clang  9.0.0svn
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.getName()->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  /// Flag to indicate we parsed a noderef attribute. This is used for
186  /// validating that noderef was used on a pointer or array.
187  bool parsedNoDeref;
188 
189  public:
190  TypeProcessingState(Sema &sema, Declarator &declarator)
191  : sema(sema), declarator(declarator),
192  chunkIndex(declarator.getNumTypeObjects()), trivial(true),
193  hasSavedAttrs(false), parsedNoDeref(false) {}
194 
195  Sema &getSema() const {
196  return sema;
197  }
198 
199  Declarator &getDeclarator() const {
200  return declarator;
201  }
202 
203  bool isProcessingDeclSpec() const {
204  return chunkIndex == declarator.getNumTypeObjects();
205  }
206 
207  unsigned getCurrentChunkIndex() const {
208  return chunkIndex;
209  }
210 
211  void setCurrentChunkIndex(unsigned idx) {
212  assert(idx <= declarator.getNumTypeObjects());
213  chunkIndex = idx;
214  }
215 
216  ParsedAttributesView &getCurrentAttributes() const {
217  if (isProcessingDeclSpec())
218  return getMutableDeclSpec().getAttributes();
219  return declarator.getTypeObject(chunkIndex).getAttrs();
220  }
221 
222  /// Save the current set of attributes on the DeclSpec.
223  void saveDeclSpecAttrs() {
224  // Don't try to save them multiple times.
225  if (hasSavedAttrs) return;
226 
227  DeclSpec &spec = getMutableDeclSpec();
228  for (ParsedAttr &AL : spec.getAttributes())
229  savedAttrs.push_back(&AL);
230  trivial &= savedAttrs.empty();
231  hasSavedAttrs = true;
232  }
233 
234  /// Record that we had nowhere to put the given type attribute.
235  /// We will diagnose such attributes later.
236  void addIgnoredTypeAttr(ParsedAttr &attr) {
237  ignoredTypeAttrs.push_back(&attr);
238  }
239 
240  /// Diagnose all the ignored type attributes, given that the
241  /// declarator worked out to the given type.
242  void diagnoseIgnoredTypeAttrs(QualType type) const {
243  for (auto *Attr : ignoredTypeAttrs)
244  diagnoseBadTypeAttribute(getSema(), *Attr, type);
245  }
246 
247  /// Get an attributed type for the given attribute, and remember the Attr
248  /// object so that we can attach it to the AttributedTypeLoc.
249  QualType getAttributedType(Attr *A, QualType ModifiedType,
250  QualType EquivType) {
251  QualType T =
252  sema.Context.getAttributedType(A->getKind(), ModifiedType, EquivType);
253  AttrsForTypes.push_back({cast<AttributedType>(T.getTypePtr()), A});
254  AttrsForTypesSorted = false;
255  return T;
256  }
257 
258  /// Extract and remove the Attr* for a given attributed type.
259  const Attr *takeAttrForAttributedType(const AttributedType *AT) {
260  if (!AttrsForTypesSorted) {
261  std::stable_sort(AttrsForTypes.begin(), AttrsForTypes.end(),
262  [](const TypeAttrPair &A, const TypeAttrPair &B) {
263  return A.first < B.first;
264  });
265  AttrsForTypesSorted = true;
266  }
267 
268  // FIXME: This is quadratic if we have lots of reuses of the same
269  // attributed type.
270  for (auto It = std::partition_point(
271  AttrsForTypes.begin(), AttrsForTypes.end(),
272  [=](const TypeAttrPair &A) { return A.first < AT; });
273  It != AttrsForTypes.end() && It->first == AT; ++It) {
274  if (It->second) {
275  const Attr *Result = It->second;
276  It->second = nullptr;
277  return Result;
278  }
279  }
280 
281  llvm_unreachable("no Attr* for AttributedType*");
282  }
283 
284  void setParsedNoDeref(bool parsed) { parsedNoDeref = parsed; }
285 
286  bool didParseNoDeref() const { return parsedNoDeref; }
287 
288  ~TypeProcessingState() {
289  if (trivial) return;
290 
291  restoreDeclSpecAttrs();
292  }
293 
294  private:
295  DeclSpec &getMutableDeclSpec() const {
296  return const_cast<DeclSpec&>(declarator.getDeclSpec());
297  }
298 
299  void restoreDeclSpecAttrs() {
300  assert(hasSavedAttrs);
301 
302  getMutableDeclSpec().getAttributes().clearListOnly();
303  for (ParsedAttr *AL : savedAttrs)
304  getMutableDeclSpec().getAttributes().addAtEnd(AL);
305  }
306  };
307 } // end anonymous namespace
308 
310  ParsedAttributesView &fromList,
311  ParsedAttributesView &toList) {
312  fromList.remove(&attr);
313  toList.addAtEnd(&attr);
314 }
315 
316 /// The location of a type attribute.
318  /// The attribute is in the decl-specifier-seq.
320  /// The attribute is part of a DeclaratorChunk.
322  /// The attribute is immediately after the declaration's name.
324 };
325 
326 static void processTypeAttrs(TypeProcessingState &state, QualType &type,
328 
329 static bool handleFunctionTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
330  QualType &type);
331 
332 static bool handleMSPointerTypeQualifierAttr(TypeProcessingState &state,
333  ParsedAttr &attr, QualType &type);
334 
335 static bool handleObjCGCTypeAttr(TypeProcessingState &state, ParsedAttr &attr,
336  QualType &type);
337 
338 static bool handleObjCOwnershipTypeAttr(TypeProcessingState &state,
339  ParsedAttr &attr, QualType &type);
340 
341 static bool handleObjCPointerTypeAttr(TypeProcessingState &state,
342  ParsedAttr &attr, QualType &type) {
343  if (attr.getKind() == ParsedAttr::AT_ObjCGC)
344  return handleObjCGCTypeAttr(state, attr, type);
345  assert(attr.getKind() == ParsedAttr::AT_ObjCOwnership);
346  return handleObjCOwnershipTypeAttr(state, attr, type);
347 }
348 
349 /// Given the index of a declarator chunk, check whether that chunk
350 /// directly specifies the return type of a function and, if so, find
351 /// an appropriate place for it.
352 ///
353 /// \param i - a notional index which the search will start
354 /// immediately inside
355 ///
356 /// \param onlyBlockPointers Whether we should only look into block
357 /// pointer types (vs. all pointer types).
359  unsigned i,
360  bool onlyBlockPointers) {
361  assert(i <= declarator.getNumTypeObjects());
362 
363  DeclaratorChunk *result = nullptr;
364 
365  // First, look inwards past parens for a function declarator.
366  for (; i != 0; --i) {
367  DeclaratorChunk &fnChunk = declarator.getTypeObject(i-1);
368  switch (fnChunk.Kind) {
370  continue;
371 
372  // If we find anything except a function, bail out.
379  return result;
380 
381  // If we do find a function declarator, scan inwards from that,
382  // looking for a (block-)pointer declarator.
384  for (--i; i != 0; --i) {
385  DeclaratorChunk &ptrChunk = declarator.getTypeObject(i-1);
386  switch (ptrChunk.Kind) {
392  continue;
393 
396  if (onlyBlockPointers)
397  continue;
398 
399  LLVM_FALLTHROUGH;
400 
402  result = &ptrChunk;
403  goto continue_outer;
404  }
405  llvm_unreachable("bad declarator chunk kind");
406  }
407 
408  // If we run out of declarators doing that, we're done.
409  return result;
410  }
411  llvm_unreachable("bad declarator chunk kind");
412 
413  // Okay, reconsider from our new point.
414  continue_outer: ;
415  }
416 
417  // Ran out of chunks, bail out.
418  return result;
419 }
420 
421 /// Given that an objc_gc attribute was written somewhere on a
422 /// declaration *other* than on the declarator itself (for which, use
423 /// distributeObjCPointerTypeAttrFromDeclarator), and given that it
424 /// didn't apply in whatever position it was written in, try to move
425 /// it to a more appropriate position.
426 static void distributeObjCPointerTypeAttr(TypeProcessingState &state,
427  ParsedAttr &attr, QualType type) {
428  Declarator &declarator = state.getDeclarator();
429 
430  // Move it to the outermost normal or block pointer declarator.
431  for (unsigned i = state.getCurrentChunkIndex(); i != 0; --i) {
432  DeclaratorChunk &chunk = declarator.getTypeObject(i-1);
433  switch (chunk.Kind) {
436  // But don't move an ARC ownership attribute to the return type
437  // of a block.
438  DeclaratorChunk *destChunk = nullptr;
439  if (state.isProcessingDeclSpec() &&
440  attr.getKind() == ParsedAttr::AT_ObjCOwnership)
441  destChunk = maybeMovePastReturnType(declarator, i - 1,
442  /*onlyBlockPointers=*/true);
443  if (!destChunk) destChunk = &chunk;
444 
445  moveAttrFromListToList(attr, state.getCurrentAttributes(),
446  destChunk->getAttrs());
447  return;
448  }
449 
452  continue;
453 
454  // We may be starting at the return type of a block.
456  if (state.isProcessingDeclSpec() &&
457  attr.getKind() == ParsedAttr::AT_ObjCOwnership) {
459  declarator, i,
460  /*onlyBlockPointers=*/true)) {
461  moveAttrFromListToList(attr, state.getCurrentAttributes(),
462  dest->getAttrs());
463  return;
464  }
465  }
466  goto error;
467 
468  // Don't walk through these.
472  goto error;
473  }
474  }
475  error:
476 
477  diagnoseBadTypeAttribute(state.getSema(), attr, type);
478 }
479 
480 /// Distribute an objc_gc type attribute that was written on the
481 /// declarator.
483  TypeProcessingState &state, ParsedAttr &attr, QualType &declSpecType) {
484  Declarator &declarator = state.getDeclarator();
485 
486  // objc_gc goes on the innermost pointer to something that's not a
487  // pointer.
488  unsigned innermost = -1U;
489  bool considerDeclSpec = true;
490  for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
491  DeclaratorChunk &chunk = declarator.getTypeObject(i);
492  switch (chunk.Kind) {
495  innermost = i;
496  continue;
497 
503  continue;
504 
506  considerDeclSpec = false;
507  goto done;
508  }
509  }
510  done:
511 
512  // That might actually be the decl spec if we weren't blocked by
513  // anything in the declarator.
514  if (considerDeclSpec) {
515  if (handleObjCPointerTypeAttr(state, attr, declSpecType)) {
516  // Splice the attribute into the decl spec. Prevents the
517  // attribute from being applied multiple times and gives
518  // the source-location-filler something to work with.
519  state.saveDeclSpecAttrs();
520  moveAttrFromListToList(attr, declarator.getAttributes(),
521  declarator.getMutableDeclSpec().getAttributes());
522  return;
523  }
524  }
525 
526  // Otherwise, if we found an appropriate chunk, splice the attribute
527  // into it.
528  if (innermost != -1U) {
529  moveAttrFromListToList(attr, declarator.getAttributes(),
530  declarator.getTypeObject(innermost).getAttrs());
531  return;
532  }
533 
534  // Otherwise, diagnose when we're done building the type.
535  declarator.getAttributes().remove(&attr);
536  state.addIgnoredTypeAttr(attr);
537 }
538 
539 /// A function type attribute was written somewhere in a declaration
540 /// *other* than on the declarator itself or in the decl spec. Given
541 /// that it didn't apply in whatever position it was written in, try
542 /// to move it to a more appropriate position.
543 static void distributeFunctionTypeAttr(TypeProcessingState &state,
544  ParsedAttr &attr, QualType type) {
545  Declarator &declarator = state.getDeclarator();
546 
547  // Try to push the attribute from the return type of a function to
548  // the function itself.
549  for (unsigned i = state.getCurrentChunkIndex(); i != 0; --i) {
550  DeclaratorChunk &chunk = declarator.getTypeObject(i-1);
551  switch (chunk.Kind) {
553  moveAttrFromListToList(attr, state.getCurrentAttributes(),
554  chunk.getAttrs());
555  return;
556 
564  continue;
565  }
566  }
567 
568  diagnoseBadTypeAttribute(state.getSema(), attr, type);
569 }
570 
571 /// Try to distribute a function type attribute to the innermost
572 /// function chunk or type. Returns true if the attribute was
573 /// distributed, false if no location was found.
575  TypeProcessingState &state, ParsedAttr &attr,
576  ParsedAttributesView &attrList, QualType &declSpecType) {
577  Declarator &declarator = state.getDeclarator();
578 
579  // Put it on the innermost function chunk, if there is one.
580  for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
581  DeclaratorChunk &chunk = declarator.getTypeObject(i);
582  if (chunk.Kind != DeclaratorChunk::Function) continue;
583 
584  moveAttrFromListToList(attr, attrList, chunk.getAttrs());
585  return true;
586  }
587 
588  return handleFunctionTypeAttr(state, attr, declSpecType);
589 }
590 
591 /// A function type attribute was written in the decl spec. Try to
592 /// apply it somewhere.
593 static void distributeFunctionTypeAttrFromDeclSpec(TypeProcessingState &state,
594  ParsedAttr &attr,
595  QualType &declSpecType) {
596  state.saveDeclSpecAttrs();
597 
598  // C++11 attributes before the decl specifiers actually appertain to
599  // the declarators. Move them straight there. We don't support the
600  // 'put them wherever you like' semantics we allow for GNU attributes.
601  if (attr.isCXX11Attribute()) {
602  moveAttrFromListToList(attr, state.getCurrentAttributes(),
603  state.getDeclarator().getAttributes());
604  return;
605  }
606 
607  // Try to distribute to the innermost.
609  state, attr, state.getCurrentAttributes(), declSpecType))
610  return;
611 
612  // If that failed, diagnose the bad attribute when the declarator is
613  // fully built.
614  state.addIgnoredTypeAttr(attr);
615 }
616 
617 /// A function type attribute was written on the declarator. Try to
618 /// apply it somewhere.
619 static void distributeFunctionTypeAttrFromDeclarator(TypeProcessingState &state,
620  ParsedAttr &attr,
621  QualType &declSpecType) {
622  Declarator &declarator = state.getDeclarator();
623 
624  // Try to distribute to the innermost.
626  state, attr, declarator.getAttributes(), declSpecType))
627  return;
628 
629  // If that failed, diagnose the bad attribute when the declarator is
630  // fully built.
631  declarator.getAttributes().remove(&attr);
632  state.addIgnoredTypeAttr(attr);
633 }
634 
635 /// Given that there are attributes written on the declarator
636 /// itself, try to distribute any type attributes to the appropriate
637 /// declarator chunk.
638 ///
639 /// These are attributes like the following:
640 /// int f ATTR;
641 /// int (f ATTR)();
642 /// but not necessarily this:
643 /// int f() ATTR;
644 static void distributeTypeAttrsFromDeclarator(TypeProcessingState &state,
645  QualType &declSpecType) {
646  // Collect all the type attributes from the declarator itself.
647  assert(!state.getDeclarator().getAttributes().empty() &&
648  "declarator has no attrs!");
649  // The called functions in this loop actually remove things from the current
650  // list, so iterating over the existing list isn't possible. Instead, make a
651  // non-owning copy and iterate over that.
652  ParsedAttributesView AttrsCopy{state.getDeclarator().getAttributes()};
653  for (ParsedAttr &attr : AttrsCopy) {
654  // Do not distribute C++11 attributes. They have strict rules for what
655  // they appertain to.
656  if (attr.isCXX11Attribute())
657  continue;
658 
659  switch (attr.getKind()) {
661  distributeObjCPointerTypeAttrFromDeclarator(state, attr, declSpecType);
662  break;
663 
665  distributeFunctionTypeAttrFromDeclarator(state, attr, declSpecType);
666  break;
667 
669  // Microsoft type attributes cannot go after the declarator-id.
670  continue;
671 
673  // Nullability specifiers cannot go after the declarator-id.
674 
675  // Objective-C __kindof does not get distributed.
676  case ParsedAttr::AT_ObjCKindOf:
677  continue;
678 
679  default:
680  break;
681  }
682  }
683 }
684 
685 /// Add a synthetic '()' to a block-literal declarator if it is
686 /// required, given the return type.
687 static void maybeSynthesizeBlockSignature(TypeProcessingState &state,
688  QualType declSpecType) {
689  Declarator &declarator = state.getDeclarator();
690 
691  // First, check whether the declarator would produce a function,
692  // i.e. whether the innermost semantic chunk is a function.
693  if (declarator.isFunctionDeclarator()) {
694  // If so, make that declarator a prototyped declarator.
695  declarator.getFunctionTypeInfo().hasPrototype = true;
696  return;
697  }
698 
699  // If there are any type objects, the type as written won't name a
700  // function, regardless of the decl spec type. This is because a
701  // block signature declarator is always an abstract-declarator, and
702  // abstract-declarators can't just be parentheses chunks. Therefore
703  // we need to build a function chunk unless there are no type
704  // objects and the decl spec type is a function.
705  if (!declarator.getNumTypeObjects() && declSpecType->isFunctionType())
706  return;
707 
708  // Note that there *are* cases with invalid declarators where
709  // declarators consist solely of parentheses. In general, these
710  // occur only in failed efforts to make function declarators, so
711  // faking up the function chunk is still the right thing to do.
712 
713  // Otherwise, we need to fake up a function declarator.
714  SourceLocation loc = declarator.getBeginLoc();
715 
716  // ...and *prepend* it to the declarator.
717  SourceLocation NoLoc;
719  /*HasProto=*/true,
720  /*IsAmbiguous=*/false,
721  /*LParenLoc=*/NoLoc,
722  /*ArgInfo=*/nullptr,
723  /*NumArgs=*/0,
724  /*EllipsisLoc=*/NoLoc,
725  /*RParenLoc=*/NoLoc,
726  /*RefQualifierIsLvalueRef=*/true,
727  /*RefQualifierLoc=*/NoLoc,
728  /*MutableLoc=*/NoLoc, EST_None,
729  /*ESpecRange=*/SourceRange(),
730  /*Exceptions=*/nullptr,
731  /*ExceptionRanges=*/nullptr,
732  /*NumExceptions=*/0,
733  /*NoexceptExpr=*/nullptr,
734  /*ExceptionSpecTokens=*/nullptr,
735  /*DeclsInPrototype=*/None, loc, loc, declarator));
736 
737  // For consistency, make sure the state still has us as processing
738  // the decl spec.
739  assert(state.getCurrentChunkIndex() == declarator.getNumTypeObjects() - 1);
740  state.setCurrentChunkIndex(declarator.getNumTypeObjects());
741 }
742 
744  unsigned &TypeQuals,
745  QualType TypeSoFar,
746  unsigned RemoveTQs,
747  unsigned DiagID) {
748  // If this occurs outside a template instantiation, warn the user about
749  // it; they probably didn't mean to specify a redundant qualifier.
750  typedef std::pair<DeclSpec::TQ, SourceLocation> QualLoc;
751  for (QualLoc Qual : {QualLoc(DeclSpec::TQ_const, DS.getConstSpecLoc()),
754  QualLoc(DeclSpec::TQ_atomic, DS.getAtomicSpecLoc())}) {
755  if (!(RemoveTQs & Qual.first))
756  continue;
757 
758  if (!S.inTemplateInstantiation()) {
759  if (TypeQuals & Qual.first)
760  S.Diag(Qual.second, DiagID)
761  << DeclSpec::getSpecifierName(Qual.first) << TypeSoFar
762  << FixItHint::CreateRemoval(Qual.second);
763  }
764 
765  TypeQuals &= ~Qual.first;
766  }
767 }
768 
769 /// Return true if this is omitted block return type. Also check type
770 /// attributes and type qualifiers when returning true.
771 static bool checkOmittedBlockReturnType(Sema &S, Declarator &declarator,
772  QualType Result) {
773  if (!isOmittedBlockReturnType(declarator))
774  return false;
775 
776  // Warn if we see type attributes for omitted return type on a block literal.
777  SmallVector<ParsedAttr *, 2> ToBeRemoved;
778  for (ParsedAttr &AL : declarator.getMutableDeclSpec().getAttributes()) {
779  if (AL.isInvalid() || !AL.isTypeAttr())
780  continue;
781  S.Diag(AL.getLoc(),
782  diag::warn_block_literal_attributes_on_omitted_return_type)
783  << AL.getName();
784  ToBeRemoved.push_back(&AL);
785  }
786  // Remove bad attributes from the list.
787  for (ParsedAttr *AL : ToBeRemoved)
788  declarator.getMutableDeclSpec().getAttributes().remove(AL);
789 
790  // Warn if we see type qualifiers for omitted return type on a block literal.
791  const DeclSpec &DS = declarator.getDeclSpec();
792  unsigned TypeQuals = DS.getTypeQualifiers();
793  diagnoseAndRemoveTypeQualifiers(S, DS, TypeQuals, Result, (unsigned)-1,
794  diag::warn_block_literal_qualifiers_on_omitted_return_type);
796 
797  return true;
798 }
799 
800 /// Apply Objective-C type arguments to the given type.
803  SourceRange typeArgsRange,
804  bool failOnError = false) {
805  // We can only apply type arguments to an Objective-C class type.
806  const auto *objcObjectType = type->getAs<ObjCObjectType>();
807  if (!objcObjectType || !objcObjectType->getInterface()) {
808  S.Diag(loc, diag::err_objc_type_args_non_class)
809  << type
810  << typeArgsRange;
811 
812  if (failOnError)
813  return QualType();
814  return type;
815  }
816 
817  // The class type must be parameterized.
818  ObjCInterfaceDecl *objcClass = objcObjectType->getInterface();
819  ObjCTypeParamList *typeParams = objcClass->getTypeParamList();
820  if (!typeParams) {
821  S.Diag(loc, diag::err_objc_type_args_non_parameterized_class)
822  << objcClass->getDeclName()
823  << FixItHint::CreateRemoval(typeArgsRange);
824 
825  if (failOnError)
826  return QualType();
827 
828  return type;
829  }
830 
831  // The type must not already be specialized.
832  if (objcObjectType->isSpecialized()) {
833  S.Diag(loc, diag::err_objc_type_args_specialized_class)
834  << type
835  << FixItHint::CreateRemoval(typeArgsRange);
836 
837  if (failOnError)
838  return QualType();
839 
840  return type;
841  }
842 
843  // Check the type arguments.
844  SmallVector<QualType, 4> finalTypeArgs;
845  unsigned numTypeParams = typeParams->size();
846  bool anyPackExpansions = false;
847  for (unsigned i = 0, n = typeArgs.size(); i != n; ++i) {
848  TypeSourceInfo *typeArgInfo = typeArgs[i];
849  QualType typeArg = typeArgInfo->getType();
850 
851  // Type arguments cannot have explicit qualifiers or nullability.
852  // We ignore indirect sources of these, e.g. behind typedefs or
853  // template arguments.
854  if (TypeLoc qual = typeArgInfo->getTypeLoc().findExplicitQualifierLoc()) {
855  bool diagnosed = false;
856  SourceRange rangeToRemove;
857  if (auto attr = qual.getAs<AttributedTypeLoc>()) {
858  rangeToRemove = attr.getLocalSourceRange();
859  if (attr.getTypePtr()->getImmediateNullability()) {
860  typeArg = attr.getTypePtr()->getModifiedType();
861  S.Diag(attr.getBeginLoc(),
862  diag::err_objc_type_arg_explicit_nullability)
863  << typeArg << FixItHint::CreateRemoval(rangeToRemove);
864  diagnosed = true;
865  }
866  }
867 
868  if (!diagnosed) {
869  S.Diag(qual.getBeginLoc(), diag::err_objc_type_arg_qualified)
870  << typeArg << typeArg.getQualifiers().getAsString()
871  << FixItHint::CreateRemoval(rangeToRemove);
872  }
873  }
874 
875  // Remove qualifiers even if they're non-local.
876  typeArg = typeArg.getUnqualifiedType();
877 
878  finalTypeArgs.push_back(typeArg);
879 
880  if (typeArg->getAs<PackExpansionType>())
881  anyPackExpansions = true;
882 
883  // Find the corresponding type parameter, if there is one.
884  ObjCTypeParamDecl *typeParam = nullptr;
885  if (!anyPackExpansions) {
886  if (i < numTypeParams) {
887  typeParam = typeParams->begin()[i];
888  } else {
889  // Too many arguments.
890  S.Diag(loc, diag::err_objc_type_args_wrong_arity)
891  << false
892  << objcClass->getDeclName()
893  << (unsigned)typeArgs.size()
894  << numTypeParams;
895  S.Diag(objcClass->getLocation(), diag::note_previous_decl)
896  << objcClass;
897 
898  if (failOnError)
899  return QualType();
900 
901  return type;
902  }
903  }
904 
905  // Objective-C object pointer types must be substitutable for the bounds.
906  if (const auto *typeArgObjC = typeArg->getAs<ObjCObjectPointerType>()) {
907  // If we don't have a type parameter to match against, assume
908  // everything is fine. There was a prior pack expansion that
909  // means we won't be able to match anything.
910  if (!typeParam) {
911  assert(anyPackExpansions && "Too many arguments?");
912  continue;
913  }
914 
915  // Retrieve the bound.
916  QualType bound = typeParam->getUnderlyingType();
917  const auto *boundObjC = bound->getAs<ObjCObjectPointerType>();
918 
919  // Determine whether the type argument is substitutable for the bound.
920  if (typeArgObjC->isObjCIdType()) {
921  // When the type argument is 'id', the only acceptable type
922  // parameter bound is 'id'.
923  if (boundObjC->isObjCIdType())
924  continue;
925  } else if (S.Context.canAssignObjCInterfaces(boundObjC, typeArgObjC)) {
926  // Otherwise, we follow the assignability rules.
927  continue;
928  }
929 
930  // Diagnose the mismatch.
931  S.Diag(typeArgInfo->getTypeLoc().getBeginLoc(),
932  diag::err_objc_type_arg_does_not_match_bound)
933  << typeArg << bound << typeParam->getDeclName();
934  S.Diag(typeParam->getLocation(), diag::note_objc_type_param_here)
935  << typeParam->getDeclName();
936 
937  if (failOnError)
938  return QualType();
939 
940  return type;
941  }
942 
943  // Block pointer types are permitted for unqualified 'id' bounds.
944  if (typeArg->isBlockPointerType()) {
945  // If we don't have a type parameter to match against, assume
946  // everything is fine. There was a prior pack expansion that
947  // means we won't be able to match anything.
948  if (!typeParam) {
949  assert(anyPackExpansions && "Too many arguments?");
950  continue;
951  }
952 
953  // Retrieve the bound.
954  QualType bound = typeParam->getUnderlyingType();
956  continue;
957 
958  // Diagnose the mismatch.
959  S.Diag(typeArgInfo->getTypeLoc().getBeginLoc(),
960  diag::err_objc_type_arg_does_not_match_bound)
961  << typeArg << bound << typeParam->getDeclName();
962  S.Diag(typeParam->getLocation(), diag::note_objc_type_param_here)
963  << typeParam->getDeclName();
964 
965  if (failOnError)
966  return QualType();
967 
968  return type;
969  }
970 
971  // Dependent types will be checked at instantiation time.
972  if (typeArg->isDependentType()) {
973  continue;
974  }
975 
976  // Diagnose non-id-compatible type arguments.
977  S.Diag(typeArgInfo->getTypeLoc().getBeginLoc(),
978  diag::err_objc_type_arg_not_id_compatible)
979  << typeArg << typeArgInfo->getTypeLoc().getSourceRange();
980 
981  if (failOnError)
982  return QualType();
983 
984  return type;
985  }
986 
987  // Make sure we didn't have the wrong number of arguments.
988  if (!anyPackExpansions && finalTypeArgs.size() != numTypeParams) {
989  S.Diag(loc, diag::err_objc_type_args_wrong_arity)
990  << (typeArgs.size() < typeParams->size())
991  << objcClass->getDeclName()
992  << (unsigned)finalTypeArgs.size()
993  << (unsigned)numTypeParams;
994  S.Diag(objcClass->getLocation(), diag::note_previous_decl)
995  << objcClass;
996 
997  if (failOnError)
998  return QualType();
999 
1000  return type;
1001  }
1002 
1003  // Success. Form the specialized type.
1004  return S.Context.getObjCObjectType(type, finalTypeArgs, { }, false);
1005 }
1006 
1008  SourceLocation ProtocolLAngleLoc,
1009  ArrayRef<ObjCProtocolDecl *> Protocols,
1010  ArrayRef<SourceLocation> ProtocolLocs,
1011  SourceLocation ProtocolRAngleLoc,
1012  bool FailOnError) {
1013  QualType Result = QualType(Decl->getTypeForDecl(), 0);
1014  if (!Protocols.empty()) {
1015  bool HasError;
1016  Result = Context.applyObjCProtocolQualifiers(Result, Protocols,
1017  HasError);
1018  if (HasError) {
1019  Diag(SourceLocation(), diag::err_invalid_protocol_qualifiers)
1020  << SourceRange(ProtocolLAngleLoc, ProtocolRAngleLoc);
1021  if (FailOnError) Result = QualType();
1022  }
1023  if (FailOnError && Result.isNull())
1024  return QualType();
1025  }
1026 
1027  return Result;
1028 }
1029 
1031  SourceLocation Loc,
1032  SourceLocation TypeArgsLAngleLoc,
1033  ArrayRef<TypeSourceInfo *> TypeArgs,
1034  SourceLocation TypeArgsRAngleLoc,
1035  SourceLocation ProtocolLAngleLoc,
1036  ArrayRef<ObjCProtocolDecl *> Protocols,
1037  ArrayRef<SourceLocation> ProtocolLocs,
1038  SourceLocation ProtocolRAngleLoc,
1039  bool FailOnError) {
1040  QualType Result = BaseType;
1041  if (!TypeArgs.empty()) {
1042  Result = applyObjCTypeArgs(*this, Loc, Result, TypeArgs,
1043  SourceRange(TypeArgsLAngleLoc,
1044  TypeArgsRAngleLoc),
1045  FailOnError);
1046  if (FailOnError && Result.isNull())
1047  return QualType();
1048  }
1049 
1050  if (!Protocols.empty()) {
1051  bool HasError;
1052  Result = Context.applyObjCProtocolQualifiers(Result, Protocols,
1053  HasError);
1054  if (HasError) {
1055  Diag(Loc, diag::err_invalid_protocol_qualifiers)
1056  << SourceRange(ProtocolLAngleLoc, ProtocolRAngleLoc);
1057  if (FailOnError) Result = QualType();
1058  }
1059  if (FailOnError && Result.isNull())
1060  return QualType();
1061  }
1062 
1063  return Result;
1064 }
1065 
1067  SourceLocation lAngleLoc,
1068  ArrayRef<Decl *> protocols,
1069  ArrayRef<SourceLocation> protocolLocs,
1070  SourceLocation rAngleLoc) {
1071  // Form id<protocol-list>.
1072  QualType Result = Context.getObjCObjectType(
1073  Context.ObjCBuiltinIdTy, { },
1074  llvm::makeArrayRef(
1075  (ObjCProtocolDecl * const *)protocols.data(),
1076  protocols.size()),
1077  false);
1078  Result = Context.getObjCObjectPointerType(Result);
1079 
1080  TypeSourceInfo *ResultTInfo = Context.CreateTypeSourceInfo(Result);
1081  TypeLoc ResultTL = ResultTInfo->getTypeLoc();
1082 
1083  auto ObjCObjectPointerTL = ResultTL.castAs<ObjCObjectPointerTypeLoc>();
1084  ObjCObjectPointerTL.setStarLoc(SourceLocation()); // implicit
1085 
1086  auto ObjCObjectTL = ObjCObjectPointerTL.getPointeeLoc()
1087  .castAs<ObjCObjectTypeLoc>();
1088  ObjCObjectTL.setHasBaseTypeAsWritten(false);
1089  ObjCObjectTL.getBaseLoc().initialize(Context, SourceLocation());
1090 
1091  // No type arguments.
1092  ObjCObjectTL.setTypeArgsLAngleLoc(SourceLocation());
1093  ObjCObjectTL.setTypeArgsRAngleLoc(SourceLocation());
1094 
1095  // Fill in protocol qualifiers.
1096  ObjCObjectTL.setProtocolLAngleLoc(lAngleLoc);
1097  ObjCObjectTL.setProtocolRAngleLoc(rAngleLoc);
1098  for (unsigned i = 0, n = protocols.size(); i != n; ++i)
1099  ObjCObjectTL.setProtocolLoc(i, protocolLocs[i]);
1100 
1101  // We're done. Return the completed type to the parser.
1102  return CreateParsedType(Result, ResultTInfo);
1103 }
1104 
1106  Scope *S,
1107  SourceLocation Loc,
1108  ParsedType BaseType,
1109  SourceLocation TypeArgsLAngleLoc,
1110  ArrayRef<ParsedType> TypeArgs,
1111  SourceLocation TypeArgsRAngleLoc,
1112  SourceLocation ProtocolLAngleLoc,
1113  ArrayRef<Decl *> Protocols,
1114  ArrayRef<SourceLocation> ProtocolLocs,
1115  SourceLocation ProtocolRAngleLoc) {
1116  TypeSourceInfo *BaseTypeInfo = nullptr;
1117  QualType T = GetTypeFromParser(BaseType, &BaseTypeInfo);
1118  if (T.isNull())
1119  return true;
1120 
1121  // Handle missing type-source info.
1122  if (!BaseTypeInfo)
1123  BaseTypeInfo = Context.getTrivialTypeSourceInfo(T, Loc);
1124 
1125  // Extract type arguments.
1126  SmallVector<TypeSourceInfo *, 4> ActualTypeArgInfos;
1127  for (unsigned i = 0, n = TypeArgs.size(); i != n; ++i) {
1128  TypeSourceInfo *TypeArgInfo = nullptr;
1129  QualType TypeArg = GetTypeFromParser(TypeArgs[i], &TypeArgInfo);
1130  if (TypeArg.isNull()) {
1131  ActualTypeArgInfos.clear();
1132  break;
1133  }
1134 
1135  assert(TypeArgInfo && "No type source info?");
1136  ActualTypeArgInfos.push_back(TypeArgInfo);
1137  }
1138 
1139  // Build the object type.
1140  QualType Result = BuildObjCObjectType(
1141  T, BaseTypeInfo->getTypeLoc().getSourceRange().getBegin(),
1142  TypeArgsLAngleLoc, ActualTypeArgInfos, TypeArgsRAngleLoc,
1143  ProtocolLAngleLoc,
1144  llvm::makeArrayRef((ObjCProtocolDecl * const *)Protocols.data(),
1145  Protocols.size()),
1146  ProtocolLocs, ProtocolRAngleLoc,
1147  /*FailOnError=*/false);
1148 
1149  if (Result == T)
1150  return BaseType;
1151 
1152  // Create source information for this type.
1153  TypeSourceInfo *ResultTInfo = Context.CreateTypeSourceInfo(Result);
1154  TypeLoc ResultTL = ResultTInfo->getTypeLoc();
1155 
1156  // For id<Proto1, Proto2> or Class<Proto1, Proto2>, we'll have an
1157  // object pointer type. Fill in source information for it.
1158  if (auto ObjCObjectPointerTL = ResultTL.getAs<ObjCObjectPointerTypeLoc>()) {
1159  // The '*' is implicit.
1160  ObjCObjectPointerTL.setStarLoc(SourceLocation());
1161  ResultTL = ObjCObjectPointerTL.getPointeeLoc();
1162  }
1163 
1164  if (auto OTPTL = ResultTL.getAs<ObjCTypeParamTypeLoc>()) {
1165  // Protocol qualifier information.
1166  if (OTPTL.getNumProtocols() > 0) {
1167  assert(OTPTL.getNumProtocols() == Protocols.size());
1168  OTPTL.setProtocolLAngleLoc(ProtocolLAngleLoc);
1169  OTPTL.setProtocolRAngleLoc(ProtocolRAngleLoc);
1170  for (unsigned i = 0, n = Protocols.size(); i != n; ++i)
1171  OTPTL.setProtocolLoc(i, ProtocolLocs[i]);
1172  }
1173 
1174  // We're done. Return the completed type to the parser.
1175  return CreateParsedType(Result, ResultTInfo);
1176  }
1177 
1178  auto ObjCObjectTL = ResultTL.castAs<ObjCObjectTypeLoc>();
1179 
1180  // Type argument information.
1181  if (ObjCObjectTL.getNumTypeArgs() > 0) {
1182  assert(ObjCObjectTL.getNumTypeArgs() == ActualTypeArgInfos.size());
1183  ObjCObjectTL.setTypeArgsLAngleLoc(TypeArgsLAngleLoc);
1184  ObjCObjectTL.setTypeArgsRAngleLoc(TypeArgsRAngleLoc);
1185  for (unsigned i = 0, n = ActualTypeArgInfos.size(); i != n; ++i)
1186  ObjCObjectTL.setTypeArgTInfo(i, ActualTypeArgInfos[i]);
1187  } else {
1188  ObjCObjectTL.setTypeArgsLAngleLoc(SourceLocation());
1189  ObjCObjectTL.setTypeArgsRAngleLoc(SourceLocation());
1190  }
1191 
1192  // Protocol qualifier information.
1193  if (ObjCObjectTL.getNumProtocols() > 0) {
1194  assert(ObjCObjectTL.getNumProtocols() == Protocols.size());
1195  ObjCObjectTL.setProtocolLAngleLoc(ProtocolLAngleLoc);
1196  ObjCObjectTL.setProtocolRAngleLoc(ProtocolRAngleLoc);
1197  for (unsigned i = 0, n = Protocols.size(); i != n; ++i)
1198  ObjCObjectTL.setProtocolLoc(i, ProtocolLocs[i]);
1199  } else {
1200  ObjCObjectTL.setProtocolLAngleLoc(SourceLocation());
1201  ObjCObjectTL.setProtocolRAngleLoc(SourceLocation());
1202  }
1203 
1204  // Base type.
1205  ObjCObjectTL.setHasBaseTypeAsWritten(true);
1206  if (ObjCObjectTL.getType() == T)
1207  ObjCObjectTL.getBaseLoc().initializeFullCopy(BaseTypeInfo->getTypeLoc());
1208  else
1209  ObjCObjectTL.getBaseLoc().initialize(Context, Loc);
1210 
1211  // We're done. Return the completed type to the parser.
1212  return CreateParsedType(Result, ResultTInfo);
1213 }
1214 
1215 static OpenCLAccessAttr::Spelling
1217  for (const ParsedAttr &AL : Attrs)
1218  if (AL.getKind() == ParsedAttr::AT_OpenCLAccess)
1219  return static_cast<OpenCLAccessAttr::Spelling>(AL.getSemanticSpelling());
1220  return OpenCLAccessAttr::Keyword_read_only;
1221 }
1222 
1223 /// Convert the specified declspec to the appropriate type
1224 /// object.
1225 /// \param state Specifies the declarator containing the declaration specifier
1226 /// to be converted, along with other associated processing state.
1227 /// \returns The type described by the declaration specifiers. This function
1228 /// never returns null.
1229 static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
1230  // FIXME: Should move the logic from DeclSpec::Finish to here for validity
1231  // checking.
1232 
1233  Sema &S = state.getSema();
1234  Declarator &declarator = state.getDeclarator();
1235  DeclSpec &DS = declarator.getMutableDeclSpec();
1236  SourceLocation DeclLoc = declarator.getIdentifierLoc();
1237  if (DeclLoc.isInvalid())
1238  DeclLoc = DS.getBeginLoc();
1239 
1240  ASTContext &Context = S.Context;
1241 
1242  QualType Result;
1243  switch (DS.getTypeSpecType()) {
1244  case DeclSpec::TST_void:
1245  Result = Context.VoidTy;
1246  break;
1247  case DeclSpec::TST_char:
1249  Result = Context.CharTy;
1250  else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed)
1251  Result = Context.SignedCharTy;
1252  else {
1253  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
1254  "Unknown TSS value");
1255  Result = Context.UnsignedCharTy;
1256  }
1257  break;
1258  case DeclSpec::TST_wchar:
1260  Result = Context.WCharTy;
1261  else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed) {
1262  S.Diag(DS.getTypeSpecSignLoc(), diag::ext_invalid_sign_spec)
1263  << DS.getSpecifierName(DS.getTypeSpecType(),
1264  Context.getPrintingPolicy());
1265  Result = Context.getSignedWCharType();
1266  } else {
1267  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
1268  "Unknown TSS value");
1269  S.Diag(DS.getTypeSpecSignLoc(), diag::ext_invalid_sign_spec)
1270  << DS.getSpecifierName(DS.getTypeSpecType(),
1271  Context.getPrintingPolicy());
1272  Result = Context.getUnsignedWCharType();
1273  }
1274  break;
1275  case DeclSpec::TST_char8:
1276  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
1277  "Unknown TSS value");
1278  Result = Context.Char8Ty;
1279  break;
1280  case DeclSpec::TST_char16:
1281  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
1282  "Unknown TSS value");
1283  Result = Context.Char16Ty;
1284  break;
1285  case DeclSpec::TST_char32:
1286  assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
1287  "Unknown TSS value");
1288  Result = Context.Char32Ty;
1289  break;
1291  // If this is a missing declspec in a block literal return context, then it
1292  // is inferred from the return statements inside the block.
1293  // The declspec is always missing in a lambda expr context; it is either
1294  // specified with a trailing return type or inferred.
1295  if (S.getLangOpts().CPlusPlus14 &&
1297  // In C++1y, a lambda's implicit return type is 'auto'.
1298  Result = Context.getAutoDeductType();
1299  break;
1300  } else if (declarator.getContext() ==
1302  checkOmittedBlockReturnType(S, declarator,
1303  Context.DependentTy)) {
1304  Result = Context.DependentTy;
1305  break;
1306  }
1307 
1308  // Unspecified typespec defaults to int in C90. However, the C90 grammar
1309  // [C90 6.5] only allows a decl-spec if there was *some* type-specifier,
1310  // type-qualifier, or storage-class-specifier. If not, emit an extwarn.
1311  // Note that the one exception to this is function definitions, which are
1312  // allowed to be completely missing a declspec. This is handled in the
1313  // parser already though by it pretending to have seen an 'int' in this
1314  // case.
1315  if (S.getLangOpts().ImplicitInt) {
1316  // In C89 mode, we only warn if there is a completely missing declspec
1317  // when one is not allowed.
1318  if (DS.isEmpty()) {
1319  S.Diag(DeclLoc, diag::ext_missing_declspec)
1320  << DS.getSourceRange()
1321  << FixItHint::CreateInsertion(DS.getBeginLoc(), "int");
1322  }
1323  } else if (!DS.hasTypeSpecifier()) {
1324  // C99 and C++ require a type specifier. For example, C99 6.7.2p2 says:
1325  // "At least one type specifier shall be given in the declaration
1326  // specifiers in each declaration, and in the specifier-qualifier list in
1327  // each struct declaration and type name."
1328  if (S.getLangOpts().CPlusPlus) {
1329  S.Diag(DeclLoc, diag::err_missing_type_specifier)
1330  << DS.getSourceRange();
1331 
1332  // When this occurs in C++ code, often something is very broken with the
1333  // value being declared, poison it as invalid so we don't get chains of
1334  // errors.
1335  declarator.setInvalidType(true);
1336  } else if (S.getLangOpts().OpenCLVersion >= 200 && DS.isTypeSpecPipe()){
1337  S.Diag(DeclLoc, diag::err_missing_actual_pipe_type)
1338  << DS.getSourceRange();
1339  declarator.setInvalidType(true);
1340  } else {
1341  S.Diag(DeclLoc, diag::ext_missing_type_specifier)
1342  << DS.getSourceRange();
1343  }
1344  }
1345 
1346  LLVM_FALLTHROUGH;
1347  case DeclSpec::TST_int: {
1349  switch (DS.getTypeSpecWidth()) {
1350  case DeclSpec::TSW_unspecified: Result = Context.IntTy; break;
1351  case DeclSpec::TSW_short: Result = Context.ShortTy; break;
1352  case DeclSpec::TSW_long: Result = Context.LongTy; break;
1354  Result = Context.LongLongTy;
1355 
1356  // 'long long' is a C99 or C++11 feature.
1357  if (!S.getLangOpts().C99) {
1358  if (S.getLangOpts().CPlusPlus)
1359  S.Diag(DS.getTypeSpecWidthLoc(),
1360  S.getLangOpts().CPlusPlus11 ?
1361  diag::warn_cxx98_compat_longlong : diag::ext_cxx11_longlong);
1362  else
1363  S.Diag(DS.getTypeSpecWidthLoc(), diag::ext_c99_longlong);
1364  }
1365  break;
1366  }
1367  } else {
1368  switch (DS.getTypeSpecWidth()) {
1369  case DeclSpec::TSW_unspecified: Result = Context.UnsignedIntTy; break;
1370  case DeclSpec::TSW_short: Result = Context.UnsignedShortTy; break;
1371  case DeclSpec::TSW_long: Result = Context.UnsignedLongTy; break;
1373  Result = Context.UnsignedLongLongTy;
1374 
1375  // 'long long' is a C99 or C++11 feature.
1376  if (!S.getLangOpts().C99) {
1377  if (S.getLangOpts().CPlusPlus)
1378  S.Diag(DS.getTypeSpecWidthLoc(),
1379  S.getLangOpts().CPlusPlus11 ?
1380  diag::warn_cxx98_compat_longlong : diag::ext_cxx11_longlong);
1381  else
1382  S.Diag(DS.getTypeSpecWidthLoc(), diag::ext_c99_longlong);
1383  }
1384  break;
1385  }
1386  }
1387  break;
1388  }
1389  case DeclSpec::TST_accum: {
1390  switch (DS.getTypeSpecWidth()) {
1391  case DeclSpec::TSW_short:
1392  Result = Context.ShortAccumTy;
1393  break;
1395  Result = Context.AccumTy;
1396  break;
1397  case DeclSpec::TSW_long:
1398  Result = Context.LongAccumTy;
1399  break;
1401  llvm_unreachable("Unable to specify long long as _Accum width");
1402  }
1403 
1405  Result = Context.getCorrespondingUnsignedType(Result);
1406 
1407  if (DS.isTypeSpecSat())
1408  Result = Context.getCorrespondingSaturatedType(Result);
1409 
1410  break;
1411  }
1412  case DeclSpec::TST_fract: {
1413  switch (DS.getTypeSpecWidth()) {
1414  case DeclSpec::TSW_short:
1415  Result = Context.ShortFractTy;
1416  break;
1418  Result = Context.FractTy;
1419  break;
1420  case DeclSpec::TSW_long:
1421  Result = Context.LongFractTy;
1422  break;
1424  llvm_unreachable("Unable to specify long long as _Fract width");
1425  }
1426 
1428  Result = Context.getCorrespondingUnsignedType(Result);
1429 
1430  if (DS.isTypeSpecSat())
1431  Result = Context.getCorrespondingSaturatedType(Result);
1432 
1433  break;
1434  }
1435  case DeclSpec::TST_int128:
1436  if (!S.Context.getTargetInfo().hasInt128Type() &&
1437  !(S.getLangOpts().OpenMP && S.getLangOpts().OpenMPIsDevice))
1438  S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_unsupported)
1439  << "__int128";
1441  Result = Context.UnsignedInt128Ty;
1442  else
1443  Result = Context.Int128Ty;
1444  break;
1445  case DeclSpec::TST_float16:
1446  // CUDA host and device may have different _Float16 support, therefore
1447  // do not diagnose _Float16 usage to avoid false alarm.
1448  // ToDo: more precise diagnostics for CUDA.
1449  if (!S.Context.getTargetInfo().hasFloat16Type() && !S.getLangOpts().CUDA &&
1450  !(S.getLangOpts().OpenMP && S.getLangOpts().OpenMPIsDevice))
1451  S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_unsupported)
1452  << "_Float16";
1453  Result = Context.Float16Ty;
1454  break;
1455  case DeclSpec::TST_half: Result = Context.HalfTy; break;
1456  case DeclSpec::TST_float: Result = Context.FloatTy; break;
1457  case DeclSpec::TST_double:
1459  Result = Context.LongDoubleTy;
1460  else
1461  Result = Context.DoubleTy;
1462  break;
1465  !(S.getLangOpts().OpenMP && S.getLangOpts().OpenMPIsDevice))
1466  S.Diag(DS.getTypeSpecTypeLoc(), diag::err_type_unsupported)
1467  << "__float128";
1468  Result = Context.Float128Ty;
1469  break;
1470  case DeclSpec::TST_bool: Result = Context.BoolTy; break; // _Bool or bool
1471  break;
1472  case DeclSpec::TST_decimal32: // _Decimal32
1473  case DeclSpec::TST_decimal64: // _Decimal64
1474  case DeclSpec::TST_decimal128: // _Decimal128
1475  S.Diag(DS.getTypeSpecTypeLoc(), diag::err_decimal_unsupported);
1476  Result = Context.IntTy;
1477  declarator.setInvalidType(true);
1478  break;
1479  case DeclSpec::TST_class:
1480  case DeclSpec::TST_enum:
1481  case DeclSpec::TST_union:
1482  case DeclSpec::TST_struct:
1483  case DeclSpec::TST_interface: {
1484  TagDecl *D = dyn_cast_or_null<TagDecl>(DS.getRepAsDecl());
1485  if (!D) {
1486  // This can happen in C++ with ambiguous lookups.
1487  Result = Context.IntTy;
1488  declarator.setInvalidType(true);
1489  break;
1490  }
1491 
1492  // If the type is deprecated or unavailable, diagnose it.
1494 
1495  assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
1496  DS.getTypeSpecSign() == 0 && "No qualifiers on tag names!");
1497 
1498  // TypeQuals handled by caller.
1499  Result = Context.getTypeDeclType(D);
1500 
1501  // In both C and C++, make an ElaboratedType.
1502  ElaboratedTypeKeyword Keyword
1504  Result = S.getElaboratedType(Keyword, DS.getTypeSpecScope(), Result,
1505  DS.isTypeSpecOwned() ? D : nullptr);
1506  break;
1507  }
1508  case DeclSpec::TST_typename: {
1509  assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
1510  DS.getTypeSpecSign() == 0 &&
1511  "Can't handle qualifiers on typedef names yet!");
1512  Result = S.GetTypeFromParser(DS.getRepAsType());
1513  if (Result.isNull()) {
1514  declarator.setInvalidType(true);
1515  }
1516 
1517  // TypeQuals handled by caller.
1518  break;
1519  }
1521  // FIXME: Preserve type source info.
1522  Result = S.GetTypeFromParser(DS.getRepAsType());
1523  assert(!Result.isNull() && "Didn't get a type for typeof?");
1524  if (!Result->isDependentType())
1525  if (const TagType *TT = Result->getAs<TagType>())
1526  S.DiagnoseUseOfDecl(TT->getDecl(), DS.getTypeSpecTypeLoc());
1527  // TypeQuals handled by caller.
1528  Result = Context.getTypeOfType(Result);
1529  break;
1530  case DeclSpec::TST_typeofExpr: {
1531  Expr *E = DS.getRepAsExpr();
1532  assert(E && "Didn't get an expression for typeof?");
1533  // TypeQuals handled by caller.
1534  Result = S.BuildTypeofExprType(E, DS.getTypeSpecTypeLoc());
1535  if (Result.isNull()) {
1536  Result = Context.IntTy;
1537  declarator.setInvalidType(true);
1538  }
1539  break;
1540  }
1541  case DeclSpec::TST_decltype: {
1542  Expr *E = DS.getRepAsExpr();
1543  assert(E && "Didn't get an expression for decltype?");
1544  // TypeQuals handled by caller.
1545  Result = S.BuildDecltypeType(E, DS.getTypeSpecTypeLoc());
1546  if (Result.isNull()) {
1547  Result = Context.IntTy;
1548  declarator.setInvalidType(true);
1549  }
1550  break;
1551  }
1553  Result = S.GetTypeFromParser(DS.getRepAsType());
1554  assert(!Result.isNull() && "Didn't get a type for __underlying_type?");
1555  Result = S.BuildUnaryTransformType(Result,
1557  DS.getTypeSpecTypeLoc());
1558  if (Result.isNull()) {
1559  Result = Context.IntTy;
1560  declarator.setInvalidType(true);
1561  }
1562  break;
1563 
1564  case DeclSpec::TST_auto:
1565  Result = Context.getAutoType(QualType(), AutoTypeKeyword::Auto, false);
1566  break;
1567 
1569  Result = Context.getAutoType(QualType(), AutoTypeKeyword::GNUAutoType, false);
1570  break;
1571 
1574  /*IsDependent*/ false);
1575  break;
1576 
1578  Result = Context.UnknownAnyTy;
1579  break;
1580 
1581  case DeclSpec::TST_atomic:
1582  Result = S.GetTypeFromParser(DS.getRepAsType());
1583  assert(!Result.isNull() && "Didn't get a type for _Atomic?");
1584  Result = S.BuildAtomicType(Result, DS.getTypeSpecTypeLoc());
1585  if (Result.isNull()) {
1586  Result = Context.IntTy;
1587  declarator.setInvalidType(true);
1588  }
1589  break;
1590 
1591 #define GENERIC_IMAGE_TYPE(ImgType, Id) \
1592  case DeclSpec::TST_##ImgType##_t: \
1593  switch (getImageAccess(DS.getAttributes())) { \
1594  case OpenCLAccessAttr::Keyword_write_only: \
1595  Result = Context.Id##WOTy; \
1596  break; \
1597  case OpenCLAccessAttr::Keyword_read_write: \
1598  Result = Context.Id##RWTy; \
1599  break; \
1600  case OpenCLAccessAttr::Keyword_read_only: \
1601  Result = Context.Id##ROTy; \
1602  break; \
1603  } \
1604  break;
1605 #include "clang/Basic/OpenCLImageTypes.def"
1606 
1607  case DeclSpec::TST_error:
1608  Result = Context.IntTy;
1609  declarator.setInvalidType(true);
1610  break;
1611  }
1612 
1613  if (S.getLangOpts().OpenCL &&
1615  declarator.setInvalidType(true);
1616 
1617  bool IsFixedPointType = DS.getTypeSpecType() == DeclSpec::TST_accum ||
1618  DS.getTypeSpecType() == DeclSpec::TST_fract;
1619 
1620  // Only fixed point types can be saturated
1621  if (DS.isTypeSpecSat() && !IsFixedPointType)
1622  S.Diag(DS.getTypeSpecSatLoc(), diag::err_invalid_saturation_spec)
1623  << DS.getSpecifierName(DS.getTypeSpecType(),
1624  Context.getPrintingPolicy());
1625 
1626  // Handle complex types.
1627  if (DS.getTypeSpecComplex() == DeclSpec::TSC_complex) {
1628  if (S.getLangOpts().Freestanding)
1629  S.Diag(DS.getTypeSpecComplexLoc(), diag::ext_freestanding_complex);
1630  Result = Context.getComplexType(Result);
1631  } else if (DS.isTypeAltiVecVector()) {
1632  unsigned typeSize = static_cast<unsigned>(Context.getTypeSize(Result));
1633  assert(typeSize > 0 && "type size for vector must be greater than 0 bits");
1635  if (DS.isTypeAltiVecPixel())
1636  VecKind = VectorType::AltiVecPixel;
1637  else if (DS.isTypeAltiVecBool())
1638  VecKind = VectorType::AltiVecBool;
1639  Result = Context.getVectorType(Result, 128/typeSize, VecKind);
1640  }
1641 
1642  // FIXME: Imaginary.
1643  if (DS.getTypeSpecComplex() == DeclSpec::TSC_imaginary)
1644  S.Diag(DS.getTypeSpecComplexLoc(), diag::err_imaginary_not_supported);
1645 
1646  // Before we process any type attributes, synthesize a block literal
1647  // function declarator if necessary.
1648  if (declarator.getContext() == DeclaratorContext::BlockLiteralContext)
1650 
1651  // Apply any type attributes from the decl spec. This may cause the
1652  // list of type attributes to be temporarily saved while the type
1653  // attributes are pushed around.
1654  // pipe attributes will be handled later ( at GetFullTypeForDeclarator )
1655  if (!DS.isTypeSpecPipe())
1656  processTypeAttrs(state, Result, TAL_DeclSpec, DS.getAttributes());
1657 
1658  // Apply const/volatile/restrict qualifiers to T.
1659  if (unsigned TypeQuals = DS.getTypeQualifiers()) {
1660  // Warn about CV qualifiers on function types.
1661  // C99 6.7.3p8:
1662  // If the specification of a function type includes any type qualifiers,
1663  // the behavior is undefined.
1664  // C++11 [dcl.fct]p7:
1665  // The effect of a cv-qualifier-seq in a function declarator is not the
1666  // same as adding cv-qualification on top of the function type. In the
1667  // latter case, the cv-qualifiers are ignored.
1668  if (TypeQuals && Result->isFunctionType()) {
1670  S, DS, TypeQuals, Result, DeclSpec::TQ_const | DeclSpec::TQ_volatile,
1671  S.getLangOpts().CPlusPlus
1672  ? diag::warn_typecheck_function_qualifiers_ignored
1673  : diag::warn_typecheck_function_qualifiers_unspecified);
1674  // No diagnostic for 'restrict' or '_Atomic' applied to a
1675  // function type; we'll diagnose those later, in BuildQualifiedType.
1676  }
1677 
1678  // C++11 [dcl.ref]p1:
1679  // Cv-qualified references are ill-formed except when the
1680  // cv-qualifiers are introduced through the use of a typedef-name
1681  // or decltype-specifier, in which case the cv-qualifiers are ignored.
1682  //
1683  // There don't appear to be any other contexts in which a cv-qualified
1684  // reference type could be formed, so the 'ill-formed' clause here appears
1685  // to never happen.
1686  if (TypeQuals && Result->isReferenceType()) {
1688  S, DS, TypeQuals, Result,
1690  diag::warn_typecheck_reference_qualifiers);
1691  }
1692 
1693  // C90 6.5.3 constraints: "The same type qualifier shall not appear more
1694  // than once in the same specifier-list or qualifier-list, either directly
1695  // or via one or more typedefs."
1696  if (!S.getLangOpts().C99 && !S.getLangOpts().CPlusPlus
1697  && TypeQuals & Result.getCVRQualifiers()) {
1698  if (TypeQuals & DeclSpec::TQ_const && Result.isConstQualified()) {
1699  S.Diag(DS.getConstSpecLoc(), diag::ext_duplicate_declspec)
1700  << "const";
1701  }
1702 
1703  if (TypeQuals & DeclSpec::TQ_volatile && Result.isVolatileQualified()) {
1704  S.Diag(DS.getVolatileSpecLoc(), diag::ext_duplicate_declspec)
1705  << "volatile";
1706  }
1707 
1708  // C90 doesn't have restrict nor _Atomic, so it doesn't force us to
1709  // produce a warning in this case.
1710  }
1711 
1712  QualType Qualified = S.BuildQualifiedType(Result, DeclLoc, TypeQuals, &DS);
1713 
1714  // If adding qualifiers fails, just use the unqualified type.
1715  if (Qualified.isNull())
1716  declarator.setInvalidType(true);
1717  else
1718  Result = Qualified;
1719  }
1720 
1721  assert(!Result.isNull() && "This function should not return a null type");
1722  return Result;
1723 }
1724 
1725 static std::string getPrintableNameForEntity(DeclarationName Entity) {
1726  if (Entity)
1727  return Entity.getAsString();
1728 
1729  return "type name";
1730 }
1731 
1733  Qualifiers Qs, const DeclSpec *DS) {
1734  if (T.isNull())
1735  return QualType();
1736 
1737  // Ignore any attempt to form a cv-qualified reference.
1738  if (T->isReferenceType()) {
1739  Qs.removeConst();
1740  Qs.removeVolatile();
1741  }
1742 
1743  // Enforce C99 6.7.3p2: "Types other than pointer types derived from
1744  // object or incomplete types shall not be restrict-qualified."
1745  if (Qs.hasRestrict()) {
1746  unsigned DiagID = 0;
1747  QualType ProblemTy;
1748 
1749  if (T->isAnyPointerType() || T->isReferenceType() ||
1750  T->isMemberPointerType()) {
1751  QualType EltTy;
1752  if (T->isObjCObjectPointerType())
1753  EltTy = T;
1754  else if (const MemberPointerType *PTy = T->getAs<MemberPointerType>())
1755  EltTy = PTy->getPointeeType();
1756  else
1757  EltTy = T->getPointeeType();
1758 
1759  // If we have a pointer or reference, the pointee must have an object
1760  // incomplete type.
1761  if (!EltTy->isIncompleteOrObjectType()) {
1762  DiagID = diag::err_typecheck_invalid_restrict_invalid_pointee;
1763  ProblemTy = EltTy;
1764  }
1765  } else if (!T->isDependentType()) {
1766  DiagID = diag::err_typecheck_invalid_restrict_not_pointer;
1767  ProblemTy = T;
1768  }
1769 
1770  if (DiagID) {
1771  Diag(DS ? DS->getRestrictSpecLoc() : Loc, DiagID) << ProblemTy;
1772  Qs.removeRestrict();
1773  }
1774  }
1775 
1776  return Context.getQualifiedType(T, Qs);
1777 }
1778 
1780  unsigned CVRAU, const DeclSpec *DS) {
1781  if (T.isNull())
1782  return QualType();
1783 
1784  // Ignore any attempt to form a cv-qualified reference.
1785  if (T->isReferenceType())
1786  CVRAU &=
1788 
1789  // Convert from DeclSpec::TQ to Qualifiers::TQ by just dropping TQ_atomic and
1790  // TQ_unaligned;
1791  unsigned CVR = CVRAU & ~(DeclSpec::TQ_atomic | DeclSpec::TQ_unaligned);
1792 
1793  // C11 6.7.3/5:
1794  // If the same qualifier appears more than once in the same
1795  // specifier-qualifier-list, either directly or via one or more typedefs,
1796  // the behavior is the same as if it appeared only once.
1797  //
1798  // It's not specified what happens when the _Atomic qualifier is applied to
1799  // a type specified with the _Atomic specifier, but we assume that this
1800  // should be treated as if the _Atomic qualifier appeared multiple times.
1801  if (CVRAU & DeclSpec::TQ_atomic && !T->isAtomicType()) {
1802  // C11 6.7.3/5:
1803  // If other qualifiers appear along with the _Atomic qualifier in a
1804  // specifier-qualifier-list, the resulting type is the so-qualified
1805  // atomic type.
1806  //
1807  // Don't need to worry about array types here, since _Atomic can't be
1808  // applied to such types.
1810  T = BuildAtomicType(QualType(Split.Ty, 0),
1811  DS ? DS->getAtomicSpecLoc() : Loc);
1812  if (T.isNull())
1813  return T;
1814  Split.Quals.addCVRQualifiers(CVR);
1815  return BuildQualifiedType(T, Loc, Split.Quals);
1816  }
1817 
1820  return BuildQualifiedType(T, Loc, Q, DS);
1821 }
1822 
1823 /// Build a paren type including \p T.
1825  return Context.getParenType(T);
1826 }
1827 
1828 /// Given that we're building a pointer or reference to the given
1830  SourceLocation loc,
1831  bool isReference) {
1832  // Bail out if retention is unrequired or already specified.
1833  if (!type->isObjCLifetimeType() ||
1835  return type;
1836 
1838 
1839  // If the object type is const-qualified, we can safely use
1840  // __unsafe_unretained. This is safe (because there are no read
1841  // barriers), and it'll be safe to coerce anything but __weak* to
1842  // the resulting type.
1843  if (type.isConstQualified()) {
1844  implicitLifetime = Qualifiers::OCL_ExplicitNone;
1845 
1846  // Otherwise, check whether the static type does not require
1847  // retaining. This currently only triggers for Class (possibly
1848  // protocol-qualifed, and arrays thereof).
1849  } else if (type->isObjCARCImplicitlyUnretainedType()) {
1850  implicitLifetime = Qualifiers::OCL_ExplicitNone;
1851 
1852  // If we are in an unevaluated context, like sizeof, skip adding a
1853  // qualification.
1854  } else if (S.isUnevaluatedContext()) {
1855  return type;
1856 
1857  // If that failed, give an error and recover using __strong. __strong
1858  // is the option most likely to prevent spurious second-order diagnostics,
1859  // like when binding a reference to a field.
1860  } else {
1861  // These types can show up in private ivars in system headers, so
1862  // we need this to not be an error in those cases. Instead we
1863  // want to delay.
1867  diag::err_arc_indirect_no_ownership, type, isReference));
1868  } else {
1869  S.Diag(loc, diag::err_arc_indirect_no_ownership) << type << isReference;
1870  }
1871  implicitLifetime = Qualifiers::OCL_Strong;
1872  }
1873  assert(implicitLifetime && "didn't infer any lifetime!");
1874 
1875  Qualifiers qs;
1876  qs.addObjCLifetime(implicitLifetime);
1877  return S.Context.getQualifiedType(type, qs);
1878 }
1879 
1880 static std::string getFunctionQualifiersAsString(const FunctionProtoType *FnTy){
1881  std::string Quals = FnTy->getMethodQuals().getAsString();
1882 
1883  switch (FnTy->getRefQualifier()) {
1884  case RQ_None:
1885  break;
1886 
1887  case RQ_LValue:
1888  if (!Quals.empty())
1889  Quals += ' ';
1890  Quals += '&';
1891  break;
1892 
1893  case RQ_RValue:
1894  if (!Quals.empty())
1895  Quals += ' ';
1896  Quals += "&&";
1897  break;
1898  }
1899 
1900  return Quals;
1901 }
1902 
1903 namespace {
1904 /// Kinds of declarator that cannot contain a qualified function type.
1905 ///
1906 /// C++98 [dcl.fct]p4 / C++11 [dcl.fct]p6:
1907 /// a function type with a cv-qualifier or a ref-qualifier can only appear
1908 /// at the topmost level of a type.
1909 ///
1910 /// Parens and member pointers are permitted. We don't diagnose array and
1911 /// function declarators, because they don't allow function types at all.
1912 ///
1913 /// The values of this enum are used in diagnostics.
1914 enum QualifiedFunctionKind { QFK_BlockPointer, QFK_Pointer, QFK_Reference };
1915 } // end anonymous namespace
1916 
1917 /// Check whether the type T is a qualified function type, and if it is,
1918 /// diagnose that it cannot be contained within the given kind of declarator.
1920  QualifiedFunctionKind QFK) {
1921  // Does T refer to a function type with a cv-qualifier or a ref-qualifier?
1922  const FunctionProtoType *FPT = T->getAs<FunctionProtoType>();
1923  if (!FPT || (FPT->getMethodQuals().empty() && FPT->getRefQualifier() == RQ_None))
1924  return false;
1925 
1926  S.Diag(Loc, diag::err_compound_qualified_function_type)
1927  << QFK << isa<FunctionType>(T.IgnoreParens()) << T
1929  return true;
1930 }
1931 
1932 /// Build a pointer type.
1933 ///
1934 /// \param T The type to which we'll be building a pointer.
1935 ///
1936 /// \param Loc The location of the entity whose type involves this
1937 /// pointer type or, if there is no such entity, the location of the
1938 /// type that will have pointer type.
1939 ///
1940 /// \param Entity The name of the entity that involves the pointer
1941 /// type, if known.
1942 ///
1943 /// \returns A suitable pointer type, if there are no
1944 /// errors. Otherwise, returns a NULL type.
1946  SourceLocation Loc, DeclarationName Entity) {
1947  if (T->isReferenceType()) {
1948  // C++ 8.3.2p4: There shall be no ... pointers to references ...
1949  Diag(Loc, diag::err_illegal_decl_pointer_to_reference)
1950  << getPrintableNameForEntity(Entity) << T;
1951  return QualType();
1952  }
1953 
1954  if (T->isFunctionType() && getLangOpts().OpenCL) {
1955  Diag(Loc, diag::err_opencl_function_pointer);
1956  return QualType();
1957  }
1958 
1959  if (checkQualifiedFunction(*this, T, Loc, QFK_Pointer))
1960  return QualType();
1961 
1962  assert(!T->isObjCObjectType() && "Should build ObjCObjectPointerType");
1963 
1964  // In ARC, it is forbidden to build pointers to unqualified pointers.
1965  if (getLangOpts().ObjCAutoRefCount)
1966  T = inferARCLifetimeForPointee(*this, T, Loc, /*reference*/ false);
1967 
1968  // Build the pointer type.
1969  return Context.getPointerType(T);
1970 }
1971 
1972 /// Build a reference type.
1973 ///
1974 /// \param T The type to which we'll be building a reference.
1975 ///
1976 /// \param Loc The location of the entity whose type involves this
1977 /// reference type or, if there is no such entity, the location of the
1978 /// type that will have reference type.
1979 ///
1980 /// \param Entity The name of the entity that involves the reference
1981 /// type, if known.
1982 ///
1983 /// \returns A suitable reference type, if there are no
1984 /// errors. Otherwise, returns a NULL type.
1986  SourceLocation Loc,
1987  DeclarationName Entity) {
1988  assert(Context.getCanonicalType(T) != Context.OverloadTy &&
1989  "Unresolved overloaded function type");
1990 
1991  // C++0x [dcl.ref]p6:
1992  // If a typedef (7.1.3), a type template-parameter (14.3.1), or a
1993  // decltype-specifier (7.1.6.2) denotes a type TR that is a reference to a
1994  // type T, an attempt to create the type "lvalue reference to cv TR" creates
1995  // the type "lvalue reference to T", while an attempt to create the type
1996  // "rvalue reference to cv TR" creates the type TR.
1997  bool LValueRef = SpelledAsLValue || T->getAs<LValueReferenceType>();
1998 
1999  // C++ [dcl.ref]p4: There shall be no references to references.
2000  //
2001  // According to C++ DR 106, references to references are only
2002  // diagnosed when they are written directly (e.g., "int & &"),
2003  // but not when they happen via a typedef:
2004  //
2005  // typedef int& intref;
2006  // typedef intref& intref2;
2007  //
2008  // Parser::ParseDeclaratorInternal diagnoses the case where
2009  // references are written directly; here, we handle the
2010  // collapsing of references-to-references as described in C++0x.
2011  // DR 106 and 540 introduce reference-collapsing into C++98/03.
2012 
2013  // C++ [dcl.ref]p1:
2014  // A declarator that specifies the type "reference to cv void"
2015  // is ill-formed.
2016  if (T->isVoidType()) {
2017  Diag(Loc, diag::err_reference_to_void);
2018  return QualType();
2019  }
2020 
2021  if (checkQualifiedFunction(*this, T, Loc, QFK_Reference))
2022  return QualType();
2023 
2024  // In ARC, it is forbidden to build references to unqualified pointers.
2025  if (getLangOpts().ObjCAutoRefCount)
2026  T = inferARCLifetimeForPointee(*this, T, Loc, /*reference*/ true);
2027 
2028  // Handle restrict on references.
2029  if (LValueRef)
2030  return Context.getLValueReferenceType(T, SpelledAsLValue);
2031  return Context.getRValueReferenceType(T);
2032 }
2033 
2034 /// Build a Read-only Pipe type.
2035 ///
2036 /// \param T The type to which we'll be building a Pipe.
2037 ///
2038 /// \param Loc We do not use it for now.
2039 ///
2040 /// \returns A suitable pipe type, if there are no errors. Otherwise, returns a
2041 /// NULL type.
2043  return Context.getReadPipeType(T);
2044 }
2045 
2046 /// Build a Write-only Pipe type.
2047 ///
2048 /// \param T The type to which we'll be building a Pipe.
2049 ///
2050 /// \param Loc We do not use it for now.
2051 ///
2052 /// \returns A suitable pipe type, if there are no errors. Otherwise, returns a
2053 /// NULL type.
2055  return Context.getWritePipeType(T);
2056 }
2057 
2058 /// Check whether the specified array size makes the array type a VLA. If so,
2059 /// return true, if not, return the size of the array in SizeVal.
2060 static bool isArraySizeVLA(Sema &S, Expr *ArraySize, llvm::APSInt &SizeVal) {
2061  // If the size is an ICE, it certainly isn't a VLA. If we're in a GNU mode
2062  // (like gnu99, but not c99) accept any evaluatable value as an extension.
2063  class VLADiagnoser : public Sema::VerifyICEDiagnoser {
2064  public:
2065  VLADiagnoser() : Sema::VerifyICEDiagnoser(true) {}
2066 
2067  void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) override {
2068  }
2069 
2070  void diagnoseFold(Sema &S, SourceLocation Loc, SourceRange SR) override {
2071  S.Diag(Loc, diag::ext_vla_folded_to_constant) << SR;
2072  }
2073  } Diagnoser;
2074 
2075  return S.VerifyIntegerConstantExpression(ArraySize, &SizeVal, Diagnoser,
2076  S.LangOpts.GNUMode ||
2077  S.LangOpts.OpenCL).isInvalid();
2078 }
2079 
2080 /// Build an array type.
2081 ///
2082 /// \param T The type of each element in the array.
2083 ///
2084 /// \param ASM C99 array size modifier (e.g., '*', 'static').
2085 ///
2086 /// \param ArraySize Expression describing the size of the array.
2087 ///
2088 /// \param Brackets The range from the opening '[' to the closing ']'.
2089 ///
2090 /// \param Entity The name of the entity that involves the array
2091 /// type, if known.
2092 ///
2093 /// \returns A suitable array type, if there are no errors. Otherwise,
2094 /// returns a NULL type.
2096  Expr *ArraySize, unsigned Quals,
2097  SourceRange Brackets, DeclarationName Entity) {
2098 
2099  SourceLocation Loc = Brackets.getBegin();
2100  if (getLangOpts().CPlusPlus) {
2101  // C++ [dcl.array]p1:
2102  // T is called the array element type; this type shall not be a reference
2103  // type, the (possibly cv-qualified) type void, a function type or an
2104  // abstract class type.
2105  //
2106  // C++ [dcl.array]p3:
2107  // When several "array of" specifications are adjacent, [...] only the
2108  // first of the constant expressions that specify the bounds of the arrays
2109  // may be omitted.
2110  //
2111  // Note: function types are handled in the common path with C.
2112  if (T->isReferenceType()) {
2113  Diag(Loc, diag::err_illegal_decl_array_of_references)
2114  << getPrintableNameForEntity(Entity) << T;
2115  return QualType();
2116  }
2117 
2118  if (T->isVoidType() || T->isIncompleteArrayType()) {
2119  Diag(Loc, diag::err_illegal_decl_array_incomplete_type) << T;
2120  return QualType();
2121  }
2122 
2123  if (RequireNonAbstractType(Brackets.getBegin(), T,
2124  diag::err_array_of_abstract_type))
2125  return QualType();
2126 
2127  // Mentioning a member pointer type for an array type causes us to lock in
2128  // an inheritance model, even if it's inside an unused typedef.
2129  if (Context.getTargetInfo().getCXXABI().isMicrosoft())
2130  if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>())
2131  if (!MPTy->getClass()->isDependentType())
2132  (void)isCompleteType(Loc, T);
2133 
2134  } else {
2135  // C99 6.7.5.2p1: If the element type is an incomplete or function type,
2136  // reject it (e.g. void ary[7], struct foo ary[7], void ary[7]())
2137  if (RequireCompleteType(Loc, T,
2138  diag::err_illegal_decl_array_incomplete_type))
2139  return QualType();
2140  }
2141 
2142  if (T->isFunctionType()) {
2143  Diag(Loc, diag::err_illegal_decl_array_of_functions)
2144  << getPrintableNameForEntity(Entity) << T;
2145  return QualType();
2146  }
2147 
2148  if (const RecordType *EltTy = T->getAs<RecordType>()) {
2149  // If the element type is a struct or union that contains a variadic
2150  // array, accept it as a GNU extension: C99 6.7.2.1p2.
2151  if (EltTy->getDecl()->hasFlexibleArrayMember())
2152  Diag(Loc, diag::ext_flexible_array_in_array) << T;
2153  } else if (T->isObjCObjectType()) {
2154  Diag(Loc, diag::err_objc_array_of_interfaces) << T;
2155  return QualType();
2156  }
2157 
2158  // Do placeholder conversions on the array size expression.
2159  if (ArraySize && ArraySize->hasPlaceholderType()) {
2160  ExprResult Result = CheckPlaceholderExpr(ArraySize);
2161  if (Result.isInvalid()) return QualType();
2162  ArraySize = Result.get();
2163  }
2164 
2165  // Do lvalue-to-rvalue conversions on the array size expression.
2166  if (ArraySize && !ArraySize->isRValue()) {
2167  ExprResult Result = DefaultLvalueConversion(ArraySize);
2168  if (Result.isInvalid())
2169  return QualType();
2170 
2171  ArraySize = Result.get();
2172  }
2173 
2174  // C99 6.7.5.2p1: The size expression shall have integer type.
2175  // C++11 allows contextual conversions to such types.
2176  if (!getLangOpts().CPlusPlus11 &&
2177  ArraySize && !ArraySize->isTypeDependent() &&
2178  !ArraySize->getType()->isIntegralOrUnscopedEnumerationType()) {
2179  Diag(ArraySize->getBeginLoc(), diag::err_array_size_non_int)
2180  << ArraySize->getType() << ArraySize->getSourceRange();
2181  return QualType();
2182  }
2183 
2184  llvm::APSInt ConstVal(Context.getTypeSize(Context.getSizeType()));
2185  if (!ArraySize) {
2186  if (ASM == ArrayType::Star)
2187  T = Context.getVariableArrayType(T, nullptr, ASM, Quals, Brackets);
2188  else
2189  T = Context.getIncompleteArrayType(T, ASM, Quals);
2190  } else if (ArraySize->isTypeDependent() || ArraySize->isValueDependent()) {
2191  T = Context.getDependentSizedArrayType(T, ArraySize, ASM, Quals, Brackets);
2192  } else if ((!T->isDependentType() && !T->isIncompleteType() &&
2193  !T->isConstantSizeType()) ||
2194  isArraySizeVLA(*this, ArraySize, ConstVal)) {
2195  // Even in C++11, don't allow contextual conversions in the array bound
2196  // of a VLA.
2197  if (getLangOpts().CPlusPlus11 &&
2198  !ArraySize->getType()->isIntegralOrUnscopedEnumerationType()) {
2199  Diag(ArraySize->getBeginLoc(), diag::err_array_size_non_int)
2200  << ArraySize->getType() << ArraySize->getSourceRange();
2201  return QualType();
2202  }
2203 
2204  // C99: an array with an element type that has a non-constant-size is a VLA.
2205  // C99: an array with a non-ICE size is a VLA. We accept any expression
2206  // that we can fold to a non-zero positive value as an extension.
2207  T = Context.getVariableArrayType(T, ArraySize, ASM, Quals, Brackets);
2208  } else {
2209  // C99 6.7.5.2p1: If the expression is a constant expression, it shall
2210  // have a value greater than zero.
2211  if (ConstVal.isSigned() && ConstVal.isNegative()) {
2212  if (Entity)
2213  Diag(ArraySize->getBeginLoc(), diag::err_decl_negative_array_size)
2214  << getPrintableNameForEntity(Entity) << ArraySize->getSourceRange();
2215  else
2216  Diag(ArraySize->getBeginLoc(), diag::err_typecheck_negative_array_size)
2217  << ArraySize->getSourceRange();
2218  return QualType();
2219  }
2220  if (ConstVal == 0) {
2221  // GCC accepts zero sized static arrays. We allow them when
2222  // we're not in a SFINAE context.
2223  Diag(ArraySize->getBeginLoc(), isSFINAEContext()
2224  ? diag::err_typecheck_zero_array_size
2225  : diag::ext_typecheck_zero_array_size)
2226  << ArraySize->getSourceRange();
2227 
2228  if (ASM == ArrayType::Static) {
2229  Diag(ArraySize->getBeginLoc(),
2230  diag::warn_typecheck_zero_static_array_size)
2231  << ArraySize->getSourceRange();
2232  ASM = ArrayType::Normal;
2233  }
2234  } else if (!T->isDependentType() && !T->isVariablyModifiedType() &&
2235  !T->isIncompleteType() && !T->isUndeducedType()) {
2236  // Is the array too large?
2237  unsigned ActiveSizeBits
2238  = ConstantArrayType::getNumAddressingBits(Context, T, ConstVal);
2239  if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
2240  Diag(ArraySize->getBeginLoc(), diag::err_array_too_large)
2241  << ConstVal.toString(10) << ArraySize->getSourceRange();
2242  return QualType();
2243  }
2244  }
2245 
2246  T = Context.getConstantArrayType(T, ConstVal, ASM, Quals);
2247  }
2248 
2249  // OpenCL v1.2 s6.9.d: variable length arrays are not supported.
2250  if (getLangOpts().OpenCL && T->isVariableArrayType()) {
2251  Diag(Loc, diag::err_opencl_vla);
2252  return QualType();
2253  }
2254 
2255  if (T->isVariableArrayType() && !Context.getTargetInfo().isVLASupported()) {
2256  // CUDA device code and some other targets don't support VLAs.
2257  targetDiag(Loc, (getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
2258  ? diag::err_cuda_vla
2259  : diag::err_vla_unsupported)
2260  << ((getLangOpts().CUDA && getLangOpts().CUDAIsDevice)
2261  ? CurrentCUDATarget()
2262  : CFT_InvalidTarget);
2263  }
2264 
2265  // If this is not C99, extwarn about VLA's and C99 array size modifiers.
2266  if (!getLangOpts().C99) {
2267  if (T->isVariableArrayType()) {
2268  // Prohibit the use of VLAs during template argument deduction.
2269  if (isSFINAEContext()) {
2270  Diag(Loc, diag::err_vla_in_sfinae);
2271  return QualType();
2272  }
2273  // Just extwarn about VLAs.
2274  else
2275  Diag(Loc, diag::ext_vla);
2276  } else if (ASM != ArrayType::Normal || Quals != 0)
2277  Diag(Loc,
2278  getLangOpts().CPlusPlus? diag::err_c99_array_usage_cxx
2279  : diag::ext_c99_array_usage) << ASM;
2280  }
2281 
2282  if (T->isVariableArrayType()) {
2283  // Warn about VLAs for -Wvla.
2284  Diag(Loc, diag::warn_vla_used);
2285  }
2286 
2287  // OpenCL v2.0 s6.12.5 - Arrays of blocks are not supported.
2288  // OpenCL v2.0 s6.16.13.1 - Arrays of pipe type are not supported.
2289  // OpenCL v2.0 s6.9.b - Arrays of image/sampler type are not supported.
2290  if (getLangOpts().OpenCL) {
2291  const QualType ArrType = Context.getBaseElementType(T);
2292  if (ArrType->isBlockPointerType() || ArrType->isPipeType() ||
2293  ArrType->isSamplerT() || ArrType->isImageType()) {
2294  Diag(Loc, diag::err_opencl_invalid_type_array) << ArrType;
2295  return QualType();
2296  }
2297  }
2298 
2299  return T;
2300 }
2301 
2303  SourceLocation AttrLoc) {
2304  // The base type must be integer (not Boolean or enumeration) or float, and
2305  // can't already be a vector.
2306  if (!CurType->isDependentType() &&
2307  (!CurType->isBuiltinType() || CurType->isBooleanType() ||
2308  (!CurType->isIntegerType() && !CurType->isRealFloatingType()))) {
2309  Diag(AttrLoc, diag::err_attribute_invalid_vector_type) << CurType;
2310  return QualType();
2311  }
2312 
2313  if (SizeExpr->isTypeDependent() || SizeExpr->isValueDependent())
2314  return Context.getDependentVectorType(CurType, SizeExpr, AttrLoc,
2316 
2317  llvm::APSInt VecSize(32);
2318  if (!SizeExpr->isIntegerConstantExpr(VecSize, Context)) {
2319  Diag(AttrLoc, diag::err_attribute_argument_type)
2320  << "vector_size" << AANT_ArgumentIntegerConstant
2321  << SizeExpr->getSourceRange();
2322  return QualType();
2323  }
2324 
2325  if (CurType->isDependentType())
2326  return Context.getDependentVectorType(CurType, SizeExpr, AttrLoc,
2328 
2329  unsigned VectorSize = static_cast<unsigned>(VecSize.getZExtValue() * 8);
2330  unsigned TypeSize = static_cast<unsigned>(Context.getTypeSize(CurType));
2331 
2332  if (VectorSize == 0) {
2333  Diag(AttrLoc, diag::err_attribute_zero_size) << SizeExpr->getSourceRange();
2334  return QualType();
2335  }
2336 
2337  // vecSize is specified in bytes - convert to bits.
2338  if (VectorSize % TypeSize) {
2339  Diag(AttrLoc, diag::err_attribute_invalid_size)
2340  << SizeExpr->getSourceRange();
2341  return QualType();
2342  }
2343 
2344  if (VectorType::isVectorSizeTooLarge(VectorSize / TypeSize)) {
2345  Diag(AttrLoc, diag::err_attribute_size_too_large)
2346  << SizeExpr->getSourceRange();
2347  return QualType();
2348  }
2349 
2350  return Context.getVectorType(CurType, VectorSize / TypeSize,
2352 }
2353 
2354 /// Build an ext-vector type.
2355 ///
2356 /// Run the required checks for the extended vector type.
2358  SourceLocation AttrLoc) {
2359  // Unlike gcc's vector_size attribute, we do not allow vectors to be defined
2360  // in conjunction with complex types (pointers, arrays, functions, etc.).
2361  //
2362  // Additionally, OpenCL prohibits vectors of booleans (they're considered a
2363  // reserved data type under OpenCL v2.0 s6.1.4), we don't support selects
2364  // on bitvectors, and we have no well-defined ABI for bitvectors, so vectors
2365  // of bool aren't allowed.
2366  if ((!T->isDependentType() && !T->isIntegerType() &&
2367  !T->isRealFloatingType()) ||
2368  T->isBooleanType()) {
2369  Diag(AttrLoc, diag::err_attribute_invalid_vector_type) << T;
2370  return QualType();
2371  }
2372 
2373  if (!ArraySize->isTypeDependent() && !ArraySize->isValueDependent()) {
2374  llvm::APSInt vecSize(32);
2375  if (!ArraySize->isIntegerConstantExpr(vecSize, Context)) {
2376  Diag(AttrLoc, diag::err_attribute_argument_type)
2377  << "ext_vector_type" << AANT_ArgumentIntegerConstant
2378  << ArraySize->getSourceRange();
2379  return QualType();
2380  }
2381 
2382  // Unlike gcc's vector_size attribute, the size is specified as the
2383  // number of elements, not the number of bytes.
2384  unsigned vectorSize = static_cast<unsigned>(vecSize.getZExtValue());
2385 
2386  if (vectorSize == 0) {
2387  Diag(AttrLoc, diag::err_attribute_zero_size)
2388  << ArraySize->getSourceRange();
2389  return QualType();
2390  }
2391 
2392  if (VectorType::isVectorSizeTooLarge(vectorSize)) {
2393  Diag(AttrLoc, diag::err_attribute_size_too_large)
2394  << ArraySize->getSourceRange();
2395  return QualType();
2396  }
2397 
2398  return Context.getExtVectorType(T, vectorSize);
2399  }
2400 
2401  return Context.getDependentSizedExtVectorType(T, ArraySize, AttrLoc);
2402 }
2403 
2405  if (T->isArrayType() || T->isFunctionType()) {
2406  Diag(Loc, diag::err_func_returning_array_function)
2407  << T->isFunctionType() << T;
2408  return true;
2409  }
2410 
2411  // Functions cannot return half FP.
2412  if (T->isHalfType() && !getLangOpts().HalfArgsAndReturns) {
2413  Diag(Loc, diag::err_parameters_retval_cannot_have_fp16_type) << 1 <<
2414  FixItHint::CreateInsertion(Loc, "*");
2415  return true;
2416  }
2417 
2418  // Methods cannot return interface types. All ObjC objects are
2419  // passed by reference.
2420  if (T->isObjCObjectType()) {
2421  Diag(Loc, diag::err_object_cannot_be_passed_returned_by_value)
2422  << 0 << T << FixItHint::CreateInsertion(Loc, "*");
2423  return true;
2424  }
2425 
2426  return false;
2427 }
2428 
2429 /// Check the extended parameter information. Most of the necessary
2430 /// checking should occur when applying the parameter attribute; the
2431 /// only other checks required are positional restrictions.
2434  llvm::function_ref<SourceLocation(unsigned)> getParamLoc) {
2435  assert(EPI.ExtParameterInfos && "shouldn't get here without param infos");
2436 
2437  bool hasCheckedSwiftCall = false;
2438  auto checkForSwiftCC = [&](unsigned paramIndex) {
2439  // Only do this once.
2440  if (hasCheckedSwiftCall) return;
2441  hasCheckedSwiftCall = true;
2442  if (EPI.ExtInfo.getCC() == CC_Swift) return;
2443  S.Diag(getParamLoc(paramIndex), diag::err_swift_param_attr_not_swiftcall)
2444  << getParameterABISpelling(EPI.ExtParameterInfos[paramIndex].getABI());
2445  };
2446 
2447  for (size_t paramIndex = 0, numParams = paramTypes.size();
2448  paramIndex != numParams; ++paramIndex) {
2449  switch (EPI.ExtParameterInfos[paramIndex].getABI()) {
2450  // Nothing interesting to check for orindary-ABI parameters.
2452  continue;
2453 
2454  // swift_indirect_result parameters must be a prefix of the function
2455  // arguments.
2457  checkForSwiftCC(paramIndex);
2458  if (paramIndex != 0 &&
2459  EPI.ExtParameterInfos[paramIndex - 1].getABI()
2461  S.Diag(getParamLoc(paramIndex),
2462  diag::err_swift_indirect_result_not_first);
2463  }
2464  continue;
2465 
2467  checkForSwiftCC(paramIndex);
2468  continue;
2469 
2470  // swift_error parameters must be preceded by a swift_context parameter.
2472  checkForSwiftCC(paramIndex);
2473  if (paramIndex == 0 ||
2474  EPI.ExtParameterInfos[paramIndex - 1].getABI() !=
2476  S.Diag(getParamLoc(paramIndex),
2477  diag::err_swift_error_result_not_after_swift_context);
2478  }
2479  continue;
2480  }
2481  llvm_unreachable("bad ABI kind");
2482  }
2483 }
2484 
2486  MutableArrayRef<QualType> ParamTypes,
2487  SourceLocation Loc, DeclarationName Entity,
2488  const FunctionProtoType::ExtProtoInfo &EPI) {
2489  bool Invalid = false;
2490 
2491  Invalid |= CheckFunctionReturnType(T, Loc);
2492 
2493  for (unsigned Idx = 0, Cnt = ParamTypes.size(); Idx < Cnt; ++Idx) {
2494  // FIXME: Loc is too inprecise here, should use proper locations for args.
2495  QualType ParamType = Context.getAdjustedParameterType(ParamTypes[Idx]);
2496  if (ParamType->isVoidType()) {
2497  Diag(Loc, diag::err_param_with_void_type);
2498  Invalid = true;
2499  } else if (ParamType->isHalfType() && !getLangOpts().HalfArgsAndReturns) {
2500  // Disallow half FP arguments.
2501  Diag(Loc, diag::err_parameters_retval_cannot_have_fp16_type) << 0 <<
2502  FixItHint::CreateInsertion(Loc, "*");
2503  Invalid = true;
2504  }
2505 
2506  ParamTypes[Idx] = ParamType;
2507  }
2508 
2509  if (EPI.ExtParameterInfos) {
2510  checkExtParameterInfos(*this, ParamTypes, EPI,
2511  [=](unsigned i) { return Loc; });
2512  }
2513 
2514  if (EPI.ExtInfo.getProducesResult()) {
2515  // This is just a warning, so we can't fail to build if we see it.
2516  checkNSReturnsRetainedReturnType(Loc, T);
2517  }
2518 
2519  if (Invalid)
2520  return QualType();
2521 
2522  return Context.getFunctionType(T, ParamTypes, EPI);
2523 }
2524 
2525 /// Build a member pointer type \c T Class::*.
2526 ///
2527 /// \param T the type to which the member pointer refers.
2528 /// \param Class the class type into which the member pointer points.
2529 /// \param Loc the location where this type begins
2530 /// \param Entity the name of the entity that will have this member pointer type
2531 ///
2532 /// \returns a member pointer type, if successful, or a NULL type if there was
2533 /// an error.
2535  SourceLocation Loc,
2536  DeclarationName Entity) {
2537  // Verify that we're not building a pointer to pointer to function with
2538  // exception specification.
2539  if (CheckDistantExceptionSpec(T)) {
2540  Diag(Loc, diag::err_distant_exception_spec);
2541  return QualType();
2542  }
2543 
2544  // C++ 8.3.3p3: A pointer to member shall not point to ... a member
2545  // with reference type, or "cv void."
2546  if (T->isReferenceType()) {
2547  Diag(Loc, diag::err_illegal_decl_mempointer_to_reference)
2548  << getPrintableNameForEntity(Entity) << T;
2549  return QualType();
2550  }
2551 
2552  if (T->isVoidType()) {
2553  Diag(Loc, diag::err_illegal_decl_mempointer_to_void)
2554  << getPrintableNameForEntity(Entity);
2555  return QualType();
2556  }
2557 
2558  if (!Class->isDependentType() && !Class->isRecordType()) {
2559  Diag(Loc, diag::err_mempointer_in_nonclass_type) << Class;
2560  return QualType();
2561  }
2562 
2563  // Adjust the default free function calling convention to the default method
2564  // calling convention.
2565  bool IsCtorOrDtor =
2568  if (T->isFunctionType())
2569  adjustMemberFunctionCC(T, /*IsStatic=*/false, IsCtorOrDtor, Loc);
2570 
2571  return Context.getMemberPointerType(T, Class.getTypePtr());
2572 }
2573 
2574 /// Build a block pointer type.
2575 ///
2576 /// \param T The type to which we'll be building a block pointer.
2577 ///
2578 /// \param Loc The source location, used for diagnostics.
2579 ///
2580 /// \param Entity The name of the entity that involves the block pointer
2581 /// type, if known.
2582 ///
2583 /// \returns A suitable block pointer type, if there are no
2584 /// errors. Otherwise, returns a NULL type.
2586  SourceLocation Loc,
2587  DeclarationName Entity) {
2588  if (!T->isFunctionType()) {
2589  Diag(Loc, diag::err_nonfunction_block_type);
2590  return QualType();
2591  }
2592 
2593  if (checkQualifiedFunction(*this, T, Loc, QFK_BlockPointer))
2594  return QualType();
2595 
2596  return Context.getBlockPointerType(T);
2597 }
2598 
2600  QualType QT = Ty.get();
2601  if (QT.isNull()) {
2602  if (TInfo) *TInfo = nullptr;
2603  return QualType();
2604  }
2605 
2606  TypeSourceInfo *DI = nullptr;
2607  if (const LocInfoType *LIT = dyn_cast<LocInfoType>(QT)) {
2608  QT = LIT->getType();
2609  DI = LIT->getTypeSourceInfo();
2610  }
2611 
2612  if (TInfo) *TInfo = DI;
2613  return QT;
2614 }
2615 
2616 static void transferARCOwnershipToDeclaratorChunk(TypeProcessingState &state,
2617  Qualifiers::ObjCLifetime ownership,
2618  unsigned chunkIndex);
2619 
2620 /// Given that this is the declaration of a parameter under ARC,
2621 /// attempt to infer attributes and such for pointer-to-whatever
2622 /// types.
2623 static void inferARCWriteback(TypeProcessingState &state,
2624  QualType &declSpecType) {
2625  Sema &S = state.getSema();
2626  Declarator &declarator = state.getDeclarator();
2627 
2628  // TODO: should we care about decl qualifiers?
2629 
2630  // Check whether the declarator has the expected form. We walk
2631  // from the inside out in order to make the block logic work.
2632  unsigned outermostPointerIndex = 0;
2633  bool isBlockPointer = false;
2634  unsigned numPointers = 0;
2635  for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
2636  unsigned chunkIndex = i;
2637  DeclaratorChunk &chunk = declarator.getTypeObject(chunkIndex);
2638  switch (chunk.Kind) {
2640  // Ignore parens.
2641  break;
2642 
2645  // Count the number of pointers. Treat references
2646  // interchangeably as pointers; if they're mis-ordered, normal
2647  // type building will discover that.
2648  outermostPointerIndex = chunkIndex;
2649  numPointers++;
2650  break;
2651 
2653  // If we have a pointer to block pointer, that's an acceptable
2654  // indirect reference; anything else is not an application of
2655  // the rules.
2656  if (numPointers != 1) return;
2657  numPointers++;
2658  outermostPointerIndex = chunkIndex;
2659  isBlockPointer = true;
2660 
2661  // We don't care about pointer structure in return values here.
2662  goto done;
2663 
2664  case DeclaratorChunk::Array: // suppress if written (id[])?
2667  case DeclaratorChunk::Pipe:
2668  return;
2669  }
2670  }
2671  done:
2672 
2673  // If we have *one* pointer, then we want to throw the qualifier on
2674  // the declaration-specifiers, which means that it needs to be a
2675  // retainable object type.
2676  if (numPointers == 1) {
2677  // If it's not a retainable object type, the rule doesn't apply.
2678  if (!declSpecType->isObjCRetainableType()) return;
2679 
2680  // If it already has lifetime, don't do anything.
2681  if (declSpecType.getObjCLifetime()) return;
2682 
2683  // Otherwise, modify the type in-place.
2684  Qualifiers qs;
2685 
2686  if (declSpecType->isObjCARCImplicitlyUnretainedType())
2688  else
2690  declSpecType = S.Context.getQualifiedType(declSpecType, qs);
2691 
2692  // If we have *two* pointers, then we want to throw the qualifier on
2693  // the outermost pointer.
2694  } else if (numPointers == 2) {
2695  // If we don't have a block pointer, we need to check whether the
2696  // declaration-specifiers gave us something that will turn into a
2697  // retainable object pointer after we slap the first pointer on it.
2698  if (!isBlockPointer && !declSpecType->isObjCObjectType())
2699  return;
2700 
2701  // Look for an explicit lifetime attribute there.
2702  DeclaratorChunk &chunk = declarator.getTypeObject(outermostPointerIndex);
2703  if (chunk.Kind != DeclaratorChunk::Pointer &&
2705  return;
2706  for (const ParsedAttr &AL : chunk.getAttrs())
2707  if (AL.getKind() == ParsedAttr::AT_ObjCOwnership)
2708  return;
2709 
2711  outermostPointerIndex);
2712 
2713  // Any other number of pointers/references does not trigger the rule.
2714  } else return;
2715 
2716  // TODO: mark whether we did this inference?
2717 }
2718 
2719 void Sema::diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
2720  SourceLocation FallbackLoc,
2721  SourceLocation ConstQualLoc,
2722  SourceLocation VolatileQualLoc,
2723  SourceLocation RestrictQualLoc,
2724  SourceLocation AtomicQualLoc,
2725  SourceLocation UnalignedQualLoc) {
2726  if (!Quals)
2727  return;
2728 
2729  struct Qual {
2730  const char *Name;
2731  unsigned Mask;
2732  SourceLocation Loc;
2733  } const QualKinds[5] = {
2734  { "const", DeclSpec::TQ_const, ConstQualLoc },
2735  { "volatile", DeclSpec::TQ_volatile, VolatileQualLoc },
2736  { "restrict", DeclSpec::TQ_restrict, RestrictQualLoc },
2737  { "__unaligned", DeclSpec::TQ_unaligned, UnalignedQualLoc },
2738  { "_Atomic", DeclSpec::TQ_atomic, AtomicQualLoc }
2739  };
2740 
2741  SmallString<32> QualStr;
2742  unsigned NumQuals = 0;
2743  SourceLocation Loc;
2744  FixItHint FixIts[5];
2745 
2746  // Build a string naming the redundant qualifiers.
2747  for (auto &E : QualKinds) {
2748  if (Quals & E.Mask) {
2749  if (!QualStr.empty()) QualStr += ' ';
2750  QualStr += E.Name;
2751 
2752  // If we have a location for the qualifier, offer a fixit.
2753  SourceLocation QualLoc = E.Loc;
2754  if (QualLoc.isValid()) {
2755  FixIts[NumQuals] = FixItHint::CreateRemoval(QualLoc);
2756  if (Loc.isInvalid() ||
2757  getSourceManager().isBeforeInTranslationUnit(QualLoc, Loc))
2758  Loc = QualLoc;
2759  }
2760 
2761  ++NumQuals;
2762  }
2763  }
2764 
2765  Diag(Loc.isInvalid() ? FallbackLoc : Loc, DiagID)
2766  << QualStr << NumQuals << FixIts[0] << FixIts[1] << FixIts[2] << FixIts[3];
2767 }
2768 
2769 // Diagnose pointless type qualifiers on the return type of a function.
2771  Declarator &D,
2772  unsigned FunctionChunkIndex) {
2773  if (D.getTypeObject(FunctionChunkIndex).Fun.hasTrailingReturnType()) {
2774  // FIXME: TypeSourceInfo doesn't preserve location information for
2775  // qualifiers.
2776  S.diagnoseIgnoredQualifiers(diag::warn_qual_return_type,
2777  RetTy.getLocalCVRQualifiers(),
2778  D.getIdentifierLoc());
2779  return;
2780  }
2781 
2782  for (unsigned OuterChunkIndex = FunctionChunkIndex + 1,
2783  End = D.getNumTypeObjects();
2784  OuterChunkIndex != End; ++OuterChunkIndex) {
2785  DeclaratorChunk &OuterChunk = D.getTypeObject(OuterChunkIndex);
2786  switch (OuterChunk.Kind) {
2788  continue;
2789 
2790  case DeclaratorChunk::Pointer: {
2791  DeclaratorChunk::PointerTypeInfo &PTI = OuterChunk.Ptr;
2793  diag::warn_qual_return_type,
2794  PTI.TypeQuals,
2795  SourceLocation(),
2801  return;
2802  }
2803 
2809  case DeclaratorChunk::Pipe:
2810  // FIXME: We can't currently provide an accurate source location and a
2811  // fix-it hint for these.
2812  unsigned AtomicQual = RetTy->isAtomicType() ? DeclSpec::TQ_atomic : 0;
2813  S.diagnoseIgnoredQualifiers(diag::warn_qual_return_type,
2814  RetTy.getCVRQualifiers() | AtomicQual,
2815  D.getIdentifierLoc());
2816  return;
2817  }
2818 
2819  llvm_unreachable("unknown declarator chunk kind");
2820  }
2821 
2822  // If the qualifiers come from a conversion function type, don't diagnose
2823  // them -- they're not necessarily redundant, since such a conversion
2824  // operator can be explicitly called as "x.operator const int()".
2826  return;
2827 
2828  // Just parens all the way out to the decl specifiers. Diagnose any qualifiers
2829  // which are present there.
2830  S.diagnoseIgnoredQualifiers(diag::warn_qual_return_type,
2832  D.getIdentifierLoc(),
2838 }
2839 
2840 static QualType GetDeclSpecTypeForDeclarator(TypeProcessingState &state,
2841  TypeSourceInfo *&ReturnTypeInfo) {
2842  Sema &SemaRef = state.getSema();
2843  Declarator &D = state.getDeclarator();
2844  QualType T;
2845  ReturnTypeInfo = nullptr;
2846 
2847  // The TagDecl owned by the DeclSpec.
2848  TagDecl *OwnedTagDecl = nullptr;
2849 
2850  switch (D.getName().getKind()) {
2856  T = ConvertDeclSpecToType(state);
2857 
2858  if (!D.isInvalidType() && D.getDeclSpec().isTypeSpecOwned()) {
2859  OwnedTagDecl = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
2860  // Owned declaration is embedded in declarator.
2861  OwnedTagDecl->setEmbeddedInDeclarator(true);
2862  }
2863  break;
2864 
2868  // Constructors and destructors don't have return types. Use
2869  // "void" instead.
2870  T = SemaRef.Context.VoidTy;
2871  processTypeAttrs(state, T, TAL_DeclSpec,
2873  break;
2874 
2876  // Deduction guides have a trailing return type and no type in their
2877  // decl-specifier sequence. Use a placeholder return type for now.
2878  T = SemaRef.Context.DependentTy;
2879  break;
2880 
2882  // The result type of a conversion function is the type that it
2883  // converts to.
2885  &ReturnTypeInfo);
2886  break;
2887  }
2888 
2889  if (!D.getAttributes().empty())
2891 
2892  // C++11 [dcl.spec.auto]p5: reject 'auto' if it is not in an allowed context.
2893  if (DeducedType *Deduced = T->getContainedDeducedType()) {
2894  AutoType *Auto = dyn_cast<AutoType>(Deduced);
2895  int Error = -1;
2896 
2897  // Is this a 'auto' or 'decltype(auto)' type (as opposed to __auto_type or
2898  // class template argument deduction)?
2899  bool IsCXXAutoType =
2900  (Auto && Auto->getKeyword() != AutoTypeKeyword::GNUAutoType);
2901  bool IsDeducedReturnType = false;
2902 
2903  switch (D.getContext()) {
2905  // Declared return type of a lambda-declarator is implicit and is always
2906  // 'auto'.
2907  break;
2911  Error = 0;
2912  break;
2914  // In C++14, generic lambdas allow 'auto' in their parameters.
2915  if (!SemaRef.getLangOpts().CPlusPlus14 ||
2916  !Auto || Auto->getKeyword() != AutoTypeKeyword::Auto)
2917  Error = 16;
2918  else {
2919  // If auto is mentioned in a lambda parameter context, convert it to a
2920  // template parameter type.
2921  sema::LambdaScopeInfo *LSI = SemaRef.getCurLambda();
2922  assert(LSI && "No LambdaScopeInfo on the stack!");
2923  const unsigned TemplateParameterDepth = LSI->AutoTemplateParameterDepth;
2924  const unsigned AutoParameterPosition = LSI->AutoTemplateParams.size();
2925  const bool IsParameterPack = D.hasEllipsis();
2926 
2927  // Create the TemplateTypeParmDecl here to retrieve the corresponding
2928  // template parameter type. Template parameters are temporarily added
2929  // to the TU until the associated TemplateDecl is created.
2930  TemplateTypeParmDecl *CorrespondingTemplateParam =
2932  SemaRef.Context, SemaRef.Context.getTranslationUnitDecl(),
2933  /*KeyLoc*/ SourceLocation(), /*NameLoc*/ D.getBeginLoc(),
2934  TemplateParameterDepth, AutoParameterPosition,
2935  /*Identifier*/ nullptr, false, IsParameterPack);
2936  LSI->AutoTemplateParams.push_back(CorrespondingTemplateParam);
2937  // Replace the 'auto' in the function parameter with this invented
2938  // template type parameter.
2939  // FIXME: Retain some type sugar to indicate that this was written
2940  // as 'auto'.
2941  T = SemaRef.ReplaceAutoType(
2942  T, QualType(CorrespondingTemplateParam->getTypeForDecl(), 0));
2943  }
2944  break;
2948  break;
2949  bool Cxx = SemaRef.getLangOpts().CPlusPlus;
2950  switch (cast<TagDecl>(SemaRef.CurContext)->getTagKind()) {
2951  case TTK_Enum: llvm_unreachable("unhandled tag kind");
2952  case TTK_Struct: Error = Cxx ? 1 : 2; /* Struct member */ break;
2953  case TTK_Union: Error = Cxx ? 3 : 4; /* Union member */ break;
2954  case TTK_Class: Error = 5; /* Class member */ break;
2955  case TTK_Interface: Error = 6; /* Interface member */ break;
2956  }
2957  if (D.getDeclSpec().isFriendSpecified())
2958  Error = 20; // Friend type
2959  break;
2960  }
2963  Error = 7; // Exception declaration
2964  break;
2966  if (isa<DeducedTemplateSpecializationType>(Deduced))
2967  Error = 19; // Template parameter
2968  else if (!SemaRef.getLangOpts().CPlusPlus17)
2969  Error = 8; // Template parameter (until C++17)
2970  break;
2972  Error = 9; // Block literal
2973  break;
2975  // Within a template argument list, a deduced template specialization
2976  // type will be reinterpreted as a template template argument.
2977  if (isa<DeducedTemplateSpecializationType>(Deduced) &&
2978  !D.getNumTypeObjects() &&
2980  break;
2981  LLVM_FALLTHROUGH;
2983  Error = 10; // Template type argument
2984  break;
2987  Error = 12; // Type alias
2988  break;
2991  if (!SemaRef.getLangOpts().CPlusPlus14 || !IsCXXAutoType)
2992  Error = 13; // Function return type
2993  IsDeducedReturnType = true;
2994  break;
2996  if (!SemaRef.getLangOpts().CPlusPlus14 || !IsCXXAutoType)
2997  Error = 14; // conversion-type-id
2998  IsDeducedReturnType = true;
2999  break;
3001  if (isa<DeducedTemplateSpecializationType>(Deduced))
3002  break;
3003  LLVM_FALLTHROUGH;
3005  Error = 15; // Generic
3006  break;
3012  // FIXME: P0091R3 (erroneously) does not permit class template argument
3013  // deduction in conditions, for-init-statements, and other declarations
3014  // that are not simple-declarations.
3015  break;
3017  // FIXME: P0091R3 does not permit class template argument deduction here,
3018  // but we follow GCC and allow it anyway.
3019  if (!IsCXXAutoType && !isa<DeducedTemplateSpecializationType>(Deduced))
3020  Error = 17; // 'new' type
3021  break;
3023  Error = 18; // K&R function parameter
3024  break;
3025  }
3026 
3028  Error = 11;
3029 
3030  // In Objective-C it is an error to use 'auto' on a function declarator
3031  // (and everywhere for '__auto_type').
3032  if (D.isFunctionDeclarator() &&
3033  (!SemaRef.getLangOpts().CPlusPlus11 || !IsCXXAutoType))
3034  Error = 13;
3035 
3036  bool HaveTrailing = false;
3037 
3038  // C++11 [dcl.spec.auto]p2: 'auto' is always fine if the declarator
3039  // contains a trailing return type. That is only legal at the outermost
3040  // level. Check all declarator chunks (outermost first) anyway, to give
3041  // better diagnostics.
3042  // We don't support '__auto_type' with trailing return types.
3043  // FIXME: Should we only do this for 'auto' and not 'decltype(auto)'?
3044  if (SemaRef.getLangOpts().CPlusPlus11 && IsCXXAutoType &&
3045  D.hasTrailingReturnType()) {
3046  HaveTrailing = true;
3047  Error = -1;
3048  }
3049 
3050  SourceRange AutoRange = D.getDeclSpec().getTypeSpecTypeLoc();
3052  AutoRange = D.getName().getSourceRange();
3053 
3054  if (Error != -1) {
3055  unsigned Kind;
3056  if (Auto) {
3057  switch (Auto->getKeyword()) {
3058  case AutoTypeKeyword::Auto: Kind = 0; break;
3059  case AutoTypeKeyword::DecltypeAuto: Kind = 1; break;
3060  case AutoTypeKeyword::GNUAutoType: Kind = 2; break;
3061  }
3062  } else {
3063  assert(isa<DeducedTemplateSpecializationType>(Deduced) &&
3064  "unknown auto type");
3065  Kind = 3;
3066  }
3067 
3068  auto *DTST = dyn_cast<DeducedTemplateSpecializationType>(Deduced);
3069  TemplateName TN = DTST ? DTST->getTemplateName() : TemplateName();
3070 
3071  SemaRef.Diag(AutoRange.getBegin(), diag::err_auto_not_allowed)
3072  << Kind << Error << (int)SemaRef.getTemplateNameKindForDiagnostics(TN)
3073  << QualType(Deduced, 0) << AutoRange;
3074  if (auto *TD = TN.getAsTemplateDecl())
3075  SemaRef.Diag(TD->getLocation(), diag::note_template_decl_here);
3076 
3077  T = SemaRef.Context.IntTy;
3078  D.setInvalidType(true);
3079  } else if (!HaveTrailing &&
3081  // If there was a trailing return type, we already got
3082  // warn_cxx98_compat_trailing_return_type in the parser.
3083  SemaRef.Diag(AutoRange.getBegin(),
3084  D.getContext() ==
3086  ? diag::warn_cxx11_compat_generic_lambda
3087  : IsDeducedReturnType
3088  ? diag::warn_cxx11_compat_deduced_return_type
3089  : diag::warn_cxx98_compat_auto_type_specifier)
3090  << AutoRange;
3091  }
3092  }
3093 
3094  if (SemaRef.getLangOpts().CPlusPlus &&
3095  OwnedTagDecl && OwnedTagDecl->isCompleteDefinition()) {
3096  // Check the contexts where C++ forbids the declaration of a new class
3097  // or enumeration in a type-specifier-seq.
3098  unsigned DiagID = 0;
3099  switch (D.getContext()) {
3102  // Class and enumeration definitions are syntactically not allowed in
3103  // trailing return types.
3104  llvm_unreachable("parser should not have allowed this");
3105  break;
3113  // C++11 [dcl.type]p3:
3114  // A type-specifier-seq shall not define a class or enumeration unless
3115  // it appears in the type-id of an alias-declaration (7.1.3) that is not
3116  // the declaration of a template-declaration.
3118  break;
3120  DiagID = diag::err_type_defined_in_alias_template;
3121  break;
3131  DiagID = diag::err_type_defined_in_type_specifier;
3132  break;
3138  // C++ [dcl.fct]p6:
3139  // Types shall not be defined in return or parameter types.
3140  DiagID = diag::err_type_defined_in_param_type;
3141  break;
3143  // C++ 6.4p2:
3144  // The type-specifier-seq shall not contain typedef and shall not declare
3145  // a new class or enumeration.
3146  DiagID = diag::err_type_defined_in_condition;
3147  break;
3148  }
3149 
3150  if (DiagID != 0) {
3151  SemaRef.Diag(OwnedTagDecl->getLocation(), DiagID)
3152  << SemaRef.Context.getTypeDeclType(OwnedTagDecl);
3153  D.setInvalidType(true);
3154  }
3155  }
3156 
3157  assert(!T.isNull() && "This function should not return a null type");
3158  return T;
3159 }
3160 
3161 /// Produce an appropriate diagnostic for an ambiguity between a function
3162 /// declarator and a C++ direct-initializer.
3164  DeclaratorChunk &DeclType, QualType RT) {
3165  const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
3166  assert(FTI.isAmbiguous && "no direct-initializer / function ambiguity");
3167 
3168  // If the return type is void there is no ambiguity.
3169  if (RT->isVoidType())
3170  return;
3171 
3172  // An initializer for a non-class type can have at most one argument.
3173  if (!RT->isRecordType() && FTI.NumParams > 1)
3174  return;
3175 
3176  // An initializer for a reference must have exactly one argument.
3177  if (RT->isReferenceType() && FTI.NumParams != 1)
3178  return;
3179 
3180  // Only warn if this declarator is declaring a function at block scope, and
3181  // doesn't have a storage class (such as 'extern') specified.
3182  if (!D.isFunctionDeclarator() ||
3187  return;
3188 
3189  // Inside a condition, a direct initializer is not permitted. We allow one to
3190  // be parsed in order to give better diagnostics in condition parsing.
3192  return;
3193 
3194  SourceRange ParenRange(DeclType.Loc, DeclType.EndLoc);
3195 
3196  S.Diag(DeclType.Loc,
3197  FTI.NumParams ? diag::warn_parens_disambiguated_as_function_declaration
3198  : diag::warn_empty_parens_are_function_decl)
3199  << ParenRange;
3200 
3201  // If the declaration looks like:
3202  // T var1,
3203  // f();
3204  // and name lookup finds a function named 'f', then the ',' was
3205  // probably intended to be a ';'.
3206  if (!D.isFirstDeclarator() && D.getIdentifier()) {
3209  if (Comma.getFileID() != Name.getFileID() ||
3210  Comma.getSpellingLineNumber() != Name.getSpellingLineNumber()) {
3213  if (S.LookupName(Result, S.getCurScope()))
3214  S.Diag(D.getCommaLoc(), diag::note_empty_parens_function_call)
3216  << D.getIdentifier();
3217  Result.suppressDiagnostics();
3218  }
3219  }
3220 
3221  if (FTI.NumParams > 0) {
3222  // For a declaration with parameters, eg. "T var(T());", suggest adding
3223  // parens around the first parameter to turn the declaration into a
3224  // variable declaration.
3225  SourceRange Range = FTI.Params[0].Param->getSourceRange();
3226  SourceLocation B = Range.getBegin();
3227  SourceLocation E = S.getLocForEndOfToken(Range.getEnd());
3228  // FIXME: Maybe we should suggest adding braces instead of parens
3229  // in C++11 for classes that don't have an initializer_list constructor.
3230  S.Diag(B, diag::note_additional_parens_for_variable_declaration)
3231  << FixItHint::CreateInsertion(B, "(")
3232  << FixItHint::CreateInsertion(E, ")");
3233  } else {
3234  // For a declaration without parameters, eg. "T var();", suggest replacing
3235  // the parens with an initializer to turn the declaration into a variable
3236  // declaration.
3237  const CXXRecordDecl *RD = RT->getAsCXXRecordDecl();
3238 
3239  // Empty parens mean value-initialization, and no parens mean
3240  // default initialization. These are equivalent if the default
3241  // constructor is user-provided or if zero-initialization is a
3242  // no-op.
3243  if (RD && RD->hasDefinition() &&
3244  (RD->isEmpty() || RD->hasUserProvidedDefaultConstructor()))
3245  S.Diag(DeclType.Loc, diag::note_empty_parens_default_ctor)
3246  << FixItHint::CreateRemoval(ParenRange);
3247  else {
3248  std::string Init =
3249  S.getFixItZeroInitializerForType(RT, ParenRange.getBegin());
3250  if (Init.empty() && S.LangOpts.CPlusPlus11)
3251  Init = "{}";
3252  if (!Init.empty())
3253  S.Diag(DeclType.Loc, diag::note_empty_parens_zero_initialize)
3254  << FixItHint::CreateReplacement(ParenRange, Init);
3255  }
3256  }
3257 }
3258 
3259 /// Produce an appropriate diagnostic for a declarator with top-level
3260 /// parentheses.
3263  assert(Paren.Kind == DeclaratorChunk::Paren &&
3264  "do not have redundant top-level parentheses");
3265 
3266  // This is a syntactic check; we're not interested in cases that arise
3267  // during template instantiation.
3268  if (S.inTemplateInstantiation())
3269  return;
3270 
3271  // Check whether this could be intended to be a construction of a temporary
3272  // object in C++ via a function-style cast.
3273  bool CouldBeTemporaryObject =
3274  S.getLangOpts().CPlusPlus && D.isExpressionContext() &&
3275  !D.isInvalidType() && D.getIdentifier() &&
3277  (T->isRecordType() || T->isDependentType()) &&
3279 
3280  bool StartsWithDeclaratorId = true;
3281  for (auto &C : D.type_objects()) {
3282  switch (C.Kind) {
3284  if (&C == &Paren)
3285  continue;
3286  LLVM_FALLTHROUGH;
3288  StartsWithDeclaratorId = false;
3289  continue;
3290 
3292  if (!C.Arr.NumElts)
3293  CouldBeTemporaryObject = false;
3294  continue;
3295 
3297  // FIXME: Suppress the warning here if there is no initializer; we're
3298  // going to give an error anyway.
3299  // We assume that something like 'T (&x) = y;' is highly likely to not
3300  // be intended to be a temporary object.
3301  CouldBeTemporaryObject = false;
3302  StartsWithDeclaratorId = false;
3303  continue;
3304 
3306  // In a new-type-id, function chunks require parentheses.
3308  return;
3309  // FIXME: "A(f())" deserves a vexing-parse warning, not just a
3310  // redundant-parens warning, but we don't know whether the function
3311  // chunk was syntactically valid as an expression here.
3312  CouldBeTemporaryObject = false;
3313  continue;
3314 
3317  case DeclaratorChunk::Pipe:
3318  // These cannot appear in expressions.
3319  CouldBeTemporaryObject = false;
3320  StartsWithDeclaratorId = false;
3321  continue;
3322  }
3323  }
3324 
3325  // FIXME: If there is an initializer, assume that this is not intended to be
3326  // a construction of a temporary object.
3327 
3328  // Check whether the name has already been declared; if not, this is not a
3329  // function-style cast.
3330  if (CouldBeTemporaryObject) {
3333  if (!S.LookupName(Result, S.getCurScope()))
3334  CouldBeTemporaryObject = false;
3335  Result.suppressDiagnostics();
3336  }
3337 
3338  SourceRange ParenRange(Paren.Loc, Paren.EndLoc);
3339 
3340  if (!CouldBeTemporaryObject) {
3341  // If we have A (::B), the parentheses affect the meaning of the program.
3342  // Suppress the warning in that case. Don't bother looking at the DeclSpec
3343  // here: even (e.g.) "int ::x" is visually ambiguous even though it's
3344  // formally unambiguous.
3345  if (StartsWithDeclaratorId && D.getCXXScopeSpec().isValid()) {
3346  for (NestedNameSpecifier *NNS = D.getCXXScopeSpec().getScopeRep(); NNS;
3347  NNS = NNS->getPrefix()) {
3348  if (NNS->getKind() == NestedNameSpecifier::Global)
3349  return;
3350  }
3351  }
3352 
3353  S.Diag(Paren.Loc, diag::warn_redundant_parens_around_declarator)
3354  << ParenRange << FixItHint::CreateRemoval(Paren.Loc)
3355  << FixItHint::CreateRemoval(Paren.EndLoc);
3356  return;
3357  }
3358 
3359  S.Diag(Paren.Loc, diag::warn_parens_disambiguated_as_variable_declaration)
3360  << ParenRange << D.getIdentifier();
3361  auto *RD = T->getAsCXXRecordDecl();
3362  if (!RD || !RD->hasDefinition() || RD->hasNonTrivialDestructor())
3363  S.Diag(Paren.Loc, diag::note_raii_guard_add_name)
3364  << FixItHint::CreateInsertion(Paren.Loc, " varname") << T
3365  << D.getIdentifier();
3366  // FIXME: A cast to void is probably a better suggestion in cases where it's
3367  // valid (when there is no initializer and we're not in a condition).
3368  S.Diag(D.getBeginLoc(), diag::note_function_style_cast_add_parentheses)
3371  S.Diag(Paren.Loc, diag::note_remove_parens_for_variable_declaration)
3372  << FixItHint::CreateRemoval(Paren.Loc)
3373  << FixItHint::CreateRemoval(Paren.EndLoc);
3374 }
3375 
3376 /// Helper for figuring out the default CC for a function declarator type. If
3377 /// this is the outermost chunk, then we can determine the CC from the
3378 /// declarator context. If not, then this could be either a member function
3379 /// type or normal function type.
3381  Sema &S, Declarator &D, const ParsedAttributesView &AttrList,
3382  const DeclaratorChunk::FunctionTypeInfo &FTI, unsigned ChunkIndex) {
3383  assert(D.getTypeObject(ChunkIndex).Kind == DeclaratorChunk::Function);
3384 
3385  // Check for an explicit CC attribute.
3386  for (const ParsedAttr &AL : AttrList) {
3387  switch (AL.getKind()) {
3389  // Ignore attributes that don't validate or can't apply to the
3390  // function type. We'll diagnose the failure to apply them in
3391  // handleFunctionTypeAttr.
3392  CallingConv CC;
3393  if (!S.CheckCallingConvAttr(AL, CC) &&
3394  (!FTI.isVariadic || supportsVariadicCall(CC))) {
3395  return CC;
3396  }
3397  break;
3398  }
3399 
3400  default:
3401  break;
3402  }
3403  }
3404 
3405  bool IsCXXInstanceMethod = false;
3406 
3407  if (S.getLangOpts().CPlusPlus) {
3408  // Look inwards through parentheses to see if this chunk will form a
3409  // member pointer type or if we're the declarator. Any type attributes
3410  // between here and there will override the CC we choose here.
3411  unsigned I = ChunkIndex;
3412  bool FoundNonParen = false;
3413  while (I && !FoundNonParen) {
3414  --I;
3416  FoundNonParen = true;
3417  }
3418 
3419  if (FoundNonParen) {
3420  // If we're not the declarator, we're a regular function type unless we're
3421  // in a member pointer.
3422  IsCXXInstanceMethod =
3425  // This can only be a call operator for a lambda, which is an instance
3426  // method.
3427  IsCXXInstanceMethod = true;
3428  } else {
3429  // We're the innermost decl chunk, so must be a function declarator.
3430  assert(D.isFunctionDeclarator());
3431 
3432  // If we're inside a record, we're declaring a method, but it could be
3433  // explicitly or implicitly static.
3434  IsCXXInstanceMethod =
3437  !D.isStaticMember();
3438  }
3439  }
3440 
3442  IsCXXInstanceMethod);
3443 
3444  // Attribute AT_OpenCLKernel affects the calling convention for SPIR
3445  // and AMDGPU targets, hence it cannot be treated as a calling
3446  // convention attribute. This is the simplest place to infer
3447  // calling convention for OpenCL kernels.
3448  if (S.getLangOpts().OpenCL) {
3449  for (const ParsedAttr &AL : D.getDeclSpec().getAttributes()) {
3450  if (AL.getKind() == ParsedAttr::AT_OpenCLKernel) {
3451  CC = CC_OpenCLKernel;
3452  break;
3453  }
3454  }
3455  }
3456 
3457  return CC;
3458 }
3459 
3460 namespace {
3461  /// A simple notion of pointer kinds, which matches up with the various
3462  /// pointer declarators.
3463  enum class SimplePointerKind {
3464  Pointer,
3465  BlockPointer,
3466  MemberPointer,
3467  Array,
3468  };
3469 } // end anonymous namespace
3470 
3472  switch (nullability) {
3474  if (!Ident__Nonnull)
3475  Ident__Nonnull = PP.getIdentifierInfo("_Nonnull");
3476  return Ident__Nonnull;
3477 
3479  if (!Ident__Nullable)
3480  Ident__Nullable = PP.getIdentifierInfo("_Nullable");
3481  return Ident__Nullable;
3482 
3484  if (!Ident__Null_unspecified)
3485  Ident__Null_unspecified = PP.getIdentifierInfo("_Null_unspecified");
3486  return Ident__Null_unspecified;
3487  }
3488  llvm_unreachable("Unknown nullability kind.");
3489 }
3490 
3491 /// Retrieve the identifier "NSError".
3493  if (!Ident_NSError)
3494  Ident_NSError = PP.getIdentifierInfo("NSError");
3495 
3496  return Ident_NSError;
3497 }
3498 
3499 /// Check whether there is a nullability attribute of any kind in the given
3500 /// attribute list.
3501 static bool hasNullabilityAttr(const ParsedAttributesView &attrs) {
3502  for (const ParsedAttr &AL : attrs) {
3503  if (AL.getKind() == ParsedAttr::AT_TypeNonNull ||
3504  AL.getKind() == ParsedAttr::AT_TypeNullable ||
3505  AL.getKind() == ParsedAttr::AT_TypeNullUnspecified)
3506  return true;
3507  }
3508 
3509  return false;
3510 }
3511 
3512 namespace {
3513  /// Describes the kind of a pointer a declarator describes.
3515  // Not a pointer.
3516  NonPointer,
3517  // Single-level pointer.
3518  SingleLevelPointer,
3519  // Multi-level pointer (of any pointer kind).
3520  MultiLevelPointer,
3521  // CFFooRef*
3522  MaybePointerToCFRef,
3523  // CFErrorRef*
3524  CFErrorRefPointer,
3525  // NSError**
3526  NSErrorPointerPointer,
3527  };
3528 
3529  /// Describes a declarator chunk wrapping a pointer that marks inference as
3530  /// unexpected.
3531  // These values must be kept in sync with diagnostics.
3533  /// Pointer is top-level.
3534  None = -1,
3535  /// Pointer is an array element.
3536  Array = 0,
3537  /// Pointer is the referent type of a C++ reference.
3538  Reference = 1
3539  };
3540 } // end anonymous namespace
3541 
3542 /// Classify the given declarator, whose type-specified is \c type, based on
3543 /// what kind of pointer it refers to.
3544 ///
3545 /// This is used to determine the default nullability.
3546 static PointerDeclaratorKind
3548  PointerWrappingDeclaratorKind &wrappingKind) {
3549  unsigned numNormalPointers = 0;
3550 
3551  // For any dependent type, we consider it a non-pointer.
3552  if (type->isDependentType())
3553  return PointerDeclaratorKind::NonPointer;
3554 
3555  // Look through the declarator chunks to identify pointers.
3556  for (unsigned i = 0, n = declarator.getNumTypeObjects(); i != n; ++i) {
3557  DeclaratorChunk &chunk = declarator.getTypeObject(i);
3558  switch (chunk.Kind) {
3560  if (numNormalPointers == 0)
3561  wrappingKind = PointerWrappingDeclaratorKind::Array;
3562  break;
3563 
3565  case DeclaratorChunk::Pipe:
3566  break;
3567 
3570  return numNormalPointers > 0 ? PointerDeclaratorKind::MultiLevelPointer
3571  : PointerDeclaratorKind::SingleLevelPointer;
3572 
3574  break;
3575 
3577  if (numNormalPointers == 0)
3578  wrappingKind = PointerWrappingDeclaratorKind::Reference;
3579  break;
3580 
3582  ++numNormalPointers;
3583  if (numNormalPointers > 2)
3584  return PointerDeclaratorKind::MultiLevelPointer;
3585  break;
3586  }
3587  }
3588 
3589  // Then, dig into the type specifier itself.
3590  unsigned numTypeSpecifierPointers = 0;
3591  do {
3592  // Decompose normal pointers.
3593  if (auto ptrType = type->getAs<PointerType>()) {
3594  ++numNormalPointers;
3595 
3596  if (numNormalPointers > 2)
3597  return PointerDeclaratorKind::MultiLevelPointer;
3598 
3599  type = ptrType->getPointeeType();
3600  ++numTypeSpecifierPointers;
3601  continue;
3602  }
3603 
3604  // Decompose block pointers.
3605  if (type->getAs<BlockPointerType>()) {
3606  return numNormalPointers > 0 ? PointerDeclaratorKind::MultiLevelPointer
3607  : PointerDeclaratorKind::SingleLevelPointer;
3608  }
3609 
3610  // Decompose member pointers.
3611  if (type->getAs<MemberPointerType>()) {
3612  return numNormalPointers > 0 ? PointerDeclaratorKind::MultiLevelPointer
3613  : PointerDeclaratorKind::SingleLevelPointer;
3614  }
3615 
3616  // Look at Objective-C object pointers.
3617  if (auto objcObjectPtr = type->getAs<ObjCObjectPointerType>()) {
3618  ++numNormalPointers;
3619  ++numTypeSpecifierPointers;
3620 
3621  // If this is NSError**, report that.
3622  if (auto objcClassDecl = objcObjectPtr->getInterfaceDecl()) {
3623  if (objcClassDecl->getIdentifier() == S.getNSErrorIdent() &&
3624  numNormalPointers == 2 && numTypeSpecifierPointers < 2) {
3625  return PointerDeclaratorKind::NSErrorPointerPointer;
3626  }
3627  }
3628 
3629  break;
3630  }
3631 
3632  // Look at Objective-C class types.
3633  if (auto objcClass = type->getAs<ObjCInterfaceType>()) {
3634  if (objcClass->getInterface()->getIdentifier() == S.getNSErrorIdent()) {
3635  if (numNormalPointers == 2 && numTypeSpecifierPointers < 2)
3636  return PointerDeclaratorKind::NSErrorPointerPointer;
3637  }
3638 
3639  break;
3640  }
3641 
3642  // If at this point we haven't seen a pointer, we won't see one.
3643  if (numNormalPointers == 0)
3644  return PointerDeclaratorKind::NonPointer;
3645 
3646  if (auto recordType = type->getAs<RecordType>()) {
3647  RecordDecl *recordDecl = recordType->getDecl();
3648 
3649  bool isCFError = false;
3650  if (S.CFError) {
3651  // If we already know about CFError, test it directly.
3652  isCFError = (S.CFError == recordDecl);
3653  } else {
3654  // Check whether this is CFError, which we identify based on its bridge
3655  // to NSError. CFErrorRef used to be declared with "objc_bridge" but is
3656  // now declared with "objc_bridge_mutable", so look for either one of
3657  // the two attributes.
3658  if (recordDecl->getTagKind() == TTK_Struct && numNormalPointers > 0) {
3659  IdentifierInfo *bridgedType = nullptr;
3660  if (auto bridgeAttr = recordDecl->getAttr<ObjCBridgeAttr>())
3661  bridgedType = bridgeAttr->getBridgedType();
3662  else if (auto bridgeAttr =
3663  recordDecl->getAttr<ObjCBridgeMutableAttr>())
3664  bridgedType = bridgeAttr->getBridgedType();
3665 
3666  if (bridgedType == S.getNSErrorIdent()) {
3667  S.CFError = recordDecl;
3668  isCFError = true;
3669  }
3670  }
3671  }
3672 
3673  // If this is CFErrorRef*, report it as such.
3674  if (isCFError && numNormalPointers == 2 && numTypeSpecifierPointers < 2) {
3675  return PointerDeclaratorKind::CFErrorRefPointer;
3676  }
3677  break;
3678  }
3679 
3680  break;
3681  } while (true);
3682 
3683  switch (numNormalPointers) {
3684  case 0:
3685  return PointerDeclaratorKind::NonPointer;
3686 
3687  case 1:
3688  return PointerDeclaratorKind::SingleLevelPointer;
3689 
3690  case 2:
3691  return PointerDeclaratorKind::MaybePointerToCFRef;
3692 
3693  default:
3694  return PointerDeclaratorKind::MultiLevelPointer;
3695  }
3696 }
3697 
3699  SourceLocation loc) {
3700  // If we're anywhere in a function, method, or closure context, don't perform
3701  // completeness checks.
3702  for (DeclContext *ctx = S.CurContext; ctx; ctx = ctx->getParent()) {
3703  if (ctx->isFunctionOrMethod())
3704  return FileID();
3705 
3706  if (ctx->isFileContext())
3707  break;
3708  }
3709 
3710  // We only care about the expansion location.
3711  loc = S.SourceMgr.getExpansionLoc(loc);
3712  FileID file = S.SourceMgr.getFileID(loc);
3713  if (file.isInvalid())
3714  return FileID();
3715 
3716  // Retrieve file information.
3717  bool invalid = false;
3718  const SrcMgr::SLocEntry &sloc = S.SourceMgr.getSLocEntry(file, &invalid);
3719  if (invalid || !sloc.isFile())
3720  return FileID();
3721 
3722  // We don't want to perform completeness checks on the main file or in
3723  // system headers.
3724  const SrcMgr::FileInfo &fileInfo = sloc.getFile();
3725  if (fileInfo.getIncludeLoc().isInvalid())
3726  return FileID();
3727  if (fileInfo.getFileCharacteristic() != SrcMgr::C_User &&
3729  return FileID();
3730  }
3731 
3732  return file;
3733 }
3734 
3735 /// Creates a fix-it to insert a C-style nullability keyword at \p pointerLoc,
3736 /// taking into account whitespace before and after.
3738  SourceLocation PointerLoc,
3740  assert(PointerLoc.isValid());
3741  if (PointerLoc.isMacroID())
3742  return;
3743 
3744  SourceLocation FixItLoc = S.getLocForEndOfToken(PointerLoc);
3745  if (!FixItLoc.isValid() || FixItLoc == PointerLoc)
3746  return;
3747 
3748  const char *NextChar = S.SourceMgr.getCharacterData(FixItLoc);
3749  if (!NextChar)
3750  return;
3751 
3752  SmallString<32> InsertionTextBuf{" "};
3753  InsertionTextBuf += getNullabilitySpelling(Nullability);
3754  InsertionTextBuf += " ";
3755  StringRef InsertionText = InsertionTextBuf.str();
3756 
3757  if (isWhitespace(*NextChar)) {
3758  InsertionText = InsertionText.drop_back();
3759  } else if (NextChar[-1] == '[') {
3760  if (NextChar[0] == ']')
3761  InsertionText = InsertionText.drop_back().drop_front();
3762  else
3763  InsertionText = InsertionText.drop_front();
3764  } else if (!isIdentifierBody(NextChar[0], /*allow dollar*/true) &&
3765  !isIdentifierBody(NextChar[-1], /*allow dollar*/true)) {
3766  InsertionText = InsertionText.drop_back().drop_front();
3767  }
3768 
3769  Diag << FixItHint::CreateInsertion(FixItLoc, InsertionText);
3770 }
3771 
3773  SimplePointerKind PointerKind,
3774  SourceLocation PointerLoc,
3775  SourceLocation PointerEndLoc) {
3776  assert(PointerLoc.isValid());
3777 
3778  if (PointerKind == SimplePointerKind::Array) {
3779  S.Diag(PointerLoc, diag::warn_nullability_missing_array);
3780  } else {
3781  S.Diag(PointerLoc, diag::warn_nullability_missing)
3782  << static_cast<unsigned>(PointerKind);
3783  }
3784 
3785  auto FixItLoc = PointerEndLoc.isValid() ? PointerEndLoc : PointerLoc;
3786  if (FixItLoc.isMacroID())
3787  return;
3788 
3789  auto addFixIt = [&](NullabilityKind Nullability) {
3790  auto Diag = S.Diag(FixItLoc, diag::note_nullability_fix_it);
3791  Diag << static_cast<unsigned>(Nullability);
3792  Diag << static_cast<unsigned>(PointerKind);
3793  fixItNullability(S, Diag, FixItLoc, Nullability);
3794  };
3795  addFixIt(NullabilityKind::Nullable);
3796  addFixIt(NullabilityKind::NonNull);
3797 }
3798 
3799 /// Complains about missing nullability if the file containing \p pointerLoc
3800 /// has other uses of nullability (either the keywords or the \c assume_nonnull
3801 /// pragma).
3802 ///
3803 /// If the file has \e not seen other uses of nullability, this particular
3804 /// pointer is saved for possible later diagnosis. See recordNullabilitySeen().
3805 static void
3807  SourceLocation pointerLoc,
3808  SourceLocation pointerEndLoc = SourceLocation()) {
3809  // Determine which file we're performing consistency checking for.
3810  FileID file = getNullabilityCompletenessCheckFileID(S, pointerLoc);
3811  if (file.isInvalid())
3812  return;
3813 
3814  // If we haven't seen any type nullability in this file, we won't warn now
3815  // about anything.
3816  FileNullability &fileNullability = S.NullabilityMap[file];
3817  if (!fileNullability.SawTypeNullability) {
3818  // If this is the first pointer declarator in the file, and the appropriate
3819  // warning is on, record it in case we need to diagnose it retroactively.
3820  diag::kind diagKind;
3821  if (pointerKind == SimplePointerKind::Array)
3822  diagKind = diag::warn_nullability_missing_array;
3823  else
3824  diagKind = diag::warn_nullability_missing;
3825 
3826  if (fileNullability.PointerLoc.isInvalid() &&
3827  !S.Context.getDiagnostics().isIgnored(diagKind, pointerLoc)) {
3828  fileNullability.PointerLoc = pointerLoc;
3829  fileNullability.PointerEndLoc = pointerEndLoc;
3830  fileNullability.PointerKind = static_cast<unsigned>(pointerKind);
3831  }
3832 
3833  return;
3834  }
3835 
3836  // Complain about missing nullability.
3837  emitNullabilityConsistencyWarning(S, pointerKind, pointerLoc, pointerEndLoc);
3838 }
3839 
3840 /// Marks that a nullability feature has been used in the file containing
3841 /// \p loc.
3842 ///
3843 /// If this file already had pointer types in it that were missing nullability,
3844 /// the first such instance is retroactively diagnosed.
3845 ///
3846 /// \sa checkNullabilityConsistency
3849  if (file.isInvalid())
3850  return;
3851 
3852  FileNullability &fileNullability = S.NullabilityMap[file];
3853  if (fileNullability.SawTypeNullability)
3854  return;
3855  fileNullability.SawTypeNullability = true;
3856 
3857  // If we haven't seen any type nullability before, now we have. Retroactively
3858  // diagnose the first unannotated pointer, if there was one.
3859  if (fileNullability.PointerLoc.isInvalid())
3860  return;
3861 
3862  auto kind = static_cast<SimplePointerKind>(fileNullability.PointerKind);
3864  fileNullability.PointerEndLoc);
3865 }
3866 
3867 /// Returns true if any of the declarator chunks before \p endIndex include a
3868 /// level of indirection: array, pointer, reference, or pointer-to-member.
3869 ///
3870 /// Because declarator chunks are stored in outer-to-inner order, testing
3871 /// every chunk before \p endIndex is testing all chunks that embed the current
3872 /// chunk as part of their type.
3873 ///
3874 /// It is legal to pass the result of Declarator::getNumTypeObjects() as the
3875 /// end index, in which case all chunks are tested.
3876 static bool hasOuterPointerLikeChunk(const Declarator &D, unsigned endIndex) {
3877  unsigned i = endIndex;
3878  while (i != 0) {
3879  // Walk outwards along the declarator chunks.
3880  --i;
3881  const DeclaratorChunk &DC = D.getTypeObject(i);
3882  switch (DC.Kind) {
3884  break;
3889  return true;
3892  case DeclaratorChunk::Pipe:
3893  // These are invalid anyway, so just ignore.
3894  break;
3895  }
3896  }
3897  return false;
3898 }
3899 
3901  return (Chunk.Kind == DeclaratorChunk::Pointer ||
3902  Chunk.Kind == DeclaratorChunk::Array);
3903 }
3904 
3905 template<typename AttrT>
3907  Attr.setUsedAsTypeAttr();
3908  return ::new (Ctx)
3909  AttrT(Attr.getRange(), Ctx, Attr.getAttributeSpellingListIndex());
3910 }
3911 
3913  NullabilityKind NK) {
3914  switch (NK) {
3916  return createSimpleAttr<TypeNonNullAttr>(Ctx, Attr);
3917 
3919  return createSimpleAttr<TypeNullableAttr>(Ctx, Attr);
3920 
3922  return createSimpleAttr<TypeNullUnspecifiedAttr>(Ctx, Attr);
3923  }
3924  llvm_unreachable("unknown NullabilityKind");
3925 }
3926 
3927 // Diagnose whether this is a case with the multiple addr spaces.
3928 // Returns true if this is an invalid case.
3929 // ISO/IEC TR 18037 S5.3 (amending C99 6.7.3): "No type shall be qualified
3930 // by qualifiers for two or more different address spaces."
3932  LangAS ASNew,
3933  SourceLocation AttrLoc) {
3934  if (ASOld != LangAS::Default) {
3935  if (ASOld != ASNew) {
3936  S.Diag(AttrLoc, diag::err_attribute_address_multiple_qualifiers);
3937  return true;
3938  }
3939  // Emit a warning if they are identical; it's likely unintended.
3940  S.Diag(AttrLoc,
3941  diag::warn_attribute_address_multiple_identical_qualifiers);
3942  }
3943  return false;
3944 }
3945 
3946 static TypeSourceInfo *
3947 GetTypeSourceInfoForDeclarator(TypeProcessingState &State,
3948  QualType T, TypeSourceInfo *ReturnTypeInfo);
3949 
3950 static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
3951  QualType declSpecType,
3952  TypeSourceInfo *TInfo) {
3953  // The TypeSourceInfo that this function returns will not be a null type.
3954  // If there is an error, this function will fill in a dummy type as fallback.
3955  QualType T = declSpecType;
3956  Declarator &D = state.getDeclarator();
3957  Sema &S = state.getSema();
3958  ASTContext &Context = S.Context;
3959  const LangOptions &LangOpts = S.getLangOpts();
3960 
3961  // The name we're declaring, if any.
3962  DeclarationName Name;
3963  if (D.getIdentifier())
3964  Name = D.getIdentifier();
3965 
3966  // Does this declaration declare a typedef-name?
3967  bool IsTypedefName =
3971 
3972  // Does T refer to a function type with a cv-qualifier or a ref-qualifier?
3973  bool IsQualifiedFunction = T->isFunctionProtoType() &&
3974  (!T->castAs<FunctionProtoType>()->getMethodQuals().empty() ||
3975  T->castAs<FunctionProtoType>()->getRefQualifier() != RQ_None);
3976 
3977  // If T is 'decltype(auto)', the only declarators we can have are parens
3978  // and at most one function declarator if this is a function declaration.
3979  // If T is a deduced class template specialization type, we can have no
3980  // declarator chunks at all.
3981  if (auto *DT = T->getAs<DeducedType>()) {
3982  const AutoType *AT = T->getAs<AutoType>();
3983  bool IsClassTemplateDeduction = isa<DeducedTemplateSpecializationType>(DT);
3984  if ((AT && AT->isDecltypeAuto()) || IsClassTemplateDeduction) {
3985  for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
3986  unsigned Index = E - I - 1;
3987  DeclaratorChunk &DeclChunk = D.getTypeObject(Index);
3988  unsigned DiagId = IsClassTemplateDeduction
3989  ? diag::err_deduced_class_template_compound_type
3990  : diag::err_decltype_auto_compound_type;
3991  unsigned DiagKind = 0;
3992  switch (DeclChunk.Kind) {
3994  // FIXME: Rejecting this is a little silly.
3995  if (IsClassTemplateDeduction) {
3996  DiagKind = 4;
3997  break;
3998  }
3999  continue;
4001  if (IsClassTemplateDeduction) {
4002  DiagKind = 3;
4003  break;
4004  }
4005  unsigned FnIndex;
4006  if (D.isFunctionDeclarationContext() &&
4007  D.isFunctionDeclarator(FnIndex) && FnIndex == Index)
4008  continue;
4009  DiagId = diag::err_decltype_auto_function_declarator_not_declaration;
4010  break;
4011  }
4015  DiagKind = 0;
4016  break;
4018  DiagKind = 1;
4019  break;
4021  DiagKind = 2;
4022  break;
4023  case DeclaratorChunk::Pipe:
4024  break;
4025  }
4026 
4027  S.Diag(DeclChunk.Loc, DiagId) << DiagKind;
4028  D.setInvalidType(true);
4029  break;
4030  }
4031  }
4032  }
4033 
4034  // Determine whether we should infer _Nonnull on pointer types.
4035  Optional<NullabilityKind> inferNullability;
4036  bool inferNullabilityCS = false;
4037  bool inferNullabilityInnerOnly = false;
4038  bool inferNullabilityInnerOnlyComplete = false;
4039 
4040  // Are we in an assume-nonnull region?
4041  bool inAssumeNonNullRegion = false;
4042  SourceLocation assumeNonNullLoc = S.PP.getPragmaAssumeNonNullLoc();
4043  if (assumeNonNullLoc.isValid()) {
4044  inAssumeNonNullRegion = true;
4045  recordNullabilitySeen(S, assumeNonNullLoc);
4046  }
4047 
4048  // Whether to complain about missing nullability specifiers or not.
4049  enum {
4050  /// Never complain.
4051  CAMN_No,
4052  /// Complain on the inner pointers (but not the outermost
4053  /// pointer).
4054  CAMN_InnerPointers,
4055  /// Complain about any pointers that don't have nullability
4056  /// specified or inferred.
4057  CAMN_Yes
4058  } complainAboutMissingNullability = CAMN_No;
4059  unsigned NumPointersRemaining = 0;
4060  auto complainAboutInferringWithinChunk = PointerWrappingDeclaratorKind::None;
4061 
4062  if (IsTypedefName) {
4063  // For typedefs, we do not infer any nullability (the default),
4064  // and we only complain about missing nullability specifiers on
4065  // inner pointers.
4066  complainAboutMissingNullability = CAMN_InnerPointers;
4067 
4068  if (T->canHaveNullability(/*ResultIfUnknown*/false) &&
4069  !T->getNullability(S.Context)) {
4070  // Note that we allow but don't require nullability on dependent types.
4071  ++NumPointersRemaining;
4072  }
4073 
4074  for (unsigned i = 0, n = D.getNumTypeObjects(); i != n; ++i) {
4075  DeclaratorChunk &chunk = D.getTypeObject(i);
4076  switch (chunk.Kind) {
4079  case DeclaratorChunk::Pipe:
4080  break;
4081 
4084  ++NumPointersRemaining;
4085  break;
4086 
4089  continue;
4090 
4092  ++NumPointersRemaining;
4093  continue;
4094  }
4095  }
4096  } else {
4097  bool isFunctionOrMethod = false;
4098  switch (auto context = state.getDeclarator().getContext()) {
4104  isFunctionOrMethod = true;
4105  LLVM_FALLTHROUGH;
4106 
4108  if (state.getDeclarator().isObjCIvar() && !isFunctionOrMethod) {
4109  complainAboutMissingNullability = CAMN_No;
4110  break;
4111  }
4112 
4113  // Weak properties are inferred to be nullable.
4114  if (state.getDeclarator().isObjCWeakProperty() && inAssumeNonNullRegion) {
4115  inferNullability = NullabilityKind::Nullable;
4116  break;
4117  }
4118 
4119  LLVM_FALLTHROUGH;
4120 
4123  complainAboutMissingNullability = CAMN_Yes;
4124 
4125  // Nullability inference depends on the type and declarator.
4126  auto wrappingKind = PointerWrappingDeclaratorKind::None;
4127  switch (classifyPointerDeclarator(S, T, D, wrappingKind)) {
4128  case PointerDeclaratorKind::NonPointer:
4129  case PointerDeclaratorKind::MultiLevelPointer:
4130  // Cannot infer nullability.
4131  break;
4132 
4133  case PointerDeclaratorKind::SingleLevelPointer:
4134  // Infer _Nonnull if we are in an assumes-nonnull region.
4135  if (inAssumeNonNullRegion) {
4136  complainAboutInferringWithinChunk = wrappingKind;
4137  inferNullability = NullabilityKind::NonNull;
4138  inferNullabilityCS =
4141  }
4142  break;
4143 
4144  case PointerDeclaratorKind::CFErrorRefPointer:
4145  case PointerDeclaratorKind::NSErrorPointerPointer:
4146  // Within a function or method signature, infer _Nullable at both
4147  // levels.
4148  if (isFunctionOrMethod && inAssumeNonNullRegion)
4149  inferNullability = NullabilityKind::Nullable;
4150  break;
4151 
4152  case PointerDeclaratorKind::MaybePointerToCFRef:
4153  if (isFunctionOrMethod) {
4154  // On pointer-to-pointer parameters marked cf_returns_retained or
4155  // cf_returns_not_retained, if the outer pointer is explicit then
4156  // infer the inner pointer as _Nullable.
4157  auto hasCFReturnsAttr =
4158  [](const ParsedAttributesView &AttrList) -> bool {
4159  return AttrList.hasAttribute(ParsedAttr::AT_CFReturnsRetained) ||
4160  AttrList.hasAttribute(ParsedAttr::AT_CFReturnsNotRetained);
4161  };
4162  if (const auto *InnermostChunk = D.getInnermostNonParenChunk()) {
4163  if (hasCFReturnsAttr(D.getAttributes()) ||
4164  hasCFReturnsAttr(InnermostChunk->getAttrs()) ||
4165  hasCFReturnsAttr(D.getDeclSpec().getAttributes())) {
4166  inferNullability = NullabilityKind::Nullable;
4167  inferNullabilityInnerOnly = true;
4168  }
4169  }
4170  }
4171  break;
4172  }
4173  break;
4174  }
4175 
4177  complainAboutMissingNullability = CAMN_Yes;
4178  break;
4179 
4197  // Don't infer in these contexts.
4198  break;
4199  }
4200  }
4201 
4202  // Local function that returns true if its argument looks like a va_list.
4203  auto isVaList = [&S](QualType T) -> bool {
4204  auto *typedefTy = T->getAs<TypedefType>();
4205  if (!typedefTy)
4206  return false;
4207  TypedefDecl *vaListTypedef = S.Context.getBuiltinVaListDecl();
4208  do {
4209  if (typedefTy->getDecl() == vaListTypedef)
4210  return true;
4211  if (auto *name = typedefTy->getDecl()->getIdentifier())
4212  if (name->isStr("va_list"))
4213  return true;
4214  typedefTy = typedefTy->desugar()->getAs<TypedefType>();
4215  } while (typedefTy);
4216  return false;
4217  };
4218 
4219  // Local function that checks the nullability for a given pointer declarator.
4220  // Returns true if _Nonnull was inferred.
4221  auto inferPointerNullability =
4222  [&](SimplePointerKind pointerKind, SourceLocation pointerLoc,
4223  SourceLocation pointerEndLoc,
4224  ParsedAttributesView &attrs, AttributePool &Pool) -> ParsedAttr * {
4225  // We've seen a pointer.
4226  if (NumPointersRemaining > 0)
4227  --NumPointersRemaining;
4228 
4229  // If a nullability attribute is present, there's nothing to do.
4230  if (hasNullabilityAttr(attrs))
4231  return nullptr;
4232 
4233  // If we're supposed to infer nullability, do so now.
4234  if (inferNullability && !inferNullabilityInnerOnlyComplete) {
4235  ParsedAttr::Syntax syntax = inferNullabilityCS
4238  ParsedAttr *nullabilityAttr = Pool.create(
4239  S.getNullabilityKeyword(*inferNullability), SourceRange(pointerLoc),
4240  nullptr, SourceLocation(), nullptr, 0, syntax);
4241 
4242  attrs.addAtEnd(nullabilityAttr);
4243 
4244  if (inferNullabilityCS) {
4245  state.getDeclarator().getMutableDeclSpec().getObjCQualifiers()
4246  ->setObjCDeclQualifier(ObjCDeclSpec::DQ_CSNullability);
4247  }
4248 
4249  if (pointerLoc.isValid() &&
4250  complainAboutInferringWithinChunk !=
4252  auto Diag =
4253  S.Diag(pointerLoc, diag::warn_nullability_inferred_on_nested_type);
4254  Diag << static_cast<int>(complainAboutInferringWithinChunk);
4256  }
4257 
4258  if (inferNullabilityInnerOnly)
4259  inferNullabilityInnerOnlyComplete = true;
4260  return nullabilityAttr;
4261  }
4262 
4263  // If we're supposed to complain about missing nullability, do so
4264  // now if it's truly missing.
4265  switch (complainAboutMissingNullability) {
4266  case CAMN_No:
4267  break;
4268 
4269  case CAMN_InnerPointers:
4270  if (NumPointersRemaining == 0)
4271  break;
4272  LLVM_FALLTHROUGH;
4273 
4274  case CAMN_Yes:
4275  checkNullabilityConsistency(S, pointerKind, pointerLoc, pointerEndLoc);
4276  }
4277  return nullptr;
4278  };
4279 
4280  // If the type itself could have nullability but does not, infer pointer
4281  // nullability and perform consistency checking.
4282  if (S.CodeSynthesisContexts.empty()) {
4283  if (T->canHaveNullability(/*ResultIfUnknown*/false) &&
4284  !T->getNullability(S.Context)) {
4285  if (isVaList(T)) {
4286  // Record that we've seen a pointer, but do nothing else.
4287  if (NumPointersRemaining > 0)
4288  --NumPointersRemaining;
4289  } else {
4290  SimplePointerKind pointerKind = SimplePointerKind::Pointer;
4291  if (T->isBlockPointerType())
4292  pointerKind = SimplePointerKind::BlockPointer;
4293  else if (T->isMemberPointerType())
4294  pointerKind = SimplePointerKind::MemberPointer;
4295 
4296  if (auto *attr = inferPointerNullability(
4297  pointerKind, D.getDeclSpec().getTypeSpecTypeLoc(),
4298  D.getDeclSpec().getEndLoc(),
4301  T = state.getAttributedType(
4302  createNullabilityAttr(Context, *attr, *inferNullability), T, T);
4303  }
4304  }
4305  }
4306 
4307  if (complainAboutMissingNullability == CAMN_Yes &&
4308  T->isArrayType() && !T->getNullability(S.Context) && !isVaList(T) &&
4309  D.isPrototypeContext() &&
4311  checkNullabilityConsistency(S, SimplePointerKind::Array,
4313  }
4314  }
4315 
4316  bool ExpectNoDerefChunk =
4317  state.getCurrentAttributes().hasAttribute(ParsedAttr::AT_NoDeref);
4318 
4319  // Walk the DeclTypeInfo, building the recursive type as we go.
4320  // DeclTypeInfos are ordered from the identifier out, which is
4321  // opposite of what we want :).
4322  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
4323  unsigned chunkIndex = e - i - 1;
4324  state.setCurrentChunkIndex(chunkIndex);
4325  DeclaratorChunk &DeclType = D.getTypeObject(chunkIndex);
4326  IsQualifiedFunction &= DeclType.Kind == DeclaratorChunk::Paren;
4327  switch (DeclType.Kind) {
4329  if (i == 0)
4330  warnAboutRedundantParens(S, D, T);
4331  T = S.BuildParenType(T);
4332  break;
4334  // If blocks are disabled, emit an error.
4335  if (!LangOpts.Blocks)
4336  S.Diag(DeclType.Loc, diag::err_blocks_disable) << LangOpts.OpenCL;
4337 
4338  // Handle pointer nullability.
4339  inferPointerNullability(SimplePointerKind::BlockPointer, DeclType.Loc,
4340  DeclType.EndLoc, DeclType.getAttrs(),
4341  state.getDeclarator().getAttributePool());
4342 
4343  T = S.BuildBlockPointerType(T, D.getIdentifierLoc(), Name);
4344  if (DeclType.Cls.TypeQuals || LangOpts.OpenCL) {
4345  // OpenCL v2.0, s6.12.5 - Block variable declarations are implicitly
4346  // qualified with const.
4347  if (LangOpts.OpenCL)
4348  DeclType.Cls.TypeQuals |= DeclSpec::TQ_const;
4349  T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Cls.TypeQuals);
4350  }
4351  break;
4353  // Verify that we're not building a pointer to pointer to function with
4354  // exception specification.
4355  if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
4356  S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
4357  D.setInvalidType(true);
4358  // Build the type anyway.
4359  }
4360 
4361  // Handle pointer nullability
4362  inferPointerNullability(SimplePointerKind::Pointer, DeclType.Loc,
4363  DeclType.EndLoc, DeclType.getAttrs(),
4364  state.getDeclarator().getAttributePool());
4365 
4366  if (LangOpts.ObjC && T->getAs<ObjCObjectType>()) {
4367  T = Context.getObjCObjectPointerType(T);
4368  if (DeclType.Ptr.TypeQuals)
4369  T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Ptr.TypeQuals);
4370  break;
4371  }
4372 
4373  // OpenCL v2.0 s6.9b - Pointer to image/sampler cannot be used.
4374  // OpenCL v2.0 s6.13.16.1 - Pointer to pipe cannot be used.
4375  // OpenCL v2.0 s6.12.5 - Pointers to Blocks are not allowed.
4376  if (LangOpts.OpenCL) {
4377  if (T->isImageType() || T->isSamplerT() || T->isPipeType() ||
4378  T->isBlockPointerType()) {
4379  S.Diag(D.getIdentifierLoc(), diag::err_opencl_pointer_to_type) << T;
4380  D.setInvalidType(true);
4381  }
4382  }
4383 
4384  T = S.BuildPointerType(T, DeclType.Loc, Name);
4385  if (DeclType.Ptr.TypeQuals)
4386  T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Ptr.TypeQuals);
4387  break;
4389  // Verify that we're not building a reference to pointer to function with
4390  // exception specification.
4391  if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
4392  S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
4393  D.setInvalidType(true);
4394  // Build the type anyway.
4395  }
4396  T = S.BuildReferenceType(T, DeclType.Ref.LValueRef, DeclType.Loc, Name);
4397 
4398  if (DeclType.Ref.HasRestrict)
4399  T = S.BuildQualifiedType(T, DeclType.Loc, Qualifiers::Restrict);
4400  break;
4401  }
4402  case DeclaratorChunk::Array: {
4403  // Verify that we're not building an array of pointers to function with
4404  // exception specification.
4405  if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
4406  S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
4407  D.setInvalidType(true);
4408  // Build the type anyway.
4409  }
4410  DeclaratorChunk::ArrayTypeInfo &ATI = DeclType.Arr;
4411  Expr *ArraySize = static_cast<Expr*>(ATI.NumElts);
4413  if (ATI.isStar)
4414  ASM = ArrayType::Star;
4415  else if (ATI.hasStatic)
4416  ASM = ArrayType::Static;
4417  else
4418  ASM = ArrayType::Normal;
4419  if (ASM == ArrayType::Star && !D.isPrototypeContext()) {
4420  // FIXME: This check isn't quite right: it allows star in prototypes
4421  // for function definitions, and disallows some edge cases detailed
4422  // in http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00133.html
4423  S.Diag(DeclType.Loc, diag::err_array_star_outside_prototype);
4424  ASM = ArrayType::Normal;
4425  D.setInvalidType(true);
4426  }
4427 
4428  // C99 6.7.5.2p1: The optional type qualifiers and the keyword static
4429  // shall appear only in a declaration of a function parameter with an
4430  // array type, ...
4431  if (ASM == ArrayType::Static || ATI.TypeQuals) {
4432  if (!(D.isPrototypeContext() ||
4434  S.Diag(DeclType.Loc, diag::err_array_static_outside_prototype) <<
4435  (ASM == ArrayType::Static ? "'static'" : "type qualifier");
4436  // Remove the 'static' and the type qualifiers.
4437  if (ASM == ArrayType::Static)
4438  ASM = ArrayType::Normal;
4439  ATI.TypeQuals = 0;
4440  D.setInvalidType(true);
4441  }
4442 
4443  // C99 6.7.5.2p1: ... and then only in the outermost array type
4444  // derivation.
4445  if (hasOuterPointerLikeChunk(D, chunkIndex)) {
4446  S.Diag(DeclType.Loc, diag::err_array_static_not_outermost) <<
4447  (ASM == ArrayType::Static ? "'static'" : "type qualifier");
4448  if (ASM == ArrayType::Static)
4449  ASM = ArrayType::Normal;
4450  ATI.TypeQuals = 0;
4451  D.setInvalidType(true);
4452  }
4453  }
4454  const AutoType *AT = T->getContainedAutoType();
4455  // Allow arrays of auto if we are a generic lambda parameter.
4456  // i.e. [](auto (&array)[5]) { return array[0]; }; OK
4457  if (AT &&
4459  // We've already diagnosed this for decltype(auto).
4460  if (!AT->isDecltypeAuto())
4461  S.Diag(DeclType.Loc, diag::err_illegal_decl_array_of_auto)
4462  << getPrintableNameForEntity(Name) << T;
4463  T = QualType();
4464  break;
4465  }
4466 
4467  // Array parameters can be marked nullable as well, although it's not
4468  // necessary if they're marked 'static'.
4469  if (complainAboutMissingNullability == CAMN_Yes &&
4470  !hasNullabilityAttr(DeclType.getAttrs()) &&
4471  ASM != ArrayType::Static &&
4472  D.isPrototypeContext() &&
4473  !hasOuterPointerLikeChunk(D, chunkIndex)) {
4474  checkNullabilityConsistency(S, SimplePointerKind::Array, DeclType.Loc);
4475  }
4476 
4477  T = S.BuildArrayType(T, ASM, ArraySize, ATI.TypeQuals,
4478  SourceRange(DeclType.Loc, DeclType.EndLoc), Name);
4479  break;
4480  }
4482  // If the function declarator has a prototype (i.e. it is not () and
4483  // does not have a K&R-style identifier list), then the arguments are part
4484  // of the type, otherwise the argument list is ().
4485  const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
4486  IsQualifiedFunction =
4488 
4489  // Check for auto functions and trailing return type and adjust the
4490  // return type accordingly.
4491  if (!D.isInvalidType()) {
4492  // trailing-return-type is only required if we're declaring a function,
4493  // and not, for instance, a pointer to a function.
4494  if (D.getDeclSpec().hasAutoTypeSpec() &&
4495  !FTI.hasTrailingReturnType() && chunkIndex == 0) {
4496  if (!S.getLangOpts().CPlusPlus14) {
4499  ? diag::err_auto_missing_trailing_return
4500  : diag::err_deduced_return_type);
4501  T = Context.IntTy;
4502  D.setInvalidType(true);
4503  } else {
4505  diag::warn_cxx11_compat_deduced_return_type);
4506  }
4507  } else if (FTI.hasTrailingReturnType()) {
4508  // T must be exactly 'auto' at this point. See CWG issue 681.
4509  if (isa<ParenType>(T)) {
4510  S.Diag(D.getBeginLoc(), diag::err_trailing_return_in_parens)
4511  << T << D.getSourceRange();
4512  D.setInvalidType(true);
4513  } else if (D.getName().getKind() ==
4515  if (T != Context.DependentTy) {
4516  S.Diag(D.getDeclSpec().getBeginLoc(),
4517  diag::err_deduction_guide_with_complex_decl)
4518  << D.getSourceRange();
4519  D.setInvalidType(true);
4520  }
4522  (T.hasQualifiers() || !isa<AutoType>(T) ||
4523  cast<AutoType>(T)->getKeyword() !=
4526  diag::err_trailing_return_without_auto)
4527  << T << D.getDeclSpec().getSourceRange();
4528  D.setInvalidType(true);
4529  }
4530  T = S.GetTypeFromParser(FTI.getTrailingReturnType(), &TInfo);
4531  if (T.isNull()) {
4532  // An error occurred parsing the trailing return type.
4533  T = Context.IntTy;
4534  D.setInvalidType(true);
4535  }
4536  } else {
4537  // This function type is not the type of the entity being declared,
4538  // so checking the 'auto' is not the responsibility of this chunk.
4539  }
4540  }
4541 
4542  // C99 6.7.5.3p1: The return type may not be a function or array type.
4543  // For conversion functions, we'll diagnose this particular error later.
4544  if (!D.isInvalidType() && (T->isArrayType() || T->isFunctionType()) &&
4545  (D.getName().getKind() !=
4547  unsigned diagID = diag::err_func_returning_array_function;
4548  // Last processing chunk in block context means this function chunk
4549  // represents the block.
4550  if (chunkIndex == 0 &&
4552  diagID = diag::err_block_returning_array_function;
4553  S.Diag(DeclType.Loc, diagID) << T->isFunctionType() << T;
4554  T = Context.IntTy;
4555  D.setInvalidType(true);
4556  }
4557 
4558  // Do not allow returning half FP value.
4559  // FIXME: This really should be in BuildFunctionType.
4560  if (T->isHalfType()) {
4561  if (S.getLangOpts().OpenCL) {
4562  if (!S.getOpenCLOptions().isEnabled("cl_khr_fp16")) {
4563  S.Diag(D.getIdentifierLoc(), diag::err_opencl_invalid_return)
4564  << T << 0 /*pointer hint*/;
4565  D.setInvalidType(true);
4566  }
4567  } else if (!S.getLangOpts().HalfArgsAndReturns) {
4568  S.Diag(D.getIdentifierLoc(),
4569  diag::err_parameters_retval_cannot_have_fp16_type) << 1;
4570  D.setInvalidType(true);
4571  }
4572  }
4573 
4574  if (LangOpts.OpenCL) {
4575  // OpenCL v2.0 s6.12.5 - A block cannot be the return value of a
4576  // function.
4577  if (T->isBlockPointerType() || T->isImageType() || T->isSamplerT() ||
4578  T->isPipeType()) {
4579  S.Diag(D.getIdentifierLoc(), diag::err_opencl_invalid_return)
4580  << T << 1 /*hint off*/;
4581  D.setInvalidType(true);
4582  }
4583  // OpenCL doesn't support variadic functions and blocks
4584  // (s6.9.e and s6.12.5 OpenCL v2.0) except for printf.
4585  // We also allow here any toolchain reserved identifiers.
4586  if (FTI.isVariadic &&
4587  !(D.getIdentifier() &&
4588  ((D.getIdentifier()->getName() == "printf" &&
4589  (LangOpts.OpenCLCPlusPlus || LangOpts.OpenCLVersion >= 120)) ||
4590  D.getIdentifier()->getName().startswith("__")))) {
4591  S.Diag(D.getIdentifierLoc(), diag::err_opencl_variadic_function);
4592  D.setInvalidType(true);
4593  }
4594  }
4595 
4596  // Methods cannot return interface types. All ObjC objects are
4597  // passed by reference.
4598  if (T->isObjCObjectType()) {
4599  SourceLocation DiagLoc, FixitLoc;
4600  if (TInfo) {
4601  DiagLoc = TInfo->getTypeLoc().getBeginLoc();
4602  FixitLoc = S.getLocForEndOfToken(TInfo->getTypeLoc().getEndLoc());
4603  } else {
4604  DiagLoc = D.getDeclSpec().getTypeSpecTypeLoc();
4605  FixitLoc = S.getLocForEndOfToken(D.getDeclSpec().getEndLoc());
4606  }
4607  S.Diag(DiagLoc, diag::err_object_cannot_be_passed_returned_by_value)
4608  << 0 << T
4609  << FixItHint::CreateInsertion(FixitLoc, "*");
4610 
4611  T = Context.getObjCObjectPointerType(T);
4612  if (TInfo) {
4613  TypeLocBuilder TLB;
4614  TLB.pushFullCopy(TInfo->getTypeLoc());
4616  TLoc.setStarLoc(FixitLoc);
4617  TInfo = TLB.getTypeSourceInfo(Context, T);
4618  }
4619 
4620  D.setInvalidType(true);
4621  }
4622 
4623  // cv-qualifiers on return types are pointless except when the type is a
4624  // class type in C++.
4625  if ((T.getCVRQualifiers() || T->isAtomicType()) &&
4626  !(S.getLangOpts().CPlusPlus &&
4627  (T->isDependentType() || T->isRecordType()))) {
4628  if (T->isVoidType() && !S.getLangOpts().CPlusPlus &&
4630  // [6.9.1/3] qualified void return is invalid on a C
4631  // function definition. Apparently ok on declarations and
4632  // in C++ though (!)
4633  S.Diag(DeclType.Loc, diag::err_func_returning_qualified_void) << T;
4634  } else
4635  diagnoseRedundantReturnTypeQualifiers(S, T, D, chunkIndex);
4636  }
4637 
4638  // Objective-C ARC ownership qualifiers are ignored on the function
4639  // return type (by type canonicalization). Complain if this attribute
4640  // was written here.
4641  if (T.getQualifiers().hasObjCLifetime()) {
4642  SourceLocation AttrLoc;
4643  if (chunkIndex + 1 < D.getNumTypeObjects()) {
4644  DeclaratorChunk ReturnTypeChunk = D.getTypeObject(chunkIndex + 1);
4645  for (const ParsedAttr &AL : ReturnTypeChunk.getAttrs()) {
4646  if (AL.getKind() == ParsedAttr::AT_ObjCOwnership) {
4647  AttrLoc = AL.getLoc();
4648  break;
4649  }
4650  }
4651  }
4652  if (AttrLoc.isInvalid()) {
4653  for (const ParsedAttr &AL : D.getDeclSpec().getAttributes()) {
4654  if (AL.getKind() == ParsedAttr::AT_ObjCOwnership) {
4655  AttrLoc = AL.getLoc();
4656  break;
4657  }
4658  }
4659  }
4660 
4661  if (AttrLoc.isValid()) {
4662  // The ownership attributes are almost always written via
4663  // the predefined
4664  // __strong/__weak/__autoreleasing/__unsafe_unretained.
4665  if (AttrLoc.isMacroID())
4666  AttrLoc =
4668 
4669  S.Diag(AttrLoc, diag::warn_arc_lifetime_result_type)
4670  << T.getQualifiers().getObjCLifetime();
4671  }
4672  }
4673 
4674  if (LangOpts.CPlusPlus && D.getDeclSpec().hasTagDefinition()) {
4675  // C++ [dcl.fct]p6:
4676  // Types shall not be defined in return or parameter types.
4677  TagDecl *Tag = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
4678  S.Diag(Tag->getLocation(), diag::err_type_defined_in_result_type)
4679  << Context.getTypeDeclType(Tag);
4680  }
4681 
4682  // Exception specs are not allowed in typedefs. Complain, but add it
4683  // anyway.
4684  if (IsTypedefName && FTI.getExceptionSpecType() && !LangOpts.CPlusPlus17)
4685  S.Diag(FTI.getExceptionSpecLocBeg(),
4686  diag::err_exception_spec_in_typedef)
4689 
4690  // If we see "T var();" or "T var(T());" at block scope, it is probably
4691  // an attempt to initialize a variable, not a function declaration.
4692  if (FTI.isAmbiguous)
4693  warnAboutAmbiguousFunction(S, D, DeclType, T);
4694 
4696  getCCForDeclaratorChunk(S, D, DeclType.getAttrs(), FTI, chunkIndex));
4697 
4698  if (!FTI.NumParams && !FTI.isVariadic && !LangOpts.CPlusPlus
4699  && !LangOpts.OpenCL) {
4700  // Simple void foo(), where the incoming T is the result type.
4701  T = Context.getFunctionNoProtoType(T, EI);
4702  } else {
4703  // We allow a zero-parameter variadic function in C if the
4704  // function is marked with the "overloadable" attribute. Scan
4705  // for this attribute now.
4706  if (!FTI.NumParams && FTI.isVariadic && !LangOpts.CPlusPlus)
4707  if (!D.getAttributes().hasAttribute(ParsedAttr::AT_Overloadable))
4708  S.Diag(FTI.getEllipsisLoc(), diag::err_ellipsis_first_param);
4709 
4710  if (FTI.NumParams && FTI.Params[0].Param == nullptr) {
4711  // C99 6.7.5.3p3: Reject int(x,y,z) when it's not a function
4712  // definition.
4713  S.Diag(FTI.Params[0].IdentLoc,
4714  diag::err_ident_list_in_fn_declaration);
4715  D.setInvalidType(true);
4716  // Recover by creating a K&R-style function type.
4717  T = Context.getFunctionNoProtoType(T, EI);
4718  break;
4719  }
4720 
4722  EPI.ExtInfo = EI;
4723  EPI.Variadic = FTI.isVariadic;
4727  : 0);
4728  EPI.RefQualifier = !FTI.hasRefQualifier()? RQ_None
4730  : RQ_RValue;
4731 
4732  // Otherwise, we have a function with a parameter list that is
4733  // potentially variadic.
4734  SmallVector<QualType, 16> ParamTys;
4735  ParamTys.reserve(FTI.NumParams);
4736 
4738  ExtParameterInfos(FTI.NumParams);
4739  bool HasAnyInterestingExtParameterInfos = false;
4740 
4741  for (unsigned i = 0, e = FTI.NumParams; i != e; ++i) {
4742  ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
4743  QualType ParamTy = Param->getType();
4744  assert(!ParamTy.isNull() && "Couldn't parse type?");
4745 
4746  // Look for 'void'. void is allowed only as a single parameter to a
4747  // function with no other parameters (C99 6.7.5.3p10). We record
4748  // int(void) as a FunctionProtoType with an empty parameter list.
4749  if (ParamTy->isVoidType()) {
4750  // If this is something like 'float(int, void)', reject it. 'void'
4751  // is an incomplete type (C99 6.2.5p19) and function decls cannot
4752  // have parameters of incomplete type.
4753  if (FTI.NumParams != 1 || FTI.isVariadic) {
4754  S.Diag(DeclType.Loc, diag::err_void_only_param);
4755  ParamTy = Context.IntTy;
4756  Param->setType(ParamTy);
4757  } else if (FTI.Params[i].Ident) {
4758  // Reject, but continue to parse 'int(void abc)'.
4759  S.Diag(FTI.Params[i].IdentLoc, diag::err_param_with_void_type);
4760  ParamTy = Context.IntTy;
4761  Param->setType(ParamTy);
4762  } else {
4763  // Reject, but continue to parse 'float(const void)'.
4764  if (ParamTy.hasQualifiers())
4765  S.Diag(DeclType.Loc, diag::err_void_param_qualified);
4766 
4767  // Do not add 'void' to the list.
4768  break;
4769  }
4770  } else if (ParamTy->isHalfType()) {
4771  // Disallow half FP parameters.
4772  // FIXME: This really should be in BuildFunctionType.
4773  if (S.getLangOpts().OpenCL) {
4774  if (!S.getOpenCLOptions().isEnabled("cl_khr_fp16")) {
4775  S.Diag(Param->getLocation(),
4776  diag::err_opencl_half_param) << ParamTy;
4777  D.setInvalidType();
4778  Param->setInvalidDecl();
4779  }
4780  } else if (!S.getLangOpts().HalfArgsAndReturns) {
4781  S.Diag(Param->getLocation(),
4782  diag::err_parameters_retval_cannot_have_fp16_type) << 0;
4783  D.setInvalidType();
4784  }
4785  } else if (!FTI.hasPrototype) {
4786  if (ParamTy->isPromotableIntegerType()) {
4787  ParamTy = Context.getPromotedIntegerType(ParamTy);
4788  Param->setKNRPromoted(true);
4789  } else if (const BuiltinType* BTy = ParamTy->getAs<BuiltinType>()) {
4790  if (BTy->getKind() == BuiltinType::Float) {
4791  ParamTy = Context.DoubleTy;
4792  Param->setKNRPromoted(true);
4793  }
4794  }
4795  }
4796 
4797  if (LangOpts.ObjCAutoRefCount && Param->hasAttr<NSConsumedAttr>()) {
4798  ExtParameterInfos[i] = ExtParameterInfos[i].withIsConsumed(true);
4799  HasAnyInterestingExtParameterInfos = true;
4800  }
4801 
4802  if (auto attr = Param->getAttr<ParameterABIAttr>()) {
4803  ExtParameterInfos[i] =
4804  ExtParameterInfos[i].withABI(attr->getABI());
4805  HasAnyInterestingExtParameterInfos = true;
4806  }
4807 
4808  if (Param->hasAttr<PassObjectSizeAttr>()) {
4809  ExtParameterInfos[i] = ExtParameterInfos[i].withHasPassObjectSize();
4810  HasAnyInterestingExtParameterInfos = true;
4811  }
4812 
4813  if (Param->hasAttr<NoEscapeAttr>()) {
4814  ExtParameterInfos[i] = ExtParameterInfos[i].withIsNoEscape(true);
4815  HasAnyInterestingExtParameterInfos = true;
4816  }
4817 
4818  ParamTys.push_back(ParamTy);
4819  }
4820 
4821  if (HasAnyInterestingExtParameterInfos) {
4822  EPI.ExtParameterInfos = ExtParameterInfos.data();
4823  checkExtParameterInfos(S, ParamTys, EPI,
4824  [&](unsigned i) { return FTI.Params[i].Param->getLocation(); });
4825  }
4826 
4827  SmallVector<QualType, 4> Exceptions;
4828  SmallVector<ParsedType, 2> DynamicExceptions;
4829  SmallVector<SourceRange, 2> DynamicExceptionRanges;
4830  Expr *NoexceptExpr = nullptr;
4831 
4832  if (FTI.getExceptionSpecType() == EST_Dynamic) {
4833  // FIXME: It's rather inefficient to have to split into two vectors
4834  // here.
4835  unsigned N = FTI.getNumExceptions();
4836  DynamicExceptions.reserve(N);
4837  DynamicExceptionRanges.reserve(N);
4838  for (unsigned I = 0; I != N; ++I) {
4839  DynamicExceptions.push_back(FTI.Exceptions[I].Ty);
4840  DynamicExceptionRanges.push_back(FTI.Exceptions[I].Range);
4841  }
4842  } else if (isComputedNoexcept(FTI.getExceptionSpecType())) {
4843  NoexceptExpr = FTI.NoexceptExpr;
4844  }
4845 
4847  FTI.getExceptionSpecType(),
4848  DynamicExceptions,
4849  DynamicExceptionRanges,
4850  NoexceptExpr,
4851  Exceptions,
4852  EPI.ExceptionSpec);
4853 
4854  // FIXME: Set address space from attrs for C++ mode here.
4855  // OpenCLCPlusPlus: A class member function has an address space.
4856  auto IsClassMember = [&]() {
4857  return (!state.getDeclarator().getCXXScopeSpec().isEmpty() &&
4858  state.getDeclarator()
4859  .getCXXScopeSpec()
4860  .getScopeRep()
4861  ->getKind() == NestedNameSpecifier::TypeSpec) ||
4862  state.getDeclarator().getContext() ==
4864  };
4865 
4866  if (state.getSema().getLangOpts().OpenCLCPlusPlus && IsClassMember()) {
4867  LangAS ASIdx = LangAS::Default;
4868  // Take address space attr if any and mark as invalid to avoid adding
4869  // them later while creating QualType.
4870  if (FTI.MethodQualifiers)
4871  for (ParsedAttr &attr : FTI.MethodQualifiers->getAttributes()) {
4872  LangAS ASIdxNew = attr.asOpenCLLangAS();
4873  if (DiagnoseMultipleAddrSpaceAttributes(S, ASIdx, ASIdxNew,
4874  attr.getLoc()))
4875  D.setInvalidType(true);
4876  else
4877  ASIdx = ASIdxNew;
4878  }
4879  // If a class member function's address space is not set, set it to
4880  // __generic.
4881  LangAS AS =
4882  (ASIdx == LangAS::Default ? LangAS::opencl_generic : ASIdx);
4883  EPI.TypeQuals.addAddressSpace(AS);
4884  }
4885  T = Context.getFunctionType(T, ParamTys, EPI);
4886  }
4887  break;
4888  }
4890  // The scope spec must refer to a class, or be dependent.
4891  CXXScopeSpec &SS = DeclType.Mem.Scope();
4892  QualType ClsType;
4893 
4894  // Handle pointer nullability.
4895  inferPointerNullability(SimplePointerKind::MemberPointer, DeclType.Loc,
4896  DeclType.EndLoc, DeclType.getAttrs(),
4897  state.getDeclarator().getAttributePool());
4898 
4899  if (SS.isInvalid()) {
4900  // Avoid emitting extra errors if we already errored on the scope.
4901  D.setInvalidType(true);
4902  } else if (S.isDependentScopeSpecifier(SS) ||
4903  dyn_cast_or_null<CXXRecordDecl>(S.computeDeclContext(SS))) {
4904  NestedNameSpecifier *NNS = SS.getScopeRep();
4905  NestedNameSpecifier *NNSPrefix = NNS->getPrefix();
4906  switch (NNS->getKind()) {
4908  ClsType = Context.getDependentNameType(ETK_None, NNSPrefix,
4909  NNS->getAsIdentifier());
4910  break;
4911 
4916  llvm_unreachable("Nested-name-specifier must name a type");
4917 
4920  ClsType = QualType(NNS->getAsType(), 0);
4921  // Note: if the NNS has a prefix and ClsType is a nondependent
4922  // TemplateSpecializationType, then the NNS prefix is NOT included
4923  // in ClsType; hence we wrap ClsType into an ElaboratedType.
4924  // NOTE: in particular, no wrap occurs if ClsType already is an
4925  // Elaborated, DependentName, or DependentTemplateSpecialization.
4926  if (NNSPrefix && isa<TemplateSpecializationType>(NNS->getAsType()))
4927  ClsType = Context.getElaboratedType(ETK_None, NNSPrefix, ClsType);
4928  break;
4929  }
4930  } else {
4931  S.Diag(DeclType.Mem.Scope().getBeginLoc(),
4932  diag::err_illegal_decl_mempointer_in_nonclass)
4933  << (D.getIdentifier() ? D.getIdentifier()->getName() : "type name")
4934  << DeclType.Mem.Scope().getRange();
4935  D.setInvalidType(true);
4936  }
4937 
4938  if (!ClsType.isNull())
4939  T = S.BuildMemberPointerType(T, ClsType, DeclType.Loc,
4940  D.getIdentifier());
4941  if (T.isNull()) {
4942  T = Context.IntTy;
4943  D.setInvalidType(true);
4944  } else if (DeclType.Mem.TypeQuals) {
4945  T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Mem.TypeQuals);
4946  }
4947  break;
4948  }
4949 
4950  case DeclaratorChunk::Pipe: {
4951  T = S.BuildReadPipeType(T, DeclType.Loc);
4952  processTypeAttrs(state, T, TAL_DeclSpec,
4954  break;
4955  }
4956  }
4957 
4958  if (T.isNull()) {
4959  D.setInvalidType(true);
4960  T = Context.IntTy;
4961  }
4962 
4963  // See if there are any attributes on this declarator chunk.
4964  processTypeAttrs(state, T, TAL_DeclChunk, DeclType.getAttrs());
4965 
4966  if (DeclType.Kind != DeclaratorChunk::Paren) {
4967  if (ExpectNoDerefChunk) {
4968  if (!IsNoDerefableChunk(DeclType))
4969  S.Diag(DeclType.Loc, diag::warn_noderef_on_non_pointer_or_array);
4970  ExpectNoDerefChunk = false;
4971  }
4972 
4973  ExpectNoDerefChunk = state.didParseNoDeref();
4974  }
4975  }
4976 
4977  if (ExpectNoDerefChunk)
4978  S.Diag(state.getDeclarator().getBeginLoc(),
4979  diag::warn_noderef_on_non_pointer_or_array);
4980 
4981  // GNU warning -Wstrict-prototypes
4982  // Warn if a function declaration is without a prototype.
4983  // This warning is issued for all kinds of unprototyped function
4984  // declarations (i.e. function type typedef, function pointer etc.)
4985  // C99 6.7.5.3p14:
4986  // The empty list in a function declarator that is not part of a definition
4987  // of that function specifies that no information about the number or types
4988  // of the parameters is supplied.
4989  if (!LangOpts.CPlusPlus && D.getFunctionDefinitionKind() == FDK_Declaration) {
4990  bool IsBlock = false;
4991  for (const DeclaratorChunk &DeclType : D.type_objects()) {
4992  switch (DeclType.Kind) {
4994  IsBlock = true;
4995  break;
4997  const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
4998  if (FTI.NumParams == 0 && !FTI.isVariadic)
4999  S.Diag(DeclType.Loc, diag::warn_strict_prototypes)
5000  << IsBlock
5001  << FixItHint::CreateInsertion(FTI.getRParenLoc(), "void");
5002  IsBlock = false;
5003  break;
5004  }
5005  default:
5006  break;
5007  }
5008  }
5009  }
5010 
5011  assert(!T.isNull() && "T must not be null after this point");
5012 
5013  if (LangOpts.CPlusPlus && T->isFunctionType()) {
5014  const FunctionProtoType *FnTy = T->getAs<FunctionProtoType>();
5015  assert(FnTy && "Why oh why is there not a FunctionProtoType here?");
5016 
5017  // C++ 8.3.5p4:
5018  // A cv-qualifier-seq shall only be part of the function type
5019  // for a nonstatic member function, the function type to which a pointer
5020  // to member refers, or the top-level function type of a function typedef
5021  // declaration.
5022  //
5023  // Core issue 547 also allows cv-qualifiers on function types that are
5024  // top-level template type arguments.
5025  enum { NonMember, Member, DeductionGuide } Kind = NonMember;
5027  Kind = DeductionGuide;
5028  else if (!D.getCXXScopeSpec().isSet()) {
5032  Kind = Member;
5033  } else {
5035  if (!DC || DC->isRecord())
5036  Kind = Member;
5037  }
5038 
5039  // C++11 [dcl.fct]p6 (w/DR1417):
5040  // An attempt to specify a function type with a cv-qualifier-seq or a
5041  // ref-qualifier (including by typedef-name) is ill-formed unless it is:
5042  // - the function type for a non-static member function,
5043  // - the function type to which a pointer to member refers,
5044  // - the top-level function type of a function typedef declaration or
5045  // alias-declaration,
5046  // - the type-id in the default argument of a type-parameter, or
5047  // - the type-id of a template-argument for a type-parameter
5048  //
5049  // FIXME: Checking this here is insufficient. We accept-invalid on:
5050  //
5051  // template<typename T> struct S { void f(T); };
5052  // S<int() const> s;
5053  //
5054  // ... for instance.
5055  if (IsQualifiedFunction &&
5056  !(Kind == Member &&
5058  !IsTypedefName &&
5061  SourceLocation Loc = D.getBeginLoc();
5062  SourceRange RemovalRange;
5063  unsigned I;
5064  if (D.isFunctionDeclarator(I)) {
5065  SmallVector<SourceLocation, 4> RemovalLocs;
5066  const DeclaratorChunk &Chunk = D.getTypeObject(I);
5067  assert(Chunk.Kind == DeclaratorChunk::Function);
5068 
5069  if (Chunk.Fun.hasRefQualifier())
5070  RemovalLocs.push_back(Chunk.Fun.getRefQualifierLoc());
5071 
5072  if (Chunk.Fun.hasMethodTypeQualifiers())
5074  [&](DeclSpec::TQ TypeQual, StringRef QualName,
5075  SourceLocation SL) { RemovalLocs.push_back(SL); });
5076 
5077  if (!RemovalLocs.empty()) {
5078  llvm::sort(RemovalLocs,
5080  RemovalRange = SourceRange(RemovalLocs.front(), RemovalLocs.back());
5081  Loc = RemovalLocs.front();
5082  }
5083  }
5084 
5085  S.Diag(Loc, diag::err_invalid_qualified_function_type)
5086  << Kind << D.isFunctionDeclarator() << T
5088  << FixItHint::CreateRemoval(RemovalRange);
5089 
5090  // Strip the cv-qualifiers and ref-qualifiers from the type.
5093  EPI.RefQualifier = RQ_None;
5094 
5095  T = Context.getFunctionType(FnTy->getReturnType(), FnTy->getParamTypes(),
5096  EPI);
5097  // Rebuild any parens around the identifier in the function type.
5098  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
5100  break;
5101  T = S.BuildParenType(T);
5102  }
5103  }
5104  }
5105 
5106  // Apply any undistributed attributes from the declarator.
5108 
5109  // Diagnose any ignored type attributes.
5110  state.diagnoseIgnoredTypeAttrs(T);
5111 
5112  // C++0x [dcl.constexpr]p9:
5113  // A constexpr specifier used in an object declaration declares the object
5114  // as const.
5115  if (D.getDeclSpec().isConstexprSpecified() && T->isObjectType()) {
5116  T.addConst();
5117  }
5118 
5119  // If there was an ellipsis in the declarator, the declaration declares a
5120  // parameter pack whose type may be a pack expansion type.
5121  if (D.hasEllipsis()) {
5122  // C++0x [dcl.fct]p13:
5123  // A declarator-id or abstract-declarator containing an ellipsis shall
5124  // only be used in a parameter-declaration. Such a parameter-declaration
5125  // is a parameter pack (14.5.3). [...]
5126  switch (D.getContext()) {
5129  // C++0x [dcl.fct]p13:
5130  // [...] When it is part of a parameter-declaration-clause, the
5131  // parameter pack is a function parameter pack (14.5.3). The type T
5132  // of the declarator-id of the function parameter pack shall contain
5133  // a template parameter pack; each template parameter pack in T is
5134  // expanded by the function parameter pack.
5135  //
5136  // We represent function parameter packs as function parameters whose
5137  // type is a pack expansion.
5138  if (!T->containsUnexpandedParameterPack()) {
5139  S.Diag(D.getEllipsisLoc(),
5140  diag::err_function_parameter_pack_without_parameter_packs)
5141  << T << D.getSourceRange();
5143  } else {
5144  T = Context.getPackExpansionType(T, None);
5145  }
5146  break;
5148  // C++0x [temp.param]p15:
5149  // If a template-parameter is a [...] is a parameter-declaration that
5150  // declares a parameter pack (8.3.5), then the template-parameter is a
5151  // template parameter pack (14.5.3).
5152  //
5153  // Note: core issue 778 clarifies that, if there are any unexpanded
5154  // parameter packs in the type of the non-type template parameter, then
5155  // it expands those parameter packs.
5157  T = Context.getPackExpansionType(T, None);
5158  else
5159  S.Diag(D.getEllipsisLoc(),
5160  LangOpts.CPlusPlus11
5161  ? diag::warn_cxx98_compat_variadic_templates
5162  : diag::ext_variadic_templates);
5163  break;
5164 
5167  case DeclaratorContext::ObjCParameterContext: // FIXME: special diagnostic
5168  // here?
5169  case DeclaratorContext::ObjCResultContext: // FIXME: special diagnostic
5170  // here?
5190  // FIXME: We may want to allow parameter packs in block-literal contexts
5191  // in the future.
5192  S.Diag(D.getEllipsisLoc(),
5193  diag::err_ellipsis_in_declarator_not_parameter);
5195  break;
5196  }
5197  }
5198 
5199  assert(!T.isNull() && "T must not be null at the end of this function");
5200  if (D.isInvalidType())
5201  return Context.getTrivialTypeSourceInfo(T);
5202 
5203  return GetTypeSourceInfoForDeclarator(state, T, TInfo);
5204 }
5205 
5206 /// GetTypeForDeclarator - Convert the type for the specified
5207 /// declarator to Type instances.
5208 ///
5209 /// The result of this call will never be null, but the associated
5210 /// type may be a null type if there's an unrecoverable error.
5212  // Determine the type of the declarator. Not all forms of declarator
5213  // have a type.
5214 
5215  TypeProcessingState state(*this, D);
5216 
5217  TypeSourceInfo *ReturnTypeInfo = nullptr;
5218  QualType T = GetDeclSpecTypeForDeclarator(state, ReturnTypeInfo);
5219  if (D.isPrototypeContext() && getLangOpts().ObjCAutoRefCount)
5220  inferARCWriteback(state, T);
5221 
5222  return GetFullTypeForDeclarator(state, T, ReturnTypeInfo);
5223 }
5224 
5226  QualType &declSpecTy,
5227  Qualifiers::ObjCLifetime ownership) {
5228  if (declSpecTy->isObjCRetainableType() &&
5229  declSpecTy.getObjCLifetime() == Qualifiers::OCL_None) {
5230  Qualifiers qs;
5231  qs.addObjCLifetime(ownership);
5232  declSpecTy = S.Context.getQualifiedType(declSpecTy, qs);
5233  }
5234 }
5235 
5236 static void transferARCOwnershipToDeclaratorChunk(TypeProcessingState &state,
5237  Qualifiers::ObjCLifetime ownership,
5238  unsigned chunkIndex) {
5239  Sema &S = state.getSema();
5240  Declarator &D = state.getDeclarator();
5241 
5242  // Look for an explicit lifetime attribute.
5243  DeclaratorChunk &chunk = D.getTypeObject(chunkIndex);
5244  if (chunk.getAttrs().hasAttribute(ParsedAttr::AT_ObjCOwnership))
5245  return;
5246 
5247  const char *attrStr = nullptr;
5248  switch (ownership) {
5249  case Qualifiers::OCL_None: llvm_unreachable("no ownership!");
5250  case Qualifiers::OCL_ExplicitNone: attrStr = "none"; break;
5251  case Qualifiers::OCL_Strong: attrStr = "strong"; break;
5252  case Qualifiers::OCL_Weak: attrStr = "weak"; break;
5253  case Qualifiers::OCL_Autoreleasing: attrStr = "autoreleasing"; break;
5254  }
5255 
5256  IdentifierLoc *Arg = new (S.Context) IdentifierLoc;
5257  Arg->Ident = &S.Context.Idents.get(attrStr);
5258  Arg->Loc = SourceLocation();
5259 
5260  ArgsUnion Args(Arg);
5261 
5262  // If there wasn't one, add one (with an invalid source location
5263  // so that we don't make an AttributedType for it).
5264  ParsedAttr *attr = D.getAttributePool().create(
5265  &S.Context.Idents.get("objc_ownership"), SourceLocation(),
5266  /*scope*/ nullptr, SourceLocation(),
5267  /*args*/ &Args, 1, ParsedAttr::AS_GNU);
5268  chunk.getAttrs().addAtEnd(attr);
5269  // TODO: mark whether we did this inference?
5270 }
5271 
5272 /// Used for transferring ownership in casts resulting in l-values.
5273 static void transferARCOwnership(TypeProcessingState &state,
5274  QualType &declSpecTy,
5275  Qualifiers::ObjCLifetime ownership) {
5276  Sema &S = state.getSema();
5277  Declarator &D = state.getDeclarator();
5278 
5279  int inner = -1;
5280  bool hasIndirection = false;
5281  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
5282  DeclaratorChunk &chunk = D.getTypeObject(i);
5283  switch (chunk.Kind) {
5285  // Ignore parens.
5286  break;
5287 
5291  if (inner != -1)
5292  hasIndirection = true;
5293  inner = i;
5294  break;
5295 
5297  if (inner != -1)
5298  transferARCOwnershipToDeclaratorChunk(state, ownership, i);
5299  return;
5300 
5303  case DeclaratorChunk::Pipe:
5304  return;
5305  }
5306  }
5307 
5308  if (inner == -1)
5309  return;
5310 
5311  DeclaratorChunk &chunk = D.getTypeObject(inner);
5312  if (chunk.Kind == DeclaratorChunk::Pointer) {
5313  if (declSpecTy->isObjCRetainableType())
5314  return transferARCOwnershipToDeclSpec(S, declSpecTy, ownership);
5315  if (declSpecTy->isObjCObjectType() && hasIndirection)
5316  return transferARCOwnershipToDeclaratorChunk(state, ownership, inner);
5317  } else {
5318  assert(chunk.Kind == DeclaratorChunk::Array ||
5319  chunk.Kind == DeclaratorChunk::Reference);
5320  return transferARCOwnershipToDeclSpec(S, declSpecTy, ownership);
5321  }
5322 }
5323 
5325  TypeProcessingState state(*this, D);
5326 
5327  TypeSourceInfo *ReturnTypeInfo = nullptr;
5328  QualType declSpecTy = GetDeclSpecTypeForDeclarator(state, ReturnTypeInfo);
5329 
5330  if (getLangOpts().ObjC) {
5331  Qualifiers::ObjCLifetime ownership = Context.getInnerObjCOwnership(FromTy);
5332  if (ownership != Qualifiers::OCL_None)
5333  transferARCOwnership(state, declSpecTy, ownership);
5334  }
5335 
5336  return GetFullTypeForDeclarator(state, declSpecTy, ReturnTypeInfo);
5337 }
5338 
5340  TypeProcessingState &State) {
5341  TL.setAttr(State.takeAttrForAttributedType(TL.getTypePtr()));
5342 }
5343 
5344 namespace {
5345  class TypeSpecLocFiller : public TypeLocVisitor<TypeSpecLocFiller> {
5346  ASTContext &Context;
5347  TypeProcessingState &State;
5348  const DeclSpec &DS;
5349 
5350  public:
5351  TypeSpecLocFiller(ASTContext &Context, TypeProcessingState &State,
5352  const DeclSpec &DS)
5353  : Context(Context), State(State), DS(DS) {}
5354 
5355  void VisitAttributedTypeLoc(AttributedTypeLoc TL) {
5356  Visit(TL.getModifiedLoc());
5357  fillAttributedTypeLoc(TL, State);
5358  }
5359  void VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
5360  Visit(TL.getUnqualifiedLoc());
5361  }
5362  void VisitTypedefTypeLoc(TypedefTypeLoc TL) {
5363  TL.setNameLoc(DS.getTypeSpecTypeLoc());
5364  }
5365  void VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
5366  TL.setNameLoc(DS.getTypeSpecTypeLoc());
5367  // FIXME. We should have DS.getTypeSpecTypeEndLoc(). But, it requires
5368  // addition field. What we have is good enough for dispay of location
5369  // of 'fixit' on interface name.
5370  TL.setNameEndLoc(DS.getEndLoc());
5371  }
5372  void VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
5373  TypeSourceInfo *RepTInfo = nullptr;
5374  Sema::GetTypeFromParser(DS.getRepAsType(), &RepTInfo);
5375  TL.copy(RepTInfo->getTypeLoc());
5376  }
5377  void VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
5378  TypeSourceInfo *RepTInfo = nullptr;
5379  Sema::GetTypeFromParser(DS.getRepAsType(), &RepTInfo);
5380  TL.copy(RepTInfo->getTypeLoc());
5381  }
5382  void VisitTemplateSpecializationTypeLoc(TemplateSpecializationTypeLoc TL) {
5383  TypeSourceInfo *TInfo = nullptr;
5384  Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
5385 
5386  // If we got no dec