clang  10.0.0git
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_AmbiguousCandidates;
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_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 << this->DestType << 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_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 (Self.RequireCompleteType(OpRange.getBegin(), DestType,
1186  diag::err_bad_cast_incomplete)) {
1187  SrcExpr = ExprError();
1188  return TC_Failed;
1189  }
1190  if (SrcType->isIntegralOrEnumerationType()) {
1191  Kind = CK_IntegralCast;
1192  return TC_Success;
1193  } else if (SrcType->isRealFloatingType()) {
1194  Kind = CK_FloatingToIntegral;
1195  return TC_Success;
1196  }
1197  }
1198 
1199  // Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
1200  // C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
1201  tcr = TryStaticPointerDowncast(Self, SrcType, DestType, CStyle, OpRange, msg,
1202  Kind, BasePath);
1203  if (tcr != TC_NotApplicable)
1204  return tcr;
1205 
1206  // Reverse member pointer conversion. C++ 4.11 specifies member pointer
1207  // conversion. C++ 5.2.9p9 has additional information.
1208  // DR54's access restrictions apply here also.
1209  tcr = TryStaticMemberPointerUpcast(Self, SrcExpr, SrcType, DestType, CStyle,
1210  OpRange, msg, Kind, BasePath);
1211  if (tcr != TC_NotApplicable)
1212  return tcr;
1213 
1214  // Reverse pointer conversion to void*. C++ 4.10.p2 specifies conversion to
1215  // void*. C++ 5.2.9p10 specifies additional restrictions, which really is
1216  // just the usual constness stuff.
1217  if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
1218  QualType SrcPointee = SrcPointer->getPointeeType();
1219  if (SrcPointee->isVoidType()) {
1220  if (const PointerType *DestPointer = DestType->getAs<PointerType>()) {
1221  QualType DestPointee = DestPointer->getPointeeType();
1222  if (DestPointee->isIncompleteOrObjectType()) {
1223  // This is definitely the intended conversion, but it might fail due
1224  // to a qualifier violation. Note that we permit Objective-C lifetime
1225  // and GC qualifier mismatches here.
1226  if (!CStyle) {
1227  Qualifiers DestPointeeQuals = DestPointee.getQualifiers();
1228  Qualifiers SrcPointeeQuals = SrcPointee.getQualifiers();
1229  DestPointeeQuals.removeObjCGCAttr();
1230  DestPointeeQuals.removeObjCLifetime();
1231  SrcPointeeQuals.removeObjCGCAttr();
1232  SrcPointeeQuals.removeObjCLifetime();
1233  if (DestPointeeQuals != SrcPointeeQuals &&
1234  !DestPointeeQuals.compatiblyIncludes(SrcPointeeQuals)) {
1235  msg = diag::err_bad_cxx_cast_qualifiers_away;
1236  return TC_Failed;
1237  }
1238  }
1239  Kind = IsAddressSpaceConversion(SrcType, DestType)
1240  ? CK_AddressSpaceConversion
1241  : CK_BitCast;
1242  return TC_Success;
1243  }
1244 
1245  // Microsoft permits static_cast from 'pointer-to-void' to
1246  // 'pointer-to-function'.
1247  if (!CStyle && Self.getLangOpts().MSVCCompat &&
1248  DestPointee->isFunctionType()) {
1249  Self.Diag(OpRange.getBegin(), diag::ext_ms_cast_fn_obj) << OpRange;
1250  Kind = CK_BitCast;
1251  return TC_Success;
1252  }
1253  }
1254  else if (DestType->isObjCObjectPointerType()) {
1255  // allow both c-style cast and static_cast of objective-c pointers as
1256  // they are pervasive.
1257  Kind = CK_CPointerToObjCPointerCast;
1258  return TC_Success;
1259  }
1260  else if (CStyle && DestType->isBlockPointerType()) {
1261  // allow c-style cast of void * to block pointers.
1262  Kind = CK_AnyPointerToBlockPointerCast;
1263  return TC_Success;
1264  }
1265  }
1266  }
1267  // Allow arbitrary objective-c pointer conversion with static casts.
1268  if (SrcType->isObjCObjectPointerType() &&
1269  DestType->isObjCObjectPointerType()) {
1270  Kind = CK_BitCast;
1271  return TC_Success;
1272  }
1273  // Allow ns-pointer to cf-pointer conversion in either direction
1274  // with static casts.
1275  if (!CStyle &&
1276  Self.CheckTollFreeBridgeStaticCast(DestType, SrcExpr.get(), Kind))
1277  return TC_Success;
1278 
1279  // See if it looks like the user is trying to convert between
1280  // related record types, and select a better diagnostic if so.
1281  if (auto SrcPointer = SrcType->getAs<PointerType>())
1282  if (auto DestPointer = DestType->getAs<PointerType>())
1283  if (SrcPointer->getPointeeType()->getAs<RecordType>() &&
1284  DestPointer->getPointeeType()->getAs<RecordType>())
1285  msg = diag::err_bad_cxx_cast_unrelated_class;
1286 
1287  // We tried everything. Everything! Nothing works! :-(
1288  return TC_NotApplicable;
1289 }
1290 
1291 /// Tests whether a conversion according to N2844 is valid.
1293  QualType DestType, bool CStyle,
1294  CastKind &Kind, CXXCastPath &BasePath,
1295  unsigned &msg) {
1296  // C++11 [expr.static.cast]p3:
1297  // A glvalue of type "cv1 T1" can be cast to type "rvalue reference to
1298  // cv2 T2" if "cv2 T2" is reference-compatible with "cv1 T1".
1299  const RValueReferenceType *R = DestType->getAs<RValueReferenceType>();
1300  if (!R)
1301  return TC_NotApplicable;
1302 
1303  if (!SrcExpr->isGLValue())
1304  return TC_NotApplicable;
1305 
1306  // Because we try the reference downcast before this function, from now on
1307  // this is the only cast possibility, so we issue an error if we fail now.
1308  // FIXME: Should allow casting away constness if CStyle.
1309  QualType FromType = SrcExpr->getType();
1310  QualType ToType = R->getPointeeType();
1311  if (CStyle) {
1312  FromType = FromType.getUnqualifiedType();
1313  ToType = ToType.getUnqualifiedType();
1314  }
1315 
1318  SrcExpr->getBeginLoc(), ToType, FromType, &RefConv);
1319  if (RefResult != Sema::Ref_Compatible) {
1320  if (CStyle || RefResult == Sema::Ref_Incompatible)
1321  return TC_NotApplicable;
1322  // Diagnose types which are reference-related but not compatible here since
1323  // we can provide better diagnostics. In these cases forwarding to
1324  // [expr.static.cast]p4 should never result in a well-formed cast.
1325  msg = SrcExpr->isLValue() ? diag::err_bad_lvalue_to_rvalue_cast
1326  : diag::err_bad_rvalue_to_rvalue_cast;
1327  return TC_Failed;
1328  }
1329 
1330  if (RefConv & Sema::ReferenceConversions::DerivedToBase) {
1331  Kind = CK_DerivedToBase;
1332  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1333  /*DetectVirtual=*/true);
1334  if (!Self.IsDerivedFrom(SrcExpr->getBeginLoc(), SrcExpr->getType(),
1335  R->getPointeeType(), Paths))
1336  return TC_NotApplicable;
1337 
1338  Self.BuildBasePathArray(Paths, BasePath);
1339  } else
1340  Kind = CK_NoOp;
1341 
1342  return TC_Success;
1343 }
1344 
1345 /// Tests whether a conversion according to C++ 5.2.9p5 is valid.
1347 TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr, QualType DestType,
1348  bool CStyle, SourceRange OpRange,
1349  unsigned &msg, CastKind &Kind,
1350  CXXCastPath &BasePath) {
1351  // C++ 5.2.9p5: An lvalue of type "cv1 B", where B is a class type, can be
1352  // cast to type "reference to cv2 D", where D is a class derived from B,
1353  // if a valid standard conversion from "pointer to D" to "pointer to B"
1354  // exists, cv2 >= cv1, and B is not a virtual base class of D.
1355  // In addition, DR54 clarifies that the base must be accessible in the
1356  // current context. Although the wording of DR54 only applies to the pointer
1357  // variant of this rule, the intent is clearly for it to apply to the this
1358  // conversion as well.
1359 
1360  const ReferenceType *DestReference = DestType->getAs<ReferenceType>();
1361  if (!DestReference) {
1362  return TC_NotApplicable;
1363  }
1364  bool RValueRef = DestReference->isRValueReferenceType();
1365  if (!RValueRef && !SrcExpr->isLValue()) {
1366  // We know the left side is an lvalue reference, so we can suggest a reason.
1367  msg = diag::err_bad_cxx_cast_rvalue;
1368  return TC_NotApplicable;
1369  }
1370 
1371  QualType DestPointee = DestReference->getPointeeType();
1372 
1373  // FIXME: If the source is a prvalue, we should issue a warning (because the
1374  // cast always has undefined behavior), and for AST consistency, we should
1375  // materialize a temporary.
1376  return TryStaticDowncast(Self,
1377  Self.Context.getCanonicalType(SrcExpr->getType()),
1378  Self.Context.getCanonicalType(DestPointee), CStyle,
1379  OpRange, SrcExpr->getType(), DestType, msg, Kind,
1380  BasePath);
1381 }
1382 
1383 /// Tests whether a conversion according to C++ 5.2.9p8 is valid.
1386  bool CStyle, SourceRange OpRange,
1387  unsigned &msg, CastKind &Kind,
1388  CXXCastPath &BasePath) {
1389  // C++ 5.2.9p8: An rvalue of type "pointer to cv1 B", where B is a class
1390  // type, can be converted to an rvalue of type "pointer to cv2 D", where D
1391  // is a class derived from B, if a valid standard conversion from "pointer
1392  // to D" to "pointer to B" exists, cv2 >= cv1, and B is not a virtual base
1393  // class of D.
1394  // In addition, DR54 clarifies that the base must be accessible in the
1395  // current context.
1396 
1397  const PointerType *DestPointer = DestType->getAs<PointerType>();
1398  if (!DestPointer) {
1399  return TC_NotApplicable;
1400  }
1401 
1402  const PointerType *SrcPointer = SrcType->getAs<PointerType>();
1403  if (!SrcPointer) {
1404  msg = diag::err_bad_static_cast_pointer_nonpointer;
1405  return TC_NotApplicable;
1406  }
1407 
1408  return TryStaticDowncast(Self,
1409  Self.Context.getCanonicalType(SrcPointer->getPointeeType()),
1410  Self.Context.getCanonicalType(DestPointer->getPointeeType()),
1411  CStyle, OpRange, SrcType, DestType, msg, Kind,
1412  BasePath);
1413 }
1414 
1415 /// TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and
1416 /// TryStaticPointerDowncast. Tests whether a static downcast from SrcType to
1417 /// DestType is possible and allowed.
1420  bool CStyle, SourceRange OpRange, QualType OrigSrcType,
1421  QualType OrigDestType, unsigned &msg,
1422  CastKind &Kind, CXXCastPath &BasePath) {
1423  // We can only work with complete types. But don't complain if it doesn't work
1424  if (!Self.isCompleteType(OpRange.getBegin(), SrcType) ||
1425  !Self.isCompleteType(OpRange.getBegin(), DestType))
1426  return TC_NotApplicable;
1427 
1428  // Downcast can only happen in class hierarchies, so we need classes.
1429  if (!DestType->getAs<RecordType>() || !SrcType->getAs<RecordType>()) {
1430  return TC_NotApplicable;
1431  }
1432 
1433  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1434  /*DetectVirtual=*/true);
1435  if (!Self.IsDerivedFrom(OpRange.getBegin(), DestType, SrcType, Paths)) {
1436  return TC_NotApplicable;
1437  }
1438 
1439  // Target type does derive from source type. Now we're serious. If an error
1440  // appears now, it's not ignored.
1441  // This may not be entirely in line with the standard. Take for example:
1442  // struct A {};
1443  // struct B : virtual A {
1444  // B(A&);
1445  // };
1446  //
1447  // void f()
1448  // {
1449  // (void)static_cast<const B&>(*((A*)0));
1450  // }
1451  // As far as the standard is concerned, p5 does not apply (A is virtual), so
1452  // p2 should be used instead - "const B& t(*((A*)0));" is perfectly valid.
1453  // However, both GCC and Comeau reject this example, and accepting it would
1454  // mean more complex code if we're to preserve the nice error message.
1455  // FIXME: Being 100% compliant here would be nice to have.
1456 
1457  // Must preserve cv, as always, unless we're in C-style mode.
1458  if (!CStyle && !DestType.isAtLeastAsQualifiedAs(SrcType)) {
1459  msg = diag::err_bad_cxx_cast_qualifiers_away;
1460  return TC_Failed;
1461  }
1462 
1463  if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
1464  // This code is analoguous to that in CheckDerivedToBaseConversion, except
1465  // that it builds the paths in reverse order.
1466  // To sum up: record all paths to the base and build a nice string from
1467  // them. Use it to spice up the error message.
1468  if (!Paths.isRecordingPaths()) {
1469  Paths.clear();
1470  Paths.setRecordingPaths(true);
1471  Self.IsDerivedFrom(OpRange.getBegin(), DestType, SrcType, Paths);
1472  }
1473  std::string PathDisplayStr;
1474  std::set<unsigned> DisplayedPaths;
1475  for (clang::CXXBasePath &Path : Paths) {
1476  if (DisplayedPaths.insert(Path.back().SubobjectNumber).second) {
1477  // We haven't displayed a path to this particular base
1478  // class subobject yet.
1479  PathDisplayStr += "\n ";
1480  for (CXXBasePathElement &PE : llvm::reverse(Path))
1481  PathDisplayStr += PE.Base->getType().getAsString() + " -> ";
1482  PathDisplayStr += QualType(DestType).getAsString();
1483  }
1484  }
1485 
1486  Self.Diag(OpRange.getBegin(), diag::err_ambiguous_base_to_derived_cast)
1487  << QualType(SrcType).getUnqualifiedType()
1488  << QualType(DestType).getUnqualifiedType()
1489  << PathDisplayStr << OpRange;
1490  msg = 0;
1491  return TC_Failed;
1492  }
1493 
1494  if (Paths.getDetectedVirtual() != nullptr) {
1495  QualType VirtualBase(Paths.getDetectedVirtual(), 0);
1496  Self.Diag(OpRange.getBegin(), diag::err_static_downcast_via_virtual)
1497  << OrigSrcType << OrigDestType << VirtualBase << OpRange;
1498  msg = 0;
1499  return TC_Failed;
1500  }
1501 
1502  if (!CStyle) {
1503  switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
1504  SrcType, DestType,
1505  Paths.front(),
1506  diag::err_downcast_from_inaccessible_base)) {
1507  case Sema::AR_accessible:
1508  case Sema::AR_delayed: // be optimistic
1509  case Sema::AR_dependent: // be optimistic
1510  break;
1511 
1512  case Sema::AR_inaccessible:
1513  msg = 0;
1514  return TC_Failed;
1515  }
1516  }
1517 
1518  Self.BuildBasePathArray(Paths, BasePath);
1519  Kind = CK_BaseToDerived;
1520  return TC_Success;
1521 }
1522 
1523 /// TryStaticMemberPointerUpcast - Tests whether a conversion according to
1524 /// C++ 5.2.9p9 is valid:
1525 ///
1526 /// An rvalue of type "pointer to member of D of type cv1 T" can be
1527 /// converted to an rvalue of type "pointer to member of B of type cv2 T",
1528 /// where B is a base class of D [...].
1529 ///
1532  QualType DestType, bool CStyle,
1533  SourceRange OpRange,
1534  unsigned &msg, CastKind &Kind,
1535  CXXCastPath &BasePath) {
1536  const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>();
1537  if (!DestMemPtr)
1538  return TC_NotApplicable;
1539 
1540  bool WasOverloadedFunction = false;
1541  DeclAccessPair FoundOverload;
1542  if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
1543  if (FunctionDecl *Fn
1544  = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(), DestType, false,
1545  FoundOverload)) {
1546  CXXMethodDecl *M = cast<CXXMethodDecl>(Fn);
1547  SrcType = Self.Context.getMemberPointerType(Fn->getType(),
1548  Self.Context.getTypeDeclType(M->getParent()).getTypePtr());
1549  WasOverloadedFunction = true;
1550  }
1551  }
1552 
1553  const MemberPointerType *SrcMemPtr = SrcType->getAs<MemberPointerType>();
1554  if (!SrcMemPtr) {
1555  msg = diag::err_bad_static_cast_member_pointer_nonmp;
1556  return TC_NotApplicable;
1557  }
1558 
1559  // Lock down the inheritance model right now in MS ABI, whether or not the
1560  // pointee types are the same.
1561  if (Self.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
1562  (void)Self.isCompleteType(OpRange.getBegin(), SrcType);
1563  (void)Self.isCompleteType(OpRange.getBegin(), DestType);
1564  }
1565 
1566  // T == T, modulo cv
1567  if (!Self.Context.hasSameUnqualifiedType(SrcMemPtr->getPointeeType(),
1568  DestMemPtr->getPointeeType()))
1569  return TC_NotApplicable;
1570 
1571  // B base of D
1572  QualType SrcClass(SrcMemPtr->getClass(), 0);
1573  QualType DestClass(DestMemPtr->getClass(), 0);
1574  CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1575  /*DetectVirtual=*/true);
1576  if (!Self.IsDerivedFrom(OpRange.getBegin(), SrcClass, DestClass, Paths))
1577  return TC_NotApplicable;
1578 
1579  // B is a base of D. But is it an allowed base? If not, it's a hard error.
1580  if (Paths.isAmbiguous(Self.Context.getCanonicalType(DestClass))) {
1581  Paths.clear();
1582  Paths.setRecordingPaths(true);
1583  bool StillOkay =
1584  Self.IsDerivedFrom(OpRange.getBegin(), SrcClass, DestClass, Paths);
1585  assert(StillOkay);
1586  (void)StillOkay;
1587  std::string PathDisplayStr = Self.getAmbiguousPathsDisplayString(Paths);
1588  Self.Diag(OpRange.getBegin(), diag::err_ambiguous_memptr_conv)
1589  << 1 << SrcClass << DestClass << PathDisplayStr << OpRange;
1590  msg = 0;
1591  return TC_Failed;
1592  }
1593 
1594  if (const RecordType *VBase = Paths.getDetectedVirtual()) {
1595  Self.Diag(OpRange.getBegin(), diag::err_memptr_conv_via_virtual)
1596  << SrcClass << DestClass << QualType(VBase, 0) << OpRange;
1597  msg = 0;
1598  return TC_Failed;
1599  }
1600 
1601  if (!CStyle) {
1602  switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
1603  DestClass, SrcClass,
1604  Paths.front(),
1605  diag::err_upcast_to_inaccessible_base)) {
1606  case Sema::AR_accessible:
1607  case Sema::AR_delayed:
1608  case Sema::AR_dependent:
1609  // Optimistically assume that the delayed and dependent cases
1610  // will work out.
1611  break;
1612 
1613  case Sema::AR_inaccessible:
1614  msg = 0;
1615  return TC_Failed;
1616  }
1617  }
1618 
1619  if (WasOverloadedFunction) {
1620  // Resolve the address of the overloaded function again, this time
1621  // allowing complaints if something goes wrong.
1623  DestType,
1624  true,
1625  FoundOverload);
1626  if (!Fn) {
1627  msg = 0;
1628  return TC_Failed;
1629  }
1630 
1631  SrcExpr = Self.FixOverloadedFunctionReference(SrcExpr, FoundOverload, Fn);
1632  if (!SrcExpr.isUsable()) {
1633  msg = 0;
1634  return TC_Failed;
1635  }
1636  }
1637 
1638  Self.BuildBasePathArray(Paths, BasePath);
1639  Kind = CK_DerivedToBaseMemberPointer;
1640  return TC_Success;
1641 }
1642 
1643 /// TryStaticImplicitCast - Tests whether a conversion according to C++ 5.2.9p2
1644 /// is valid:
1645 ///
1646 /// An expression e can be explicitly converted to a type T using a
1647 /// @c static_cast if the declaration "T t(e);" is well-formed [...].
1649 TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr, QualType DestType,
1651  SourceRange OpRange, unsigned &msg,
1652  CastKind &Kind, bool ListInitialization) {
1653  if (DestType->isRecordType()) {
1654  if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
1655  diag::err_bad_cast_incomplete) ||
1656  Self.RequireNonAbstractType(OpRange.getBegin(), DestType,
1657  diag::err_allocation_of_abstract_type)) {
1658  msg = 0;
1659  return TC_Failed;
1660  }
1661  }
1662 
1664  InitializationKind InitKind
1665  = (CCK == Sema::CCK_CStyleCast)
1666  ? InitializationKind::CreateCStyleCast(OpRange.getBegin(), OpRange,
1667  ListInitialization)
1668  : (CCK == Sema::CCK_FunctionalCast)
1669  ? InitializationKind::CreateFunctionalCast(OpRange, ListInitialization)
1670  : InitializationKind::CreateCast(OpRange);
1671  Expr *SrcExprRaw = SrcExpr.get();
1672  // FIXME: Per DR242, we should check for an implicit conversion sequence
1673  // or for a constructor that could be invoked by direct-initialization
1674  // here, not for an initialization sequence.
1675  InitializationSequence InitSeq(Self, Entity, InitKind, SrcExprRaw);
1676 
1677  // At this point of CheckStaticCast, if the destination is a reference,
1678  // or the expression is an overload expression this has to work.
1679  // There is no other way that works.
1680  // On the other hand, if we're checking a C-style cast, we've still got
1681  // the reinterpret_cast way.
1682  bool CStyle
1683  = (CCK == Sema::CCK_CStyleCast || CCK == Sema::CCK_FunctionalCast);
1684  if (InitSeq.Failed() && (CStyle || !DestType->isReferenceType()))
1685  return TC_NotApplicable;
1686 
1687  ExprResult Result = InitSeq.Perform(Self, Entity, InitKind, SrcExprRaw);
1688  if (Result.isInvalid()) {
1689  msg = 0;
1690  return TC_Failed;
1691  }
1692 
1693  if (InitSeq.isConstructorInitialization())
1694  Kind = CK_ConstructorConversion;
1695  else
1696  Kind = CK_NoOp;
1697 
1698  SrcExpr = Result;
1699  return TC_Success;
1700 }
1701 
1702 /// TryConstCast - See if a const_cast from source to destination is allowed,
1703 /// and perform it if it is.
1705  QualType DestType, bool CStyle,
1706  unsigned &msg) {
1707  DestType = Self.Context.getCanonicalType(DestType);
1708  QualType SrcType = SrcExpr.get()->getType();
1709  bool NeedToMaterializeTemporary = false;
1710 
1711  if (const ReferenceType *DestTypeTmp =DestType->getAs<ReferenceType>()) {
1712  // C++11 5.2.11p4:
1713  // if a pointer to T1 can be explicitly converted to the type "pointer to
1714  // T2" using a const_cast, then the following conversions can also be
1715  // made:
1716  // -- an lvalue of type T1 can be explicitly converted to an lvalue of
1717  // type T2 using the cast const_cast<T2&>;
1718  // -- a glvalue of type T1 can be explicitly converted to an xvalue of
1719  // type T2 using the cast const_cast<T2&&>; and
1720  // -- if T1 is a class type, a prvalue of type T1 can be explicitly
1721  // converted to an xvalue of type T2 using the cast const_cast<T2&&>.
1722 
1723  if (isa<LValueReferenceType>(DestTypeTmp) && !SrcExpr.get()->isLValue()) {
1724  // Cannot const_cast non-lvalue to lvalue reference type. But if this
1725  // is C-style, static_cast might find a way, so we simply suggest a
1726  // message and tell the parent to keep searching.
1727  msg = diag::err_bad_cxx_cast_rvalue;
1728  return TC_NotApplicable;
1729  }
1730 
1731  if (isa<RValueReferenceType>(DestTypeTmp) && SrcExpr.get()->isRValue()) {
1732  if (!SrcType->isRecordType()) {
1733  // Cannot const_cast non-class prvalue to rvalue reference type. But if
1734  // this is C-style, static_cast can do this.
1735  msg = diag::err_bad_cxx_cast_rvalue;
1736  return TC_NotApplicable;
1737  }
1738 
1739  // Materialize the class prvalue so that the const_cast can bind a
1740  // reference to it.
1741  NeedToMaterializeTemporary = true;
1742  }
1743 
1744  // It's not completely clear under the standard whether we can
1745  // const_cast bit-field gl-values. Doing so would not be
1746  // intrinsically complicated, but for now, we say no for
1747  // consistency with other compilers and await the word of the
1748  // committee.
1749  if (SrcExpr.get()->refersToBitField()) {
1750  msg = diag::err_bad_cxx_cast_bitfield;
1751  return TC_NotApplicable;
1752  }
1753 
1754  DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
1755  SrcType = Self.Context.getPointerType(SrcType);
1756  }
1757 
1758  // C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
1759  // the rules for const_cast are the same as those used for pointers.
1760 
1761  if (!DestType->isPointerType() &&
1762  !DestType->isMemberPointerType() &&
1763  !DestType->isObjCObjectPointerType()) {
1764  // Cannot cast to non-pointer, non-reference type. Note that, if DestType
1765  // was a reference type, we converted it to a pointer above.
1766  // The status of rvalue references isn't entirely clear, but it looks like
1767  // conversion to them is simply invalid.
1768  // C++ 5.2.11p3: For two pointer types [...]
1769  if (!CStyle)
1770  msg = diag::err_bad_const_cast_dest;
1771  return TC_NotApplicable;
1772  }
1773  if (DestType->isFunctionPointerType() ||
1774  DestType->isMemberFunctionPointerType()) {
1775  // Cannot cast direct function pointers.
1776  // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
1777  // T is the ultimate pointee of source and target type.
1778  if (!CStyle)
1779  msg = diag::err_bad_const_cast_dest;
1780  return TC_NotApplicable;
1781  }
1782 
1783  // C++ [expr.const.cast]p3:
1784  // "For two similar types T1 and T2, [...]"
1785  //
1786  // We only allow a const_cast to change cvr-qualifiers, not other kinds of
1787  // type qualifiers. (Likewise, we ignore other changes when determining
1788  // whether a cast casts away constness.)
1789  if (!Self.Context.hasCvrSimilarType(SrcType, DestType))
1790  return TC_NotApplicable;
1791 
1792  if (NeedToMaterializeTemporary)
1793  // This is a const_cast from a class prvalue to an rvalue reference type.
1794  // Materialize a temporary to store the result of the conversion.
1795  SrcExpr = Self.CreateMaterializeTemporaryExpr(SrcExpr.get()->getType(),
1796  SrcExpr.get(),
1797  /*IsLValueReference*/ false);
1798 
1799  return TC_Success;
1800 }
1801 
1802 // Checks for undefined behavior in reinterpret_cast.
1803 // The cases that is checked for is:
1804 // *reinterpret_cast<T*>(&a)
1805 // reinterpret_cast<T&>(a)
1806 // where accessing 'a' as type 'T' will result in undefined behavior.
1808  bool IsDereference,
1809  SourceRange Range) {
1810  unsigned DiagID = IsDereference ?
1811  diag::warn_pointer_indirection_from_incompatible_type :
1812  diag::warn_undefined_reinterpret_cast;
1813 
1814  if (Diags.isIgnored(DiagID, Range.getBegin()))
1815  return;
1816 
1817  QualType SrcTy, DestTy;
1818  if (IsDereference) {
1819  if (!SrcType->getAs<PointerType>() || !DestType->getAs<PointerType>()) {
1820  return;
1821  }
1822  SrcTy = SrcType->getPointeeType();
1823  DestTy = DestType->getPointeeType();
1824  } else {
1825  if (!DestType->getAs<ReferenceType>()) {
1826  return;
1827  }
1828  SrcTy = SrcType;
1829  DestTy = DestType->getPointeeType();
1830  }
1831 
1832  // Cast is compatible if the types are the same.
1833  if (Context.hasSameUnqualifiedType(DestTy, SrcTy)) {
1834  return;
1835  }
1836  // or one of the types is a char or void type
1837  if (DestTy->isAnyCharacterType() || DestTy->isVoidType() ||
1838  SrcTy->isAnyCharacterType() || SrcTy->isVoidType()) {
1839  return;
1840  }
1841  // or one of the types is a tag type.
1842  if (SrcTy->getAs<TagType>() || DestTy->getAs<TagType>()) {
1843  return;
1844  }
1845 
1846  // FIXME: Scoped enums?
1847  if ((SrcTy->isUnsignedIntegerType() && DestTy->isSignedIntegerType()) ||
1848  (SrcTy->isSignedIntegerType() && DestTy->isUnsignedIntegerType())) {
1849  if (Context.getTypeSize(DestTy) == Context.getTypeSize(SrcTy)) {
1850  return;
1851  }
1852  }
1853 
1854  Diag(Range.getBegin(), DiagID) << SrcType << DestType << Range;
1855 }
1856 
1857 static void DiagnoseCastOfObjCSEL(Sema &Self, const ExprResult &SrcExpr,
1858  QualType DestType) {
1859  QualType SrcType = SrcExpr.get()->getType();
1860  if (Self.Context.hasSameType(SrcType, DestType))
1861  return;
1862  if (const PointerType *SrcPtrTy = SrcType->getAs<PointerType>())
1863  if (SrcPtrTy->isObjCSelType()) {
1864  QualType DT = DestType;
1865  if (isa<PointerType>(DestType))
1866  DT = DestType->getPointeeType();
1867  if (!DT.getUnqualifiedType()->isVoidType())
1868  Self.Diag(SrcExpr.get()->getExprLoc(),
1869  diag::warn_cast_pointer_from_sel)
1870  << SrcType << DestType << SrcExpr.get()->getSourceRange();
1871  }
1872 }
1873 
1874 /// Diagnose casts that change the calling convention of a pointer to a function
1875 /// defined in the current TU.
1876 static void DiagnoseCallingConvCast(Sema &Self, const ExprResult &SrcExpr,
1877  QualType DstType, SourceRange OpRange) {
1878  // Check if this cast would change the calling convention of a function
1879  // pointer type.
1880  QualType SrcType = SrcExpr.get()->getType();
1881  if (Self.Context.hasSameType(SrcType, DstType) ||
1882  !SrcType->isFunctionPointerType() || !DstType->isFunctionPointerType())
1883  return;
1884  const auto *SrcFTy =
1885  SrcType->castAs<PointerType>()->getPointeeType()->castAs<FunctionType>();
1886  const auto *DstFTy =
1887  DstType->castAs<PointerType>()->getPointeeType()->castAs<FunctionType>();
1888  CallingConv SrcCC = SrcFTy->getCallConv();
1889  CallingConv DstCC = DstFTy->getCallConv();
1890  if (SrcCC == DstCC)
1891  return;
1892 
1893  // We have a calling convention cast. Check if the source is a pointer to a
1894  // known, specific function that has already been defined.
1895  Expr *Src = SrcExpr.get()->IgnoreParenImpCasts();
1896  if (auto *UO = dyn_cast<UnaryOperator>(Src))
1897  if (UO->getOpcode() == UO_AddrOf)
1898  Src = UO->getSubExpr()->IgnoreParenImpCasts();
1899  auto *DRE = dyn_cast<DeclRefExpr>(Src);
1900  if (!DRE)
1901  return;
1902  auto *FD = dyn_cast<FunctionDecl>(DRE->getDecl());
1903  if (!FD)
1904  return;
1905 
1906  // Only warn if we are casting from the default convention to a non-default
1907  // convention. This can happen when the programmer forgot to apply the calling
1908  // convention to the function declaration and then inserted this cast to
1909  // satisfy the type system.
1911  FD->isVariadic(), FD->isCXXInstanceMember());
1912  if (DstCC == DefaultCC || SrcCC != DefaultCC)
1913  return;
1914 
1915  // Diagnose this cast, as it is probably bad.
1916  StringRef SrcCCName = FunctionType::getNameForCallConv(SrcCC);
1917  StringRef DstCCName = FunctionType::getNameForCallConv(DstCC);
1918  Self.Diag(OpRange.getBegin(), diag::warn_cast_calling_conv)
1919  << SrcCCName << DstCCName << OpRange;
1920 
1921  // The checks above are cheaper than checking if the diagnostic is enabled.
1922  // However, it's worth checking if the warning is enabled before we construct
1923  // a fixit.
1924  if (Self.Diags.isIgnored(diag::warn_cast_calling_conv, OpRange.getBegin()))
1925  return;
1926 
1927  // Try to suggest a fixit to change the calling convention of the function
1928  // whose address was taken. Try to use the latest macro for the convention.
1929  // For example, users probably want to write "WINAPI" instead of "__stdcall"
1930  // to match the Windows header declarations.
1931  SourceLocation NameLoc = FD->getFirstDecl()->getNameInfo().getLoc();
1932  Preprocessor &PP = Self.getPreprocessor();
1933  SmallVector<TokenValue, 6> AttrTokens;
1934  SmallString<64> CCAttrText;
1935  llvm::raw_svector_ostream OS(CCAttrText);
1936  if (Self.getLangOpts().MicrosoftExt) {
1937  // __stdcall or __vectorcall
1938  OS << "__" << DstCCName;
1939  IdentifierInfo *II = PP.getIdentifierInfo(OS.str());
1940  AttrTokens.push_back(II->isKeyword(Self.getLangOpts())
1941  ? TokenValue(II->getTokenID())
1942  : TokenValue(II));
1943  } else {
1944  // __attribute__((stdcall)) or __attribute__((vectorcall))
1945  OS << "__attribute__((" << DstCCName << "))";
1946  AttrTokens.push_back(tok::kw___attribute);
1947  AttrTokens.push_back(tok::l_paren);
1948  AttrTokens.push_back(tok::l_paren);
1949  IdentifierInfo *II = PP.getIdentifierInfo(DstCCName);
1950  AttrTokens.push_back(II->isKeyword(Self.getLangOpts())
1951  ? TokenValue(II->getTokenID())
1952  : TokenValue(II));
1953  AttrTokens.push_back(tok::r_paren);
1954  AttrTokens.push_back(tok::r_paren);
1955  }
1956  StringRef AttrSpelling = PP.getLastMacroWithSpelling(NameLoc, AttrTokens);
1957  if (!AttrSpelling.empty())
1958  CCAttrText = AttrSpelling;
1959  OS << ' ';
1960  Self.Diag(NameLoc, diag::note_change_calling_conv_fixit)
1961  << FD << DstCCName << FixItHint::CreateInsertion(NameLoc, CCAttrText);
1962 }
1963 
1964 static void checkIntToPointerCast(bool CStyle, SourceLocation Loc,
1965  const Expr *SrcExpr, QualType DestType,
1966  Sema &Self) {
1967  QualType SrcType = SrcExpr->getType();
1968 
1969  // Not warning on reinterpret_cast, boolean, constant expressions, etc
1970  // are not explicit design choices, but consistent with GCC's behavior.
1971  // Feel free to modify them if you've reason/evidence for an alternative.
1972  if (CStyle && SrcType->isIntegralType(Self.Context)
1973  && !SrcType->isBooleanType()
1974  && !SrcType->isEnumeralType()
1975  && !SrcExpr->isIntegerConstantExpr(Self.Context)
1976  && Self.Context.getTypeSize(DestType) >
1977  Self.Context.getTypeSize(SrcType)) {
1978  // Separate between casts to void* and non-void* pointers.
1979  // Some APIs use (abuse) void* for something like a user context,
1980  // and often that value is an integer even if it isn't a pointer itself.
1981  // Having a separate warning flag allows users to control the warning
1982  // for their workflow.
1983  unsigned Diag = DestType->isVoidPointerType() ?
1984  diag::warn_int_to_void_pointer_cast
1985  : diag::warn_int_to_pointer_cast;
1986  Self.Diag(Loc, Diag) << SrcType << DestType;
1987  }
1988 }
1989 
1990 static bool fixOverloadedReinterpretCastExpr(Sema &Self, QualType DestType,
1991  ExprResult &Result) {
1992  // We can only fix an overloaded reinterpret_cast if
1993  // - it is a template with explicit arguments that resolves to an lvalue
1994  // unambiguously, or
1995  // - it is the only function in an overload set that may have its address
1996  // taken.
1997 
1998  Expr *E = Result.get();
1999  // TODO: what if this fails because of DiagnoseUseOfDecl or something
2000  // like it?
2002  Result,
2003  Expr::getValueKindForType(DestType) == VK_RValue // Convert Fun to Ptr
2004  ) &&
2005  Result.isUsable())
2006  return true;
2007 
2008  // No guarantees that ResolveAndFixSingleFunctionTemplateSpecialization
2009  // preserves Result.
2010  Result = E;
2012  Result, /*DoFunctionPointerConversion=*/true))
2013  return false;
2014  return Result.isUsable();
2015 }
2016 
2018  QualType DestType, bool CStyle,
2019  SourceRange OpRange,
2020  unsigned &msg,
2021  CastKind &Kind) {
2022  bool IsLValueCast = false;
2023 
2024  DestType = Self.Context.getCanonicalType(DestType);
2025  QualType SrcType = SrcExpr.get()->getType();
2026 
2027  // Is the source an overloaded name? (i.e. &foo)
2028  // If so, reinterpret_cast generally can not help us here (13.4, p1, bullet 5)
2029  if (SrcType == Self.Context.OverloadTy) {
2030  ExprResult FixedExpr = SrcExpr;
2031  if (!fixOverloadedReinterpretCastExpr(Self, DestType, FixedExpr))
2032  return TC_NotApplicable;
2033 
2034  assert(FixedExpr.isUsable() && "Invalid result fixing overloaded expr");
2035  SrcExpr = FixedExpr;
2036  SrcType = SrcExpr.get()->getType();
2037  }
2038 
2039  if (const ReferenceType *DestTypeTmp = DestType->getAs<ReferenceType>()) {
2040  if (!SrcExpr.get()->isGLValue()) {
2041  // Cannot cast non-glvalue to (lvalue or rvalue) reference type. See the
2042  // similar comment in const_cast.
2043  msg = diag::err_bad_cxx_cast_rvalue;
2044  return TC_NotApplicable;
2045  }
2046 
2047  if (!CStyle) {
2048  Self.CheckCompatibleReinterpretCast(SrcType, DestType,
2049  /*IsDereference=*/false, OpRange);
2050  }
2051 
2052  // C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
2053  // same effect as the conversion *reinterpret_cast<T*>(&x) with the
2054  // built-in & and * operators.
2055 
2056  const char *inappropriate = nullptr;
2057  switch (SrcExpr.get()->getObjectKind()) {
2058  case OK_Ordinary:
2059  break;
2060  case OK_BitField:
2061  msg = diag::err_bad_cxx_cast_bitfield;
2062  return TC_NotApplicable;
2063  // FIXME: Use a specific diagnostic for the rest of these cases.
2064  case OK_VectorComponent: inappropriate = "vector element"; break;
2065  case OK_ObjCProperty: inappropriate = "property expression"; break;
2066  case OK_ObjCSubscript: inappropriate = "container subscripting expression";
2067  break;
2068  }
2069  if (inappropriate) {
2070  Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_reference)
2071  << inappropriate << DestType
2072  << OpRange << SrcExpr.get()->getSourceRange();
2073  msg = 0; SrcExpr = ExprError();
2074  return TC_NotApplicable;
2075  }
2076 
2077  // This code does this transformation for the checked types.
2078  DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
2079  SrcType = Self.Context.getPointerType(SrcType);
2080 
2081  IsLValueCast = true;
2082  }
2083 
2084  // Canonicalize source for comparison.
2085  SrcType = Self.Context.getCanonicalType(SrcType);
2086 
2087  const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>(),
2088  *SrcMemPtr = SrcType->getAs<MemberPointerType>();
2089  if (DestMemPtr && SrcMemPtr) {
2090  // C++ 5.2.10p9: An rvalue of type "pointer to member of X of type T1"
2091  // can be explicitly converted to an rvalue of type "pointer to member
2092  // of Y of type T2" if T1 and T2 are both function types or both object
2093  // types.
2094  if (DestMemPtr->isMemberFunctionPointer() !=
2095  SrcMemPtr->isMemberFunctionPointer())
2096  return TC_NotApplicable;
2097 
2098  if (Self.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
2099  // We need to determine the inheritance model that the class will use if
2100  // haven't yet.
2101  (void)Self.isCompleteType(OpRange.getBegin(), SrcType);
2102  (void)Self.isCompleteType(OpRange.getBegin(), DestType);
2103  }
2104 
2105  // Don't allow casting between member pointers of different sizes.
2106  if (Self.Context.getTypeSize(DestMemPtr) !=
2107  Self.Context.getTypeSize(SrcMemPtr)) {
2108  msg = diag::err_bad_cxx_cast_member_pointer_size;
2109  return TC_Failed;
2110  }
2111 
2112  // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away
2113  // constness.
2114  // A reinterpret_cast followed by a const_cast can, though, so in C-style,
2115  // we accept it.
2116  if (auto CACK =
2117  CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
2118  /*CheckObjCLifetime=*/CStyle))
2119  return getCastAwayConstnessCastKind(CACK, msg);
2120 
2121  // A valid member pointer cast.
2122  assert(!IsLValueCast);
2123  Kind = CK_ReinterpretMemberPointer;
2124  return TC_Success;
2125  }
2126 
2127  // See below for the enumeral issue.
2128  if (SrcType->isNullPtrType() && DestType->isIntegralType(Self.Context)) {
2129  // C++0x 5.2.10p4: A pointer can be explicitly converted to any integral
2130  // type large enough to hold it. A value of std::nullptr_t can be
2131  // converted to an integral type; the conversion has the same meaning
2132  // and validity as a conversion of (void*)0 to the integral type.
2133  if (Self.Context.getTypeSize(SrcType) >
2134  Self.Context.getTypeSize(DestType)) {
2135  msg = diag::err_bad_reinterpret_cast_small_int;
2136  return TC_Failed;
2137  }
2138  Kind = CK_PointerToIntegral;
2139  return TC_Success;
2140  }
2141 
2142  // Allow reinterpret_casts between vectors of the same size and
2143  // between vectors and integers of the same size.
2144  bool destIsVector = DestType->isVectorType();
2145  bool srcIsVector = SrcType->isVectorType();
2146  if (srcIsVector || destIsVector) {
2147  // The non-vector type, if any, must have integral type. This is
2148  // the same rule that C vector casts use; note, however, that enum
2149  // types are not integral in C++.
2150  if ((!destIsVector && !DestType->isIntegralType(Self.Context)) ||
2151  (!srcIsVector && !SrcType->isIntegralType(Self.Context)))
2152  return TC_NotApplicable;
2153 
2154  // The size we want to consider is eltCount * eltSize.
2155  // That's exactly what the lax-conversion rules will check.
2156  if (Self.areLaxCompatibleVectorTypes(SrcType, DestType)) {
2157  Kind = CK_BitCast;
2158  return TC_Success;
2159  }
2160 
2161  // Otherwise, pick a reasonable diagnostic.
2162  if (!destIsVector)
2163  msg = diag::err_bad_cxx_cast_vector_to_scalar_different_size;
2164  else if (!srcIsVector)
2165  msg = diag::err_bad_cxx_cast_scalar_to_vector_different_size;
2166  else
2167  msg = diag::err_bad_cxx_cast_vector_to_vector_different_size;
2168 
2169  return TC_Failed;
2170  }
2171 
2172  if (SrcType == DestType) {
2173  // C++ 5.2.10p2 has a note that mentions that, subject to all other
2174  // restrictions, a cast to the same type is allowed so long as it does not
2175  // cast away constness. In C++98, the intent was not entirely clear here,
2176  // since all other paragraphs explicitly forbid casts to the same type.
2177  // C++11 clarifies this case with p2.
2178  //
2179  // The only allowed types are: integral, enumeration, pointer, or
2180  // pointer-to-member types. We also won't restrict Obj-C pointers either.
2181  Kind = CK_NoOp;
2183  if (SrcType->isIntegralOrEnumerationType() ||
2184  SrcType->isAnyPointerType() ||
2185  SrcType->isMemberPointerType() ||
2186  SrcType->isBlockPointerType()) {
2187  Result = TC_Success;
2188  }
2189  return Result;
2190  }
2191 
2192  bool destIsPtr = DestType->isAnyPointerType() ||
2193  DestType->isBlockPointerType();
2194  bool srcIsPtr = SrcType->isAnyPointerType() ||
2195  SrcType->isBlockPointerType();
2196  if (!destIsPtr && !srcIsPtr) {
2197  // Except for std::nullptr_t->integer and lvalue->reference, which are
2198  // handled above, at least one of the two arguments must be a pointer.
2199  return TC_NotApplicable;
2200  }
2201 
2202  if (DestType->isIntegralType(Self.Context)) {
2203  assert(srcIsPtr && "One type must be a pointer");
2204  // C++ 5.2.10p4: A pointer can be explicitly converted to any integral
2205  // type large enough to hold it; except in Microsoft mode, where the
2206  // integral type size doesn't matter (except we don't allow bool).
2207  bool MicrosoftException = Self.getLangOpts().MicrosoftExt &&
2208  !DestType->isBooleanType();
2209  if ((Self.Context.getTypeSize(SrcType) >
2210  Self.Context.getTypeSize(DestType)) &&
2211  !MicrosoftException) {
2212  msg = diag::err_bad_reinterpret_cast_small_int;
2213  return TC_Failed;
2214  }
2215  Kind = CK_PointerToIntegral;
2216  return TC_Success;
2217  }
2218 
2219  if (SrcType->isIntegralOrEnumerationType()) {
2220  assert(destIsPtr && "One type must be a pointer");
2221  checkIntToPointerCast(CStyle, OpRange.getBegin(), SrcExpr.get(), DestType,
2222  Self);
2223  // C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
2224  // converted to a pointer.
2225  // C++ 5.2.10p9: [Note: ...a null pointer constant of integral type is not
2226  // necessarily converted to a null pointer value.]
2227  Kind = CK_IntegralToPointer;
2228  return TC_Success;
2229  }
2230 
2231  if (!destIsPtr || !srcIsPtr) {
2232  // With the valid non-pointer conversions out of the way, we can be even
2233  // more stringent.
2234  return TC_NotApplicable;
2235  }
2236 
2237  // Cannot convert between block pointers and Objective-C object pointers.
2238  if ((SrcType->isBlockPointerType() && DestType->isObjCObjectPointerType()) ||
2239  (DestType->isBlockPointerType() && SrcType->isObjCObjectPointerType()))
2240  return TC_NotApplicable;
2241 
2242  // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
2243  // The C-style cast operator can.
2244  TryCastResult SuccessResult = TC_Success;
2245  if (auto CACK =
2246  CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
2247  /*CheckObjCLifetime=*/CStyle))
2248  SuccessResult = getCastAwayConstnessCastKind(CACK, msg);
2249 
2250  if (IsAddressSpaceConversion(SrcType, DestType)) {
2251  Kind = CK_AddressSpaceConversion;
2252  assert(SrcType->isPointerType() && DestType->isPointerType());
2253  if (!CStyle &&
2255  SrcType->getPointeeType().getQualifiers())) {
2256  SuccessResult = TC_Failed;
2257  }
2258  } else if (IsLValueCast) {
2259  Kind = CK_LValueBitCast;
2260  } else if (DestType->isObjCObjectPointerType()) {
2261  Kind = Self.PrepareCastToObjCObjectPointer(SrcExpr);
2262  } else if (DestType->isBlockPointerType()) {
2263  if (!SrcType->isBlockPointerType()) {
2264  Kind = CK_AnyPointerToBlockPointerCast;
2265  } else {
2266  Kind = CK_BitCast;
2267  }
2268  } else {
2269  Kind = CK_BitCast;
2270  }
2271 
2272  // Any pointer can be cast to an Objective-C pointer type with a C-style
2273  // cast.
2274  if (CStyle && DestType->isObjCObjectPointerType()) {
2275  return SuccessResult;
2276  }
2277  if (CStyle)
2278  DiagnoseCastOfObjCSEL(Self, SrcExpr, DestType);
2279 
2280  DiagnoseCallingConvCast(Self, SrcExpr, DestType, OpRange);
2281 
2282  // Not casting away constness, so the only remaining check is for compatible
2283  // pointer categories.
2284 
2285  if (SrcType->isFunctionPointerType()) {
2286  if (DestType->isFunctionPointerType()) {
2287  // C++ 5.2.10p6: A pointer to a function can be explicitly converted to
2288  // a pointer to a function of a different type.
2289  return SuccessResult;
2290  }
2291 
2292  // C++0x 5.2.10p8: Converting a pointer to a function into a pointer to
2293  // an object type or vice versa is conditionally-supported.
2294  // Compilers support it in C++03 too, though, because it's necessary for
2295  // casting the return value of dlsym() and GetProcAddress().
2296  // FIXME: Conditionally-supported behavior should be configurable in the
2297  // TargetInfo or similar.
2298  Self.Diag(OpRange.getBegin(),
2299  Self.getLangOpts().CPlusPlus11 ?
2300  diag::warn_cxx98_compat_cast_fn_obj : diag::ext_cast_fn_obj)
2301  << OpRange;
2302  return SuccessResult;
2303  }
2304 
2305  if (DestType->isFunctionPointerType()) {
2306  // See above.
2307  Self.Diag(OpRange.getBegin(),
2308  Self.getLangOpts().CPlusPlus11 ?
2309  diag::warn_cxx98_compat_cast_fn_obj : diag::ext_cast_fn_obj)
2310  << OpRange;
2311  return SuccessResult;
2312  }
2313 
2314  // Diagnose address space conversion in nested pointers.
2315  QualType DestPtee = DestType->getPointeeType().isNull()
2316  ? DestType->getPointeeType()
2317  : DestType->getPointeeType()->getPointeeType();
2318  QualType SrcPtee = SrcType->getPointeeType().isNull()
2319  ? SrcType->getPointeeType()
2320  : SrcType->getPointeeType()->getPointeeType();
2321  while (!DestPtee.isNull() && !SrcPtee.isNull()) {
2322  if (DestPtee.getAddressSpace() != SrcPtee.getAddressSpace()) {
2323  Self.Diag(OpRange.getBegin(),
2324  diag::warn_bad_cxx_cast_nested_pointer_addr_space)
2325  << CStyle << SrcType << DestType << SrcExpr.get()->getSourceRange();
2326  break;
2327  }
2328  DestPtee = DestPtee->getPointeeType();
2329  SrcPtee = SrcPtee->getPointeeType();
2330  }
2331 
2332  // C++ 5.2.10p7: A pointer to an object can be explicitly converted to
2333  // a pointer to an object of different type.
2334  // Void pointers are not specified, but supported by every compiler out there.
2335  // So we finish by allowing everything that remains - it's got to be two
2336  // object pointers.
2337  return SuccessResult;
2338 }
2339 
2341  QualType DestType, bool CStyle,
2342  unsigned &msg) {
2343  if (!Self.getLangOpts().OpenCL)
2344  // FIXME: As compiler doesn't have any information about overlapping addr
2345  // spaces at the moment we have to be permissive here.
2346  return TC_NotApplicable;
2347  // Even though the logic below is general enough and can be applied to
2348  // non-OpenCL mode too, we fast-path above because no other languages
2349  // define overlapping address spaces currently.
2350  auto SrcType = SrcExpr.get()->getType();
2351  auto SrcPtrType = SrcType->getAs<PointerType>();
2352  if (!SrcPtrType)
2353  return TC_NotApplicable;
2354  auto DestPtrType = DestType->getAs<PointerType>();
2355  if (!DestPtrType)
2356  return TC_NotApplicable;
2357  auto SrcPointeeType = SrcPtrType->getPointeeType();
2358  auto DestPointeeType = DestPtrType->getPointeeType();
2359  if (SrcPointeeType.getAddressSpace() == DestPointeeType.getAddressSpace())
2360  return TC_NotApplicable;
2361  if (!DestPtrType->isAddressSpaceOverlapping(*SrcPtrType)) {
2362  msg = diag::err_bad_cxx_cast_addr_space_mismatch;
2363  return TC_Failed;
2364  }
2365  auto SrcPointeeTypeWithoutAS =
2366  Self.Context.removeAddrSpaceQualType(SrcPointeeType.getCanonicalType());
2367  auto DestPointeeTypeWithoutAS =
2368  Self.Context.removeAddrSpaceQualType(DestPointeeType.getCanonicalType());
2369  return Self.Context.hasSameType(SrcPointeeTypeWithoutAS,
2370  DestPointeeTypeWithoutAS)
2371  ? TC_Success
2372  : TC_NotApplicable;
2373 }
2374 
2375 void CastOperation::checkAddressSpaceCast(QualType SrcType, QualType DestType) {
2376  // In OpenCL only conversions between pointers to objects in overlapping
2377  // addr spaces are allowed. v2.0 s6.5.5 - Generic addr space overlaps
2378  // with any named one, except for constant.
2379 
2380  // Converting the top level pointee addrspace is permitted for compatible
2381  // addrspaces (such as 'generic int *' to 'local int *' or vice versa), but
2382  // if any of the nested pointee addrspaces differ, we emit a warning
2383  // regardless of addrspace compatibility. This makes
2384  // local int ** p;
2385  // return (generic int **) p;
2386  // warn even though local -> generic is permitted.
2387  if (Self.getLangOpts().OpenCL) {
2388  const Type *DestPtr, *SrcPtr;
2389  bool Nested = false;
2390  unsigned DiagID = diag::err_typecheck_incompatible_address_space;
2391  DestPtr = Self.getASTContext().getCanonicalType(DestType.getTypePtr()),
2392  SrcPtr = Self.getASTContext().getCanonicalType(SrcType.getTypePtr());
2393 
2394  while (isa<PointerType>(DestPtr) && isa<PointerType>(SrcPtr)) {
2395  const PointerType *DestPPtr = cast<PointerType>(DestPtr);
2396  const PointerType *SrcPPtr = cast<PointerType>(SrcPtr);
2397  QualType DestPPointee = DestPPtr->getPointeeType();
2398  QualType SrcPPointee = SrcPPtr->getPointeeType();
2399  if (Nested ? DestPPointee.getAddressSpace() !=
2400  SrcPPointee.getAddressSpace()
2401  : !DestPPtr->isAddressSpaceOverlapping(*SrcPPtr)) {
2402  Self.Diag(OpRange.getBegin(), DiagID)
2403  << SrcType << DestType << Sema::AA_Casting
2404  << SrcExpr.get()->getSourceRange();
2405  if (!Nested)
2406  SrcExpr = ExprError();
2407  return;
2408  }
2409 
2410  DestPtr = DestPPtr->getPointeeType().getTypePtr();
2411  SrcPtr = SrcPPtr->getPointeeType().getTypePtr();
2412  Nested = true;
2413  DiagID = diag::ext_nested_pointer_qualifier_mismatch;
2414  }
2415  }
2416 }
2417 
2418 void CastOperation::CheckCXXCStyleCast(bool FunctionalStyle,
2419  bool ListInitialization) {
2420  assert(Self.getLangOpts().CPlusPlus);
2421 
2422  // Handle placeholders.
2423  if (isPlaceholder()) {
2424  // C-style casts can resolve __unknown_any types.
2425  if (claimPlaceholder(BuiltinType::UnknownAny)) {
2426  SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
2427  SrcExpr.get(), Kind,
2428  ValueKind, BasePath);
2429  return;
2430  }
2431 
2432  checkNonOverloadPlaceholders();
2433  if (SrcExpr.isInvalid())
2434  return;
2435  }
2436 
2437  // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
2438  // This test is outside everything else because it's the only case where
2439  // a non-lvalue-reference target type does not lead to decay.
2440  if (DestType->isVoidType()) {
2441  Kind = CK_ToVoid;
2442 
2443  if (claimPlaceholder(BuiltinType::Overload)) {
2445  SrcExpr, /* Decay Function to ptr */ false,
2446  /* Complain */ true, DestRange, DestType,
2447  diag::err_bad_cstyle_cast_overload);
2448  if (SrcExpr.isInvalid())
2449  return;
2450  }
2451 
2452  SrcExpr = Self.IgnoredValueConversions(SrcExpr.get());
2453  return;
2454  }
2455 
2456  // If the type is dependent, we won't do any other semantic analysis now.
2457  if (DestType->isDependentType() || SrcExpr.get()->isTypeDependent() ||
2458  SrcExpr.get()->isValueDependent()) {
2459  assert(Kind == CK_Dependent);
2460  return;
2461  }
2462 
2463  if (ValueKind == VK_RValue && !DestType->isRecordType() &&
2464  !isPlaceholder(BuiltinType::Overload)) {
2465  SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
2466  if (SrcExpr.isInvalid())
2467  return;
2468  }
2469 
2470  // AltiVec vector initialization with a single literal.
2471  if (const VectorType *vecTy = DestType->getAs<VectorType>())
2472  if (vecTy->getVectorKind() == VectorType::AltiVecVector
2473  && (SrcExpr.get()->getType()->isIntegerType()
2474  || SrcExpr.get()->getType()->isFloatingType())) {
2475  Kind = CK_VectorSplat;
2476  SrcExpr = Self.prepareVectorSplat(DestType, SrcExpr.get());
2477  return;
2478  }
2479 
2480  // C++ [expr.cast]p5: The conversions performed by
2481  // - a const_cast,
2482  // - a static_cast,
2483  // - a static_cast followed by a const_cast,
2484  // - a reinterpret_cast, or
2485  // - a reinterpret_cast followed by a const_cast,
2486  // can be performed using the cast notation of explicit type conversion.
2487  // [...] If a conversion can be interpreted in more than one of the ways
2488  // listed above, the interpretation that appears first in the list is used,
2489  // even if a cast resulting from that interpretation is ill-formed.
2490  // In plain language, this means trying a const_cast ...
2491  // Note that for address space we check compatibility after const_cast.
2492  unsigned msg = diag::err_bad_cxx_cast_generic;
2493  TryCastResult tcr = TryConstCast(Self, SrcExpr, DestType,
2494  /*CStyle*/ true, msg);
2495  if (SrcExpr.isInvalid())
2496  return;
2497  if (isValidCast(tcr))
2498  Kind = CK_NoOp;
2499 
2501  FunctionalStyle ? Sema::CCK_FunctionalCast : Sema::CCK_CStyleCast;
2502  if (tcr == TC_NotApplicable) {
2503  tcr = TryAddressSpaceCast(Self, SrcExpr, DestType, /*CStyle*/ true, msg);
2504  if (SrcExpr.isInvalid())
2505  return;
2506 
2507  if (isValidCast(tcr))
2508  Kind = CK_AddressSpaceConversion;
2509 
2510  if (tcr == TC_NotApplicable) {
2511  // ... or if that is not possible, a static_cast, ignoring const, ...
2512  tcr = TryStaticCast(Self, SrcExpr, DestType, CCK, OpRange, msg, Kind,
2513  BasePath, ListInitialization);
2514  if (SrcExpr.isInvalid())
2515  return;
2516 
2517  if (tcr == TC_NotApplicable) {
2518  // ... and finally a reinterpret_cast, ignoring const.
2519  tcr = TryReinterpretCast(Self, SrcExpr, DestType, /*CStyle*/ true,
2520  OpRange, msg, Kind);
2521  if (SrcExpr.isInvalid())
2522  return;
2523  }
2524  }
2525  }
2526 
2528  isValidCast(tcr))
2529  checkObjCConversion(CCK);
2530 
2531  if (tcr != TC_Success && msg != 0) {
2532  if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
2533  DeclAccessPair Found;
2535  DestType,
2536  /*Complain*/ true,
2537  Found);
2538  if (Fn) {
2539  // If DestType is a function type (not to be confused with the function
2540  // pointer type), it will be possible to resolve the function address,
2541  // but the type cast should be considered as failure.
2542  OverloadExpr *OE = OverloadExpr::find(SrcExpr.get()).Expression;
2543  Self.Diag(OpRange.getBegin(), diag::err_bad_cstyle_cast_overload)
2544  << OE->getName() << DestType << OpRange
2545  << OE->getQualifierLoc().getSourceRange();
2546  Self.NoteAllOverloadCandidates(SrcExpr.get());
2547  }
2548  } else {
2549  diagnoseBadCast(Self, msg, (FunctionalStyle ? CT_Functional : CT_CStyle),
2550  OpRange, SrcExpr.get(), DestType, ListInitialization);
2551  }
2552  }
2553 
2554  if (isValidCast(tcr)) {
2555  if (Kind == CK_BitCast)
2556  checkCastAlign();
2557  } else {
2558  SrcExpr = ExprError();
2559  }
2560 }
2561 
2562 /// DiagnoseBadFunctionCast - Warn whenever a function call is cast to a
2563 /// non-matching type. Such as enum function call to int, int call to
2564 /// pointer; etc. Cast to 'void' is an exception.
2565 static void DiagnoseBadFunctionCast(Sema &Self, const ExprResult &SrcExpr,
2566  QualType DestType) {
2567  if (Self.Diags.isIgnored(diag::warn_bad_function_cast,
2568  SrcExpr.get()->getExprLoc()))
2569  return;
2570 
2571  if (!isa<CallExpr>(SrcExpr.get()))
2572  return;
2573 
2574  QualType SrcType = SrcExpr.get()->getType();
2575  if (DestType.getUnqualifiedType()->isVoidType())
2576  return;
2577  if ((SrcType->isAnyPointerType() || SrcType->isBlockPointerType())
2578  && (DestType->isAnyPointerType() || DestType->isBlockPointerType()))
2579  return;
2580  if (SrcType->isIntegerType() && DestType->isIntegerType() &&
2581  (SrcType->isBooleanType() == DestType->isBooleanType()) &&
2582  (SrcType->isEnumeralType() == DestType->isEnumeralType()))
2583  return;
2584  if (SrcType->isRealFloatingType() && DestType->isRealFloatingType())
2585  return;
2586  if (SrcType->isEnumeralType() && DestType->isEnumeralType())
2587  return;
2588  if (SrcType->isComplexType() && DestType->isComplexType())
2589  return;
2590  if (SrcType->isComplexIntegerType() && DestType->isComplexIntegerType())
2591  return;
2592 
2593  Self.Diag(SrcExpr.get()->getExprLoc(),
2594  diag::warn_bad_function_cast)
2595  << SrcType << DestType << SrcExpr.get()->getSourceRange();
2596 }
2597 
2598 /// Check the semantics of a C-style cast operation, in C.
2599 void CastOperation::CheckCStyleCast() {
2600  assert(!Self.getLangOpts().CPlusPlus);
2601 
2602  // C-style casts can resolve __unknown_any types.
2603  if (claimPlaceholder(BuiltinType::UnknownAny)) {
2604  SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
2605  SrcExpr.get(), Kind,
2606  ValueKind, BasePath);
2607  return;
2608  }
2609 
2610  // C99 6.5.4p2: the cast type needs to be void or scalar and the expression
2611  // type needs to be scalar.
2612  if (DestType->isVoidType()) {
2613  // We don't necessarily do lvalue-to-rvalue conversions on this.
2614  SrcExpr = Self.IgnoredValueConversions(SrcExpr.get());
2615  if (SrcExpr.isInvalid())
2616  return;
2617 
2618  // Cast to void allows any expr type.
2619  Kind = CK_ToVoid;
2620  return;
2621  }
2622 
2623  // Overloads are allowed with C extensions, so we need to support them.
2624  if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
2625  DeclAccessPair DAP;
2627  SrcExpr.get(), DestType, /*Complain=*/true, DAP))
2628  SrcExpr = Self.FixOverloadedFunctionReference(SrcExpr.get(), DAP, FD);
2629  else
2630  return;
2631  assert(SrcExpr.isUsable());
2632  }
2633  SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
2634  if (SrcExpr.isInvalid())
2635  return;
2636  QualType SrcType = SrcExpr.get()->getType();
2637 
2638  assert(!SrcType->isPlaceholderType());
2639 
2640  checkAddressSpaceCast(SrcType, DestType);
2641  if (SrcExpr.isInvalid())
2642  return;
2643 
2644  if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
2645  diag::err_typecheck_cast_to_incomplete)) {
2646  SrcExpr = ExprError();
2647  return;
2648  }
2649 
2650  if (!DestType->isScalarType() && !DestType->isVectorType()) {
2651  const RecordType *DestRecordTy = DestType->getAs<RecordType>();
2652 
2653  if (DestRecordTy && Self.Context.hasSameUnqualifiedType(DestType, SrcType)){
2654  // GCC struct/union extension: allow cast to self.
2655  Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_nonscalar)
2656  << DestType << SrcExpr.get()->getSourceRange();
2657  Kind = CK_NoOp;
2658  return;
2659  }
2660 
2661  // GCC's cast to union extension.
2662  if (DestRecordTy && DestRecordTy->getDecl()->isUnion()) {
2663  RecordDecl *RD = DestRecordTy->getDecl();
2664  if (CastExpr::getTargetFieldForToUnionCast(RD, SrcType)) {
2665  Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_to_union)
2666  << SrcExpr.get()->getSourceRange();
2667  Kind = CK_ToUnion;
2668  return;
2669  } else {
2670  Self.Diag(OpRange.getBegin(), diag::err_typecheck_cast_to_union_no_type)
2671  << SrcType << SrcExpr.get()->getSourceRange();
2672  SrcExpr = ExprError();
2673  return;
2674  }
2675  }
2676 
2677  // OpenCL v2.0 s6.13.10 - Allow casts from '0' to event_t type.
2678  if (Self.getLangOpts().OpenCL && DestType->isEventT()) {
2680  if (SrcExpr.get()->EvaluateAsInt(Result, Self.Context)) {
2681  llvm::APSInt CastInt = Result.Val.getInt();
2682  if (0 == CastInt) {
2683  Kind = CK_ZeroToOCLOpaqueType;
2684  return;
2685  }
2686  Self.Diag(OpRange.getBegin(),
2687  diag::err_opencl_cast_non_zero_to_event_t)
2688  << CastInt.toString(10) << SrcExpr.get()->getSourceRange();
2689  SrcExpr = ExprError();
2690  return;
2691  }
2692  }
2693 
2694  // Reject any other conversions to non-scalar types.
2695  Self.Diag(OpRange.getBegin(), diag::err_typecheck_cond_expect_scalar)
2696  << DestType << SrcExpr.get()->getSourceRange();
2697  SrcExpr = ExprError();
2698  return;
2699  }
2700 
2701  // The type we're casting to is known to be a scalar or vector.
2702 
2703  // Require the operand to be a scalar or vector.
2704  if (!SrcType->isScalarType() && !SrcType->isVectorType()) {
2705  Self.Diag(SrcExpr.get()->getExprLoc(),
2706  diag::err_typecheck_expect_scalar_operand)
2707  << SrcType << SrcExpr.get()->getSourceRange();
2708  SrcExpr = ExprError();
2709  return;
2710  }
2711 
2712  if (DestType->isExtVectorType()) {
2713  SrcExpr = Self.CheckExtVectorCast(OpRange, DestType, SrcExpr.get(), Kind);
2714  return;
2715  }
2716 
2717  if (const VectorType *DestVecTy = DestType->getAs<VectorType>()) {
2718  if (DestVecTy->getVectorKind() == VectorType::AltiVecVector &&
2719  (SrcType->isIntegerType() || SrcType->isFloatingType())) {
2720  Kind = CK_VectorSplat;
2721  SrcExpr = Self.prepareVectorSplat(DestType, SrcExpr.get());
2722  } else if (Self.CheckVectorCast(OpRange, DestType, SrcType, Kind)) {
2723  SrcExpr = ExprError();
2724  }
2725  return;
2726  }
2727 
2728  if (SrcType->isVectorType()) {
2729  if (Self.CheckVectorCast(OpRange, SrcType, DestType, Kind))
2730  SrcExpr = ExprError();
2731  return;
2732  }
2733 
2734  // The source and target types are both scalars, i.e.
2735  // - arithmetic types (fundamental, enum, and complex)
2736  // - all kinds of pointers
2737  // Note that member pointers were filtered out with C++, above.
2738 
2739  if (isa<ObjCSelectorExpr>(SrcExpr.get())) {
2740  Self.Diag(SrcExpr.get()->getExprLoc(), diag::err_cast_selector_expr);
2741  SrcExpr = ExprError();
2742  return;
2743  }
2744 
2745  // If either type is a pointer, the other type has to be either an
2746  // integer or a pointer.
2747  if (!DestType->isArithmeticType()) {
2748  if (!SrcType->isIntegralType(Self.Context) && SrcType->isArithmeticType()) {
2749  Self.Diag(SrcExpr.get()->getExprLoc(),
2750  diag::err_cast_pointer_from_non_pointer_int)
2751  << SrcType << SrcExpr.get()->getSourceRange();
2752  SrcExpr = ExprError();
2753  return;
2754  }
2755  checkIntToPointerCast(/* CStyle */ true, OpRange.getBegin(), SrcExpr.get(),
2756  DestType, Self);
2757  } else if (!SrcType->isArithmeticType()) {
2758  if (!DestType->isIntegralType(Self.Context) &&
2759  DestType->isArithmeticType()) {
2760  Self.Diag(SrcExpr.get()->getBeginLoc(),
2761  diag::err_cast_pointer_to_non_pointer_int)
2762  << DestType << SrcExpr.get()->getSourceRange();
2763  SrcExpr = ExprError();
2764  return;
2765  }
2766  }
2767 
2768  if (Self.getLangOpts().OpenCL &&
2769  !Self.getOpenCLOptions().isEnabled("cl_khr_fp16")) {
2770  if (DestType->isHalfType()) {
2771  Self.Diag(SrcExpr.get()->getBeginLoc(), diag::err_opencl_cast_to_half)
2772  << DestType << SrcExpr.get()->getSourceRange();
2773  SrcExpr = ExprError();
2774  return;
2775  }
2776  }
2777 
2778  // ARC imposes extra restrictions on casts.
2780  checkObjCConversion(Sema::CCK_CStyleCast);
2781  if (SrcExpr.isInvalid())
2782  return;
2783 
2784  const PointerType *CastPtr = DestType->getAs<PointerType>();
2785  if (Self.getLangOpts().ObjCAutoRefCount && CastPtr) {
2786  if (const PointerType *ExprPtr = SrcType->getAs<PointerType>()) {
2787  Qualifiers CastQuals = CastPtr->getPointeeType().getQualifiers();
2788  Qualifiers ExprQuals = ExprPtr->getPointeeType().getQualifiers();
2789  if (CastPtr->getPointeeType()->isObjCLifetimeType() &&
2790  ExprPtr->getPointeeType()->isObjCLifetimeType() &&
2791  !CastQuals.compatiblyIncludesObjCLifetime(ExprQuals)) {
2792  Self.Diag(SrcExpr.get()->getBeginLoc(),
2793  diag::err_typecheck_incompatible_ownership)
2794  << SrcType << DestType << Sema::AA_Casting
2795  << SrcExpr.get()->getSourceRange();
2796  return;
2797  }
2798  }
2799  }
2800  else if (!Self.CheckObjCARCUnavailableWeakConversion(DestType, SrcType)) {
2801  Self.Diag(SrcExpr.get()->getBeginLoc(),
2802  diag::err_arc_convesion_of_weak_unavailable)
2803  << 1 << SrcType << DestType << SrcExpr.get()->getSourceRange();
2804  SrcExpr = ExprError();
2805  return;
2806  }
2807  }
2808 
2809  DiagnoseCastOfObjCSEL(Self, SrcExpr, DestType);
2810  DiagnoseCallingConvCast(Self, SrcExpr, DestType, OpRange);
2811  DiagnoseBadFunctionCast(Self, SrcExpr, DestType);
2812  Kind = Self.PrepareScalarCast(SrcExpr, DestType);
2813  if (SrcExpr.isInvalid())
2814  return;
2815 
2816  if (Kind == CK_BitCast)
2817  checkCastAlign();
2818 }
2819 
2820 void CastOperation::CheckBuiltinBitCast() {
2821  QualType SrcType = SrcExpr.get()->getType();
2822 
2823  if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
2824  diag::err_typecheck_cast_to_incomplete) ||
2825  Self.RequireCompleteType(OpRange.getBegin(), SrcType,
2826  diag::err_incomplete_type)) {
2827  SrcExpr = ExprError();
2828  return;
2829  }
2830 
2831  if (SrcExpr.get()->isRValue())
2832  SrcExpr = Self.CreateMaterializeTemporaryExpr(SrcType, SrcExpr.get(),
2833  /*IsLValueReference=*/false);
2834 
2835  CharUnits DestSize = Self.Context.getTypeSizeInChars(DestType);
2836  CharUnits SourceSize = Self.Context.getTypeSizeInChars(SrcType);
2837  if (DestSize != SourceSize) {
2838  Self.Diag(OpRange.getBegin(), diag::err_bit_cast_type_size_mismatch)
2839  << (int)SourceSize.getQuantity() << (int)DestSize.getQuantity();
2840  SrcExpr = ExprError();
2841  return;
2842  }
2843 
2844  if (!DestType.isTriviallyCopyableType(Self.Context)) {
2845  Self.Diag(OpRange.getBegin(), diag::err_bit_cast_non_trivially_copyable)
2846  << 1;
2847  SrcExpr = ExprError();
2848  return;
2849  }
2850 
2851  if (!SrcType.isTriviallyCopyableType(Self.Context)) {
2852  Self.Diag(OpRange.getBegin(), diag::err_bit_cast_non_trivially_copyable)
2853  << 0;
2854  SrcExpr = ExprError();
2855  return;
2856  }
2857 
2858  Kind = CK_LValueToRValueBitCast;
2859 }
2860 
2861 /// DiagnoseCastQual - Warn whenever casts discards a qualifiers, be it either
2862 /// const, volatile or both.
2863 static void DiagnoseCastQual(Sema &Self, const ExprResult &SrcExpr,
2864  QualType DestType) {
2865  if (SrcExpr.isInvalid())
2866  return;
2867 
2868  QualType SrcType = SrcExpr.get()->getType();
2869  if (!((SrcType->isAnyPointerType() && DestType->isAnyPointerType()) ||
2870  DestType->isLValueReferenceType()))
2871  return;
2872 
2873  QualType TheOffendingSrcType, TheOffendingDestType;
2874  Qualifiers CastAwayQualifiers;
2875  if (CastsAwayConstness(Self, SrcType, DestType, true, false,
2876  &TheOffendingSrcType, &TheOffendingDestType,
2877  &CastAwayQualifiers) !=
2878  CastAwayConstnessKind::CACK_Similar)
2879  return;
2880 
2881  // FIXME: 'restrict' is not properly handled here.
2882  int qualifiers = -1;
2883  if (CastAwayQualifiers.hasConst() && CastAwayQualifiers.hasVolatile()) {
2884  qualifiers = 0;
2885  } else if (CastAwayQualifiers.hasConst()) {
2886  qualifiers = 1;
2887  } else if (CastAwayQualifiers.hasVolatile()) {
2888  qualifiers = 2;
2889  }
2890  // This is a variant of int **x; const int **y = (const int **)x;
2891  if (qualifiers == -1)
2892  Self.Diag(SrcExpr.get()->getBeginLoc(), diag::warn_cast_qual2)
2893  << SrcType << DestType;
2894  else
2895  Self.Diag(SrcExpr.get()->getBeginLoc(), diag::warn_cast_qual)
2896  << TheOffendingSrcType << TheOffendingDestType << qualifiers;
2897 }
2898 
2900  TypeSourceInfo *CastTypeInfo,
2901  SourceLocation RPLoc,
2902  Expr *CastExpr) {
2903  CastOperation Op(*this, CastTypeInfo->getType(), CastExpr);
2904  Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
2905  Op.OpRange = SourceRange(LPLoc, CastExpr->getEndLoc());
2906 
2907  if (getLangOpts().CPlusPlus) {
2908  Op.CheckCXXCStyleCast(/*FunctionalCast=*/ false,
2909  isa<InitListExpr>(CastExpr));
2910  } else {
2911  Op.CheckCStyleCast();
2912  }
2913 
2914  if (Op.SrcExpr.isInvalid())
2915  return ExprError();
2916 
2917  // -Wcast-qual
2918  DiagnoseCastQual(Op.Self, Op.SrcExpr, Op.DestType);
2919 
2920  return Op.complete(CStyleCastExpr::Create(Context, Op.ResultType,
2921  Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
2922  &Op.BasePath, CastTypeInfo, LPLoc, RPLoc));
2923 }
2924 
2926  QualType Type,
2927  SourceLocation LPLoc,
2928  Expr *CastExpr,
2929  SourceLocation RPLoc) {
2930  assert(LPLoc.isValid() && "List-initialization shouldn't get here.");
2931  CastOperation Op(*this, Type, CastExpr);
2932  Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
2933  Op.OpRange = SourceRange(Op.DestRange.getBegin(), CastExpr->getEndLoc());
2934 
2935  Op.CheckCXXCStyleCast(/*FunctionalCast=*/true, /*ListInit=*/false);
2936  if (Op.SrcExpr.isInvalid())
2937  return ExprError();
2938 
2939  auto *SubExpr = Op.SrcExpr.get();
2940  if (auto *BindExpr = dyn_cast<CXXBindTemporaryExpr>(SubExpr))
2941  SubExpr = BindExpr->getSubExpr();
2942  if (auto *ConstructExpr = dyn_cast<CXXConstructExpr>(SubExpr))
2943  ConstructExpr->setParenOrBraceRange(SourceRange(LPLoc, RPLoc));
2944 
2945  return Op.complete(CXXFunctionalCastExpr::Create(Context, Op.ResultType,
2946  Op.ValueKind, CastTypeInfo, Op.Kind,
2947  Op.SrcExpr.get(), &Op.BasePath, LPLoc, RPLoc));
2948 }
Defines the clang::ASTContext interface.
bool RequireNonAbstractType(SourceLocation Loc, QualType T, TypeDiagnoser &Diagnoser)
Represents a function declaration or definition.
Definition: Decl.h:1783
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:2614
QualType getPointeeType() const
Definition: Type.h:2627
A (possibly-)qualified type.
Definition: Type.h:654
bool isBlockPointerType() const
Definition: Type.h:6512
bool isMemberPointerType() const
Definition: Type.h:6552
IdentifierInfo * getIdentifierInfo(StringRef Name) const
Return information about the specified preprocessor identifier token.
A cast other than a C-style cast.
Definition: Sema.h:10464
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:2036
FunctionType - C99 6.7.5.3 - Function Declarators.
Definition: Type.h:3422
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:557
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:799
bool isRealFloatingType() const
Floating point categories.
Definition: Type.cpp:2021
bool isRecordType() const
Definition: Type.h:6594
SemaDiagnosticBuilder Diag(SourceLocation Loc, unsigned DiagID)
Emit a diagnostic.
Definition: Sema.h:1411
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:6610
The cast method is appropriate and successful.
Definition: SemaCast.cpp:34
FailureKind getFailureKind() const
Determine why initialization failed.
CanQualType ARCUnbridgedCastTy
Definition: ASTContext.h:1047
The base class of the type hierarchy.
Definition: Type.h:1450
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:116
Ambiguous candidates found.
Definition: Overload.h:59
const TargetInfo & getTargetInfo() const
Definition: ASTContext.h:707
A container of type source information.
Definition: Type.h:6227
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:895
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:228
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:3324
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:1968
bool CheckVectorCast(SourceRange R, QualType VectorTy, QualType Ty, CastKind &Kind)
Definition: SemaExpr.cpp:6684
An Objective-C array/dictionary subscripting which reads an object or writes at the subscripted array...
Definition: Specifiers.h:156
RangeSelector range(RangeSelector Begin, RangeSelector End)
Selects from the start of Begin and to the end of End.
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:1792
void removeObjCLifetime()
Definition: Type.h:339
DiagnosticsEngine & Diags
Definition: Sema.h:387
bool isEnumeralType() const
Definition: Type.h:6598
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:1876
const T * getAs() const
Member-template getAs<specific type>&#39;.
Definition: Type.h:7002
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:2953
bool isInvalidDecl() const
Definition: DeclBase.h:553
ReferenceCompareResult CompareReferenceRelationship(SourceLocation Loc, QualType T1, QualType T2, ReferenceConversions *Conv=nullptr)
CompareReferenceRelationship - Compare the two types T1 and T2 to determine whether they are referenc...
OpenCLOptions & getOpenCLOptions()
Definition: Sema.h:1325
Defines the clang::Expr interface and subclasses for C++ expressions.
The collection of all-type qualifiers we support.
Definition: Type.h:143
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:58
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:3748
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:1063
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:168
bool allowsNonTrivialObjCLifetimeQualifiers() const
True if any ObjC types may have non-trivial lifetime qualifiers.
Definition: LangOptions.h:344
bool isObjCLifetimeType() const
Returns true if objects of this type have lifetime semantics under ARC.
Definition: Type.cpp:4080
The cast method is not applicable.
Definition: SemaCast.cpp:33
A C-style cast.
Definition: Sema.h:10460
RecordDecl * getDefinition() const
Returns the RecordDecl that actually defines this struct/union/class.
Definition: Decl.h:3953
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:275
TryCastResult
Definition: SemaCast.cpp:32
static TryCastResult getCastAwayConstnessCastKind(CastAwayConstnessKind CACK, unsigned &DiagID)
Definition: SemaCast.cpp:687
void removeConst()
Definition: Type.h:262
bool isReferenceType() const
Definition: Type.h:6516
static CharUnits Zero()
Zero - Construct a CharUnits quantity of zero.
Definition: CharUnits.h:53
Ref_Incompatible - The two types are incompatible, so direct reference binding is not possible...
Definition: Sema.h:10864
Expr * getSubExpr()
Definition: Expr.h:3202
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:6433
bool isIntegralOrEnumerationType() const
Determine whether this type is an integral or enumeration type.
Definition: Type.h:6881
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:2530
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:1817
An rvalue reference type, per C++11 [dcl.ref].
Definition: Type.h:2815
ReferenceConversions
The conversions that would be performed on an lvalue of type T2 when binding a reference of type T1 t...
Definition: Sema.h:10878
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:38
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:588
Ref_Compatible - The two types are reference-compatible.
Definition: Sema.h:10870
bool isTriviallyCopyableType(const ASTContext &Context) const
Return true if this is a trivially copyable type (C++0x [basic.types]p9)
Definition: Type.cpp:2289
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:2867
bool isRValueReferenceType() const
Definition: Type.h:6524
CheckedConversionKind
The kind of conversion being performed.
Definition: Sema.h:10456
static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr, QualType DestType, bool CStyle, SourceRange OpRange, unsigned &msg, CastKind &Kind)
Definition: SemaCast.cpp:2017
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:7750
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:6256
CastExpr - Base class for type casts, including both implicit casts (ImplicitCastExpr) and explicit c...
Definition: Expr.h:3150
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:2863
const internal::VariadicDynCastAllOfMatcher< Stmt, CastExpr > castExpr
Matches any cast nodes of Clang&#39;s AST.
const LangOptions & getLangOpts() const
Definition: Sema.h:1324
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:691
bool isScalarType() const
Definition: Type.h:6866
bool compatiblyIncludesObjCLifetime(Qualifiers other) const
Determines if these qualifiers compatibly include another set of qualifiers from the narrow perspecti...
Definition: Type.h:517
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:6394
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:260
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:6783
Sema - This implements semantic analysis and AST building for C.
Definition: Sema.h:336
CXXRecordDecl * getAsCXXRecordDecl() const
Retrieves the CXXRecordDecl that this type refers to, either because the type is a RecordType or beca...
Definition: Type.cpp:1690
A functional-style cast.
Definition: Sema.h:10462
bool compatiblyIncludes(Qualifiers other) const
Determines if these qualifiers compatibly include another set.
Definition: Type.h:496
bool isComplexType() const
isComplexType() does not include complex integers (a GCC extension).
Definition: Type.cpp:533
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:1998
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:1704
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:179
unsigned Offset
Definition: Format.cpp:1827
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:191
bool isEventT() const
Definition: Type.h:6687
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:2771
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:2904
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:1675
const T * castAs() const
Member-template castAs<specific type>.
Definition: Type.h:7067
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:6802
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:774
CXXRecordDecl * getDefinition() const
Definition: DeclCXX.h:533
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:89
ExprResult CheckPlaceholderExpr(Expr *E)
Check for operands with placeholder types and complain if found.
Definition: SemaExpr.cpp:17987
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:1649
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:10861
bool RequireCompleteType(SourceLocation Loc, QualType T, TypeDiagnoser &Diagnoser)
Ensure that the type T is a complete type.
Definition: SemaType.cpp:7919
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:1928
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:1531
bool ResolveAndFixSingleFunctionTemplateSpecialization(ExprResult &SrcExpr, bool DoFunctionPointerConverion=false, bool Complain=false, SourceRange OpRangeForComplaining=SourceRange(), QualType DestTypeForComplaining=QualType(), unsigned DiagIDForComplaining=0)
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:1330
Represents a GCC generic vector type.
Definition: Type.h:3235
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:1347
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:1417
The result type of a method or function.
bool isNull() const
Return true if this QualType doesn&#39;t point to a type yet.
Definition: Type.h:719
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:288
unsigned getCVRQualifiers() const
Retrieve the set of CVR (const-volatile-restrict) qualifiers applied to this type.
Definition: Type.h:6289
ExprResult BuildCStyleCastExpr(SourceLocation LParenLoc, TypeSourceInfo *Ty, SourceLocation RParenLoc, Expr *Op)
Definition: SemaCast.cpp:2899
bool isVoidPointerType() const
Definition: Type.cpp:521
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:6629
RecordDecl * getDecl() const
Definition: Type.h:4505
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:1419
CanQualType OverloadTy
Definition: ASTContext.h:1045
static CXXConstCastExpr * Create(const ASTContext &Context, QualType T, ExprValueKind VK, Expr *Op, TypeSourceInfo *WrittenTy, SourceLocation L, SourceLocation RParenLoc, SourceRange AngleBrackets)
Definition: ExprCXX.cpp:881
Kind
A reference to an overloaded function set, either an UnresolvedLookupExpr or an UnresolvedMemberExpr...
Definition: ExprCXX.h:2844
ActionResult - This structure is used while parsing/acting on expressions, stmts, etc...
Definition: Ownership.h:153
ASTContext & getASTContext() const
Definition: Sema.h:1331
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:4521
llvm::APSInt APSInt
CastKind PrepareCastToObjCObjectPointer(ExprResult &E)
Prepare a conversion of the given expression to an ObjC object pointer type.
Definition: SemaExpr.cpp:6379
LangAS getAddressSpace() const
Return the address space of this type.
Definition: Type.h:6377
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:1385
static const FieldDecl * getTargetFieldForToUnionCast(QualType unionType, QualType opType)
Definition: Expr.cpp:1978
Represents a C++2a __builtin_bit_cast(T, v) expression.
Definition: ExprCXX.h:4812
Requests that only tied-for-best candidates be shown.
Definition: Overload.h:74
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:1844
Represents a static or instance method of a struct/union/class.
Definition: DeclCXX.h:1931
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:6556
bool isObjCObjectPointerType() const
Definition: Type.h:6618
bool isAnyPointerType() const
Definition: Type.h:6508
bool resolveAndFixAddressOfSingleOverloadCandidate(ExprResult &SrcExpr, bool DoFunctionPointerConversion=false)
Given an overloaded function, tries to turn it into a non-overloaded function reference using resolve...
ImplicitCastExpr - Allows us to explicitly represent implicit type conversions, which have no direct ...
Definition: Expr.h:3274
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:3242
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:2637
bool isAnyCharacterType() const
Determine whether this type is any of the built-in character types.
Definition: Type.cpp:1907
bool isVectorType() const
Definition: Type.h:6606
void removeObjCGCAttr()
Definition: Type.h:311
OverloadCandidateSet - A set of overload candidates, used in C++ overload resolution (C++ 13...
Definition: Overload.h:896
reinterpret_cast
Definition: SemaCast.cpp:48
static TryCastResult TryAddressSpaceCast(Sema &Self, ExprResult &SrcExpr, QualType DestType, bool CStyle, unsigned &msg)
Definition: SemaCast.cpp:2340
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:2345
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:858
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:17895
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:6751
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:586
void CheckCompatibleReinterpretCast(QualType SrcType, QualType DestType, bool IsDereference, SourceRange Range)
Definition: SemaCast.cpp:1807
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:990
const CXXRecordDecl * getParent() const
Return the parent of this method declaration, which is the class in which this method is defined...
Definition: DeclCXX.h:2046
bool isBooleanType() const
Definition: Type.h:6894
ExprResult prepareVectorSplat(QualType VectorTy, Expr *SplattedExpr)
Prepare SplattedExpr for a vector splat operation, adding implicit casts if necessary.
Definition: SemaExpr.cpp:6704
static void checkIntToPointerCast(bool CStyle, SourceLocation Loc, const Expr *SrcExpr, QualType DestType, Sema &Self)
Definition: SemaCast.cpp:1964
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:2833
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:1857
static bool fixOverloadedReinterpretCastExpr(Sema &Self, QualType DestType, ExprResult &Result)
Definition: SemaCast.cpp:1990
Expr * IgnoreParenImpCasts() LLVM_READONLY
Skip past any parentheses and implicit casts which might surround this expression until reaching a fi...
Definition: Expr.cpp:2995
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:152
A helper class that allows the use of isa/cast/dyncast to detect TagType objects of structs/unions/cl...
Definition: Type.h:4495
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:6811
ExprResult CheckExtVectorCast(SourceRange R, QualType DestTy, Expr *CastExpr, CastKind &Kind)
Definition: SemaExpr.cpp:6737
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:2024
bool CheckDerivedToBaseConversion(QualType Derived, QualType Base, SourceLocation Loc, SourceRange Range, CXXCastPath *BasePath=nullptr, bool IgnoreAccess=false)
bool isFunctionType() const
Definition: Type.h:6500
MaterializeTemporaryExpr * CreateMaterializeTemporaryExpr(QualType T, Expr *Temporary, bool BoundToLvalueReference)
Definition: SemaInit.cpp:7698
CXXBasePath & front()
Base for LValueReferenceType and RValueReferenceType.
Definition: Type.h:2750
bool hasSameType(QualType T1, QualType T2) const
Determine whether the given types T1 and T2 are equivalent.
Definition: ASTContext.h:2321
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:1292
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:2915
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:2104
bool isObjCObjectType() const
Definition: Type.h:6622
QualType withCVRQualifiers(unsigned CVR) const
Definition: Type.h:846
CanQualType getCanonicalType(QualType T) const
Return the canonical (structural) type corresponding to the specified potentially non-canonical type ...
Definition: ASTContext.h:2305
bool isLValueReferenceType() const
Definition: Type.h:6520
ExprResult BuildCXXFunctionalCastExpr(TypeSourceInfo *TInfo, QualType Type, SourceLocation LParenLoc, Expr *CastExpr, SourceLocation RParenLoc)
Definition: SemaCast.cpp:2925
TypeLoc getTypeLoc() const
Return the TypeLoc wrapper for the type source info.
Definition: TypeLoc.h:244
bool Failed() const
Determine whether the initialization sequence is invalid.
CallingConv getCallConv() const
Definition: Type.h:3690
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:6336
Represents a C++ struct/union/class.
Definition: DeclCXX.h:253
bool isMemberFunctionPointer() const
Returns true if the member type (i.e.
Definition: Type.h:2857
bool isVoidType() const
Definition: Type.h:6777
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:6283
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:476
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:2465
SourceRange getSourceRange() const LLVM_READONLY
SourceLocation tokens are not useful in isolation - they are low level value objects created/interpre...
Definition: Stmt.cpp:263
Defines the clang::TargetInfo interface.
bool isComplexIntegerType() const
Definition: Type.cpp:539
bool isMicrosoft() const
Is this ABI an MSVC-compatible ABI?
Definition: TargetCXXABI.h:160
unsigned getCVRQualifiers() const
Definition: Type.h:276
ExprResult ExprError()
Definition: Ownership.h:279
static Qualifiers fromCVRMask(unsigned CVR)
Definition: Type.h:236
bool hasVolatile() const
Definition: Type.h:265
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:2565
bool isDependentType() const
Whether this type is a dependent type, meaning that its definition somehow depends on a template para...
Definition: Type.h:2150
A reference to a declared variable, function, enum, etc.
Definition: Expr.h:1171
bool isIgnored(unsigned DiagID, SourceLocation Loc) const
Determine whether the diagnostic is known to be ignored.
Definition: Diagnostic.h:825
bool isUnion() const
Definition: Decl.h:3407
NestedNameSpecifierLoc getQualifierLoc() const
Fetches the nested-name qualifier with source-location information, if one was given.
Definition: ExprCXX.h:2965
bool isPointerType() const
Definition: Type.h:6504
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:2931
bool isFloatingType() const
Definition: Type.cpp:2005
A trivial tuple used to represent a source range.
ASTContext & Context
Definition: Sema.h:385
paths_iterator end()
APSInt & getInt()
Definition: APValue.h:380
Describes an entity that is being initialized.
bool isFunctionPointerType() const
Definition: Type.h:6538
SourceLocation getBegin() const
const LangOptions & getLangOpts() const
Definition: ASTContext.h:724
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:1926
CastType
Definition: SemaCast.cpp:45
QualType getPointeeType() const
Definition: Type.h:2853
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: Type.h:6238
Engages in a tight little dance with the lexer to efficiently preprocess tokens.
Definition: Preprocessor.h:128