Files
clang-p2996/clang/lib/AST/ItaniumCXXABI.cpp
Rafael Espindola 3497069784 Switch to the new MingW ABI.
GCC 4.7 changed the MingW ABI. On the clang side this means that methods now
have the thiscall calling convention by default.

llvm-svn: 197164
2013-12-12 16:07:11 +00:00

101 lines
3.2 KiB
C++

//===------- ItaniumCXXABI.cpp - AST support for the Itanium 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 Itanium C++ ABI, which is
// documented at:
// http://www.codesourcery.com/public/cxx-abi/abi.html
// http://www.codesourcery.com/public/cxx-abi/abi-eh.html
//
// It also supports the closely-related ARM C++ ABI, documented at:
// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0041c/IHI0041C_cppabi.pdf
//
//===----------------------------------------------------------------------===//
#include "CXXABI.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/DeclCXX.h"
#include "clang/AST/MangleNumberingContext.h"
#include "clang/AST/RecordLayout.h"
#include "clang/AST/Type.h"
#include "clang/Basic/TargetInfo.h"
using namespace clang;
namespace {
/// \brief Keeps track of the mangled names of lambda expressions and block
/// literals within a particular context.
class ItaniumNumberingContext : public MangleNumberingContext {
llvm::DenseMap<IdentifierInfo*, unsigned> VarManglingNumbers;
public:
/// Variable decls are numbered by identifier.
virtual unsigned getManglingNumber(const VarDecl *VD) {
return ++VarManglingNumbers[VD->getIdentifier()];
}
};
class ItaniumCXXABI : public CXXABI {
protected:
ASTContext &Context;
public:
ItaniumCXXABI(ASTContext &Ctx) : Context(Ctx) { }
std::pair<uint64_t, unsigned>
getMemberPointerWidthAndAlign(const MemberPointerType *MPT) const {
const TargetInfo &Target = Context.getTargetInfo();
TargetInfo::IntType PtrDiff = Target.getPtrDiffType(0);
uint64_t Width = Target.getTypeWidth(PtrDiff);
unsigned Align = Target.getTypeAlign(PtrDiff);
if (MPT->getPointeeType()->isFunctionType())
Width = 2 * Width;
return std::make_pair(Width, Align);
}
CallingConv getDefaultMethodCallConv(bool isVariadic) const {
const llvm::Triple &T = Context.getTargetInfo().getTriple();
if (!isVariadic && T.getOS() == llvm::Triple::MinGW32 &&
T.getArch() == llvm::Triple::x86)
return CC_X86ThisCall;
return CC_C;
}
// We cheat and just check that the class has a vtable pointer, and that it's
// only big enough to have a vtable pointer and nothing more (or less).
bool isNearlyEmpty(const CXXRecordDecl *RD) const {
// Check that the class has a vtable pointer.
if (!RD->isDynamicClass())
return false;
const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD);
CharUnits PointerSize =
Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0));
return Layout.getNonVirtualSize() == PointerSize;
}
virtual MangleNumberingContext *createMangleNumberingContext() const {
return new ItaniumNumberingContext();
}
};
class ARMCXXABI : public ItaniumCXXABI {
public:
ARMCXXABI(ASTContext &Ctx) : ItaniumCXXABI(Ctx) { }
};
}
CXXABI *clang::CreateItaniumCXXABI(ASTContext &Ctx) {
return new ItaniumCXXABI(Ctx);
}
CXXABI *clang::CreateARMCXXABI(ASTContext &Ctx) {
return new ARMCXXABI(Ctx);
}