clang-1/lib/AST/MicrosoftCXXABI.cpp

72 строки
2.1 KiB
C++

//===------- MicrosoftCXXABI.cpp - AST support for the Microsoft C++ ABI --===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This provides C++ AST support targeting the Microsoft Visual C++
// ABI.
//
//===----------------------------------------------------------------------===//
#include "CXXABI.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/Type.h"
#include "clang/Basic/TargetInfo.h"
using namespace clang;
namespace {
class MicrosoftCXXABI : public CXXABI {
ASTContext &Context;
public:
MicrosoftCXXABI(ASTContext &Ctx) : Context(Ctx) { }
unsigned getMemberPointerSize(const MemberPointerType *MPT) const;
CallingConv getDefaultMethodCallConv(bool isVariadic) const {
if (!isVariadic && Context.getTargetInfo().getTriple().getArch() == llvm::Triple::x86)
return CC_X86ThisCall;
else
return CC_C;
}
bool isNearlyEmpty(const CXXRecordDecl *RD) const {
// FIXME: Audit the corners
if (!RD->isDynamicClass())
return false;
const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
// In the Microsoft ABI, classes can have one or two vtable pointers.
CharUnits PointerSize =
Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0));
return Layout.getNonVirtualSize() == PointerSize ||
Layout.getNonVirtualSize() == PointerSize * 2;
}
};
}
unsigned MicrosoftCXXABI::getMemberPointerSize(const MemberPointerType *MPT) const {
QualType Pointee = MPT->getPointeeType();
CXXRecordDecl *RD = MPT->getClass()->getAsCXXRecordDecl();
if (RD->getNumVBases() > 0) {
if (Pointee->isFunctionType())
return 3;
else
return 2;
} else if (RD->getNumBases() > 1 && Pointee->isFunctionType())
return 2;
return 1;
}
CXXABI *clang::CreateMicrosoftCXXABI(ASTContext &Ctx) {
return new MicrosoftCXXABI(Ctx);
}