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ffa7dc379f
More helpful diagnostic on casts between unrelated class hierarchies. llvm-svn: 227371
2480 lines
95 KiB
C++
2480 lines
95 KiB
C++
//===--- SemaCast.cpp - Semantic Analysis for 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 cast expressions, including
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// 1) C-style casts like '(int) x'
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// 2) C++ functional casts like 'int(x)'
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// 3) C++ named casts like 'static_cast<int>(x)'
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//
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//===----------------------------------------------------------------------===//
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#include "clang/Sema/SemaInternal.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/AST/CXXInheritance.h"
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#include "clang/AST/ExprCXX.h"
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#include "clang/AST/ExprObjC.h"
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#include "clang/AST/RecordLayout.h"
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#include "clang/Basic/PartialDiagnostic.h"
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#include "clang/Basic/TargetInfo.h"
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#include "clang/Sema/Initialization.h"
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#include "llvm/ADT/SmallVector.h"
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#include <set>
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using namespace clang;
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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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namespace {
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struct CastOperation {
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CastOperation(Sema &S, QualType destType, ExprResult src)
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: Self(S), SrcExpr(src), DestType(destType),
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ResultType(destType.getNonLValueExprType(S.Context)),
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ValueKind(Expr::getValueKindForType(destType)),
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Kind(CK_Dependent), IsARCUnbridgedCast(false) {
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if (const BuiltinType *placeholder =
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src.get()->getType()->getAsPlaceholderType()) {
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PlaceholderKind = placeholder->getKind();
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} else {
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PlaceholderKind = (BuiltinType::Kind) 0;
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}
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}
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Sema &Self;
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ExprResult SrcExpr;
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QualType DestType;
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QualType ResultType;
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ExprValueKind ValueKind;
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CastKind Kind;
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BuiltinType::Kind PlaceholderKind;
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CXXCastPath BasePath;
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bool IsARCUnbridgedCast;
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SourceRange OpRange;
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SourceRange DestRange;
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// Top-level semantics-checking routines.
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void CheckConstCast();
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void CheckReinterpretCast();
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void CheckStaticCast();
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void CheckDynamicCast();
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void CheckCXXCStyleCast(bool FunctionalCast, bool ListInitialization);
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void CheckCStyleCast();
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/// Complete an apparently-successful cast operation that yields
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/// the given expression.
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ExprResult complete(CastExpr *castExpr) {
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// If this is an unbridged cast, wrap the result in an implicit
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// cast that yields the unbridged-cast placeholder type.
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if (IsARCUnbridgedCast) {
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castExpr = ImplicitCastExpr::Create(Self.Context,
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Self.Context.ARCUnbridgedCastTy,
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CK_Dependent, castExpr, nullptr,
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castExpr->getValueKind());
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}
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return castExpr;
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}
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// Internal convenience methods.
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/// Try to handle the given placeholder expression kind. Return
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/// true if the source expression has the appropriate placeholder
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/// kind. A placeholder can only be claimed once.
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bool claimPlaceholder(BuiltinType::Kind K) {
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if (PlaceholderKind != K) return false;
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PlaceholderKind = (BuiltinType::Kind) 0;
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return true;
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}
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bool isPlaceholder() const {
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return PlaceholderKind != 0;
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}
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bool isPlaceholder(BuiltinType::Kind K) const {
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return PlaceholderKind == K;
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}
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void checkCastAlign() {
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Self.CheckCastAlign(SrcExpr.get(), DestType, OpRange);
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}
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void checkObjCARCConversion(Sema::CheckedConversionKind CCK) {
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assert(Self.getLangOpts().ObjCAutoRefCount);
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Expr *src = SrcExpr.get();
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if (Self.CheckObjCARCConversion(OpRange, DestType, src, CCK) ==
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Sema::ACR_unbridged)
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IsARCUnbridgedCast = true;
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SrcExpr = src;
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}
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/// Check for and handle non-overload placeholder expressions.
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void checkNonOverloadPlaceholders() {
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if (!isPlaceholder() || isPlaceholder(BuiltinType::Overload))
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return;
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SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.get());
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if (SrcExpr.isInvalid())
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return;
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PlaceholderKind = (BuiltinType::Kind) 0;
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}
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};
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}
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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, bool CStyle,
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CastKind &Kind,
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CXXCastPath &BasePath,
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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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CastKind &Kind,
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CXXCastPath &BasePath);
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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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CastKind &Kind,
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CXXCastPath &BasePath);
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static TryCastResult TryStaticDowncast(Sema &Self, CanQualType SrcType,
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CanQualType 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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CastKind &Kind,
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CXXCastPath &BasePath);
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static TryCastResult TryStaticMemberPointerUpcast(Sema &Self, ExprResult &SrcExpr,
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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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CastKind &Kind,
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CXXCastPath &BasePath);
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static TryCastResult TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr,
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QualType DestType,
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Sema::CheckedConversionKind CCK,
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const SourceRange &OpRange,
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unsigned &msg, CastKind &Kind,
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bool ListInitialization);
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static TryCastResult TryStaticCast(Sema &Self, ExprResult &SrcExpr,
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QualType DestType,
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Sema::CheckedConversionKind CCK,
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const SourceRange &OpRange,
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unsigned &msg, CastKind &Kind,
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CXXCastPath &BasePath,
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bool ListInitialization);
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static TryCastResult TryConstCast(Sema &Self, ExprResult &SrcExpr,
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QualType DestType, bool CStyle,
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unsigned &msg);
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static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &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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CastKind &Kind);
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/// ActOnCXXNamedCast - Parse {dynamic,static,reinterpret,const}_cast's.
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ExprResult
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Sema::ActOnCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
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SourceLocation LAngleBracketLoc, Declarator &D,
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SourceLocation RAngleBracketLoc,
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SourceLocation LParenLoc, Expr *E,
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SourceLocation RParenLoc) {
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assert(!D.isInvalidType());
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TypeSourceInfo *TInfo = GetTypeForDeclaratorCast(D, E->getType());
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if (D.isInvalidType())
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return ExprError();
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if (getLangOpts().CPlusPlus) {
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// Check that there are no default arguments (C++ only).
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CheckExtraCXXDefaultArguments(D);
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}
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return BuildCXXNamedCast(OpLoc, Kind, TInfo, E,
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SourceRange(LAngleBracketLoc, RAngleBracketLoc),
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SourceRange(LParenLoc, RParenLoc));
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}
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ExprResult
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Sema::BuildCXXNamedCast(SourceLocation OpLoc, tok::TokenKind Kind,
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TypeSourceInfo *DestTInfo, Expr *E,
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SourceRange AngleBrackets, SourceRange Parens) {
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ExprResult Ex = E;
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QualType DestType = DestTInfo->getType();
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// If the type is dependent, we won't do the semantic analysis now.
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bool TypeDependent =
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DestType->isDependentType() || Ex.get()->isTypeDependent();
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CastOperation Op(*this, DestType, E);
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Op.OpRange = SourceRange(OpLoc, Parens.getEnd());
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Op.DestRange = AngleBrackets;
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switch (Kind) {
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default: llvm_unreachable("Unknown C++ cast!");
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case tok::kw_const_cast:
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if (!TypeDependent) {
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Op.CheckConstCast();
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if (Op.SrcExpr.isInvalid())
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return ExprError();
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}
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return Op.complete(CXXConstCastExpr::Create(Context, Op.ResultType,
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Op.ValueKind, Op.SrcExpr.get(), DestTInfo,
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OpLoc, Parens.getEnd(),
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AngleBrackets));
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case tok::kw_dynamic_cast: {
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if (!TypeDependent) {
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Op.CheckDynamicCast();
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if (Op.SrcExpr.isInvalid())
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return ExprError();
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}
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return Op.complete(CXXDynamicCastExpr::Create(Context, Op.ResultType,
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Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
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&Op.BasePath, DestTInfo,
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OpLoc, Parens.getEnd(),
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AngleBrackets));
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}
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case tok::kw_reinterpret_cast: {
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if (!TypeDependent) {
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Op.CheckReinterpretCast();
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if (Op.SrcExpr.isInvalid())
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return ExprError();
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}
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return Op.complete(CXXReinterpretCastExpr::Create(Context, Op.ResultType,
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Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
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nullptr, DestTInfo, OpLoc,
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Parens.getEnd(),
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AngleBrackets));
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}
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case tok::kw_static_cast: {
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if (!TypeDependent) {
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Op.CheckStaticCast();
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if (Op.SrcExpr.isInvalid())
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return ExprError();
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}
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return Op.complete(CXXStaticCastExpr::Create(Context, Op.ResultType,
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Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
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&Op.BasePath, DestTInfo,
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OpLoc, Parens.getEnd(),
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AngleBrackets));
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}
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}
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}
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/// Try to diagnose a failed overloaded cast. Returns true if
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/// diagnostics were emitted.
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static bool tryDiagnoseOverloadedCast(Sema &S, CastType CT,
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SourceRange range, Expr *src,
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QualType destType,
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bool listInitialization) {
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switch (CT) {
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// These cast kinds don't consider user-defined conversions.
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case CT_Const:
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case CT_Reinterpret:
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case CT_Dynamic:
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return false;
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// These do.
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case CT_Static:
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case CT_CStyle:
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case CT_Functional:
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break;
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}
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QualType srcType = src->getType();
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if (!destType->isRecordType() && !srcType->isRecordType())
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return false;
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InitializedEntity entity = InitializedEntity::InitializeTemporary(destType);
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InitializationKind initKind
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= (CT == CT_CStyle)? InitializationKind::CreateCStyleCast(range.getBegin(),
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range, listInitialization)
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: (CT == CT_Functional)? InitializationKind::CreateFunctionalCast(range,
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listInitialization)
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: InitializationKind::CreateCast(/*type range?*/ range);
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InitializationSequence sequence(S, entity, initKind, src);
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assert(sequence.Failed() && "initialization succeeded on second try?");
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switch (sequence.getFailureKind()) {
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default: return false;
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case InitializationSequence::FK_ConstructorOverloadFailed:
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case InitializationSequence::FK_UserConversionOverloadFailed:
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break;
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}
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OverloadCandidateSet &candidates = sequence.getFailedCandidateSet();
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unsigned msg = 0;
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OverloadCandidateDisplayKind howManyCandidates = OCD_AllCandidates;
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switch (sequence.getFailedOverloadResult()) {
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case OR_Success: llvm_unreachable("successful failed overload");
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case OR_No_Viable_Function:
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if (candidates.empty())
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msg = diag::err_ovl_no_conversion_in_cast;
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else
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msg = diag::err_ovl_no_viable_conversion_in_cast;
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howManyCandidates = OCD_AllCandidates;
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break;
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case OR_Ambiguous:
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msg = diag::err_ovl_ambiguous_conversion_in_cast;
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howManyCandidates = OCD_ViableCandidates;
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break;
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case OR_Deleted:
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msg = diag::err_ovl_deleted_conversion_in_cast;
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howManyCandidates = OCD_ViableCandidates;
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break;
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}
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S.Diag(range.getBegin(), msg)
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<< CT << srcType << destType
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<< range << src->getSourceRange();
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candidates.NoteCandidates(S, howManyCandidates, src);
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return true;
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}
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/// Diagnose a failed cast.
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static void diagnoseBadCast(Sema &S, unsigned msg, CastType castType,
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SourceRange opRange, Expr *src, QualType destType,
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bool listInitialization) {
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if (msg == diag::err_bad_cxx_cast_generic &&
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tryDiagnoseOverloadedCast(S, castType, opRange, src, destType,
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listInitialization))
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return;
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S.Diag(opRange.getBegin(), msg) << castType
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<< src->getType() << destType << opRange << src->getSourceRange();
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// Detect if both types are (ptr to) class, and note any incompleteness.
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int DifferentPtrness = 0;
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QualType From = destType;
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if (auto Ptr = From->getAs<PointerType>()) {
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From = Ptr->getPointeeType();
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DifferentPtrness++;
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}
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QualType To = src->getType();
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if (auto Ptr = To->getAs<PointerType>()) {
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To = Ptr->getPointeeType();
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DifferentPtrness--;
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}
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if (!DifferentPtrness) {
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auto RecFrom = From->getAs<RecordType>();
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auto RecTo = To->getAs<RecordType>();
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if (RecFrom && RecTo) {
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auto DeclFrom = RecFrom->getAsCXXRecordDecl();
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if (!DeclFrom->isCompleteDefinition())
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S.Diag(DeclFrom->getLocation(), diag::note_type_incomplete)
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<< DeclFrom->getDeclName();
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auto DeclTo = RecTo->getAsCXXRecordDecl();
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if (!DeclTo->isCompleteDefinition())
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S.Diag(DeclTo->getLocation(), diag::note_type_incomplete)
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<< DeclTo->getDeclName();
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}
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}
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}
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/// UnwrapDissimilarPointerTypes - Like Sema::UnwrapSimilarPointerTypes,
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/// this removes one level of indirection from both types, provided that they're
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/// the same kind of pointer (plain or to-member). Unlike the Sema function,
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/// this one doesn't care if the two pointers-to-member don't point into the
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/// same class. This is because CastsAwayConstness doesn't care.
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static bool UnwrapDissimilarPointerTypes(QualType& T1, QualType& T2) {
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const PointerType *T1PtrType = T1->getAs<PointerType>(),
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*T2PtrType = T2->getAs<PointerType>();
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if (T1PtrType && T2PtrType) {
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T1 = T1PtrType->getPointeeType();
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T2 = T2PtrType->getPointeeType();
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return true;
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}
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const ObjCObjectPointerType *T1ObjCPtrType =
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T1->getAs<ObjCObjectPointerType>(),
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*T2ObjCPtrType =
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T2->getAs<ObjCObjectPointerType>();
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if (T1ObjCPtrType) {
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if (T2ObjCPtrType) {
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T1 = T1ObjCPtrType->getPointeeType();
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T2 = T2ObjCPtrType->getPointeeType();
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return true;
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}
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else if (T2PtrType) {
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T1 = T1ObjCPtrType->getPointeeType();
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T2 = T2PtrType->getPointeeType();
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return true;
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}
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}
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else if (T2ObjCPtrType) {
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if (T1PtrType) {
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T2 = T2ObjCPtrType->getPointeeType();
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T1 = T1PtrType->getPointeeType();
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return true;
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}
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}
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const MemberPointerType *T1MPType = T1->getAs<MemberPointerType>(),
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*T2MPType = T2->getAs<MemberPointerType>();
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if (T1MPType && T2MPType) {
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T1 = T1MPType->getPointeeType();
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T2 = T2MPType->getPointeeType();
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return true;
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}
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const BlockPointerType *T1BPType = T1->getAs<BlockPointerType>(),
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*T2BPType = T2->getAs<BlockPointerType>();
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if (T1BPType && T2BPType) {
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T1 = T1BPType->getPointeeType();
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T2 = T2BPType->getPointeeType();
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return true;
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}
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return false;
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}
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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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///
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/// \param CheckCVR Whether to check for const/volatile/restrict qualifiers.
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///
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/// \param CheckObjCLifetime Whether to check Objective-C lifetime qualifiers.
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static bool
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CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType,
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bool CheckCVR, bool CheckObjCLifetime,
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QualType *TheOffendingSrcType = nullptr,
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QualType *TheOffendingDestType = nullptr,
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Qualifiers *CastAwayQualifiers = nullptr) {
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// If the only checking we care about is for Objective-C lifetime qualifiers,
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// and we're not in ARC mode, there's nothing to check.
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if (!CheckCVR && CheckObjCLifetime &&
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!Self.Context.getLangOpts().ObjCAutoRefCount)
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return false;
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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
|
|
// the rules are non-trivial. So first we construct Tcv *...cv* as described
|
|
// in C++ 5.2.11p8.
|
|
assert((SrcType->isAnyPointerType() || SrcType->isMemberPointerType() ||
|
|
SrcType->isBlockPointerType()) &&
|
|
"Source type is not pointer or pointer to member.");
|
|
assert((DestType->isAnyPointerType() || DestType->isMemberPointerType() ||
|
|
DestType->isBlockPointerType()) &&
|
|
"Destination type is not pointer or pointer to member.");
|
|
|
|
QualType UnwrappedSrcType = Self.Context.getCanonicalType(SrcType),
|
|
UnwrappedDestType = Self.Context.getCanonicalType(DestType);
|
|
SmallVector<Qualifiers, 8> cv1, cv2;
|
|
|
|
// Find the qualifiers. We only care about cvr-qualifiers for the
|
|
// purpose of this check, because other qualifiers (address spaces,
|
|
// Objective-C GC, etc.) are part of the type's identity.
|
|
QualType PrevUnwrappedSrcType = UnwrappedSrcType;
|
|
QualType PrevUnwrappedDestType = UnwrappedDestType;
|
|
while (UnwrapDissimilarPointerTypes(UnwrappedSrcType, UnwrappedDestType)) {
|
|
// Determine the relevant qualifiers at this level.
|
|
Qualifiers SrcQuals, DestQuals;
|
|
Self.Context.getUnqualifiedArrayType(UnwrappedSrcType, SrcQuals);
|
|
Self.Context.getUnqualifiedArrayType(UnwrappedDestType, DestQuals);
|
|
|
|
Qualifiers RetainedSrcQuals, RetainedDestQuals;
|
|
if (CheckCVR) {
|
|
RetainedSrcQuals.setCVRQualifiers(SrcQuals.getCVRQualifiers());
|
|
RetainedDestQuals.setCVRQualifiers(DestQuals.getCVRQualifiers());
|
|
|
|
if (RetainedSrcQuals != RetainedDestQuals && TheOffendingSrcType &&
|
|
TheOffendingDestType && CastAwayQualifiers) {
|
|
*TheOffendingSrcType = PrevUnwrappedSrcType;
|
|
*TheOffendingDestType = PrevUnwrappedDestType;
|
|
*CastAwayQualifiers = RetainedSrcQuals - RetainedDestQuals;
|
|
}
|
|
}
|
|
|
|
if (CheckObjCLifetime &&
|
|
!DestQuals.compatiblyIncludesObjCLifetime(SrcQuals))
|
|
return true;
|
|
|
|
cv1.push_back(RetainedSrcQuals);
|
|
cv2.push_back(RetainedDestQuals);
|
|
|
|
PrevUnwrappedSrcType = UnwrappedSrcType;
|
|
PrevUnwrappedDestType = UnwrappedDestType;
|
|
}
|
|
if (cv1.empty())
|
|
return false;
|
|
|
|
// Construct void pointers with those qualifiers (in reverse order of
|
|
// unwrapping, of course).
|
|
QualType SrcConstruct = Self.Context.VoidTy;
|
|
QualType DestConstruct = Self.Context.VoidTy;
|
|
ASTContext &Context = Self.Context;
|
|
for (SmallVectorImpl<Qualifiers>::reverse_iterator i1 = cv1.rbegin(),
|
|
i2 = cv2.rbegin();
|
|
i1 != cv1.rend(); ++i1, ++i2) {
|
|
SrcConstruct
|
|
= Context.getPointerType(Context.getQualifiedType(SrcConstruct, *i1));
|
|
DestConstruct
|
|
= Context.getPointerType(Context.getQualifiedType(DestConstruct, *i2));
|
|
}
|
|
|
|
// Test if they're compatible.
|
|
bool ObjCLifetimeConversion;
|
|
return SrcConstruct != DestConstruct &&
|
|
!Self.IsQualificationConversion(SrcConstruct, DestConstruct, false,
|
|
ObjCLifetimeConversion);
|
|
}
|
|
|
|
/// 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 CastOperation::CheckDynamicCast() {
|
|
if (ValueKind == VK_RValue)
|
|
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
|
|
else if (isPlaceholder())
|
|
SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.get());
|
|
if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
|
|
return;
|
|
|
|
QualType OrigSrcType = SrcExpr.get()->getType();
|
|
QualType DestType = Self.Context.getCanonicalType(this->DestType);
|
|
|
|
// 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->getAs<PointerType>();
|
|
const ReferenceType *DestReference = nullptr;
|
|
if (DestPointer) {
|
|
DestPointee = DestPointer->getPointeeType();
|
|
} else if ((DestReference = DestType->getAs<ReferenceType>())) {
|
|
DestPointee = DestReference->getPointeeType();
|
|
} else {
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ref_or_ptr)
|
|
<< this->DestType << DestRange;
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
const RecordType *DestRecord = DestPointee->getAs<RecordType>();
|
|
if (DestPointee->isVoidType()) {
|
|
assert(DestPointer && "Reference to void is not possible");
|
|
} else if (DestRecord) {
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), DestPointee,
|
|
diag::err_bad_dynamic_cast_incomplete,
|
|
DestRange)) {
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
} else {
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
|
|
<< DestPointee.getUnqualifiedType() << DestRange;
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
// 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 class type, [...]
|
|
QualType SrcType = Self.Context.getCanonicalType(OrigSrcType);
|
|
QualType SrcPointee;
|
|
if (DestPointer) {
|
|
if (const PointerType *SrcPointer = SrcType->getAs<PointerType>()) {
|
|
SrcPointee = SrcPointer->getPointeeType();
|
|
} else {
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_ptr)
|
|
<< OrigSrcType << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
} else if (DestReference->isLValueReferenceType()) {
|
|
if (!SrcExpr.get()->isLValue()) {
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_rvalue)
|
|
<< CT_Dynamic << OrigSrcType << this->DestType << OpRange;
|
|
}
|
|
SrcPointee = SrcType;
|
|
} else {
|
|
// If we're dynamic_casting from a prvalue to an rvalue reference, we need
|
|
// to materialize the prvalue before we bind the reference to it.
|
|
if (SrcExpr.get()->isRValue())
|
|
SrcExpr = new (Self.Context) MaterializeTemporaryExpr(
|
|
SrcType, SrcExpr.get(), /*IsLValueReference*/false);
|
|
SrcPointee = SrcType;
|
|
}
|
|
|
|
const RecordType *SrcRecord = SrcPointee->getAs<RecordType>();
|
|
if (SrcRecord) {
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), SrcPointee,
|
|
diag::err_bad_dynamic_cast_incomplete,
|
|
SrcExpr.get())) {
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
} else {
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_class)
|
|
<< SrcPointee.getUnqualifiedType() << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
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)) {
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cxx_cast_qualifiers_away)
|
|
<< CT_Dynamic << OrigSrcType << this->DestType << OpRange;
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
// C++ 5.2.7p3: If the type of v is the same as the required result type,
|
|
// [except for cv].
|
|
if (DestRecord == SrcRecord) {
|
|
Kind = CK_NoOp;
|
|
return;
|
|
}
|
|
|
|
// C++ 5.2.7p5
|
|
// Upcasts are resolved statically.
|
|
if (DestRecord && Self.IsDerivedFrom(SrcPointee, DestPointee)) {
|
|
if (Self.CheckDerivedToBaseConversion(SrcPointee, DestPointee,
|
|
OpRange.getBegin(), OpRange,
|
|
&BasePath)) {
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
Kind = CK_DerivedToBase;
|
|
return;
|
|
}
|
|
|
|
// C++ 5.2.7p6: Otherwise, v shall be [polymorphic].
|
|
const RecordDecl *SrcDecl = SrcRecord->getDecl()->getDefinition();
|
|
assert(SrcDecl && "Definition missing");
|
|
if (!cast<CXXRecordDecl>(SrcDecl)->isPolymorphic()) {
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_dynamic_cast_not_polymorphic)
|
|
<< SrcPointee.getUnqualifiedType() << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
}
|
|
|
|
// dynamic_cast is not available with -fno-rtti.
|
|
// As an exception, dynamic_cast to void* is available because it doesn't
|
|
// use RTTI.
|
|
if (!Self.getLangOpts().RTTI && !DestPointee->isVoidType()) {
|
|
Self.Diag(OpRange.getBegin(), diag::err_no_dynamic_cast_with_fno_rtti);
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
// Done. Everything else is run-time checks.
|
|
Kind = CK_Dynamic;
|
|
}
|
|
|
|
/// 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 CastOperation::CheckConstCast() {
|
|
if (ValueKind == VK_RValue)
|
|
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
|
|
else if (isPlaceholder())
|
|
SrcExpr = Self.CheckPlaceholderExpr(SrcExpr.get());
|
|
if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
|
|
return;
|
|
|
|
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.get()->getType() << DestType << OpRange;
|
|
SrcExpr = ExprError();
|
|
}
|
|
}
|
|
|
|
/// Check that a reinterpret_cast\<DestType\>(SrcExpr) is not used as upcast
|
|
/// or downcast between respective pointers or references.
|
|
static void DiagnoseReinterpretUpDownCast(Sema &Self, const Expr *SrcExpr,
|
|
QualType DestType,
|
|
SourceRange OpRange) {
|
|
QualType SrcType = SrcExpr->getType();
|
|
// When casting from pointer or reference, get pointee type; use original
|
|
// type otherwise.
|
|
const CXXRecordDecl *SrcPointeeRD = SrcType->getPointeeCXXRecordDecl();
|
|
const CXXRecordDecl *SrcRD =
|
|
SrcPointeeRD ? SrcPointeeRD : SrcType->getAsCXXRecordDecl();
|
|
|
|
// Examining subobjects for records is only possible if the complete and
|
|
// valid definition is available. Also, template instantiation is not
|
|
// allowed here.
|
|
if (!SrcRD || !SrcRD->isCompleteDefinition() || SrcRD->isInvalidDecl())
|
|
return;
|
|
|
|
const CXXRecordDecl *DestRD = DestType->getPointeeCXXRecordDecl();
|
|
|
|
if (!DestRD || !DestRD->isCompleteDefinition() || DestRD->isInvalidDecl())
|
|
return;
|
|
|
|
enum {
|
|
ReinterpretUpcast,
|
|
ReinterpretDowncast
|
|
} ReinterpretKind;
|
|
|
|
CXXBasePaths BasePaths;
|
|
|
|
if (SrcRD->isDerivedFrom(DestRD, BasePaths))
|
|
ReinterpretKind = ReinterpretUpcast;
|
|
else if (DestRD->isDerivedFrom(SrcRD, BasePaths))
|
|
ReinterpretKind = ReinterpretDowncast;
|
|
else
|
|
return;
|
|
|
|
bool VirtualBase = true;
|
|
bool NonZeroOffset = false;
|
|
for (CXXBasePaths::const_paths_iterator I = BasePaths.begin(),
|
|
E = BasePaths.end();
|
|
I != E; ++I) {
|
|
const CXXBasePath &Path = *I;
|
|
CharUnits Offset = CharUnits::Zero();
|
|
bool IsVirtual = false;
|
|
for (CXXBasePath::const_iterator IElem = Path.begin(), EElem = Path.end();
|
|
IElem != EElem; ++IElem) {
|
|
IsVirtual = IElem->Base->isVirtual();
|
|
if (IsVirtual)
|
|
break;
|
|
const CXXRecordDecl *BaseRD = IElem->Base->getType()->getAsCXXRecordDecl();
|
|
assert(BaseRD && "Base type should be a valid unqualified class type");
|
|
// Don't check if any base has invalid declaration or has no definition
|
|
// since it has no layout info.
|
|
const CXXRecordDecl *Class = IElem->Class,
|
|
*ClassDefinition = Class->getDefinition();
|
|
if (Class->isInvalidDecl() || !ClassDefinition ||
|
|
!ClassDefinition->isCompleteDefinition())
|
|
return;
|
|
|
|
const ASTRecordLayout &DerivedLayout =
|
|
Self.Context.getASTRecordLayout(Class);
|
|
Offset += DerivedLayout.getBaseClassOffset(BaseRD);
|
|
}
|
|
if (!IsVirtual) {
|
|
// Don't warn if any path is a non-virtually derived base at offset zero.
|
|
if (Offset.isZero())
|
|
return;
|
|
// Offset makes sense only for non-virtual bases.
|
|
else
|
|
NonZeroOffset = true;
|
|
}
|
|
VirtualBase = VirtualBase && IsVirtual;
|
|
}
|
|
|
|
(void) NonZeroOffset; // Silence set but not used warning.
|
|
assert((VirtualBase || NonZeroOffset) &&
|
|
"Should have returned if has non-virtual base with zero offset");
|
|
|
|
QualType BaseType =
|
|
ReinterpretKind == ReinterpretUpcast? DestType : SrcType;
|
|
QualType DerivedType =
|
|
ReinterpretKind == ReinterpretUpcast? SrcType : DestType;
|
|
|
|
SourceLocation BeginLoc = OpRange.getBegin();
|
|
Self.Diag(BeginLoc, diag::warn_reinterpret_different_from_static)
|
|
<< DerivedType << BaseType << !VirtualBase << int(ReinterpretKind)
|
|
<< OpRange;
|
|
Self.Diag(BeginLoc, diag::note_reinterpret_updowncast_use_static)
|
|
<< int(ReinterpretKind)
|
|
<< FixItHint::CreateReplacement(BeginLoc, "static_cast");
|
|
}
|
|
|
|
/// 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 CastOperation::CheckReinterpretCast() {
|
|
if (ValueKind == VK_RValue && !isPlaceholder(BuiltinType::Overload))
|
|
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
|
|
else
|
|
checkNonOverloadPlaceholders();
|
|
if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
|
|
return;
|
|
|
|
unsigned msg = diag::err_bad_cxx_cast_generic;
|
|
TryCastResult tcr =
|
|
TryReinterpretCast(Self, SrcExpr, DestType,
|
|
/*CStyle*/false, OpRange, msg, Kind);
|
|
if (tcr != TC_Success && msg != 0)
|
|
{
|
|
if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
|
|
return;
|
|
if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
|
|
//FIXME: &f<int>; is overloaded and resolvable
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_overload)
|
|
<< OverloadExpr::find(SrcExpr.get()).Expression->getName()
|
|
<< DestType << OpRange;
|
|
Self.NoteAllOverloadCandidates(SrcExpr.get());
|
|
|
|
} else {
|
|
diagnoseBadCast(Self, msg, CT_Reinterpret, OpRange, SrcExpr.get(),
|
|
DestType, /*listInitialization=*/false);
|
|
}
|
|
SrcExpr = ExprError();
|
|
} else if (tcr == TC_Success) {
|
|
if (Self.getLangOpts().ObjCAutoRefCount)
|
|
checkObjCARCConversion(Sema::CCK_OtherCast);
|
|
DiagnoseReinterpretUpDownCast(Self, SrcExpr.get(), DestType, OpRange);
|
|
}
|
|
}
|
|
|
|
|
|
/// 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 CastOperation::CheckStaticCast() {
|
|
if (isPlaceholder()) {
|
|
checkNonOverloadPlaceholders();
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
}
|
|
|
|
// 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()) {
|
|
Kind = CK_ToVoid;
|
|
|
|
if (claimPlaceholder(BuiltinType::Overload)) {
|
|
Self.ResolveAndFixSingleFunctionTemplateSpecialization(SrcExpr,
|
|
false, // Decay Function to ptr
|
|
true, // Complain
|
|
OpRange, DestType, diag::err_bad_static_cast_overload);
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
}
|
|
|
|
SrcExpr = Self.IgnoredValueConversions(SrcExpr.get());
|
|
return;
|
|
}
|
|
|
|
if (ValueKind == VK_RValue && !DestType->isRecordType() &&
|
|
!isPlaceholder(BuiltinType::Overload)) {
|
|
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
|
|
if (SrcExpr.isInvalid()) // if conversion failed, don't report another error
|
|
return;
|
|
}
|
|
|
|
unsigned msg = diag::err_bad_cxx_cast_generic;
|
|
TryCastResult tcr
|
|
= TryStaticCast(Self, SrcExpr, DestType, Sema::CCK_OtherCast, OpRange, msg,
|
|
Kind, BasePath, /*ListInitialization=*/false);
|
|
if (tcr != TC_Success && msg != 0) {
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
|
|
OverloadExpr* oe = OverloadExpr::find(SrcExpr.get()).Expression;
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_static_cast_overload)
|
|
<< oe->getName() << DestType << OpRange
|
|
<< oe->getQualifierLoc().getSourceRange();
|
|
Self.NoteAllOverloadCandidates(SrcExpr.get());
|
|
} else {
|
|
diagnoseBadCast(Self, msg, CT_Static, OpRange, SrcExpr.get(), DestType,
|
|
/*listInitialization=*/false);
|
|
}
|
|
SrcExpr = ExprError();
|
|
} else if (tcr == TC_Success) {
|
|
if (Kind == CK_BitCast)
|
|
checkCastAlign();
|
|
if (Self.getLangOpts().ObjCAutoRefCount)
|
|
checkObjCARCConversion(Sema::CCK_OtherCast);
|
|
} else if (Kind == CK_BitCast) {
|
|
checkCastAlign();
|
|
}
|
|
}
|
|
|
|
/// 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, ExprResult &SrcExpr,
|
|
QualType DestType,
|
|
Sema::CheckedConversionKind CCK,
|
|
const SourceRange &OpRange, unsigned &msg,
|
|
CastKind &Kind, CXXCastPath &BasePath,
|
|
bool ListInitialization) {
|
|
// Determine whether we have the semantics of a C-style cast.
|
|
bool CStyle
|
|
= (CCK == Sema::CCK_CStyleCast || CCK == Sema::CCK_FunctionalCast);
|
|
|
|
// 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".
|
|
// Done outside this function.
|
|
|
|
TryCastResult tcr;
|
|
|
|
// C++ 5.2.9p5, reference downcast.
|
|
// See the function for details.
|
|
// DR 427 specifies that this is to be applied before paragraph 2.
|
|
tcr = TryStaticReferenceDowncast(Self, SrcExpr.get(), DestType, CStyle,
|
|
OpRange, msg, Kind, BasePath);
|
|
if (tcr != TC_NotApplicable)
|
|
return tcr;
|
|
|
|
// C++0x [expr.static.cast]p3:
|
|
// A glvalue of type "cv1 T1" can be cast to type "rvalue reference to cv2
|
|
// T2" if "cv2 T2" is reference-compatible with "cv1 T1".
|
|
tcr = TryLValueToRValueCast(Self, SrcExpr.get(), DestType, CStyle, Kind,
|
|
BasePath, msg);
|
|
if (tcr != TC_NotApplicable)
|
|
return tcr;
|
|
|
|
// C++ 5.2.9p2: An expression e can be explicitly converted to a type T
|
|
// [...] if the declaration "T t(e);" is well-formed, [...].
|
|
tcr = TryStaticImplicitCast(Self, SrcExpr, DestType, CCK, OpRange, msg,
|
|
Kind, ListInitialization);
|
|
if (SrcExpr.isInvalid())
|
|
return TC_Failed;
|
|
if (tcr != TC_NotApplicable)
|
|
return tcr;
|
|
|
|
// 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.
|
|
// In the CStyle case, the earlier attempt to const_cast should have taken
|
|
// care of reverse qualification conversions.
|
|
|
|
QualType SrcType = Self.Context.getCanonicalType(SrcExpr.get()->getType());
|
|
|
|
// C++0x 5.2.9p9: A value of a scoped enumeration type can be explicitly
|
|
// converted to an integral type. [...] A value of a scoped enumeration type
|
|
// can also be explicitly converted to a floating-point type [...].
|
|
if (const EnumType *Enum = SrcType->getAs<EnumType>()) {
|
|
if (Enum->getDecl()->isScoped()) {
|
|
if (DestType->isBooleanType()) {
|
|
Kind = CK_IntegralToBoolean;
|
|
return TC_Success;
|
|
} else if (DestType->isIntegralType(Self.Context)) {
|
|
Kind = CK_IntegralCast;
|
|
return TC_Success;
|
|
} else if (DestType->isRealFloatingType()) {
|
|
Kind = CK_IntegralToFloating;
|
|
return TC_Success;
|
|
}
|
|
}
|
|
}
|
|
|
|
// 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->isIntegralOrEnumerationType()) {
|
|
Kind = CK_IntegralCast;
|
|
return TC_Success;
|
|
} else if (SrcType->isRealFloatingType()) {
|
|
Kind = CK_FloatingToIntegral;
|
|
return TC_Success;
|
|
}
|
|
}
|
|
|
|
// Reverse pointer upcast. C++ 4.10p3 specifies pointer upcast.
|
|
// C++ 5.2.9p8 additionally disallows a cast path through virtual inheritance.
|
|
tcr = TryStaticPointerDowncast(Self, SrcType, DestType, CStyle, OpRange, msg,
|
|
Kind, BasePath);
|
|
if (tcr != TC_NotApplicable)
|
|
return tcr;
|
|
|
|
// Reverse member pointer conversion. C++ 4.11 specifies member pointer
|
|
// conversion. C++ 5.2.9p9 has additional information.
|
|
// DR54's access restrictions apply here also.
|
|
tcr = TryStaticMemberPointerUpcast(Self, SrcExpr, SrcType, DestType, CStyle,
|
|
OpRange, msg, Kind, BasePath);
|
|
if (tcr != TC_NotApplicable)
|
|
return tcr;
|
|
|
|
// 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->getAs<PointerType>()) {
|
|
QualType SrcPointee = SrcPointer->getPointeeType();
|
|
if (SrcPointee->isVoidType()) {
|
|
if (const PointerType *DestPointer = DestType->getAs<PointerType>()) {
|
|
QualType DestPointee = DestPointer->getPointeeType();
|
|
if (DestPointee->isIncompleteOrObjectType()) {
|
|
// This is definitely the intended conversion, but it might fail due
|
|
// to a qualifier violation. Note that we permit Objective-C lifetime
|
|
// and GC qualifier mismatches here.
|
|
if (!CStyle) {
|
|
Qualifiers DestPointeeQuals = DestPointee.getQualifiers();
|
|
Qualifiers SrcPointeeQuals = SrcPointee.getQualifiers();
|
|
DestPointeeQuals.removeObjCGCAttr();
|
|
DestPointeeQuals.removeObjCLifetime();
|
|
SrcPointeeQuals.removeObjCGCAttr();
|
|
SrcPointeeQuals.removeObjCLifetime();
|
|
if (DestPointeeQuals != SrcPointeeQuals &&
|
|
!DestPointeeQuals.compatiblyIncludes(SrcPointeeQuals)) {
|
|
msg = diag::err_bad_cxx_cast_qualifiers_away;
|
|
return TC_Failed;
|
|
}
|
|
}
|
|
Kind = CK_BitCast;
|
|
return TC_Success;
|
|
}
|
|
}
|
|
else if (DestType->isObjCObjectPointerType()) {
|
|
// allow both c-style cast and static_cast of objective-c pointers as
|
|
// they are pervasive.
|
|
Kind = CK_CPointerToObjCPointerCast;
|
|
return TC_Success;
|
|
}
|
|
else if (CStyle && DestType->isBlockPointerType()) {
|
|
// allow c-style cast of void * to block pointers.
|
|
Kind = CK_AnyPointerToBlockPointerCast;
|
|
return TC_Success;
|
|
}
|
|
}
|
|
}
|
|
// Allow arbitray objective-c pointer conversion with static casts.
|
|
if (SrcType->isObjCObjectPointerType() &&
|
|
DestType->isObjCObjectPointerType()) {
|
|
Kind = CK_BitCast;
|
|
return TC_Success;
|
|
}
|
|
// Allow ns-pointer to cf-pointer conversion in either direction
|
|
// with static casts.
|
|
if (!CStyle &&
|
|
Self.CheckTollFreeBridgeStaticCast(DestType, SrcExpr.get(), Kind))
|
|
return TC_Success;
|
|
|
|
// See if it looks like the user is trying to convert between
|
|
// related record types, and select a better diagnostic if so.
|
|
if (auto SrcPointer = SrcType->getAs<PointerType>())
|
|
if (auto DestPointer = DestType->getAs<PointerType>())
|
|
if (SrcPointer->getPointeeType()->getAs<RecordType>() &&
|
|
DestPointer->getPointeeType()->getAs<RecordType>())
|
|
msg = diag::err_bad_cxx_cast_unrelated_class;
|
|
|
|
// We tried everything. Everything! Nothing works! :-(
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
/// Tests whether a conversion according to N2844 is valid.
|
|
TryCastResult
|
|
TryLValueToRValueCast(Sema &Self, Expr *SrcExpr, QualType DestType,
|
|
bool CStyle, CastKind &Kind, CXXCastPath &BasePath,
|
|
unsigned &msg) {
|
|
// C++0x [expr.static.cast]p3:
|
|
// A glvalue 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->getAs<RValueReferenceType>();
|
|
if (!R)
|
|
return TC_NotApplicable;
|
|
|
|
if (!SrcExpr->isGLValue())
|
|
return TC_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.
|
|
// FIXME: Should allow casting away constness if CStyle.
|
|
bool DerivedToBase;
|
|
bool ObjCConversion;
|
|
bool ObjCLifetimeConversion;
|
|
QualType FromType = SrcExpr->getType();
|
|
QualType ToType = R->getPointeeType();
|
|
if (CStyle) {
|
|
FromType = FromType.getUnqualifiedType();
|
|
ToType = ToType.getUnqualifiedType();
|
|
}
|
|
|
|
if (Self.CompareReferenceRelationship(SrcExpr->getLocStart(),
|
|
ToType, FromType,
|
|
DerivedToBase, ObjCConversion,
|
|
ObjCLifetimeConversion)
|
|
< Sema::Ref_Compatible_With_Added_Qualification) {
|
|
msg = diag::err_bad_lvalue_to_rvalue_cast;
|
|
return TC_Failed;
|
|
}
|
|
|
|
if (DerivedToBase) {
|
|
Kind = CK_DerivedToBase;
|
|
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
|
|
/*DetectVirtual=*/true);
|
|
if (!Self.IsDerivedFrom(SrcExpr->getType(), R->getPointeeType(), Paths))
|
|
return TC_NotApplicable;
|
|
|
|
Self.BuildBasePathArray(Paths, BasePath);
|
|
} else
|
|
Kind = CK_NoOp;
|
|
|
|
return TC_Success;
|
|
}
|
|
|
|
/// Tests whether a conversion according to C++ 5.2.9p5 is valid.
|
|
TryCastResult
|
|
TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr, QualType DestType,
|
|
bool CStyle, const SourceRange &OpRange,
|
|
unsigned &msg, CastKind &Kind,
|
|
CXXCastPath &BasePath) {
|
|
// 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.
|
|
|
|
const ReferenceType *DestReference = DestType->getAs<ReferenceType>();
|
|
if (!DestReference) {
|
|
return TC_NotApplicable;
|
|
}
|
|
bool RValueRef = DestReference->isRValueReferenceType();
|
|
if (!RValueRef && !SrcExpr->isLValue()) {
|
|
// 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;
|
|
}
|
|
|
|
QualType DestPointee = DestReference->getPointeeType();
|
|
|
|
// FIXME: If the source is a prvalue, we should issue a warning (because the
|
|
// cast always has undefined behavior), and for AST consistency, we should
|
|
// materialize a temporary.
|
|
return TryStaticDowncast(Self,
|
|
Self.Context.getCanonicalType(SrcExpr->getType()),
|
|
Self.Context.getCanonicalType(DestPointee), CStyle,
|
|
OpRange, SrcExpr->getType(), DestType, msg, Kind,
|
|
BasePath);
|
|
}
|
|
|
|
/// Tests whether a conversion according to C++ 5.2.9p8 is valid.
|
|
TryCastResult
|
|
TryStaticPointerDowncast(Sema &Self, QualType SrcType, QualType DestType,
|
|
bool CStyle, const SourceRange &OpRange,
|
|
unsigned &msg, CastKind &Kind,
|
|
CXXCastPath &BasePath) {
|
|
// 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 *DestPointer = DestType->getAs<PointerType>();
|
|
if (!DestPointer) {
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
const PointerType *SrcPointer = SrcType->getAs<PointerType>();
|
|
if (!SrcPointer) {
|
|
msg = diag::err_bad_static_cast_pointer_nonpointer;
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
return TryStaticDowncast(Self,
|
|
Self.Context.getCanonicalType(SrcPointer->getPointeeType()),
|
|
Self.Context.getCanonicalType(DestPointer->getPointeeType()),
|
|
CStyle, OpRange, SrcType, DestType, msg, Kind,
|
|
BasePath);
|
|
}
|
|
|
|
/// TryStaticDowncast - Common functionality of TryStaticReferenceDowncast and
|
|
/// TryStaticPointerDowncast. Tests whether a static downcast from SrcType to
|
|
/// DestType is possible and allowed.
|
|
TryCastResult
|
|
TryStaticDowncast(Sema &Self, CanQualType SrcType, CanQualType DestType,
|
|
bool CStyle, const SourceRange &OpRange, QualType OrigSrcType,
|
|
QualType OrigDestType, unsigned &msg,
|
|
CastKind &Kind, CXXCastPath &BasePath) {
|
|
// We can only work with complete types. But don't complain if it doesn't work
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), SrcType, 0) ||
|
|
Self.RequireCompleteType(OpRange.getBegin(), DestType, 0))
|
|
return TC_NotApplicable;
|
|
|
|
// Downcast can only happen in class hierarchies, so we need classes.
|
|
if (!DestType->getAs<RecordType>() || !SrcType->getAs<RecordType>()) {
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
|
|
/*DetectVirtual=*/true);
|
|
if (!Self.IsDerivedFrom(DestType, SrcType, Paths)) {
|
|
return TC_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, unless we're in C-style mode.
|
|
if (!CStyle && !DestType.isAtLeastAsQualifiedAs(SrcType)) {
|
|
msg = diag::err_bad_cxx_cast_qualifiers_away;
|
|
return TC_Failed;
|
|
}
|
|
|
|
if (Paths.isAmbiguous(SrcType.getUnqualifiedType())) {
|
|
// 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.
|
|
if (!Paths.isRecordingPaths()) {
|
|
Paths.clear();
|
|
Paths.setRecordingPaths(true);
|
|
Self.IsDerivedFrom(DestType, SrcType, Paths);
|
|
}
|
|
std::string PathDisplayStr;
|
|
std::set<unsigned> DisplayedPaths;
|
|
for (CXXBasePaths::paths_iterator PI = Paths.begin(), PE = Paths.end();
|
|
PI != PE; ++PI) {
|
|
if (DisplayedPaths.insert(PI->back().SubobjectNumber).second) {
|
|
// We haven't displayed a path to this particular base
|
|
// class subobject yet.
|
|
PathDisplayStr += "\n ";
|
|
for (CXXBasePath::const_reverse_iterator EI = PI->rbegin(),
|
|
EE = PI->rend();
|
|
EI != EE; ++EI)
|
|
PathDisplayStr += EI->Base->getType().getAsString() + " -> ";
|
|
PathDisplayStr += QualType(DestType).getAsString();
|
|
}
|
|
}
|
|
|
|
Self.Diag(OpRange.getBegin(), diag::err_ambiguous_base_to_derived_cast)
|
|
<< QualType(SrcType).getUnqualifiedType()
|
|
<< QualType(DestType).getUnqualifiedType()
|
|
<< PathDisplayStr << OpRange;
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
|
|
if (Paths.getDetectedVirtual() != nullptr) {
|
|
QualType VirtualBase(Paths.getDetectedVirtual(), 0);
|
|
Self.Diag(OpRange.getBegin(), diag::err_static_downcast_via_virtual)
|
|
<< OrigSrcType << OrigDestType << VirtualBase << OpRange;
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
|
|
if (!CStyle) {
|
|
switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
|
|
SrcType, DestType,
|
|
Paths.front(),
|
|
diag::err_downcast_from_inaccessible_base)) {
|
|
case Sema::AR_accessible:
|
|
case Sema::AR_delayed: // be optimistic
|
|
case Sema::AR_dependent: // be optimistic
|
|
break;
|
|
|
|
case Sema::AR_inaccessible:
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
}
|
|
|
|
Self.BuildBasePathArray(Paths, BasePath);
|
|
Kind = CK_BaseToDerived;
|
|
return TC_Success;
|
|
}
|
|
|
|
/// 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 [...].
|
|
///
|
|
TryCastResult
|
|
TryStaticMemberPointerUpcast(Sema &Self, ExprResult &SrcExpr, QualType SrcType,
|
|
QualType DestType, bool CStyle,
|
|
const SourceRange &OpRange,
|
|
unsigned &msg, CastKind &Kind,
|
|
CXXCastPath &BasePath) {
|
|
const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>();
|
|
if (!DestMemPtr)
|
|
return TC_NotApplicable;
|
|
|
|
bool WasOverloadedFunction = false;
|
|
DeclAccessPair FoundOverload;
|
|
if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
|
|
if (FunctionDecl *Fn
|
|
= Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(), DestType, false,
|
|
FoundOverload)) {
|
|
CXXMethodDecl *M = cast<CXXMethodDecl>(Fn);
|
|
SrcType = Self.Context.getMemberPointerType(Fn->getType(),
|
|
Self.Context.getTypeDeclType(M->getParent()).getTypePtr());
|
|
WasOverloadedFunction = true;
|
|
}
|
|
}
|
|
|
|
const MemberPointerType *SrcMemPtr = SrcType->getAs<MemberPointerType>();
|
|
if (!SrcMemPtr) {
|
|
msg = diag::err_bad_static_cast_member_pointer_nonmp;
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
// T == T, modulo cv
|
|
if (!Self.Context.hasSameUnqualifiedType(SrcMemPtr->getPointeeType(),
|
|
DestMemPtr->getPointeeType()))
|
|
return TC_NotApplicable;
|
|
|
|
// B base of D
|
|
QualType SrcClass(SrcMemPtr->getClass(), 0);
|
|
QualType DestClass(DestMemPtr->getClass(), 0);
|
|
CXXBasePaths Paths(/*FindAmbiguities=*/true, /*RecordPaths=*/true,
|
|
/*DetectVirtual=*/true);
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), SrcClass, 0) ||
|
|
!Self.IsDerivedFrom(SrcClass, DestClass, Paths)) {
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
// B is a base of D. But is it an allowed base? If not, it's a hard error.
|
|
if (Paths.isAmbiguous(Self.Context.getCanonicalType(DestClass))) {
|
|
Paths.clear();
|
|
Paths.setRecordingPaths(true);
|
|
bool StillOkay = Self.IsDerivedFrom(SrcClass, DestClass, Paths);
|
|
assert(StillOkay);
|
|
(void)StillOkay;
|
|
std::string PathDisplayStr = Self.getAmbiguousPathsDisplayString(Paths);
|
|
Self.Diag(OpRange.getBegin(), diag::err_ambiguous_memptr_conv)
|
|
<< 1 << SrcClass << DestClass << PathDisplayStr << OpRange;
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
|
|
if (const RecordType *VBase = Paths.getDetectedVirtual()) {
|
|
Self.Diag(OpRange.getBegin(), diag::err_memptr_conv_via_virtual)
|
|
<< SrcClass << DestClass << QualType(VBase, 0) << OpRange;
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
|
|
if (!CStyle) {
|
|
switch (Self.CheckBaseClassAccess(OpRange.getBegin(),
|
|
DestClass, SrcClass,
|
|
Paths.front(),
|
|
diag::err_upcast_to_inaccessible_base)) {
|
|
case Sema::AR_accessible:
|
|
case Sema::AR_delayed:
|
|
case Sema::AR_dependent:
|
|
// Optimistically assume that the delayed and dependent cases
|
|
// will work out.
|
|
break;
|
|
|
|
case Sema::AR_inaccessible:
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
}
|
|
|
|
if (WasOverloadedFunction) {
|
|
// Resolve the address of the overloaded function again, this time
|
|
// allowing complaints if something goes wrong.
|
|
FunctionDecl *Fn = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(),
|
|
DestType,
|
|
true,
|
|
FoundOverload);
|
|
if (!Fn) {
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
|
|
SrcExpr = Self.FixOverloadedFunctionReference(SrcExpr, FoundOverload, Fn);
|
|
if (!SrcExpr.isUsable()) {
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
}
|
|
|
|
Self.BuildBasePathArray(Paths, BasePath);
|
|
Kind = CK_DerivedToBaseMemberPointer;
|
|
return TC_Success;
|
|
}
|
|
|
|
/// 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 [...].
|
|
TryCastResult
|
|
TryStaticImplicitCast(Sema &Self, ExprResult &SrcExpr, QualType DestType,
|
|
Sema::CheckedConversionKind CCK,
|
|
const SourceRange &OpRange, unsigned &msg,
|
|
CastKind &Kind, bool ListInitialization) {
|
|
if (DestType->isRecordType()) {
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
|
|
diag::err_bad_dynamic_cast_incomplete) ||
|
|
Self.RequireNonAbstractType(OpRange.getBegin(), DestType,
|
|
diag::err_allocation_of_abstract_type)) {
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
} else if (DestType->isMemberPointerType()) {
|
|
if (Self.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
|
|
Self.RequireCompleteType(OpRange.getBegin(), DestType, 0);
|
|
}
|
|
}
|
|
|
|
InitializedEntity Entity = InitializedEntity::InitializeTemporary(DestType);
|
|
InitializationKind InitKind
|
|
= (CCK == Sema::CCK_CStyleCast)
|
|
? InitializationKind::CreateCStyleCast(OpRange.getBegin(), OpRange,
|
|
ListInitialization)
|
|
: (CCK == Sema::CCK_FunctionalCast)
|
|
? InitializationKind::CreateFunctionalCast(OpRange, ListInitialization)
|
|
: InitializationKind::CreateCast(OpRange);
|
|
Expr *SrcExprRaw = SrcExpr.get();
|
|
InitializationSequence InitSeq(Self, Entity, InitKind, SrcExprRaw);
|
|
|
|
// At this point of CheckStaticCast, if the destination is a reference,
|
|
// or the expression is an overload expression this has to work.
|
|
// There is no other way that works.
|
|
// On the other hand, if we're checking a C-style cast, we've still got
|
|
// the reinterpret_cast way.
|
|
bool CStyle
|
|
= (CCK == Sema::CCK_CStyleCast || CCK == Sema::CCK_FunctionalCast);
|
|
if (InitSeq.Failed() && (CStyle || !DestType->isReferenceType()))
|
|
return TC_NotApplicable;
|
|
|
|
ExprResult Result = InitSeq.Perform(Self, Entity, InitKind, SrcExprRaw);
|
|
if (Result.isInvalid()) {
|
|
msg = 0;
|
|
return TC_Failed;
|
|
}
|
|
|
|
if (InitSeq.isConstructorInitialization())
|
|
Kind = CK_ConstructorConversion;
|
|
else
|
|
Kind = CK_NoOp;
|
|
|
|
SrcExpr = Result;
|
|
return TC_Success;
|
|
}
|
|
|
|
/// TryConstCast - See if a const_cast from source to destination is allowed,
|
|
/// and perform it if it is.
|
|
static TryCastResult TryConstCast(Sema &Self, ExprResult &SrcExpr,
|
|
QualType DestType, bool CStyle,
|
|
unsigned &msg) {
|
|
DestType = Self.Context.getCanonicalType(DestType);
|
|
QualType SrcType = SrcExpr.get()->getType();
|
|
bool NeedToMaterializeTemporary = false;
|
|
|
|
if (const ReferenceType *DestTypeTmp =DestType->getAs<ReferenceType>()) {
|
|
// C++11 5.2.11p4:
|
|
// if a pointer to T1 can be explicitly converted to the type "pointer to
|
|
// T2" using a const_cast, then the following conversions can also be
|
|
// made:
|
|
// -- an lvalue of type T1 can be explicitly converted to an lvalue of
|
|
// type T2 using the cast const_cast<T2&>;
|
|
// -- a glvalue of type T1 can be explicitly converted to an xvalue of
|
|
// type T2 using the cast const_cast<T2&&>; and
|
|
// -- if T1 is a class type, a prvalue of type T1 can be explicitly
|
|
// converted to an xvalue of type T2 using the cast const_cast<T2&&>.
|
|
|
|
if (isa<LValueReferenceType>(DestTypeTmp) && !SrcExpr.get()->isLValue()) {
|
|
// 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;
|
|
}
|
|
|
|
if (isa<RValueReferenceType>(DestTypeTmp) && SrcExpr.get()->isRValue()) {
|
|
if (!SrcType->isRecordType()) {
|
|
// Cannot const_cast non-class prvalue to rvalue reference type. But if
|
|
// this is C-style, static_cast can do this.
|
|
msg = diag::err_bad_cxx_cast_rvalue;
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
// Materialize the class prvalue so that the const_cast can bind a
|
|
// reference to it.
|
|
NeedToMaterializeTemporary = true;
|
|
}
|
|
|
|
// It's not completely clear under the standard whether we can
|
|
// const_cast bit-field gl-values. Doing so would not be
|
|
// intrinsically complicated, but for now, we say no for
|
|
// consistency with other compilers and await the word of the
|
|
// committee.
|
|
if (SrcExpr.get()->refersToBitField()) {
|
|
msg = diag::err_bad_cxx_cast_bitfield;
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
|
|
SrcType = Self.Context.getPointerType(SrcType);
|
|
}
|
|
|
|
// 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() &&
|
|
!DestType->isObjCObjectPointerType()) {
|
|
// 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;
|
|
}
|
|
SrcType = Self.Context.getCanonicalType(SrcType);
|
|
|
|
// Unwrap the pointers. Ignore qualifiers. Terminate early if the types are
|
|
// completely equal.
|
|
// 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.Context.UnwrapSimilarPointerTypes(SrcType, DestType)) {
|
|
Qualifiers SrcQuals, DestQuals;
|
|
SrcType = Self.Context.getUnqualifiedArrayType(SrcType, SrcQuals);
|
|
DestType = Self.Context.getUnqualifiedArrayType(DestType, DestQuals);
|
|
|
|
// const_cast is permitted to strip cvr-qualifiers, only. Make sure that
|
|
// the other qualifiers (e.g., address spaces) are identical.
|
|
SrcQuals.removeCVRQualifiers();
|
|
DestQuals.removeCVRQualifiers();
|
|
if (SrcQuals != DestQuals)
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
// Since we're dealing in canonical types, the remainder must be the same.
|
|
if (SrcType != DestType)
|
|
return TC_NotApplicable;
|
|
|
|
if (NeedToMaterializeTemporary)
|
|
// This is a const_cast from a class prvalue to an rvalue reference type.
|
|
// Materialize a temporary to store the result of the conversion.
|
|
SrcExpr = new (Self.Context) MaterializeTemporaryExpr(
|
|
SrcType, SrcExpr.get(), /*IsLValueReference*/ false);
|
|
|
|
return TC_Success;
|
|
}
|
|
|
|
// Checks for undefined behavior in reinterpret_cast.
|
|
// The cases that is checked for is:
|
|
// *reinterpret_cast<T*>(&a)
|
|
// reinterpret_cast<T&>(a)
|
|
// where accessing 'a' as type 'T' will result in undefined behavior.
|
|
void Sema::CheckCompatibleReinterpretCast(QualType SrcType, QualType DestType,
|
|
bool IsDereference,
|
|
SourceRange Range) {
|
|
unsigned DiagID = IsDereference ?
|
|
diag::warn_pointer_indirection_from_incompatible_type :
|
|
diag::warn_undefined_reinterpret_cast;
|
|
|
|
if (Diags.isIgnored(DiagID, Range.getBegin()))
|
|
return;
|
|
|
|
QualType SrcTy, DestTy;
|
|
if (IsDereference) {
|
|
if (!SrcType->getAs<PointerType>() || !DestType->getAs<PointerType>()) {
|
|
return;
|
|
}
|
|
SrcTy = SrcType->getPointeeType();
|
|
DestTy = DestType->getPointeeType();
|
|
} else {
|
|
if (!DestType->getAs<ReferenceType>()) {
|
|
return;
|
|
}
|
|
SrcTy = SrcType;
|
|
DestTy = DestType->getPointeeType();
|
|
}
|
|
|
|
// Cast is compatible if the types are the same.
|
|
if (Context.hasSameUnqualifiedType(DestTy, SrcTy)) {
|
|
return;
|
|
}
|
|
// or one of the types is a char or void type
|
|
if (DestTy->isAnyCharacterType() || DestTy->isVoidType() ||
|
|
SrcTy->isAnyCharacterType() || SrcTy->isVoidType()) {
|
|
return;
|
|
}
|
|
// or one of the types is a tag type.
|
|
if (SrcTy->getAs<TagType>() || DestTy->getAs<TagType>()) {
|
|
return;
|
|
}
|
|
|
|
// FIXME: Scoped enums?
|
|
if ((SrcTy->isUnsignedIntegerType() && DestTy->isSignedIntegerType()) ||
|
|
(SrcTy->isSignedIntegerType() && DestTy->isUnsignedIntegerType())) {
|
|
if (Context.getTypeSize(DestTy) == Context.getTypeSize(SrcTy)) {
|
|
return;
|
|
}
|
|
}
|
|
|
|
Diag(Range.getBegin(), DiagID) << SrcType << DestType << Range;
|
|
}
|
|
|
|
static void DiagnoseCastOfObjCSEL(Sema &Self, const ExprResult &SrcExpr,
|
|
QualType DestType) {
|
|
QualType SrcType = SrcExpr.get()->getType();
|
|
if (Self.Context.hasSameType(SrcType, DestType))
|
|
return;
|
|
if (const PointerType *SrcPtrTy = SrcType->getAs<PointerType>())
|
|
if (SrcPtrTy->isObjCSelType()) {
|
|
QualType DT = DestType;
|
|
if (isa<PointerType>(DestType))
|
|
DT = DestType->getPointeeType();
|
|
if (!DT.getUnqualifiedType()->isVoidType())
|
|
Self.Diag(SrcExpr.get()->getExprLoc(),
|
|
diag::warn_cast_pointer_from_sel)
|
|
<< SrcType << DestType << SrcExpr.get()->getSourceRange();
|
|
}
|
|
}
|
|
|
|
static void checkIntToPointerCast(bool CStyle, SourceLocation Loc,
|
|
const Expr *SrcExpr, QualType DestType,
|
|
Sema &Self) {
|
|
QualType SrcType = SrcExpr->getType();
|
|
|
|
// Not warning on reinterpret_cast, boolean, constant expressions, etc
|
|
// are not explicit design choices, but consistent with GCC's behavior.
|
|
// Feel free to modify them if you've reason/evidence for an alternative.
|
|
if (CStyle && SrcType->isIntegralType(Self.Context)
|
|
&& !SrcType->isBooleanType()
|
|
&& !SrcType->isEnumeralType()
|
|
&& !SrcExpr->isIntegerConstantExpr(Self.Context)
|
|
&& Self.Context.getTypeSize(DestType) >
|
|
Self.Context.getTypeSize(SrcType)) {
|
|
// Separate between casts to void* and non-void* pointers.
|
|
// Some APIs use (abuse) void* for something like a user context,
|
|
// and often that value is an integer even if it isn't a pointer itself.
|
|
// Having a separate warning flag allows users to control the warning
|
|
// for their workflow.
|
|
unsigned Diag = DestType->isVoidPointerType() ?
|
|
diag::warn_int_to_void_pointer_cast
|
|
: diag::warn_int_to_pointer_cast;
|
|
Self.Diag(Loc, Diag) << SrcType << DestType;
|
|
}
|
|
}
|
|
|
|
static TryCastResult TryReinterpretCast(Sema &Self, ExprResult &SrcExpr,
|
|
QualType DestType, bool CStyle,
|
|
const SourceRange &OpRange,
|
|
unsigned &msg,
|
|
CastKind &Kind) {
|
|
bool IsLValueCast = false;
|
|
|
|
DestType = Self.Context.getCanonicalType(DestType);
|
|
QualType SrcType = SrcExpr.get()->getType();
|
|
|
|
// Is the source an overloaded name? (i.e. &foo)
|
|
// If so, reinterpret_cast can not help us here (13.4, p1, bullet 5) ...
|
|
if (SrcType == Self.Context.OverloadTy) {
|
|
// ... unless foo<int> resolves to an lvalue unambiguously.
|
|
// TODO: what if this fails because of DiagnoseUseOfDecl or something
|
|
// like it?
|
|
ExprResult SingleFunctionExpr = SrcExpr;
|
|
if (Self.ResolveAndFixSingleFunctionTemplateSpecialization(
|
|
SingleFunctionExpr,
|
|
Expr::getValueKindForType(DestType) == VK_RValue // Convert Fun to Ptr
|
|
) && SingleFunctionExpr.isUsable()) {
|
|
SrcExpr = SingleFunctionExpr;
|
|
SrcType = SrcExpr.get()->getType();
|
|
} else {
|
|
return TC_NotApplicable;
|
|
}
|
|
}
|
|
|
|
if (const ReferenceType *DestTypeTmp = DestType->getAs<ReferenceType>()) {
|
|
if (!SrcExpr.get()->isGLValue()) {
|
|
// Cannot cast non-glvalue to (lvalue or rvalue) reference type. See the
|
|
// similar comment in const_cast.
|
|
msg = diag::err_bad_cxx_cast_rvalue;
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
if (!CStyle) {
|
|
Self.CheckCompatibleReinterpretCast(SrcType, DestType,
|
|
/*isDereference=*/false, OpRange);
|
|
}
|
|
|
|
// 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.
|
|
|
|
const char *inappropriate = nullptr;
|
|
switch (SrcExpr.get()->getObjectKind()) {
|
|
case OK_Ordinary:
|
|
break;
|
|
case OK_BitField: inappropriate = "bit-field"; break;
|
|
case OK_VectorComponent: inappropriate = "vector element"; break;
|
|
case OK_ObjCProperty: inappropriate = "property expression"; break;
|
|
case OK_ObjCSubscript: inappropriate = "container subscripting expression";
|
|
break;
|
|
}
|
|
if (inappropriate) {
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_reinterpret_cast_reference)
|
|
<< inappropriate << DestType
|
|
<< OpRange << SrcExpr.get()->getSourceRange();
|
|
msg = 0; SrcExpr = ExprError();
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
// This code does this transformation for the checked types.
|
|
DestType = Self.Context.getPointerType(DestTypeTmp->getPointeeType());
|
|
SrcType = Self.Context.getPointerType(SrcType);
|
|
|
|
IsLValueCast = true;
|
|
}
|
|
|
|
// Canonicalize source for comparison.
|
|
SrcType = Self.Context.getCanonicalType(SrcType);
|
|
|
|
const MemberPointerType *DestMemPtr = DestType->getAs<MemberPointerType>(),
|
|
*SrcMemPtr = SrcType->getAs<MemberPointerType>();
|
|
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 (CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
|
|
/*CheckObjCLifetime=*/CStyle)) {
|
|
msg = diag::err_bad_cxx_cast_qualifiers_away;
|
|
return TC_Failed;
|
|
}
|
|
|
|
if (Self.Context.getTargetInfo().getCXXABI().isMicrosoft()) {
|
|
// We need to determine the inheritance model that the class will use if
|
|
// haven't yet.
|
|
Self.RequireCompleteType(OpRange.getBegin(), SrcType, 0);
|
|
Self.RequireCompleteType(OpRange.getBegin(), DestType, 0);
|
|
}
|
|
|
|
// Don't allow casting between member pointers of different sizes.
|
|
if (Self.Context.getTypeSize(DestMemPtr) !=
|
|
Self.Context.getTypeSize(SrcMemPtr)) {
|
|
msg = diag::err_bad_cxx_cast_member_pointer_size;
|
|
return TC_Failed;
|
|
}
|
|
|
|
// A valid member pointer cast.
|
|
assert(!IsLValueCast);
|
|
Kind = CK_ReinterpretMemberPointer;
|
|
return TC_Success;
|
|
}
|
|
|
|
// See below for the enumeral issue.
|
|
if (SrcType->isNullPtrType() && DestType->isIntegralType(Self.Context)) {
|
|
// 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;
|
|
}
|
|
Kind = CK_PointerToIntegral;
|
|
return TC_Success;
|
|
}
|
|
|
|
bool destIsVector = DestType->isVectorType();
|
|
bool srcIsVector = SrcType->isVectorType();
|
|
if (srcIsVector || destIsVector) {
|
|
// FIXME: Should this also apply to floating point types?
|
|
bool srcIsScalar = SrcType->isIntegralType(Self.Context);
|
|
bool destIsScalar = DestType->isIntegralType(Self.Context);
|
|
|
|
// 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)) {
|
|
Kind = CK_BitCast;
|
|
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;
|
|
}
|
|
|
|
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 so long as it does not
|
|
// cast away constness. In C++98, the intent was not entirely clear here,
|
|
// since all other paragraphs explicitly forbid casts to the same type.
|
|
// C++11 clarifies this case with p2.
|
|
//
|
|
// The only allowed types are: integral, enumeration, pointer, or
|
|
// pointer-to-member types. We also won't restrict Obj-C pointers either.
|
|
Kind = CK_NoOp;
|
|
TryCastResult Result = TC_NotApplicable;
|
|
if (SrcType->isIntegralOrEnumerationType() ||
|
|
SrcType->isAnyPointerType() ||
|
|
SrcType->isMemberPointerType() ||
|
|
SrcType->isBlockPointerType()) {
|
|
Result = TC_Success;
|
|
}
|
|
return Result;
|
|
}
|
|
|
|
bool destIsPtr = DestType->isAnyPointerType() ||
|
|
DestType->isBlockPointerType();
|
|
bool srcIsPtr = SrcType->isAnyPointerType() ||
|
|
SrcType->isBlockPointerType();
|
|
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;
|
|
}
|
|
|
|
if (DestType->isIntegralType(Self.Context)) {
|
|
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; except in Microsoft mode, where the
|
|
// integral type size doesn't matter (except we don't allow bool).
|
|
bool MicrosoftException = Self.getLangOpts().MicrosoftExt &&
|
|
!DestType->isBooleanType();
|
|
if ((Self.Context.getTypeSize(SrcType) >
|
|
Self.Context.getTypeSize(DestType)) &&
|
|
!MicrosoftException) {
|
|
msg = diag::err_bad_reinterpret_cast_small_int;
|
|
return TC_Failed;
|
|
}
|
|
Kind = CK_PointerToIntegral;
|
|
return TC_Success;
|
|
}
|
|
|
|
if (SrcType->isIntegralOrEnumerationType()) {
|
|
assert(destIsPtr && "One type must be a pointer");
|
|
checkIntToPointerCast(CStyle, OpRange.getBegin(), SrcExpr.get(), DestType,
|
|
Self);
|
|
// C++ 5.2.10p5: A value of integral or enumeration type can be explicitly
|
|
// converted to a pointer.
|
|
// C++ 5.2.10p9: [Note: ...a null pointer constant of integral type is not
|
|
// necessarily converted to a null pointer value.]
|
|
Kind = CK_IntegralToPointer;
|
|
return TC_Success;
|
|
}
|
|
|
|
if (!destIsPtr || !srcIsPtr) {
|
|
// With the valid non-pointer conversions out of the way, we can be even
|
|
// more stringent.
|
|
return TC_NotApplicable;
|
|
}
|
|
|
|
// C++ 5.2.10p2: The reinterpret_cast operator shall not cast away constness.
|
|
// The C-style cast operator can.
|
|
if (CastsAwayConstness(Self, SrcType, DestType, /*CheckCVR=*/!CStyle,
|
|
/*CheckObjCLifetime=*/CStyle)) {
|
|
msg = diag::err_bad_cxx_cast_qualifiers_away;
|
|
return TC_Failed;
|
|
}
|
|
|
|
// Cannot convert between block pointers and Objective-C object pointers.
|
|
if ((SrcType->isBlockPointerType() && DestType->isObjCObjectPointerType()) ||
|
|
(DestType->isBlockPointerType() && SrcType->isObjCObjectPointerType()))
|
|
return TC_NotApplicable;
|
|
|
|
if (IsLValueCast) {
|
|
Kind = CK_LValueBitCast;
|
|
} else if (DestType->isObjCObjectPointerType()) {
|
|
Kind = Self.PrepareCastToObjCObjectPointer(SrcExpr);
|
|
} else if (DestType->isBlockPointerType()) {
|
|
if (!SrcType->isBlockPointerType()) {
|
|
Kind = CK_AnyPointerToBlockPointerCast;
|
|
} else {
|
|
Kind = CK_BitCast;
|
|
}
|
|
} else {
|
|
Kind = CK_BitCast;
|
|
}
|
|
|
|
// Any pointer can be cast to an Objective-C pointer type with a C-style
|
|
// cast.
|
|
if (CStyle && DestType->isObjCObjectPointerType()) {
|
|
return TC_Success;
|
|
}
|
|
if (CStyle)
|
|
DiagnoseCastOfObjCSEL(Self, SrcExpr, DestType);
|
|
|
|
// 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 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.
|
|
Self.Diag(OpRange.getBegin(),
|
|
Self.getLangOpts().CPlusPlus11 ?
|
|
diag::warn_cxx98_compat_cast_fn_obj : diag::ext_cast_fn_obj)
|
|
<< OpRange;
|
|
return TC_Success;
|
|
}
|
|
|
|
if (DestType->isFunctionPointerType()) {
|
|
// See above.
|
|
Self.Diag(OpRange.getBegin(),
|
|
Self.getLangOpts().CPlusPlus11 ?
|
|
diag::warn_cxx98_compat_cast_fn_obj : 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.
|
|
return TC_Success;
|
|
}
|
|
|
|
void CastOperation::CheckCXXCStyleCast(bool FunctionalStyle,
|
|
bool ListInitialization) {
|
|
// Handle placeholders.
|
|
if (isPlaceholder()) {
|
|
// C-style casts can resolve __unknown_any types.
|
|
if (claimPlaceholder(BuiltinType::UnknownAny)) {
|
|
SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
|
|
SrcExpr.get(), Kind,
|
|
ValueKind, BasePath);
|
|
return;
|
|
}
|
|
|
|
checkNonOverloadPlaceholders();
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
}
|
|
|
|
// C++ 5.2.9p4: Any expression can be explicitly converted to type "cv void".
|
|
// This test is outside everything else because it's the only case where
|
|
// a non-lvalue-reference target type does not lead to decay.
|
|
if (DestType->isVoidType()) {
|
|
Kind = CK_ToVoid;
|
|
|
|
if (claimPlaceholder(BuiltinType::Overload)) {
|
|
Self.ResolveAndFixSingleFunctionTemplateSpecialization(
|
|
SrcExpr, /* Decay Function to ptr */ false,
|
|
/* Complain */ true, DestRange, DestType,
|
|
diag::err_bad_cstyle_cast_overload);
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
}
|
|
|
|
SrcExpr = Self.IgnoredValueConversions(SrcExpr.get());
|
|
return;
|
|
}
|
|
|
|
// If the type is dependent, we won't do any other semantic analysis now.
|
|
if (DestType->isDependentType() || SrcExpr.get()->isTypeDependent() ||
|
|
SrcExpr.get()->isValueDependent()) {
|
|
assert(Kind == CK_Dependent);
|
|
return;
|
|
}
|
|
|
|
if (ValueKind == VK_RValue && !DestType->isRecordType() &&
|
|
!isPlaceholder(BuiltinType::Overload)) {
|
|
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
}
|
|
|
|
// AltiVec vector initialization with a single literal.
|
|
if (const VectorType *vecTy = DestType->getAs<VectorType>())
|
|
if (vecTy->getVectorKind() == VectorType::AltiVecVector
|
|
&& (SrcExpr.get()->getType()->isIntegerType()
|
|
|| SrcExpr.get()->getType()->isFloatingType())) {
|
|
Kind = CK_VectorSplat;
|
|
return;
|
|
}
|
|
|
|
// 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;
|
|
TryCastResult tcr = TryConstCast(Self, SrcExpr, DestType,
|
|
/*CStyle*/true, msg);
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
if (tcr == TC_Success)
|
|
Kind = CK_NoOp;
|
|
|
|
Sema::CheckedConversionKind CCK
|
|
= FunctionalStyle? Sema::CCK_FunctionalCast
|
|
: Sema::CCK_CStyleCast;
|
|
if (tcr == TC_NotApplicable) {
|
|
// ... or if that is not possible, a static_cast, ignoring const, ...
|
|
tcr = TryStaticCast(Self, SrcExpr, DestType, CCK, OpRange,
|
|
msg, Kind, BasePath, ListInitialization);
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
|
|
if (tcr == TC_NotApplicable) {
|
|
// ... and finally a reinterpret_cast, ignoring const.
|
|
tcr = TryReinterpretCast(Self, SrcExpr, DestType, /*CStyle*/true,
|
|
OpRange, msg, Kind);
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (Self.getLangOpts().ObjCAutoRefCount && tcr == TC_Success)
|
|
checkObjCARCConversion(CCK);
|
|
|
|
if (tcr != TC_Success && msg != 0) {
|
|
if (SrcExpr.get()->getType() == Self.Context.OverloadTy) {
|
|
DeclAccessPair Found;
|
|
FunctionDecl *Fn = Self.ResolveAddressOfOverloadedFunction(SrcExpr.get(),
|
|
DestType,
|
|
/*Complain*/ true,
|
|
Found);
|
|
if (Fn) {
|
|
// If DestType is a function type (not to be confused with the function
|
|
// pointer type), it will be possible to resolve the function address,
|
|
// but the type cast should be considered as failure.
|
|
OverloadExpr *OE = OverloadExpr::find(SrcExpr.get()).Expression;
|
|
Self.Diag(OpRange.getBegin(), diag::err_bad_cstyle_cast_overload)
|
|
<< OE->getName() << DestType << OpRange
|
|
<< OE->getQualifierLoc().getSourceRange();
|
|
Self.NoteAllOverloadCandidates(SrcExpr.get());
|
|
}
|
|
} else {
|
|
diagnoseBadCast(Self, msg, (FunctionalStyle ? CT_Functional : CT_CStyle),
|
|
OpRange, SrcExpr.get(), DestType, ListInitialization);
|
|
}
|
|
} else if (Kind == CK_BitCast) {
|
|
checkCastAlign();
|
|
}
|
|
|
|
// Clear out SrcExpr if there was a fatal error.
|
|
if (tcr != TC_Success)
|
|
SrcExpr = ExprError();
|
|
}
|
|
|
|
/// DiagnoseBadFunctionCast - Warn whenever a function call is cast to a
|
|
/// non-matching type. Such as enum function call to int, int call to
|
|
/// pointer; etc. Cast to 'void' is an exception.
|
|
static void DiagnoseBadFunctionCast(Sema &Self, const ExprResult &SrcExpr,
|
|
QualType DestType) {
|
|
if (Self.Diags.isIgnored(diag::warn_bad_function_cast,
|
|
SrcExpr.get()->getExprLoc()))
|
|
return;
|
|
|
|
if (!isa<CallExpr>(SrcExpr.get()))
|
|
return;
|
|
|
|
QualType SrcType = SrcExpr.get()->getType();
|
|
if (DestType.getUnqualifiedType()->isVoidType())
|
|
return;
|
|
if ((SrcType->isAnyPointerType() || SrcType->isBlockPointerType())
|
|
&& (DestType->isAnyPointerType() || DestType->isBlockPointerType()))
|
|
return;
|
|
if (SrcType->isIntegerType() && DestType->isIntegerType() &&
|
|
(SrcType->isBooleanType() == DestType->isBooleanType()) &&
|
|
(SrcType->isEnumeralType() == DestType->isEnumeralType()))
|
|
return;
|
|
if (SrcType->isRealFloatingType() && DestType->isRealFloatingType())
|
|
return;
|
|
if (SrcType->isEnumeralType() && DestType->isEnumeralType())
|
|
return;
|
|
if (SrcType->isComplexType() && DestType->isComplexType())
|
|
return;
|
|
if (SrcType->isComplexIntegerType() && DestType->isComplexIntegerType())
|
|
return;
|
|
|
|
Self.Diag(SrcExpr.get()->getExprLoc(),
|
|
diag::warn_bad_function_cast)
|
|
<< SrcType << DestType << SrcExpr.get()->getSourceRange();
|
|
}
|
|
|
|
/// Check the semantics of a C-style cast operation, in C.
|
|
void CastOperation::CheckCStyleCast() {
|
|
assert(!Self.getLangOpts().CPlusPlus);
|
|
|
|
// C-style casts can resolve __unknown_any types.
|
|
if (claimPlaceholder(BuiltinType::UnknownAny)) {
|
|
SrcExpr = Self.checkUnknownAnyCast(DestRange, DestType,
|
|
SrcExpr.get(), Kind,
|
|
ValueKind, BasePath);
|
|
return;
|
|
}
|
|
|
|
// C99 6.5.4p2: the cast type needs to be void or scalar and the expression
|
|
// type needs to be scalar.
|
|
if (DestType->isVoidType()) {
|
|
// We don't necessarily do lvalue-to-rvalue conversions on this.
|
|
SrcExpr = Self.IgnoredValueConversions(SrcExpr.get());
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
|
|
// Cast to void allows any expr type.
|
|
Kind = CK_ToVoid;
|
|
return;
|
|
}
|
|
|
|
SrcExpr = Self.DefaultFunctionArrayLvalueConversion(SrcExpr.get());
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
QualType SrcType = SrcExpr.get()->getType();
|
|
|
|
assert(!SrcType->isPlaceholderType());
|
|
|
|
// OpenCL v1 s6.5: Casting a pointer to address space A to a pointer to
|
|
// address space B is illegal.
|
|
if (Self.getLangOpts().OpenCL && DestType->isPointerType() &&
|
|
SrcType->isPointerType()) {
|
|
const PointerType *DestPtr = DestType->getAs<PointerType>();
|
|
if (!DestPtr->isAddressSpaceOverlapping(*SrcType->getAs<PointerType>())) {
|
|
Self.Diag(OpRange.getBegin(),
|
|
diag::err_typecheck_incompatible_address_space)
|
|
<< SrcType << DestType << Sema::AA_Casting
|
|
<< SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (Self.RequireCompleteType(OpRange.getBegin(), DestType,
|
|
diag::err_typecheck_cast_to_incomplete)) {
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
if (!DestType->isScalarType() && !DestType->isVectorType()) {
|
|
const RecordType *DestRecordTy = DestType->getAs<RecordType>();
|
|
|
|
if (DestRecordTy && Self.Context.hasSameUnqualifiedType(DestType, SrcType)){
|
|
// GCC struct/union extension: allow cast to self.
|
|
Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_nonscalar)
|
|
<< DestType << SrcExpr.get()->getSourceRange();
|
|
Kind = CK_NoOp;
|
|
return;
|
|
}
|
|
|
|
// GCC's cast to union extension.
|
|
if (DestRecordTy && DestRecordTy->getDecl()->isUnion()) {
|
|
RecordDecl *RD = DestRecordTy->getDecl();
|
|
RecordDecl::field_iterator Field, FieldEnd;
|
|
for (Field = RD->field_begin(), FieldEnd = RD->field_end();
|
|
Field != FieldEnd; ++Field) {
|
|
if (Self.Context.hasSameUnqualifiedType(Field->getType(), SrcType) &&
|
|
!Field->isUnnamedBitfield()) {
|
|
Self.Diag(OpRange.getBegin(), diag::ext_typecheck_cast_to_union)
|
|
<< SrcExpr.get()->getSourceRange();
|
|
break;
|
|
}
|
|
}
|
|
if (Field == FieldEnd) {
|
|
Self.Diag(OpRange.getBegin(), diag::err_typecheck_cast_to_union_no_type)
|
|
<< SrcType << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
Kind = CK_ToUnion;
|
|
return;
|
|
}
|
|
|
|
// Reject any other conversions to non-scalar types.
|
|
Self.Diag(OpRange.getBegin(), diag::err_typecheck_cond_expect_scalar)
|
|
<< DestType << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
// The type we're casting to is known to be a scalar or vector.
|
|
|
|
// Require the operand to be a scalar or vector.
|
|
if (!SrcType->isScalarType() && !SrcType->isVectorType()) {
|
|
Self.Diag(SrcExpr.get()->getExprLoc(),
|
|
diag::err_typecheck_expect_scalar_operand)
|
|
<< SrcType << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
if (DestType->isExtVectorType()) {
|
|
SrcExpr = Self.CheckExtVectorCast(OpRange, DestType, SrcExpr.get(), Kind);
|
|
return;
|
|
}
|
|
|
|
if (const VectorType *DestVecTy = DestType->getAs<VectorType>()) {
|
|
if (DestVecTy->getVectorKind() == VectorType::AltiVecVector &&
|
|
(SrcType->isIntegerType() || SrcType->isFloatingType())) {
|
|
Kind = CK_VectorSplat;
|
|
} else if (Self.CheckVectorCast(OpRange, DestType, SrcType, Kind)) {
|
|
SrcExpr = ExprError();
|
|
}
|
|
return;
|
|
}
|
|
|
|
if (SrcType->isVectorType()) {
|
|
if (Self.CheckVectorCast(OpRange, SrcType, DestType, Kind))
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
// The source and target types are both scalars, i.e.
|
|
// - arithmetic types (fundamental, enum, and complex)
|
|
// - all kinds of pointers
|
|
// Note that member pointers were filtered out with C++, above.
|
|
|
|
if (isa<ObjCSelectorExpr>(SrcExpr.get())) {
|
|
Self.Diag(SrcExpr.get()->getExprLoc(), diag::err_cast_selector_expr);
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
|
|
// If either type is a pointer, the other type has to be either an
|
|
// integer or a pointer.
|
|
if (!DestType->isArithmeticType()) {
|
|
if (!SrcType->isIntegralType(Self.Context) && SrcType->isArithmeticType()) {
|
|
Self.Diag(SrcExpr.get()->getExprLoc(),
|
|
diag::err_cast_pointer_from_non_pointer_int)
|
|
<< SrcType << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
checkIntToPointerCast(/* CStyle */ true, OpRange.getBegin(), SrcExpr.get(),
|
|
DestType, Self);
|
|
} else if (!SrcType->isArithmeticType()) {
|
|
if (!DestType->isIntegralType(Self.Context) &&
|
|
DestType->isArithmeticType()) {
|
|
Self.Diag(SrcExpr.get()->getLocStart(),
|
|
diag::err_cast_pointer_to_non_pointer_int)
|
|
<< DestType << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
}
|
|
|
|
if (Self.getLangOpts().OpenCL && !Self.getOpenCLOptions().cl_khr_fp16) {
|
|
if (DestType->isHalfType()) {
|
|
Self.Diag(SrcExpr.get()->getLocStart(), diag::err_opencl_cast_to_half)
|
|
<< DestType << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
}
|
|
|
|
// ARC imposes extra restrictions on casts.
|
|
if (Self.getLangOpts().ObjCAutoRefCount) {
|
|
checkObjCARCConversion(Sema::CCK_CStyleCast);
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
|
|
if (const PointerType *CastPtr = DestType->getAs<PointerType>()) {
|
|
if (const PointerType *ExprPtr = SrcType->getAs<PointerType>()) {
|
|
Qualifiers CastQuals = CastPtr->getPointeeType().getQualifiers();
|
|
Qualifiers ExprQuals = ExprPtr->getPointeeType().getQualifiers();
|
|
if (CastPtr->getPointeeType()->isObjCLifetimeType() &&
|
|
ExprPtr->getPointeeType()->isObjCLifetimeType() &&
|
|
!CastQuals.compatiblyIncludesObjCLifetime(ExprQuals)) {
|
|
Self.Diag(SrcExpr.get()->getLocStart(),
|
|
diag::err_typecheck_incompatible_ownership)
|
|
<< SrcType << DestType << Sema::AA_Casting
|
|
<< SrcExpr.get()->getSourceRange();
|
|
return;
|
|
}
|
|
}
|
|
}
|
|
else if (!Self.CheckObjCARCUnavailableWeakConversion(DestType, SrcType)) {
|
|
Self.Diag(SrcExpr.get()->getLocStart(),
|
|
diag::err_arc_convesion_of_weak_unavailable)
|
|
<< 1 << SrcType << DestType << SrcExpr.get()->getSourceRange();
|
|
SrcExpr = ExprError();
|
|
return;
|
|
}
|
|
}
|
|
|
|
DiagnoseCastOfObjCSEL(Self, SrcExpr, DestType);
|
|
DiagnoseBadFunctionCast(Self, SrcExpr, DestType);
|
|
Kind = Self.PrepareScalarCast(SrcExpr, DestType);
|
|
if (SrcExpr.isInvalid())
|
|
return;
|
|
|
|
if (Kind == CK_BitCast)
|
|
checkCastAlign();
|
|
|
|
// -Wcast-qual
|
|
QualType TheOffendingSrcType, TheOffendingDestType;
|
|
Qualifiers CastAwayQualifiers;
|
|
if (SrcType->isAnyPointerType() && DestType->isAnyPointerType() &&
|
|
CastsAwayConstness(Self, SrcType, DestType, true, false,
|
|
&TheOffendingSrcType, &TheOffendingDestType,
|
|
&CastAwayQualifiers)) {
|
|
int qualifiers = -1;
|
|
if (CastAwayQualifiers.hasConst() && CastAwayQualifiers.hasVolatile()) {
|
|
qualifiers = 0;
|
|
} else if (CastAwayQualifiers.hasConst()) {
|
|
qualifiers = 1;
|
|
} else if (CastAwayQualifiers.hasVolatile()) {
|
|
qualifiers = 2;
|
|
}
|
|
// This is a variant of int **x; const int **y = (const int **)x;
|
|
if (qualifiers == -1)
|
|
Self.Diag(SrcExpr.get()->getLocStart(), diag::warn_cast_qual2) <<
|
|
SrcType << DestType;
|
|
else
|
|
Self.Diag(SrcExpr.get()->getLocStart(), diag::warn_cast_qual) <<
|
|
TheOffendingSrcType << TheOffendingDestType << qualifiers;
|
|
}
|
|
}
|
|
|
|
ExprResult Sema::BuildCStyleCastExpr(SourceLocation LPLoc,
|
|
TypeSourceInfo *CastTypeInfo,
|
|
SourceLocation RPLoc,
|
|
Expr *CastExpr) {
|
|
CastOperation Op(*this, CastTypeInfo->getType(), CastExpr);
|
|
Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
|
|
Op.OpRange = SourceRange(LPLoc, CastExpr->getLocEnd());
|
|
|
|
if (getLangOpts().CPlusPlus) {
|
|
Op.CheckCXXCStyleCast(/*FunctionalStyle=*/ false,
|
|
isa<InitListExpr>(CastExpr));
|
|
} else {
|
|
Op.CheckCStyleCast();
|
|
}
|
|
|
|
if (Op.SrcExpr.isInvalid())
|
|
return ExprError();
|
|
|
|
return Op.complete(CStyleCastExpr::Create(Context, Op.ResultType,
|
|
Op.ValueKind, Op.Kind, Op.SrcExpr.get(),
|
|
&Op.BasePath, CastTypeInfo, LPLoc, RPLoc));
|
|
}
|
|
|
|
ExprResult Sema::BuildCXXFunctionalCastExpr(TypeSourceInfo *CastTypeInfo,
|
|
SourceLocation LPLoc,
|
|
Expr *CastExpr,
|
|
SourceLocation RPLoc) {
|
|
assert(LPLoc.isValid() && "List-initialization shouldn't get here.");
|
|
CastOperation Op(*this, CastTypeInfo->getType(), CastExpr);
|
|
Op.DestRange = CastTypeInfo->getTypeLoc().getSourceRange();
|
|
Op.OpRange = SourceRange(Op.DestRange.getBegin(), CastExpr->getLocEnd());
|
|
|
|
Op.CheckCXXCStyleCast(/*FunctionalStyle=*/true, /*ListInit=*/false);
|
|
if (Op.SrcExpr.isInvalid())
|
|
return ExprError();
|
|
|
|
if (CXXConstructExpr *ConstructExpr = dyn_cast<CXXConstructExpr>(Op.SrcExpr.get()))
|
|
ConstructExpr->setParenOrBraceRange(SourceRange(LPLoc, RPLoc));
|
|
|
|
return Op.complete(CXXFunctionalCastExpr::Create(Context, Op.ResultType,
|
|
Op.ValueKind, CastTypeInfo, Op.Kind,
|
|
Op.SrcExpr.get(), &Op.BasePath, LPLoc, RPLoc));
|
|
}
|