Mangler.cpp revision 205218
1202878Srdivacky//===-- Mangler.cpp - Self-contained c/asm llvm name mangler --------------===// 2202878Srdivacky// 3202878Srdivacky// The LLVM Compiler Infrastructure 4202878Srdivacky// 5202878Srdivacky// This file is distributed under the University of Illinois Open Source 6202878Srdivacky// License. See LICENSE.TXT for details. 7202878Srdivacky// 8202878Srdivacky//===----------------------------------------------------------------------===// 9202878Srdivacky// 10202878Srdivacky// Unified name mangler for assembly backends. 11202878Srdivacky// 12202878Srdivacky//===----------------------------------------------------------------------===// 13202878Srdivacky 14202878Srdivacky#include "llvm/Target/Mangler.h" 15205218Srdivacky#include "llvm/DerivedTypes.h" 16205218Srdivacky#include "llvm/Function.h" 17205218Srdivacky#include "llvm/Target/TargetData.h" 18202878Srdivacky#include "llvm/MC/MCAsmInfo.h" 19205218Srdivacky#include "llvm/MC/MCContext.h" 20205218Srdivacky#include "llvm/Support/raw_ostream.h" 21202878Srdivacky#include "llvm/ADT/SmallString.h" 22202878Srdivacky#include "llvm/ADT/Twine.h" 23202878Srdivackyusing namespace llvm; 24202878Srdivacky 25202878Srdivackystatic bool isAcceptableChar(char C) { 26202878Srdivacky if ((C < 'a' || C > 'z') && 27202878Srdivacky (C < 'A' || C > 'Z') && 28202878Srdivacky (C < '0' || C > '9') && 29202878Srdivacky C != '_' && C != '$' && C != '.' && C != '@') 30202878Srdivacky return false; 31202878Srdivacky return true; 32202878Srdivacky} 33202878Srdivacky 34202878Srdivackystatic char HexDigit(int V) { 35202878Srdivacky return V < 10 ? V+'0' : V+'A'-10; 36202878Srdivacky} 37202878Srdivacky 38202878Srdivackystatic void MangleLetter(SmallVectorImpl<char> &OutName, unsigned char C) { 39202878Srdivacky OutName.push_back('_'); 40202878Srdivacky OutName.push_back(HexDigit(C >> 4)); 41202878Srdivacky OutName.push_back(HexDigit(C & 15)); 42202878Srdivacky OutName.push_back('_'); 43202878Srdivacky} 44202878Srdivacky 45202878Srdivacky/// NameNeedsEscaping - Return true if the identifier \arg Str needs quotes 46202878Srdivacky/// for this assembler. 47202878Srdivackystatic bool NameNeedsEscaping(StringRef Str, const MCAsmInfo &MAI) { 48202878Srdivacky assert(!Str.empty() && "Cannot create an empty MCSymbol"); 49202878Srdivacky 50202878Srdivacky // If the first character is a number and the target does not allow this, we 51202878Srdivacky // need quotes. 52202878Srdivacky if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9') 53202878Srdivacky return true; 54202878Srdivacky 55202878Srdivacky // If any of the characters in the string is an unacceptable character, force 56202878Srdivacky // quotes. 57202878Srdivacky for (unsigned i = 0, e = Str.size(); i != e; ++i) 58202878Srdivacky if (!isAcceptableChar(Str[i])) 59202878Srdivacky return true; 60202878Srdivacky return false; 61202878Srdivacky} 62202878Srdivacky 63202878Srdivacky/// appendMangledName - Add the specified string in mangled form if it uses 64202878Srdivacky/// any unusual characters. 65202878Srdivackystatic void appendMangledName(SmallVectorImpl<char> &OutName, StringRef Str, 66205218Srdivacky const MCAsmInfo &MAI) { 67202878Srdivacky // The first character is not allowed to be a number unless the target 68202878Srdivacky // explicitly allows it. 69205218Srdivacky if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9') { 70202878Srdivacky MangleLetter(OutName, Str[0]); 71202878Srdivacky Str = Str.substr(1); 72202878Srdivacky } 73202878Srdivacky 74202878Srdivacky for (unsigned i = 0, e = Str.size(); i != e; ++i) { 75202878Srdivacky if (!isAcceptableChar(Str[i])) 76202878Srdivacky MangleLetter(OutName, Str[i]); 77202878Srdivacky else 78202878Srdivacky OutName.push_back(Str[i]); 79202878Srdivacky } 80202878Srdivacky} 81202878Srdivacky 82202878Srdivacky 83202878Srdivacky/// appendMangledQuotedName - On systems that support quoted symbols, we still 84202878Srdivacky/// have to escape some (obscure) characters like " and \n which would break the 85202878Srdivacky/// assembler's lexing. 86202878Srdivackystatic void appendMangledQuotedName(SmallVectorImpl<char> &OutName, 87202878Srdivacky StringRef Str) { 88202878Srdivacky for (unsigned i = 0, e = Str.size(); i != e; ++i) { 89202878Srdivacky if (Str[i] == '"' || Str[i] == '\n') 90202878Srdivacky MangleLetter(OutName, Str[i]); 91202878Srdivacky else 92202878Srdivacky OutName.push_back(Str[i]); 93202878Srdivacky } 94202878Srdivacky} 95202878Srdivacky 96202878Srdivacky 97202878Srdivacky/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix 98202878Srdivacky/// and the specified name as the global variable name. GVName must not be 99202878Srdivacky/// empty. 100202878Srdivackyvoid Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, 101202878Srdivacky const Twine &GVName, ManglerPrefixTy PrefixTy) { 102202878Srdivacky SmallString<256> TmpData; 103202878Srdivacky StringRef Name = GVName.toStringRef(TmpData); 104202878Srdivacky assert(!Name.empty() && "getNameWithPrefix requires non-empty name"); 105202878Srdivacky 106205218Srdivacky const MCAsmInfo &MAI = Context.getAsmInfo(); 107205218Srdivacky 108202878Srdivacky // If the global name is not led with \1, add the appropriate prefixes. 109202878Srdivacky if (Name[0] == '\1') { 110202878Srdivacky Name = Name.substr(1); 111202878Srdivacky } else { 112202878Srdivacky if (PrefixTy == Mangler::Private) { 113202878Srdivacky const char *Prefix = MAI.getPrivateGlobalPrefix(); 114202878Srdivacky OutName.append(Prefix, Prefix+strlen(Prefix)); 115202878Srdivacky } else if (PrefixTy == Mangler::LinkerPrivate) { 116202878Srdivacky const char *Prefix = MAI.getLinkerPrivateGlobalPrefix(); 117202878Srdivacky OutName.append(Prefix, Prefix+strlen(Prefix)); 118202878Srdivacky } 119202878Srdivacky 120202878Srdivacky const char *Prefix = MAI.getGlobalPrefix(); 121202878Srdivacky if (Prefix[0] == 0) 122202878Srdivacky ; // Common noop, no prefix. 123202878Srdivacky else if (Prefix[1] == 0) 124202878Srdivacky OutName.push_back(Prefix[0]); // Common, one character prefix. 125202878Srdivacky else 126202878Srdivacky OutName.append(Prefix, Prefix+strlen(Prefix)); // Arbitrary length prefix. 127202878Srdivacky } 128202878Srdivacky 129202878Srdivacky // If this is a simple string that doesn't need escaping, just append it. 130202878Srdivacky if (!NameNeedsEscaping(Name, MAI) || 131202878Srdivacky // If quotes are supported, they can be used unless the string contains 132202878Srdivacky // a quote or newline. 133202878Srdivacky (MAI.doesAllowQuotesInName() && 134202878Srdivacky Name.find_first_of("\n\"") == StringRef::npos)) { 135202878Srdivacky OutName.append(Name.begin(), Name.end()); 136202878Srdivacky return; 137202878Srdivacky } 138202878Srdivacky 139202878Srdivacky // On systems that do not allow quoted names, we need to mangle most 140202878Srdivacky // strange characters. 141202878Srdivacky if (!MAI.doesAllowQuotesInName()) 142205218Srdivacky return appendMangledName(OutName, Name, MAI); 143202878Srdivacky 144202878Srdivacky // Okay, the system allows quoted strings. We can quote most anything, the 145202878Srdivacky // only characters that need escaping are " and \n. 146202878Srdivacky assert(Name.find_first_of("\n\"") != StringRef::npos); 147202878Srdivacky return appendMangledQuotedName(OutName, Name); 148202878Srdivacky} 149202878Srdivacky 150205218Srdivacky/// AddFastCallStdCallSuffix - Microsoft fastcall and stdcall functions require 151205218Srdivacky/// a suffix on their name indicating the number of words of arguments they 152205218Srdivacky/// take. 153205218Srdivackystatic void AddFastCallStdCallSuffix(SmallVectorImpl<char> &OutName, 154205218Srdivacky const Function *F, const TargetData &TD) { 155205218Srdivacky // Calculate arguments size total. 156205218Srdivacky unsigned ArgWords = 0; 157205218Srdivacky for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end(); 158205218Srdivacky AI != AE; ++AI) { 159205218Srdivacky const Type *Ty = AI->getType(); 160205218Srdivacky // 'Dereference' type in case of byval parameter attribute 161205218Srdivacky if (AI->hasByValAttr()) 162205218Srdivacky Ty = cast<PointerType>(Ty)->getElementType(); 163205218Srdivacky // Size should be aligned to DWORD boundary 164205218Srdivacky ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4; 165205218Srdivacky } 166205218Srdivacky 167205218Srdivacky raw_svector_ostream(OutName) << '@' << ArgWords; 168205218Srdivacky} 169202878Srdivacky 170205218Srdivacky 171202878Srdivacky/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix 172202878Srdivacky/// and the specified global variable's name. If the global variable doesn't 173202878Srdivacky/// have a name, this fills in a unique name for the global. 174202878Srdivackyvoid Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, 175202878Srdivacky const GlobalValue *GV, 176202878Srdivacky bool isImplicitlyPrivate) { 177202878Srdivacky ManglerPrefixTy PrefixTy = Mangler::Default; 178202878Srdivacky if (GV->hasPrivateLinkage() || isImplicitlyPrivate) 179202878Srdivacky PrefixTy = Mangler::Private; 180202878Srdivacky else if (GV->hasLinkerPrivateLinkage()) 181202878Srdivacky PrefixTy = Mangler::LinkerPrivate; 182202878Srdivacky 183202878Srdivacky // If this global has a name, handle it simply. 184205218Srdivacky if (GV->hasName()) { 185205218Srdivacky getNameWithPrefix(OutName, GV->getName(), PrefixTy); 186205218Srdivacky } else { 187205218Srdivacky // Get the ID for the global, assigning a new one if we haven't got one 188205218Srdivacky // already. 189205218Srdivacky unsigned &ID = AnonGlobalIDs[GV]; 190205218Srdivacky if (ID == 0) ID = NextAnonGlobalID++; 191202878Srdivacky 192205218Srdivacky // Must mangle the global into a unique ID. 193205218Srdivacky getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy); 194205218Srdivacky } 195202878Srdivacky 196205218Srdivacky // If we are supposed to add a microsoft-style suffix for stdcall/fastcall, 197205218Srdivacky // add it. 198205218Srdivacky if (Context.getAsmInfo().hasMicrosoftFastStdCallMangling()) { 199205218Srdivacky if (const Function *F = dyn_cast<Function>(GV)) { 200205218Srdivacky CallingConv::ID CC = F->getCallingConv(); 201205218Srdivacky 202205218Srdivacky // fastcall functions need to start with @. 203205218Srdivacky // FIXME: This logic seems unlikely to be right. 204205218Srdivacky if (CC == CallingConv::X86_FastCall) { 205205218Srdivacky if (OutName[0] == '_') 206205218Srdivacky OutName[0] = '@'; 207205218Srdivacky else 208205218Srdivacky OutName.insert(OutName.begin(), '@'); 209205218Srdivacky } 210205218Srdivacky 211205218Srdivacky // fastcall and stdcall functions usually need @42 at the end to specify 212205218Srdivacky // the argument info. 213205218Srdivacky const FunctionType *FT = F->getFunctionType(); 214205218Srdivacky if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) && 215205218Srdivacky // "Pure" variadic functions do not receive @0 suffix. 216205218Srdivacky (!FT->isVarArg() || FT->getNumParams() == 0 || 217205218Srdivacky (FT->getNumParams() == 1 && F->hasStructRetAttr()))) 218205218Srdivacky AddFastCallStdCallSuffix(OutName, F, TD); 219205218Srdivacky } 220205218Srdivacky } 221202878Srdivacky} 222202878Srdivacky 223202878Srdivacky/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix 224202878Srdivacky/// and the specified global variable's name. If the global variable doesn't 225202878Srdivacky/// have a name, this fills in a unique name for the global. 226202878Srdivackystd::string Mangler::getNameWithPrefix(const GlobalValue *GV, 227202878Srdivacky bool isImplicitlyPrivate) { 228202878Srdivacky SmallString<64> Buf; 229202878Srdivacky getNameWithPrefix(Buf, GV, isImplicitlyPrivate); 230202878Srdivacky return std::string(Buf.begin(), Buf.end()); 231202878Srdivacky} 232205218Srdivacky 233205218Srdivacky/// getSymbol - Return the MCSymbol for the specified global value. This 234205218Srdivacky/// symbol is the main label that is the address of the global. 235205218SrdivackyMCSymbol *Mangler::getSymbol(const GlobalValue *GV) { 236205218Srdivacky SmallString<60> NameStr; 237205218Srdivacky getNameWithPrefix(NameStr, GV, false); 238205218Srdivacky if (!GV->hasPrivateLinkage()) 239205218Srdivacky return Context.GetOrCreateSymbol(NameStr.str()); 240205218Srdivacky 241205218Srdivacky return Context.GetOrCreateTemporarySymbol(NameStr.str()); 242205218Srdivacky} 243205218Srdivacky 244205218Srdivacky 245