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, 48 const Twine &GVName, ManglerPrefixTy PrefixTy) { 49 return getNameWithPrefixx(OS, GVName, PrefixTy, *DL, false); 50 } 51 52 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, 53 const Twine &GVName, ManglerPrefixTy PrefixTy) { 54 raw_svector_ostream OS(OutName); 55 return getNameWithPrefix(OS, GVName, PrefixTy); 56 } 57 58 /// AddFastCallStdCallSuffix - Microsoft fastcall and stdcall functions require 59 /// a suffix on their name indicating the number of words of arguments they 60 /// take. 61 static void AddFastCallStdCallSuffix(raw_ostream &OS, const Function *F, 62 const DataLayout &TD) { 63 // Calculate arguments size total. 64 unsigned ArgWords = 0; 65 for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end(); 66 AI != AE; ++AI) { 67 Type *Ty = AI->getType(); 68 // 'Dereference' type in case of byval parameter attribute 69 if (AI->hasByValAttr()) 70 Ty = cast<PointerType>(Ty)->getElementType(); 71 // Size should be aligned to DWORD boundary 72 ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4; 73 } 74 75 OS << '@' << ArgWords; 76 } 77 78 void Mangler::getNameWithPrefix(raw_ostream &OS, const GlobalValue *GV) { 79 ManglerPrefixTy PrefixTy = Mangler::Default; 80 if (GV->hasPrivateLinkage()) 81 PrefixTy = Mangler::Private; 82 else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage()) 83 PrefixTy = Mangler::LinkerPrivate; 84 85 if (!GV->hasName()) { 86 // Get the ID for the global, assigning a new one if we haven't got one 87 // already. 88 unsigned &ID = AnonGlobalIDs[GV]; 89 if (ID == 0) 90 ID = NextAnonGlobalID++; 91 92 // Must mangle the global into a unique ID. 93 getNameWithPrefix(OS, "__unnamed_" + Twine(ID), PrefixTy); 94 return; 95 } 96 97 StringRef Name = GV->getName(); 98 99 // No need to do anything special if the global has the special "do not 100 // mangle" flag in the name. 101 if (Name[0] == '\1') { 102 OS << Name.substr(1); 103 return; 104 } 105 106 bool UseAt = false; 107 const Function *MSFunc = NULL; 108 CallingConv::ID CC; 109 if (DL->hasMicrosoftFastStdCallMangling()) { 110 if ((MSFunc = dyn_cast<Function>(GV))) { 111 CC = MSFunc->getCallingConv(); 112 // fastcall functions need to start with @ instead of _. 113 if (CC == CallingConv::X86_FastCall) 114 UseAt = true; 115 } 116 } 117 118 getNameWithPrefixx(OS, Name, PrefixTy, *DL, UseAt); 119 120 if (!MSFunc) 121 return; 122 123 // If we are supposed to add a microsoft-style suffix for stdcall/fastcall, 124 // add it. 125 // fastcall and stdcall functions usually need @42 at the end to specify 126 // the argument info. 127 FunctionType *FT = MSFunc->getFunctionType(); 128 if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) && 129 // "Pure" variadic functions do not receive @0 suffix. 130 (!FT->isVarArg() || FT->getNumParams() == 0 || 131 (FT->getNumParams() == 1 && MSFunc->hasStructRetAttr()))) 132 AddFastCallStdCallSuffix(OS, MSFunc, *DL); 133 } 134 135 void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, 136 const GlobalValue *GV) { 137 raw_svector_ostream OS(OutName); 138 getNameWithPrefix(OS, GV); 139 } 140