| //===-- Mangler.cpp - Self-contained c/asm llvm name mangler --------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // Unified name mangler for assembly backends. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/IR/Mangler.h" |
| #include "llvm/ADT/SmallString.h" |
| #include "llvm/ADT/StringExtras.h" |
| #include "llvm/ADT/Triple.h" |
| #include "llvm/ADT/Twine.h" |
| #include "llvm/IR/DataLayout.h" |
| #include "llvm/IR/DerivedTypes.h" |
| #include "llvm/IR/Function.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/Support/raw_ostream.h" |
| using namespace llvm; |
| |
| namespace { |
| enum ManglerPrefixTy { |
| Default, ///< Emit default string before each symbol. |
| Private, ///< Emit "private" prefix before each symbol. |
| LinkerPrivate ///< Emit "linker private" prefix before each symbol. |
| }; |
| } |
| |
| static void getNameWithPrefixImpl(raw_ostream &OS, const Twine &GVName, |
| ManglerPrefixTy PrefixTy, |
| const DataLayout &DL, char Prefix) { |
| SmallString<256> TmpData; |
| StringRef Name = GVName.toStringRef(TmpData); |
| assert(!Name.empty() && "getNameWithPrefix requires non-empty name"); |
| |
| // No need to do anything special if the global has the special "do not |
| // mangle" flag in the name. |
| if (Name[0] == '\1') { |
| OS << Name.substr(1); |
| return; |
| } |
| |
| if (DL.doNotMangleLeadingQuestionMark() && Name[0] == '?') |
| Prefix = '\0'; |
| |
| if (PrefixTy == Private) |
| OS << DL.getPrivateGlobalPrefix(); |
| else if (PrefixTy == LinkerPrivate) |
| OS << DL.getLinkerPrivateGlobalPrefix(); |
| |
| if (Prefix != '\0') |
| OS << Prefix; |
| |
| // If this is a simple string that doesn't need escaping, just append it. |
| OS << Name; |
| } |
| |
| static void getNameWithPrefixImpl(raw_ostream &OS, const Twine &GVName, |
| const DataLayout &DL, |
| ManglerPrefixTy PrefixTy) { |
| char Prefix = DL.getGlobalPrefix(); |
| return getNameWithPrefixImpl(OS, GVName, PrefixTy, DL, Prefix); |
| } |
| |
| void Mangler::getNameWithPrefix(raw_ostream &OS, const Twine &GVName, |
| const DataLayout &DL) { |
| return getNameWithPrefixImpl(OS, GVName, DL, Default); |
| } |
| |
| void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, |
| const Twine &GVName, const DataLayout &DL) { |
| raw_svector_ostream OS(OutName); |
| char Prefix = DL.getGlobalPrefix(); |
| return getNameWithPrefixImpl(OS, GVName, Default, DL, Prefix); |
| } |
| |
| static bool hasByteCountSuffix(CallingConv::ID CC) { |
| switch (CC) { |
| case CallingConv::X86_FastCall: |
| case CallingConv::X86_StdCall: |
| case CallingConv::X86_VectorCall: |
| return true; |
| default: |
| return false; |
| } |
| } |
| |
| /// Microsoft fastcall and stdcall functions require a suffix on their name |
| /// indicating the number of words of arguments they take. |
| static void addByteCountSuffix(raw_ostream &OS, const Function *F, |
| const DataLayout &DL) { |
| // Calculate arguments size total. |
| unsigned ArgWords = 0; |
| |
| const unsigned PtrSize = DL.getPointerSize(); |
| |
| for (const Argument &A : F->args()) { |
| // For the purposes of the byte count suffix, structs returned by pointer |
| // do not count as function arguments. |
| if (A.hasStructRetAttr()) |
| continue; |
| |
| // 'Dereference' type in case of byval or inalloca parameter attribute. |
| uint64_t AllocSize = A.hasPassPointeeByValueCopyAttr() ? |
| A.getPassPointeeByValueCopySize(DL) : |
| DL.getTypeAllocSize(A.getType()); |
| |
| // Size should be aligned to pointer size. |
| ArgWords += alignTo(AllocSize, PtrSize); |
| } |
| |
| OS << '@' << ArgWords; |
| } |
| |
| void Mangler::getNameWithPrefix(raw_ostream &OS, const GlobalValue *GV, |
| bool CannotUsePrivateLabel) const { |
| ManglerPrefixTy PrefixTy = Default; |
| if (GV->hasPrivateLinkage()) { |
| if (CannotUsePrivateLabel) |
| PrefixTy = LinkerPrivate; |
| else |
| PrefixTy = Private; |
| } |
| |
| const DataLayout &DL = GV->getParent()->getDataLayout(); |
| if (!GV->hasName()) { |
| // 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 = AnonGlobalIDs.size(); |
| |
| // Must mangle the global into a unique ID. |
| getNameWithPrefixImpl(OS, "__unnamed_" + Twine(ID), DL, PrefixTy); |
| return; |
| } |
| |
| StringRef Name = GV->getName(); |
| char Prefix = DL.getGlobalPrefix(); |
| |
| // Mangle functions with Microsoft calling conventions specially. Only do |
| // this mangling for x86_64 vectorcall and 32-bit x86. |
| const Function *MSFunc = dyn_cast<Function>(GV); |
| |
| // Don't add byte count suffixes when '\01' or '?' are in the first |
| // character. |
| if (Name.startswith("\01") || |
| (DL.doNotMangleLeadingQuestionMark() && Name.startswith("?"))) |
| MSFunc = nullptr; |
| |
| CallingConv::ID CC = |
| MSFunc ? MSFunc->getCallingConv() : (unsigned)CallingConv::C; |
| if (!DL.hasMicrosoftFastStdCallMangling() && |
| CC != CallingConv::X86_VectorCall) |
| MSFunc = nullptr; |
| if (MSFunc) { |
| if (CC == CallingConv::X86_FastCall) |
| Prefix = '@'; // fastcall functions have an @ prefix instead of _. |
| else if (CC == CallingConv::X86_VectorCall) |
| Prefix = '\0'; // vectorcall functions have no prefix. |
| } |
| |
| getNameWithPrefixImpl(OS, Name, PrefixTy, DL, Prefix); |
| |
| if (!MSFunc) |
| return; |
| |
| // If we are supposed to add a microsoft-style suffix for stdcall, fastcall, |
| // or vectorcall, add it. These functions have a suffix of @N where N is the |
| // cumulative byte size of all of the parameters to the function in decimal. |
| if (CC == CallingConv::X86_VectorCall) |
| OS << '@'; // vectorcall functions use a double @ suffix. |
| FunctionType *FT = MSFunc->getFunctionType(); |
| if (hasByteCountSuffix(CC) && |
| // "Pure" variadic functions do not receive @0 suffix. |
| (!FT->isVarArg() || FT->getNumParams() == 0 || |
| (FT->getNumParams() == 1 && MSFunc->hasStructRetAttr()))) |
| addByteCountSuffix(OS, MSFunc, DL); |
| } |
| |
| void Mangler::getNameWithPrefix(SmallVectorImpl<char> &OutName, |
| const GlobalValue *GV, |
| bool CannotUsePrivateLabel) const { |
| raw_svector_ostream OS(OutName); |
| getNameWithPrefix(OS, GV, CannotUsePrivateLabel); |
| } |
| |
| // Check if the name needs quotes to be safe for the linker to interpret. |
| static bool canBeUnquotedInDirective(char C) { |
| return isAlnum(C) || C == '_' || C == '@'; |
| } |
| |
| static bool canBeUnquotedInDirective(StringRef Name) { |
| if (Name.empty()) |
| return false; |
| |
| // If any of the characters in the string is an unacceptable character, force |
| // quotes. |
| for (char C : Name) { |
| if (!canBeUnquotedInDirective(C)) |
| return false; |
| } |
| |
| return true; |
| } |
| |
| void llvm::emitLinkerFlagsForGlobalCOFF(raw_ostream &OS, const GlobalValue *GV, |
| const Triple &TT, Mangler &Mangler) { |
| if (!GV->hasDLLExportStorageClass() || GV->isDeclaration()) |
| return; |
| |
| if (TT.isWindowsMSVCEnvironment()) |
| OS << " /EXPORT:"; |
| else |
| OS << " -export:"; |
| |
| bool NeedQuotes = GV->hasName() && !canBeUnquotedInDirective(GV->getName()); |
| if (NeedQuotes) |
| OS << "\""; |
| if (TT.isWindowsGNUEnvironment() || TT.isWindowsCygwinEnvironment()) { |
| std::string Flag; |
| raw_string_ostream FlagOS(Flag); |
| Mangler.getNameWithPrefix(FlagOS, GV, false); |
| FlagOS.flush(); |
| if (Flag[0] == GV->getParent()->getDataLayout().getGlobalPrefix()) |
| OS << Flag.substr(1); |
| else |
| OS << Flag; |
| } else { |
| Mangler.getNameWithPrefix(OS, GV, false); |
| } |
| if (NeedQuotes) |
| OS << "\""; |
| |
| if (!GV->getValueType()->isFunctionTy()) { |
| if (TT.isWindowsMSVCEnvironment()) |
| OS << ",DATA"; |
| else |
| OS << ",data"; |
| } |
| } |
| |
| void llvm::emitLinkerFlagsForUsedCOFF(raw_ostream &OS, const GlobalValue *GV, |
| const Triple &T, Mangler &M) { |
| if (!T.isWindowsMSVCEnvironment()) |
| return; |
| |
| OS << " /INCLUDE:"; |
| bool NeedQuotes = GV->hasName() && !canBeUnquotedInDirective(GV->getName()); |
| if (NeedQuotes) |
| OS << "\""; |
| M.getNameWithPrefix(OS, GV, false); |
| if (NeedQuotes) |
| OS << "\""; |
| } |
| |