path: root/lib/Sema/SemaCXXCast.cpp

//===--- SemaNamedCast.cpp - Semantic Analysis for Named Casts ------------===//
//
//                     The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
//  This file implements semantic analysis for C++ named casts.
//
//===----------------------------------------------------------------------===//

#include "Sema.h"
#include "clang/AST/ExprCXX.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/CXXInheritance.h"
#include "clang/Basic/PartialDiagnostic.h"
#include "llvm/ADT/SmallVector.h"
#include <set>
using namespace clang;

enum TryCastResult {
  TC_NotApplicable, ///< The cast method is not applicable.
  TC_Success,       ///< The cast method is appropriate and successful.
  TC_Failed         ///< The cast method is appropriate, but failed. A
                    ///< diagnostic has been emitted.
};

enum CastType {
  CT_Const,       ///< const_cast
  CT_Static,      ///< static_cast
  CT_Reinterpret, ///< reinterpret_cast
  CT_Dynamic,     ///< dynamic_cast
  CT_CStyle,      ///< (Type)expr
  CT_Functional   ///< Type(expr)
};

static void CheckConstCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
                           const SourceRange &OpRange,
                           const SourceRange &DestRange);
static void CheckReinterpretCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
                                 const SourceRange &OpRange,
                                 const SourceRange &DestRange,
                                 CastExpr::CastKind &Kind);
static void CheckStaticCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
                            const SourceRange &OpRange,
                            CastExpr::CastKind &Kind,
                            CXXMethodDecl *&ConversionDecl);
static void CheckDynamicCast(Sema &Self, Expr *&SrcExpr, QualType DestType,
                             const SourceRange &OpRange,
                             const SourceRange &DestRange,
                             CastExpr::CastKind &Kind);

static bool CastsAwayConstness(Sema &Self, QualType SrcType, QualType DestType);

// The Try functions attempt a specific way of casting. If they succeed, they
// return TC_Success. If their way of casting is not appropriate for the given
// arguments, they return TC_NotApplicable and *may* set diag to a diagnostic
// to emit if no other way succeeds. If their way of casting is appropriate but
// fails, they return TC_Failed and *must* set diag; they can set it to 0 if
// they emit a specialized diagnostic.
// All diagnostics returned by these functions must expect the same three
// arguments:
// %0: Cast Type (a value from the CastType enumeration)
// %1: Source Type
// %2: Destination Type
static TryCastResult TryLValueToRValueCast(Sema &Self, Expr *SrcExpr,
                                           QualType DestType, unsigned &msg);
static TryCastResult TryStaticReferenceDowncast(Sema &Self, Expr *SrcExpr,
                                                QualType DestType, bool CStyle,
                                                const SourceRange &OpRange,
                                                unsigned &msg,
                                                CastExpr::CastKind &Kind);
static TryCastResult TryStaticPointerDowncast(Sema &Self, QualType SrcType,
                                              QualType DestType, bool CStyle,
                                              const SourceRange &OpRange,
                                              unsigned &msg,
                                              CastExpr::CastKind &Kind);
static TryCastResult TryStaticDowncast(Sema &Self, CanQualType SrcType,
                                       CanQualType DestType, bool CStyle,
                                       const SourceRange &OpRange,
                                       QualType OrigSrcType,
                                       QualType OrigDestType, unsigned &msg,
                                       CastExpr::CastKind &Kind);
static TryCastResult TryStaticMemberPointerUpcast