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 "TypeLocBuilder.h"
16 #include "clang/AST/ASTConsumer.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/Expr.h"
23 #include "clang/AST/TypeLoc.h"
24 #include "clang/AST/TypeLocVisitor.h"
25 #include "clang/Basic/PartialDiagnostic.h"
26 #include "clang/Basic/TargetInfo.h"
27 #include "clang/Parse/ParseDiagnostic.h"
28 #include "clang/Sema/DeclSpec.h"
29 #include "clang/Sema/DelayedDiagnostic.h"
30 #include "clang/Sema/Lookup.h"
31 #include "clang/Sema/ScopeInfo.h"
32 #include "clang/Sema/Template.h"
33 #include "llvm/ADT/SmallPtrSet.h"
34 #include "llvm/ADT/SmallString.h"
35 #include "llvm/Support/ErrorHandling.h"
36 
37 using namespace clang;
38 
39 enum TypeDiagSelector {
40   TDS_Function,
41   TDS_Pointer,
42   TDS_ObjCObjOrBlock
43 };
44 
45 /// isOmittedBlockReturnType - Return true if this declarator is missing a
46 /// return type because this is a omitted return type on a block literal.
47 static bool isOmittedBlockReturnType(const Declarator &D) {
48   if (D.getContext() != Declarator::BlockLiteralContext ||
49       D.getDeclSpec().hasTypeSpecifier())
50     return false;
51 
52   if (D.getNumTypeObjects() == 0)
53     return true;   // ^{ ... }
54 
55   if (D.getNumTypeObjects() == 1 &&
56       D.getTypeObject(0).Kind == DeclaratorChunk::Function)
57     return true;   // ^(int X, float Y) { ... }
58 
59   return false;
60 }
61 
62 /// diagnoseBadTypeAttribute - Diagnoses a type attribute which
63 /// doesn't apply to the given type.
64 static void diagnoseBadTypeAttribute(Sema &S, const AttributeList &attr,
65                                      QualType type) {
66   TypeDiagSelector WhichType;
67   bool useExpansionLoc = true;
68   switch (attr.getKind()) {
69   case AttributeList::AT_ObjCGC:        WhichType = TDS_Pointer; break;
70   case AttributeList::AT_ObjCOwnership: WhichType = TDS_ObjCObjOrBlock; break;
71   default:
72     // Assume everything else was a function attribute.
73     WhichType = TDS_Function;
74     useExpansionLoc = false;
75     break;
76   }
77 
78   SourceLocation loc = attr.getLoc();
79   StringRef name = attr.getName()->getName();
80 
81   // The GC attributes are usually written with macros;  special-case them.
82   IdentifierInfo *II = attr.isArgIdent(0) ? attr.getArgAsIdent(0)->Ident
83                                           : nullptr;
84   if (useExpansionLoc && loc.isMacroID() && II) {
85     if (II->isStr("strong")) {
86       if (S.findMacroSpelling(loc, "__strong")) name = "__strong";
87     } else if (II->isStr("weak")) {
88       if (S.findMacroSpelling(loc, "__weak")) name = "__weak";
89     }
90   }
91 
92   S.Diag(loc, diag::warn_type_attribute_wrong_type) << name << WhichType
93     << type;
94 }
95 
96 // objc_gc applies to Objective-C pointers or, otherwise, to the
97 // smallest available pointer type (i.e. 'void*' in 'void**').
98 #define OBJC_POINTER_TYPE_ATTRS_CASELIST \
99     case AttributeList::AT_ObjCGC: \
100     case AttributeList::AT_ObjCOwnership
101 
102 // Function type attributes.
103 #define FUNCTION_TYPE_ATTRS_CASELIST \
104     case AttributeList::AT_NoReturn: \
105     case AttributeList::AT_CDecl: \
106     case AttributeList::AT_FastCall: \
107     case AttributeList::AT_StdCall: \
108     case AttributeList::AT_ThisCall: \
109     case AttributeList::AT_Pascal: \
110     case AttributeList::AT_VectorCall: \
111     case AttributeList::AT_MSABI: \
112     case AttributeList::AT_SysVABI: \
113     case AttributeList::AT_Regparm: \
114     case AttributeList::AT_Pcs: \
115     case AttributeList::AT_PnaclCall: \
116     case AttributeList::AT_IntelOclBicc
117 
118 // Microsoft-specific type qualifiers.
119 #define MS_TYPE_ATTRS_CASELIST  \
120     case AttributeList::AT_Ptr32: \
121     case AttributeList::AT_Ptr64: \
122     case AttributeList::AT_SPtr: \
123     case AttributeList::AT_UPtr
124 
125 namespace {
126   /// An object which stores processing state for the entire
127   /// GetTypeForDeclarator process.
128   class TypeProcessingState {
129     Sema &sema;
130 
131     /// The declarator being processed.
132     Declarator &declarator;
133 
134     /// The index of the declarator chunk we're currently processing.
135     /// May be the total number of valid chunks, indicating the
136     /// DeclSpec.
137     unsigned chunkIndex;
138 
139     /// Whether there are non-trivial modifications to the decl spec.
140     bool trivial;
141 
142     /// Whether we saved the attributes in the decl spec.
143     bool hasSavedAttrs;
144 
145     /// The original set of attributes on the DeclSpec.
146     SmallVector<AttributeList*, 2> savedAttrs;
147 
148     /// A list of attributes to diagnose the uselessness of when the
149     /// processing is complete.
150     SmallVector<AttributeList*, 2> ignoredTypeAttrs;
151 
152   public:
153     TypeProcessingState(Sema &sema, Declarator &declarator)
154       : sema(sema), declarator(declarator),
155         chunkIndex(declarator.getNumTypeObjects()),
156         trivial(true), hasSavedAttrs(false) {}
157 
158     Sema &getSema() const {
159       return sema;
160     }
161 
162     Declarator &getDeclarator() const {
163       return declarator;
164     }
165 
166     bool isProcessingDeclSpec() const {
167       return chunkIndex == declarator.getNumTypeObjects();
168     }
169 
170     unsigned getCurrentChunkIndex() const {
171       return chunkIndex;
172     }
173 
174     void setCurrentChunkIndex(unsigned idx) {
175       assert(idx <= declarator.getNumTypeObjects());
176       chunkIndex = idx;
177     }
178 
179     AttributeList *&getCurrentAttrListRef() const {
180       if (isProcessingDeclSpec())
181         return getMutableDeclSpec().getAttributes().getListRef();
182       return declarator.getTypeObject(chunkIndex).getAttrListRef();
183     }
184 
185     /// Save the current set of attributes on the DeclSpec.
186     void saveDeclSpecAttrs() {
187       // Don't try to save them multiple times.
188       if (hasSavedAttrs) return;
189 
190       DeclSpec &spec = getMutableDeclSpec();
191       for (AttributeList *attr = spec.getAttributes().getList(); attr;
192              attr = attr->getNext())
193         savedAttrs.push_back(attr);
194       trivial &= savedAttrs.empty();
195       hasSavedAttrs = true;
196     }
197 
198     /// Record that we had nowhere to put the given type attribute.
199     /// We will diagnose such attributes later.
200     void addIgnoredTypeAttr(AttributeList &attr) {
201       ignoredTypeAttrs.push_back(&attr);
202     }
203 
204     /// Diagnose all the ignored type attributes, given that the
205     /// declarator worked out to the given type.
206     void diagnoseIgnoredTypeAttrs(QualType type) const {
207       for (SmallVectorImpl<AttributeList*>::const_iterator
208              i = ignoredTypeAttrs.begin(), e = ignoredTypeAttrs.end();
209            i != e; ++i)
210         diagnoseBadTypeAttribute(getSema(), **i, type);
211     }
212 
213     ~TypeProcessingState() {
214       if (trivial) return;
215 
216       restoreDeclSpecAttrs();
217     }
218 
219   private:
220     DeclSpec &getMutableDeclSpec() const {
221       return const_cast<DeclSpec&>(declarator.getDeclSpec());
222     }
223 
224     void restoreDeclSpecAttrs() {
225       assert(hasSavedAttrs);
226 
227       if (savedAttrs.empty()) {
228         getMutableDeclSpec().getAttributes().set(nullptr);
229         return;
230       }
231 
232       getMutableDeclSpec().getAttributes().set(savedAttrs[0]);
233       for (unsigned i = 0, e = savedAttrs.size() - 1; i != e; ++i)
234         savedAttrs[i]->setNext(savedAttrs[i+1]);
235       savedAttrs.back()->setNext(nullptr);
236     }
237   };
238 }
239 
240 static void spliceAttrIntoList(AttributeList &attr, AttributeList *&head) {
241   attr.setNext(head);
242   head = &attr;
243 }
244 
245 static 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 
262 static void moveAttrFromListToList(AttributeList &attr,
263                                    AttributeList *&fromList,
264                                    AttributeList *&toList) {
265   spliceAttrOutOfList(attr, fromList);
266   spliceAttrIntoList(attr, toList);
267 }
268 
269 /// The location of a type attribute.
270 enum TypeAttrLocation {
271   /// The attribute is in the decl-specifier-seq.
272   TAL_DeclSpec,
273   /// The attribute is part of a DeclaratorChunk.
274   TAL_DeclChunk,
275   /// The attribute is immediately after the declaration's name.
276   TAL_DeclName
277 };
278 
279 static void processTypeAttrs(TypeProcessingState &state,
280                              QualType &type, TypeAttrLocation TAL,
281                              AttributeList *attrs);
282 
283 static bool handleFunctionTypeAttr(TypeProcessingState &state,
284                                    AttributeList &attr,
285                                    QualType &type);
286 
287 static bool handleMSPointerTypeQualifierAttr(TypeProcessingState &state,
288                                              AttributeList &attr,
289                                              QualType &type);
290 
291 static bool handleObjCGCTypeAttr(TypeProcessingState &state,
292                                  AttributeList &attr, QualType &type);
293 
294 static bool handleObjCOwnershipTypeAttr(TypeProcessingState &state,
295                                        AttributeList &attr, QualType &type);
296 
297 static bool handleObjCPointerTypeAttr(TypeProcessingState &state,
298                                       AttributeList &attr, QualType &type) {
299   if (attr.getKind() == AttributeList::AT_ObjCGC)
300     return handleObjCGCTypeAttr(state, attr, type);
301   assert(attr.getKind() == AttributeList::AT_ObjCOwnership);
302   return handleObjCOwnershipTypeAttr(state, attr, type);
303 }
304 
305 /// Given the index of a declarator chunk, check whether that chunk
306 /// directly specifies the return type of a function and, if so, find
307 /// an appropriate place for it.
308 ///
309 /// \param i - a notional index which the search will start
310 ///   immediately inside
311 static DeclaratorChunk *maybeMovePastReturnType(Declarator &declarator,
312                                                 unsigned i) {
313   assert(i <= declarator.getNumTypeObjects());
314 
315   DeclaratorChunk *result = nullptr;
316 
317   // First, look inwards past parens for a function declarator.
318   for (; i != 0; --i) {
319     DeclaratorChunk &fnChunk = declarator.getTypeObject(i-1);
320     switch (fnChunk.Kind) {
321     case DeclaratorChunk::Paren:
322       continue;
323 
324     // If we find anything except a function, bail out.
325     case DeclaratorChunk::Pointer:
326     case DeclaratorChunk::BlockPointer:
327     case DeclaratorChunk::Array:
328     case DeclaratorChunk::Reference:
329     case DeclaratorChunk::MemberPointer:
330       return result;
331 
332     // If we do find a function declarator, scan inwards from that,
333     // looking for a block-pointer declarator.
334     case DeclaratorChunk::Function:
335       for (--i; i != 0; --i) {
336         DeclaratorChunk &blockChunk = declarator.getTypeObject(i-1);
337         switch (blockChunk.Kind) {
338         case DeclaratorChunk::Paren:
339         case DeclaratorChunk::Pointer:
340         case DeclaratorChunk::Array:
341         case DeclaratorChunk::Function:
342         case DeclaratorChunk::Reference:
343         case DeclaratorChunk::MemberPointer:
344           continue;
345         case DeclaratorChunk::BlockPointer:
346           result = &blockChunk;
347           goto continue_outer;
348         }
349         llvm_unreachable("bad declarator chunk kind");
350       }
351 
352       // If we run out of declarators doing that, we're done.
353       return result;
354     }
355     llvm_unreachable("bad declarator chunk kind");
356 
357     // Okay, reconsider from our new point.
358   continue_outer: ;
359   }
360 
361   // Ran out of chunks, bail out.
362   return result;
363 }
364 
365 /// Given that an objc_gc attribute was written somewhere on a
366 /// declaration *other* than on the declarator itself (for which, use
367 /// distributeObjCPointerTypeAttrFromDeclarator), and given that it
368 /// didn't apply in whatever position it was written in, try to move
369 /// it to a more appropriate position.
370 static void distributeObjCPointerTypeAttr(TypeProcessingState &state,
371                                           AttributeList &attr,
372                                           QualType type) {
373   Declarator &declarator = state.getDeclarator();
374 
375   // Move it to the outermost normal or block pointer declarator.
376   for (unsigned i = state.getCurrentChunkIndex(); i != 0; --i) {
377     DeclaratorChunk &chunk = declarator.getTypeObject(i-1);
378     switch (chunk.Kind) {
379     case DeclaratorChunk::Pointer:
380     case DeclaratorChunk::BlockPointer: {
381       // But don't move an ARC ownership attribute to the return type
382       // of a block.
383       DeclaratorChunk *destChunk = nullptr;
384       if (state.isProcessingDeclSpec() &&
385           attr.getKind() == AttributeList::AT_ObjCOwnership)
386         destChunk = maybeMovePastReturnType(declarator, i - 1);
387       if (!destChunk) destChunk = &chunk;
388 
389       moveAttrFromListToList(attr, state.getCurrentAttrListRef(),
390                              destChunk->getAttrListRef());
391       return;
392     }
393 
394     case DeclaratorChunk::Paren:
395     case DeclaratorChunk::Array:
396       continue;
397 
398     // We may be starting at the return type of a block.
399     case DeclaratorChunk::Function:
400       if (state.isProcessingDeclSpec() &&
401           attr.getKind() == AttributeList::AT_ObjCOwnership) {
402         if (DeclaratorChunk *dest = maybeMovePastReturnType(declarator, i)) {
403           moveAttrFromListToList(attr, state.getCurrentAttrListRef(),
404                                  dest->getAttrListRef());
405           return;
406         }
407       }
408       goto error;
409 
410     // Don't walk through these.
411     case DeclaratorChunk::Reference:
412     case DeclaratorChunk::MemberPointer:
413       goto error;
414     }
415   }
416  error:
417 
418   diagnoseBadTypeAttribute(state.getSema(), attr, type);
419 }
420 
421 /// Distribute an objc_gc type attribute that was written on the
422 /// declarator.
423 static void
424 distributeObjCPointerTypeAttrFromDeclarator(TypeProcessingState &state,
425                                             AttributeList &attr,
426                                             QualType &declSpecType) {
427   Declarator &declarator = state.getDeclarator();
428 
429   // objc_gc goes on the innermost pointer to something that's not a
430   // pointer.
431   unsigned innermost = -1U;
432   bool considerDeclSpec = true;
433   for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
434     DeclaratorChunk &chunk = declarator.getTypeObject(i);
435     switch (chunk.Kind) {
436     case DeclaratorChunk::Pointer:
437     case DeclaratorChunk::BlockPointer:
438       innermost = i;
439       continue;
440 
441     case DeclaratorChunk::Reference:
442     case DeclaratorChunk::MemberPointer:
443     case DeclaratorChunk::Paren:
444     case DeclaratorChunk::Array:
445       continue;
446 
447     case DeclaratorChunk::Function:
448       considerDeclSpec = false;
449       goto done;
450     }
451   }
452  done:
453 
454   // That might actually be the decl spec if we weren't blocked by
455   // anything in the declarator.
456   if (considerDeclSpec) {
457     if (handleObjCPointerTypeAttr(state, attr, declSpecType)) {
458       // Splice the attribute into the decl spec.  Prevents the
459       // attribute from being applied multiple times and gives
460       // the source-location-filler something to work with.
461       state.saveDeclSpecAttrs();
462       moveAttrFromListToList(attr, declarator.getAttrListRef(),
463                declarator.getMutableDeclSpec().getAttributes().getListRef());
464       return;
465     }
466   }
467 
468   // Otherwise, if we found an appropriate chunk, splice the attribute
469   // into it.
470   if (innermost != -1U) {
471     moveAttrFromListToList(attr, declarator.getAttrListRef(),
472                        declarator.getTypeObject(innermost).getAttrListRef());
473     return;
474   }
475 
476   // Otherwise, diagnose when we're done building the type.
477   spliceAttrOutOfList(attr, declarator.getAttrListRef());
478   state.addIgnoredTypeAttr(attr);
479 }
480 
481 /// A function type attribute was written somewhere in a declaration
482 /// *other* than on the declarator itself or in the decl spec.  Given
483 /// that it didn't apply in whatever position it was written in, try
484 /// to move it to a more appropriate position.
485 static void distributeFunctionTypeAttr(TypeProcessingState &state,
486                                        AttributeList &attr,
487                                        QualType type) {
488   Declarator &declarator = state.getDeclarator();
489 
490   // Try to push the attribute from the return type of a function to
491   // the function itself.
492   for (unsigned i = state.getCurrentChunkIndex(); i != 0; --i) {
493     DeclaratorChunk &chunk = declarator.getTypeObject(i-1);
494     switch (chunk.Kind) {
495     case DeclaratorChunk::Function:
496       moveAttrFromListToList(attr, state.getCurrentAttrListRef(),
497                              chunk.getAttrListRef());
498       return;
499 
500     case DeclaratorChunk::Paren:
501     case DeclaratorChunk::Pointer:
502     case DeclaratorChunk::BlockPointer:
503     case DeclaratorChunk::Array:
504     case DeclaratorChunk::Reference:
505     case DeclaratorChunk::MemberPointer:
506       continue;
507     }
508   }
509 
510   diagnoseBadTypeAttribute(state.getSema(), attr, type);
511 }
512 
513 /// Try to distribute a function type attribute to the innermost
514 /// function chunk or type.  Returns true if the attribute was
515 /// distributed, false if no location was found.
516 static bool
517 distributeFunctionTypeAttrToInnermost(TypeProcessingState &state,
518                                       AttributeList &attr,
519                                       AttributeList *&attrList,
520                                       QualType &declSpecType) {
521   Declarator &declarator = state.getDeclarator();
522 
523   // Put it on the innermost function chunk, if there is one.
524   for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
525     DeclaratorChunk &chunk = declarator.getTypeObject(i);
526     if (chunk.Kind != DeclaratorChunk::Function) continue;
527 
528     moveAttrFromListToList(attr, attrList, chunk.getAttrListRef());
529     return true;
530   }
531 
532   return handleFunctionTypeAttr(state, attr, declSpecType);
533 }
534 
535 /// A function type attribute was written in the decl spec.  Try to
536 /// apply it somewhere.
537 static void
538 distributeFunctionTypeAttrFromDeclSpec(TypeProcessingState &state,
539                                        AttributeList &attr,
540                                        QualType &declSpecType) {
541   state.saveDeclSpecAttrs();
542 
543   // C++11 attributes before the decl specifiers actually appertain to
544   // the declarators. Move them straight there. We don't support the
545   // 'put them wherever you like' semantics we allow for GNU attributes.
546   if (attr.isCXX11Attribute()) {
547     moveAttrFromListToList(attr, state.getCurrentAttrListRef(),
548                            state.getDeclarator().getAttrListRef());
549     return;
550   }
551 
552   // Try to distribute to the innermost.
553   if (distributeFunctionTypeAttrToInnermost(state, attr,
554                                             state.getCurrentAttrListRef(),
555                                             declSpecType))
556     return;
557 
558   // If that failed, diagnose the bad attribute when the declarator is
559   // fully built.
560   state.addIgnoredTypeAttr(attr);
561 }
562 
563 /// A function type attribute was written on the declarator.  Try to
564 /// apply it somewhere.
565 static void
566 distributeFunctionTypeAttrFromDeclarator(TypeProcessingState &state,
567                                          AttributeList &attr,
568                                          QualType &declSpecType) {
569   Declarator &declarator = state.getDeclarator();
570 
571   // Try to distribute to the innermost.
572   if (distributeFunctionTypeAttrToInnermost(state, attr,
573                                             declarator.getAttrListRef(),
574                                             declSpecType))
575     return;
576 
577   // If that failed, diagnose the bad attribute when the declarator is
578   // fully built.
579   spliceAttrOutOfList(attr, declarator.getAttrListRef());
580   state.addIgnoredTypeAttr(attr);
581 }
582 
583 /// \brief Given that there are attributes written on the declarator
584 /// itself, try to distribute any type attributes to the appropriate
585 /// declarator chunk.
586 ///
587 /// These are attributes like the following:
588 ///   int f ATTR;
589 ///   int (f ATTR)();
590 /// but not necessarily this:
591 ///   int f() ATTR;
592 static void distributeTypeAttrsFromDeclarator(TypeProcessingState &state,
593                                               QualType &declSpecType) {
594   // Collect all the type attributes from the declarator itself.
595   assert(state.getDeclarator().getAttributes() && "declarator has no attrs!");
596   AttributeList *attr = state.getDeclarator().getAttributes();
597   AttributeList *next;
598   do {
599     next = attr->getNext();
600 
601     // Do not distribute C++11 attributes. They have strict rules for what
602     // they appertain to.
603     if (attr->isCXX11Attribute())
604       continue;
605 
606     switch (attr->getKind()) {
607     OBJC_POINTER_TYPE_ATTRS_CASELIST:
608       distributeObjCPointerTypeAttrFromDeclarator(state, *attr, declSpecType);
609       break;
610 
611     case AttributeList::AT_NSReturnsRetained:
612       if (!state.getSema().getLangOpts().ObjCAutoRefCount)
613         break;
614       // fallthrough
615 
616     FUNCTION_TYPE_ATTRS_CASELIST:
617       distributeFunctionTypeAttrFromDeclarator(state, *attr, declSpecType);
618       break;
619 
620     MS_TYPE_ATTRS_CASELIST:
621       // Microsoft type attributes cannot go after the declarator-id.
622       continue;
623 
624     default:
625       break;
626     }
627   } while ((attr = next));
628 }
629 
630 /// Add a synthetic '()' to a block-literal declarator if it is
631 /// required, given the return type.
632 static void maybeSynthesizeBlockSignature(TypeProcessingState &state,
633                                           QualType declSpecType) {
634   Declarator &declarator = state.getDeclarator();
635 
636   // First, check whether the declarator would produce a function,
637   // i.e. whether the innermost semantic chunk is a function.
638   if (declarator.isFunctionDeclarator()) {
639     // If so, make that declarator a prototyped declarator.
640     declarator.getFunctionTypeInfo().hasPrototype = true;
641     return;
642   }
643 
644   // If there are any type objects, the type as written won't name a
645   // function, regardless of the decl spec type.  This is because a
646   // block signature declarator is always an abstract-declarator, and
647   // abstract-declarators can't just be parentheses chunks.  Therefore
648   // we need to build a function chunk unless there are no type
649   // objects and the decl spec type is a function.
650   if (!declarator.getNumTypeObjects() && declSpecType->isFunctionType())
651     return;
652 
653   // Note that there *are* cases with invalid declarators where
654   // declarators consist solely of parentheses.  In general, these
655   // occur only in failed efforts to make function declarators, so
656   // faking up the function chunk is still the right thing to do.
657 
658   // Otherwise, we need to fake up a function declarator.
659   SourceLocation loc = declarator.getLocStart();
660 
661   // ...and *prepend* it to the declarator.
662   SourceLocation NoLoc;
663   declarator.AddInnermostTypeInfo(DeclaratorChunk::getFunction(
664       /*HasProto=*/true,
665       /*IsAmbiguous=*/false,
666       /*LParenLoc=*/NoLoc,
667       /*ArgInfo=*/nullptr,
668       /*NumArgs=*/0,
669       /*EllipsisLoc=*/NoLoc,
670       /*RParenLoc=*/NoLoc,
671       /*TypeQuals=*/0,
672       /*RefQualifierIsLvalueRef=*/true,
673       /*RefQualifierLoc=*/NoLoc,
674       /*ConstQualifierLoc=*/NoLoc,
675       /*VolatileQualifierLoc=*/NoLoc,
676       /*RestrictQualifierLoc=*/NoLoc,
677       /*MutableLoc=*/NoLoc, EST_None,
678       /*ESpecLoc=*/NoLoc,
679       /*Exceptions=*/nullptr,
680       /*ExceptionRanges=*/nullptr,
681       /*NumExceptions=*/0,
682       /*NoexceptExpr=*/nullptr,
683       /*ExceptionSpecTokens=*/nullptr,
684       loc, loc, declarator));
685 
686   // For consistency, make sure the state still has us as processing
687   // the decl spec.
688   assert(state.getCurrentChunkIndex() == declarator.getNumTypeObjects() - 1);
689   state.setCurrentChunkIndex(declarator.getNumTypeObjects());
690 }
691 
692 /// \brief Convert the specified declspec to the appropriate type
693 /// object.
694 /// \param state Specifies the declarator containing the declaration specifier
695 /// to be converted, along with other associated processing state.
696 /// \returns The type described by the declaration specifiers.  This function
697 /// never returns null.
698 static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
699   // FIXME: Should move the logic from DeclSpec::Finish to here for validity
700   // checking.
701 
702   Sema &S = state.getSema();
703   Declarator &declarator = state.getDeclarator();
704   const DeclSpec &DS = declarator.getDeclSpec();
705   SourceLocation DeclLoc = declarator.getIdentifierLoc();
706   if (DeclLoc.isInvalid())
707     DeclLoc = DS.getLocStart();
708 
709   ASTContext &Context = S.Context;
710 
711   QualType Result;
712   switch (DS.getTypeSpecType()) {
713   case DeclSpec::TST_void:
714     Result = Context.VoidTy;
715     break;
716   case DeclSpec::TST_char:
717     if (DS.getTypeSpecSign() == DeclSpec::TSS_unspecified)
718       Result = Context.CharTy;
719     else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed)
720       Result = Context.SignedCharTy;
721     else {
722       assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
723              "Unknown TSS value");
724       Result = Context.UnsignedCharTy;
725     }
726     break;
727   case DeclSpec::TST_wchar:
728     if (DS.getTypeSpecSign() == DeclSpec::TSS_unspecified)
729       Result = Context.WCharTy;
730     else if (DS.getTypeSpecSign() == DeclSpec::TSS_signed) {
731       S.Diag(DS.getTypeSpecSignLoc(), diag::ext_invalid_sign_spec)
732         << DS.getSpecifierName(DS.getTypeSpecType(),
733                                Context.getPrintingPolicy());
734       Result = Context.getSignedWCharType();
735     } else {
736       assert(DS.getTypeSpecSign() == DeclSpec::TSS_unsigned &&
737         "Unknown TSS value");
738       S.Diag(DS.getTypeSpecSignLoc(), diag::ext_invalid_sign_spec)
739         << DS.getSpecifierName(DS.getTypeSpecType(),
740                                Context.getPrintingPolicy());
741       Result = Context.getUnsignedWCharType();
742     }
743     break;
744   case DeclSpec::TST_char16:
745       assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
746         "Unknown TSS value");
747       Result = Context.Char16Ty;
748     break;
749   case DeclSpec::TST_char32:
750       assert(DS.getTypeSpecSign() == DeclSpec::TSS_unspecified &&
751         "Unknown TSS value");
752       Result = Context.Char32Ty;
753     break;
754   case DeclSpec::TST_unspecified:
755     // "<proto1,proto2>" is an objc qualified ID with a missing id.
756     if (DeclSpec::ProtocolQualifierListTy PQ = DS.getProtocolQualifiers()) {
757       Result = Context.getObjCObjectType(Context.ObjCBuiltinIdTy,
758                                          (ObjCProtocolDecl*const*)PQ,
759                                          DS.getNumProtocolQualifiers());
760       Result = Context.getObjCObjectPointerType(Result);
761       break;
762     }
763 
764     // If this is a missing declspec in a block literal return context, then it
765     // is inferred from the return statements inside the block.
766     // The declspec is always missing in a lambda expr context; it is either
767     // specified with a trailing return type or inferred.
768     if (S.getLangOpts().CPlusPlus14 &&
769         declarator.getContext() == Declarator::LambdaExprContext) {
770       // In C++1y, a lambda's implicit return type is 'auto'.
771       Result = Context.getAutoDeductType();
772       break;
773     } else if (declarator.getContext() == Declarator::LambdaExprContext ||
774                isOmittedBlockReturnType(declarator)) {
775       Result = Context.DependentTy;
776       break;
777     }
778 
779     // Unspecified typespec defaults to int in C90.  However, the C90 grammar
780     // [C90 6.5] only allows a decl-spec if there was *some* type-specifier,
781     // type-qualifier, or storage-class-specifier.  If not, emit an extwarn.
782     // Note that the one exception to this is function definitions, which are
783     // allowed to be completely missing a declspec.  This is handled in the
784     // parser already though by it pretending to have seen an 'int' in this
785     // case.
786     if (S.getLangOpts().ImplicitInt) {
787       // In C89 mode, we only warn if there is a completely missing declspec
788       // when one is not allowed.
789       if (DS.isEmpty()) {
790         S.Diag(DeclLoc, diag::ext_missing_declspec)
791           << DS.getSourceRange()
792         << FixItHint::CreateInsertion(DS.getLocStart(), "int");
793       }
794     } else if (!DS.hasTypeSpecifier()) {
795       // C99 and C++ require a type specifier.  For example, C99 6.7.2p2 says:
796       // "At least one type specifier shall be given in the declaration
797       // specifiers in each declaration, and in the specifier-qualifier list in
798       // each struct declaration and type name."
799       if (S.getLangOpts().CPlusPlus) {
800         S.Diag(DeclLoc, diag::err_missing_type_specifier)
801           << DS.getSourceRange();
802 
803         // When this occurs in C++ code, often something is very broken with the
804         // value being declared, poison it as invalid so we don't get chains of
805         // errors.
806         declarator.setInvalidType(true);
807       } else {
808         S.Diag(DeclLoc, diag::ext_missing_type_specifier)
809           << DS.getSourceRange();
810       }
811     }
812 
813     // FALL THROUGH.
814   case DeclSpec::TST_int: {
815     if (DS.getTypeSpecSign() != DeclSpec::TSS_unsigned) {
816       switch (DS.getTypeSpecWidth()) {
817       case DeclSpec::TSW_unspecified: Result = Context.IntTy; break;
818       case DeclSpec::TSW_short:       Result = Context.ShortTy; break;
819       case DeclSpec::TSW_long:        Result = Context.LongTy; break;
820       case DeclSpec::TSW_longlong:
821         Result = Context.LongLongTy;
822 
823         // 'long long' is a C99 or C++11 feature.
824         if (!S.getLangOpts().C99) {
825           if (S.getLangOpts().CPlusPlus)
826             S.Diag(DS.getTypeSpecWidthLoc(),
827                    S.getLangOpts().CPlusPlus11 ?
828                    diag::warn_cxx98_compat_longlong : diag::ext_cxx11_longlong);
829           else
830             S.Diag(DS.getTypeSpecWidthLoc(), diag::ext_c99_longlong);
831         }
832         break;
833       }
834     } else {
835       switch (DS.getTypeSpecWidth()) {
836       case DeclSpec::TSW_unspecified: Result = Context.UnsignedIntTy; break;
837       case DeclSpec::TSW_short:       Result = Context.UnsignedShortTy; break;
838       case DeclSpec::TSW_long:        Result = Context.UnsignedLongTy; break;
839       case DeclSpec::TSW_longlong:
840         Result = Context.UnsignedLongLongTy;
841 
842         // 'long long' is a C99 or C++11 feature.
843         if (!S.getLangOpts().C99) {
844           if (S.getLangOpts().CPlusPlus)
845             S.Diag(DS.getTypeSpecWidthLoc(),
846                    S.getLangOpts().CPlusPlus11 ?
847                    diag::warn_cxx98_compat_longlong : diag::ext_cxx11_longlong);
848           else
849             S.Diag(DS.getTypeSpecWidthLoc(), diag::ext_c99_longlong);
850         }
851         break;
852       }
853     }
854     break;
855   }
856   case DeclSpec::TST_int128:
857     if (!S.Context.getTargetInfo().hasInt128Type())
858       S.Diag(DS.getTypeSpecTypeLoc(), diag::err_int128_unsupported);
859     if (DS.getTypeSpecSign() == DeclSpec::TSS_unsigned)
860       Result = Context.UnsignedInt128Ty;
861     else
862       Result = Context.Int128Ty;
863     break;
864   case DeclSpec::TST_half: Result = Context.HalfTy; break;
865   case DeclSpec::TST_float: Result = Context.FloatTy; break;
866   case DeclSpec::TST_double:
867     if (DS.getTypeSpecWidth() == DeclSpec::TSW_long)
868       Result = Context.LongDoubleTy;
869     else
870       Result = Context.DoubleTy;
871 
872     if (S.getLangOpts().OpenCL && !S.getOpenCLOptions().cl_khr_fp64) {
873       S.Diag(DS.getTypeSpecTypeLoc(), diag::err_double_requires_fp64);
874       declarator.setInvalidType(true);
875     }
876     break;
877   case DeclSpec::TST_bool: Result = Context.BoolTy; break; // _Bool or bool
878   case DeclSpec::TST_decimal32:    // _Decimal32
879   case DeclSpec::TST_decimal64:    // _Decimal64
880   case DeclSpec::TST_decimal128:   // _Decimal128
881     S.Diag(DS.getTypeSpecTypeLoc(), diag::err_decimal_unsupported);
882     Result = Context.IntTy;
883     declarator.setInvalidType(true);
884     break;
885   case DeclSpec::TST_class:
886   case DeclSpec::TST_enum:
887   case DeclSpec::TST_union:
888   case DeclSpec::TST_struct:
889   case DeclSpec::TST_interface: {
890     TypeDecl *D = dyn_cast_or_null<TypeDecl>(DS.getRepAsDecl());
891     if (!D) {
892       // This can happen in C++ with ambiguous lookups.
893       Result = Context.IntTy;
894       declarator.setInvalidType(true);
895       break;
896     }
897 
898     // If the type is deprecated or unavailable, diagnose it.
899     S.DiagnoseUseOfDecl(D, DS.getTypeSpecTypeNameLoc());
900 
901     assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
902            DS.getTypeSpecSign() == 0 && "No qualifiers on tag names!");
903 
904     // TypeQuals handled by caller.
905     Result = Context.getTypeDeclType(D);
906 
907     // In both C and C++, make an ElaboratedType.
908     ElaboratedTypeKeyword Keyword
909       = ElaboratedType::getKeywordForTypeSpec(DS.getTypeSpecType());
910     Result = S.getElaboratedType(Keyword, DS.getTypeSpecScope(), Result);
911     break;
912   }
913   case DeclSpec::TST_typename: {
914     assert(DS.getTypeSpecWidth() == 0 && DS.getTypeSpecComplex() == 0 &&
915            DS.getTypeSpecSign() == 0 &&
916            "Can't handle qualifiers on typedef names yet!");
917     Result = S.GetTypeFromParser(DS.getRepAsType());
918     if (Result.isNull())
919       declarator.setInvalidType(true);
920     else if (DeclSpec::ProtocolQualifierListTy PQ
921                = DS.getProtocolQualifiers()) {
922       if (const ObjCObjectType *ObjT = Result->getAs<ObjCObjectType>()) {
923         // Silently drop any existing protocol qualifiers.
924         // TODO: determine whether that's the right thing to do.
925         if (ObjT->getNumProtocols())
926           Result = ObjT->getBaseType();
927 
928         if (DS.getNumProtocolQualifiers())
929           Result = Context.getObjCObjectType(Result,
930                                              (ObjCProtocolDecl*const*) PQ,
931                                              DS.getNumProtocolQualifiers());
932       } else if (Result->isObjCIdType()) {
933         // id<protocol-list>
934         Result = Context.getObjCObjectType(Context.ObjCBuiltinIdTy,
935                                            (ObjCProtocolDecl*const*) PQ,
936                                            DS.getNumProtocolQualifiers());
937         Result = Context.getObjCObjectPointerType(Result);
938       } else if (Result->isObjCClassType()) {
939         // Class<protocol-list>
940         Result = Context.getObjCObjectType(Context.ObjCBuiltinClassTy,
941                                            (ObjCProtocolDecl*const*) PQ,
942                                            DS.getNumProtocolQualifiers());
943         Result = Context.getObjCObjectPointerType(Result);
944       } else {
945         S.Diag(DeclLoc, diag::err_invalid_protocol_qualifiers)
946           << DS.getSourceRange();
947         declarator.setInvalidType(true);
948       }
949     }
950 
951     // TypeQuals handled by caller.
952     break;
953   }
954   case DeclSpec::TST_typeofType:
955     // FIXME: Preserve type source info.
956     Result = S.GetTypeFromParser(DS.getRepAsType());
957     assert(!Result.isNull() && "Didn't get a type for typeof?");
958     if (!Result->isDependentType())
959       if (const TagType *TT = Result->getAs<TagType>())
960         S.DiagnoseUseOfDecl(TT->getDecl(), DS.getTypeSpecTypeLoc());
961     // TypeQuals handled by caller.
962     Result = Context.getTypeOfType(Result);
963     break;
964   case DeclSpec::TST_typeofExpr: {
965     Expr *E = DS.getRepAsExpr();
966     assert(E && "Didn't get an expression for typeof?");
967     // TypeQuals handled by caller.
968     Result = S.BuildTypeofExprType(E, DS.getTypeSpecTypeLoc());
969     if (Result.isNull()) {
970       Result = Context.IntTy;
971       declarator.setInvalidType(true);
972     }
973     break;
974   }
975   case DeclSpec::TST_decltype: {
976     Expr *E = DS.getRepAsExpr();
977     assert(E && "Didn't get an expression for decltype?");
978     // TypeQuals handled by caller.
979     Result = S.BuildDecltypeType(E, DS.getTypeSpecTypeLoc());
980     if (Result.isNull()) {
981       Result = Context.IntTy;
982       declarator.setInvalidType(true);
983     }
984     break;
985   }
986   case DeclSpec::TST_underlyingType:
987     Result = S.GetTypeFromParser(DS.getRepAsType());
988     assert(!Result.isNull() && "Didn't get a type for __underlying_type?");
989     Result = S.BuildUnaryTransformType(Result,
990                                        UnaryTransformType::EnumUnderlyingType,
991                                        DS.getTypeSpecTypeLoc());
992     if (Result.isNull()) {
993       Result = Context.IntTy;
994       declarator.setInvalidType(true);
995     }
996     break;
997 
998   case DeclSpec::TST_auto:
999     // TypeQuals handled by caller.
1000     // If auto is mentioned in a lambda parameter context, convert it to a
1001     // template parameter type immediately, with the appropriate depth and
1002     // index, and update sema's state (LambdaScopeInfo) for the current lambda
1003     // being analyzed (which tracks the invented type template parameter).
1004     if (declarator.getContext() == Declarator::LambdaExprParameterContext) {
1005       sema::LambdaScopeInfo *LSI = S.getCurLambda();
1006       assert(LSI && "No LambdaScopeInfo on the stack!");
1007       const unsigned TemplateParameterDepth = LSI->AutoTemplateParameterDepth;
1008       const unsigned AutoParameterPosition = LSI->AutoTemplateParams.size();
1009       const bool IsParameterPack = declarator.hasEllipsis();
1010 
1011       // Create a name for the invented template parameter type.
1012       std::string InventedTemplateParamName = "$auto-";
1013       llvm::raw_string_ostream ss(InventedTemplateParamName);
1014       ss << TemplateParameterDepth;
1015       ss << "-" << AutoParameterPosition;
1016       ss.flush();
1017 
1018       IdentifierInfo& TemplateParamII = Context.Idents.get(
1019                                         InventedTemplateParamName.c_str());
1020       // Turns out we must create the TemplateTypeParmDecl here to
1021       // retrieve the corresponding template parameter type.
1022       TemplateTypeParmDecl *CorrespondingTemplateParam =
1023         TemplateTypeParmDecl::Create(Context,
1024         // Temporarily add to the TranslationUnit DeclContext.  When the
1025         // associated TemplateParameterList is attached to a template
1026         // declaration (such as FunctionTemplateDecl), the DeclContext
1027         // for each template parameter gets updated appropriately via
1028         // a call to AdoptTemplateParameterList.
1029         Context.getTranslationUnitDecl(),
1030         /*KeyLoc*/ SourceLocation(),
1031         /*NameLoc*/ declarator.getLocStart(),
1032         TemplateParameterDepth,
1033         AutoParameterPosition,  // our template param index
1034         /* Identifier*/ &TemplateParamII, false, IsParameterPack);
1035       LSI->AutoTemplateParams.push_back(CorrespondingTemplateParam);
1036       // Replace the 'auto' in the function parameter with this invented
1037       // template type parameter.
1038       Result = QualType(CorrespondingTemplateParam->getTypeForDecl(), 0);
1039     } else {
1040       Result = Context.getAutoType(QualType(), /*decltype(auto)*/false, false);
1041     }
1042     break;
1043 
1044   case DeclSpec::TST_decltype_auto:
1045     Result = Context.getAutoType(QualType(),
1046                                  /*decltype(auto)*/true,
1047                                  /*IsDependent*/   false);
1048     break;
1049 
1050   case DeclSpec::TST_unknown_anytype:
1051     Result = Context.UnknownAnyTy;
1052     break;
1053 
1054   case DeclSpec::TST_atomic:
1055     Result = S.GetTypeFromParser(DS.getRepAsType());
1056     assert(!Result.isNull() && "Didn't get a type for _Atomic?");
1057     Result = S.BuildAtomicType(Result, DS.getTypeSpecTypeLoc());
1058     if (Result.isNull()) {
1059       Result = Context.IntTy;
1060       declarator.setInvalidType(true);
1061     }
1062     break;
1063 
1064   case DeclSpec::TST_error:
1065     Result = Context.IntTy;
1066     declarator.setInvalidType(true);
1067     break;
1068   }
1069 
1070   // Handle complex types.
1071   if (DS.getTypeSpecComplex() == DeclSpec::TSC_complex) {
1072     if (S.getLangOpts().Freestanding)
1073       S.Diag(DS.getTypeSpecComplexLoc(), diag::ext_freestanding_complex);
1074     Result = Context.getComplexType(Result);
1075   } else if (DS.isTypeAltiVecVector()) {
1076     unsigned typeSize = static_cast<unsigned>(Context.getTypeSize(Result));
1077     assert(typeSize > 0 && "type size for vector must be greater than 0 bits");
1078     VectorType::VectorKind VecKind = VectorType::AltiVecVector;
1079     if (DS.isTypeAltiVecPixel())
1080       VecKind = VectorType::AltiVecPixel;
1081     else if (DS.isTypeAltiVecBool())
1082       VecKind = VectorType::AltiVecBool;
1083     Result = Context.getVectorType(Result, 128/typeSize, VecKind);
1084   }
1085 
1086   // FIXME: Imaginary.
1087   if (DS.getTypeSpecComplex() == DeclSpec::TSC_imaginary)
1088     S.Diag(DS.getTypeSpecComplexLoc(), diag::err_imaginary_not_supported);
1089 
1090   // Before we process any type attributes, synthesize a block literal
1091   // function declarator if necessary.
1092   if (declarator.getContext() == Declarator::BlockLiteralContext)
1093     maybeSynthesizeBlockSignature(state, Result);
1094 
1095   // Apply any type attributes from the decl spec.  This may cause the
1096   // list of type attributes to be temporarily saved while the type
1097   // attributes are pushed around.
1098   if (AttributeList *attrs = DS.getAttributes().getList())
1099     processTypeAttrs(state, Result, TAL_DeclSpec, attrs);
1100 
1101   // Apply const/volatile/restrict qualifiers to T.
1102   if (unsigned TypeQuals = DS.getTypeQualifiers()) {
1103 
1104     // Warn about CV qualifiers on functions: C99 6.7.3p8: "If the specification
1105     // of a function type includes any type qualifiers, the behavior is
1106     // undefined."
1107     if (Result->isFunctionType() && TypeQuals) {
1108       if (TypeQuals & DeclSpec::TQ_const)
1109         S.Diag(DS.getConstSpecLoc(), diag::warn_typecheck_function_qualifiers)
1110           << Result << DS.getSourceRange();
1111       else if (TypeQuals & DeclSpec::TQ_volatile)
1112         S.Diag(DS.getVolatileSpecLoc(), diag::warn_typecheck_function_qualifiers)
1113           << Result << DS.getSourceRange();
1114       else {
1115         assert((TypeQuals & (DeclSpec::TQ_restrict | DeclSpec::TQ_atomic)) &&
1116                "Has CVRA quals but not C, V, R, or A?");
1117         // No diagnostic; we'll diagnose 'restrict' or '_Atomic' applied to a
1118         // function type later, in BuildQualifiedType.
1119       }
1120     }
1121 
1122     // C++11 [dcl.ref]p1:
1123     //   Cv-qualified references are ill-formed except when the
1124     //   cv-qualifiers are introduced through the use of a typedef-name
1125     //   or decltype-specifier, in which case the cv-qualifiers are ignored.
1126     //
1127     // There don't appear to be any other contexts in which a cv-qualified
1128     // reference type could be formed, so the 'ill-formed' clause here appears
1129     // to never happen.
1130     if (DS.getTypeSpecType() == DeclSpec::TST_typename &&
1131         TypeQuals && Result->isReferenceType()) {
1132       // If this occurs outside a template instantiation, warn the user about
1133       // it; they probably didn't mean to specify a redundant qualifier.
1134       typedef std::pair<DeclSpec::TQ, SourceLocation> QualLoc;
1135       QualLoc Quals[] = {
1136         QualLoc(DeclSpec::TQ_const, DS.getConstSpecLoc()),
1137         QualLoc(DeclSpec::TQ_volatile, DS.getVolatileSpecLoc()),
1138         QualLoc(DeclSpec::TQ_atomic, DS.getAtomicSpecLoc())
1139       };
1140       for (unsigned I = 0, N = llvm::array_lengthof(Quals); I != N; ++I) {
1141         if (S.ActiveTemplateInstantiations.empty()) {
1142           if (TypeQuals & Quals[I].first)
1143             S.Diag(Quals[I].second, diag::warn_typecheck_reference_qualifiers)
1144               << DeclSpec::getSpecifierName(Quals[I].first) << Result
1145               << FixItHint::CreateRemoval(Quals[I].second);
1146         }
1147         TypeQuals &= ~Quals[I].first;
1148       }
1149     }
1150 
1151     // C90 6.5.3 constraints: "The same type qualifier shall not appear more
1152     // than once in the same specifier-list or qualifier-list, either directly
1153     // or via one or more typedefs."
1154     if (!S.getLangOpts().C99 && !S.getLangOpts().CPlusPlus
1155         && TypeQuals & Result.getCVRQualifiers()) {
1156       if (TypeQuals & DeclSpec::TQ_const && Result.isConstQualified()) {
1157         S.Diag(DS.getConstSpecLoc(), diag::ext_duplicate_declspec)
1158           << "const";
1159       }
1160 
1161       if (TypeQuals & DeclSpec::TQ_volatile && Result.isVolatileQualified()) {
1162         S.Diag(DS.getVolatileSpecLoc(), diag::ext_duplicate_declspec)
1163           << "volatile";
1164       }
1165 
1166       // C90 doesn't have restrict nor _Atomic, so it doesn't force us to
1167       // produce a warning in this case.
1168     }
1169 
1170     QualType Qualified = S.BuildQualifiedType(Result, DeclLoc, TypeQuals, &DS);
1171 
1172     // If adding qualifiers fails, just use the unqualified type.
1173     if (Qualified.isNull())
1174       declarator.setInvalidType(true);
1175     else
1176       Result = Qualified;
1177   }
1178 
1179   return Result;
1180 }
1181 
1182 static std::string getPrintableNameForEntity(DeclarationName Entity) {
1183   if (Entity)
1184     return Entity.getAsString();
1185 
1186   return "type name";
1187 }
1188 
1189 QualType Sema::BuildQualifiedType(QualType T, SourceLocation Loc,
1190                                   Qualifiers Qs, const DeclSpec *DS) {
1191   // Enforce C99 6.7.3p2: "Types other than pointer types derived from
1192   // object or incomplete types shall not be restrict-qualified."
1193   if (Qs.hasRestrict()) {
1194     unsigned DiagID = 0;
1195     QualType ProblemTy;
1196 
1197     if (T->isAnyPointerType() || T->isReferenceType() ||
1198         T->isMemberPointerType()) {
1199       QualType EltTy;
1200       if (T->isObjCObjectPointerType())
1201         EltTy = T;
1202       else if (const MemberPointerType *PTy = T->getAs<MemberPointerType>())
1203         EltTy = PTy->getPointeeType();
1204       else
1205         EltTy = T->getPointeeType();
1206 
1207       // If we have a pointer or reference, the pointee must have an object
1208       // incomplete type.
1209       if (!EltTy->isIncompleteOrObjectType()) {
1210         DiagID = diag::err_typecheck_invalid_restrict_invalid_pointee;
1211         ProblemTy = EltTy;
1212       }
1213     } else if (!T->isDependentType()) {
1214       DiagID = diag::err_typecheck_invalid_restrict_not_pointer;
1215       ProblemTy = T;
1216     }
1217 
1218     if (DiagID) {
1219       Diag(DS ? DS->getRestrictSpecLoc() : Loc, DiagID) << ProblemTy;
1220       Qs.removeRestrict();
1221     }
1222   }
1223 
1224   return Context.getQualifiedType(T, Qs);
1225 }
1226 
1227 QualType Sema::BuildQualifiedType(QualType T, SourceLocation Loc,
1228                                   unsigned CVRA, const DeclSpec *DS) {
1229   // Convert from DeclSpec::TQ to Qualifiers::TQ by just dropping TQ_atomic.
1230   unsigned CVR = CVRA & ~DeclSpec::TQ_atomic;
1231 
1232   // C11 6.7.3/5:
1233   //   If the same qualifier appears more than once in the same
1234   //   specifier-qualifier-list, either directly or via one or more typedefs,
1235   //   the behavior is the same as if it appeared only once.
1236   //
1237   // It's not specified what happens when the _Atomic qualifier is applied to
1238   // a type specified with the _Atomic specifier, but we assume that this
1239   // should be treated as if the _Atomic qualifier appeared multiple times.
1240   if (CVRA & DeclSpec::TQ_atomic && !T->isAtomicType()) {
1241     // C11 6.7.3/5:
1242     //   If other qualifiers appear along with the _Atomic qualifier in a
1243     //   specifier-qualifier-list, the resulting type is the so-qualified
1244     //   atomic type.
1245     //
1246     // Don't need to worry about array types here, since _Atomic can't be
1247     // applied to such types.
1248     SplitQualType Split = T.getSplitUnqualifiedType();
1249     T = BuildAtomicType(QualType(Split.Ty, 0),
1250                         DS ? DS->getAtomicSpecLoc() : Loc);
1251     if (T.isNull())
1252       return T;
1253     Split.Quals.addCVRQualifiers(CVR);
1254     return BuildQualifiedType(T, Loc, Split.Quals);
1255   }
1256 
1257   return BuildQualifiedType(T, Loc, Qualifiers::fromCVRMask(CVR), DS);
1258 }
1259 
1260 /// \brief Build a paren type including \p T.
1261 QualType Sema::BuildParenType(QualType T) {
1262   return Context.getParenType(T);
1263 }
1264 
1265 /// Given that we're building a pointer or reference to the given
1266 static QualType inferARCLifetimeForPointee(Sema &S, QualType type,
1267                                            SourceLocation loc,
1268                                            bool isReference) {
1269   // Bail out if retention is unrequired or already specified.
1270   if (!type->isObjCLifetimeType() ||
1271       type.getObjCLifetime() != Qualifiers::OCL_None)
1272     return type;
1273 
1274   Qualifiers::ObjCLifetime implicitLifetime = Qualifiers::OCL_None;
1275 
1276   // If the object type is const-qualified, we can safely use
1277   // __unsafe_unretained.  This is safe (because there are no read
1278   // barriers), and it'll be safe to coerce anything but __weak* to
1279   // the resulting type.
1280   if (type.isConstQualified()) {
1281     implicitLifetime = Qualifiers::OCL_ExplicitNone;
1282 
1283   // Otherwise, check whether the static type does not require
1284   // retaining.  This currently only triggers for Class (possibly
1285   // protocol-qualifed, and arrays thereof).
1286   } else if (type->isObjCARCImplicitlyUnretainedType()) {
1287     implicitLifetime = Qualifiers::OCL_ExplicitNone;
1288 
1289   // If we are in an unevaluated context, like sizeof, skip adding a
1290   // qualification.
1291   } else if (S.isUnevaluatedContext()) {
1292     return type;
1293 
1294   // If that failed, give an error and recover using __strong.  __strong
1295   // is the option most likely to prevent spurious second-order diagnostics,
1296   // like when binding a reference to a field.
1297   } else {
1298     // These types can show up in private ivars in system headers, so
1299     // we need this to not be an error in those cases.  Instead we
1300     // want to delay.
1301     if (S.DelayedDiagnostics.shouldDelayDiagnostics()) {
1302       S.DelayedDiagnostics.add(
1303           sema::DelayedDiagnostic::makeForbiddenType(loc,
1304               diag::err_arc_indirect_no_ownership, type, isReference));
1305     } else {
1306       S.Diag(loc, diag::err_arc_indirect_no_ownership) << type << isReference;
1307     }
1308     implicitLifetime = Qualifiers::OCL_Strong;
1309   }
1310   assert(implicitLifetime && "didn't infer any lifetime!");
1311 
1312   Qualifiers qs;
1313   qs.addObjCLifetime(implicitLifetime);
1314   return S.Context.getQualifiedType(type, qs);
1315 }
1316 
1317 static std::string getFunctionQualifiersAsString(const FunctionProtoType *FnTy){
1318   std::string Quals =
1319     Qualifiers::fromCVRMask(FnTy->getTypeQuals()).getAsString();
1320 
1321   switch (FnTy->getRefQualifier()) {
1322   case RQ_None:
1323     break;
1324 
1325   case RQ_LValue:
1326     if (!Quals.empty())
1327       Quals += ' ';
1328     Quals += '&';
1329     break;
1330 
1331   case RQ_RValue:
1332     if (!Quals.empty())
1333       Quals += ' ';
1334     Quals += "&&";
1335     break;
1336   }
1337 
1338   return Quals;
1339 }
1340 
1341 namespace {
1342 /// Kinds of declarator that cannot contain a qualified function type.
1343 ///
1344 /// C++98 [dcl.fct]p4 / C++11 [dcl.fct]p6:
1345 ///     a function type with a cv-qualifier or a ref-qualifier can only appear
1346 ///     at the topmost level of a type.
1347 ///
1348 /// Parens and member pointers are permitted. We don't diagnose array and
1349 /// function declarators, because they don't allow function types at all.
1350 ///
1351 /// The values of this enum are used in diagnostics.
1352 enum QualifiedFunctionKind { QFK_BlockPointer, QFK_Pointer, QFK_Reference };
1353 }
1354 
1355 /// Check whether the type T is a qualified function type, and if it is,
1356 /// diagnose that it cannot be contained within the given kind of declarator.
1357 static bool checkQualifiedFunction(Sema &S, QualType T, SourceLocation Loc,
1358                                    QualifiedFunctionKind QFK) {
1359   // Does T refer to a function type with a cv-qualifier or a ref-qualifier?
1360   const FunctionProtoType *FPT = T->getAs<FunctionProtoType>();
1361   if (!FPT || (FPT->getTypeQuals() == 0 && FPT->getRefQualifier() == RQ_None))
1362     return false;
1363 
1364   S.Diag(Loc, diag::err_compound_qualified_function_type)
1365     << QFK << isa<FunctionType>(T.IgnoreParens()) << T
1366     << getFunctionQualifiersAsString(FPT);
1367   return true;
1368 }
1369 
1370 /// \brief Build a pointer type.
1371 ///
1372 /// \param T The type to which we'll be building a pointer.
1373 ///
1374 /// \param Loc The location of the entity whose type involves this
1375 /// pointer type or, if there is no such entity, the location of the
1376 /// type that will have pointer type.
1377 ///
1378 /// \param Entity The name of the entity that involves the pointer
1379 /// type, if known.
1380 ///
1381 /// \returns A suitable pointer type, if there are no
1382 /// errors. Otherwise, returns a NULL type.
1383 QualType Sema::BuildPointerType(QualType T,
1384                                 SourceLocation Loc, DeclarationName Entity) {
1385   if (T->isReferenceType()) {
1386     // C++ 8.3.2p4: There shall be no ... pointers to references ...
1387     Diag(Loc, diag::err_illegal_decl_pointer_to_reference)
1388       << getPrintableNameForEntity(Entity) << T;
1389     return QualType();
1390   }
1391 
1392   if (checkQualifiedFunction(*this, T, Loc, QFK_Pointer))
1393     return QualType();
1394 
1395   assert(!T->isObjCObjectType() && "Should build ObjCObjectPointerType");
1396 
1397   // In ARC, it is forbidden to build pointers to unqualified pointers.
1398   if (getLangOpts().ObjCAutoRefCount)
1399     T = inferARCLifetimeForPointee(*this, T, Loc, /*reference*/ false);
1400 
1401   // Build the pointer type.
1402   return Context.getPointerType(T);
1403 }
1404 
1405 /// \brief Build a reference type.
1406 ///
1407 /// \param T The type to which we'll be building a reference.
1408 ///
1409 /// \param Loc The location of the entity whose type involves this
1410 /// reference type or, if there is no such entity, the location of the
1411 /// type that will have reference type.
1412 ///
1413 /// \param Entity The name of the entity that involves the reference
1414 /// type, if known.
1415 ///
1416 /// \returns A suitable reference type, if there are no
1417 /// errors. Otherwise, returns a NULL type.
1418 QualType Sema::BuildReferenceType(QualType T, bool SpelledAsLValue,
1419                                   SourceLocation Loc,
1420                                   DeclarationName Entity) {
1421   assert(Context.getCanonicalType(T) != Context.OverloadTy &&
1422          "Unresolved overloaded function type");
1423 
1424   // C++0x [dcl.ref]p6:
1425   //   If a typedef (7.1.3), a type template-parameter (14.3.1), or a
1426   //   decltype-specifier (7.1.6.2) denotes a type TR that is a reference to a
1427   //   type T, an attempt to create the type "lvalue reference to cv TR" creates
1428   //   the type "lvalue reference to T", while an attempt to create the type
1429   //   "rvalue reference to cv TR" creates the type TR.
1430   bool LValueRef = SpelledAsLValue || T->getAs<LValueReferenceType>();
1431 
1432   // C++ [dcl.ref]p4: There shall be no references to references.
1433   //
1434   // According to C++ DR 106, references to references are only
1435   // diagnosed when they are written directly (e.g., "int & &"),
1436   // but not when they happen via a typedef:
1437   //
1438   //   typedef int& intref;
1439   //   typedef intref& intref2;
1440   //
1441   // Parser::ParseDeclaratorInternal diagnoses the case where
1442   // references are written directly; here, we handle the
1443   // collapsing of references-to-references as described in C++0x.
1444   // DR 106 and 540 introduce reference-collapsing into C++98/03.
1445 
1446   // C++ [dcl.ref]p1:
1447   //   A declarator that specifies the type "reference to cv void"
1448   //   is ill-formed.
1449   if (T->isVoidType()) {
1450     Diag(Loc, diag::err_reference_to_void);
1451     return QualType();
1452   }
1453 
1454   if (checkQualifiedFunction(*this, T, Loc, QFK_Reference))
1455     return QualType();
1456 
1457   // In ARC, it is forbidden to build references to unqualified pointers.
1458   if (getLangOpts().ObjCAutoRefCount)
1459     T = inferARCLifetimeForPointee(*this, T, Loc, /*reference*/ true);
1460 
1461   // Handle restrict on references.
1462   if (LValueRef)
1463     return Context.getLValueReferenceType(T, SpelledAsLValue);
1464   return Context.getRValueReferenceType(T);
1465 }
1466 
1467 /// Check whether the specified array size makes the array type a VLA.  If so,
1468 /// return true, if not, return the size of the array in SizeVal.
1469 static bool isArraySizeVLA(Sema &S, Expr *ArraySize, llvm::APSInt &SizeVal) {
1470   // If the size is an ICE, it certainly isn't a VLA. If we're in a GNU mode
1471   // (like gnu99, but not c99) accept any evaluatable value as an extension.
1472   class VLADiagnoser : public Sema::VerifyICEDiagnoser {
1473   public:
1474     VLADiagnoser() : Sema::VerifyICEDiagnoser(true) {}
1475 
1476     void diagnoseNotICE(Sema &S, SourceLocation Loc, SourceRange SR) override {
1477     }
1478 
1479     void diagnoseFold(Sema &S, SourceLocation Loc, SourceRange SR) override {
1480       S.Diag(Loc, diag::ext_vla_folded_to_constant) << SR;
1481     }
1482   } Diagnoser;
1483 
1484   return S.VerifyIntegerConstantExpression(ArraySize, &SizeVal, Diagnoser,
1485                                            S.LangOpts.GNUMode).isInvalid();
1486 }
1487 
1488 
1489 /// \brief Build an array type.
1490 ///
1491 /// \param T The type of each element in the array.
1492 ///
1493 /// \param ASM C99 array size modifier (e.g., '*', 'static').
1494 ///
1495 /// \param ArraySize Expression describing the size of the array.
1496 ///
1497 /// \param Brackets The range from the opening '[' to the closing ']'.
1498 ///
1499 /// \param Entity The name of the entity that involves the array
1500 /// type, if known.
1501 ///
1502 /// \returns A suitable array type, if there are no errors. Otherwise,
1503 /// returns a NULL type.
1504 QualType Sema::BuildArrayType(QualType T, ArrayType::ArraySizeModifier ASM,
1505                               Expr *ArraySize, unsigned Quals,
1506                               SourceRange Brackets, DeclarationName Entity) {
1507 
1508   SourceLocation Loc = Brackets.getBegin();
1509   if (getLangOpts().CPlusPlus) {
1510     // C++ [dcl.array]p1:
1511     //   T is called the array element type; this type shall not be a reference
1512     //   type, the (possibly cv-qualified) type void, a function type or an
1513     //   abstract class type.
1514     //
1515     // C++ [dcl.array]p3:
1516     //   When several "array of" specifications are adjacent, [...] only the
1517     //   first of the constant expressions that specify the bounds of the arrays
1518     //   may be omitted.
1519     //
1520     // Note: function types are handled in the common path with C.
1521     if (T->isReferenceType()) {
1522       Diag(Loc, diag::err_illegal_decl_array_of_references)
1523       << getPrintableNameForEntity(Entity) << T;
1524       return QualType();
1525     }
1526 
1527     if (T->isVoidType() || T->isIncompleteArrayType()) {
1528       Diag(Loc, diag::err_illegal_decl_array_incomplete_type) << T;
1529       return QualType();
1530     }
1531 
1532     if (RequireNonAbstractType(Brackets.getBegin(), T,
1533                                diag::err_array_of_abstract_type))
1534       return QualType();
1535 
1536     // Mentioning a member pointer type for an array type causes us to lock in
1537     // an inheritance model, even if it's inside an unused typedef.
1538     if (Context.getTargetInfo().getCXXABI().isMicrosoft())
1539       if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>())
1540         if (!MPTy->getClass()->isDependentType())
1541           RequireCompleteType(Loc, T, 0);
1542 
1543   } else {
1544     // C99 6.7.5.2p1: If the element type is an incomplete or function type,
1545     // reject it (e.g. void ary[7], struct foo ary[7], void ary[7]())
1546     if (RequireCompleteType(Loc, T,
1547                             diag::err_illegal_decl_array_incomplete_type))
1548       return QualType();
1549   }
1550 
1551   if (T->isFunctionType()) {
1552     Diag(Loc, diag::err_illegal_decl_array_of_functions)
1553       << getPrintableNameForEntity(Entity) << T;
1554     return QualType();
1555   }
1556 
1557   if (const RecordType *EltTy = T->getAs<RecordType>()) {
1558     // If the element type is a struct or union that contains a variadic
1559     // array, accept it as a GNU extension: C99 6.7.2.1p2.
1560     if (EltTy->getDecl()->hasFlexibleArrayMember())
1561       Diag(Loc, diag::ext_flexible_array_in_array) << T;
1562   } else if (T->isObjCObjectType()) {
1563     Diag(Loc, diag::err_objc_array_of_interfaces) << T;
1564     return QualType();
1565   }
1566 
1567   // Do placeholder conversions on the array size expression.
1568   if (ArraySize && ArraySize->hasPlaceholderType()) {
1569     ExprResult Result = CheckPlaceholderExpr(ArraySize);
1570     if (Result.isInvalid()) return QualType();
1571     ArraySize = Result.get();
1572   }
1573 
1574   // Do lvalue-to-rvalue conversions on the array size expression.
1575   if (ArraySize && !ArraySize->isRValue()) {
1576     ExprResult Result = DefaultLvalueConversion(ArraySize);
1577     if (Result.isInvalid())
1578       return QualType();
1579 
1580     ArraySize = Result.get();
1581   }
1582 
1583   // C99 6.7.5.2p1: The size expression shall have integer type.
1584   // C++11 allows contextual conversions to such types.
1585   if (!getLangOpts().CPlusPlus11 &&
1586       ArraySize && !ArraySize->isTypeDependent() &&
1587       !ArraySize->getType()->isIntegralOrUnscopedEnumerationType()) {
1588     Diag(ArraySize->getLocStart(), diag::err_array_size_non_int)
1589       << ArraySize->getType() << ArraySize->getSourceRange();
1590     return QualType();
1591   }
1592 
1593   llvm::APSInt ConstVal(Context.getTypeSize(Context.getSizeType()));
1594   if (!ArraySize) {
1595     if (ASM == ArrayType::Star)
1596       T = Context.getVariableArrayType(T, nullptr, ASM, Quals, Brackets);
1597     else
1598       T = Context.getIncompleteArrayType(T, ASM, Quals);
1599   } else if (ArraySize->isTypeDependent() || ArraySize->isValueDependent()) {
1600     T = Context.getDependentSizedArrayType(T, ArraySize, ASM, Quals, Brackets);
1601   } else if ((!T->isDependentType() && !T->isIncompleteType() &&
1602               !T->isConstantSizeType()) ||
1603              isArraySizeVLA(*this, ArraySize, ConstVal)) {
1604     // Even in C++11, don't allow contextual conversions in the array bound
1605     // of a VLA.
1606     if (getLangOpts().CPlusPlus11 &&
1607         !ArraySize->getType()->isIntegralOrUnscopedEnumerationType()) {
1608       Diag(ArraySize->getLocStart(), diag::err_array_size_non_int)
1609         << ArraySize->getType() << ArraySize->getSourceRange();
1610       return QualType();
1611     }
1612 
1613     // C99: an array with an element type that has a non-constant-size is a VLA.
1614     // C99: an array with a non-ICE size is a VLA.  We accept any expression
1615     // that we can fold to a non-zero positive value as an extension.
1616     T = Context.getVariableArrayType(T, ArraySize, ASM, Quals, Brackets);
1617   } else {
1618     // C99 6.7.5.2p1: If the expression is a constant expression, it shall
1619     // have a value greater than zero.
1620     if (ConstVal.isSigned() && ConstVal.isNegative()) {
1621       if (Entity)
1622         Diag(ArraySize->getLocStart(), diag::err_decl_negative_array_size)
1623           << getPrintableNameForEntity(Entity) << ArraySize->getSourceRange();
1624       else
1625         Diag(ArraySize->getLocStart(), diag::err_typecheck_negative_array_size)
1626           << ArraySize->getSourceRange();
1627       return QualType();
1628     }
1629     if (ConstVal == 0) {
1630       // GCC accepts zero sized static arrays. We allow them when
1631       // we're not in a SFINAE context.
1632       Diag(ArraySize->getLocStart(),
1633            isSFINAEContext()? diag::err_typecheck_zero_array_size
1634                             : diag::ext_typecheck_zero_array_size)
1635         << ArraySize->getSourceRange();
1636 
1637       if (ASM == ArrayType::Static) {
1638         Diag(ArraySize->getLocStart(),
1639              diag::warn_typecheck_zero_static_array_size)
1640           << ArraySize->getSourceRange();
1641         ASM = ArrayType::Normal;
1642       }
1643     } else if (!T->isDependentType() && !T->isVariablyModifiedType() &&
1644                !T->isIncompleteType() && !T->isUndeducedType()) {
1645       // Is the array too large?
1646       unsigned ActiveSizeBits
1647         = ConstantArrayType::getNumAddressingBits(Context, T, ConstVal);
1648       if (ActiveSizeBits > ConstantArrayType::getMaxSizeBits(Context)) {
1649         Diag(ArraySize->getLocStart(), diag::err_array_too_large)
1650           << ConstVal.toString(10)
1651           << ArraySize->getSourceRange();
1652         return QualType();
1653       }
1654     }
1655 
1656     T = Context.getConstantArrayType(T, ConstVal, ASM, Quals);
1657   }
1658 
1659   // OpenCL v1.2 s6.9.d: variable length arrays are not supported.
1660   if (getLangOpts().OpenCL && T->isVariableArrayType()) {
1661     Diag(Loc, diag::err_opencl_vla);
1662     return QualType();
1663   }
1664   // If this is not C99, extwarn about VLA's and C99 array size modifiers.
1665   if (!getLangOpts().C99) {
1666     if (T->isVariableArrayType()) {
1667       // Prohibit the use of non-POD types in VLAs.
1668       QualType BaseT = Context.getBaseElementType(T);
1669       if (!T->isDependentType() &&
1670           !RequireCompleteType(Loc, BaseT, 0) &&
1671           !BaseT.isPODType(Context) &&
1672           !BaseT->isObjCLifetimeType()) {
1673         Diag(Loc, diag::err_vla_non_pod)
1674           << BaseT;
1675         return QualType();
1676       }
1677       // Prohibit the use of VLAs during template argument deduction.
1678       else if (isSFINAEContext()) {
1679         Diag(Loc, diag::err_vla_in_sfinae);
1680         return QualType();
1681       }
1682       // Just extwarn about VLAs.
1683       else
1684         Diag(Loc, diag::ext_vla);
1685     } else if (ASM != ArrayType::Normal || Quals != 0)
1686       Diag(Loc,
1687            getLangOpts().CPlusPlus? diag::err_c99_array_usage_cxx
1688                                      : diag::ext_c99_array_usage) << ASM;
1689   }
1690 
1691   if (T->isVariableArrayType()) {
1692     // Warn about VLAs for -Wvla.
1693     Diag(Loc, diag::warn_vla_used);
1694   }
1695 
1696   return T;
1697 }
1698 
1699 /// \brief Build an ext-vector type.
1700 ///
1701 /// Run the required checks for the extended vector type.
1702 QualType Sema::BuildExtVectorType(QualType T, Expr *ArraySize,
1703                                   SourceLocation AttrLoc) {
1704   // unlike gcc's vector_size attribute, we do not allow vectors to be defined
1705   // in conjunction with complex types (pointers, arrays, functions, etc.).
1706   if (!T->isDependentType() &&
1707       !T->isIntegerType() && !T->isRealFloatingType()) {
1708     Diag(AttrLoc, diag::err_attribute_invalid_vector_type) << T;
1709     return QualType();
1710   }
1711 
1712   if (!ArraySize->isTypeDependent() && !ArraySize->isValueDependent()) {
1713     llvm::APSInt vecSize(32);
1714     if (!ArraySize->isIntegerConstantExpr(vecSize, Context)) {
1715       Diag(AttrLoc, diag::err_attribute_argument_type)
1716         << "ext_vector_type" << AANT_ArgumentIntegerConstant
1717         << ArraySize->getSourceRange();
1718       return QualType();
1719     }
1720 
1721     // unlike gcc's vector_size attribute, the size is specified as the
1722     // number of elements, not the number of bytes.
1723     unsigned vectorSize = static_cast<unsigned>(vecSize.getZExtValue());
1724 
1725     if (vectorSize == 0) {
1726       Diag(AttrLoc, diag::err_attribute_zero_size)
1727       << ArraySize->getSourceRange();
1728       return QualType();
1729     }
1730 
1731     if (VectorType::isVectorSizeTooLarge(vectorSize)) {
1732       Diag(AttrLoc, diag::err_attribute_size_too_large)
1733         << ArraySize->getSourceRange();
1734       return QualType();
1735     }
1736 
1737     return Context.getExtVectorType(T, vectorSize);
1738   }
1739 
1740   return Context.getDependentSizedExtVectorType(T, ArraySize, AttrLoc);
1741 }
1742 
1743 bool Sema::CheckFunctionReturnType(QualType T, SourceLocation Loc) {
1744   if (T->isArrayType() || T->isFunctionType()) {
1745     Diag(Loc, diag::err_func_returning_array_function)
1746       << T->isFunctionType() << T;
1747     return true;
1748   }
1749 
1750   // Functions cannot return half FP.
1751   if (T->isHalfType() && !getLangOpts().HalfArgsAndReturns) {
1752     Diag(Loc, diag::err_parameters_retval_cannot_have_fp16_type) << 1 <<
1753       FixItHint::CreateInsertion(Loc, "*");
1754     return true;
1755   }
1756 
1757   // Methods cannot return interface types. All ObjC objects are
1758   // passed by reference.
1759   if (T->isObjCObjectType()) {
1760     Diag(Loc, diag::err_object_cannot_be_passed_returned_by_value) << 0 << T;
1761     return 0;
1762   }
1763 
1764   return false;
1765 }
1766 
1767 QualType Sema::BuildFunctionType(QualType T,
1768                                  MutableArrayRef<QualType> ParamTypes,
1769                                  SourceLocation Loc, DeclarationName Entity,
1770                                  const FunctionProtoType::ExtProtoInfo &EPI) {
1771   bool Invalid = false;
1772 
1773   Invalid |= CheckFunctionReturnType(T, Loc);
1774 
1775   for (unsigned Idx = 0, Cnt = ParamTypes.size(); Idx < Cnt; ++Idx) {
1776     // FIXME: Loc is too inprecise here, should use proper locations for args.
1777     QualType ParamType = Context.getAdjustedParameterType(ParamTypes[Idx]);
1778     if (ParamType->isVoidType()) {
1779       Diag(Loc, diag::err_param_with_void_type);
1780       Invalid = true;
1781     } else if (ParamType->isHalfType() && !getLangOpts().HalfArgsAndReturns) {
1782       // Disallow half FP arguments.
1783       Diag(Loc, diag::err_parameters_retval_cannot_have_fp16_type) << 0 <<
1784         FixItHint::CreateInsertion(Loc, "*");
1785       Invalid = true;
1786     }
1787 
1788     ParamTypes[Idx] = ParamType;
1789   }
1790 
1791   if (Invalid)
1792     return QualType();
1793 
1794   return Context.getFunctionType(T, ParamTypes, EPI);
1795 }
1796 
1797 /// \brief Build a member pointer type \c T Class::*.
1798 ///
1799 /// \param T the type to which the member pointer refers.
1800 /// \param Class the class type into which the member pointer points.
1801 /// \param Loc the location where this type begins
1802 /// \param Entity the name of the entity that will have this member pointer type
1803 ///
1804 /// \returns a member pointer type, if successful, or a NULL type if there was
1805 /// an error.
1806 QualType Sema::BuildMemberPointerType(QualType T, QualType Class,
1807                                       SourceLocation Loc,
1808                                       DeclarationName Entity) {
1809   // Verify that we're not building a pointer to pointer to function with
1810   // exception specification.
1811   if (CheckDistantExceptionSpec(T)) {
1812     Diag(Loc, diag::err_distant_exception_spec);
1813 
1814     // FIXME: If we're doing this as part of template instantiation,
1815     // we should return immediately.
1816 
1817     // Build the type anyway, but use the canonical type so that the
1818     // exception specifiers are stripped off.
1819     T = Context.getCanonicalType(T);
1820   }
1821 
1822   // C++ 8.3.3p3: A pointer to member shall not point to ... a member
1823   //   with reference type, or "cv void."
1824   if (T->isReferenceType()) {
1825     Diag(Loc, diag::err_illegal_decl_mempointer_to_reference)
1826       << getPrintableNameForEntity(Entity) << T;
1827     return QualType();
1828   }
1829 
1830   if (T->isVoidType()) {
1831     Diag(Loc, diag::err_illegal_decl_mempointer_to_void)
1832       << getPrintableNameForEntity(Entity);
1833     return QualType();
1834   }
1835 
1836   if (!Class->isDependentType() && !Class->isRecordType()) {
1837     Diag(Loc, diag::err_mempointer_in_nonclass_type) << Class;
1838     return QualType();
1839   }
1840 
1841   // Adjust the default free function calling convention to the default method
1842   // calling convention.
1843   if (T->isFunctionType())
1844     adjustMemberFunctionCC(T, /*IsStatic=*/false);
1845 
1846   return Context.getMemberPointerType(T, Class.getTypePtr());
1847 }
1848 
1849 /// \brief Build a block pointer type.
1850 ///
1851 /// \param T The type to which we'll be building a block pointer.
1852 ///
1853 /// \param Loc The source location, used for diagnostics.
1854 ///
1855 /// \param Entity The name of the entity that involves the block pointer
1856 /// type, if known.
1857 ///
1858 /// \returns A suitable block pointer type, if there are no
1859 /// errors. Otherwise, returns a NULL type.
1860 QualType Sema::BuildBlockPointerType(QualType T,
1861                                      SourceLocation Loc,
1862                                      DeclarationName Entity) {
1863   if (!T->isFunctionType()) {
1864     Diag(Loc, diag::err_nonfunction_block_type);
1865     return QualType();
1866   }
1867 
1868   if (checkQualifiedFunction(*this, T, Loc, QFK_BlockPointer))
1869     return QualType();
1870 
1871   return Context.getBlockPointerType(T);
1872 }
1873 
1874 QualType Sema::GetTypeFromParser(ParsedType Ty, TypeSourceInfo **TInfo) {
1875   QualType QT = Ty.get();
1876   if (QT.isNull()) {
1877     if (TInfo) *TInfo = nullptr;
1878     return QualType();
1879   }
1880 
1881   TypeSourceInfo *DI = nullptr;
1882   if (const LocInfoType *LIT = dyn_cast<LocInfoType>(QT)) {
1883     QT = LIT->getType();
1884     DI = LIT->getTypeSourceInfo();
1885   }
1886 
1887   if (TInfo) *TInfo = DI;
1888   return QT;
1889 }
1890 
1891 static void transferARCOwnershipToDeclaratorChunk(TypeProcessingState &state,
1892                                             Qualifiers::ObjCLifetime ownership,
1893                                             unsigned chunkIndex);
1894 
1895 /// Given that this is the declaration of a parameter under ARC,
1896 /// attempt to infer attributes and such for pointer-to-whatever
1897 /// types.
1898 static void inferARCWriteback(TypeProcessingState &state,
1899                               QualType &declSpecType) {
1900   Sema &S = state.getSema();
1901   Declarator &declarator = state.getDeclarator();
1902 
1903   // TODO: should we care about decl qualifiers?
1904 
1905   // Check whether the declarator has the expected form.  We walk
1906   // from the inside out in order to make the block logic work.
1907   unsigned outermostPointerIndex = 0;
1908   bool isBlockPointer = false;
1909   unsigned numPointers = 0;
1910   for (unsigned i = 0, e = declarator.getNumTypeObjects(); i != e; ++i) {
1911     unsigned chunkIndex = i;
1912     DeclaratorChunk &chunk = declarator.getTypeObject(chunkIndex);
1913     switch (chunk.Kind) {
1914     case DeclaratorChunk::Paren:
1915       // Ignore parens.
1916       break;
1917 
1918     case DeclaratorChunk::Reference:
1919     case DeclaratorChunk::Pointer:
1920       // Count the number of pointers.  Treat references
1921       // interchangeably as pointers; if they're mis-ordered, normal
1922       // type building will discover that.
1923       outermostPointerIndex = chunkIndex;
1924       numPointers++;
1925       break;
1926 
1927     case DeclaratorChunk::BlockPointer:
1928       // If we have a pointer to block pointer, that's an acceptable
1929       // indirect reference; anything else is not an application of
1930       // the rules.
1931       if (numPointers != 1) return;
1932       numPointers++;
1933       outermostPointerIndex = chunkIndex;
1934       isBlockPointer = true;
1935 
1936       // We don't care about pointer structure in return values here.
1937       goto done;
1938 
1939     case DeclaratorChunk::Array: // suppress if written (id[])?
1940     case DeclaratorChunk::Function:
1941     case DeclaratorChunk::MemberPointer:
1942       return;
1943     }
1944   }
1945  done:
1946 
1947   // If we have *one* pointer, then we want to throw the qualifier on
1948   // the declaration-specifiers, which means that it needs to be a
1949   // retainable object type.
1950   if (numPointers == 1) {
1951     // If it's not a retainable object type, the rule doesn't apply.
1952     if (!declSpecType->isObjCRetainableType()) return;
1953 
1954     // If it already has lifetime, don't do anything.
1955     if (declSpecType.getObjCLifetime()) return;
1956 
1957     // Otherwise, modify the type in-place.
1958     Qualifiers qs;
1959 
1960     if (declSpecType->isObjCARCImplicitlyUnretainedType())
1961       qs.addObjCLifetime(Qualifiers::OCL_ExplicitNone);
1962     else
1963       qs.addObjCLifetime(Qualifiers::OCL_Autoreleasing);
1964     declSpecType = S.Context.getQualifiedType(declSpecType, qs);
1965 
1966   // If we have *two* pointers, then we want to throw the qualifier on
1967   // the outermost pointer.
1968   } else if (numPointers == 2) {
1969     // If we don't have a block pointer, we need to check whether the
1970     // declaration-specifiers gave us something that will turn into a
1971     // retainable object pointer after we slap the first pointer on it.
1972     if (!isBlockPointer && !declSpecType->isObjCObjectType())
1973       return;
1974 
1975     // Look for an explicit lifetime attribute there.
1976     DeclaratorChunk &chunk = declarator.getTypeObject(outermostPointerIndex);
1977     if (chunk.Kind != DeclaratorChunk::Pointer &&
1978         chunk.Kind != DeclaratorChunk::BlockPointer)
1979       return;
1980     for (const AttributeList *attr = chunk.getAttrs(); attr;
1981            attr = attr->getNext())
1982       if (attr->getKind() == AttributeList::AT_ObjCOwnership)
1983         return;
1984 
1985     transferARCOwnershipToDeclaratorChunk(state, Qualifiers::OCL_Autoreleasing,
1986                                           outermostPointerIndex);
1987 
1988   // Any other number of pointers/references does not trigger the rule.
1989   } else return;
1990 
1991   // TODO: mark whether we did this inference?
1992 }
1993 
1994 void Sema::diagnoseIgnoredQualifiers(unsigned DiagID, unsigned Quals,
1995                                      SourceLocation FallbackLoc,
1996                                      SourceLocation ConstQualLoc,
1997                                      SourceLocation VolatileQualLoc,
1998                                      SourceLocation RestrictQualLoc,
1999                                      SourceLocation AtomicQualLoc) {
2000   if (!Quals)
2001     return;
2002 
2003   struct Qual {
2004     unsigned Mask;
2005     const char *Name;
2006     SourceLocation Loc;
2007   } const QualKinds[4] = {
2008     { DeclSpec::TQ_const, "const", ConstQualLoc },
2009     { DeclSpec::TQ_volatile, "volatile", VolatileQualLoc },
2010     { DeclSpec::TQ_restrict, "restrict", RestrictQualLoc },
2011     { DeclSpec::TQ_atomic, "_Atomic", AtomicQualLoc }
2012   };
2013 
2014   SmallString<32> QualStr;
2015   unsigned NumQuals = 0;
2016   SourceLocation Loc;
2017   FixItHint FixIts[4];
2018 
2019   // Build a string naming the redundant qualifiers.
2020   for (unsigned I = 0; I != 4; ++I) {
2021     if (Quals & QualKinds[I].Mask) {
2022       if (!QualStr.empty()) QualStr += ' ';
2023       QualStr += QualKinds[I].Name;
2024 
2025       // If we have a location for the qualifier, offer a fixit.
2026       SourceLocation QualLoc = QualKinds[I].Loc;
2027       if (!QualLoc.isInvalid()) {
2028         FixIts[NumQuals] = FixItHint::CreateRemoval(QualLoc);
2029         if (Loc.isInvalid() ||
2030             getSourceManager().isBeforeInTranslationUnit(QualLoc, Loc))
2031           Loc = QualLoc;
2032       }
2033 
2034       ++NumQuals;
2035     }
2036   }
2037 
2038   Diag(Loc.isInvalid() ? FallbackLoc : Loc, DiagID)
2039     << QualStr << NumQuals << FixIts[0] << FixIts[1] << FixIts[2] << FixIts[3];
2040 }
2041 
2042 // Diagnose pointless type qualifiers on the return type of a function.
2043 static void diagnoseRedundantReturnTypeQualifiers(Sema &S, QualType RetTy,
2044                                                   Declarator &D,
2045                                                   unsigned FunctionChunkIndex) {
2046   if (D.getTypeObject(FunctionChunkIndex).Fun.hasTrailingReturnType()) {
2047     // FIXME: TypeSourceInfo doesn't preserve location information for
2048     // qualifiers.
2049     S.diagnoseIgnoredQualifiers(diag::warn_qual_return_type,
2050                                 RetTy.getLocalCVRQualifiers(),
2051                                 D.getIdentifierLoc());
2052     return;
2053   }
2054 
2055   for (unsigned OuterChunkIndex = FunctionChunkIndex + 1,
2056                 End = D.getNumTypeObjects();
2057        OuterChunkIndex != End; ++OuterChunkIndex) {
2058     DeclaratorChunk &OuterChunk = D.getTypeObject(OuterChunkIndex);
2059     switch (OuterChunk.Kind) {
2060     case DeclaratorChunk::Paren:
2061       continue;
2062 
2063     case DeclaratorChunk::Pointer: {
2064       DeclaratorChunk::PointerTypeInfo &PTI = OuterChunk.Ptr;
2065       S.diagnoseIgnoredQualifiers(
2066           diag::warn_qual_return_type,
2067           PTI.TypeQuals,
2068           SourceLocation(),
2069           SourceLocation::getFromRawEncoding(PTI.ConstQualLoc),
2070           SourceLocation::getFromRawEncoding(PTI.VolatileQualLoc),
2071           SourceLocation::getFromRawEncoding(PTI.RestrictQualLoc),
2072           SourceLocation::getFromRawEncoding(PTI.AtomicQualLoc));
2073       return;
2074     }
2075 
2076     case DeclaratorChunk::Function:
2077     case DeclaratorChunk::BlockPointer:
2078     case DeclaratorChunk::Reference:
2079     case DeclaratorChunk::Array:
2080     case DeclaratorChunk::MemberPointer:
2081       // FIXME: We can't currently provide an accurate source location and a
2082       // fix-it hint for these.
2083       unsigned AtomicQual = RetTy->isAtomicType() ? DeclSpec::TQ_atomic : 0;
2084       S.diagnoseIgnoredQualifiers(diag::warn_qual_return_type,
2085                                   RetTy.getCVRQualifiers() | AtomicQual,
2086                                   D.getIdentifierLoc());
2087       return;
2088     }
2089 
2090     llvm_unreachable("unknown declarator chunk kind");
2091   }
2092 
2093   // If the qualifiers come from a conversion function type, don't diagnose
2094   // them -- they're not necessarily redundant, since such a conversion
2095   // operator can be explicitly called as "x.operator const int()".
2096   if (D.getName().getKind() == UnqualifiedId::IK_ConversionFunctionId)
2097     return;
2098 
2099   // Just parens all the way out to the decl specifiers. Diagnose any qualifiers
2100   // which are present there.
2101   S.diagnoseIgnoredQualifiers(diag::warn_qual_return_type,
2102                               D.getDeclSpec().getTypeQualifiers(),
2103                               D.getIdentifierLoc(),
2104                               D.getDeclSpec().getConstSpecLoc(),
2105                               D.getDeclSpec().getVolatileSpecLoc(),
2106                               D.getDeclSpec().getRestrictSpecLoc(),
2107                               D.getDeclSpec().getAtomicSpecLoc());
2108 }
2109 
2110 static QualType GetDeclSpecTypeForDeclarator(TypeProcessingState &state,
2111                                              TypeSourceInfo *&ReturnTypeInfo) {
2112   Sema &SemaRef = state.getSema();
2113   Declarator &D = state.getDeclarator();
2114   QualType T;
2115   ReturnTypeInfo = nullptr;
2116 
2117   // The TagDecl owned by the DeclSpec.
2118   TagDecl *OwnedTagDecl = nullptr;
2119 
2120   bool ContainsPlaceholderType = false;
2121 
2122   switch (D.getName().getKind()) {
2123   case UnqualifiedId::IK_ImplicitSelfParam:
2124   case UnqualifiedId::IK_OperatorFunctionId:
2125   case UnqualifiedId::IK_Identifier:
2126   case UnqualifiedId::IK_LiteralOperatorId:
2127   case UnqualifiedId::IK_TemplateId:
2128     T = ConvertDeclSpecToType(state);
2129     ContainsPlaceholderType = D.getDeclSpec().containsPlaceholderType();
2130 
2131     if (!D.isInvalidType() && D.getDeclSpec().isTypeSpecOwned()) {
2132       OwnedTagDecl = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
2133       // Owned declaration is embedded in declarator.
2134       OwnedTagDecl->setEmbeddedInDeclarator(true);
2135     }
2136     break;
2137 
2138   case UnqualifiedId::IK_ConstructorName:
2139   case UnqualifiedId::IK_ConstructorTemplateId:
2140   case UnqualifiedId::IK_DestructorName:
2141     // Constructors and destructors don't have return types. Use
2142     // "void" instead.
2143     T = SemaRef.Context.VoidTy;
2144     if (AttributeList *attrs = D.getDeclSpec().getAttributes().getList())
2145       processTypeAttrs(state, T, TAL_DeclSpec, attrs);
2146     break;
2147 
2148   case UnqualifiedId::IK_ConversionFunctionId:
2149     // The result type of a conversion function is the type that it
2150     // converts to.
2151     T = SemaRef.GetTypeFromParser(D.getName().ConversionFunctionId,
2152                                   &ReturnTypeInfo);
2153     ContainsPlaceholderType = T->getContainedAutoType();
2154     break;
2155   }
2156 
2157   if (D.getAttributes())
2158     distributeTypeAttrsFromDeclarator(state, T);
2159 
2160   // C++11 [dcl.spec.auto]p5: reject 'auto' if it is not in an allowed context.
2161   // In C++11, a function declarator using 'auto' must have a trailing return
2162   // type (this is checked later) and we can skip this. In other languages
2163   // using auto, we need to check regardless.
2164   // C++14 In generic lambdas allow 'auto' in their parameters.
2165   if (ContainsPlaceholderType &&
2166       (!SemaRef.getLangOpts().CPlusPlus11 || !D.isFunctionDeclarator())) {
2167     int Error = -1;
2168 
2169     switch (D.getContext()) {
2170     case Declarator::KNRTypeListContext:
2171       llvm_unreachable("K&R type lists aren't allowed in C++");
2172     case Declarator::LambdaExprContext:
2173       llvm_unreachable("Can't specify a type specifier in lambda grammar");
2174     case Declarator::ObjCParameterContext:
2175     case Declarator::ObjCResultContext:
2176     case Declarator::PrototypeContext:
2177       Error = 0;
2178       break;
2179     case Declarator::LambdaExprParameterContext:
2180       if (!(SemaRef.getLangOpts().CPlusPlus14
2181               && D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_auto))
2182         Error = 14;
2183       break;
2184     case Declarator::MemberContext:
2185       if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_static)
2186         break;
2187       switch (cast<TagDecl>(SemaRef.CurContext)->getTagKind()) {
2188       case TTK_Enum: llvm_unreachable("unhandled tag kind");
2189       case TTK_Struct: Error = 1; /* Struct member */ break;
2190       case TTK_Union:  Error = 2; /* Union member */ break;
2191       case TTK_Class:  Error = 3; /* Class member */ break;
2192       case TTK_Interface: Error = 4; /* Interface member */ break;
2193       }
2194       break;
2195     case Declarator::CXXCatchContext:
2196     case Declarator::ObjCCatchContext:
2197       Error = 5; // Exception declaration
2198       break;
2199     case Declarator::TemplateParamContext:
2200       Error = 6; // Template parameter
2201       break;
2202     case Declarator::BlockLiteralContext:
2203       Error = 7; // Block literal
2204       break;
2205     case Declarator::TemplateTypeArgContext:
2206       Error = 8; // Template type argument
2207       break;
2208     case Declarator::AliasDeclContext:
2209     case Declarator::AliasTemplateContext:
2210       Error = 10; // Type alias
2211       break;
2212     case Declarator::TrailingReturnContext:
2213       if (!SemaRef.getLangOpts().CPlusPlus14)
2214         Error = 11; // Function return type
2215       break;
2216     case Declarator::ConversionIdContext:
2217       if (!SemaRef.getLangOpts().CPlusPlus14)
2218         Error = 12; // conversion-type-id
2219       break;
2220     case Declarator::TypeNameContext:
2221       Error = 13; // Generic
2222       break;
2223     case Declarator::FileContext:
2224     case Declarator::BlockContext:
2225     case Declarator::ForContext:
2226     case Declarator::ConditionContext:
2227     case Declarator::CXXNewContext:
2228       break;
2229     }
2230 
2231     if (D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef)
2232       Error = 9;
2233 
2234     // In Objective-C it is an error to use 'auto' on a function declarator.
2235     if (D.isFunctionDeclarator())
2236       Error = 11;
2237 
2238     // C++11 [dcl.spec.auto]p2: 'auto' is always fine if the declarator
2239     // contains a trailing return type. That is only legal at the outermost
2240     // level. Check all declarator chunks (outermost first) anyway, to give
2241     // better diagnostics.
2242     if (SemaRef.getLangOpts().CPlusPlus11 && Error != -1) {
2243       for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
2244         unsigned chunkIndex = e - i - 1;
2245         state.setCurrentChunkIndex(chunkIndex);
2246         DeclaratorChunk &DeclType = D.getTypeObject(chunkIndex);
2247         if (DeclType.Kind == DeclaratorChunk::Function) {
2248           const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
2249           if (FTI.hasTrailingReturnType()) {
2250             Error = -1;
2251             break;
2252           }
2253         }
2254       }
2255     }
2256 
2257     SourceRange AutoRange = D.getDeclSpec().getTypeSpecTypeLoc();
2258     if (D.getName().getKind() == UnqualifiedId::IK_ConversionFunctionId)
2259       AutoRange = D.getName().getSourceRange();
2260 
2261     if (Error != -1) {
2262       const bool IsDeclTypeAuto =
2263           D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_decltype_auto;
2264       SemaRef.Diag(AutoRange.getBegin(), diag::err_auto_not_allowed)
2265         << IsDeclTypeAuto << Error << AutoRange;
2266       T = SemaRef.Context.IntTy;
2267       D.setInvalidType(true);
2268     } else
2269       SemaRef.Diag(AutoRange.getBegin(),
2270                    diag::warn_cxx98_compat_auto_type_specifier)
2271         << AutoRange;
2272   }
2273 
2274   if (SemaRef.getLangOpts().CPlusPlus &&
2275       OwnedTagDecl && OwnedTagDecl->isCompleteDefinition()) {
2276     // Check the contexts where C++ forbids the declaration of a new class
2277     // or enumeration in a type-specifier-seq.
2278     switch (D.getContext()) {
2279     case Declarator::TrailingReturnContext:
2280       // Class and enumeration definitions are syntactically not allowed in
2281       // trailing return types.
2282       llvm_unreachable("parser should not have allowed this");
2283       break;
2284     case Declarator::FileContext:
2285     case Declarator::MemberContext:
2286     case Declarator::BlockContext:
2287     case Declarator::ForContext:
2288     case Declarator::BlockLiteralContext:
2289     case Declarator::LambdaExprContext:
2290       // C++11 [dcl.type]p3:
2291       //   A type-specifier-seq shall not define a class or enumeration unless
2292       //   it appears in the type-id of an alias-declaration (7.1.3) that is not
2293       //   the declaration of a template-declaration.
2294     case Declarator::AliasDeclContext:
2295       break;
2296     case Declarator::AliasTemplateContext:
2297       SemaRef.Diag(OwnedTagDecl->getLocation(),
2298              diag::err_type_defined_in_alias_template)
2299         << SemaRef.Context.getTypeDeclType(OwnedTagDecl);
2300       D.setInvalidType(true);
2301       break;
2302     case Declarator::TypeNameContext:
2303     case Declarator::ConversionIdContext:
2304     case Declarator::TemplateParamContext:
2305     case Declarator::CXXNewContext:
2306     case Declarator::CXXCatchContext:
2307     case Declarator::ObjCCatchContext:
2308     case Declarator::TemplateTypeArgContext:
2309       SemaRef.Diag(OwnedTagDecl->getLocation(),
2310              diag::err_type_defined_in_type_specifier)
2311         << SemaRef.Context.getTypeDeclType(OwnedTagDecl);
2312       D.setInvalidType(true);
2313       break;
2314     case Declarator::PrototypeContext:
2315     case Declarator::LambdaExprParameterContext:
2316     case Declarator::ObjCParameterContext:
2317     case Declarator::ObjCResultContext:
2318     case Declarator::KNRTypeListContext:
2319       // C++ [dcl.fct]p6:
2320       //   Types shall not be defined in return or parameter types.
2321       SemaRef.Diag(OwnedTagDecl->getLocation(),
2322                    diag::err_type_defined_in_param_type)
2323         << SemaRef.Context.getTypeDeclType(OwnedTagDecl);
2324       D.setInvalidType(true);
2325       break;
2326     case Declarator::ConditionContext:
2327       // C++ 6.4p2:
2328       // The type-specifier-seq shall not contain typedef and shall not declare
2329       // a new class or enumeration.
2330       SemaRef.Diag(OwnedTagDecl->getLocation(),
2331                    diag::err_type_defined_in_condition);
2332       D.setInvalidType(true);
2333       break;
2334     }
2335   }
2336 
2337   return T;
2338 }
2339 
2340 /// Produce an appropriate diagnostic for an ambiguity between a function
2341 /// declarator and a C++ direct-initializer.
2342 static void warnAboutAmbiguousFunction(Sema &S, Declarator &D,
2343                                        DeclaratorChunk &DeclType, QualType RT) {
2344   const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
2345   assert(FTI.isAmbiguous && "no direct-initializer / function ambiguity");
2346 
2347   // If the return type is void there is no ambiguity.
2348   if (RT->isVoidType())
2349     return;
2350 
2351   // An initializer for a non-class type can have at most one argument.
2352   if (!RT->isRecordType() && FTI.NumParams > 1)
2353     return;
2354 
2355   // An initializer for a reference must have exactly one argument.
2356   if (RT->isReferenceType() && FTI.NumParams != 1)
2357     return;
2358 
2359   // Only warn if this declarator is declaring a function at block scope, and
2360   // doesn't have a storage class (such as 'extern') specified.
2361   if (!D.isFunctionDeclarator() ||
2362       D.getFunctionDefinitionKind() != FDK_Declaration ||
2363       !S.CurContext->isFunctionOrMethod() ||
2364       D.getDeclSpec().getStorageClassSpec()
2365         != DeclSpec::SCS_unspecified)
2366     return;
2367 
2368   // Inside a condition, a direct initializer is not permitted. We allow one to
2369   // be parsed in order to give better diagnostics in condition parsing.
2370   if (D.getContext() == Declarator::ConditionContext)
2371     return;
2372 
2373   SourceRange ParenRange(DeclType.Loc, DeclType.EndLoc);
2374 
2375   S.Diag(DeclType.Loc,
2376          FTI.NumParams ? diag::warn_parens_disambiguated_as_function_declaration
2377                        : diag::warn_empty_parens_are_function_decl)
2378       << ParenRange;
2379 
2380   // If the declaration looks like:
2381   //   T var1,
2382   //   f();
2383   // and name lookup finds a function named 'f', then the ',' was
2384   // probably intended to be a ';'.
2385   if (!D.isFirstDeclarator() && D.getIdentifier()) {
2386     FullSourceLoc Comma(D.getCommaLoc(), S.SourceMgr);
2387     FullSourceLoc Name(D.getIdentifierLoc(), S.SourceMgr);
2388     if (Comma.getFileID() != Name.getFileID() ||
2389         Comma.getSpellingLineNumber() != Name.getSpellingLineNumber()) {
2390       LookupResult Result(S, D.getIdentifier(), SourceLocation(),
2391                           Sema::LookupOrdinaryName);
2392       if (S.LookupName(Result, S.getCurScope()))
2393         S.Diag(D.getCommaLoc(), diag::note_empty_parens_function_call)
2394           << FixItHint::CreateReplacement(D.getCommaLoc(), ";")
2395           << D.getIdentifier();
2396     }
2397   }
2398 
2399   if (FTI.NumParams > 0) {
2400     // For a declaration with parameters, eg. "T var(T());", suggest adding
2401     // parens around the first parameter to turn the declaration into a
2402     // variable declaration.
2403     SourceRange Range = FTI.Params[0].Param->getSourceRange();
2404     SourceLocation B = Range.getBegin();
2405     SourceLocation E = S.getLocForEndOfToken(Range.getEnd());
2406     // FIXME: Maybe we should suggest adding braces instead of parens
2407     // in C++11 for classes that don't have an initializer_list constructor.
2408     S.Diag(B, diag::note_additional_parens_for_variable_declaration)
2409       << FixItHint::CreateInsertion(B, "(")
2410       << FixItHint::CreateInsertion(E, ")");
2411   } else {
2412     // For a declaration without parameters, eg. "T var();", suggest replacing
2413     // the parens with an initializer to turn the declaration into a variable
2414     // declaration.
2415     const CXXRecordDecl *RD = RT->getAsCXXRecordDecl();
2416 
2417     // Empty parens mean value-initialization, and no parens mean
2418     // default initialization. These are equivalent if the default
2419     // constructor is user-provided or if zero-initialization is a
2420     // no-op.
2421     if (RD && RD->hasDefinition() &&
2422         (RD->isEmpty() || RD->hasUserProvidedDefaultConstructor()))
2423       S.Diag(DeclType.Loc, diag::note_empty_parens_default_ctor)
2424         << FixItHint::CreateRemoval(ParenRange);
2425     else {
2426       std::string Init =
2427           S.getFixItZeroInitializerForType(RT, ParenRange.getBegin());
2428       if (Init.empty() && S.LangOpts.CPlusPlus11)
2429         Init = "{}";
2430       if (!Init.empty())
2431         S.Diag(DeclType.Loc, diag::note_empty_parens_zero_initialize)
2432           << FixItHint::CreateReplacement(ParenRange, Init);
2433     }
2434   }
2435 }
2436 
2437 /// Helper for figuring out the default CC for a function declarator type.  If
2438 /// this is the outermost chunk, then we can determine the CC from the
2439 /// declarator context.  If not, then this could be either a member function
2440 /// type or normal function type.
2441 static CallingConv
2442 getCCForDeclaratorChunk(Sema &S, Declarator &D,
2443                         const DeclaratorChunk::FunctionTypeInfo &FTI,
2444                         unsigned ChunkIndex) {
2445   assert(D.getTypeObject(ChunkIndex).Kind == DeclaratorChunk::Function);
2446 
2447   bool IsCXXInstanceMethod = false;
2448 
2449   if (S.getLangOpts().CPlusPlus) {
2450     // Look inwards through parentheses to see if this chunk will form a
2451     // member pointer type or if we're the declarator.  Any type attributes
2452     // between here and there will override the CC we choose here.
2453     unsigned I = ChunkIndex;
2454     bool FoundNonParen = false;
2455     while (I && !FoundNonParen) {
2456       --I;
2457       if (D.getTypeObject(I).Kind != DeclaratorChunk::Paren)
2458         FoundNonParen = true;
2459     }
2460 
2461     if (FoundNonParen) {
2462       // If we're not the declarator, we're a regular function type unless we're
2463       // in a member pointer.
2464       IsCXXInstanceMethod =
2465           D.getTypeObject(I).Kind == DeclaratorChunk::MemberPointer;
2466     } else {
2467       // We're the innermost decl chunk, so must be a function declarator.
2468       assert(D.isFunctionDeclarator());
2469 
2470       // If we're inside a record, we're declaring a method, but it could be
2471       // explicitly or implicitly static.
2472       IsCXXInstanceMethod =
2473           D.isFirstDeclarationOfMember() &&
2474           D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_typedef &&
2475           !D.isStaticMember();
2476     }
2477   }
2478 
2479   return S.Context.getDefaultCallingConvention(FTI.isVariadic,
2480                                                IsCXXInstanceMethod);
2481 }
2482 
2483 static TypeSourceInfo *GetFullTypeForDeclarator(TypeProcessingState &state,
2484                                                 QualType declSpecType,
2485                                                 TypeSourceInfo *TInfo) {
2486 
2487   QualType T = declSpecType;
2488   Declarator &D = state.getDeclarator();
2489   Sema &S = state.getSema();
2490   ASTContext &Context = S.Context;
2491   const LangOptions &LangOpts = S.getLangOpts();
2492 
2493   // The name we're declaring, if any.
2494   DeclarationName Name;
2495   if (D.getIdentifier())
2496     Name = D.getIdentifier();
2497 
2498   // Does this declaration declare a typedef-name?
2499   bool IsTypedefName =
2500     D.getDeclSpec().getStorageClassSpec() == DeclSpec::SCS_typedef ||
2501     D.getContext() == Declarator::AliasDeclContext ||
2502     D.getContext() == Declarator::AliasTemplateContext;
2503 
2504   // Does T refer to a function type with a cv-qualifier or a ref-qualifier?
2505   bool IsQualifiedFunction = T->isFunctionProtoType() &&
2506       (T->castAs<FunctionProtoType>()->getTypeQuals() != 0 ||
2507        T->castAs<FunctionProtoType>()->getRefQualifier() != RQ_None);
2508 
2509   // If T is 'decltype(auto)', the only declarators we can have are parens
2510   // and at most one function declarator if this is a function declaration.
2511   if (const AutoType *AT = T->getAs<AutoType>()) {
2512     if (AT->isDecltypeAuto()) {
2513       for (unsigned I = 0, E = D.getNumTypeObjects(); I != E; ++I) {
2514         unsigned Index = E - I - 1;
2515         DeclaratorChunk &DeclChunk = D.getTypeObject(Index);
2516         unsigned DiagId = diag::err_decltype_auto_compound_type;
2517         unsigned DiagKind = 0;
2518         switch (DeclChunk.Kind) {
2519         case DeclaratorChunk::Paren:
2520           continue;
2521         case DeclaratorChunk::Function: {
2522           unsigned FnIndex;
2523           if (D.isFunctionDeclarationContext() &&
2524               D.isFunctionDeclarator(FnIndex) && FnIndex == Index)
2525             continue;
2526           DiagId = diag::err_decltype_auto_function_declarator_not_declaration;
2527           break;
2528         }
2529         case DeclaratorChunk::Pointer:
2530         case DeclaratorChunk::BlockPointer:
2531         case DeclaratorChunk::MemberPointer:
2532           DiagKind = 0;
2533           break;
2534         case DeclaratorChunk::Reference:
2535           DiagKind = 1;
2536           break;
2537         case DeclaratorChunk::Array:
2538           DiagKind = 2;
2539           break;
2540         }
2541 
2542         S.Diag(DeclChunk.Loc, DiagId) << DiagKind;
2543         D.setInvalidType(true);
2544         break;
2545       }
2546     }
2547   }
2548 
2549   // Walk the DeclTypeInfo, building the recursive type as we go.
2550   // DeclTypeInfos are ordered from the identifier out, which is
2551   // opposite of what we want :).
2552   for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
2553     unsigned chunkIndex = e - i - 1;
2554     state.setCurrentChunkIndex(chunkIndex);
2555     DeclaratorChunk &DeclType = D.getTypeObject(chunkIndex);
2556     IsQualifiedFunction &= DeclType.Kind == DeclaratorChunk::Paren;
2557     switch (DeclType.Kind) {
2558     case DeclaratorChunk::Paren:
2559       T = S.BuildParenType(T);
2560       break;
2561     case DeclaratorChunk::BlockPointer:
2562       // If blocks are disabled, emit an error.
2563       if (!LangOpts.Blocks)
2564         S.Diag(DeclType.Loc, diag::err_blocks_disable);
2565 
2566       T = S.BuildBlockPointerType(T, D.getIdentifierLoc(), Name);
2567       if (DeclType.Cls.TypeQuals)
2568         T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Cls.TypeQuals);
2569       break;
2570     case DeclaratorChunk::Pointer:
2571       // Verify that we're not building a pointer to pointer to function with
2572       // exception specification.
2573       if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
2574         S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
2575         D.setInvalidType(true);
2576         // Build the type anyway.
2577       }
2578       if (LangOpts.ObjC1 && T->getAs<ObjCObjectType>()) {
2579         T = Context.getObjCObjectPointerType(T);
2580         if (DeclType.Ptr.TypeQuals)
2581           T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Ptr.TypeQuals);
2582         break;
2583       }
2584       T = S.BuildPointerType(T, DeclType.Loc, Name);
2585       if (DeclType.Ptr.TypeQuals)
2586         T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Ptr.TypeQuals);
2587 
2588       break;
2589     case DeclaratorChunk::Reference: {
2590       // Verify that we're not building a reference to pointer to function with
2591       // exception specification.
2592       if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
2593         S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
2594         D.setInvalidType(true);
2595         // Build the type anyway.
2596       }
2597       T = S.BuildReferenceType(T, DeclType.Ref.LValueRef, DeclType.Loc, Name);
2598 
2599       if (DeclType.Ref.HasRestrict)
2600         T = S.BuildQualifiedType(T, DeclType.Loc, Qualifiers::Restrict);
2601       break;
2602     }
2603     case DeclaratorChunk::Array: {
2604       // Verify that we're not building an array of pointers to function with
2605       // exception specification.
2606       if (LangOpts.CPlusPlus && S.CheckDistantExceptionSpec(T)) {
2607         S.Diag(D.getIdentifierLoc(), diag::err_distant_exception_spec);
2608         D.setInvalidType(true);
2609         // Build the type anyway.
2610       }
2611       DeclaratorChunk::ArrayTypeInfo &ATI = DeclType.Arr;
2612       Expr *ArraySize = static_cast<Expr*>(ATI.NumElts);
2613       ArrayType::ArraySizeModifier ASM;
2614       if (ATI.isStar)
2615         ASM = ArrayType::Star;
2616       else if (ATI.hasStatic)
2617         ASM = ArrayType::Static;
2618       else
2619         ASM = ArrayType::Normal;
2620       if (ASM == ArrayType::Star && !D.isPrototypeContext()) {
2621         // FIXME: This check isn't quite right: it allows star in prototypes
2622         // for function definitions, and disallows some edge cases detailed
2623         // in http://gcc.gnu.org/ml/gcc-patches/2009-02/msg00133.html
2624         S.Diag(DeclType.Loc, diag::err_array_star_outside_prototype);
2625         ASM = ArrayType::Normal;
2626         D.setInvalidType(true);
2627       }
2628 
2629       // C99 6.7.5.2p1: The optional type qualifiers and the keyword static
2630       // shall appear only in a declaration of a function parameter with an
2631       // array type, ...
2632       if (ASM == ArrayType::Static || ATI.TypeQuals) {
2633         if (!(D.isPrototypeContext() ||
2634               D.getContext() == Declarator::KNRTypeListContext)) {
2635           S.Diag(DeclType.Loc, diag::err_array_static_outside_prototype) <<
2636               (ASM == ArrayType::Static ? "'static'" : "type qualifier");
2637           // Remove the 'static' and the type qualifiers.
2638           if (ASM == ArrayType::Static)
2639             ASM = ArrayType::Normal;
2640           ATI.TypeQuals = 0;
2641           D.setInvalidType(true);
2642         }
2643 
2644         // C99 6.7.5.2p1: ... and then only in the outermost array type
2645         // derivation.
2646         unsigned x = chunkIndex;
2647         while (x != 0) {
2648           // Walk outwards along the declarator chunks.
2649           x--;
2650           const DeclaratorChunk &DC = D.getTypeObject(x);
2651           switch (DC.Kind) {
2652           case DeclaratorChunk::Paren:
2653             continue;
2654           case DeclaratorChunk::Array:
2655           case DeclaratorChunk::Pointer:
2656           case DeclaratorChunk::Reference:
2657           case DeclaratorChunk::MemberPointer:
2658             S.Diag(DeclType.Loc, diag::err_array_static_not_outermost) <<
2659               (ASM == ArrayType::Static ? "'static'" : "type qualifier");
2660             if (ASM == ArrayType::Static)
2661               ASM = ArrayType::Normal;
2662             ATI.TypeQuals = 0;
2663             D.setInvalidType(true);
2664             break;
2665           case DeclaratorChunk::Function:
2666           case DeclaratorChunk::BlockPointer:
2667             // These are invalid anyway, so just ignore.
2668             break;
2669           }
2670         }
2671       }
2672       const AutoType *AT = T->getContainedAutoType();
2673       // Allow arrays of auto if we are a generic lambda parameter.
2674       // i.e. [](auto (&array)[5]) { return array[0]; }; OK
2675       if (AT && D.getContext() != Declarator::LambdaExprParameterContext) {
2676         // We've already diagnosed this for decltype(auto).
2677         if (!AT->isDecltypeAuto())
2678           S.Diag(DeclType.Loc, diag::err_illegal_decl_array_of_auto)
2679             << getPrintableNameForEntity(Name) << T;
2680         T = QualType();
2681         break;
2682       }
2683 
2684       T = S.BuildArrayType(T, ASM, ArraySize, ATI.TypeQuals,
2685                            SourceRange(DeclType.Loc, DeclType.EndLoc), Name);
2686       break;
2687     }
2688     case DeclaratorChunk::Function: {
2689       // If the function declarator has a prototype (i.e. it is not () and
2690       // does not have a K&R-style identifier list), then the arguments are part
2691       // of the type, otherwise the argument list is ().
2692       const DeclaratorChunk::FunctionTypeInfo &FTI = DeclType.Fun;
2693       IsQualifiedFunction = FTI.TypeQuals || FTI.hasRefQualifier();
2694 
2695       // Check for auto functions and trailing return type and adjust the
2696       // return type accordingly.
2697       if (!D.isInvalidType()) {
2698         // trailing-return-type is only required if we're declaring a function,
2699         // and not, for instance, a pointer to a function.
2700         if (D.getDeclSpec().containsPlaceholderType() &&
2701             !FTI.hasTrailingReturnType() && chunkIndex == 0 &&
2702             !S.getLangOpts().CPlusPlus14) {
2703           S.Diag(D.getDeclSpec().getTypeSpecTypeLoc(),
2704                  D.getDeclSpec().getTypeSpecType() == DeclSpec::TST_auto
2705                      ? diag::err_auto_missing_trailing_return
2706                      : diag::err_deduced_return_type);
2707           T = Context.IntTy;
2708           D.setInvalidType(true);
2709         } else if (FTI.hasTrailingReturnType()) {
2710           // T must be exactly 'auto' at this point. See CWG issue 681.
2711           if (isa<ParenType>(T)) {
2712             S.Diag(D.getDeclSpec().getTypeSpecTypeLoc(),
2713                  diag::err_trailing_return_in_parens)
2714               << T << D.getDeclSpec().getSourceRange();
2715             D.setInvalidType(true);
2716           } else if (D.getContext() != Declarator::LambdaExprContext &&
2717                      (T.hasQualifiers() || !isa<AutoType>(T) ||
2718                       cast<AutoType>(T)->isDecltypeAuto())) {
2719             S.Diag(D.getDeclSpec().getTypeSpecTypeLoc(),
2720                  diag::err_trailing_return_without_auto)
2721               << T << D.getDeclSpec().getSourceRange();
2722             D.setInvalidType(true);
2723           }
2724           T = S.GetTypeFromParser(FTI.getTrailingReturnType(), &TInfo);
2725           if (T.isNull()) {
2726             // An error occurred parsing the trailing return type.
2727             T = Context.IntTy;
2728             D.setInvalidType(true);
2729           }
2730         }
2731       }
2732 
2733       // C99 6.7.5.3p1: The return type may not be a function or array type.
2734       // For conversion functions, we'll diagnose this particular error later.
2735       if ((T->isArrayType() || T->isFunctionType()) &&
2736           (D.getName().getKind() != UnqualifiedId::IK_ConversionFunctionId)) {
2737         unsigned diagID = diag::err_func_returning_array_function;
2738         // Last processing chunk in block context means this function chunk
2739         // represents the block.
2740         if (chunkIndex == 0 &&
2741             D.getContext() == Declarator::BlockLiteralContext)
2742           diagID = diag::err_block_returning_array_function;
2743         S.Diag(DeclType.Loc, diagID) << T->isFunctionType() << T;
2744         T = Context.IntTy;
2745         D.setInvalidType(true);
2746       }
2747 
2748       // Do not allow returning half FP value.
2749       // FIXME: This really should be in BuildFunctionType.
2750       if (T->isHalfType()) {
2751         if (S.getLangOpts().OpenCL) {
2752           if (!S.getOpenCLOptions().cl_khr_fp16) {
2753             S.Diag(D.getIdentifierLoc(), diag::err_opencl_half_return) << T;
2754             D.setInvalidType(true);
2755           }
2756         } else if (!S.getLangOpts().HalfArgsAndReturns) {
2757           S.Diag(D.getIdentifierLoc(),
2758             diag::err_parameters_retval_cannot_have_fp16_type) << 1;
2759           D.setInvalidType(true);
2760         }
2761       }
2762 
2763       // Methods cannot return interface types. All ObjC objects are
2764       // passed by reference.
2765       if (T->isObjCObjectType()) {
2766         SourceLocation DiagLoc, FixitLoc;
2767         if (TInfo) {
2768           DiagLoc = TInfo->getTypeLoc().getLocStart();
2769           FixitLoc = S.getLocForEndOfToken(TInfo->getTypeLoc().getLocEnd());
2770         } else {
2771           DiagLoc = D.getDeclSpec().getTypeSpecTypeLoc();
2772           FixitLoc = S.getLocForEndOfToken(D.getDeclSpec().getLocEnd());
2773         }
2774         S.Diag(DiagLoc, diag::err_object_cannot_be_passed_returned_by_value)
2775           << 0 << T
2776           << FixItHint::CreateInsertion(FixitLoc, "*");
2777 
2778         T = Context.getObjCObjectPointerType(T);
2779         if (TInfo) {
2780           TypeLocBuilder TLB;
2781           TLB.pushFullCopy(TInfo->getTypeLoc());
2782           ObjCObjectPointerTypeLoc TLoc = TLB.push<ObjCObjectPointerTypeLoc>(T);
2783           TLoc.setStarLoc(FixitLoc);
2784           TInfo = TLB.getTypeSourceInfo(Context, T);
2785         }
2786 
2787         D.setInvalidType(true);
2788       }
2789 
2790       // cv-qualifiers on return types are pointless except when the type is a
2791       // class type in C++.
2792       if ((T.getCVRQualifiers() || T->isAtomicType()) &&
2793           !(S.getLangOpts().CPlusPlus &&
2794             (T->isDependentType() || T->isRecordType())))
2795         diagnoseRedundantReturnTypeQualifiers(S, T, D, chunkIndex);
2796 
2797       // Objective-C ARC ownership qualifiers are ignored on the function
2798       // return type (by type canonicalization). Complain if this attribute
2799       // was written here.
2800       if (T.getQualifiers().hasObjCLifetime()) {
2801         SourceLocation AttrLoc;
2802         if (chunkIndex + 1 < D.getNumTypeObjects()) {
2803           DeclaratorChunk ReturnTypeChunk = D.getTypeObject(chunkIndex + 1);
2804           for (const AttributeList *Attr = ReturnTypeChunk.getAttrs();
2805                Attr; Attr = Attr->getNext()) {
2806             if (Attr->getKind() == AttributeList::AT_ObjCOwnership) {
2807               AttrLoc = Attr->getLoc();
2808               break;
2809             }
2810           }
2811         }
2812         if (AttrLoc.isInvalid()) {
2813           for (const AttributeList *Attr
2814                  = D.getDeclSpec().getAttributes().getList();
2815                Attr; Attr = Attr->getNext()) {
2816             if (Attr->getKind() == AttributeList::AT_ObjCOwnership) {
2817               AttrLoc = Attr->getLoc();
2818               break;
2819             }
2820           }
2821         }
2822 
2823         if (AttrLoc.isValid()) {
2824           // The ownership attributes are almost always written via
2825           // the predefined
2826           // __strong/__weak/__autoreleasing/__unsafe_unretained.
2827           if (AttrLoc.isMacroID())
2828             AttrLoc = S.SourceMgr.getImmediateExpansionRange(AttrLoc).first;
2829 
2830           S.Diag(AttrLoc, diag::warn_arc_lifetime_result_type)
2831             << T.getQualifiers().getObjCLifetime();
2832         }
2833       }
2834 
2835       if (LangOpts.CPlusPlus && D.getDeclSpec().hasTagDefinition()) {
2836         // C++ [dcl.fct]p6:
2837         //   Types shall not be defined in return or parameter types.
2838         TagDecl *Tag = cast<TagDecl>(D.getDeclSpec().getRepAsDecl());
2839         S.Diag(Tag->getLocation(), diag::err_type_defined_in_result_type)
2840           << Context.getTypeDeclType(Tag);
2841       }
2842 
2843       // Exception specs are not allowed in typedefs. Complain, but add it
2844       // anyway.
2845       if (IsTypedefName && FTI.getExceptionSpecType())
2846         S.Diag(FTI.getExceptionSpecLoc(), diag::err_exception_spec_in_typedef)
2847           << (D.getContext() == Declarator::AliasDeclContext ||
2848               D.getContext() == Declarator::AliasTemplateContext);
2849 
2850       // If we see "T var();" or "T var(T());" at block scope, it is probably
2851       // an attempt to initialize a variable, not a function declaration.
2852       if (FTI.isAmbiguous)
2853         warnAboutAmbiguousFunction(S, D, DeclType, T);
2854 
2855       FunctionType::ExtInfo EI(getCCForDeclaratorChunk(S, D, FTI, chunkIndex));
2856 
2857       if (!FTI.NumParams && !FTI.isVariadic && !LangOpts.CPlusPlus) {
2858         // Simple void foo(), where the incoming T is the result type.
2859         T = Context.getFunctionNoProtoType(T, EI);
2860       } else {
2861         // We allow a zero-parameter variadic function in C if the
2862         // function is marked with the "overloadable" attribute. Scan
2863         // for this attribute now.
2864         if (!FTI.NumParams && FTI.isVariadic && !LangOpts.CPlusPlus) {
2865           bool Overloadable = false;
2866           for (const AttributeList *Attrs = D.getAttributes();
2867                Attrs; Attrs = Attrs->getNext()) {
2868             if (Attrs->getKind() == AttributeList::AT_Overloadable) {
2869               Overloadable = true;
2870               break;
2871             }
2872           }
2873 
2874           if (!Overloadable)
2875             S.Diag(FTI.getEllipsisLoc(), diag::err_ellipsis_first_param);
2876         }
2877 
2878         if (FTI.NumParams && FTI.Params[0].Param == nullptr) {
2879           // C99 6.7.5.3p3: Reject int(x,y,z) when it's not a function
2880           // definition.
2881           S.Diag(FTI.Params[0].IdentLoc,
2882                  diag::err_ident_list_in_fn_declaration);
2883           D.setInvalidType(true);
2884           // Recover by creating a K&R-style function type.
2885           T = Context.getFunctionNoProtoType(T, EI);
2886           break;
2887         }
2888 
2889         FunctionProtoType::ExtProtoInfo EPI;
2890         EPI.ExtInfo = EI;
2891         EPI.Variadic = FTI.isVariadic;
2892         EPI.HasTrailingReturn = FTI.hasTrailingReturnType();
2893         EPI.TypeQuals = FTI.TypeQuals;
2894         EPI.RefQualifier = !FTI.hasRefQualifier()? RQ_None
2895                     : FTI.RefQualifierIsLValueRef? RQ_LValue
2896                     : RQ_RValue;
2897 
2898         // Otherwise, we have a function with a parameter list that is
2899         // potentially variadic.
2900         SmallVector<QualType, 16> ParamTys;
2901         ParamTys.reserve(FTI.NumParams);
2902 
2903         SmallVector<bool, 16> ConsumedParameters;
2904         ConsumedParameters.reserve(FTI.NumParams);
2905         bool HasAnyConsumedParameters = false;
2906 
2907         for (unsigned i = 0, e = FTI.NumParams; i != e; ++i) {
2908           ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
2909           QualType ParamTy = Param->getType();
2910           assert(!ParamTy.isNull() && "Couldn't parse type?");
2911 
2912           // Look for 'void'.  void is allowed only as a single parameter to a
2913           // function with no other parameters (C99 6.7.5.3p10).  We record
2914           // int(void) as a FunctionProtoType with an empty parameter list.
2915           if (ParamTy->isVoidType()) {
2916             // If this is something like 'float(int, void)', reject it.  'void'
2917             // is an incomplete type (C99 6.2.5p19) and function decls cannot
2918             // have parameters of incomplete type.
2919             if (FTI.NumParams != 1 || FTI.isVariadic) {
2920               S.Diag(DeclType.Loc, diag::err_void_only_param);
2921               ParamTy = Context.IntTy;
2922               Param->setType(ParamTy);
2923             } else if (FTI.Params[i].Ident) {
2924               // Reject, but continue to parse 'int(void abc)'.
2925               S.Diag(FTI.Params[i].IdentLoc, diag::err_param_with_void_type);
2926               ParamTy = Context.IntTy;
2927               Param->setType(ParamTy);
2928             } else {
2929               // Reject, but continue to parse 'float(const void)'.
2930               if (ParamTy.hasQualifiers())
2931                 S.Diag(DeclType.Loc, diag::err_void_param_qualified);
2932 
2933               // Do not add 'void' to the list.
2934               break;
2935             }
2936           } else if (ParamTy->isHalfType()) {
2937             // Disallow half FP parameters.
2938             // FIXME: This really should be in BuildFunctionType.
2939             if (S.getLangOpts().OpenCL) {
2940               if (!S.getOpenCLOptions().cl_khr_fp16) {
2941                 S.Diag(Param->getLocation(),
2942                   diag::err_opencl_half_param) << ParamTy;
2943                 D.setInvalidType();
2944                 Param->setInvalidDecl();
2945               }
2946             } else if (!S.getLangOpts().HalfArgsAndReturns) {
2947               S.Diag(Param->getLocation(),
2948                 diag::err_parameters_retval_cannot_have_fp16_type) << 0;
2949               D.setInvalidType();
2950             }
2951           } else if (!FTI.hasPrototype) {
2952             if (ParamTy->isPromotableIntegerType()) {
2953               ParamTy = Context.getPromotedIntegerType(ParamTy);
2954               Param->setKNRPromoted(true);
2955             } else if (const BuiltinType* BTy = ParamTy->getAs<BuiltinType>()) {
2956               if (BTy->getKind() == BuiltinType::Float) {
2957                 ParamTy = Context.DoubleTy;
2958                 Param->setKNRPromoted(true);
2959               }
2960             }
2961           }
2962 
2963           if (LangOpts.ObjCAutoRefCount) {
2964             bool Consumed = Param->hasAttr<NSConsumedAttr>();
2965             ConsumedParameters.push_back(Consumed);
2966             HasAnyConsumedParameters |= Consumed;
2967           }
2968 
2969           ParamTys.push_back(ParamTy);
2970         }
2971 
2972         if (HasAnyConsumedParameters)
2973           EPI.ConsumedParameters = ConsumedParameters.data();
2974 
2975         SmallVector<QualType, 4> Exceptions;
2976         SmallVector<ParsedType, 2> DynamicExceptions;
2977         SmallVector<SourceRange, 2> DynamicExceptionRanges;
2978         Expr *NoexceptExpr = nullptr;
2979 
2980         if (FTI.getExceptionSpecType() == EST_Dynamic) {
2981           // FIXME: It's rather inefficient to have to split into two vectors
2982           // here.
2983           unsigned N = FTI.NumExceptions;
2984           DynamicExceptions.reserve(N);
2985           DynamicExceptionRanges.reserve(N);
2986           for (unsigned I = 0; I != N; ++I) {
2987             DynamicExceptions.push_back(FTI.Exceptions[I].Ty);
2988             DynamicExceptionRanges.push_back(FTI.Exceptions[I].Range);
2989           }
2990         } else if (FTI.getExceptionSpecType() == EST_ComputedNoexcept) {
2991           NoexceptExpr = FTI.NoexceptExpr;
2992         }
2993 
2994         S.checkExceptionSpecification(D.isFunctionDeclarationContext(),
2995                                       FTI.getExceptionSpecType(),
2996                                       DynamicExceptions,
2997                                       DynamicExceptionRanges,
2998                                       NoexceptExpr,
2999                                       Exceptions,
3000                                       EPI.ExceptionSpec);
3001 
3002         T = Context.getFunctionType(T, ParamTys, EPI);
3003       }
3004 
3005       break;
3006     }
3007     case DeclaratorChunk::MemberPointer:
3008       // The scope spec must refer to a class, or be dependent.
3009       CXXScopeSpec &SS = DeclType.Mem.Scope();
3010       QualType ClsType;
3011       if (SS.isInvalid()) {
3012         // Avoid emitting extra errors if we already errored on the scope.
3013         D.setInvalidType(true);
3014       } else if (S.isDependentScopeSpecifier(SS) ||
3015                  dyn_cast_or_null<CXXRecordDecl>(S.computeDeclContext(SS))) {
3016         NestedNameSpecifier *NNS = SS.getScopeRep();
3017         NestedNameSpecifier *NNSPrefix = NNS->getPrefix();
3018         switch (NNS->getKind()) {
3019         case NestedNameSpecifier::Identifier:
3020           ClsType = Context.getDependentNameType(ETK_None, NNSPrefix,
3021                                                  NNS->getAsIdentifier());
3022           break;
3023 
3024         case NestedNameSpecifier::Namespace:
3025         case NestedNameSpecifier::NamespaceAlias:
3026         case NestedNameSpecifier::Global:
3027         case NestedNameSpecifier::Super:
3028           llvm_unreachable("Nested-name-specifier must name a type");
3029 
3030         case NestedNameSpecifier::TypeSpec:
3031         case NestedNameSpecifier::TypeSpecWithTemplate:
3032           ClsType = QualType(NNS->getAsType(), 0);
3033           // Note: if the NNS has a prefix and ClsType is a nondependent
3034           // TemplateSpecializationType, then the NNS prefix is NOT included
3035           // in ClsType; hence we wrap ClsType into an ElaboratedType.
3036           // NOTE: in particular, no wrap occurs if ClsType already is an
3037           // Elaborated, DependentName, or DependentTemplateSpecialization.
3038           if (NNSPrefix && isa<TemplateSpecializationType>(NNS->getAsType()))
3039             ClsType = Context.getElaboratedType(ETK_None, NNSPrefix, ClsType);
3040           break;
3041         }
3042       } else {
3043         S.Diag(DeclType.Mem.Scope().getBeginLoc(),
3044              diag::err_illegal_decl_mempointer_in_nonclass)
3045           << (D.getIdentifier() ? D.getIdentifier()->getName() : "type name")
3046           << DeclType.Mem.Scope().getRange();
3047         D.setInvalidType(true);
3048       }
3049 
3050       if (!ClsType.isNull())
3051         T = S.BuildMemberPointerType(T, ClsType, DeclType.Loc, D.getIdentifier());
3052       if (T.isNull()) {
3053         T = Context.IntTy;
3054         D.setInvalidType(true);
3055       } else if (DeclType.Mem.TypeQuals) {
3056         T = S.BuildQualifiedType(T, DeclType.Loc, DeclType.Mem.TypeQuals);
3057       }
3058       break;
3059     }
3060 
3061     if (T.isNull()) {
3062       D.setInvalidType(true);
3063       T = Context.IntTy;
3064     }
3065 
3066     // See if there are any attributes on this declarator chunk.
3067     if (AttributeList *attrs = const_cast<AttributeList*>(DeclType.getAttrs()))
3068       processTypeAttrs(state, T, TAL_DeclChunk, attrs);
3069   }
3070 
3071   if (LangOpts.CPlusPlus && T->isFunctionType()) {
3072     const FunctionProtoType *FnTy = T->getAs<FunctionProtoType>();
3073     assert(FnTy && "Why oh why is there not a FunctionProtoType here?");
3074 
3075     // C++ 8.3.5p4:
3076     //   A cv-qualifier-seq shall only be part of the function type
3077     //   for a nonstatic member function, the function type to which a pointer
3078     //   to member refers, or the top-level function type of a function typedef
3079     //   declaration.
3080     //
3081     // Core issue 547 also allows cv-qualifiers on function types that are
3082     // top-level template type arguments.
3083     bool FreeFunction;
3084     if (!D.getCXXScopeSpec().isSet()) {
3085       FreeFunction = ((D.getContext() != Declarator::MemberContext &&
3086                        D.getContext() != Declarator::LambdaExprContext) ||
3087                       D.getDeclSpec().isFriendSpecified());
3088     } else {
3089       DeclContext *DC = S.computeDeclContext(D.getCXXScopeSpec());
3090       FreeFunction = (DC && !DC->isRecord());
3091     }
3092 
3093     // C++11 [dcl.fct]p6 (w/DR1417):
3094     // An attempt to specify a function type with a cv-qualifier-seq or a
3095     // ref-qualifier (including by typedef-name) is ill-formed unless it is:
3096     //  - the function type for a non-static member function,
3097     //  - the function type to which a pointer to member refers,
3098     //  - the top-level function type of a function typedef declaration or
3099     //    alias-declaration,
3100     //  - the type-id in the default argument of a type-parameter, or
3101     //  - the type-id of a template-argument for a type-parameter
3102     //
3103     // FIXME: Checking this here is insufficient. We accept-invalid on:
3104     //
3105     //   template<typename T> struct S { void f(T); };
3106     //   S<int() const> s;
3107     //
3108     // ... for instance.
3109     if (IsQualifiedFunction &&
3110         !(!FreeFunction &&
3111           D.getDeclSpec().getStorageClassSpec() != DeclSpec::SCS_static) &&
3112         !IsTypedefName &&
3113         D.getContext() != Declarator::TemplateTypeArgContext) {
3114       SourceLocation Loc = D.getLocStart();
3115       SourceRange RemovalRange;
3116       unsigned I;
3117       if (D.isFunctionDeclarator(I)) {
3118         SmallVector<SourceLocation, 4> RemovalLocs;
3119         const DeclaratorChunk &Chunk = D.getTypeObject(I);
3120         assert(Chunk.Kind == DeclaratorChunk::Function);
3121         if (Chunk.Fun.hasRefQualifier())
3122           RemovalLocs.push_back(Chunk.Fun.getRefQualifierLoc());
3123         if (Chunk.Fun.TypeQuals & Qualifiers::Const)
3124           RemovalLocs.push_back(Chunk.Fun.getConstQualifierLoc());
3125         if (Chunk.Fun.TypeQuals & Qualifiers::Volatile)
3126           RemovalLocs.push_back(Chunk.Fun.getVolatileQualifierLoc());
3127         if (Chunk.Fun.TypeQuals & Qualifiers::Restrict)
3128           RemovalLocs.push_back(Chunk.Fun.getRestrictQualifierLoc());
3129         if (!RemovalLocs.empty()) {
3130           std::sort(RemovalLocs.begin(), RemovalLocs.end(),
3131                     BeforeThanCompare<SourceLocation>(S.getSourceManager()));
3132           RemovalRange = SourceRange(RemovalLocs.front(), RemovalLocs.back());
3133           Loc = RemovalLocs.front();
3134         }
3135       }
3136 
3137       S.Diag(Loc, diag::err_invalid_qualified_function_type)
3138         << FreeFunction << D.isFunctionDeclarator() << T
3139         << getFunctionQualifiersAsString(FnTy)
3140         << FixItHint::CreateRemoval(RemovalRange);
3141 
3142       // Strip the cv-qualifiers and ref-qualifiers from the type.
3143       FunctionProtoType::ExtProtoInfo EPI = FnTy->getExtProtoInfo();
3144       EPI.TypeQuals = 0;
3145       EPI.RefQualifier = RQ_None;
3146 
3147       T = Context.getFunctionType(FnTy->getReturnType(), FnTy->getParamTypes(),
3148                                   EPI);
3149       // Rebuild any parens around the identifier in the function type.
3150       for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
3151         if (D.getTypeObject(i).Kind != DeclaratorChunk::Paren)
3152           break;
3153         T = S.BuildParenType(T);
3154       }
3155     }
3156   }
3157 
3158   // Apply any undistributed attributes from the declarator.
3159   if (!T.isNull())
3160     if (AttributeList *attrs = D.getAttributes())
3161       processTypeAttrs(state, T, TAL_DeclName, attrs);
3162 
3163   // Diagnose any ignored type attributes.
3164   if (!T.isNull()) state.diagnoseIgnoredTypeAttrs(T);
3165 
3166   // C++0x [dcl.constexpr]p9:
3167   //  A constexpr specifier used in an object declaration declares the object
3168   //  as const.
3169   if (D.getDeclSpec().isConstexprSpecified() && T->isObjectType()) {
3170     T.addConst();
3171   }
3172 
3173   // If there was an ellipsis in the declarator, the declaration declares a
3174   // parameter pack whose type may be a pack expansion type.
3175   if (D.hasEllipsis() && !T.isNull()) {
3176     // C++0x [dcl.fct]p13:
3177     //   A declarator-id or abstract-declarator containing an ellipsis shall
3178     //   only be used in a parameter-declaration. Such a parameter-declaration
3179     //   is a parameter pack (14.5.3). [...]
3180     switch (D.getContext()) {
3181     case Declarator::PrototypeContext:
3182     case Declarator::LambdaExprParameterContext:
3183       // C++0x [dcl.fct]p13:
3184       //   [...] When it is part of a parameter-declaration-clause, the
3185       //   parameter pack is a function parameter pack (14.5.3). The type T
3186       //   of the declarator-id of the function parameter pack shall contain
3187       //   a template parameter pack; each template parameter pack in T is
3188       //   expanded by the function parameter pack.
3189       //
3190       // We represent function parameter packs as function parameters whose
3191       // type is a pack expansion.
3192       if (!T->containsUnexpandedParameterPack()) {
3193         S.Diag(D.getEllipsisLoc(),
3194              diag::err_function_parameter_pack_without_parameter_packs)
3195           << T <<  D.getSourceRange();
3196         D.setEllipsisLoc(SourceLocation());
3197       } else {
3198         T = Context.getPackExpansionType(T, None);
3199       }
3200       break;
3201     case Declarator::TemplateParamContext:
3202       // C++0x [temp.param]p15:
3203       //   If a template-parameter is a [...] is a parameter-declaration that
3204       //   declares a parameter pack (8.3.5), then the template-parameter is a
3205       //   template parameter pack (14.5.3).
3206       //
3207       // Note: core issue 778 clarifies that, if there are any unexpanded
3208       // parameter packs in the type of the non-type template parameter, then
3209       // it expands those parameter packs.
3210       if (T->containsUnexpandedParameterPack())
3211         T = Context.getPackExpansionType(T, None);
3212       else
3213         S.Diag(D.getEllipsisLoc(),
3214                LangOpts.CPlusPlus11
3215                  ? diag::warn_cxx98_compat_variadic_templates
3216                  : diag::ext_variadic_templates);
3217       break;
3218 
3219     case Declarator::FileContext:
3220     case Declarator::KNRTypeListContext:
3221     case Declarator::ObjCParameterContext:  // FIXME: special diagnostic here?
3222     case Declarator::ObjCResultContext:     // FIXME: special diagnostic here?
3223     case Declarator::TypeNameContext:
3224     case Declarator::CXXNewContext:
3225     case Declarator::AliasDeclContext:
3226     case Declarator::AliasTemplateContext:
3227     case Declarator::MemberContext:
3228     case Declarator::BlockContext:
3229     case Declarator::ForContext:
3230     case Declarator::ConditionContext:
3231     case Declarator::CXXCatchContext:
3232     case Declarator::ObjCCatchContext:
3233     case Declarator::BlockLiteralContext:
3234     case Declarator::LambdaExprContext:
3235     case Declarator::ConversionIdContext:
3236     case Declarator::TrailingReturnContext:
3237     case Declarator::TemplateTypeArgContext:
3238       // FIXME: We may want to allow parameter packs in block-literal contexts
3239       // in the future.
3240       S.Diag(D.getEllipsisLoc(), diag::err_ellipsis_in_declarator_not_parameter);
3241       D.setEllipsisLoc(SourceLocation());
3242       break;
3243     }
3244   }
3245 
3246   if (T.isNull())
3247     return Context.getNullTypeSourceInfo();
3248   else if (D.isInvalidType())
3249     return Context.getTrivialTypeSourceInfo(T);
3250 
3251   return S.GetTypeSourceInfoForDeclarator(D, T, TInfo);
3252 }
3253 
3254 /// GetTypeForDeclarator - Convert the type for the specified
3255 /// declarator to Type instances.
3256 ///
3257 /// The result of this call will never be null, but the associated
3258 /// type may be a null type if there's an unrecoverable error.
3259 TypeSourceInfo *Sema::GetTypeForDeclarator(Declarator &D, Scope *S) {
3260   // Determine the type of the declarator. Not all forms of declarator
3261   // have a type.
3262 
3263   TypeProcessingState state(*this, D);
3264 
3265   TypeSourceInfo *ReturnTypeInfo = nullptr;
3266   QualType T = GetDeclSpecTypeForDeclarator(state, ReturnTypeInfo);
3267   if (T.isNull())
3268     return Context.getNullTypeSourceInfo();
3269 
3270   if (D.isPrototypeContext() && getLangOpts().ObjCAutoRefCount)
3271     inferARCWriteback(state, T);
3272 
3273   return GetFullTypeForDeclarator(state, T, ReturnTypeInfo);
3274 }
3275 
3276 static void transferARCOwnershipToDeclSpec(Sema &S,
3277                                            QualType &declSpecTy,
3278                                            Qualifiers::ObjCLifetime ownership) {
3279   if (declSpecTy->isObjCRetainableType() &&
3280       declSpecTy.getObjCLifetime() == Qualifiers::OCL_None) {
3281     Qualifiers qs;
3282     qs.addObjCLifetime(ownership);
3283     declSpecTy = S.Context.getQualifiedType(declSpecTy, qs);
3284   }
3285 }
3286 
3287 static void transferARCOwnershipToDeclaratorChunk(TypeProcessingState &state,
3288                                             Qualifiers::ObjCLifetime ownership,
3289                                             unsigned chunkIndex) {
3290   Sema &S = state.getSema();
3291   Declarator &D = state.getDeclarator();
3292 
3293   // Look for an explicit lifetime attribute.
3294   DeclaratorChunk &chunk = D.getTypeObject(chunkIndex);
3295   for (const AttributeList *attr = chunk.getAttrs(); attr;
3296          attr = attr->getNext())
3297     if (attr->getKind() == AttributeList::AT_ObjCOwnership)
3298       return;
3299 
3300   const char *attrStr = nullptr;
3301   switch (ownership) {
3302   case Qualifiers::OCL_None: llvm_unreachable("no ownership!");
3303   case Qualifiers::OCL_ExplicitNone: attrStr = "none"; break;
3304   case Qualifiers::OCL_Strong: attrStr = "strong"; break;
3305   case Qualifiers::OCL_Weak: attrStr = "weak"; break;
3306   case Qualifiers::OCL_Autoreleasing: attrStr = "autoreleasing"; break;
3307   }
3308 
3309   IdentifierLoc *Arg = new (S.Context) IdentifierLoc;
3310   Arg->Ident = &S.Context.Idents.get(attrStr);
3311   Arg->Loc = SourceLocation();
3312 
3313   ArgsUnion Args(Arg);
3314 
3315   // If there wasn't one, add one (with an invalid source location
3316   // so that we don't make an AttributedType for it).
3317   AttributeList *attr = D.getAttributePool()
3318     .create(&S.Context.Idents.get("objc_ownership"), SourceLocation(),
3319             /*scope*/ nullptr, SourceLocation(),
3320             /*args*/ &Args, 1, AttributeList::AS_GNU);
3321   spliceAttrIntoList(*attr, chunk.getAttrListRef());
3322 
3323   // TODO: mark whether we did this inference?
3324 }
3325 
3326 /// \brief Used for transferring ownership in casts resulting in l-values.
3327 static void transferARCOwnership(TypeProcessingState &state,
3328                                  QualType &declSpecTy,
3329                                  Qualifiers::ObjCLifetime ownership) {
3330   Sema &S = state.getSema();
3331   Declarator &D = state.getDeclarator();
3332 
3333   int inner = -1;
3334   bool hasIndirection = false;
3335   for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
3336     DeclaratorChunk &chunk = D.getTypeObject(i);
3337     switch (chunk.Kind) {
3338     case DeclaratorChunk::Paren:
3339       // Ignore parens.
3340       break;
3341 
3342     case DeclaratorChunk::Array:
3343     case DeclaratorChunk::Reference:
3344     case DeclaratorChunk::Pointer:
3345       if (inner != -1)
3346         hasIndirection = true;
3347       inner = i;
3348       break;
3349 
3350     case DeclaratorChunk::BlockPointer:
3351       if (inner != -1)
3352         transferARCOwnershipToDeclaratorChunk(state, ownership, i);
3353       return;
3354 
3355     case DeclaratorChunk::Function:
3356     case DeclaratorChunk::MemberPointer:
3357       return;
3358     }
3359   }
3360 
3361   if (inner == -1)
3362     return;
3363 
3364   DeclaratorChunk &chunk = D.getTypeObject(inner);
3365   if (chunk.Kind == DeclaratorChunk::Pointer) {
3366     if (declSpecTy->isObjCRetainableType())
3367       return transferARCOwnershipToDeclSpec(S, declSpecTy, ownership);
3368     if (declSpecTy->isObjCObjectType() && hasIndirection)
3369       return transferARCOwnershipToDeclaratorChunk(state, ownership, inner);
3370   } else {
3371     assert(chunk.Kind == DeclaratorChunk::Array ||
3372            chunk.Kind == DeclaratorChunk::Reference);
3373     return transferARCOwnershipToDeclSpec(S, declSpecTy, ownership);
3374   }
3375 }
3376 
3377 TypeSourceInfo *Sema::GetTypeForDeclaratorCast(Declarator &D, QualType FromTy) {
3378   TypeProcessingState state(*this, D);
3379 
3380   TypeSourceInfo *ReturnTypeInfo = nullptr;
3381   QualType declSpecTy = GetDeclSpecTypeForDeclarator(state, ReturnTypeInfo);
3382   if (declSpecTy.isNull())
3383     return Context.getNullTypeSourceInfo();
3384 
3385   if (getLangOpts().ObjCAutoRefCount) {
3386     Qualifiers::ObjCLifetime ownership = Context.getInnerObjCOwnership(FromTy);
3387     if (ownership != Qualifiers::OCL_None)
3388       transferARCOwnership(state, declSpecTy, ownership);
3389   }
3390 
3391   return GetFullTypeForDeclarator(state, declSpecTy, ReturnTypeInfo);
3392 }
3393 
3394 /// Map an AttributedType::Kind to an AttributeList::Kind.
3395 static AttributeList::Kind getAttrListKind(AttributedType::Kind kind) {
3396   switch (kind) {
3397   case AttributedType::attr_address_space:
3398     return AttributeList::AT_AddressSpace;
3399   case AttributedType::attr_regparm:
3400     return AttributeList::AT_Regparm;
3401   case AttributedType::attr_vector_size:
3402     return AttributeList::AT_VectorSize;
3403   case AttributedType::attr_neon_vector_type:
3404     return AttributeList::AT_NeonVectorType;
3405   case AttributedType::attr_neon_polyvector_type:
3406     return AttributeList::AT_NeonPolyVectorType;
3407   case AttributedType::attr_objc_gc:
3408     return AttributeList::AT_ObjCGC;
3409   case AttributedType::attr_objc_ownership:
3410     return AttributeList::AT_ObjCOwnership;
3411   case AttributedType::attr_noreturn:
3412     return AttributeList::AT_NoReturn;
3413   case AttributedType::attr_cdecl:
3414     return AttributeList::AT_CDecl;
3415   case AttributedType::attr_fastcall:
3416     return AttributeList::AT_FastCall;
3417   case AttributedType::attr_stdcall:
3418     return AttributeList::AT_StdCall;
3419   case AttributedType::attr_thiscall:
3420     return AttributeList::AT_ThisCall;
3421   case AttributedType::attr_pascal:
3422     return AttributeList::AT_Pascal;
3423   case AttributedType::attr_vectorcall:
3424     return AttributeList::AT_VectorCall;
3425   case AttributedType::attr_pcs:
3426   case AttributedType::attr_pcs_vfp:
3427     return AttributeList::AT_Pcs;
3428   case AttributedType::attr_pnaclcall:
3429     return AttributeList::AT_PnaclCall;
3430   case AttributedType::attr_inteloclbicc:
3431     return AttributeList::AT_IntelOclBicc;
3432   case AttributedType::attr_ms_abi:
3433     return AttributeList::AT_MSABI;
3434   case AttributedType::attr_sysv_abi:
3435     return AttributeList::AT_SysVABI;
3436   case AttributedType::attr_ptr32:
3437     return AttributeList::AT_Ptr32;
3438   case AttributedType::attr_ptr64:
3439     return AttributeList::AT_Ptr64;
3440   case AttributedType::attr_sptr:
3441     return AttributeList::AT_SPtr;
3442   case AttributedType::attr_uptr:
3443     return AttributeList::AT_UPtr;
3444   }
3445   llvm_unreachable("unexpected attribute kind!");
3446 }
3447 
3448 static void fillAttributedTypeLoc(AttributedTypeLoc TL,
3449                                   const AttributeList *attrs) {
3450   AttributedType::Kind kind = TL.getAttrKind();
3451 
3452   assert(attrs && "no type attributes in the expected location!");
3453   AttributeList::Kind parsedKind = getAttrListKind(kind);
3454   while (attrs->getKind() != parsedKind) {
3455     attrs = attrs->getNext();
3456     assert(attrs && "no matching attribute in expected location!");
3457   }
3458 
3459   TL.setAttrNameLoc(attrs->getLoc());
3460   if (TL.hasAttrExprOperand()) {
3461     assert(attrs->isArgExpr(0) && "mismatched attribute operand kind");
3462     TL.setAttrExprOperand(attrs->getArgAsExpr(0));
3463   } else if (TL.hasAttrEnumOperand()) {
3464     assert((attrs->isArgIdent(0) || attrs->isArgExpr(0)) &&
3465            "unexpected attribute operand kind");
3466     if (attrs->isArgIdent(0))
3467       TL.setAttrEnumOperandLoc(attrs->getArgAsIdent(0)->Loc);
3468     else
3469       TL.setAttrEnumOperandLoc(attrs->getArgAsExpr(0)->getExprLoc());
3470   }
3471 
3472   // FIXME: preserve this information to here.
3473   if (TL.hasAttrOperand())
3474     TL.setAttrOperandParensRange(SourceRange());
3475 }
3476 
3477 namespace {
3478   class TypeSpecLocFiller : public TypeLocVisitor<TypeSpecLocFiller> {
3479     ASTContext &Context;
3480     const DeclSpec &DS;
3481 
3482   public:
3483     TypeSpecLocFiller(ASTContext &Context, const DeclSpec &DS)
3484       : Context(Context), DS(DS) {}
3485 
3486     void VisitAttributedTypeLoc(AttributedTypeLoc TL) {
3487       fillAttributedTypeLoc(TL, DS.getAttributes().getList());
3488       Visit(TL.getModifiedLoc());
3489     }
3490     void VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
3491       Visit(TL.getUnqualifiedLoc());
3492     }
3493     void VisitTypedefTypeLoc(TypedefTypeLoc TL) {
3494       TL.setNameLoc(DS.getTypeSpecTypeLoc());
3495     }
3496     void VisitObjCInterfaceTypeLoc(ObjCInterfaceTypeLoc TL) {
3497       TL.setNameLoc(DS.getTypeSpecTypeLoc());
3498       // FIXME. We should have DS.getTypeSpecTypeEndLoc(). But, it requires
3499       // addition field. What we have is good enough for dispay of location
3500       // of 'fixit' on interface name.
3501       TL.setNameEndLoc(DS.getLocEnd());
3502     }
3503     void VisitObjCObjectTypeLoc(ObjCObjectTypeLoc TL) {
3504       // Handle the base type, which might not have been written explicitly.
3505       if (DS.getTypeSpecType() == DeclSpec::TST_unspecified) {
3506         TL.setHasBaseTypeAsWritten(false);
3507         TL.getBaseLoc().initialize(Context, SourceLocation());
3508       } else {
3509         TL.setHasBaseTypeAsWritten(true);
3510         Visit(TL.getBaseLoc());
3511       }
3512 
3513       // Protocol qualifiers.
3514       if (DS.getProtocolQualifiers()) {
3515         assert(TL.getNumProtocols() > 0);
3516         assert(TL.getNumProtocols() == DS.getNumProtocolQualifiers());
3517         TL.setLAngleLoc(DS.getProtocolLAngleLoc());
3518         TL.setRAngleLoc(DS.getSourceRange().getEnd());
3519         for (unsigned i = 0, e = DS.getNumProtocolQualifiers(); i != e; ++i)
3520           TL.setProtocolLoc(i, DS.getProtocolLocs()[i]);
3521       } else {
3522         assert(TL.getNumProtocols() == 0);
3523         TL.setLAngleLoc(SourceLocation());
3524         TL.setRAngleLoc(SourceLocation());
3525       }
3526     }
3527     void VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
3528       TL.setStarLoc(SourceLocation());
3529       Visit(TL.getPointeeLoc());
3530     }
3531     void VisitTemplateSpecializationTypeLoc(TemplateSpecializationTypeLoc TL) {
3532       TypeSourceInfo *TInfo = nullptr;
3533       Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
3534 
3535       // If we got no declarator info from previous Sema routines,
3536       // just fill with the typespec loc.
3537       if (!TInfo) {
3538         TL.initialize(Context, DS.getTypeSpecTypeNameLoc());
3539         return;
3540       }
3541 
3542       TypeLoc OldTL = TInfo->getTypeLoc();
3543       if (TInfo->getType()->getAs<ElaboratedType>()) {
3544         ElaboratedTypeLoc ElabTL = OldTL.castAs<ElaboratedTypeLoc>();
3545         TemplateSpecializationTypeLoc NamedTL = ElabTL.getNamedTypeLoc()
3546             .castAs<TemplateSpecializationTypeLoc>();
3547         TL.copy(NamedTL);
3548       } else {
3549         TL.copy(OldTL.castAs<TemplateSpecializationTypeLoc>());
3550         assert(TL.getRAngleLoc() == OldTL.castAs<TemplateSpecializationTypeLoc>().getRAngleLoc());
3551       }
3552 
3553     }
3554     void VisitTypeOfExprTypeLoc(TypeOfExprTypeLoc TL) {
3555       assert(DS.getTypeSpecType() == DeclSpec::TST_typeofExpr);
3556       TL.setTypeofLoc(DS.getTypeSpecTypeLoc());
3557       TL.setParensRange(DS.getTypeofParensRange());
3558     }
3559     void VisitTypeOfTypeLoc(TypeOfTypeLoc TL) {
3560       assert(DS.getTypeSpecType() == DeclSpec::TST_typeofType);
3561       TL.setTypeofLoc(DS.getTypeSpecTypeLoc());
3562       TL.setParensRange(DS.getTypeofParensRange());
3563       assert(DS.getRepAsType());
3564       TypeSourceInfo *TInfo = nullptr;
3565       Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
3566       TL.setUnderlyingTInfo(TInfo);
3567     }
3568     void VisitUnaryTransformTypeLoc(UnaryTransformTypeLoc TL) {
3569       // FIXME: This holds only because we only have one unary transform.
3570       assert(DS.getTypeSpecType() == DeclSpec::TST_underlyingType);
3571       TL.setKWLoc(DS.getTypeSpecTypeLoc());
3572       TL.setParensRange(DS.getTypeofParensRange());
3573       assert(DS.getRepAsType());
3574       TypeSourceInfo *TInfo = nullptr;
3575       Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
3576       TL.setUnderlyingTInfo(TInfo);
3577     }
3578     void VisitBuiltinTypeLoc(BuiltinTypeLoc TL) {
3579       // By default, use the source location of the type specifier.
3580       TL.setBuiltinLoc(DS.getTypeSpecTypeLoc());
3581       if (TL.needsExtraLocalData()) {
3582         // Set info for the written builtin specifiers.
3583         TL.getWrittenBuiltinSpecs() = DS.getWrittenBuiltinSpecs();
3584         // Try to have a meaningful source location.
3585         if (TL.getWrittenSignSpec() != TSS_unspecified)
3586           // Sign spec loc overrides the others (e.g., 'unsigned long').
3587           TL.setBuiltinLoc(DS.getTypeSpecSignLoc());
3588         else if (TL.getWrittenWidthSpec() != TSW_unspecified)
3589           // Width spec loc overrides type spec loc (e.g., 'short int').
3590           TL.setBuiltinLoc(DS.getTypeSpecWidthLoc());
3591       }
3592     }
3593     void VisitElaboratedTypeLoc(ElaboratedTypeLoc TL) {
3594       ElaboratedTypeKeyword Keyword
3595         = TypeWithKeyword::getKeywordForTypeSpec(DS.getTypeSpecType());
3596       if (DS.getTypeSpecType() == TST_typename) {
3597         TypeSourceInfo *TInfo = nullptr;
3598         Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
3599         if (TInfo) {
3600           TL.copy(TInfo->getTypeLoc().castAs<ElaboratedTypeLoc>());
3601           return;
3602         }
3603       }
3604       TL.setElaboratedKeywordLoc(Keyword != ETK_None
3605                                  ? DS.getTypeSpecTypeLoc()
3606                                  : SourceLocation());
3607       const CXXScopeSpec& SS = DS.getTypeSpecScope();
3608       TL.setQualifierLoc(SS.getWithLocInContext(Context));
3609       Visit(TL.getNextTypeLoc().getUnqualifiedLoc());
3610     }
3611     void VisitDependentNameTypeLoc(DependentNameTypeLoc TL) {
3612       assert(DS.getTypeSpecType() == TST_typename);
3613       TypeSourceInfo *TInfo = nullptr;
3614       Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
3615       assert(TInfo);
3616       TL.copy(TInfo->getTypeLoc().castAs<DependentNameTypeLoc>());
3617     }
3618     void VisitDependentTemplateSpecializationTypeLoc(
3619                                  DependentTemplateSpecializationTypeLoc TL) {
3620       assert(DS.getTypeSpecType() == TST_typename);
3621       TypeSourceInfo *TInfo = nullptr;
3622       Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
3623       assert(TInfo);
3624       TL.copy(
3625           TInfo->getTypeLoc().castAs<DependentTemplateSpecializationTypeLoc>());
3626     }
3627     void VisitTagTypeLoc(TagTypeLoc TL) {
3628       TL.setNameLoc(DS.getTypeSpecTypeNameLoc());
3629     }
3630     void VisitAtomicTypeLoc(AtomicTypeLoc TL) {
3631       // An AtomicTypeLoc can come from either an _Atomic(...) type specifier
3632       // or an _Atomic qualifier.
3633       if (DS.getTypeSpecType() == DeclSpec::TST_atomic) {
3634         TL.setKWLoc(DS.getTypeSpecTypeLoc());
3635         TL.setParensRange(DS.getTypeofParensRange());
3636 
3637         TypeSourceInfo *TInfo = nullptr;
3638         Sema::GetTypeFromParser(DS.getRepAsType(), &TInfo);
3639         assert(TInfo);
3640         TL.getValueLoc().initializeFullCopy(TInfo->getTypeLoc());
3641       } else {
3642         TL.setKWLoc(DS.getAtomicSpecLoc());
3643         // No parens, to indicate this was spelled as an _Atomic qualifier.
3644         TL.setParensRange(SourceRange());
3645         Visit(TL.getValueLoc());
3646       }
3647     }
3648 
3649     void VisitTypeLoc(TypeLoc TL) {
3650       // FIXME: add other typespec types and change this to an assert.
3651       TL.initialize(Context, DS.getTypeSpecTypeLoc());
3652     }
3653   };
3654 
3655   class DeclaratorLocFiller : public TypeLocVisitor<DeclaratorLocFiller> {
3656     ASTContext &Context;
3657     const DeclaratorChunk &Chunk;
3658 
3659   public:
3660     DeclaratorLocFiller(ASTContext &Context, const DeclaratorChunk &Chunk)
3661       : Context(Context), Chunk(Chunk) {}
3662 
3663     void VisitQualifiedTypeLoc(QualifiedTypeLoc TL) {
3664       llvm_unreachable("qualified type locs not expected here!");
3665     }
3666     void VisitDecayedTypeLoc(DecayedTypeLoc TL) {
3667       llvm_unreachable("decayed type locs not expected here!");
3668     }
3669 
3670     void VisitAttributedTypeLoc(AttributedTypeLoc TL) {
3671       fillAttributedTypeLoc(TL, Chunk.getAttrs());
3672     }
3673     void VisitAdjustedTypeLoc(AdjustedTypeLoc TL) {
3674       // nothing
3675     }
3676     void VisitBlockPointerTypeLoc(BlockPointerTypeLoc TL) {
3677       assert(Chunk.Kind == DeclaratorChunk::BlockPointer);
3678       TL.setCaretLoc(Chunk.Loc);
3679     }
3680     void VisitPointerTypeLoc(PointerTypeLoc TL) {
3681       assert(Chunk.Kind == DeclaratorChunk::Pointer);
3682       TL.setStarLoc(Chunk.Loc);
3683     }
3684     void VisitObjCObjectPointerTypeLoc(ObjCObjectPointerTypeLoc TL) {
3685       assert(Chunk.Kind == DeclaratorChunk::Pointer);
3686       TL.setStarLoc(Chunk.Loc);
3687     }
3688     void VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
3689       assert(Chunk.Kind == DeclaratorChunk::MemberPointer);
3690       const CXXScopeSpec& SS = Chunk.Mem.Scope();
3691       NestedNameSpecifierLoc NNSLoc = SS.getWithLocInContext(Context);
3692 
3693       const Type* ClsTy = TL.getClass();
3694       QualType ClsQT = QualType(ClsTy, 0);
3695       TypeSourceInfo *ClsTInfo = Context.CreateTypeSourceInfo(ClsQT, 0);
3696       // Now copy source location info into the type loc component.
3697       TypeLoc ClsTL = ClsTInfo->getTypeLoc();
3698       switch (NNSLoc.getNestedNameSpecifier()->getKind()) {
3699       case NestedNameSpecifier::Identifier:
3700         assert(isa<DependentNameType>(ClsTy) && "Unexpected TypeLoc");
3701         {
3702           DependentNameTypeLoc DNTLoc = ClsTL.castAs<DependentNameTypeLoc>();
3703           DNTLoc.setElaboratedKeywordLoc(SourceLocation());
3704           DNTLoc.setQualifierLoc(NNSLoc.getPrefix());
3705           DNTLoc.setNameLoc(NNSLoc.getLocalBeginLoc());
3706         }
3707         break;
3708 
3709       case NestedNameSpecifier::TypeSpec:
3710       case NestedNameSpecifier::TypeSpecWithTemplate:
3711         if (isa<ElaboratedType>(ClsTy)) {
3712           ElaboratedTypeLoc ETLoc = ClsTL.castAs<ElaboratedTypeLoc>();
3713           ETLoc.setElaboratedKeywordLoc(SourceLocation());
3714           ETLoc.setQualifierLoc(NNSLoc.getPrefix());
3715           TypeLoc NamedTL = ETLoc.getNamedTypeLoc();
3716           NamedTL.initializeFullCopy(NNSLoc.getTypeLoc());
3717         } else {
3718           ClsTL.initializeFullCopy(NNSLoc.getTypeLoc());
3719         }
3720         break;
3721 
3722       case NestedNameSpecifier::Namespace:
3723       case NestedNameSpecifier::NamespaceAlias:
3724       case NestedNameSpecifier::Global:
3725       case NestedNameSpecifier::Super:
3726         llvm_unreachable("Nested-name-specifier must name a type");
3727       }
3728 
3729       // Finally fill in MemberPointerLocInfo fields.
3730       TL.setStarLoc(Chunk.Loc);
3731       TL.setClassTInfo(ClsTInfo);
3732     }
3733     void VisitLValueReferenceTypeLoc(LValueReferenceTypeLoc TL) {
3734       assert(Chunk.Kind == DeclaratorChunk::Reference);
3735       // 'Amp' is misleading: this might have been originally
3736       /// spelled with AmpAmp.
3737       TL.setAmpLoc(Chunk.Loc);
3738     }
3739     void VisitRValueReferenceTypeLoc(RValueReferenceTypeLoc TL) {
3740       assert(Chunk.Kind == DeclaratorChunk::Reference);
3741       assert(!Chunk.Ref.LValueRef);
3742       TL.setAmpAmpLoc(Chunk.Loc);
3743     }
3744     void VisitArrayTypeLoc(ArrayTypeLoc TL) {
3745       assert(Chunk.Kind == DeclaratorChunk::Array);
3746       TL.setLBracketLoc(Chunk.Loc);
3747       TL.setRBracketLoc(Chunk.EndLoc);
3748       TL.setSizeExpr(static_cast<Expr*>(Chunk.Arr.NumElts));
3749     }
3750     void VisitFunctionTypeLoc(FunctionTypeLoc TL) {
3751       assert(Chunk.Kind == DeclaratorChunk::Function);
3752       TL.setLocalRangeBegin(Chunk.Loc);
3753       TL.setLocalRangeEnd(Chunk.EndLoc);
3754 
3755       const DeclaratorChunk::FunctionTypeInfo &FTI = Chunk.Fun;
3756       TL.setLParenLoc(FTI.getLParenLoc());
3757       TL.setRParenLoc(FTI.getRParenLoc());
3758       for (unsigned i = 0, e = TL.getNumParams(), tpi = 0; i != e; ++i) {
3759         ParmVarDecl *Param = cast<ParmVarDecl>(FTI.Params[i].Param);
3760         TL.setParam(tpi++, Param);
3761       }
3762       // FIXME: exception specs
3763     }
3764     void VisitParenTypeLoc(ParenTypeLoc TL) {
3765       assert(Chunk.Kind == DeclaratorChunk::Paren);
3766       TL.setLParenLoc(Chunk.Loc);
3767       TL.setRParenLoc(Chunk.EndLoc);
3768     }
3769 
3770     void VisitTypeLoc(TypeLoc TL) {
3771       llvm_unreachable("unsupported TypeLoc kind in declarator!");
3772     }
3773   };
3774 }
3775 
3776 static void fillAtomicQualLoc(AtomicTypeLoc ATL, const DeclaratorChunk &Chunk) {
3777   SourceLocation Loc;
3778   switch (Chunk.Kind) {
3779   case DeclaratorChunk::Function:
3780   case DeclaratorChunk::Array:
3781   case DeclaratorChunk::Paren:
3782     llvm_unreachable("cannot be _Atomic qualified");
3783 
3784   case DeclaratorChunk::Pointer:
3785     Loc = SourceLocation::getFromRawEncoding(Chunk.Ptr.AtomicQualLoc);
3786     break;
3787 
3788   case DeclaratorChunk::BlockPointer:
3789   case DeclaratorChunk::Reference:
3790   case DeclaratorChunk::MemberPointer:
3791     // FIXME: Provide a source location for the _Atomic keyword.
3792     break;
3793   }
3794 
3795   ATL.setKWLoc(Loc);
3796   ATL.setParensRange(SourceRange());
3797 }
3798 
3799 /// \brief Create and instantiate a TypeSourceInfo with type source information.
3800 ///
3801 /// \param T QualType referring to the type as written in source code.
3802 ///
3803 /// \param ReturnTypeInfo For declarators whose return type does not show
3804 /// up in the normal place in the declaration specifiers (such as a C++
3805 /// conversion function), this pointer will refer to a type source information
3806 /// for that return type.
3807 TypeSourceInfo *
3808 Sema::GetTypeSourceInfoForDeclarator(Declarator &D, QualType T,
3809                                      TypeSourceInfo *ReturnTypeInfo) {
3810   TypeSourceInfo *TInfo = Context.CreateTypeSourceInfo(T);
3811   UnqualTypeLoc CurrTL = TInfo->getTypeLoc().getUnqualifiedLoc();
3812 
3813   // Handle parameter packs whose type is a pack expansion.
3814   if (isa<PackExpansionType>(T)) {
3815     CurrTL.castAs<PackExpansionTypeLoc>().setEllipsisLoc(D.getEllipsisLoc());
3816     CurrTL = CurrTL.getNextTypeLoc().getUnqualifiedLoc();
3817   }
3818 
3819   for (unsigned i = 0, e = D.getNumTypeObjects(); i != e; ++i) {
3820     // An AtomicTypeLoc might be produced by an atomic qualifier in this
3821     // declarator chunk.
3822     if (AtomicTypeLoc ATL = CurrTL.getAs<AtomicTypeLoc>()) {
3823       fillAtomicQualLoc(ATL, D.getTypeObject(i));
3824       CurrTL = ATL.getValueLoc().getUnqualifiedLoc();
3825     }
3826 
3827     while (AttributedTypeLoc TL = CurrTL.getAs<AttributedTypeLoc>()) {
3828       fillAttributedTypeLoc(TL, D.getTypeObject(i).getAttrs());
3829       CurrTL = TL.getNextTypeLoc().getUnqualifiedLoc();
3830     }
3831 
3832     // FIXME: Ordering here?
3833     while (AdjustedTypeLoc TL = CurrTL.getAs<AdjustedTypeLoc>())
3834       CurrTL = TL.getNextTypeLoc().getUnqualifiedLoc();
3835 
3836     DeclaratorLocFiller(Context, D.getTypeObject(i)).Visit(CurrTL);
3837     CurrTL = CurrTL.getNextTypeLoc().getUnqualifiedLoc();
3838   }
3839 
3840   // If we have different source information for the return type, use
3841   // that.  This really only applies to C++ conversion functions.
3842   if (ReturnTypeInfo) {
3843     TypeLoc TL = ReturnTypeInfo->getTypeLoc();
3844     assert(TL.getFullDataSize() == CurrTL.getFullDataSize());
3845     memcpy(CurrTL.getOpaqueData(), TL.getOpaqueData(), TL.getFullDataSize());
3846   } else {
3847     TypeSpecLocFiller(Context, D.getDeclSpec()).Visit(CurrTL);
3848   }
3849 
3850   return TInfo;
3851 }
3852 
3853 /// \brief Create a LocInfoType to hold the given QualType and TypeSourceInfo.
3854 ParsedType Sema::CreateParsedType(QualType T, TypeSourceInfo *TInfo) {
3855   // FIXME: LocInfoTypes are "transient", only needed for passing to/from Parser
3856   // and Sema during declaration parsing. Try deallocating/caching them when
3857   // it's appropriate, instead of allocating them and keeping them around.
3858   LocInfoType *LocT = (LocInfoType*)BumpAlloc.Allocate(sizeof(LocInfoType),
3859                                                        TypeAlignment);
3860   new (LocT) LocInfoType(T, TInfo);
3861   assert(LocT->getTypeClass() != T->getTypeClass() &&
3862          "LocInfoType's TypeClass conflicts with an existing Type class");
3863   return ParsedType::make(QualType(LocT, 0));
3864 }
3865 
3866 void LocInfoType::getAsStringInternal(std::string &Str,
3867                                       const PrintingPolicy &Policy) const {
3868   llvm_unreachable("LocInfoType leaked into the type system; an opaque TypeTy*"
3869          " was used directly instead of getting the QualType through"
3870          " GetTypeFromParser");
3871 }
3872 
3873 TypeResult Sema::ActOnTypeName(Scope *S, Declarator &D) {
3874   // C99 6.7.6: Type names have no identifier.  This is already validated by
3875   // the parser.
3876   assert(D.getIdentifier() == nullptr &&
3877          "Type name should have no identifier!");
3878 
3879   TypeSourceInfo *TInfo = GetTypeForDeclarator(D, S);
3880   QualType T = TInfo->getType();
3881   if (D.isInvalidType())
3882     return true;
3883 
3884   // Make sure there are no unused decl attributes on the declarator.
3885   // We don't want to do this for ObjC parameters because we're going
3886   // to apply them to the actual parameter declaration.
3887   // Likewise, we don't want to do this for alias declarations, because
3888   // we are actually going to build a declaration from this eventually.
3889   if (D.getContext() != Declarator::ObjCParameterContext &&
3890       D.getContext() != Declarator::AliasDeclContext &&
3891       D.getContext() != Declarator::AliasTemplateContext)
3892     checkUnusedDeclAttributes(D);
3893 
3894   if (getLangOpts().CPlusPlus) {
3895     // Check that there are no default arguments (C++ only).
3896     CheckExtraCXXDefaultArguments(D);
3897   }
3898 
3899   return CreateParsedType(T, TInfo);
3900 }
3901 
3902 ParsedType Sema::ActOnObjCInstanceType(SourceLocation Loc) {
3903   QualType T = Context.getObjCInstanceType();
3904   TypeSourceInfo *TInfo = Context.getTrivialTypeSourceInfo(T, Loc);
3905   return CreateParsedType(T, TInfo);
3906 }
3907 
3908 
3909 //===----------------------------------------------------------------------===//
3910 // Type Attribute Processing
3911 //===----------------------------------------------------------------------===//
3912 
3913 /// HandleAddressSpaceTypeAttribute - Process an address_space attribute on the
3914 /// specified type.  The attribute contains 1 argument, the id of the address
3915 /// space for the type.
3916 static void HandleAddressSpaceTypeAttribute(QualType &Type,
3917                                             const AttributeList &Attr, Sema &S){
3918 
3919   // If this type is already address space qualified, reject it.
3920   // ISO/IEC TR 18037 S5.3 (amending C99 6.7.3): "No type shall be qualified by
3921   // qualifiers for two or more different address spaces."
3922   if (Type.getAddressSpace()) {
3923     S.Diag(Attr.getLoc(), diag::err_attribute_address_multiple_qualifiers);
3924     Attr.setInvalid();
3925     return;
3926   }
3927 
3928   // ISO/IEC TR 18037 S5.3 (amending C99 6.7.3): "A function type shall not be
3929   // qualified by an address-space qualifier."
3930   if (Type->isFunctionType()) {
3931     S.Diag(Attr.getLoc(), diag::err_attribute_address_function_type);
3932     Attr.setInvalid();
3933     return;
3934   }
3935 
3936   unsigned ASIdx;
3937   if (Attr.getKind() == AttributeList::AT_AddressSpace) {
3938     // Check the attribute arguments.
3939     if (Attr.getNumArgs() != 1) {
3940       S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments)
3941         << Attr.getName() << 1;
3942       Attr.setInvalid();
3943       return;
3944     }
3945     Expr *ASArgExpr = static_cast<Expr *>(Attr.getArgAsExpr(0));
3946     llvm::APSInt addrSpace(32);
3947     if (ASArgExpr->isTypeDependent() || ASArgExpr->isValueDependent() ||
3948         !ASArgExpr->isIntegerConstantExpr(addrSpace, S.Context)) {
3949       S.Diag(Attr.getLoc(), diag::err_attribute_argument_type)
3950         << Attr.getName() << AANT_ArgumentIntegerConstant
3951         << ASArgExpr->getSourceRange();
3952       Attr.setInvalid();
3953       return;
3954     }
3955 
3956     // Bounds checking.
3957     if (addrSpace.isSigned()) {
3958       if (addrSpace.isNegative()) {
3959         S.Diag(Attr.getLoc(), diag::err_attribute_address_space_negative)
3960           << ASArgExpr->getSourceRange();
3961         Attr.setInvalid();
3962         return;
3963       }
3964       addrSpace.setIsSigned(false);
3965     }
3966     llvm::APSInt max(addrSpace.getBitWidth());
3967     max = Qualifiers::MaxAddressSpace;
3968     if (addrSpace > max) {
3969       S.Diag(Attr.getLoc(), diag::err_attribute_address_space_too_high)
3970         << int(Qualifiers::MaxAddressSpace) << ASArgExpr->getSourceRange();
3971       Attr.setInvalid();
3972       return;
3973     }
3974     ASIdx = static_cast<unsigned>(addrSpace.getZExtValue());
3975   } else {
3976     // The keyword-based type attributes imply which address space to use.
3977     switch (Attr.getKind()) {
3978     case AttributeList::AT_OpenCLGlobalAddressSpace:
3979       ASIdx = LangAS::opencl_global; break;
3980     case AttributeList::AT_OpenCLLocalAddressSpace:
3981       ASIdx = LangAS::opencl_local; break;
3982     case AttributeList::AT_OpenCLConstantAddressSpace:
3983       ASIdx = LangAS::opencl_constant; break;
3984     case AttributeList::AT_OpenCLGenericAddressSpace:
3985       ASIdx = LangAS::opencl_generic; break;
3986     default:
3987       assert(Attr.getKind() == AttributeList::AT_OpenCLPrivateAddressSpace);
3988       ASIdx = 0; break;
3989     }
3990   }
3991 
3992   Type = S.Context.getAddrSpaceQualType(Type, ASIdx);
3993 }
3994 
3995 /// Does this type have a "direct" ownership qualifier?  That is,
3996 /// is it written like "__strong id", as opposed to something like
3997 /// "typeof(foo)", where that happens to be strong?
3998 static bool hasDirectOwnershipQualifier(QualType type) {
3999   // Fast path: no qualifier at all.
4000   assert(type.getQualifiers().hasObjCLifetime());
4001 
4002   while (true) {
4003     // __strong id
4004     if (const AttributedType *attr = dyn_cast<AttributedType>(type)) {
4005       if (attr->getAttrKind() == AttributedType::attr_objc_ownership)
4006         return true;
4007 
4008       type = attr->getModifiedType();
4009 
4010     // X *__strong (...)
4011     } else if (const ParenType *paren = dyn_cast<ParenType>(type)) {
4012       type = paren->getInnerType();
4013 
4014     // That's it for things we want to complain about.  In particular,
4015     // we do not want to look through typedefs, typeof(expr),
4016     // typeof(type), or any other way that the type is somehow
4017     // abstracted.
4018     } else {
4019 
4020       return false;
4021     }
4022   }
4023 }
4024 
4025 /// handleObjCOwnershipTypeAttr - Process an objc_ownership
4026 /// attribute on the specified type.
4027 ///
4028 /// Returns 'true' if the attribute was handled.
4029 static bool handleObjCOwnershipTypeAttr(TypeProcessingState &state,
4030                                        AttributeList &attr,
4031                                        QualType &type) {
4032   bool NonObjCPointer = false;
4033 
4034   if (!type->isDependentType() && !type->isUndeducedType()) {
4035     if (const PointerType *ptr = type->getAs<PointerType>()) {
4036       QualType pointee = ptr->getPointeeType();
4037       if (pointee->isObjCRetainableType() || pointee->isPointerType())
4038         return false;
4039       // It is important not to lose the source info that there was an attribute
4040       // applied to non-objc pointer. We will create an attributed type but
4041       // its type will be the same as the original type.
4042       NonObjCPointer = true;
4043     } else if (!type->isObjCRetainableType()) {
4044       return false;
4045     }
4046 
4047     // Don't accept an ownership attribute in the declspec if it would
4048     // just be the return type of a block pointer.
4049     if (state.isProcessingDeclSpec()) {
4050       Declarator &D = state.getDeclarator();
4051       if (maybeMovePastReturnType(D, D.getNumTypeObjects()))
4052         return false;
4053     }
4054   }
4055 
4056   Sema &S = state.getSema();
4057   SourceLocation AttrLoc = attr.getLoc();
4058   if (AttrLoc.isMacroID())
4059     AttrLoc = S.getSourceManager().getImmediateExpansionRange(AttrLoc).first;
4060 
4061   if (!attr.isArgIdent(0)) {
4062     S.Diag(AttrLoc, diag::err_attribute_argument_type)
4063       << attr.getName() << AANT_ArgumentString;
4064     attr.setInvalid();
4065     return true;
4066   }
4067 
4068   // Consume lifetime attributes without further comment outside of
4069   // ARC mode.
4070   if (!S.getLangOpts().ObjCAutoRefCount)
4071     return true;
4072 
4073   IdentifierInfo *II = attr.getArgAsIdent(0)->Ident;
4074   Qualifiers::ObjCLifetime lifetime;
4075   if (II->isStr("none"))
4076     lifetime = Qualifiers::OCL_ExplicitNone;
4077   else if (II->isStr("strong"))
4078     lifetime = Qualifiers::OCL_Strong;
4079   else if (II->isStr("weak"))
4080     lifetime = Qualifiers::OCL_Weak;
4081   else if (II->isStr("autoreleasing"))
4082     lifetime = Qualifiers::OCL_Autoreleasing;
4083   else {
4084     S.Diag(AttrLoc, diag::warn_attribute_type_not_supported)
4085       << attr.getName() << II;
4086     attr.setInvalid();
4087     return true;
4088   }
4089 
4090   SplitQualType underlyingType = type.split();
4091 
4092   // Check for redundant/conflicting ownership qualifiers.
4093   if (Qualifiers::ObjCLifetime previousLifetime
4094         = type.getQualifiers().getObjCLifetime()) {
4095     // If it's written directly, that's an error.
4096     if (hasDirectOwnershipQualifier(type)) {
4097       S.Diag(AttrLoc, diag::err_attr_objc_ownership_redundant)
4098         << type;
4099       return true;
4100     }
4101 
4102     // Otherwise, if the qualifiers actually conflict, pull sugar off
4103     // until we reach a type that is directly qualified.
4104     if (previousLifetime != lifetime) {
4105       // This should always terminate: the canonical type is
4106       // qualified, so some bit of sugar must be hiding it.
4107       while (!underlyingType.Quals.hasObjCLifetime()) {
4108         underlyingType = underlyingType.getSingleStepDesugaredType();
4109       }
4110       underlyingType.Quals.removeObjCLifetime();
4111     }
4112   }
4113 
4114   underlyingType.Quals.addObjCLifetime(lifetime);
4115 
4116   if (NonObjCPointer) {
4117     StringRef name = attr.getName()->getName();
4118     switch (lifetime) {
4119     case Qualifiers::OCL_None:
4120     case Qualifiers::OCL_ExplicitNone:
4121       break;
4122     case Qualifiers::OCL_Strong: name = "__strong"; break;
4123     case Qualifiers::OCL_Weak: name = "__weak"; break;
4124     case Qualifiers::OCL_Autoreleasing: name = "__autoreleasing"; break;
4125     }
4126     S.Diag(AttrLoc, diag::warn_type_attribute_wrong_type) << name
4127       << TDS_ObjCObjOrBlock << type;
4128   }
4129 
4130   QualType origType = type;
4131   if (!NonObjCPointer)
4132     type = S.Context.getQualifiedType(underlyingType);
4133 
4134   // If we have a valid source location for the attribute, use an
4135   // AttributedType instead.
4136   if (AttrLoc.isValid())
4137     type = S.Context.getAttributedType(AttributedType::attr_objc_ownership,
4138                                        origType, type);
4139 
4140   // Forbid __weak if the runtime doesn't support it.
4141   if (lifetime == Qualifiers::OCL_Weak &&
4142       !S.getLangOpts().ObjCARCWeak && !NonObjCPointer) {
4143 
4144     // Actually, delay this until we know what we're parsing.
4145     if (S.DelayedDiagnostics.shouldDelayDiagnostics()) {
4146       S.DelayedDiagnostics.add(
4147           sema::DelayedDiagnostic::makeForbiddenType(
4148               S.getSourceManager().getExpansionLoc(AttrLoc),
4149               diag::err_arc_weak_no_runtime, type, /*ignored*/ 0));
4150     } else {
4151       S.Diag(AttrLoc, diag::err_arc_weak_no_runtime);
4152     }
4153 
4154     attr.setInvalid();
4155     return true;
4156   }
4157 
4158   // Forbid __weak for class objects marked as
4159   // objc_arc_weak_reference_unavailable
4160   if (lifetime == Qualifiers::OCL_Weak) {
4161     if (const ObjCObjectPointerType *ObjT =
4162           type->getAs<ObjCObjectPointerType>()) {
4163       if (ObjCInterfaceDecl *Class = ObjT->getInterfaceDecl()) {
4164         if (Class->isArcWeakrefUnavailable()) {
4165             S.Diag(AttrLoc, diag::err_arc_unsupported_weak_class);
4166             S.Diag(ObjT->getInterfaceDecl()->getLocation(),
4167                    diag::note_class_declared);
4168         }
4169       }
4170     }
4171   }
4172 
4173   return true;
4174 }
4175 
4176 /// handleObjCGCTypeAttr - Process the __attribute__((objc_gc)) type
4177 /// attribute on the specified type.  Returns true to indicate that
4178 /// the attribute was handled, false to indicate that the type does
4179 /// not permit the attribute.
4180 static bool handleObjCGCTypeAttr(TypeProcessingState &state,
4181                                  AttributeList &attr,
4182                                  QualType &type) {
4183   Sema &S = state.getSema();
4184 
4185   // Delay if this isn't some kind of pointer.
4186   if (!type->isPointerType() &&
4187       !type->isObjCObjectPointerType() &&
4188       !type->isBlockPointerType())
4189     return false;
4190 
4191   if (type.getObjCGCAttr() != Qualifiers::GCNone) {
4192     S.Diag(attr.getLoc(), diag::err_attribute_multiple_objc_gc);
4193     attr.setInvalid();
4194     return true;
4195   }
4196 
4197   // Check the attribute arguments.
4198   if (!attr.isArgIdent(0)) {
4199     S.Diag(attr.getLoc(), diag::err_attribute_argument_type)
4200       << attr.getName() << AANT_ArgumentString;
4201     attr.setInvalid();
4202     return true;
4203   }
4204   Qualifiers::GC GCAttr;
4205   if (attr.getNumArgs() > 1) {
4206     S.Diag(attr.getLoc(), diag::err_attribute_wrong_number_arguments)
4207       << attr.getName() << 1;
4208     attr.setInvalid();
4209     return true;
4210   }
4211 
4212   IdentifierInfo *II = attr.getArgAsIdent(0)->Ident;
4213   if (II->isStr("weak"))
4214     GCAttr = Qualifiers::Weak;
4215   else if (II->isStr("strong"))
4216     GCAttr = Qualifiers::Strong;
4217   else {
4218     S.Diag(attr.getLoc(), diag::warn_attribute_type_not_supported)
4219       << attr.getName() << II;
4220     attr.setInvalid();
4221     return true;
4222   }
4223 
4224   QualType origType = type;
4225   type = S.Context.getObjCGCQualType(origType, GCAttr);
4226 
4227   // Make an attributed type to preserve the source information.
4228   if (attr.getLoc().isValid())
4229     type = S.Context.getAttributedType(AttributedType::attr_objc_gc,
4230                                        origType, type);
4231 
4232   return true;
4233 }
4234 
4235 namespace {
4236   /// A helper class to unwrap a type down to a function for the
4237   /// purposes of applying attributes there.
4238   ///
4239   /// Use:
4240   ///   FunctionTypeUnwrapper unwrapped(SemaRef, T);
4241   ///   if (unwrapped.isFunctionType()) {
4242   ///     const FunctionType *fn = unwrapped.get();
4243   ///     // change fn somehow
4244   ///     T = unwrapped.wrap(fn);
4245   ///   }
4246   struct FunctionTypeUnwrapper {
4247     enum WrapKind {
4248       Desugar,
4249       Parens,
4250       Pointer,
4251       BlockPointer,
4252       Reference,
4253       MemberPointer
4254     };
4255 
4256     QualType Original;
4257     const FunctionType *Fn;
4258     SmallVector<unsigned char /*WrapKind*/, 8> Stack;
4259 
4260     FunctionTypeUnwrapper(Sema &S, QualType T) : Original(T) {
4261       while (true) {
4262         const Type *Ty = T.getTypePtr();
4263         if (isa<FunctionType>(Ty)) {
4264           Fn = cast<FunctionType>(Ty);
4265           return;
4266         } else if (isa<ParenType>(Ty)) {
4267           T = cast<ParenType>(Ty)->getInnerType();
4268           Stack.push_back(Parens);
4269         } else if (isa<PointerType>(Ty)) {
4270           T = cast<PointerType>(Ty)->getPointeeType();
4271           Stack.push_back(Pointer);
4272         } else if (isa<BlockPointerType>(Ty)) {
4273           T = cast<BlockPointerType>(Ty)->getPointeeType();
4274           Stack.push_back(BlockPointer);
4275         } else if (isa<MemberPointerType>(Ty)) {
4276           T = cast<MemberPointerType>(Ty)->getPointeeType();
4277           Stack.push_back(MemberPointer);
4278         } else if (isa<ReferenceType>(Ty)) {
4279           T = cast<ReferenceType>(Ty)->getPointeeType();
4280           Stack.push_back(Reference);
4281         } else {
4282           const Type *DTy = Ty->getUnqualifiedDesugaredType();
4283           if (Ty == DTy) {
4284             Fn = nullptr;
4285             return;
4286           }
4287 
4288           T = QualType(DTy, 0);
4289           Stack.push_back(Desugar);
4290         }
4291       }
4292     }
4293 
4294     bool isFunctionType() const { return (Fn != nullptr); }
4295     const FunctionType *get() const { return Fn; }
4296 
4297     QualType wrap(Sema &S, const FunctionType *New) {
4298       // If T wasn't modified from the unwrapped type, do nothing.
4299       if (New == get()) return Original;
4300 
4301       Fn = New;
4302       return wrap(S.Context, Original, 0);
4303     }
4304 
4305   private:
4306     QualType wrap(ASTContext &C, QualType Old, unsigned I) {
4307       if (I == Stack.size())
4308         return C.getQualifiedType(Fn, Old.getQualifiers());
4309 
4310       // Build up the inner type, applying the qualifiers from the old
4311       // type to the new type.
4312       SplitQualType SplitOld = Old.split();
4313 
4314       // As a special case, tail-recurse if there are no qualifiers.
4315       if (SplitOld.Quals.empty())
4316         return wrap(C, SplitOld.Ty, I);
4317       return C.getQualifiedType(wrap(C, SplitOld.Ty, I), SplitOld.Quals);
4318     }
4319 
4320     QualType wrap(ASTContext &C, const Type *Old, unsigned I) {
4321       if (I == Stack.size()) return QualType(Fn, 0);
4322 
4323       switch (static_cast<WrapKind>(Stack[I++])) {
4324       case Desugar:
4325         // This is the point at which we potentially lose source
4326         // information.
4327         return wrap(C, Old->getUnqualifiedDesugaredType(), I);
4328 
4329       case Parens: {
4330         QualType New = wrap(C, cast<ParenType>(Old)->getInnerType(), I);
4331         return C.getParenType(New);
4332       }
4333 
4334       case Pointer: {
4335         QualType New = wrap(C, cast<PointerType>(Old)->getPointeeType(), I);
4336         return C.getPointerType(New);
4337       }
4338 
4339       case BlockPointer: {
4340         QualType New = wrap(C, cast<BlockPointerType>(Old)->getPointeeType(),I);
4341         return C.getBlockPointerType(New);
4342       }
4343 
4344       case MemberPointer: {
4345         const MemberPointerType *OldMPT = cast<MemberPointerType>(Old);
4346         QualType New = wrap(C, OldMPT->getPointeeType(), I);
4347         return C.getMemberPointerType(New, OldMPT->getClass());
4348       }
4349 
4350       case Reference: {
4351         const ReferenceType *OldRef = cast<ReferenceType>(Old);
4352         QualType New = wrap(C, OldRef->getPointeeType(), I);
4353         if (isa<LValueReferenceType>(OldRef))
4354           return C.getLValueReferenceType(New, OldRef->isSpelledAsLValue());
4355         else
4356           return C.getRValueReferenceType(New);
4357       }
4358       }
4359 
4360       llvm_unreachable("unknown wrapping kind");
4361     }
4362   };
4363 }
4364 
4365 static bool handleMSPointerTypeQualifierAttr(TypeProcessingState &State,
4366                                              AttributeList &Attr,
4367                                              QualType &Type) {
4368   Sema &S = State.getSema();
4369 
4370   AttributeList::Kind Kind = Attr.getKind();
4371   QualType Desugared = Type;
4372   const AttributedType *AT = dyn_cast<AttributedType>(Type);
4373   while (AT) {
4374     AttributedType::Kind CurAttrKind = AT->getAttrKind();
4375 
4376     // You cannot specify duplicate type attributes, so if the attribute has
4377     // already been applied, flag it.
4378     if (getAttrListKind(CurAttrKind) == Kind) {
4379       S.Diag(Attr.getLoc(), diag::warn_duplicate_attribute_exact)
4380         << Attr.getName();
4381       return true;
4382     }
4383 
4384     // You cannot have both __sptr and __uptr on the same type, nor can you
4385     // have __ptr32 and __ptr64.
4386     if ((CurAttrKind == AttributedType::attr_ptr32 &&
4387          Kind == AttributeList::AT_Ptr64) ||
4388         (CurAttrKind == AttributedType::attr_ptr64 &&
4389          Kind == AttributeList::AT_Ptr32)) {
4390       S.Diag(Attr.getLoc(), diag::err_attributes_are_not_compatible)
4391         << "'__ptr32'" << "'__ptr64'";
4392       return true;
4393     } else if ((CurAttrKind == AttributedType::attr_sptr &&
4394                 Kind == AttributeList::AT_UPtr) ||
4395                (CurAttrKind == AttributedType::attr_uptr &&
4396                 Kind == AttributeList::AT_SPtr)) {
4397       S.Diag(Attr.getLoc(), diag::err_attributes_are_not_compatible)
4398         << "'__sptr'" << "'__uptr'";
4399       return true;
4400     }
4401 
4402     Desugared = AT->getEquivalentType();
4403     AT = dyn_cast<AttributedType>(Desugared);
4404   }
4405 
4406   // Pointer type qualifiers can only operate on pointer types, but not
4407   // pointer-to-member types.
4408   if (!isa<PointerType>(Desugared)) {
4409     S.Diag(Attr.getLoc(), Type->isMemberPointerType() ?
4410                           diag::err_attribute_no_member_pointers :
4411                           diag::err_attribute_pointers_only) << Attr.getName();
4412     return true;
4413   }
4414 
4415   AttributedType::Kind TAK;
4416   switch (Kind) {
4417   default: llvm_unreachable("Unknown attribute kind");
4418   case AttributeList::AT_Ptr32: TAK = AttributedType::attr_ptr32; break;
4419   case AttributeList::AT_Ptr64: TAK = AttributedType::attr_ptr64; break;
4420   case AttributeList::AT_SPtr: TAK = AttributedType::attr_sptr; break;
4421   case AttributeList::AT_UPtr: TAK = AttributedType::attr_uptr; break;
4422   }
4423 
4424   Type = S.Context.getAttributedType(TAK, Type, Type);
4425   return false;
4426 }
4427 
4428 static AttributedType::Kind getCCTypeAttrKind(AttributeList &Attr) {
4429   assert(!Attr.isInvalid());
4430   switch (Attr.getKind()) {
4431   default:
4432     llvm_unreachable("not a calling convention attribute");
4433   case AttributeList::AT_CDecl:
4434     return AttributedType::attr_cdecl;
4435   case AttributeList::AT_FastCall:
4436     return AttributedType::attr_fastcall;
4437   case AttributeList::AT_StdCall:
4438     return AttributedType::attr_stdcall;
4439   case AttributeList::AT_ThisCall:
4440     return AttributedType::attr_thiscall;
4441   case AttributeList::AT_Pascal:
4442     return AttributedType::attr_pascal;
4443   case AttributeList::AT_VectorCall:
4444     return AttributedType::attr_vectorcall;
4445   case AttributeList::AT_Pcs: {
4446     // The attribute may have had a fixit applied where we treated an
4447     // identifier as a string literal.  The contents of the string are valid,
4448     // but the form may not be.
4449     StringRef Str;
4450     if (Attr.isArgExpr(0))
4451       Str = cast<StringLiteral>(Attr.getArgAsExpr(0))->getString();
4452     else
4453       Str = Attr.getArgAsIdent(0)->Ident->getName();
4454     return llvm::StringSwitch<AttributedType::Kind>(Str)
4455         .Case("aapcs", AttributedType::attr_pcs)
4456         .Case("aapcs-vfp", AttributedType::attr_pcs_vfp);
4457   }
4458   case AttributeList::AT_PnaclCall:
4459     return AttributedType::attr_pnaclcall;
4460   case AttributeList::AT_IntelOclBicc:
4461     return AttributedType::attr_inteloclbicc;
4462   case AttributeList::AT_MSABI:
4463     return AttributedType::attr_ms_abi;
4464   case AttributeList::AT_SysVABI:
4465     return AttributedType::attr_sysv_abi;
4466   }
4467   llvm_unreachable("unexpected attribute kind!");
4468 }
4469 
4470 /// Process an individual function attribute.  Returns true to
4471 /// indicate that the attribute was handled, false if it wasn't.
4472 static bool handleFunctionTypeAttr(TypeProcessingState &state,
4473                                    AttributeList &attr,
4474                                    QualType &type) {
4475   Sema &S = state.getSema();
4476 
4477   FunctionTypeUnwrapper unwrapped(S, type);
4478 
4479   if (attr.getKind() == AttributeList::AT_NoReturn) {
4480     if (S.CheckNoReturnAttr(attr))
4481       return true;
4482 
4483     // Delay if this is not a function type.
4484     if (!unwrapped.isFunctionType())
4485       return false;
4486 
4487     // Otherwise we can process right away.
4488     FunctionType::ExtInfo EI = unwrapped.get()->getExtInfo().withNoReturn(true);
4489     type = unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
4490     return true;
4491   }
4492 
4493   // ns_returns_retained is not always a type attribute, but if we got
4494   // here, we're treating it as one right now.
4495   if (attr.getKind() == AttributeList::AT_NSReturnsRetained) {
4496     assert(S.getLangOpts().ObjCAutoRefCount &&
4497            "ns_returns_retained treated as type attribute in non-ARC");
4498     if (attr.getNumArgs()) return true;
4499 
4500     // Delay if this is not a function type.
4501     if (!unwrapped.isFunctionType())
4502       return false;
4503 
4504     FunctionType::ExtInfo EI
4505       = unwrapped.get()->getExtInfo().withProducesResult(true);
4506     type = unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
4507     return true;
4508   }
4509 
4510   if (attr.getKind() == AttributeList::AT_Regparm) {
4511     unsigned value;
4512     if (S.CheckRegparmAttr(attr, value))
4513       return true;
4514 
4515     // Delay if this is not a function type.
4516     if (!unwrapped.isFunctionType())
4517       return false;
4518 
4519     // Diagnose regparm with fastcall.
4520     const FunctionType *fn = unwrapped.get();
4521     CallingConv CC = fn->getCallConv();
4522     if (CC == CC_X86FastCall) {
4523       S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
4524         << FunctionType::getNameForCallConv(CC)
4525         << "regparm";
4526       attr.setInvalid();
4527       return true;
4528     }
4529 
4530     FunctionType::ExtInfo EI =
4531       unwrapped.get()->getExtInfo().withRegParm(value);
4532     type = unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
4533     return true;
4534   }
4535 
4536   // Delay if the type didn't work out to a function.
4537   if (!unwrapped.isFunctionType()) return false;
4538 
4539   // Otherwise, a calling convention.
4540   CallingConv CC;
4541   if (S.CheckCallingConvAttr(attr, CC))
4542     return true;
4543 
4544   const FunctionType *fn = unwrapped.get();
4545   CallingConv CCOld = fn->getCallConv();
4546   AttributedType::Kind CCAttrKind = getCCTypeAttrKind(attr);
4547 
4548   if (CCOld != CC) {
4549     // Error out on when there's already an attribute on the type
4550     // and the CCs don't match.
4551     const AttributedType *AT = S.getCallingConvAttributedType(type);
4552     if (AT && AT->getAttrKind() != CCAttrKind) {
4553       S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
4554         << FunctionType::getNameForCallConv(CC)
4555         << FunctionType::getNameForCallConv(CCOld);
4556       attr.setInvalid();
4557       return true;
4558     }
4559   }
4560 
4561   // Diagnose use of callee-cleanup calling convention on variadic functions.
4562   if (!supportsVariadicCall(CC)) {
4563     const FunctionProtoType *FnP = dyn_cast<FunctionProtoType>(fn);
4564     if (FnP && FnP->isVariadic()) {
4565       unsigned DiagID = diag::err_cconv_varargs;
4566       // stdcall and fastcall are ignored with a warning for GCC and MS
4567       // compatibility.
4568       if (CC == CC_X86StdCall || CC == CC_X86FastCall)
4569         DiagID = diag::warn_cconv_varargs;
4570 
4571       S.Diag(attr.getLoc(), DiagID) << FunctionType::getNameForCallConv(CC);
4572       attr.setInvalid();
4573       return true;
4574     }
4575   }
4576 
4577   // Also diagnose fastcall with regparm.
4578   if (CC == CC_X86FastCall && fn->getHasRegParm()) {
4579     S.Diag(attr.getLoc(), diag::err_attributes_are_not_compatible)
4580         << "regparm" << FunctionType::getNameForCallConv(CC_X86FastCall);
4581     attr.setInvalid();
4582     return true;
4583   }
4584 
4585   // Modify the CC from the wrapped function type, wrap it all back, and then
4586   // wrap the whole thing in an AttributedType as written.  The modified type
4587   // might have a different CC if we ignored the attribute.
4588   FunctionType::ExtInfo EI = unwrapped.get()->getExtInfo().withCallingConv(CC);
4589   QualType Equivalent =
4590       unwrapped.wrap(S, S.Context.adjustFunctionType(unwrapped.get(), EI));
4591   type = S.Context.getAttributedType(CCAttrKind, type, Equivalent);
4592   return true;
4593 }
4594 
4595 bool Sema::hasExplicitCallingConv(QualType &T) {
4596   QualType R = T.IgnoreParens();
4597   while (const AttributedType *AT = dyn_cast<AttributedType>(R)) {
4598     if (AT->isCallingConv())
4599       return true;
4600     R = AT->getModifiedType().IgnoreParens();
4601   }
4602   return false;
4603 }
4604 
4605 void Sema::adjustMemberFunctionCC(QualType &T, bool IsStatic) {
4606   FunctionTypeUnwrapper Unwrapped(*this, T);
4607   const FunctionType *FT = Unwrapped.get();
4608   bool IsVariadic = (isa<FunctionProtoType>(FT) &&
4609                      cast<FunctionProtoType>(FT)->isVariadic());
4610 
4611   // Only adjust types with the default convention.  For example, on Windows we
4612   // should adjust a __cdecl type to __thiscall for instance methods, and a
4613   // __thiscall type to __cdecl for static methods.
4614   CallingConv CurCC = FT->getCallConv();
4615   CallingConv FromCC =
4616       Context.getDefaultCallingConvention(IsVariadic, IsStatic);
4617   CallingConv ToCC = Context.getDefaultCallingConvention(IsVariadic, !IsStatic);
4618   if (CurCC != FromCC || FromCC == ToCC)
4619     return;
4620 
4621   if (hasExplicitCallingConv(T))
4622     return;
4623 
4624   FT = Context.adjustFunctionType(FT, FT->getExtInfo().withCallingConv(ToCC));
4625   QualType Wrapped = Unwrapped.wrap(*this, FT);
4626   T = Context.getAdjustedType(T, Wrapped);
4627 }
4628 
4629 /// HandleVectorSizeAttribute - this attribute is only applicable to integral
4630 /// and float scalars, although arrays, pointers, and function return values are
4631 /// allowed in conjunction with this construct. Aggregates with this attribute
4632 /// are invalid, even if they are of the same size as a corresponding scalar.
4633 /// The raw attribute should contain precisely 1 argument, the vector size for
4634 /// the variable, measured in bytes. If curType and rawAttr are well formed,
4635 /// this routine will return a new vector type.
4636 static void HandleVectorSizeAttr(QualType& CurType, const AttributeList &Attr,
4637                                  Sema &S) {
4638   // Check the attribute arguments.
4639   if (Attr.getNumArgs() != 1) {
4640     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments)
4641       << Attr.getName() << 1;
4642     Attr.setInvalid();
4643     return;
4644   }
4645   Expr *sizeExpr = static_cast<Expr *>(Attr.getArgAsExpr(0));
4646   llvm::APSInt vecSize(32);
4647   if (sizeExpr->isTypeDependent() || sizeExpr->isValueDependent() ||
4648       !sizeExpr->isIntegerConstantExpr(vecSize, S.Context)) {
4649     S.Diag(Attr.getLoc(), diag::err_attribute_argument_type)
4650       << Attr.getName() << AANT_ArgumentIntegerConstant
4651       << sizeExpr->getSourceRange();
4652     Attr.setInvalid();
4653     return;
4654   }
4655   // The base type must be integer (not Boolean or enumeration) or float, and
4656   // can't already be a vector.
4657   if (!CurType->isBuiltinType() || CurType->isBooleanType() ||
4658       (!CurType->isIntegerType() && !CurType->isRealFloatingType())) {
4659     S.Diag(Attr.getLoc(), diag::err_attribute_invalid_vector_type) << CurType;
4660     Attr.setInvalid();
4661     return;
4662   }
4663   unsigned typeSize = static_cast<unsigned>(S.Context.getTypeSize(CurType));
4664   // vecSize is specified in bytes - convert to bits.
4665   unsigned vectorSize = static_cast<unsigned>(vecSize.getZExtValue() * 8);
4666 
4667   // the vector size needs to be an integral multiple of the type size.
4668   if (vectorSize % typeSize) {
4669     S.Diag(Attr.getLoc(), diag::err_attribute_invalid_size)
4670       << sizeExpr->getSourceRange();
4671     Attr.setInvalid();
4672     return;
4673   }
4674   if (VectorType::isVectorSizeTooLarge(vectorSize / typeSize)) {
4675     S.Diag(Attr.getLoc(), diag::err_attribute_size_too_large)
4676       << sizeExpr->getSourceRange();
4677     Attr.setInvalid();
4678     return;
4679   }
4680   if (vectorSize == 0) {
4681     S.Diag(Attr.getLoc(), diag::err_attribute_zero_size)
4682       << sizeExpr->getSourceRange();
4683     Attr.setInvalid();
4684     return;
4685   }
4686 
4687   // Success! Instantiate the vector type, the number of elements is > 0, and
4688   // not required to be a power of 2, unlike GCC.
4689   CurType = S.Context.getVectorType(CurType, vectorSize/typeSize,
4690                                     VectorType::GenericVector);
4691 }
4692 
4693 /// \brief Process the OpenCL-like ext_vector_type attribute when it occurs on
4694 /// a type.
4695 static void HandleExtVectorTypeAttr(QualType &CurType,
4696                                     const AttributeList &Attr,
4697                                     Sema &S) {
4698   // check the attribute arguments.
4699   if (Attr.getNumArgs() != 1) {
4700     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments)
4701       << Attr.getName() << 1;
4702     return;
4703   }
4704 
4705   Expr *sizeExpr;
4706 
4707   // Special case where the argument is a template id.
4708   if (Attr.isArgIdent(0)) {
4709     CXXScopeSpec SS;
4710     SourceLocation TemplateKWLoc;
4711     UnqualifiedId id;
4712     id.setIdentifier(Attr.getArgAsIdent(0)->Ident, Attr.getLoc());
4713 
4714     ExprResult Size = S.ActOnIdExpression(S.getCurScope(), SS, TemplateKWLoc,
4715                                           id, false, false);
4716     if (Size.isInvalid())
4717       return;
4718 
4719     sizeExpr = Size.get();
4720   } else {
4721     sizeExpr = Attr.getArgAsExpr(0);
4722   }
4723 
4724   // Create the vector type.
4725   QualType T = S.BuildExtVectorType(CurType, sizeExpr, Attr.getLoc());
4726   if (!T.isNull())
4727     CurType = T;
4728 }
4729 
4730 static bool isPermittedNeonBaseType(QualType &Ty,
4731                                     VectorType::VectorKind VecKind, Sema &S) {
4732   const BuiltinType *BTy = Ty->getAs<BuiltinType>();
4733   if (!BTy)
4734     return false;
4735 
4736   llvm::Triple Triple = S.Context.getTargetInfo().getTriple();
4737 
4738   // Signed poly is mathematically wrong, but has been baked into some ABIs by
4739   // now.
4740   bool IsPolyUnsigned = Triple.getArch() == llvm::Triple::aarch64 ||
4741                         Triple.getArch() == llvm::Triple::aarch64_be;
4742   if (VecKind == VectorType::NeonPolyVector) {
4743     if (IsPolyUnsigned) {
4744       // AArch64 polynomial vectors are unsigned and support poly64.
4745       return BTy->getKind() == BuiltinType::UChar ||
4746              BTy->getKind() == BuiltinType::UShort ||
4747              BTy->getKind() == BuiltinType::ULong ||
4748              BTy->getKind() == BuiltinType::ULongLong;
4749     } else {
4750       // AArch32 polynomial vector are signed.
4751       return BTy->getKind() == BuiltinType::SChar ||
4752              BTy->getKind() == BuiltinType::Short;
4753     }
4754   }
4755 
4756   // Non-polynomial vector types: the usual suspects are allowed, as well as
4757   // float64_t on AArch64.
4758   bool Is64Bit = Triple.getArch() == llvm::Triple::aarch64 ||
4759                  Triple.getArch() == llvm::Triple::aarch64_be;
4760 
4761   if (Is64Bit && BTy->getKind() == BuiltinType::Double)
4762     return true;
4763 
4764   return BTy->getKind() == BuiltinType::SChar ||
4765          BTy->getKind() == BuiltinType::UChar ||
4766          BTy->getKind() == BuiltinType::Short ||
4767          BTy->getKind() == BuiltinType::UShort ||
4768          BTy->getKind() == BuiltinType::Int ||
4769          BTy->getKind() == BuiltinType::UInt ||
4770          BTy->getKind() == BuiltinType::Long ||
4771          BTy->getKind() == BuiltinType::ULong ||
4772          BTy->getKind() == BuiltinType::LongLong ||
4773          BTy->getKind() == BuiltinType::ULongLong ||
4774          BTy->getKind() == BuiltinType::Float ||
4775          BTy->getKind() == BuiltinType::Half;
4776 }
4777 
4778 /// HandleNeonVectorTypeAttr - The "neon_vector_type" and
4779 /// "neon_polyvector_type" attributes are used to create vector types that
4780 /// are mangled according to ARM's ABI.  Otherwise, these types are identical
4781 /// to those created with the "vector_size" attribute.  Unlike "vector_size"
4782 /// the argument to these Neon attributes is the number of vector elements,
4783 /// not the vector size in bytes.  The vector width and element type must
4784 /// match one of the standard Neon vector types.
4785 static void HandleNeonVectorTypeAttr(QualType& CurType,
4786                                      const AttributeList &Attr, Sema &S,
4787                                      VectorType::VectorKind VecKind) {
4788   // Target must have NEON
4789   if (!S.Context.getTargetInfo().hasFeature("neon")) {
4790     S.Diag(Attr.getLoc(), diag::err_attribute_unsupported) << Attr.getName();
4791     Attr.setInvalid();
4792     return;
4793   }
4794   // Check the attribute arguments.
4795   if (Attr.getNumArgs() != 1) {
4796     S.Diag(Attr.getLoc(), diag::err_attribute_wrong_number_arguments)
4797       << Attr.getName() << 1;
4798     Attr.setInvalid();
4799     return;
4800   }
4801   // The number of elements must be an ICE.
4802   Expr *numEltsExpr = static_cast<Expr *>(Attr.getArgAsExpr(0));
4803   llvm::APSInt numEltsInt(32);
4804   if (numEltsExpr->isTypeDependent() || numEltsExpr->isValueDependent() ||
4805       !numEltsExpr->isIntegerConstantExpr(numEltsInt, S.Context)) {
4806     S.Diag(Attr.getLoc(), diag::err_attribute_argument_type)
4807       << Attr.getName() << AANT_ArgumentIntegerConstant
4808       << numEltsExpr->getSourceRange();
4809     Attr.setInvalid();
4810     return;
4811   }
4812   // Only certain element types are supported for Neon vectors.
4813   if (!isPermittedNeonBaseType(CurType, VecKind, S)) {
4814     S.Diag(Attr.getLoc(), diag::err_attribute_invalid_vector_type) << CurType;
4815     Attr.setInvalid();
4816     return;
4817   }
4818 
4819   // The total size of the vector must be 64 or 128 bits.
4820   unsigned typeSize = static_cast<unsigned>(S.Context.getTypeSize(CurType));
4821   unsigned numElts = static_cast<unsigned>(numEltsInt.getZExtValue());
4822   unsigned vecSize = typeSize * numElts;
4823   if (vecSize != 64 && vecSize != 128) {
4824     S.Diag(Attr.getLoc(), diag::err_attribute_bad_neon_vector_size) << CurType;
4825     Attr.setInvalid();
4826     return;
4827   }
4828 
4829   CurType = S.Context.getVectorType(CurType, numElts, VecKind);
4830 }
4831 
4832 static void processTypeAttrs(TypeProcessingState &state, QualType &type,
4833                              TypeAttrLocation TAL, AttributeList *attrs) {
4834   // Scan through and apply attributes to this type where it makes sense.  Some
4835   // attributes (such as __address_space__, __vector_size__, etc) apply to the
4836   // type, but others can be present in the type specifiers even though they
4837   // apply to the decl.  Here we apply type attributes and ignore the rest.
4838 
4839   AttributeList *next;
4840   do {
4841     AttributeList &attr = *attrs;
4842     next = attr.getNext();
4843 
4844     // Skip attributes that were marked to be invalid.
4845     if (attr.isInvalid())
4846       continue;
4847 
4848     if (attr.isCXX11Attribute()) {
4849       // [[gnu::...]] attributes are treated as declaration attributes, so may
4850       // not appertain to a DeclaratorChunk, even if we handle them as type
4851       // attributes.
4852       if (attr.getScopeName() && attr.getScopeName()->isStr("gnu")) {
4853         if (TAL == TAL_DeclChunk) {
4854           state.getSema().Diag(attr.getLoc(),
4855                                diag::warn_cxx11_gnu_attribute_on_type)
4856               << attr.getName();
4857           continue;
4858         }
4859       } else if (TAL != TAL_DeclChunk) {
4860         // Otherwise, only consider type processing for a C++11 attribute if
4861         // it's actually been applied to a type.
4862         continue;
4863       }
4864     }
4865 
4866     // If this is an attribute we can handle, do so now,
4867     // otherwise, add it to the FnAttrs list for rechaining.
4868     switch (attr.getKind()) {
4869     default:
4870       // A C++11 attribute on a declarator chunk must appertain to a type.
4871       if (attr.isCXX11Attribute() && TAL == TAL_DeclChunk) {
4872         state.getSema().Diag(attr.getLoc(), diag::err_attribute_not_type_attr)
4873           << attr.getName();
4874         attr.setUsedAsTypeAttr();
4875       }
4876       break;
4877 
4878     case AttributeList::UnknownAttribute:
4879       if (attr.isCXX11Attribute() && TAL == TAL_DeclChunk)
4880         state.getSema().Diag(attr.getLoc(),
4881                              diag::warn_unknown_attribute_ignored)
4882           << attr.getName();
4883       break;
4884 
4885     case AttributeList::IgnoredAttribute:
4886       break;
4887 
4888     case AttributeList::AT_MayAlias:
4889       // FIXME: This attribute needs to actually be handled, but if we ignore
4890       // it it breaks large amounts of Linux software.
4891       attr.setUsedAsTypeAttr();
4892       break;
4893     case AttributeList::AT_OpenCLPrivateAddressSpace:
4894     case AttributeList::AT_OpenCLGlobalAddressSpace:
4895     case AttributeList::AT_OpenCLLocalAddressSpace:
4896     case AttributeList::AT_OpenCLConstantAddressSpace:
4897     case AttributeList::AT_OpenCLGenericAddressSpace:
4898     case AttributeList::AT_AddressSpace:
4899       HandleAddressSpaceTypeAttribute(type, attr, state.getSema());
4900       attr.setUsedAsTypeAttr();
4901       break;
4902     OBJC_POINTER_TYPE_ATTRS_CASELIST:
4903       if (!handleObjCPointerTypeAttr(state, attr, type))
4904         distributeObjCPointerTypeAttr(state, attr, type);
4905       attr.setUsedAsTypeAttr();
4906       break;
4907     case AttributeList::AT_VectorSize:
4908       HandleVectorSizeAttr(type, attr, state.getSema());
4909       attr.setUsedAsTypeAttr();
4910       break;
4911     case AttributeList::AT_ExtVectorType:
4912       HandleExtVectorTypeAttr(type, attr, state.getSema());
4913       attr.setUsedAsTypeAttr();
4914       break;
4915     case AttributeList::AT_NeonVectorType:
4916       HandleNeonVectorTypeAttr(type, attr, state.getSema(),
4917                                VectorType::NeonVector);
4918       attr.setUsedAsTypeAttr();
4919       break;
4920     case AttributeList::AT_NeonPolyVectorType:
4921       HandleNeonVectorTypeAttr(type, attr, state.getSema(),
4922                                VectorType::NeonPolyVector);
4923       attr.setUsedAsTypeAttr();
4924       break;
4925     case AttributeList::AT_OpenCLImageAccess:
4926       // FIXME: there should be some type checking happening here, I would
4927       // imagine, but the original handler's checking was entirely superfluous.
4928       attr.setUsedAsTypeAttr();
4929       break;
4930 
4931     MS_TYPE_ATTRS_CASELIST:
4932       if (!handleMSPointerTypeQualifierAttr(state, attr, type))
4933         attr.setUsedAsTypeAttr();
4934       break;
4935 
4936     case AttributeList::AT_NSReturnsRetained:
4937       if (!state.getSema().getLangOpts().ObjCAutoRefCount)
4938         break;
4939       // fallthrough into the function attrs
4940 
4941     FUNCTION_TYPE_ATTRS_CASELIST:
4942       attr.setUsedAsTypeAttr();
4943 
4944       // Never process function type attributes as part of the
4945       // declaration-specifiers.
4946       if (TAL == TAL_DeclSpec)
4947         distributeFunctionTypeAttrFromDeclSpec(state, attr, type);
4948 
4949       // Otherwise, handle the possible delays.
4950       else if (!handleFunctionTypeAttr(state, attr, type))
4951         distributeFunctionTypeAttr(state, attr, type);
4952       break;
4953     }
4954   } while ((attrs = next));
4955 }
4956 
4957 /// \brief Ensure that the type of the given expression is complete.
4958 ///
4959 /// This routine checks whether the expression \p E has a complete type. If the
4960 /// expression refers to an instantiable construct, that instantiation is
4961 /// performed as needed to complete its type. Furthermore
4962 /// Sema::RequireCompleteType is called for the expression's type (or in the
4963 /// case of a reference type, the referred-to type).
4964 ///
4965 /// \param E The expression whose type is required to be complete.
4966 /// \param Diagnoser The object that will emit a diagnostic if the type is
4967 /// incomplete.
4968 ///
4969 /// \returns \c true if the type of \p E is incomplete and diagnosed, \c false
4970 /// otherwise.
4971 bool Sema::RequireCompleteExprType(Expr *E, TypeDiagnoser &Diagnoser){
4972   QualType T = E->getType();
4973 
4974   // Fast path the case where the type is already complete.
4975   if (!T->isIncompleteType())
4976     // FIXME: The definition might not be visible.
4977     return false;
4978 
4979   // Incomplete array types may be completed by the initializer attached to
4980   // their definitions. For static data members of class templates and for
4981   // variable templates, we need to instantiate the definition to get this
4982   // initializer and complete the type.
4983   if (T->isIncompleteArrayType()) {
4984     if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParens())) {
4985       if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
4986         if (isTemplateInstantiation(Var->getTemplateSpecializationKind())) {
4987           SourceLocation PointOfInstantiation = E->getExprLoc();
4988 
4989           if (MemberSpecializationInfo *MSInfo =
4990                   Var->getMemberSpecializationInfo()) {
4991             // If we don't already have a point of instantiation, this is it.
4992             if (MSInfo->getPointOfInstantiation().isInvalid()) {
4993               MSInfo->setPointOfInstantiation(PointOfInstantiation);
4994 
4995               // This is a modification of an existing AST node. Notify
4996               // listeners.
4997               if (ASTMutationListener *L = getASTMutationListener())
4998                 L->StaticDataMemberInstantiated(Var);
4999             }
5000           } else {
5001             VarTemplateSpecializationDecl *VarSpec =
5002                 cast<VarTemplateSpecializationDecl>(Var);
5003             if (VarSpec->getPointOfInstantiation().isInvalid())
5004               VarSpec->setPointOfInstantiation(PointOfInstantiation);
5005           }
5006 
5007           InstantiateVariableDefinition(PointOfInstantiation, Var);
5008 
5009           // Update the type to the newly instantiated definition's type both
5010           // here and within the expression.
5011           if (VarDecl *Def = Var->getDefinition()) {
5012             DRE->setDecl(Def);
5013             T = Def->getType();
5014             DRE->setType(T);
5015             E->setType(T);
5016           }
5017 
5018           // We still go on to try to complete the type independently, as it
5019           // may also require instantiations or diagnostics if it remains
5020           // incomplete.
5021         }
5022       }
5023     }
5024   }
5025 
5026   // FIXME: Are there other cases which require instantiating something other
5027   // than the type to complete the type of an expression?
5028 
5029   // Look through reference types and complete the referred type.
5030   if (const ReferenceType *Ref = T->getAs<ReferenceType>())
5031     T = Ref->getPointeeType();
5032 
5033   return RequireCompleteType(E->getExprLoc(), T, Diagnoser);
5034 }
5035 
5036 namespace {
5037   struct TypeDiagnoserDiag : Sema::TypeDiagnoser {
5038     unsigned DiagID;
5039 
5040     TypeDiagnoserDiag(unsigned DiagID)
5041       : Sema::TypeDiagnoser(DiagID == 0), DiagID(DiagID) {}
5042 
5043     void diagnose(Sema &S, SourceLocation Loc, QualType T) override {
5044       if (Suppressed) return;
5045       S.Diag(Loc, DiagID) << T;
5046     }
5047   };
5048 }
5049 
5050 bool Sema::RequireCompleteExprType(Expr *E, unsigned DiagID) {
5051   TypeDiagnoserDiag Diagnoser(DiagID);
5052   return RequireCompleteExprType(E, Diagnoser);
5053 }
5054 
5055 /// @brief Ensure that the type T is a complete type.
5056 ///
5057 /// This routine checks whether the type @p T is complete in any
5058 /// context where a complete type is required. If @p T is a complete
5059 /// type, returns false. If @p T is a class template specialization,
5060 /// this routine then attempts to perform class template
5061 /// instantiation. If instantiation fails, or if @p T is incomplete
5062 /// and cannot be completed, issues the diagnostic @p diag (giving it
5063 /// the type @p T) and returns true.
5064 ///
5065 /// @param Loc  The location in the source that the incomplete type
5066 /// diagnostic should refer to.
5067 ///
5068 /// @param T  The type that this routine is examining for completeness.
5069 ///
5070 /// @returns @c true if @p T is incomplete and a diagnostic was emitted,
5071 /// @c false otherwise.
5072 bool Sema::RequireCompleteType(SourceLocation Loc, QualType T,
5073                                TypeDiagnoser &Diagnoser) {
5074   if (RequireCompleteTypeImpl(Loc, T, Diagnoser))
5075     return true;
5076   if (const TagType *Tag = T->getAs<TagType>()) {
5077     if (!Tag->getDecl()->isCompleteDefinitionRequired()) {
5078       Tag->getDecl()->setCompleteDefinitionRequired();
5079       Consumer.HandleTagDeclRequiredDefinition(Tag->getDecl());
5080     }
5081   }
5082   return false;
5083 }
5084 
5085 /// \brief Determine whether there is any declaration of \p D that was ever a
5086 ///        definition (perhaps before module merging) and is currently visible.
5087 /// \param D The definition of the entity.
5088 /// \param Suggested Filled in with the declaration that should be made visible
5089 ///        in order to provide a definition of this entity.
5090 static bool hasVisibleDefinition(Sema &S, NamedDecl *D, NamedDecl **Suggested) {
5091   // Easy case: if we don't have modules, all declarations are visible.
5092   if (!S.getLangOpts().Modules)
5093     return true;
5094 
5095   // If this definition was instantiated from a template, map back to the
5096   // pattern from which it was instantiated.
5097   if (auto *RD = dyn_cast<CXXRecordDecl>(D)) {
5098     if (auto *Pattern = RD->getTemplateInstantiationPattern())
5099       RD = Pattern;
5100     D = RD->getDefinition();
5101   } else if (auto *ED = dyn_cast<EnumDecl>(D)) {
5102     while (auto *NewED = ED->getInstantiatedFromMemberEnum())
5103       ED = NewED;
5104     if (ED->isFixed()) {
5105       // If the enum has a fixed underlying type, any declaration of it will do.
5106       *Suggested = nullptr;
5107       for (auto *Redecl : ED->redecls()) {
5108         if (LookupResult::isVisible(S, Redecl))
5109           return true;
5110         if (Redecl->isThisDeclarationADefinition() ||
5111             (Redecl->isCanonicalDecl() && !*Suggested))
5112           *Suggested = Redecl;
5113       }
5114       return false;
5115     }
5116     D = ED->getDefinition();
5117   }
5118   assert(D && "missing definition for pattern of instantiated definition");
5119 
5120   // FIXME: If we merged any other decl into D, and that declaration is visible,
5121   // then we should consider a definition to be visible.
5122   *Suggested = D;
5123   return LookupResult::isVisible(S, D);
5124 }
5125 
5126 /// Locks in the inheritance model for the given class and all of its bases.
5127 static void assignInheritanceModel(Sema &S, CXXRecordDecl *RD) {
5128   RD = RD->getMostRecentDecl();
5129   if (!RD->hasAttr<MSInheritanceAttr>()) {
5130     MSInheritanceAttr::Spelling IM;
5131 
5132     switch (S.MSPointerToMemberRepresentationMethod) {
5133     case LangOptions::PPTMK_BestCase:
5134       IM = RD->calculateInheritanceModel();
5135       break;
5136     case LangOptions::PPTMK_FullGeneralitySingleInheritance:
5137       IM = MSInheritanceAttr::Keyword_single_inheritance;
5138       break;
5139     case LangOptions::PPTMK_FullGeneralityMultipleInheritance:
5140       IM = MSInheritanceAttr::Keyword_multiple_inheritance;
5141       break;
5142     case LangOptions::PPTMK_FullGeneralityVirtualInheritance:
5143       IM = MSInheritanceAttr::Keyword_unspecified_inheritance;
5144       break;
5145     }
5146 
5147     RD->addAttr(MSInheritanceAttr::CreateImplicit(
5148         S.getASTContext(), IM,
5149         /*BestCase=*/S.MSPointerToMemberRepresentationMethod ==
5150             LangOptions::PPTMK_BestCase,
5151         S.ImplicitMSInheritanceAttrLoc.isValid()
5152             ? S.ImplicitMSInheritanceAttrLoc
5153             : RD->getSourceRange()));
5154   }
5155 }
5156 
5157 /// \brief The implementation of RequireCompleteType
5158 bool Sema::RequireCompleteTypeImpl(SourceLocation Loc, QualType T,
5159                                    TypeDiagnoser &Diagnoser) {
5160   // FIXME: Add this assertion to make sure we always get instantiation points.
5161   //  assert(!Loc.isInvalid() && "Invalid location in RequireCompleteType");
5162   // FIXME: Add this assertion to help us flush out problems with
5163   // checking for dependent types and type-dependent expressions.
5164   //
5165   //  assert(!T->isDependentType() &&
5166   //         "Can't ask whether a dependent type is complete");
5167 
5168   // If we have a complete type, we're done.
5169   NamedDecl *Def = nullptr;
5170   if (!T->isIncompleteType(&Def)) {
5171     // If we know about the definition but it is not visible, complain.
5172     NamedDecl *SuggestedDef = nullptr;
5173     if (!Diagnoser.Suppressed && Def &&
5174         !hasVisibleDefinition(*this, Def, &SuggestedDef)) {
5175       // Suppress this error outside of a SFINAE context if we've already
5176       // emitted the error once for this type. There's no usefulness in
5177       // repeating the diagnostic.
5178       // FIXME: Add a Fix-It that imports the corresponding module or includes
5179       // the header.
5180       Module *Owner = SuggestedDef->getOwningModule();
5181       Diag(Loc, diag::err_module_private_definition)
5182         << T << Owner->getFullModuleName();
5183       Diag(SuggestedDef->getLocation(), diag::note_previous_definition);
5184 
5185       // Try to recover by implicitly importing this module.
5186       createImplicitModuleImportForErrorRecovery(Loc, Owner);
5187     }
5188 
5189     // We lock in the inheritance model once somebody has asked us to ensure
5190     // that a pointer-to-member type is complete.
5191     if (Context.getTargetInfo().getCXXABI().isMicrosoft()) {
5192       if (const MemberPointerType *MPTy = T->getAs<MemberPointerType>()) {
5193         if (!MPTy->getClass()->isDependentType()) {
5194           RequireCompleteType(Loc, QualType(MPTy->getClass(), 0), 0);
5195           assignInheritanceModel(*this, MPTy->getMostRecentCXXRecordDecl());
5196         }
5197       }
5198     }
5199 
5200     return false;
5201   }
5202 
5203   const TagType *Tag = T->getAs<TagType>();
5204   const ObjCInterfaceType *IFace = T->getAs<ObjCInterfaceType>();
5205 
5206   // If there's an unimported definition of this type in a module (for
5207   // instance, because we forward declared it, then imported the definition),
5208   // import that definition now.
5209   //
5210   // FIXME: What about other cases where an import extends a redeclaration
5211   // chain for a declaration that can be accessed through a mechanism other
5212   // than name lookup (eg, referenced in a template, or a variable whose type
5213   // could be completed by the module)?
5214   if (Tag || IFace) {
5215     NamedDecl *D =
5216         Tag ? static_cast<NamedDecl *>(Tag->getDecl()) : IFace->getDecl();
5217 
5218     // Avoid diagnosing invalid decls as incomplete.
5219     if (D->isInvalidDecl())
5220       return true;
5221 
5222     // Give the external AST source a chance to complete the type.
5223     if (auto *Source = Context.getExternalSource()) {
5224       if (Tag)
5225         Source->CompleteType(Tag->getDecl());
5226       else
5227         Source->CompleteType(IFace->getDecl());
5228 
5229       // If the external source completed the type, go through the motions
5230       // again to ensure we're allowed to use the completed type.
5231       if (!T->isIncompleteType())
5232         return RequireCompleteTypeImpl(Loc, T, Diagnoser);
5233     }
5234   }
5235 
5236   // If we have a class template specialization or a class member of a
5237   // class template specialization, or an array with known size of such,
5238   // try to instantiate it.
5239   QualType MaybeTemplate = T;
5240   while (const ConstantArrayType *Array
5241            = Context.getAsConstantArrayType(MaybeTemplate))
5242     MaybeTemplate = Array->getElementType();
5243   if (const RecordType *Record = MaybeTemplate->getAs<RecordType>()) {
5244     if (ClassTemplateSpecializationDecl *ClassTemplateSpec
5245           = dyn_cast<ClassTemplateSpecializationDecl>(Record->getDecl())) {
5246       if (ClassTemplateSpec->getSpecializationKind() == TSK_Undeclared)
5247         return InstantiateClassTemplateSpecialization(Loc, ClassTemplateSpec,
5248                                                       TSK_ImplicitInstantiation,
5249                                             /*Complain=*/!Diagnoser.Suppressed);
5250     } else if (CXXRecordDecl *Rec
5251                  = dyn_cast<CXXRecordDecl>(Record->getDecl())) {
5252       CXXRecordDecl *Pattern = Rec->getInstantiatedFromMemberClass();
5253       if (!Rec->isBeingDefined() && Pattern) {
5254         MemberSpecializationInfo *MSI = Rec->getMemberSpecializationInfo();
5255         assert(MSI && "Missing member specialization information?");
5256         // This record was instantiated from a class within a template.
5257         if (MSI->getTemplateSpecializationKind() != TSK_ExplicitSpecialization)
5258           return InstantiateClass(Loc, Rec, Pattern,
5259                                   getTemplateInstantiationArgs(Rec),
5260                                   TSK_ImplicitInstantiation,
5261                                   /*Complain=*/!Diagnoser.Suppressed);
5262       }
5263     }
5264   }
5265 
5266   if (Diagnoser.Suppressed)
5267     return true;
5268 
5269   // We have an incomplete type. Produce a diagnostic.
5270   if (Ident___float128 &&
5271       T == Context.getTypeDeclType(Context.getFloat128StubType())) {
5272     Diag(Loc, diag::err_typecheck_decl_incomplete_type___float128);
5273     return true;
5274   }
5275 
5276   Diagnoser.diagnose(*this, Loc, T);
5277 
5278   // If the type was a forward declaration of a class/struct/union
5279   // type, produce a note.
5280   if (Tag && !Tag->getDecl()->isInvalidDecl())
5281     Diag(Tag->getDecl()->getLocation(),
5282          Tag->isBeingDefined() ? diag::note_type_being_defined
5283                                : diag::note_forward_declaration)
5284       << QualType(Tag, 0);
5285 
5286   // If the Objective-C class was a forward declaration, produce a note.
5287   if (IFace && !IFace->getDecl()->isInvalidDecl())
5288     Diag(IFace->getDecl()->getLocation(), diag::note_forward_class);
5289 
5290   // If we have external information that we can use to suggest a fix,
5291   // produce a note.
5292   if (ExternalSource)
5293     ExternalSource->MaybeDiagnoseMissingCompleteType(Loc, T);
5294 
5295   return true;
5296 }
5297 
5298 bool Sema::RequireCompleteType(SourceLocation Loc, QualType T,
5299                                unsigned DiagID) {
5300   TypeDiagnoserDiag Diagnoser(DiagID);
5301   return RequireCompleteType(Loc, T, Diagnoser);
5302 }
5303 
5304 /// \brief Get diagnostic %select index for tag kind for
5305 /// literal type diagnostic message.
5306 /// WARNING: Indexes apply to particular diagnostics only!
5307 ///
5308 /// \returns diagnostic %select index.
5309 static unsigned getLiteralDiagFromTagKind(TagTypeKind Tag) {
5310   switch (Tag) {
5311   case TTK_Struct: return 0;
5312   case TTK_Interface: return 1;
5313   case TTK_Class:  return 2;
5314   default: llvm_unreachable("Invalid tag kind for literal type diagnostic!");
5315   }
5316 }
5317 
5318 /// @brief Ensure that the type T is a literal type.
5319 ///
5320 /// This routine checks whether the type @p T is a literal type. If @p T is an
5321 /// incomplete type, an attempt is made to complete it. If @p T is a literal
5322 /// type, or @p AllowIncompleteType is true and @p T is an incomplete type,
5323 /// returns false. Otherwise, this routine issues the diagnostic @p PD (giving
5324 /// it the type @p T), along with notes explaining why the type is not a
5325 /// literal type, and returns true.
5326 ///
5327 /// @param Loc  The location in the source that the non-literal type
5328 /// diagnostic should refer to.
5329 ///
5330 /// @param T  The type that this routine is examining for literalness.
5331 ///
5332 /// @param Diagnoser Emits a diagnostic if T is not a literal type.
5333 ///
5334 /// @returns @c true if @p T is not a literal type and a diagnostic was emitted,
5335 /// @c false otherwise.
5336 bool Sema::RequireLiteralType(SourceLocation Loc, QualType T,
5337                               TypeDiagnoser &Diagnoser) {
5338   assert(!T->isDependentType() && "type should not be dependent");
5339 
5340   QualType ElemType = Context.getBaseElementType(T);
5341   RequireCompleteType(Loc, ElemType, 0);
5342 
5343   if (T->isLiteralType(Context))
5344     return false;
5345 
5346   if (Diagnoser.Suppressed)
5347     return true;
5348 
5349   Diagnoser.diagnose(*this, Loc, T);
5350 
5351   if (T->isVariableArrayType())
5352     return true;
5353 
5354   const RecordType *RT = ElemType->getAs<RecordType>();
5355   if (!RT)
5356     return true;
5357 
5358   const CXXRecordDecl *RD = cast<CXXRecordDecl>(RT->getDecl());
5359 
5360   // A partially-defined class type can't be a literal type, because a literal
5361   // class type must have a trivial destructor (which can't be checked until
5362   // the class definition is complete).
5363   if (!RD->isCompleteDefinition()) {
5364     RequireCompleteType(Loc, ElemType, diag::note_non_literal_incomplete, T);
5365     return true;
5366   }
5367 
5368   // If the class has virtual base classes, then it's not an aggregate, and
5369   // cannot have any constexpr constructors or a trivial default constructor,
5370   // so is non-literal. This is better to diagnose than the resulting absence
5371   // of constexpr constructors.
5372   if (RD->getNumVBases()) {
5373     Diag(RD->getLocation(), diag::note_non_literal_virtual_base)
5374       << getLiteralDiagFromTagKind(RD->getTagKind()) << RD->getNumVBases();
5375     for (const auto &I : RD->vbases())
5376       Diag(I.getLocStart(), diag::note_constexpr_virtual_base_here)
5377           << I.getSourceRange();
5378   } else if (!RD->isAggregate() && !RD->hasConstexprNonCopyMoveConstructor() &&
5379              !RD->hasTrivialDefaultConstructor()) {
5380     Diag(RD->getLocation(), diag::note_non_literal_no_constexpr_ctors) << RD;
5381   } else if (RD->hasNonLiteralTypeFieldsOrBases()) {
5382     for (const auto &I : RD->bases()) {
5383       if (!I.getType()->isLiteralType(Context)) {
5384         Diag(I.getLocStart(),
5385              diag::note_non_literal_base_class)
5386           << RD << I.getType() << I.getSourceRange();
5387         return true;
5388       }
5389     }
5390     for (const auto *I : RD->fields()) {
5391       if (!I->getType()->isLiteralType(Context) ||
5392           I->getType().isVolatileQualified()) {
5393         Diag(I->getLocation(), diag::note_non_literal_field)
5394           << RD << I << I->getType()
5395           << I->getType().isVolatileQualified();
5396         return true;
5397       }
5398     }
5399   } else if (!RD->hasTrivialDestructor()) {
5400     // All fields and bases are of literal types, so have trivial destructors.
5401     // If this class's destructor is non-trivial it must be user-declared.
5402     CXXDestructorDecl *Dtor = RD->getDestructor();
5403     assert(Dtor && "class has literal fields and bases but no dtor?");
5404     if (!Dtor)
5405       return true;
5406 
5407     Diag(Dtor->getLocation(), Dtor->isUserProvided() ?
5408          diag::note_non_literal_user_provided_dtor :
5409          diag::note_non_literal_nontrivial_dtor) << RD;
5410     if (!Dtor->isUserProvided())
5411       SpecialMemberIsTrivial(Dtor, CXXDestructor, /*Diagnose*/true);
5412   }
5413 
5414   return true;
5415 }
5416 
5417 bool Sema::RequireLiteralType(SourceLocation Loc, QualType T, unsigned DiagID) {
5418   TypeDiagnoserDiag Diagnoser(DiagID);
5419   return RequireLiteralType(Loc, T, Diagnoser);
5420 }
5421 
5422 /// \brief Retrieve a version of the type 'T' that is elaborated by Keyword
5423 /// and qualified by the nested-name-specifier contained in SS.
5424 QualType Sema::getElaboratedType(ElaboratedTypeKeyword Keyword,
5425                                  const CXXScopeSpec &SS, QualType T) {
5426   if (T.isNull())
5427     return T;
5428   NestedNameSpecifier *NNS;
5429   if (SS.isValid())
5430     NNS = SS.getScopeRep();
5431   else {
5432     if (Keyword == ETK_None)
5433       return T;
5434     NNS = nullptr;
5435   }
5436   return Context.getElaboratedType(Keyword, NNS, T);
5437 }
5438 
5439 QualType Sema::BuildTypeofExprType(Expr *E, SourceLocation Loc) {
5440   ExprResult ER = CheckPlaceholderExpr(E);
5441   if (ER.isInvalid()) return QualType();
5442   E = ER.get();
5443 
5444   if (!E->isTypeDependent()) {
5445     QualType T = E->getType();
5446     if (const TagType *TT = T->getAs<TagType>())
5447       DiagnoseUseOfDecl(TT->getDecl(), E->getExprLoc());
5448   }
5449   return Context.getTypeOfExprType(E);
5450 }
5451 
5452 /// getDecltypeForExpr - Given an expr, will return the decltype for
5453 /// that expression, according to the rules in C++11
5454 /// [dcl.type.simple]p4 and C++11 [expr.lambda.prim]p18.
5455 static QualType getDecltypeForExpr(Sema &S, Expr *E) {
5456   if (E->isTypeDependent())
5457     return S.Context.DependentTy;
5458 
5459   // C++11 [dcl.type.simple]p4:
5460   //   The type denoted by decltype(e) is defined as follows:
5461   //
5462   //     - if e is an unparenthesized id-expression or an unparenthesized class
5463   //       member access (5.2.5), decltype(e) is the type of the entity named
5464   //       by e. If there is no such entity, or if e names a set of overloaded
5465   //       functions, the program is ill-formed;
5466   //
5467   // We apply the same rules for Objective-C ivar and property references.
5468   if (const DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E)) {
5469     if (const ValueDecl *VD = dyn_cast<ValueDecl>(DRE->getDecl()))
5470       return VD->getType();
5471   } else if (const MemberExpr *ME = dyn_cast<MemberExpr>(E)) {
5472     if (const FieldDecl *FD = dyn_cast<FieldDecl>(ME->getMemberDecl()))
5473       return FD->getType();
5474   } else if (const ObjCIvarRefExpr *IR = dyn_cast<ObjCIvarRefExpr>(E)) {
5475     return IR->getDecl()->getType();
5476   } else if (const ObjCPropertyRefExpr *PR = dyn_cast<ObjCPropertyRefExpr>(E)) {
5477     if (PR->isExplicitProperty())
5478       return PR->getExplicitProperty()->getType();
5479   } else if (auto *PE = dyn_cast<PredefinedExpr>(E)) {
5480     return PE->getType();
5481   }
5482 
5483   // C++11 [expr.lambda.prim]p18:
5484   //   Every occurrence of decltype((x)) where x is a possibly
5485   //   parenthesized id-expression that names an entity of automatic
5486   //   storage duration is treated as if x were transformed into an
5487   //   access to a corresponding data member of the closure type that
5488   //   would have been declared if x were an odr-use of the denoted
5489   //   entity.
5490   using namespace sema;
5491   if (S.getCurLambda()) {
5492     if (isa<ParenExpr>(E)) {
5493       if (DeclRefExpr *DRE = dyn_cast<DeclRefExpr>(E->IgnoreParens())) {
5494         if (VarDecl *Var = dyn_cast<VarDecl>(DRE->getDecl())) {
5495           QualType T = S.getCapturedDeclRefType(Var, DRE->getLocation());
5496           if (!T.isNull())
5497             return S.Context.getLValueReferenceType(T);
5498         }
5499       }
5500     }
5501   }
5502 
5503 
5504   // C++11 [dcl.type.simple]p4:
5505   //   [...]
5506   QualType T = E->getType();
5507   switch (E->getValueKind()) {
5508   //     - otherwise, if e is an xvalue, decltype(e) is T&&, where T is the
5509   //       type of e;
5510   case VK_XValue: T = S.Context.getRValueReferenceType(T); break;
5511   //     - otherwise, if e is an lvalue, decltype(e) is T&, where T is the
5512   //       type of e;
5513   case VK_LValue: T = S.Context.getLValueReferenceType(T); break;
5514   //  - otherwise, decltype(e) is the type of e.
5515   case VK_RValue: break;
5516   }
5517 
5518   return T;
5519 }
5520 
5521 QualType Sema::BuildDecltypeType(Expr *E, SourceLocation Loc) {
5522   ExprResult ER = CheckPlaceholderExpr(E);
5523   if (ER.isInvalid()) return QualType();
5524   E = ER.get();
5525 
5526   return Context.getDecltypeType(E, getDecltypeForExpr(*this, E));
5527 }
5528 
5529 QualType Sema::BuildUnaryTransformType(QualType BaseType,
5530                                        UnaryTransformType::UTTKind UKind,
5531                                        SourceLocation Loc) {
5532   switch (UKind) {
5533   case UnaryTransformType::EnumUnderlyingType:
5534     if (!BaseType->isDependentType() && !BaseType->isEnumeralType()) {
5535       Diag(Loc, diag::err_only_enums_have_underlying_types);
5536       return QualType();
5537     } else {
5538       QualType Underlying = BaseType;
5539       if (!BaseType->isDependentType()) {
5540         // The enum could be incomplete if we're parsing its definition or
5541         // recovering from an error.
5542         NamedDecl *FwdDecl = nullptr;
5543         if (BaseType->isIncompleteType(&FwdDecl)) {
5544           Diag(Loc, diag::err_underlying_type_of_incomplete_enum) << BaseType;
5545           Diag(FwdDecl->getLocation(), diag::note_forward_declaration) << FwdDecl;
5546           return QualType();
5547         }
5548 
5549         EnumDecl *ED = BaseType->getAs<EnumType>()->getDecl();
5550         assert(ED && "EnumType has no EnumDecl");
5551 
5552         DiagnoseUseOfDecl(ED, Loc);
5553 
5554         Underlying = ED->getIntegerType();
5555         assert(!Underlying.isNull());
5556       }
5557       return Context.getUnaryTransformType(BaseType, Underlying,
5558                                         UnaryTransformType::EnumUnderlyingType);
5559     }
5560   }
5561   llvm_unreachable("unknown unary transform type");
5562 }
5563 
5564 QualType Sema::BuildAtomicType(QualType T, SourceLocation Loc) {
5565   if (!T->isDependentType()) {
5566     // FIXME: It isn't entirely clear whether incomplete atomic types
5567     // are allowed or not; for simplicity, ban them for the moment.
5568     if (RequireCompleteType(Loc, T, diag::err_atomic_specifier_bad_type, 0))
5569       return QualType();
5570 
5571     int DisallowedKind = -1;
5572     if (T->isArrayType())
5573       DisallowedKind = 1;
5574     else if (T->isFunctionType())
5575       DisallowedKind = 2;
5576     else if (T->isReferenceType())
5577       DisallowedKind = 3;
5578     else if (T->isAtomicType())
5579       DisallowedKind = 4;
5580     else if (T.hasQualifiers())
5581       DisallowedKind = 5;
5582     else if (!T.isTriviallyCopyableType(Context))
5583       // Some other non-trivially-copyable type (probably a C++ class)
5584       DisallowedKind = 6;
5585 
5586     if (DisallowedKind != -1) {
5587       Diag(Loc, diag::err_atomic_specifier_bad_type) << DisallowedKind << T;
5588       return QualType();
5589     }
5590 
5591     // FIXME: Do we need any handling for ARC here?
5592   }
5593 
5594   // Build the pointer type.
5595   return Context.getAtomicType(T);
5596 }
5597