2008-11-06 00:50:06 +03:00
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//===--- SemaNamedCast.cpp - Semantic Analysis for Named Casts ------------===//
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//
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// The LLVM Compiler Infrastructure
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//
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//
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//===----------------------------------------------------------------------===//
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//
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// This file implements semantic analysis for C++ named casts.
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//
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//===----------------------------------------------------------------------===//
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#include "Sema.h"
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#include "clang/AST/ExprCXX.h"
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#include "clang/AST/ASTContext.h"
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2009-10-06 21:59:45 +04:00
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#include "clang/AST/CXXInheritance.h"
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2009-08-27 03:45:07 +04:00
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#include "clang/Basic/PartialDiagnostic.h"
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2008-11-06 00:50:06 +03:00
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#include "llvm/ADT/SmallVector.h"
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2008-11-08 02:29:29 +03:00
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#include <set>
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2008-11-06 00:50:06 +03:00
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using namespace clang;
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2009-07-25 19:41:38 +04:00
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enum TryCastResult {
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TC_NotApplicable, ///< The cast method is not applicable.
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TC_Success, ///< The cast method is appropriate and successful.
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TC_Failed ///< The cast method is appropriate, but failed. A
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///< diagnostic has been emitted.
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};
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enum CastType {
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CT_Const, ///< const_cast
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CT_Static, ///< static_cast
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CT_Reinterpret, ///< reinterpret_cast
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CT_Dynamic, ///< dynamic_cast
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CT_CStyle, ///< (Type)expr
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CT_Functional ///< Type(expr)
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};
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static void CheckConstCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
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const SourceRange &OpRange,
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const SourceRange &DestRange);
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static void CheckReinterpretCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
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const SourceRange &OpRange,
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const SourceRange &DestRange,
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CastExpr::CastKind &Kind);
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2008-11-08 16:00:26 +03:00
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static void CheckStaticCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
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2009-08-08 02:21:05 +04:00
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const SourceRange &OpRange,
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2009-09-10 01:33:21 +04:00
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CastExpr::CastKind &Kind,
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CXXMethodDecl *&ConversionDecl);
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2008-11-08 16:00:26 +03:00
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static void CheckDynamicCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
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const SourceRange &OpRange,
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2009-09-09 19:08:12 +04:00
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const SourceRange &DestRange,
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2009-08-02 23:07:59 +04:00
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CastExpr::CastKind &Kind);
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2008-11-08 16:00:26 +03:00
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static bool CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType);
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2009-07-25 19:41:38 +04:00
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// The Try functions attempt a specific way of casting. If they succeed, they
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// return TC_Success. If their way of casting is not appropriate for the given
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// arguments, they return TC_NotApplicable and *may* set diag to a diagnostic
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// to emit if no other way succeeds. If their way of casting is appropriate but
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// fails, they return TC_Failed and *must* set diag; they can set it to 0 if
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// they emit a specialized diagnostic.
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// All diagnostics returned by these functions must expect the same three
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// arguments:
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// %0: Cast Type (a value from the CastType enumeration)
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// %1: Source Type
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// %2: Destination Type
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static TryCastResult TryLValueToRValueCast(Sema &Self, Expr *SrcExpr,
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QualType DestType, unsigned &msg);
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static TryCastResult TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr,
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QualType DestType, bool CStyle,
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const SourceRange &OpRange,
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unsigned &msg);
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static TryCastResult TryStaticPointerDowncast(Sema &Self, QualType SrcType,
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QualType DestType, bool CStyle,
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const SourceRange &OpRange,
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unsigned &msg);
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static TryCastResult TryStaticDowncast(Sema &Self, QualType SrcType,
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QualType DestType, bool CStyle,
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const SourceRange &OpRange,
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QualType OrigSrcType,
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QualType OrigDestType, unsigned &msg);
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static TryCastResult TryStaticMemberPointerUpcast(Sema &Self, QualType SrcType,
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QualType DestType,bool CStyle,
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const SourceRange &OpRange,
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unsigned &msg);
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static TryCastResult TryStaticImplicitCast(Sema &Self, Expr *SrcExpr,
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QualType DestType, bool CStyle,
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const SourceRange &OpRange,
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unsigned &msg,
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2009-09-26 04:12:34 +04:00
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CastExpr::CastKind &Kind,
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CXXMethodDecl *&ConversionDecl);
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static TryCastResult TryStaticCast(Sema &Self, Expr *SrcExpr,
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QualType DestType, bool CStyle,
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const SourceRange &OpRange,
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2009-09-02 00:52:42 +04:00
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unsigned &msg,
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CastExpr::CastKind &Kind,
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CXXMethodDecl *&ConversionDecl);
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static TryCastResult TryConstCast(Sema &Self, Expr *SrcExpr, QualType DestType,
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bool CStyle, unsigned &msg);
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static TryCastResult TryReinterpretCast(Sema &Self, Expr *SrcExpr,
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QualType DestType, bool CStyle,
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const SourceRange &OpRange,
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2009-09-26 04:12:34 +04:00
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unsigned &msg,
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CastExpr::CastKind &Kind);
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2008-11-08 16:00:26 +03:00
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2008-11-06 00:50:06 +03:00
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/// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
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2009-03-15 20:47:39 +03:00
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Action::OwningExprResult
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Sema::ActOnCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
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SourceLocation LAngleBracketLoc, TypeTy *Ty,
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SourceLocation RAngleBracketLoc,
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SourceLocation LParenLoc, ExprArg E,
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SourceLocation RParenLoc) {
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2009-05-01 23:49:17 +04:00
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Expr *Ex = E.takeAs<Expr>();
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2009-08-19 05:28:28 +04:00
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// FIXME: Preserve type source info.
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QualType DestType = GetTypeFromParser(Ty);
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SourceRange OpRange(OpLoc, RParenLoc);
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SourceRange DestRange(LAngleBracketLoc, RAngleBracketLoc);
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2008-12-18 01:52:20 +03:00
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// If the type is dependent, we won't do the semantic analysis now.
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// FIXME: should we check this in a more fine-grained manner?
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bool TypeDependent = DestType->isDependentType() || Ex->isTypeDependent();
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2008-11-06 00:50:06 +03:00
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switch (Kind) {
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default: assert(0 && "Unknown C++ cast!");
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case tok::kw_const_cast:
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if (!TypeDependent)
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CheckConstCast(*this, Ex, DestType, OpRange, DestRange);
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return Owned(new (Context) CXXConstCastExpr(DestType.getNonReferenceType(),
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Ex, DestType, OpLoc));
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2008-11-06 00:50:06 +03:00
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2009-08-02 23:07:59 +04:00
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case tok::kw_dynamic_cast: {
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CastExpr::CastKind Kind = CastExpr::CK_Unknown;
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if (!TypeDependent)
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CheckDynamicCast(*this, Ex, DestType, OpRange, DestRange, Kind);
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return Owned(new (Context)CXXDynamicCastExpr(DestType.getNonReferenceType(),
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Kind, Ex, DestType, OpLoc));
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}
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2009-09-15 08:48:33 +04:00
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case tok::kw_reinterpret_cast: {
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CastExpr::CastKind Kind = CastExpr::CK_Unknown;
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2008-12-18 01:52:20 +03:00
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if (!TypeDependent)
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CheckReinterpretCast(*this, Ex, DestType, OpRange, DestRange, Kind);
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return Owned(new (Context) CXXReinterpretCastExpr(
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DestType.getNonReferenceType(),
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Kind, Ex, DestType, OpLoc));
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}
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2009-08-08 02:21:05 +04:00
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case tok::kw_static_cast: {
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CastExpr::CastKind Kind = CastExpr::CK_Unknown;
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2009-09-10 01:33:21 +04:00
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if (!TypeDependent) {
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CXXMethodDecl *Method = 0;
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CheckStaticCast(*this, Ex, DestType, OpRange, Kind, Method);
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if (Method) {
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OwningExprResult CastArg
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= BuildCXXCastArgument(OpLoc, DestType.getNonReferenceType(),
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Kind, Method, Owned(Ex));
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if (CastArg.isInvalid())
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return ExprError();
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Ex = CastArg.takeAs<Expr>();
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}
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}
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2009-03-15 20:47:39 +03:00
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return Owned(new (Context) CXXStaticCastExpr(DestType.getNonReferenceType(),
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2009-08-08 02:21:05 +04:00
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Kind, Ex, DestType, OpLoc));
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}
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2008-11-06 00:50:06 +03:00
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}
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2009-03-15 20:47:39 +03:00
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return ExprError();
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2008-11-06 00:50:06 +03:00
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}
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2009-07-25 19:41:38 +04:00
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/// CastsAwayConstness - Check if the pointer conversion from SrcType to
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/// DestType casts away constness as defined in C++ 5.2.11p8ff. This is used by
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/// the cast checkers. Both arguments must denote pointer (possibly to member)
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/// types.
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2009-10-22 19:07:22 +04:00
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static bool
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CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType) {
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2009-07-25 19:41:38 +04:00
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// Casting away constness is defined in C++ 5.2.11p8 with reference to
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// C++ 4.4. We piggyback on Sema::IsQualificationConversion for this, since
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// the rules are non-trivial. So first we construct Tcv *...cv* as described
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// in C++ 5.2.11p8.
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assert((SrcType->isPointerType() || SrcType->isMemberPointerType()) &&
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"Source type is not pointer or pointer to member.");
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assert((DestType->isPointerType() || DestType->isMemberPointerType()) &&
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"Destination type is not pointer or pointer to member.");
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2009-01-27 01:19:12 +03:00
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2009-07-25 19:41:38 +04:00
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QualType UnwrappedSrcType = SrcType, UnwrappedDestType = DestType;
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2009-09-24 23:53:00 +04:00
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llvm::SmallVector<Qualifiers, 8> cv1, cv2;
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2008-11-06 00:50:06 +03:00
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2009-07-25 19:41:38 +04:00
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// Find the qualifications.
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while (Self.UnwrapSimilarPointerTypes(UnwrappedSrcType, UnwrappedDestType)) {
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2009-09-24 23:53:00 +04:00
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cv1.push_back(UnwrappedSrcType.getQualifiers());
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cv2.push_back(UnwrappedDestType.getQualifiers());
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2008-11-06 00:50:06 +03:00
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}
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2009-07-25 19:41:38 +04:00
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assert(cv1.size() > 0 && "Must have at least one pointer level.");
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2008-11-06 00:50:06 +03:00
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2009-07-25 19:41:38 +04:00
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// Construct void pointers with those qualifiers (in reverse order of
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// unwrapping, of course).
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QualType SrcConstruct = Self.Context.VoidTy;
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QualType DestConstruct = Self.Context.VoidTy;
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2009-09-24 23:53:00 +04:00
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ASTContext &Context = Self.Context;
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for (llvm::SmallVector<Qualifiers, 8>::reverse_iterator i1 = cv1.rbegin(),
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i2 = cv2.rbegin();
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2009-09-09 19:08:12 +04:00
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i1 != cv1.rend(); ++i1, ++i2) {
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2009-09-24 23:53:00 +04:00
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SrcConstruct
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= Context.getPointerType(Context.getQualifiedType(SrcConstruct, *i1));
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DestConstruct
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= Context.getPointerType(Context.getQualifiedType(DestConstruct, *i2));
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2008-11-06 00:50:06 +03:00
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}
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2009-07-25 19:41:38 +04:00
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// Test if they're compatible.
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return SrcConstruct != DestConstruct &&
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!Self.IsQualificationConversion(SrcConstruct, DestConstruct);
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2008-11-06 00:50:06 +03:00
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}
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2009-07-25 19:41:38 +04:00
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/// CheckDynamicCast - Check that a dynamic_cast\<DestType\>(SrcExpr) is valid.
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/// Refer to C++ 5.2.7 for details. Dynamic casts are used mostly for runtime-
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/// checked downcasts in class hierarchies.
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2009-08-02 23:07:59 +04:00
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static void
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2009-07-25 19:41:38 +04:00
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CheckDynamicCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
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const SourceRange &OpRange,
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2009-09-09 19:08:12 +04:00
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const SourceRange &DestRange, CastExpr::CastKind &Kind) {
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2008-11-06 00:50:06 +03:00
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QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
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2008-11-08 16:00:26 +03:00
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DestType = Self.Context.getCanonicalType(DestType);
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2008-11-06 00:50:06 +03:00
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2009-07-25 19:41:38 +04:00
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// C++ 5.2.7p1: T shall be a pointer or reference to a complete class type,
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// or "pointer to cv void".
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2009-03-17 02:22:08 +03:00
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2009-07-25 19:41:38 +04:00
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QualType DestPointee;
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2009-07-30 01:53:49 +04:00
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const PointerType *DestPointer = DestType->getAs<PointerType>();
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const ReferenceType *DestReference = DestType->getAs<ReferenceType>();
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2009-07-25 19:41:38 +04:00
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if (DestPointer) {
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DestPointee = DestPointer->getPointeeType();
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} else if (DestReference) {
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DestPointee = DestReference->getPointeeType();
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2008-11-06 00:50:06 +03:00
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} else {
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2009-07-25 19:41:38 +04:00
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Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ref_or_ptr)
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<< OrigDestType << DestRange;
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2009-05-10 22:38:11 +04:00
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return;
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}
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2009-07-30 01:53:49 +04:00
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const RecordType *DestRecord = DestPointee->getAs<RecordType>();
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2009-07-25 19:41:38 +04:00
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if (DestPointee->isVoidType()) {
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assert(DestPointer && "Reference to void is not possible");
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} else if (DestRecord) {
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if (Self.RequireCompleteType(OpRange.getBegin(), DestPointee,
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2009-08-27 03:45:07 +04:00
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PDiag(diag::err_bad_dynamic_cast_incomplete)
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<< DestRange))
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2009-07-25 19:41:38 +04:00
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return;
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} else {
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Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
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<< DestPointee.getUnqualifiedType() << DestRange;
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2008-11-06 00:50:06 +03:00
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return;
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}
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2009-07-25 19:41:38 +04:00
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// C++0x 5.2.7p2: If T is a pointer type, v shall be an rvalue of a pointer to
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// complete class type, [...]. If T is an lvalue reference type, v shall be
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// an lvalue of a complete class type, [...]. If T is an rvalue reference
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// type, v shall be an expression having a complete effective class type,
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// [...]
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2008-11-06 00:50:06 +03:00
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2009-07-25 19:41:38 +04:00
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QualType SrcType = Self.Context.getCanonicalType(OrigSrcType);
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QualType SrcPointee;
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if (DestPointer) {
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2009-07-30 01:53:49 +04:00
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if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
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2009-07-25 19:41:38 +04:00
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SrcPointee = SrcPointer->getPointeeType();
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} else {
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Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ptr)
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<< OrigSrcType << SrcExpr->getSourceRange();
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return;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
2009-07-25 19:41:38 +04:00
|
|
|
} else if (DestReference->isLValueReferenceType()) {
|
|
|
|
if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
|
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
|
|
|
|
<< CT_Dynamic << OrigSrcType << OrigDestType << OpRange;
|
|
|
|
}
|
|
|
|
SrcPointee = SrcType;
|
|
|
|
} else {
|
|
|
|
SrcPointee = SrcType;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-30 01:53:49 +04:00
|
|
|
const RecordType *SrcRecord = SrcPointee->getAs<RecordType>();
|
2009-07-25 19:41:38 +04:00
|
|
|
if (SrcRecord) {
|
|
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), SrcPointee,
|
2009-08-27 03:45:07 +04:00
|
|
|
PDiag(diag::err_bad_dynamic_cast_incomplete)
|
|
|
|
<< SrcExpr->getSourceRange()))
|
2009-07-25 19:41:38 +04:00
|
|
|
return;
|
|
|
|
} else {
|
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
|
|
|
|
<< SrcPointee.getUnqualifiedType() << SrcExpr->getSourceRange();
|
2008-11-06 00:50:06 +03:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
assert((DestPointer || DestReference) &&
|
|
|
|
"Bad destination non-ptr/ref slipped through.");
|
|
|
|
assert((DestRecord || DestPointee->isVoidType()) &&
|
|
|
|
"Bad destination pointee slipped through.");
|
|
|
|
assert(SrcRecord && "Bad source pointee slipped through.");
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// C++ 5.2.7p1: The dynamic_cast operator shall not cast away constness.
|
|
|
|
if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
|
2008-11-19 01:52:51 +03:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
|
2009-07-25 19:41:38 +04:00
|
|
|
<< CT_Dynamic << OrigSrcType << OrigDestType << OpRange;
|
2008-11-06 00:50:06 +03:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// C++ 5.2.7p3: If the type of v is the same as the required result type,
|
|
|
|
// [except for cv].
|
|
|
|
if (DestRecord == SrcRecord) {
|
2008-11-06 00:50:06 +03:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// C++ 5.2.7p5
|
|
|
|
// Upcasts are resolved statically.
|
|
|
|
if (DestRecord && Self.IsDerivedFrom(SrcPointee, DestPointee)) {
|
|
|
|
Self.CheckDerivedToBaseConversion(SrcPointee, DestPointee,
|
|
|
|
OpRange.getBegin(), OpRange);
|
2009-08-02 23:07:59 +04:00
|
|
|
Kind = CastExpr::CK_DerivedToBase;
|
2009-07-25 19:41:38 +04:00
|
|
|
// Diagnostic already emitted on error.
|
2008-11-06 00:50:06 +03:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// C++ 5.2.7p6: Otherwise, v shall be [polymorphic].
|
|
|
|
const RecordDecl *SrcDecl = SrcRecord->getDecl()->getDefinition(Self.Context);
|
|
|
|
assert(SrcDecl && "Definition missing");
|
|
|
|
if (!cast<CXXRecordDecl>(SrcDecl)->isPolymorphic()) {
|
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_polymorphic)
|
|
|
|
<< SrcPointee.getUnqualifiedType() << SrcExpr->getSourceRange();
|
|
|
|
}
|
|
|
|
|
|
|
|
// Done. Everything else is run-time checks.
|
2009-08-02 23:07:59 +04:00
|
|
|
Kind = CastExpr::CK_Dynamic;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
/// CheckConstCast - Check that a const_cast\<DestType\>(SrcExpr) is valid.
|
|
|
|
/// Refer to C++ 5.2.11 for details. const_cast is typically used in code
|
|
|
|
/// like this:
|
|
|
|
/// const char *str = "literal";
|
|
|
|
/// legacy_function(const_cast\<char*\>(str));
|
|
|
|
void
|
|
|
|
CheckConstCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
|
2009-09-09 19:08:12 +04:00
|
|
|
const SourceRange &OpRange, const SourceRange &DestRange) {
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!DestType->isLValueReferenceType())
|
|
|
|
Self.DefaultFunctionArrayConversion(SrcExpr);
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
unsigned msg = diag::err_bad_cxx_cast_generic;
|
|
|
|
if (TryConstCast(Self, SrcExpr, DestType, /*CStyle*/false, msg) != TC_Success
|
|
|
|
&& msg != 0)
|
|
|
|
Self.Diag(OpRange.getBegin(), msg) << CT_Const
|
|
|
|
<< SrcExpr->getType() << DestType << OpRange;
|
|
|
|
}
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
/// CheckReinterpretCast - Check that a reinterpret_cast\<DestType\>(SrcExpr) is
|
|
|
|
/// valid.
|
|
|
|
/// Refer to C++ 5.2.10 for details. reinterpret_cast is typically used in code
|
|
|
|
/// like this:
|
|
|
|
/// char *bytes = reinterpret_cast\<char*\>(int_ptr);
|
|
|
|
void
|
|
|
|
CheckReinterpretCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
|
2009-09-15 08:48:33 +04:00
|
|
|
const SourceRange &OpRange, const SourceRange &DestRange,
|
|
|
|
CastExpr::CastKind &Kind) {
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!DestType->isLValueReferenceType())
|
|
|
|
Self.DefaultFunctionArrayConversion(SrcExpr);
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
unsigned msg = diag::err_bad_cxx_cast_generic;
|
2009-09-26 04:12:34 +04:00
|
|
|
if (TryReinterpretCast(Self, SrcExpr, DestType, /*CStyle*/false, OpRange,
|
|
|
|
msg, Kind)
|
2009-07-25 19:41:38 +04:00
|
|
|
!= TC_Success && msg != 0)
|
|
|
|
Self.Diag(OpRange.getBegin(), msg) << CT_Reinterpret
|
|
|
|
<< SrcExpr->getType() << DestType << OpRange;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
|
2008-11-06 00:50:06 +03:00
|
|
|
/// CheckStaticCast - Check that a static_cast\<DestType\>(SrcExpr) is valid.
|
|
|
|
/// Refer to C++ 5.2.9 for details. Static casts are mostly used for making
|
|
|
|
/// implicit conversions explicit and getting rid of data loss warnings.
|
|
|
|
void
|
2008-11-08 16:00:26 +03:00
|
|
|
CheckStaticCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
|
2009-09-10 01:33:21 +04:00
|
|
|
const SourceRange &OpRange, CastExpr::CastKind &Kind,
|
|
|
|
CXXMethodDecl *&ConversionDecl) {
|
2009-07-25 19:41:38 +04:00
|
|
|
// This test is outside everything else because it's the only case where
|
|
|
|
// a non-lvalue-reference target type does not lead to decay.
|
|
|
|
// C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
|
|
|
|
if (DestType->isVoidType()) {
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!DestType->isLValueReferenceType())
|
|
|
|
Self.DefaultFunctionArrayConversion(SrcExpr);
|
|
|
|
|
|
|
|
unsigned msg = diag::err_bad_cxx_cast_generic;
|
2009-09-26 04:12:34 +04:00
|
|
|
if (TryStaticCast(Self, SrcExpr, DestType, /*CStyle*/false,OpRange, msg,
|
|
|
|
Kind, ConversionDecl)
|
2009-07-25 19:41:38 +04:00
|
|
|
!= TC_Success && msg != 0)
|
|
|
|
Self.Diag(OpRange.getBegin(), msg) << CT_Static
|
|
|
|
<< SrcExpr->getType() << DestType << OpRange;
|
|
|
|
}
|
|
|
|
|
|
|
|
/// TryStaticCast - Check if a static cast can be performed, and do so if
|
|
|
|
/// possible. If @p CStyle, ignore access restrictions on hierarchy casting
|
|
|
|
/// and casting away constness.
|
|
|
|
static TryCastResult TryStaticCast(Sema &Self, Expr *SrcExpr,
|
|
|
|
QualType DestType, bool CStyle,
|
2009-09-02 00:52:42 +04:00
|
|
|
const SourceRange &OpRange, unsigned &msg,
|
2009-09-26 04:12:34 +04:00
|
|
|
CastExpr::CastKind &Kind,
|
2009-09-09 19:08:12 +04:00
|
|
|
CXXMethodDecl *&ConversionDecl) {
|
2008-11-06 00:50:06 +03:00
|
|
|
// The order the tests is not entirely arbitrary. There is one conversion
|
|
|
|
// that can be handled in two different ways. Given:
|
|
|
|
// struct A {};
|
|
|
|
// struct B : public A {
|
|
|
|
// B(); B(const A&);
|
|
|
|
// };
|
|
|
|
// const A &a = B();
|
|
|
|
// the cast static_cast<const B&>(a) could be seen as either a static
|
|
|
|
// reference downcast, or an explicit invocation of the user-defined
|
|
|
|
// conversion using B's conversion constructor.
|
|
|
|
// DR 427 specifies that the downcast is to be applied here.
|
|
|
|
|
|
|
|
// C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
|
2009-07-25 19:41:38 +04:00
|
|
|
// Done outside this function.
|
|
|
|
|
|
|
|
TryCastResult tcr;
|
2008-11-06 00:50:06 +03:00
|
|
|
|
|
|
|
// C++ 5.2.9p5, reference downcast.
|
|
|
|
// See the function for details.
|
|
|
|
// DR 427 specifies that this is to be applied before paragraph 2.
|
2009-07-25 19:41:38 +04:00
|
|
|
tcr = TryStaticReferenceDowncast(Self, SrcExpr, DestType, CStyle,OpRange,msg);
|
|
|
|
if (tcr != TC_NotApplicable)
|
|
|
|
return tcr;
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-03-23 01:30:06 +03:00
|
|
|
// N2844 5.2.9p3: An lvalue of type "cv1 T1" can be cast to type "rvalue
|
|
|
|
// reference to cv2 T2" if "cv2 T2" is reference-compatible with "cv1 T1".
|
2009-07-25 19:41:38 +04:00
|
|
|
tcr = TryLValueToRValueCast(Self, SrcExpr, DestType, msg);
|
|
|
|
if (tcr != TC_NotApplicable)
|
|
|
|
return tcr;
|
2009-03-23 01:30:06 +03:00
|
|
|
|
2008-11-06 00:50:06 +03:00
|
|
|
// C++ 5.2.9p2: An expression e can be explicitly converted to a type T
|
|
|
|
// [...] if the declaration "T t(e);" is well-formed, [...].
|
2009-08-26 22:55:36 +04:00
|
|
|
tcr = TryStaticImplicitCast(Self, SrcExpr, DestType, CStyle, OpRange, msg,
|
2009-09-26 04:12:34 +04:00
|
|
|
Kind, ConversionDecl);
|
|
|
|
if (tcr != TC_NotApplicable)
|
2009-07-25 19:41:38 +04:00
|
|
|
return tcr;
|
2009-09-10 01:33:21 +04:00
|
|
|
|
2008-11-06 00:50:06 +03:00
|
|
|
// C++ 5.2.9p6: May apply the reverse of any standard conversion, except
|
|
|
|
// lvalue-to-rvalue, array-to-pointer, function-to-pointer, and boolean
|
|
|
|
// conversions, subject to further restrictions.
|
|
|
|
// Also, C++ 5.2.9p1 forbids casting away constness, which makes reversal
|
|
|
|
// of qualification conversions impossible.
|
2009-07-25 19:41:38 +04:00
|
|
|
// In the CStyle case, the earlier attempt to const_cast should have taken
|
|
|
|
// care of reverse qualification conversions.
|
2008-11-06 00:50:06 +03:00
|
|
|
|
|
|
|
QualType OrigSrcType = SrcExpr->getType();
|
|
|
|
|
2008-11-08 16:00:26 +03:00
|
|
|
QualType SrcType = Self.Context.getCanonicalType(SrcExpr->getType());
|
2008-11-06 00:50:06 +03:00
|
|
|
|
|
|
|
// Reverse integral promotion/conversion. All such conversions are themselves
|
|
|
|
// again integral promotions or conversions and are thus already handled by
|
|
|
|
// p2 (TryDirectInitialization above).
|
|
|
|
// (Note: any data loss warnings should be suppressed.)
|
|
|
|
// The exception is the reverse of enum->integer, i.e. integer->enum (and
|
|
|
|
// enum->enum). See also C++ 5.2.9p7.
|
|
|
|
// The same goes for reverse floating point promotion/conversion and
|
|
|
|
// floating-integral conversions. Again, only floating->enum is relevant.
|
|
|
|
if (DestType->isEnumeralType()) {
|
|
|
|
if (SrcType->isComplexType() || SrcType->isVectorType()) {
|
|
|
|
// Fall through - these cannot be converted.
|
2009-07-25 19:41:38 +04:00
|
|
|
} else if (SrcType->isArithmeticType() || SrcType->isEnumeralType())
|
|
|
|
return TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
// Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
|
|
|
|
// C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
|
2009-07-25 19:41:38 +04:00
|
|
|
tcr = TryStaticPointerDowncast(Self, SrcType, DestType, CStyle, OpRange, msg);
|
|
|
|
if (tcr != TC_NotApplicable)
|
|
|
|
return tcr;
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-01-28 21:33:18 +03:00
|
|
|
// Reverse member pointer conversion. C++ 4.11 specifies member pointer
|
2008-11-06 00:50:06 +03:00
|
|
|
// conversion. C++ 5.2.9p9 has additional information.
|
|
|
|
// DR54's access restrictions apply here also.
|
2009-07-25 19:41:38 +04:00
|
|
|
tcr = TryStaticMemberPointerUpcast(Self, SrcType, DestType, CStyle,
|
|
|
|
OpRange, msg);
|
|
|
|
if (tcr != TC_NotApplicable)
|
|
|
|
return tcr;
|
2008-11-06 00:50:06 +03:00
|
|
|
|
|
|
|
// Reverse pointer conversion to void*. C++ 4.10.p2 specifies conversion to
|
|
|
|
// void*. C++ 5.2.9p10 specifies additional restrictions, which really is
|
|
|
|
// just the usual constness stuff.
|
2009-07-30 01:53:49 +04:00
|
|
|
if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
|
2008-11-06 00:50:06 +03:00
|
|
|
QualType SrcPointee = SrcPointer->getPointeeType();
|
|
|
|
if (SrcPointee->isVoidType()) {
|
2009-07-30 01:53:49 +04:00
|
|
|
if (const PointerType *DestPointer = DestType->getAs<PointerType>()) {
|
2008-11-06 00:50:06 +03:00
|
|
|
QualType DestPointee = DestPointer->getPointeeType();
|
2009-03-24 23:13:58 +03:00
|
|
|
if (DestPointee->isIncompleteOrObjectType()) {
|
2008-11-06 00:50:06 +03:00
|
|
|
// This is definitely the intended conversion, but it might fail due
|
|
|
|
// to a const violation.
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!CStyle && !DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
|
|
|
|
msg = diag::err_bad_cxx_cast_const_away;
|
|
|
|
return TC_Failed;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
// We tried everything. Everything! Nothing works! :-(
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-03-23 01:30:06 +03:00
|
|
|
/// Tests whether a conversion according to N2844 is valid.
|
2009-07-25 19:41:38 +04:00
|
|
|
TryCastResult
|
2009-03-23 01:30:06 +03:00
|
|
|
TryLValueToRValueCast(Sema &Self, Expr *SrcExpr, QualType DestType,
|
2009-09-09 19:08:12 +04:00
|
|
|
unsigned &msg) {
|
2009-03-23 01:30:06 +03:00
|
|
|
// N2844 5.2.9p3: An lvalue of type "cv1 T1" can be cast to type "rvalue
|
|
|
|
// reference to cv2 T2" if "cv2 T2" is reference-compatible with "cv1 T1".
|
2009-07-30 01:53:49 +04:00
|
|
|
const RValueReferenceType *R = DestType->getAs<RValueReferenceType>();
|
2009-03-23 01:30:06 +03:00
|
|
|
if (!R)
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
2009-03-23 01:30:06 +03:00
|
|
|
|
|
|
|
if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid)
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
2009-03-23 01:30:06 +03:00
|
|
|
|
|
|
|
// Because we try the reference downcast before this function, from now on
|
|
|
|
// this is the only cast possibility, so we issue an error if we fail now.
|
2009-07-25 19:41:38 +04:00
|
|
|
// FIXME: Should allow casting away constness if CStyle.
|
2009-03-23 01:30:06 +03:00
|
|
|
bool DerivedToBase;
|
|
|
|
if (Self.CompareReferenceRelationship(SrcExpr->getType(), R->getPointeeType(),
|
|
|
|
DerivedToBase) <
|
|
|
|
Sema::Ref_Compatible_With_Added_Qualification) {
|
2009-07-25 19:41:38 +04:00
|
|
|
msg = diag::err_bad_lvalue_to_rvalue_cast;
|
|
|
|
return TC_Failed;
|
2009-03-23 01:30:06 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
// FIXME: Similar to CheckReferenceInit, we actually need more AST annotation
|
|
|
|
// than nothing.
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
2009-03-23 01:30:06 +03:00
|
|
|
}
|
|
|
|
|
2008-11-06 00:50:06 +03:00
|
|
|
/// Tests whether a conversion according to C++ 5.2.9p5 is valid.
|
2009-07-25 19:41:38 +04:00
|
|
|
TryCastResult
|
2008-11-08 16:00:26 +03:00
|
|
|
TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr, QualType DestType,
|
2009-07-25 19:41:38 +04:00
|
|
|
bool CStyle, const SourceRange &OpRange,
|
2009-09-09 19:08:12 +04:00
|
|
|
unsigned &msg) {
|
2008-11-06 00:50:06 +03:00
|
|
|
// C++ 5.2.9p5: An lvalue of type "cv1 B", where B is a class type, can be
|
|
|
|
// cast to type "reference to cv2 D", where D is a class derived from B,
|
|
|
|
// if a valid standard conversion from "pointer to D" to "pointer to B"
|
|
|
|
// exists, cv2 >= cv1, and B is not a virtual base class of D.
|
|
|
|
// In addition, DR54 clarifies that the base must be accessible in the
|
|
|
|
// current context. Although the wording of DR54 only applies to the pointer
|
|
|
|
// variant of this rule, the intent is clearly for it to apply to the this
|
2009-07-25 19:41:38 +04:00
|
|
|
// conversion as well.
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-30 01:53:49 +04:00
|
|
|
const ReferenceType *DestReference = DestType->getAs<ReferenceType>();
|
2008-11-06 00:50:06 +03:00
|
|
|
if (!DestReference) {
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
|
|
|
}
|
|
|
|
bool RValueRef = DestReference->isRValueReferenceType();
|
|
|
|
if (!RValueRef && SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
|
|
|
|
// We know the left side is an lvalue reference, so we can suggest a reason.
|
|
|
|
msg = diag::err_bad_cxx_cast_rvalue;
|
|
|
|
return TC_NotApplicable;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
2009-07-25 19:41:38 +04:00
|
|
|
|
2008-11-06 00:50:06 +03:00
|
|
|
QualType DestPointee = DestReference->getPointeeType();
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
return TryStaticDowncast(Self, SrcExpr->getType(), DestPointee, CStyle,
|
|
|
|
OpRange, SrcExpr->getType(), DestType, msg);
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
/// Tests whether a conversion according to C++ 5.2.9p8 is valid.
|
2009-07-25 19:41:38 +04:00
|
|
|
TryCastResult
|
2008-11-08 16:00:26 +03:00
|
|
|
TryStaticPointerDowncast(Sema &Self, QualType SrcType, QualType DestType,
|
2009-09-09 19:08:12 +04:00
|
|
|
bool CStyle, const SourceRange &OpRange,
|
|
|
|
unsigned &msg) {
|
2008-11-06 00:50:06 +03:00
|
|
|
// C++ 5.2.9p8: An rvalue of type "pointer to cv1 B", where B is a class
|
|
|
|
// type, can be converted to an rvalue of type "pointer to cv2 D", where D
|
|
|
|
// is a class derived from B, if a valid standard conversion from "pointer
|
|
|
|
// to D" to "pointer to B" exists, cv2 >= cv1, and B is not a virtual base
|
|
|
|
// class of D.
|
|
|
|
// In addition, DR54 clarifies that the base must be accessible in the
|
|
|
|
// current context.
|
|
|
|
|
2009-07-30 01:53:49 +04:00
|
|
|
const PointerType *DestPointer = DestType->getAs<PointerType>();
|
2008-11-06 00:50:06 +03:00
|
|
|
if (!DestPointer) {
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
|
|
|
}
|
|
|
|
|
2009-07-30 01:53:49 +04:00
|
|
|
const PointerType *SrcPointer = SrcType->getAs<PointerType>();
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!SrcPointer) {
|
|
|
|
msg = diag::err_bad_static_cast_pointer_nonpointer;
|
|
|
|
return TC_NotApplicable;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2008-11-08 16:00:26 +03:00
|
|
|
return TryStaticDowncast(Self, SrcPointer->getPointeeType(),
|
2009-07-25 19:41:38 +04:00
|
|
|
DestPointer->getPointeeType(), CStyle,
|
|
|
|
OpRange, SrcType, DestType, msg);
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2008-11-08 02:29:29 +03:00
|
|
|
/// TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and
|
|
|
|
/// TryStaticPointerDowncast. Tests whether a static downcast from SrcType to
|
2008-11-06 00:50:06 +03:00
|
|
|
/// DestType, both of which must be canonical, is possible and allowed.
|
2009-07-25 19:41:38 +04:00
|
|
|
TryCastResult
|
2008-11-08 16:00:26 +03:00
|
|
|
TryStaticDowncast(Sema &Self, QualType SrcType, QualType DestType,
|
2009-07-25 19:41:38 +04:00
|
|
|
bool CStyle, const SourceRange &OpRange, QualType OrigSrcType,
|
2009-09-09 19:08:12 +04:00
|
|
|
QualType OrigDestType, unsigned &msg) {
|
2009-10-22 19:07:22 +04:00
|
|
|
// We can only work with complete types. But don't complain if it doesn't work
|
|
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), SrcType, PDiag(0)) ||
|
|
|
|
Self.RequireCompleteType(OpRange.getBegin(), DestType, PDiag(0)))
|
|
|
|
return TC_NotApplicable;
|
|
|
|
|
2008-11-06 00:50:06 +03:00
|
|
|
// Downcast can only happen in class hierarchies, so we need classes.
|
|
|
|
if (!DestType->isRecordType() || !SrcType->isRecordType()) {
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-10-06 21:59:45 +04:00
|
|
|
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/!CStyle,
|
|
|
|
/*DetectVirtual=*/true);
|
2008-11-08 16:00:26 +03:00
|
|
|
if (!Self.IsDerivedFrom(DestType, SrcType, Paths)) {
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
2008-11-08 02:29:29 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
// Target type does derive from source type. Now we're serious. If an error
|
|
|
|
// appears now, it's not ignored.
|
|
|
|
// This may not be entirely in line with the standard. Take for example:
|
|
|
|
// struct A {};
|
|
|
|
// struct B : virtual A {
|
|
|
|
// B(A&);
|
|
|
|
// };
|
2009-09-09 19:08:12 +04:00
|
|
|
//
|
2008-11-08 02:29:29 +03:00
|
|
|
// void f()
|
|
|
|
// {
|
|
|
|
// (void)static_cast<const B&>(*((A*)0));
|
|
|
|
// }
|
|
|
|
// As far as the standard is concerned, p5 does not apply (A is virtual), so
|
|
|
|
// p2 should be used instead - "const B& t(*((A*)0));" is perfectly valid.
|
|
|
|
// However, both GCC and Comeau reject this example, and accepting it would
|
|
|
|
// mean more complex code if we're to preserve the nice error message.
|
|
|
|
// FIXME: Being 100% compliant here would be nice to have.
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// Must preserve cv, as always, unless we're in C-style mode.
|
|
|
|
if (!CStyle && !DestType.isAtLeastAsQualifiedAs(SrcType)) {
|
|
|
|
msg = diag::err_bad_cxx_cast_const_away;
|
|
|
|
return TC_Failed;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
|
2008-11-08 02:29:29 +03:00
|
|
|
// This code is analoguous to that in CheckDerivedToBaseConversion, except
|
|
|
|
// that it builds the paths in reverse order.
|
|
|
|
// To sum up: record all paths to the base and build a nice string from
|
|
|
|
// them. Use it to spice up the error message.
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!Paths.isRecordingPaths()) {
|
|
|
|
Paths.clear();
|
|
|
|
Paths.setRecordingPaths(true);
|
|
|
|
Self.IsDerivedFrom(DestType, SrcType, Paths);
|
|
|
|
}
|
2008-11-08 02:29:29 +03:00
|
|
|
std::string PathDisplayStr;
|
|
|
|
std::set<unsigned> DisplayedPaths;
|
2009-10-06 21:59:45 +04:00
|
|
|
for (CXXBasePaths::paths_iterator PI = Paths.begin(), PE = Paths.end();
|
2009-07-25 19:41:38 +04:00
|
|
|
PI != PE; ++PI) {
|
|
|
|
if (DisplayedPaths.insert(PI->back().SubobjectNumber).second) {
|
2008-11-08 02:29:29 +03:00
|
|
|
// We haven't displayed a path to this particular base
|
|
|
|
// class subobject yet.
|
|
|
|
PathDisplayStr += "\n ";
|
2009-10-06 21:59:45 +04:00
|
|
|
for (CXXBasePath::const_reverse_iterator EI = PI->rbegin(),
|
|
|
|
EE = PI->rend();
|
2009-07-25 19:41:38 +04:00
|
|
|
EI != EE; ++EI)
|
|
|
|
PathDisplayStr += EI->Base->getType().getAsString() + " -> ";
|
2008-11-08 02:29:29 +03:00
|
|
|
PathDisplayStr += DestType.getAsString();
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2008-11-19 01:52:51 +03:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_ambiguous_base_to_derived_cast)
|
2008-11-24 09:25:27 +03:00
|
|
|
<< SrcType.getUnqualifiedType() << DestType.getUnqualifiedType()
|
2008-11-19 01:52:51 +03:00
|
|
|
<< PathDisplayStr << OpRange;
|
2009-07-25 19:41:38 +04:00
|
|
|
msg = 0;
|
|
|
|
return TC_Failed;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
if (Paths.getDetectedVirtual() != 0) {
|
2008-11-08 02:29:29 +03:00
|
|
|
QualType VirtualBase(Paths.getDetectedVirtual(), 0);
|
2008-11-19 01:52:51 +03:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_static_downcast_via_virtual)
|
2008-11-24 09:25:27 +03:00
|
|
|
<< OrigSrcType << OrigDestType << VirtualBase << OpRange;
|
2009-07-25 19:41:38 +04:00
|
|
|
msg = 0;
|
|
|
|
return TC_Failed;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!CStyle && Self.CheckBaseClassAccess(DestType, SrcType,
|
|
|
|
diag::err_downcast_from_inaccessible_base, Paths,
|
|
|
|
OpRange.getBegin(), DeclarationName())) {
|
|
|
|
msg = 0;
|
|
|
|
return TC_Failed;
|
|
|
|
}
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-01-28 21:33:18 +03:00
|
|
|
/// TryStaticMemberPointerUpcast - Tests whether a conversion according to
|
|
|
|
/// C++ 5.2.9p9 is valid:
|
|
|
|
///
|
|
|
|
/// An rvalue of type "pointer to member of D of type cv1 T" can be
|
|
|
|
/// converted to an rvalue of type "pointer to member of B of type cv2 T",
|
|
|
|
/// where B is a base class of D [...].
|
|
|
|
///
|
2009-07-25 19:41:38 +04:00
|
|
|
TryCastResult
|
2009-01-28 21:33:18 +03:00
|
|
|
TryStaticMemberPointerUpcast(Sema &Self, QualType SrcType, QualType DestType,
|
2009-07-25 19:41:38 +04:00
|
|
|
bool CStyle, const SourceRange &OpRange,
|
2009-09-09 19:08:12 +04:00
|
|
|
unsigned &msg) {
|
2009-07-30 01:53:49 +04:00
|
|
|
const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>();
|
2009-01-28 21:33:18 +03:00
|
|
|
if (!DestMemPtr)
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
2009-07-30 01:53:49 +04:00
|
|
|
const MemberPointerType *SrcMemPtr = SrcType->getAs<MemberPointerType>();
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!SrcMemPtr) {
|
|
|
|
msg = diag::err_bad_static_cast_member_pointer_nonmp;
|
|
|
|
return TC_NotApplicable;
|
|
|
|
}
|
2009-01-28 21:33:18 +03:00
|
|
|
|
|
|
|
// T == T, modulo cv
|
|
|
|
if (Self.Context.getCanonicalType(
|
|
|
|
SrcMemPtr->getPointeeType().getUnqualifiedType()) !=
|
|
|
|
Self.Context.getCanonicalType(DestMemPtr->getPointeeType().
|
|
|
|
getUnqualifiedType()))
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
2009-01-28 21:33:18 +03:00
|
|
|
|
|
|
|
// B base of D
|
|
|
|
QualType SrcClass(SrcMemPtr->getClass(), 0);
|
|
|
|
QualType DestClass(DestMemPtr->getClass(), 0);
|
2009-10-06 21:59:45 +04:00
|
|
|
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/!CStyle,
|
2009-01-28 21:33:18 +03:00
|
|
|
/*DetectVirtual=*/true);
|
|
|
|
if (!Self.IsDerivedFrom(SrcClass, DestClass, Paths)) {
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_NotApplicable;
|
2009-01-28 21:33:18 +03:00
|
|
|
}
|
|
|
|
|
|
|
|
// B is a base of D. But is it an allowed base? If not, it's a hard error.
|
|
|
|
if (Paths.isAmbiguous(DestClass)) {
|
|
|
|
Paths.clear();
|
|
|
|
Paths.setRecordingPaths(true);
|
|
|
|
bool StillOkay = Self.IsDerivedFrom(SrcClass, DestClass, Paths);
|
|
|
|
assert(StillOkay);
|
|
|
|
StillOkay = StillOkay;
|
|
|
|
std::string PathDisplayStr = Self.getAmbiguousPathsDisplayString(Paths);
|
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_ambiguous_memptr_conv)
|
|
|
|
<< 1 << SrcClass << DestClass << PathDisplayStr << OpRange;
|
2009-07-25 19:41:38 +04:00
|
|
|
msg = 0;
|
|
|
|
return TC_Failed;
|
2009-01-28 21:33:18 +03:00
|
|
|
}
|
|
|
|
|
2009-02-28 04:32:25 +03:00
|
|
|
if (const RecordType *VBase = Paths.getDetectedVirtual()) {
|
2009-01-28 21:33:18 +03:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_memptr_conv_via_virtual)
|
|
|
|
<< SrcClass << DestClass << QualType(VBase, 0) << OpRange;
|
2009-07-25 19:41:38 +04:00
|
|
|
msg = 0;
|
|
|
|
return TC_Failed;
|
2009-01-28 21:33:18 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!CStyle && Self.CheckBaseClassAccess(DestType, SrcType,
|
|
|
|
diag::err_downcast_from_inaccessible_base, Paths,
|
|
|
|
OpRange.getBegin(), DeclarationName())) {
|
|
|
|
msg = 0;
|
|
|
|
return TC_Failed;
|
|
|
|
}
|
2009-01-28 21:33:18 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
2009-01-28 21:33:18 +03:00
|
|
|
}
|
|
|
|
|
2008-11-08 02:29:29 +03:00
|
|
|
/// TryStaticImplicitCast - Tests whether a conversion according to C++ 5.2.9p2
|
|
|
|
/// is valid:
|
|
|
|
///
|
|
|
|
/// An expression e can be explicitly converted to a type T using a
|
|
|
|
/// @c static_cast if the declaration "T t(e);" is well-formed [...].
|
2009-07-25 19:41:38 +04:00
|
|
|
TryCastResult
|
2008-11-08 16:00:26 +03:00
|
|
|
TryStaticImplicitCast(Sema &Self, Expr *SrcExpr, QualType DestType,
|
2009-08-26 22:55:36 +04:00
|
|
|
bool CStyle, const SourceRange &OpRange, unsigned &msg,
|
2009-09-26 04:12:34 +04:00
|
|
|
CastExpr::CastKind &Kind,
|
2009-09-09 19:08:12 +04:00
|
|
|
CXXMethodDecl *&ConversionDecl) {
|
2009-09-07 22:25:47 +04:00
|
|
|
if (DestType->isRecordType()) {
|
|
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
|
|
|
|
diag::err_bad_dynamic_cast_incomplete)) {
|
|
|
|
msg = 0;
|
|
|
|
return TC_Failed;
|
|
|
|
}
|
|
|
|
}
|
2009-09-09 19:08:12 +04:00
|
|
|
|
2008-11-08 02:29:29 +03:00
|
|
|
if (DestType->isReferenceType()) {
|
|
|
|
// At this point of CheckStaticCast, if the destination is a reference,
|
|
|
|
// this has to work. There is no other way that works.
|
2009-07-25 19:41:38 +04:00
|
|
|
// On the other hand, if we're checking a C-style cast, we've still got
|
|
|
|
// the reinterpret_cast way. In that case, we pass an ICS so we don't
|
|
|
|
// get error messages.
|
|
|
|
ImplicitConversionSequence ICS;
|
2009-09-09 19:08:12 +04:00
|
|
|
bool failed = Self.CheckReferenceInit(SrcExpr, DestType,
|
2009-09-24 03:04:10 +04:00
|
|
|
OpRange.getBegin(),
|
2009-08-27 21:30:43 +04:00
|
|
|
/*SuppressUserConversions=*/false,
|
|
|
|
/*AllowExplicit=*/false,
|
|
|
|
/*ForceRValue=*/false,
|
|
|
|
CStyle ? &ICS : 0);
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!failed)
|
|
|
|
return TC_Success;
|
|
|
|
if (CStyle)
|
|
|
|
return TC_NotApplicable;
|
|
|
|
// If we didn't pass the ICS, we already got an error message.
|
|
|
|
msg = 0;
|
|
|
|
return TC_Failed;
|
2008-11-08 02:29:29 +03:00
|
|
|
}
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2008-11-08 02:29:29 +03:00
|
|
|
// FIXME: To get a proper error from invalid conversions here, we need to
|
|
|
|
// reimplement more of this.
|
2009-07-25 19:41:38 +04:00
|
|
|
// FIXME: This does not actually perform the conversion, and thus does not
|
|
|
|
// check for ambiguity or access.
|
2009-09-09 19:08:12 +04:00
|
|
|
ImplicitConversionSequence ICS =
|
2009-08-27 21:24:15 +04:00
|
|
|
Self.TryImplicitConversion(SrcExpr, DestType,
|
|
|
|
/*SuppressUserConversions=*/false,
|
2009-08-28 20:22:20 +04:00
|
|
|
/*AllowExplicit=*/true,
|
2009-08-28 19:33:32 +04:00
|
|
|
/*ForceRValue=*/false,
|
2009-10-02 00:39:51 +04:00
|
|
|
/*InOverloadResolution=*/false,
|
|
|
|
/*one of user provided casts*/true);
|
2009-09-09 19:08:12 +04:00
|
|
|
|
2009-09-26 04:12:34 +04:00
|
|
|
if (ICS.ConversionKind == ImplicitConversionSequence::BadConversion)
|
|
|
|
return TC_NotApplicable;
|
|
|
|
|
2009-09-10 01:33:21 +04:00
|
|
|
if (ICS.ConversionKind == ImplicitConversionSequence::UserDefinedConversion) {
|
2009-09-26 04:12:34 +04:00
|
|
|
ConversionDecl = cast<CXXMethodDecl>(ICS.UserDefined.ConversionFunction);
|
|
|
|
if (isa<CXXConstructorDecl>(ConversionDecl))
|
|
|
|
Kind = CastExpr::CK_ConstructorConversion;
|
|
|
|
else if (isa<CXXConversionDecl>(ConversionDecl))
|
|
|
|
Kind = CastExpr::CK_UserDefinedConversion;
|
|
|
|
} else if (ICS.ConversionKind ==
|
|
|
|
ImplicitConversionSequence::StandardConversion) {
|
|
|
|
// FIXME: Set the cast kind depending on which types of conversions we have.
|
2009-09-10 01:33:21 +04:00
|
|
|
}
|
2009-09-26 04:12:34 +04:00
|
|
|
|
|
|
|
return TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
/// TryConstCast - See if a const_cast from source to destination is allowed,
|
|
|
|
/// and perform it if it is.
|
|
|
|
static TryCastResult TryConstCast(Sema &Self, Expr *SrcExpr, QualType DestType,
|
|
|
|
bool CStyle, unsigned &msg) {
|
2008-11-08 16:00:26 +03:00
|
|
|
DestType = Self.Context.getCanonicalType(DestType);
|
2009-07-25 19:41:38 +04:00
|
|
|
QualType SrcType = SrcExpr->getType();
|
|
|
|
if (const LValueReferenceType *DestTypeTmp =
|
2009-07-30 01:53:49 +04:00
|
|
|
DestType->getAs<LValueReferenceType>()) {
|
2009-07-25 19:41:38 +04:00
|
|
|
if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
|
|
|
|
// Cannot const_cast non-lvalue to lvalue reference type. But if this
|
|
|
|
// is C-style, static_cast might find a way, so we simply suggest a
|
|
|
|
// message and tell the parent to keep searching.
|
|
|
|
msg = diag::err_bad_cxx_cast_rvalue;
|
|
|
|
return TC_NotApplicable;
|
|
|
|
}
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
|
|
|
|
// [...] if a pointer to T1 can be [cast] to the type pointer to T2.
|
|
|
|
DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
|
|
|
|
SrcType = Self.Context.getPointerType(SrcType);
|
|
|
|
}
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
|
|
|
|
// the rules for const_cast are the same as those used for pointers.
|
|
|
|
|
|
|
|
if (!DestType->isPointerType() && !DestType->isMemberPointerType()) {
|
|
|
|
// Cannot cast to non-pointer, non-reference type. Note that, if DestType
|
|
|
|
// was a reference type, we converted it to a pointer above.
|
|
|
|
// The status of rvalue references isn't entirely clear, but it looks like
|
|
|
|
// conversion to them is simply invalid.
|
|
|
|
// C++ 5.2.11p3: For two pointer types [...]
|
|
|
|
if (!CStyle)
|
|
|
|
msg = diag::err_bad_const_cast_dest;
|
|
|
|
return TC_NotApplicable;
|
|
|
|
}
|
|
|
|
if (DestType->isFunctionPointerType() ||
|
|
|
|
DestType->isMemberFunctionPointerType()) {
|
|
|
|
// Cannot cast direct function pointers.
|
|
|
|
// C++ 5.2.11p2: [...] where T is any object type or the void type [...]
|
|
|
|
// T is the ultimate pointee of source and target type.
|
|
|
|
if (!CStyle)
|
|
|
|
msg = diag::err_bad_const_cast_dest;
|
|
|
|
return TC_NotApplicable;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
2009-07-25 19:41:38 +04:00
|
|
|
SrcType = Self.Context.getCanonicalType(SrcType);
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
|
|
|
|
// completely equal.
|
|
|
|
// FIXME: const_cast should probably not be able to convert between pointers
|
|
|
|
// to different address spaces.
|
|
|
|
// C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
|
|
|
|
// in multi-level pointers may change, but the level count must be the same,
|
|
|
|
// as must be the final pointee type.
|
|
|
|
while (SrcType != DestType &&
|
|
|
|
Self.UnwrapSimilarPointerTypes(SrcType, DestType)) {
|
|
|
|
SrcType = SrcType.getUnqualifiedType();
|
|
|
|
DestType = DestType.getUnqualifiedType();
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// Since we're dealing in canonical types, the remainder must be the same.
|
|
|
|
if (SrcType != DestType)
|
|
|
|
return TC_NotApplicable;
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
|
|
|
}
|
|
|
|
|
|
|
|
static TryCastResult TryReinterpretCast(Sema &Self, Expr *SrcExpr,
|
|
|
|
QualType DestType, bool CStyle,
|
|
|
|
const SourceRange &OpRange,
|
2009-09-26 04:12:34 +04:00
|
|
|
unsigned &msg,
|
|
|
|
CastExpr::CastKind &Kind) {
|
2009-07-25 19:41:38 +04:00
|
|
|
QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
|
|
|
|
|
|
|
|
DestType = Self.Context.getCanonicalType(DestType);
|
|
|
|
QualType SrcType = SrcExpr->getType();
|
2009-07-30 01:53:49 +04:00
|
|
|
if (const ReferenceType *DestTypeTmp = DestType->getAs<ReferenceType>()) {
|
2009-07-25 19:41:38 +04:00
|
|
|
bool LValue = DestTypeTmp->isLValueReferenceType();
|
|
|
|
if (LValue && SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
|
|
|
|
// Cannot cast non-lvalue to reference type. See the similar comment in
|
|
|
|
// const_cast.
|
|
|
|
msg = diag::err_bad_cxx_cast_rvalue;
|
|
|
|
return TC_NotApplicable;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
2009-07-25 19:41:38 +04:00
|
|
|
|
|
|
|
// C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
|
|
|
|
// same effect as the conversion *reinterpret_cast<T*>(&x) with the
|
|
|
|
// built-in & and * operators.
|
|
|
|
// This code does this transformation for the checked types.
|
|
|
|
DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
|
|
|
|
SrcType = Self.Context.getPointerType(SrcType);
|
|
|
|
}
|
|
|
|
|
|
|
|
// Canonicalize source for comparison.
|
|
|
|
SrcType = Self.Context.getCanonicalType(SrcType);
|
|
|
|
|
2009-07-30 01:53:49 +04:00
|
|
|
const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>(),
|
|
|
|
*SrcMemPtr = SrcType->getAs<MemberPointerType>();
|
2009-07-25 19:41:38 +04:00
|
|
|
if (DestMemPtr && SrcMemPtr) {
|
|
|
|
// C++ 5.2.10p9: An rvalue of type "pointer to member of X of type T1"
|
|
|
|
// can be explicitly converted to an rvalue of type "pointer to member
|
|
|
|
// of Y of type T2" if T1 and T2 are both function types or both object
|
|
|
|
// types.
|
|
|
|
if (DestMemPtr->getPointeeType()->isFunctionType() !=
|
|
|
|
SrcMemPtr->getPointeeType()->isFunctionType())
|
|
|
|
return TC_NotApplicable;
|
|
|
|
|
|
|
|
// C++ 5.2.10p2: The reinterpret_cast operator shall not cast away
|
|
|
|
// constness.
|
|
|
|
// A reinterpret_cast followed by a const_cast can, though, so in C-style,
|
|
|
|
// we accept it.
|
|
|
|
if (!CStyle && CastsAwayConstness(Self, SrcType, DestType)) {
|
|
|
|
msg = diag::err_bad_cxx_cast_const_away;
|
|
|
|
return TC_Failed;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
2009-07-25 19:41:38 +04:00
|
|
|
|
|
|
|
// A valid member pointer cast.
|
2009-10-19 00:31:03 +04:00
|
|
|
Kind = CastExpr::CK_BitCast;
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// See below for the enumeral issue.
|
|
|
|
if (SrcType->isNullPtrType() && DestType->isIntegralType() &&
|
|
|
|
!DestType->isEnumeralType()) {
|
|
|
|
// C++0x 5.2.10p4: A pointer can be explicitly converted to any integral
|
|
|
|
// type large enough to hold it. A value of std::nullptr_t can be
|
|
|
|
// converted to an integral type; the conversion has the same meaning
|
|
|
|
// and validity as a conversion of (void*)0 to the integral type.
|
|
|
|
if (Self.Context.getTypeSize(SrcType) >
|
|
|
|
Self.Context.getTypeSize(DestType)) {
|
|
|
|
msg = diag::err_bad_reinterpret_cast_small_int;
|
|
|
|
return TC_Failed;
|
|
|
|
}
|
2009-09-15 08:48:33 +04:00
|
|
|
Kind = CastExpr::CK_PointerToIntegral;
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-09-16 23:19:43 +04:00
|
|
|
bool destIsVector = DestType->isVectorType();
|
|
|
|
bool srcIsVector = SrcType->isVectorType();
|
|
|
|
if (srcIsVector || destIsVector) {
|
|
|
|
bool srcIsScalar = SrcType->isIntegralType() && !SrcType->isEnumeralType();
|
|
|
|
bool destIsScalar =
|
|
|
|
DestType->isIntegralType() && !DestType->isEnumeralType();
|
|
|
|
|
|
|
|
// Check if this is a cast between a vector and something else.
|
|
|
|
if (!(srcIsScalar && destIsVector) && !(srcIsVector && destIsScalar) &&
|
|
|
|
!(srcIsVector && destIsVector))
|
|
|
|
return TC_NotApplicable;
|
|
|
|
|
|
|
|
// If both types have the same size, we can successfully cast.
|
|
|
|
if (Self.Context.getTypeSize(SrcType) == Self.Context.getTypeSize(DestType))
|
|
|
|
return TC_Success;
|
|
|
|
|
|
|
|
if (destIsScalar)
|
|
|
|
msg = diag::err_bad_cxx_cast_vector_to_scalar_different_size;
|
|
|
|
else if (srcIsScalar)
|
|
|
|
msg = diag::err_bad_cxx_cast_scalar_to_vector_different_size;
|
|
|
|
else
|
|
|
|
msg = diag::err_bad_cxx_cast_vector_to_vector_different_size;
|
|
|
|
|
|
|
|
return TC_Failed;
|
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
bool destIsPtr = DestType->isPointerType();
|
|
|
|
bool srcIsPtr = SrcType->isPointerType();
|
|
|
|
if (!destIsPtr && !srcIsPtr) {
|
|
|
|
// Except for std::nullptr_t->integer and lvalue->reference, which are
|
|
|
|
// handled above, at least one of the two arguments must be a pointer.
|
|
|
|
return TC_NotApplicable;
|
|
|
|
}
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
if (SrcType == DestType) {
|
|
|
|
// C++ 5.2.10p2 has a note that mentions that, subject to all other
|
|
|
|
// restrictions, a cast to the same type is allowed. The intent is not
|
|
|
|
// entirely clear here, since all other paragraphs explicitly forbid casts
|
|
|
|
// to the same type. However, the behavior of compilers is pretty consistent
|
|
|
|
// on this point: allow same-type conversion if the involved types are
|
|
|
|
// pointers, disallow otherwise.
|
|
|
|
return TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// Note: Clang treats enumeration types as integral types. If this is ever
|
|
|
|
// changed for C++, the additional check here will be redundant.
|
|
|
|
if (DestType->isIntegralType() && !DestType->isEnumeralType()) {
|
|
|
|
assert(srcIsPtr && "One type must be a pointer");
|
|
|
|
// C++ 5.2.10p4: A pointer can be explicitly converted to any integral
|
|
|
|
// type large enough to hold it.
|
|
|
|
if (Self.Context.getTypeSize(SrcType) >
|
|
|
|
Self.Context.getTypeSize(DestType)) {
|
|
|
|
msg = diag::err_bad_reinterpret_cast_small_int;
|
|
|
|
return TC_Failed;
|
|
|
|
}
|
2009-09-15 08:48:33 +04:00
|
|
|
Kind = CastExpr::CK_PointerToIntegral;
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
if (SrcType->isIntegralType() || SrcType->isEnumeralType()) {
|
|
|
|
assert(destIsPtr && "One type must be a pointer");
|
|
|
|
// C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
|
|
|
|
// converted to a pointer.
|
2009-09-15 08:48:33 +04:00
|
|
|
Kind = CastExpr::CK_IntegralToPointer;
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
if (!destIsPtr || !srcIsPtr) {
|
|
|
|
// With the valid non-pointer conversions out of the way, we can be even
|
|
|
|
// more stringent.
|
|
|
|
return TC_NotApplicable;
|
2008-11-06 18:59:35 +03:00
|
|
|
}
|
2008-11-06 00:50:06 +03:00
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
// C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
|
|
|
|
// The C-style cast operator can.
|
|
|
|
if (!CStyle && CastsAwayConstness(Self, SrcType, DestType)) {
|
|
|
|
msg = diag::err_bad_cxx_cast_const_away;
|
|
|
|
return TC_Failed;
|
|
|
|
}
|
|
|
|
|
|
|
|
// Not casting away constness, so the only remaining check is for compatible
|
|
|
|
// pointer categories.
|
2009-10-19 00:31:03 +04:00
|
|
|
Kind = CastExpr::CK_BitCast;
|
2009-07-25 19:41:38 +04:00
|
|
|
|
|
|
|
if (SrcType->isFunctionPointerType()) {
|
|
|
|
if (DestType->isFunctionPointerType()) {
|
|
|
|
// C++ 5.2.10p6: A pointer to a function can be explicitly converted to
|
|
|
|
// a pointer to a function of a different type.
|
|
|
|
return TC_Success;
|
|
|
|
}
|
|
|
|
|
|
|
|
// C++0x 5.2.10p8: Converting a pointer to a function into a pointer to
|
|
|
|
// an object type or vice versa is conditionally-supported.
|
|
|
|
// Compilers support it in C++03 too, though, because it's necessary for
|
|
|
|
// casting the return value of dlsym() and GetProcAddress().
|
|
|
|
// FIXME: Conditionally-supported behavior should be configurable in the
|
|
|
|
// TargetInfo or similar.
|
|
|
|
if (!Self.getLangOptions().CPlusPlus0x)
|
|
|
|
Self.Diag(OpRange.getBegin(), diag::ext_cast_fn_obj) << OpRange;
|
|
|
|
return TC_Success;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (DestType->isFunctionPointerType()) {
|
|
|
|
// See above.
|
|
|
|
if (!Self.getLangOptions().CPlusPlus0x)
|
|
|
|
Self.Diag(OpRange.getBegin(), diag::ext_cast_fn_obj) << OpRange;
|
|
|
|
return TC_Success;
|
|
|
|
}
|
|
|
|
|
|
|
|
// C++ 5.2.10p7: A pointer to an object can be explicitly converted to
|
|
|
|
// a pointer to an object of different type.
|
|
|
|
// Void pointers are not specified, but supported by every compiler out there.
|
|
|
|
// So we finish by allowing everything that remains - it's got to be two
|
|
|
|
// object pointers.
|
2009-09-02 00:52:42 +04:00
|
|
|
Kind = CastExpr::CK_BitCast;
|
2009-07-25 19:41:38 +04:00
|
|
|
return TC_Success;
|
|
|
|
}
|
|
|
|
|
2009-07-29 17:50:23 +04:00
|
|
|
bool Sema::CXXCheckCStyleCast(SourceRange R, QualType CastTy, Expr *&CastExpr,
|
2009-08-26 22:55:36 +04:00
|
|
|
CastExpr::CastKind &Kind, bool FunctionalStyle,
|
2009-09-09 19:08:12 +04:00
|
|
|
CXXMethodDecl *&ConversionDecl) {
|
2009-07-25 19:41:38 +04:00
|
|
|
// This test is outside everything else because it's the only case where
|
|
|
|
// a non-lvalue-reference target type does not lead to decay.
|
|
|
|
// C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
|
2009-10-19 00:31:03 +04:00
|
|
|
if (CastTy->isVoidType()) {
|
|
|
|
Kind = CastExpr::CK_ToVoid;
|
2009-07-25 19:41:38 +04:00
|
|
|
return false;
|
2009-10-19 00:31:03 +04:00
|
|
|
}
|
2009-07-25 19:41:38 +04:00
|
|
|
|
|
|
|
// If the type is dependent, we won't do any other semantic analysis now.
|
|
|
|
if (CastTy->isDependentType() || CastExpr->isTypeDependent())
|
|
|
|
return false;
|
|
|
|
|
|
|
|
if (!CastTy->isLValueReferenceType())
|
|
|
|
DefaultFunctionArrayConversion(CastExpr);
|
|
|
|
|
|
|
|
// C++ [expr.cast]p5: The conversions performed by
|
|
|
|
// - a const_cast,
|
|
|
|
// - a static_cast,
|
|
|
|
// - a static_cast followed by a const_cast,
|
|
|
|
// - a reinterpret_cast, or
|
|
|
|
// - a reinterpret_cast followed by a const_cast,
|
|
|
|
// can be performed using the cast notation of explicit type conversion.
|
|
|
|
// [...] If a conversion can be interpreted in more than one of the ways
|
|
|
|
// listed above, the interpretation that appears first in the list is used,
|
|
|
|
// even if a cast resulting from that interpretation is ill-formed.
|
|
|
|
// In plain language, this means trying a const_cast ...
|
|
|
|
unsigned msg = diag::err_bad_cxx_cast_generic;
|
2009-09-02 00:52:42 +04:00
|
|
|
TryCastResult tcr = TryConstCast(*this, CastExpr, CastTy, /*CStyle*/true,
|
|
|
|
msg);
|
2009-10-19 22:14:28 +04:00
|
|
|
if (tcr == TC_Success)
|
|
|
|
Kind = CastExpr::CK_NoOp;
|
|
|
|
|
2009-07-25 19:41:38 +04:00
|
|
|
if (tcr == TC_NotApplicable) {
|
|
|
|
// ... or if that is not possible, a static_cast, ignoring const, ...
|
2009-09-26 04:12:34 +04:00
|
|
|
tcr = TryStaticCast(*this, CastExpr, CastTy, /*CStyle*/true, R, msg,
|
|
|
|
Kind, ConversionDecl);
|
2009-07-25 19:41:38 +04:00
|
|
|
if (tcr == TC_NotApplicable) {
|
|
|
|
// ... and finally a reinterpret_cast, ignoring const.
|
2009-09-26 04:12:34 +04:00
|
|
|
tcr = TryReinterpretCast(*this, CastExpr, CastTy, /*CStyle*/true, R, msg,
|
|
|
|
Kind);
|
2009-07-25 19:41:38 +04:00
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
if (tcr != TC_Success && msg != 0)
|
2009-07-29 17:50:23 +04:00
|
|
|
Diag(R.getBegin(), msg) << (FunctionalStyle ? CT_Functional : CT_CStyle)
|
2009-07-25 19:41:38 +04:00
|
|
|
<< CastExpr->getType() << CastTy << R;
|
|
|
|
|
|
|
|
return tcr != TC_Success;
|
2008-11-06 00:50:06 +03:00
|
|
|
}
|