1212795Sdim//===------- ItaniumCXXABI.cpp - AST support for the Itanium C++ ABI ------===// 2212795Sdim// 3212795Sdim// The LLVM Compiler Infrastructure 4212795Sdim// 5212795Sdim// This file is distributed under the University of Illinois Open Source 6212795Sdim// License. See LICENSE.TXT for details. 7212795Sdim// 8212795Sdim//===----------------------------------------------------------------------===// 9212795Sdim// 10221345Sdim// This provides C++ AST support targeting the Itanium C++ ABI, which is 11212795Sdim// documented at: 12212795Sdim// http://www.codesourcery.com/public/cxx-abi/abi.html 13212795Sdim// http://www.codesourcery.com/public/cxx-abi/abi-eh.html 14212795Sdim// 15212795Sdim// It also supports the closely-related ARM C++ ABI, documented at: 16212795Sdim// http://infocenter.arm.com/help/topic/com.arm.doc.ihi0041c/IHI0041C_cppabi.pdf 17212795Sdim// 18212795Sdim//===----------------------------------------------------------------------===// 19212795Sdim 20212795Sdim#include "CXXABI.h" 21212795Sdim#include "clang/AST/ASTContext.h" 22249423Sdim#include "clang/AST/DeclCXX.h" 23218893Sdim#include "clang/AST/RecordLayout.h" 24212795Sdim#include "clang/AST/Type.h" 25218893Sdim#include "clang/Basic/TargetInfo.h" 26212795Sdim 27212795Sdimusing namespace clang; 28212795Sdim 29212795Sdimnamespace { 30212795Sdimclass ItaniumCXXABI : public CXXABI { 31212795Sdimprotected: 32212795Sdim ASTContext &Context; 33212795Sdimpublic: 34212795Sdim ItaniumCXXABI(ASTContext &Ctx) : Context(Ctx) { } 35212795Sdim 36249423Sdim std::pair<uint64_t, unsigned> 37249423Sdim getMemberPointerWidthAndAlign(const MemberPointerType *MPT) const { 38249423Sdim const TargetInfo &Target = Context.getTargetInfo(); 39249423Sdim TargetInfo::IntType PtrDiff = Target.getPtrDiffType(0); 40249423Sdim uint64_t Width = Target.getTypeWidth(PtrDiff); 41249423Sdim unsigned Align = Target.getTypeAlign(PtrDiff); 42249423Sdim if (MPT->getPointeeType()->isFunctionType()) 43249423Sdim Width = 2 * Width; 44249423Sdim return std::make_pair(Width, Align); 45212795Sdim } 46218893Sdim 47239462Sdim CallingConv getDefaultMethodCallConv(bool isVariadic) const { 48218893Sdim return CC_C; 49218893Sdim } 50218893Sdim 51218893Sdim // We cheat and just check that the class has a vtable pointer, and that it's 52218893Sdim // only big enough to have a vtable pointer and nothing more (or less). 53218893Sdim bool isNearlyEmpty(const CXXRecordDecl *RD) const { 54218893Sdim 55218893Sdim // Check that the class has a vtable pointer. 56218893Sdim if (!RD->isDynamicClass()) 57218893Sdim return false; 58218893Sdim 59218893Sdim const ASTRecordLayout &Layout = Context.getASTRecordLayout(RD); 60218893Sdim CharUnits PointerSize = 61226633Sdim Context.toCharUnitsFromBits(Context.getTargetInfo().getPointerWidth(0)); 62218893Sdim return Layout.getNonVirtualSize() == PointerSize; 63218893Sdim } 64212795Sdim}; 65212795Sdim 66212795Sdimclass ARMCXXABI : public ItaniumCXXABI { 67212795Sdimpublic: 68212795Sdim ARMCXXABI(ASTContext &Ctx) : ItaniumCXXABI(Ctx) { } 69212795Sdim}; 70212795Sdim} 71212795Sdim 72212795SdimCXXABI *clang::CreateItaniumCXXABI(ASTContext &Ctx) { 73212795Sdim return new ItaniumCXXABI(Ctx); 74212795Sdim} 75212795Sdim 76212795SdimCXXABI *clang::CreateARMCXXABI(ASTContext &Ctx) { 77212795Sdim return new ARMCXXABI(Ctx); 78212795Sdim} 79