2008-11-06 05:50:06 +08:00
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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 "SemaInherit.h"
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#include "clang/AST/ExprCXX.h"
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#include "clang/AST/ASTContext.h"
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#include "llvm/ADT/SmallVector.h"
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2008-11-08 07:29:29 +08:00
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#include <set>
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2008-11-06 05:50:06 +08:00
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using namespace clang;
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2008-11-08 21:00:26 +08:00
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enum TryStaticCastResult {
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TSC_NotApplicable, ///< The cast method is not applicable.
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TSC_Success, ///< The cast method is appropriate and successful.
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TSC_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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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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static void CheckStaticCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
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const SourceRange &OpRange);
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static void CheckDynamicCast(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 bool CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType);
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2009-03-23 06:30:06 +08:00
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static TryStaticCastResult TryLValueToRValueCast(
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Sema &Self, Expr *SrcExpr, QualType DestType, const SourceRange &OpRange);
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2008-11-08 21:00:26 +08:00
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static TryStaticCastResult TryStaticReferenceDowncast(
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Sema &Self, Expr *SrcExpr, QualType DestType, const SourceRange &OpRange);
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static TryStaticCastResult TryStaticPointerDowncast(
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Sema &Self, QualType SrcType, QualType DestType, const SourceRange &OpRange);
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2009-01-29 02:33:18 +08:00
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static TryStaticCastResult TryStaticMemberPointerUpcast(
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Sema &Self, QualType SrcType, QualType DestType, const SourceRange &OpRange);
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2008-11-08 21:00:26 +08:00
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static TryStaticCastResult TryStaticDowncast(Sema &Self, QualType SrcType,
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QualType DestType,
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const SourceRange &OpRange,
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QualType OrigSrcType,
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QualType OrigDestType);
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static TryStaticCastResult TryStaticImplicitCast(Sema &Self, Expr *SrcExpr,
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QualType DestType,
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const SourceRange &OpRange);
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2008-11-06 05:50:06 +08:00
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/// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
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2009-03-16 01:47:39 +08:00
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Action::OwningExprResult
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2008-11-06 05:50:06 +08:00
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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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2008-11-06 05:50:06 +08:00
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SourceLocation RParenLoc) {
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2009-05-02 03:49:17 +08:00
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Expr *Ex = E.takeAs<Expr>();
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2008-11-06 05:50:06 +08:00
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QualType DestType = QualType::getFromOpaquePtr(Ty);
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SourceRange OpRange(OpLoc, RParenLoc);
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SourceRange DestRange(LAngleBracketLoc, RAngleBracketLoc);
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2008-12-18 06:52:20 +08:00
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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 05:50:06 +08:00
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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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2008-12-18 06:52:20 +08:00
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if (!TypeDependent)
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CheckConstCast(*this, Ex, DestType, OpRange, DestRange);
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2009-03-16 01:47:39 +08:00
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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 05:50:06 +08:00
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case tok::kw_dynamic_cast:
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2008-12-18 06:52:20 +08:00
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if (!TypeDependent)
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CheckDynamicCast(*this, Ex, DestType, OpRange, DestRange);
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2009-03-16 01:47:39 +08:00
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return Owned(new (Context)CXXDynamicCastExpr(DestType.getNonReferenceType(),
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Ex, DestType, OpLoc));
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2008-11-06 05:50:06 +08:00
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case tok::kw_reinterpret_cast:
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2008-12-18 06:52:20 +08:00
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if (!TypeDependent)
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CheckReinterpretCast(*this, Ex, DestType, OpRange, DestRange);
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2009-03-16 01:47:39 +08:00
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return Owned(new (Context) CXXReinterpretCastExpr(
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DestType.getNonReferenceType(),
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Ex, DestType, OpLoc));
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2008-11-06 05:50:06 +08:00
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case tok::kw_static_cast:
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2008-12-18 06:52:20 +08:00
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if (!TypeDependent)
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CheckStaticCast(*this, Ex, DestType, OpRange);
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2009-03-16 01:47:39 +08:00
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return Owned(new (Context) CXXStaticCastExpr(DestType.getNonReferenceType(),
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Ex, DestType, OpLoc));
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2008-11-06 05:50:06 +08:00
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}
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2009-03-16 01:47:39 +08:00
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return ExprError();
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2008-11-06 05:50:06 +08:00
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}
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/// CheckConstCast - Check that a const_cast\<DestType\>(SrcExpr) is valid.
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/// Refer to C++ 5.2.11 for details. const_cast is typically used in code
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/// like this:
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/// const char *str = "literal";
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/// legacy_function(const_cast\<char*\>(str));
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void
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2008-11-08 21:00:26 +08:00
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CheckConstCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
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const SourceRange &OpRange, const SourceRange &DestRange)
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2008-11-06 05:50:06 +08:00
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{
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QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
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2008-11-08 21:00:26 +08:00
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DestType = Self.Context.getCanonicalType(DestType);
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2008-11-06 05:50:06 +08:00
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QualType SrcType = SrcExpr->getType();
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2009-03-17 07:22:08 +08:00
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if (const LValueReferenceType *DestTypeTmp =
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DestType->getAsLValueReferenceType()) {
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2008-11-08 21:00:26 +08:00
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if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
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2009-03-17 07:22:08 +08:00
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// Cannot cast non-lvalue to lvalue reference type.
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2008-11-19 06:52:51 +08:00
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Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
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2008-11-24 14:25:27 +08:00
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<< "const_cast" << OrigDestType << SrcExpr->getSourceRange();
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2008-11-06 05:50:06 +08:00
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return;
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}
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// C++ 5.2.11p4: An lvalue of type T1 can be [cast] to an lvalue of type T2
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// [...] if a pointer to T1 can be [cast] to the type pointer to T2.
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2008-11-08 21:00:26 +08:00
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DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
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SrcType = Self.Context.getPointerType(SrcType);
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2008-11-06 05:50:06 +08:00
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} else {
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// C++ 5.2.11p1: Otherwise, the result is an rvalue and the
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// lvalue-to-rvalue, array-to-pointer, and function-to-pointer standard
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// conversions are performed on the expression.
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2008-11-08 21:00:26 +08:00
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Self.DefaultFunctionArrayConversion(SrcExpr);
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2008-11-06 05:50:06 +08:00
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SrcType = SrcExpr->getType();
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}
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2009-01-27 06:19:12 +08:00
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// C++ 5.2.11p5: For a const_cast involving pointers to data members [...]
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// the rules for const_cast are the same as those used for pointers.
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if (!DestType->isPointerType() && !DestType->isMemberPointerType()) {
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2008-11-06 05:50:06 +08:00
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// Cannot cast to non-pointer, non-reference type. Note that, if DestType
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// was a reference type, we converted it to a pointer above.
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2009-03-17 07:22:08 +08:00
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// The status of rvalue references isn't entirely clear, but it looks like
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// conversion to them is simply invalid.
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2008-11-06 05:50:06 +08:00
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// C++ 5.2.11p3: For two pointer types [...]
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2008-11-19 06:52:51 +08:00
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Self.Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest)
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2008-11-24 14:25:27 +08:00
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<< OrigDestType << DestRange;
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2008-11-06 05:50:06 +08:00
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return;
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}
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2009-01-27 06:19:12 +08:00
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if (DestType->isFunctionPointerType() ||
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DestType->isMemberFunctionPointerType()) {
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2008-11-06 05:50:06 +08:00
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// Cannot cast direct function pointers.
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// C++ 5.2.11p2: [...] where T is any object type or the void type [...]
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// T is the ultimate pointee of source and target type.
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2008-11-19 06:52:51 +08:00
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Self.Diag(OpRange.getBegin(), diag::err_bad_const_cast_dest)
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2008-11-24 14:25:27 +08:00
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<< OrigDestType << DestRange;
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2008-11-06 05:50:06 +08:00
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return;
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}
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2008-11-08 21:00:26 +08:00
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SrcType = Self.Context.getCanonicalType(SrcType);
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2008-11-06 05:50:06 +08:00
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// Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
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// completely equal.
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// FIXME: const_cast should probably not be able to convert between pointers
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// to different address spaces.
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// C++ 5.2.11p3 describes the core semantics of const_cast. All cv specifiers
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// in multi-level pointers may change, but the level count must be the same,
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// as must be the final pointee type.
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2008-11-08 21:00:26 +08:00
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while (SrcType != DestType &&
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Self.UnwrapSimilarPointerTypes(SrcType, DestType)) {
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2008-11-06 05:50:06 +08:00
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SrcType = SrcType.getUnqualifiedType();
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DestType = DestType.getUnqualifiedType();
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}
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// Doug Gregor said to disallow this until users complain.
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#if 0
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// If we end up with constant arrays of equal size, unwrap those too. A cast
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// from const int [N] to int (&)[N] is invalid by my reading of the
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// standard, but g++ accepts it even with -ansi -pedantic.
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// No more than one level, though, so don't embed this in the unwrap loop
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// above.
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const ConstantArrayType *SrcTypeArr, *DestTypeArr;
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2008-11-08 21:00:26 +08:00
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if ((SrcTypeArr = Self.Context.getAsConstantArrayType(SrcType)) &&
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(DestTypeArr = Self.Context.getAsConstantArrayType(DestType)))
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2008-11-06 05:50:06 +08:00
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{
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if (SrcTypeArr->getSize() != DestTypeArr->getSize()) {
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// Different array sizes.
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2008-11-19 06:52:51 +08:00
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Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
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2008-11-24 14:25:27 +08:00
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<< "const_cast" << OrigDestType << OrigSrcType << OpRange;
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2008-11-06 05:50:06 +08:00
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return;
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}
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SrcType = SrcTypeArr->getElementType().getUnqualifiedType();
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DestType = DestTypeArr->getElementType().getUnqualifiedType();
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}
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#endif
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// Since we're dealing in canonical types, the remainder must be the same.
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if (SrcType != DestType) {
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// Cast between unrelated types.
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2008-11-19 06:52:51 +08:00
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Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
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2008-11-24 14:25:27 +08:00
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<< "const_cast" << OrigDestType << OrigSrcType << OpRange;
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2008-11-06 05:50:06 +08:00
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return;
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}
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}
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/// CheckReinterpretCast - Check that a reinterpret_cast\<DestType\>(SrcExpr) is
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/// valid.
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/// Refer to C++ 5.2.10 for details. reinterpret_cast is typically used in code
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/// like this:
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/// char *bytes = reinterpret_cast\<char*\>(int_ptr);
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void
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2008-11-08 21:00:26 +08:00
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CheckReinterpretCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
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const SourceRange &OpRange, const SourceRange &DestRange)
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2008-11-06 05:50:06 +08:00
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{
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QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
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2008-11-08 21:00:26 +08:00
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DestType = Self.Context.getCanonicalType(DestType);
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2008-11-06 05:50:06 +08:00
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QualType SrcType = SrcExpr->getType();
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2009-03-17 07:22:08 +08:00
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if (const LValueReferenceType *DestTypeTmp =
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DestType->getAsLValueReferenceType()) {
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2008-11-08 21:00:26 +08:00
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if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
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2008-11-06 05:50:06 +08:00
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// Cannot cast non-lvalue to reference type.
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2008-11-19 06:52:51 +08:00
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Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
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2008-11-24 14:25:27 +08:00
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<< "reinterpret_cast" << OrigDestType << SrcExpr->getSourceRange();
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2008-11-06 05:50:06 +08:00
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return;
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}
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// C++ 5.2.10p10: [...] a reference cast reinterpret_cast<T&>(x) has the
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// same effect as the conversion *reinterpret_cast<T*>(&x) with the
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// built-in & and * operators.
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// This code does this transformation for the checked types.
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2009-03-17 07:22:08 +08:00
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DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
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SrcType = Self.Context.getPointerType(SrcType);
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} else if (const RValueReferenceType *DestTypeTmp =
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DestType->getAsRValueReferenceType()) {
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// Both the reference conversion and the rvalue rules apply.
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Self.DefaultFunctionArrayConversion(SrcExpr);
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SrcType = SrcExpr->getType();
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2008-11-08 21:00:26 +08:00
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DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
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SrcType = Self.Context.getPointerType(SrcType);
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2008-11-06 05:50:06 +08:00
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} else {
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// C++ 5.2.10p1: [...] the lvalue-to-rvalue, array-to-pointer, and
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// function-to-pointer standard conversions are performed on the
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// expression v.
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2008-11-08 21:00:26 +08:00
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Self.DefaultFunctionArrayConversion(SrcExpr);
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2008-11-06 05:50:06 +08:00
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SrcType = SrcExpr->getType();
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}
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// Canonicalize source for comparison.
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2008-11-08 21:00:26 +08:00
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SrcType = Self.Context.getCanonicalType(SrcType);
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2008-11-06 05:50:06 +08:00
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2009-01-28 07:18:31 +08:00
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const MemberPointerType *DestMemPtr = DestType->getAsMemberPointerType(),
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*SrcMemPtr = SrcType->getAsMemberPointerType();
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if (DestMemPtr && SrcMemPtr) {
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// C++ 5.2.10p9: An rvalue of type "pointer to member of X of type T1"
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// can be explicitly converted to an rvalue of type "pointer to member
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// of Y of type T2" if T1 and T2 are both function types or both object
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// types.
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if (DestMemPtr->getPointeeType()->isFunctionType() !=
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SrcMemPtr->getPointeeType()->isFunctionType()) {
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Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
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<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
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return;
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}
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// C++ 5.2.10p2: The reinterpret_cast operator shall not cast away
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// constness.
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if (CastsAwayConstness(Self, SrcType, DestType)) {
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|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
|
|
|
|
<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// A valid member pointer cast.
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2009-05-11 02:38:11 +08:00
|
|
|
// 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)) {
|
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_small_int)
|
|
|
|
<< OrigDestType << DestRange;
|
|
|
|
}
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2008-11-06 05:50:06 +08:00
|
|
|
bool destIsPtr = DestType->isPointerType();
|
|
|
|
bool srcIsPtr = SrcType->isPointerType();
|
|
|
|
if (!destIsPtr && !srcIsPtr) {
|
2009-05-11 02:38:11 +08:00
|
|
|
// Except for std::nullptr_t->integer and lvalue->reference, which are
|
|
|
|
// handled above, at least one of the two arguments must be a pointer.
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
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
|
2009-01-28 07:18:31 +08:00
|
|
|
// on this point: allow same-type conversion if the involved types are
|
|
|
|
// pointers, disallow otherwise.
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// 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()) {
|
2008-11-06 06:15:14 +08:00
|
|
|
assert(srcIsPtr && "One type must be a pointer");
|
2008-11-06 05:50:06 +08:00
|
|
|
// C++ 5.2.10p4: A pointer can be explicitly converted to any integral
|
|
|
|
// type large enough to hold it.
|
2008-11-08 21:00:26 +08:00
|
|
|
if (Self.Context.getTypeSize(SrcType) >
|
|
|
|
Self.Context.getTypeSize(DestType)) {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_small_int)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< OrigDestType << DestRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (SrcType->isIntegralType() || SrcType->isEnumeralType()) {
|
2008-11-06 06:15:14 +08:00
|
|
|
assert(destIsPtr && "One type must be a pointer");
|
2008-11-06 05:50:06 +08:00
|
|
|
// C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
|
|
|
|
// converted to a pointer.
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (!destIsPtr || !srcIsPtr) {
|
|
|
|
// With the valid non-pointer conversions out of the way, we can be even
|
|
|
|
// more stringent.
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
|
2008-11-08 21:00:26 +08:00
|
|
|
if (CastsAwayConstness(Self, SrcType, DestType)) {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< "reinterpret_cast" << OrigDestType << OrigSrcType << OpRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// Not casting away constness, so the only remaining check is for compatible
|
|
|
|
// pointer categories.
|
|
|
|
|
|
|
|
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;
|
|
|
|
}
|
|
|
|
|
|
|
|
// 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.
|
2008-11-08 21:00:26 +08:00
|
|
|
if (!Self.getLangOptions().CPlusPlus0x) {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::ext_reinterpret_cast_fn_obj)
|
|
|
|
<< OpRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
if (DestType->isFunctionPointerType()) {
|
|
|
|
// See above.
|
2008-11-08 21:00:26 +08:00
|
|
|
if (!Self.getLangOptions().CPlusPlus0x) {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::ext_reinterpret_cast_fn_obj)
|
|
|
|
<< OpRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// 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.
|
|
|
|
}
|
|
|
|
|
2009-01-28 07:18:31 +08:00
|
|
|
/// CastsAwayConstness - Check if the pointer conversion from SrcType to
|
|
|
|
/// DestType casts away constness as defined in C++ 5.2.11p8ff. This is used by
|
|
|
|
/// the cast checkers. Both arguments must denote pointer (possibly to member)
|
|
|
|
/// types.
|
2008-11-06 05:50:06 +08:00
|
|
|
bool
|
2008-11-08 21:00:26 +08:00
|
|
|
CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType)
|
2008-11-06 05:50:06 +08:00
|
|
|
{
|
2009-01-28 07:18:31 +08:00
|
|
|
// Casting away constness is defined in C++ 5.2.11p8 with reference to
|
|
|
|
// C++ 4.4. We piggyback on Sema::IsQualificationConversion for this, since
|
|
|
|
// the rules are non-trivial. So first we construct Tcv *...cv* as described
|
|
|
|
// in C++ 5.2.11p8.
|
|
|
|
assert((SrcType->isPointerType() || SrcType->isMemberPointerType()) &&
|
|
|
|
"Source type is not pointer or pointer to member.");
|
|
|
|
assert((DestType->isPointerType() || DestType->isMemberPointerType()) &&
|
|
|
|
"Destination type is not pointer or pointer to member.");
|
2008-11-06 05:50:06 +08:00
|
|
|
|
|
|
|
QualType UnwrappedSrcType = SrcType, UnwrappedDestType = DestType;
|
|
|
|
llvm::SmallVector<unsigned, 8> cv1, cv2;
|
|
|
|
|
|
|
|
// Find the qualifications.
|
2008-11-08 21:00:26 +08:00
|
|
|
while (Self.UnwrapSimilarPointerTypes(UnwrappedSrcType, UnwrappedDestType)) {
|
2008-11-06 05:50:06 +08:00
|
|
|
cv1.push_back(UnwrappedSrcType.getCVRQualifiers());
|
|
|
|
cv2.push_back(UnwrappedDestType.getCVRQualifiers());
|
|
|
|
}
|
|
|
|
assert(cv1.size() > 0 && "Must have at least one pointer level.");
|
|
|
|
|
|
|
|
// Construct void pointers with those qualifiers (in reverse order of
|
|
|
|
// unwrapping, of course).
|
2008-11-08 21:00:26 +08:00
|
|
|
QualType SrcConstruct = Self.Context.VoidTy;
|
|
|
|
QualType DestConstruct = Self.Context.VoidTy;
|
2008-11-06 05:50:06 +08:00
|
|
|
for (llvm::SmallVector<unsigned, 8>::reverse_iterator i1 = cv1.rbegin(),
|
|
|
|
i2 = cv2.rbegin();
|
|
|
|
i1 != cv1.rend(); ++i1, ++i2)
|
|
|
|
{
|
2008-11-08 21:00:26 +08:00
|
|
|
SrcConstruct = Self.Context.getPointerType(
|
|
|
|
SrcConstruct.getQualifiedType(*i1));
|
|
|
|
DestConstruct = Self.Context.getPointerType(
|
|
|
|
DestConstruct.getQualifiedType(*i2));
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
// Test if they're compatible.
|
|
|
|
return SrcConstruct != DestConstruct &&
|
2008-11-08 21:00:26 +08:00
|
|
|
!Self.IsQualificationConversion(SrcConstruct, DestConstruct);
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/// 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 21:00:26 +08:00
|
|
|
CheckStaticCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
|
|
|
|
const SourceRange &OpRange)
|
2008-11-06 05:50:06 +08:00
|
|
|
{
|
|
|
|
// 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.
|
|
|
|
|
2009-03-17 07:22:08 +08:00
|
|
|
// FIXME: With N2812, casts to rvalue refs will change.
|
|
|
|
|
2008-11-06 05:50:06 +08:00
|
|
|
// C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
|
|
|
|
if (DestType->isVoidType()) {
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// C++ 5.2.9p5, reference downcast.
|
|
|
|
// See the function for details.
|
|
|
|
// DR 427 specifies that this is to be applied before paragraph 2.
|
2008-11-08 21:00:26 +08:00
|
|
|
if (TryStaticReferenceDowncast(Self, SrcExpr, DestType, OpRange)
|
2008-11-08 07:29:29 +08:00
|
|
|
> TSC_NotApplicable) {
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2009-03-23 06:30:06 +08:00
|
|
|
// 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".
|
|
|
|
if (TryLValueToRValueCast(Self, SrcExpr, DestType, OpRange) >
|
|
|
|
TSC_NotApplicable) {
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2008-11-06 05:50:06 +08:00
|
|
|
// C++ 5.2.9p2: An expression e can be explicitly converted to a type T
|
|
|
|
// [...] if the declaration "T t(e);" is well-formed, [...].
|
2008-11-08 21:00:26 +08:00
|
|
|
if (TryStaticImplicitCast(Self, SrcExpr, DestType, OpRange) >
|
|
|
|
TSC_NotApplicable) {
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// 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.
|
|
|
|
|
|
|
|
// The lvalue-to-rvalue, array-to-pointer and function-to-pointer conversions
|
|
|
|
// are applied to the expression.
|
|
|
|
QualType OrigSrcType = SrcExpr->getType();
|
2008-11-08 21:00:26 +08:00
|
|
|
Self.DefaultFunctionArrayConversion(SrcExpr);
|
2008-11-06 05:50:06 +08:00
|
|
|
|
2008-11-08 21:00:26 +08:00
|
|
|
QualType SrcType = Self.Context.getCanonicalType(SrcExpr->getType());
|
2008-11-06 05:50:06 +08:00
|
|
|
|
|
|
|
// 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.
|
|
|
|
} else if (SrcType->isArithmeticType() || SrcType->isEnumeralType()) {
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
// Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
|
|
|
|
// C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
|
2008-11-08 21:00:26 +08:00
|
|
|
if (TryStaticPointerDowncast(Self, SrcType, DestType, OpRange)
|
2008-11-08 07:29:29 +08:00
|
|
|
> TSC_NotApplicable) {
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2009-01-29 02:33:18 +08:00
|
|
|
// Reverse member pointer conversion. C++ 4.11 specifies member pointer
|
2008-11-06 05:50:06 +08:00
|
|
|
// conversion. C++ 5.2.9p9 has additional information.
|
|
|
|
// DR54's access restrictions apply here also.
|
2009-01-29 02:33:18 +08:00
|
|
|
if (TryStaticMemberPointerUpcast(Self, SrcType, DestType, OpRange)
|
|
|
|
> TSC_NotApplicable) {
|
|
|
|
return;
|
|
|
|
}
|
2008-11-06 05:50:06 +08:00
|
|
|
|
|
|
|
// 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.
|
|
|
|
if (const PointerType *SrcPointer = SrcType->getAsPointerType()) {
|
|
|
|
QualType SrcPointee = SrcPointer->getPointeeType();
|
|
|
|
if (SrcPointee->isVoidType()) {
|
|
|
|
if (const PointerType *DestPointer = DestType->getAsPointerType()) {
|
|
|
|
QualType DestPointee = DestPointer->getPointeeType();
|
2009-03-25 04:13:58 +08:00
|
|
|
if (DestPointee->isIncompleteOrObjectType()) {
|
2008-11-06 05:50:06 +08:00
|
|
|
// This is definitely the intended conversion, but it might fail due
|
|
|
|
// to a const violation.
|
|
|
|
if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< "static_cast" << DestType << OrigSrcType << OpRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
|
|
|
// We tried everything. Everything! Nothing works! :-(
|
2009-05-16 15:39:55 +08:00
|
|
|
// FIXME: Error reporting could be a lot better. Should store the reason why
|
|
|
|
// every substep failed and, at the end, select the most specific and report
|
|
|
|
// that.
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_generic)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< "static_cast" << DestType << OrigSrcType
|
2008-11-19 06:52:51 +08:00
|
|
|
<< OpRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
2009-03-23 06:30:06 +08:00
|
|
|
/// Tests whether a conversion according to N2844 is valid.
|
|
|
|
TryStaticCastResult
|
|
|
|
TryLValueToRValueCast(Sema &Self, Expr *SrcExpr, QualType DestType,
|
|
|
|
const SourceRange &OpRange)
|
|
|
|
{
|
|
|
|
// 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".
|
|
|
|
const RValueReferenceType *R = DestType->getAsRValueReferenceType();
|
|
|
|
if (!R)
|
|
|
|
return TSC_NotApplicable;
|
|
|
|
|
|
|
|
if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid)
|
|
|
|
return TSC_NotApplicable;
|
|
|
|
|
|
|
|
// 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.
|
|
|
|
bool DerivedToBase;
|
|
|
|
if (Self.CompareReferenceRelationship(SrcExpr->getType(), R->getPointeeType(),
|
|
|
|
DerivedToBase) <
|
|
|
|
Sema::Ref_Compatible_With_Added_Qualification) {
|
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_lvalue_to_rvalue_cast)
|
|
|
|
<< SrcExpr->getType() << R->getPointeeType() << OpRange;
|
|
|
|
return TSC_Failed;
|
|
|
|
}
|
|
|
|
|
|
|
|
// FIXME: Similar to CheckReferenceInit, we actually need more AST annotation
|
|
|
|
// than nothing.
|
|
|
|
return TSC_Success;
|
|
|
|
}
|
|
|
|
|
2008-11-06 05:50:06 +08:00
|
|
|
/// Tests whether a conversion according to C++ 5.2.9p5 is valid.
|
2008-11-08 21:00:26 +08:00
|
|
|
TryStaticCastResult
|
|
|
|
TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr, QualType DestType,
|
|
|
|
const SourceRange &OpRange)
|
2008-11-06 05:50:06 +08:00
|
|
|
{
|
|
|
|
// 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
|
|
|
|
// conversion as well.
|
|
|
|
|
2008-11-08 21:00:26 +08:00
|
|
|
if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_NotApplicable;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
const ReferenceType *DestReference = DestType->getAsReferenceType();
|
|
|
|
if (!DestReference) {
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_NotApplicable;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
QualType DestPointee = DestReference->getPointeeType();
|
|
|
|
|
2008-11-08 21:00:26 +08:00
|
|
|
return TryStaticDowncast(Self, SrcExpr->getType(), DestPointee, OpRange,
|
2008-11-08 07:29:29 +08:00
|
|
|
SrcExpr->getType(), DestType);
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/// Tests whether a conversion according to C++ 5.2.9p8 is valid.
|
2008-11-08 21:00:26 +08:00
|
|
|
TryStaticCastResult
|
|
|
|
TryStaticPointerDowncast(Sema &Self, QualType SrcType, QualType DestType,
|
|
|
|
const SourceRange &OpRange)
|
2008-11-06 05:50:06 +08:00
|
|
|
{
|
|
|
|
// 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.
|
|
|
|
|
|
|
|
const PointerType *SrcPointer = SrcType->getAsPointerType();
|
|
|
|
if (!SrcPointer) {
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_NotApplicable;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
const PointerType *DestPointer = DestType->getAsPointerType();
|
|
|
|
if (!DestPointer) {
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_NotApplicable;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
2008-11-08 21:00:26 +08:00
|
|
|
return TryStaticDowncast(Self, SrcPointer->getPointeeType(),
|
2008-11-08 07:29:29 +08:00
|
|
|
DestPointer->getPointeeType(),
|
|
|
|
OpRange, SrcType, DestType);
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
2008-11-08 07:29:29 +08:00
|
|
|
/// TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and
|
|
|
|
/// TryStaticPointerDowncast. Tests whether a static downcast from SrcType to
|
2008-11-06 05:50:06 +08:00
|
|
|
/// DestType, both of which must be canonical, is possible and allowed.
|
2008-11-08 21:00:26 +08:00
|
|
|
TryStaticCastResult
|
|
|
|
TryStaticDowncast(Sema &Self, QualType SrcType, QualType DestType,
|
|
|
|
const SourceRange &OpRange, QualType OrigSrcType,
|
|
|
|
QualType OrigDestType)
|
2008-11-06 05:50:06 +08:00
|
|
|
{
|
|
|
|
// Downcast can only happen in class hierarchies, so we need classes.
|
|
|
|
if (!DestType->isRecordType() || !SrcType->isRecordType()) {
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_NotApplicable;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
|
|
|
|
/*DetectVirtual=*/true);
|
2008-11-08 21:00:26 +08:00
|
|
|
if (!Self.IsDerivedFrom(DestType, SrcType, Paths)) {
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_NotApplicable;
|
|
|
|
}
|
|
|
|
|
|
|
|
// 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&);
|
|
|
|
// };
|
|
|
|
//
|
|
|
|
// 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.
|
|
|
|
|
|
|
|
// Must preserve cv, as always.
|
|
|
|
if (!DestType.isAtLeastAsQualifiedAs(SrcType)) {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< "static_cast" << OrigDestType << OrigSrcType << OpRange;
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_Failed;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
|
2008-11-08 07:29:29 +08:00
|
|
|
// 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.
|
|
|
|
Paths.clear();
|
|
|
|
Paths.setRecordingPaths(true);
|
2008-11-08 21:00:26 +08:00
|
|
|
Self.IsDerivedFrom(DestType, SrcType, Paths);
|
2008-11-08 07:29:29 +08:00
|
|
|
std::string PathDisplayStr;
|
|
|
|
std::set<unsigned> DisplayedPaths;
|
|
|
|
for (BasePaths::paths_iterator Path = Paths.begin();
|
|
|
|
Path != Paths.end(); ++Path) {
|
|
|
|
if (DisplayedPaths.insert(Path->back().SubobjectNumber).second) {
|
|
|
|
// We haven't displayed a path to this particular base
|
|
|
|
// class subobject yet.
|
|
|
|
PathDisplayStr += "\n ";
|
|
|
|
for (BasePath::const_reverse_iterator Element = Path->rbegin();
|
|
|
|
Element != Path->rend(); ++Element)
|
|
|
|
PathDisplayStr += Element->Base->getType().getAsString() + " -> ";
|
|
|
|
PathDisplayStr += DestType.getAsString();
|
|
|
|
}
|
|
|
|
}
|
|
|
|
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_ambiguous_base_to_derived_cast)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< SrcType.getUnqualifiedType() << DestType.getUnqualifiedType()
|
2008-11-19 06:52:51 +08:00
|
|
|
<< PathDisplayStr << OpRange;
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_Failed;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
if (Paths.getDetectedVirtual() != 0) {
|
2008-11-08 07:29:29 +08:00
|
|
|
QualType VirtualBase(Paths.getDetectedVirtual(), 0);
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_static_downcast_via_virtual)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< OrigSrcType << OrigDestType << VirtualBase << OpRange;
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_Failed;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
// FIXME: Test accessibility.
|
|
|
|
|
2008-11-08 07:29:29 +08:00
|
|
|
return TSC_Success;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
2009-01-29 02:33:18 +08:00
|
|
|
/// 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 [...].
|
|
|
|
///
|
|
|
|
TryStaticCastResult
|
|
|
|
TryStaticMemberPointerUpcast(Sema &Self, QualType SrcType, QualType DestType,
|
|
|
|
const SourceRange &OpRange)
|
|
|
|
{
|
|
|
|
const MemberPointerType *SrcMemPtr = SrcType->getAsMemberPointerType();
|
|
|
|
if (!SrcMemPtr)
|
|
|
|
return TSC_NotApplicable;
|
|
|
|
const MemberPointerType *DestMemPtr = DestType->getAsMemberPointerType();
|
|
|
|
if (!DestMemPtr)
|
|
|
|
return TSC_NotApplicable;
|
|
|
|
|
|
|
|
// T == T, modulo cv
|
|
|
|
if (Self.Context.getCanonicalType(
|
|
|
|
SrcMemPtr->getPointeeType().getUnqualifiedType()) !=
|
|
|
|
Self.Context.getCanonicalType(DestMemPtr->getPointeeType().
|
|
|
|
getUnqualifiedType()))
|
|
|
|
return TSC_NotApplicable;
|
|
|
|
|
|
|
|
// B base of D
|
|
|
|
QualType SrcClass(SrcMemPtr->getClass(), 0);
|
|
|
|
QualType DestClass(DestMemPtr->getClass(), 0);
|
|
|
|
BasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/false,
|
|
|
|
/*DetectVirtual=*/true);
|
|
|
|
if (!Self.IsDerivedFrom(SrcClass, DestClass, Paths)) {
|
|
|
|
return TSC_NotApplicable;
|
|
|
|
}
|
|
|
|
|
|
|
|
// 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;
|
|
|
|
return TSC_Failed;
|
|
|
|
}
|
|
|
|
|
2009-02-28 09:32:25 +08:00
|
|
|
if (const RecordType *VBase = Paths.getDetectedVirtual()) {
|
2009-01-29 02:33:18 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_memptr_conv_via_virtual)
|
|
|
|
<< SrcClass << DestClass << QualType(VBase, 0) << OpRange;
|
|
|
|
return TSC_Failed;
|
|
|
|
}
|
|
|
|
|
|
|
|
// FIXME: Test accessibility.
|
|
|
|
|
|
|
|
return TSC_Success;
|
|
|
|
}
|
|
|
|
|
2008-11-08 07:29:29 +08:00
|
|
|
/// 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 [...].
|
2008-11-08 21:00:26 +08:00
|
|
|
TryStaticCastResult
|
|
|
|
TryStaticImplicitCast(Sema &Self, Expr *SrcExpr, QualType DestType,
|
|
|
|
const SourceRange &OpRange)
|
2008-11-06 05:50:06 +08:00
|
|
|
{
|
2008-11-08 07:29:29 +08:00
|
|
|
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.
|
2008-11-08 21:00:26 +08:00
|
|
|
return Self.CheckReferenceInit(SrcExpr, DestType) ?
|
|
|
|
TSC_Failed : TSC_Success;
|
2008-11-08 07:29:29 +08:00
|
|
|
}
|
|
|
|
if (DestType->isRecordType()) {
|
|
|
|
// FIXME: Use an implementation of C++ [over.match.ctor] for this.
|
|
|
|
return TSC_NotApplicable;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
2008-11-08 07:29:29 +08:00
|
|
|
// FIXME: To get a proper error from invalid conversions here, we need to
|
|
|
|
// reimplement more of this.
|
2008-11-08 21:00:26 +08:00
|
|
|
ImplicitConversionSequence ICS = Self.TryImplicitConversion(
|
|
|
|
SrcExpr, DestType);
|
2008-11-08 07:29:29 +08:00
|
|
|
return ICS.ConversionKind == ImplicitConversionSequence::BadConversion ?
|
|
|
|
TSC_NotApplicable : TSC_Success;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
/// CheckDynamicCast - Check that a dynamic_cast\<DestType\>(SrcExpr) is valid.
|
|
|
|
/// Refer to C++ 5.2.7 for details. Dynamic casts are used mostly for runtime-
|
|
|
|
/// checked downcasts in class hierarchies.
|
|
|
|
void
|
2008-11-08 21:00:26 +08:00
|
|
|
CheckDynamicCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
|
|
|
|
const SourceRange &OpRange,
|
|
|
|
const SourceRange &DestRange)
|
2008-11-06 05:50:06 +08:00
|
|
|
{
|
|
|
|
QualType OrigDestType = DestType, OrigSrcType = SrcExpr->getType();
|
2008-11-08 21:00:26 +08:00
|
|
|
DestType = Self.Context.getCanonicalType(DestType);
|
2008-11-06 05:50:06 +08:00
|
|
|
|
|
|
|
// C++ 5.2.7p1: T shall be a pointer or reference to a complete class type,
|
|
|
|
// or "pointer to cv void".
|
|
|
|
|
|
|
|
QualType DestPointee;
|
|
|
|
const PointerType *DestPointer = DestType->getAsPointerType();
|
|
|
|
const ReferenceType *DestReference = DestType->getAsReferenceType();
|
|
|
|
if (DestPointer) {
|
|
|
|
DestPointee = DestPointer->getPointeeType();
|
|
|
|
} else if (DestReference) {
|
|
|
|
DestPointee = DestReference->getPointeeType();
|
|
|
|
} else {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ref_or_ptr)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< OrigDestType << DestRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
const RecordType *DestRecord = DestPointee->getAsRecordType();
|
|
|
|
if (DestPointee->isVoidType()) {
|
|
|
|
assert(DestPointer && "Reference to void is not possible");
|
|
|
|
} else if (DestRecord) {
|
2009-03-10 00:13:40 +08:00
|
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), DestPointee,
|
2009-01-20 03:26:10 +08:00
|
|
|
diag::err_bad_dynamic_cast_incomplete,
|
|
|
|
DestRange))
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
} else {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< DestPointee.getUnqualifiedType() << DestRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
2009-03-17 07:22:08 +08:00
|
|
|
// C++0x 5.2.7p2: If T is a pointer type, v shall be an rvalue of a pointer to
|
|
|
|
// complete class type, [...]. If T is an lvalue reference type, v shall be
|
|
|
|
// an lvalue of a complete class type, [...]. If T is an rvalue reference
|
|
|
|
// type, v shall be an expression having a complete effective class type,
|
|
|
|
// [...]
|
2008-11-06 05:50:06 +08:00
|
|
|
|
2008-11-08 21:00:26 +08:00
|
|
|
QualType SrcType = Self.Context.getCanonicalType(OrigSrcType);
|
2008-11-06 05:50:06 +08:00
|
|
|
QualType SrcPointee;
|
|
|
|
if (DestPointer) {
|
|
|
|
if (const PointerType *SrcPointer = SrcType->getAsPointerType()) {
|
|
|
|
SrcPointee = SrcPointer->getPointeeType();
|
|
|
|
} else {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ptr)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< OrigSrcType << SrcExpr->getSourceRange();
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
2009-03-17 07:22:08 +08:00
|
|
|
} else if (DestReference->isLValueReferenceType()) {
|
2008-11-08 21:00:26 +08:00
|
|
|
if (SrcExpr->isLvalue(Self.Context) != Expr::LV_Valid) {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< "dynamic_cast" << OrigDestType << OpRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
SrcPointee = SrcType;
|
2009-03-17 07:22:08 +08:00
|
|
|
} else {
|
|
|
|
SrcPointee = SrcType;
|
2008-11-06 05:50:06 +08:00
|
|
|
}
|
|
|
|
|
|
|
|
const RecordType *SrcRecord = SrcPointee->getAsRecordType();
|
|
|
|
if (SrcRecord) {
|
2009-03-10 00:13:40 +08:00
|
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), SrcPointee,
|
2009-01-20 03:26:10 +08:00
|
|
|
diag::err_bad_dynamic_cast_incomplete,
|
|
|
|
SrcExpr->getSourceRange()))
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
} else {
|
2008-11-20 14:06:08 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< SrcPointee.getUnqualifiedType() << SrcExpr->getSourceRange();
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
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.");
|
|
|
|
|
|
|
|
// C++ 5.2.7p1: The dynamic_cast operator shall not cast away constness.
|
|
|
|
if (!DestPointee.isAtLeastAsQualifiedAs(SrcPointee)) {
|
2008-11-19 06:52:51 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_const_away)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< "dynamic_cast" << OrigDestType << OrigSrcType << OpRange;
|
2008-11-06 05:50:06 +08:00
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// C++ 5.2.7p3: If the type of v is the same as the required result type,
|
|
|
|
// [except for cv].
|
|
|
|
if (DestRecord == SrcRecord) {
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// C++ 5.2.7p5
|
|
|
|
// Upcasts are resolved statically.
|
2008-11-08 21:00:26 +08:00
|
|
|
if (DestRecord && Self.IsDerivedFrom(SrcPointee, DestPointee)) {
|
|
|
|
Self.CheckDerivedToBaseConversion(SrcPointee, DestPointee,
|
2008-11-24 14:25:27 +08:00
|
|
|
OpRange.getBegin(), OpRange);
|
2008-11-06 05:50:06 +08:00
|
|
|
// Diagnostic already emitted on error.
|
|
|
|
return;
|
|
|
|
}
|
|
|
|
|
|
|
|
// C++ 5.2.7p6: Otherwise, v shall be [polymorphic].
|
2008-11-08 21:00:26 +08:00
|
|
|
const RecordDecl *SrcDecl = SrcRecord->getDecl()->getDefinition(Self.Context);
|
2008-11-06 23:59:35 +08:00
|
|
|
assert(SrcDecl && "Definition missing");
|
|
|
|
if (!cast<CXXRecordDecl>(SrcDecl)->isPolymorphic()) {
|
2008-11-20 14:06:08 +08:00
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_polymorphic)
|
2008-11-24 14:25:27 +08:00
|
|
|
<< SrcPointee.getUnqualifiedType() << SrcExpr->getSourceRange();
|
2008-11-06 23:59:35 +08:00
|
|
|
}
|
2008-11-06 05:50:06 +08:00
|
|
|
|
|
|
|
// Done. Everything else is run-time checks.
|
|
|
|
}
|