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" 15249423Sdim#include "llvm/ADT/SmallString.h" 16249423Sdim#include "llvm/ADT/Twine.h" 17249423Sdim#include "llvm/IR/DataLayout.h" 18249423Sdim#include "llvm/IR/DerivedTypes.h" 19249423Sdim#include "llvm/IR/Function.h" 20202878Srdivacky#include "llvm/MC/MCAsmInfo.h" 21205218Srdivacky#include "llvm/MC/MCContext.h" 22205218Srdivacky#include "llvm/Support/raw_ostream.h" 23202878Srdivackyusing namespace llvm; 24202878Srdivacky 25234353Sdimstatic bool isAcceptableChar(char C, bool AllowPeriod, bool AllowUTF8) { 26202878Srdivacky if ((C < 'a' || C > 'z') && 27202878Srdivacky (C < 'A' || C > 'Z') && 28202878Srdivacky (C < '0' || C > '9') && 29207618Srdivacky C != '_' && C != '$' && C != '@' && 30234353Sdim !(AllowPeriod && C == '.') && 31234353Sdim !(AllowUTF8 && (C & 0x80))) 32202878Srdivacky return false; 33202878Srdivacky return true; 34202878Srdivacky} 35202878Srdivacky 36202878Srdivackystatic char HexDigit(int V) { 37202878Srdivacky return V < 10 ? V+'0' : V+'A'-10; 38202878Srdivacky} 39202878Srdivacky 40202878Srdivackystatic void MangleLetter(SmallVectorImpl<char> &OutName, unsigned char C) { 41202878Srdivacky OutName.push_back('_'); 42202878Srdivacky OutName.push_back(HexDigit(C >> 4)); 43202878Srdivacky OutName.push_back(HexDigit(C & 15)); 44202878Srdivacky OutName.push_back('_'); 45202878Srdivacky} 46202878Srdivacky 47243830Sdim/// NameNeedsEscaping - Return true if the identifier \p Str needs quotes 48202878Srdivacky/// for this assembler. 49202878Srdivackystatic bool NameNeedsEscaping(StringRef Str, const MCAsmInfo &MAI) { 50202878Srdivacky assert(!Str.empty() && "Cannot create an empty MCSymbol"); 51202878Srdivacky 52202878Srdivacky // If the first character is a number and the target does not allow this, we 53202878Srdivacky // need quotes. 54202878Srdivacky if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9') 55202878Srdivacky return true; 56202878Srdivacky 57202878Srdivacky // If any of the characters in the string is an unacceptable character, force 58202878Srdivacky // quotes. 59207618Srdivacky bool AllowPeriod = MAI.doesAllowPeriodsInName(); 60234353Sdim bool AllowUTF8 = MAI.doesAllowUTF8(); 61202878Srdivacky for (unsigned i = 0, e = Str.size(); i != e; ++i) 62234353Sdim if (!isAcceptableChar(Str[i], AllowPeriod, AllowUTF8)) 63202878Srdivacky return true; 64202878Srdivacky return false; 65202878Srdivacky} 66202878Srdivacky 67202878Srdivacky/// appendMangledName - Add the specified string in mangled form if it uses 68202878Srdivacky/// any unusual characters. 69202878Srdivackystatic void appendMangledName(SmallVectorImpl<char> &OutName, StringRef Str, 70205218Srdivacky const MCAsmInfo &MAI) { 71202878Srdivacky // The first character is not allowed to be a number unless the target 72202878Srdivacky // explicitly allows it. 73205218Srdivacky if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9') { 74202878Srdivacky MangleLetter(OutName, Str[0]); 75202878Srdivacky Str = Str.substr(1); 76202878Srdivacky } 77207618Srdivacky 78207618Srdivacky bool AllowPeriod = MAI.doesAllowPeriodsInName(); 79234353Sdim bool AllowUTF8 = MAI.doesAllowUTF8(); 80202878Srdivacky for (unsigned i = 0, e = Str.size(); i != e; ++i) { 81234353Sdim if (!isAcceptableChar(Str[i], AllowPeriod, AllowUTF8)) 82202878Srdivacky MangleLetter(OutName, Str[i]); 83202878Srdivacky else 84202878Srdivacky OutName.push_back(Str[i]); 85202878Srdivacky } 86202878Srdivacky} 87202878Srdivacky 88202878Srdivacky 89202878Srdivacky/// appendMangledQuotedName - On systems that support quoted symbols, we still 90202878Srdivacky/// have to escape some (obscure) characters like " and \n which would break the 91202878Srdivacky/// assembler's lexing. 92202878Srdivackystatic void appendMangledQuotedName(SmallVectorImpl<char> &OutName, 93202878Srdivacky StringRef Str) { 94202878Srdivacky for (unsigned i = 0, e = Str.size(); i != e; ++i) { 95202878Srdivacky if (Str[i] == '"' || Str[i] == '\n') 96202878Srdivacky MangleLetter(OutName, Str[i]); 97202878Srdivacky else 98202878Srdivacky OutName.push_back(Str[i]); 99202878Srdivacky } 100202878Srdivacky} 101202878Srdivacky 102202878Srdivacky 103202878Srdivacky/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix 104202878Srdivacky/// and the specified name as the global variable name. GVName must not be 105202878Srdivacky/// empty. 106202878Srdivackyvoid Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, 107202878Srdivacky const Twine &GVName, ManglerPrefixTy PrefixTy) { 108202878Srdivacky SmallString<256> TmpData; 109202878Srdivacky StringRef Name = GVName.toStringRef(TmpData); 110202878Srdivacky assert(!Name.empty() && "getNameWithPrefix requires non-empty name"); 111202878Srdivacky 112205218Srdivacky const MCAsmInfo &MAI = Context.getAsmInfo(); 113205218Srdivacky 114202878Srdivacky // If the global name is not led with \1, add the appropriate prefixes. 115202878Srdivacky if (Name[0] == '\1') { 116202878Srdivacky Name = Name.substr(1); 117202878Srdivacky } else { 118202878Srdivacky if (PrefixTy == Mangler::Private) { 119202878Srdivacky const char *Prefix = MAI.getPrivateGlobalPrefix(); 120202878Srdivacky OutName.append(Prefix, Prefix+strlen(Prefix)); 121202878Srdivacky } else if (PrefixTy == Mangler::LinkerPrivate) { 122202878Srdivacky const char *Prefix = MAI.getLinkerPrivateGlobalPrefix(); 123202878Srdivacky OutName.append(Prefix, Prefix+strlen(Prefix)); 124202878Srdivacky } 125202878Srdivacky 126202878Srdivacky const char *Prefix = MAI.getGlobalPrefix(); 127202878Srdivacky if (Prefix[0] == 0) 128202878Srdivacky ; // Common noop, no prefix. 129202878Srdivacky else if (Prefix[1] == 0) 130202878Srdivacky OutName.push_back(Prefix[0]); // Common, one character prefix. 131202878Srdivacky else 132202878Srdivacky OutName.append(Prefix, Prefix+strlen(Prefix)); // Arbitrary length prefix. 133202878Srdivacky } 134202878Srdivacky 135202878Srdivacky // If this is a simple string that doesn't need escaping, just append it. 136202878Srdivacky if (!NameNeedsEscaping(Name, MAI) || 137202878Srdivacky // If quotes are supported, they can be used unless the string contains 138202878Srdivacky // a quote or newline. 139202878Srdivacky (MAI.doesAllowQuotesInName() && 140202878Srdivacky Name.find_first_of("\n\"") == StringRef::npos)) { 141202878Srdivacky OutName.append(Name.begin(), Name.end()); 142202878Srdivacky return; 143202878Srdivacky } 144202878Srdivacky 145202878Srdivacky // On systems that do not allow quoted names, we need to mangle most 146202878Srdivacky // strange characters. 147202878Srdivacky if (!MAI.doesAllowQuotesInName()) 148205218Srdivacky return appendMangledName(OutName, Name, MAI); 149202878Srdivacky 150202878Srdivacky // Okay, the system allows quoted strings. We can quote most anything, the 151202878Srdivacky // only characters that need escaping are " and \n. 152202878Srdivacky assert(Name.find_first_of("\n\"") != StringRef::npos); 153202878Srdivacky return appendMangledQuotedName(OutName, Name); 154202878Srdivacky} 155202878Srdivacky 156205218Srdivacky/// AddFastCallStdCallSuffix - Microsoft fastcall and stdcall functions require 157205218Srdivacky/// a suffix on their name indicating the number of words of arguments they 158205218Srdivacky/// take. 159205218Srdivackystatic void AddFastCallStdCallSuffix(SmallVectorImpl<char> &OutName, 160243830Sdim const Function *F, const DataLayout &TD) { 161205218Srdivacky // Calculate arguments size total. 162205218Srdivacky unsigned ArgWords = 0; 163205218Srdivacky for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end(); 164205218Srdivacky AI != AE; ++AI) { 165226633Sdim Type *Ty = AI->getType(); 166205218Srdivacky // 'Dereference' type in case of byval parameter attribute 167205218Srdivacky if (AI->hasByValAttr()) 168205218Srdivacky Ty = cast<PointerType>(Ty)->getElementType(); 169205218Srdivacky // Size should be aligned to DWORD boundary 170205218Srdivacky ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4; 171205218Srdivacky } 172205218Srdivacky 173205218Srdivacky raw_svector_ostream(OutName) << '@' << ArgWords; 174205218Srdivacky} 175202878Srdivacky 176205218Srdivacky 177202878Srdivacky/// getNameWithPrefix - Fill OutName with the name of the appropriate prefix 178202878Srdivacky/// and the specified global variable's name. If the global variable doesn't 179202878Srdivacky/// have a name, this fills in a unique name for the global. 180202878Srdivackyvoid Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, 181202878Srdivacky const GlobalValue *GV, 182202878Srdivacky bool isImplicitlyPrivate) { 183202878Srdivacky ManglerPrefixTy PrefixTy = Mangler::Default; 184202878Srdivacky if (GV->hasPrivateLinkage() || isImplicitlyPrivate) 185202878Srdivacky PrefixTy = Mangler::Private; 186243830Sdim else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage()) 187202878Srdivacky PrefixTy = Mangler::LinkerPrivate; 188202878Srdivacky 189202878Srdivacky // If this global has a name, handle it simply. 190205218Srdivacky if (GV->hasName()) { 191251662Sdim StringRef Name = GV->getName(); 192251662Sdim getNameWithPrefix(OutName, Name, PrefixTy); 193251662Sdim // No need to do anything else if the global has the special "do not mangle" 194251662Sdim // flag in the name. 195251662Sdim if (Name[0] == 1) 196251662Sdim return; 197205218Srdivacky } else { 198205218Srdivacky // Get the ID for the global, assigning a new one if we haven't got one 199205218Srdivacky // already. 200205218Srdivacky unsigned &ID = AnonGlobalIDs[GV]; 201205218Srdivacky if (ID == 0) ID = NextAnonGlobalID++; 202202878Srdivacky 203205218Srdivacky // Must mangle the global into a unique ID. 204205218Srdivacky getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy); 205205218Srdivacky } 206202878Srdivacky 207205218Srdivacky // If we are supposed to add a microsoft-style suffix for stdcall/fastcall, 208205218Srdivacky // add it. 209205218Srdivacky if (Context.getAsmInfo().hasMicrosoftFastStdCallMangling()) { 210205218Srdivacky if (const Function *F = dyn_cast<Function>(GV)) { 211205218Srdivacky CallingConv::ID CC = F->getCallingConv(); 212205218Srdivacky 213205218Srdivacky // fastcall functions need to start with @. 214205218Srdivacky // FIXME: This logic seems unlikely to be right. 215205218Srdivacky if (CC == CallingConv::X86_FastCall) { 216205218Srdivacky if (OutName[0] == '_') 217205218Srdivacky OutName[0] = '@'; 218205218Srdivacky else 219205218Srdivacky OutName.insert(OutName.begin(), '@'); 220205218Srdivacky } 221205218Srdivacky 222205218Srdivacky // fastcall and stdcall functions usually need @42 at the end to specify 223205218Srdivacky // the argument info. 224226633Sdim FunctionType *FT = F->getFunctionType(); 225205218Srdivacky if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) && 226205218Srdivacky // "Pure" variadic functions do not receive @0 suffix. 227205218Srdivacky (!FT->isVarArg() || FT->getNumParams() == 0 || 228205218Srdivacky (FT->getNumParams() == 1 && F->hasStructRetAttr()))) 229205218Srdivacky AddFastCallStdCallSuffix(OutName, F, TD); 230205218Srdivacky } 231205218Srdivacky } 232202878Srdivacky} 233202878Srdivacky 234205218Srdivacky/// getSymbol - Return the MCSymbol for the specified global value. This 235205218Srdivacky/// symbol is the main label that is the address of the global. 236205218SrdivackyMCSymbol *Mangler::getSymbol(const GlobalValue *GV) { 237205218Srdivacky SmallString<60> NameStr; 238205218Srdivacky getNameWithPrefix(NameStr, GV, false); 239206083Srdivacky return Context.GetOrCreateSymbol(NameStr.str()); 240205218Srdivacky} 241205218Srdivacky 242205218Srdivacky 243