  for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
612  DeclaratorChunk &chunk = declarator.getTypeObject(i);
613  if (chunk.Kind != DeclaratorChunk::Function) continue;
614 
615  moveAttrFromListToList(attr, attrList, chunk.getAttrs());
616  return true;
617  }
618 
619  return handleFunctionTypeAttr(state, attr, declSpecType);
620 }
621 
622 /// A function type attribute was written in the decl spec. Try to
623 /// apply it somewhere.
624 static void distributeFunctionTypeAttrFromDeclSpec(TypeProcessingState &state,
625  ParsedAttr &attr,
626  QualType &declSpecType) {
627  state.saveDeclSpecAttrs();
628 
629  // C++11 attributes before the decl specifiers actually appertain to
630  // the declarators. Move them straight there. We don't support the
631  // 'put them wherever you like' semantics we allow for GNU attributes.
632  if (attr.isCXX11Attribute()) {
633  moveAttrFromListToList(attr, state.getCurrentAttributes(),
634  state.getDeclarator().getAttributes());
635  return;
636  }
637 
638  // Try to distribute to the innermost.
640  state, attr, state.getCurrentAttributes(), declSpecType))
641  return;
642 
643  // If that failed, diagnose the bad attribute when the declarator is
644  // fully built.
645  state.addIgnoredTypeAttr(attr);
646 }
647 
648 /// A function type attribute was written on the declarator. Try to
649 /// apply it somewhere.
650 static void distributeFunctionTypeAttrFromDeclarator(TypeProcessingState &state,
651  ParsedAttr &attr,
652  QualType &declSpecType) {
653  Declarator &declarator = state.getDeclarator();
654 
655  // Try to distribute to the innermost.
657  state, attr, declarator.getAttributes(), declSpecType))
658  return;
659 
660  // If that failed, diagnose the bad attribute when the declarator is
661  // fully built.
662  declarator.getAttributes().remove(&attr);
663  state.addIgnoredTypeAttr(attr);
664 }
665 
666 /// Given that there are attributes written on the declarator
667 /// itself, try to distribute any type attributes to the appropriate
668 /// declarator chunk.
669 ///
670 /// These are attributes like the following:
671 /// int f ATTR;
672 /// int (f ATTR)();
673 /// but not necessarily this:
674 /// int f() ATTR;
675 static void distributeTypeAttrsFromDeclarator(TypeProcessingState &state,
676  QualType &declSpecType) {
677  // Collect all the type attributes from the declarator itself.
678  assert(!state.getDeclarator().getAttributes().empty() &&
679  "declarator has no attrs!");
680  // The called functions in this loop actually remove things from the current
681  // list, so iterating over the existing list isn't possible. Instead, make a
682  // non-owning copy and iterate over that.
683  ParsedAttributesView AttrsCopy{state.getDeclarator().getAttributes()};
684  for (ParsedAttr &attr : AttrsCopy) {
685  // Do not distribute C++11 attributes. They have strict rules for what
686  // they appertain to.
687  if (attr.isCXX11Attribute())
688  continue;
689 
690  switch (attr.getKind()) {
692  distributeObjCPointerTypeAttrFromDeclarator(state, attr, declSpecType);
693  break;
694 
696  distributeFunctionTypeAttrFromDeclarator(state, attr, declSpecType);
697  break;
698 
700  // Microsoft type attributes cannot go after the declarator-id.
701  continue;
702 
704  // Nullability specifiers cannot go after the declarator-id.
705 
706  // Objective-C __kindof does not get distributed.
707  case ParsedAttr::AT_ObjCKindOf:
708  continue;
709 
710  default:
711  break;
712  }
713  }
714 }
715 
716 /// Add a synthetic '()' to a block-literal declarator if it is
717 /// required, given the return type.
718 static void maybeSynthesizeBlockSignature(TypeProcessingState &state,
719  QualType declSpecType) {
720  Declarator &declarator = state.getDeclarator();
721 
722  // First, check whether the declarator would produce a function,
723  // i.e. whether the innermost semantic chunk is a function.
724  if (declarator.isFunctionDeclarator()) {
725  // If so, make that declarator a prototyped declarator.
726  declarator.getFunctionTypeInfo().hasPrototype = true;
727  return;
728  }
729 
730  // If there are any type objects, the type as written won't name a
731  // function, regardless of the decl spec type. This is because a
732  // block signature declarator is always an abstract-declarator, and
733  // abstract-declarators can't just be parentheses chunks. Therefore
734  // we need to build a function chunk unless there are no type
735  // objects and the decl spec type is a function.
736  if (!declarator.getNumTypeObjects() && declSpecType->isFunctionType())
737  return;
738 
739  // Note that there *are* cases with invalid declarators where
740  // declarators consist solely of parentheses. In general, these
741  // occur only in failed efforts to make function declarators, so
742  // faking up the function chunk is still the right thing to do.
743 
744  // Otherwise, we need to fake up a function declarator.
745  SourceLocation loc = declarator.getBeginLoc();
746 
747  // ...and *prepend* it to the declarator.
748  SourceLocation NoLoc;
750  /*HasProto=*/true,
751  /*IsAmbiguous=*/false,
752  /*LParenLoc=*/NoLoc,
753  /*ArgInfo=*/nullptr,
754  /*NumParams=*/0,
755  /*EllipsisLoc=*/NoLoc,
756  /*RParenLoc=*/NoLoc,
757  /*RefQualifierIsLvalueRef=*/true,
758  /*RefQualifierLoc=*/NoLoc,
759  /*MutableLoc=*/NoLoc, EST_None,
760  /*ESpecRange=*/SourceRange(),
761  /*Exceptions=*/nullptr,
762  /*ExceptionRanges=*/nullptr,
763  /*NumExceptions=*/0,
764  /*NoexceptExpr=*/nullptr,
765  /*ExceptionSpecTokens=*/nullptr,
766  /*DeclsInPrototype=*/None, loc, loc, declarator));
767 
768  // For consistency, make sure the state still has us as processing
769  // the decl spec.
770  assert(state.getCurrentChunkIndex() == declarator.getNumTypeObjects() - 1);
771  state.setCurrentChunkIndex(declarator.getNumTypeObjects());
772 }
773 
775  unsigned &TypeQuals,
776  QualType TypeSoFar,
777  unsigned RemoveTQs,
778  unsigned DiagID) {
779  // If this occurs outside a template instantiation, warn the user about
780  // it; they probably didn't mean to specify a redundant qualifier.
781  typedef std::pair<DeclSpec::TQ, SourceLocation> QualLoc;
782  for (QualLoc Qual : {QualLoc(DeclSpec::TQ_const, DS.getConstSpecLoc()),
785  QualLoc(DeclSpec::TQ_atomic, DS.getAtomicSpecLoc())}) {
786  if (!(RemoveTQs & Qual.first))
787  continue;
788 
789  if (!S.inTemplateInstantiation()) {
790  if (TypeQuals & Qual.first)
791  S.Diag(Qual.second, DiagID)
792  << DeclSpec::getSpecifierName(Qual.first) << TypeSoFar
793  << FixItHint::CreateRemoval(Qual.second);
794  }
795 
796  TypeQuals &= ~Qual.first;
797  }
798 }
799 
800 /// Return true if this is omitted block return type. Also check type
801 /// attributes and type qualifiers when returning true.
802 static bool checkOmittedBlockReturnType(Sema &S, Declarator &declarator,
803  QualType Result) {
804  if (!isOmittedBlockReturnType(declarator))
805  return false;
806 
807  // Warn if we see type attributes for omitted return type on a block literal.
808  SmallVector<ParsedAttr *, 2> ToBeRemoved;
809  for (ParsedAttr &AL : declarator.getMutableDeclSpec().getAttributes()) {
810  if (AL.isInvalid() || !AL.isTypeAttr())
811  continue;
812  S.Diag(AL.getLoc(),
813  diag::warn_block_literal_attributes_on_omitted_return_type)
814  << AL;
815  ToBeRemoved.push_back(&AL);
816  }
817  // Remove bad attributes from the list.
818  for (ParsedAttr *AL : ToBeRemoved)
819  declarator.getMutableDeclSpec().getAttributes().remove(AL);
820 
821  // Warn if we see type qualifiers for omitted return type on a block literal.
822  const DeclSpec &DS = declarator.getDeclSpec();
823  unsigned TypeQuals = DS.getTypeQualifiers();
824  diagnoseAndRemoveTypeQualifiers(S, DS, TypeQuals, Result, (unsigned)-1,
825  diag::warn_block_literal_qualifiers_on_omitted_return_type);
827 
828  return true;
829 }
830 
831 /// Apply Objective-C type arguments to the given type.
834  SourceRange typeArgsRange,
835  bool failOnError = false) {
836  // We can only apply type arguments to an Objective-C class type.
837  const auto *objcObjectType = type->getAs<ObjCObjectType>();
838  if (!objcObjectType || !objcObjectType->getInterface()) {
839  S.Diag(loc, diag::err_objc_type_args_non_class)
840  << type
841  << typeArgsRange;
842 
843  if (failOnError)
844  return QualType();
845  return type;
846  }
847 
848  // The class type must be parameterized.
849  ObjCInterfaceDecl *objcClass = objcObjectType->getInterface();
850  ObjCTypeParamList *typeParams = objcClass->getTypeParamList();
851  if (!typeParams) {
852  S.Diag(loc, diag::err_objc_type_args_non_parameterized_class)
853  << objcClass->getDeclName()
854  << FixItHint::CreateRemoval(typeArgsRange);
855 
856  if (failOnError)
857  return QualType();
858 
859  return type;
860  }
861 
862  // The type must not already be specialized.
863  if (objcObjectType->isSpecialized()) {
864  S.Diag(loc, diag::err_objc_type_args_specialized_class)
865  << type
866  << FixItHint::CreateRemoval(typeArgsRange);
867 
868  if (failOnError)
869  return QualType();
870 
871  return type;
872  }
873 
874  // Check the type arguments.
875  SmallVector<QualType, 4> finalTypeArgs;
876  unsigned numTypeParams = typeParams->size();
877  bool anyPackExpansions = false;
878  for (unsigned i = 0, n = typeArgs.size(); i != n; ++i) {
879  TypeSourceInfo *typeArgInfo = typeArgs[i];
880  QualType typeArg = typeArgInfo->getType();
881 
882  // Type arguments cannot have explicit qualifiers or nullability.
883  // We ignore indirect sources of these, e.g. behind typedefs or
884  // template arguments.
885  if (TypeLoc qual = typeArgInfo->getTypeLoc().findExplicitQualifierLoc()) {
886  bool diagnosed = false;
887  SourceRange rangeToRemove;
888  if (auto attr = qual.getAs<AttributedTypeLoc>()) {
889  rangeToRemove = attr.getLocalSourceRange();
890  if (attr.getTypePtr()->getImmediateNullability()) {
891  typeArg = attr.getTypePtr()->getModifiedType();
892  S.Diag(attr.getBeginLoc(),
893  diag::err_objc_type_arg_explicit_nullability)
894  << typeArg << FixItHint::CreateRemoval(rangeToRemove);
895  diagnosed = true;
896  }
897  }
898 
899  if (!diagnosed) {
900  S.Diag(qual.getBeginLoc(), diag::err_objc_type_arg_qualified)
901  << typeArg << typeArg.getQualifiers().getAsString()
902  << FixItHint::CreateRemoval(rangeToRemove);
903  }
904  }
905 
906  // Remove qualifiers even if they're non-local.
907  typeArg = typeArg.getUnqualifiedType();
908 
909  finalTypeArgs.push_back(typeArg);
910 
911  if (typeArg->getAs<PackExpansionType>())
912  anyPackExpansions = true;
913 
914  // Find the corresponding type parameter, if there is one.
915  ObjCTypeParamDecl *typeParam = nullptr;
916  if (!anyPackExpansions) {
917  if (i < numTypeParams) {
918  typeParam = typeParams->begin()[i];
919  } else {
920  // Too many arguments.
921  S.Diag(loc, diag::err_objc_type_args_wrong_arity)
922  << false
923  << objcClass->getDeclName()
924  << (unsigned)typeArgs.size()
925  << numTypeParams;
926  S.Diag(objcClass->getLocation(), diag::note_previous_decl)
927  << objcClass;
928 
929  if (failOnError)
930  return QualType();
931 
932  return type;
933  }
934  }
935 
936  // Objective-C object pointer types must be substitutable for the bounds.
937  if (const auto *typeArgObjC = typeArg->getAs<ObjCObjectPointerType>()) {
938  // If we don't have a type parameter to match against, assume
939  // everything is fine. There was a prior pack expansion that
940  // means we won't be able to match anything.
941  if (!typeParam) {
942  assert(anyPackExpansions && "Too many arguments?");
943  continue;
944  }
945 
946  // Retrieve the bound.
947  QualType bound = typeParam->getUnderlyingType();
948  const auto *boundObjC = bound->getAs<ObjCObjectPointerType>();
949 
950  // Determine whether the type argument is substitutable for the bound.
951  if (typeArgObjC->isObjCIdType()) {
952  // When the type argument is 'id', the only acceptable type
953  // parameter bound is 'id'.
954  if (boundObjC->isObjCIdType())
955  continue;
956  } else if (S.Context.canAssignObjCInterfaces(boundObjC, typeArgObjC)) {
957  // Otherwise, we follow the assignability rules.
958  continue;
959  }
960 
961  // Diagnose the mismatch.
962  S.Diag(typeArgInfo->getTypeLoc().getBeginLoc(),
963  diag::err_objc_type_arg_does_not_match_bound)
964  << typeArg << bound << typeParam->getDeclName();
965  S.Diag(typeParam->getLocation(), diag::note_objc_type_param_here)
966  << typeParam->getDeclName();
967 
968  if (failOnError)
969  return QualType();
970 
971  return type;
972  }
973 
974  // Block pointer types are permitted for unqualified 'id' bounds.
975  if (typeArg->isBlockPointerType()) {
976  // If we don't have a type parameter to match against, assume
977  // everything is fine. There was a prior pack expansion that
978  // means we won't be able to match anything.
979  if (!typeParam) {
980  assert(anyPackExpansions && "Too many arguments?");
981  continue;
982  }
983 
984  // Retrieve the bound.
985  QualType bound = typeParam->getUnderlyingType();
987  continue;
988 
989  // Diagnose the mismatch.
990  S.Diag(typeArgInfo->getTypeLoc().getBeginLoc(),
991  diag::err_objc_type_arg_does_not_match_bound)
992  << typeArg << bound << typeParam->getDeclName();
993  S.Diag(typeParam->getLocation(), diag::note_objc_type_param_here)
994  << typeParam->getDeclName();
995 
996  if (failOnError)
997  return QualType();
998 
999  return type;
1000  }
1001 
1002  // Dependent types will be checked at instantiation time.
1003  if (typeArg->isDependentType()) {
1004  continue;
1005  }
1006 
1007  // Diagnose non-id-compatible type arguments.
1008  S.Diag(typeArgInfo->getTypeLoc().getBeginLoc(),
1009  diag::err_objc_type_arg_not_id_compatible)
1010  << typeArg << typeArgInfo->getTypeLoc().getSourceRange();
1011 
1012  if (failOnError)
1013  return QualType();
1014 
1015  return type;
1016  }
1017 
1018  // Make sure we didn't have the wrong number of arguments.
1019  if (!anyPackExpansions && finalTypeArgs.size() != numTypeParams) {
1020  S.Diag(loc, diag::err_objc_type_args_wrong_arity)
1021  << (typeArgs.size() < typeParams->size())
1022  << objcClass->getDeclName()
1023  << (unsigned)finalTypeArgs.size()
1024  << (unsigned)numTypeParams;
1025  S.Diag(objcClass->getLocation(), diag::note_previous_decl)
1026  << objcClass;
1027 
1028  if (failOnError)
1029  return QualType();
1030 
1031  return type;
1032  }
1033 
1034  // Success. Form the specialized type.
1035  return S.Context.getObjCObjectType(type, finalTypeArgs, { }, false);
1036 }
1037 
1039  SourceLocation ProtocolLAngleLoc,
1040  ArrayRef<ObjCProtocolDecl *> Protocols,
1041  ArrayRef<SourceLocation> ProtocolLocs,
1042  SourceLocation ProtocolRAngleLoc,
1043  bool FailOnError) {
1044  QualType Result = QualType(Decl->getTypeForDecl(), 0);
1045  if (!Protocols.empty()) {
1046  bool HasError;
1047  Result = Context.applyObjCProtocolQualifiers(Result, Protocols,
1048  HasError);
1049  if (HasError) {
1050  Diag(SourceLocation(), diag::err_invalid_protocol_qualifiers)
1051  << SourceRange(ProtocolLAngleLoc, ProtocolRAngleLoc);
1052  if (FailOnError) Result = QualType();
1053  }
1054  if (FailOnError && Result.isNull())
1055  return QualType();
1056  }
1057 
1058  return Result;
1059 }
1060 
1062  SourceLocation Loc,
1063  SourceLocation TypeArgsLAngleLoc,
1064  ArrayRef<TypeSourceInfo *> TypeArgs,
1065  SourceLocation TypeArgsRAngleLoc,
1066  SourceLocation ProtocolLAngleLoc,
1067  ArrayRef<ObjCProtocolDecl *> Protocols,
1068  ArrayRef<SourceLocation> ProtocolLocs,
1069  SourceLocation ProtocolRAngleLoc,
1070  bool FailOnError) {
1071  QualType Result = BaseType;
1072  if (!TypeArgs.empty()) {
1073  Result = applyObjCTypeArgs(*this, Loc, Result, TypeArgs,
1074  SourceRange(TypeArgsLAngleLoc,
1075  TypeArgsRAngleLoc),
1076  FailOnError);
1077  if (FailOnError && Result.isNull())
1078  return QualType();
1079  }
1080 
1081  if (!Protocols.empty()) {
1082  bool HasError;
1083  Result = Context.applyObjCProtocolQualifiers(Result, Protocols,
1084  HasError);
1085  if (HasError) {
1086  Diag(Loc, diag::err_invalid_protocol_qualifiers)
1087  << SourceRange(ProtocolLAngleLoc, ProtocolRAngleLoc);
1088  if (FailOnError) Result = QualType();
1089  }
1090  if (FailOnError && Result.isNull())
1091  return QualType();
1092  }
1093 
1094  return Result;
1095 }
1096 
1098  SourceLocation lAngleLoc,
1099  ArrayRef<Decl *> protocols,
1100  ArrayRef<SourceLocation> protocolLocs,
1101  SourceLocation rAngleLoc) {
1102  // Form id<protocol-list>.
1103  QualType Result = Context.getObjCObjectType(
1104  Context.ObjCBuiltinIdTy, { },
1105  llvm::makeArrayRef(
1106  (ObjCProtocolDecl * const *)protocols.data(),
1107  protocols.size()),
1108  false);
1109  Result = Context.getObjCObjectPointerType(Result);
1110 
1111  TypeSourceInfo *ResultTInfo = Context.CreateTypeSourceInfo(Result);
1112  TypeLoc ResultTL = ResultTInfo->getTypeLoc();
1113 
1114  auto ObjCObjectPointerTL = ResultTL.castAs<ObjCObjectPointerTypeLoc>();
1115  ObjCObjectPointerTL.setStarLoc(SourceLocation()); // implicit
1116 
1117  auto ObjCObjectTL = ObjCObjectPointerTL.getPointeeLoc()
1118  .castAs<ObjCObjectTypeLoc>();
1119  ObjCObjectTL.setHasBaseTypeAsWritten(false);
1120  ObjCObjectTL.getBaseLoc().initialize(Context, SourceLocation());
1121 
1122  // No type arguments.
1123  ObjCObjectTL.setTypeArgsLAngleLoc(SourceLocation());
1124  ObjCObjectTL.setTypeArgsRAngleLoc(SourceLocation());
1125 
1126  // Fill in protocol qualifiers.
1127  ObjCObjectTL.setProtocolLAngleLoc(lAngleLoc);
1128  ObjCObjectTL.setProtocolRAngleLoc(rAngleLoc);
1129  for (unsigned i = 0, n = protocols.size(); i != n; ++i)
1130  ObjCObjectTL.setProtocolLoc(i, protocolLocs[i]);
1131 
1132  // We're done. Return the completed type to the parser.
1133  return CreateParsedType(Result, ResultTInfo);
1134 }
1135 
1137  Scope *S,
1138  SourceLocation Loc,
1139  ParsedType BaseType,
1140  SourceLocation TypeArgsLAngleLoc,
1141  ArrayRef<ParsedType> TypeArgs,
1142  SourceLocation TypeArgsRAngleLoc,
1143  SourceLocation ProtocolLAngleLoc,
1144  ArrayRef<Decl *> Protocols,
1145  ArrayRef<SourceLocation> ProtocolLocs,
1146  SourceLocation ProtocolRAngleLoc) {
1147  TypeSourceInfo *BaseTypeInfo = nullptr;
1148  QualType T = GetTypeFromParser(BaseType, &BaseTypeInfo);
1149  if (T.isNull())
1150  return true;
1151 
1152  // Handle missing type-source info.
1153  if (!BaseTypeInfo)
1154  BaseTypeInfo = Context.getTrivialTypeSourceInfo(T, Loc);
1155 
1156  // Extract type arguments.
1157  SmallVector<TypeSourceInfo *, 4> ActualTypeArgInfos;
1158  for (unsigned i = 0, n = TypeArgs.size(); i != n; ++i) {
1159  TypeSourceInfo *TypeArgInfo = nullptr;
1160  QualType TypeArg = GetTypeFromParser(TypeArgs[i], &TypeArgInfo);
1161  if (TypeArg.isNull()) {
1162  ActualTypeArgInfos.clear();
1163  break;
1164  }
1165 
1166  assert(TypeArgInfo && "No type source info?");
1167  ActualTypeArgInfos.push_back(TypeArgInfo);
1168  }
1169 
1170  // Build the object type.
1171  QualType Result = BuildObjCObjectType(
1172  T, BaseTypeInfo->getTypeLoc().getSourceRange().getBegin(),
1173  TypeArgsLAngleLoc, ActualTypeArgInfos, TypeArgsRAngleLoc,
1174  ProtocolLAngleLoc,
1175  llvm::makeArrayRef((ObjCProtocolDecl * const *)Protocols.data(),
1176  Protocols.size()),
1177  ProtocolLocs, ProtocolRAngleLoc,
1178  /*FailOnError=*/false);
1179 
1180  if (Result == T)
1181  return BaseType;
1182 
1183  // Create source information for this type.
1184  TypeSourceInfo *ResultTInfo = Context.CreateTypeSourceInfo(Result);
1185  TypeLoc ResultTL = ResultTInfo->getTypeLoc();
1186 
1187  // For id<Proto1, Proto2> or Class<Proto1, Proto2>, we'll have an
1188  // object pointer type. Fill in source information for it.
1189  if (auto ObjCObjectPointerTL = ResultTL.getAs<ObjCObjectPointerTypeLoc>()) {
1190  // The '*' is implicit.
1191  ObjCObjectPointerTL.setStarLoc(SourceLocation());
1192  ResultTL = ObjCObjectPointerTL.getPointeeLoc();
1193  }
1194 
1195  if (auto OTPTL = ResultTL.getAs<ObjCTypeParamTypeLoc>()) {
1196  // Protocol qualifier information.
1197  if (OTPTL.getNumProtocols() > 0) {
1198  assert(OTPTL.getNumProtocols() == Protocols.size());
1199  OTPTL.setProtocolLAngleLoc(ProtocolLAngleLoc);
1200  OTPTL.setProtocolRAngleLoc(ProtocolRAngleLoc);
1201  for (unsigned i = 0, n = Protocols.size(); i != n; ++i)
1202  OTPTL.setProtocolLoc(i, ProtocolLocs[i]);
1203  }
1204 
1205  // We're done. Return the completed type to the parser.
1206  return CreateParsedType(Result, ResultTInfo);
1207  }
1208 
1209  auto ObjCObjectTL = ResultTL.castAs<ObjCObjectTypeLoc>();
1210 
1211  // Type argument information.
1212  if (ObjCObjectTL.getNumTypeArgs() > 0) {
1213  assert(ObjCObjectTL.getNumTypeArgs() == ActualTypeArgInfos.size());
1214  ObjCObjectTL.setTypeArgsLAngleLoc(TypeArgsLAngleLoc);
1215  ObjCObjectTL.setTypeArgsRAngleLoc(TypeArgsRAngleLoc);
1216  for (unsigned i = 0, n = ActualTypeArgInfos.size(); i != n; ++i)
1217  ObjCObjectTL.setTypeArgTInfo(i, ActualTypeArgInfos[i]);
1218  } else {
1219  ObjCObjectTL.setTypeArgsLAngleLoc(SourceLocation());
1220  ObjCObjectTL.setTypeArgsRAngleLoc(SourceLocation());
1221  }
1222 
1223  // Protocol qualifier information.
1224  if (ObjCObjectTL.getNumProtocols() > 0) {
1225  assert(ObjCObjectTL.getNumProtocols() == Protocols.size());
1226  ObjCObjectTL.setProtocolLAngleLoc(ProtocolLAngleLoc);
1227  ObjCObjectTL.setProtocolRAngleLoc(ProtocolRAngleLoc);
1228  for (unsigned i = 0, n = Protocols.size(); i != n; ++i)
1229  ObjCObjectTL.setProtocolLoc(i, ProtocolLocs[i]);
1230  } else {
1231  ObjCObjectTL.setProtocolLAngleLoc(SourceLocation());
1232  ObjCObjectTL.setProtocolRAngleLoc(SourceLocation());
1233  }
1234 
1235  // Base type.
1236  ObjCObjectTL.setHasBaseTypeAsWritten(true);
1237  if (ObjCObjectTL.getType() == T)
1238  ObjCObjectTL.getBaseLoc().initializeFullCopy(BaseTypeInfo->getTypeLoc());
1239  else
1240  ObjCObjectTL.getBaseLoc().initialize(Context, Loc);
1241 
1242  // We're done. Return the completed type to the parser.
1243  return CreateParsedType(Result, ResultTInfo);
1244 }
1245 
1246 static OpenCLAccessAttr::Spelling
1248  for (const ParsedAttr &AL : Attrs)
1249  if (AL.getKind() == ParsedAttr::AT_OpenCLAccess)
1250  return static_cast<OpenCLAccessAttr::Spelling>(AL.getSemanticSpelling());
1251  return OpenCLAccessAttr::Keyword_read_only;
1252 }
1253 
1254 /// Convert the specified declspec to the appropriate type
1255 /// object.
1256 /// \param state Specifies the declarator containing the declaration specifier
1257 /// to be converted, along with other associated processing state.
1258 /// \returns The type described by the declaration specifiers. This function
1259 /// never returns null.
1260 static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
1261  // FIXME: Should move the logic from DeclSpec::Finish to here for validity
1262  // checking.
1263 
1264  Sema &S = state.getSema();
1265  Declarator &declarator = state.getDeclarator();
1266  DeclSpec &DS = declarator.getMutableDeclSpec();
1267  SourceLocation DeclLoc = declarator.getIdentifierLoc();
1268  if (DeclLoc.isInvalid())
1269  DeclLoc = DS.getBeginLoc();
1270 
1271  ASTContext &Context = S.Context;
1272 
1273  QualType Result;
1274  switch (DS.getTypeSpecType()) {
1275  case DeclSpec::TST_void:
1276  Result = Context.VoidTy;
1277  break;
1278  case DeclSpec::TST_char:
1280  Result = Context.CharTy;
1281  else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed)
1282  Result = Context.SignedCharTy;
1283  else {
1284  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
1285  "Unknown TSS value");
1286  Result = Context.UnsignedCharTy;
1287  }
1288  break;
1289  case DeclSpec::TST_wchar:
1291  Result = Context.WCharTy;
1292  else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed) {
1293  S.Diag(DS.getTypeSpecSignLoc(), diag::ext_wchar_t_sign_spec)
1294  << DS.getSpecifierName(DS.getTypeSpecType(),
1295  Context.getPrintingPolicy());
1296  Result = Context.getSignedWCharType();
1297  } else {
1298  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
1299  "Unknown TSS value");
1300  S.Diag(DS.getTypeSpecSignLoc(), diag::ext_wchar_t_sign_spec)
1301  << DS.getSpecifierName(DS.getTypeSpecType(),
1302  Context.getPrintingPolicy());
1303  Result = Context.getUnsignedWCharType();
1304  }
1305  break;
1306  case DeclSpec::TST_char8:
1307  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
1308  "Unknown TSS value");
1309  Result = Context.Char8Ty;
1310  break;
1311  case DeclSpec::TST_char16:
1312  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
1313  "Unknown TSS value");
1314  Result = Context.Char16Ty;
1315  break;
1316  case DeclSpec::TST_char32:
1317  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
1318  "Unknown TSS value");
1319  Result = Context.Char32Ty;
1320  break;
1322  // If this is a missing declspec in a block literal return context, then it
1323  // is inferred from the return statements inside the block.
1324  // The declspec is always missing in a lambda expr context; it is either
1325  // specified with a trailing return type or inferred.
1326  if (S.getLangOpts().CPlusPlus14 &&
1328  // In C++1y, a lambda's implicit return type is 'auto'.
1329  Result = Context.getAutoDeductType();
1330  break;
1331  } else if (declarator.getContext() ==
1333  checkOmittedBlockReturnType(S, declarator,
1334  Context.DependentTy)) {
1335  Result = Context.DependentTy;
1336  break;
1337  }
1338 
1339  // Unspecified typespec defaults to int in C90. However, the C90 grammar
1340  // [C90 6.5] only allows a decl-spec if there was *some* type-specifier,
1341  // type-qualifier, or storage-class-specifier. If not, emit an extwarn.
1342  // Note that the one exception to this is function definitions, which are
1343  // allowed to be completely missing a declspec. This is handled in the
1344  // parser already though by it pretending to have seen an 'int' in this
1345  // case.
1346  if (S.getLangOpts().ImplicitInt) {
1347  // In C89 mode, we only warn if there is a completely missing declspec
1348  // when one is not allowed.
1349  if (DS.isEmpty()) {
1350  S.Diag(DeclLoc, diag::ext_missing_declspec)
1351  << DS.getSourceRange()
1352  << FixItHint::CreateInsertion(DS.getBeginLoc(), "int");
1353  }
1354  } else if (!DS.hasTypeSpecifier()) {
1355  // C99 and C++ require a type specifier. For example, C99 6.7.2p2 says:
1356  // "At least one type specifier shall be given in the declaration
1357  // specifiers in each declaration, and in the specifier-qualifier list in
1358  // each struct declaration and type name."
1359  if (S.getLangOpts().CPlusPlus && !DS.isTypeSpecPipe()) {
1360  S.Diag(DeclLoc, diag::err_missing_type_specifier)
1361  << DS.getSourceRange();
1362 
1363  // When this occurs in C++ code, often something is very broken with the
1364  // value being declared, poison it as invalid so we don't get chains of
1365  // errors.
1366  declarator.setInvalidType(true);
1367  } else if ((S.getLangOpts().OpenCLVersion >= 200 ||
1368  S.getLangOpts().OpenCLCPlusPlus) &&
1369  DS.isTypeSpecPipe()) {
1370  S.Diag(DeclLoc, diag::err_missing_actual_pipe_type)
1371  << DS.getSourceRange();
1372  declarator.setInvalidType(true);
1373  } else {
1374  S.Diag(DeclLoc, diag::ext_missing_type_specifier)
1375  << DS.getSourceRange();
1376  }
1377  }
1378 
1379  LLVM_FALLTHROUGH;
1380  case DeclSpec::TST_int: {
1382  switch (DS.getTypeSpecWidth()) {
1383  case DeclSpec::TSW_unspecified: Result = Context.IntTy; break;
1384  case DeclSpec::TSW_short: Result = Context.ShortTy; break;
1385  case DeclSpec::TSW_long: Result = Context.LongTy; break;
1387  Result = Context.LongLongTy;
1388 
1389  // 'long long' is a C99 or C++11 feature.
1390  if (!S.getLangOpts().C99) {
1391  if (S.getLangOpts().CPlusPlus)
1392  S.Diag(DS.getTypeSpecWidthLoc(),
1393  S.getLangOpts().CPlusPlus11 ?
1394  diag::warn_cxx98_compat_longlong : diag::ext_cxx11_longlong);
1395  else
1396  S.Diag(DS.getTypeSpecWidthLoc(), diag::ext_c99_longlong);
1397  }
1398  break;
1399  }
1400  } else {
1401  switch (DS.getTypeSpecWidth()) {
1402  case DeclSpec::TSW_unspecified: Result = Context.UnsignedIntTy; break;
1403  case DeclSpec::TSW_short: Result = Context.UnsignedShortTy; break;
1404  case DeclSpec::TSW_long: Result = Context.UnsignedLongTy; break;
1406  Result = Context.UnsignedLongLongTy;
1407 
1408  // 'long long' is a C99 or C++11 feature.
1409  if (!S.getLangOpts().C99) {
1410  if (S.getLangOpts().CPlusPlus)
1411  S.Diag(DS.getTypeSpecWidthLoc(),
1412  S.getLangOpts().CPlusPlus11 ?
1413  diag::warn_cxx98_compat_longlong : diag::ext_cxx11_longlong);
1414  else
1415  S.Diag(DS.getTypeSpecWidthLoc(), diag::ext_c99_longlong);
1416  }
1417  break;
1418  }
1419  }
1420  break;
1421  }
1422  case DeclSpec::TST_accum: {
1423  switch (DS.getTypeSpecWidth()) {
1424  case DeclSpec::TSW_short:
1425  Result = Context.ShortAccumTy;
1426  break;
1428  Result = Context.AccumTy;
1429  break;
1430  case DeclSpec::TSW_long:
1431  Result = Context.LongAccumTy;
1432  break;
1434  llvm_unreachable("Unable to specify long long as _Accum width");
1435  }
1436 
1438  Result = Context.getCorrespondingUnsignedType(Result);
1439 
1440  if (DS.isTypeSpecSat())
1441  Result = Context.getCorrespondingSaturatedType(Result);
1442 
1443  break;
1444  }
1445  case DeclSpec::TST_fract: {
1446  switch (DS.getTypeSpecWidth()) {
1447  case DeclSpec::TSW_short:
1448  Result = Context.ShortFractTy;
1449  break;
1451  Result = Context.FractTy;
1452  break;
1453  case DeclSpec::TSW_long:
1454  Result = Context.LongFractTy;
1455  break;
1457  llvm_unreachable("Unable to specify long long as _Fract width");
1458  }
1459 
1461  Result = Context.getCorrespondingUnsignedType(Result);
1462 
1463  if (DS.isTypeSpecSat())
1464  Result = Context.getCorrespondingSaturatedType(Result);
1465 
1466  break;
1467  }
1468  case DeclSpec::TST_int128:
1469  if (!S.Context.getTargetInfo().hasInt128Type() &&
1470  !(S.getLangOpts().OpenMP && S.getLangOpts().OpenMPIsDevice))
1471  S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_unsupported)
1472  << "__int128";
1474  Result = Context.UnsignedInt128Ty;
1475  else
1476  Result = Context.Int128Ty;
1477  break;
1478  case DeclSpec::TST_float16:
1479  // CUDA host and device may have different _Float16 support, therefore
1480  // do not diagnose _Float16 usage to avoid false alarm.
1481  // ToDo: more precise diagnostics for CUDA.
1482  if (!S.Context.getTargetInfo().hasFloat16Type() && !S.getLangOpts().CUDA &&
1483  !(S.getLangOpts().OpenMP && S.getLangOpts().OpenMPIsDevice))
1484  S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_unsupported)
1485  << "_Float16";
1486  Result = Context.Float16Ty;
1487  break;
1488  case DeclSpec::TST_half: Result = Context.HalfTy; break;
1489  case DeclSpec::TST_float: Result = Context.FloatTy; break;
1490  case DeclSpec::TST_double:
1492  Result = Context.LongDoubleTy;
1493  else
1494  Result = Context.DoubleTy;
1495  break;
1498  !(S.getLangOpts().OpenMP && S.getLangOpts().OpenMPIsDevice))
1499  S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_unsupported)
1500  << "__float128";
1501  Result = Context.Float128Ty;
1502  break;
1503  case DeclSpec::TST_bool: Result = Context.BoolTy; break; // _Bool or bool
1504  break;
1505  case DeclSpec::TST_decimal32: // _Decimal32
1506  case DeclSpec::TST_decimal64: // _Decimal64
1507  case DeclSpec::TST_decimal128: // _Decimal128
1508  S.Diag(DS.getTypeSpecTypeLoc(), diag::err_decimal_unsupported);
1509  Result = Context.IntTy;
1510  declarator.setInvalidType(true);
1511  break;
1512  case DeclSpec::TST_class:
1513  case DeclSpec::TST_enum:
1514  case DeclSpec::TST_union:
1515  case DeclSpec::TST_struct:
1516  case DeclSpec::TST_interface: {
1517  TagDecl *D = dyn_cast_or_null<TagDecl>(DS.getRepAsDecl());
1518  if (!D) {
1519  // This can happen in C++ with ambiguous lookups.
1520  Result = Context.IntTy;
1521  declarator.setInvalidType(true);
1522  break;
1523  }
1524 
1525  // If the type is deprecated or unavailable, diagnose it.
1527 
1528  assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
1529  DS.getTypeSpecSign() == 0 && "No qualifiers on tag names!");
1530 
1531  // TypeQuals handled by caller.
1532  Result = Context.getTypeDeclType(D);
1533 
1534  // In both C and C++, make an ElaboratedType.
1535  ElaboratedTypeKeyword Keyword
1537  Result = S.getElaboratedType(Keyword, DS.getTypeSpecScope(), Result,
1538  DS.isTypeSpecOwned() ? D : nullptr);
1539  break;
1540  }
1541  case DeclSpec::TST_typename: {
1542  assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
1543  DS.getTypeSpecSign() == 0 &&
1544  "Can't handle qualifiers on typedef names yet!");
1545  Result = S.GetTypeFromParser(DS.getRepAsType());
1546  if (Result.isNull()) {
1547  declarator.setInvalidType(true);
1548  }
1549 
1550  // TypeQuals handled by caller.
1551  break;
1552  }
1554  // FIXME: Preserve type source info.
1555  Result = S.GetTypeFromParser(DS.getRepAsType());
1556  assert(!Result.isNull() && "Didn't get a type for typeof?");
1557  if (!Result->isDependentType())
1558  if (const TagType *TT = Result->getAs<TagType>())
1559  S.DiagnoseUseOfDecl(TT->getDecl(), DS.getTypeSpecTypeLoc());
1560  // TypeQuals handled by caller.
1561  Result = Context.getTypeOfType(Result);
1562  break;
1563  case DeclSpec::TST_typeofExpr: {
1564  Expr *E = DS.getRepAsExpr();
1565  assert(E && "Didn't get an expression for typeof?");
1566  // TypeQuals handled by caller.
1567  Result = S.BuildTypeofExprType(E, DS.getTypeSpecTypeLoc());
1568  if (Result.isNull()) {
1569  Result = Context.IntTy;
1570  declarator.setInvalidType(true);
1571  }
1572  break;
1573  }
1574  case DeclSpec::TST_decltype: {
1575  Expr *E = DS.getRepAsExpr();
1576  assert(E && "Didn't get an expression for decltype?");
1577  // TypeQuals handled by caller.
1578  Result = S.BuildDecltypeType(E, DS.getTypeSpecTypeLoc());
1579  if (Result.isNull()) {
1580  Result = Context.IntTy;
1581  declarator.setInvalidType(true);
1582  }
1583  break;
1584  }
1586  Result = S.GetTypeFromParser(DS.getRepAsType());
1587  assert(!Result.isNull() && "Didn't get a type for __underlying_type?");
1588  Result = S.BuildUnaryTransformType(Result,
1590  DS.getTypeSpecTypeLoc());
1591  if (Result.isNull()) {
1592  Result = Context.IntTy;
1593  declarator.setInvalidType(true);
1594  }
1595  break;
1596 
1597  case DeclSpec::TST_auto:
1598  Result = Context.getAutoType(QualType(), AutoTypeKeyword::Auto, false);
1599  break;
1600 
1602  Result = Context.getAutoType(QualType(), AutoTypeKeyword::GNUAutoType, false);
1603  break;
1604 
1607  /*IsDependent*/ false);
1608  break;
1609 
1611  Result = Context.UnknownAnyTy;
1612  break;
1613 
1614  case DeclSpec::TST_atomic:
1615  Result = S.GetTypeFromParser(DS.getRepAsType());
1616  assert(!Result.isNull() && "Didn't get a type for _Atomic?");
1617  Result = S.BuildAtomicType(Result, DS.getTypeSpecTypeLoc());
1618  if (Result.isNull()) {
1619  Result = Context.IntTy;
1620  declarator.setInvalidType(true);
1621  }
1622  break;
1623 
1624 #define GENERIC_IMAGE_TYPE(ImgType, Id) \
1625  case DeclSpec::TST_##ImgType##_t: \
1626  switch (getImageAccess(DS.getAttributes())) { \
1627  case OpenCLAccessAttr::Keyword_write_only: \
1628  Result = Context.Id##WOTy; \
1629  break; \
1630  case OpenCLAccessAttr::Keyword_read_write: \
1631  Result = Context.Id##RWTy; \
1632  break; \
1633  case OpenCLAccessAttr::Keyword_read_only: \
1634  Result = Context.Id##ROTy; \
1635  break; \
1636  case OpenCLAccessAttr::SpellingNotCalculated: \
1637  llvm_unreachable("Spelling not yet calculated"); \
1638  } \
1639  break;
1640 #include "clang/Basic/OpenCLImageTypes.def"
1641 
1642  case DeclSpec::TST_error:
1643  Result = Context.IntTy;
1644  declarator.setInvalidType(true);
1645  break;
1646  }
1647 
1648  if (S.getLangOpts().OpenCL &&
1650  declarator.setInvalidType(true);
1651 
1652  bool IsFixedPointType = DS.getTypeSpecType() == DeclSpec::TST_accum ||
1653  DS.getTypeSpecType() == DeclSpec::TST_fract;
1654 
1655  // Only fixed point types can be saturated
1656  if (DS.isTypeSpecSat() && !IsFixedPointType)
1657  S.Diag(DS.getTypeSpecSatLoc(), diag::err_invalid_saturation_spec)
1658  << DS.getSpecifierName(DS.getTypeSpecType(),
1659  Context.getPrintingPolicy());
1660 
1661  // Handle complex types.
1662  if (DS.getTypeSpecComplex() == DeclSpec::TSC_complex) {
1663  if (S.getLangOpts().Freestanding)
1664  S.Diag(DS.getTypeSpecComplexLoc(), diag::ext_freestanding_complex);
1665  Result = Context.getComplexType(Result);
1666  } else if (DS.isTypeAltiVecVector()) {
1667  unsigned typeSize = static_cast<unsigned>(Context.getTypeSize(Result));
1668  assert(typeSize > 0 && "type size for vector must be greater than 0 bits");
1670  if (DS.isTypeAltiVecPixel())
1671  VecKind = VectorType::AltiVecPixel;
1672  else if (DS.isTypeAltiVecBool())
1673  VecKind = VectorType::AltiVecBool;
1674  Result = Context.getVectorType(Result, 128/typeSize, VecKind);
1675  }
1676 
1677  // FIXME: Imaginary.
1678  if (DS.getTypeSpecComplex() == DeclSpec::TSC_imaginary)
1679  S.Diag(DS.getTypeSpecComplexLoc(), diag::err_imaginary_not_supported);
1680 
1681  // Before we process any type attributes, synthesize a block literal
1682  // function declarator if necessary.
1683  if (declarator.getContext() == DeclaratorContext::BlockLiteralContext)
1685 
1686  // Apply any type attributes from the decl spec. This may cause the
1687  // list of type attributes to be temporarily saved while the type
1688  // attributes are pushed around.
1689  // pipe attributes will be handled later ( at GetFullTypeForDeclarator )
1690  if (!DS.isTypeSpecPipe())
1691  processTypeAttrs(state, Result, TAL_DeclSpec, DS.getAttributes());
1692 
1693  // Apply const/volatile/restrict qualifiers to T.
1694  if (unsigned TypeQuals = DS.getTypeQualifiers()) {
1695  // Warn about CV qualifiers on function types.
1696  // C99 6.7.3p8:
1697  // If the specification of a function type includes any type qualifiers,
1698  // the behavior is undefined.
1699  // C++11 [dcl.fct]p7:
1700  // The effect of a cv-qualifier-seq in a function declarator is not the
1701  // same as adding cv-qualification on top of the function type. In the
1702  // latter case, the cv-qualifiers are ignored.
1703  if (TypeQuals && Result->isFunctionType()) {
1705  S, DS, TypeQuals, Result, DeclSpec::TQ_const | DeclSpec::TQ_volatile,
1706  S.getLangOpts().CPlusPlus
1707  ? diag::warn_typecheck_function_qualifiers_ignored
1708  : diag::warn_typecheck_function_qualifiers_unspecified);
1709  // No diagnostic for 'restrict' or '_Atomic' applied to a
1710  // function type; we'll diagnose those later, in BuildQualifiedType.
1711  }
1712 
1713  // C++11 [dcl.ref]p1:
1714  // Cv-qualified references are ill-formed except when the
1715  // cv-qualifiers are introduced through the use of a typedef-name
1716  // or decltype-specifier, in which case the cv-qualifiers are ignored.
1717  //
1718  // There don't appear to be any other contexts in which a cv-qualified
1719  // reference type could be formed, so the 'ill-formed' clause here appears
1720  // to never happen.
1721  if (TypeQuals && Result->isReferenceType()) {
1723  S, DS, TypeQuals, Result,
1725  diag::warn_typecheck_reference_qualifiers);
1726  }
1727 
1728  // C90 6.5.3 constraints: "The same type qualifier shall not appear more
1729  // than once in the same specifier-list or qualifier-list, either directly
1730  // or via one or more typedefs."
1731  if (!S.getLangOpts().C99 && !S.getLangOpts().CPlusPlus
1732  && TypeQuals & Result.getCVRQualifiers()) {
1733  if (TypeQuals & DeclSpec::TQ_const && Result.isConstQualified()) {
1734  S.Diag(DS.getConstSpecLoc(), diag::ext_duplicate_declspec)
1735  << "const";
1736  }
1737 
1738  if (TypeQuals & DeclSpec::TQ_volatile && Result.isVolatileQualified()) {
1739  S.Diag(DS.getVolatileSpecLoc(), diag::ext_duplicate_declspec)
1740  << "volatile";
1741  }
1742 
1743  // C90 doesn't have restrict nor _Atomic, so it doesn't force us to
1744  // produce a warning in this case.
1745  }
1746 
1747  QualType Qualified = S.BuildQualifiedType(Result, DeclLoc, TypeQuals, &DS);
1748 
1749  // If adding qualifiers fails, just use the unqualified type.
1750  if (Qualified.isNull())
1751  declarator.setInvalidType(true);
1752  else
1753  Result = Qualified;
1754  }
1755 
1756  assert(!Result.isNull() && "This function should not return a null type");
1757  return Result;
1758 }
1759 
1760 static std::string getPrintableNameForEntity(DeclarationName Entity) {
1761  if (Entity)
1762  return Entity.getAsString();
1763 
1764  return "type name";
1765 }
1766 
1768  Qualifiers Qs, const DeclSpec *DS) {
1769  if (T.isNull())
1770  return QualType();
1771 
1772  // Ignore any attempt to form a cv-qualified reference.
1773  if (T->isReferenceType()) {
1774  Qs.removeConst();
1775  Qs.removeVolatile();
1776  }
1777 
1778  // Enforce C99 6.7.3p2: "Types other than pointer types derived from
1779  // object or incomplete types shall not be restrict-qualified."
1780  if (Qs.hasRestrict()) {
1781  unsigned DiagID = 0;
1782  QualType ProblemTy;
1783 
1784  if (T->isAnyPointerType() || T->isReferenceType() ||
1785  T->isMemberPointerType()) {
1786  QualType EltTy;
1787  if (T->isObjCObjectPointerType())
1788  EltTy = T;
1789  else if (const MemberPointerType *PTy = T->getAs<MemberPointerType>())
1790  EltTy = PTy->getPointeeType();
1791  else
1792  EltTy = T->getPointeeType();
1793 
1794  // If we have a pointer or reference, the pointee must have an object
1795  // incomplete type.
1796  if (!EltTy->isIncompleteOrObjectType()) {
1797  DiagID = diag::err_typecheck_invalid_restrict_invalid_pointee;
1798  ProblemTy = EltTy;
1799  }
1800  } else if (!T->isDependentType()) {
1801  DiagID = diag::err_typecheck_invalid_restrict_not_pointer;
1802  ProblemTy = T;
1803  }
1804 
1805  if (DiagID) {
1806  Diag(DS ? DS->getRestrictSpecLoc() : Loc, DiagID) << ProblemTy;
1807  Qs.removeRestrict();
1808  }
1809  }
1810 
1811  return Context.getQualifiedType(T, Qs);
1812 }
1813 
1815  unsigned CVRAU, const DeclSpec *DS) {
1816  if (T.isNull())
1817  return QualType();
1818 
1819  // Ignore any attempt to form a cv-qualified reference.
1820  if (T->isReferenceType())
1821  CVRAU &=
1823 
1824  // Convert from DeclSpec::TQ to Qualifiers::TQ by just dropping TQ_atomic and
1825  // TQ_unaligned;
1826  unsigned CVR = CVRAU & ~(DeclSpec::TQ_atomic | DeclSpec::TQ_unaligned);
1827 
1828  // C11 6.7.3/5:
1829  // If the same qualifier appears more than once in the same
1830  // specifier-qualifier-list, either directly or via one or more typedefs,
1831  // the behavior is the same as if it appeared only once.
1832  //
1833  // It's not specified what happens when the _Atomic qualifier is applied to
1834  // a type specified with the _Atomic specifier, but we assume that this
1835  // should be treated as if the _Atomic qualifier appeared multiple times.
1836  if (CVRAU & DeclSpec::TQ_atomic && !T->isAtomicType()) {
1837  // C11 6.7.3/5:
1838  // If other qualifiers appear along with the _Atomic qualifier in a
1839  // specifier-qualifier-list, the resulting type is the so-qualified
1840  // atomic type.
1841  //
1842  // Don't need to worry about array types here, since _Atomic can't be
1843  // applied to such types.
1845  T = BuildAtomicType(QualType(Split.Ty, 0),
1846  DS ? DS->getAtomicSpecLoc() : Loc);
1847  if (T.isNull())
1848  return T;
1849  Split.Quals.addCVRQualifiers(CVR);
1850  return BuildQualifiedType(T, Loc, Split.Quals);
1851  }
1852 
1855  return BuildQualifiedType(T, Loc, Q, DS);
1856 }
1857 
1858 /// Build a paren type including \p T.
1860  return Context.getParenType(T);
1861 }
1862 
1863 /// Given that we're building a pointer or reference to the given
1865  SourceLocation loc,
1866  bool isReference) {
1867  // Bail out if retention is unrequired or already specified.
1868  if (!type->isObjCLifetimeType() ||
1870  return type;
1871 
1873 
1874  // If the object type is const-qualified, we can safely use
1875  // __unsafe_unretained. This is safe (because there are no read
1876  // barriers), and it'll be safe to coerce anything but __weak* to
1877  // the resulting type.
1878  if (type.isConstQualified()) {
1879  implicitLifetime = Qualifiers::OCL_ExplicitNone;
1880 
1881  // Otherwise, check whether the static type does not require
1882  // retaining. This currently only triggers for Class (possibly
1883  // protocol-qualifed, and arrays thereof).
1884  } else if (type->isObjCARCImplicitlyUnretainedType()) {
1885  implicitLifetime = Qualifiers::OCL_ExplicitNone;
1886 
1887  // If we are in an unevaluated context, like sizeof, skip adding a
1888  // qualification.
1889  } else if (S.isUnevaluatedContext()) {
1890  return type;
1891 
1892  // If that failed, give an error and recover using __strong. __strong
1893  // is the option most likely to prevent spurious second-order diagnostics,
1894  // like when binding a reference to a field.
1895  } else {
1896  // These types can show up in private ivars in system headers, so
1897  // we need this to not be an error in those cases. Instead we
1898  // want to delay.
1902  diag::err_arc_indirect_no_ownership, type, isReference));
1903  } else {
1904  S.Diag(loc, diag::err_arc_indirect_no_ownership) << type << isReference;
1905  }
1906  implicitLifetime = Qualifiers::OCL_Strong;
1907  }
1908  assert(implicitLifetime && "didn't infer any lifetime!");
1909 
1910  Qualifiers qs;
1911  qs.addObjCLifetime(implicitLifetime);
1912  return S.Context.getQualifiedType(type, qs);
1913 }
1914 
1915 static std::string getFunctionQualifiersAsString(const FunctionProtoType *FnTy){
1916  std::string Quals = FnTy->getMethodQuals().getAsString();
1917 
1918  switch (FnTy->getRefQualifier()) {
1919  case RQ_None:
1920  break;
1921 
1922  case RQ_LValue:
1923  if (!Quals.empty())
1924  Quals += ' ';
1925  Quals += '&';
1926  break;
1927 
1928  case RQ_RValue:
1929  if (!Quals.empty())
1930  Quals += ' ';
1931  Quals += "&&";
1932  break;
1933  }
1934 
1935  return Quals;
1936 }
1937 
1938 namespace {
1939 /// Kinds of declarator that cannot contain a qualified function type.
1940 ///
1941 /// C++98 [dcl.fct]p4 / C++11 [dcl.fct]p6:
1942 /// a function type with a cv-qualifier or a ref-qualifier can only appear
1943 /// at the topmost level of a type.
1944 ///
1945 /// Parens and member pointers are permitted. We don't diagnose array and
1946 /// function declarators, because they don't allow function types at all.
1947 ///
1948 /// The values of this enum are used in diagnostics.
1949 enum QualifiedFunctionKind { QFK_BlockPointer, QFK_Pointer, QFK_Reference };
1950 } // end anonymous namespace
1951 
1952 /// Check whether the type T is a qualified function type, and if it is,
1953 /// diagnose that it cannot be contained within the given kind of declarator.
1955  QualifiedFunctionKind QFK) {
1956  // Does T refer to a function type with a cv-qualifier or a ref-qualifier?
1957  const FunctionProtoType *FPT = T->getAs<FunctionProtoType>();
1958  if (!FPT ||
1959  (FPT->getMethodQuals().empty() && FPT->getRefQualifier() == RQ_None))
1960  return false;
1961 
1962  S.Diag(Loc, diag::err_compound_qualified_function_type)
1963  << QFK << isa<FunctionType>(T.IgnoreParens()) << T
1965  return true;
1966 }
1967 
1969  const FunctionProtoType *FPT = T->getAs<FunctionProtoType>();
1970  if (!FPT ||
1971  (FPT->getMethodQuals().empty() && FPT->getRefQualifier() == RQ_None))
1972  return false;
1973 
1974  Diag(Loc, diag::err_qualified_function_typeid)
1975  << T << getFunctionQualifiersAsString(FPT);
1976  return true;
1977 }
1978 
1979 /// Build a pointer type.
1980 ///
1981 /// \param T The type to which we'll be building a pointer.
1982 ///
1983 /// \param Loc The location of the entity whose type involves this
1984 /// pointer type or, if there is no such entity, the location of the
1985 /// type that will have pointer type.
1986 ///
1987 /// \param Entity The name of the entity that involves the pointer
1988 /// type, if known.
1989 ///
1990 /// \returns A suitable pointer type, if there are no
1991 /// errors. Otherwise, returns a NULL type.
1993  SourceLocation Loc, DeclarationName Entity) {
1994  if (T->isReferenceType()) {
1995  // C++ 8.3.2p4: There shall be no ... pointers to references ...
1996  Diag(Loc, diag::err_illegal_decl_pointer_to_reference)
1997  << getPrintableNameForEntity(Entity) << T;
1998  return QualType();
1999  }
2000 
2001  if (T->isFunctionType() && getLangOpts().OpenCL) {
2002  Diag(Loc, diag::err_opencl_function_pointer);
2003  return QualType();
2004  }
2005 
2006  if (checkQualifiedFunction(*this, T, Loc, QFK_Pointer))
2007  return QualType();
2008 
2009  assert(!T->isObjCObjectType() && "Should build ObjCObjectPointerType");
2010 
2011  // In ARC, it is forbidden to build pointers to unqualified pointers.
2012  if (getLangOpts().ObjCAutoRefCount)
2013  T = inferARCLifetimeForPointee(*this, T, Loc, /*reference*/ false);
2014 
2015  // Build the pointer type.
2016  return Context.getPointerType(T);
2017 }
2018 
2019 /// Build a reference type.
2020 ///
2021 /// \param T The type to which we'll be building a reference.
2022 ///
2023 /// \param Loc The location of the entity whose type involves this
2024 /// reference type or, if there is no such entity, the location of the
2025 /// type that will have reference type.
2026 ///
2027 /// \param Entity The name of the entity that involves the reference
2028 /// type, if known.
2029 ///
2030 /// \returns A suitable reference type, if there are no
2031 /// errors. Otherwise, returns a NULL type.
2033  SourceLocation Loc,
2034  DeclarationName Entity) {
2035  assert(Context.getCanonicalType(T) != Context.OverloadTy &&
2036  "Unresolved overloaded function type");
2037 
2038  // C++0x [dcl.ref]p6:
2039  // If a typedef (7.1.3), a type template-parameter (14.3.1), or a
2040  // decltype-specifier (7.1.6.2) denotes a type TR that is a reference to a
2041  // type T, an attempt to create the type "lvalue reference to cv TR" creates
2042  // the type "lvalue reference to T", while an attempt to create the type
2043  // "rvalue reference to cv TR" creates the type TR.
2044  bool LValueRef = SpelledAsLValue || T->getAs<LValueReferenceType>();
2045 
2046  // C++ [dcl.ref]p4: There shall be no references to references.
2047  //
2048  // According to C++ DR 106, references to references are only
2049  // diagnosed when they are written directly (e.g., "int & &"),
2050  // but not when they happen via a typedef:
2051  //
2052  // typedef int& intref;
2053  // typedef intref& intref2;
2054  //
2055  // Parser::ParseDeclaratorInternal diagnoses the case where
2056  // references are written directly; here, we handle the
2057  // collapsing of references-to-references as described in C++0x.
2058  // DR 106 and 540 introduce reference-collapsing into C++98/03.
2059 
2060  // C++ [dcl.ref]p1:
2061  // A declarator that specifies the type "reference to cv void"
2062  // is ill-formed.
2063  if (T->isVoidType()) {
2064  Diag(Loc, diag::err_reference_to_void);
2065  return QualType();
2066  }
2067 
2068  if (checkQualifiedFunction(*this, T, Loc, QFK_Reference))
2069  return QualType();
2070 
2071  // In ARC, it is forbidden to build references to unqualified pointers.
2072  if (getLangOpts().ObjCAutoRefCount)
2073  T = inferARCLifetimeForPointee(*this, T, Loc, /*reference*/ true);
2074 
2075  // Handle restrict on references.
2076  if (LValueRef)
2077  return Context.getLValueReferenceType(T, SpelledAsLValue);
2078  return Context.getRValueReferenceType(T);
2079 }
2080 
2081 /// Build a Read-only Pipe type.
2082 ///
2083 /// \param T The type to which we'll be building a Pipe.
2084 ///
2085 /// \param Loc We do not use it for now.
2086 ///
2087 /// \returns A suitable pipe type, if there are no errors. Otherwise, returns a
2088 /// NULL type.
2090  return Context.getReadPipeType(T);
2091 }
2092 
2093 /// Build a Write-only Pipe type.
2094 ///
2095 /// \param T The type to which we'll be building a Pipe.
2096 ///
2097 /// \param Loc We do not use it for now.
2098 ///
2099 /// \returns A suitable pipe type, if there are no errors. Otherwise, returns a
2100 /// NULL type.
2102  return Context.getWritePipeType(T);
2103 }
2104 
2105 /// Check whether the specified array size makes the array type a VLA. If so,
2106 /// return true, if not, return the size of the array in SizeVal.
2107 static bool isArraySizeVLA(Sema &S, Expr *ArraySize, llvm::APSInt &SizeVal) {
2108  // If the size is an ICE, it certainly isn't a VLA. If we're in a GNU mode
2109  // (like gnu99, but not c99) accept any evaluatable value as an extension.
2110  class VLADiagnoser : public Sema::VerifyICEDiagnoser {
2111  public:
2112  VLADiagnoser() : Sema::VerifyICEDiagnoser(true) {}
2113 
2114  void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) override {
2115  }
2116 
2117  void diagnoseFold(Sema &S, SourceLocation Loc, SourceRange SR) override {
2118  S.Diag(Loc, diag::ext_vla_folded_to_constant) << SR;
2119  }
2120  } Diagnoser;
2121 
2122  return S.VerifyIntegerConstantExpression(ArraySize, &SizeVal, Diagnoser,
2123  S.LangOpts.GNUMode ||
2124  S.LangOpts.OpenCL).isInvalid();
2125 }
2126 
2127 /// Build an array type.
2128 ///
2129 /// \param T The type of each element in the array.
2130 ///
2131 /// \param ASM C99 array size modifier (e.g., '*', 'static').
2132 ///
2133 /// \param ArraySize Expression describing the size of the array.
2134 ///
2135 /// \param Brackets The range from the opening '[' to the closing ']'.
2136 ///
2137 /// \param Entity The name of the entity that involves the array
2138 /// type, if known.
2139 ///
2140 /// \returns A suitable array type, if there are no errors. Otherwise,
2141 /// returns a NULL type.
2143  Expr *ArraySize, unsigned Quals,
2144  SourceRange Brackets, DeclarationName Entity) {
2145 
2146  SourceLocation Loc = Brackets.getBegin();
2147  if (getLangOpts().CPlusPlus) {
2148  // C++ [dcl.array]p1:
2149  // T is called the array element type; this type shall not be a reference
2150  // type, the (possibly cv-qualified) type void, a function type or an
2151  // abstract class type.
2152  //
2153  // C++ [dcl.array]p3:
2154  // When several "array of" specifications are adjacent, [...] only the
2155  // first of the constant expressions that specify the bounds of the arrays
2156  // may be omitted.
2157  //
2158  // Note: function types are handled in the common path with C.
2159  if (T->isReferenceType()) {
2160  Diag(Loc, diag::err_illegal_decl_array_of_references)
2161  << getPrintableNameForEntity(Entity) << T;
2162  return QualType();
2163  }
2164 
2165  if (T->isVoidType() || T->isIncompleteArrayType()) {
2166  Diag(Loc, diag::err_illegal_decl_array_incomplete_type) << T;
2167  return QualType();
2168  }
2169 
2170  if (RequireNonAbstractType(Brackets.getBegin(), T,
2171  diag::err_array_of_abstract_type))
2172  return QualType();
2173 
2174  // Mentioning a member pointer type for an array type causes us to lock in
2175  // an inheritance model, even if it's inside an unused typedef.
2176  if (Context.getTargetInfo().getCXXABI().isMicrosoft())
2177  if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>())
2178  if (!MPTy->getClass()->isDependentType())
2179  (void)isCompleteType(Loc, T);
2180 
2181  } else {
2182  // C99 6.7.5.2p1: If the element type is an incomplete or function type,
2183  // reject it (e.g. void ary[7], struct foo ary[7], void ary[7]())
2184  if (RequireCompleteType(Loc, T,
2185  diag::err_illegal_decl_array_incomplete_type))
2186  return QualType();
2187  }
2188 
2189  if (T->isFunctionType()) {
2190  Diag(Loc, diag::err_illegal_decl_array_of_functions)
2191  << getPrintableNameForEntity(Entity) << T;
2192  return QualType();
2193  }
2194 
2195  if (const RecordType *EltTy = T->getAs<RecordType>()) {
2196  // If the element type is a struct or union that contains a variadic
2197  // array, accept it as a GNU extension: C99 6.7.2.1p2.
2198  if (EltTy->getDecl()->hasFlexibleArrayMember())
2199  Diag(Loc, diag::ext_flexible_array_in_array) << T;
2200  } else if (T->isObjCObjectType()) {
2201  Diag(Loc, diag::err_objc_array_of_interfaces) << T;
2202  return QualType();
2203  }
2204 
2205  // Do placeholder conversions on the array size expression.
2206  if (ArraySize && ArraySize->hasPlaceholderType()) {
2207  ExprResult Result = CheckPlaceholderExpr(ArraySize);
2208  if (Result.isInvalid()) return QualType();
2209  ArraySize = Result.get();
2210  }
2211 
2212  // Do lvalue-to-rvalue conversions on the array size expression.
2213  if (ArraySize && !ArraySize->isRValue()) {
2214  ExprResult Result = DefaultLvalueConversion(ArraySize);
2215  if (Result.isInvalid())
2216  return QualType();
2217 
2218  ArraySize = Result.get();
2219  }
2220 
2221  // C99 6.7.5.2p1: The size expression shall have integer type.
2222  // C++11 allows contextual conversions to such types.
2223  if (!getLangOpts().CPlusPlus11 &&
2224  ArraySize && !ArraySize->isTypeDependent() &&
2225  !ArraySize->getType()->isIntegralOrUnscopedEnumerationType()) {
2226  Diag(ArraySize->getBeginLoc(), diag::err_array_size_non_int)
2227  << ArraySize->getType() << ArraySize->getSourceRange();
2228  return QualType();
2229  }
2230 
2231  llvm::APSInt ConstVal(Context.getTypeSize(Context.getSizeType()));
2232  if (!ArraySize) {
2233  if (ASM == ArrayType::Star)
2234  T = Context.getVariableArrayType(T, nullptr, ASM, Quals, Brackets);
2235  else
2236  T = Context.getIncompleteArrayType(T, ASM, Quals);
2237  } else if (ArraySize->isTypeDependent() || ArraySize->isValueDependent()) {
2238  T = Context.getDependentSizedArrayType(T, ArraySize, ASM, Quals, Brackets);
2239  } else if ((!T->isDependentType() && !T->isIncompleteType() &&
2240  !T->isConstantSizeType()) ||
2241  isArraySizeVLA(*this, ArraySize, ConstVal)) {
2242  // Even in C++11, don't allow contextual conversions in the array bound
2243  // of a VLA.
2244  if (getLangOpts().CPlusPlus11 &&
2245  !ArraySize->getType()->isIntegralOrUnscopedEnumerationType()) {
2246  Diag(ArraySize->getBeginLoc(), diag::err_array_size_non_int)
2247  << ArraySize->getType() << ArraySize->getSourceRange();
2248  return QualType();
2249  }
2250 
2251  // C99: an array with an element type that has a non-constant-size is a VLA.
2252  // C99: an array with a non-ICE size is a VLA. We accept any expression
2253  // that we can fold to a non-zero positive value as an extension.
2254  T = Context.getVariableArrayType(T, ArraySize, ASM, Quals, Brackets);
2255  } else {
2256  // C99 6.7.5.2p1: If the expression is a constant expression, it shall
2257  // have a value greater than zero.
2258  if (ConstVal.isSigned() && ConstVal.isNegative()) {
2259  if (Entity)
2260  Diag(ArraySize->getBeginLoc(), diag::err_decl_negative_array_size)
2261  << getPrintableNameForEntity(Entity) << ArraySize->getSourceRange();
2262  else
2263  Diag(ArraySize->getBeginLoc(), diag::err_typecheck_negative_array_size)
2264  << ArraySize->getSourceRange();
2265  return QualType();
2266  }
2267  if (ConstVal == 0) {
2268  // GCC accepts zero sized static arrays. We allow them when
2269  // we're not in a SFINAE context.
2270  Diag(ArraySize->getBeginLoc(), isSFINAEContext()
2271  ? diag::err_typecheck_zero_array_size
2272  : diag::ext_typecheck_zero_array_size)
2273  << ArraySize->getSourceRange();
2274 
2275  if (ASM == ArrayType::Static) {
2276  Diag(ArraySize->getBeginLoc(),
2277  diag::warn_typecheck_zero_static_array_size)
2278  << ArraySize->getSourceRange();
2279  ASM = ArrayType::Normal;
2280  }
2281  } else if (!T->isDependentType() && !T->isVariablyModifiedType() &&
2282  !T->isIncompleteType() && !T->isUndeducedType()) {
2283  // Is the array too large?
2284  unsigned ActiveSizeBits
2285  = ConstantArrayType::getNumAddressingBits(Context, T, ConstVal);
2286  if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
2287  Diag(ArraySize->getBeginLoc(), diag::err_array_too_large)
2288  << ConstVal.toString(10) << ArraySize->getSourceRange();
2289  return QualType();
2290  }
2291  }
2292 
2293  T = Context.getConstantArrayType(T, ConstVal, ArraySize, ASM, Quals);
2294  }
2295 
2296  // OpenCL v1.2 s6.9.d: variable length arrays are not supported.
2297  if (getLangOpts().OpenCL && T->isVariableArrayType()) {
2298  Diag(Loc, diag::err_opencl_vla);
2299  return QualType();
2300  }
2301 
2302  if (T->isVariableArrayType() && !Context.getTargetInfo().isVLASupported()) {
2303  // CUDA device code and some other targets don't support VLAs.
2304  targetDiag(Loc, (getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
2305  ? diag::err_cuda_vla
2306  : diag::err_vla_unsupported)
2307  << ((getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
2308  ? CurrentCUDATarget()
2309  : CFT_InvalidTarget);
2310  }
2311 
2312  // If this is not C99, extwarn about VLA's and C99 array size modifiers.
2313  if (!getLangOpts().C99) {
2314  if (T->isVariableArrayType()) {
2315  // Prohibit the use of VLAs during template argument deduction.
2316  if (isSFINAEContext()) {
2317  Diag(Loc, diag::err_vla_in_sfinae);
2318  return QualType();
2319  }
2320  // Just extwarn about VLAs.
2321  else
2322  Diag(Loc, diag::ext_vla);
2323  } else if (ASM != ArrayType::Normal || Quals != 0)
2324  Diag(Loc,
2325  getLangOpts().CPlusPlus? diag::err_c99_array_usage_cxx
2326  : diag::ext_c99_array_usage) << ASM;
2327  }
2328 
2329  if (T->isVariableArrayType()) {
2330  // Warn about VLAs for -Wvla.
2331  Diag(Loc, diag::warn_vla_used);
2332  }
2333 
2334  // OpenCL v2.0 s6.12.5 - Arrays of blocks are not supported.
2335  // OpenCL v2.0 s6.16.13.1 - Arrays of pipe type are not supported.
2336  // OpenCL v2.0 s6.9.b - Arrays of image/sampler type are not supported.
2337  if (getLangOpts().OpenCL) {
2338  const QualType ArrType = Context.getBaseElementType(T);
2339  if (ArrType->isBlockPointerType() || ArrType->isPipeType() ||
2340  ArrType->isSamplerT() || ArrType->isImageType()) {
2341  Diag(Loc, diag::err_opencl_invalid_type_array) << ArrType;
2342  return QualType();
2343  }
2344  }
2345 
2346  return T;
2347 }
2348 
2350  SourceLocation AttrLoc) {
2351  // The base type must be integer (not Boolean or enumeration) or float, and
2352  // can't already be a vector.
2353  if (!CurType->isDependentType() &&
2354  (!CurType->isBuiltinType() || CurType->isBooleanType() ||
2355  (!CurType->isIntegerType() && !CurType->isRealFloatingType()))) {
2356  Diag(AttrLoc, diag::err_attribute_invalid_vector_type) << CurType;
2357  return QualType();
2358  }
2359 
2360  if (SizeExpr->isTypeDependent() || SizeExpr->isValueDependent())
2361  return Context.getDependentVectorType(CurType, SizeExpr, AttrLoc,
2363 
2364  llvm::APSInt VecSize(32);
2365  if (!SizeExpr->isIntegerConstantExpr(VecSize, Context)) {
2366  Diag(AttrLoc, diag::err_attribute_argument_type)
2367  << "vector_size" << AANT_ArgumentIntegerConstant
2368  << SizeExpr->getSourceRange();
2369  return QualType();
2370  }
2371 
2372  if (CurType->isDependentType())
2373  return Context.getDependentVectorType(CurType, SizeExpr, AttrLoc,
2375 
2376  unsigned VectorSize = static_cast<unsigned>(VecSize.getZExtValue() * 8);
2377  unsigned TypeSize = static_cast<unsigned>(Context.getTypeSize(CurType));
2378 
2379  if (VectorSize == 0) {
2380  Diag(AttrLoc, diag::err_attribute_zero_size) << SizeExpr->getSourceRange();
2381  return QualType();
2382  }
2383 
2384  // vecSize is specified in bytes - convert to bits.
2385  if (VectorSize % TypeSize) {
2386  Diag(AttrLoc, diag::err_attribute_invalid_size)
2387  << SizeExpr->getSourceRange();
2388  return QualType();
2389  }
2390 
2391  if (VectorType::isVectorSizeTooLarge(VectorSize / TypeSize)) {
2392  Diag(AttrLoc, diag::err_attribute_size_too_large)
2393  << SizeExpr->getSourceRange();
2394  return QualType();
2395  }
2396 
2397  return Context.getVectorType(CurType, VectorSize / TypeSize,
2399 }
2400 
2401 /// Build an ext-vector type.
2402 ///
2403 /// Run the required checks for the extended vector type.
2405  SourceLocation AttrLoc) {
2406  // Unlike gcc's vector_size attribute, we do not allow vectors to be defined
2407  // in conjunction with complex types (pointers, arrays, functions, etc.).
2408  //
2409  // Additionally, OpenCL prohibits vectors of booleans (they're considered a
2410  // reserved data type under OpenCL v2.0 s6.1.4), we don't support selects
2411  // on bitvectors, and we have no well-defined ABI for bitvectors, so vectors
2412  // of bool aren't allowed.
2413  if ((!T->isDependentType() && !T->isIntegerType() &&
2414  !T->isRealFloatingType()) ||
2415  T->isBooleanType()) {
2416  Diag(AttrLoc, diag::err_attribute_invalid_vector_type) << T;
2417  return QualType();
2418  }
2419 
2420  if (!ArraySize->isTypeDependent() && !ArraySize->isValueDependent()) {
2421  llvm::APSInt vecSize(32);
2422  if (!ArraySize->isIntegerConstantExpr(vecSize, Context)) {
2423  Diag(AttrLoc, diag::err_attribute_argument_type)
2424  << "ext_vector_type" << AANT_ArgumentIntegerConstant
2425  << ArraySize->getSourceRange();
2426  return QualType();
2427  }
2428 
2429  // Unlike gcc's vector_size attribute, the size is specified as the
2430  // number of elements, not the number of bytes.
2431  unsigned vectorSize = static_cast<unsigned>(vecSize.getZExtValue());
2432 
2433  if (vectorSize == 0) {
2434  Diag(AttrLoc, diag::err_attribute_zero_size)
2435  << ArraySize->getSourceRange();
2436  return QualType();
2437  }
2438 
2439  if (VectorType::isVectorSizeTooLarge(vectorSize)) {
2440  Diag(AttrLoc, diag::err_attribute_size_too_large)
2441  << ArraySize->getSourceRange();
2442  return QualType();
2443  }
2444 
2445  return Context.getExtVectorType(T, vectorSize);
2446  }
2447 
2448  return Context.getDependentSizedExtVectorType(T, ArraySize, AttrLoc);
2449 }
2450 
2452  if (T->isArrayType() || T->isFunctionType()) {
2453  Diag(Loc, diag::err_func_returning_array_function)
2454  << T->isFunctionType() << T;
2455  return true;
2456  }
2457 
2458  // Functions cannot return half FP.
2459  if (T->isHalfType() && !getLangOpts().HalfArgsAndReturns) {
2460  Diag(Loc, diag::err_parameters_retval_cannot_have_fp16_type) << 1 <<
2461  FixItHint::CreateInsertion(Loc, "*");
2462  return true;
2463  }
2464 
2465  // Methods cannot return interface types. All ObjC objects are
2466  // passed by reference.
2467  if (T->isObjCObjectType()) {
2468  Diag(Loc, diag::err_object_cannot_be_passed_returned_by_value)
2469  << 0 << T << FixItHint::CreateInsertion(Loc, "*");
2470  return true;
2471  }
2472 
2475  checkNonTrivialCUnion(T, Loc, NTCUC_FunctionReturn,
2476  NTCUK_Destruct|NTCUK_Copy);
2477 
2478  // C++2a [dcl.fct]p12:
2479  // A volatile-qualified return type is deprecated
2480  if (T.isVolatileQualified() && getLangOpts().CPlusPlus2a)
2481  Diag(Loc, diag::warn_deprecated_volatile_return) << T;
2482 
2483  return false;
2484 }
2485 
2486 /// Check the extended parameter information. Most of the necessary
2487 /// checking should occur when applying the parameter attribute; the
2488 /// only other checks required are positional restrictions.
2491  llvm::function_ref<SourceLocation(unsigned)> getParamLoc) {
2492  assert(EPI.ExtParameterInfos && "shouldn't get here without param infos");
2493 
2494  bool hasCheckedSwiftCall = false;
2495  auto checkForSwiftCC = [&](unsigned paramIndex) {
2496  // Only do this once.
2497  if (hasCheckedSwiftCall) return;
2498  hasCheckedSwiftCall = true;
2499  if (EPI.ExtInfo.getCC() == CC_Swift) return;
2500  S.Diag(getParamLoc(paramIndex), diag::err_swift_param_attr_not_swiftcall)
2501  << getParameterABISpelling(EPI.ExtParameterInfos[paramIndex].getABI());
2502  };
2503 
2504  for (size_t paramIndex = 0, numParams = paramTypes.size();
2505  paramIndex != numParams; ++paramIndex) {
2506  switch (EPI.ExtParameterInfos[paramIndex].getABI()) {
2507  // Nothing interesting to check for orindary-ABI parameters.
2509  continue;
2510 
2511  // swift_indirect_result parameters must be a prefix of the function
2512  // arguments.
2514  checkForSwiftCC(paramIndex);
2515  if (paramIndex != 0 &&
2516  EPI.ExtParameterInfos[paramIndex - 1].getABI()
2518  S.Diag(getParamLoc(paramIndex),
2519  diag::err_swift_indirect_result_not_first);
2520  }
2521  continue;
2522 
2524  checkForSwiftCC(paramIndex);
2525  continue;
2526 
2527  // swift_error parameters must be preceded by a swift_context parameter.
2529  checkForSwiftCC(paramIndex);
2530  if (paramIndex == 0 ||
2531  EPI.ExtParameterInfos[paramIndex - 1].getABI() !=
2533  S.Diag(getParamLoc(paramIndex),
2534  diag::err_swift_error_result_not_after_swift_context);
2535  }
2536  continue;
2537  }
2538  llvm_unreachable("bad ABI kind");
2539  }
2540 }
2541 
2543  MutableArrayRef<QualType> ParamTypes,
2544  SourceLocation Loc, DeclarationName Entity,
2545  const FunctionProtoType::ExtProtoInfo &EPI) {
2546  bool Invalid = false;
2547 
2548  Invalid |= CheckFunctionReturnType(T, Loc);
2549 
2550  for (unsigned Idx = 0, Cnt = ParamTypes.size(); Idx < Cnt; ++Idx) {
2551  // FIXME: Loc is too inprecise here, should use proper locations for args.
2552  QualType ParamType = Context.getAdjustedParameterType(ParamTypes[Idx]);
2553  if (ParamType->isVoidType()) {
2554  Diag(Loc, diag::err_param_with_void_type);
2555  Invalid = true;
2556  } else if (ParamType->isHalfType() && !getLangOpts().HalfArgsAndReturns) {
2557  // Disallow half FP arguments.
2558  Diag(Loc, diag::err_parameters_retval_cannot_have_fp16_type) << 0 <<
2559  FixItHint::CreateInsertion(Loc, "*");
2560  Invalid = true;
2561  }
2562 
2563  // C++2a [dcl.fct]p4:
2564  // A parameter with volatile-qualified type is deprecated
2565  if (ParamType.isVolatileQualified() && getLangOpts().CPlusPlus2a)
2566  Diag(Loc, diag::warn_deprecated_volatile_param) << ParamType;
2567 
2568  ParamTypes[Idx] = ParamType;
2569  }
2570 
2571  if (EPI.ExtParameterInfos) {
2572  checkExtParameterInfos(*this, ParamTypes, EPI,
2573  [=](unsigned i) { return Loc; });
2574  }
2575 
2576  if (EPI.ExtInfo.getProducesResult()) {
2577  // This is just a warning, so we can't fail to build if we see it.
2578  checkNSReturnsRetainedReturnType(Loc, T);
2579  }
2580 
2581  if (Invalid)
2582  return QualType();
2583 
2584  return Context.getFunctionType(T, ParamTypes, EPI);
2585 }
2586 
2587 /// Build a member pointer type \c T Class::*.
2588 ///
2589 /// \param T the type to which the member pointer refers.
2590 /// \param Class the class type into which the member pointer points.
2591 /// \param Loc the location where this type begins
2592 /// \param Entity the name of the entity that will have this member pointer type
2593 ///
2594 /// \returns a member pointer type, if successful, or a NULL type if there was
2595 /// an error.
2597  SourceLocation Loc,
2598  DeclarationName Entity) {
2599  // Verify that we're not building a pointer to pointer to function with
2600  // exception specification.
2601  if (CheckDistantExceptionSpec(T)) {
2602  Diag(Loc, diag::err_distant_exception_spec);
2603  return QualType();
2604  }
2605 
2606  // C++ 8.3.3p3: A pointer to member shall not point to ... a member
2607  // with reference type, or "cv void."
2608  if (T->isReferenceType()) {
2609  Diag(Loc, diag::err_illegal_decl_mempointer_to_reference)
2610  << getPrintableNameForEntity(Entity) << T;
2611  return QualType();
2612  }
2613 
2614  if (T->isVoidType()) {
2615  Diag(Loc, diag::err_illegal_decl_mempointer_to_void)
2616  << getPrintableNameForEntity(Entity);
2617  return QualType();
2618  }
2619 
2620  if (!Class->isDependentType() && !Class->isRecordType()) {
2621  Diag(Loc, diag::err_mempointer_in_nonclass_type) << Class;
2622  return QualType();
2623  }
2624 
2625  // Adjust the default free function calling convention to the default method
2626  // calling convention.
2627  bool IsCtorOrDtor =
2630  if (T->isFunctionType())
2631  adjustMemberFunctionCC(T, /*IsStatic=*/false, IsCtorOrDtor, Loc);
2632 
2633  return Context.getMemberPointerType(T, Class.getTypePtr());
2634 }
2635 
2636 /// Build a block pointer type.
2637 ///
2638 /// \param T The type to which we'll be building a block pointer.
2639 ///
2640 /// \param Loc The source location, used for diagnostics.
2641 ///
2642 /// \param Entity The name of the entity that involves the block pointer
2643 /// type, if known.
2644 ///
2645 /// \returns A suitable block pointer type, if there are no
2646 /// errors. Otherwise, returns a NULL type.
2648  SourceLocation Loc,
2649  DeclarationName Entity) {
2650  if (!T->isFunctionType()) {
2651  Diag(Loc, diag::err_nonfunction_block_type);
2652  return QualType();
2653  }
2654 
2655  if (checkQualifiedFunction(*this, T, Loc, QFK_BlockPointer))
2656  return QualType();
2657 
2658  return Context.getBlockPointerType(T);
2659 }
2660 
2662  QualType QT = Ty.get();
2663  if (QT.isNull()) {
2664  if (TInfo) *TInfo = nullptr;
2665  return QualType();
2666  }
2667 
2668  TypeSourceInfo *DI = nullptr;
2669  if (const LocInfoType *LIT = dyn_cast<LocInfoType>(QT)) {
2670  QT = LIT->getType();
2671  DI = LIT->getTypeSourceInfo();
2672  }
2673 
2674  if (TInfo) *TInfo = DI;
2675  return QT;
2676 }
2677 
2678 static void transferARCOwnershipToDeclaratorChunk(TypeProcessingState &state,
2679  Qualifiers::ObjCLifetime ownership,
2680  unsigned chunkIndex);
2681 
2682 /// Given that this is the declaration of a parameter under ARC,
2683 /// attempt to infer attributes and such for pointer-to-whatever
2684 /// types.
2685 static void inferARCWriteback(TypeProcessingState &state,
2686  QualType &declSpecType) {
2687  Sema &S = state.getSema();
2688  Declarator &declarator = state.getDeclarator();
2689 
2690  // TODO: should we care about decl qualifiers?
2691 
2692  // Check whether the declarator has the expected form. We walk
2693  // from the inside out in order to make the block logic work.
2694  unsigned outermostPointerIndex = 0;
2695  bool isBlockPointer = false;
2696  unsigned numPointers = 0;
2697  for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
2698  unsigned chunkIndex = i;
2699  DeclaratorChunk &chunk = declarator.getTypeObject(chunkIndex);
2700  switch (chunk.Kind) {
2702  // Ignore parens.
2703  break;
2704 
2707  // Count the number of pointers. Treat references
2708  // interchangeably as pointers; if they're mis-ordered, normal
2709  // type building will discover that.
2710  outermostPointerIndex = chunkIndex;
2711  numPointers++;
2712  break;
2713 
2715  // If we have a pointer to block pointer, that's an acceptable
2716  // indirect reference; anything else is not an application of
2717  // the rules.
2718  if (numPointers != 1) return;
2719  numPointers++;
2720  outermostPointerIndex = chunkIndex;
2721  isBlockPointer = true;
2722 
2723  // We don't care about pointer structure in return values here.
2724  goto done;
2725 
2726  case DeclaratorChunk::Array: // suppress if written (id[])?
2729  case DeclaratorChunk::Pipe:
2730  return;
2731  }
2732  }
2733  done:
2734 
2735  // If we have *one* pointer, then we want to throw the qualifier on
2736  // the declaration-specifiers, which means that it needs to be a
2737  // retainable object type.
2738  if (numPointers == 1) {
2739  // If it's not a retainable object type, the rule doesn't apply.
2740  if (!declSpecType->isObjCRetainableType()) return;
2741 
2742  // If it already has lifetime, don't do anything.
2743  if (declSpecType.getObjCLifetime()) return;
2744 
2745  // Otherwise, modify the type in-place.
2746  Qualifiers qs;
2747 
2748  if (declSpecType->isObjCARCImplicitlyUnretainedType())
2750  else
2752  declSpecType = S.Context.getQualifiedType(declSpecType, qs);
2753 
2754  // If we have *two* pointers, then we want to throw the qualifier on
2755  // the outermost pointer.
2756  } else if (numPointers == 2) {
2757  // If we don't have a block pointer, we need to check whether the
2758  // declaration-specifiers gave us something that will turn into a
2759  // retainable object pointer after we slap the first pointer on it.
2760  if (!isBlockPointer && !declSpecType->isObjCObjectType())
2761  return;
2762 
2763  // Look for an explicit lifetime attribute there.
2764  DeclaratorChunk &chunk = declarator.getTypeObject(outermostPointerIndex);
2765  if (chunk.Kind != DeclaratorChunk::Pointer &&
2767  return;
2768  for (const ParsedAttr &AL : chunk.getAttrs())
2769  if (AL.getKind() == ParsedAttr::AT_ObjCOwnership)
2770  return;
2771 
2773  outermostPointerIndex);
2774 
2775  // Any other number of pointers/references does not trigger the rule.
2776  } else return;
2777 
2778  // TODO: mark whether we did this inference?
2779 }
2780 
2781 void Sema::diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
2782  SourceLocation FallbackLoc,
2783  SourceLocation ConstQualLoc,
2784  SourceLocation VolatileQualLoc,
2785  SourceLocation RestrictQualLoc,
2786  SourceLocation AtomicQualLoc,
2787  SourceLocation UnalignedQualLoc) {
2788  if (!Quals)
2789  return;
2790 
2791  struct Qual {
2792  const char *Name;
2793  unsigned Mask;
2794  SourceLocation Loc;
2795  } const QualKinds[5] = {
2796  { "const", DeclSpec::TQ_const, ConstQualLoc },
2797  { "volatile", DeclSpec::TQ_volatile, VolatileQualLoc },
2798  { "restrict", DeclSpec::TQ_restrict, RestrictQualLoc },
2799  { "__unaligned", DeclSpec::TQ_unaligned, UnalignedQualLoc },
2800  { "_Atomic", DeclSpec::TQ_atomic, AtomicQualLoc }
2801  };
2802 
2803  SmallString<32> QualStr;
2804  unsigned NumQuals = 0;
2805  SourceLocation Loc;
2806  FixItHint FixIts[5];
2807 
2808  // Build a string naming the redundant qualifiers.
2809  for (auto &E : QualKinds) {
2810  if (Quals & E.Mask) {
2811  if (!QualStr.empty()) QualStr += ' ';
2812  QualStr += E.Name;
2813 
2814  // If we have a location for the qualifier, offer a fixit.
2815  SourceLocation QualLoc = E.Loc;
2816  if (QualLoc.isValid()) {
2817  FixIts[NumQuals] = FixItHint::CreateRemoval(QualLoc);
2818  if (Loc.isInvalid() ||
2819  getSourceManager().isBeforeInTranslationUnit(QualLoc, Loc))
2820  Loc = QualLoc;
2821  }
2822 
2823  ++NumQuals;
2824  }
2825  }
2826 
2827  Diag(Loc.isInvalid() ? FallbackLoc : Loc, DiagID)
2828  << QualStr << NumQuals << FixIts[0] << FixIts[1] << FixIts[2] << FixIts[3];
2829 }
2830 
2831 // Diagnose pointless type qualifiers on the return type of a function.
2833  Declarator &D,
2834  unsigned FunctionChunkIndex) {
2835  if (D.getTypeObject(FunctionChunkIndex).Fun.hasTrailingReturnType()) {
2836  // FIXME: TypeSourceInfo doesn't preserve location information for
2837  // qualifiers.
2838  S.diagnoseIgnoredQualifiers(diag::warn_qual_return_type,
2839  RetTy.getLocalCVRQualifiers(),
2840  D.getIdentifierLoc());
2841  return;
2842  }
2843 
2844  for (unsigned OuterChunkIndex = FunctionChunkIndex + 1,
2845  End = D.getNumTypeObjects();
2846  OuterChunkIndex != End; ++OuterChunkIndex) {
2847  DeclaratorChunk &OuterChunk = D.getTypeObject(OuterChunkIndex);
2848  switch (OuterChunk.Kind) {
2850  continue;
2851 
2852  case DeclaratorChunk::Pointer: {
2853  DeclaratorChunk::PointerTypeInfo &PTI = OuterChunk.Ptr;
2855  diag::warn_qual_return_type,
2856  PTI.TypeQuals,
2857  SourceLocation(),
2863  return;
2864  }
2865 
2871  case DeclaratorChunk::Pipe:
2872  // FIXME: We can't currently provide an accurate source location and a
2873  // fix-it hint for these.
2874  unsigned AtomicQual = RetTy->isAtomicType() ? DeclSpec::TQ_atomic : 0;
2875  S.diagnoseIgnoredQualifiers(diag::warn_qual_return_type,
2876  RetTy.getCVRQualifiers() | AtomicQual,
2877  D.getIdentifierLoc());
2878  return;
2879  }
2880 
2881  llvm_unreachable("unknown declarator chunk kind");
2882  }
2883 
2884  // If the qualifiers come from a conversion function type, don't diagnose
2885  // them -- they're not necessarily redundant, since such a conversion
2886  // operator can be explicitly called as "x.operator const int()".
2888  return;
2889 
2890  // Just parens all the way out to the decl specifiers. Diagnose any qualifiers
2891  // which are present there.
2892  S.diagnoseIgnoredQualifiers(diag::warn_qual_return_type,
2894  D.getIdentifierLoc(),
2900 }
2901 
2902 static QualType GetDeclSpecTypeForDeclarator(TypeProcessingState &state,
2903  TypeSourceInfo *&ReturnTypeInfo) {
2904  Sema &SemaRef = state.getSema();
2905  Declarator &D = state.getDeclarator();
2906  QualType T;
2907  ReturnTypeInfo = nullptr;
2908 
2909  // The TagDecl owned by the DeclSpec.
2910  TagDecl *OwnedTagDecl = nullptr;
2911 
2912  switch (D.getName().getKind()) {
2918  T = ConvertDeclSpecToType(state);
2919 
2920  if (!D.isInvalidType() && D.getDeclSpec().isTypeSpecOwned()) {
2921  OwnedTagDecl = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
2922  // Owned declaration is embedded in declarator.
2923  OwnedTagDecl->setEmbeddedInDeclarator(true);
2924  }
2925  break;
2926 
2930  // Constructors and destructors don't have return types. Use
2931  // "void" instead.
2932  T = SemaRef.Context.VoidTy;
2933  processTypeAttrs(state, T, TAL_DeclSpec,
2935  break;
2936 
2938  // Deduction guides have a trailing return type and no type in their
2939  // decl-specifier sequence. Use a placeholder return type for now.
2940  T = SemaRef.Context.DependentTy;
2941  break;
2942 
2944  // The result type of a conversion function is the type that it
2945  // converts to.
2947  &ReturnTypeInfo);
2948  break;
2949  }
2950 
2951  if (!D.getAttributes().empty())
2953 
2954  // C++11 [dcl.spec.auto]p5: reject 'auto' if it is not in an allowed context.
2955  if (DeducedType *Deduced = T->getContainedDeducedType()) {
2956  AutoType *Auto = dyn_cast<AutoType>(Deduced);
2957  int Error = -1;
2958 
2959  // Is this a 'auto' or 'decltype(auto)' type (as opposed to __auto_type or
2960  // class template argument deduction)?
2961  bool IsCXXAutoType =
2962  (Auto && Auto->getKeyword() != AutoTypeKeyword::GNUAutoType);
2963  bool IsDeducedReturnType = false;
2964 
2965  switch (D.getContext()) {
2967  // Declared return type of a lambda-declarator is implicit and is always
2968  // 'auto'.
2969  break;
2973  Error = 0;
2974  break;
2976  // In C++14, generic lambdas allow 'auto' in their parameters.
2977  if (!SemaRef.getLangOpts().CPlusPlus14 ||
2978  !Auto || Auto->getKeyword() != AutoTypeKeyword::Auto)
2979  Error = 16;
2980  else {
2981  // If auto is mentioned in a lambda parameter context, convert it to a
2982  // template parameter type.
2983  sema::LambdaScopeInfo *LSI = SemaRef.getCurLambda();
2984  assert(LSI && "No LambdaScopeInfo on the stack!");
2985  const unsigned TemplateParameterDepth = LSI->AutoTemplateParameterDepth;
2986  const unsigned AutoParameterPosition = LSI->TemplateParams.size();
2987  const bool IsParameterPack = D.hasEllipsis();
2988 
2989  // Create the TemplateTypeParmDecl here to retrieve the corresponding
2990  // template parameter type. Template parameters are temporarily added
2991  // to the TU until the associated TemplateDecl is created.
2992  TemplateTypeParmDecl *CorrespondingTemplateParam =
2994  SemaRef.Context, SemaRef.Context.getTranslationUnitDecl(),
2995  /*KeyLoc*/ SourceLocation(), /*NameLoc*/ D.getBeginLoc(),
2996  TemplateParameterDepth, AutoParameterPosition,
2997  /*Identifier*/ nullptr, false, IsParameterPack);
2998  CorrespondingTemplateParam->setImplicit();
2999  LSI->TemplateParams.push_back(CorrespondingTemplateParam);
3000  // Replace the 'auto' in the function parameter with this invented
3001  // template type parameter.
3002  // FIXME: Retain some type sugar to indicate that this was written
3003  // as 'auto'.
3004  T = state.ReplaceAutoType(
3005  T, QualType(CorrespondingTemplateParam->getTypeForDecl(), 0));
3006  }
3007  break;
3011  break;
3012  bool Cxx = SemaRef.getLangOpts().CPlusPlus;
3013  switch (cast<TagDecl>(SemaRef.CurContext)->getTagKind()) {
3014  case TTK_Enum: llvm_unreachable("unhandled tag kind");
3015  case TTK_Struct: Error = Cxx ? 1 : 2; /* Struct member */ break;
3016  case TTK_Union: Error = Cxx ? 3 : 4; /* Union member */ break;
3017  case TTK_Class: Error = 5; /* Class member */ break;
3018  case TTK_Interface: Error = 6; /* Interface member */ break;
3019  }
3020  if (D.getDeclSpec().isFriendSpecified())
3021  Error = 20; // Friend type
3022  break;
3023  }
3026  Error = 7; // Exception declaration
3027  break;
3029  if (isa<DeducedTemplateSpecializationType>(Deduced))
3030  Error = 19; // Template parameter
3031  else if (!SemaRef.getLangOpts().CPlusPlus17)
3032  Error = 8; // Template parameter (until C++17)
3033  break;
3035  Error = 9; // Block literal
3036  break;
3038  // Within a template argument list, a deduced template specialization
3039  // type will be reinterpreted as a template template argument.
3040  if (isa<DeducedTemplateSpecializationType>(Deduced) &&
3041  !D.getNumTypeObjects() &&
3043  break;
3044  LLVM_FALLTHROUGH;
3046  Error = 10; // Template type argument
3047  break;
3050  Error = 12; // Type alias
3051  break;
3054  if (!SemaRef.getLangOpts().CPlusPlus14 || !IsCXXAutoType)
3055  Error = 13; // Function return type
3056  IsDeducedReturnType = true;
3057  break;
3059  if (!SemaRef.getLangOpts().CPlusPlus14 || !IsCXXAutoType)
3060  Error = 14; // conversion-type-id
3061  IsDeducedReturnType = true;
3062  break;
3064  if (isa<DeducedTemplateSpecializationType>(Deduced))
3065  break;
3066  LLVM_FALLTHROUGH;
3068  Error = 15; // Generic
3069  break;
3075  // FIXME: P0091R3 (erroneously) does not permit class template argument
3076  // deduction in conditions, for-init-statements, and other declarations
3077  // that are not simple-declarations.
3078  break;
3080  // FIXME: P0091R3 does not permit class template argument deduction here,
3081  // but we follow GCC and allow it anyway.
3082  if (!IsCXXAutoType && !isa<DeducedTemplateSpecializationType>(Deduced))
3083  Error = 17; // 'new' type
3084  break;
3086  Error = 18; // K&R function parameter
3087  break;
3088  }
3089 
3091  Error = 11;
3092 
3093  // In Objective-C it is an error to use 'auto' on a function declarator
3094  // (and everywhere for '__auto_type').
3095  if (D.isFunctionDeclarator() &&
3096  (!SemaRef.getLangOpts().CPlusPlus11 || !IsCXXAutoType))
3097  Error = 13;
3098 
3099  bool HaveTrailing = false;
3100 
3101  // C++11 [dcl.spec.auto]p2: 'auto' is always fine if the declarator
3102  // contains a trailing return type. That is only legal at the outermost
3103  // level. Check all declarator chunks (outermost first) anyway, to give
3104  // better diagnostics.
3105  // We don't support '__auto_type' with trailing return types.
3106  // FIXME: Should we only do this for 'auto' and not 'decltype(auto)'?
3107  if (SemaRef.getLangOpts().CPlusPlus11 && IsCXXAutoType &&
3108  D.hasTrailingReturnType()) {
3109  HaveTrailing = true;
3110  Error = -1;
3111  }
3112 
3113  SourceRange AutoRange = D.getDeclSpec().getTypeSpecTypeLoc();
3115  AutoRange = D.getName().getSourceRange();
3116 
3117  if (Error != -1) {
3118  unsigned Kind;
3119  if (Auto) {
3120  switch (Auto->getKeyword()) {
3121  case AutoTypeKeyword::Auto: Kind = 0; break;
3122  case AutoTypeKeyword::DecltypeAuto: Kind = 1; break;
3123  case AutoTypeKeyword::GNUAutoType: Kind = 2; break;
3124  }
3125  } else {
3126  assert(isa<DeducedTemplateSpecializationType>(Deduced) &&
3127  "unknown auto type");
3128  Kind = 3;
3129  }
3130 
3131  auto *DTST = dyn_cast<DeducedTemplateSpecializationType>(Deduced);
3132  TemplateName TN = DTST ? DTST->getTemplateName() : TemplateName();
3133 
3134  SemaRef.Diag(AutoRange.getBegin(), diag::err_auto_not_allowed)
3135  << Kind << Error << (int)SemaRef.getTemplateNameKindForDiagnostics(TN)
3136  << QualType(Deduced, 0) << AutoRange;
3137  if (auto *TD = TN.getAsTemplateDecl())
3138  SemaRef.Diag(TD->getLocation(), diag::note_template_decl_here);
3139 
3140  T = SemaRef.Context.IntTy;
3141  D.setInvalidType(true);
3142  } else if (!HaveTrailing &&
3144  // If there was a trailing return type, we already got
3145  // warn_cxx98_compat_trailing_return_type in the parser.
3146  SemaRef.Diag(AutoRange.getBegin(),
3147  D.getContext() ==
3149  ? diag::warn_cxx11_compat_generic_lambda
3150  : IsDeducedReturnType
3151  ? diag::warn_cxx11_compat_deduced_return_type
3152  : diag::warn_cxx98_compat_auto_type_specifier)
3153  << AutoRange;
3154  }
3155  }
3156 
3157  if (SemaRef.getLangOpts().CPlusPlus &&
3158  OwnedTagDecl && OwnedTagDecl->isCompleteDefinition()) {
3159  // Check the contexts where C++ forbids the declaration of a new class
3160  // or enumeration in a type-specifier-seq.
3161  unsigned DiagID = 0;
3162  switch (D.getContext()) {
3165  // Class and enumeration definitions are syntactically not allowed in
3166  // trailing return types.
3167  llvm_unreachable("parser should not have allowed this");
3168  break;
3176  // C++11 [dcl.type]p3:
3177  // A type-specifier-seq shall not define a class or enumeration unless
3178  // it appears in the type-id of an alias-declaration (7.1.3) that is not
3179  // the declaration of a template-declaration.
3181  break;
3183  DiagID = diag::err_type_defined_in_alias_template;
3184  break;
3194  DiagID = diag::err_type_defined_in_type_specifier;
3195  break;
3201  // C++ [dcl.fct]p6:
3202  // Types shall not be defined in return or parameter types.
3203  DiagID = diag::err_type_defined_in_param_type;
3204  break;
3206  // C++ 6.4p2:
3207  // The type-specifier-seq shall not contain typedef and shall not declare
3208  // a new class or enumeration.
3209  DiagID = diag::err_type_defined_in_condition;
3210  break;
3211  }
3212 
3213  if (DiagID != 0) {
3214  SemaRef.Diag(OwnedTagDecl->getLocation(), DiagID)
3215  << SemaRef.Context.getTypeDeclType(OwnedTagDecl);
3216  D.setInvalidType(true);
3217  }
3218  }
3219 
3220  assert(!T.isNull() && "This function should not return a null type");
3221  return T;
3222 }
3223 
3224 /// Produce an appropriate diagnostic for an ambiguity between a function
3225 /// declarator and a C++ direct-initializer.
3227  DeclaratorChunk &DeclType, QualType RT) {
3228  const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
3229  assert(FTI.isAmbiguous && "no direct-initializer / function ambiguity");
3230 
3231  // If the return type is void there is no ambiguity.
3232  if (RT->isVoidType())
3233  return;
3234 
3235  // An initializer for a non-class type can have at most one argument.
3236  if (!RT->isRecordType() && FTI.NumParams > 1)
3237  return;
3238 
3239  // An initializer for a reference must have exactly one argument.
3240  if (RT->isReferenceType() && FTI.NumParams != 1)
3241  return;
3242 
3243  // Only warn if this declarator is declaring a function at block scope, and
3244  // doesn't have a storage class (such as 'extern') specified.
3245  if (!D.isFunctionDeclarator() ||
3250  return;
3251 
3252  // Inside a condition, a direct initializer is not permitted. We allow one to
3253  // be parsed in order to give better diagnostics in condition parsing.
3255  return;
3256 
3257  SourceRange ParenRange(DeclType.Loc, DeclType.EndLoc);
3258 
3259  S.Diag(DeclType.Loc,
3260  FTI.NumParams ? diag::warn_parens_disambiguated_as_function_declaration
3261  : diag::warn_empty_parens_are_function_decl)
3262  << ParenRange;
3263 
3264  // If the declaration looks like:
3265  // T var1,
3266  // f();
3267  // and name lookup finds a function named 'f', then the ',' was
3268  // probably intended to be a ';'.
3269  if (!D.isFirstDeclarator() && D.getIdentifier()) {
3272  if (Comma.getFileID() != Name.getFileID() ||
3273  Comma.getSpellingLineNumber() != Name.getSpellingLineNumber()) {
3276  if (S.LookupName(Result, S.getCurScope()))
3277  S.Diag(D.getCommaLoc(), diag::note_empty_parens_function_call)
3279  << D.getIdentifier();
3280  Result.suppressDiagnostics();
3281  }
3282  }
3283 
3284  if (FTI.NumParams > 0) {
3285  // For a declaration with parameters, eg. "T var(T());", suggest adding
3286  // parens around the first parameter to turn the declaration into a
3287  // variable declaration.
3288  SourceRange Range = FTI.Params[0].Param->getSourceRange();
3289  SourceLocation B = Range.getBegin();
3290  SourceLocation E = S.getLocForEndOfToken(Range.getEnd());
3291  // FIXME: Maybe we should suggest adding braces instead of parens
3292  // in C++11 for classes that don't have an initializer_list constructor.
3293  S.Diag(B, diag::note_additional_parens_for_variable_declaration)
3294  << FixItHint::CreateInsertion(B, "(")
3295  << FixItHint::CreateInsertion(E, ")");
3296  } else {
3297  // For a declaration without parameters, eg. "T var();", suggest replacing
3298  // the parens with an initializer to turn the declaration into a variable
3299  // declaration.
3300  const CXXRecordDecl *RD = RT->getAsCXXRecordDecl();
3301 
3302  // Empty parens mean value-initialization, and no parens mean
3303  // default initialization. These are equivalent if the default
3304  // constructor is user-provided or if zero-initialization is a
3305  // no-op.
3306  if (RD && RD->hasDefinition() &&
3307  (RD->isEmpty() || RD->hasUserProvidedDefaultConstructor()))
3308  S.Diag(DeclType.Loc, diag::note_empty_parens_default_ctor)
3309  << FixItHint::CreateRemoval(ParenRange);
3310  else {
3311  std::string Init =
3312  S.getFixItZeroInitializerForType(RT, ParenRange.getBegin());
3313  if (Init.empty() && S.LangOpts.CPlusPlus11)
3314  Init = "{}";
3315  if (!Init.empty())
3316  S.Diag(DeclType.Loc, diag::note_empty_parens_zero_initialize)
3317  << FixItHint::CreateReplacement(ParenRange, Init);
3318  }
3319  }
3320 }
3321 
3322 /// Produce an appropriate diagnostic for a declarator with top-level
3323 /// parentheses.
3326  assert(Paren.Kind == DeclaratorChunk::Paren &&
3327  "do not have redundant top-level parentheses");
3328 
3329  // This is a syntactic check; we're not interested in cases that arise
3330  // during template instantiation.
3331  if (S.inTemplateInstantiation())
3332  return;
3333 
3334  // Check whether this could be intended to be a construction of a temporary
3335  // object in C++ via a function-style cast.
3336  bool CouldBeTemporaryObject =
3337  S.getLangOpts().CPlusPlus && D.isExpressionContext() &&
3338  !D.isInvalidType() && D.getIdentifier() &&
3340  (T->isRecordType() || T->isDependentType()) &&
3342 
3343  bool StartsWithDeclaratorId = true;
3344  for (auto &C : D.type_objects()) {
3345  switch (C.Kind) {
3347  if (&C == &Paren)
3348  continue;
3349  LLVM_FALLTHROUGH;
3351  StartsWithDeclaratorId = false;
3352  continue;
3353 
3355  if (!C.Arr.NumElts)
3356  CouldBeTemporaryObject = false;
3357  continue;
3358 
3360  // FIXME: Suppress the warning here if there is no initializer; we're
3361  // going to give an error anyway.
3362  // We assume that something like 'T (&x) = y;' is highly likely to not
3363  // be intended to be a temporary object.
3364  CouldBeTemporaryObject = false;
3365  StartsWithDeclaratorId = false;
3366  continue;
3367 
3369  // In a new-type-id, function chunks require parentheses.
3371  return;
3372  // FIXME: "A(f())" deserves a vexing-parse warning, not just a
3373  // redundant-parens warning, but we don't know whether the function
3374  // chunk was syntactically valid as an expression here.
3375  CouldBeTemporaryObject = false;
3376  continue;
3377 
3380  case DeclaratorChunk::Pipe:
3381  // These cannot appear in expressions.
3382  CouldBeTemporaryObject = false;
3383  StartsWithDeclaratorId = false;
3384  continue;
3385  }
3386  }
3387 
3388  // FIXME: If there is an initializer, assume that this is not intended to be
3389  // a construction of a temporary object.
3390 
3391  // Check whether the name has already been declared; if not, this is not a
3392  // function-style cast.
3393  if (CouldBeTemporaryObject) {
3396  if (!S.LookupName(Result, S.getCurScope()))
3397  CouldBeTemporaryObject = false;
3398  Result.suppressDiagnostics();
3399  }
3400 
3401  SourceRange ParenRange(Paren.Loc, Paren.EndLoc);
3402 
3403  if (!CouldBeTemporaryObject) {
3404  // If we have A (::B), the parentheses affect the meaning of the program.
3405  // Suppress the warning in that case. Don't bother looking at the DeclSpec
3406  // here: even (e.g.) "int ::x" is visually ambiguous even though it's
3407  // formally unambiguous.
3408  if (StartsWithDeclaratorId && D.getCXXScopeSpec().isValid()) {
3409  for (NestedNameSpecifier *NNS = D.getCXXScopeSpec().getScopeRep(); NNS;
3410  NNS = NNS->getPrefix()) {
3411  if (NNS->getKind() == NestedNameSpecifier::Global)
3412  return;
3413  }
3414  }
3415 
3416  S.Diag(Paren.Loc, diag::warn_redundant_parens_around_declarator)
3417  << ParenRange << FixItHint::CreateRemoval(Paren.Loc)
3418  << FixItHint::CreateRemoval(Paren.EndLoc);
3419  return;
3420  }
3421 
3422  S.Diag(Paren.Loc, diag::warn_parens_disambiguated_as_variable_declaration)
3423  << ParenRange << D.getIdentifier();
3424  auto *RD = T->getAsCXXRecordDecl();
3425  if (!RD || !RD->hasDefinition() || RD->hasNonTrivialDestructor())
3426  S.Diag(Paren.Loc, diag::note_raii_guard_add_name)
3427  << FixItHint::CreateInsertion(Paren.Loc, " varname") << T
3428  << D.getIdentifier();
3429  // FIXME: A cast to void is probably a better suggestion in cases where it's
3430  // valid (when there is no initializer and we're not in a condition).
3431  S.Diag(D.getBeginLoc(), diag::note_function_style_cast_add_parentheses)
3434  S.Diag(Paren.Loc, diag::note_remove_parens_for_variable_declaration)
3435  << FixItHint::CreateRemoval(Paren.Loc)
3436  << FixItHint::CreateRemoval(Paren.EndLoc);
3437 }
3438 
3439 /// Helper for figuring out the default CC for a function declarator type. If
3440 /// this is the outermost chunk, then we can determine the CC from the
3441 /// declarator context. If not, then this could be either a member function
3442 /// type or normal function type.
3444  Sema &S, Declarator &D, const ParsedAttributesView &AttrList,
3445  const DeclaratorChunk::FunctionTypeInfo &FTI, unsigned ChunkIndex) {
3446  assert(D.getTypeObject(ChunkIndex).Kind == DeclaratorChunk::Function);
3447 
3448  // Check for an explicit CC attribute.
3449  for (const ParsedAttr &AL : AttrList) {
3450  switch (AL.getKind()) {
3452  // Ignore attributes that don't validate or can't apply to the
3453  // function type. We'll diagnose the failure to apply them in
3454  // handleFunctionTypeAttr.
3455  CallingConv CC;
3456  if (!S.CheckCallingConvAttr(AL, CC) &&
3457  (!FTI.isVariadic || supportsVariadicCall(CC))) {
3458  return CC;
3459  }
3460  break;
3461  }
3462 
3463  default:
3464  break;
3465  }
3466  }
3467 
3468  bool IsCXXInstanceMethod = false;
3469 
3470  if (S.getLangOpts().CPlusPlus) {
3471  // Look inwards through parentheses to see if this chunk will form a
3472  // member pointer type or if we're the declarator. Any type attributes
3473  // between here and there will override the CC we choose here.
3474  unsigned I = ChunkIndex;
3475  bool FoundNonParen = false;
3476  while (I && !FoundNonParen) {
3477  --I;
3479  FoundNonParen = true;
3480  }
3481 
3482  if (FoundNonParen) {
3483  // If we're not the declarator, we're a regular function type unless we're
3484  // in a member pointer.
3485  IsCXXInstanceMethod =
3488  // This can only be a call operator for a lambda, which is an instance
3489  // method.
3490  IsCXXInstanceMethod = true;
3491  } else {
3492  // We're the innermost decl chunk, so must be a function declarator.
3493  assert(D.isFunctionDeclarator());
3494 
3495  // If we're inside a record, we're declaring a method, but it could be
3496  // explicitly or implicitly static.
3497  IsCXXInstanceMethod =
3500  !D.isStaticMember();
3501  }
3502  }
3503 
3505  IsCXXInstanceMethod);
3506 
3507  // Attribute AT_OpenCLKernel affects the calling convention for SPIR
3508  // and AMDGPU targets, hence it cannot be treated as a calling
3509  // convention attribute. This is the simplest place to infer
3510  // calling convention for OpenCL kernels.
3511  if (S.getLangOpts().OpenCL) {
3512  for (const ParsedAttr &AL : D.getDeclSpec().getAttributes()) {
3513  if (AL.getKind() == ParsedAttr::AT_OpenCLKernel) {
3514  CC = CC_OpenCLKernel;
3515  break;
3516  }
3517  }
3518  }
3519 
3520  return CC;
3521 }
3522 
3523 namespace {
3524  /// A simple notion of pointer kinds, which matches up with the various
3525  /// pointer declarators.
3526  enum class SimplePointerKind {
3527  Pointer,
3528  BlockPointer,
3529  MemberPointer,
3530  Array,
3531  };
3532 } // end anonymous namespace
3533 
3535  switch (nullability) {
3537  if (!Ident__Nonnull)
3538  Ident__Nonnull = PP.getIdentifierInfo("_Nonnull");
3539  return Ident__Nonnull;
3540 
3542  if (!Ident__Nullable)
3543  Ident__Nullable = PP.getIdentifierInfo("_Nullable");
3544  return Ident__Nullable;
3545 
3547  if (!Ident__Null_unspecified)
3548  Ident__Null_unspecified = PP.getIdentifierInfo("_Null_unspecified");
3549  return Ident__Null_unspecified;
3550  }
3551  llvm_unreachable("Unknown nullability kind.");
3552 }
3553 
3554 /// Retrieve the identifier "NSError".
3556  if (!Ident_NSError)
3557  Ident_NSError = PP.getIdentifierInfo("NSError");
3558 
3559  return Ident_NSError;
3560 }
3561 
3562 /// Check whether there is a nullability attribute of any kind in the given
3563 /// attribute list.
3564 static bool hasNullabilityAttr(const ParsedAttributesView &attrs) {
3565  for (const ParsedAttr &AL : attrs) {
3566  if (AL.getKind() == ParsedAttr::AT_TypeNonNull ||
3567  AL.getKind() == ParsedAttr::AT_TypeNullable ||
3568  AL.getKind() == ParsedAttr::AT_TypeNullUnspecified)
3569  return true;
3570  }
3571 
3572  return false;
3573 }
3574 
3575 namespace {
3576  /// Describes the kind of a pointer a declarator describes.
3578  // Not a pointer.
3579  NonPointer,
3580  // Single-level pointer.
3581  SingleLevelPointer,
3582  // Multi-level pointer (of any pointer kind).
3583  MultiLevelPointer,
3584  // CFFooRef*
3585  MaybePointerToCFRef,
3586  // CFErrorRef*
3587  CFErrorRefPointer,
3588  // NSError**
3589  NSErrorPointerPointer,
3590  };
3591 
3592  /// Describes a declarator chunk wrapping a pointer that marks inference as
3593  /// unexpected.
3594  // These values must be kept in sync with diagnostics.
3596  /// Pointer is top-level.
3597  None = -1,
3598  /// Pointer is an array element.
3599  Array = 0,
3600  /// Pointer is the referent type of a C++ reference.
3601  Reference = 1
3602  };
3603 } // end anonymous namespace
3604 
3605 /// Classify the given declarator, whose type-specified is \c type, based on
3606 /// what kind of pointer it refers to.
3607 ///
3608 /// This is used to determine the default nullability.
3609 static PointerDeclaratorKind
3611  PointerWrappingDeclaratorKind &wrappingKind) {
3612  unsigned numNormalPointers = 0;
3613 
3614  // For any dependent type, we consider it a non-pointer.
3615  if (type->isDependentType())
3616  return PointerDeclaratorKind::NonPointer;
3617 
3618  // Look through the declarator chunks to identify pointers.
3619  for (unsigned i = 0, n = declarator.getNumTypeObjects(); i != n; ++i) {
3620  DeclaratorChunk &chunk = declarator.getTypeObject(i);
3621  switch (chunk.Kind) {
3623  if (numNormalPointers == 0)
3624  wrappingKind = PointerWrappingDeclaratorKind::Array;
3625  break;
3626 
3628  case DeclaratorChunk::Pipe:
3629  break;
3630 
3633  return numNormalPointers > 0 ? PointerDeclaratorKind::MultiLevelPointer
3634  : PointerDeclaratorKind::SingleLevelPointer;
3635 
3637  break;
3638 
3640  if (numNormalPointers == 0)
3641  wrappingKind = PointerWrappingDeclaratorKind::Reference;
3642  break;
3643 
3645  ++numNormalPointers;
3646  if (numNormalPointers > 2)
3647  return PointerDeclaratorKind::MultiLevelPointer;
3648  break;
3649  }
3650  }
3651 
3652  // Then, dig into the type specifier itself.
3653  unsigned numTypeSpecifierPointers = 0;
3654  do {
3655  // Decompose normal pointers.
3656  if (auto ptrType = type->getAs<PointerType>()) {
3657  ++numNormalPointers;
3658 
3659  if (numNormalPointers > 2)
3660  return PointerDeclaratorKind::MultiLevelPointer;
3661 
3662  type = ptrType->getPointeeType();
3663  ++numTypeSpecifierPointers;
3664  continue;
3665  }
3666 
3667  // Decompose block pointers.
3668  if (type->getAs<BlockPointerType>()) {
3669  return numNormalPointers > 0 ? PointerDeclaratorKind::MultiLevelPointer
3670  : PointerDeclaratorKind::SingleLevelPointer;
3671  }
3672 
3673  // Decompose member pointers.
3674  if (type->getAs<MemberPointerType>()) {
3675  return numNormalPointers > 0 ? PointerDeclaratorKind::MultiLevelPointer
3676  : PointerDeclaratorKind::SingleLevelPointer;
3677  }
3678 
3679  // Look at Objective-C object pointers.
3680  if (auto objcObjectPtr = type->getAs<ObjCObjectPointerType>()) {
3681  ++numNormalPointers;
3682  ++numTypeSpecifierPointers;
3683 
3684  // If this is NSError**, report that.
3685  if (auto objcClassDecl = objcObjectPtr->getInterfaceDecl()) {
3686  if (objcClassDecl->getIdentifier() == S.getNSErrorIdent() &&
3687  numNormalPointers == 2 && numTypeSpecifierPointers < 2) {
3688  return PointerDeclaratorKind::NSErrorPointerPointer;
3689  }
3690  }
3691 
3692  break;
3693  }
3694 
3695  // Look at Objective-C class types.
3696  if (auto objcClass = type->getAs<ObjCInterfaceType>()) {
3697  if (objcClass->getInterface()->getIdentifier() == S.getNSErrorIdent()) {
3698  if (numNormalPointers == 2 && numTypeSpecifierPointers < 2)
3699  return PointerDeclaratorKind::NSErrorPointerPointer;
3700  }
3701 
3702  break;
3703  }
3704 
3705  // If at this point we haven't seen a pointer, we won't see one.
3706  if (numNormalPointers == 0)
3707  return PointerDeclaratorKind::NonPointer;
3708 
3709  if (auto recordType = type->getAs<RecordType>()) {
3710  RecordDecl *recordDecl = recordType->getDecl();
3711 
3712  bool isCFError = false;
3713  if (S.CFError) {
3714  // If we already know about CFError, test it directly.
3715  isCFError = (S.CFError == recordDecl);
3716  } else {
3717  // Check whether this is CFError, which we identify based on its bridge
3718  // to NSError. CFErrorRef used to be declared with "objc_bridge" but is
3719  // now declared with "objc_bridge_mutable", so look for either one of
3720  // the two attributes.
3721  if (recordDecl->getTagKind() == TTK_Struct && numNormalPointers > 0) {
3722  IdentifierInfo *bridgedType = nullptr;
3723  if (auto bridgeAttr = recordDecl->getAttr<ObjCBridgeAttr>())
3724  bridgedType = bridgeAttr->getBridgedType();
3725  else if (auto bridgeAttr =
3726  recordDecl->getAttr<ObjCBridgeMutableAttr>())
3727  bridgedType = bridgeAttr->getBridgedType();
3728 
3729  if (bridgedType == S.getNSErrorIdent()) {
3730  S.CFError = recordDecl;
3731  isCFError = true;
3732  }
3733  }
3734  }
3735 
3736  // If this is CFErrorRef*, report it as such.
3737  if (isCFError && numNormalPointers == 2 && numTypeSpecifierPointers < 2) {
3738  return PointerDeclaratorKind::CFErrorRefPointer;
3739  }
3740  break;
3741  }
3742 
3743  break;
3744  } while (true);
3745 
3746  switch (numNormalPointers) {
3747  case 0:
3748  return PointerDeclaratorKind::NonPointer;
3749 
3750  case 1:
3751  return PointerDeclaratorKind::SingleLevelPointer;
3752 
3753  case 2:
3754  return PointerDeclaratorKind::MaybePointerToCFRef;
3755 
3756  default:
3757  return PointerDeclaratorKind::MultiLevelPointer;
3758  }
3759 }
3760 
3762  SourceLocation loc) {
3763  // If we're anywhere in a function, method, or closure context, don't perform
3764  // completeness checks.
3765  for (DeclContext *ctx = S.CurContext; ctx; ctx = ctx->getParent()) {
3766  if (ctx->isFunctionOrMethod())
3767  return FileID();
3768 
3769  if (ctx->isFileContext())
3770  break;
3771  }
3772 
3773  // We only care about the expansion location.
3774  loc = S.SourceMgr.getExpansionLoc(loc);
3775  FileID file = S.SourceMgr.getFileID(loc);
3776  if (file.isInvalid())
3777  return FileID();
3778 
3779  // Retrieve file information.
3780  bool invalid = false;
3781  const SrcMgr::SLocEntry &sloc = S.SourceMgr.getSLocEntry(file, &invalid);
3782  if (invalid || !sloc.isFile())
3783  return FileID();
3784 
3785  // We don't want to perform completeness checks on the main file or in
3786  // system headers.
3787  const SrcMgr::FileInfo &fileInfo = sloc.getFile();
3788  if (fileInfo.getIncludeLoc().isInvalid())
3789  return FileID();
3790  if (fileInfo.getFileCharacteristic() != SrcMgr::C_User &&
3792  return FileID();
3793  }
3794 
3795  return file;
3796 }
3797 
3798 /// Creates a fix-it to insert a C-style nullability keyword at \p pointerLoc,
3799 /// taking into account whitespace before and after.
3801  SourceLocation PointerLoc,
3803  assert(PointerLoc.isValid());
3804  if (PointerLoc.isMacroID())
3805  return;
3806 
3807  SourceLocation FixItLoc = S.getLocForEndOfToken(PointerLoc);
3808  if (!FixItLoc.isValid() || FixItLoc == PointerLoc)
3809  return;
3810 
3811  const char *NextChar = S.SourceMgr.getCharacterData(FixItLoc);
3812  if (!NextChar)
3813  return;
3814 
3815  SmallString<32> InsertionTextBuf{" "};
3816  InsertionTextBuf += getNullabilitySpelling(Nullability);
3817  InsertionTextBuf += " ";
3818  StringRef InsertionText = InsertionTextBuf.str();
3819 
3820  if (isWhitespace(*NextChar)) {
3821  InsertionText = InsertionText.drop_back();
3822  } else if (NextChar[-1] == '[') {
3823  if (NextChar[0] == ']')
3824  InsertionText = InsertionText.drop_back().drop_front();
3825  else
3826  InsertionText = InsertionText.drop_front();
3827  } else if (!isIdentifierBody(NextChar[0], /*allow dollar*/true) &&
3828  !isIdentifierBody(NextChar[-1], /*allow dollar*/true)) {
3829  InsertionText = InsertionText.drop_back().drop_front();
3830  }
3831 
3832  Diag << FixItHint::CreateInsertion(FixItLoc, InsertionText);
3833 }
3834 
3836  SimplePointerKind PointerKind,
3837  SourceLocation PointerLoc,
3838  SourceLocation PointerEndLoc) {
3839  assert(PointerLoc.isValid());
3840 
3841  if (PointerKind == SimplePointerKind::Array) {
3842  S.Diag(PointerLoc, diag::warn_nullability_missing_array);
3843  } else {
3844  S.Diag(PointerLoc, diag::warn_nullability_missing)
3845  << static_cast<unsigned>(PointerKind);
3846  }
3847 
3848  auto FixItLoc = PointerEndLoc.isValid() ? PointerEndLoc : PointerLoc;
3849  if (FixItLoc.isMacroID())
3850  return;
3851 
3852  auto addFixIt = [&](NullabilityKind Nullability) {
3853  auto Diag = S.Diag(FixItLoc, diag::note_nullability_fix_it);
3854  Diag << static_cast<unsigned>(Nullability);
3855  Diag << static_cast<unsigned>(PointerKind);
3856  fixItNullability(S, Diag, FixItLoc, Nullability);
3857  };
3858  addFixIt(NullabilityKind::Nullable);
3859  addFixIt(NullabilityKind::NonNull);
3860 }
3861 
3862 /// Complains about missing nullability if the file containing \p pointerLoc
3863 /// has other uses of nullability (either the keywords or the \c assume_nonnull
3864 /// pragma).
3865 ///
3866 /// If the file has \e not seen other uses of nullability, this particular
3867 /// pointer is saved for possible later diagnosis. See recordNullabilitySeen().
3868 static void
3870  SourceLocation pointerLoc,
3871  SourceLocation pointerEndLoc = SourceLocation()) {
3872  // Determine which file we're performing consistency checking for.
3873  FileID file = getNullabilityCompletenessCheckFileID(S, pointerLoc);
3874  if (file.isInvalid())
3875  return;
3876 
3877  // If we haven't seen any type nullability in this file, we won't warn now
3878  // about anything.
3879  FileNullability &fileNullability = S.NullabilityMap[file];
3880  if (!fileNullability.SawTypeNullability) {
3881  // If this is the first pointer declarator in the file, and the appropriate
3882  // warning is on, record it in case we need to diagnose it retroactively.
3883  diag::kind diagKind;
3884  if (pointerKind == SimplePointerKind::Array)
3885  diagKind = diag::warn_nullability_missing_array;
3886  else
3887  diagKind = diag::warn_nullability_missing;
3888 
3889  if (fileNullability.PointerLoc.isInvalid() &&
3890  !S.Context.getDiagnostics().isIgnored(diagKind, pointerLoc)) {
3891  fileNullability.PointerLoc = pointerLoc;
3892  fileNullability.PointerEndLoc = pointerEndLoc;
3893  fileNullability.PointerKind = static_cast<unsigned>(pointerKind);
3894  }
3895 
3896  return;
3897  }
3898 
3899  // Complain about missing nullability.
3900  emitNullabilityConsistencyWarning(S, pointerKind, pointerLoc, pointerEndLoc);
3901 }
3902 
3903 /// Marks that a nullability feature has been used in the file containing
3904 /// \p loc.
3905 ///
3906 /// If this file already had pointer types in it that were missing nullability,
3907 /// the first such instance is retroactively diagnosed.
3908 ///
3909 /// \sa checkNullabilityConsistency
3912  if (file.isInvalid())
3913  return;
3914 
3915  FileNullability &fileNullability = S.NullabilityMap[file];
3916  if (fileNullability.SawTypeNullability)
3917  return;
3918  fileNullability.SawTypeNullability = true;
3919 
3920  // If we haven't seen any type nullability before, now we have. Retroactively
3921  // diagnose the first unannotated pointer, if there was one.
3922  if (fileNullability.PointerLoc.isInvalid())
3923  return;
3924 
3925  auto kind = static_cast<SimplePointerKind>(fileNullability.PointerKind);
3927  fileNullability.PointerEndLoc);
3928 }
3929 
3930 /// Returns true if any of the declarator chunks before \p endIndex include a
3931 /// level of indirection: array, pointer, reference, or pointer-to-member.
3932 ///
3933 /// Because declarator chunks are stored in outer-to-inner order, testing
3934 /// every chunk before \p endIndex is testing all chunks that embed the current
3935 /// chunk as part of their type.
3936 ///
3937 /// It is legal to pass the result of Declarator::getNumTypeObjects() as the
3938 /// end index, in which case all chunks are tested.
3939 static bool hasOuterPointerLikeChunk(const Declarator &D, unsigned endIndex) {
3940  unsigned i = endIndex;
3941  while (i != 0) {
3942  // Walk outwards along the declarator chunks.
3943  --i;
3944  const DeclaratorChunk &DC = D.getTypeObject(i);
3945  switch (DC.Kind) {
3947  break;
3952  return true;
3955  case DeclaratorChunk::Pipe:
3956  // These are invalid anyway, so just ignore.
3957  break;
3958  }
3959  }
3960  return false;
3961 }
3962 
3964  return (Chunk.Kind == DeclaratorChunk::Pointer ||
3965  Chunk.Kind == DeclaratorChunk::Array);
3966 }
3967 
3968 template<typename AttrT>
3969 static AttrT *createSimpleAttr(ASTContext &Ctx, ParsedAttr &AL) {
3970  AL.setUsedAsTypeAttr();
3971  return ::new (Ctx) AttrT(Ctx, AL);
3972 }
3973 
3975  NullabilityKind NK) {
3976  switch (NK) {
3978  return createSimpleAttr<TypeNonNullAttr>(Ctx, Attr);
3979 
3981  return createSimpleAttr<TypeNullableAttr>(Ctx, Attr);
3982 
3984  return createSimpleAttr<TypeNullUnspecifiedAttr>(Ctx, Attr);
3985  }
3986  llvm_unreachable("unknown NullabilityKind");
3987 }
3988 
3989 // Diagnose whether this is a case with the multiple addr spaces.
3990 // Returns true if this is an invalid case.
3991 // ISO/IEC TR 18037 S5.3 (amending C99 6.7.3): "No type shall be qualified
3992 // by qualifiers for two or more different address spaces."
3994  LangAS ASNew,
3995  SourceLocation AttrLoc) {
3996  if (ASOld != LangAS::Default) {
3997  if (ASOld != ASNew) {
3998  S.Diag(AttrLoc, diag::err_attribute_address_multiple_qualifiers);
3999  return true;
4000  }
4001  // Emit a warning if they are identical; it's likely unintended.
4002  S.Diag(AttrLoc,
4003  diag::warn_attribute_address_multiple_identical_qualifiers);
4004  }
4005  return false;
4006 }
4007 
4008 static TypeSourceInfo *
4009 GetTypeSourceInfoForDeclarator(TypeProcessingState &State,
4010  QualType T, TypeSourceInfo *ReturnTypeInfo);
4011 
4012 static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
4013  QualType declSpecType,
4014  TypeSourceInfo *TInfo) {
4015  // The TypeSourceInfo that this function returns will not be a null type.
4016  // If there is an error, this function will fill in a dummy type as fallback.
4017  QualType T = declSpecType;
4018  Declarator &D = state.getDeclarator();
4019  Sema &S = state.getSema();
4020  ASTContext &Context = S.Context;
4021  const LangOptions &LangOpts = S.getLangOpts();
4022 
4023  // The name we're declaring, if any.
4024  DeclarationName Name;
4025  if (D.getIdentifier())
4026  Name = D.getIdentifier();
4027 
4028  // Does this declaration declare a typedef-name?
4029  bool IsTypedefName =
4033 
4034  // Does T refer to a function type with a cv-qualifier or a ref-qualifier?
4035  bool IsQualifiedFunction = T->isFunctionProtoType() &&
4036  (!T->castAs<FunctionProtoType>()->getMethodQuals().empty() ||
4037  T->castAs<FunctionProtoType>()->getRefQualifier() != RQ_None);
4038 
4039  // If T is 'decltype(auto)', the only declarators we can have are parens
4040  // and at most one function declarator if this is a function declaration.
4041  // If T is a deduced class template specialization type, we can have no
4042  // declarator chunks at all.
4043  if (auto *DT = T->getAs<DeducedType>()) {
4044  const AutoType *AT = T->getAs<AutoType>();
4045  bool IsClassTemplateDeduction = isa<DeducedTemplateSpecializationType>(DT);
4046  if ((AT && AT->isDecltypeAuto()) || IsClassTemplateDeduction) {
4047  for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
4048  unsigned Index = E - I - 1;
4049  DeclaratorChunk &DeclChunk = D.getTypeObject(Index);
4050  unsigned DiagId = IsClassTemplateDeduction
4051  ? diag::err_deduced_class_template_compound_type
4052  : diag::err_decltype_auto_compound_type;
4053  unsigned DiagKind = 0;
4054  switch (DeclChunk.Kind) {
4056  // FIXME: Rejecting this is a little silly.
4057  if (IsClassTemplateDeduction) {
4058  DiagKind = 4;
4059  break;
4060  }
4061  continue;
4063  if (IsClassTemplateDeduction) {
4064  DiagKind = 3;
4065  break;
4066  }
4067  unsigned FnIndex;
4068  if (D.isFunctionDeclarationContext() &&
4069  D.isFunctionDeclarator(FnIndex) && FnIndex == Index)
4070  continue;
4071  DiagId = diag::err_decltype_auto_function_declarator_not_declaration;
4072  break;
4073  }
4077  DiagKind = 0;
4078  break;
4080  DiagKind = 1;
4081  break;
4083  DiagKind = 2;
4084  break;
4085  case DeclaratorChunk::Pipe:
4086  break;
4087  }
4088 
4089  S.Diag(DeclChunk.Loc, DiagId) << DiagKind;
4090  D.setInvalidType(true);
4091  break;
4092  }
4093  }
4094  }
4095 
4096  // Determine whether we should infer _Nonnull on pointer types.
4097  Optional<NullabilityKind> inferNullability;
4098  bool inferNullabilityCS = false;
4099  bool inferNullabilityInnerOnly = false;
4100  bool inferNullabilityInnerOnlyComplete = false;
4101 
4102  // Are we in an assume-nonnull region?
4103  bool inAssumeNonNullRegion = false;
4104  SourceLocation assumeNonNullLoc = S.PP.getPragmaAssumeNonNullLoc();
4105  if (assumeNonNullLoc.isValid()) {
4106  inAssumeNonNullRegion = true;
4107  recordNullabilitySeen(S, assumeNonNullLoc);
4108  }
4109 
4110  // Whether to complain about missing nullability specifiers or not.
4111  enum {
4112  /// Never complain.
4113  CAMN_No,
4114  /// Complain on the inner pointers (but not the outermost
4115  /// pointer).
4116  CAMN_InnerPointers,
4117  /// Complain about any pointers that don't have nullability
4118  /// specified or inferred.
4119  CAMN_Yes
4120  } complainAboutMissingNullability = CAMN_No;
4121  unsigned NumPointersRemaining = 0;
4122  auto complainAboutInferringWithinChunk = PointerWrappingDeclaratorKind::None;
4123 
4124  if (IsTypedefName) {
4125  // For typedefs, we do not infer any nullability (the default),
4126  // and we only complain about missing nullability specifiers on
4127  // inner pointers.
4128  complainAboutMissingNullability = CAMN_InnerPointers;
4129 
4130  if (T->canHaveNullability(/*ResultIfUnknown*/false) &&
4131  !T->getNullability(S.Context)) {
4132  // Note that we allow but don't require nullability on dependent types.
4133  ++NumPointersRemaining;
4134  }
4135 
4136  for (unsigned i = 0, n = D.getNumTypeObjects(); i != n; ++i) {
4137  DeclaratorChunk &chunk = D.getTypeObject(i);
4138  switch (chunk.Kind) {
4141  case DeclaratorChunk::Pipe:
4142  break;
4143 
4146  ++NumPointersRemaining;
4147  break;
4148 
4151  continue;
4152 
4154  ++NumPointersRemaining;
4155  continue;
4156  }
4157  }
4158  } else {
4159  bool isFunctionOrMethod = false;
4160  switch (auto context = state.getDeclarator().getContext()) {
4166  isFunctionOrMethod = true;
4167  LLVM_FALLTHROUGH;
4168 
4170  if (state.getDeclarator().isObjCIvar() && !isFunctionOrMethod) {
4171  complainAboutMissingNullability = CAMN_No;
4172  break;
4173  }
4174 
4175  // Weak properties are inferred to be nullable.
4176  if (state.getDeclarator().isObjCWeakProperty() && inAssumeNonNullRegion) {
4177  inferNullability = NullabilityKind::Nullable;
4178  break;
4179  }
4180 
4181  LLVM_FALLTHROUGH;
4182 
4185  complainAboutMissingNullability = CAMN_Yes;
4186 
4187  // Nullability inference depends on the type and declarator.
4188  auto wrappingKind = PointerWrappingDeclaratorKind::None;
4189  switch (classifyPointerDeclarator(S, T, D, wrappingKind)) {
4190  case PointerDeclaratorKind::NonPointer:
4191  case PointerDeclaratorKind::MultiLevelPointer:
4192  // Cannot infer nullability.
4193  break;
4194 
4195  case PointerDeclaratorKind::SingleLevelPointer:
4196  // Infer _Nonnull if we are in an assumes-nonnull region.
4197  if (inAssumeNonNullRegion) {
4198  complainAboutInferringWithinChunk = wrappingKind;
4199  inferNullability = NullabilityKind::NonNull;
4200  inferNullabilityCS =
4203  }
4204  break;
4205 
4206  case PointerDeclaratorKind::CFErrorRefPointer:
4207  case PointerDeclaratorKind::NSErrorPointerPointer:
4208  // Within a function or method signature, infer _Nullable at both
4209  // levels.
4210  if (isFunctionOrMethod && inAssumeNonNullRegion)
4211  inferNullability = NullabilityKind::Nullable;
4212  break;
4213 
4214  case PointerDeclaratorKind::MaybePointerToCFRef:
4215  if (isFunctionOrMethod) {
4216  // On pointer-to-pointer parameters marked cf_returns_retained or
4217  // cf_returns_not_retained, if the outer pointer is explicit then
4218  // infer the inner pointer as _Nullable.
4219  auto hasCFReturnsAttr =
4220  [](const ParsedAttributesView &AttrList) -> bool {
4221  return AttrList.hasAttribute(ParsedAttr::AT_CFReturnsRetained) ||
4222  AttrList.hasAttribute(ParsedAttr::AT_CFReturnsNotRetained);
4223  };
4224  if (const auto *InnermostChunk = D.getInnermostNonParenChunk()) {
4225  if (hasCFReturnsAttr(D.getAttributes()) ||
4226  hasCFReturnsAttr(InnermostChunk->getAttrs()) ||
4227  hasCFReturnsAttr(D.getDeclSpec().getAttributes())) {
4228  inferNullability = NullabilityKind::Nullable;
4229  inferNullabilityInnerOnly = true;
4230  }
4231  }
4232  }
4233  break;
4234  }
4235  break;
4236  }
4237 
4239  complainAboutMissingNullability = CAMN_Yes;
4240  break;
4241 
4259  // Don't infer in these contexts.
4260  break;
4261  }
4262  }
4263 
4264  // Local function that returns true if its argument looks like a va_list.
4265  auto isVaList = [&S](QualType T) -> bool {
4266  auto *typedefTy = T->getAs<TypedefType>();
4267  if (!typedefTy)
4268  return false;
4269  TypedefDecl *vaListTypedef = S.Context.getBuiltinVaListDecl();
4270  do {
4271  if (typedefTy->getDecl() == vaListTypedef)
4272  return true;
4273  if (auto *name = typedefTy->getDecl()->getIdentifier())
4274  if (name->isStr("va_list"))
4275  return true;
4276  typedefTy = typedefTy->desugar()->getAs<TypedefType>();
4277  } while (typedefTy);
4278  return false;
4279  };
4280 
4281  // Local function that checks the nullability for a given pointer declarator.
4282  // Returns true if _Nonnull was inferred.
4283  auto inferPointerNullability =
4284  [&](SimplePointerKind pointerKind, SourceLocation pointerLoc,
4285  SourceLocation pointerEndLoc,
4286  ParsedAttributesView &attrs, AttributePool &Pool) -> ParsedAttr * {
4287  // We've seen a pointer.
4288  if (NumPointersRemaining > 0)
4289  --NumPointersRemaining;
4290 
4291  // If a nullability attribute is present, there's nothing to do.
4292  if (hasNullabilityAttr(attrs))
4293  return nullptr;
4294 
4295  // If we're supposed to infer nullability, do so now.
4296  if (inferNullability && !inferNullabilityInnerOnlyComplete) {
4297  ParsedAttr::Syntax syntax = inferNullabilityCS
4300  ParsedAttr *nullabilityAttr = Pool.create(
4301  S.getNullabilityKeyword(*inferNullability), SourceRange(pointerLoc),
4302  nullptr, SourceLocation(), nullptr, 0, syntax);
4303 
4304  attrs.addAtEnd(nullabilityAttr);
4305 
4306  if (inferNullabilityCS) {
4307  state.getDeclarator().getMutableDeclSpec().getObjCQualifiers()
4308  ->setObjCDeclQualifier(ObjCDeclSpec::DQ_CSNullability);
4309  }
4310 
4311  if (pointerLoc.isValid() &&
4312  complainAboutInferringWithinChunk !=
4314  auto Diag =
4315  S.Diag(pointerLoc, diag::warn_nullability_inferred_on_nested_type);
4316  Diag << static_cast<int>(complainAboutInferringWithinChunk);
4318  }
4319 
4320  if (inferNullabilityInnerOnly)
4321  inferNullabilityInnerOnlyComplete = true;
4322  return nullabilityAttr;
4323  }
4324 
4325  // If we're supposed to complain about missing nullability, do so
4326  // now if it's truly missing.
4327  switch (complainAboutMissingNullability) {
4328  case CAMN_No:
4329  break;
4330 
4331  case CAMN_InnerPointers:
4332  if (NumPointersRemaining == 0)
4333  break;
4334  LLVM_FALLTHROUGH;
4335 
4336  case CAMN_Yes:
4337  checkNullabilityConsistency(S, pointerKind, pointerLoc, pointerEndLoc);
4338  }
4339  return nullptr;
4340  };
4341 
4342  // If the type itself could have nullability but does not, infer pointer
4343  // nullability and perform consistency checking.
4344  if (S.CodeSynthesisContexts.empty()) {
4345  if (T->canHaveNullability(/*ResultIfUnknown*/false) &&
4346  !T->getNullability(S.Context)) {
4347  if (isVaList(T)) {
4348  // Record that we've seen a pointer, but do nothing else.
4349  if (NumPointersRemaining > 0)
4350  --NumPointersRemaining;
4351  } else {
4352  SimplePointerKind pointerKind = SimplePointerKind::Pointer;
4353  if (T->isBlockPointerType())
4354  pointerKind = SimplePointerKind::BlockPointer;
4355  else if (T->isMemberPointerType())
4356  pointerKind = SimplePointerKind::MemberPointer;
4357 
4358  if (auto *attr = inferPointerNullability(
4359  pointerKind, D.getDeclSpec().getTypeSpecTypeLoc(),
4360  D.getDeclSpec().getEndLoc(),
4363  T = state.getAttributedType(
4364  createNullabilityAttr(Context, *attr, *inferNullability), T, T);
4365  }
4366  }
4367  }
4368 
4369  if (complainAboutMissingNullability == CAMN_Yes &&
4370  T->isArrayType() && !T->getNullability(S.Context) && !isVaList(T) &&
4371  D.isPrototypeContext() &&
4373  checkNullabilityConsistency(S, SimplePointerKind::Array,
4375  }
4376  }
4377 
4378  bool ExpectNoDerefChunk =
4379  state.getCurrentAttributes().hasAttribute(ParsedAttr::AT_NoDeref);
4380 
4381  // Walk the DeclTypeInfo, building the recursive type as we go.
4382  // DeclTypeInfos are ordered from the identifier out, which is
4383  // opposite of what we want :).
4384  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
4385  unsigned chunkIndex = e - i - 1;
4386  state.setCurrentChunkIndex(chunkIndex);
4387  DeclaratorChunk &DeclType = D.getTypeObject(chunkIndex);
4388  IsQualifiedFunction &= DeclType.Kind == DeclaratorChunk::Paren;
4389  switch (DeclType.Kind) {
4391  if (i == 0)
4392  warnAboutRedundantParens(S, D, T);
4393  T = S.BuildParenType(T);
4394  break;
4396  // If blocks are disabled, emit an error.
4397  if (!LangOpts.Blocks)
4398  S.Diag(DeclType.Loc, diag::err_blocks_disable) << LangOpts.OpenCL;
4399 
4400  // Handle pointer nullability.
4401  inferPointerNullability(SimplePointerKind::BlockPointer, DeclType.Loc,
4402  DeclType.EndLoc, DeclType.getAttrs(),
4403  state.getDeclarator().getAttributePool());
4404 
4405  T = S.BuildBlockPointerType(T, D.getIdentifierLoc(), Name);
4406  if (DeclType.Cls.TypeQuals || LangOpts.OpenCL) {
4407  // OpenCL v2.0, s6.12.5 - Block variable declarations are implicitly
4408  // qualified with const.
4409  if (LangOpts.OpenCL)
4410  DeclType.Cls.TypeQuals |= DeclSpec::TQ_const;
4411  T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Cls.TypeQuals);
4412  }
4413  break;
4415  // Verify that we're not building a pointer to pointer to function with
4416  // exception specification.
4417  if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
4418  S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
4419  D.setInvalidType(true);
4420  // Build the type anyway.
4421  }
4422 
4423  // Handle pointer nullability
4424  inferPointerNullability(SimplePointerKind::Pointer, DeclType.Loc,
4425  DeclType.EndLoc, DeclType.getAttrs(),
4426  state.getDeclarator().getAttributePool());
4427 
4428  if (LangOpts.ObjC && T->getAs<ObjCObjectType>()) {
4429  T = Context.getObjCObjectPointerType(T);
4430  if (DeclType.Ptr.TypeQuals)
4431  T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Ptr.TypeQuals);
4432  break;
4433  }
4434 
4435  // OpenCL v2.0 s6.9b - Pointer to image/sampler cannot be used.
4436  // OpenCL v2.0 s6.13.16.1 - Pointer to pipe cannot be used.
4437  // OpenCL v2.0 s6.12.5 - Pointers to Blocks are not allowed.
4438  if (LangOpts.OpenCL) {
4439  if (T->isImageType() || T->isSamplerT() || T->isPipeType() ||
4440  T->isBlockPointerType()) {
4441  S.Diag(D.getIdentifierLoc(), diag::err_opencl_pointer_to_type) << T;
4442  D.setInvalidType(true);
4443  }
4444  }
4445 
4446  T = S.BuildPointerType(T, DeclType.Loc, Name);
4447  if (DeclType.Ptr.TypeQuals)
4448  T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Ptr.TypeQuals);
4449  break;
4451  // Verify that we're not building a reference to pointer to function with
4452  // exception specification.
4453  if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
4454  S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
4455  D.setInvalidType(true);
4456  // Build the type anyway.
4457  }
4458  T = S.BuildReferenceType(T, DeclType.Ref.LValueRef, DeclType.Loc, Name);
4459 
4460  if (DeclType.Ref.HasRestrict)
4461  T = S.BuildQualifiedType(T, DeclType.Loc, Qualifiers::Restrict);
4462  break;
4463  }
4464  case DeclaratorChunk::Array: {
4465  // Verify that we're not building an array of pointers to function with
4466  // exception specification.
4467  if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
4468  S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
4469  D.setInvalidType(true);
4470  // Build the type anyway.
4471  }
4472  DeclaratorChunk::ArrayTypeInfo &ATI = DeclType.Arr;
4473  Expr *ArraySize = static_cast<Expr*>(ATI.NumElts);
4475  if (ATI.isStar)
4476  ASM = ArrayType::Star;
4477  else if (ATI.hasStatic)
4478  ASM = ArrayType::Static;
4479  else
4480  ASM = ArrayType::Normal;
4481  if (ASM == ArrayType::Star && !D.isPrototypeContext()) {
4482  // FIXME: This check isn't quite right: it allows star in prototypes
4483  // for function definitions, and disallows some edge cases detailed
4484  // in http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00133.html
4485  S.Diag(DeclType.Loc, diag::err_array_star_outside_prototype);
4486  ASM = ArrayType::Normal;
4487  D.setInvalidType(true);
4488  }
4489 
4490  // C99 6.7.5.2p1: The optional type qualifiers and the keyword static
4491  // shall appear only in a declaration of a function parameter with an
4492  // array type, ...
4493  if (ASM == ArrayType::Static || ATI.TypeQuals) {
4494  if (!(D.isPrototypeContext() ||
4496  S.Diag(DeclType.Loc, diag::err_array_static_outside_prototype) <<
4497  (ASM == ArrayType::Static ? "'static'" : "type qualifier");
4498  // Remove the 'static' and the type qualifiers.
4499  if (ASM == ArrayType::Static)
4500  ASM = ArrayType::Normal;
4501  ATI.TypeQuals = 0;
4502  D.setInvalidType(true);
4503  }
4504 
4505  // C99 6.7.5.2p1: ... and then only in the outermost array type
4506  // derivation.
4507  if (hasOuterPointerLikeChunk(D, chunkIndex)) {
4508  S.Diag(DeclType.Loc, diag::err_array_static_not_outermost) <<
4509  (ASM == ArrayType::Static ? "'static'" : "type qualifier");
4510  if (ASM == ArrayType::Static)
4511  ASM = ArrayType::Normal;
4512  ATI.TypeQuals = 0;
4513  D.setInvalidType(true);
4514  }
4515  }
4516  const AutoType *AT = T->getContainedAutoType();
4517  // Allow arrays of auto if we are a generic lambda parameter.
4518  // i.e. [](auto (&array)[5]) { return array[0]; }; OK
4519  if (AT &&
4521  // We've already diagnosed this for decltype(auto).
4522  if (!AT->isDecltypeAuto())
4523  S.Diag(DeclType.Loc, diag::err_illegal_decl_array_of_auto)
4524  << getPrintableNameForEntity(Name) << T;
4525  T = QualType();
4526  break;
4527  }
4528 
4529  // Array parameters can be marked nullable as well, although it's not
4530  // necessary if they're marked 'static'.
4531  if (complainAboutMissingNullability == CAMN_Yes &&
4532  !hasNullabilityAttr(DeclType.getAttrs()) &&
4533  ASM != ArrayType::Static &&
4534  D.isPrototypeContext() &&
4535  !hasOuterPointerLikeChunk(D, chunkIndex)) {
4536  checkNullabilityConsistency(S, SimplePointerKind::Array, DeclType.Loc);
4537  }
4538 
4539  T = S.BuildArrayType(T, ASM, ArraySize, ATI.TypeQuals,
4540  SourceRange(DeclType.Loc, DeclType.EndLoc), Name);
4541  break;
4542  }
4544  // If the function declarator has a prototype (i.e. it is not () and
4545  // does not have a K&R-style identifier list), then the arguments are part
4546  // of the type, otherwise the argument list is ().
4547  DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
4548  IsQualifiedFunction =
4550 
4551  // Check for auto functions and trailing return type and adjust the
4552  // return type accordingly.
4553  if (!D.isInvalidType()) {
4554  // trailing-return-type is only required if we're declaring a function,
4555  // and not, for instance, a pointer to a function.
4556  if (D.getDeclSpec().hasAutoTypeSpec() &&
4557  !FTI.hasTrailingReturnType() && chunkIndex == 0) {
4558  if (!S.getLangOpts().CPlusPlus14) {
4561  ? diag::err_auto_missing_trailing_return
4562  : diag::err_deduced_return_type);
4563  T = Context.IntTy;
4564  D.setInvalidType(true);
4565  } else {
4567  diag::warn_cxx11_compat_deduced_return_type);
4568  }
4569  } else if (FTI.hasTrailingReturnType()) {
4570  // T must be exactly 'auto' at this point. See CWG issue 681.
4571  if (isa<ParenType>(T)) {
4572  S.Diag(D.getBeginLoc(), diag::err_trailing_return_in_parens)
4573  << T << D.getSourceRange();
4574  D.setInvalidType(true);
4575  } else if (D.getName().getKind() ==
4577  if (T != Context.DependentTy) {
4578  S.Diag(D.getDeclSpec().getBeginLoc(),
4579  diag::err_deduction_guide_with_complex_decl)
4580  << D.getSourceRange();
4581  D.setInvalidType(true);
4582  }
4584  (T.hasQualifiers() || !isa<AutoType>(T) ||
4585  cast<AutoType>(T)->getKeyword() !=
4588  diag::err_trailing_return_without_auto)
4589  << T << D.getDeclSpec().getSourceRange();
4590  D.setInvalidType(true);
4591  }
4592  T = S.GetTypeFromParser(FTI.getTrailingReturnType(), &TInfo);
4593  if (T.isNull()) {
4594  // An error occurred parsing the trailing return type.
4595  T = Context.IntTy;
4596  D.setInvalidType(true);
4597  }
4598  } else {
4599  // This function type is not the type of the entity being declared,
4600  // so checking the 'auto' is not the responsibility of this chunk.
4601  }
4602  }
4603 
4604  // C99 6.7.5.3p1: The return type may not be a function or array type.
4605  // For conversion functions, we'll diagnose this particular error later.
4606  if (!D.isInvalidType() && (T->isArrayType() || T->isFunctionType()) &&
4607  (D.getName().getKind() !=
4609  unsigned diagID = diag::err_func_returning_array_function;
4610  // Last processing chunk in block context means this function chunk
4611  // represents the block.
4612  if (chunkIndex == 0 &&
4614  diagID = diag::err_block_returning_array_function;
4615  S.Diag(DeclType.Loc, diagID) << T->isFunctionType() << T;
4616  T = Context.IntTy;
4617  D.setInvalidType(true);
4618  }
4619 
4620  // Do not allow returning half FP value.
4621  // FIXME: This really should be in BuildFunctionType.
4622  if (T->isHalfType()) {
4623  if (S.getLangOpts().OpenCL) {
4624  if (!S.getOpenCLOptions().isEnabled("cl_khr_fp16")) {
4625  S.Diag(D.getIdentifierLoc(), diag::err_opencl_invalid_return)
4626  << T << 0 /*pointer hint*/;
4627  D.setInvalidType(true);
4628  }
4629  } else if (!S.getLangOpts().HalfArgsAndReturns) {
4630  S.Diag(D.getIdentifierLoc(),
4631  diag::err_parameters_retval_cannot_have_fp16_type) << 1;
4632  D.setInvalidType(true);
4633  }
4634  }
4635 
4636  if (LangOpts.OpenCL) {
4637  // OpenCL v2.0 s6.12.5 - A block cannot be the return value of a
4638  // function.
4639  if (T->isBlockPointerType() || T->isImageType() || T->isSamplerT() ||
4640  T->isPipeType()) {
4641  S.Diag(D.getIdentifierLoc(), diag::err_opencl_invalid_return)
4642  << T << 1 /*hint off*/;
4643  D.setInvalidType(true);
4644  }
4645  // OpenCL doesn't support variadic functions and blocks
4646  // (s6.9.e and s6.12.5 OpenCL v2.0) except for printf.
4647  // We also allow here any toolchain reserved identifiers.
4648  if (FTI.isVariadic &&
4649  !(D.getIdentifier() &&
4650  ((D.getIdentifier()->getName() == "printf" &&
4651  (LangOpts.OpenCLCPlusPlus || LangOpts.OpenCLVersion >= 120)) ||
4652  D.getIdentifier()->getName().startswith("__")))) {
4653  S.Diag(D.getIdentifierLoc(), diag::err_opencl_variadic_function);
4654  D.setInvalidType(true);
4655  }
4656  }
4657 
4658  // Methods cannot return interface types. All ObjC objects are
4659  // passed by reference.
4660  if (T->isObjCObjectType()) {
4661  SourceLocation DiagLoc, FixitLoc;
4662  if (TInfo) {
4663  DiagLoc = TInfo->getTypeLoc().getBeginLoc();
4664  FixitLoc = S.getLocForEndOfToken(TInfo->getTypeLoc().getEndLoc());
4665  } else {
4666  DiagLoc = D.getDeclSpec().getTypeSpecTypeLoc();
4667  FixitLoc = S.getLocForEndOfToken(D.getDeclSpec().getEndLoc());
4668  }
4669  S.Diag(DiagLoc, diag::err_object_cannot_be_passed_returned_by_value)
4670  << 0 << T
4671  << FixItHint::CreateInsertion(FixitLoc, "*");
4672 
4673  T = Context.getObjCObjectPointerType(T);
4674  if (TInfo) {
4675  TypeLocBuilder TLB;
4676  TLB.pushFullCopy(TInfo->getTypeLoc());
4678  TLoc.setStarLoc(FixitLoc);
4679  TInfo = TLB.getTypeSourceInfo(Context, T);
4680  }
4681 
4682  D.setInvalidType(true);
4683  }
4684 
4685  // cv-qualifiers on return types are pointless except when the type is a
4686  // class type in C++.
4687  if ((T.getCVRQualifiers() || T->isAtomicType()) &&
4688  !(S.getLangOpts().CPlusPlus &&
4689  (T->isDependentType() || T->isRecordType()))) {
4690  if (T->isVoidType() && !S.getLangOpts().CPlusPlus &&
4692  // [6.9.1/3] qualified void return is invalid on a C
4693  // function definition. Apparently ok on declarations and
4694  // in C++ though (!)
4695  S.Diag(DeclType.Loc, diag::err_func_returning_qualified_void) << T;
4696  } else
4697  diagnoseRedundantReturnTypeQualifiers(S, T, D, chunkIndex);
4698 
4699  // C++2a [dcl.fct]p12:
4700  // A volatile-qualified return type is deprecated
4701  if (T.isVolatileQualified() && S.getLangOpts().CPlusPlus2a)
4702  S.Diag(DeclType.Loc, diag::warn_deprecated_volatile_return) << T;
4703  }
4704 
4705  // Objective-C ARC ownership qualifiers are ignored on the function
4706  // return type (by type canonicalization). Complain if this attribute
4707  // was written here.
4708  if (T.getQualifiers().hasObjCLifetime()) {
4709  SourceLocation AttrLoc;
4710  if (chunkIndex + 1 < D.getNumTypeObjects()) {
4711  DeclaratorChunk ReturnTypeChunk = D.getTypeObject(chunkIndex + 1);
4712  for (const ParsedAttr &AL : ReturnTypeChunk.getAttrs()) {
4713  if (AL.getKind() == ParsedAttr::AT_ObjCOwnership) {
4714  AttrLoc = AL.getLoc();
4715  break;
4716  }
4717  }
4718  }
4719  if (AttrLoc.isInvalid()) {
4720  for (const ParsedAttr &AL : D.getDeclSpec().getAttributes()) {
4721  if (AL.getKind() == ParsedAttr::AT_ObjCOwnership) {
4722  AttrLoc = AL.getLoc();
4723  break;
4724  }
4725  }
4726  }
4727 
4728  if (AttrLoc.isValid()) {
4729  // The ownership attributes are almost always written via
4730  // the predefined
4731  // __strong/__weak/__autoreleasing/__unsafe_unretained.
4732  if (AttrLoc.isMacroID())
4733  AttrLoc =
4735 
4736  S.Diag(AttrLoc, diag::warn_arc_lifetime_result_type)
4737  << T.getQualifiers().getObjCLifetime();
4738  }
4739  }
4740 
4741  if (LangOpts.CPlusPlus && D.getDeclSpec().hasTagDefinition()) {
4742  // C++ [dcl.fct]p6:
4743  // Types shall not be defined in return or parameter types.
4744  TagDecl *Tag = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
4745  S.Diag(Tag->getLocation(), diag::err_type_defined_in_result_type)
4746  << Context.getTypeDeclType(Tag);
4747  }
4748 
4749  // Exception specs are not allowed in typedefs. Complain, but add it
4750  // anyway.
4751  if (IsTypedefName && FTI.getExceptionSpecType() && !LangOpts.CPlusPlus17)
4752  S.Diag(FTI.getExceptionSpecLocBeg(),
4753  diag::err_exception_spec_in_typedef)
4756 
4757  // If we see "T var();" or "T var(T());" at block scope, it is probably
4758  // an attempt to initialize a variable, not a function declaration.
4759  if (FTI.isAmbiguous)
4760  warnAboutAmbiguousFunction(S, D, DeclType, T);
4761 
4763  getCCForDeclaratorChunk(S, D, DeclType.getAttrs(), FTI, chunkIndex));
4764 
4765  if (!FTI.NumParams && !FTI.isVariadic && !LangOpts.CPlusPlus
4766  && !LangOpts.OpenCL) {
4767  // Simple void foo(), where the incoming T is the result type.
4768  T = Context.getFunctionNoProtoType(T, EI);
4769  } else {
4770  // We allow a zero-parameter variadic function in C if the
4771  // function is marked with the "overloadable" attribute. Scan
4772  // for this attribute now.
4773  if (!FTI.NumParams && FTI.isVariadic && !LangOpts.CPlusPlus)
4774  if (!D.getAttributes().hasAttribute(ParsedAttr::AT_Overloadable))
4775  S.Diag(FTI.getEllipsisLoc(), diag::err_ellipsis_first_param);
4776 
4777  if (FTI.NumParams && FTI.Params[0].Param == nullptr) {
4778  // C99 6.7.5.3p3: Reject int(x,y,z) when it's not a function
4779  // definition.
4780  S.Diag(FTI.Params[0].IdentLoc,
4781  diag::err_ident_list_in_fn_declaration);
4782  D.setInvalidType(true);
4783  // Recover by creating a K&R-style function type.
4784  T = Context.getFunctionNoProtoType(T, EI);
4785  break;
4786  }
4787 
4789  EPI.ExtInfo = EI;
4790  EPI.Variadic = FTI.isVariadic;
4794  : 0);
4795  EPI.RefQualifier = !FTI.hasRefQualifier()? RQ_None
4797  : RQ_RValue;
4798 
4799  // Otherwise, we have a function with a parameter list that is
4800  // potentially variadic.
4801  SmallVector<QualType, 16> ParamTys;
4802  ParamTys.reserve(FTI.NumParams);
4803 
4805  ExtParameterInfos(FTI.NumParams);
4806  bool HasAnyInterestingExtParameterInfos = false;
4807 
4808  for (unsigned i = 0, e = FTI.NumParams; i != e; ++i) {
4809  ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
4810  QualType ParamTy = Param->getType();
4811  assert(!ParamTy.isNull() && "Couldn't parse type?");
4812 
4813  // Look for 'void'. void is allowed only as a single parameter to a
4814  // function with no other parameters (C99 6.7.5.3p10). We record
4815  // int(void) as a FunctionProtoType with an empty parameter list.
4816  if (ParamTy->isVoidType()) {
4817  // If this is something like 'float(int, void)', reject it. 'void'
4818  // is an incomplete type (C99 6.2.5p19) and function decls cannot
4819  // have parameters of incomplete type.
4820  if (FTI.NumParams != 1 || FTI.isVariadic) {
4821  S.Diag(DeclType.Loc, diag::err_void_only_param);
4822  ParamTy = Context.IntTy;
4823  Param->setType(ParamTy);
4824  } else if (FTI.Params[i].Ident) {
4825  // Reject, but continue to parse 'int(void abc)'.
4826  S.Diag(FTI.Params[i].IdentLoc, diag::err_param_with_void_type);
4827  ParamTy = Context.IntTy;
4828  Param->setType(ParamTy);
4829  } else {
4830  // Reject, but continue to parse 'float(const void)'.
4831  if (ParamTy.hasQualifiers())
4832  S.Diag(DeclType.Loc, diag::err_void_param_qualified);
4833 
4834  // Do not add 'void' to the list.
4835  break;
4836  }
4837  } else if (ParamTy->isHalfType()) {
4838  // Disallow half FP parameters.
4839  // FIXME: This really should be in BuildFunctionType.
4840  if (S.getLangOpts().OpenCL) {
4841  if (!S.getOpenCLOptions().isEnabled("cl_khr_fp16")) {
4842  S.Diag(Param->getLocation(),
4843  diag::err_opencl_half_param) << ParamTy;
4844  D.setInvalidType();
4845  Param->setInvalidDecl();
4846  }
4847  } else if (!S.getLangOpts().HalfArgsAndReturns) {
4848  S.Diag(Param->getLocation(),
4849  diag::err_parameters_retval_cannot_have_fp16_type) << 0;
4850  D.setInvalidType();
4851  }
4852  } else if (!FTI.hasPrototype) {
4853  if (ParamTy->isPromotableIntegerType()) {
4854  ParamTy = Context.getPromotedIntegerType(ParamTy);
4855  Param->setKNRPromoted(true);
4856  } else if (const BuiltinType* BTy = ParamTy->getAs<BuiltinType>()) {
4857  if (BTy->getKind() == BuiltinType::Float) {
4858  ParamTy = Context.DoubleTy;
4859  Param->setKNRPromoted(true);
4860  }
4861  }
4862  }
4863 
4864  if (LangOpts.ObjCAutoRefCount && Param->hasAttr<NSConsumedAttr>()) {
4865  ExtParameterInfos[i] = ExtParameterInfos[i].withIsConsumed(true);
4866  HasAnyInterestingExtParameterInfos = true;
4867  }
4868 
4869  if (auto attr = Param->getAttr<ParameterABIAttr>()) {
4870  ExtParameterInfos[i] =
4871  ExtParameterInfos[i].withABI(attr->getABI());
4872  HasAnyInterestingExtParameterInfos = true;
4873  }
4874 
4875  if (Param->hasAttr<PassObjectSizeAttr>()) {
4876  ExtParameterInfos[i] = ExtParameterInfos[i].withHasPassObjectSize();
4877  HasAnyInterestingExtParameterInfos = true;
4878  }
4879 
4880  if (Param->hasAttr<NoEscapeAttr>()) {
4881  ExtParameterInfos[i] = ExtParameterInfos[i].withIsNoEscape(true);
4882  HasAnyInterestingExtParameterInfos = true;
4883  }
4884 
4885  ParamTys.push_back(ParamTy);
4886  }
4887 
4888  if (HasAnyInterestingExtParameterInfos) {
4889  EPI.ExtParameterInfos = ExtParameterInfos.data();
4890  checkExtParameterInfos(S, ParamTys, EPI,
4891  [&](unsigned i) { return FTI.Params[i].Param->getLocation(); });
4892  }
4893 
4894  SmallVector<QualType, 4> Exceptions;
4895  SmallVector<ParsedType, 2> DynamicExceptions;
4896  SmallVector<SourceRange, 2> DynamicExceptionRanges;
4897  Expr *NoexceptExpr = nullptr;
4898 
4899  if (FTI.getExceptionSpecType() == EST_Dynamic) {
4900  // FIXME: It's rather inefficient to have to split into two vectors
4901  // here.
4902  unsigned N = FTI.getNumExceptions();
4903  DynamicExceptions.reserve(N);
4904  DynamicExceptionRanges.reserve(N);
4905  for (unsigned I = 0; I != N; ++I) {
4906  DynamicExceptions.push_back(FTI.Exceptions[I].Ty);
4907  DynamicExceptionRanges.push_back(FTI.Exceptions[I].Range);
4908  }
4909  } else if (isComputedNoexcept(FTI.getExceptionSpecType())) {
4910  NoexceptExpr = FTI.NoexceptExpr;
4911  }
4912 
4914  FTI.getExceptionSpecType(),
4915  DynamicExceptions,
4916  DynamicExceptionRanges,
4917  NoexceptExpr,
4918  Exceptions,
4919  EPI.ExceptionSpec);
4920 
4921  // FIXME: Set address space from attrs for C++ mode here.
4922  // OpenCLCPlusPlus: A class member function has an address space.
4923  auto IsClassMember = [&]() {
4924  return (!state.getDeclarator().getCXXScopeSpec().isEmpty() &&
4925  state.getDeclarator()
4926  .getCXXScopeSpec()
4927  .getScopeRep()
4928  ->getKind() == NestedNameSpecifier::TypeSpec) ||
4929  state.getDeclarator().getContext() ==
4931  };
4932 
4933  if (state.getSema().getLangOpts().OpenCLCPlusPlus && IsClassMember()) {
4934  LangAS ASIdx = LangAS::Default;
4935  // Take address space attr if any and mark as invalid to avoid adding
4936  // them later while creating QualType.
4937  if (FTI.MethodQualifiers)
4938  for (ParsedAttr &attr : FTI.MethodQualifiers->getAttributes()) {
4939  LangAS ASIdxNew = attr.asOpenCLLangAS();
4940  if (DiagnoseMultipleAddrSpaceAttributes(S, ASIdx, ASIdxNew,
4941  attr.getLoc()))
4942  D.setInvalidType(true);
4943  else
4944  ASIdx = ASIdxNew;
4945  }
4946  // If a class member function's address space is not set, set it to
4947  // __generic.
4948  LangAS AS =
4949  (ASIdx == LangAS::Default ? LangAS::opencl_generic : ASIdx);
4950  EPI.TypeQuals.addAddressSpace(AS);
4951  }
4952  T = Context.getFunctionType(T, ParamTys, EPI);
4953  }
4954  break;
4955  }
4957  // The scope spec must refer to a class, or be dependent.
4958  CXXScopeSpec &SS = DeclType.Mem.Scope();
4959  QualType ClsType;
4960 
4961  // Handle pointer nullability.
4962  inferPointerNullability(SimplePointerKind::MemberPointer, DeclType.Loc,
4963  DeclType.EndLoc, DeclType.getAttrs(),
4964  state.getDeclarator().getAttributePool());
4965 
4966  if (SS.isInvalid()) {
4967  // Avoid emitting extra errors if we already errored on the scope.
4968  D.setInvalidType(true);
4969  } else if (S.isDependentScopeSpecifier(SS) ||
4970  dyn_cast_or_null<CXXRecordDecl>(S.computeDeclContext(SS))) {
4971  NestedNameSpecifier *NNS = SS.getScopeRep();
4972  NestedNameSpecifier *NNSPrefix = NNS->getPrefix();
4973  switch (NNS->getKind()) {
4975  ClsType = Context.getDependentNameType(ETK_None, NNSPrefix,
4976  NNS->getAsIdentifier());
4977  break;
4978 
4983  llvm_unreachable("Nested-name-specifier must name a type");
4984 
4987  ClsType = QualType(NNS->getAsType(), 0);
4988  // Note: if the NNS has a prefix and ClsType is a nondependent
4989  // TemplateSpecializationType, then the NNS prefix is NOT included
4990  // in ClsType; hence we wrap ClsType into an ElaboratedType.
4991  // NOTE: in particular, no wrap occurs if ClsType already is an
4992  // Elaborated, DependentName, or DependentTemplateSpecialization.
4993  if (NNSPrefix && isa<TemplateSpecializationType>(NNS->getAsType()))
4994  ClsType = Context.getElaboratedType(ETK_None, NNSPrefix, ClsType);
4995  break;
4996  }
4997  } else {
4998  S.Diag(DeclType.Mem.Scope().getBeginLoc(),
4999  diag::err_illegal_decl_mempointer_in_nonclass)
5000  << (D.getIdentifier() ? D.getIdentifier()->getName() : "type name")
5001  << DeclType.Mem.Scope().getRange();
5002  D.setInvalidType(true);
5003  }
5004 
5005  if (!ClsType.isNull())
5006  T = S.BuildMemberPointerType(T, ClsType, DeclType.Loc,
5007  D.getIdentifier());
5008  if (T.isNull()) {
5009  T = Context.IntTy;
5010  D.setInvalidType(true);
5011  } else if (DeclType.Mem.TypeQuals) {
5012  T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Mem.TypeQuals);
5013  }
5014  break;
5015  }
5016 
5017  case DeclaratorChunk::Pipe: {
5018  T = S.BuildReadPipeType(T, DeclType.Loc);
5019  processTypeAttrs(state, T, TAL_DeclSpec,
5021  break;
5022  }
5023  }
5024 
5025  if (T.isNull()) {
5026  D.setInvalidType(true);
5027  T = Context.IntTy;
5028  }
5029 
5030  // See if there are any attributes on this declarator chunk.
5031  processTypeAttrs(state, T, TAL_DeclChunk, DeclType.getAttrs());
5032 
5033  if (DeclType.Kind != DeclaratorChunk::Paren) {
5034  if (ExpectNoDerefChunk && !IsNoDerefableChunk(DeclType))
5035  S.Diag(DeclType.Loc, diag::warn_noderef_on_non_pointer_or_array);
5036 
5037  ExpectNoDerefChunk = state.didParseNoDeref();
5038  }
5039  }
5040 
5041  if (ExpectNoDerefChunk)
5042  S.Diag(state.getDeclarator().getBeginLoc(),
5043  diag::warn_noderef_on_non_pointer_or_array);
5044 
5045  // GNU warning -Wstrict-prototypes
5046  // Warn if a function declaration is without a prototype.
5047  // This warning is issued for all kinds of unprototyped function
5048  // declarations (i.e. function type typedef, function pointer etc.)
5049  // C99 6.7.5.3p14:
5050  // The empty list in a function declarator that is not part of a definition
5051  // of that function specifies that no information about the number or types
5052  // of the parameters is supplied.
5053  if (!LangOpts.CPlusPlus && D.getFunctionDefinitionKind() == FDK_Declaration) {
5054  bool IsBlock = false;
5055  for (const DeclaratorChunk &DeclType : D.type_objects()) {
5056  switch (DeclType.Kind) {
5058  IsBlock = true;
5059  break;
5061  const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
5062  // We supress the warning when there's no LParen location, as this
5063  // indicates the declaration was an implicit declaration, which gets
5064  // warned about separately via -Wimplicit-function-declaration.
5065  if (FTI.NumParams == 0 && !FTI.isVariadic && FTI.getLParenLoc().isValid())
5066  S.Diag(DeclType.Loc, diag::warn_strict_prototypes)
5067  << IsBlock
5068  << FixItHint::CreateInsertion(FTI.getRParenLoc(), "void");
5069  IsBlock = false;
5070  break;
5071  }
5072  default:
5073  break;
5074  }
5075  }
5076  }
5077 
5078  assert(!T.isNull() && "T must not be null after this point");
5079 
5080  if (LangOpts.CPlusPlus && T->isFunctionType()) {
5081  const FunctionProtoType *FnTy = T->getAs<FunctionProtoType>();
5082  assert(FnTy && "Why oh why is there not a FunctionProtoType here?");
5083 
5084  // C++ 8.3.5p4:
5085  // A cv-qualifier-seq shall only be part of the function type
5086  // for a nonstatic member function, the function type to which a pointer
5087  // to member refers, or the top-level function type of a function typedef
5088  // declaration.
5089  //
5090  // Core issue 547 also allows cv-qualifiers on function types that are
5091  // top-level template type arguments.
5092  enum { NonMember, Member, DeductionGuide } Kind = NonMember;
5094  Kind = DeductionGuide;
5095  else if (!D.getCXXScopeSpec().isSet()) {
5099  Kind = Member;
5100  } else {
5102  if (!DC || DC->isRecord())
5103  Kind = Member;
5104  }
5105 
5106  // C++11 [dcl.fct]p6 (w/DR1417):
5107  // An attempt to specify a function type with a cv-qualifier-seq or a
5108  // ref-qualifier (including by typedef-name) is ill-formed unless it is:
5109  // - the function type for a non-static member function,
5110  // - the function type to which a pointer to member refers,
5111  // - the top-level function type of a function typedef declaration or
5112  // alias-declaration,
5113  // - the type-id in the default argument of a type-parameter, or
5114  // - the type-id of a template-argument for a type-parameter
5115  //
5116  // FIXME: Checking this here is insufficient. We accept-invalid on:
5117  //
5118  // template<typename T> struct S { void f(T); };
5119  // S<int() const> s;
5120  //
5121  // ... for instance.
5122  if (IsQualifiedFunction &&
5123  !(Kind == Member &&
5125  !IsTypedefName &&
5128  SourceLocation Loc = D.getBeginLoc();
5129  SourceRange RemovalRange;
5130  unsigned I;
5131  if (D.isFunctionDeclarator(I)) {
5132  SmallVector<SourceLocation, 4> RemovalLocs;
5133  const DeclaratorChunk &Chunk = D.getTypeObject(I);
5134  assert(Chunk.Kind == DeclaratorChunk::Function);
5135 
5136  if (Chunk.Fun.hasRefQualifier())
5137  RemovalLocs.push_back(Chunk.Fun.getRefQualifierLoc());
5138 
5139  if (Chunk.Fun.hasMethodTypeQualifiers())
5141  [&](DeclSpec::TQ TypeQual, StringRef QualName,
5142  SourceLocation SL) { RemovalLocs.push_back(SL); });
5143 
5144  if (!RemovalLocs.empty()) {
5145  llvm::sort(RemovalLocs,
5147  RemovalRange = SourceRange(RemovalLocs.front(), RemovalLocs.back());
5148  Loc = RemovalLocs.front();
5149  }
5150  }
5151 
5152  S.Diag(Loc, diag::err_invalid_qualified_function_type)
5153  << Kind << D.isFunctionDeclarator() << T
5155  << FixItHint::CreateRemoval(RemovalRange);
5156 
5157  // Strip the cv-qualifiers and ref-qualifiers from the type.
5160  EPI.RefQualifier = RQ_None;
5161 
5162  T = Context.getFunctionType(FnTy->getReturnType(), FnTy->getParamTypes(),
5163  EPI);
5164  // Rebuild any parens around the identifier in the function type.
5165  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
5167  break;
5168  T = S.BuildParenType(T);
5169  }
5170  }
5171  }
5172 
5173  // Apply any undistributed attributes from the declarator.
5175 
5176  // Diagnose any ignored type attributes.
5177  state.diagnoseIgnoredTypeAttrs(T);
5178 
5179  // C++0x [dcl.constexpr]p9:
5180  // A constexpr specifier used in an object declaration declares the object
5181  // as const.
5183  T->isObjectType())
5184  T.addConst();
5185 
5186  // C++2a [dcl.fct]p4:
5187  // A parameter with volatile-qualified type is deprecated
5188  if (T.isVolatileQualified() && S.getLangOpts().CPlusPlus2a &&
5191  S.Diag(D.getIdentifierLoc(), diag::warn_deprecated_volatile_param) << T;
5192 
5193  // If there was an ellipsis in the declarator, the declaration declares a
5194  // parameter pack whose type may be a pack expansion type.
5195  if (D.hasEllipsis()) {
5196  // C++0x [dcl.fct]p13:
5197  // A declarator-id or abstract-declarator containing an ellipsis shall
5198  // only be used in a parameter-declaration. Such a parameter-declaration
5199  // is a parameter pack (14.5.3). [...]
5200  switch (D.getContext()) {
5203  // C++0x [dcl.fct]p13:
5204  // [...] When it is part of a parameter-declaration-clause, the
5205  // parameter pack is a function parameter pack (14.5.3). The type T
5206  // of the declarator-id of the function parameter pack shall contain
5207  // a template parameter pack; each template parameter pack in T is
5208  // expanded by the function parameter pack.
5209  //
5210  // We represent function parameter packs as function parameters whose
5211  // type is a pack expansion.
5212  if (!T->containsUnexpandedParameterPack()) {
5213  S.Diag(D.getEllipsisLoc(),
5214  diag::err_function_parameter_pack_without_parameter_packs)
5215  << T << D.getSourceRange();
5217  } else {
5218  T = Context.getPackExpansionType(T, None);
5219  }
5220  break;
5222  // C++0x [temp.param]p15:
5223  // If a template-parameter is a [...] is a parameter-declaration that
5224  // declares a parameter pack (8.3.5), then the template-parameter is a
5225  // template parameter pack (14.5.3).
5226  //
5227  // Note: core issue 778 clarifies that, if there are any unexpanded
5228  // parameter packs in the type of the non-type template parameter, then
5229  // it expands those parameter packs.
5231  T = Context.getPackExpansionType(T, None);
5232  else
5233  S.Diag(D.getEllipsisLoc(),
5234  LangOpts.CPlusPlus11
5235  ? diag::warn_cxx98_compat_variadic_templates
5236  : diag::ext_variadic_templates);
5237  break;
5238 
5241  case DeclaratorContext::ObjCParameterContext: // FIXME: special diagnostic
5242  // here?
5243  case DeclaratorContext::ObjCResultContext: // FIXME: special diagnostic
5244  // here?
5264  // FIXME: We may want to allow parameter packs in block-literal contexts
5265  // in the future.
5266  S.Diag(D.getEllipsisLoc(),
5267  diag::err_ellipsis_in_declarator_not_parameter);
5269  break;
5270  }
5271  }
5272 
5273  assert(!T.isNull() && "T must not be null at the end of this function");
5274  if (D.isInvalidType())
5275  return Context.getTrivialTypeSourceInfo(T);
5276 
5277  return GetTypeSourceInfoForDeclarator(state, T, TInfo);
5278 }
5279 
5280 /// GetTypeForDeclarator - Convert the type for the specified
5281 /// declarator to Type instances.
5282 ///
5283 /// The result of this call will never be null, but the associated
5284 /// type may be a null type if there's an unrecoverable error.
5286  // Determine the type of the declarator. Not all forms of declarator
5287  // have a type.
5288 
5289  TypeProcessingState state(*this, D);
5290 
5291  TypeSourceInfo *ReturnTypeInfo = nullptr;
5292  QualType T = GetDeclSpecTypeForDeclarator(state, ReturnTypeInfo);
5293  if (D.isPrototypeContext() && getLangOpts().ObjCAutoRefCount)
5294  inferARCWriteback(state, T);
5295 
5296  return GetFullTypeForDeclarator(state, T, ReturnTypeInfo);
5297 }
5298 
5300  QualType &declSpecTy,
5301  Qualifiers::ObjCLifetime ownership) {
5302  if (declSpecTy->isObjCRetainableType() &&
5303  declSpecTy.getObjCLifetime() == Qualifiers::OCL_None) {
5304  Qualifiers qs;
5305  qs.addObjCLifetime(ownership);
5306  declSpecTy = S.Context.getQualifiedType(declSpecTy, qs);
5307  }
5308 }
5309 
5310 static void transferARCOwnershipToDeclaratorChunk(TypeProcessingState &state,
5311  Qualifiers::ObjCLifetime ownership,
5312  unsigned chunkIndex) {
5313  Sema &S = state.getSema();
5314  Declarator &D = state.getDeclarator();
5315 
5316  // Look for an explicit lifetime attribute.
5317  DeclaratorChunk &chunk = D.getTypeObject(chunkIndex);
5318  if (chunk.getAttrs().hasAttribute(ParsedAttr::AT_ObjCOwnership))
5319  return;
5320 
5321  const char *attrStr = nullptr;
5322  switch (ownership) {
5323  case Qualifiers::OCL_None: llvm_unreachable("no ownership!");
5324  case Qualifiers::OCL_ExplicitNone: attrStr = "none"; break;
5325  case Qualifiers::OCL_Strong: attrStr = "strong"; break;
5326  case Qualifiers::OCL_Weak: attrStr = "weak"; break;
5327  case Qualifiers::OCL_Autoreleasing: attrStr = "autoreleasing"; break;
5328  }
5329 
5330  IdentifierLoc *Arg = new (S.Context) IdentifierLoc;
5331  Arg->Ident = &S.Context.Idents.get(attrStr);
5332  Arg->Loc = SourceLocation();
5333 
5334  ArgsUnion Args(Arg);
5335 
5336  // If there wasn't one, add one (with an invalid source location
5337  // so that we don't make an AttributedType for it).
5338  ParsedAttr *attr = D.getAttributePool().create(
5339  &S.Context.Idents.get("objc_ownership"), SourceLocation(),
5340  /*scope*/ nullptr, SourceLocation(),
5341  /*args*/ &Args, 1, ParsedAttr::AS_GNU);
5342  chunk.getAttrs().addAtEnd(attr);
5343  // TODO: mark whether we did this inference?
5344 }
5345 
5346 /// Used for transferring ownership in casts resulting in l-values.
5347 static void transferARCOwnership(TypeProcessingState &state,
5348  QualType &declSpecTy,
5349  Qualifiers::ObjCLifetime ownership) {
5350  Sema &S = state.getSema();
5351  Declarator &D = state.getDeclarator();
5352 
5353  int inner = -1;
5354  bool hasIndirection = false;
5355  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
5356  DeclaratorChunk &chunk = D.getTypeObject(i);
5357  switch (chunk.Kind) {
5359  // Ignore parens.
5360  break;
5361 
5365  if (inner != -1)
5366  hasIndirection = true;
5367  inner = i;
5368  break;
5369 
5371  if (inner != -1)
5372  transferARCOwnershipToDeclaratorChunk(state, ownership, i);
5373  return;
5374 
5377  case DeclaratorChunk::Pipe:
5378  return;
5379  }
5380  }
5381 
5382  if (inner == -1)
5383  return;
5384 
5385  DeclaratorChunk &chunk = D.getTypeObject(inner);
5386  if (chunk.Kind ==