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" 21 using namespace llvm; 22 23 static 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 47 void Mangler::getNameWithPrefix(raw_ostream &OS, const Twine &GVName, 48 ManglerPrefixTy PrefixTy) const { 49 return getNameWithPrefixx(OS, GVName, PrefixTy, *DL, false); 50 } 51 52 void 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. 62 static 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 79 void 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 } else if (GV->hasLinkerPrivateLinkage() || 88 GV->hasLinkerPrivateWeakLinkage()) { 89 PrefixTy = Mangler::LinkerPrivate; 90 } 91 92 if (!GV->hasName()) { 93 // Get the ID for the global, assigning a new one if we haven't got one 94 // already. 95 unsigned &ID = AnonGlobalIDs[GV]; 96 if (ID == 0) 97 ID = NextAnonGlobalID++; 98 99 // Must mangle the global into a unique ID. 100 getNameWithPrefix(OS, "__unnamed_" + Twine(ID), PrefixTy); 101 return; 102 } 103 104 StringRef Name = GV->getName(); 105 106 // No need to do anything special if the global has the special "do not 107 // mangle" flag in the name. 108 if (Name[0] == '\1') { 109 OS << Name.substr(1); 110 return; 111 } 112 113 bool UseAt = false; 114 const Function *MSFunc = NULL; 115 CallingConv::ID CC; 116 if (DL->hasMicrosoftFastStdCallMangling()) { 117 if ((MSFunc = dyn_cast<Function>(GV))) { 118 CC = MSFunc->getCallingConv(); 119 // fastcall functions need to start with @ instead of _. 120 if (CC == CallingConv::X86_FastCall) 121 UseAt = true; 122 } 123 } 124 125 getNameWithPrefixx(OS, Name, PrefixTy, *DL, UseAt); 126 127 if (!MSFunc) 128 return; 129 130 // If we are supposed to add a microsoft-style suffix for stdcall/fastcall, 131 // add it. 132 // fastcall and stdcall functions usually need @42 at the end to specify 133 // the argument info. 134 FunctionType *FT = MSFunc->getFunctionType(); 135 if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) && 136 // "Pure" variadic functions do not receive @0 suffix. 137 (!FT->isVarArg() || FT->getNumParams() == 0 || 138 (FT->getNumParams() == 1 && MSFunc->hasStructRetAttr()))) 139 AddFastCallStdCallSuffix(OS, MSFunc, *DL); 140 } 141 142 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, 143 const GlobalValue *GV, 144 bool CannotUsePrivateLabel) const { 145 raw_svector_ostream OS(OutName); 146 getNameWithPrefix(OS, GV, CannotUsePrivateLabel); 147 } 148