| //===-- Mangler.cpp - Self-contained c/asm llvm name mangler --------------===// |
| // |
| // The LLVM Compiler Infrastructure |
| // |
| // This file is distributed under the University of Illinois Open Source |
| // License. See LICENSE.TXT for details. |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Unified name mangler for assembly backends. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/Target/Mangler.h" |
| #include "llvm/DerivedTypes.h" |
| #include "llvm/Function.h" |
| #include "llvm/Target/TargetData.h" |
| #include "llvm/MC/MCAsmInfo.h" |
| #include "llvm/MC/MCContext.h" |
| #include "llvm/Support/raw_ostream.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/Twine.h" |
| using namespace llvm; |
| |
| static bool isAcceptableChar(char C, bool AllowPeriod) { |
| if ((C < 'a' || C > 'z') && |
| (C < 'A' || C > 'Z') && |
| (C < '0' || C > '9') && |
| C != '_' && C != '$' && C != '@' && |
| !(AllowPeriod && C == '.')) |
| return false; |
| return true; |
| } |
| |
| static char HexDigit(int V) { |
| return V < 10 ? V+'0' : V+'A'-10; |
| } |
| |
| static void MangleLetter(SmallVectorImpl<char> &OutName, unsigned char C) { |
| OutName.push_back('_'); |
| OutName.push_back(HexDigit(C >> 4)); |
| OutName.push_back(HexDigit(C & 15)); |
| OutName.push_back('_'); |
| } |
| |
| /// NameNeedsEscaping - Return true if the identifier \arg Str needs quotes |
| /// for this assembler. |
| static bool NameNeedsEscaping(StringRef Str, const MCAsmInfo &MAI) { |
| assert(!Str.empty() && "Cannot create an empty MCSymbol"); |
| |
| // If the first character is a number and the target does not allow this, we |
| // need quotes. |
| if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9') |
| return true; |
| |
| // If any of the characters in the string is an unacceptable character, force |
| // quotes. |
| bool AllowPeriod = MAI.doesAllowPeriodsInName(); |
| for (unsigned i = 0, e = Str.size(); i != e; ++i) |
| if (!isAcceptableChar(Str[i], AllowPeriod)) |
| return true; |
| return false; |
| } |
| |
| /// appendMangledName - Add the specified string in mangled form if it uses |
| /// any unusual characters. |
| static void appendMangledName(SmallVectorImpl<char> &OutName, StringRef Str, |
| const MCAsmInfo &MAI) { |
| // The first character is not allowed to be a number unless the target |
| // explicitly allows it. |
| if (!MAI.doesAllowNameToStartWithDigit() && Str[0] >= '0' && Str[0] <= '9') { |
| MangleLetter(OutName, Str[0]); |
| Str = Str.substr(1); |
| } |
| |
| bool AllowPeriod = MAI.doesAllowPeriodsInName(); |
| for (unsigned i = 0, e = Str.size(); i != e; ++i) { |
| if (!isAcceptableChar(Str[i], AllowPeriod)) |
| MangleLetter(OutName, Str[i]); |
| else |
| OutName.push_back(Str[i]); |
| } |
| } |
| |
| |
| /// appendMangledQuotedName - On systems that support quoted symbols, we still |
| /// have to escape some (obscure) characters like " and \n which would break the |
| /// assembler's lexing. |
| static void appendMangledQuotedName(SmallVectorImpl<char> &OutName, |
| StringRef Str) { |
| for (unsigned i = 0, e = Str.size(); i != e; ++i) { |
| if (Str[i] == '"' || Str[i] == '\n') |
| MangleLetter(OutName, Str[i]); |
| else |
| OutName.push_back(Str[i]); |
| } |
| } |
| |
| |
| /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix |
| /// and the specified name as the global variable name. GVName must not be |
| /// empty. |
| void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, |
| const Twine &GVName, ManglerPrefixTy PrefixTy) { |
| SmallString<256> TmpData; |
| StringRef Name = GVName.toStringRef(TmpData); |
| assert(!Name.empty() && "getNameWithPrefix requires non-empty name"); |
| |
| const MCAsmInfo &MAI = Context.getAsmInfo(); |
| |
| // If the global name is not led with \1, add the appropriate prefixes. |
| if (Name[0] == '\1') { |
| Name = Name.substr(1); |
| } else { |
| if (PrefixTy == Mangler::Private) { |
| const char *Prefix = MAI.getPrivateGlobalPrefix(); |
| OutName.append(Prefix, Prefix+strlen(Prefix)); |
| } else if (PrefixTy == Mangler::LinkerPrivate) { |
| const char *Prefix = MAI.getLinkerPrivateGlobalPrefix(); |
| OutName.append(Prefix, Prefix+strlen(Prefix)); |
| } |
| |
| const char *Prefix = MAI.getGlobalPrefix(); |
| if (Prefix[0] == 0) |
| ; // Common noop, no prefix. |
| else if (Prefix[1] == 0) |
| OutName.push_back(Prefix[0]); // Common, one character prefix. |
| else |
| OutName.append(Prefix, Prefix+strlen(Prefix)); // Arbitrary length prefix. |
| } |
| |
| // If this is a simple string that doesn't need escaping, just append it. |
| if (!NameNeedsEscaping(Name, MAI) || |
| // If quotes are supported, they can be used unless the string contains |
| // a quote or newline. |
| (MAI.doesAllowQuotesInName() && |
| Name.find_first_of("\n\"") == StringRef::npos)) { |
| OutName.append(Name.begin(), Name.end()); |
| return; |
| } |
| |
| // On systems that do not allow quoted names, we need to mangle most |
| // strange characters. |
| if (!MAI.doesAllowQuotesInName()) |
| return appendMangledName(OutName, Name, MAI); |
| |
| // Okay, the system allows quoted strings. We can quote most anything, the |
| // only characters that need escaping are " and \n. |
| assert(Name.find_first_of("\n\"") != StringRef::npos); |
| return appendMangledQuotedName(OutName, Name); |
| } |
| |
| /// AddFastCallStdCallSuffix - Microsoft fastcall and stdcall functions require |
| /// a suffix on their name indicating the number of words of arguments they |
| /// take. |
| static void AddFastCallStdCallSuffix(SmallVectorImpl<char> &OutName, |
| const Function *F, const TargetData &TD) { |
| // Calculate arguments size total. |
| unsigned ArgWords = 0; |
| for (Function::const_arg_iterator AI = F->arg_begin(), AE = F->arg_end(); |
| AI != AE; ++AI) { |
| Type *Ty = AI->getType(); |
| // 'Dereference' type in case of byval parameter attribute |
| if (AI->hasByValAttr()) |
| Ty = cast<PointerType>(Ty)->getElementType(); |
| // Size should be aligned to DWORD boundary |
| ArgWords += ((TD.getTypeAllocSize(Ty) + 3)/4)*4; |
| } |
| |
| raw_svector_ostream(OutName) << '@' << ArgWords; |
| } |
| |
| |
| /// getNameWithPrefix - Fill OutName with the name of the appropriate prefix |
| /// and the specified global variable's name. If the global variable doesn't |
| /// have a name, this fills in a unique name for the global. |
| void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, |
| const GlobalValue *GV, |
| bool isImplicitlyPrivate) { |
| ManglerPrefixTy PrefixTy = Mangler::Default; |
| if (GV->hasPrivateLinkage() || isImplicitlyPrivate) |
| PrefixTy = Mangler::Private; |
| else if (GV->hasLinkerPrivateLinkage() || GV->hasLinkerPrivateWeakLinkage() || |
| GV->hasLinkerPrivateWeakDefAutoLinkage()) |
| PrefixTy = Mangler::LinkerPrivate; |
| |
| // If this global has a name, handle it simply. |
| if (GV->hasName()) { |
| getNameWithPrefix(OutName, GV->getName(), PrefixTy); |
| } else { |
| // Get the ID for the global, assigning a new one if we haven't got one |
| // already. |
| unsigned &ID = AnonGlobalIDs[GV]; |
| if (ID == 0) ID = NextAnonGlobalID++; |
| |
| // Must mangle the global into a unique ID. |
| getNameWithPrefix(OutName, "__unnamed_" + Twine(ID), PrefixTy); |
| } |
| |
| // If we are supposed to add a microsoft-style suffix for stdcall/fastcall, |
| // add it. |
| if (Context.getAsmInfo().hasMicrosoftFastStdCallMangling()) { |
| if (const Function *F = dyn_cast<Function>(GV)) { |
| CallingConv::ID CC = F->getCallingConv(); |
| |
| // fastcall functions need to start with @. |
| // FIXME: This logic seems unlikely to be right. |
| if (CC == CallingConv::X86_FastCall) { |
| if (OutName[0] == '_') |
| OutName[0] = '@'; |
| else |
| OutName.insert(OutName.begin(), '@'); |
| } |
| |
| // fastcall and stdcall functions usually need @42 at the end to specify |
| // the argument info. |
| FunctionType *FT = F->getFunctionType(); |
| if ((CC == CallingConv::X86_FastCall || CC == CallingConv::X86_StdCall) && |
| // "Pure" variadic functions do not receive @0 suffix. |
| (!FT->isVarArg() || FT->getNumParams() == 0 || |
| (FT->getNumParams() == 1 && F->hasStructRetAttr()))) |
| AddFastCallStdCallSuffix(OutName, F, TD); |
| } |
| } |
| } |
| |
| /// getSymbol - Return the MCSymbol for the specified global value. This |
| /// symbol is the main label that is the address of the global. |
| MCSymbol *Mangler::getSymbol(const GlobalValue *GV) { |
| SmallString<60> NameStr; |
| getNameWithPrefix(NameStr, GV, false); |
| return Context.GetOrCreateSymbol(NameStr.str()); |
| } |
| |
| |