SemaType.cpp revision 66581d41527628d4b37f7b05c288f77be7415d7d
1//===--- SemaType.cpp - Semantic Analysis for Types -----------------------===//
2//
3//                     The LLVM Compiler Infrastructure
4//
5// This file is distributed under the University of Illinois Open Source
6// License. See LICENSE.TXT for details.
7//
8//===----------------------------------------------------------------------===//
9//
10//  This file implements type-related semantic analysis.
11//
12//===----------------------------------------------------------------------===//
13
14#include "clang/Sema/SemaInternal.h"
15#include "clang/Sema/Template.h"
16#include "clang/Basic/OpenCL.h"
17#include "clang/AST/ASTContext.h"
18#include "clang/AST/ASTMutationListener.h"
19#include "clang/AST/CXXInheritance.h"
20#include "clang/AST/DeclObjC.h"
21#include "clang/AST/DeclTemplate.h"
22#include "clang/AST/TypeLoc.h"
23#include "clang/AST/TypeLocVisitor.h"
24#include "clang/AST/Expr.h"
25#include "clang/Basic/PartialDiagnostic.h"
26#include "clang/Basic/TargetInfo.h"
27#include "clang/Lex/Preprocessor.h"
28#include "clang/Sema/DeclSpec.h"
29#include "clang/Sema/DelayedDiagnostic.h"
30#include "clang/Sema/Lookup.h"
31#include "llvm/ADT/SmallPtrSet.h"
32#include "llvm/Support/ErrorHandling.h"
33using namespace clang;
34
35/// isOmittedBlockReturnType - Return true if this declarator is missing a
36/// return type because this is a omitted return type on a block literal.
37static bool isOmittedBlockReturnType(const Declarator &D) {
38  if (D.getContext() != Declarator::BlockLiteralContext ||
39      D.getDeclSpec().hasTypeSpecifier())
40    return false;
41
42  if (D.getNumTypeObjects() == 0)
43    return true;   // ^{ ... }
44
45  if (D.getNumTypeObjects() == 1 &&
46      D.getTypeObject(0).Kind == DeclaratorChunk::Function)
47    return true;   // ^(int X, float Y) { ... }
48
49  return false;
50}
51
52/// diagnoseBadTypeAttribute - Diagnoses a type attribute which
53/// doesn't apply to the given type.
54static void diagnoseBadTypeAttribute(Sema &S, const AttributeList &attr,
55                                     QualType type) {
56  bool useExpansionLoc = false;
57
58  unsigned diagID = 0;
59  switch (attr.getKind()) {
60  case AttributeList::AT_objc_gc:
61    diagID = diag::warn_pointer_attribute_wrong_type;
62    useExpansionLoc = true;
63    break;
64
65  case AttributeList::AT_objc_ownership:
66    diagID = diag::warn_objc_object_attribute_wrong_type;
67    useExpansionLoc = true;
68    break;
69
70  default:
71    // Assume everything else was a function attribute.
72    diagID = diag::warn_function_attribute_wrong_type;
73    break;
74  }
75
76  SourceLocation loc = attr.getLoc();
77  StringRef name = attr.getName()->getName();
78
79  // The GC attributes are usually written with macros;  special-case them.
80  if (useExpansionLoc && loc.isMacroID() && attr.getParameterName()) {
81    if (attr.getParameterName()->isStr("strong")) {
82      if (S.findMacroSpelling(loc, "__strong")) name = "__strong";
83    } else if (attr.getParameterName()->isStr("weak")) {
84      if (S.findMacroSpelling(loc, "__weak")) name = "__weak";
85    }
86  }
87
88  S.Diag(loc, diagID) << name << type;
89}
90
91// objc_gc applies to Objective-C pointers or, otherwise, to the
92// smallest available pointer type (i.e. 'void*' in 'void**').
93#define OBJC_POINTER_TYPE_ATTRS_CASELIST \
94    case AttributeList::AT_objc_gc: \
95    case AttributeList::AT_objc_ownership
96
97// Function type attributes.
98#define FUNCTION_TYPE_ATTRS_CASELIST \
99    case AttributeList::AT_noreturn: \
100    case AttributeList::AT_cdecl: \
101    case AttributeList::AT_fastcall: \
102    case AttributeList::AT_stdcall: \
103    case AttributeList::AT_thiscall: \
104    case AttributeList::AT_pascal: \
105    case AttributeList::AT_regparm: \
106    case AttributeList::AT_pcs \
107
108namespace {
109  /// An object which stores processing state for the entire
110  /// GetTypeForDeclarator process.
111  class TypeProcessingState {
112    Sema &sema;
113
114    /// The declarator being processed.
115    Declarator &declarator;
116
117    /// The index of the declarator chunk we're currently processing.
118    /// May be the total number of valid chunks, indicating the
119    /// DeclSpec.
120    unsigned chunkIndex;
121
122    /// Whether there are non-trivial modifications to the decl spec.
123    bool trivial;
124
125    /// Whether we saved the attributes in the decl spec.
126    bool hasSavedAttrs;
127
128    /// The original set of attributes on the DeclSpec.
129    SmallVector<AttributeList*, 2> savedAttrs;
130
131    /// A list of attributes to diagnose the uselessness of when the
132    /// processing is complete.
133    SmallVector<AttributeList*, 2> ignoredTypeAttrs;
134
135  public:
136    TypeProcessingState(Sema &sema, Declarator &declarator)
137      : sema(sema), declarator(declarator),
138        chunkIndex(declarator.getNumTypeObjects()),
139        trivial(true), hasSavedAttrs(false) {}
140
141    Sema &getSema() const {
142      return sema;
143    }
144
145    Declarator &getDeclarator() const {
146      return declarator;
147    }
148
149    unsigned getCurrentChunkIndex() const {
150      return chunkIndex;
151    }
152
153    void setCurrentChunkIndex(unsigned idx) {
154      assert(idx <= declarator.getNumTypeObjects());
155      chunkIndex = idx;
156    }
157
158    AttributeList *&getCurrentAttrListRef() const {
159      assert(chunkIndex <= declarator.getNumTypeObjects());
160      if (chunkIndex == declarator.getNumTypeObjects())
161        return getMutableDeclSpec().getAttributes().getListRef();
162      return declarator.getTypeObject(chunkIndex).getAttrListRef();
163    }
164
165    /// Save the current set of attributes on the DeclSpec.
166    void saveDeclSpecAttrs() {
167      // Don't try to save them multiple times.
168      if (hasSavedAttrs) return;
169
170      DeclSpec &spec = getMutableDeclSpec();
171      for (AttributeList *attr = spec.getAttributes().getList(); attr;
172             attr = attr->getNext())
173        savedAttrs.push_back(attr);
174      trivial &= savedAttrs.empty();
175      hasSavedAttrs = true;
176    }
177
178    /// Record that we had nowhere to put the given type attribute.
179    /// We will diagnose such attributes later.
180    void addIgnoredTypeAttr(AttributeList &attr) {
181      ignoredTypeAttrs.push_back(&attr);
182    }
183
184    /// Diagnose all the ignored type attributes, given that the
185    /// declarator worked out to the given type.
186    void diagnoseIgnoredTypeAttrs(QualType type) const {
187      for (SmallVectorImpl<AttributeList*>::const_iterator
188             i = ignoredTypeAttrs.begin(), e = ignoredTypeAttrs.end();
189           i != e; ++i)
190        diagnoseBadTypeAttribute(getSema(), **i, type);
191    }
192
193    ~TypeProcessingState() {
194      if (trivial) return;
195
196      restoreDeclSpecAttrs();
197    }
198
199  private:
200    DeclSpec &getMutableDeclSpec() const {
201      return const_cast<DeclSpec&>(declarator.getDeclSpec());
202    }
203
204    void restoreDeclSpecAttrs() {
205      assert(hasSavedAttrs);
206
207      if (savedAttrs.empty()) {
208        getMutableDeclSpec().getAttributes().set(0);
209        return;
210      }
211
212      getMutableDeclSpec().getAttributes().set(savedAttrs[0]);
213      for (unsigned i = 0, e = savedAttrs.size() - 1; i != e; ++i)
214        savedAttrs[i]->setNext(savedAttrs[i+1]);
215      savedAttrs.back()->setNext(0);
216    }
217  };
218
219  /// Basically std::pair except that we really want to avoid an
220  /// implicit operator= for safety concerns.  It's also a minor
221  /// link-time optimization for this to be a private type.
222  struct AttrAndList {
223    /// The attribute.
224    AttributeList &first;
225
226    /// The head of the list the attribute is currently in.
227    AttributeList *&second;
228
229    AttrAndList(AttributeList &attr, AttributeList *&head)
230      : first(attr), second(head) {}
231  };
232}
233
234namespace llvm {
235  template <> struct isPodLike<AttrAndList> {
236    static const bool value = true;
237  };
238}
239
240static void spliceAttrIntoList(AttributeList &attr, AttributeList *&head) {
241  attr.setNext(head);
242  head = &attr;
243}
244
245static void spliceAttrOutOfList(AttributeList &attr, AttributeList *&head) {
246  if (head == &attr) {
247    head = attr.getNext();
248    return;
249  }
250
251  AttributeList *cur = head;
252  while (true) {
253    assert(cur && cur->getNext() && "ran out of attrs?");
254    if (cur->getNext() == &attr) {
255      cur->setNext(attr.getNext());
256      return;
257    }
258    cur = cur->getNext();
259  }
260}
261
262static void moveAttrFromListToList(AttributeList &attr,
263                                   AttributeList *&fromList,
264                                   AttributeList *&toList) {
265  spliceAttrOutOfList(attr, fromList);
266  spliceAttrIntoList(attr, toList);
267}
268
269static void processTypeAttrs(TypeProcessingState &state,
270                             QualType &type, bool isDeclSpec,
271                             AttributeList *attrs);
272
273static bool handleFunctionTypeAttr(TypeProcessingState &state,
274                                   AttributeList &attr,
275                                   QualType &type);
276
277static bool handleObjCGCTypeAttr(TypeProcessingState &state,
278                                 AttributeList &attr, QualType &type);
279
280static bool handleObjCOwnershipTypeAttr(TypeProcessingState &state,
281                                       AttributeList &attr, QualType &type);
282
283static bool handleObjCPointerTypeAttr(TypeProcessingState &state,
284                                      AttributeList &attr, QualType &type) {
285  if (attr.getKind() == AttributeList::AT_objc_gc)
286    return handleObjCGCTypeAttr(state, attr, type);
287  assert(attr.getKind() == AttributeList::AT_objc_ownership);
288  return handleObjCOwnershipTypeAttr(state, attr, type);
289}
290
291/// Given that an objc_gc attribute was written somewhere on a
292/// declaration *other* than on the declarator itself (for which, use
293/// distributeObjCPointerTypeAttrFromDeclarator), and given that it
294/// didn't apply in whatever position it was written in, try to move
295/// it to a more appropriate position.
296static void distributeObjCPointerTypeAttr(TypeProcessingState &state,
297                                          AttributeList &attr,
298                                          QualType type) {
299  Declarator &declarator = state.getDeclarator();
300  for (unsigned i = state.getCurrentChunkIndex(); i != 0; --i) {
301    DeclaratorChunk &chunk = declarator.getTypeObject(i-1);
302    switch (chunk.Kind) {
303    case DeclaratorChunk::Pointer:
304    case DeclaratorChunk::BlockPointer:
305      moveAttrFromListToList(attr, state.getCurrentAttrListRef(),
306                             chunk.getAttrListRef());
307      return;
308
309    case DeclaratorChunk::Paren:
310    case DeclaratorChunk::Array:
311      continue;
312
313    // Don't walk through these.
314    case DeclaratorChunk::Reference:
315    case DeclaratorChunk::Function:
316    case DeclaratorChunk::MemberPointer:
317      goto error;
318    }
319  }
320 error:
321
322  diagnoseBadTypeAttribute(state.getSema(), attr, type);
323}
324
325/// Distribute an objc_gc type attribute that was written on the
326/// declarator.
327static void
328distributeObjCPointerTypeAttrFromDeclarator(TypeProcessingState &state,
329                                            AttributeList &attr,
330                                            QualType &declSpecType) {
331  Declarator &declarator = state.getDeclarator();
332
333  // objc_gc goes on the innermost pointer to something that's not a
334  // pointer.
335  unsigned innermost = -1U;
336  bool considerDeclSpec = true;
337  for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
338    DeclaratorChunk &chunk = declarator.getTypeObject(i);
339    switch (chunk.Kind) {
340    case DeclaratorChunk::Pointer:
341    case DeclaratorChunk::BlockPointer:
342      innermost = i;
343      continue;
344
345    case DeclaratorChunk::Reference:
346    case DeclaratorChunk::MemberPointer:
347    case DeclaratorChunk::Paren:
348    case DeclaratorChunk::Array:
349      continue;
350
351    case DeclaratorChunk::Function:
352      considerDeclSpec = false;
353      goto done;
354    }
355  }
356 done:
357
358  // That might actually be the decl spec if we weren't blocked by
359  // anything in the declarator.
360  if (considerDeclSpec) {
361    if (handleObjCPointerTypeAttr(state, attr, declSpecType)) {
362      // Splice the attribute into the decl spec.  Prevents the
363      // attribute from being applied multiple times and gives
364      // the source-location-filler something to work with.
365      state.saveDeclSpecAttrs();
366      moveAttrFromListToList(attr, declarator.getAttrListRef(),
367               declarator.getMutableDeclSpec().getAttributes().getListRef());
368      return;
369    }
370  }
371
372  // Otherwise, if we found an appropriate chunk, splice the attribute
373  // into it.
374  if (innermost != -1U) {
375    moveAttrFromListToList(attr, declarator.getAttrListRef(),
376                       declarator.getTypeObject(innermost).getAttrListRef());
377    return;
378  }
379
380  // Otherwise, diagnose when we're done building the type.
381  spliceAttrOutOfList(attr, declarator.getAttrListRef());
382  state.addIgnoredTypeAttr(attr);
383}
384
385/// A function type attribute was written somewhere in a declaration
386/// *other* than on the declarator itself or in the decl spec.  Given
387/// that it didn't apply in whatever position it was written in, try
388/// to move it to a more appropriate position.
389static void distributeFunctionTypeAttr(TypeProcessingState &state,
390                                       AttributeList &attr,
391                                       QualType type) {
392  Declarator &declarator = state.getDeclarator();
393
394  // Try to push the attribute from the return type of a function to
395  // the function itself.
396  for (unsigned i = state.getCurrentChunkIndex(); i != 0; --i) {
397    DeclaratorChunk &chunk = declarator.getTypeObject(i-1);
398    switch (chunk.Kind) {
399    case DeclaratorChunk::Function:
400      moveAttrFromListToList(attr, state.getCurrentAttrListRef(),
401                             chunk.getAttrListRef());
402      return;
403
404    case DeclaratorChunk::Paren:
405    case DeclaratorChunk::Pointer:
406    case DeclaratorChunk::BlockPointer:
407    case DeclaratorChunk::Array:
408    case DeclaratorChunk::Reference:
409    case DeclaratorChunk::MemberPointer:
410      continue;
411    }
412  }
413
414  diagnoseBadTypeAttribute(state.getSema(), attr, type);
415}
416
417/// Try to distribute a function type attribute to the innermost
418/// function chunk or type.  Returns true if the attribute was
419/// distributed, false if no location was found.
420static bool
421distributeFunctionTypeAttrToInnermost(TypeProcessingState &state,
422                                      AttributeList &attr,
423                                      AttributeList *&attrList,
424                                      QualType &declSpecType) {
425  Declarator &declarator = state.getDeclarator();
426
427  // Put it on the innermost function chunk, if there is one.
428  for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
429    DeclaratorChunk &chunk = declarator.getTypeObject(i);
430    if (chunk.Kind != DeclaratorChunk::Function) continue;
431
432    moveAttrFromListToList(attr, attrList, chunk.getAttrListRef());
433    return true;
434  }
435
436  if (handleFunctionTypeAttr(state, attr, declSpecType)) {
437    spliceAttrOutOfList(attr, attrList);
438    return true;
439  }
440
441  return false;
442}
443
444/// A function type attribute was written in the decl spec.  Try to
445/// apply it somewhere.
446static void
447distributeFunctionTypeAttrFromDeclSpec(TypeProcessingState &state,
448                                       AttributeList &attr,
449                                       QualType &declSpecType) {
450  state.saveDeclSpecAttrs();
451
452  // Try to distribute to the innermost.
453  if (distributeFunctionTypeAttrToInnermost(state, attr,
454                                            state.getCurrentAttrListRef(),
455                                            declSpecType))
456    return;
457
458  // If that failed, diagnose the bad attribute when the declarator is
459  // fully built.
460  state.addIgnoredTypeAttr(attr);
461}
462
463/// A function type attribute was written on the declarator.  Try to
464/// apply it somewhere.
465static void
466distributeFunctionTypeAttrFromDeclarator(TypeProcessingState &state,
467                                         AttributeList &attr,
468                                         QualType &declSpecType) {
469  Declarator &declarator = state.getDeclarator();
470
471  // Try to distribute to the innermost.
472  if (distributeFunctionTypeAttrToInnermost(state, attr,
473                                            declarator.getAttrListRef(),
474                                            declSpecType))
475    return;
476
477  // If that failed, diagnose the bad attribute when the declarator is
478  // fully built.
479  spliceAttrOutOfList(attr, declarator.getAttrListRef());
480  state.addIgnoredTypeAttr(attr);
481}
482
483/// \brief Given that there are attributes written on the declarator
484/// itself, try to distribute any type attributes to the appropriate
485/// declarator chunk.
486///
487/// These are attributes like the following:
488///   int f ATTR;
489///   int (f ATTR)();
490/// but not necessarily this:
491///   int f() ATTR;
492static void distributeTypeAttrsFromDeclarator(TypeProcessingState &state,
493                                              QualType &declSpecType) {
494  // Collect all the type attributes from the declarator itself.
495  assert(state.getDeclarator().getAttributes() && "declarator has no attrs!");
496  AttributeList *attr = state.getDeclarator().getAttributes();
497  AttributeList *next;
498  do {
499    next = attr->getNext();
500
501    switch (attr->getKind()) {
502    OBJC_POINTER_TYPE_ATTRS_CASELIST:
503      distributeObjCPointerTypeAttrFromDeclarator(state, *attr, declSpecType);
504      break;
505
506    case AttributeList::AT_ns_returns_retained:
507      if (!state.getSema().getLangOptions().ObjCAutoRefCount)
508        break;
509      // fallthrough
510
511    FUNCTION_TYPE_ATTRS_CASELIST:
512      distributeFunctionTypeAttrFromDeclarator(state, *attr, declSpecType);
513      break;
514
515    default:
516      break;
517    }
518  } while ((attr = next));
519}
520
521/// Add a synthetic '()' to a block-literal declarator if it is
522/// required, given the return type.
523static void maybeSynthesizeBlockSignature(TypeProcessingState &state,
524                                          QualType declSpecType) {
525  Declarator &declarator = state.getDeclarator();
526
527  // First, check whether the declarator would produce a function,
528  // i.e. whether the innermost semantic chunk is a function.
529  if (declarator.isFunctionDeclarator()) {
530    // If so, make that declarator a prototyped declarator.
531    declarator.getFunctionTypeInfo().hasPrototype = true;
532    return;
533  }
534
535  // If there are any type objects, the type as written won't name a
536  // function, regardless of the decl spec type.  This is because a
537  // block signature declarator is always an abstract-declarator, and
538  // abstract-declarators can't just be parentheses chunks.  Therefore
539  // we need to build a function chunk unless there are no type
540  // objects and the decl spec type is a function.
541  if (!declarator.getNumTypeObjects() && declSpecType->isFunctionType())
542    return;
543
544  // Note that there *are* cases with invalid declarators where
545  // declarators consist solely of parentheses.  In general, these
546  // occur only in failed efforts to make function declarators, so
547  // faking up the function chunk is still the right thing to do.
548
549  // Otherwise, we need to fake up a function declarator.
550  SourceLocation loc = declarator.getSourceRange().getBegin();
551
552  // ...and *prepend* it to the declarator.
553  declarator.AddInnermostTypeInfo(DeclaratorChunk::getFunction(
554                             /*proto*/ true,
555                             /*variadic*/ false, SourceLocation(),
556                             /*args*/ 0, 0,
557                             /*type quals*/ 0,
558                             /*ref-qualifier*/true, SourceLocation(),
559                             /*const qualifier*/SourceLocation(),
560                             /*volatile qualifier*/SourceLocation(),
561                             /*mutable qualifier*/SourceLocation(),
562                             /*EH*/ EST_None, SourceLocation(), 0, 0, 0, 0,
563                             /*parens*/ loc, loc,
564                             declarator));
565
566  // For consistency, make sure the state still has us as processing
567  // the decl spec.
568  assert(state.getCurrentChunkIndex() == declarator.getNumTypeObjects() - 1);
569  state.setCurrentChunkIndex(declarator.getNumTypeObjects());
570}
571
572/// \brief Convert the specified declspec to the appropriate type
573/// object.
574/// \param D  the declarator containing the declaration specifier.
575/// \returns The type described by the declaration specifiers.  This function
576/// never returns null.
577static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
578  // FIXME: Should move the logic from DeclSpec::Finish to here for validity
579  // checking.
580
581  Sema &S = state.getSema();
582  Declarator &declarator = state.getDeclarator();
583  const DeclSpec &DS = declarator.getDeclSpec();
584  SourceLocation DeclLoc = declarator.getIdentifierLoc();
585  if (DeclLoc.isInvalid())
586    DeclLoc = DS.getSourceRange().getBegin();
587
588  ASTContext &Context = S.Context;
589
590  QualType Result;
591  switch (DS.getTypeSpecType()) {
592  case DeclSpec::TST_void:
593    Result = Context.VoidTy;
594    break;
595  case DeclSpec::TST_char:
596    if (DS.getTypeSpecSign() == DeclSpec::TSS_unspecified)
597      Result = Context.CharTy;
598    else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed)
599      Result = Context.SignedCharTy;
600    else {
601      assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
602             "Unknown TSS value");
603      Result = Context.UnsignedCharTy;
604    }
605    break;
606  case DeclSpec::TST_wchar:
607    if (DS.getTypeSpecSign() == DeclSpec::TSS_unspecified)
608      Result = Context.WCharTy;
609    else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed) {
610      S.Diag(DS.getTypeSpecSignLoc(), diag::ext_invalid_sign_spec)
611        << DS.getSpecifierName(DS.getTypeSpecType());
612      Result = Context.getSignedWCharType();
613    } else {
614      assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
615        "Unknown TSS value");
616      S.Diag(DS.getTypeSpecSignLoc(), diag::ext_invalid_sign_spec)
617        << DS.getSpecifierName(DS.getTypeSpecType());
618      Result = Context.getUnsignedWCharType();
619    }
620    break;
621  case DeclSpec::TST_char16:
622      assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
623        "Unknown TSS value");
624      Result = Context.Char16Ty;
625    break;
626  case DeclSpec::TST_char32:
627      assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
628        "Unknown TSS value");
629      Result = Context.Char32Ty;
630    break;
631  case DeclSpec::TST_unspecified:
632    // "<proto1,proto2>" is an objc qualified ID with a missing id.
633    if (DeclSpec::ProtocolQualifierListTy PQ = DS.getProtocolQualifiers()) {
634      Result = Context.getObjCObjectType(Context.ObjCBuiltinIdTy,
635                                         (ObjCProtocolDecl**)PQ,
636                                         DS.getNumProtocolQualifiers());
637      Result = Context.getObjCObjectPointerType(Result);
638      break;
639    }
640
641    // If this is a missing declspec in a block literal return context, then it
642    // is inferred from the return statements inside the block.
643    // The declspec is always missing in a lambda expr context; it is either
644    // specified with a trailing return type or inferred.
645    if (declarator.getContext() == Declarator::LambdaExprContext ||
646        isOmittedBlockReturnType(declarator)) {
647      Result = Context.DependentTy;
648      break;
649    }
650
651    // Unspecified typespec defaults to int in C90.  However, the C90 grammar
652    // [C90 6.5] only allows a decl-spec if there was *some* type-specifier,
653    // type-qualifier, or storage-class-specifier.  If not, emit an extwarn.
654    // Note that the one exception to this is function definitions, which are
655    // allowed to be completely missing a declspec.  This is handled in the
656    // parser already though by it pretending to have seen an 'int' in this
657    // case.
658    if (S.getLangOptions().ImplicitInt) {
659      // In C89 mode, we only warn if there is a completely missing declspec
660      // when one is not allowed.
661      if (DS.isEmpty()) {
662        S.Diag(DeclLoc, diag::ext_missing_declspec)
663          << DS.getSourceRange()
664        << FixItHint::CreateInsertion(DS.getSourceRange().getBegin(), "int");
665      }
666    } else if (!DS.hasTypeSpecifier()) {
667      // C99 and C++ require a type specifier.  For example, C99 6.7.2p2 says:
668      // "At least one type specifier shall be given in the declaration
669      // specifiers in each declaration, and in the specifier-qualifier list in
670      // each struct declaration and type name."
671      // FIXME: Does Microsoft really have the implicit int extension in C++?
672      if (S.getLangOptions().CPlusPlus &&
673          !S.getLangOptions().MicrosoftExt) {
674        S.Diag(DeclLoc, diag::err_missing_type_specifier)
675          << DS.getSourceRange();
676
677        // When this occurs in C++ code, often something is very broken with the
678        // value being declared, poison it as invalid so we don't get chains of
679        // errors.
680        declarator.setInvalidType(true);
681      } else {
682        S.Diag(DeclLoc, diag::ext_missing_type_specifier)
683          << DS.getSourceRange();
684      }
685    }
686
687    // FALL THROUGH.
688  case DeclSpec::TST_int: {
689    if (DS.getTypeSpecSign() != DeclSpec::TSS_unsigned) {
690      switch (DS.getTypeSpecWidth()) {
691      case DeclSpec::TSW_unspecified: Result = Context.IntTy; break;
692      case DeclSpec::TSW_short:       Result = Context.ShortTy; break;
693      case DeclSpec::TSW_long:        Result = Context.LongTy; break;
694      case DeclSpec::TSW_longlong:
695        Result = Context.LongLongTy;
696
697        // long long is a C99 feature.
698        if (!S.getLangOptions().C99)
699          S.Diag(DS.getTypeSpecWidthLoc(),
700                 S.getLangOptions().CPlusPlus0x ?
701                   diag::warn_cxx98_compat_longlong : diag::ext_longlong);
702        break;
703      }
704    } else {
705      switch (DS.getTypeSpecWidth()) {
706      case DeclSpec::TSW_unspecified: Result = Context.UnsignedIntTy; break;
707      case DeclSpec::TSW_short:       Result = Context.UnsignedShortTy; break;
708      case DeclSpec::TSW_long:        Result = Context.UnsignedLongTy; break;
709      case DeclSpec::TSW_longlong:
710        Result = Context.UnsignedLongLongTy;
711
712        // long long is a C99 feature.
713        if (!S.getLangOptions().C99)
714          S.Diag(DS.getTypeSpecWidthLoc(),
715                 S.getLangOptions().CPlusPlus0x ?
716                   diag::warn_cxx98_compat_longlong : diag::ext_longlong);
717        break;
718      }
719    }
720    break;
721  }
722  case DeclSpec::TST_half: Result = Context.HalfTy; break;
723  case DeclSpec::TST_float: Result = Context.FloatTy; break;
724  case DeclSpec::TST_double:
725    if (DS.getTypeSpecWidth() == DeclSpec::TSW_long)
726      Result = Context.LongDoubleTy;
727    else
728      Result = Context.DoubleTy;
729
730    if (S.getLangOptions().OpenCL && !S.getOpenCLOptions().cl_khr_fp64) {
731      S.Diag(DS.getTypeSpecTypeLoc(), diag::err_double_requires_fp64);
732      declarator.setInvalidType(true);
733    }
734    break;
735  case DeclSpec::TST_bool: Result = Context.BoolTy; break; // _Bool or bool
736  case DeclSpec::TST_decimal32:    // _Decimal32
737  case DeclSpec::TST_decimal64:    // _Decimal64
738  case DeclSpec::TST_decimal128:   // _Decimal128
739    S.Diag(DS.getTypeSpecTypeLoc(), diag::err_decimal_unsupported);
740    Result = Context.IntTy;
741    declarator.setInvalidType(true);
742    break;
743  case DeclSpec::TST_class:
744  case DeclSpec::TST_enum:
745  case DeclSpec::TST_union:
746  case DeclSpec::TST_struct: {
747    TypeDecl *D = dyn_cast_or_null<TypeDecl>(DS.getRepAsDecl());
748    if (!D) {
749      // This can happen in C++ with ambiguous lookups.
750      Result = Context.IntTy;
751      declarator.setInvalidType(true);
752      break;
753    }
754
755    // If the type is deprecated or unavailable, diagnose it.
756    S.DiagnoseUseOfDecl(D, DS.getTypeSpecTypeNameLoc());
757
758    assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
759           DS.getTypeSpecSign() == 0 && "No qualifiers on tag names!");
760
761    // TypeQuals handled by caller.
762    Result = Context.getTypeDeclType(D);
763
764    // In both C and C++, make an ElaboratedType.
765    ElaboratedTypeKeyword Keyword
766      = ElaboratedType::getKeywordForTypeSpec(DS.getTypeSpecType());
767    Result = S.getElaboratedType(Keyword, DS.getTypeSpecScope(), Result);
768
769    if (D->isInvalidDecl())
770      declarator.setInvalidType(true);
771    break;
772  }
773  case DeclSpec::TST_typename: {
774    assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
775           DS.getTypeSpecSign() == 0 &&
776           "Can't handle qualifiers on typedef names yet!");
777    Result = S.GetTypeFromParser(DS.getRepAsType());
778    if (Result.isNull())
779      declarator.setInvalidType(true);
780    else if (DeclSpec::ProtocolQualifierListTy PQ
781               = DS.getProtocolQualifiers()) {
782      if (const ObjCObjectType *ObjT = Result->getAs<ObjCObjectType>()) {
783        // Silently drop any existing protocol qualifiers.
784        // TODO: determine whether that's the right thing to do.
785        if (ObjT->getNumProtocols())
786          Result = ObjT->getBaseType();
787
788        if (DS.getNumProtocolQualifiers())
789          Result = Context.getObjCObjectType(Result,
790                                             (ObjCProtocolDecl**) PQ,
791                                             DS.getNumProtocolQualifiers());
792      } else if (Result->isObjCIdType()) {
793        // id<protocol-list>
794        Result = Context.getObjCObjectType(Context.ObjCBuiltinIdTy,
795                                           (ObjCProtocolDecl**) PQ,
796                                           DS.getNumProtocolQualifiers());
797        Result = Context.getObjCObjectPointerType(Result);
798      } else if (Result->isObjCClassType()) {
799        // Class<protocol-list>
800        Result = Context.getObjCObjectType(Context.ObjCBuiltinClassTy,
801                                           (ObjCProtocolDecl**) PQ,
802                                           DS.getNumProtocolQualifiers());
803        Result = Context.getObjCObjectPointerType(Result);
804      } else {
805        S.Diag(DeclLoc, diag::err_invalid_protocol_qualifiers)
806          << DS.getSourceRange();
807        declarator.setInvalidType(true);
808      }
809    }
810
811    // TypeQuals handled by caller.
812    break;
813  }
814  case DeclSpec::TST_typeofType:
815    // FIXME: Preserve type source info.
816    Result = S.GetTypeFromParser(DS.getRepAsType());
817    assert(!Result.isNull() && "Didn't get a type for typeof?");
818    if (!Result->isDependentType())
819      if (const TagType *TT = Result->getAs<TagType>())
820        S.DiagnoseUseOfDecl(TT->getDecl(), DS.getTypeSpecTypeLoc());
821    // TypeQuals handled by caller.
822    Result = Context.getTypeOfType(Result);
823    break;
824  case DeclSpec::TST_typeofExpr: {
825    Expr *E = DS.getRepAsExpr();
826    assert(E && "Didn't get an expression for typeof?");
827    // TypeQuals handled by caller.
828    Result = S.BuildTypeofExprType(E, DS.getTypeSpecTypeLoc());
829    if (Result.isNull()) {
830      Result = Context.IntTy;
831      declarator.setInvalidType(true);
832    }
833    break;
834  }
835  case DeclSpec::TST_decltype: {
836    Expr *E = DS.getRepAsExpr();
837    assert(E && "Didn't get an expression for decltype?");
838    // TypeQuals handled by caller.
839    Result = S.BuildDecltypeType(E, DS.getTypeSpecTypeLoc());
840    if (Result.isNull()) {
841      Result = Context.IntTy;
842      declarator.setInvalidType(true);
843    }
844    break;
845  }
846  case DeclSpec::TST_underlyingType:
847    Result = S.GetTypeFromParser(DS.getRepAsType());
848    assert(!Result.isNull() && "Didn't get a type for __underlying_type?");
849    Result = S.BuildUnaryTransformType(Result,
850                                       UnaryTransformType::EnumUnderlyingType,
851                                       DS.getTypeSpecTypeLoc());
852    if (Result.isNull()) {
853      Result = Context.IntTy;
854      declarator.setInvalidType(true);
855    }
856    break;
857
858  case DeclSpec::TST_auto: {
859    // TypeQuals handled by caller.
860    Result = Context.getAutoType(QualType());
861    break;
862  }
863
864  case DeclSpec::TST_unknown_anytype:
865    Result = Context.UnknownAnyTy;
866    break;
867
868  case DeclSpec::TST_atomic:
869    Result = S.GetTypeFromParser(DS.getRepAsType());
870    assert(!Result.isNull() && "Didn't get a type for _Atomic?");
871    Result = S.BuildAtomicType(Result, DS.getTypeSpecTypeLoc());
872    if (Result.isNull()) {
873      Result = Context.IntTy;
874      declarator.setInvalidType(true);
875    }
876    break;
877
878  case DeclSpec::TST_error:
879    Result = Context.IntTy;
880    declarator.setInvalidType(true);
881    break;
882  }
883
884  // Handle complex types.
885  if (DS.getTypeSpecComplex() == DeclSpec::TSC_complex) {
886    if (S.getLangOptions().Freestanding)
887      S.Diag(DS.getTypeSpecComplexLoc(), diag::ext_freestanding_complex);
888    Result = Context.getComplexType(Result);
889  } else if (DS.isTypeAltiVecVector()) {
890    unsigned typeSize = static_cast<unsigned>(Context.getTypeSize(Result));
891    assert(typeSize > 0 && "type size for vector must be greater than 0 bits");
892    VectorType::VectorKind VecKind = VectorType::AltiVecVector;
893    if (DS.isTypeAltiVecPixel())
894      VecKind = VectorType::AltiVecPixel;
895    else if (DS.isTypeAltiVecBool())
896      VecKind = VectorType::AltiVecBool;
897    Result = Context.getVectorType(Result, 128/typeSize, VecKind);
898  }
899
900  // FIXME: Imaginary.
901  if (DS.getTypeSpecComplex() == DeclSpec::TSC_imaginary)
902    S.Diag(DS.getTypeSpecComplexLoc(), diag::err_imaginary_not_supported);
903
904  // Before we process any type attributes, synthesize a block literal
905  // function declarator if necessary.
906  if (declarator.getContext() == Declarator::BlockLiteralContext)
907    maybeSynthesizeBlockSignature(state, Result);
908
909  // Apply any type attributes from the decl spec.  This may cause the
910  // list of type attributes to be temporarily saved while the type
911  // attributes are pushed around.
912  if (AttributeList *attrs = DS.getAttributes().getList())
913    processTypeAttrs(state, Result, true, attrs);
914
915  // Apply const/volatile/restrict qualifiers to T.
916  if (unsigned TypeQuals = DS.getTypeQualifiers()) {
917
918    // Enforce C99 6.7.3p2: "Types other than pointer types derived from object
919    // or incomplete types shall not be restrict-qualified."  C++ also allows
920    // restrict-qualified references.
921    if (TypeQuals & DeclSpec::TQ_restrict) {
922      if (Result->isAnyPointerType() || Result->isReferenceType()) {
923        QualType EltTy;
924        if (Result->isObjCObjectPointerType())
925          EltTy = Result;
926        else
927          EltTy = Result->isPointerType() ?
928                    Result->getAs<PointerType>()->getPointeeType() :
929                    Result->getAs<ReferenceType>()->getPointeeType();
930
931        // If we have a pointer or reference, the pointee must have an object
932        // incomplete type.
933        if (!EltTy->isIncompleteOrObjectType()) {
934          S.Diag(DS.getRestrictSpecLoc(),
935               diag::err_typecheck_invalid_restrict_invalid_pointee)
936            << EltTy << DS.getSourceRange();
937          TypeQuals &= ~DeclSpec::TQ_restrict; // Remove the restrict qualifier.
938        }
939      } else {
940        S.Diag(DS.getRestrictSpecLoc(),
941               diag::err_typecheck_invalid_restrict_not_pointer)
942          << Result << DS.getSourceRange();
943        TypeQuals &= ~DeclSpec::TQ_restrict; // Remove the restrict qualifier.
944      }
945    }
946
947    // Warn about CV qualifiers on functions: C99 6.7.3p8: "If the specification
948    // of a function type includes any type qualifiers, the behavior is
949    // undefined."
950    if (Result->isFunctionType() && TypeQuals) {
951      // Get some location to point at, either the C or V location.
952      SourceLocation Loc;
953      if (TypeQuals & DeclSpec::TQ_const)
954        Loc = DS.getConstSpecLoc();
955      else if (TypeQuals & DeclSpec::TQ_volatile)
956        Loc = DS.getVolatileSpecLoc();
957      else {
958        assert((TypeQuals & DeclSpec::TQ_restrict) &&
959               "Has CVR quals but not C, V, or R?");
960        Loc = DS.getRestrictSpecLoc();
961      }
962      S.Diag(Loc, diag::warn_typecheck_function_qualifiers)
963        << Result << DS.getSourceRange();
964    }
965
966    // C++ [dcl.ref]p1:
967    //   Cv-qualified references are ill-formed except when the
968    //   cv-qualifiers are introduced through the use of a typedef
969    //   (7.1.3) or of a template type argument (14.3), in which
970    //   case the cv-qualifiers are ignored.
971    // FIXME: Shouldn't we be checking SCS_typedef here?
972    if (DS.getTypeSpecType() == DeclSpec::TST_typename &&
973        TypeQuals && Result->isReferenceType()) {
974      TypeQuals &= ~DeclSpec::TQ_const;
975      TypeQuals &= ~DeclSpec::TQ_volatile;
976    }
977
978    Qualifiers Quals = Qualifiers::fromCVRMask(TypeQuals);
979    Result = Context.getQualifiedType(Result, Quals);
980  }
981
982  return Result;
983}
984
985static std::string getPrintableNameForEntity(DeclarationName Entity) {
986  if (Entity)
987    return Entity.getAsString();
988
989  return "type name";
990}
991
992QualType Sema::BuildQualifiedType(QualType T, SourceLocation Loc,
993                                  Qualifiers Qs) {
994  // Enforce C99 6.7.3p2: "Types other than pointer types derived from
995  // object or incomplete types shall not be restrict-qualified."
996  if (Qs.hasRestrict()) {
997    unsigned DiagID = 0;
998    QualType ProblemTy;
999
1000    const Type *Ty = T->getCanonicalTypeInternal().getTypePtr();
1001    if (const ReferenceType *RTy = dyn_cast<ReferenceType>(Ty)) {
1002      if (!RTy->getPointeeType()->isIncompleteOrObjectType()) {
1003        DiagID = diag::err_typecheck_invalid_restrict_invalid_pointee;
1004        ProblemTy = T->getAs<ReferenceType>()->getPointeeType();
1005      }
1006    } else if (const PointerType *PTy = dyn_cast<PointerType>(Ty)) {
1007      if (!PTy->getPointeeType()->isIncompleteOrObjectType()) {
1008        DiagID = diag::err_typecheck_invalid_restrict_invalid_pointee;
1009        ProblemTy = T->getAs<PointerType>()->getPointeeType();
1010      }
1011    } else if (const MemberPointerType *PTy = dyn_cast<MemberPointerType>(Ty)) {
1012      if (!PTy->getPointeeType()->isIncompleteOrObjectType()) {
1013        DiagID = diag::err_typecheck_invalid_restrict_invalid_pointee;
1014        ProblemTy = T->getAs<PointerType>()->getPointeeType();
1015      }
1016    } else if (!Ty->isDependentType()) {
1017      // FIXME: this deserves a proper diagnostic
1018      DiagID = diag::err_typecheck_invalid_restrict_invalid_pointee;
1019      ProblemTy = T;
1020    }
1021
1022    if (DiagID) {
1023      Diag(Loc, DiagID) << ProblemTy;
1024      Qs.removeRestrict();
1025    }
1026  }
1027
1028  return Context.getQualifiedType(T, Qs);
1029}
1030
1031/// \brief Build a paren type including \p T.
1032QualType Sema::BuildParenType(QualType T) {
1033  return Context.getParenType(T);
1034}
1035
1036/// Given that we're building a pointer or reference to the given
1037static QualType inferARCLifetimeForPointee(Sema &S, QualType type,
1038                                           SourceLocation loc,
1039                                           bool isReference) {
1040  // Bail out if retention is unrequired or already specified.
1041  if (!type->isObjCLifetimeType() ||
1042      type.getObjCLifetime() != Qualifiers::OCL_None)
1043    return type;
1044
1045  Qualifiers::ObjCLifetime implicitLifetime = Qualifiers::OCL_None;
1046
1047  // If the object type is const-qualified, we can safely use
1048  // __unsafe_unretained.  This is safe (because there are no read
1049  // barriers), and it'll be safe to coerce anything but __weak* to
1050  // the resulting type.
1051  if (type.isConstQualified()) {
1052    implicitLifetime = Qualifiers::OCL_ExplicitNone;
1053
1054  // Otherwise, check whether the static type does not require
1055  // retaining.  This currently only triggers for Class (possibly
1056  // protocol-qualifed, and arrays thereof).
1057  } else if (type->isObjCARCImplicitlyUnretainedType()) {
1058    implicitLifetime = Qualifiers::OCL_ExplicitNone;
1059
1060  // If we are in an unevaluated context, like sizeof, skip adding a
1061  // qualification.
1062  } else if (S.ExprEvalContexts.back().Context == Sema::Unevaluated) {
1063    return type;
1064
1065  // If that failed, give an error and recover using __strong.  __strong
1066  // is the option most likely to prevent spurious second-order diagnostics,
1067  // like when binding a reference to a field.
1068  } else {
1069    // These types can show up in private ivars in system headers, so
1070    // we need this to not be an error in those cases.  Instead we
1071    // want to delay.
1072    if (S.DelayedDiagnostics.shouldDelayDiagnostics()) {
1073      S.DelayedDiagnostics.add(
1074          sema::DelayedDiagnostic::makeForbiddenType(loc,
1075              diag::err_arc_indirect_no_ownership, type, isReference));
1076    } else {
1077      S.Diag(loc, diag::err_arc_indirect_no_ownership) << type << isReference;
1078    }
1079    implicitLifetime = Qualifiers::OCL_Strong;
1080  }
1081  assert(implicitLifetime && "didn't infer any lifetime!");
1082
1083  Qualifiers qs;
1084  qs.addObjCLifetime(implicitLifetime);
1085  return S.Context.getQualifiedType(type, qs);
1086}
1087
1088/// \brief Build a pointer type.
1089///
1090/// \param T The type to which we'll be building a pointer.
1091///
1092/// \param Loc The location of the entity whose type involves this
1093/// pointer type or, if there is no such entity, the location of the
1094/// type that will have pointer type.
1095///
1096/// \param Entity The name of the entity that involves the pointer
1097/// type, if known.
1098///
1099/// \returns A suitable pointer type, if there are no
1100/// errors. Otherwise, returns a NULL type.
1101QualType Sema::BuildPointerType(QualType T,
1102                                SourceLocation Loc, DeclarationName Entity) {
1103  if (T->isReferenceType()) {
1104    // C++ 8.3.2p4: There shall be no ... pointers to references ...
1105    Diag(Loc, diag::err_illegal_decl_pointer_to_reference)
1106      << getPrintableNameForEntity(Entity) << T;
1107    return QualType();
1108  }
1109
1110  assert(!T->isObjCObjectType() && "Should build ObjCObjectPointerType");
1111
1112  // In ARC, it is forbidden to build pointers to unqualified pointers.
1113  if (getLangOptions().ObjCAutoRefCount)
1114    T = inferARCLifetimeForPointee(*this, T, Loc, /*reference*/ false);
1115
1116  // Build the pointer type.
1117  return Context.getPointerType(T);
1118}
1119
1120/// \brief Build a reference type.
1121///
1122/// \param T The type to which we'll be building a reference.
1123///
1124/// \param Loc The location of the entity whose type involves this
1125/// reference type or, if there is no such entity, the location of the
1126/// type that will have reference type.
1127///
1128/// \param Entity The name of the entity that involves the reference
1129/// type, if known.
1130///
1131/// \returns A suitable reference type, if there are no
1132/// errors. Otherwise, returns a NULL type.
1133QualType Sema::BuildReferenceType(QualType T, bool SpelledAsLValue,
1134                                  SourceLocation Loc,
1135                                  DeclarationName Entity) {
1136  assert(Context.getCanonicalType(T) != Context.OverloadTy &&
1137         "Unresolved overloaded function type");
1138
1139  // C++0x [dcl.ref]p6:
1140  //   If a typedef (7.1.3), a type template-parameter (14.3.1), or a
1141  //   decltype-specifier (7.1.6.2) denotes a type TR that is a reference to a
1142  //   type T, an attempt to create the type "lvalue reference to cv TR" creates
1143  //   the type "lvalue reference to T", while an attempt to create the type
1144  //   "rvalue reference to cv TR" creates the type TR.
1145  bool LValueRef = SpelledAsLValue || T->getAs<LValueReferenceType>();
1146
1147  // C++ [dcl.ref]p4: There shall be no references to references.
1148  //
1149  // According to C++ DR 106, references to references are only
1150  // diagnosed when they are written directly (e.g., "int & &"),
1151  // but not when they happen via a typedef:
1152  //
1153  //   typedef int& intref;
1154  //   typedef intref& intref2;
1155  //
1156  // Parser::ParseDeclaratorInternal diagnoses the case where
1157  // references are written directly; here, we handle the
1158  // collapsing of references-to-references as described in C++0x.
1159  // DR 106 and 540 introduce reference-collapsing into C++98/03.
1160
1161  // C++ [dcl.ref]p1:
1162  //   A declarator that specifies the type "reference to cv void"
1163  //   is ill-formed.
1164  if (T->isVoidType()) {
1165    Diag(Loc, diag::err_reference_to_void);
1166    return QualType();
1167  }
1168
1169  // In ARC, it is forbidden to build references to unqualified pointers.
1170  if (getLangOptions().ObjCAutoRefCount)
1171    T = inferARCLifetimeForPointee(*this, T, Loc, /*reference*/ true);
1172
1173  // Handle restrict on references.
1174  if (LValueRef)
1175    return Context.getLValueReferenceType(T, SpelledAsLValue);
1176  return Context.getRValueReferenceType(T);
1177}
1178
1179/// Check whether the specified array size makes the array type a VLA.  If so,
1180/// return true, if not, return the size of the array in SizeVal.
1181static bool isArraySizeVLA(Sema &S, Expr *ArraySize, llvm::APSInt &SizeVal) {
1182  // If the size is an ICE, it certainly isn't a VLA. If we're in a GNU mode
1183  // (like gnu99, but not c99) accept any evaluatable value as an extension.
1184  return S.VerifyIntegerConstantExpression(
1185      ArraySize, &SizeVal, S.PDiag(), S.LangOpts.GNUMode,
1186      S.PDiag(diag::ext_vla_folded_to_constant)).isInvalid();
1187}
1188
1189
1190/// \brief Build an array type.
1191///
1192/// \param T The type of each element in the array.
1193///
1194/// \param ASM C99 array size modifier (e.g., '*', 'static').
1195///
1196/// \param ArraySize Expression describing the size of the array.
1197///
1198/// \param Loc The location of the entity whose type involves this
1199/// array type or, if there is no such entity, the location of the
1200/// type that will have array type.
1201///
1202/// \param Entity The name of the entity that involves the array
1203/// type, if known.
1204///
1205/// \returns A suitable array type, if there are no errors. Otherwise,
1206/// returns a NULL type.
1207QualType Sema::BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
1208                              Expr *ArraySize, unsigned Quals,
1209                              SourceRange Brackets, DeclarationName Entity) {
1210
1211  SourceLocation Loc = Brackets.getBegin();
1212  if (getLangOptions().CPlusPlus) {
1213    // C++ [dcl.array]p1:
1214    //   T is called the array element type; this type shall not be a reference
1215    //   type, the (possibly cv-qualified) type void, a function type or an
1216    //   abstract class type.
1217    //
1218    // Note: function types are handled in the common path with C.
1219    if (T->isReferenceType()) {
1220      Diag(Loc, diag::err_illegal_decl_array_of_references)
1221      << getPrintableNameForEntity(Entity) << T;
1222      return QualType();
1223    }
1224
1225    if (T->isVoidType()) {
1226      Diag(Loc, diag::err_illegal_decl_array_incomplete_type) << T;
1227      return QualType();
1228    }
1229
1230    if (RequireNonAbstractType(Brackets.getBegin(), T,
1231                               diag::err_array_of_abstract_type))
1232      return QualType();
1233
1234  } else {
1235    // C99 6.7.5.2p1: If the element type is an incomplete or function type,
1236    // reject it (e.g. void ary[7], struct foo ary[7], void ary[7]())
1237    if (RequireCompleteType(Loc, T,
1238                            diag::err_illegal_decl_array_incomplete_type))
1239      return QualType();
1240  }
1241
1242  if (T->isFunctionType()) {
1243    Diag(Loc, diag::err_illegal_decl_array_of_functions)
1244      << getPrintableNameForEntity(Entity) << T;
1245    return QualType();
1246  }
1247
1248  if (T->getContainedAutoType()) {
1249    Diag(Loc, diag::err_illegal_decl_array_of_auto)
1250      << getPrintableNameForEntity(Entity) << T;
1251    return QualType();
1252  }
1253
1254  if (const RecordType *EltTy = T->getAs<RecordType>()) {
1255    // If the element type is a struct or union that contains a variadic
1256    // array, accept it as a GNU extension: C99 6.7.2.1p2.
1257    if (EltTy->getDecl()->hasFlexibleArrayMember())
1258      Diag(Loc, diag::ext_flexible_array_in_array) << T;
1259  } else if (T->isObjCObjectType()) {
1260    Diag(Loc, diag::err_objc_array_of_interfaces) << T;
1261    return QualType();
1262  }
1263
1264  // Do placeholder conversions on the array size expression.
1265  if (ArraySize && ArraySize->hasPlaceholderType()) {
1266    ExprResult Result = CheckPlaceholderExpr(ArraySize);
1267    if (Result.isInvalid()) return QualType();
1268    ArraySize = Result.take();
1269  }
1270
1271  // Do lvalue-to-rvalue conversions on the array size expression.
1272  if (ArraySize && !ArraySize->isRValue()) {
1273    ExprResult Result = DefaultLvalueConversion(ArraySize);
1274    if (Result.isInvalid())
1275      return QualType();
1276
1277    ArraySize = Result.take();
1278  }
1279
1280  // C99 6.7.5.2p1: The size expression shall have integer type.
1281  // C++11 allows contextual conversions to such types.
1282  if (!getLangOptions().CPlusPlus0x &&
1283      ArraySize && !ArraySize->isTypeDependent() &&
1284      !ArraySize->getType()->isIntegralOrUnscopedEnumerationType()) {
1285    Diag(ArraySize->getLocStart(), diag::err_array_size_non_int)
1286      << ArraySize->getType() << ArraySize->getSourceRange();
1287    return QualType();
1288  }
1289
1290  llvm::APSInt ConstVal(Context.getTypeSize(Context.getSizeType()));
1291  if (!ArraySize) {
1292    if (ASM == ArrayType::Star)
1293      T = Context.getVariableArrayType(T, 0, ASM, Quals, Brackets);
1294    else
1295      T = Context.getIncompleteArrayType(T, ASM, Quals);
1296  } else if (ArraySize->isTypeDependent() || ArraySize->isValueDependent()) {
1297    T = Context.getDependentSizedArrayType(T, ArraySize, ASM, Quals, Brackets);
1298  } else if ((!T->isDependentType() && !T->isIncompleteType() &&
1299              !T->isConstantSizeType()) ||
1300             isArraySizeVLA(*this, ArraySize, ConstVal)) {
1301    // Even in C++11, don't allow contextual conversions in the array bound
1302    // of a VLA.
1303    if (getLangOptions().CPlusPlus0x &&
1304        !ArraySize->getType()->isIntegralOrUnscopedEnumerationType()) {
1305      Diag(ArraySize->getLocStart(), diag::err_array_size_non_int)
1306        << ArraySize->getType() << ArraySize->getSourceRange();
1307      return QualType();
1308    }
1309
1310    // C99: an array with an element type that has a non-constant-size is a VLA.
1311    // C99: an array with a non-ICE size is a VLA.  We accept any expression
1312    // that we can fold to a non-zero positive value as an extension.
1313    T = Context.getVariableArrayType(T, ArraySize, ASM, Quals, Brackets);
1314  } else {
1315    // C99 6.7.5.2p1: If the expression is a constant expression, it shall
1316    // have a value greater than zero.
1317    if (ConstVal.isSigned() && ConstVal.isNegative()) {
1318      if (Entity)
1319        Diag(ArraySize->getLocStart(), diag::err_decl_negative_array_size)
1320          << getPrintableNameForEntity(Entity) << ArraySize->getSourceRange();
1321      else
1322        Diag(ArraySize->getLocStart(), diag::err_typecheck_negative_array_size)
1323          << ArraySize->getSourceRange();
1324      return QualType();
1325    }
1326    if (ConstVal == 0) {
1327      // GCC accepts zero sized static arrays. We allow them when
1328      // we're not in a SFINAE context.
1329      Diag(ArraySize->getLocStart(),
1330           isSFINAEContext()? diag::err_typecheck_zero_array_size
1331                            : diag::ext_typecheck_zero_array_size)
1332        << ArraySize->getSourceRange();
1333
1334      if (ASM == ArrayType::Static) {
1335        Diag(ArraySize->getLocStart(),
1336             diag::warn_typecheck_zero_static_array_size)
1337          << ArraySize->getSourceRange();
1338        ASM = ArrayType::Normal;
1339      }
1340    } else if (!T->isDependentType() && !T->isVariablyModifiedType() &&
1341               !T->isIncompleteType()) {
1342      // Is the array too large?
1343      unsigned ActiveSizeBits
1344        = ConstantArrayType::getNumAddressingBits(Context, T, ConstVal);
1345      if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context))
1346        Diag(ArraySize->getLocStart(), diag::err_array_too_large)
1347          << ConstVal.toString(10)
1348          << ArraySize->getSourceRange();
1349    }
1350
1351    T = Context.getConstantArrayType(T, ConstVal, ASM, Quals);
1352  }
1353  // If this is not C99, extwarn about VLA's and C99 array size modifiers.
1354  if (!getLangOptions().C99) {
1355    if (T->isVariableArrayType()) {
1356      // Prohibit the use of non-POD types in VLAs.
1357      QualType BaseT = Context.getBaseElementType(T);
1358      if (!T->isDependentType() &&
1359          !BaseT.isPODType(Context) &&
1360          !BaseT->isObjCLifetimeType()) {
1361        Diag(Loc, diag::err_vla_non_pod)
1362          << BaseT;
1363        return QualType();
1364      }
1365      // Prohibit the use of VLAs during template argument deduction.
1366      else if (isSFINAEContext()) {
1367        Diag(Loc, diag::err_vla_in_sfinae);
1368        return QualType();
1369      }
1370      // Just extwarn about VLAs.
1371      else
1372        Diag(Loc, diag::ext_vla);
1373    } else if (ASM != ArrayType::Normal || Quals != 0)
1374      Diag(Loc,
1375           getLangOptions().CPlusPlus? diag::err_c99_array_usage_cxx
1376                                     : diag::ext_c99_array_usage) << ASM;
1377  }
1378
1379  return T;
1380}
1381
1382/// \brief Build an ext-vector type.
1383///
1384/// Run the required checks for the extended vector type.
1385QualType Sema::BuildExtVectorType(QualType T, Expr *ArraySize,
1386                                  SourceLocation AttrLoc) {
1387  // unlike gcc's vector_size attribute, we do not allow vectors to be defined
1388  // in conjunction with complex types (pointers, arrays, functions, etc.).
1389  if (!T->isDependentType() &&
1390      !T->isIntegerType() && !T->isRealFloatingType()) {
1391    Diag(AttrLoc, diag::err_attribute_invalid_vector_type) << T;
1392    return QualType();
1393  }
1394
1395  if (!ArraySize->isTypeDependent() && !ArraySize->isValueDependent()) {
1396    llvm::APSInt vecSize(32);
1397    if (!ArraySize->isIntegerConstantExpr(vecSize, Context)) {
1398      Diag(AttrLoc, diag::err_attribute_argument_not_int)
1399        << "ext_vector_type" << ArraySize->getSourceRange();
1400      return QualType();
1401    }
1402
1403    // unlike gcc's vector_size attribute, the size is specified as the
1404    // number of elements, not the number of bytes.
1405    unsigned vectorSize = static_cast<unsigned>(vecSize.getZExtValue());
1406
1407    if (vectorSize == 0) {
1408      Diag(AttrLoc, diag::err_attribute_zero_size)
1409      << ArraySize->getSourceRange();
1410      return QualType();
1411    }
1412
1413    return Context.getExtVectorType(T, vectorSize);
1414  }
1415
1416  return Context.getDependentSizedExtVectorType(T, ArraySize, AttrLoc);
1417}
1418
1419/// \brief Build a function type.
1420///
1421/// This routine checks the function type according to C++ rules and
1422/// under the assumption that the result type and parameter types have
1423/// just been instantiated from a template. It therefore duplicates
1424/// some of the behavior of GetTypeForDeclarator, but in a much
1425/// simpler form that is only suitable for this narrow use case.
1426///
1427/// \param T The return type of the function.
1428///
1429/// \param ParamTypes The parameter types of the function. This array
1430/// will be modified to account for adjustments to the types of the
1431/// function parameters.
1432///
1433/// \param NumParamTypes The number of parameter types in ParamTypes.
1434///
1435/// \param Variadic Whether this is a variadic function type.
1436///
1437/// \param Quals The cvr-qualifiers to be applied to the function type.
1438///
1439/// \param Loc The location of the entity whose type involves this
1440/// function type or, if there is no such entity, the location of the
1441/// type that will have function type.
1442///
1443/// \param Entity The name of the entity that involves the function
1444/// type, if known.
1445///
1446/// \returns A suitable function type, if there are no
1447/// errors. Otherwise, returns a NULL type.
1448QualType Sema::BuildFunctionType(QualType T,
1449                                 QualType *ParamTypes,
1450                                 unsigned NumParamTypes,
1451                                 bool Variadic, unsigned Quals,
1452                                 RefQualifierKind RefQualifier,
1453                                 SourceLocation Loc, DeclarationName Entity,
1454                                 FunctionType::ExtInfo Info) {
1455  if (T->isArrayType() || T->isFunctionType()) {
1456    Diag(Loc, diag::err_func_returning_array_function)
1457      << T->isFunctionType() << T;
1458    return QualType();
1459  }
1460
1461  // Functions cannot return half FP.
1462  if (T->isHalfType()) {
1463    Diag(Loc, diag::err_parameters_retval_cannot_have_fp16_type) << 1 <<
1464      FixItHint::CreateInsertion(Loc, "*");
1465    return QualType();
1466  }
1467
1468  bool Invalid = false;
1469  for (unsigned Idx = 0; Idx < NumParamTypes; ++Idx) {
1470    // FIXME: Loc is too inprecise here, should use proper locations for args.
1471    QualType ParamType = Context.getAdjustedParameterType(ParamTypes[Idx]);
1472    if (ParamType->isVoidType()) {
1473      Diag(Loc, diag::err_param_with_void_type);
1474      Invalid = true;
1475    } else if (ParamType->isHalfType()) {
1476      // Disallow half FP arguments.
1477      Diag(Loc, diag::err_parameters_retval_cannot_have_fp16_type) << 0 <<
1478        FixItHint::CreateInsertion(Loc, "*");
1479      Invalid = true;
1480    }
1481
1482    ParamTypes[Idx] = ParamType;
1483  }
1484
1485  if (Invalid)
1486    return QualType();
1487
1488  FunctionProtoType::ExtProtoInfo EPI;
1489  EPI.Variadic = Variadic;
1490  EPI.TypeQuals = Quals;
1491  EPI.RefQualifier = RefQualifier;
1492  EPI.ExtInfo = Info;
1493
1494  return Context.getFunctionType(T, ParamTypes, NumParamTypes, EPI);
1495}
1496
1497/// \brief Build a member pointer type \c T Class::*.
1498///
1499/// \param T the type to which the member pointer refers.
1500/// \param Class the class type into which the member pointer points.
1501/// \param CVR Qualifiers applied to the member pointer type
1502/// \param Loc the location where this type begins
1503/// \param Entity the name of the entity that will have this member pointer type
1504///
1505/// \returns a member pointer type, if successful, or a NULL type if there was
1506/// an error.
1507QualType Sema::BuildMemberPointerType(QualType T, QualType Class,
1508                                      SourceLocation Loc,
1509                                      DeclarationName Entity) {
1510  // Verify that we're not building a pointer to pointer to function with
1511  // exception specification.
1512  if (CheckDistantExceptionSpec(T)) {
1513    Diag(Loc, diag::err_distant_exception_spec);
1514
1515    // FIXME: If we're doing this as part of template instantiation,
1516    // we should return immediately.
1517
1518    // Build the type anyway, but use the canonical type so that the
1519    // exception specifiers are stripped off.
1520    T = Context.getCanonicalType(T);
1521  }
1522
1523  // C++ 8.3.3p3: A pointer to member shall not point to ... a member
1524  //   with reference type, or "cv void."
1525  if (T->isReferenceType()) {
1526    Diag(Loc, diag::err_illegal_decl_mempointer_to_reference)
1527      << (Entity? Entity.getAsString() : "type name") << T;
1528    return QualType();
1529  }
1530
1531  if (T->isVoidType()) {
1532    Diag(Loc, diag::err_illegal_decl_mempointer_to_void)
1533      << (Entity? Entity.getAsString() : "type name");
1534    return QualType();
1535  }
1536
1537  if (!Class->isDependentType() && !Class->isRecordType()) {
1538    Diag(Loc, diag::err_mempointer_in_nonclass_type) << Class;
1539    return QualType();
1540  }
1541
1542  // In the Microsoft ABI, the class is allowed to be an incomplete
1543  // type. In such cases, the compiler makes a worst-case assumption.
1544  // We make no such assumption right now, so emit an error if the
1545  // class isn't a complete type.
1546  if (Context.getTargetInfo().getCXXABI() == CXXABI_Microsoft &&
1547      RequireCompleteType(Loc, Class, diag::err_incomplete_type))
1548    return QualType();
1549
1550  return Context.getMemberPointerType(T, Class.getTypePtr());
1551}
1552
1553/// \brief Build a block pointer type.
1554///
1555/// \param T The type to which we'll be building a block pointer.
1556///
1557/// \param CVR The cvr-qualifiers to be applied to the block pointer type.
1558///
1559/// \param Loc The location of the entity whose type involves this
1560/// block pointer type or, if there is no such entity, the location of the
1561/// type that will have block pointer type.
1562///
1563/// \param Entity The name of the entity that involves the block pointer
1564/// type, if known.
1565///
1566/// \returns A suitable block pointer type, if there are no
1567/// errors. Otherwise, returns a NULL type.
1568QualType Sema::BuildBlockPointerType(QualType T,
1569                                     SourceLocation Loc,
1570                                     DeclarationName Entity) {
1571  if (!T->isFunctionType()) {
1572    Diag(Loc, diag::err_nonfunction_block_type);
1573    return QualType();
1574  }
1575
1576  return Context.getBlockPointerType(T);
1577}
1578
1579QualType Sema::GetTypeFromParser(ParsedType Ty, TypeSourceInfo **TInfo) {
1580  QualType QT = Ty.get();
1581  if (QT.isNull()) {
1582    if (TInfo) *TInfo = 0;
1583    return QualType();
1584  }
1585
1586  TypeSourceInfo *DI = 0;
1587  if (const LocInfoType *LIT = dyn_cast<LocInfoType>(QT)) {
1588    QT = LIT->getType();
1589    DI = LIT->getTypeSourceInfo();
1590  }
1591
1592  if (TInfo) *TInfo = DI;
1593  return QT;
1594}
1595
1596static void transferARCOwnershipToDeclaratorChunk(TypeProcessingState &state,
1597                                            Qualifiers::ObjCLifetime ownership,
1598                                            unsigned chunkIndex);
1599
1600/// Given that this is the declaration of a parameter under ARC,
1601/// attempt to infer attributes and such for pointer-to-whatever
1602/// types.
1603static void inferARCWriteback(TypeProcessingState &state,
1604                              QualType &declSpecType) {
1605  Sema &S = state.getSema();
1606  Declarator &declarator = state.getDeclarator();
1607
1608  // TODO: should we care about decl qualifiers?
1609
1610  // Check whether the declarator has the expected form.  We walk
1611  // from the inside out in order to make the block logic work.
1612  unsigned outermostPointerIndex = 0;
1613  bool isBlockPointer = false;
1614  unsigned numPointers = 0;
1615  for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
1616    unsigned chunkIndex = i;
1617    DeclaratorChunk &chunk = declarator.getTypeObject(chunkIndex);
1618    switch (chunk.Kind) {
1619    case DeclaratorChunk::Paren:
1620      // Ignore parens.
1621      break;
1622
1623    case DeclaratorChunk::Reference:
1624    case DeclaratorChunk::Pointer:
1625      // Count the number of pointers.  Treat references
1626      // interchangeably as pointers; if they're mis-ordered, normal
1627      // type building will discover that.
1628      outermostPointerIndex = chunkIndex;
1629      numPointers++;
1630      break;
1631
1632    case DeclaratorChunk::BlockPointer:
1633      // If we have a pointer to block pointer, that's an acceptable
1634      // indirect reference; anything else is not an application of
1635      // the rules.
1636      if (numPointers != 1) return;
1637      numPointers++;
1638      outermostPointerIndex = chunkIndex;
1639      isBlockPointer = true;
1640
1641      // We don't care about pointer structure in return values here.
1642      goto done;
1643
1644    case DeclaratorChunk::Array: // suppress if written (id[])?
1645    case DeclaratorChunk::Function:
1646    case DeclaratorChunk::MemberPointer:
1647      return;
1648    }
1649  }
1650 done:
1651
1652  // If we have *one* pointer, then we want to throw the qualifier on
1653  // the declaration-specifiers, which means that it needs to be a
1654  // retainable object type.
1655  if (numPointers == 1) {
1656    // If it's not a retainable object type, the rule doesn't apply.
1657    if (!declSpecType->isObjCRetainableType()) return;
1658
1659    // If it already has lifetime, don't do anything.
1660    if (declSpecType.getObjCLifetime()) return;
1661
1662    // Otherwise, modify the type in-place.
1663    Qualifiers qs;
1664
1665    if (declSpecType->isObjCARCImplicitlyUnretainedType())
1666      qs.addObjCLifetime(Qualifiers::OCL_ExplicitNone);
1667    else
1668      qs.addObjCLifetime(Qualifiers::OCL_Autoreleasing);
1669    declSpecType = S.Context.getQualifiedType(declSpecType, qs);
1670
1671  // If we have *two* pointers, then we want to throw the qualifier on
1672  // the outermost pointer.
1673  } else if (numPointers == 2) {
1674    // If we don't have a block pointer, we need to check whether the
1675    // declaration-specifiers gave us something that will turn into a
1676    // retainable object pointer after we slap the first pointer on it.
1677    if (!isBlockPointer && !declSpecType->isObjCObjectType())
1678      return;
1679
1680    // Look for an explicit lifetime attribute there.
1681    DeclaratorChunk &chunk = declarator.getTypeObject(outermostPointerIndex);
1682    if (chunk.Kind != DeclaratorChunk::Pointer &&
1683        chunk.Kind != DeclaratorChunk::BlockPointer)
1684      return;
1685    for (const AttributeList *attr = chunk.getAttrs(); attr;
1686           attr = attr->getNext())
1687      if (attr->getKind() == AttributeList::AT_objc_ownership)
1688        return;
1689
1690    transferARCOwnershipToDeclaratorChunk(state, Qualifiers::OCL_Autoreleasing,
1691                                          outermostPointerIndex);
1692
1693  // Any other number of pointers/references does not trigger the rule.
1694  } else return;
1695
1696  // TODO: mark whether we did this inference?
1697}
1698
1699static void DiagnoseIgnoredQualifiers(unsigned Quals,
1700                                      SourceLocation ConstQualLoc,
1701                                      SourceLocation VolatileQualLoc,
1702                                      SourceLocation RestrictQualLoc,
1703                                      Sema& S) {
1704  std::string QualStr;
1705  unsigned NumQuals = 0;
1706  SourceLocation Loc;
1707
1708  FixItHint ConstFixIt;
1709  FixItHint VolatileFixIt;
1710  FixItHint RestrictFixIt;
1711
1712  const SourceManager &SM = S.getSourceManager();
1713
1714  // FIXME: The locations here are set kind of arbitrarily. It'd be nicer to
1715  // find a range and grow it to encompass all the qualifiers, regardless of
1716  // the order in which they textually appear.
1717  if (Quals & Qualifiers::Const) {
1718    ConstFixIt = FixItHint::CreateRemoval(ConstQualLoc);
1719    QualStr = "const";
1720    ++NumQuals;
1721    if (!Loc.isValid() || SM.isBeforeInTranslationUnit(ConstQualLoc, Loc))
1722      Loc = ConstQualLoc;
1723  }
1724  if (Quals & Qualifiers::Volatile) {
1725    VolatileFixIt = FixItHint::CreateRemoval(VolatileQualLoc);
1726    QualStr += (NumQuals == 0 ? "volatile" : " volatile");
1727    ++NumQuals;
1728    if (!Loc.isValid() || SM.isBeforeInTranslationUnit(VolatileQualLoc, Loc))
1729      Loc = VolatileQualLoc;
1730  }
1731  if (Quals & Qualifiers::Restrict) {
1732    RestrictFixIt = FixItHint::CreateRemoval(RestrictQualLoc);
1733    QualStr += (NumQuals == 0 ? "restrict" : " restrict");
1734    ++NumQuals;
1735    if (!Loc.isValid() || SM.isBeforeInTranslationUnit(RestrictQualLoc, Loc))
1736      Loc = RestrictQualLoc;
1737  }
1738
1739  assert(NumQuals > 0 && "No known qualifiers?");
1740
1741  S.Diag(Loc, diag::warn_qual_return_type)
1742    << QualStr << NumQuals << ConstFixIt << VolatileFixIt << RestrictFixIt;
1743}
1744
1745static QualType GetDeclSpecTypeForDeclarator(TypeProcessingState &state,
1746                                             TypeSourceInfo *&ReturnTypeInfo) {
1747  Sema &SemaRef = state.getSema();
1748  Declarator &D = state.getDeclarator();
1749  QualType T;
1750  ReturnTypeInfo = 0;
1751
1752  // The TagDecl owned by the DeclSpec.
1753  TagDecl *OwnedTagDecl = 0;
1754
1755  switch (D.getName().getKind()) {
1756  case UnqualifiedId::IK_ImplicitSelfParam:
1757  case UnqualifiedId::IK_OperatorFunctionId:
1758  case UnqualifiedId::IK_Identifier:
1759  case UnqualifiedId::IK_LiteralOperatorId:
1760  case UnqualifiedId::IK_TemplateId:
1761    T = ConvertDeclSpecToType(state);
1762
1763    if (!D.isInvalidType() && D.getDeclSpec().isTypeSpecOwned()) {
1764      OwnedTagDecl = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
1765      // Owned declaration is embedded in declarator.
1766      OwnedTagDecl->setEmbeddedInDeclarator(true);
1767    }
1768    break;
1769
1770  case UnqualifiedId::IK_ConstructorName:
1771  case UnqualifiedId::IK_ConstructorTemplateId:
1772  case UnqualifiedId::IK_DestructorName:
1773    // Constructors and destructors don't have return types. Use
1774    // "void" instead.
1775    T = SemaRef.Context.VoidTy;
1776    break;
1777
1778  case UnqualifiedId::IK_ConversionFunctionId:
1779    // The result type of a conversion function is the type that it
1780    // converts to.
1781    T = SemaRef.GetTypeFromParser(D.getName().ConversionFunctionId,
1782                                  &ReturnTypeInfo);
1783    break;
1784  }
1785
1786  if (D.getAttributes())
1787    distributeTypeAttrsFromDeclarator(state, T);
1788
1789  // C++0x [dcl.spec.auto]p5: reject 'auto' if it is not in an allowed context.
1790  // In C++0x, a function declarator using 'auto' must have a trailing return
1791  // type (this is checked later) and we can skip this. In other languages
1792  // using auto, we need to check regardless.
1793  if (D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_auto &&
1794      (!SemaRef.getLangOptions().CPlusPlus0x || !D.isFunctionDeclarator())) {
1795    int Error = -1;
1796
1797    switch (D.getContext()) {
1798    case Declarator::KNRTypeListContext:
1799      llvm_unreachable("K&R type lists aren't allowed in C++");
1800    case Declarator::LambdaExprContext:
1801      llvm_unreachable("Can't specify a type specifier in lambda grammar");
1802    case Declarator::ObjCParameterContext:
1803    case Declarator::ObjCResultContext:
1804    case Declarator::PrototypeContext:
1805      Error = 0; // Function prototype
1806      break;
1807    case Declarator::MemberContext:
1808      if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static)
1809        break;
1810      switch (cast<TagDecl>(SemaRef.CurContext)->getTagKind()) {
1811      case TTK_Enum: llvm_unreachable("unhandled tag kind");
1812      case TTK_Struct: Error = 1; /* Struct member */ break;
1813      case TTK_Union:  Error = 2; /* Union member */ break;
1814      case TTK_Class:  Error = 3; /* Class member */ break;
1815      }
1816      break;
1817    case Declarator::CXXCatchContext:
1818    case Declarator::ObjCCatchContext:
1819      Error = 4; // Exception declaration
1820      break;
1821    case Declarator::TemplateParamContext:
1822      Error = 5; // Template parameter
1823      break;
1824    case Declarator::BlockLiteralContext:
1825      Error = 6; // Block literal
1826      break;
1827    case Declarator::TemplateTypeArgContext:
1828      Error = 7; // Template type argument
1829      break;
1830    case Declarator::AliasDeclContext:
1831    case Declarator::AliasTemplateContext:
1832      Error = 9; // Type alias
1833      break;
1834    case Declarator::TypeNameContext:
1835      Error = 11; // Generic
1836      break;
1837    case Declarator::FileContext:
1838    case Declarator::BlockContext:
1839    case Declarator::ForContext:
1840    case Declarator::ConditionContext:
1841    case Declarator::CXXNewContext:
1842      break;
1843    }
1844
1845    if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
1846      Error = 8;
1847
1848    // In Objective-C it is an error to use 'auto' on a function declarator.
1849    if (D.isFunctionDeclarator())
1850      Error = 10;
1851
1852    // C++0x [dcl.spec.auto]p2: 'auto' is always fine if the declarator
1853    // contains a trailing return type. That is only legal at the outermost
1854    // level. Check all declarator chunks (outermost first) anyway, to give
1855    // better diagnostics.
1856    if (SemaRef.getLangOptions().CPlusPlus0x && Error != -1) {
1857      for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
1858        unsigned chunkIndex = e - i - 1;
1859        state.setCurrentChunkIndex(chunkIndex);
1860        DeclaratorChunk &DeclType = D.getTypeObject(chunkIndex);
1861        if (DeclType.Kind == DeclaratorChunk::Function) {
1862          const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
1863          if (FTI.TrailingReturnType) {
1864            Error = -1;
1865            break;
1866          }
1867        }
1868      }
1869    }
1870
1871    if (Error != -1) {
1872      SemaRef.Diag(D.getDeclSpec().getTypeSpecTypeLoc(),
1873                   diag::err_auto_not_allowed)
1874        << Error;
1875      T = SemaRef.Context.IntTy;
1876      D.setInvalidType(true);
1877    } else
1878      SemaRef.Diag(D.getDeclSpec().getTypeSpecTypeLoc(),
1879                   diag::warn_cxx98_compat_auto_type_specifier);
1880  }
1881
1882  if (SemaRef.getLangOptions().CPlusPlus &&
1883      OwnedTagDecl && OwnedTagDecl->isCompleteDefinition()) {
1884    // Check the contexts where C++ forbids the declaration of a new class
1885    // or enumeration in a type-specifier-seq.
1886    switch (D.getContext()) {
1887    case Declarator::FileContext:
1888    case Declarator::MemberContext:
1889    case Declarator::BlockContext:
1890    case Declarator::ForContext:
1891    case Declarator::BlockLiteralContext:
1892    case Declarator::LambdaExprContext:
1893      // C++0x [dcl.type]p3:
1894      //   A type-specifier-seq shall not define a class or enumeration unless
1895      //   it appears in the type-id of an alias-declaration (7.1.3) that is not
1896      //   the declaration of a template-declaration.
1897    case Declarator::AliasDeclContext:
1898      break;
1899    case Declarator::AliasTemplateContext:
1900      SemaRef.Diag(OwnedTagDecl->getLocation(),
1901             diag::err_type_defined_in_alias_template)
1902        << SemaRef.Context.getTypeDeclType(OwnedTagDecl);
1903      break;
1904    case Declarator::TypeNameContext:
1905    case Declarator::TemplateParamContext:
1906    case Declarator::CXXNewContext:
1907    case Declarator::CXXCatchContext:
1908    case Declarator::ObjCCatchContext:
1909    case Declarator::TemplateTypeArgContext:
1910      SemaRef.Diag(OwnedTagDecl->getLocation(),
1911             diag::err_type_defined_in_type_specifier)
1912        << SemaRef.Context.getTypeDeclType(OwnedTagDecl);
1913      break;
1914    case Declarator::PrototypeContext:
1915    case Declarator::ObjCParameterContext:
1916    case Declarator::ObjCResultContext:
1917    case Declarator::KNRTypeListContext:
1918      // C++ [dcl.fct]p6:
1919      //   Types shall not be defined in return or parameter types.
1920      SemaRef.Diag(OwnedTagDecl->getLocation(),
1921                   diag::err_type_defined_in_param_type)
1922        << SemaRef.Context.getTypeDeclType(OwnedTagDecl);
1923      break;
1924    case Declarator::ConditionContext:
1925      // C++ 6.4p2:
1926      // The type-specifier-seq shall not contain typedef and shall not declare
1927      // a new class or enumeration.
1928      SemaRef.Diag(OwnedTagDecl->getLocation(),
1929                   diag::err_type_defined_in_condition);
1930      break;
1931    }
1932  }
1933
1934  return T;
1935}
1936
1937static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
1938                                                QualType declSpecType,
1939                                                TypeSourceInfo *TInfo) {
1940
1941  QualType T = declSpecType;
1942  Declarator &D = state.getDeclarator();
1943  Sema &S = state.getSema();
1944  ASTContext &Context = S.Context;
1945  const LangOptions &LangOpts = S.getLangOptions();
1946
1947  bool ImplicitlyNoexcept = false;
1948  if (D.getName().getKind() == UnqualifiedId::IK_OperatorFunctionId &&
1949      LangOpts.CPlusPlus0x) {
1950    OverloadedOperatorKind OO = D.getName().OperatorFunctionId.Operator;
1951    /// In C++0x, deallocation functions (normal and array operator delete)
1952    /// are implicitly noexcept.
1953    if (OO == OO_Delete || OO == OO_Array_Delete)
1954      ImplicitlyNoexcept = true;
1955  }
1956
1957  // The name we're declaring, if any.
1958  DeclarationName Name;
1959  if (D.getIdentifier())
1960    Name = D.getIdentifier();
1961
1962  // Does this declaration declare a typedef-name?
1963  bool IsTypedefName =
1964    D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef ||
1965    D.getContext() == Declarator::AliasDeclContext ||
1966    D.getContext() == Declarator::AliasTemplateContext;
1967
1968  // Walk the DeclTypeInfo, building the recursive type as we go.
1969  // DeclTypeInfos are ordered from the identifier out, which is
1970  // opposite of what we want :).
1971  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
1972    unsigned chunkIndex = e - i - 1;
1973    state.setCurrentChunkIndex(chunkIndex);
1974    DeclaratorChunk &DeclType = D.getTypeObject(chunkIndex);
1975    switch (DeclType.Kind) {
1976    case DeclaratorChunk::Paren:
1977      T = S.BuildParenType(T);
1978      break;
1979    case DeclaratorChunk::BlockPointer:
1980      // If blocks are disabled, emit an error.
1981      if (!LangOpts.Blocks)
1982        S.Diag(DeclType.Loc, diag::err_blocks_disable);
1983
1984      T = S.BuildBlockPointerType(T, D.getIdentifierLoc(), Name);
1985      if (DeclType.Cls.TypeQuals)
1986        T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Cls.TypeQuals);
1987      break;
1988    case DeclaratorChunk::Pointer:
1989      // Verify that we're not building a pointer to pointer to function with
1990      // exception specification.
1991      if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
1992        S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
1993        D.setInvalidType(true);
1994        // Build the type anyway.
1995      }
1996      if (LangOpts.ObjC1 && T->getAs<ObjCObjectType>()) {
1997        T = Context.getObjCObjectPointerType(T);
1998        if (DeclType.Ptr.TypeQuals)
1999          T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Ptr.TypeQuals);
2000        break;
2001      }
2002      T = S.BuildPointerType(T, DeclType.Loc, Name);
2003      if (DeclType.Ptr.TypeQuals)
2004        T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Ptr.TypeQuals);
2005
2006      break;
2007    case DeclaratorChunk::Reference: {
2008      // Verify that we're not building a reference to pointer to function with
2009      // exception specification.
2010      if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
2011        S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
2012        D.setInvalidType(true);
2013        // Build the type anyway.
2014      }
2015      T = S.BuildReferenceType(T, DeclType.Ref.LValueRef, DeclType.Loc, Name);
2016
2017      Qualifiers Quals;
2018      if (DeclType.Ref.HasRestrict)
2019        T = S.BuildQualifiedType(T, DeclType.Loc, Qualifiers::Restrict);
2020      break;
2021    }
2022    case DeclaratorChunk::Array: {
2023      // Verify that we're not building an array of pointers to function with
2024      // exception specification.
2025      if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
2026        S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
2027        D.setInvalidType(true);
2028        // Build the type anyway.
2029      }
2030      DeclaratorChunk::ArrayTypeInfo &ATI = DeclType.Arr;
2031      Expr *ArraySize = static_cast<Expr*>(ATI.NumElts);
2032      ArrayType::ArraySizeModifier ASM;
2033      if (ATI.isStar)
2034        ASM = ArrayType::Star;
2035      else if (ATI.hasStatic)
2036        ASM = ArrayType::Static;
2037      else
2038        ASM = ArrayType::Normal;
2039      if (ASM == ArrayType::Star && !D.isPrototypeContext()) {
2040        // FIXME: This check isn't quite right: it allows star in prototypes
2041        // for function definitions, and disallows some edge cases detailed
2042        // in http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00133.html
2043        S.Diag(DeclType.Loc, diag::err_array_star_outside_prototype);
2044        ASM = ArrayType::Normal;
2045        D.setInvalidType(true);
2046      }
2047      T = S.BuildArrayType(T, ASM, ArraySize, ATI.TypeQuals,
2048                           SourceRange(DeclType.Loc, DeclType.EndLoc), Name);
2049      break;
2050    }
2051    case DeclaratorChunk::Function: {
2052      // If the function declarator has a prototype (i.e. it is not () and
2053      // does not have a K&R-style identifier list), then the arguments are part
2054      // of the type, otherwise the argument list is ().
2055      const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
2056
2057      // Check for auto functions and trailing return type and adjust the
2058      // return type accordingly.
2059      if (!D.isInvalidType()) {
2060        // trailing-return-type is only required if we're declaring a function,
2061        // and not, for instance, a pointer to a function.
2062        if (D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_auto &&
2063            !FTI.TrailingReturnType && chunkIndex == 0) {
2064          S.Diag(D.getDeclSpec().getTypeSpecTypeLoc(),
2065               diag::err_auto_missing_trailing_return);
2066          T = Context.IntTy;
2067          D.setInvalidType(true);
2068        } else if (FTI.TrailingReturnType) {
2069          // T must be exactly 'auto' at this point. See CWG issue 681.
2070          if (isa<ParenType>(T)) {
2071            S.Diag(D.getDeclSpec().getTypeSpecTypeLoc(),
2072                 diag::err_trailing_return_in_parens)
2073              << T << D.getDeclSpec().getSourceRange();
2074            D.setInvalidType(true);
2075          } else if (D.getContext() != Declarator::LambdaExprContext &&
2076                     (T.hasQualifiers() || !isa<AutoType>(T))) {
2077            S.Diag(D.getDeclSpec().getTypeSpecTypeLoc(),
2078                 diag::err_trailing_return_without_auto)
2079              << T << D.getDeclSpec().getSourceRange();
2080            D.setInvalidType(true);
2081          }
2082
2083          T = S.GetTypeFromParser(
2084            ParsedType::getFromOpaquePtr(FTI.TrailingReturnType),
2085            &TInfo);
2086        }
2087      }
2088
2089      // C99 6.7.5.3p1: The return type may not be a function or array type.
2090      // For conversion functions, we'll diagnose this particular error later.
2091      if ((T->isArrayType() || T->isFunctionType()) &&
2092          (D.getName().getKind() != UnqualifiedId::IK_ConversionFunctionId)) {
2093        unsigned diagID = diag::err_func_returning_array_function;
2094        // Last processing chunk in block context means this function chunk
2095        // represents the block.
2096        if (chunkIndex == 0 &&
2097            D.getContext() == Declarator::BlockLiteralContext)
2098          diagID = diag::err_block_returning_array_function;
2099        S.Diag(DeclType.Loc, diagID) << T->isFunctionType() << T;
2100        T = Context.IntTy;
2101        D.setInvalidType(true);
2102      }
2103
2104      // Do not allow returning half FP value.
2105      // FIXME: This really should be in BuildFunctionType.
2106      if (T->isHalfType()) {
2107        S.Diag(D.getIdentifierLoc(),
2108             diag::err_parameters_retval_cannot_have_fp16_type) << 1
2109          << FixItHint::CreateInsertion(D.getIdentifierLoc(), "*");
2110        D.setInvalidType(true);
2111      }
2112
2113      // cv-qualifiers on return types are pointless except when the type is a
2114      // class type in C++.
2115      if (isa<PointerType>(T) && T.getLocalCVRQualifiers() &&
2116          (D.getName().getKind() != UnqualifiedId::IK_ConversionFunctionId) &&
2117          (!LangOpts.CPlusPlus || !T->isDependentType())) {
2118        assert(chunkIndex + 1 < e && "No DeclaratorChunk for the return type?");
2119        DeclaratorChunk ReturnTypeChunk = D.getTypeObject(chunkIndex + 1);
2120        assert(ReturnTypeChunk.Kind == DeclaratorChunk::Pointer);
2121
2122        DeclaratorChunk::PointerTypeInfo &PTI = ReturnTypeChunk.Ptr;
2123
2124        DiagnoseIgnoredQualifiers(PTI.TypeQuals,
2125            SourceLocation::getFromRawEncoding(PTI.ConstQualLoc),
2126            SourceLocation::getFromRawEncoding(PTI.VolatileQualLoc),
2127            SourceLocation::getFromRawEncoding(PTI.RestrictQualLoc),
2128            S);
2129
2130      } else if (T.getCVRQualifiers() && D.getDeclSpec().getTypeQualifiers() &&
2131          (!LangOpts.CPlusPlus ||
2132           (!T->isDependentType() && !T->isRecordType()))) {
2133
2134        DiagnoseIgnoredQualifiers(D.getDeclSpec().getTypeQualifiers(),
2135                                  D.getDeclSpec().getConstSpecLoc(),
2136                                  D.getDeclSpec().getVolatileSpecLoc(),
2137                                  D.getDeclSpec().getRestrictSpecLoc(),
2138                                  S);
2139      }
2140
2141      if (LangOpts.CPlusPlus && D.getDeclSpec().isTypeSpecOwned()) {
2142        // C++ [dcl.fct]p6:
2143        //   Types shall not be defined in return or parameter types.
2144        TagDecl *Tag = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
2145        if (Tag->isCompleteDefinition())
2146          S.Diag(Tag->getLocation(), diag::err_type_defined_in_result_type)
2147            << Context.getTypeDeclType(Tag);
2148      }
2149
2150      // Exception specs are not allowed in typedefs. Complain, but add it
2151      // anyway.
2152      if (IsTypedefName && FTI.getExceptionSpecType())
2153        S.Diag(FTI.getExceptionSpecLoc(), diag::err_exception_spec_in_typedef)
2154          << (D.getContext() == Declarator::AliasDeclContext ||
2155              D.getContext() == Declarator::AliasTemplateContext);
2156
2157      if (!FTI.NumArgs && !FTI.isVariadic && !LangOpts.CPlusPlus) {
2158        // Simple void foo(), where the incoming T is the result type.
2159        T = Context.getFunctionNoProtoType(T);
2160      } else {
2161        // We allow a zero-parameter variadic function in C if the
2162        // function is marked with the "overloadable" attribute. Scan
2163        // for this attribute now.
2164        if (!FTI.NumArgs && FTI.isVariadic && !LangOpts.CPlusPlus) {
2165          bool Overloadable = false;
2166          for (const AttributeList *Attrs = D.getAttributes();
2167               Attrs; Attrs = Attrs->getNext()) {
2168            if (Attrs->getKind() == AttributeList::AT_overloadable) {
2169              Overloadable = true;
2170              break;
2171            }
2172          }
2173
2174          if (!Overloadable)
2175            S.Diag(FTI.getEllipsisLoc(), diag::err_ellipsis_first_arg);
2176        }
2177
2178        if (FTI.NumArgs && FTI.ArgInfo[0].Param == 0) {
2179          // C99 6.7.5.3p3: Reject int(x,y,z) when it's not a function
2180          // definition.
2181          S.Diag(FTI.ArgInfo[0].IdentLoc, diag::err_ident_list_in_fn_declaration);
2182          D.setInvalidType(true);
2183          break;
2184        }
2185
2186        FunctionProtoType::ExtProtoInfo EPI;
2187        EPI.Variadic = FTI.isVariadic;
2188        EPI.TypeQuals = FTI.TypeQuals;
2189        EPI.RefQualifier = !FTI.hasRefQualifier()? RQ_None
2190                    : FTI.RefQualifierIsLValueRef? RQ_LValue
2191                    : RQ_RValue;
2192
2193        // Otherwise, we have a function with an argument list that is
2194        // potentially variadic.
2195        SmallVector<QualType, 16> ArgTys;
2196        ArgTys.reserve(FTI.NumArgs);
2197
2198        SmallVector<bool, 16> ConsumedArguments;
2199        ConsumedArguments.reserve(FTI.NumArgs);
2200        bool HasAnyConsumedArguments = false;
2201
2202        for (unsigned i = 0, e = FTI.NumArgs; i != e; ++i) {
2203          ParmVarDecl *Param = cast<ParmVarDecl>(FTI.ArgInfo[i].Param);
2204          QualType ArgTy = Param->getType();
2205          assert(!ArgTy.isNull() && "Couldn't parse type?");
2206
2207          // Adjust the parameter type.
2208          assert((ArgTy == Context.getAdjustedParameterType(ArgTy)) &&
2209                 "Unadjusted type?");
2210
2211          // Look for 'void'.  void is allowed only as a single argument to a
2212          // function with no other parameters (C99 6.7.5.3p10).  We record
2213          // int(void) as a FunctionProtoType with an empty argument list.
2214          if (ArgTy->isVoidType()) {
2215            // If this is something like 'float(int, void)', reject it.  'void'
2216            // is an incomplete type (C99 6.2.5p19) and function decls cannot
2217            // have arguments of incomplete type.
2218            if (FTI.NumArgs != 1 || FTI.isVariadic) {
2219              S.Diag(DeclType.Loc, diag::err_void_only_param);
2220              ArgTy = Context.IntTy;
2221              Param->setType(ArgTy);
2222            } else if (FTI.ArgInfo[i].Ident) {
2223              // Reject, but continue to parse 'int(void abc)'.
2224              S.Diag(FTI.ArgInfo[i].IdentLoc,
2225                   diag::err_param_with_void_type);
2226              ArgTy = Context.IntTy;
2227              Param->setType(ArgTy);
2228            } else {
2229              // Reject, but continue to parse 'float(const void)'.
2230              if (ArgTy.hasQualifiers())
2231                S.Diag(DeclType.Loc, diag::err_void_param_qualified);
2232
2233              // Do not add 'void' to the ArgTys list.
2234              break;
2235            }
2236          } else if (ArgTy->isHalfType()) {
2237            // Disallow half FP arguments.
2238            // FIXME: This really should be in BuildFunctionType.
2239            S.Diag(Param->getLocation(),
2240               diag::err_parameters_retval_cannot_have_fp16_type) << 0
2241            << FixItHint::CreateInsertion(Param->getLocation(), "*");
2242            D.setInvalidType();
2243          } else if (!FTI.hasPrototype) {
2244            if (ArgTy->isPromotableIntegerType()) {
2245              ArgTy = Context.getPromotedIntegerType(ArgTy);
2246              Param->setKNRPromoted(true);
2247            } else if (const BuiltinType* BTy = ArgTy->getAs<BuiltinType>()) {
2248              if (BTy->getKind() == BuiltinType::Float) {
2249                ArgTy = Context.DoubleTy;
2250                Param->setKNRPromoted(true);
2251              }
2252            }
2253          }
2254
2255          if (LangOpts.ObjCAutoRefCount) {
2256            bool Consumed = Param->hasAttr<NSConsumedAttr>();
2257            ConsumedArguments.push_back(Consumed);
2258            HasAnyConsumedArguments |= Consumed;
2259          }
2260
2261          ArgTys.push_back(ArgTy);
2262        }
2263
2264        if (HasAnyConsumedArguments)
2265          EPI.ConsumedArguments = ConsumedArguments.data();
2266
2267        SmallVector<QualType, 4> Exceptions;
2268        EPI.ExceptionSpecType = FTI.getExceptionSpecType();
2269        if (FTI.getExceptionSpecType() == EST_Dynamic) {
2270          Exceptions.reserve(FTI.NumExceptions);
2271          for (unsigned ei = 0, ee = FTI.NumExceptions; ei != ee; ++ei) {
2272            // FIXME: Preserve type source info.
2273            QualType ET = S.GetTypeFromParser(FTI.Exceptions[ei].Ty);
2274            // Check that the type is valid for an exception spec, and
2275            // drop it if not.
2276            if (!S.CheckSpecifiedExceptionType(ET, FTI.Exceptions[ei].Range))
2277              Exceptions.push_back(ET);
2278          }
2279          EPI.NumExceptions = Exceptions.size();
2280          EPI.Exceptions = Exceptions.data();
2281        } else if (FTI.getExceptionSpecType() == EST_ComputedNoexcept) {
2282          // If an error occurred, there's no expression here.
2283          if (Expr *NoexceptExpr = FTI.NoexceptExpr) {
2284            assert((NoexceptExpr->isTypeDependent() ||
2285                    NoexceptExpr->getType()->getCanonicalTypeUnqualified() ==
2286                        Context.BoolTy) &&
2287                 "Parser should have made sure that the expression is boolean");
2288            if (!NoexceptExpr->isValueDependent())
2289              NoexceptExpr = S.VerifyIntegerConstantExpression(NoexceptExpr, 0,
2290                S.PDiag(diag::err_noexcept_needs_constant_expression),
2291                /*AllowFold*/ false).take();
2292            EPI.NoexceptExpr = NoexceptExpr;
2293          }
2294        } else if (FTI.getExceptionSpecType() == EST_None &&
2295                   ImplicitlyNoexcept && chunkIndex == 0) {
2296          // Only the outermost chunk is marked noexcept, of course.
2297          EPI.ExceptionSpecType = EST_BasicNoexcept;
2298        }
2299
2300        T = Context.getFunctionType(T, ArgTys.data(), ArgTys.size(), EPI);
2301      }
2302
2303      break;
2304    }
2305    case DeclaratorChunk::MemberPointer:
2306      // The scope spec must refer to a class, or be dependent.
2307      CXXScopeSpec &SS = DeclType.Mem.Scope();
2308      QualType ClsType;
2309      if (SS.isInvalid()) {
2310        // Avoid emitting extra errors if we already errored on the scope.
2311        D.setInvalidType(true);
2312      } else if (S.isDependentScopeSpecifier(SS) ||
2313                 dyn_cast_or_null<CXXRecordDecl>(S.computeDeclContext(SS))) {
2314        NestedNameSpecifier *NNS
2315          = static_cast<NestedNameSpecifier*>(SS.getScopeRep());
2316        NestedNameSpecifier *NNSPrefix = NNS->getPrefix();
2317        switch (NNS->getKind()) {
2318        case NestedNameSpecifier::Identifier:
2319          ClsType = Context.getDependentNameType(ETK_None, NNSPrefix,
2320                                                 NNS->getAsIdentifier());
2321          break;
2322
2323        case NestedNameSpecifier::Namespace:
2324        case NestedNameSpecifier::NamespaceAlias:
2325        case NestedNameSpecifier::Global:
2326          llvm_unreachable("Nested-name-specifier must name a type");
2327
2328        case NestedNameSpecifier::TypeSpec:
2329        case NestedNameSpecifier::TypeSpecWithTemplate:
2330          ClsType = QualType(NNS->getAsType(), 0);
2331          // Note: if the NNS has a prefix and ClsType is a nondependent
2332          // TemplateSpecializationType, then the NNS prefix is NOT included
2333          // in ClsType; hence we wrap ClsType into an ElaboratedType.
2334          // NOTE: in particular, no wrap occurs if ClsType already is an
2335          // Elaborated, DependentName, or DependentTemplateSpecialization.
2336          if (NNSPrefix && isa<TemplateSpecializationType>(NNS->getAsType()))
2337            ClsType = Context.getElaboratedType(ETK_None, NNSPrefix, ClsType);
2338          break;
2339        }
2340      } else {
2341        S.Diag(DeclType.Mem.Scope().getBeginLoc(),
2342             diag::err_illegal_decl_mempointer_in_nonclass)
2343          << (D.getIdentifier() ? D.getIdentifier()->getName() : "type name")
2344          << DeclType.Mem.Scope().getRange();
2345        D.setInvalidType(true);
2346      }
2347
2348      if (!ClsType.isNull())
2349        T = S.BuildMemberPointerType(T, ClsType, DeclType.Loc, D.getIdentifier());
2350      if (T.isNull()) {
2351        T = Context.IntTy;
2352        D.setInvalidType(true);
2353      } else if (DeclType.Mem.TypeQuals) {
2354        T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Mem.TypeQuals);
2355      }
2356      break;
2357    }
2358
2359    if (T.isNull()) {
2360      D.setInvalidType(true);
2361      T = Context.IntTy;
2362    }
2363
2364    // See if there are any attributes on this declarator chunk.
2365    if (AttributeList *attrs = const_cast<AttributeList*>(DeclType.getAttrs()))
2366      processTypeAttrs(state, T, false, attrs);
2367  }
2368
2369  if (LangOpts.CPlusPlus && T->isFunctionType()) {
2370    const FunctionProtoType *FnTy = T->getAs<FunctionProtoType>();
2371    assert(FnTy && "Why oh why is there not a FunctionProtoType here?");
2372
2373    // C++ 8.3.5p4:
2374    //   A cv-qualifier-seq shall only be part of the function type
2375    //   for a nonstatic member function, the function type to which a pointer
2376    //   to member refers, or the top-level function type of a function typedef
2377    //   declaration.
2378    //
2379    // Core issue 547 also allows cv-qualifiers on function types that are
2380    // top-level template type arguments.
2381    bool FreeFunction;
2382    if (!D.getCXXScopeSpec().isSet()) {
2383      FreeFunction = ((D.getContext() != Declarator::MemberContext &&
2384                       D.getContext() != Declarator::LambdaExprContext) ||
2385                      D.getDeclSpec().isFriendSpecified());
2386    } else {
2387      DeclContext *DC = S.computeDeclContext(D.getCXXScopeSpec());
2388      FreeFunction = (DC && !DC->isRecord());
2389    }
2390
2391    // C++0x [dcl.constexpr]p8: A constexpr specifier for a non-static member
2392    // function that is not a constructor declares that function to be const.
2393    if (D.getDeclSpec().isConstexprSpecified() && !FreeFunction &&
2394        D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static &&
2395        D.getName().getKind() != UnqualifiedId::IK_ConstructorName &&
2396        D.getName().getKind() != UnqualifiedId::IK_ConstructorTemplateId &&
2397        !(FnTy->getTypeQuals() & DeclSpec::TQ_const)) {
2398      // Rebuild function type adding a 'const' qualifier.
2399      FunctionProtoType::ExtProtoInfo EPI = FnTy->getExtProtoInfo();
2400      EPI.TypeQuals |= DeclSpec::TQ_const;
2401      T = Context.getFunctionType(FnTy->getResultType(),
2402                                  FnTy->arg_type_begin(),
2403                                  FnTy->getNumArgs(), EPI);
2404    }
2405
2406    // C++0x [dcl.fct]p6:
2407    //   A ref-qualifier shall only be part of the function type for a
2408    //   non-static member function, the function type to which a pointer to
2409    //   member refers, or the top-level function type of a function typedef
2410    //   declaration.
2411    if ((FnTy->getTypeQuals() != 0 || FnTy->getRefQualifier()) &&
2412        !(D.getContext() == Declarator::TemplateTypeArgContext &&
2413          !D.isFunctionDeclarator()) && !IsTypedefName &&
2414        (FreeFunction ||
2415         D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static)) {
2416      if (D.getContext() == Declarator::TemplateTypeArgContext) {
2417        // Accept qualified function types as template type arguments as a GNU
2418        // extension. This is also the subject of C++ core issue 547.
2419        std::string Quals;
2420        if (FnTy->getTypeQuals() != 0)
2421          Quals = Qualifiers::fromCVRMask(FnTy->getTypeQuals()).getAsString();
2422
2423        switch (FnTy->getRefQualifier()) {
2424        case RQ_None:
2425          break;
2426
2427        case RQ_LValue:
2428          if (!Quals.empty())
2429            Quals += ' ';
2430          Quals += '&';
2431          break;
2432
2433        case RQ_RValue:
2434          if (!Quals.empty())
2435            Quals += ' ';
2436          Quals += "&&";
2437          break;
2438        }
2439
2440        S.Diag(D.getIdentifierLoc(),
2441             diag::ext_qualified_function_type_template_arg)
2442          << Quals;
2443      } else {
2444        if (FnTy->getTypeQuals() != 0) {
2445          if (D.isFunctionDeclarator()) {
2446            SourceRange Range = D.getIdentifierLoc();
2447            for (unsigned I = 0, N = D.getNumTypeObjects(); I != N; ++I) {
2448              const DeclaratorChunk &Chunk = D.getTypeObject(N-I-1);
2449              if (Chunk.Kind == DeclaratorChunk::Function &&
2450                  Chunk.Fun.TypeQuals != 0) {
2451                switch (Chunk.Fun.TypeQuals) {
2452                case Qualifiers::Const:
2453                  Range = Chunk.Fun.getConstQualifierLoc();
2454                  break;
2455                case Qualifiers::Volatile:
2456                  Range = Chunk.Fun.getVolatileQualifierLoc();
2457                  break;
2458                case Qualifiers::Const | Qualifiers::Volatile: {
2459                    SourceLocation CLoc = Chunk.Fun.getConstQualifierLoc();
2460                    SourceLocation VLoc = Chunk.Fun.getVolatileQualifierLoc();
2461                    if (S.getSourceManager()
2462                        .isBeforeInTranslationUnit(CLoc, VLoc)) {
2463                      Range = SourceRange(CLoc, VLoc);
2464                    } else {
2465                      Range = SourceRange(VLoc, CLoc);
2466                    }
2467                  }
2468                  break;
2469                }
2470                break;
2471              }
2472            }
2473            S.Diag(Range.getBegin(), diag::err_invalid_qualified_function_type)
2474                << FixItHint::CreateRemoval(Range);
2475          } else
2476            S.Diag(D.getIdentifierLoc(),
2477                 diag::err_invalid_qualified_typedef_function_type_use)
2478              << FreeFunction;
2479        }
2480
2481        if (FnTy->getRefQualifier()) {
2482          if (D.isFunctionDeclarator()) {
2483            SourceLocation Loc = D.getIdentifierLoc();
2484            for (unsigned I = 0, N = D.getNumTypeObjects(); I != N; ++I) {
2485              const DeclaratorChunk &Chunk = D.getTypeObject(N-I-1);
2486              if (Chunk.Kind == DeclaratorChunk::Function &&
2487                  Chunk.Fun.hasRefQualifier()) {
2488                Loc = Chunk.Fun.getRefQualifierLoc();
2489                break;
2490              }
2491            }
2492
2493            S.Diag(Loc, diag::err_invalid_ref_qualifier_function_type)
2494              << (FnTy->getRefQualifier() == RQ_LValue)
2495              << FixItHint::CreateRemoval(Loc);
2496          } else {
2497            S.Diag(D.getIdentifierLoc(),
2498                 diag::err_invalid_ref_qualifier_typedef_function_type_use)
2499              << FreeFunction
2500              << (FnTy->getRefQualifier() == RQ_LValue);
2501          }
2502        }
2503
2504        // Strip the cv-qualifiers and ref-qualifiers from the type.
2505        FunctionProtoType::ExtProtoInfo EPI = FnTy->getExtProtoInfo();
2506        EPI.TypeQuals = 0;
2507        EPI.RefQualifier = RQ_None;
2508
2509        T = Context.getFunctionType(FnTy->getResultType(),
2510                                    FnTy->arg_type_begin(),
2511                                    FnTy->getNumArgs(), EPI);
2512      }
2513    }
2514  }
2515
2516  // Apply any undistributed attributes from the declarator.
2517  if (!T.isNull())
2518    if (AttributeList *attrs = D.getAttributes())
2519      processTypeAttrs(state, T, false, attrs);
2520
2521  // Diagnose any ignored type attributes.
2522  if (!T.isNull()) state.diagnoseIgnoredTypeAttrs(T);
2523
2524  // C++0x [dcl.constexpr]p9:
2525  //  A constexpr specifier used in an object declaration declares the object
2526  //  as const.
2527  if (D.getDeclSpec().isConstexprSpecified() && T->isObjectType()) {
2528    T.addConst();
2529  }
2530
2531  // If there was an ellipsis in the declarator, the declaration declares a
2532  // parameter pack whose type may be a pack expansion type.
2533  if (D.hasEllipsis() && !T.isNull()) {
2534    // C++0x [dcl.fct]p13:
2535    //   A declarator-id or abstract-declarator containing an ellipsis shall
2536    //   only be used in a parameter-declaration. Such a parameter-declaration
2537    //   is a parameter pack (14.5.3). [...]
2538    switch (D.getContext()) {
2539    case Declarator::PrototypeContext:
2540      // C++0x [dcl.fct]p13:
2541      //   [...] When it is part of a parameter-declaration-clause, the
2542      //   parameter pack is a function parameter pack (14.5.3). The type T
2543      //   of the declarator-id of the function parameter pack shall contain
2544      //   a template parameter pack; each template parameter pack in T is
2545      //   expanded by the function parameter pack.
2546      //
2547      // We represent function parameter packs as function parameters whose
2548      // type is a pack expansion.
2549      if (!T->containsUnexpandedParameterPack()) {
2550        S.Diag(D.getEllipsisLoc(),
2551             diag::err_function_parameter_pack_without_parameter_packs)
2552          << T <<  D.getSourceRange();
2553        D.setEllipsisLoc(SourceLocation());
2554      } else {
2555        T = Context.getPackExpansionType(T, llvm::Optional<unsigned>());
2556      }
2557      break;
2558
2559    case Declarator::TemplateParamContext:
2560      // C++0x [temp.param]p15:
2561      //   If a template-parameter is a [...] is a parameter-declaration that
2562      //   declares a parameter pack (8.3.5), then the template-parameter is a
2563      //   template parameter pack (14.5.3).
2564      //
2565      // Note: core issue 778 clarifies that, if there are any unexpanded
2566      // parameter packs in the type of the non-type template parameter, then
2567      // it expands those parameter packs.
2568      if (T->containsUnexpandedParameterPack())
2569        T = Context.getPackExpansionType(T, llvm::Optional<unsigned>());
2570      else
2571        S.Diag(D.getEllipsisLoc(),
2572               LangOpts.CPlusPlus0x
2573                 ? diag::warn_cxx98_compat_variadic_templates
2574                 : diag::ext_variadic_templates);
2575      break;
2576
2577    case Declarator::FileContext:
2578    case Declarator::KNRTypeListContext:
2579    case Declarator::ObjCParameterContext:  // FIXME: special diagnostic here?
2580    case Declarator::ObjCResultContext:     // FIXME: special diagnostic here?
2581    case Declarator::TypeNameContext:
2582    case Declarator::CXXNewContext:
2583    case Declarator::AliasDeclContext:
2584    case Declarator::AliasTemplateContext:
2585    case Declarator::MemberContext:
2586    case Declarator::BlockContext:
2587    case Declarator::ForContext:
2588    case Declarator::ConditionContext:
2589    case Declarator::CXXCatchContext:
2590    case Declarator::ObjCCatchContext:
2591    case Declarator::BlockLiteralContext:
2592    case Declarator::LambdaExprContext:
2593    case Declarator::TemplateTypeArgContext:
2594      // FIXME: We may want to allow parameter packs in block-literal contexts
2595      // in the future.
2596      S.Diag(D.getEllipsisLoc(), diag::err_ellipsis_in_declarator_not_parameter);
2597      D.setEllipsisLoc(SourceLocation());
2598      break;
2599    }
2600  }
2601
2602  if (T.isNull())
2603    return Context.getNullTypeSourceInfo();
2604  else if (D.isInvalidType())
2605    return Context.getTrivialTypeSourceInfo(T);
2606
2607  return S.GetTypeSourceInfoForDeclarator(D, T, TInfo);
2608}
2609
2610/// GetTypeForDeclarator - Convert the type for the specified
2611/// declarator to Type instances.
2612///
2613/// The result of this call will never be null, but the associated
2614/// type may be a null type if there's an unrecoverable error.
2615TypeSourceInfo *Sema::GetTypeForDeclarator(Declarator &D, Scope *S) {
2616  // Determine the type of the declarator. Not all forms of declarator
2617  // have a type.
2618
2619  TypeProcessingState state(*this, D);
2620
2621  TypeSourceInfo *ReturnTypeInfo = 0;
2622  QualType T = GetDeclSpecTypeForDeclarator(state, ReturnTypeInfo);
2623  if (T.isNull())
2624    return Context.getNullTypeSourceInfo();
2625
2626  if (D.isPrototypeContext() && getLangOptions().ObjCAutoRefCount)
2627    inferARCWriteback(state, T);
2628
2629  return GetFullTypeForDeclarator(state, T, ReturnTypeInfo);
2630}
2631
2632static void transferARCOwnershipToDeclSpec(Sema &S,
2633                                           QualType &declSpecTy,
2634                                           Qualifiers::ObjCLifetime ownership) {
2635  if (declSpecTy->isObjCRetainableType() &&
2636      declSpecTy.getObjCLifetime() == Qualifiers::OCL_None) {
2637    Qualifiers qs;
2638    qs.addObjCLifetime(ownership);
2639    declSpecTy = S.Context.getQualifiedType(declSpecTy, qs);
2640  }
2641}
2642
2643static void transferARCOwnershipToDeclaratorChunk(TypeProcessingState &state,
2644                                            Qualifiers::ObjCLifetime ownership,
2645                                            unsigned chunkIndex) {
2646  Sema &S = state.getSema();
2647  Declarator &D = state.getDeclarator();
2648
2649  // Look for an explicit lifetime attribute.
2650  DeclaratorChunk &chunk = D.getTypeObject(chunkIndex);
2651  for (const AttributeList *attr = chunk.getAttrs(); attr;
2652         attr = attr->getNext())
2653    if (attr->getKind() == AttributeList::AT_objc_ownership)
2654      return;
2655
2656  const char *attrStr = 0;
2657  switch (ownership) {
2658  case Qualifiers::OCL_None: llvm_unreachable("no ownership!");
2659  case Qualifiers::OCL_ExplicitNone: attrStr = "none"; break;
2660  case Qualifiers::OCL_Strong: attrStr = "strong"; break;
2661  case Qualifiers::OCL_Weak: attrStr = "weak"; break;
2662  case Qualifiers::OCL_Autoreleasing: attrStr = "autoreleasing"; break;
2663  }
2664
2665  // If there wasn't one, add one (with an invalid source location
2666  // so that we don't make an AttributedType for it).
2667  AttributeList *attr = D.getAttributePool()
2668    .create(&S.Context.Idents.get("objc_ownership"), SourceLocation(),
2669            /*scope*/ 0, SourceLocation(),
2670            &S.Context.Idents.get(attrStr), SourceLocation(),
2671            /*args*/ 0, 0,
2672            /*declspec*/ false, /*C++0x*/ false);
2673  spliceAttrIntoList(*attr, chunk.getAttrListRef());
2674
2675  // TODO: mark whether we did this inference?
2676}
2677
2678/// \brief Used for transfering ownership in casts resulting in l-values.
2679static void transferARCOwnership(TypeProcessingState &state,
2680                                 QualType &declSpecTy,
2681                                 Qualifiers::ObjCLifetime ownership) {
2682  Sema &S = state.getSema();
2683  Declarator &D = state.getDeclarator();
2684
2685  int inner = -1;
2686  bool hasIndirection = false;
2687  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
2688    DeclaratorChunk &chunk = D.getTypeObject(i);
2689    switch (chunk.Kind) {
2690    case DeclaratorChunk::Paren:
2691      // Ignore parens.
2692      break;
2693
2694    case DeclaratorChunk::Array:
2695    case DeclaratorChunk::Reference:
2696    case DeclaratorChunk::Pointer:
2697      if (inner != -1)
2698        hasIndirection = true;
2699      inner = i;
2700      break;
2701
2702    case DeclaratorChunk::BlockPointer:
2703      if (inner != -1)
2704        transferARCOwnershipToDeclaratorChunk(state, ownership, i);
2705      return;
2706
2707    case DeclaratorChunk::Function:
2708    case DeclaratorChunk::MemberPointer:
2709      return;
2710    }
2711  }
2712
2713  if (inner == -1)
2714    return;
2715
2716  DeclaratorChunk &chunk = D.getTypeObject(inner);
2717  if (chunk.Kind == DeclaratorChunk::Pointer) {
2718    if (declSpecTy->isObjCRetainableType())
2719      return transferARCOwnershipToDeclSpec(S, declSpecTy, ownership);
2720    if (declSpecTy->isObjCObjectType() && hasIndirection)
2721      return transferARCOwnershipToDeclaratorChunk(state, ownership, inner);
2722  } else {
2723    assert(chunk.Kind == DeclaratorChunk::Array ||
2724           chunk.Kind == DeclaratorChunk::Reference);
2725    return transferARCOwnershipToDeclSpec(S, declSpecTy, ownership);
2726  }
2727}
2728
2729TypeSourceInfo *Sema::GetTypeForDeclaratorCast(Declarator &D, QualType FromTy) {
2730  TypeProcessingState state(*this, D);
2731
2732  TypeSourceInfo *ReturnTypeInfo = 0;
2733  QualType declSpecTy = GetDeclSpecTypeForDeclarator(state, ReturnTypeInfo);
2734  if (declSpecTy.isNull())
2735    return Context.getNullTypeSourceInfo();
2736
2737  if (getLangOptions().ObjCAutoRefCount) {
2738    Qualifiers::ObjCLifetime ownership = Context.getInnerObjCOwnership(FromTy);
2739    if (ownership != Qualifiers::OCL_None)
2740      transferARCOwnership(state, declSpecTy, ownership);
2741  }
2742
2743  return GetFullTypeForDeclarator(state, declSpecTy, ReturnTypeInfo);
2744}
2745
2746/// Map an AttributedType::Kind to an AttributeList::Kind.
2747static AttributeList::Kind getAttrListKind(AttributedType::Kind kind) {
2748  switch (kind) {
2749  case AttributedType::attr_address_space:
2750    return AttributeList::AT_address_space;
2751  case AttributedType::attr_regparm:
2752    return AttributeList::AT_regparm;
2753  case AttributedType::attr_vector_size:
2754    return AttributeList::AT_vector_size;
2755  case AttributedType::attr_neon_vector_type:
2756    return AttributeList::AT_neon_vector_type;
2757  case AttributedType::attr_neon_polyvector_type:
2758    return AttributeList::AT_neon_polyvector_type;
2759  case AttributedType::attr_objc_gc:
2760    return AttributeList::AT_objc_gc;
2761  case AttributedType::attr_objc_ownership:
2762    return AttributeList::AT_objc_ownership;
2763  case AttributedType::attr_noreturn:
2764    return AttributeList::AT_noreturn;
2765  case AttributedType::attr_cdecl:
2766    return AttributeList::AT_cdecl;
2767  case AttributedType::attr_fastcall:
2768    return AttributeList::AT_fastcall;
2769  case AttributedType::attr_stdcall:
2770    return AttributeList::AT_stdcall;
2771  case AttributedType::attr_thiscall:
2772    return AttributeList::AT_thiscall;
2773  case AttributedType::attr_pascal:
2774    return AttributeList::AT_pascal;
2775  case AttributedType::attr_pcs:
2776    return AttributeList::AT_pcs;
2777  }
2778  llvm_unreachable("unexpected attribute kind!");
2779}
2780
2781static void fillAttributedTypeLoc(AttributedTypeLoc TL,
2782                                  const AttributeList *attrs) {
2783  AttributedType::Kind kind = TL.getAttrKind();
2784
2785  assert(attrs && "no type attributes in the expected location!");
2786  AttributeList::Kind parsedKind = getAttrListKind(kind);
2787  while (attrs->getKind() != parsedKind) {
2788    attrs = attrs->getNext();
2789    assert(attrs && "no matching attribute in expected location!");
2790  }
2791
2792  TL.setAttrNameLoc(attrs->getLoc());
2793  if (TL.hasAttrExprOperand())
2794    TL.setAttrExprOperand(attrs->getArg(0));
2795  else if (TL.hasAttrEnumOperand())
2796    TL.setAttrEnumOperandLoc(attrs->getParameterLoc());
2797
2798  // FIXME: preserve this information to here.
2799  if (TL.hasAttrOperand())
2800    TL.setAttrOperandParensRange(SourceRange());
2801}
2802
2803namespace {
2804  class TypeSpecLocFiller : public TypeLocVisitor<TypeSpecLocFiller> {
2805    ASTContext &Context;
2806    const DeclSpec &DS;
2807
2808  public:
2809    TypeSpecLocFiller(ASTContext &Context, const DeclSpec &DS)
2810      : Context(Context), DS(DS) {}
2811
2812    void VisitAttributedTypeLoc(AttributedTypeLoc TL) {
2813      fillAttributedTypeLoc(TL, DS.getAttributes().getList());
2814      Visit(TL.getModifiedLoc());
2815    }
2816    void VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
2817      Visit(TL.getUnqualifiedLoc());
2818    }
2819    void VisitTypedefTypeLoc(TypedefTypeLoc TL) {
2820      TL.setNameLoc(DS.getTypeSpecTypeLoc());
2821    }
2822    void VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
2823      TL.setNameLoc(DS.getTypeSpecTypeLoc());
2824    }
2825    void VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
2826      // Handle the base type, which might not have been written explicitly.
2827      if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) {
2828        TL.setHasBaseTypeAsWritten(false);
2829        TL.getBaseLoc().initialize(Context, SourceLocation());
2830      } else {
2831        TL.setHasBaseTypeAsWritten(true);
2832        Visit(TL.getBaseLoc());
2833      }
2834
2835      // Protocol qualifiers.
2836      if (DS.getProtocolQualifiers()) {
2837        assert(TL.getNumProtocols() > 0);
2838        assert(TL.getNumProtocols() == DS.getNumProtocolQualifiers());
2839        TL.setLAngleLoc(DS.getProtocolLAngleLoc());
2840        TL.setRAngleLoc(DS.getSourceRange().getEnd());
2841        for (unsigned i = 0, e = DS.getNumProtocolQualifiers(); i != e; ++i)
2842          TL.setProtocolLoc(i, DS.getProtocolLocs()[i]);
2843      } else {
2844        assert(TL.getNumProtocols() == 0);
2845        TL.setLAngleLoc(SourceLocation());
2846        TL.setRAngleLoc(SourceLocation());
2847      }
2848    }
2849    void VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
2850      TL.setStarLoc(SourceLocation());
2851      Visit(TL.getPointeeLoc());
2852    }
2853    void VisitTemplateSpecializationTypeLoc(TemplateSpecializationTypeLoc TL) {
2854      TypeSourceInfo *TInfo = 0;
2855      Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
2856
2857      // If we got no declarator info from previous Sema routines,
2858      // just fill with the typespec loc.
2859      if (!TInfo) {
2860        TL.initialize(Context, DS.getTypeSpecTypeNameLoc());
2861        return;
2862      }
2863
2864      TypeLoc OldTL = TInfo->getTypeLoc();
2865      if (TInfo->getType()->getAs<ElaboratedType>()) {
2866        ElaboratedTypeLoc ElabTL = cast<ElaboratedTypeLoc>(OldTL);
2867        TemplateSpecializationTypeLoc NamedTL =
2868          cast<TemplateSpecializationTypeLoc>(ElabTL.getNamedTypeLoc());
2869        TL.copy(NamedTL);
2870      }
2871      else
2872        TL.copy(cast<TemplateSpecializationTypeLoc>(OldTL));
2873    }
2874    void VisitTypeOfExprTypeLoc(TypeOfExprTypeLoc TL) {
2875      assert(DS.getTypeSpecType() == DeclSpec::TST_typeofExpr);
2876      TL.setTypeofLoc(DS.getTypeSpecTypeLoc());
2877      TL.setParensRange(DS.getTypeofParensRange());
2878    }
2879    void VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
2880      assert(DS.getTypeSpecType() == DeclSpec::TST_typeofType);
2881      TL.setTypeofLoc(DS.getTypeSpecTypeLoc());
2882      TL.setParensRange(DS.getTypeofParensRange());
2883      assert(DS.getRepAsType());
2884      TypeSourceInfo *TInfo = 0;
2885      Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
2886      TL.setUnderlyingTInfo(TInfo);
2887    }
2888    void VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
2889      // FIXME: This holds only because we only have one unary transform.
2890      assert(DS.getTypeSpecType() == DeclSpec::TST_underlyingType);
2891      TL.setKWLoc(DS.getTypeSpecTypeLoc());
2892      TL.setParensRange(DS.getTypeofParensRange());
2893      assert(DS.getRepAsType());
2894      TypeSourceInfo *TInfo = 0;
2895      Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
2896      TL.setUnderlyingTInfo(TInfo);
2897    }
2898    void VisitBuiltinTypeLoc(BuiltinTypeLoc TL) {
2899      // By default, use the source location of the type specifier.
2900      TL.setBuiltinLoc(DS.getTypeSpecTypeLoc());
2901      if (TL.needsExtraLocalData()) {
2902        // Set info for the written builtin specifiers.
2903        TL.getWrittenBuiltinSpecs() = DS.getWrittenBuiltinSpecs();
2904        // Try to have a meaningful source location.
2905        if (TL.getWrittenSignSpec() != TSS_unspecified)
2906          // Sign spec loc overrides the others (e.g., 'unsigned long').
2907          TL.setBuiltinLoc(DS.getTypeSpecSignLoc());
2908        else if (TL.getWrittenWidthSpec() != TSW_unspecified)
2909          // Width spec loc overrides type spec loc (e.g., 'short int').
2910          TL.setBuiltinLoc(DS.getTypeSpecWidthLoc());
2911      }
2912    }
2913    void VisitElaboratedTypeLoc(ElaboratedTypeLoc TL) {
2914      ElaboratedTypeKeyword Keyword
2915        = TypeWithKeyword::getKeywordForTypeSpec(DS.getTypeSpecType());
2916      if (DS.getTypeSpecType() == TST_typename) {
2917        TypeSourceInfo *TInfo = 0;
2918        Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
2919        if (TInfo) {
2920          TL.copy(cast<ElaboratedTypeLoc>(TInfo->getTypeLoc()));
2921          return;
2922        }
2923      }
2924      TL.setElaboratedKeywordLoc(Keyword != ETK_None
2925                                 ? DS.getTypeSpecTypeLoc()
2926                                 : SourceLocation());
2927      const CXXScopeSpec& SS = DS.getTypeSpecScope();
2928      TL.setQualifierLoc(SS.getWithLocInContext(Context));
2929      Visit(TL.getNextTypeLoc().getUnqualifiedLoc());
2930    }
2931    void VisitDependentNameTypeLoc(DependentNameTypeLoc TL) {
2932      assert(DS.getTypeSpecType() == TST_typename);
2933      TypeSourceInfo *TInfo = 0;
2934      Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
2935      assert(TInfo);
2936      TL.copy(cast<DependentNameTypeLoc>(TInfo->getTypeLoc()));
2937    }
2938    void VisitDependentTemplateSpecializationTypeLoc(
2939                                 DependentTemplateSpecializationTypeLoc TL) {
2940      assert(DS.getTypeSpecType() == TST_typename);
2941      TypeSourceInfo *TInfo = 0;
2942      Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
2943      assert(TInfo);
2944      TL.copy(cast<DependentTemplateSpecializationTypeLoc>(
2945                TInfo->getTypeLoc()));
2946    }
2947    void VisitTagTypeLoc(TagTypeLoc TL) {
2948      TL.setNameLoc(DS.getTypeSpecTypeNameLoc());
2949    }
2950    void VisitAtomicTypeLoc(AtomicTypeLoc TL) {
2951      TL.setKWLoc(DS.getTypeSpecTypeLoc());
2952      TL.setParensRange(DS.getTypeofParensRange());
2953
2954      TypeSourceInfo *TInfo = 0;
2955      Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
2956      TL.getValueLoc().initializeFullCopy(TInfo->getTypeLoc());
2957    }
2958
2959    void VisitTypeLoc(TypeLoc TL) {
2960      // FIXME: add other typespec types and change this to an assert.
2961      TL.initialize(Context, DS.getTypeSpecTypeLoc());
2962    }
2963  };
2964
2965  class DeclaratorLocFiller : public TypeLocVisitor<DeclaratorLocFiller> {
2966    ASTContext &Context;
2967    const DeclaratorChunk &Chunk;
2968
2969  public:
2970    DeclaratorLocFiller(ASTContext &Context, const DeclaratorChunk &Chunk)
2971      : Context(Context), Chunk(Chunk) {}
2972
2973    void VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
2974      llvm_unreachable("qualified type locs not expected here!");
2975    }
2976
2977    void VisitAttributedTypeLoc(AttributedTypeLoc TL) {
2978      fillAttributedTypeLoc(TL, Chunk.getAttrs());
2979    }
2980    void VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
2981      assert(Chunk.Kind == DeclaratorChunk::BlockPointer);
2982      TL.setCaretLoc(Chunk.Loc);
2983    }
2984    void VisitPointerTypeLoc(PointerTypeLoc TL) {
2985      assert(Chunk.Kind == DeclaratorChunk::Pointer);
2986      TL.setStarLoc(Chunk.Loc);
2987    }
2988    void VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
2989      assert(Chunk.Kind == DeclaratorChunk::Pointer);
2990      TL.setStarLoc(Chunk.Loc);
2991    }
2992    void VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
2993      assert(Chunk.Kind == DeclaratorChunk::MemberPointer);
2994      const CXXScopeSpec& SS = Chunk.Mem.Scope();
2995      NestedNameSpecifierLoc NNSLoc = SS.getWithLocInContext(Context);
2996
2997      const Type* ClsTy = TL.getClass();
2998      QualType ClsQT = QualType(ClsTy, 0);
2999      TypeSourceInfo *ClsTInfo = Context.CreateTypeSourceInfo(ClsQT, 0);
3000      // Now copy source location info into the type loc component.
3001      TypeLoc ClsTL = ClsTInfo->getTypeLoc();
3002      switch (NNSLoc.getNestedNameSpecifier()->getKind()) {
3003      case NestedNameSpecifier::Identifier:
3004        assert(isa<DependentNameType>(ClsTy) && "Unexpected TypeLoc");
3005        {
3006          DependentNameTypeLoc DNTLoc = cast<DependentNameTypeLoc>(ClsTL);
3007          DNTLoc.setElaboratedKeywordLoc(SourceLocation());
3008          DNTLoc.setQualifierLoc(NNSLoc.getPrefix());
3009          DNTLoc.setNameLoc(NNSLoc.getLocalBeginLoc());
3010        }
3011        break;
3012
3013      case NestedNameSpecifier::TypeSpec:
3014      case NestedNameSpecifier::TypeSpecWithTemplate:
3015        if (isa<ElaboratedType>(ClsTy)) {
3016          ElaboratedTypeLoc ETLoc = *cast<ElaboratedTypeLoc>(&ClsTL);
3017          ETLoc.setElaboratedKeywordLoc(SourceLocation());
3018          ETLoc.setQualifierLoc(NNSLoc.getPrefix());
3019          TypeLoc NamedTL = ETLoc.getNamedTypeLoc();
3020          NamedTL.initializeFullCopy(NNSLoc.getTypeLoc());
3021        } else {
3022          ClsTL.initializeFullCopy(NNSLoc.getTypeLoc());
3023        }
3024        break;
3025
3026      case NestedNameSpecifier::Namespace:
3027      case NestedNameSpecifier::NamespaceAlias:
3028      case NestedNameSpecifier::Global:
3029        llvm_unreachable("Nested-name-specifier must name a type");
3030      }
3031
3032      // Finally fill in MemberPointerLocInfo fields.
3033      TL.setStarLoc(Chunk.Loc);
3034      TL.setClassTInfo(ClsTInfo);
3035    }
3036    void VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {
3037      assert(Chunk.Kind == DeclaratorChunk::Reference);
3038      // 'Amp' is misleading: this might have been originally
3039      /// spelled with AmpAmp.
3040      TL.setAmpLoc(Chunk.Loc);
3041    }
3042    void VisitRValueReferenceTypeLoc(RValueReferenceTypeLoc TL) {
3043      assert(Chunk.Kind == DeclaratorChunk::Reference);
3044      assert(!Chunk.Ref.LValueRef);
3045      TL.setAmpAmpLoc(Chunk.Loc);
3046    }
3047    void VisitArrayTypeLoc(ArrayTypeLoc TL) {
3048      assert(Chunk.Kind == DeclaratorChunk::Array);
3049      TL.setLBracketLoc(Chunk.Loc);
3050      TL.setRBracketLoc(Chunk.EndLoc);
3051      TL.setSizeExpr(static_cast<Expr*>(Chunk.Arr.NumElts));
3052    }
3053    void VisitFunctionTypeLoc(FunctionTypeLoc TL) {
3054      assert(Chunk.Kind == DeclaratorChunk::Function);
3055      TL.setLocalRangeBegin(Chunk.Loc);
3056      TL.setLocalRangeEnd(Chunk.EndLoc);
3057      TL.setTrailingReturn(!!Chunk.Fun.TrailingReturnType);
3058
3059      const DeclaratorChunk::FunctionTypeInfo &FTI = Chunk.Fun;
3060      for (unsigned i = 0, e = TL.getNumArgs(), tpi = 0; i != e; ++i) {
3061        ParmVarDecl *Param = cast<ParmVarDecl>(FTI.ArgInfo[i].Param);
3062        TL.setArg(tpi++, Param);
3063      }
3064      // FIXME: exception specs
3065    }
3066    void VisitParenTypeLoc(ParenTypeLoc TL) {
3067      assert(Chunk.Kind == DeclaratorChunk::Paren);
3068      TL.setLParenLoc(Chunk.Loc);
3069      TL.setRParenLoc(Chunk.EndLoc);
3070    }
3071
3072    void VisitTypeLoc(TypeLoc TL) {
3073      llvm_unreachable("unsupported TypeLoc kind in declarator!");
3074    }
3075  };
3076}
3077
3078/// \brief Create and instantiate a TypeSourceInfo with type source information.
3079///
3080/// \param T QualType referring to the type as written in source code.
3081///
3082/// \param ReturnTypeInfo For declarators whose return type does not show
3083/// up in the normal place in the declaration specifiers (such as a C++
3084/// conversion function), this pointer will refer to a type source information
3085/// for that return type.
3086TypeSourceInfo *
3087Sema::GetTypeSourceInfoForDeclarator(Declarator &D, QualType T,
3088                                     TypeSourceInfo *ReturnTypeInfo) {
3089  TypeSourceInfo *TInfo = Context.CreateTypeSourceInfo(T);
3090  UnqualTypeLoc CurrTL = TInfo->getTypeLoc().getUnqualifiedLoc();
3091
3092  // Handle parameter packs whose type is a pack expansion.
3093  if (isa<PackExpansionType>(T)) {
3094    cast<PackExpansionTypeLoc>(CurrTL).setEllipsisLoc(D.getEllipsisLoc());
3095    CurrTL = CurrTL.getNextTypeLoc().getUnqualifiedLoc();
3096  }
3097
3098  for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
3099    while (isa<AttributedTypeLoc>(CurrTL)) {
3100      AttributedTypeLoc TL = cast<AttributedTypeLoc>(CurrTL);
3101      fillAttributedTypeLoc(TL, D.getTypeObject(i).getAttrs());
3102      CurrTL = TL.getNextTypeLoc().getUnqualifiedLoc();
3103    }
3104
3105    DeclaratorLocFiller(Context, D.getTypeObject(i)).Visit(CurrTL);
3106    CurrTL = CurrTL.getNextTypeLoc().getUnqualifiedLoc();
3107  }
3108
3109  // If we have different source information for the return type, use
3110  // that.  This really only applies to C++ conversion functions.
3111  if (ReturnTypeInfo) {
3112    TypeLoc TL = ReturnTypeInfo->getTypeLoc();
3113    assert(TL.getFullDataSize() == CurrTL.getFullDataSize());
3114    memcpy(CurrTL.getOpaqueData(), TL.getOpaqueData(), TL.getFullDataSize());
3115  } else {
3116    TypeSpecLocFiller(Context, D.getDeclSpec()).Visit(CurrTL);
3117  }
3118
3119  return TInfo;
3120}
3121
3122/// \brief Create a LocInfoType to hold the given QualType and TypeSourceInfo.
3123ParsedType Sema::CreateParsedType(QualType T, TypeSourceInfo *TInfo) {
3124  // FIXME: LocInfoTypes are "transient", only needed for passing to/from Parser
3125  // and Sema during declaration parsing. Try deallocating/caching them when
3126  // it's appropriate, instead of allocating them and keeping them around.
3127  LocInfoType *LocT = (LocInfoType*)BumpAlloc.Allocate(sizeof(LocInfoType),
3128                                                       TypeAlignment);
3129  new (LocT) LocInfoType(T, TInfo);
3130  assert(LocT->getTypeClass() != T->getTypeClass() &&
3131         "LocInfoType's TypeClass conflicts with an existing Type class");
3132  return ParsedType::make(QualType(LocT, 0));
3133}
3134
3135void LocInfoType::getAsStringInternal(std::string &Str,
3136                                      const PrintingPolicy &Policy) const {
3137  llvm_unreachable("LocInfoType leaked into the type system; an opaque TypeTy*"
3138         " was used directly instead of getting the QualType through"
3139         " GetTypeFromParser");
3140}
3141
3142TypeResult Sema::ActOnTypeName(Scope *S, Declarator &D) {
3143  // C99 6.7.6: Type names have no identifier.  This is already validated by
3144  // the parser.
3145  assert(D.getIdentifier() == 0 && "Type name should have no identifier!");
3146
3147  TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
3148  QualType T = TInfo->getType();
3149  if (D.isInvalidType())
3150    return true;
3151
3152  // Make sure there are no unused decl attributes on the declarator.
3153  // We don't want to do this for ObjC parameters because we're going
3154  // to apply them to the actual parameter declaration.
3155  if (D.getContext() != Declarator::ObjCParameterContext)
3156    checkUnusedDeclAttributes(D);
3157
3158  if (getLangOptions().CPlusPlus) {
3159    // Check that there are no default arguments (C++ only).
3160    CheckExtraCXXDefaultArguments(D);
3161  }
3162
3163  return CreateParsedType(T, TInfo);
3164}
3165
3166ParsedType Sema::ActOnObjCInstanceType(SourceLocation Loc) {
3167  QualType T = Context.getObjCInstanceType();
3168  TypeSourceInfo *TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
3169  return CreateParsedType(T, TInfo);
3170}
3171
3172
3173//===----------------------------------------------------------------------===//
3174// Type Attribute Processing
3175//===----------------------------------------------------------------------===//
3176
3177/// HandleAddressSpaceTypeAttribute - Process an address_space attribute on the
3178/// specified type.  The attribute contains 1 argument, the id of the address
3179/// space for the type.
3180static void HandleAddressSpaceTypeAttribute(QualType &Type,
3181                                            const AttributeList &Attr, Sema &S){
3182
3183  // If this type is already address space qualified, reject it.
3184  // ISO/IEC TR 18037 S5.3 (amending C99 6.7.3): "No type shall be qualified by
3185  // qualifiers for two or more different address spaces."
3186  if (Type.getAddressSpace()) {
3187    S.Diag(Attr.getLoc(), diag::err_attribute_address_multiple_qualifiers);
3188    Attr.setInvalid();
3189    return;
3190  }
3191
3192  // ISO/IEC TR 18037 S5.3 (amending C99 6.7.3): "A function type shall not be
3193  // qualified by an address-space qualifier."
3194  if (Type->isFunctionType()) {
3195    S.Diag(Attr.getLoc(), diag::err_attribute_address_function_type);
3196    Attr.setInvalid();
3197    return;
3198  }
3199
3200  // Check the attribute arguments.
3201  if (Attr.getNumArgs() != 1) {
3202    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
3203    Attr.setInvalid();
3204    return;
3205  }
3206  Expr *ASArgExpr = static_cast<Expr *>(Attr.getArg(0));
3207  llvm::APSInt addrSpace(32);
3208  if (ASArgExpr->isTypeDependent() || ASArgExpr->isValueDependent() ||
3209      !ASArgExpr->isIntegerConstantExpr(addrSpace, S.Context)) {
3210    S.Diag(Attr.getLoc(), diag::err_attribute_address_space_not_int)
3211      << ASArgExpr->getSourceRange();
3212    Attr.setInvalid();
3213    return;
3214  }
3215
3216  // Bounds checking.
3217  if (addrSpace.isSigned()) {
3218    if (addrSpace.isNegative()) {
3219      S.Diag(Attr.getLoc(), diag::err_attribute_address_space_negative)
3220        << ASArgExpr->getSourceRange();
3221      Attr.setInvalid();
3222      return;
3223    }
3224    addrSpace.setIsSigned(false);
3225  }
3226  llvm::APSInt max(addrSpace.getBitWidth());
3227  max = Qualifiers::MaxAddressSpace;
3228  if (addrSpace > max) {
3229    S.Diag(Attr.getLoc(), diag::err_attribute_address_space_too_high)
3230      << Qualifiers::MaxAddressSpace << ASArgExpr->getSourceRange();
3231    Attr.setInvalid();
3232    return;
3233  }
3234
3235  unsigned ASIdx = static_cast<unsigned>(addrSpace.getZExtValue());
3236  Type = S.Context.getAddrSpaceQualType(Type, ASIdx);
3237}
3238
3239/// handleObjCOwnershipTypeAttr - Process an objc_ownership
3240/// attribute on the specified type.
3241///
3242/// Returns 'true' if the attribute was handled.
3243static bool handleObjCOwnershipTypeAttr(TypeProcessingState &state,
3244                                       AttributeList &attr,
3245                                       QualType &type) {
3246  bool NonObjCPointer = false;
3247
3248  if (!type->isDependentType()) {
3249    if (const PointerType *ptr = type->getAs<PointerType>()) {
3250      QualType pointee = ptr->getPointeeType();
3251      if (pointee->isObjCRetainableType() || pointee->isPointerType())
3252        return false;
3253      // It is important not to lose the source info that there was an attribute
3254      // applied to non-objc pointer. We will create an attributed type but
3255      // its type will be the same as the original type.
3256      NonObjCPointer = true;
3257    } else if (!type->isObjCRetainableType()) {
3258      return false;
3259    }
3260  }
3261
3262  Sema &S = state.getSema();
3263  SourceLocation AttrLoc = attr.getLoc();
3264  if (AttrLoc.isMacroID())
3265    AttrLoc = S.getSourceManager().getImmediateExpansionRange(AttrLoc).first;
3266
3267  if (type.getQualifiers().getObjCLifetime()) {
3268    S.Diag(AttrLoc, diag::err_attr_objc_ownership_redundant)
3269      << type;
3270    return true;
3271  }
3272
3273  if (!attr.getParameterName()) {
3274    S.Diag(AttrLoc, diag::err_attribute_argument_n_not_string)
3275      << "objc_ownership" << 1;
3276    attr.setInvalid();
3277    return true;
3278  }
3279
3280  Qualifiers::ObjCLifetime lifetime;
3281  if (attr.getParameterName()->isStr("none"))
3282    lifetime = Qualifiers::OCL_ExplicitNone;
3283  else if (attr.getParameterName()->isStr("strong"))
3284    lifetime = Qualifiers::OCL_Strong;
3285  else if (attr.getParameterName()->isStr("weak"))
3286    lifetime = Qualifiers::OCL_Weak;
3287  else if (attr.getParameterName()->isStr("autoreleasing"))
3288    lifetime = Qualifiers::OCL_Autoreleasing;
3289  else {
3290    S.Diag(AttrLoc, diag::warn_attribute_type_not_supported)
3291      << "objc_ownership" << attr.getParameterName();
3292    attr.setInvalid();
3293    return true;
3294  }
3295
3296  // Consume lifetime attributes without further comment outside of
3297  // ARC mode.
3298  if (!S.getLangOptions().ObjCAutoRefCount)
3299    return true;
3300
3301  if (NonObjCPointer) {
3302    StringRef name = attr.getName()->getName();
3303    switch (lifetime) {
3304    case Qualifiers::OCL_None:
3305    case Qualifiers::OCL_ExplicitNone:
3306      break;
3307    case Qualifiers::OCL_Strong: name = "__strong"; break;
3308    case Qualifiers::OCL_Weak: name = "__weak"; break;
3309    case Qualifiers::OCL_Autoreleasing: name = "__autoreleasing"; break;
3310    }
3311    S.Diag(AttrLoc, diag::warn_objc_object_attribute_wrong_type)
3312      << name << type;
3313  }
3314
3315  Qualifiers qs;
3316  qs.setObjCLifetime(lifetime);
3317  QualType origType = type;
3318  if (!NonObjCPointer)
3319    type = S.Context.getQualifiedType(type, qs);
3320
3321  // If we have a valid source location for the attribute, use an
3322  // AttributedType instead.
3323  if (AttrLoc.isValid())
3324    type = S.Context.getAttributedType(AttributedType::attr_objc_ownership,
3325                                       origType, type);
3326
3327  // Forbid __weak if the runtime doesn't support it.
3328  if (lifetime == Qualifiers::OCL_Weak &&
3329      !S.getLangOptions().ObjCRuntimeHasWeak && !NonObjCPointer) {
3330
3331    // Actually, delay this until we know what we're parsing.
3332    if (S.DelayedDiagnostics.shouldDelayDiagnostics()) {
3333      S.DelayedDiagnostics.add(
3334          sema::DelayedDiagnostic::makeForbiddenType(
3335              S.getSourceManager().getExpansionLoc(AttrLoc),
3336              diag::err_arc_weak_no_runtime, type, /*ignored*/ 0));
3337    } else {
3338      S.Diag(AttrLoc, diag::err_arc_weak_no_runtime);
3339    }
3340
3341    attr.setInvalid();
3342    return true;
3343  }
3344
3345  // Forbid __weak for class objects marked as
3346  // objc_arc_weak_reference_unavailable
3347  if (lifetime == Qualifiers::OCL_Weak) {
3348    QualType T = type;
3349    while (const PointerType *ptr = T->getAs<PointerType>())
3350      T = ptr->getPointeeType();
3351    if (const ObjCObjectPointerType *ObjT = T->getAs<ObjCObjectPointerType>()) {
3352      ObjCInterfaceDecl *Class = ObjT->getInterfaceDecl();
3353      if (Class->isArcWeakrefUnavailable()) {
3354          S.Diag(AttrLoc, diag::err_arc_unsupported_weak_class);
3355          S.Diag(ObjT->getInterfaceDecl()->getLocation(),
3356                 diag::note_class_declared);
3357      }
3358    }
3359  }
3360
3361  return true;
3362}
3363
3364/// handleObjCGCTypeAttr - Process the __attribute__((objc_gc)) type
3365/// attribute on the specified type.  Returns true to indicate that
3366/// the attribute was handled, false to indicate that the type does
3367/// not permit the attribute.
3368static bool handleObjCGCTypeAttr(TypeProcessingState &state,
3369                                 AttributeList &attr,
3370                                 QualType &type) {
3371  Sema &S = state.getSema();
3372
3373  // Delay if this isn't some kind of pointer.
3374  if (!type->isPointerType() &&
3375      !type->isObjCObjectPointerType() &&
3376      !type->isBlockPointerType())
3377    return false;
3378
3379  if (type.getObjCGCAttr() != Qualifiers::GCNone) {
3380    S.Diag(attr.getLoc(), diag::err_attribute_multiple_objc_gc);
3381    attr.setInvalid();
3382    return true;
3383  }
3384
3385  // Check the attribute arguments.
3386  if (!attr.getParameterName()) {
3387    S.Diag(attr.getLoc(), diag::err_attribute_argument_n_not_string)
3388      << "objc_gc" << 1;
3389    attr.setInvalid();
3390    return true;
3391  }
3392  Qualifiers::GC GCAttr;
3393  if (attr.getNumArgs() != 0) {
3394    S.Diag(attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
3395    attr.setInvalid();
3396    return true;
3397  }
3398  if (attr.getParameterName()->isStr("weak"))
3399    GCAttr = Qualifiers::Weak;
3400  else if (attr.getParameterName()->isStr("strong"))
3401    GCAttr = Qualifiers::Strong;
3402  else {
3403    S.Diag(attr.getLoc(), diag::warn_attribute_type_not_supported)
3404      << "objc_gc" << attr.getParameterName();
3405    attr.setInvalid();
3406    return true;
3407  }
3408
3409  QualType origType = type;
3410  type = S.Context.getObjCGCQualType(origType, GCAttr);
3411
3412  // Make an attributed type to preserve the source information.
3413  if (attr.getLoc().isValid())
3414    type = S.Context.getAttributedType(AttributedType::attr_objc_gc,
3415                                       origType, type);
3416
3417  return true;
3418}
3419
3420namespace {
3421  /// A helper class to unwrap a type down to a function for the
3422  /// purposes of applying attributes there.
3423  ///
3424  /// Use:
3425  ///   FunctionTypeUnwrapper unwrapped(SemaRef, T);
3426  ///   if (unwrapped.isFunctionType()) {
3427  ///     const FunctionType *fn = unwrapped.get();
3428  ///     // change fn somehow
3429  ///     T = unwrapped.wrap(fn);
3430  ///   }
3431  struct FunctionTypeUnwrapper {
3432    enum WrapKind {
3433      Desugar,
3434      Parens,
3435      Pointer,
3436      BlockPointer,
3437      Reference,
3438      MemberPointer
3439    };
3440
3441    QualType Original;
3442    const FunctionType *Fn;
3443    SmallVector<unsigned char /*WrapKind*/, 8> Stack;
3444
3445    FunctionTypeUnwrapper(Sema &S, QualType T) : Original(T) {
3446      while (true) {
3447        const Type *Ty = T.getTypePtr();
3448        if (isa<FunctionType>(Ty)) {
3449          Fn = cast<FunctionType>(Ty);
3450          return;
3451        } else if (isa<ParenType>(Ty)) {
3452          T = cast<ParenType>(Ty)->getInnerType();
3453          Stack.push_back(Parens);
3454        } else if (isa<PointerType>(Ty)) {
3455          T = cast<PointerType>(Ty)->getPointeeType();
3456          Stack.push_back(Pointer);
3457        } else if (isa<BlockPointerType>(Ty)) {
3458          T = cast<BlockPointerType>(Ty)->getPointeeType();
3459          Stack.push_back(BlockPointer);
3460        } else if (isa<MemberPointerType>(Ty)) {
3461          T = cast<MemberPointerType>(Ty)->getPointeeType();
3462          Stack.push_back(MemberPointer);
3463        } else if (isa<ReferenceType>(Ty)) {
3464          T = cast<ReferenceType>(Ty)->getPointeeType();
3465          Stack.push_back(Reference);
3466        } else {
3467          const Type *DTy = Ty->getUnqualifiedDesugaredType();
3468          if (Ty == DTy) {
3469            Fn = 0;
3470            return;
3471          }
3472
3473          T = QualType(DTy, 0);
3474          Stack.push_back(Desugar);
3475        }
3476      }
3477    }
3478
3479    bool isFunctionType() const { return (Fn != 0); }
3480    const FunctionType *get() const { return Fn; }
3481
3482    QualType wrap(Sema &S, const FunctionType *New) {
3483      // If T wasn't modified from the unwrapped type, do nothing.
3484      if (New == get()) return Original;
3485
3486      Fn = New;
3487      return wrap(S.Context, Original, 0);
3488    }
3489
3490  private:
3491    QualType wrap(ASTContext &C, QualType Old, unsigned I) {
3492      if (I == Stack.size())
3493        return C.getQualifiedType(Fn, Old.getQualifiers());
3494
3495      // Build up the inner type, applying the qualifiers from the old
3496      // type to the new type.
3497      SplitQualType SplitOld = Old.split();
3498
3499      // As a special case, tail-recurse if there are no qualifiers.
3500      if (SplitOld.second.empty())
3501        return wrap(C, SplitOld.first, I);
3502      return C.getQualifiedType(wrap(C, SplitOld.first, I), SplitOld.second);
3503    }
3504
3505    QualType wrap(ASTContext &C, const Type *Old, unsigned I) {
3506      if (I == Stack.size()) return QualType(Fn, 0);
3507
3508      switch (static_cast<WrapKind>(Stack[I++])) {
3509      case Desugar:
3510        // This is the point at which we potentially lose source
3511        // information.
3512        return wrap(C, Old->getUnqualifiedDesugaredType(), I);
3513
3514      case Parens: {
3515        QualType New = wrap(C, cast<ParenType>(Old)->getInnerType(), I);
3516        return C.getParenType(New);
3517      }
3518
3519      case Pointer: {
3520        QualType New = wrap(C, cast<PointerType>(Old)->getPointeeType(), I);
3521        return C.getPointerType(New);
3522      }
3523
3524      case BlockPointer: {
3525        QualType New = wrap(C, cast<BlockPointerType>(Old)->getPointeeType(),I);
3526        return C.getBlockPointerType(New);
3527      }
3528
3529      case MemberPointer: {
3530        const MemberPointerType *OldMPT = cast<MemberPointerType>(Old);
3531        QualType New = wrap(C, OldMPT->getPointeeType(), I);
3532        return C.getMemberPointerType(New, OldMPT->getClass());
3533      }
3534
3535      case Reference: {
3536        const ReferenceType *OldRef = cast<ReferenceType>(Old);
3537        QualType New = wrap(C, OldRef->getPointeeType(), I);
3538        if (isa<LValueReferenceType>(OldRef))
3539          return C.getLValueReferenceType(New, OldRef->isSpelledAsLValue());
3540        else
3541          return C.getRValueReferenceType(New);
3542      }
3543      }
3544
3545      llvm_unreachable("unknown wrapping kind");
3546    }
3547  };
3548}
3549
3550/// Process an individual function attribute.  Returns true to
3551/// indicate that the attribute was handled, false if it wasn't.
3552static bool handleFunctionTypeAttr(TypeProcessingState &state,
3553                                   AttributeList &attr,
3554                                   QualType &type) {
3555  Sema &S = state.getSema();
3556
3557  FunctionTypeUnwrapper unwrapped(S, type);
3558
3559  if (attr.getKind() == AttributeList::AT_noreturn) {
3560    if (S.CheckNoReturnAttr(attr))
3561      return true;
3562
3563    // Delay if this is not a function type.
3564    if (!unwrapped.isFunctionType())
3565      return false;
3566
3567    // Otherwise we can process right away.
3568    FunctionType::ExtInfo EI = unwrapped.get()->getExtInfo().withNoReturn(true);
3569    type = unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
3570    return true;
3571  }
3572
3573  // ns_returns_retained is not always a type attribute, but if we got
3574  // here, we're treating it as one right now.
3575  if (attr.getKind() == AttributeList::AT_ns_returns_retained) {
3576    assert(S.getLangOptions().ObjCAutoRefCount &&
3577           "ns_returns_retained treated as type attribute in non-ARC");
3578    if (attr.getNumArgs()) return true;
3579
3580    // Delay if this is not a function type.
3581    if (!unwrapped.isFunctionType())
3582      return false;
3583
3584    FunctionType::ExtInfo EI
3585      = unwrapped.get()->getExtInfo().withProducesResult(true);
3586    type = unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
3587    return true;
3588  }
3589
3590  if (attr.getKind() == AttributeList::AT_regparm) {
3591    unsigned value;
3592    if (S.CheckRegparmAttr(attr, value))
3593      return true;
3594
3595    // Delay if this is not a function type.
3596    if (!unwrapped.isFunctionType())
3597      return false;
3598
3599    // Diagnose regparm with fastcall.
3600    const FunctionType *fn = unwrapped.get();
3601    CallingConv CC = fn->getCallConv();
3602    if (CC == CC_X86FastCall) {
3603      S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
3604        << FunctionType::getNameForCallConv(CC)
3605        << "regparm";
3606      attr.setInvalid();
3607      return true;
3608    }
3609
3610    FunctionType::ExtInfo EI =
3611      unwrapped.get()->getExtInfo().withRegParm(value);
3612    type = unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
3613    return true;
3614  }
3615
3616  // Otherwise, a calling convention.
3617  CallingConv CC;
3618  if (S.CheckCallingConvAttr(attr, CC))
3619    return true;
3620
3621  // Delay if the type didn't work out to a function.
3622  if (!unwrapped.isFunctionType()) return false;
3623
3624  const FunctionType *fn = unwrapped.get();
3625  CallingConv CCOld = fn->getCallConv();
3626  if (S.Context.getCanonicalCallConv(CC) ==
3627      S.Context.getCanonicalCallConv(CCOld)) {
3628    FunctionType::ExtInfo EI= unwrapped.get()->getExtInfo().withCallingConv(CC);
3629    type = unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
3630    return true;
3631  }
3632
3633  if (CCOld != (S.LangOpts.MRTD ? CC_X86StdCall : CC_Default)) {
3634    // Should we diagnose reapplications of the same convention?
3635    S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
3636      << FunctionType::getNameForCallConv(CC)
3637      << FunctionType::getNameForCallConv(CCOld);
3638    attr.setInvalid();
3639    return true;
3640  }
3641
3642  // Diagnose the use of X86 fastcall on varargs or unprototyped functions.
3643  if (CC == CC_X86FastCall) {
3644    if (isa<FunctionNoProtoType>(fn)) {
3645      S.Diag(attr.getLoc(), diag::err_cconv_knr)
3646        << FunctionType::getNameForCallConv(CC);
3647      attr.setInvalid();
3648      return true;
3649    }
3650
3651    const FunctionProtoType *FnP = cast<FunctionProtoType>(fn);
3652    if (FnP->isVariadic()) {
3653      S.Diag(attr.getLoc(), diag::err_cconv_varargs)
3654        << FunctionType::getNameForCallConv(CC);
3655      attr.setInvalid();
3656      return true;
3657    }
3658
3659    // Also diagnose fastcall with regparm.
3660    if (fn->getHasRegParm()) {
3661      S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
3662        << "regparm"
3663        << FunctionType::getNameForCallConv(CC);
3664      attr.setInvalid();
3665      return true;
3666    }
3667  }
3668
3669  FunctionType::ExtInfo EI = unwrapped.get()->getExtInfo().withCallingConv(CC);
3670  type = unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
3671  return true;
3672}
3673
3674/// Handle OpenCL image access qualifiers: read_only, write_only, read_write
3675static void HandleOpenCLImageAccessAttribute(QualType& CurType,
3676                                             const AttributeList &Attr,
3677                                             Sema &S) {
3678  // Check the attribute arguments.
3679  if (Attr.getNumArgs() != 1) {
3680    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
3681    Attr.setInvalid();
3682    return;
3683  }
3684  Expr *sizeExpr = static_cast<Expr *>(Attr.getArg(0));
3685  llvm::APSInt arg(32);
3686  if (sizeExpr->isTypeDependent() || sizeExpr->isValueDependent() ||
3687      !sizeExpr->isIntegerConstantExpr(arg, S.Context)) {
3688    S.Diag(Attr.getLoc(), diag::err_attribute_argument_not_int)
3689      << "opencl_image_access" << sizeExpr->getSourceRange();
3690    Attr.setInvalid();
3691    return;
3692  }
3693  unsigned iarg = static_cast<unsigned>(arg.getZExtValue());
3694  switch (iarg) {
3695  case CLIA_read_only:
3696  case CLIA_write_only:
3697  case CLIA_read_write:
3698    // Implemented in a separate patch
3699    break;
3700  default:
3701    // Implemented in a separate patch
3702    S.Diag(Attr.getLoc(), diag::err_attribute_invalid_size)
3703      << sizeExpr->getSourceRange();
3704    Attr.setInvalid();
3705    break;
3706  }
3707}
3708
3709/// HandleVectorSizeAttribute - this attribute is only applicable to integral
3710/// and float scalars, although arrays, pointers, and function return values are
3711/// allowed in conjunction with this construct. Aggregates with this attribute
3712/// are invalid, even if they are of the same size as a corresponding scalar.
3713/// The raw attribute should contain precisely 1 argument, the vector size for
3714/// the variable, measured in bytes. If curType and rawAttr are well formed,
3715/// this routine will return a new vector type.
3716static void HandleVectorSizeAttr(QualType& CurType, const AttributeList &Attr,
3717                                 Sema &S) {
3718  // Check the attribute arguments.
3719  if (Attr.getNumArgs() != 1) {
3720    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
3721    Attr.setInvalid();
3722    return;
3723  }
3724  Expr *sizeExpr = static_cast<Expr *>(Attr.getArg(0));
3725  llvm::APSInt vecSize(32);
3726  if (sizeExpr->isTypeDependent() || sizeExpr->isValueDependent() ||
3727      !sizeExpr->isIntegerConstantExpr(vecSize, S.Context)) {
3728    S.Diag(Attr.getLoc(), diag::err_attribute_argument_not_int)
3729      << "vector_size" << sizeExpr->getSourceRange();
3730    Attr.setInvalid();
3731    return;
3732  }
3733  // the base type must be integer or float, and can't already be a vector.
3734  if (!CurType->isIntegerType() && !CurType->isRealFloatingType()) {
3735    S.Diag(Attr.getLoc(), diag::err_attribute_invalid_vector_type) << CurType;
3736    Attr.setInvalid();
3737    return;
3738  }
3739  unsigned typeSize = static_cast<unsigned>(S.Context.getTypeSize(CurType));
3740  // vecSize is specified in bytes - convert to bits.
3741  unsigned vectorSize = static_cast<unsigned>(vecSize.getZExtValue() * 8);
3742
3743  // the vector size needs to be an integral multiple of the type size.
3744  if (vectorSize % typeSize) {
3745    S.Diag(Attr.getLoc(), diag::err_attribute_invalid_size)
3746      << sizeExpr->getSourceRange();
3747    Attr.setInvalid();
3748    return;
3749  }
3750  if (vectorSize == 0) {
3751    S.Diag(Attr.getLoc(), diag::err_attribute_zero_size)
3752      << sizeExpr->getSourceRange();
3753    Attr.setInvalid();
3754    return;
3755  }
3756
3757  // Success! Instantiate the vector type, the number of elements is > 0, and
3758  // not required to be a power of 2, unlike GCC.
3759  CurType = S.Context.getVectorType(CurType, vectorSize/typeSize,
3760                                    VectorType::GenericVector);
3761}
3762
3763/// \brief Process the OpenCL-like ext_vector_type attribute when it occurs on
3764/// a type.
3765static void HandleExtVectorTypeAttr(QualType &CurType,
3766                                    const AttributeList &Attr,
3767                                    Sema &S) {
3768  Expr *sizeExpr;
3769
3770  // Special case where the argument is a template id.
3771  if (Attr.getParameterName()) {
3772    CXXScopeSpec SS;
3773    SourceLocation TemplateKWLoc;
3774    UnqualifiedId id;
3775    id.setIdentifier(Attr.getParameterName(), Attr.getLoc());
3776
3777    ExprResult Size = S.ActOnIdExpression(S.getCurScope(), SS, TemplateKWLoc,
3778                                          id, false, false);
3779    if (Size.isInvalid())
3780      return;
3781
3782    sizeExpr = Size.get();
3783  } else {
3784    // check the attribute arguments.
3785    if (Attr.getNumArgs() != 1) {
3786      S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
3787      return;
3788    }
3789    sizeExpr = Attr.getArg(0);
3790  }
3791
3792  // Create the vector type.
3793  QualType T = S.BuildExtVectorType(CurType, sizeExpr, Attr.getLoc());
3794  if (!T.isNull())
3795    CurType = T;
3796}
3797
3798/// HandleNeonVectorTypeAttr - The "neon_vector_type" and
3799/// "neon_polyvector_type" attributes are used to create vector types that
3800/// are mangled according to ARM's ABI.  Otherwise, these types are identical
3801/// to those created with the "vector_size" attribute.  Unlike "vector_size"
3802/// the argument to these Neon attributes is the number of vector elements,
3803/// not the vector size in bytes.  The vector width and element type must
3804/// match one of the standard Neon vector types.
3805static void HandleNeonVectorTypeAttr(QualType& CurType,
3806                                     const AttributeList &Attr, Sema &S,
3807                                     VectorType::VectorKind VecKind,
3808                                     const char *AttrName) {
3809  // Check the attribute arguments.
3810  if (Attr.getNumArgs() != 1) {
3811    S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments) << 1;
3812    Attr.setInvalid();
3813    return;
3814  }
3815  // The number of elements must be an ICE.
3816  Expr *numEltsExpr = static_cast<Expr *>(Attr.getArg(0));
3817  llvm::APSInt numEltsInt(32);
3818  if (numEltsExpr->isTypeDependent() || numEltsExpr->isValueDependent() ||
3819      !numEltsExpr->isIntegerConstantExpr(numEltsInt, S.Context)) {
3820    S.Diag(Attr.getLoc(), diag::err_attribute_argument_not_int)
3821      << AttrName << numEltsExpr->getSourceRange();
3822    Attr.setInvalid();
3823    return;
3824  }
3825  // Only certain element types are supported for Neon vectors.
3826  const BuiltinType* BTy = CurType->getAs<BuiltinType>();
3827  if (!BTy ||
3828      (VecKind == VectorType::NeonPolyVector &&
3829       BTy->getKind() != BuiltinType::SChar &&
3830       BTy->getKind() != BuiltinType::Short) ||
3831      (BTy->getKind() != BuiltinType::SChar &&
3832       BTy->getKind() != BuiltinType::UChar &&
3833       BTy->getKind() != BuiltinType::Short &&
3834       BTy->getKind() != BuiltinType::UShort &&
3835       BTy->getKind() != BuiltinType::Int &&
3836       BTy->getKind() != BuiltinType::UInt &&
3837       BTy->getKind() != BuiltinType::LongLong &&
3838       BTy->getKind() != BuiltinType::ULongLong &&
3839       BTy->getKind() != BuiltinType::Float)) {
3840    S.Diag(Attr.getLoc(), diag::err_attribute_invalid_vector_type) <<CurType;
3841    Attr.setInvalid();
3842    return;
3843  }
3844  // The total size of the vector must be 64 or 128 bits.
3845  unsigned typeSize = static_cast<unsigned>(S.Context.getTypeSize(CurType));
3846  unsigned numElts = static_cast<unsigned>(numEltsInt.getZExtValue());
3847  unsigned vecSize = typeSize * numElts;
3848  if (vecSize != 64 && vecSize != 128) {
3849    S.Diag(Attr.getLoc(), diag::err_attribute_bad_neon_vector_size) << CurType;
3850    Attr.setInvalid();
3851    return;
3852  }
3853
3854  CurType = S.Context.getVectorType(CurType, numElts, VecKind);
3855}
3856
3857static void processTypeAttrs(TypeProcessingState &state, QualType &type,
3858                             bool isDeclSpec, AttributeList *attrs) {
3859  // Scan through and apply attributes to this type where it makes sense.  Some
3860  // attributes (such as __address_space__, __vector_size__, etc) apply to the
3861  // type, but others can be present in the type specifiers even though they
3862  // apply to the decl.  Here we apply type attributes and ignore the rest.
3863
3864  AttributeList *next;
3865  do {
3866    AttributeList &attr = *attrs;
3867    next = attr.getNext();
3868
3869    // Skip attributes that were marked to be invalid.
3870    if (attr.isInvalid())
3871      continue;
3872
3873    // If this is an attribute we can handle, do so now,
3874    // otherwise, add it to the FnAttrs list for rechaining.
3875    switch (attr.getKind()) {
3876    default: break;
3877
3878    case AttributeList::AT_may_alias:
3879      // FIXME: This attribute needs to actually be handled, but if we ignore
3880      // it it breaks large amounts of Linux software.
3881      attr.setUsedAsTypeAttr();
3882      break;
3883    case AttributeList::AT_address_space:
3884      HandleAddressSpaceTypeAttribute(type, attr, state.getSema());
3885      attr.setUsedAsTypeAttr();
3886      break;
3887    OBJC_POINTER_TYPE_ATTRS_CASELIST:
3888      if (!handleObjCPointerTypeAttr(state, attr, type))
3889        distributeObjCPointerTypeAttr(state, attr, type);
3890      attr.setUsedAsTypeAttr();
3891      break;
3892    case AttributeList::AT_vector_size:
3893      HandleVectorSizeAttr(type, attr, state.getSema());
3894      attr.setUsedAsTypeAttr();
3895      break;
3896    case AttributeList::AT_ext_vector_type:
3897      if (state.getDeclarator().getDeclSpec().getStorageClassSpec()
3898            != DeclSpec::SCS_typedef)
3899        HandleExtVectorTypeAttr(type, attr, state.getSema());
3900      attr.setUsedAsTypeAttr();
3901      break;
3902    case AttributeList::AT_neon_vector_type:
3903      HandleNeonVectorTypeAttr(type, attr, state.getSema(),
3904                               VectorType::NeonVector, "neon_vector_type");
3905      attr.setUsedAsTypeAttr();
3906      break;
3907    case AttributeList::AT_neon_polyvector_type:
3908      HandleNeonVectorTypeAttr(type, attr, state.getSema(),
3909                               VectorType::NeonPolyVector,
3910                               "neon_polyvector_type");
3911      attr.setUsedAsTypeAttr();
3912      break;
3913    case AttributeList::AT_opencl_image_access:
3914      HandleOpenCLImageAccessAttribute(type, attr, state.getSema());
3915      attr.setUsedAsTypeAttr();
3916      break;
3917
3918    case AttributeList::AT_ns_returns_retained:
3919      if (!state.getSema().getLangOptions().ObjCAutoRefCount)
3920	break;
3921      // fallthrough into the function attrs
3922
3923    FUNCTION_TYPE_ATTRS_CASELIST:
3924      attr.setUsedAsTypeAttr();
3925
3926      // Never process function type attributes as part of the
3927      // declaration-specifiers.
3928      if (isDeclSpec)
3929        distributeFunctionTypeAttrFromDeclSpec(state, attr, type);
3930
3931      // Otherwise, handle the possible delays.
3932      else if (!handleFunctionTypeAttr(state, attr, type))
3933        distributeFunctionTypeAttr(state, attr, type);
3934      break;
3935    }
3936  } while ((attrs = next));
3937}
3938
3939/// \brief Ensure that the type of the given expression is complete.
3940///
3941/// This routine checks whether the expression \p E has a complete type. If the
3942/// expression refers to an instantiable construct, that instantiation is
3943/// performed as needed to complete its type. Furthermore
3944/// Sema::RequireCompleteType is called for the expression's type (or in the
3945/// case of a reference type, the referred-to type).
3946///
3947/// \param E The expression whose type is required to be complete.
3948/// \param PD The partial diagnostic that will be printed out if the type cannot
3949/// be completed.
3950///
3951/// \returns \c true if the type of \p E is incomplete and diagnosed, \c false
3952/// otherwise.
3953bool Sema::RequireCompleteExprType(Expr *E, const PartialDiagnostic &PD,
3954                                   std::pair<SourceLocation,
3955                                             PartialDiagnostic> Note) {
3956  QualType T = E->getType();
3957
3958  // Fast path the case where the type is already complete.
3959  if (!T->isIncompleteType())
3960    return false;
3961
3962  // Incomplete array types may be completed by the initializer attached to
3963  // their definitions. For static data members of class templates we need to
3964  // instantiate the definition to get this initializer and complete the type.
3965  if (T->isIncompleteArrayType()) {
3966    if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParens())) {
3967      if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
3968        if (Var->isStaticDataMember() &&
3969            Var->getInstantiatedFromStaticDataMember()) {
3970
3971          MemberSpecializationInfo *MSInfo = Var->getMemberSpecializationInfo();
3972          assert(MSInfo && "Missing member specialization information?");
3973          if (MSInfo->getTemplateSpecializationKind()
3974                != TSK_ExplicitSpecialization) {
3975            // If we don't already have a point of instantiation, this is it.
3976            if (MSInfo->getPointOfInstantiation().isInvalid()) {
3977              MSInfo->setPointOfInstantiation(E->getLocStart());
3978
3979              // This is a modification of an existing AST node. Notify
3980              // listeners.
3981              if (ASTMutationListener *L = getASTMutationListener())
3982                L->StaticDataMemberInstantiated(Var);
3983            }
3984
3985            InstantiateStaticDataMemberDefinition(E->getExprLoc(), Var);
3986
3987            // Update the type to the newly instantiated definition's type both
3988            // here and within the expression.
3989            if (VarDecl *Def = Var->getDefinition()) {
3990              DRE->setDecl(Def);
3991              T = Def->getType();
3992              DRE->setType(T);
3993              E->setType(T);
3994            }
3995          }
3996
3997          // We still go on to try to complete the type independently, as it
3998          // may also require instantiations or diagnostics if it remains
3999          // incomplete.
4000        }
4001      }
4002    }
4003  }
4004
4005  // FIXME: Are there other cases which require instantiating something other
4006  // than the type to complete the type of an expression?
4007
4008  // Look through reference types and complete the referred type.
4009  if (const ReferenceType *Ref = T->getAs<ReferenceType>())
4010    T = Ref->getPointeeType();
4011
4012  return RequireCompleteType(E->getExprLoc(), T, PD, Note);
4013}
4014
4015/// @brief Ensure that the type T is a complete type.
4016///
4017/// This routine checks whether the type @p T is complete in any
4018/// context where a complete type is required. If @p T is a complete
4019/// type, returns false. If @p T is a class template specialization,
4020/// this routine then attempts to perform class template
4021/// instantiation. If instantiation fails, or if @p T is incomplete
4022/// and cannot be completed, issues the diagnostic @p diag (giving it
4023/// the type @p T) and returns true.
4024///
4025/// @param Loc  The location in the source that the incomplete type
4026/// diagnostic should refer to.
4027///
4028/// @param T  The type that this routine is examining for completeness.
4029///
4030/// @param PD The partial diagnostic that will be printed out if T is not a
4031/// complete type.
4032///
4033/// @returns @c true if @p T is incomplete and a diagnostic was emitted,
4034/// @c false otherwise.
4035bool Sema::RequireCompleteType(SourceLocation Loc, QualType T,
4036                               const PartialDiagnostic &PD,
4037                               std::pair<SourceLocation,
4038                                         PartialDiagnostic> Note) {
4039  unsigned diag = PD.getDiagID();
4040
4041  // FIXME: Add this assertion to make sure we always get instantiation points.
4042  //  assert(!Loc.isInvalid() && "Invalid location in RequireCompleteType");
4043  // FIXME: Add this assertion to help us flush out problems with
4044  // checking for dependent types and type-dependent expressions.
4045  //
4046  //  assert(!T->isDependentType() &&
4047  //         "Can't ask whether a dependent type is complete");
4048
4049  // If we have a complete type, we're done.
4050  NamedDecl *Def = 0;
4051  if (!T->isIncompleteType(&Def)) {
4052    // If we know about the definition but it is not visible, complain.
4053    if (diag != 0 && Def && !LookupResult::isVisible(Def)) {
4054      // Suppress this error outside of a SFINAE context if we've already
4055      // emitted the error once for this type. There's no usefulness in
4056      // repeating the diagnostic.
4057      // FIXME: Add a Fix-It that imports the corresponding module or includes
4058      // the header.
4059      if (isSFINAEContext() || HiddenDefinitions.insert(Def)) {
4060        Diag(Loc, diag::err_module_private_definition) << T;
4061        Diag(Def->getLocation(), diag::note_previous_definition);
4062      }
4063    }
4064
4065    return false;
4066  }
4067
4068  const TagType *Tag = T->getAs<TagType>();
4069  const ObjCInterfaceType *IFace = 0;
4070
4071  if (Tag) {
4072    // Avoid diagnosing invalid decls as incomplete.
4073    if (Tag->getDecl()->isInvalidDecl())
4074      return true;
4075
4076    // Give the external AST source a chance to complete the type.
4077    if (Tag->getDecl()->hasExternalLexicalStorage()) {
4078      Context.getExternalSource()->CompleteType(Tag->getDecl());
4079      if (!Tag->isIncompleteType())
4080        return false;
4081    }
4082  }
4083  else if ((IFace = T->getAs<ObjCInterfaceType>())) {
4084    // Avoid diagnosing invalid decls as incomplete.
4085    if (IFace->getDecl()->isInvalidDecl())
4086      return true;
4087
4088    // Give the external AST source a chance to complete the type.
4089    if (IFace->getDecl()->hasExternalLexicalStorage()) {
4090      Context.getExternalSource()->CompleteType(IFace->getDecl());
4091      if (!IFace->isIncompleteType())
4092        return false;
4093    }
4094  }
4095
4096  // If we have a class template specialization or a class member of a
4097  // class template specialization, or an array with known size of such,
4098  // try to instantiate it.
4099  QualType MaybeTemplate = T;
4100  if (const ConstantArrayType *Array = Context.getAsConstantArrayType(T))
4101    MaybeTemplate = Array->getElementType();
4102  if (const RecordType *Record = MaybeTemplate->getAs<RecordType>()) {
4103    if (ClassTemplateSpecializationDecl *ClassTemplateSpec
4104          = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) {
4105      if (ClassTemplateSpec->getSpecializationKind() == TSK_Undeclared)
4106        return InstantiateClassTemplateSpecialization(Loc, ClassTemplateSpec,
4107                                                      TSK_ImplicitInstantiation,
4108                                                      /*Complain=*/diag != 0);
4109    } else if (CXXRecordDecl *Rec
4110                 = dyn_cast<CXXRecordDecl>(Record->getDecl())) {
4111      if (CXXRecordDecl *Pattern = Rec->getInstantiatedFromMemberClass()) {
4112        MemberSpecializationInfo *MSInfo = Rec->getMemberSpecializationInfo();
4113        assert(MSInfo && "Missing member specialization information?");
4114        // This record was instantiated from a class within a template.
4115        if (MSInfo->getTemplateSpecializationKind()
4116                                               != TSK_ExplicitSpecialization)
4117          return InstantiateClass(Loc, Rec, Pattern,
4118                                  getTemplateInstantiationArgs(Rec),
4119                                  TSK_ImplicitInstantiation,
4120                                  /*Complain=*/diag != 0);
4121      }
4122    }
4123  }
4124
4125  if (diag == 0)
4126    return true;
4127
4128  // We have an incomplete type. Produce a diagnostic.
4129  Diag(Loc, PD) << T;
4130
4131  // If we have a note, produce it.
4132  if (!Note.first.isInvalid())
4133    Diag(Note.first, Note.second);
4134
4135  // If the type was a forward declaration of a class/struct/union
4136  // type, produce a note.
4137  if (Tag && !Tag->getDecl()->isInvalidDecl())
4138    Diag(Tag->getDecl()->getLocation(),
4139         Tag->isBeingDefined() ? diag::note_type_being_defined
4140                               : diag::note_forward_declaration)
4141      << QualType(Tag, 0);
4142
4143  // If the Objective-C class was a forward declaration, produce a note.
4144  if (IFace && !IFace->getDecl()->isInvalidDecl())
4145    Diag(IFace->getDecl()->getLocation(), diag::note_forward_class);
4146
4147  return true;
4148}
4149
4150bool Sema::RequireCompleteType(SourceLocation Loc, QualType T,
4151                               const PartialDiagnostic &PD) {
4152  return RequireCompleteType(Loc, T, PD,
4153                             std::make_pair(SourceLocation(), PDiag(0)));
4154}
4155
4156bool Sema::RequireCompleteType(SourceLocation Loc, QualType T,
4157                               unsigned DiagID) {
4158  return RequireCompleteType(Loc, T, PDiag(DiagID),
4159                             std::make_pair(SourceLocation(), PDiag(0)));
4160}
4161
4162/// @brief Ensure that the type T is a literal type.
4163///
4164/// This routine checks whether the type @p T is a literal type. If @p T is an
4165/// incomplete type, an attempt is made to complete it. If @p T is a literal
4166/// type, or @p AllowIncompleteType is true and @p T is an incomplete type,
4167/// returns false. Otherwise, this routine issues the diagnostic @p PD (giving
4168/// it the type @p T), along with notes explaining why the type is not a
4169/// literal type, and returns true.
4170///
4171/// @param Loc  The location in the source that the non-literal type
4172/// diagnostic should refer to.
4173///
4174/// @param T  The type that this routine is examining for literalness.
4175///
4176/// @param PD The partial diagnostic that will be printed out if T is not a
4177/// literal type.
4178///
4179/// @param AllowIncompleteType If true, an incomplete type will be considered
4180/// acceptable.
4181///
4182/// @returns @c true if @p T is not a literal type and a diagnostic was emitted,
4183/// @c false otherwise.
4184bool Sema::RequireLiteralType(SourceLocation Loc, QualType T,
4185                              const PartialDiagnostic &PD,
4186                              bool AllowIncompleteType) {
4187  assert(!T->isDependentType() && "type should not be dependent");
4188
4189  bool Incomplete = RequireCompleteType(Loc, T, 0);
4190  if (T->isLiteralType() ||
4191      (AllowIncompleteType && Incomplete && !T->isVoidType()))
4192    return false;
4193
4194  if (PD.getDiagID() == 0)
4195    return true;
4196
4197  Diag(Loc, PD) << T;
4198
4199  if (T->isVariableArrayType())
4200    return true;
4201
4202  const RecordType *RT = T->getBaseElementTypeUnsafe()->getAs<RecordType>();
4203  if (!RT)
4204    return true;
4205
4206  const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
4207
4208  // If the class has virtual base classes, then it's not an aggregate, and
4209  // cannot have any constexpr constructors, so is non-literal. This is better
4210  // to diagnose than the resulting absence of constexpr constructors.
4211  if (RD->getNumVBases()) {
4212    Diag(RD->getLocation(), diag::note_non_literal_virtual_base)
4213      << RD->isStruct() << RD->getNumVBases();
4214    for (CXXRecordDecl::base_class_const_iterator I = RD->vbases_begin(),
4215           E = RD->vbases_end(); I != E; ++I)
4216      Diag(I->getSourceRange().getBegin(),
4217           diag::note_constexpr_virtual_base_here) << I->getSourceRange();
4218  } else if (!RD->isAggregate() && !RD->hasConstexprNonCopyMoveConstructor()) {
4219    Diag(RD->getLocation(), diag::note_non_literal_no_constexpr_ctors) << RD;
4220
4221    switch (RD->getTemplateSpecializationKind()) {
4222    case TSK_Undeclared:
4223    case TSK_ExplicitSpecialization:
4224      break;
4225
4226    case TSK_ImplicitInstantiation:
4227    case TSK_ExplicitInstantiationDeclaration:
4228    case TSK_ExplicitInstantiationDefinition:
4229      // If the base template had constexpr constructors which were
4230      // instantiated as non-constexpr constructors, explain why.
4231      for (CXXRecordDecl::ctor_iterator I = RD->ctor_begin(),
4232           E = RD->ctor_end(); I != E; ++I) {
4233        if ((*I)->isCopyConstructor() || (*I)->isMoveConstructor())
4234          continue;
4235
4236        FunctionDecl *Base = (*I)->getInstantiatedFromMemberFunction();
4237        if (Base && Base->isConstexpr())
4238          CheckConstexprFunctionDecl(*I, CCK_NoteNonConstexprInstantiation);
4239      }
4240    }
4241  } else if (RD->hasNonLiteralTypeFieldsOrBases()) {
4242    for (CXXRecordDecl::base_class_const_iterator I = RD->bases_begin(),
4243         E = RD->bases_end(); I != E; ++I) {
4244      if (!I->getType()->isLiteralType()) {
4245        Diag(I->getSourceRange().getBegin(),
4246             diag::note_non_literal_base_class)
4247          << RD << I->getType() << I->getSourceRange();
4248        return true;
4249      }
4250    }
4251    for (CXXRecordDecl::field_iterator I = RD->field_begin(),
4252         E = RD->field_end(); I != E; ++I) {
4253      if (!(*I)->getType()->isLiteralType()) {
4254        Diag((*I)->getLocation(), diag::note_non_literal_field)
4255          << RD << (*I) << (*I)->getType();
4256        return true;
4257      } else if ((*I)->isMutable()) {
4258        Diag((*I)->getLocation(), diag::note_non_literal_mutable_field) << RD;
4259        return true;
4260      }
4261    }
4262  } else if (!RD->hasTrivialDestructor()) {
4263    // All fields and bases are of literal types, so have trivial destructors.
4264    // If this class's destructor is non-trivial it must be user-declared.
4265    CXXDestructorDecl *Dtor = RD->getDestructor();
4266    assert(Dtor && "class has literal fields and bases but no dtor?");
4267    if (!Dtor)
4268      return true;
4269
4270    Diag(Dtor->getLocation(), Dtor->isUserProvided() ?
4271         diag::note_non_literal_user_provided_dtor :
4272         diag::note_non_literal_nontrivial_dtor) << RD;
4273  }
4274
4275  return true;
4276}
4277
4278/// \brief Retrieve a version of the type 'T' that is elaborated by Keyword
4279/// and qualified by the nested-name-specifier contained in SS.
4280QualType Sema::getElaboratedType(ElaboratedTypeKeyword Keyword,
4281                                 const CXXScopeSpec &SS, QualType T) {
4282  if (T.isNull())
4283    return T;
4284  NestedNameSpecifier *NNS;
4285  if (SS.isValid())
4286    NNS = static_cast<NestedNameSpecifier *>(SS.getScopeRep());
4287  else {
4288    if (Keyword == ETK_None)
4289      return T;
4290    NNS = 0;
4291  }
4292  return Context.getElaboratedType(Keyword, NNS, T);
4293}
4294
4295QualType Sema::BuildTypeofExprType(Expr *E, SourceLocation Loc) {
4296  ExprResult ER = CheckPlaceholderExpr(E);
4297  if (ER.isInvalid()) return QualType();
4298  E = ER.take();
4299
4300  if (!E->isTypeDependent()) {
4301    QualType T = E->getType();
4302    if (const TagType *TT = T->getAs<TagType>())
4303      DiagnoseUseOfDecl(TT->getDecl(), E->getExprLoc());
4304  }
4305  return Context.getTypeOfExprType(E);
4306}
4307
4308QualType Sema::BuildDecltypeType(Expr *E, SourceLocation Loc) {
4309  ExprResult ER = CheckPlaceholderExpr(E);
4310  if (ER.isInvalid()) return QualType();
4311  E = ER.take();
4312
4313  return Context.getDecltypeType(E);
4314}
4315
4316QualType Sema::BuildUnaryTransformType(QualType BaseType,
4317                                       UnaryTransformType::UTTKind UKind,
4318                                       SourceLocation Loc) {
4319  switch (UKind) {
4320  case UnaryTransformType::EnumUnderlyingType:
4321    if (!BaseType->isDependentType() && !BaseType->isEnumeralType()) {
4322      Diag(Loc, diag::err_only_enums_have_underlying_types);
4323      return QualType();
4324    } else {
4325      QualType Underlying = BaseType;
4326      if (!BaseType->isDependentType()) {
4327        EnumDecl *ED = BaseType->getAs<EnumType>()->getDecl();
4328        assert(ED && "EnumType has no EnumDecl");
4329        DiagnoseUseOfDecl(ED, Loc);
4330        Underlying = ED->getIntegerType();
4331      }
4332      assert(!Underlying.isNull());
4333      return Context.getUnaryTransformType(BaseType, Underlying,
4334                                        UnaryTransformType::EnumUnderlyingType);
4335    }
4336  }
4337  llvm_unreachable("unknown unary transform type");
4338}
4339
4340QualType Sema::BuildAtomicType(QualType T, SourceLocation Loc) {
4341  if (!T->isDependentType()) {
4342    int DisallowedKind = -1;
4343    if (T->isIncompleteType())
4344      // FIXME: It isn't entirely clear whether incomplete atomic types
4345      // are allowed or not; for simplicity, ban them for the moment.
4346      DisallowedKind = 0;
4347    else if (T->isArrayType())
4348      DisallowedKind = 1;
4349    else if (T->isFunctionType())
4350      DisallowedKind = 2;
4351    else if (T->isReferenceType())
4352      DisallowedKind = 3;
4353    else if (T->isAtomicType())
4354      DisallowedKind = 4;
4355    else if (T.hasQualifiers())
4356      DisallowedKind = 5;
4357    else if (!T.isTriviallyCopyableType(Context))
4358      // Some other non-trivially-copyable type (probably a C++ class)
4359      DisallowedKind = 6;
4360
4361    if (DisallowedKind != -1) {
4362      Diag(Loc, diag::err_atomic_specifier_bad_type) << DisallowedKind << T;
4363      return QualType();
4364    }
4365
4366    // FIXME: Do we need any handling for ARC here?
4367  }
4368
4369  // Build the pointer type.
4370  return Context.getAtomicType(T);
4371}
4372