1 //===--- SemaCast.cpp - Semantic Analysis for Casts -----------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements semantic analysis for cast expressions, including
11 // 1) C-style casts like '(int) x'
12 // 2) C++ functional casts like 'int(x)'
13 // 3) C++ named casts like 'static_cast<int>(x)'
15 //===----------------------------------------------------------------------===//
17 #include "clang/Sema/SemaInternal.h"
18 #include "clang/Sema/Initialization.h"
19 #include "clang/AST/ExprCXX.h"
20 #include "clang/AST/ExprObjC.h"
21 #include "clang/AST/ASTContext.h"
22 #include "clang/AST/CXXInheritance.h"
23 #include "clang/Basic/PartialDiagnostic.h"
24 #include "llvm/ADT/SmallVector.h"
26 using namespace clang;
31 TC_NotApplicable, ///< The cast method is not applicable.
32 TC_Success, ///< The cast method is appropriate and successful.
33 TC_Failed ///< The cast method is appropriate, but failed. A
34 ///< diagnostic has been emitted.
38 CT_Const, ///< const_cast
39 CT_Static, ///< static_cast
40 CT_Reinterpret, ///< reinterpret_cast
41 CT_Dynamic, ///< dynamic_cast
42 CT_CStyle, ///< (Type)expr
43 CT_Functional ///< Type(expr)
47 struct CastOperation {
48 CastOperation(Sema &S, QualType destType, ExprResult src)
49 : Self(S), SrcExpr(src), DestType(destType),
50 ResultType(destType.getNonLValueExprType(S.Context)),
51 ValueKind(Expr::getValueKindForType(destType)),
52 Kind(CK_Dependent), IsARCUnbridgedCast(false) {
54 if (const BuiltinType *placeholder =
55 src.get()->getType()->getAsPlaceholderType()) {
56 PlaceholderKind = placeholder->getKind();
58 PlaceholderKind = (BuiltinType::Kind) 0;
66 ExprValueKind ValueKind;
68 BuiltinType::Kind PlaceholderKind;
70 bool IsARCUnbridgedCast;
73 SourceRange DestRange;
75 // Top-level semantics-checking routines.
76 void CheckConstCast();
77 void CheckReinterpretCast();
78 void CheckStaticCast();
79 void CheckDynamicCast();
80 void CheckCXXCStyleCast(bool FunctionalCast, bool ListInitialization);
81 void CheckCStyleCast();
83 /// Complete an apparently-successful cast operation that yields
84 /// the given expression.
85 ExprResult complete(CastExpr *castExpr) {
86 // If this is an unbridged cast, wrap the result in an implicit
87 // cast that yields the unbridged-cast placeholder type.
88 if (IsARCUnbridgedCast) {
89 castExpr = ImplicitCastExpr::Create(Self.Context,
90 Self.Context.ARCUnbridgedCastTy,
91 CK_Dependent, castExpr, 0,
92 castExpr->getValueKind());
94 return Self.Owned(castExpr);
97 // Internal convenience methods.
99 /// Try to handle the given placeholder expression kind. Return
100 /// true if the source expression has the appropriate placeholder
101 /// kind. A placeholder can only be claimed once.
102 bool claimPlaceholder(BuiltinType::Kind K) {
103 if (PlaceholderKind != K) return false;
105 PlaceholderKind = (BuiltinType::Kind) 0;
109 bool isPlaceholder() const {
110 return PlaceholderKind != 0;
112 bool isPlaceholder(BuiltinType::Kind K) const {
113 return PlaceholderKind == K;
116 void checkCastAlign() {
117 Self.CheckCastAlign(SrcExpr.get(), DestType, OpRange);
120 void checkObjCARCConversion(Sema::CheckedConversionKind CCK) {
121 assert(Self.getLangOpts().ObjCAutoRefCount);
123 Expr *src = SrcExpr.get();
124 if (Self.CheckObjCARCConversion(OpRange, DestType, src, CCK) ==
126 IsARCUnbridgedCast = true;
130 /// Check for and handle non-overload placeholder expressions.
131 void checkNonOverloadPlaceholders() {
132 if (!isPlaceholder() || isPlaceholder(BuiltinType::Overload))
135 SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.take());
136 if (SrcExpr.isInvalid())
138 PlaceholderKind = (BuiltinType::Kind) 0;
143 static bool CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType,
144 bool CheckCVR, bool CheckObjCLifetime);
146 // The Try functions attempt a specific way of casting. If they succeed, they
147 // return TC_Success. If their way of casting is not appropriate for the given
148 // arguments, they return TC_NotApplicable and *may* set diag to a diagnostic
149 // to emit if no other way succeeds. If their way of casting is appropriate but
150 // fails, they return TC_Failed and *must* set diag; they can set it to 0 if
151 // they emit a specialized diagnostic.
152 // All diagnostics returned by these functions must expect the same three
154 // %0: Cast Type (a value from the CastType enumeration)
156 // %2: Destination Type
157 static TryCastResult TryLValueToRValueCast(Sema &Self, Expr *SrcExpr,
158 QualType DestType, bool CStyle,
160 CXXCastPath &BasePath,
162 static TryCastResult TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr,
163 QualType DestType, bool CStyle,
164 const SourceRange &OpRange,
167 CXXCastPath &BasePath);
168 static TryCastResult TryStaticPointerDowncast(Sema &Self, QualType SrcType,
169 QualType DestType, bool CStyle,
170 const SourceRange &OpRange,
173 CXXCastPath &BasePath);
174 static TryCastResult TryStaticDowncast(Sema &Self, CanQualType SrcType,
175 CanQualType DestType, bool CStyle,
176 const SourceRange &OpRange,
177 QualType OrigSrcType,
178 QualType OrigDestType, unsigned &msg,
180 CXXCastPath &BasePath);
181 static TryCastResult TryStaticMemberPointerUpcast(Sema &Self, ExprResult &SrcExpr,
183 QualType DestType,bool CStyle,
184 const SourceRange &OpRange,
187 CXXCastPath &BasePath);
189 static TryCastResult TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr,
191 Sema::CheckedConversionKind CCK,
192 const SourceRange &OpRange,
193 unsigned &msg, CastKind &Kind,
194 bool ListInitialization);
195 static TryCastResult TryStaticCast(Sema &Self, ExprResult &SrcExpr,
197 Sema::CheckedConversionKind CCK,
198 const SourceRange &OpRange,
199 unsigned &msg, CastKind &Kind,
200 CXXCastPath &BasePath,
201 bool ListInitialization);
202 static TryCastResult TryConstCast(Sema &Self, Expr *SrcExpr, QualType DestType,
203 bool CStyle, unsigned &msg);
204 static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr,
205 QualType DestType, bool CStyle,
206 const SourceRange &OpRange,
211 /// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
213 Sema::ActOnCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
214 SourceLocation LAngleBracketLoc, Declarator &D,
215 SourceLocation RAngleBracketLoc,
216 SourceLocation LParenLoc, Expr *E,
217 SourceLocation RParenLoc) {
219 assert(!D.isInvalidType());
221 TypeSourceInfo *TInfo = GetTypeForDeclaratorCast(D, E->getType());
222 if (D.isInvalidType())
225 if (getLangOpts().CPlusPlus) {
226 // Check that there are no default arguments (C++ only).
227 CheckExtraCXXDefaultArguments(D);
230 return BuildCXXNamedCast(OpLoc, Kind, TInfo, move(E),
231 SourceRange(LAngleBracketLoc, RAngleBracketLoc),
232 SourceRange(LParenLoc, RParenLoc));
236 Sema::BuildCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
237 TypeSourceInfo *DestTInfo, Expr *E,
238 SourceRange AngleBrackets, SourceRange Parens) {
239 ExprResult Ex = Owned(E);
240 QualType DestType = DestTInfo->getType();
242 // If the type is dependent, we won't do the semantic analysis now.
243 // FIXME: should we check this in a more fine-grained manner?
244 bool TypeDependent = DestType->isDependentType() || Ex.get()->isTypeDependent();
246 CastOperation Op(*this, DestType, E);
247 Op.OpRange = SourceRange(OpLoc, Parens.getEnd());
248 Op.DestRange = AngleBrackets;
251 default: llvm_unreachable("Unknown C++ cast!");
253 case tok::kw_const_cast:
254 if (!TypeDependent) {
256 if (Op.SrcExpr.isInvalid())
259 return Op.complete(CXXConstCastExpr::Create(Context, Op.ResultType,
260 Op.ValueKind, Op.SrcExpr.take(), DestTInfo,
261 OpLoc, Parens.getEnd()));
263 case tok::kw_dynamic_cast: {
264 if (!TypeDependent) {
265 Op.CheckDynamicCast();
266 if (Op.SrcExpr.isInvalid())
269 return Op.complete(CXXDynamicCastExpr::Create(Context, Op.ResultType,
270 Op.ValueKind, Op.Kind, Op.SrcExpr.take(),
271 &Op.BasePath, DestTInfo,
272 OpLoc, Parens.getEnd()));
274 case tok::kw_reinterpret_cast: {
275 if (!TypeDependent) {
276 Op.CheckReinterpretCast();
277 if (Op.SrcExpr.isInvalid())
280 return Op.complete(CXXReinterpretCastExpr::Create(Context, Op.ResultType,
281 Op.ValueKind, Op.Kind, Op.SrcExpr.take(),
285 case tok::kw_static_cast: {
286 if (!TypeDependent) {
287 Op.CheckStaticCast();
288 if (Op.SrcExpr.isInvalid())
292 return Op.complete(CXXStaticCastExpr::Create(Context, Op.ResultType,
293 Op.ValueKind, Op.Kind, Op.SrcExpr.take(),
294 &Op.BasePath, DestTInfo,
295 OpLoc, Parens.getEnd()));
300 /// Try to diagnose a failed overloaded cast. Returns true if
301 /// diagnostics were emitted.
302 static bool tryDiagnoseOverloadedCast(Sema &S, CastType CT,
303 SourceRange range, Expr *src,
305 bool listInitialization) {
307 // These cast kinds don't consider user-defined conversions.
320 QualType srcType = src->getType();
321 if (!destType->isRecordType() && !srcType->isRecordType())
324 InitializedEntity entity = InitializedEntity::InitializeTemporary(destType);
325 InitializationKind initKind
326 = (CT == CT_CStyle)? InitializationKind::CreateCStyleCast(range.getBegin(),
327 range, listInitialization)
328 : (CT == CT_Functional)? InitializationKind::CreateFunctionalCast(range,
330 : InitializationKind::CreateCast(/*type range?*/ range);
331 InitializationSequence sequence(S, entity, initKind, &src, 1);
333 assert(sequence.Failed() && "initialization succeeded on second try?");
334 switch (sequence.getFailureKind()) {
335 default: return false;
337 case InitializationSequence::FK_ConstructorOverloadFailed:
338 case InitializationSequence::FK_UserConversionOverloadFailed:
342 OverloadCandidateSet &candidates = sequence.getFailedCandidateSet();
345 OverloadCandidateDisplayKind howManyCandidates = OCD_AllCandidates;
347 switch (sequence.getFailedOverloadResult()) {
348 case OR_Success: llvm_unreachable("successful failed overload");
349 case OR_No_Viable_Function:
350 if (candidates.empty())
351 msg = diag::err_ovl_no_conversion_in_cast;
353 msg = diag::err_ovl_no_viable_conversion_in_cast;
354 howManyCandidates = OCD_AllCandidates;
358 msg = diag::err_ovl_ambiguous_conversion_in_cast;
359 howManyCandidates = OCD_ViableCandidates;
363 msg = diag::err_ovl_deleted_conversion_in_cast;
364 howManyCandidates = OCD_ViableCandidates;
368 S.Diag(range.getBegin(), msg)
369 << CT << srcType << destType
370 << range << src->getSourceRange();
372 candidates.NoteCandidates(S, howManyCandidates, src);
377 /// Diagnose a failed cast.
378 static void diagnoseBadCast(Sema &S, unsigned msg, CastType castType,
379 SourceRange opRange, Expr *src, QualType destType,
380 bool listInitialization) {
381 if (src->getType() == S.Context.BoundMemberTy) {
382 (void) S.CheckPlaceholderExpr(src); // will always fail
386 if (msg == diag::err_bad_cxx_cast_generic &&
387 tryDiagnoseOverloadedCast(S, castType, opRange, src, destType,
391 S.Diag(opRange.getBegin(), msg) << castType
392 << src->getType() << destType << opRange << src->getSourceRange();
395 /// UnwrapDissimilarPointerTypes - Like Sema::UnwrapSimilarPointerTypes,
396 /// this removes one level of indirection from both types, provided that they're
397 /// the same kind of pointer (plain or to-member). Unlike the Sema function,
398 /// this one doesn't care if the two pointers-to-member don't point into the
399 /// same class. This is because CastsAwayConstness doesn't care.
400 static bool UnwrapDissimilarPointerTypes(QualType& T1, QualType& T2) {
401 const PointerType *T1PtrType = T1->getAs<PointerType>(),
402 *T2PtrType = T2->getAs<PointerType>();
403 if (T1PtrType && T2PtrType) {
404 T1 = T1PtrType->getPointeeType();
405 T2 = T2PtrType->getPointeeType();
408 const ObjCObjectPointerType *T1ObjCPtrType =
409 T1->getAs<ObjCObjectPointerType>(),
411 T2->getAs<ObjCObjectPointerType>();
414 T1 = T1ObjCPtrType->getPointeeType();
415 T2 = T2ObjCPtrType->getPointeeType();
418 else if (T2PtrType) {
419 T1 = T1ObjCPtrType->getPointeeType();
420 T2 = T2PtrType->getPointeeType();
424 else if (T2ObjCPtrType) {
426 T2 = T2ObjCPtrType->getPointeeType();
427 T1 = T1PtrType->getPointeeType();
432 const MemberPointerType *T1MPType = T1->getAs<MemberPointerType>(),
433 *T2MPType = T2->getAs<MemberPointerType>();
434 if (T1MPType && T2MPType) {
435 T1 = T1MPType->getPointeeType();
436 T2 = T2MPType->getPointeeType();
440 const BlockPointerType *T1BPType = T1->getAs<BlockPointerType>(),
441 *T2BPType = T2->getAs<BlockPointerType>();
442 if (T1BPType && T2BPType) {
443 T1 = T1BPType->getPointeeType();
444 T2 = T2BPType->getPointeeType();
451 /// CastsAwayConstness - Check if the pointer conversion from SrcType to
452 /// DestType casts away constness as defined in C++ 5.2.11p8ff. This is used by
453 /// the cast checkers. Both arguments must denote pointer (possibly to member)
456 /// \param CheckCVR Whether to check for const/volatile/restrict qualifiers.
458 /// \param CheckObjCLifetime Whether to check Objective-C lifetime qualifiers.
460 CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType,
461 bool CheckCVR, bool CheckObjCLifetime) {
462 // If the only checking we care about is for Objective-C lifetime qualifiers,
463 // and we're not in ARC mode, there's nothing to check.
464 if (!CheckCVR && CheckObjCLifetime &&
465 !Self.Context.getLangOpts().ObjCAutoRefCount)
468 // Casting away constness is defined in C++ 5.2.11p8 with reference to
469 // C++ 4.4. We piggyback on Sema::IsQualificationConversion for this, since
470 // the rules are non-trivial. So first we construct Tcv *...cv* as described
472 assert((SrcType->isAnyPointerType() || SrcType->isMemberPointerType() ||
473 SrcType->isBlockPointerType()) &&
474 "Source type is not pointer or pointer to member.");
475 assert((DestType->isAnyPointerType() || DestType->isMemberPointerType() ||
476 DestType->isBlockPointerType()) &&
477 "Destination type is not pointer or pointer to member.");
479 QualType UnwrappedSrcType = Self.Context.getCanonicalType(SrcType),
480 UnwrappedDestType = Self.Context.getCanonicalType(DestType);
481 SmallVector<Qualifiers, 8> cv1, cv2;
483 // Find the qualifiers. We only care about cvr-qualifiers for the
484 // purpose of this check, because other qualifiers (address spaces,
485 // Objective-C GC, etc.) are part of the type's identity.
486 while (UnwrapDissimilarPointerTypes(UnwrappedSrcType, UnwrappedDestType)) {
487 // Determine the relevant qualifiers at this level.
488 Qualifiers SrcQuals, DestQuals;
489 Self.Context.getUnqualifiedArrayType(UnwrappedSrcType, SrcQuals);
490 Self.Context.getUnqualifiedArrayType(UnwrappedDestType, DestQuals);
492 Qualifiers RetainedSrcQuals, RetainedDestQuals;
494 RetainedSrcQuals.setCVRQualifiers(SrcQuals.getCVRQualifiers());
495 RetainedDestQuals.setCVRQualifiers(DestQuals.getCVRQualifiers());
498 if (CheckObjCLifetime &&
499 !DestQuals.compatiblyIncludesObjCLifetime(SrcQuals))
502 cv1.push_back(RetainedSrcQuals);
503 cv2.push_back(RetainedDestQuals);
508 // Construct void pointers with those qualifiers (in reverse order of
509 // unwrapping, of course).
510 QualType SrcConstruct = Self.Context.VoidTy;
511 QualType DestConstruct = Self.Context.VoidTy;
512 ASTContext &Context = Self.Context;
513 for (SmallVector<Qualifiers, 8>::reverse_iterator i1 = cv1.rbegin(),
515 i1 != cv1.rend(); ++i1, ++i2) {
517 = Context.getPointerType(Context.getQualifiedType(SrcConstruct, *i1));
519 = Context.getPointerType(Context.getQualifiedType(DestConstruct, *i2));
522 // Test if they're compatible.
523 bool ObjCLifetimeConversion;
524 return SrcConstruct != DestConstruct &&
525 !Self.IsQualificationConversion(SrcConstruct, DestConstruct, false,
526 ObjCLifetimeConversion);
529 /// CheckDynamicCast - Check that a dynamic_cast\<DestType\>(SrcExpr) is valid.
530 /// Refer to C++ 5.2.7 for details. Dynamic casts are used mostly for runtime-
531 /// checked downcasts in class hierarchies.
532 void CastOperation::CheckDynamicCast() {
533 if (ValueKind == VK_RValue)
534 SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
535 else if (isPlaceholder())
536 SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.take());
537 if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
540 QualType OrigSrcType = SrcExpr.get()->getType();
541 QualType DestType = Self.Context.getCanonicalType(this->DestType);
543 // C++ 5.2.7p1: T shall be a pointer or reference to a complete class type,
544 // or "pointer to cv void".
546 QualType DestPointee;
547 const PointerType *DestPointer = DestType->getAs<PointerType>();
548 const ReferenceType *DestReference = 0;
550 DestPointee = DestPointer->getPointeeType();
551 } else if ((DestReference = DestType->getAs<ReferenceType>())) {
552 DestPointee = DestReference->getPointeeType();
554 Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ref_or_ptr)
555 << this->DestType << DestRange;
559 const RecordType *DestRecord = DestPointee->getAs<RecordType>();
560 if (DestPointee->isVoidType()) {
561 assert(DestPointer && "Reference to void is not possible");
562 } else if (DestRecord) {
563 if (Self.RequireCompleteType(OpRange.getBegin(), DestPointee,
564 Self.PDiag(diag::err_bad_dynamic_cast_incomplete)
568 Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
569 << DestPointee.getUnqualifiedType() << DestRange;
573 // C++0x 5.2.7p2: If T is a pointer type, v shall be an rvalue of a pointer to
574 // complete class type, [...]. If T is an lvalue reference type, v shall be
575 // an lvalue of a complete class type, [...]. If T is an rvalue reference
576 // type, v shall be an expression having a complete class type, [...]
577 QualType SrcType = Self.Context.getCanonicalType(OrigSrcType);
580 if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
581 SrcPointee = SrcPointer->getPointeeType();
583 Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ptr)
584 << OrigSrcType << SrcExpr.get()->getSourceRange();
587 } else if (DestReference->isLValueReferenceType()) {
588 if (!SrcExpr.get()->isLValue()) {
589 Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
590 << CT_Dynamic << OrigSrcType << this->DestType << OpRange;
592 SrcPointee = SrcType;
594 SrcPointee = SrcType;
597 const RecordType *SrcRecord = SrcPointee->getAs<RecordType>();
599 if (Self.RequireCompleteType(OpRange.getBegin(), SrcPointee,
600 Self.PDiag(diag::err_bad_dynamic_cast_incomplete)
601 << SrcExpr.get()->getSourceRange()))
604 Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
605 << SrcPointee.getUnqualifiedType() << SrcExpr.get()->getSourceRange();
609 assert((DestPointer || DestReference) &&
610 "Bad destination non-ptr/ref slipped through.");
611 assert((DestRecord || DestPointee->isVoidType()) &&
612 "Bad destination pointee slipped through.");
613 assert(SrcRecord && "Bad source pointee slipped through.");
615 // C++ 5.2.7p1: The dynamic_cast operator shall not cast away constness.
616 if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
617 Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_qualifiers_away)
618 << CT_Dynamic << OrigSrcType << this->DestType << OpRange;
622 // C++ 5.2.7p3: If the type of v is the same as the required result type,
624 if (DestRecord == SrcRecord) {
630 // Upcasts are resolved statically.
631 if (DestRecord && Self.IsDerivedFrom(SrcPointee, DestPointee)) {
632 if (Self.CheckDerivedToBaseConversion(SrcPointee, DestPointee,
633 OpRange.getBegin(), OpRange,
637 Kind = CK_DerivedToBase;
639 // If we are casting to or through a virtual base class, we need a
641 if (Self.BasePathInvolvesVirtualBase(BasePath))
642 Self.MarkVTableUsed(OpRange.getBegin(),
643 cast<CXXRecordDecl>(SrcRecord->getDecl()));
647 // C++ 5.2.7p6: Otherwise, v shall be [polymorphic].
648 const RecordDecl *SrcDecl = SrcRecord->getDecl()->getDefinition();
649 assert(SrcDecl && "Definition missing");
650 if (!cast<CXXRecordDecl>(SrcDecl)->isPolymorphic()) {
651 Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_polymorphic)
652 << SrcPointee.getUnqualifiedType() << SrcExpr.get()->getSourceRange();
654 Self.MarkVTableUsed(OpRange.getBegin(),
655 cast<CXXRecordDecl>(SrcRecord->getDecl()));
657 // Done. Everything else is run-time checks.
661 /// CheckConstCast - Check that a const_cast\<DestType\>(SrcExpr) is valid.
662 /// Refer to C++ 5.2.11 for details. const_cast is typically used in code
664 /// const char *str = "literal";
665 /// legacy_function(const_cast\<char*\>(str));
666 void CastOperation::CheckConstCast() {
667 if (ValueKind == VK_RValue)
668 SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
669 else if (isPlaceholder())
670 SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.take());
671 if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
674 unsigned msg = diag::err_bad_cxx_cast_generic;
675 if (TryConstCast(Self, SrcExpr.get(), DestType, /*CStyle*/false, msg) != TC_Success
677 Self.Diag(OpRange.getBegin(), msg) << CT_Const
678 << SrcExpr.get()->getType() << DestType << OpRange;
681 /// CheckReinterpretCast - Check that a reinterpret_cast\<DestType\>(SrcExpr) is
683 /// Refer to C++ 5.2.10 for details. reinterpret_cast is typically used in code
685 /// char *bytes = reinterpret_cast\<char*\>(int_ptr);
686 void CastOperation::CheckReinterpretCast() {
687 if (ValueKind == VK_RValue && !isPlaceholder(BuiltinType::Overload))
688 SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
690 checkNonOverloadPlaceholders();
691 if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
694 unsigned msg = diag::err_bad_cxx_cast_generic;
696 TryReinterpretCast(Self, SrcExpr, DestType,
697 /*CStyle*/false, OpRange, msg, Kind);
698 if (tcr != TC_Success && msg != 0)
700 if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
702 if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
703 //FIXME: &f<int>; is overloaded and resolvable
704 Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_overload)
705 << OverloadExpr::find(SrcExpr.get()).Expression->getName()
706 << DestType << OpRange;
707 Self.NoteAllOverloadCandidates(SrcExpr.get());
710 diagnoseBadCast(Self, msg, CT_Reinterpret, OpRange, SrcExpr.get(),
711 DestType, /*listInitialization=*/false);
713 } else if (tcr == TC_Success && Self.getLangOpts().ObjCAutoRefCount) {
714 checkObjCARCConversion(Sema::CCK_OtherCast);
719 /// CheckStaticCast - Check that a static_cast\<DestType\>(SrcExpr) is valid.
720 /// Refer to C++ 5.2.9 for details. Static casts are mostly used for making
721 /// implicit conversions explicit and getting rid of data loss warnings.
722 void CastOperation::CheckStaticCast() {
723 if (isPlaceholder()) {
724 checkNonOverloadPlaceholders();
725 if (SrcExpr.isInvalid())
729 // This test is outside everything else because it's the only case where
730 // a non-lvalue-reference target type does not lead to decay.
731 // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
732 if (DestType->isVoidType()) {
735 if (claimPlaceholder(BuiltinType::Overload)) {
736 Self.ResolveAndFixSingleFunctionTemplateSpecialization(SrcExpr,
737 false, // Decay Function to ptr
739 OpRange, DestType, diag::err_bad_static_cast_overload);
740 if (SrcExpr.isInvalid())
744 SrcExpr = Self.IgnoredValueConversions(SrcExpr.take());
748 if (ValueKind == VK_RValue && !DestType->isRecordType() &&
749 !isPlaceholder(BuiltinType::Overload)) {
750 SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
751 if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
755 unsigned msg = diag::err_bad_cxx_cast_generic;
757 = TryStaticCast(Self, SrcExpr, DestType, Sema::CCK_OtherCast, OpRange, msg,
758 Kind, BasePath, /*ListInitialization=*/false);
759 if (tcr != TC_Success && msg != 0) {
760 if (SrcExpr.isInvalid())
762 if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
763 OverloadExpr* oe = OverloadExpr::find(SrcExpr.get()).Expression;
764 Self.Diag(OpRange.getBegin(), diag::err_bad_static_cast_overload)
765 << oe->getName() << DestType << OpRange
766 << oe->getQualifierLoc().getSourceRange();
767 Self.NoteAllOverloadCandidates(SrcExpr.get());
769 diagnoseBadCast(Self, msg, CT_Static, OpRange, SrcExpr.get(), DestType,
770 /*listInitialization=*/false);
772 } else if (tcr == TC_Success) {
773 if (Kind == CK_BitCast)
775 if (Self.getLangOpts().ObjCAutoRefCount)
776 checkObjCARCConversion(Sema::CCK_OtherCast);
777 } else if (Kind == CK_BitCast) {
782 /// TryStaticCast - Check if a static cast can be performed, and do so if
783 /// possible. If @p CStyle, ignore access restrictions on hierarchy casting
784 /// and casting away constness.
785 static TryCastResult TryStaticCast(Sema &Self, ExprResult &SrcExpr,
787 Sema::CheckedConversionKind CCK,
788 const SourceRange &OpRange, unsigned &msg,
789 CastKind &Kind, CXXCastPath &BasePath,
790 bool ListInitialization) {
791 // Determine whether we have the semantics of a C-style cast.
793 = (CCK == Sema::CCK_CStyleCast || CCK == Sema::CCK_FunctionalCast);
795 // The order the tests is not entirely arbitrary. There is one conversion
796 // that can be handled in two different ways. Given:
798 // struct B : public A {
802 // the cast static_cast<const B&>(a) could be seen as either a static
803 // reference downcast, or an explicit invocation of the user-defined
804 // conversion using B's conversion constructor.
805 // DR 427 specifies that the downcast is to be applied here.
807 // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
808 // Done outside this function.
812 // C++ 5.2.9p5, reference downcast.
813 // See the function for details.
814 // DR 427 specifies that this is to be applied before paragraph 2.
815 tcr = TryStaticReferenceDowncast(Self, SrcExpr.get(), DestType, CStyle,
816 OpRange, msg, Kind, BasePath);
817 if (tcr != TC_NotApplicable)
820 // C++0x [expr.static.cast]p3:
821 // A glvalue of type "cv1 T1" can be cast to type "rvalue reference to cv2
822 // T2" if "cv2 T2" is reference-compatible with "cv1 T1".
823 tcr = TryLValueToRValueCast(Self, SrcExpr.get(), DestType, CStyle, Kind,
825 if (tcr != TC_NotApplicable)
828 // C++ 5.2.9p2: An expression e can be explicitly converted to a type T
829 // [...] if the declaration "T t(e);" is well-formed, [...].
830 tcr = TryStaticImplicitCast(Self, SrcExpr, DestType, CCK, OpRange, msg,
831 Kind, ListInitialization);
832 if (SrcExpr.isInvalid())
834 if (tcr != TC_NotApplicable)
837 // C++ 5.2.9p6: May apply the reverse of any standard conversion, except
838 // lvalue-to-rvalue, array-to-pointer, function-to-pointer, and boolean
839 // conversions, subject to further restrictions.
840 // Also, C++ 5.2.9p1 forbids casting away constness, which makes reversal
841 // of qualification conversions impossible.
842 // In the CStyle case, the earlier attempt to const_cast should have taken
843 // care of reverse qualification conversions.
845 QualType SrcType = Self.Context.getCanonicalType(SrcExpr.get()->getType());
847 // C++0x 5.2.9p9: A value of a scoped enumeration type can be explicitly
848 // converted to an integral type. [...] A value of a scoped enumeration type
849 // can also be explicitly converted to a floating-point type [...].
850 if (const EnumType *Enum = SrcType->getAs<EnumType>()) {
851 if (Enum->getDecl()->isScoped()) {
852 if (DestType->isBooleanType()) {
853 Kind = CK_IntegralToBoolean;
855 } else if (DestType->isIntegralType(Self.Context)) {
856 Kind = CK_IntegralCast;
858 } else if (DestType->isRealFloatingType()) {
859 Kind = CK_IntegralToFloating;
865 // Reverse integral promotion/conversion. All such conversions are themselves
866 // again integral promotions or conversions and are thus already handled by
867 // p2 (TryDirectInitialization above).
868 // (Note: any data loss warnings should be suppressed.)
869 // The exception is the reverse of enum->integer, i.e. integer->enum (and
870 // enum->enum). See also C++ 5.2.9p7.
871 // The same goes for reverse floating point promotion/conversion and
872 // floating-integral conversions. Again, only floating->enum is relevant.
873 if (DestType->isEnumeralType()) {
874 if (SrcType->isIntegralOrEnumerationType()) {
875 Kind = CK_IntegralCast;
877 } else if (SrcType->isRealFloatingType()) {
878 Kind = CK_FloatingToIntegral;
883 // Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
884 // C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
885 tcr = TryStaticPointerDowncast(Self, SrcType, DestType, CStyle, OpRange, msg,
887 if (tcr != TC_NotApplicable)
890 // Reverse member pointer conversion. C++ 4.11 specifies member pointer
891 // conversion. C++ 5.2.9p9 has additional information.
892 // DR54's access restrictions apply here also.
893 tcr = TryStaticMemberPointerUpcast(Self, SrcExpr, SrcType, DestType, CStyle,
894 OpRange, msg, Kind, BasePath);
895 if (tcr != TC_NotApplicable)
898 // Reverse pointer conversion to void*. C++ 4.10.p2 specifies conversion to
899 // void*. C++ 5.2.9p10 specifies additional restrictions, which really is
900 // just the usual constness stuff.
901 if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
902 QualType SrcPointee = SrcPointer->getPointeeType();
903 if (SrcPointee->isVoidType()) {
904 if (const PointerType *DestPointer = DestType->getAs<PointerType>()) {
905 QualType DestPointee = DestPointer->getPointeeType();
906 if (DestPointee->isIncompleteOrObjectType()) {
907 // This is definitely the intended conversion, but it might fail due
908 // to a qualifier violation. Note that we permit Objective-C lifetime
909 // and GC qualifier mismatches here.
911 Qualifiers DestPointeeQuals = DestPointee.getQualifiers();
912 Qualifiers SrcPointeeQuals = SrcPointee.getQualifiers();
913 DestPointeeQuals.removeObjCGCAttr();
914 DestPointeeQuals.removeObjCLifetime();
915 SrcPointeeQuals.removeObjCGCAttr();
916 SrcPointeeQuals.removeObjCLifetime();
917 if (DestPointeeQuals != SrcPointeeQuals &&
918 !DestPointeeQuals.compatiblyIncludes(SrcPointeeQuals)) {
919 msg = diag::err_bad_cxx_cast_qualifiers_away;
927 else if (DestType->isObjCObjectPointerType()) {
928 // allow both c-style cast and static_cast of objective-c pointers as
929 // they are pervasive.
930 Kind = CK_CPointerToObjCPointerCast;
933 else if (CStyle && DestType->isBlockPointerType()) {
934 // allow c-style cast of void * to block pointers.
935 Kind = CK_AnyPointerToBlockPointerCast;
940 // Allow arbitray objective-c pointer conversion with static casts.
941 if (SrcType->isObjCObjectPointerType() &&
942 DestType->isObjCObjectPointerType()) {
947 // We tried everything. Everything! Nothing works! :-(
948 return TC_NotApplicable;
951 /// Tests whether a conversion according to N2844 is valid.
953 TryLValueToRValueCast(Sema &Self, Expr *SrcExpr, QualType DestType,
954 bool CStyle, CastKind &Kind, CXXCastPath &BasePath,
956 // C++0x [expr.static.cast]p3:
957 // A glvalue of type "cv1 T1" can be cast to type "rvalue reference to
958 // cv2 T2" if "cv2 T2" is reference-compatible with "cv1 T1".
959 const RValueReferenceType *R = DestType->getAs<RValueReferenceType>();
961 return TC_NotApplicable;
963 if (!SrcExpr->isGLValue())
964 return TC_NotApplicable;
966 // Because we try the reference downcast before this function, from now on
967 // this is the only cast possibility, so we issue an error if we fail now.
968 // FIXME: Should allow casting away constness if CStyle.
971 bool ObjCLifetimeConversion;
972 QualType FromType = SrcExpr->getType();
973 QualType ToType = R->getPointeeType();
975 FromType = FromType.getUnqualifiedType();
976 ToType = ToType.getUnqualifiedType();
979 if (Self.CompareReferenceRelationship(SrcExpr->getLocStart(),
981 DerivedToBase, ObjCConversion,
982 ObjCLifetimeConversion)
983 < Sema::Ref_Compatible_With_Added_Qualification) {
984 msg = diag::err_bad_lvalue_to_rvalue_cast;
989 Kind = CK_DerivedToBase;
990 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
991 /*DetectVirtual=*/true);
992 if (!Self.IsDerivedFrom(SrcExpr->getType(), R->getPointeeType(), Paths))
993 return TC_NotApplicable;
995 Self.BuildBasePathArray(Paths, BasePath);
1002 /// Tests whether a conversion according to C++ 5.2.9p5 is valid.
1004 TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr, QualType DestType,
1005 bool CStyle, const SourceRange &OpRange,
1006 unsigned &msg, CastKind &Kind,
1007 CXXCastPath &BasePath) {
1008 // C++ 5.2.9p5: An lvalue of type "cv1 B", where B is a class type, can be
1009 // cast to type "reference to cv2 D", where D is a class derived from B,
1010 // if a valid standard conversion from "pointer to D" to "pointer to B"
1011 // exists, cv2 >= cv1, and B is not a virtual base class of D.
1012 // In addition, DR54 clarifies that the base must be accessible in the
1013 // current context. Although the wording of DR54 only applies to the pointer
1014 // variant of this rule, the intent is clearly for it to apply to the this
1015 // conversion as well.
1017 const ReferenceType *DestReference = DestType->getAs<ReferenceType>();
1018 if (!DestReference) {
1019 return TC_NotApplicable;
1021 bool RValueRef = DestReference->isRValueReferenceType();
1022 if (!RValueRef && !SrcExpr->isLValue()) {
1023 // We know the left side is an lvalue reference, so we can suggest a reason.
1024 msg = diag::err_bad_cxx_cast_rvalue;
1025 return TC_NotApplicable;
1028 QualType DestPointee = DestReference->getPointeeType();
1030 return TryStaticDowncast(Self,
1031 Self.Context.getCanonicalType(SrcExpr->getType()),
1032 Self.Context.getCanonicalType(DestPointee), CStyle,
1033 OpRange, SrcExpr->getType(), DestType, msg, Kind,
1037 /// Tests whether a conversion according to C++ 5.2.9p8 is valid.
1039 TryStaticPointerDowncast(Sema &Self, QualType SrcType, QualType DestType,
1040 bool CStyle, const SourceRange &OpRange,
1041 unsigned &msg, CastKind &Kind,
1042 CXXCastPath &BasePath) {
1043 // C++ 5.2.9p8: An rvalue of type "pointer to cv1 B", where B is a class
1044 // type, can be converted to an rvalue of type "pointer to cv2 D", where D
1045 // is a class derived from B, if a valid standard conversion from "pointer
1046 // to D" to "pointer to B" exists, cv2 >= cv1, and B is not a virtual base
1048 // In addition, DR54 clarifies that the base must be accessible in the
1051 const PointerType *DestPointer = DestType->getAs<PointerType>();
1053 return TC_NotApplicable;
1056 const PointerType *SrcPointer = SrcType->getAs<PointerType>();
1058 msg = diag::err_bad_static_cast_pointer_nonpointer;
1059 return TC_NotApplicable;
1062 return TryStaticDowncast(Self,
1063 Self.Context.getCanonicalType(SrcPointer->getPointeeType()),
1064 Self.Context.getCanonicalType(DestPointer->getPointeeType()),
1065 CStyle, OpRange, SrcType, DestType, msg, Kind,
1069 /// TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and
1070 /// TryStaticPointerDowncast. Tests whether a static downcast from SrcType to
1071 /// DestType is possible and allowed.
1073 TryStaticDowncast(Sema &Self, CanQualType SrcType, CanQualType DestType,
1074 bool CStyle, const SourceRange &OpRange, QualType OrigSrcType,
1075 QualType OrigDestType, unsigned &msg,
1076 CastKind &Kind, CXXCastPath &BasePath) {
1077 // We can only work with complete types. But don't complain if it doesn't work
1078 if (Self.RequireCompleteType(OpRange.getBegin(), SrcType, Self.PDiag(0)) ||
1079 Self.RequireCompleteType(OpRange.getBegin(), DestType, Self.PDiag(0)))
1080 return TC_NotApplicable;
1082 // Downcast can only happen in class hierarchies, so we need classes.
1083 if (!DestType->getAs<RecordType>() || !SrcType->getAs<RecordType>()) {
1084 return TC_NotApplicable;
1087 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1088 /*DetectVirtual=*/true);
1089 if (!Self.IsDerivedFrom(DestType, SrcType, Paths)) {
1090 return TC_NotApplicable;
1093 // Target type does derive from source type. Now we're serious. If an error
1094 // appears now, it's not ignored.
1095 // This may not be entirely in line with the standard. Take for example:
1097 // struct B : virtual A {
1103 // (void)static_cast<const B&>(*((A*)0));
1105 // As far as the standard is concerned, p5 does not apply (A is virtual), so
1106 // p2 should be used instead - "const B& t(*((A*)0));" is perfectly valid.
1107 // However, both GCC and Comeau reject this example, and accepting it would
1108 // mean more complex code if we're to preserve the nice error message.
1109 // FIXME: Being 100% compliant here would be nice to have.
1111 // Must preserve cv, as always, unless we're in C-style mode.
1112 if (!CStyle && !DestType.isAtLeastAsQualifiedAs(SrcType)) {
1113 msg = diag::err_bad_cxx_cast_qualifiers_away;
1117 if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
1118 // This code is analoguous to that in CheckDerivedToBaseConversion, except
1119 // that it builds the paths in reverse order.
1120 // To sum up: record all paths to the base and build a nice string from
1121 // them. Use it to spice up the error message.
1122 if (!Paths.isRecordingPaths()) {
1124 Paths.setRecordingPaths(true);
1125 Self.IsDerivedFrom(DestType, SrcType, Paths);
1127 std::string PathDisplayStr;
1128 std::set<unsigned> DisplayedPaths;
1129 for (CXXBasePaths::paths_iterator PI = Paths.begin(), PE = Paths.end();
1131 if (DisplayedPaths.insert(PI->back().SubobjectNumber).second) {
1132 // We haven't displayed a path to this particular base
1133 // class subobject yet.
1134 PathDisplayStr += "\n ";
1135 for (CXXBasePath::const_reverse_iterator EI = PI->rbegin(),
1138 PathDisplayStr += EI->Base->getType().getAsString() + " -> ";
1139 PathDisplayStr += QualType(DestType).getAsString();
1143 Self.Diag(OpRange.getBegin(), diag::err_ambiguous_base_to_derived_cast)
1144 << QualType(SrcType).getUnqualifiedType()
1145 << QualType(DestType).getUnqualifiedType()
1146 << PathDisplayStr << OpRange;
1151 if (Paths.getDetectedVirtual() != 0) {
1152 QualType VirtualBase(Paths.getDetectedVirtual(), 0);
1153 Self.Diag(OpRange.getBegin(), diag::err_static_downcast_via_virtual)
1154 << OrigSrcType << OrigDestType << VirtualBase << OpRange;
1160 switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
1163 diag::err_downcast_from_inaccessible_base)) {
1164 case Sema::AR_accessible:
1165 case Sema::AR_delayed: // be optimistic
1166 case Sema::AR_dependent: // be optimistic
1169 case Sema::AR_inaccessible:
1175 Self.BuildBasePathArray(Paths, BasePath);
1176 Kind = CK_BaseToDerived;
1180 /// TryStaticMemberPointerUpcast - Tests whether a conversion according to
1181 /// C++ 5.2.9p9 is valid:
1183 /// An rvalue of type "pointer to member of D of type cv1 T" can be
1184 /// converted to an rvalue of type "pointer to member of B of type cv2 T",
1185 /// where B is a base class of D [...].
1188 TryStaticMemberPointerUpcast(Sema &Self, ExprResult &SrcExpr, QualType SrcType,
1189 QualType DestType, bool CStyle,
1190 const SourceRange &OpRange,
1191 unsigned &msg, CastKind &Kind,
1192 CXXCastPath &BasePath) {
1193 const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>();
1195 return TC_NotApplicable;
1197 bool WasOverloadedFunction = false;
1198 DeclAccessPair FoundOverload;
1199 if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
1200 if (FunctionDecl *Fn
1201 = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(), DestType, false,
1203 CXXMethodDecl *M = cast<CXXMethodDecl>(Fn);
1204 SrcType = Self.Context.getMemberPointerType(Fn->getType(),
1205 Self.Context.getTypeDeclType(M->getParent()).getTypePtr());
1206 WasOverloadedFunction = true;
1210 const MemberPointerType *SrcMemPtr = SrcType->getAs<MemberPointerType>();
1212 msg = diag::err_bad_static_cast_member_pointer_nonmp;
1213 return TC_NotApplicable;
1216 // T == T, modulo cv
1217 if (!Self.Context.hasSameUnqualifiedType(SrcMemPtr->getPointeeType(),
1218 DestMemPtr->getPointeeType()))
1219 return TC_NotApplicable;
1222 QualType SrcClass(SrcMemPtr->getClass(), 0);
1223 QualType DestClass(DestMemPtr->getClass(), 0);
1224 CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
1225 /*DetectVirtual=*/true);
1226 if (!Self.IsDerivedFrom(SrcClass, DestClass, Paths)) {
1227 return TC_NotApplicable;
1230 // B is a base of D. But is it an allowed base? If not, it's a hard error.
1231 if (Paths.isAmbiguous(Self.Context.getCanonicalType(DestClass))) {
1233 Paths.setRecordingPaths(true);
1234 bool StillOkay = Self.IsDerivedFrom(SrcClass, DestClass, Paths);
1237 std::string PathDisplayStr = Self.getAmbiguousPathsDisplayString(Paths);
1238 Self.Diag(OpRange.getBegin(), diag::err_ambiguous_memptr_conv)
1239 << 1 << SrcClass << DestClass << PathDisplayStr << OpRange;
1244 if (const RecordType *VBase = Paths.getDetectedVirtual()) {
1245 Self.Diag(OpRange.getBegin(), diag::err_memptr_conv_via_virtual)
1246 << SrcClass << DestClass << QualType(VBase, 0) << OpRange;
1252 switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
1253 DestClass, SrcClass,
1255 diag::err_upcast_to_inaccessible_base)) {
1256 case Sema::AR_accessible:
1257 case Sema::AR_delayed:
1258 case Sema::AR_dependent:
1259 // Optimistically assume that the delayed and dependent cases
1263 case Sema::AR_inaccessible:
1269 if (WasOverloadedFunction) {
1270 // Resolve the address of the overloaded function again, this time
1271 // allowing complaints if something goes wrong.
1272 FunctionDecl *Fn = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(),
1281 SrcExpr = Self.FixOverloadedFunctionReference(SrcExpr, FoundOverload, Fn);
1282 if (!SrcExpr.isUsable()) {
1288 Self.BuildBasePathArray(Paths, BasePath);
1289 Kind = CK_DerivedToBaseMemberPointer;
1293 /// TryStaticImplicitCast - Tests whether a conversion according to C++ 5.2.9p2
1296 /// An expression e can be explicitly converted to a type T using a
1297 /// @c static_cast if the declaration "T t(e);" is well-formed [...].
1299 TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr, QualType DestType,
1300 Sema::CheckedConversionKind CCK,
1301 const SourceRange &OpRange, unsigned &msg,
1302 CastKind &Kind, bool ListInitialization) {
1303 if (DestType->isRecordType()) {
1304 if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
1305 diag::err_bad_dynamic_cast_incomplete)) {
1311 InitializedEntity Entity = InitializedEntity::InitializeTemporary(DestType);
1312 InitializationKind InitKind
1313 = (CCK == Sema::CCK_CStyleCast)
1314 ? InitializationKind::CreateCStyleCast(OpRange.getBegin(), OpRange,
1316 : (CCK == Sema::CCK_FunctionalCast)
1317 ? InitializationKind::CreateFunctionalCast(OpRange, ListInitialization)
1318 : InitializationKind::CreateCast(OpRange);
1319 Expr *SrcExprRaw = SrcExpr.get();
1320 InitializationSequence InitSeq(Self, Entity, InitKind, &SrcExprRaw, 1);
1322 // At this point of CheckStaticCast, if the destination is a reference,
1323 // or the expression is an overload expression this has to work.
1324 // There is no other way that works.
1325 // On the other hand, if we're checking a C-style cast, we've still got
1326 // the reinterpret_cast way.
1328 = (CCK == Sema::CCK_CStyleCast || CCK == Sema::CCK_FunctionalCast);
1329 if (InitSeq.Failed() && (CStyle || !DestType->isReferenceType()))
1330 return TC_NotApplicable;
1333 = InitSeq.Perform(Self, Entity, InitKind, MultiExprArg(Self, &SrcExprRaw, 1));
1334 if (Result.isInvalid()) {
1339 if (InitSeq.isConstructorInitialization())
1340 Kind = CK_ConstructorConversion;
1344 SrcExpr = move(Result);
1348 /// TryConstCast - See if a const_cast from source to destination is allowed,
1349 /// and perform it if it is.
1350 static TryCastResult TryConstCast(Sema &Self, Expr *SrcExpr, QualType DestType,
1351 bool CStyle, unsigned &msg) {
1352 DestType = Self.Context.getCanonicalType(DestType);
1353 QualType SrcType = SrcExpr->getType();
1354 if (const ReferenceType *DestTypeTmp =DestType->getAs<ReferenceType>()) {
1355 if (DestTypeTmp->isLValueReferenceType() && !SrcExpr->isLValue()) {
1356 // Cannot const_cast non-lvalue to lvalue reference type. But if this
1357 // is C-style, static_cast might find a way, so we simply suggest a
1358 // message and tell the parent to keep searching.
1359 msg = diag::err_bad_cxx_cast_rvalue;
1360 return TC_NotApplicable;
1363 // C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
1364 // [...] if a pointer to T1 can be [cast] to the type pointer to T2.
1365 DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
1366 SrcType = Self.Context.getPointerType(SrcType);
1369 // C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
1370 // the rules for const_cast are the same as those used for pointers.
1372 if (!DestType->isPointerType() &&
1373 !DestType->isMemberPointerType() &&
1374 !DestType->isObjCObjectPointerType()) {
1375 // Cannot cast to non-pointer, non-reference type. Note that, if DestType
1376 // was a reference type, we converted it to a pointer above.
1377 // The status of rvalue references isn't entirely clear, but it looks like
1378 // conversion to them is simply invalid.
1379 // C++ 5.2.11p3: For two pointer types [...]
1381 msg = diag::err_bad_const_cast_dest;
1382 return TC_NotApplicable;
1384 if (DestType->isFunctionPointerType() ||
1385 DestType->isMemberFunctionPointerType()) {
1386 // Cannot cast direct function pointers.
1387 // C++ 5.2.11p2: [...] where T is any object type or the void type [...]
1388 // T is the ultimate pointee of source and target type.
1390 msg = diag::err_bad_const_cast_dest;
1391 return TC_NotApplicable;
1393 SrcType = Self.Context.getCanonicalType(SrcType);
1395 // Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
1396 // completely equal.
1397 // C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
1398 // in multi-level pointers may change, but the level count must be the same,
1399 // as must be the final pointee type.
1400 while (SrcType != DestType &&
1401 Self.Context.UnwrapSimilarPointerTypes(SrcType, DestType)) {
1402 Qualifiers SrcQuals, DestQuals;
1403 SrcType = Self.Context.getUnqualifiedArrayType(SrcType, SrcQuals);
1404 DestType = Self.Context.getUnqualifiedArrayType(DestType, DestQuals);
1406 // const_cast is permitted to strip cvr-qualifiers, only. Make sure that
1407 // the other qualifiers (e.g., address spaces) are identical.
1408 SrcQuals.removeCVRQualifiers();
1409 DestQuals.removeCVRQualifiers();
1410 if (SrcQuals != DestQuals)
1411 return TC_NotApplicable;
1414 // Since we're dealing in canonical types, the remainder must be the same.
1415 if (SrcType != DestType)
1416 return TC_NotApplicable;
1421 // Checks for undefined behavior in reinterpret_cast.
1422 // The cases that is checked for is:
1423 // *reinterpret_cast<T*>(&a)
1424 // reinterpret_cast<T&>(a)
1425 // where accessing 'a' as type 'T' will result in undefined behavior.
1426 void Sema::CheckCompatibleReinterpretCast(QualType SrcType, QualType DestType,
1428 SourceRange Range) {
1429 unsigned DiagID = IsDereference ?
1430 diag::warn_pointer_indirection_from_incompatible_type :
1431 diag::warn_undefined_reinterpret_cast;
1433 if (Diags.getDiagnosticLevel(DiagID, Range.getBegin()) ==
1434 DiagnosticsEngine::Ignored) {
1438 QualType SrcTy, DestTy;
1439 if (IsDereference) {
1440 if (!SrcType->getAs<PointerType>() || !DestType->getAs<PointerType>()) {
1443 SrcTy = SrcType->getPointeeType();
1444 DestTy = DestType->getPointeeType();
1446 if (!DestType->getAs<ReferenceType>()) {
1450 DestTy = DestType->getPointeeType();
1453 // Cast is compatible if the types are the same.
1454 if (Context.hasSameUnqualifiedType(DestTy, SrcTy)) {
1457 // or one of the types is a char or void type
1458 if (DestTy->isAnyCharacterType() || DestTy->isVoidType() ||
1459 SrcTy->isAnyCharacterType() || SrcTy->isVoidType()) {
1462 // or one of the types is a tag type.
1463 if (SrcTy->getAs<TagType>() || DestTy->getAs<TagType>()) {
1467 // FIXME: Scoped enums?
1468 if ((SrcTy->isUnsignedIntegerType() && DestTy->isSignedIntegerType()) ||
1469 (SrcTy->isSignedIntegerType() && DestTy->isUnsignedIntegerType())) {
1470 if (Context.getTypeSize(DestTy) == Context.getTypeSize(SrcTy)) {
1475 Diag(Range.getBegin(), DiagID) << SrcType << DestType << Range;
1478 static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr,
1479 QualType DestType, bool CStyle,
1480 const SourceRange &OpRange,
1483 bool IsLValueCast = false;
1485 DestType = Self.Context.getCanonicalType(DestType);
1486 QualType SrcType = SrcExpr.get()->getType();
1488 // Is the source an overloaded name? (i.e. &foo)
1489 // If so, reinterpret_cast can not help us here (13.4, p1, bullet 5) ...
1490 if (SrcType == Self.Context.OverloadTy) {
1491 // ... unless foo<int> resolves to an lvalue unambiguously.
1492 // TODO: what if this fails because of DiagnoseUseOfDecl or something
1494 ExprResult SingleFunctionExpr = SrcExpr;
1495 if (Self.ResolveAndFixSingleFunctionTemplateSpecialization(
1497 Expr::getValueKindForType(DestType) == VK_RValue // Convert Fun to Ptr
1498 ) && SingleFunctionExpr.isUsable()) {
1499 SrcExpr = move(SingleFunctionExpr);
1500 SrcType = SrcExpr.get()->getType();
1502 return TC_NotApplicable;
1506 if (const ReferenceType *DestTypeTmp = DestType->getAs<ReferenceType>()) {
1507 bool LValue = DestTypeTmp->isLValueReferenceType();
1508 if (LValue && !SrcExpr.get()->isLValue()) {
1509 // Cannot cast non-lvalue to lvalue reference type. See the similar
1510 // comment in const_cast.
1511 msg = diag::err_bad_cxx_cast_rvalue;
1512 return TC_NotApplicable;
1516 Self.CheckCompatibleReinterpretCast(SrcType, DestType,
1517 /*isDereference=*/false, OpRange);
1520 // C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
1521 // same effect as the conversion *reinterpret_cast<T*>(&x) with the
1522 // built-in & and * operators.
1524 const char *inappropriate = 0;
1525 switch (SrcExpr.get()->getObjectKind()) {
1528 case OK_BitField: inappropriate = "bit-field"; break;
1529 case OK_VectorComponent: inappropriate = "vector element"; break;
1530 case OK_ObjCProperty: inappropriate = "property expression"; break;
1531 case OK_ObjCSubscript: inappropriate = "container subscripting expression";
1534 if (inappropriate) {
1535 Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_reference)
1536 << inappropriate << DestType
1537 << OpRange << SrcExpr.get()->getSourceRange();
1538 msg = 0; SrcExpr = ExprError();
1539 return TC_NotApplicable;
1542 // This code does this transformation for the checked types.
1543 DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
1544 SrcType = Self.Context.getPointerType(SrcType);
1546 IsLValueCast = true;
1549 // Canonicalize source for comparison.
1550 SrcType = Self.Context.getCanonicalType(SrcType);
1552 const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>(),
1553 *SrcMemPtr = SrcType->getAs<MemberPointerType>();
1554 if (DestMemPtr && SrcMemPtr) {
1555 // C++ 5.2.10p9: An rvalue of type "pointer to member of X of type T1"
1556 // can be explicitly converted to an rvalue of type "pointer to member
1557 // of Y of type T2" if T1 and T2 are both function types or both object
1559 if (DestMemPtr->getPointeeType()->isFunctionType() !=
1560 SrcMemPtr->getPointeeType()->isFunctionType())
1561 return TC_NotApplicable;
1563 // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away
1565 // A reinterpret_cast followed by a const_cast can, though, so in C-style,
1567 if (CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
1568 /*CheckObjCLifetime=*/CStyle)) {
1569 msg = diag::err_bad_cxx_cast_qualifiers_away;
1573 // Don't allow casting between member pointers of different sizes.
1574 if (Self.Context.getTypeSize(DestMemPtr) !=
1575 Self.Context.getTypeSize(SrcMemPtr)) {
1576 msg = diag::err_bad_cxx_cast_member_pointer_size;
1580 // A valid member pointer cast.
1581 assert(!IsLValueCast);
1582 Kind = CK_ReinterpretMemberPointer;
1586 // See below for the enumeral issue.
1587 if (SrcType->isNullPtrType() && DestType->isIntegralType(Self.Context)) {
1588 // C++0x 5.2.10p4: A pointer can be explicitly converted to any integral
1589 // type large enough to hold it. A value of std::nullptr_t can be
1590 // converted to an integral type; the conversion has the same meaning
1591 // and validity as a conversion of (void*)0 to the integral type.
1592 if (Self.Context.getTypeSize(SrcType) >
1593 Self.Context.getTypeSize(DestType)) {
1594 msg = diag::err_bad_reinterpret_cast_small_int;
1597 Kind = CK_PointerToIntegral;
1601 bool destIsVector = DestType->isVectorType();
1602 bool srcIsVector = SrcType->isVectorType();
1603 if (srcIsVector || destIsVector) {
1604 // FIXME: Should this also apply to floating point types?
1605 bool srcIsScalar = SrcType->isIntegralType(Self.Context);
1606 bool destIsScalar = DestType->isIntegralType(Self.Context);
1608 // Check if this is a cast between a vector and something else.
1609 if (!(srcIsScalar && destIsVector) && !(srcIsVector && destIsScalar) &&
1610 !(srcIsVector && destIsVector))
1611 return TC_NotApplicable;
1613 // If both types have the same size, we can successfully cast.
1614 if (Self.Context.getTypeSize(SrcType)
1615 == Self.Context.getTypeSize(DestType)) {
1621 msg = diag::err_bad_cxx_cast_vector_to_scalar_different_size;
1622 else if (srcIsScalar)
1623 msg = diag::err_bad_cxx_cast_scalar_to_vector_different_size;
1625 msg = diag::err_bad_cxx_cast_vector_to_vector_different_size;
1630 if (SrcType == DestType) {
1631 // C++ 5.2.10p2 has a note that mentions that, subject to all other
1632 // restrictions, a cast to the same type is allowed so long as it does not
1633 // cast away constness. In C++98, the intent was not entirely clear here,
1634 // since all other paragraphs explicitly forbid casts to the same type.
1635 // C++11 clarifies this case with p2.
1637 // The only allowed types are: integral, enumeration, pointer, or
1638 // pointer-to-member types. We also won't restrict Obj-C pointers either.
1640 TryCastResult Result = TC_NotApplicable;
1641 if (SrcType->isIntegralOrEnumerationType() ||
1642 SrcType->isAnyPointerType() ||
1643 SrcType->isMemberPointerType() ||
1644 SrcType->isBlockPointerType()) {
1645 Result = TC_Success;
1650 bool destIsPtr = DestType->isAnyPointerType() ||
1651 DestType->isBlockPointerType();
1652 bool srcIsPtr = SrcType->isAnyPointerType() ||
1653 SrcType->isBlockPointerType();
1654 if (!destIsPtr && !srcIsPtr) {
1655 // Except for std::nullptr_t->integer and lvalue->reference, which are
1656 // handled above, at least one of the two arguments must be a pointer.
1657 return TC_NotApplicable;
1660 if (DestType->isIntegralType(Self.Context)) {
1661 assert(srcIsPtr && "One type must be a pointer");
1662 // C++ 5.2.10p4: A pointer can be explicitly converted to any integral
1663 // type large enough to hold it; except in Microsoft mode, where the
1664 // integral type size doesn't matter.
1665 if ((Self.Context.getTypeSize(SrcType) >
1666 Self.Context.getTypeSize(DestType)) &&
1667 !Self.getLangOpts().MicrosoftExt) {
1668 msg = diag::err_bad_reinterpret_cast_small_int;
1671 Kind = CK_PointerToIntegral;
1675 if (SrcType->isIntegralOrEnumerationType()) {
1676 assert(destIsPtr && "One type must be a pointer");
1677 // C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
1678 // converted to a pointer.
1679 // C++ 5.2.10p9: [Note: ...a null pointer constant of integral type is not
1680 // necessarily converted to a null pointer value.]
1681 Kind = CK_IntegralToPointer;
1685 if (!destIsPtr || !srcIsPtr) {
1686 // With the valid non-pointer conversions out of the way, we can be even
1688 return TC_NotApplicable;
1691 // C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
1692 // The C-style cast operator can.
1693 if (CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
1694 /*CheckObjCLifetime=*/CStyle)) {
1695 msg = diag::err_bad_cxx_cast_qualifiers_away;
1699 // Cannot convert between block pointers and Objective-C object pointers.
1700 if ((SrcType->isBlockPointerType() && DestType->isObjCObjectPointerType()) ||
1701 (DestType->isBlockPointerType() && SrcType->isObjCObjectPointerType()))
1702 return TC_NotApplicable;
1705 Kind = CK_LValueBitCast;
1706 } else if (DestType->isObjCObjectPointerType()) {
1707 Kind = Self.PrepareCastToObjCObjectPointer(SrcExpr);
1708 } else if (DestType->isBlockPointerType()) {
1709 if (!SrcType->isBlockPointerType()) {
1710 Kind = CK_AnyPointerToBlockPointerCast;
1718 // Any pointer can be cast to an Objective-C pointer type with a C-style
1720 if (CStyle && DestType->isObjCObjectPointerType()) {
1724 // Not casting away constness, so the only remaining check is for compatible
1725 // pointer categories.
1727 if (SrcType->isFunctionPointerType()) {
1728 if (DestType->isFunctionPointerType()) {
1729 // C++ 5.2.10p6: A pointer to a function can be explicitly converted to
1730 // a pointer to a function of a different type.
1734 // C++0x 5.2.10p8: Converting a pointer to a function into a pointer to
1735 // an object type or vice versa is conditionally-supported.
1736 // Compilers support it in C++03 too, though, because it's necessary for
1737 // casting the return value of dlsym() and GetProcAddress().
1738 // FIXME: Conditionally-supported behavior should be configurable in the
1739 // TargetInfo or similar.
1740 Self.Diag(OpRange.getBegin(),
1741 Self.getLangOpts().CPlusPlus0x ?
1742 diag::warn_cxx98_compat_cast_fn_obj : diag::ext_cast_fn_obj)
1747 if (DestType->isFunctionPointerType()) {
1749 Self.Diag(OpRange.getBegin(),
1750 Self.getLangOpts().CPlusPlus0x ?
1751 diag::warn_cxx98_compat_cast_fn_obj : diag::ext_cast_fn_obj)
1756 // C++ 5.2.10p7: A pointer to an object can be explicitly converted to
1757 // a pointer to an object of different type.
1758 // Void pointers are not specified, but supported by every compiler out there.
1759 // So we finish by allowing everything that remains - it's got to be two
1764 void CastOperation::CheckCXXCStyleCast(bool FunctionalStyle,
1765 bool ListInitialization) {
1766 // Handle placeholders.
1767 if (isPlaceholder()) {
1768 // C-style casts can resolve __unknown_any types.
1769 if (claimPlaceholder(BuiltinType::UnknownAny)) {
1770 SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
1771 SrcExpr.get(), Kind,
1772 ValueKind, BasePath);
1776 checkNonOverloadPlaceholders();
1777 if (SrcExpr.isInvalid())
1781 // C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
1782 // This test is outside everything else because it's the only case where
1783 // a non-lvalue-reference target type does not lead to decay.
1784 if (DestType->isVoidType()) {
1787 if (claimPlaceholder(BuiltinType::Overload)) {
1788 Self.ResolveAndFixSingleFunctionTemplateSpecialization(
1789 SrcExpr, /* Decay Function to ptr */ false,
1790 /* Complain */ true, DestRange, DestType,
1791 diag::err_bad_cstyle_cast_overload);
1792 if (SrcExpr.isInvalid())
1796 SrcExpr = Self.IgnoredValueConversions(SrcExpr.take());
1797 if (SrcExpr.isInvalid())
1803 // If the type is dependent, we won't do any other semantic analysis now.
1804 if (DestType->isDependentType() || SrcExpr.get()->isTypeDependent()) {
1805 assert(Kind == CK_Dependent);
1809 if (ValueKind == VK_RValue && !DestType->isRecordType() &&
1810 !isPlaceholder(BuiltinType::Overload)) {
1811 SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
1812 if (SrcExpr.isInvalid())
1816 // AltiVec vector initialization with a single literal.
1817 if (const VectorType *vecTy = DestType->getAs<VectorType>())
1818 if (vecTy->getVectorKind() == VectorType::AltiVecVector
1819 && (SrcExpr.get()->getType()->isIntegerType()
1820 || SrcExpr.get()->getType()->isFloatingType())) {
1821 Kind = CK_VectorSplat;
1825 // C++ [expr.cast]p5: The conversions performed by
1828 // - a static_cast followed by a const_cast,
1829 // - a reinterpret_cast, or
1830 // - a reinterpret_cast followed by a const_cast,
1831 // can be performed using the cast notation of explicit type conversion.
1832 // [...] If a conversion can be interpreted in more than one of the ways
1833 // listed above, the interpretation that appears first in the list is used,
1834 // even if a cast resulting from that interpretation is ill-formed.
1835 // In plain language, this means trying a const_cast ...
1836 unsigned msg = diag::err_bad_cxx_cast_generic;
1837 TryCastResult tcr = TryConstCast(Self, SrcExpr.get(), DestType,
1838 /*CStyle*/true, msg);
1839 if (tcr == TC_Success)
1842 Sema::CheckedConversionKind CCK
1843 = FunctionalStyle? Sema::CCK_FunctionalCast
1844 : Sema::CCK_CStyleCast;
1845 if (tcr == TC_NotApplicable) {
1846 // ... or if that is not possible, a static_cast, ignoring const, ...
1847 tcr = TryStaticCast(Self, SrcExpr, DestType, CCK, OpRange,
1848 msg, Kind, BasePath, ListInitialization);
1849 if (SrcExpr.isInvalid())
1852 if (tcr == TC_NotApplicable) {
1853 // ... and finally a reinterpret_cast, ignoring const.
1854 tcr = TryReinterpretCast(Self, SrcExpr, DestType, /*CStyle*/true,
1855 OpRange, msg, Kind);
1856 if (SrcExpr.isInvalid())
1861 if (Self.getLangOpts().ObjCAutoRefCount && tcr == TC_Success)
1862 checkObjCARCConversion(CCK);
1864 if (tcr != TC_Success && msg != 0) {
1865 if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
1866 DeclAccessPair Found;
1867 FunctionDecl *Fn = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(),
1872 assert(!Fn && "cast failed but able to resolve overload expression!!");
1876 diagnoseBadCast(Self, msg, (FunctionalStyle ? CT_Functional : CT_CStyle),
1877 OpRange, SrcExpr.get(), DestType, ListInitialization);
1879 } else if (Kind == CK_BitCast) {
1883 // Clear out SrcExpr if there was a fatal error.
1884 if (tcr != TC_Success)
1885 SrcExpr = ExprError();
1888 /// Check the semantics of a C-style cast operation, in C.
1889 void CastOperation::CheckCStyleCast() {
1890 assert(!Self.getLangOpts().CPlusPlus);
1892 // C-style casts can resolve __unknown_any types.
1893 if (claimPlaceholder(BuiltinType::UnknownAny)) {
1894 SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
1895 SrcExpr.get(), Kind,
1896 ValueKind, BasePath);
1900 // C99 6.5.4p2: the cast type needs to be void or scalar and the expression
1901 // type needs to be scalar.
1902 if (DestType->isVoidType()) {
1903 // We don't necessarily do lvalue-to-rvalue conversions on this.
1904 SrcExpr = Self.IgnoredValueConversions(SrcExpr.take());
1905 if (SrcExpr.isInvalid())
1908 // Cast to void allows any expr type.
1913 SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.take());
1914 if (SrcExpr.isInvalid())
1916 QualType SrcType = SrcExpr.get()->getType();
1918 // You can cast an _Atomic(T) to anything you can cast a T to.
1919 if (const AtomicType *AtomicSrcType = SrcType->getAs<AtomicType>())
1920 SrcType = AtomicSrcType->getValueType();
1922 assert(!SrcType->isPlaceholderType());
1924 if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
1925 diag::err_typecheck_cast_to_incomplete)) {
1926 SrcExpr = ExprError();
1930 if (!DestType->isScalarType() && !DestType->isVectorType()) {
1931 const RecordType *DestRecordTy = DestType->getAs<RecordType>();
1933 if (DestRecordTy && Self.Context.hasSameUnqualifiedType(DestType, SrcType)){
1934 // GCC struct/union extension: allow cast to self.
1935 Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_nonscalar)
1936 << DestType << SrcExpr.get()->getSourceRange();
1941 // GCC's cast to union extension.
1942 if (DestRecordTy && DestRecordTy->getDecl()->isUnion()) {
1943 RecordDecl *RD = DestRecordTy->getDecl();
1944 RecordDecl::field_iterator Field, FieldEnd;
1945 for (Field = RD->field_begin(), FieldEnd = RD->field_end();
1946 Field != FieldEnd; ++Field) {
1947 if (Self.Context.hasSameUnqualifiedType(Field->getType(), SrcType) &&
1948 !Field->isUnnamedBitfield()) {
1949 Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_to_union)
1950 << SrcExpr.get()->getSourceRange();
1954 if (Field == FieldEnd) {
1955 Self.Diag(OpRange.getBegin(), diag::err_typecheck_cast_to_union_no_type)
1956 << SrcType << SrcExpr.get()->getSourceRange();
1957 SrcExpr = ExprError();
1964 // Reject any other conversions to non-scalar types.
1965 Self.Diag(OpRange.getBegin(), diag::err_typecheck_cond_expect_scalar)
1966 << DestType << SrcExpr.get()->getSourceRange();
1967 SrcExpr = ExprError();
1971 // The type we're casting to is known to be a scalar or vector.
1973 // Require the operand to be a scalar or vector.
1974 if (!SrcType->isScalarType() && !SrcType->isVectorType()) {
1975 Self.Diag(SrcExpr.get()->getExprLoc(),
1976 diag::err_typecheck_expect_scalar_operand)
1977 << SrcType << SrcExpr.get()->getSourceRange();
1978 SrcExpr = ExprError();
1982 if (DestType->isExtVectorType()) {
1983 SrcExpr = Self.CheckExtVectorCast(OpRange, DestType, SrcExpr.take(), Kind);
1987 if (const VectorType *DestVecTy = DestType->getAs<VectorType>()) {
1988 if (DestVecTy->getVectorKind() == VectorType::AltiVecVector &&
1989 (SrcType->isIntegerType() || SrcType->isFloatingType())) {
1990 Kind = CK_VectorSplat;
1991 } else if (Self.CheckVectorCast(OpRange, DestType, SrcType, Kind)) {
1992 SrcExpr = ExprError();
1997 if (SrcType->isVectorType()) {
1998 if (Self.CheckVectorCast(OpRange, SrcType, DestType, Kind))
1999 SrcExpr = ExprError();
2003 // The source and target types are both scalars, i.e.
2004 // - arithmetic types (fundamental, enum, and complex)
2005 // - all kinds of pointers
2006 // Note that member pointers were filtered out with C++, above.
2008 if (isa<ObjCSelectorExpr>(SrcExpr.get())) {
2009 Self.Diag(SrcExpr.get()->getExprLoc(), diag::err_cast_selector_expr);
2010 SrcExpr = ExprError();
2014 // If either type is a pointer, the other type has to be either an
2015 // integer or a pointer.
2016 if (!DestType->isArithmeticType()) {
2017 if (!SrcType->isIntegralType(Self.Context) && SrcType->isArithmeticType()) {
2018 Self.Diag(SrcExpr.get()->getExprLoc(),
2019 diag::err_cast_pointer_from_non_pointer_int)
2020 << SrcType << SrcExpr.get()->getSourceRange();
2021 SrcExpr = ExprError();
2024 } else if (!SrcType->isArithmeticType()) {
2025 if (!DestType->isIntegralType(Self.Context) &&
2026 DestType->isArithmeticType()) {
2027 Self.Diag(SrcExpr.get()->getLocStart(),
2028 diag::err_cast_pointer_to_non_pointer_int)
2029 << DestType << SrcExpr.get()->getSourceRange();
2030 SrcExpr = ExprError();
2035 // ARC imposes extra restrictions on casts.
2036 if (Self.getLangOpts().ObjCAutoRefCount) {
2037 checkObjCARCConversion(Sema::CCK_CStyleCast);
2038 if (SrcExpr.isInvalid())
2041 if (const PointerType *CastPtr = DestType->getAs<PointerType>()) {
2042 if (const PointerType *ExprPtr = SrcType->getAs<PointerType>()) {
2043 Qualifiers CastQuals = CastPtr->getPointeeType().getQualifiers();
2044 Qualifiers ExprQuals = ExprPtr->getPointeeType().getQualifiers();
2045 if (CastPtr->getPointeeType()->isObjCLifetimeType() &&
2046 ExprPtr->getPointeeType()->isObjCLifetimeType() &&
2047 !CastQuals.compatiblyIncludesObjCLifetime(ExprQuals)) {
2048 Self.Diag(SrcExpr.get()->getLocStart(),
2049 diag::err_typecheck_incompatible_ownership)
2050 << SrcType << DestType << Sema::AA_Casting
2051 << SrcExpr.get()->getSourceRange();
2056 else if (!Self.CheckObjCARCUnavailableWeakConversion(DestType, SrcType)) {
2057 Self.Diag(SrcExpr.get()->getLocStart(),
2058 diag::err_arc_convesion_of_weak_unavailable)
2059 << 1 << SrcType << DestType << SrcExpr.get()->getSourceRange();
2060 SrcExpr = ExprError();
2065 Kind = Self.PrepareScalarCast(SrcExpr, DestType);
2066 if (SrcExpr.isInvalid())
2069 if (Kind == CK_BitCast)
2073 ExprResult Sema::BuildCStyleCastExpr(SourceLocation LPLoc,
2074 TypeSourceInfo *CastTypeInfo,
2075 SourceLocation RPLoc,
2077 CastOperation Op(*this, CastTypeInfo->getType(), CastExpr);
2078 Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
2079 Op.OpRange = SourceRange(LPLoc, CastExpr->getLocEnd());
2081 if (getLangOpts().CPlusPlus) {
2082 Op.CheckCXXCStyleCast(/*FunctionalStyle=*/ false,
2083 isa<InitListExpr>(CastExpr));
2085 Op.CheckCStyleCast();
2088 if (Op.SrcExpr.isInvalid())
2091 return Op.complete(CStyleCastExpr::Create(Context, Op.ResultType,
2092 Op.ValueKind, Op.Kind, Op.SrcExpr.take(),
2093 &Op.BasePath, CastTypeInfo, LPLoc, RPLoc));
2096 ExprResult Sema::BuildCXXFunctionalCastExpr(TypeSourceInfo *CastTypeInfo,
2097 SourceLocation LPLoc,
2099 SourceLocation RPLoc) {
2100 assert(LPLoc.isValid() && "List-initialization shouldn't get here.");
2101 CastOperation Op(*this, CastTypeInfo->getType(), CastExpr);
2102 Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
2103 Op.OpRange = SourceRange(Op.DestRange.getBegin(), CastExpr->getLocEnd());
2105 Op.CheckCXXCStyleCast(/*FunctionalStyle=*/true, /*ListInit=*/false);
2106 if (Op.SrcExpr.isInvalid())
2109 return Op.complete(CXXFunctionalCastExpr::Create(Context, Op.ResultType,
2110 Op.ValueKind, CastTypeInfo, Op.DestRange.getBegin(),
2111 Op.Kind, Op.SrcExpr.take(), &Op.BasePath, RPLoc));