clang  10.0.0svn
SemaCast.cpp
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1 //===--- SemaCast.cpp - Semantic Analysis for Casts -----------------------===//
2 //
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6 //
7 //===----------------------------------------------------------------------===//
8 //
9 // This file implements semantic analysis for cast expressions, including
10 // 1) C-style casts like '(int) x'
11 // 2) C++ functional casts like 'int(x)'
12 // 3) C++ named casts like 'static_cast<int>(x)'
13 //
14 //===----------------------------------------------------------------------===//
15 
17 #include "clang/AST/ASTContext.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ExprObjC.h"
21 #include "clang/AST/RecordLayout.h"
23 #include "clang/Basic/TargetInfo.h"
24 #include "clang/Lex/Preprocessor.h"
26 #include "llvm/ADT/SmallVector.h"
27 #include <set>
28 using namespace clang;
29 
30 
31 
33  TC_NotApplicable, ///< The cast method is not applicable.
34  TC_Success, ///< The cast method is appropriate and successful.
35  TC_Extension, ///< The cast method is appropriate and accepted as a
36  ///< language extension.
37  TC_Failed ///< The cast method is appropriate, but failed. A
38  ///< diagnostic has been emitted.
39 };
40 
41 static bool isValidCast(TryCastResult TCR) {
42  return TCR == TC_Success || TCR == TC_Extension;
43 }
44 
45 enum CastType {
46  CT_Const, ///< const_cast
47  CT_Static, ///< static_cast
48  CT_Reinterpret, ///< reinterpret_cast
49  CT_Dynamic, ///< dynamic_cast
50  CT_CStyle, ///< (Type)expr
51  CT_Functional ///< Type(expr)
52 };
53 
54 namespace {
55  struct CastOperation {
56  CastOperation(Sema &S, QualType destType, ExprResult src)
57  : Self(S), SrcExpr(src), DestType(destType),
58  ResultType(destType.getNonLValueExprType(S.Context)),
59  ValueKind(Expr::getValueKindForType(destType)),
60  Kind(CK_Dependent), IsARCUnbridgedCast(false) {
61 
62  if (const BuiltinType *placeholder =
63  src.get()->getType()->getAsPlaceholderType()) {
64  PlaceholderKind = placeholder->getKind();
65  } else {
66  PlaceholderKind = (BuiltinType::Kind) 0;
67  }
68  }
69 
70  Sema &Self;
71  ExprResult SrcExpr;
72  QualType DestType;
73  QualType ResultType;
74  ExprValueKind ValueKind;
75  CastKind Kind;
76  BuiltinType::Kind PlaceholderKind;
77  CXXCastPath BasePath;
78  bool IsARCUnbridgedCast;
79 
80  SourceRange OpRange;
81  SourceRange DestRange;
82 
83  // Top-level semantics-checking routines.
84  void CheckConstCast();
85  void CheckReinterpretCast();
86  void CheckStaticCast();
87  void CheckDynamicCast();
88  void CheckCXXCStyleCast(bool FunctionalCast, bool ListInitialization);
89  void CheckCStyleCast();
90  void CheckBuiltinBitCast();
91 
92  void updatePartOfExplicitCastFlags(CastExpr *CE) {
93  // Walk down from the CE to the OrigSrcExpr, and mark all immediate
94  // ImplicitCastExpr's as being part of ExplicitCastExpr. The original CE
95  // (which is a ExplicitCastExpr), and the OrigSrcExpr are not touched.
96  for (; auto *ICE = dyn_cast<ImplicitCastExpr>(CE->getSubExpr()); CE = ICE)
97  ICE->setIsPartOfExplicitCast(true);
98  }
99 
100  /// Complete an apparently-successful cast operation that yields
101  /// the given expression.
102  ExprResult complete(CastExpr *castExpr) {
103  // If this is an unbridged cast, wrap the result in an implicit
104  // cast that yields the unbridged-cast placeholder type.
105  if (IsARCUnbridgedCast) {
106  castExpr = ImplicitCastExpr::Create(Self.Context,
108  CK_Dependent, castExpr, nullptr,
109  castExpr->getValueKind());
110  }
111  updatePartOfExplicitCastFlags(castExpr);
112  return castExpr;
113  }
114 
115  // Internal convenience methods.
116 
117  /// Try to handle the given placeholder expression kind. Return
118  /// true if the source expression has the appropriate placeholder
119  /// kind. A placeholder can only be claimed once.
120  bool claimPlaceholder(BuiltinType::Kind K) {
121  if (PlaceholderKind != K) return false;
122 
123  PlaceholderKind = (BuiltinType::Kind) 0;
124  return true;
125  }
126 
127  bool isPlaceholder() const {
128  return PlaceholderKind != 0;
129  }
130  bool isPlaceholder(BuiltinType::Kind K) const {
131  return PlaceholderKind == K;
132  }
133 
134  // Language specific cast restrictions for address spaces.
135  void checkAddressSpaceCast(QualType SrcType, QualType DestType);
136 
137  void checkCastAlign() {
138  Self.CheckCastAlign(SrcExpr.get(), DestType, OpRange);
139  }
140 
141  void checkObjCConversion(Sema::CheckedConversionKind CCK) {
143 
144  Expr *src = SrcExpr.get();
145  if (Self.CheckObjCConversion(OpRange, DestType, src, CCK) ==
147  IsARCUnbridgedCast = true;
148  SrcExpr = src;
149  }
150 
151  /// Check for and handle non-overload placeholder expressions.
152  void checkNonOverloadPlaceholders() {
153  if (!isPlaceholder() || isPlaceholder(BuiltinType::Overload))
154  return;
155 
156  SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.get());
157  if (SrcExpr.isInvalid())
158  return;
159  PlaceholderKind = (BuiltinType::Kind) 0;
160  }
161  };
162 }
163 
164 static void DiagnoseCastQual(Sema &Self, const ExprResult &SrcExpr,
165  QualType DestType);
166 
167 // The Try functions attempt a specific way of casting. If they succeed, they
168 // return TC_Success. If their way of casting is not appropriate for the given
169 // arguments, they return TC_NotApplicable and *may* set diag to a diagnostic
170 // to emit if no other way succeeds. If their way of casting is appropriate but
171 // fails, they return TC_Failed and *must* set diag; they can set it to 0 if
172 // they emit a specialized diagnostic.
173 // All diagnostics returned by these functions must expect the same three
174 // arguments:
175 // %0: Cast Type (a value from the CastType enumeration)
176 // %1: Source Type
177 // %2: Destination Type
178 static TryCastResult TryLValueToRValueCast(Sema &Self, Expr *SrcExpr,
179  QualType DestType, bool CStyle,
180  CastKind &Kind,
181  CXXCastPath &BasePath,
182  unsigned &msg);
183 static TryCastResult TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr,
184  QualType DestType, bool CStyle,
185  SourceRange OpRange,
186  unsigned &msg,
187  CastKind &Kind,
188  CXXCastPath &BasePath);
190  QualType DestType, bool CStyle,
191  SourceRange OpRange,
192  unsigned &msg,
193  CastKind &Kind,
194  CXXCastPath &BasePath);
195 static TryCastResult TryStaticDowncast(Sema &Self, CanQualType SrcType,
196  CanQualType DestType, bool CStyle,
197  SourceRange OpRange,
198  QualType OrigSrcType,
199  QualType OrigDestType, unsigned &msg,
200  CastKind &Kind,
201  CXXCastPath &BasePath);
203  QualType SrcType,
204  QualType DestType,bool CStyle,
205  SourceRange OpRange,
206  unsigned &msg,
207  CastKind &Kind,
208  CXXCastPath &BasePath);
209 
210 static TryCastResult TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr,
211  QualType DestType,
213  SourceRange OpRange,
214  unsigned &msg, CastKind &Kind,
215  bool ListInitialization);
216 static TryCastResult TryStaticCast(Sema &Self, ExprResult &SrcExpr,
217  QualType DestType,
219  SourceRange OpRange,
220  unsigned &msg, CastKind &Kind,
221  CXXCastPath &BasePath,
222  bool ListInitialization);
223 static TryCastResult TryConstCast(Sema &Self, ExprResult &SrcExpr,
224  QualType DestType, bool CStyle,
225  unsigned &msg);
226 static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr,
227  QualType DestType, bool CStyle,
228  SourceRange OpRange,
229  unsigned &msg,
230  CastKind &Kind);
231 
232 
233 /// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
236  SourceLocation LAngleBracketLoc, Declarator &D,
237  SourceLocation RAngleBracketLoc,
238  SourceLocation LParenLoc, Expr *E,
239  SourceLocation RParenLoc) {
240 
241  assert(!D.isInvalidType());
242 
243  TypeSourceInfo *TInfo = GetTypeForDeclaratorCast(D, E->getType());
244  if (D.isInvalidType())
245  return ExprError();
246 
247  if (getLangOpts().CPlusPlus) {
248  // Check that there are no default arguments (C++ only).
249  CheckExtraCXXDefaultArguments(D);
250  }
251 
252  return BuildCXXNamedCast(OpLoc, Kind, TInfo, E,
253  SourceRange(LAngleBracketLoc, RAngleBracketLoc),
254  SourceRange(LParenLoc, RParenLoc));
255 }
256 
259  TypeSourceInfo *DestTInfo, Expr *E,
260  SourceRange AngleBrackets, SourceRange Parens) {
261  ExprResult Ex = E;
262  QualType DestType = DestTInfo->getType();
263 
264  // If the type is dependent, we won't do the semantic analysis now.
265  bool TypeDependent =
266  DestType->isDependentType() || Ex.get()->isTypeDependent();
267 
268  CastOperation Op(*this, DestType, E);
269  Op.OpRange = SourceRange(OpLoc, Parens.getEnd());
270  Op.DestRange = AngleBrackets;
271 
272  switch (Kind) {
273  default: llvm_unreachable("Unknown C++ cast!");
274 
275  case tok::kw_const_cast:
276  if (!TypeDependent) {
277  Op.CheckConstCast();
278  if (Op.SrcExpr.isInvalid())
279  return ExprError();
280  DiscardMisalignedMemberAddress(DestType.getTypePtr(), E);
281  }
282  return Op.complete(CXXConstCastExpr::Create(Context, Op.ResultType,
283  Op.ValueKind, Op.SrcExpr.get(), DestTInfo,
284  OpLoc, Parens.getEnd(),
285  AngleBrackets));
286 
287  case tok::kw_dynamic_cast: {
288  // dynamic_cast is not supported in C++ for OpenCL.
289  if (getLangOpts().OpenCLCPlusPlus) {
290  return ExprError(Diag(OpLoc, diag::err_openclcxx_not_supported)
291  << "dynamic_cast");
292  }
293 
294  if (!TypeDependent) {
295  Op.CheckDynamicCast();
296  if (Op.SrcExpr.isInvalid())
297  return ExprError();
298  }
299  return Op.complete(CXXDynamicCastExpr::Create(Context, Op.ResultType,
300  Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
301  &Op.BasePath, DestTInfo,
302  OpLoc, Parens.getEnd(),
303  AngleBrackets));
304  }
305  case tok::kw_reinterpret_cast: {
306  if (!TypeDependent) {
307  Op.CheckReinterpretCast();
308  if (Op.SrcExpr.isInvalid())
309  return ExprError();
310  DiscardMisalignedMemberAddress(DestType.getTypePtr(), E);
311  }
312  return Op.complete(CXXReinterpretCastExpr::Create(Context, Op.ResultType,
313  Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
314  nullptr, DestTInfo, OpLoc,
315  Parens.getEnd(),
316  AngleBrackets));
317  }
318  case tok::kw_static_cast: {
319  if (!TypeDependent) {
320  Op.CheckStaticCast();
321  if (Op.SrcExpr.isInvalid())
322  return ExprError();
323  DiscardMisalignedMemberAddress(DestType.getTypePtr(), E);
324  }
325 
326  return Op.complete(CXXStaticCastExpr::Create(Context, Op.ResultType,
327  Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
328  &Op.BasePath, DestTInfo,
329  OpLoc, Parens.getEnd(),
330  AngleBrackets));
331  }
332  }
333 }
334 
336  ExprResult Operand,
337  SourceLocation RParenLoc) {
338  assert(!D.isInvalidType());
339 
340  TypeSourceInfo *TInfo = GetTypeForDeclaratorCast(D, Operand.get()->getType());
341  if (D.isInvalidType())
342  return ExprError();
343 
344  return BuildBuiltinBitCastExpr(KWLoc, TInfo, Operand.get(), RParenLoc);
345 }
346 
348  TypeSourceInfo *TSI, Expr *Operand,
349  SourceLocation RParenLoc) {
350  CastOperation Op(*this, TSI->getType(), Operand);
351  Op.OpRange = SourceRange(KWLoc, RParenLoc);
352  TypeLoc TL = TSI->getTypeLoc();
353  Op.DestRange = SourceRange(TL.getBeginLoc(), TL.getEndLoc());
354 
355  if (!Operand->isTypeDependent() && !TSI->getType()->isDependentType()) {
356  Op.CheckBuiltinBitCast();
357  if (Op.SrcExpr.isInvalid())
358  return ExprError();
359  }
360 
361  BuiltinBitCastExpr *BCE =
362  new (Context) BuiltinBitCastExpr(Op.ResultType, Op.ValueKind, Op.Kind,
363  Op.SrcExpr.get(), TSI, KWLoc, RParenLoc);
364  return Op.complete(BCE);
365 }
366 
367 /// Try to diagnose a failed overloaded cast. Returns true if
368 /// diagnostics were emitted.
370  SourceRange range, Expr *src,
371  QualType destType,
372  bool listInitialization) {
373  switch (CT) {
374  // These cast kinds don't consider user-defined conversions.
375  case CT_Const:
376  case CT_Reinterpret:
377  case CT_Dynamic:
378  return false;
379 
380  // These do.
381  case CT_Static:
382  case CT_CStyle:
383  case CT_Functional:
384  break;
385  }
386 
387  QualType srcType = src->getType();
388  if (!destType->isRecordType() && !srcType->isRecordType())
389  return false;
390 
392  InitializationKind initKind
394  range, listInitialization)
396  listInitialization)
397  : InitializationKind::CreateCast(/*type range?*/ range);
398  InitializationSequence sequence(S, entity, initKind, src);
399 
400  assert(sequence.Failed() && "initialization succeeded on second try?");
401  switch (sequence.getFailureKind()) {
402  default: return false;
403 
406  break;
407  }
408 
409  OverloadCandidateSet &candidates = sequence.getFailedCandidateSet();
410 
411  unsigned msg = 0;
413 
414  switch (sequence.getFailedOverloadResult()) {
415  case OR_Success: llvm_unreachable("successful failed overload");
417  if (candidates.empty())
418  msg = diag::err_ovl_no_conversion_in_cast;
419  else
420  msg = diag::err_ovl_no_viable_conversion_in_cast;
421  howManyCandidates = OCD_AllCandidates;
422  break;
423 
424  case OR_Ambiguous:
425  msg = diag::err_ovl_ambiguous_conversion_in_cast;
426  howManyCandidates = OCD_ViableCandidates;
427  break;
428 
429  case OR_Deleted:
430  msg = diag::err_ovl_deleted_conversion_in_cast;
431  howManyCandidates = OCD_ViableCandidates;
432  break;
433  }
434 
435  candidates.NoteCandidates(
437  S.PDiag(msg) << CT << srcType << destType << range
438  << src->getSourceRange()),
439  S, howManyCandidates, src);
440 
441  return true;
442 }
443 
444 /// Diagnose a failed cast.
445 static void diagnoseBadCast(Sema &S, unsigned msg, CastType castType,
446  SourceRange opRange, Expr *src, QualType destType,
447  bool listInitialization) {
448  if (msg == diag::err_bad_cxx_cast_generic &&
449  tryDiagnoseOverloadedCast(S, castType, opRange, src, destType,
450  listInitialization))
451  return;
452 
453  S.Diag(opRange.getBegin(), msg) << castType
454  << src->getType() << destType << opRange << src->getSourceRange();
455 
456  // Detect if both types are (ptr to) class, and note any incompleteness.
457  int DifferentPtrness = 0;
458  QualType From = destType;
459  if (auto Ptr = From->getAs<PointerType>()) {
460  From = Ptr->getPointeeType();
461  DifferentPtrness++;
462  }
463  QualType To = src->getType();
464  if (auto Ptr = To->getAs<PointerType>()) {
465  To = Ptr->getPointeeType();
466  DifferentPtrness--;
467  }
468  if (!DifferentPtrness) {
469  auto RecFrom = From->getAs<RecordType>();
470  auto RecTo = To->getAs<RecordType>();
471  if (RecFrom && RecTo) {
472  auto DeclFrom = RecFrom->getAsCXXRecordDecl();
473  if (!DeclFrom->isCompleteDefinition())
474  S.Diag(DeclFrom->getLocation(), diag::note_type_incomplete)
475  << DeclFrom->getDeclName();
476  auto DeclTo = RecTo->getAsCXXRecordDecl();
477  if (!DeclTo->isCompleteDefinition())
478  S.Diag(DeclTo->getLocation(), diag::note_type_incomplete)
479  << DeclTo->getDeclName();
480  }
481  }
482 }
483 
484 namespace {
485 /// The kind of unwrapping we did when determining whether a conversion casts
486 /// away constness.
488  /// The conversion does not cast away constness.
489  CACK_None = 0,
490  /// We unwrapped similar types.
491  CACK_Similar = 1,
492  /// We unwrapped dissimilar types with similar representations (eg, a pointer
493  /// versus an Objective-C object pointer).
494  CACK_SimilarKind = 2,
495  /// We unwrapped representationally-unrelated types, such as a pointer versus
496  /// a pointer-to-member.
497  CACK_Incoherent = 3,
498 };
499 }
500 
501 /// Unwrap one level of types for CastsAwayConstness.
502 ///
503 /// Like Sema::UnwrapSimilarTypes, this removes one level of indirection from
504 /// both types, provided that they're both pointer-like or array-like. Unlike
505 /// the Sema function, doesn't care if the unwrapped pieces are related.
506 ///
507 /// This function may remove additional levels as necessary for correctness:
508 /// the resulting T1 is unwrapped sufficiently that it is never an array type,
509 /// so that its qualifiers can be directly compared to those of T2 (which will
510 /// have the combined set of qualifiers from all indermediate levels of T2),
511 /// as (effectively) required by [expr.const.cast]p7 replacing T1's qualifiers
512 /// with those from T2.
515  enum { None, Ptr, MemPtr, BlockPtr, Array };
516  auto Classify = [](QualType T) {
517  if (T->isAnyPointerType()) return Ptr;
518  if (T->isMemberPointerType()) return MemPtr;
519  if (T->isBlockPointerType()) return BlockPtr;
520  // We somewhat-arbitrarily don't look through VLA types here. This is at
521  // least consistent with the behavior of UnwrapSimilarTypes.
522  if (T->isConstantArrayType() || T->isIncompleteArrayType()) return Array;
523  return None;
524  };
525 
526  auto Unwrap = [&](QualType T) {
527  if (auto *AT = Context.getAsArrayType(T))
528  return AT->getElementType();
529  return T->getPointeeType();
530  };
531 
533 
534  if (T2->isReferenceType()) {
535  // Special case: if the destination type is a reference type, unwrap it as
536  // the first level. (The source will have been an lvalue expression in this
537  // case, so there is no corresponding "reference to" in T1 to remove.) This
538  // simulates removing a "pointer to" from both sides.
539  T2 = T2->getPointeeType();
540  Kind = CastAwayConstnessKind::CACK_Similar;
541  } else if (Context.UnwrapSimilarTypes(T1, T2)) {
542  Kind = CastAwayConstnessKind::CACK_Similar;
543  } else {
544  // Try unwrapping mismatching levels.
545  int T1Class = Classify(T1);
546  if (T1Class == None)
547  return CastAwayConstnessKind::CACK_None;
548 
549  int T2Class = Classify(T2);
550  if (T2Class == None)
551  return CastAwayConstnessKind::CACK_None;
552 
553  T1 = Unwrap(T1);
554  T2 = Unwrap(T2);
555  Kind = T1Class == T2Class ? CastAwayConstnessKind::CACK_SimilarKind
556  : CastAwayConstnessKind::CACK_Incoherent;
557  }
558 
559  // We've unwrapped at least one level. If the resulting T1 is a (possibly
560  // multidimensional) array type, any qualifier on any matching layer of
561  // T2 is considered to correspond to T1. Decompose down to the element
562  // type of T1 so that we can compare properly.
563  while (true) {
564  Context.UnwrapSimilarArrayTypes(T1, T2);
565 
566  if (Classify(T1) != Array)
567  break;
568 
569  auto T2Class = Classify(T2);
570  if (T2Class == None)
571  break;
572 
573  if (T2Class != Array)
574  Kind = CastAwayConstnessKind::CACK_Incoherent;
575  else if (Kind != CastAwayConstnessKind::CACK_Incoherent)
576  Kind = CastAwayConstnessKind::CACK_SimilarKind;
577 
578  T1 = Unwrap(T1);
579  T2 = Unwrap(T2).withCVRQualifiers(T2.getCVRQualifiers());
580  }
581 
582  return Kind;
583 }
584 
585 /// Check if the pointer conversion from SrcType to DestType casts away
586 /// constness as defined in C++ [expr.const.cast]. This is used by the cast
587 /// checkers. Both arguments must denote pointer (possibly to member) types.
588 ///
589 /// \param CheckCVR Whether to check for const/volatile/restrict qualifiers.
590 /// \param CheckObjCLifetime Whether to check Objective-C lifetime qualifiers.
592 CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType,
593  bool CheckCVR, bool CheckObjCLifetime,
594  QualType *TheOffendingSrcType = nullptr,
595  QualType *TheOffendingDestType = nullptr,
596  Qualifiers *CastAwayQualifiers = nullptr) {
597  // If the only checking we care about is for Objective-C lifetime qualifiers,
598  // and we're not in ObjC mode, there's nothing to check.
599  if (!CheckCVR && CheckObjCLifetime && !Self.Context.getLangOpts().ObjC)
600  return CastAwayConstnessKind::CACK_None;
601 
602  if (!DestType->isReferenceType()) {
603  assert((SrcType->isAnyPointerType() || SrcType->isMemberPointerType() ||
604  SrcType->isBlockPointerType()) &&
605  "Source type is not pointer or pointer to member.");
606  assert((DestType->isAnyPointerType() || DestType->isMemberPointerType() ||
607  DestType->isBlockPointerType()) &&
608  "Destination type is not pointer or pointer to member.");
609  }
610 
611  QualType UnwrappedSrcType = Self.Context.getCanonicalType(SrcType),
612  UnwrappedDestType = Self.Context.getCanonicalType(DestType);
613 
614  // Find the qualifiers. We only care about cvr-qualifiers for the
615  // purpose of this check, because other qualifiers (address spaces,
616  // Objective-C GC, etc.) are part of the type's identity.
617  QualType PrevUnwrappedSrcType = UnwrappedSrcType;
618  QualType PrevUnwrappedDestType = UnwrappedDestType;
619  auto WorstKind = CastAwayConstnessKind::CACK_Similar;
620  bool AllConstSoFar = true;
621  while (auto Kind = unwrapCastAwayConstnessLevel(
622  Self.Context, UnwrappedSrcType, UnwrappedDestType)) {
623  // Track the worst kind of unwrap we needed to do before we found a
624  // problem.
625  if (Kind > WorstKind)
626  WorstKind = Kind;
627 
628  // Determine the relevant qualifiers at this level.
629  Qualifiers SrcQuals, DestQuals;
630  Self.Context.getUnqualifiedArrayType(UnwrappedSrcType, SrcQuals);
631  Self.Context.getUnqualifiedArrayType(UnwrappedDestType, DestQuals);
632 
633  // We do not meaningfully track object const-ness of Objective-C object
634  // types. Remove const from the source type if either the source or
635  // the destination is an Objective-C object type.
636  if (UnwrappedSrcType->isObjCObjectType() ||
637  UnwrappedDestType->isObjCObjectType())
638  SrcQuals.removeConst();
639 
640  if (CheckCVR) {
641  Qualifiers SrcCvrQuals =
643  Qualifiers DestCvrQuals =
645 
646  if (SrcCvrQuals != DestCvrQuals) {
647  if (CastAwayQualifiers)
648  *CastAwayQualifiers = SrcCvrQuals - DestCvrQuals;
649 
650  // If we removed a cvr-qualifier, this is casting away 'constness'.
651  if (!DestCvrQuals.compatiblyIncludes(SrcCvrQuals)) {
652  if (TheOffendingSrcType)
653  *TheOffendingSrcType = PrevUnwrappedSrcType;
654  if (TheOffendingDestType)
655  *TheOffendingDestType = PrevUnwrappedDestType;
656  return WorstKind;
657  }
658 
659  // If any prior level was not 'const', this is also casting away
660  // 'constness'. We noted the outermost type missing a 'const' already.
661  if (!AllConstSoFar)
662  return WorstKind;
663  }
664  }
665 
666  if (CheckObjCLifetime &&
667  !DestQuals.compatiblyIncludesObjCLifetime(SrcQuals))
668  return WorstKind;
669 
670  // If we found our first non-const-qualified type, this may be the place
671  // where things start to go wrong.
672  if (AllConstSoFar && !DestQuals.hasConst()) {
673  AllConstSoFar = false;
674  if (TheOffendingSrcType)
675  *TheOffendingSrcType = PrevUnwrappedSrcType;
676  if (TheOffendingDestType)
677  *TheOffendingDestType = PrevUnwrappedDestType;
678  }
679 
680  PrevUnwrappedSrcType = UnwrappedSrcType;
681  PrevUnwrappedDestType = UnwrappedDestType;
682  }
683 
684  return CastAwayConstnessKind::CACK_None;
685 }
686 
688  unsigned &DiagID) {
689  switch (CACK) {
690  case CastAwayConstnessKind::CACK_None:
691  llvm_unreachable("did not cast away constness");
692 
693  case CastAwayConstnessKind::CACK_Similar:
694  // FIXME: Accept these as an extension too?
695  case CastAwayConstnessKind::CACK_SimilarKind:
696  DiagID = diag::err_bad_cxx_cast_qualifiers_away;
697  return TC_Failed;
698 
699  case CastAwayConstnessKind::CACK_Incoherent:
700  DiagID = diag::ext_bad_cxx_cast_qualifiers_away_incoherent;
701  return TC_Extension;
702  }
703 
704  llvm_unreachable("unexpected cast away constness kind");
705 }
706 
707 /// CheckDynamicCast - Check that a dynamic_cast<DestType>(SrcExpr) is valid.
708 /// Refer to C++ 5.2.7 for details. Dynamic casts are used mostly for runtime-
709 /// checked downcasts in class hierarchies.
710 void CastOperation::CheckDynamicCast() {
711  if (ValueKind == VK_RValue)
712  SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
713  else if (isPlaceholder())
714  SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.get());
715  if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
716  return;
717 
718  QualType OrigSrcType = SrcExpr.get()->getType();
719  QualType DestType = Self.Context.getCanonicalType(this->DestType);
720 
721  // C++ 5.2.7p1: T shall be a pointer or reference to a complete class type,
722  // or "pointer to cv void".
723 
724  QualType DestPointee;
725  const PointerType *DestPointer = DestType->getAs<PointerType>();
726  const ReferenceType *DestReference = nullptr;
727  if (DestPointer) {
728  DestPointee = DestPointer->getPointeeType();
729  } else if ((DestReference = DestType->getAs<ReferenceType>())) {
730  DestPointee = DestReference->getPointeeType();
731  } else {
732  Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ref_or_ptr)
733  << this->DestType << DestRange;
734  SrcExpr = ExprError();
735  return;
736  }
737 
738  const RecordType *DestRecord = DestPointee->getAs<RecordType>();
739  if (DestPointee->isVoidType()) {
740  assert(DestPointer && "Reference to void is not possible");
741  } else if (DestRecord) {
742  if (Self.RequireCompleteType(OpRange.getBegin(), DestPointee,
743  diag::err_bad_dynamic_cast_incomplete,
744  DestRange)) {
745  SrcExpr = ExprError();
746  return;
747  }
748  } else {
749  Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
750  << DestPointee.getUnqualifiedType() << DestRange;
751  SrcExpr = ExprError();
752  return;
753  }
754 
755  // C++0x 5.2.7p2: If T is a pointer type, v shall be an rvalue of a pointer to
756  // complete class type, [...]. If T is an lvalue reference type, v shall be
757  // an lvalue of a complete class type, [...]. If T is an rvalue reference
758  // type, v shall be an expression having a complete class type, [...]
759  QualType SrcType = Self.Context.getCanonicalType(OrigSrcType);
760  QualType SrcPointee;
761  if (DestPointer) {
762  if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
763  SrcPointee = SrcPointer->getPointeeType();
764  } else {
765  Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ptr)
766  << OrigSrcType << SrcExpr.get()->getSourceRange();
767  SrcExpr = ExprError();
768  return;
769  }
770  } else if (DestReference->isLValueReferenceType()) {
771  if (!SrcExpr.get()->isLValue()) {
772  Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
773  << CT_Dynamic << OrigSrcType << this->DestType << OpRange;
774  }
775  SrcPointee = SrcType;
776  } else {
777  // If we're dynamic_casting from a prvalue to an rvalue reference, we need
778  // to materialize the prvalue before we bind the reference to it.
779  if (SrcExpr.get()->isRValue())
780  SrcExpr = Self.CreateMaterializeTemporaryExpr(
781  SrcType, SrcExpr.get(), /*IsLValueReference*/ false);
782  SrcPointee = SrcType;
783  }
784 
785  const RecordType *SrcRecord = SrcPointee->getAs<RecordType>();
786  if (SrcRecord) {
787  if (Self.RequireCompleteType(OpRange.getBegin(), SrcPointee,
788  diag::err_bad_dynamic_cast_incomplete,
789  SrcExpr.get())) {
790  SrcExpr = ExprError();
791  return;
792  }
793  } else {
794  Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
795  << SrcPointee.getUnqualifiedType() << SrcExpr.get()->getSourceRange();
796  SrcExpr = ExprError();
797  return;
798  }
799 
800  assert((DestPointer || DestReference) &&
801  "Bad destination non-ptr/ref slipped through.");
802  assert((DestRecord || DestPointee->isVoidType()) &&
803  "Bad destination pointee slipped through.");
804  assert(SrcRecord && "Bad source pointee slipped through.");
805 
806  // C++ 5.2.7p1: The dynamic_cast operator shall not cast away constness.
807  if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
808  Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_qualifiers_away)
809  << CT_Dynamic << OrigSrcType << this->DestType << OpRange;
810  SrcExpr = ExprError();
811  return;
812  }
813 
814  // C++ 5.2.7p3: If the type of v is the same as the required result type,
815  // [except for cv].
816  if (DestRecord == SrcRecord) {
817  Kind = CK_NoOp;
818  return;
819  }
820 
821  // C++ 5.2.7p5
822  // Upcasts are resolved statically.
823  if (DestRecord &&
824  Self.IsDerivedFrom(OpRange.getBegin(), SrcPointee, DestPointee)) {
825  if (Self.CheckDerivedToBaseConversion(SrcPointee, DestPointee,
826  OpRange.getBegin(), OpRange,
827  &BasePath)) {
828  SrcExpr = ExprError();
829  return;
830  }
831 
832  Kind = CK_DerivedToBase;
833  return;
834  }
835 
836  // C++ 5.2.7p6: Otherwise, v shall be [polymorphic].
837  const RecordDecl *SrcDecl = SrcRecord->getDecl()->getDefinition();
838  assert(SrcDecl && "Definition missing");
839  if (!cast<CXXRecordDecl>(SrcDecl)->isPolymorphic()) {
840  Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_polymorphic)
841  << SrcPointee.getUnqualifiedType() << SrcExpr.get()->getSourceRange();
842  SrcExpr = ExprError();
843  }
844 
845  // dynamic_cast is not available with -fno-rtti.
846  // As an exception, dynamic_cast to void* is available because it doesn't
847  // use RTTI.
848  if (!Self.getLangOpts().RTTI && !DestPointee->isVoidType()) {
849  Self.Diag(OpRange.getBegin(), diag::err_no_dynamic_cast_with_fno_rtti);
850  SrcExpr = ExprError();
851  return;
852  }
853 
854  // Done. Everything else is run-time checks.
855  Kind = CK_Dynamic;
856 }
857 
858 /// CheckConstCast - Check that a const_cast<DestType>(SrcExpr) is valid.
859 /// Refer to C++ 5.2.11 for details. const_cast is typically used in code
860 /// like this:
861 /// const char *str = "literal";
862 /// legacy_function(const_cast<char*>(str));
863 void CastOperation::CheckConstCast() {
864  if (ValueKind == VK_RValue)
865  SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
866  else if (isPlaceholder())
867  SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.get());
868  if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
869  return;
870 
871  unsigned msg = diag::err_bad_cxx_cast_generic;
872  auto TCR = TryConstCast(Self, SrcExpr, DestType, /*CStyle*/ false, msg);
873  if (TCR != TC_Success && msg != 0) {
874  Self.Diag(OpRange.getBegin(), msg) << CT_Const
875  << SrcExpr.get()->getType() << DestType << OpRange;
876  }
877  if (!isValidCast(TCR))
878  SrcExpr = ExprError();
879 }
880 
881 /// Check that a reinterpret_cast<DestType>(SrcExpr) is not used as upcast
882 /// or downcast between respective pointers or references.
883 static void DiagnoseReinterpretUpDownCast(Sema &Self, const Expr *SrcExpr,
884  QualType DestType,
885  SourceRange OpRange) {
886  QualType SrcType = SrcExpr->getType();
887  // When casting from pointer or reference, get pointee type; use original
888  // type otherwise.
889  const CXXRecordDecl *SrcPointeeRD = SrcType->getPointeeCXXRecordDecl();
890  const CXXRecordDecl *SrcRD =
891  SrcPointeeRD ? SrcPointeeRD : SrcType->getAsCXXRecordDecl();
892 
893  // Examining subobjects for records is only possible if the complete and
894  // valid definition is available. Also, template instantiation is not
895  // allowed here.
896  if (!SrcRD || !SrcRD->isCompleteDefinition() || SrcRD->isInvalidDecl())
897  return;
898 
899  const CXXRecordDecl *DestRD = DestType->getPointeeCXXRecordDecl();
900 
901  if (!DestRD || !DestRD->isCompleteDefinition() || DestRD->isInvalidDecl())
902  return;
903 
904  enum {
905  ReinterpretUpcast,
906  ReinterpretDowncast
907  } ReinterpretKind;
908 
909  CXXBasePaths BasePaths;
910 
911  if (SrcRD->isDerivedFrom(DestRD, BasePaths))
912  ReinterpretKind = ReinterpretUpcast;
913  else if (DestRD->isDerivedFrom(SrcRD, BasePaths))
914  ReinterpretKind = ReinterpretDowncast;
915  else
916  return;
917 
918  bool VirtualBase = true;
919  bool NonZeroOffset = false;
920  for (CXXBasePaths::const_paths_iterator I = BasePaths.begin(),
921  E = BasePaths.end();
922  I != E; ++I) {
923  const CXXBasePath &Path = *I;
925  bool IsVirtual = false;
926  for (CXXBasePath::const_iterator IElem = Path.begin(), EElem = Path.end();
927  IElem != EElem; ++IElem) {
928  IsVirtual = IElem->Base->isVirtual();
929  if (IsVirtual)
930  break;
931  const CXXRecordDecl *BaseRD = IElem->Base->getType()->getAsCXXRecordDecl();
932  assert(BaseRD && "Base type should be a valid unqualified class type");
933  // Don't check if any base has invalid declaration or has no definition
934  // since it has no layout info.
935  const CXXRecordDecl *Class = IElem->Class,
936  *ClassDefinition = Class->getDefinition();
937  if (Class->isInvalidDecl() || !ClassDefinition ||
938  !ClassDefinition->isCompleteDefinition())
939  return;
940 
941  const ASTRecordLayout &DerivedLayout =
942  Self.Context.getASTRecordLayout(Class);
943  Offset += DerivedLayout.getBaseClassOffset(BaseRD);
944  }
945  if (!IsVirtual) {
946  // Don't warn if any path is a non-virtually derived base at offset zero.
947  if (Offset.isZero())
948  return;
949  // Offset makes sense only for non-virtual bases.
950  else
951  NonZeroOffset = true;
952  }
953  VirtualBase = VirtualBase && IsVirtual;
954  }
955 
956  (void) NonZeroOffset; // Silence set but not used warning.
957  assert((VirtualBase || NonZeroOffset) &&
958  "Should have returned if has non-virtual base with zero offset");
959 
960  QualType BaseType =
961  ReinterpretKind == ReinterpretUpcast? DestType : SrcType;
962  QualType DerivedType =
963  ReinterpretKind == ReinterpretUpcast? SrcType : DestType;
964 
965  SourceLocation BeginLoc = OpRange.getBegin();
966  Self.Diag(BeginLoc, diag::warn_reinterpret_different_from_static)
967  << DerivedType << BaseType << !VirtualBase << int(ReinterpretKind)
968  << OpRange;
969  Self.Diag(BeginLoc, diag::note_reinterpret_updowncast_use_static)
970  << int(ReinterpretKind)
971  << FixItHint::CreateReplacement(BeginLoc, "static_cast");
972 }
973 
974 /// CheckReinterpretCast - Check that a reinterpret_cast<DestType>(SrcExpr) is
975 /// valid.
976 /// Refer to C++ 5.2.10 for details. reinterpret_cast is typically used in code
977 /// like this:
978 /// char *bytes = reinterpret_cast<char*>(int_ptr);
979 void CastOperation::CheckReinterpretCast() {
980  if (ValueKind == VK_RValue && !isPlaceholder(BuiltinType::Overload))
981  SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
982  else
983  checkNonOverloadPlaceholders();
984  if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
985  return;
986 
987  unsigned msg = diag::err_bad_cxx_cast_generic;
988  TryCastResult tcr =
989  TryReinterpretCast(Self, SrcExpr, DestType,
990  /*CStyle*/false, OpRange, msg, Kind);
991  if (tcr != TC_Success && msg != 0) {
992  if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
993  return;
994  if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
995  //FIXME: &f<int>; is overloaded and resolvable
996  Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_overload)
997  << OverloadExpr::find(SrcExpr.get()).Expression->getName()
998  << DestType << OpRange;
999  Self.NoteAllOverloadCandidates(SrcExpr.get());
1000 
1001  } else {
1002  diagnoseBadCast(Self, msg, CT_Reinterpret, OpRange, SrcExpr.get(),
1003  DestType, /*listInitialization=*/false);
1004  }
1005  }
1006 
1007  if (isValidCast(tcr)) {
1009  checkObjCConversion(Sema::CCK_OtherCast);
1010  DiagnoseReinterpretUpDownCast(Self, SrcExpr.get(), DestType, OpRange);
1011  } else {
1012  SrcExpr = ExprError();
1013  }
1014 }
1015 
1016 
1017 /// CheckStaticCast - Check that a static_cast<DestType>(SrcExpr) is valid.
1018 /// Refer to C++ 5.2.9 for details. Static casts are mostly used for making
1019 /// implicit conversions explicit and getting rid of data loss warnings.
1020 void CastOperation::CheckStaticCast() {
1021  if (isPlaceholder()) {
1022  checkNonOverloadPlaceholders();
1023  if (SrcExpr.isInvalid())
1024  return;
1025  }
1026 
1027  // This test is outside everything else because it's the only case where
1028  // a non-lvalue-reference target type does not lead to decay.
1029  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
1030  if (DestType->isVoidType()) {
1031  Kind = CK_ToVoid;
1032 
1033  if (claimPlaceholder(BuiltinType::Overload)) {
1035  false, // Decay Function to ptr
1036  true, // Complain
1037  OpRange, DestType, diag::err_bad_static_cast_overload);
1038  if (SrcExpr.isInvalid())
1039  return;
1040  }
1041 
1042  SrcExpr = Self.IgnoredValueConversions(SrcExpr.get());
1043  return;
1044  }
1045 
1046  if (ValueKind == VK_RValue && !DestType->isRecordType() &&
1047  !isPlaceholder(BuiltinType::Overload)) {
1048  SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
1049  if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
1050  return;
1051  }
1052 
1053  unsigned msg = diag::err_bad_cxx_cast_generic;
1054  TryCastResult tcr
1055  = TryStaticCast(Self, SrcExpr, DestType, Sema::CCK_OtherCast, OpRange, msg,
1056  Kind, BasePath, /*ListInitialization=*/false);
1057  if (tcr != TC_Success && msg != 0) {
1058  if (SrcExpr.isInvalid())
1059  return;
1060  if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
1061  OverloadExpr* oe = OverloadExpr::find(SrcExpr.get()).Expression;
1062  Self.Diag(OpRange.getBegin(), diag::err_bad_static_cast_overload)
1063  << oe->getName() << DestType << OpRange
1064  << oe->getQualifierLoc().getSourceRange();
1065  Self.NoteAllOverloadCandidates(SrcExpr.get());
1066  } else {
1067  diagnoseBadCast(Self, msg, CT_Static, OpRange, SrcExpr.get(), DestType,
1068  /*listInitialization=*/false);
1069  }
1070  }
1071 
1072  if (isValidCast(tcr)) {
1073  if (Kind == CK_BitCast)
1074  checkCastAlign();
1076  checkObjCConversion(Sema::CCK_OtherCast);
1077  } else {
1078  SrcExpr = ExprError();
1079  }
1080 }
1081 
1082 static bool IsAddressSpaceConversion(QualType SrcType, QualType DestType) {
1083  auto *SrcPtrType = SrcType->getAs<PointerType>();
1084  if (!SrcPtrType)
1085  return false;
1086  auto *DestPtrType = DestType->getAs<PointerType>();
1087  if (!DestPtrType)
1088  return false;
1089  return SrcPtrType->getPointeeType().getAddressSpace() !=
1090  DestPtrType->getPointeeType().getAddressSpace();
1091 }
1092 
1093 /// TryStaticCast - Check if a static cast can be performed, and do so if
1094 /// possible. If @p CStyle, ignore access restrictions on hierarchy casting
1095 /// and casting away constness.
1097  QualType DestType,
1099  SourceRange OpRange, unsigned &msg,
1100  CastKind &Kind, CXXCastPath &BasePath,
1101  bool ListInitialization) {
1102  // Determine whether we have the semantics of a C-style cast.
1103  bool CStyle
1104  = (CCK == Sema::CCK_CStyleCast || CCK == Sema::CCK_FunctionalCast);
1105 
1106  // The order the tests is not entirely arbitrary. There is one conversion
1107  // that can be handled in two different ways. Given:
1108  // struct A {};
1109  // struct B : public A {
1110  // B(); B(const A&);
1111  // };
1112  // const A &a = B();
1113  // the cast static_cast<const B&>(a) could be seen as either a static
1114  // reference downcast, or an explicit invocation of the user-defined
1115  // conversion using B's conversion constructor.
1116  // DR 427 specifies that the downcast is to be applied here.
1117 
1118  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
1119  // Done outside this function.
1120 
1121  TryCastResult tcr;
1122 
1123  // C++ 5.2.9p5, reference downcast.
1124  // See the function for details.
1125  // DR 427 specifies that this is to be applied before paragraph 2.
1126  tcr = TryStaticReferenceDowncast(Self, SrcExpr.get(), DestType, CStyle,
1127  OpRange, msg, Kind, BasePath);
1128  if (tcr != TC_NotApplicable)
1129  return tcr;
1130 
1131  // C++11 [expr.static.cast]p3:
1132  // A glvalue of type "cv1 T1" can be cast to type "rvalue reference to cv2
1133  // T2" if "cv2 T2" is reference-compatible with "cv1 T1".
1134  tcr = TryLValueToRValueCast(Self, SrcExpr.get(), DestType, CStyle, Kind,
1135  BasePath, msg);
1136  if (tcr != TC_NotApplicable)
1137  return tcr;
1138 
1139  // C++ 5.2.9p2: An expression e can be explicitly converted to a type T
1140  // [...] if the declaration "T t(e);" is well-formed, [...].
1141  tcr = TryStaticImplicitCast(Self, SrcExpr, DestType, CCK, OpRange, msg,
1142  Kind, ListInitialization);
1143  if (SrcExpr.isInvalid())
1144  return TC_Failed;
1145  if (tcr != TC_NotApplicable)
1146  return tcr;
1147 
1148  // C++ 5.2.9p6: May apply the reverse of any standard conversion, except
1149  // lvalue-to-rvalue, array-to-pointer, function-to-pointer, and boolean
1150  // conversions, subject to further restrictions.
1151  // Also, C++ 5.2.9p1 forbids casting away constness, which makes reversal
1152  // of qualification conversions impossible.
1153  // In the CStyle case, the earlier attempt to const_cast should have taken
1154  // care of reverse qualification conversions.
1155 
1156  QualType SrcType = Self.Context.getCanonicalType(SrcExpr.get()->getType());
1157 
1158  // C++0x 5.2.9p9: A value of a scoped enumeration type can be explicitly
1159  // converted to an integral type. [...] A value of a scoped enumeration type
1160  // can also be explicitly converted to a floating-point type [...].
1161  if (const EnumType *Enum = SrcType->getAs<EnumType>()) {
1162  if (Enum->getDecl()->isScoped()) {
1163  if (DestType->isBooleanType()) {
1164  Kind = CK_IntegralToBoolean;
1165  return TC_Success;
1166  } else if (DestType->isIntegralType(Self.Context)) {
1167  Kind = CK_IntegralCast;
1168  return TC_Success;
1169  } else if (DestType->isRealFloatingType()) {
1170  Kind = CK_IntegralToFloating;
1171  return TC_Success;
1172  }
1173  }
1174  }
1175 
1176  // Reverse integral promotion/conversion. All such conversions are themselves
1177  // again integral promotions or conversions and are thus already handled by
1178  // p2 (TryDirectInitialization above).
1179  // (Note: any data loss warnings should be suppressed.)
1180  // The exception is the reverse of enum->integer, i.e. integer->enum (and
1181  // enum->enum). See also C++ 5.2.9p7.
1182  // The same goes for reverse floating point promotion/conversion and
1183  // floating-integral conversions. Again, only floating->enum is relevant.
1184  if (DestType->isEnumeralType()) {
1185  if (SrcType->isIntegralOrEnumerationType()) {
1186  Kind = CK_IntegralCast;
1187  return TC_Success;
1188  } else if (SrcType->isRealFloatingType()) {
1189  Kind = CK_FloatingToIntegral;
1190  return TC_Success;
1191  }
1192  }
1193 
1194  // Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
1195  // C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
1196  tcr = TryStaticPointerDowncast(Self, SrcType, DestType, CStyle, OpRange, msg,
1197  Kind, BasePath);
1198  if (tcr != TC_NotApplicable)
1199  return tcr;
1200 
1201  // Reverse member pointer conversion. C++ 4.11 specifies member pointer
1202  // conversion. C++ 5.2.9p9 has additional information.
1203  // DR54's access restrictions apply here also.
1204  tcr = TryStaticMemberPointerUpcast(Self, SrcExpr, SrcType, DestType, CStyle,
1205  OpRange, msg, Kind, BasePath);
1206  if (tcr != TC_NotApplicable)
1207  return tcr;
1208 
1209  // Reverse pointer conversion to void*. C++ 4.10.p2 specifies conversion to
1210  // void*. C++ 5.2.9p10 specifies additional restrictions, which really is
1211  // just the usual constness stuff.
1212  if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
1213  QualType SrcPointee = SrcPointer->getPointeeType();
1214  if (SrcPointee->isVoidType()) {
1215  if (const PointerType *DestPointer = DestType->getAs<PointerType>()) {
1216  QualType DestPointee = DestPointer->getPointeeType();
1217  if (DestPointee->isIncompleteOrObjectType()) {
1218  // This is definitely the intended conversion, but it might fail due
1219  // to a qualifier violation. Note that we permit Objective-C lifetime
1220  // and GC qualifier mismatches here.
1221  if (!CStyle) {
1222  Qualifiers DestPointeeQuals = DestPointee.getQualifiers();
1223  Qualifiers SrcPointeeQuals = SrcPointee.getQualifiers();
1224  DestPointeeQuals.removeObjCGCAttr();
1225  DestPointeeQuals.removeObjCLifetime();
1226  SrcPointeeQuals.removeObjCGCAttr();
1227  SrcPointeeQuals.removeObjCLifetime();
1228  if (DestPointeeQuals != SrcPointeeQuals &&
1229  !DestPointeeQuals.compatiblyIncludes(SrcPointeeQuals)) {
1230  msg = diag::err_bad_cxx_cast_qualifiers_away;
1231  return TC_Failed;
1232  }
1233  }
1234  Kind = IsAddressSpaceConversion(SrcType, DestType)
1235  ? CK_AddressSpaceConversion
1236  : CK_BitCast;
1237  return TC_Success;
1238  }
1239 
1240  // Microsoft permits static_cast from 'pointer-to-void' to
1241  // 'pointer-to-function'.
1242  if (!CStyle && Self.getLangOpts().MSVCCompat &&
1243  DestPointee->isFunctionType()) {
1244  Self.Diag(OpRange.getBegin(), diag::ext_ms_cast_fn_obj) << OpRange;
1245  Kind = CK_BitCast;
1246  return TC_Success;
1247  }
1248  }
1249  else if (DestType->isObjCObjectPointerType()) {
1250  // allow both c-style cast and static_cast of objective-c pointers as
1251  // they are pervasive.
1252  Kind = CK_CPointerToObjCPointerCast;
1253  return TC_Success;
1254  }
1255  else if (CStyle && DestType->isBlockPointerType()) {
1256  // allow c-style cast of void * to block pointers.
1257  Kind = CK_AnyPointerToBlockPointerCast;
1258  return TC_Success;
1259  }
1260  }
1261  }
1262  // Allow arbitrary objective-c pointer conversion with static casts.
1263  if (SrcType->isObjCObjectPointerType() &&
1264  DestType->isObjCObjectPointerType()) {
1265  Kind = CK_BitCast;
1266  return TC_Success;
1267  }
1268  // Allow ns-pointer to cf-pointer conversion in either direction
1269  // with static casts.
1270  if (!CStyle &&
1271  Self.CheckTollFreeBridgeStaticCast(DestType, SrcExpr.get(), Kind))
1272  return TC_Success;
1273 
1274  // See if it looks like the user is trying to convert between
1275  // related record types, and select a better diagnostic if so.
1276  if (auto SrcPointer = SrcType->getAs<PointerType>())
1277  if (auto DestPointer = DestType->getAs<PointerType>())
1278  if (SrcPointer->getPointeeType()->getAs<RecordType>() &&
1279  DestPointer->getPointeeType()->getAs<RecordType>())
1280  msg = diag::err_bad_cxx_cast_unrelated_class;
1281 
1282  // We tried everything. Everything! Nothing works! :-(
1283  return TC_NotApplicable;
1284 }
1285 
1286 /// Tests whether a conversion according to N2844 is valid.
1288  QualType DestType, bool CStyle,
1289  CastKind &Kind, CXXCastPath &BasePath,
1290  unsigned &msg) {
1291  // C++11 [expr.static.cast]p3:
1292  // A glvalue of type "cv1 T1" can be cast to type "rvalue reference to
1293  // cv2 T2" if "cv2 T2" is reference-compatible with "cv1 T1".
1294  const RValueReferenceType *R = DestType->getAs<RValueReferenceType>();
1295  if (!R)
1296  return TC_NotApplicable;
1297 
1298  if (!SrcExpr->isGLValue())
1299  return TC_NotApplicable;
1300 
1301  // Because we try the reference downcast before this function, from now on
1302  // this is the only cast possibility, so we issue an error if we fail now.
1303  // FIXME: Should allow casting away constness if CStyle.
1304  bool DerivedToBase;
1305  bool ObjCConversion;
1306  bool ObjCLifetimeConversion;
1307  QualType FromType = SrcExpr->getType();
1308  QualType ToType = R->getPointeeType();
1309  if (CStyle) {
1310  FromType = FromType.getUnqualifiedType();
1311  ToType = ToType.getUnqualifiedType();
1312  }
1313 
1315  SrcExpr->getBeginLoc(), ToType, FromType, DerivedToBase, ObjCConversion,
1316  ObjCLifetimeConversion);
1317  if (RefResult != Sema::Ref_Compatible) {
1318  if (CStyle || RefResult == Sema::Ref_Incompatible)
1319  return TC_NotApplicable;
1320  // Diagnose types which are reference-related but not compatible here since
1321  // we can provide better diagnostics. In these cases forwarding to
1322  // [expr.static.cast]p4 should never result in a well-formed cast.
1323  msg = SrcExpr->isLValue() ? diag::err_bad_lvalue_to_rvalue_cast
1324  : diag::err_bad_rvalue_to_rvalue_cast;
1325  return TC_Failed;
1326  }
1327 
1328  if (DerivedToBase) {
1329  Kind = CK_DerivedToBase;
1330  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1331  /*DetectVirtual=*/true);
1332  if (!Self.IsDerivedFrom(SrcExpr->getBeginLoc(), SrcExpr->getType(),
1333  R->getPointeeType(), Paths))
1334  return TC_NotApplicable;
1335 
1336  Self.BuildBasePathArray(Paths, BasePath);
1337  } else
1338  Kind = CK_NoOp;
1339 
1340  return TC_Success;
1341 }
1342 
1343 /// Tests whether a conversion according to C++ 5.2.9p5 is valid.
1345 TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr, QualType DestType,
1346  bool CStyle, SourceRange OpRange,
1347  unsigned &msg, CastKind &Kind,
1348  CXXCastPath &BasePath) {
1349  // C++ 5.2.9p5: An lvalue of type "cv1 B", where B is a class type, can be
1350  // cast to type "reference to cv2 D", where D is a class derived from B,
1351  // if a valid standard conversion from "pointer to D" to "pointer to B"
1352  // exists, cv2 >= cv1, and B is not a virtual base class of D.
1353  // In addition, DR54 clarifies that the base must be accessible in the
1354  // current context. Although the wording of DR54 only applies to the pointer
1355  // variant of this rule, the intent is clearly for it to apply to the this
1356  // conversion as well.
1357 
1358  const ReferenceType *DestReference = DestType->getAs<ReferenceType>();
1359  if (!DestReference) {
1360  return TC_NotApplicable;
1361  }
1362  bool RValueRef = DestReference->isRValueReferenceType();
1363  if (!RValueRef && !SrcExpr->isLValue()) {
1364  // We know the left side is an lvalue reference, so we can suggest a reason.
1365  msg = diag::err_bad_cxx_cast_rvalue;
1366  return TC_NotApplicable;
1367  }
1368 
1369  QualType DestPointee = DestReference->getPointeeType();
1370 
1371  // FIXME: If the source is a prvalue, we should issue a warning (because the
1372  // cast always has undefined behavior), and for AST consistency, we should
1373  // materialize a temporary.
1374  return TryStaticDowncast(Self,
1375  Self.Context.getCanonicalType(SrcExpr->getType()),
1376  Self.Context.getCanonicalType(DestPointee), CStyle,
1377  OpRange, SrcExpr->getType(), DestType, msg, Kind,
1378  BasePath);
1379 }
1380 
1381 /// Tests whether a conversion according to C++ 5.2.9p8 is valid.
1384  bool CStyle, SourceRange OpRange,
1385  unsigned &msg, CastKind &Kind,
1386  CXXCastPath &BasePath) {
1387  // C++ 5.2.9p8: An rvalue of type "pointer to cv1 B", where B is a class
1388  // type, can be converted to an rvalue of type "pointer to cv2 D", where D
1389  // is a class derived from B, if a valid standard conversion from "pointer
1390  // to D" to "pointer to B" exists, cv2 >= cv1, and B is not a virtual base
1391  // class of D.
1392  // In addition, DR54 clarifies that the base must be accessible in the
1393  // current context.
1394 
1395  const PointerType *DestPointer = DestType->getAs<PointerType>();
1396  if (!DestPointer) {
1397  return TC_NotApplicable;
1398  }
1399 
1400  const PointerType *SrcPointer = SrcType->getAs<PointerType>();
1401  if (!SrcPointer) {
1402  msg = diag::err_bad_static_cast_pointer_nonpointer;
1403  return TC_NotApplicable;
1404  }
1405 
1406  return TryStaticDowncast(Self,
1407  Self.Context.getCanonicalType(SrcPointer->getPointeeType()),
1408  Self.Context.getCanonicalType(DestPointer->getPointeeType()),
1409  CStyle, OpRange, SrcType, DestType, msg, Kind,
1410  BasePath);
1411 }
1412 
1413 /// TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and
1414 /// TryStaticPointerDowncast. Tests whether a static downcast from SrcType to
1415 /// DestType is possible and allowed.
1418  bool CStyle, SourceRange OpRange, QualType OrigSrcType,
1419  QualType OrigDestType, unsigned &msg,
1420  CastKind &Kind, CXXCastPath &BasePath) {
1421  // We can only work with complete types. But don't complain if it doesn't work
1422  if (!Self.isCompleteType(OpRange.getBegin(), SrcType) ||
1423  !Self.isCompleteType(OpRange.getBegin(), DestType))
1424  return TC_NotApplicable;
1425 
1426  // Downcast can only happen in class hierarchies, so we need classes.
1427  if (!DestType->getAs<RecordType>() || !SrcType->getAs<RecordType>()) {
1428  return TC_NotApplicable;
1429  }
1430 
1431  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1432  /*DetectVirtual=*/true);
1433  if (!Self.IsDerivedFrom(OpRange.getBegin(), DestType, SrcType, Paths)) {
1434  return TC_NotApplicable;
1435  }
1436 
1437  // Target type does derive from source type. Now we're serious. If an error
1438  // appears now, it's not ignored.
1439  // This may not be entirely in line with the standard. Take for example:
1440  // struct A {};
1441  // struct B : virtual A {
1442  // B(A&);
1443  // };
1444  //
1445  // void f()
1446  // {
1447  // (void)static_cast<const B&>(*((A*)0));
1448  // }
1449  // As far as the standard is concerned, p5 does not apply (A is virtual), so
1450  // p2 should be used instead - "const B& t(*((A*)0));" is perfectly valid.
1451  // However, both GCC and Comeau reject this example, and accepting it would
1452  // mean more complex code if we're to preserve the nice error message.
1453  // FIXME: Being 100% compliant here would be nice to have.
1454 
1455  // Must preserve cv, as always, unless we're in C-style mode.
1456  if (!CStyle && !DestType.isAtLeastAsQualifiedAs(SrcType)) {
1457  msg = diag::err_bad_cxx_cast_qualifiers_away;
1458  return TC_Failed;
1459  }
1460 
1461  if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
1462  // This code is analoguous to that in CheckDerivedToBaseConversion, except
1463  // that it builds the paths in reverse order.
1464  // To sum up: record all paths to the base and build a nice string from
1465  // them. Use it to spice up the error message.
1466  if (!Paths.isRecordingPaths()) {
1467  Paths.clear();
1468  Paths.setRecordingPaths(true);
1469  Self.IsDerivedFrom(OpRange.getBegin(), DestType, SrcType, Paths);
1470  }
1471  std::string PathDisplayStr;
1472  std::set<unsigned> DisplayedPaths;
1473  for (clang::CXXBasePath &Path : Paths) {
1474  if (DisplayedPaths.insert(Path.back().SubobjectNumber).second) {
1475  // We haven't displayed a path to this particular base
1476  // class subobject yet.
1477  PathDisplayStr += "\n ";
1478  for (CXXBasePathElement &PE : llvm::reverse(Path))
1479  PathDisplayStr += PE.Base->getType().getAsString() + " -> ";
1480  PathDisplayStr += QualType(DestType).getAsString();
1481  }
1482  }
1483 
1484  Self.Diag(OpRange.getBegin(), diag::err_ambiguous_base_to_derived_cast)
1485  << QualType(SrcType).getUnqualifiedType()
1486  << QualType(DestType).getUnqualifiedType()
1487  << PathDisplayStr << OpRange;
1488  msg = 0;
1489  return TC_Failed;
1490  }
1491 
1492  if (Paths.getDetectedVirtual() != nullptr) {
1493  QualType VirtualBase(Paths.getDetectedVirtual(), 0);
1494  Self.Diag(OpRange.getBegin(), diag::err_static_downcast_via_virtual)
1495  << OrigSrcType << OrigDestType << VirtualBase << OpRange;
1496  msg = 0;
1497  return TC_Failed;
1498  }
1499 
1500  if (!CStyle) {
1501  switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
1502  SrcType, DestType,
1503  Paths.front(),
1504  diag::err_downcast_from_inaccessible_base)) {
1505  case Sema::AR_accessible:
1506  case Sema::AR_delayed: // be optimistic
1507  case Sema::AR_dependent: // be optimistic
1508  break;
1509 
1510  case Sema::AR_inaccessible:
1511  msg = 0;
1512  return TC_Failed;
1513  }
1514  }
1515 
1516  Self.BuildBasePathArray(Paths, BasePath);
1517  Kind = CK_BaseToDerived;
1518  return TC_Success;
1519 }
1520 
1521 /// TryStaticMemberPointerUpcast - Tests whether a conversion according to
1522 /// C++ 5.2.9p9 is valid:
1523 ///
1524 /// An rvalue of type "pointer to member of D of type cv1 T" can be
1525 /// converted to an rvalue of type "pointer to member of B of type cv2 T",
1526 /// where B is a base class of D [...].
1527 ///
1530  QualType DestType, bool CStyle,
1531  SourceRange OpRange,
1532  unsigned &msg, CastKind &Kind,
1533  CXXCastPath &BasePath) {
1534  const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>();
1535  if (!DestMemPtr)
1536  return TC_NotApplicable;
1537 
1538  bool WasOverloadedFunction = false;
1539  DeclAccessPair FoundOverload;
1540  if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
1541  if (FunctionDecl *Fn
1542  = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(), DestType, false,
1543  FoundOverload)) {
1544  CXXMethodDecl *M = cast<CXXMethodDecl>(Fn);
1545  SrcType = Self.Context.getMemberPointerType(Fn->getType(),
1546  Self.Context.getTypeDeclType(M->getParent()).getTypePtr());
1547  WasOverloadedFunction = true;
1548  }
1549  }
1550 
1551  const MemberPointerType *SrcMemPtr = SrcType->getAs<MemberPointerType>();
1552  if (!SrcMemPtr) {
1553  msg = diag::err_bad_static_cast_member_pointer_nonmp;
1554  return TC_NotApplicable;
1555  }
1556 
1557  // Lock down the inheritance model right now in MS ABI, whether or not the
1558  // pointee types are the same.
1559  if (Self.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
1560  (void)Self.isCompleteType(OpRange.getBegin(), SrcType);
1561  (void)Self.isCompleteType(OpRange.getBegin(), DestType);
1562  }
1563 
1564  // T == T, modulo cv
1565  if (!Self.Context.hasSameUnqualifiedType(SrcMemPtr->getPointeeType(),
1566  DestMemPtr->getPointeeType()))
1567  return TC_NotApplicable;
1568 
1569  // B base of D
1570  QualType SrcClass(SrcMemPtr->getClass(), 0);
1571  QualType DestClass(DestMemPtr->getClass(), 0);
1572  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1573  /*DetectVirtual=*/true);
1574  if (!Self.IsDerivedFrom(OpRange.getBegin(), SrcClass, DestClass, Paths))
1575  return TC_NotApplicable;
1576 
1577  // B is a base of D. But is it an allowed base? If not, it's a hard error.
1578  if (Paths.isAmbiguous(Self.Context.getCanonicalType(DestClass))) {
1579  Paths.clear();
1580  Paths.setRecordingPaths(true);
1581  bool StillOkay =
1582  Self.IsDerivedFrom(OpRange.getBegin(), SrcClass, DestClass, Paths);
1583  assert(StillOkay);
1584  (void)StillOkay;
1585  std::string PathDisplayStr = Self.getAmbiguousPathsDisplayString(Paths);
1586  Self.Diag(OpRange.getBegin(), diag::err_ambiguous_memptr_conv)
1587  << 1 << SrcClass << DestClass << PathDisplayStr << OpRange;
1588  msg = 0;
1589  return TC_Failed;
1590  }
1591 
1592  if (const RecordType *VBase = Paths.getDetectedVirtual()) {
1593  Self.Diag(OpRange.getBegin(), diag::err_memptr_conv_via_virtual)
1594  << SrcClass << DestClass << QualType(VBase, 0) << OpRange;
1595  msg = 0;
1596  return TC_Failed;
1597  }
1598 
1599  if (!CStyle) {
1600  switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
1601  DestClass, SrcClass,
1602  Paths.front(),
1603  diag::err_upcast_to_inaccessible_base)) {
1604  case Sema::AR_accessible:
1605  case Sema::AR_delayed:
1606  case Sema::AR_dependent:
1607  // Optimistically assume that the delayed and dependent cases
1608  // will work out.
1609  break;
1610 
1611  case Sema::AR_inaccessible:
1612  msg = 0;
1613  return TC_Failed;
1614  }
1615  }
1616 
1617  if (WasOverloadedFunction) {
1618  // Resolve the address of the overloaded function again, this time
1619  // allowing complaints if something goes wrong.
1621  DestType,
1622  true,
1623  FoundOverload);
1624  if (!Fn) {
1625  msg = 0;
1626  return TC_Failed;
1627  }
1628 
1629  SrcExpr = Self.FixOverloadedFunctionReference(SrcExpr, FoundOverload, Fn);
1630  if (!SrcExpr.isUsable()) {
1631  msg = 0;
1632  return TC_Failed;
1633  }
1634  }
1635 
1636  Self.BuildBasePathArray(Paths, BasePath);
1637  Kind = CK_DerivedToBaseMemberPointer;
1638  return TC_Success;
1639 }
1640 
1641 /// TryStaticImplicitCast - Tests whether a conversion according to C++ 5.2.9p2
1642 /// is valid:
1643 ///
1644 /// An expression e can be explicitly converted to a type T using a
1645 /// @c static_cast if the declaration "T t(e);" is well-formed [...].
1647 TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr, QualType DestType,
1649  SourceRange OpRange, unsigned &msg,
1650  CastKind &Kind, bool ListInitialization) {
1651  if (DestType->isRecordType()) {
1652  if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
1653  diag::err_bad_dynamic_cast_incomplete) ||
1654  Self.RequireNonAbstractType(OpRange.getBegin(), DestType,
1655  diag::err_allocation_of_abstract_type)) {
1656  msg = 0;
1657  return TC_Failed;
1658  }
1659  }
1660 
1662  InitializationKind InitKind
1663  = (CCK == Sema::CCK_CStyleCast)
1664  ? InitializationKind::CreateCStyleCast(OpRange.getBegin(), OpRange,
1665  ListInitialization)
1666  : (CCK == Sema::CCK_FunctionalCast)
1667  ? InitializationKind::CreateFunctionalCast(OpRange, ListInitialization)
1668  : InitializationKind::CreateCast(OpRange);
1669  Expr *SrcExprRaw = SrcExpr.get();
1670  // FIXME: Per DR242, we should check for an implicit conversion sequence
1671  // or for a constructor that could be invoked by direct-initialization
1672  // here, not for an initialization sequence.
1673  InitializationSequence InitSeq(Self, Entity, InitKind, SrcExprRaw);
1674 
1675  // At this point of CheckStaticCast, if the destination is a reference,
1676  // or the expression is an overload expression this has to work.
1677  // There is no other way that works.
1678  // On the other hand, if we're checking a C-style cast, we've still got
1679  // the reinterpret_cast way.
1680  bool CStyle
1681  = (CCK == Sema::CCK_CStyleCast || CCK == Sema::CCK_FunctionalCast);
1682  if (InitSeq.Failed() && (CStyle || !DestType->isReferenceType()))
1683  return TC_NotApplicable;
1684 
1685  ExprResult Result = InitSeq.Perform(Self, Entity, InitKind, SrcExprRaw);
1686  if (Result.isInvalid()) {
1687  msg = 0;
1688  return TC_Failed;
1689  }
1690 
1691  if (InitSeq.isConstructorInitialization())
1692  Kind = CK_ConstructorConversion;
1693  else
1694  Kind = CK_NoOp;
1695 
1696  SrcExpr = Result;
1697  return TC_Success;
1698 }
1699 
1700 /// TryConstCast - See if a const_cast from source to destination is allowed,
1701 /// and perform it if it is.
1703  QualType DestType, bool CStyle,
1704  unsigned &msg) {
1705  DestType = Self.Context.getCanonicalType(DestType);
1706  QualType SrcType = SrcExpr.get()->getType();
1707  bool NeedToMaterializeTemporary = false;
1708 
1709  if (const ReferenceType *DestTypeTmp =DestType->getAs<ReferenceType>()) {
1710  // C++11 5.2.11p4:
1711  // if a pointer to T1 can be explicitly converted to the type "pointer to
1712  // T2" using a const_cast, then the following conversions can also be
1713  // made:
1714  // -- an lvalue of type T1 can be explicitly converted to an lvalue of
1715  // type T2 using the cast const_cast<T2&>;
1716  // -- a glvalue of type T1 can be explicitly converted to an xvalue of
1717  // type T2 using the cast const_cast<T2&&>; and
1718  // -- if T1 is a class type, a prvalue of type T1 can be explicitly
1719  // converted to an xvalue of type T2 using the cast const_cast<T2&&>.
1720 
1721  if (isa<LValueReferenceType>(DestTypeTmp) && !SrcExpr.get()->isLValue()) {
1722  // Cannot const_cast non-lvalue to lvalue reference type. But if this
1723  // is C-style, static_cast might find a way, so we simply suggest a
1724  // message and tell the parent to keep searching.
1725  msg = diag::err_bad_cxx_cast_rvalue;
1726  return TC_NotApplicable;
1727  }
1728 
1729  if (isa<RValueReferenceType>(DestTypeTmp) && SrcExpr.get()->isRValue()) {
1730  if (!SrcType->isRecordType()) {
1731  // Cannot const_cast non-class prvalue to rvalue reference type. But if
1732  // this is C-style, static_cast can do this.
1733  msg = diag::err_bad_cxx_cast_rvalue;
1734  return TC_NotApplicable;
1735  }
1736 
1737  // Materialize the class prvalue so that the const_cast can bind a
1738  // reference to it.
1739  NeedToMaterializeTemporary = true;
1740  }
1741 
1742  // It's not completely clear under the standard whether we can
1743  // const_cast bit-field gl-values. Doing so would not be
1744  // intrinsically complicated, but for now, we say no for
1745  // consistency with other compilers and await the word of the
1746  // committee.
1747  if (SrcExpr.get()->refersToBitField()) {
1748  msg = diag::err_bad_cxx_cast_bitfield;
1749  return TC_NotApplicable;
1750  }
1751 
1752  DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
1753  SrcType = Self.Context.getPointerType(SrcType);
1754  }
1755 
1756  // C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
1757  // the rules for const_cast are the same as those used for pointers.
1758 
1759  if (!DestType->isPointerType() &&
1760  !DestType->isMemberPointerType() &&
1761  !DestType->isObjCObjectPointerType()) {
1762  // Cannot cast to non-pointer, non-reference type. Note that, if DestType
1763  // was a reference type, we converted it to a pointer above.
1764  // The status of rvalue references isn't entirely clear, but it looks like
1765  // conversion to them is simply invalid.
1766  // C++ 5.2.11p3: For two pointer types [...]
1767  if (!CStyle)
1768  msg = diag::err_bad_const_cast_dest;
1769  return TC_NotApplicable;
1770  }
1771  if (DestType->isFunctionPointerType() ||
1772  DestType->isMemberFunctionPointerType()) {
1773  // Cannot cast direct function pointers.
1774  // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
1775  // T is the ultimate pointee of source and target type.
1776  if (!CStyle)
1777  msg = diag::err_bad_const_cast_dest;
1778  return TC_NotApplicable;
1779  }
1780 
1781  // C++ [expr.const.cast]p3:
1782  // "For two similar types T1 and T2, [...]"
1783  //
1784  // We only allow a const_cast to change cvr-qualifiers, not other kinds of
1785  // type qualifiers. (Likewise, we ignore other changes when determining
1786  // whether a cast casts away constness.)
1787  if (!Self.Context.hasCvrSimilarType(SrcType, DestType))
1788  return TC_NotApplicable;
1789 
1790  if (NeedToMaterializeTemporary)
1791  // This is a const_cast from a class prvalue to an rvalue reference type.
1792  // Materialize a temporary to store the result of the conversion.
1793  SrcExpr = Self.CreateMaterializeTemporaryExpr(SrcExpr.get()->getType(),
1794  SrcExpr.get(),
1795  /*IsLValueReference*/ false);
1796 
1797  return TC_Success;
1798 }
1799 
1800 // Checks for undefined behavior in reinterpret_cast.
1801 // The cases that is checked for is:
1802 // *reinterpret_cast<T*>(&a)
1803 // reinterpret_cast<T&>(a)
1804 // where accessing 'a' as type 'T' will result in undefined behavior.
1806  bool IsDereference,
1807  SourceRange Range) {
1808  unsigned DiagID = IsDereference ?
1809  diag::warn_pointer_indirection_from_incompatible_type :
1810  diag::warn_undefined_reinterpret_cast;
1811 
1812  if (Diags.isIgnored(DiagID, Range.getBegin()))
1813  return;
1814 
1815  QualType SrcTy, DestTy;
1816  if (IsDereference) {
1817  if (!SrcType->getAs<PointerType>() || !DestType->getAs<PointerType>()) {
1818  return;
1819  }
1820  SrcTy = SrcType->getPointeeType();
1821  DestTy = DestType->getPointeeType();
1822  } else {
1823  if (!DestType->getAs<ReferenceType>()) {
1824  return;
1825  }
1826  SrcTy = SrcType;
1827  DestTy = DestType->getPointeeType();
1828  }
1829 
1830  // Cast is compatible if the types are the same.
1831  if (Context.hasSameUnqualifiedType(DestTy, SrcTy)) {
1832  return;
1833  }
1834  // or one of the types is a char or void type
1835  if (DestTy->isAnyCharacterType() || DestTy->isVoidType() ||
1836  SrcTy->isAnyCharacterType() || SrcTy->isVoidType()) {
1837  return;
1838  }
1839  // or one of the types is a tag type.
1840  if (SrcTy->getAs<TagType>() || DestTy->getAs<TagType>()) {
1841  return;
1842  }
1843 
1844  // FIXME: Scoped enums?
1845  if ((SrcTy->isUnsignedIntegerType() && DestTy->isSignedIntegerType()) ||
1846  (SrcTy->isSignedIntegerType() && DestTy->isUnsignedIntegerType())) {
1847  if (Context.getTypeSize(DestTy) == Context.getTypeSize(SrcTy)) {
1848  return;
1849  }
1850  }
1851 
1852  Diag(Range.getBegin(), DiagID) << SrcType << DestType << Range;
1853 }
1854 
1855 static void DiagnoseCastOfObjCSEL(Sema &Self, const ExprResult &SrcExpr,
1856  QualType DestType) {
1857  QualType SrcType = SrcExpr.get()->getType();
1858  if (Self.Context.hasSameType(SrcType, DestType))
1859  return;
1860  if (const PointerType *SrcPtrTy = SrcType->getAs<PointerType>())
1861  if (SrcPtrTy->isObjCSelType()) {
1862  QualType DT = DestType;
1863  if (isa<PointerType>(DestType))
1864  DT = DestType->getPointeeType();
1865  if (!DT.getUnqualifiedType()->isVoidType())
1866  Self.Diag(SrcExpr.get()->getExprLoc(),
1867  diag::warn_cast_pointer_from_sel)
1868  << SrcType << DestType << SrcExpr.get()->getSourceRange();
1869  }
1870 }
1871 
1872 /// Diagnose casts that change the calling convention of a pointer to a function
1873 /// defined in the current TU.
1874 static void DiagnoseCallingConvCast(Sema &Self, const ExprResult &SrcExpr,
1875  QualType DstType, SourceRange OpRange) {
1876  // Check if this cast would change the calling convention of a function
1877  // pointer type.
1878  QualType SrcType = SrcExpr.get()->getType();
1879  if (Self.Context.hasSameType(SrcType, DstType) ||
1880  !SrcType->isFunctionPointerType() || !DstType->isFunctionPointerType())
1881  return;
1882  const auto *SrcFTy =
1883  SrcType->castAs<PointerType>()->getPointeeType()->castAs<FunctionType>();
1884  const auto *DstFTy =
1885  DstType->castAs<PointerType>()->getPointeeType()->castAs<FunctionType>();
1886  CallingConv SrcCC = SrcFTy->getCallConv();
1887  CallingConv DstCC = DstFTy->getCallConv();
1888  if (SrcCC == DstCC)
1889  return;
1890 
1891  // We have a calling convention cast. Check if the source is a pointer to a
1892  // known, specific function that has already been defined.
1893  Expr *Src = SrcExpr.get()->IgnoreParenImpCasts();
1894  if (auto *UO = dyn_cast<UnaryOperator>(Src))
1895  if (UO->getOpcode() == UO_AddrOf)
1896  Src = UO->getSubExpr()->IgnoreParenImpCasts();
1897  auto *DRE = dyn_cast<DeclRefExpr>(Src);
1898  if (!DRE)
1899  return;
1900  auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
1901  if (!FD)
1902  return;
1903 
1904  // Only warn if we are casting from the default convention to a non-default
1905  // convention. This can happen when the programmer forgot to apply the calling
1906  // convention to the function declaration and then inserted this cast to
1907  // satisfy the type system.
1909  FD->isVariadic(), FD->isCXXInstanceMember());
1910  if (DstCC == DefaultCC || SrcCC != DefaultCC)
1911  return;
1912 
1913  // Diagnose this cast, as it is probably bad.
1914  StringRef SrcCCName = FunctionType::getNameForCallConv(SrcCC);
1915  StringRef DstCCName = FunctionType::getNameForCallConv(DstCC);
1916  Self.Diag(OpRange.getBegin(), diag::warn_cast_calling_conv)
1917  << SrcCCName << DstCCName << OpRange;
1918 
1919  // The checks above are cheaper than checking if the diagnostic is enabled.
1920  // However, it's worth checking if the warning is enabled before we construct
1921  // a fixit.
1922  if (Self.Diags.isIgnored(diag::warn_cast_calling_conv, OpRange.getBegin()))
1923  return;
1924 
1925  // Try to suggest a fixit to change the calling convention of the function
1926  // whose address was taken. Try to use the latest macro for the convention.
1927  // For example, users probably want to write "WINAPI" instead of "__stdcall"
1928  // to match the Windows header declarations.
1929  SourceLocation NameLoc = FD->getFirstDecl()->getNameInfo().getLoc();
1930  Preprocessor &PP = Self.getPreprocessor();
1931  SmallVector<TokenValue, 6> AttrTokens;
1932  SmallString<64> CCAttrText;
1933  llvm::raw_svector_ostream OS(CCAttrText);
1934  if (Self.getLangOpts().MicrosoftExt) {
1935  // __stdcall or __vectorcall
1936  OS << "__" << DstCCName;
1937  IdentifierInfo *II = PP.getIdentifierInfo(OS.str());
1938  AttrTokens.push_back(II->isKeyword(Self.getLangOpts())
1939  ? TokenValue(II->getTokenID())
1940  : TokenValue(II));
1941  } else {
1942  // __attribute__((stdcall)) or __attribute__((vectorcall))
1943  OS << "__attribute__((" << DstCCName << "))";
1944  AttrTokens.push_back(tok::kw___attribute);
1945  AttrTokens.push_back(tok::l_paren);
1946  AttrTokens.push_back(tok::l_paren);
1947  IdentifierInfo *II = PP.getIdentifierInfo(DstCCName);
1948  AttrTokens.push_back(II->isKeyword(Self.getLangOpts())
1949  ? TokenValue(II->getTokenID())
1950  : TokenValue(II));
1951  AttrTokens.push_back(tok::r_paren);
1952  AttrTokens.push_back(tok::r_paren);
1953  }
1954  StringRef AttrSpelling = PP.getLastMacroWithSpelling(NameLoc, AttrTokens);
1955  if (!AttrSpelling.empty())
1956  CCAttrText = AttrSpelling;
1957  OS << ' ';
1958  Self.Diag(NameLoc, diag::note_change_calling_conv_fixit)
1959  << FD << DstCCName << FixItHint::CreateInsertion(NameLoc, CCAttrText);
1960 }
1961 
1962 static void checkIntToPointerCast(bool CStyle, SourceLocation Loc,
1963  const Expr *SrcExpr, QualType DestType,
1964  Sema &Self) {
1965  QualType SrcType = SrcExpr->getType();
1966 
1967  // Not warning on reinterpret_cast, boolean, constant expressions, etc
1968  // are not explicit design choices, but consistent with GCC's behavior.
1969  // Feel free to modify them if you've reason/evidence for an alternative.
1970  if (CStyle && SrcType->isIntegralType(Self.Context)
1971  && !SrcType->isBooleanType()
1972  && !SrcType->isEnumeralType()
1973  && !SrcExpr->isIntegerConstantExpr(Self.Context)
1974  && Self.Context.getTypeSize(DestType) >
1975  Self.Context.getTypeSize(SrcType)) {
1976  // Separate between casts to void* and non-void* pointers.
1977  // Some APIs use (abuse) void* for something like a user context,
1978  // and often that value is an integer even if it isn't a pointer itself.
1979  // Having a separate warning flag allows users to control the warning
1980  // for their workflow.
1981  unsigned Diag = DestType->isVoidPointerType() ?
1982  diag::warn_int_to_void_pointer_cast
1983  : diag::warn_int_to_pointer_cast;
1984  Self.Diag(Loc, Diag) << SrcType << DestType;
1985  }
1986 }
1987 
1988 static bool fixOverloadedReinterpretCastExpr(Sema &Self, QualType DestType,
1989  ExprResult &Result) {
1990  // We can only fix an overloaded reinterpret_cast if
1991  // - it is a template with explicit arguments that resolves to an lvalue
1992  // unambiguously, or
1993  // - it is the only function in an overload set that may have its address
1994  // taken.
1995 
1996  Expr *E = Result.get();
1997  // TODO: what if this fails because of DiagnoseUseOfDecl or something
1998  // like it?
2000  Result,
2001  Expr::getValueKindForType(DestType) == VK_RValue // Convert Fun to Ptr
2002  ) &&
2003  Result.isUsable())
2004  return true;
2005 
2006  // No guarantees that ResolveAndFixSingleFunctionTemplateSpecialization
2007  // preserves Result.
2008  Result = E;
2010  Result, /*DoFunctionPointerConversion=*/true))
2011  return false;
2012  return Result.isUsable();
2013 }
2014 
2016  QualType DestType, bool CStyle,
2017  SourceRange OpRange,
2018  unsigned &msg,
2019  CastKind &Kind) {
2020  bool IsLValueCast = false;
2021 
2022  DestType = Self.Context.getCanonicalType(DestType);
2023  QualType SrcType = SrcExpr.get()->getType();
2024 
2025  // Is the source an overloaded name? (i.e. &foo)
2026  // If so, reinterpret_cast generally can not help us here (13.4, p1, bullet 5)
2027  if (SrcType == Self.Context.OverloadTy) {
2028  ExprResult FixedExpr = SrcExpr;
2029  if (!fixOverloadedReinterpretCastExpr(Self, DestType, FixedExpr))
2030  return TC_NotApplicable;
2031 
2032  assert(FixedExpr.isUsable() && "Invalid result fixing overloaded expr");
2033  SrcExpr = FixedExpr;
2034  SrcType = SrcExpr.get()->getType();
2035  }
2036 
2037  if (const ReferenceType *DestTypeTmp = DestType->getAs<ReferenceType>()) {
2038  if (!SrcExpr.get()->isGLValue()) {
2039  // Cannot cast non-glvalue to (lvalue or rvalue) reference type. See the
2040  // similar comment in const_cast.
2041  msg = diag::err_bad_cxx_cast_rvalue;
2042  return TC_NotApplicable;
2043  }
2044 
2045  if (!CStyle) {
2046  Self.CheckCompatibleReinterpretCast(SrcType, DestType,
2047  /*IsDereference=*/false, OpRange);
2048  }
2049 
2050  // C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
2051  // same effect as the conversion *reinterpret_cast<T*>(&x) with the
2052  // built-in & and * operators.
2053 
2054  const char *inappropriate = nullptr;
2055  switch (SrcExpr.get()->getObjectKind()) {
2056  case OK_Ordinary:
2057  break;
2058  case OK_BitField:
2059  msg = diag::err_bad_cxx_cast_bitfield;
2060  return TC_NotApplicable;
2061  // FIXME: Use a specific diagnostic for the rest of these cases.
2062  case OK_VectorComponent: inappropriate = "vector element"; break;
2063  case OK_ObjCProperty: inappropriate = "property expression"; break;
2064  case OK_ObjCSubscript: inappropriate = "container subscripting expression";
2065  break;
2066  }
2067  if (inappropriate) {
2068  Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_reference)
2069  << inappropriate << DestType
2070  << OpRange << SrcExpr.get()->getSourceRange();
2071  msg = 0; SrcExpr = ExprError();
2072  return TC_NotApplicable;
2073  }
2074 
2075  // This code does this transformation for the checked types.
2076  DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
2077  SrcType = Self.Context.getPointerType(SrcType);
2078 
2079  IsLValueCast = true;
2080  }
2081 
2082  // Canonicalize source for comparison.
2083  SrcType = Self.Context.getCanonicalType(SrcType);
2084 
2085  const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>(),
2086  *SrcMemPtr = SrcType->getAs<MemberPointerType>();
2087  if (DestMemPtr && SrcMemPtr) {
2088  // C++ 5.2.10p9: An rvalue of type "pointer to member of X of type T1"
2089  // can be explicitly converted to an rvalue of type "pointer to member
2090  // of Y of type T2" if T1 and T2 are both function types or both object
2091  // types.
2092  if (DestMemPtr->isMemberFunctionPointer() !=
2093  SrcMemPtr->isMemberFunctionPointer())
2094  return TC_NotApplicable;
2095 
2096  if (Self.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2097  // We need to determine the inheritance model that the class will use if
2098  // haven't yet.
2099  (void)Self.isCompleteType(OpRange.getBegin(), SrcType);
2100  (void)Self.isCompleteType(OpRange.getBegin(), DestType);
2101  }
2102 
2103  // Don't allow casting between member pointers of different sizes.
2104  if (Self.Context.getTypeSize(DestMemPtr) !=
2105  Self.Context.getTypeSize(SrcMemPtr)) {
2106  msg = diag::err_bad_cxx_cast_member_pointer_size;
2107  return TC_Failed;
2108  }
2109 
2110  // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away
2111  // constness.
2112  // A reinterpret_cast followed by a const_cast can, though, so in C-style,
2113  // we accept it.
2114  if (auto CACK =
2115  CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
2116  /*CheckObjCLifetime=*/CStyle))
2117  return getCastAwayConstnessCastKind(CACK, msg);
2118 
2119  // A valid member pointer cast.
2120  assert(!IsLValueCast);
2121  Kind = CK_ReinterpretMemberPointer;
2122  return TC_Success;
2123  }
2124 
2125  // See below for the enumeral issue.
2126  if (SrcType->isNullPtrType() && DestType->isIntegralType(Self.Context)) {
2127  // C++0x 5.2.10p4: A pointer can be explicitly converted to any integral
2128  // type large enough to hold it. A value of std::nullptr_t can be
2129  // converted to an integral type; the conversion has the same meaning
2130  // and validity as a conversion of (void*)0 to the integral type.
2131  if (Self.Context.getTypeSize(SrcType) >
2132  Self.Context.getTypeSize(DestType)) {
2133  msg = diag::err_bad_reinterpret_cast_small_int;
2134  return TC_Failed;
2135  }
2136  Kind = CK_PointerToIntegral;
2137  return TC_Success;
2138  }
2139 
2140  // Allow reinterpret_casts between vectors of the same size and
2141  // between vectors and integers of the same size.
2142  bool destIsVector = DestType->isVectorType();
2143  bool srcIsVector = SrcType->isVectorType();
2144  if (srcIsVector || destIsVector) {
2145  // The non-vector type, if any, must have integral type. This is
2146  // the same rule that C vector casts use; note, however, that enum
2147  // types are not integral in C++.
2148  if ((!destIsVector && !DestType->isIntegralType(Self.Context)) ||
2149  (!srcIsVector && !SrcType->isIntegralType(Self.Context)))
2150  return TC_NotApplicable;
2151 
2152  // The size we want to consider is eltCount * eltSize.
2153  // That's exactly what the lax-conversion rules will check.
2154  if (Self.areLaxCompatibleVectorTypes(SrcType, DestType)) {
2155  Kind = CK_BitCast;
2156  return TC_Success;
2157  }
2158 
2159  // Otherwise, pick a reasonable diagnostic.
2160  if (!destIsVector)
2161  msg = diag::err_bad_cxx_cast_vector_to_scalar_different_size;
2162  else if (!srcIsVector)
2163  msg = diag::err_bad_cxx_cast_scalar_to_vector_different_size;
2164  else
2165  msg = diag::err_bad_cxx_cast_vector_to_vector_different_size;
2166 
2167  return TC_Failed;
2168  }
2169 
2170  if (SrcType == DestType) {
2171  // C++ 5.2.10p2 has a note that mentions that, subject to all other
2172  // restrictions, a cast to the same type is allowed so long as it does not
2173  // cast away constness. In C++98, the intent was not entirely clear here,
2174  // since all other paragraphs explicitly forbid casts to the same type.
2175  // C++11 clarifies this case with p2.
2176  //
2177  // The only allowed types are: integral, enumeration, pointer, or
2178  // pointer-to-member types. We also won't restrict Obj-C pointers either.
2179  Kind = CK_NoOp;
2181  if (SrcType->isIntegralOrEnumerationType() ||
2182  SrcType->isAnyPointerType() ||
2183  SrcType->isMemberPointerType() ||
2184  SrcType->isBlockPointerType()) {
2185  Result = TC_Success;
2186  }
2187  return Result;
2188  }
2189 
2190  bool destIsPtr = DestType->isAnyPointerType() ||
2191  DestType->isBlockPointerType();
2192  bool srcIsPtr = SrcType->isAnyPointerType() ||
2193  SrcType->isBlockPointerType();
2194  if (!destIsPtr && !srcIsPtr) {
2195  // Except for std::nullptr_t->integer and lvalue->reference, which are
2196  // handled above, at least one of the two arguments must be a pointer.
2197  return TC_NotApplicable;
2198  }
2199 
2200  if (DestType->isIntegralType(Self.Context)) {
2201  assert(srcIsPtr && "One type must be a pointer");
2202  // C++ 5.2.10p4: A pointer can be explicitly converted to any integral
2203  // type large enough to hold it; except in Microsoft mode, where the
2204  // integral type size doesn't matter (except we don't allow bool).
2205  bool MicrosoftException = Self.getLangOpts().MicrosoftExt &&
2206  !DestType->isBooleanType();
2207  if ((Self.Context.getTypeSize(SrcType) >
2208  Self.Context.getTypeSize(DestType)) &&
2209  !MicrosoftException) {
2210  msg = diag::err_bad_reinterpret_cast_small_int;
2211  return TC_Failed;
2212  }
2213  Kind = CK_PointerToIntegral;
2214  return TC_Success;
2215  }
2216 
2217  if (SrcType->isIntegralOrEnumerationType()) {
2218  assert(destIsPtr && "One type must be a pointer");
2219  checkIntToPointerCast(CStyle, OpRange.getBegin(), SrcExpr.get(), DestType,
2220  Self);
2221  // C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
2222  // converted to a pointer.
2223  // C++ 5.2.10p9: [Note: ...a null pointer constant of integral type is not
2224  // necessarily converted to a null pointer value.]
2225  Kind = CK_IntegralToPointer;
2226  return TC_Success;
2227  }
2228 
2229  if (!destIsPtr || !srcIsPtr) {
2230  // With the valid non-pointer conversions out of the way, we can be even
2231  // more stringent.
2232  return TC_NotApplicable;
2233  }
2234 
2235  // Cannot convert between block pointers and Objective-C object pointers.
2236  if ((SrcType->isBlockPointerType() && DestType->isObjCObjectPointerType()) ||
2237  (DestType->isBlockPointerType() && SrcType->isObjCObjectPointerType()))
2238  return TC_NotApplicable;
2239 
2240  // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
2241  // The C-style cast operator can.
2242  TryCastResult SuccessResult = TC_Success;
2243  if (auto CACK =
2244  CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
2245  /*CheckObjCLifetime=*/CStyle))
2246  SuccessResult = getCastAwayConstnessCastKind(CACK, msg);
2247 
2248  if (IsAddressSpaceConversion(SrcType, DestType)) {
2249  Kind = CK_AddressSpaceConversion;
2250  assert(SrcType->isPointerType() && DestType->isPointerType());
2251  if (!CStyle &&
2253  SrcType->getPointeeType().getQualifiers())) {
2254  SuccessResult = TC_Failed;
2255  }
2256  } else if (IsLValueCast) {
2257  Kind = CK_LValueBitCast;
2258  } else if (DestType->isObjCObjectPointerType()) {
2259  Kind = Self.PrepareCastToObjCObjectPointer(SrcExpr);
2260  } else if (DestType->isBlockPointerType()) {
2261  if (!SrcType->isBlockPointerType()) {
2262  Kind = CK_AnyPointerToBlockPointerCast;
2263  } else {
2264  Kind = CK_BitCast;
2265  }
2266  } else {
2267  Kind = CK_BitCast;
2268  }
2269 
2270  // Any pointer can be cast to an Objective-C pointer type with a C-style
2271  // cast.
2272  if (CStyle && DestType->isObjCObjectPointerType()) {
2273  return SuccessResult;
2274  }
2275  if (CStyle)
2276  DiagnoseCastOfObjCSEL(Self, SrcExpr, DestType);
2277 
2278  DiagnoseCallingConvCast(Self, SrcExpr, DestType, OpRange);
2279 
2280  // Not casting away constness, so the only remaining check is for compatible
2281  // pointer categories.
2282 
2283  if (SrcType->isFunctionPointerType()) {
2284  if (DestType->isFunctionPointerType()) {
2285  // C++ 5.2.10p6: A pointer to a function can be explicitly converted to
2286  // a pointer to a function of a different type.
2287  return SuccessResult;
2288  }
2289 
2290  // C++0x 5.2.10p8: Converting a pointer to a function into a pointer to
2291  // an object type or vice versa is conditionally-supported.
2292  // Compilers support it in C++03 too, though, because it's necessary for
2293  // casting the return value of dlsym() and GetProcAddress().
2294  // FIXME: Conditionally-supported behavior should be configurable in the
2295  // TargetInfo or similar.
2296  Self.Diag(OpRange.getBegin(),
2297  Self.getLangOpts().CPlusPlus11 ?
2298  diag::warn_cxx98_compat_cast_fn_obj : diag::ext_cast_fn_obj)
2299  << OpRange;
2300  return SuccessResult;
2301  }
2302 
2303  if (DestType->isFunctionPointerType()) {
2304  // See above.
2305  Self.Diag(OpRange.getBegin(),
2306  Self.getLangOpts().CPlusPlus11 ?
2307  diag::warn_cxx98_compat_cast_fn_obj : diag::ext_cast_fn_obj)
2308  << OpRange;
2309  return SuccessResult;
2310  }
2311 
2312  // C++ 5.2.10p7: A pointer to an object can be explicitly converted to
2313  // a pointer to an object of different type.
2314  // Void pointers are not specified, but supported by every compiler out there.
2315  // So we finish by allowing everything that remains - it's got to be two
2316  // object pointers.
2317  return SuccessResult;
2318 }
2319 
2321  QualType DestType, bool CStyle,
2322  unsigned &msg) {
2323  if (!Self.getLangOpts().OpenCL)
2324  // FIXME: As compiler doesn't have any information about overlapping addr
2325  // spaces at the moment we have to be permissive here.
2326  return TC_NotApplicable;
2327  // Even though the logic below is general enough and can be applied to
2328  // non-OpenCL mode too, we fast-path above because no other languages
2329  // define overlapping address spaces currently.
2330  auto SrcType = SrcExpr.get()->getType();
2331  auto SrcPtrType = SrcType->getAs<PointerType>();
2332  if (!SrcPtrType)
2333  return TC_NotApplicable;
2334  auto DestPtrType = DestType->getAs<PointerType>();
2335  if (!DestPtrType)
2336  return TC_NotApplicable;
2337  auto SrcPointeeType = SrcPtrType->getPointeeType();
2338  auto DestPointeeType = DestPtrType->getPointeeType();
2339  if (SrcPointeeType.getAddressSpace() == DestPointeeType.getAddressSpace())
2340  return TC_NotApplicable;
2341  if (!DestPtrType->isAddressSpaceOverlapping(*SrcPtrType)) {
2342  msg = diag::err_bad_cxx_cast_addr_space_mismatch;
2343  return TC_Failed;
2344  }
2345  auto SrcPointeeTypeWithoutAS =
2346  Self.Context.removeAddrSpaceQualType(SrcPointeeType.getCanonicalType());
2347  auto DestPointeeTypeWithoutAS =
2348  Self.Context.removeAddrSpaceQualType(DestPointeeType.getCanonicalType());
2349  return Self.Context.hasSameType(SrcPointeeTypeWithoutAS,
2350  DestPointeeTypeWithoutAS)
2351  ? TC_Success
2352  : TC_NotApplicable;
2353 }
2354 
2355 void CastOperation::checkAddressSpaceCast(QualType SrcType, QualType DestType) {
2356  // In OpenCL only conversions between pointers to objects in overlapping
2357  // addr spaces are allowed. v2.0 s6.5.5 - Generic addr space overlaps
2358  // with any named one, except for constant.
2359 
2360  // Converting the top level pointee addrspace is permitted for compatible
2361  // addrspaces (such as 'generic int *' to 'local int *' or vice versa), but
2362  // if any of the nested pointee addrspaces differ, we emit a warning
2363  // regardless of addrspace compatibility. This makes
2364  // local int ** p;
2365  // return (generic int **) p;
2366  // warn even though local -> generic is permitted.
2367  if (Self.getLangOpts().OpenCL) {
2368  const Type *DestPtr, *SrcPtr;
2369  bool Nested = false;
2370  unsigned DiagID = diag::err_typecheck_incompatible_address_space;
2371  DestPtr = Self.getASTContext().getCanonicalType(DestType.getTypePtr()),
2372  SrcPtr = Self.getASTContext().getCanonicalType(SrcType.getTypePtr());
2373 
2374  while (isa<PointerType>(DestPtr) && isa<PointerType>(SrcPtr)) {
2375  const PointerType *DestPPtr = cast<PointerType>(DestPtr);
2376  const PointerType *SrcPPtr = cast<PointerType>(SrcPtr);
2377  QualType DestPPointee = DestPPtr->getPointeeType();
2378  QualType SrcPPointee = SrcPPtr->getPointeeType();
2379  if (Nested ? DestPPointee.getAddressSpace() !=
2380  SrcPPointee.getAddressSpace()
2381  : !DestPPtr->isAddressSpaceOverlapping(*SrcPPtr)) {
2382  Self.Diag(OpRange.getBegin(), DiagID)
2383  << SrcType << DestType << Sema::AA_Casting
2384  << SrcExpr.get()->getSourceRange();
2385  if (!Nested)
2386  SrcExpr = ExprError();
2387  return;
2388  }
2389 
2390  DestPtr = DestPPtr->getPointeeType().getTypePtr();
2391  SrcPtr = SrcPPtr->getPointeeType().getTypePtr();
2392  Nested = true;
2393  DiagID = diag::ext_nested_pointer_qualifier_mismatch;
2394  }
2395  }
2396 }
2397 
2398 void CastOperation::CheckCXXCStyleCast(bool FunctionalStyle,
2399  bool ListInitialization) {
2400  assert(Self.getLangOpts().CPlusPlus);
2401 
2402  // Handle placeholders.
2403  if (isPlaceholder()) {
2404  // C-style casts can resolve __unknown_any types.
2405  if (claimPlaceholder(BuiltinType::UnknownAny)) {
2406  SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
2407  SrcExpr.get(), Kind,
2408  ValueKind, BasePath);
2409  return;
2410  }
2411 
2412  checkNonOverloadPlaceholders();
2413  if (SrcExpr.isInvalid())
2414  return;
2415  }
2416 
2417  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
2418  // This test is outside everything else because it's the only case where
2419  // a non-lvalue-reference target type does not lead to decay.
2420  if (DestType->isVoidType()) {
2421  Kind = CK_ToVoid;
2422 
2423  if (claimPlaceholder(BuiltinType::Overload)) {
2425  SrcExpr, /* Decay Function to ptr */ false,
2426  /* Complain */ true, DestRange, DestType,
2427  diag::err_bad_cstyle_cast_overload);
2428  if (SrcExpr.isInvalid())
2429  return;
2430  }
2431 
2432  SrcExpr = Self.IgnoredValueConversions(SrcExpr.get());
2433  return;
2434  }
2435 
2436  // If the type is dependent, we won't do any other semantic analysis now.
2437  if (DestType->isDependentType() || SrcExpr.get()->isTypeDependent() ||
2438  SrcExpr.get()->isValueDependent()) {
2439  assert(Kind == CK_Dependent);
2440  return;
2441  }
2442 
2443  if (ValueKind == VK_RValue && !DestType->isRecordType() &&
2444  !isPlaceholder(BuiltinType::Overload)) {
2445  SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
2446  if (SrcExpr.isInvalid())
2447  return;
2448  }
2449 
2450  // AltiVec vector initialization with a single literal.
2451  if (const VectorType *vecTy = DestType->getAs<VectorType>())
2452  if (vecTy->getVectorKind() == VectorType::AltiVecVector
2453  && (SrcExpr.get()->getType()->isIntegerType()
2454  || SrcExpr.get()->getType()->isFloatingType())) {
2455  Kind = CK_VectorSplat;
2456  SrcExpr = Self.prepareVectorSplat(DestType, SrcExpr.get());
2457  return;
2458  }
2459 
2460  // C++ [expr.cast]p5: The conversions performed by
2461  // - a const_cast,
2462  // - a static_cast,
2463  // - a static_cast followed by a const_cast,
2464  // - a reinterpret_cast, or
2465  // - a reinterpret_cast followed by a const_cast,
2466  // can be performed using the cast notation of explicit type conversion.
2467  // [...] If a conversion can be interpreted in more than one of the ways
2468  // listed above, the interpretation that appears first in the list is used,
2469  // even if a cast resulting from that interpretation is ill-formed.
2470  // In plain language, this means trying a const_cast ...
2471  // Note that for address space we check compatibility after const_cast.
2472  unsigned msg = diag::err_bad_cxx_cast_generic;
2473  TryCastResult tcr = TryConstCast(Self, SrcExpr, DestType,
2474  /*CStyle*/ true, msg);
2475  if (SrcExpr.isInvalid())
2476  return;
2477  if (isValidCast(tcr))
2478  Kind = CK_NoOp;
2479 
2481  FunctionalStyle ? Sema::CCK_FunctionalCast : Sema::CCK_CStyleCast;
2482  if (tcr == TC_NotApplicable) {
2483  tcr = TryAddressSpaceCast(Self, SrcExpr, DestType, /*CStyle*/ true, msg);
2484  if (SrcExpr.isInvalid())
2485  return;
2486 
2487  if (isValidCast(tcr))
2488  Kind = CK_AddressSpaceConversion;
2489 
2490  if (tcr == TC_NotApplicable) {
2491  // ... or if that is not possible, a static_cast, ignoring const, ...
2492  tcr = TryStaticCast(Self, SrcExpr, DestType, CCK, OpRange, msg, Kind,
2493  BasePath, ListInitialization);
2494  if (SrcExpr.isInvalid())
2495  return;
2496 
2497  if (tcr == TC_NotApplicable) {
2498  // ... and finally a reinterpret_cast, ignoring const.
2499  tcr = TryReinterpretCast(Self, SrcExpr, DestType, /*CStyle*/ true,
2500  OpRange, msg, Kind);
2501  if (SrcExpr.isInvalid())
2502  return;
2503  }
2504  }
2505  }
2506 
2508  isValidCast(tcr))
2509  checkObjCConversion(CCK);
2510 
2511  if (tcr != TC_Success && msg != 0) {
2512  if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
2513  DeclAccessPair Found;
2515  DestType,
2516  /*Complain*/ true,
2517  Found);
2518  if (Fn) {
2519  // If DestType is a function type (not to be confused with the function
2520  // pointer type), it will be possible to resolve the function address,
2521  // but the type cast should be considered as failure.
2522  OverloadExpr *OE = OverloadExpr::find(SrcExpr.get()).Expression;
2523  Self.Diag(OpRange.getBegin(), diag::err_bad_cstyle_cast_overload)
2524  << OE->getName() << DestType << OpRange
2525  << OE->getQualifierLoc().getSourceRange();
2526  Self.NoteAllOverloadCandidates(SrcExpr.get());
2527  }
2528  } else {
2529  diagnoseBadCast(Self, msg, (FunctionalStyle ? CT_Functional : CT_CStyle),
2530  OpRange, SrcExpr.get(), DestType, ListInitialization);
2531  }
2532  }
2533 
2534  if (isValidCast(tcr)) {
2535  if (Kind == CK_BitCast)
2536  checkCastAlign();
2537  } else {
2538  SrcExpr = ExprError();
2539  }
2540 }
2541 
2542 /// DiagnoseBadFunctionCast - Warn whenever a function call is cast to a
2543 /// non-matching type. Such as enum function call to int, int call to
2544 /// pointer; etc. Cast to 'void' is an exception.
2545 static void DiagnoseBadFunctionCast(Sema &Self, const ExprResult &SrcExpr,
2546  QualType DestType) {
2547  if (Self.Diags.isIgnored(diag::warn_bad_function_cast,
2548  SrcExpr.get()->getExprLoc()))
2549  return;
2550 
2551  if (!isa<CallExpr>(SrcExpr.get()))
2552  return;
2553 
2554  QualType SrcType = SrcExpr.get()->getType();
2555  if (DestType.getUnqualifiedType()->isVoidType())
2556  return;
2557  if ((SrcType->isAnyPointerType() || SrcType->isBlockPointerType())
2558  && (DestType->isAnyPointerType() || DestType->isBlockPointerType()))
2559  return;
2560  if (SrcType->isIntegerType() && DestType->isIntegerType() &&
2561  (SrcType->isBooleanType() == DestType->isBooleanType()) &&
2562  (SrcType->isEnumeralType() == DestType->isEnumeralType()))
2563  return;
2564  if (SrcType->isRealFloatingType() && DestType->isRealFloatingType())
2565  return;
2566  if (SrcType->isEnumeralType() && DestType->isEnumeralType())
2567  return;
2568  if (SrcType->isComplexType() && DestType->isComplexType())
2569  return;
2570  if (SrcType->isComplexIntegerType() && DestType->isComplexIntegerType())
2571  return;
2572 
2573  Self.Diag(SrcExpr.get()->getExprLoc(),
2574  diag::warn_bad_function_cast)
2575  << SrcType << DestType << SrcExpr.get()->getSourceRange();
2576 }
2577 
2578 /// Check the semantics of a C-style cast operation, in C.
2579 void CastOperation::CheckCStyleCast() {
2580  assert(!Self.getLangOpts().CPlusPlus);
2581 
2582  // C-style casts can resolve __unknown_any types.
2583  if (claimPlaceholder(BuiltinType::UnknownAny)) {
2584  SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
2585  SrcExpr.get(), Kind,
2586  ValueKind, BasePath);
2587  return;
2588  }
2589 
2590  // C99 6.5.4p2: the cast type needs to be void or scalar and the expression
2591  // type needs to be scalar.
2592  if (DestType->isVoidType()) {
2593  // We don't necessarily do lvalue-to-rvalue conversions on this.
2594  SrcExpr = Self.IgnoredValueConversions(SrcExpr.get());
2595  if (SrcExpr.isInvalid())
2596  return;
2597 
2598  // Cast to void allows any expr type.
2599  Kind = CK_ToVoid;
2600  return;
2601  }
2602 
2603  // Overloads are allowed with C extensions, so we need to support them.
2604  if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
2605  DeclAccessPair DAP;
2607  SrcExpr.get(), DestType, /*Complain=*/true, DAP))
2608  SrcExpr = Self.FixOverloadedFunctionReference(SrcExpr.get(), DAP, FD);
2609  else
2610  return;
2611  assert(SrcExpr.isUsable());
2612  }
2613  SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
2614  if (SrcExpr.isInvalid())
2615  return;
2616  QualType SrcType = SrcExpr.get()->getType();
2617 
2618  assert(!SrcType->isPlaceholderType());
2619 
2620  checkAddressSpaceCast(SrcType, DestType);
2621  if (SrcExpr.isInvalid())
2622  return;
2623 
2624  if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
2625  diag::err_typecheck_cast_to_incomplete)) {
2626  SrcExpr = ExprError();
2627  return;
2628  }
2629 
2630  if (!DestType->isScalarType() && !DestType->isVectorType()) {
2631  const RecordType *DestRecordTy = DestType->getAs<RecordType>();
2632 
2633  if (DestRecordTy && Self.Context.hasSameUnqualifiedType(DestType, SrcType)){
2634  // GCC struct/union extension: allow cast to self.
2635  Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_nonscalar)
2636  << DestType << SrcExpr.get()->getSourceRange();
2637  Kind = CK_NoOp;
2638  return;
2639  }
2640 
2641  // GCC's cast to union extension.
2642  if (DestRecordTy && DestRecordTy->getDecl()->isUnion()) {
2643  RecordDecl *RD = DestRecordTy->getDecl();
2644  if (CastExpr::getTargetFieldForToUnionCast(RD, SrcType)) {
2645  Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_to_union)
2646  << SrcExpr.get()->getSourceRange();
2647  Kind = CK_ToUnion;
2648  return;
2649  } else {
2650  Self.Diag(OpRange.getBegin(), diag::err_typecheck_cast_to_union_no_type)
2651  << SrcType << SrcExpr.get()->getSourceRange();
2652  SrcExpr = ExprError();
2653  return;
2654  }
2655  }
2656 
2657  // OpenCL v2.0 s6.13.10 - Allow casts from '0' to event_t type.
2658  if (Self.getLangOpts().OpenCL && DestType->isEventT()) {
2660  if (SrcExpr.get()->EvaluateAsInt(Result, Self.Context)) {
2661  llvm::APSInt CastInt = Result.Val.getInt();
2662  if (0 == CastInt) {
2663  Kind = CK_ZeroToOCLOpaqueType;
2664  return;
2665  }
2666  Self.Diag(OpRange.getBegin(),
2667  diag::err_opencl_cast_non_zero_to_event_t)
2668  << CastInt.toString(10) << SrcExpr.get()->getSourceRange();
2669  SrcExpr = ExprError();
2670  return;
2671  }
2672  }
2673 
2674  // Reject any other conversions to non-scalar types.
2675  Self.Diag(OpRange.getBegin(), diag::err_typecheck_cond_expect_scalar)
2676  << DestType << SrcExpr.get()->getSourceRange();
2677  SrcExpr = ExprError();
2678  return;
2679  }
2680 
2681  // The type we're casting to is known to be a scalar or vector.
2682 
2683  // Require the operand to be a scalar or vector.
2684  if (!SrcType->isScalarType() && !SrcType->isVectorType()) {
2685  Self.Diag(SrcExpr.get()->getExprLoc(),
2686  diag::err_typecheck_expect_scalar_operand)
2687  << SrcType << SrcExpr.get()->getSourceRange();
2688  SrcExpr = ExprError();
2689  return;
2690  }
2691 
2692  if (DestType->isExtVectorType()) {
2693  SrcExpr = Self.CheckExtVectorCast(OpRange, DestType, SrcExpr.get(), Kind);
2694  return;
2695  }
2696 
2697  if (const VectorType *DestVecTy = DestType->getAs<VectorType>()) {
2698  if (DestVecTy->getVectorKind() == VectorType::AltiVecVector &&
2699  (SrcType->isIntegerType() || SrcType->isFloatingType())) {
2700  Kind = CK_VectorSplat;
2701  SrcExpr = Self.prepareVectorSplat(DestType, SrcExpr.get());
2702  } else if (Self.CheckVectorCast(OpRange, DestType, SrcType, Kind)) {
2703  SrcExpr = ExprError();
2704  }
2705  return;
2706  }
2707 
2708  if (SrcType->isVectorType()) {
2709  if (Self.CheckVectorCast(OpRange, SrcType, DestType, Kind))
2710  SrcExpr = ExprError();
2711  return;
2712  }
2713 
2714  // The source and target types are both scalars, i.e.
2715  // - arithmetic types (fundamental, enum, and complex)
2716  // - all kinds of pointers
2717  // Note that member pointers were filtered out with C++, above.
2718 
2719  if (isa<ObjCSelectorExpr>(SrcExpr.get())) {
2720  Self.Diag(SrcExpr.get()->getExprLoc(), diag::err_cast_selector_expr);
2721  SrcExpr = ExprError();
2722  return;
2723  }
2724 
2725  // If either type is a pointer, the other type has to be either an
2726  // integer or a pointer.
2727  if (!DestType->isArithmeticType()) {
2728  if (!SrcType->isIntegralType(Self.Context) && SrcType->isArithmeticType()) {
2729  Self.Diag(SrcExpr.get()->getExprLoc(),
2730  diag::err_cast_pointer_from_non_pointer_int)
2731  << SrcType << SrcExpr.get()->getSourceRange();
2732  SrcExpr = ExprError();
2733  return;
2734  }
2735  checkIntToPointerCast(/* CStyle */ true, OpRange.getBegin(), SrcExpr.get(),
2736  DestType, Self);
2737  } else if (!SrcType->isArithmeticType()) {
2738  if (!DestType->isIntegralType(Self.Context) &&
2739  DestType->isArithmeticType()) {
2740  Self.Diag(SrcExpr.get()->getBeginLoc(),
2741  diag::err_cast_pointer_to_non_pointer_int)
2742  << DestType << SrcExpr.get()->getSourceRange();
2743  SrcExpr = ExprError();
2744  return;
2745  }
2746  }
2747 
2748  if (Self.getLangOpts().OpenCL &&
2749  !Self.getOpenCLOptions().isEnabled("cl_khr_fp16")) {
2750  if (DestType->isHalfType()) {
2751  Self.Diag(SrcExpr.get()->getBeginLoc(), diag::err_opencl_cast_to_half)
2752  << DestType << SrcExpr.get()->getSourceRange();
2753  SrcExpr = ExprError();
2754  return;
2755  }
2756  }
2757 
2758  // ARC imposes extra restrictions on casts.
2760  checkObjCConversion(Sema::CCK_CStyleCast);
2761  if (SrcExpr.isInvalid())
2762  return;
2763 
2764  const PointerType *CastPtr = DestType->getAs<PointerType>();
2765  if (Self.getLangOpts().ObjCAutoRefCount && CastPtr) {
2766  if (const PointerType *ExprPtr = SrcType->getAs<PointerType>()) {
2767  Qualifiers CastQuals = CastPtr->getPointeeType().getQualifiers();
2768  Qualifiers ExprQuals = ExprPtr->getPointeeType().getQualifiers();
2769  if (CastPtr->getPointeeType()->isObjCLifetimeType() &&
2770  ExprPtr->getPointeeType()->isObjCLifetimeType() &&
2771  !CastQuals.compatiblyIncludesObjCLifetime(ExprQuals)) {
2772  Self.Diag(SrcExpr.get()->getBeginLoc(),
2773  diag::err_typecheck_incompatible_ownership)
2774  << SrcType << DestType << Sema::AA_Casting
2775  << SrcExpr.get()->getSourceRange();
2776  return;
2777  }
2778  }
2779  }
2780  else if (!Self.CheckObjCARCUnavailableWeakConversion(DestType, SrcType)) {
2781  Self.Diag(SrcExpr.get()->getBeginLoc(),
2782  diag::err_arc_convesion_of_weak_unavailable)
2783  << 1 << SrcType << DestType << SrcExpr.get()->getSourceRange();
2784  SrcExpr = ExprError();
2785  return;
2786  }
2787  }
2788 
2789  DiagnoseCastOfObjCSEL(Self, SrcExpr, DestType);
2790  DiagnoseCallingConvCast(Self, SrcExpr, DestType, OpRange);
2791  DiagnoseBadFunctionCast(Self, SrcExpr, DestType);
2792  Kind = Self.PrepareScalarCast(SrcExpr, DestType);
2793  if (SrcExpr.isInvalid())
2794  return;
2795 
2796  if (Kind == CK_BitCast)
2797  checkCastAlign();
2798 }
2799 
2800 void CastOperation::CheckBuiltinBitCast() {
2801  QualType SrcType = SrcExpr.get()->getType();
2802 
2803  if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
2804  diag::err_typecheck_cast_to_incomplete) ||
2805  Self.RequireCompleteType(OpRange.getBegin(), SrcType,
2806  diag::err_incomplete_type)) {
2807  SrcExpr = ExprError();
2808  return;
2809  }
2810 
2811  if (SrcExpr.get()->isRValue())
2812  SrcExpr = Self.CreateMaterializeTemporaryExpr(SrcType, SrcExpr.get(),
2813  /*IsLValueReference=*/false);
2814 
2815  CharUnits DestSize = Self.Context.getTypeSizeInChars(DestType);
2816  CharUnits SourceSize = Self.Context.getTypeSizeInChars(SrcType);
2817  if (DestSize != SourceSize) {
2818  Self.Diag(OpRange.getBegin(), diag::err_bit_cast_type_size_mismatch)
2819  << (int)SourceSize.getQuantity() << (int)DestSize.getQuantity();
2820  SrcExpr = ExprError();
2821  return;
2822  }
2823 
2824  if (!DestType.isTriviallyCopyableType(Self.Context)) {
2825  Self.Diag(OpRange.getBegin(), diag::err_bit_cast_non_trivially_copyable)
2826  << 1;
2827  SrcExpr = ExprError();
2828  return;
2829  }
2830 
2831  if (!SrcType.isTriviallyCopyableType(Self.Context)) {
2832  Self.Diag(OpRange.getBegin(), diag::err_bit_cast_non_trivially_copyable)
2833  << 0;
2834  SrcExpr = ExprError();
2835  return;
2836  }
2837 
2838  if (Self.Context.hasSameUnqualifiedType(DestType, SrcType)) {
2839  Kind = CK_NoOp;
2840  return;
2841  }
2842 
2843  Kind = CK_LValueToRValueBitCast;
2844 }
2845 
2846 /// DiagnoseCastQual - Warn whenever casts discards a qualifiers, be it either
2847 /// const, volatile or both.
2848 static void DiagnoseCastQual(Sema &Self, const ExprResult &SrcExpr,
2849  QualType DestType) {
2850  if (SrcExpr.isInvalid())
2851  return;
2852 
2853  QualType SrcType = SrcExpr.get()->getType();
2854  if (!((SrcType->isAnyPointerType() && DestType->isAnyPointerType()) ||
2855  DestType->isLValueReferenceType()))
2856  return;
2857 
2858  QualType TheOffendingSrcType, TheOffendingDestType;
2859  Qualifiers CastAwayQualifiers;
2860  if (CastsAwayConstness(Self, SrcType, DestType, true, false,
2861  &TheOffendingSrcType, &TheOffendingDestType,
2862  &CastAwayQualifiers) !=
2863  CastAwayConstnessKind::CACK_Similar)
2864  return;
2865 
2866  // FIXME: 'restrict' is not properly handled here.
2867  int qualifiers = -1;
2868  if (CastAwayQualifiers.hasConst() && CastAwayQualifiers.hasVolatile()) {
2869  qualifiers = 0;
2870  } else if (CastAwayQualifiers.hasConst()) {
2871  qualifiers = 1;
2872  } else if (CastAwayQualifiers.hasVolatile()) {
2873  qualifiers = 2;
2874  }
2875  // This is a variant of int **x; const int **y = (const int **)x;
2876  if (qualifiers == -1)
2877  Self.Diag(SrcExpr.get()->getBeginLoc(), diag::warn_cast_qual2)
2878  << SrcType << DestType;
2879  else
2880  Self.Diag(SrcExpr.get()->getBeginLoc(), diag::warn_cast_qual)
2881  << TheOffendingSrcType << TheOffendingDestType << qualifiers;
2882 }
2883 
2885  TypeSourceInfo *CastTypeInfo,
2886  SourceLocation RPLoc,
2887  Expr *CastExpr) {
2888  CastOperation Op(*this, CastTypeInfo->getType(), CastExpr);
2889  Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
2890  Op.OpRange = SourceRange(LPLoc, CastExpr->getEndLoc());
2891 
2892  if (getLangOpts().CPlusPlus) {
2893  Op.CheckCXXCStyleCast(/*FunctionalCast=*/ false,
2894  isa<InitListExpr>(CastExpr));
2895  } else {
2896  Op.CheckCStyleCast();
2897  }
2898 
2899  if (Op.SrcExpr.isInvalid())
2900  return ExprError();
2901 
2902  // -Wcast-qual
2903  DiagnoseCastQual(Op.Self, Op.SrcExpr, Op.DestType);
2904 
2905  return Op.complete(CStyleCastExpr::Create(Context, Op.ResultType,
2906  Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
2907  &Op.BasePath, CastTypeInfo, LPLoc, RPLoc));
2908 }
2909 
2911  QualType Type,
2912  SourceLocation LPLoc,
2913  Expr *CastExpr,
2914  SourceLocation RPLoc) {
2915  assert(LPLoc.isValid() && "List-initialization shouldn't get here.");
2916  CastOperation Op(*this, Type, CastExpr);
2917  Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
2918  Op.OpRange = SourceRange(Op.DestRange.getBegin(), CastExpr->getEndLoc());
2919 
2920  Op.CheckCXXCStyleCast(/*FunctionalCast=*/true, /*ListInit=*/false);
2921  if (Op.SrcExpr.isInvalid())
2922  return ExprError();
2923 
2924  auto *SubExpr = Op.SrcExpr.get();
2925  if (auto *BindExpr = dyn_cast<CXXBindTemporaryExpr>(SubExpr))
2926  SubExpr = BindExpr->getSubExpr();
2927  if (auto *ConstructExpr = dyn_cast<CXXConstructExpr>(SubExpr))
2928  ConstructExpr->setParenOrBraceRange(SourceRange(LPLoc, RPLoc));
2929 
2930  return Op.complete(CXXFunctionalCastExpr::Create(Context, Op.ResultType,
2931  Op.ValueKind, CastTypeInfo, Op.Kind,
2932  Op.SrcExpr.get(), &Op.BasePath, LPLoc, RPLoc));
2933 }
Defines the clang::ASTContext interface.
bool RequireNonAbstractType(SourceLocation Loc, QualType T, TypeDiagnoser &Diagnoser)
Represents a function declaration or definition.
Definition: Decl.h:1756
static bool IsAddressSpaceConversion(QualType SrcType, QualType DestType)
Definition: SemaCast.cpp:1082
static DiagnosticBuilder Diag(DiagnosticsEngine *Diags, const LangOptions &Features, FullSourceLoc TokLoc, const char *TokBegin, const char *TokRangeBegin, const char *TokRangeEnd, unsigned DiagID)
Produce a diagnostic highlighting some portion of a literal.
PointerType - C99 6.7.5.1 - Pointer Declarators.
Definition: Type.h:2575
QualType getPointeeType() const
Definition: Type.h:2588
A (possibly-)qualified type.
Definition: Type.h:643
bool isBlockPointerType() const
Definition: Type.h:6398
bool isMemberPointerType() const
Definition: Type.h:6428
IdentifierInfo * getIdentifierInfo(StringRef Name) const
Return information about the specified preprocessor identifier token.
A cast other than a C-style cast.
Definition: Sema.h:9851
SourceRange getSourceRange() const LLVM_READONLY
Retrieve the source range covering the entirety of this nested-name-specifier.
const ASTRecordLayout & getASTRecordLayout(const RecordDecl *D) const
Get or compute information about the layout of the specified record (struct/union/class) D...
bool isArithmeticType() const
Definition: Type.cpp:1996
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3393
ARCConversionResult CheckObjCConversion(SourceRange castRange, QualType castType, Expr *&op, CheckedConversionKind CCK, bool Diagnose=true, bool DiagnoseCFAudited=false, BinaryOperatorKind Opc=BO_PtrMemD)
Checks for invalid conversions and casts between retainable pointers and other pointer kinds for ARC ...
QualType getPointeeType() const
If this is a pointer, ObjC object pointer, or block pointer, this returns the respective pointee...
Definition: Type.cpp:518
CharUnits getBaseClassOffset(const CXXRecordDecl *Base) const
getBaseClassOffset - Get the offset, in chars, for the given base class.
Definition: RecordLayout.h:232
static CXXDynamicCastExpr * Create(const ASTContext &Context, QualType T, ExprValueKind VK, CastKind Kind, Expr *Op, const CXXCastPath *Path, TypeSourceInfo *Written, SourceLocation L, SourceLocation RParenLoc, SourceRange AngleBrackets)
Definition: ExprCXX.cpp:722
bool isRealFloatingType() const
Floating point categories.
Definition: Type.cpp:1981
bool isRecordType() const
Definition: Type.h:6470
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
Emit a diagnostic.
Definition: Sema.h:1380
static TryCastResult TryStaticCast(Sema &Self, ExprResult &SrcExpr, QualType DestType, Sema::CheckedConversionKind CCK, SourceRange OpRange, unsigned &msg, CastKind &Kind, CXXCastPath &BasePath, bool ListInitialization)
TryStaticCast - Check if a static cast can be performed, and do so if possible.
Definition: SemaCast.cpp:1096
bool isExtVectorType() const
Definition: Type.h:6486
The cast method is appropriate and successful.
Definition: SemaCast.cpp:34
FailureKind getFailureKind() const
Determine why initialization failed.
CanQualType ARCUnbridgedCastTy
Definition: ASTContext.h:1043
The base class of the type hierarchy.
Definition: Type.h:1436
bool isDerivedFrom(const CXXRecordDecl *Base) const
Determine whether this class is derived from the class Base.
StringRef getLastMacroWithSpelling(SourceLocation Loc, ArrayRef< TokenValue > Tokens) const
Return the name of the macro defined before Loc that has spelling Tokens.
static ExprValueKind getValueKindForType(QualType T)
getValueKindForType - Given a formal return or parameter type, give its value kind.
Definition: Expr.h:404
Overloading for a user-defined conversion failed.
bool isZero() const
isZero - Test whether the quantity equals zero.
Definition: CharUnits.h:115
Ambiguous candidates found.
Definition: Overload.h:59
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:703
A container of type source information.
Definition: Decl.h:86
static CXXFunctionalCastExpr * Create(const ASTContext &Context, QualType T, ExprValueKind VK, TypeSourceInfo *Written, CastKind Kind, Expr *Op, const CXXCastPath *Path, SourceLocation LPLoc, SourceLocation RPLoc)
Definition: ExprCXX.cpp:818
Represents a path from a specific derived class (which is not represented as part of the path) to a p...
static_cast
Definition: SemaCast.cpp:47
SourceLocation getEndLoc() const
Get the end source location.
Definition: TypeLoc.cpp:226
static InitializedEntity InitializeTemporary(QualType Type)
Create the initialization entity for a temporary.
bool isCompleteDefinition() const
Return true if this decl has its body fully specified.
Definition: Decl.h:3210
bool isUnsignedIntegerType() const
Return true if this is an integer type that is unsigned, according to C99 6.2.5p6 [which returns true...
Definition: Type.cpp:1928
bool CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, CastKind &Kind)
Definition: SemaExpr.cpp:6526
An Objective-C array/dictionary subscripting which reads an object or writes at the subscripted array...
Definition: Specifiers.h:156
PartialDiagnostic PDiag(unsigned DiagID=0)
Build a partial diagnostic.
Definition: SemaInternal.h:24
Information about one declarator, including the parsed type information and the identifier.
Definition: DeclSpec.h:1775
void removeObjCLifetime()
Definition: Type.h:333
DiagnosticsEngine & Diags
Definition: Sema.h:376
bool isEnumeralType() const
Definition: Type.h:6474
static void DiagnoseCallingConvCast(Sema &Self, const ExprResult &SrcExpr, QualType DstType, SourceRange OpRange)
Diagnose casts that change the calling convention of a pointer to a function defined in the current T...
Definition: SemaCast.cpp:1874
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:6857
void clear()
Clear the base-paths results.
CastAwayConstnessKind
The kind of unwrapping we did when determining whether a conversion casts away constness.
Definition: SemaCast.cpp:487
QualType getMemberPointerType(QualType T, const Type *Cls) const
Return the uniqued reference to the type for a member pointer to the specified type in the specified ...
DeclarationName getName() const
Gets the name looked up.
Definition: ExprCXX.h:2859
RangeSelector range(RangeSelector Begin, RangeSelector End)
Selects from the start of Begin and to the end of End.
bool isInvalidDecl() const
Definition: DeclBase.h:553
OpenCLOptions & getOpenCLOptions()
Definition: Sema.h:1294
Defines the clang::Expr interface and subclasses for C++ expressions.
The collection of all-type qualifiers we support.
Definition: Type.h:137
bool isRecordingPaths() const
Whether we are recording paths.
bool UnwrapSimilarTypes(QualType &T1, QualType &T2)
Attempt to unwrap two types that may be similar (C++ [conv.qual]).
Base wrapper for a particular "section" of type source info.
Definition: TypeLoc.h:56
Expr * FixOverloadedFunctionReference(Expr *E, DeclAccessPair FoundDecl, FunctionDecl *Fn)
FixOverloadedFunctionReference - E is an expression that refers to a C++ overloaded function (possibl...
Represents a struct/union/class.
Definition: Decl.h:3634
One of these records is kept for each identifier that is lexed.
TargetCXXABI getCXXABI() const
Get the C++ ABI currently in use.
Definition: TargetInfo.h:1060
void setRecordingPaths(bool RP)
Specify whether we should be recording paths or not.
A vector component is an element or range of elements on a vector.
Definition: Specifiers.h:147
(Type)expr
Definition: SemaCast.cpp:50
Holds long-lived AST nodes (such as types and decls) that can be referred to throughout the semantic ...
Definition: ASTContext.h:160
bool allowsNonTrivialObjCLifetimeQualifiers() const
True if any ObjC types may have non-trivial lifetime qualifiers.
Definition: LangOptions.h:310
bool isObjCLifetimeType() const
Returns true if objects of this type have lifetime semantics under ARC.
Definition: Type.cpp:4024
The cast method is not applicable.
Definition: SemaCast.cpp:33
A C-style cast.
Definition: Sema.h:9847
RecordDecl * getDefinition() const
Returns the RecordDecl that actually defines this struct/union/class.
Definition: Decl.h:3839
bool IsDerivedFrom(SourceLocation Loc, QualType Derived, QualType Base)
Determine whether the type Derived is a C++ class that is derived from the type Base.
SourceLocation getBeginLoc() const LLVM_READONLY
Definition: Stmt.cpp:274
TryCastResult
Definition: SemaCast.cpp:32
static TryCastResult getCastAwayConstnessCastKind(CastAwayConstnessKind CACK, unsigned &DiagID)
Definition: SemaCast.cpp:687
void removeConst()
Definition: Type.h:256
bool isReferenceType() const
Definition: Type.h:6402
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:52
Ref_Incompatible - The two types are incompatible, so direct reference binding is not possible...
Definition: Sema.h:10234
Expr * getSubExpr()
Definition: Expr.h:3172
bool isAtLeastAsQualifiedAs(QualType Other) const
Determine whether this type is at least as qualified as the other given type, requiring exact equalit...
Definition: Type.h:6320
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6753
OverloadCandidateDisplayKind
Definition: Overload.h:65
An r-value expression (a pr-value in the C++11 taxonomy) produces a temporary value.
Definition: Specifiers.h:125
bool isInvalidType() const
Definition: DeclSpec.h:2453
ExprResult ActOnBuiltinBitCastExpr(SourceLocation KWLoc, Declarator &Dcl, ExprResult Operand, SourceLocation RParenLoc)
Definition: SemaCast.cpp:335
bool isGLValue() const
Definition: Expr.h:261
static bool isValidCast(TryCastResult TCR)
Definition: SemaCast.cpp:41
bool isCompleteType(SourceLocation Loc, QualType T)
Definition: Sema.h:1768
An rvalue reference type, per C++11 [dcl.ref].
Definition: Type.h:2776
PtrTy get() const
Definition: Ownership.h:170
tok::TokenKind getTokenID() const
If this is a source-language token (e.g.
CharUnits - This is an opaque type for sizes expressed in character units.
Definition: CharUnits.h:37
ReferenceCompareResult CompareReferenceRelationship(SourceLocation Loc, QualType T1, QualType T2, bool &DerivedToBase, bool &ObjCConversion, bool &ObjCLifetimeConversion)
CompareReferenceRelationship - Compare the two types T1 and T2 to determine whether they are referenc...
Succeeded, but refers to a deleted function.
Definition: Overload.h:62
APValue Val
Val - This is the value the expression can be folded to.
Definition: Expr.h:582
Ref_Compatible - The two types are reference-compatible.
Definition: Sema.h:10240
bool isTriviallyCopyableType(const ASTContext &Context) const
Return true if this is a trivially copyable type (C++0x [basic.types]p9)
Definition: Type.cpp:2249
OverloadCandidateSet & getFailedCandidateSet()
Retrieve a reference to the candidate set when overload resolution fails.
ExprValueKind getValueKind() const
getValueKind - The value kind that this expression produces.
Definition: Expr.h:414
const Type * getClass() const
Definition: Type.h:2828
bool isRValueReferenceType() const
Definition: Type.h:6410
CheckedConversionKind
The kind of conversion being performed.
Definition: Sema.h:9843
static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr, QualType DestType, bool CStyle, SourceRange OpRange, unsigned &msg, CastKind &Kind)
Definition: SemaCast.cpp:2015
FunctionDecl * ResolveAddressOfOverloadedFunction(Expr *AddressOfExpr, QualType TargetType, bool Complain, DeclAccessPair &Found, bool *pHadMultipleCandidates=nullptr)
ResolveAddressOfOverloadedFunction - Try to resolve the address of an overloaded function (C++ [over...
ExprResult Perform(Sema &S, const InitializedEntity &Entity, const InitializationKind &Kind, MultiExprArg Args, QualType *ResultType=nullptr)
Perform the actual initialization of the given entity based on the computed initialization sequence...
Definition: SemaInit.cpp:7738
const RecordType * getDetectedVirtual() const
The virtual base discovered on the path (if we are merely detecting virtuals).
const Type * getTypePtr() const
Retrieves a pointer to the underlying (unqualified) type.
Definition: Type.h:6148
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:3120
static void DiagnoseCastQual(Sema &Self, const ExprResult &SrcExpr, QualType DestType)
DiagnoseCastQual - Warn whenever casts discards a qualifiers, be it either const, volatile or both...
Definition: SemaCast.cpp:2848
const internal::VariadicDynCastAllOfMatcher< Stmt, CastExpr > castExpr
Matches any cast nodes of Clang&#39;s AST.
const LangOptions & getLangOpts() const
Definition: Sema.h:1293
bool isTypeDependent() const
isTypeDependent - Determines whether this expression is type-dependent (C++ [temp.dep.expr]), which means that its type could change from one template instantiation to the next.
Definition: Expr.h:176
ExprResult DefaultFunctionArrayLvalueConversion(Expr *E, bool Diagnose=true)
Definition: SemaExpr.cpp:655
bool isScalarType() const
Definition: Type.h:6738
bool compatiblyIncludesObjCLifetime(Qualifiers other) const
Determines if these qualifiers compatibly include another set of qualifiers from the narrow perspecti...
Definition: Type.h:508
An ordinary object is located at an address in memory.
Definition: Specifiers.h:141
CastKind PrepareScalarCast(ExprResult &src, QualType destType)
Prepares for a scalar cast, performing all the necessary stages except the final cast and returning t...
Definition: SemaExpr.cpp:6236
static CastAwayConstnessKind unwrapCastAwayConstnessLevel(ASTContext &Context, QualType &T1, QualType &T2)
Unwrap one level of types for CastsAwayConstness.
Definition: SemaCast.cpp:514
bool hasConst() const
Definition: Type.h:254
CallingConv getDefaultCallingConvention(bool IsVariadic, bool IsCXXMethod, bool IsBuiltin=false) const
Retrieves the default calling convention for the current target.
bool isHalfType() const
Definition: Type.h:6655
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:328
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1649
A functional-style cast.
Definition: Sema.h:9849
bool compatiblyIncludes(Qualifiers other) const
Determines if these qualifiers compatibly include another set.
Definition: Type.h:487
bool isComplexType() const
isComplexType() does not include complex integers (a GCC extension).
Definition: Type.cpp:494
CastKind
CastKind - The kind of operation required for a conversion.
static ImplicitCastExpr * Create(const ASTContext &Context, QualType T, CastKind Kind, Expr *Operand, const CXXCastPath *BasePath, ExprValueKind Cat)
Definition: Expr.cpp:1981
bool UnwrapSimilarArrayTypes(QualType &T1, QualType &T2)
Attempt to unwrap two types that may both be array types with the same bound (or both be array types ...
static TryCastResult TryConstCast(Sema &Self, ExprResult &SrcExpr, QualType DestType, bool CStyle, unsigned &msg)
TryConstCast - See if a const_cast from source to destination is allowed, and perform it if it is...
Definition: SemaCast.cpp:1702
bool isEnabled(llvm::StringRef Ext) const
Definition: OpenCLOptions.h:39
QuantityType getQuantity() const
getQuantity - Get the raw integer representation of this quantity.
Definition: CharUnits.h:178
unsigned Offset
Definition: Format.cpp:1758
ASTRecordLayout - This class contains layout information for one RecordDecl, which is a struct/union/...
Definition: RecordLayout.h:38
An Objective-C property is a logical field of an Objective-C object which is read and written via Obj...
Definition: Specifiers.h:151
SourceLocation getBeginLoc() const
Get the begin source location.
Definition: TypeLoc.cpp:189
bool isEventT() const
Definition: Type.h:6559
This represents one expression.
Definition: Expr.h:108
static void diagnoseBadCast(Sema &S, unsigned msg, CastType castType, SourceRange opRange, Expr *src, QualType destType, bool listInitialization)
Diagnose a failed cast.
Definition: SemaCast.cpp:445
QualType getPointeeType() const
Definition: Type.h:2732
ExprValueKind
The categorization of expression values, currently following the C++11 scheme.
Definition: Specifiers.h:122
static InitializationKind CreateFunctionalCast(SourceRange TypeRange, bool InitList)
Create a direct initialization for a functional cast.
void BuildBasePathArray(const CXXBasePaths &Paths, CXXCastPath &BasePath)
static FindResult find(Expr *E)
Finds the overloaded expression in the given expression E of OverloadTy.
Definition: ExprCXX.h:2810
const CXXRecordDecl * getPointeeCXXRecordDecl() const
If this is a pointer or reference to a RecordType, return the CXXRecordDecl that the type refers to...
Definition: Type.cpp:1634
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:6922
OverloadingResult getFailedOverloadResult() const
Get the overloading result, for when the initialization sequence failed due to a bad overload...
The cast method is appropriate and accepted as a language extension.
Definition: SemaCast.cpp:35
Defines the clang::Preprocessor interface.
bool isNullPtrType() const
Definition: Type.h:6674
static CXXStaticCastExpr * Create(const ASTContext &Context, QualType T, ExprValueKind VK, CastKind K, Expr *Op, const CXXCastPath *Path, TypeSourceInfo *Written, SourceLocation L, SourceLocation RParenLoc, SourceRange AngleBrackets)
Definition: ExprCXX.cpp:697
CXXRecordDecl * getDefinition() const
Definition: DeclCXX.h:725
Overload resolution succeeded.
Definition: Overload.h:53
ExprResult BuildCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind, TypeSourceInfo *Ty, Expr *E, SourceRange AngleBrackets, SourceRange Parens)
Definition: SemaCast.cpp:258
Stores token information for comparing actual tokens with predefined values.
Definition: Preprocessor.h:86
ExprResult CheckPlaceholderExpr(Expr *E)
Check for operands with placeholder types and complain if found.
Definition: SemaExpr.cpp:17730
static TryCastResult TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr, QualType DestType, Sema::CheckedConversionKind CCK, SourceRange OpRange, unsigned &msg, CastKind &Kind, bool ListInitialization)
TryStaticImplicitCast - Tests whether a conversion according to C++ 5.2.9p2 is valid: ...
Definition: SemaCast.cpp:1647
bool isConstructorInitialization() const
Determine whether this initialization is direct call to a constructor.
Definition: SemaInit.cpp:3512
ReferenceCompareResult
ReferenceCompareResult - Expresses the result of comparing two types (cv1 T1 and cv2 T2) to determine...
Definition: Sema.h:10231
bool RequireCompleteType(SourceLocation Loc, QualType T, TypeDiagnoser &Diagnoser)
Ensure that the type T is a complete type.
Definition: SemaType.cpp:7792
bool isSignedIntegerType() const
Return true if this is an integer type that is signed, according to C99 6.2.5p4 [char, signed char, short, int, long..], or an enum decl which has a signed representation.
Definition: Type.cpp:1888
QualType getType() const
Definition: Expr.h:137
static TryCastResult TryStaticMemberPointerUpcast(Sema &Self, ExprResult &SrcExpr, QualType SrcType, QualType DestType, bool CStyle, SourceRange OpRange, unsigned &msg, CastKind &Kind, CXXCastPath &BasePath)
TryStaticMemberPointerUpcast - Tests whether a conversion according to C++ 5.2.9p9 is valid: ...
Definition: SemaCast.cpp:1529
bool ResolveAndFixSingleFunctionTemplateSpecialization(ExprResult &SrcExpr, bool DoFunctionPointerConverion=false, bool Complain=false, SourceRange OpRangeForComplaining=SourceRange(), QualType DestTypeForComplaining=QualType(), unsigned DiagIDForComplaining=0)
bool resolveAndFixAddressOfOnlyViableOverloadCandidate(ExprResult &SrcExpr, bool DoFunctionPointerConversion=false)
Given an overloaded function, tries to turn it into a non-overloaded function reference using resolve...
Type(expr)
Definition: SemaCast.cpp:51
bool isAtLeastAsQualifiedAs(CanQual< T > Other) const
Determines whether this canonical type is at least as qualified as the Other canonical type...
bool isInvalid() const
Definition: Ownership.h:166
SourceLocation getEnd() const
Preprocessor & getPreprocessor() const
Definition: Sema.h:1299
Represents a GCC generic vector type.
Definition: Type.h:3206
static TryCastResult TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr, QualType DestType, bool CStyle, SourceRange OpRange, unsigned &msg, CastKind &Kind, CXXCastPath &BasePath)
Tests whether a conversion according to C++ 5.2.9p5 is valid.
Definition: SemaCast.cpp:1345
bool isUsable() const
Definition: Ownership.h:167
bool CheckTollFreeBridgeStaticCast(QualType castType, Expr *castExpr, CastKind &Kind)
QualType getTypeDeclType(const TypeDecl *Decl, const TypeDecl *PrevDecl=nullptr) const
Return the unique reference to the type for the specified type declaration.
Definition: ASTContext.h:1399
The result type of a method or function.
CallingConv
CallingConv - Specifies the calling convention that a function uses.
Definition: Specifiers.h:265
bool isKeyword(const LangOptions &LangOpts) const
Return true if this token is a keyword in the specified language.
SourceLocation getEndLoc() const LLVM_READONLY
Definition: Stmt.cpp:287
unsigned getCVRQualifiers() const
Retrieve the set of CVR (const-volatile-restrict) qualifiers applied to this type.
Definition: Type.h:6181
ExprResult BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, SourceLocation RParenLoc, Expr *Op)
Definition: SemaCast.cpp:2884
bool isVoidPointerType() const
Definition: Type.cpp:482
bool areLaxCompatibleVectorTypes(QualType srcType, QualType destType)
Are the two types lax-compatible vector types? That is, given that one of them is a vector...
Definition: SemaExpr.cpp:6471
RecordDecl * getDecl() const
Definition: Type.h:4454
static TryCastResult TryStaticDowncast(Sema &Self, CanQualType SrcType, CanQualType DestType, bool CStyle, SourceRange OpRange, QualType OrigSrcType, QualType OrigDestType, unsigned &msg, CastKind &Kind, CXXCastPath &BasePath)
TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and TryStaticPointerDowncast.
Definition: SemaCast.cpp:1417
CanQualType OverloadTy
Definition: ASTContext.h:1041
static CXXConstCastExpr * Create(const ASTContext &Context, QualType T, ExprValueKind VK, Expr *Op, TypeSourceInfo *WrittenTy, SourceLocation L, SourceLocation RParenLoc, SourceRange AngleBrackets)
Definition: ExprCXX.cpp:804
Kind
A reference to an overloaded function set, either an UnresolvedLookupExpr or an UnresolvedMemberExpr...
Definition: ExprCXX.h:2750
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:153
ASTContext & getASTContext() const
Definition: Sema.h:1300
Encodes a location in the source.
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of enums...
Definition: Type.h:4470
llvm::APSInt APSInt
CastKind PrepareCastToObjCObjectPointer(ExprResult &E)
Prepare a conversion of the given expression to an ObjC object pointer type.
Definition: SemaExpr.cpp:6221
LangAS getAddressSpace() const
Return the address space of this type.
Definition: Type.h:6264
static TryCastResult TryStaticPointerDowncast(Sema &Self, QualType SrcType, QualType DestType, bool CStyle, SourceRange OpRange, unsigned &msg, CastKind &Kind, CXXCastPath &BasePath)
Tests whether a conversion according to C++ 5.2.9p8 is valid.
Definition: SemaCast.cpp:1383
static const FieldDecl * getTargetFieldForToUnionCast(QualType unionType, QualType opType)
Definition: Expr.cpp:1961
Represents a C++2a __builtin_bit_cast(T, v) expression.
Definition: ExprCXX.h:4724
std::pair< SourceLocation, PartialDiagnostic > PartialDiagnosticAt
A partial diagnostic along with the source location where this diagnostic occurs. ...
bool isIntegralType(const ASTContext &Ctx) const
Determine whether this type is an integral type.
Definition: Type.cpp:1803
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:2069
paths_iterator begin()
ExprResult ActOnCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind, SourceLocation LAngleBracketLoc, Declarator &D, SourceLocation RAngleBracketLoc, SourceLocation LParenLoc, Expr *E, SourceLocation RParenLoc)
ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast&#39;s.
Definition: SemaCast.cpp:235
bool CheckObjCARCUnavailableWeakConversion(QualType castType, QualType ExprType)
std::string getAmbiguousPathsDisplayString(CXXBasePaths &Paths)
Builds a string representing ambiguous paths from a specific derived class to different subobjects of...
const ArrayType * getAsArrayType(QualType T) const
Type Query functions.
Represents a canonical, potentially-qualified type.
Definition: CanonicalType.h:65
TokenKind
Provides a simple uniform namespace for tokens from all C languages.
Definition: TokenKinds.h:24
Describes the kind of initialization being performed, along with location information for tokens rela...
const_cast
Definition: SemaCast.cpp:46
bool isMemberFunctionPointerType() const
Definition: Type.h:6432
bool isObjCObjectPointerType() const
Definition: Type.h:6494
bool isAnyPointerType() const
Definition: Type.h:6394
ImplicitCastExpr - Allows us to explicitly represent implicit type conversions, which have no direct ...
Definition: Expr.h:3244
bool isLValue() const
isLValue - True if this expression is an "l-value" according to the rules of the current language...
Definition: Expr.h:258
Overloading for initialization by constructor failed.
is AltiVec vector
Definition: Type.h:3213
Requests that all candidates be shown.
Definition: Overload.h:68
bool isAddressSpaceOverlapping(const PointerType &other) const
Returns true if address spaces of pointers overlap.
Definition: Type.h:2598
bool isAnyCharacterType() const
Determine whether this type is any of the built-in character types.
Definition: Type.cpp:1867
bool isVectorType() const
Definition: Type.h:6482
void removeObjCGCAttr()
Definition: Type.h:305
OverloadCandidateSet - A set of overload candidates, used in C++ overload resolution (C++ 13...
Definition: Overload.h:846
reinterpret_cast
Definition: SemaCast.cpp:48
static TryCastResult TryAddressSpaceCast(Sema &Self, ExprResult &SrcExpr, QualType DestType, bool CStyle, unsigned &msg)
Definition: SemaCast.cpp:2320
static InitializationKind CreateCast(SourceRange TypeRange)
Create a direct initialization due to a cast that isn&#39;t a C-style or functional cast.
bool hasSameUnqualifiedType(QualType T1, QualType T2) const
Determine whether the given types are equivalent after cvr-qualifiers have been removed.
Definition: ASTContext.h:2326
static CXXReinterpretCastExpr * Create(const ASTContext &Context, QualType T, ExprValueKind VK, CastKind Kind, Expr *Op, const CXXCastPath *Path, TypeSourceInfo *WrittenTy, SourceLocation L, SourceLocation RParenLoc, SourceRange AngleBrackets)
Definition: ExprCXX.cpp:781
CanProxy< U > getAs() const
Retrieve a canonical type pointer with a different static type, upcasting or downcasting as needed...
ExprResult checkUnknownAnyCast(SourceRange TypeRange, QualType CastType, Expr *CastExpr, CastKind &CastKind, ExprValueKind &VK, CXXCastPath &Path)
Check a cast of an unknown-any type.
Definition: SemaExpr.cpp:17638
A POD class for pairing a NamedDecl* with an access specifier.
bool isPlaceholderType() const
Test for a type which does not represent an actual type-system type but is instead used as a placehol...
Definition: Type.h:6623
dynamic_cast
Definition: SemaCast.cpp:49
Represents an element in a path from a derived class to a base class.
std::list< CXXBasePath >::const_iterator const_paths_iterator
Dataflow Directional Tag Classes.
bool isValid() const
Return true if this is a valid SourceLocation object.
EvalResult is a struct with detailed info about an evaluated expression.
Definition: Expr.h:580
void CheckCompatibleReinterpretCast(QualType SrcType, QualType DestType, bool IsDereference, SourceRange Range)
Definition: SemaCast.cpp:1805
bool hasCvrSimilarType(QualType T1, QualType T2)
Determine if two types are similar, ignoring only CVR qualifiers.
The cast method is appropriate, but failed.
Definition: SemaCast.cpp:37
static std::string getAsString(SplitQualType split, const PrintingPolicy &Policy)
Definition: Type.h:979
const CXXRecordDecl * getParent() const
Return the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2192
bool isBooleanType() const
Definition: Type.h:6766
ExprResult prepareVectorSplat(QualType VectorTy, Expr *SplattedExpr)
Prepare SplattedExpr for a vector splat operation, adding implicit casts if necessary.
Definition: SemaExpr.cpp:6546
static void checkIntToPointerCast(bool CStyle, SourceLocation Loc, const Expr *SrcExpr, QualType DestType, Sema &Self)
Definition: SemaCast.cpp:1962
Requests that only viable candidates be shown.
Definition: Overload.h:71
bool isAmbiguous(CanQualType BaseType)
Determine whether the path from the most-derived type to the given base type is ambiguous (i...
A pointer to member type per C++ 8.3.3 - Pointers to members.
Definition: Type.h:2794
bool isIntegerConstantExpr(llvm::APSInt &Result, const ASTContext &Ctx, SourceLocation *Loc=nullptr, bool isEvaluated=true) const
isIntegerConstantExpr - Return true if this expression is a valid integer constant expression...
static InitializationKind CreateCStyleCast(SourceLocation StartLoc, SourceRange TypeRange, bool InitList)
Create a direct initialization for a C-style cast.
void CheckCastAlign(Expr *Op, QualType T, SourceRange TRange)
CheckCastAlign - Implements -Wcast-align, which warns when a pointer cast increases the alignment req...
static void DiagnoseCastOfObjCSEL(Sema &Self, const ExprResult &SrcExpr, QualType DestType)
Definition: SemaCast.cpp:1855
static bool fixOverloadedReinterpretCastExpr(Sema &Self, QualType DestType, ExprResult &Result)
Definition: SemaCast.cpp:1988
Expr * IgnoreParenImpCasts() LLVM_READONLY
Skip past any parentheses and implicit casts which might surround this expression until reaching a fi...
Definition: Expr.cpp:2966
ExprResult IgnoredValueConversions(Expr *E)
IgnoredValueConversions - Given that an expression&#39;s result is syntactically ignored, perform any conversions that are required.
SourceRange getSourceRange() const LLVM_READONLY
Get the full source range.
Definition: TypeLoc.h:150
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4444
static bool tryDiagnoseOverloadedCast(Sema &S, CastType CT, SourceRange range, Expr *src, QualType destType, bool listInitialization)
Try to diagnose a failed overloaded cast.
Definition: SemaCast.cpp:369
bool isIntegerType() const
isIntegerType() does not include complex integers (a GCC extension).
Definition: Type.h:6683
ExprResult CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *CastExpr, CastKind &Kind)
Definition: SemaExpr.cpp:6579
static CStyleCastExpr * Create(const ASTContext &Context, QualType T, ExprValueKind VK, CastKind K, Expr *Op, const CXXCastPath *BasePath, TypeSourceInfo *WrittenTy, SourceLocation L, SourceLocation R)
Definition: Expr.cpp:2007
bool CheckDerivedToBaseConversion(QualType Derived, QualType Base, SourceLocation Loc, SourceRange Range, CXXCastPath *BasePath=nullptr, bool IgnoreAccess=false)
bool isFunctionType() const
Definition: Type.h:6386
MaterializeTemporaryExpr * CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary, bool BoundToLvalueReference)
Definition: SemaInit.cpp:7686
CXXBasePath & front()
Base for LValueReferenceType and RValueReferenceType.
Definition: Type.h:2711
bool hasSameType(QualType T1, QualType T2) const
Determine whether the given types T1 and T2 are equivalent.
Definition: ASTContext.h:2302
static TryCastResult TryLValueToRValueCast(Sema &Self, Expr *SrcExpr, QualType DestType, bool CStyle, CastKind &Kind, CXXCastPath &BasePath, unsigned &msg)
Tests whether a conversion according to N2844 is valid.
Definition: SemaCast.cpp:1287
static FixItHint CreateInsertion(SourceLocation InsertionLoc, StringRef Code, bool BeforePreviousInsertions=false)
Create a code modification hint that inserts the given code string at a specific location.
Definition: Diagnostic.h:92
Implements a partial diagnostic that can be emitted anwyhere in a DiagnosticBuilder stream...
QualType getNonLValueExprType(const ASTContext &Context) const
Determine the type of a (typically non-lvalue) expression with the specified result type...
Definition: Type.cpp:2866
A bitfield object is a bitfield on a C or C++ record.
Definition: Specifiers.h:144
void NoteCandidates(PartialDiagnosticAt PA, Sema &S, OverloadCandidateDisplayKind OCD, ArrayRef< Expr *> Args, StringRef Opc="", SourceLocation Loc=SourceLocation(), llvm::function_ref< bool(OverloadCandidate &)> Filter=[](OverloadCandidate &) { return true;})
When overload resolution fails, prints diagnostic messages containing the candidates in the candidate...
uint64_t getTypeSize(QualType T) const
Return the size of the specified (complete) type T, in bits.
Definition: ASTContext.h:2085
bool isObjCObjectType() const
Definition: Type.h:6498
QualType withCVRQualifiers(unsigned CVR) const
Definition: Type.h:835
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2286
bool isLValueReferenceType() const
Definition: Type.h:6406
ExprResult BuildCXXFunctionalCastExpr(TypeSourceInfo *TInfo, QualType Type, SourceLocation LParenLoc, Expr *CastExpr, SourceLocation RParenLoc)
Definition: SemaCast.cpp:2910
TypeLoc getTypeLoc() const
Return the TypeLoc wrapper for the type source info.
Definition: TypeLoc.h:240
bool Failed() const
Determine whether the initialization sequence is invalid.
CallingConv getCallConv() const
Definition: Type.h:3661
Describes the sequence of initializations required to initialize a given object or reference with a s...
QualType getUnqualifiedType() const
Retrieve the unqualified variant of the given type, removing as little sugar as possible.
Definition: Type.h:6228
Represents a C++ struct/union/class.
Definition: DeclCXX.h:254
bool isMemberFunctionPointer() const
Returns true if the member type (i.e.
Definition: Type.h:2818
bool isVoidType() const
Definition: Type.h:6649
static CastAwayConstnessKind CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType, bool CheckCVR, bool CheckObjCLifetime, QualType *TheOffendingSrcType=nullptr, QualType *TheOffendingDestType=nullptr, Qualifiers *CastAwayQualifiers=nullptr)
Check if the pointer conversion from SrcType to DestType casts away constness as defined in C++ [expr...
Definition: SemaCast.cpp:592
Qualifiers getQualifiers() const
Retrieve the set of qualifiers applied to this type.
Definition: Type.h:6175
QualType removeAddrSpaceQualType(QualType T) const
Remove any existing address space on the type and returns the type with qualifiers intact (or that&#39;s ...
AccessResult CheckBaseClassAccess(SourceLocation AccessLoc, QualType Base, QualType Derived, const CXXBasePath &Path, unsigned DiagID, bool ForceCheck=false, bool ForceUnprivileged=false)
Checks access for a hierarchy conversion.
static bool isAddressSpaceSupersetOf(LangAS A, LangAS B)
Returns true if address space A is equal to or a superset of B.
Definition: Type.h:470
QualType getPointerType(QualType T) const
Return the uniqued reference to the type for a pointer to the specified type.
static FixItHint CreateReplacement(CharSourceRange RemoveRange, StringRef Code)
Create a code modification hint that replaces the given source range with the given code string...
Definition: Diagnostic.h:129
This class is used for builtin types like &#39;int&#39;.
Definition: Type.h:2426
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:262
Defines the clang::TargetInfo interface.
bool isComplexIntegerType() const
Definition: Type.cpp:500
bool isMicrosoft() const
Is this ABI an MSVC-compatible ABI?
Definition: TargetCXXABI.h:153
unsigned getCVRQualifiers() const
Definition: Type.h:270
ExprResult ExprError()
Definition: Ownership.h:279
static Qualifiers fromCVRMask(unsigned CVR)
Definition: Type.h:230
bool hasVolatile() const
Definition: Type.h:259
static void DiagnoseBadFunctionCast(Sema &Self, const ExprResult &SrcExpr, QualType DestType)
DiagnoseBadFunctionCast - Warn whenever a function call is cast to a non-matching type...
Definition: SemaCast.cpp:2545
bool isDependentType() const
Whether this type is a dependent type, meaning that its definition somehow depends on a template para...
Definition: Type.h:2111
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1141
bool isIgnored(unsigned DiagID, SourceLocation Loc) const
Determine whether the diagnostic is known to be ignored.
Definition: Diagnostic.h:819
bool isUnion() const
Definition: Decl.h:3293
NestedNameSpecifierLoc getQualifierLoc() const
Fetches the nested-name qualifier with source-location information, if one was given.
Definition: ExprCXX.h:2871
bool isPointerType() const
Definition: Type.h:6390
void NoteAllOverloadCandidates(Expr *E, QualType DestType=QualType(), bool TakingAddress=false)
BasePaths - Represents the set of paths from a derived class to one of its (direct or indirect) bases...
CharUnits getTypeSizeInChars(QualType T) const
Return the size of the specified (complete) type T, in characters.
No viable function found.
Definition: Overload.h:56
static StringRef getNameForCallConv(CallingConv CC)
Definition: Type.cpp:2882
bool isFloatingType() const
Definition: Type.cpp:1965
A trivial tuple used to represent a source range.
ASTContext & Context
Definition: Sema.h:374
paths_iterator end()
APSInt & getInt()
Definition: APValue.h:336
Describes an entity that is being initialized.
bool isFunctionPointerType() const
Definition: Type.h:6414
SourceLocation getBegin() const
const LangOptions & getLangOpts() const
Definition: ASTContext.h:720
ExprResult BuildBuiltinBitCastExpr(SourceLocation KWLoc, TypeSourceInfo *TSI, Expr *Operand, SourceLocation RParenLoc)
Definition: SemaCast.cpp:347
QualType getUnqualifiedArrayType(QualType T, Qualifiers &Quals)
Return this type as a completely-unqualified array type, capturing the qualifiers in Quals...
bool isIncompleteOrObjectType() const
Return true if this is an incomplete or object type, in other words, not a function type...
Definition: Type.h:1892
CastType
Definition: SemaCast.cpp:45
QualType getPointeeType() const
Definition: Type.h:2814
static void DiagnoseReinterpretUpDownCast(Sema &Self, const Expr *SrcExpr, QualType DestType, SourceRange OpRange)
Check that a reinterpret_cast<DestType>(SrcExpr) is not used as upcast or downcast between respective...
Definition: SemaCast.cpp:883
QualType getType() const
Return the type wrapped by this type source info.
Definition: Decl.h:97
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:125