Mangler.cpp revision dce4a407a24b04eebc6a376f8e62b41aaa7b071f
1//===-- Mangler.cpp - Self-contained c/asm llvm name mangler --------------===// 2// 3// The LLVM Compiler Infrastructure 4// 5// This file is distributed under the University of Illinois Open Source 6// License. See LICENSE.TXT for details. 7// 8//===----------------------------------------------------------------------===// 9// 10// Unified name mangler for assembly backends. 11// 12//===----------------------------------------------------------------------===// 13 14#include "llvm/IR/Mangler.h" 15#include "llvm/ADT/SmallString.h" 16#include "llvm/ADT/Twine.h" 17#include "llvm/IR/DataLayout.h" 18#include "llvm/IR/DerivedTypes.h" 19#include "llvm/IR/Function.h" 20#include "llvm/Support/raw_ostream.h" 21using namespace llvm; 22 23static void getNameWithPrefixx(raw_ostream &OS, const Twine &GVName, 24 Mangler::ManglerPrefixTy PrefixTy, 25 const DataLayout &DL, bool UseAt) { 26 SmallString<256> TmpData; 27 StringRef Name = GVName.toStringRef(TmpData); 28 assert(!Name.empty() && "getNameWithPrefix requires non-empty name"); 29 30 if (PrefixTy == Mangler::Private) 31 OS << DL.getPrivateGlobalPrefix(); 32 else if (PrefixTy == Mangler::LinkerPrivate) 33 OS << DL.getLinkerPrivateGlobalPrefix(); 34 35 if (UseAt) { 36 OS << '@'; 37 } else { 38 char Prefix = DL.getGlobalPrefix(); 39 if (Prefix != '\0') 40 OS << Prefix; 41 } 42 43 // If this is a simple string that doesn't need escaping, just append it. 44 OS << Name; 45} 46 47void Mangler::getNameWithPrefix(raw_ostream &OS, const Twine &GVName, 48 ManglerPrefixTy PrefixTy) const { 49 return getNameWithPrefixx(OS, GVName, PrefixTy, *DL, false); 50} 51 52void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, 53 const Twine &GVName, 54 ManglerPrefixTy PrefixTy) const { 55 raw_svector_ostream OS(OutName); 56 return getNameWithPrefix(OS, GVName, PrefixTy); 57} 58 59/// AddFastCallStdCallSuffix - Microsoft fastcall and stdcall functions require 60/// a suffix on their name indicating the number of words of arguments they 61/// take. 62static void AddFastCallStdCallSuffix(raw_ostream &OS, const Function *F, 63 const DataLayout &TD) { 64 // Calculate arguments size total. 65 unsigned ArgWords = 0; 66 for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end(); 67 AI != AE; ++AI) { 68 Type *Ty = AI->getType(); 69 // 'Dereference' type in case of byval or inalloca parameter attribute. 70 if (AI->hasByValOrInAllocaAttr()) 71 Ty = cast<PointerType>(Ty)->getElementType(); 72 // Size should be aligned to DWORD boundary 73 ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4; 74 } 75 76 OS << '@' << ArgWords; 77} 78 79void Mangler::getNameWithPrefix(raw_ostream &OS, const GlobalValue *GV, 80 bool CannotUsePrivateLabel) const { 81 ManglerPrefixTy PrefixTy = Mangler::Default; 82 if (GV->hasPrivateLinkage()) { 83 if (CannotUsePrivateLabel) 84 PrefixTy = Mangler::LinkerPrivate; 85 else 86 PrefixTy = Mangler::Private; 87 } 88 89 if (!GV->hasName()) { 90 // Get the ID for the global, assigning a new one if we haven't got one 91 // already. 92 unsigned &ID = AnonGlobalIDs[GV]; 93 if (ID == 0) 94 ID = NextAnonGlobalID++; 95 96 // Must mangle the global into a unique ID. 97 getNameWithPrefix(OS, "__unnamed_" + Twine(ID), PrefixTy); 98 return; 99 } 100 101 StringRef Name = GV->getName(); 102 103 // No need to do anything special if the global has the special "do not 104 // mangle" flag in the name. 105 if (Name[0] == '\1') { 106 OS << Name.substr(1); 107 return; 108 } 109 110 bool UseAt = false; 111 const Function *MSFunc = nullptr; 112 CallingConv::ID CC; 113 if (DL->hasMicrosoftFastStdCallMangling()) { 114 if ((MSFunc = dyn_cast<Function>(GV))) { 115 CC = MSFunc->getCallingConv(); 116 // fastcall functions need to start with @ instead of _. 117 if (CC == CallingConv::X86_FastCall) 118 UseAt = true; 119 } 120 } 121 122 getNameWithPrefixx(OS, Name, PrefixTy, *DL, UseAt); 123 124 if (!MSFunc) 125 return; 126 127 // If we are supposed to add a microsoft-style suffix for stdcall/fastcall, 128 // add it. 129 // fastcall and stdcall functions usually need @42 at the end to specify 130 // the argument info. 131 FunctionType *FT = MSFunc->getFunctionType(); 132 if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) && 133 // "Pure" variadic functions do not receive @0 suffix. 134 (!FT->isVarArg() || FT->getNumParams() == 0 || 135 (FT->getNumParams() == 1 && MSFunc->hasStructRetAttr()))) 136 AddFastCallStdCallSuffix(OS, MSFunc, *DL); 137} 138 139void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, 140 const GlobalValue *GV, 141 bool CannotUsePrivateLabel) const { 142 raw_svector_ostream OS(OutName); 143 getNameWithPrefix(OS, GV, CannotUsePrivateLabel); 144} 145