| //===-- LTOModule.cpp - LLVM Link Time Optimizer --------------------------===// |
| // |
| // 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 |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file implements the Link Time Optimization library. This library is |
| // intended to be used by linker to optimize code at link time. |
| // |
| //===----------------------------------------------------------------------===// |
| |
| #include "llvm/LTO/legacy/LTOModule.h" |
| #include "llvm/Bitcode/BitcodeReader.h" |
| #include "llvm/CodeGen/TargetSubtargetInfo.h" |
| #include "llvm/IR/Constants.h" |
| #include "llvm/IR/LLVMContext.h" |
| #include "llvm/IR/Mangler.h" |
| #include "llvm/IR/Metadata.h" |
| #include "llvm/IR/Module.h" |
| #include "llvm/MC/MCExpr.h" |
| #include "llvm/MC/MCInst.h" |
| #include "llvm/MC/MCParser/MCAsmParser.h" |
| #include "llvm/MC/MCSection.h" |
| #include "llvm/MC/MCSubtargetInfo.h" |
| #include "llvm/MC/MCSymbol.h" |
| #include "llvm/MC/SubtargetFeature.h" |
| #include "llvm/MC/TargetRegistry.h" |
| #include "llvm/Object/IRObjectFile.h" |
| #include "llvm/Object/MachO.h" |
| #include "llvm/Object/ObjectFile.h" |
| #include "llvm/Support/FileSystem.h" |
| #include "llvm/Support/MemoryBuffer.h" |
| #include "llvm/Support/Path.h" |
| #include "llvm/Support/SourceMgr.h" |
| #include "llvm/Support/TargetSelect.h" |
| #include "llvm/Target/TargetLoweringObjectFile.h" |
| #include "llvm/TargetParser/Host.h" |
| #include "llvm/TargetParser/Triple.h" |
| #include "llvm/Transforms/Utils/GlobalStatus.h" |
| #include <system_error> |
| using namespace llvm; |
| using namespace llvm::object; |
| |
| LTOModule::LTOModule(std::unique_ptr<Module> M, MemoryBufferRef MBRef, |
| llvm::TargetMachine *TM) |
| : Mod(std::move(M)), MBRef(MBRef), _target(TM) { |
| assert(_target && "target machine is null"); |
| SymTab.addModule(Mod.get()); |
| } |
| |
| LTOModule::~LTOModule() = default; |
| |
| /// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM |
| /// bitcode. |
| bool LTOModule::isBitcodeFile(const void *Mem, size_t Length) { |
| Expected<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer( |
| MemoryBufferRef(StringRef((const char *)Mem, Length), "<mem>")); |
| return !errorToBool(BCData.takeError()); |
| } |
| |
| bool LTOModule::isBitcodeFile(StringRef Path) { |
| ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr = |
| MemoryBuffer::getFile(Path); |
| if (!BufferOrErr) |
| return false; |
| |
| Expected<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer( |
| BufferOrErr.get()->getMemBufferRef()); |
| return !errorToBool(BCData.takeError()); |
| } |
| |
| bool LTOModule::isThinLTO() { |
| Expected<BitcodeLTOInfo> Result = getBitcodeLTOInfo(MBRef); |
| if (!Result) { |
| logAllUnhandledErrors(Result.takeError(), errs()); |
| return false; |
| } |
| return Result->IsThinLTO; |
| } |
| |
| bool LTOModule::isBitcodeForTarget(MemoryBuffer *Buffer, |
| StringRef TriplePrefix) { |
| Expected<MemoryBufferRef> BCOrErr = |
| IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef()); |
| if (errorToBool(BCOrErr.takeError())) |
| return false; |
| LLVMContext Context; |
| ErrorOr<std::string> TripleOrErr = |
| expectedToErrorOrAndEmitErrors(Context, getBitcodeTargetTriple(*BCOrErr)); |
| if (!TripleOrErr) |
| return false; |
| return StringRef(*TripleOrErr).startswith(TriplePrefix); |
| } |
| |
| std::string LTOModule::getProducerString(MemoryBuffer *Buffer) { |
| Expected<MemoryBufferRef> BCOrErr = |
| IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef()); |
| if (errorToBool(BCOrErr.takeError())) |
| return ""; |
| LLVMContext Context; |
| ErrorOr<std::string> ProducerOrErr = expectedToErrorOrAndEmitErrors( |
| Context, getBitcodeProducerString(*BCOrErr)); |
| if (!ProducerOrErr) |
| return ""; |
| return *ProducerOrErr; |
| } |
| |
| ErrorOr<std::unique_ptr<LTOModule>> |
| LTOModule::createFromFile(LLVMContext &Context, StringRef path, |
| const TargetOptions &options) { |
| ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr = |
| MemoryBuffer::getFile(path); |
| if (std::error_code EC = BufferOrErr.getError()) { |
| Context.emitError(EC.message()); |
| return EC; |
| } |
| std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get()); |
| return makeLTOModule(Buffer->getMemBufferRef(), options, Context, |
| /* ShouldBeLazy*/ false); |
| } |
| |
| ErrorOr<std::unique_ptr<LTOModule>> |
| LTOModule::createFromOpenFile(LLVMContext &Context, int fd, StringRef path, |
| size_t size, const TargetOptions &options) { |
| return createFromOpenFileSlice(Context, fd, path, size, 0, options); |
| } |
| |
| ErrorOr<std::unique_ptr<LTOModule>> |
| LTOModule::createFromOpenFileSlice(LLVMContext &Context, int fd, StringRef path, |
| size_t map_size, off_t offset, |
| const TargetOptions &options) { |
| ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr = |
| MemoryBuffer::getOpenFileSlice(sys::fs::convertFDToNativeFile(fd), path, |
| map_size, offset); |
| if (std::error_code EC = BufferOrErr.getError()) { |
| Context.emitError(EC.message()); |
| return EC; |
| } |
| std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get()); |
| return makeLTOModule(Buffer->getMemBufferRef(), options, Context, |
| /* ShouldBeLazy */ false); |
| } |
| |
| ErrorOr<std::unique_ptr<LTOModule>> |
| LTOModule::createFromBuffer(LLVMContext &Context, const void *mem, |
| size_t length, const TargetOptions &options, |
| StringRef path) { |
| StringRef Data((const char *)mem, length); |
| MemoryBufferRef Buffer(Data, path); |
| return makeLTOModule(Buffer, options, Context, /* ShouldBeLazy */ false); |
| } |
| |
| ErrorOr<std::unique_ptr<LTOModule>> |
| LTOModule::createInLocalContext(std::unique_ptr<LLVMContext> Context, |
| const void *mem, size_t length, |
| const TargetOptions &options, StringRef path) { |
| StringRef Data((const char *)mem, length); |
| MemoryBufferRef Buffer(Data, path); |
| // If we own a context, we know this is being used only for symbol extraction, |
| // not linking. Be lazy in that case. |
| ErrorOr<std::unique_ptr<LTOModule>> Ret = |
| makeLTOModule(Buffer, options, *Context, /* ShouldBeLazy */ true); |
| if (Ret) |
| (*Ret)->OwnedContext = std::move(Context); |
| return Ret; |
| } |
| |
| static ErrorOr<std::unique_ptr<Module>> |
| parseBitcodeFileImpl(MemoryBufferRef Buffer, LLVMContext &Context, |
| bool ShouldBeLazy) { |
| // Find the buffer. |
| Expected<MemoryBufferRef> MBOrErr = |
| IRObjectFile::findBitcodeInMemBuffer(Buffer); |
| if (Error E = MBOrErr.takeError()) { |
| std::error_code EC = errorToErrorCode(std::move(E)); |
| Context.emitError(EC.message()); |
| return EC; |
| } |
| |
| if (!ShouldBeLazy) { |
| // Parse the full file. |
| return expectedToErrorOrAndEmitErrors(Context, |
| parseBitcodeFile(*MBOrErr, Context)); |
| } |
| |
| // Parse lazily. |
| return expectedToErrorOrAndEmitErrors( |
| Context, |
| getLazyBitcodeModule(*MBOrErr, Context, true /*ShouldLazyLoadMetadata*/)); |
| } |
| |
| ErrorOr<std::unique_ptr<LTOModule>> |
| LTOModule::makeLTOModule(MemoryBufferRef Buffer, const TargetOptions &options, |
| LLVMContext &Context, bool ShouldBeLazy) { |
| ErrorOr<std::unique_ptr<Module>> MOrErr = |
| parseBitcodeFileImpl(Buffer, Context, ShouldBeLazy); |
| if (std::error_code EC = MOrErr.getError()) |
| return EC; |
| std::unique_ptr<Module> &M = *MOrErr; |
| |
| std::string TripleStr = M->getTargetTriple(); |
| if (TripleStr.empty()) |
| TripleStr = sys::getDefaultTargetTriple(); |
| llvm::Triple Triple(TripleStr); |
| |
| // find machine architecture for this module |
| std::string errMsg; |
| const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg); |
| if (!march) |
| return make_error_code(object::object_error::arch_not_found); |
| |
| // construct LTOModule, hand over ownership of module and target |
| SubtargetFeatures Features; |
| Features.getDefaultSubtargetFeatures(Triple); |
| std::string FeatureStr = Features.getString(); |
| // Set a default CPU for Darwin triples. |
| std::string CPU; |
| if (Triple.isOSDarwin()) { |
| if (Triple.getArch() == llvm::Triple::x86_64) |
| CPU = "core2"; |
| else if (Triple.getArch() == llvm::Triple::x86) |
| CPU = "yonah"; |
| else if (Triple.isArm64e()) |
| CPU = "apple-a12"; |
| else if (Triple.getArch() == llvm::Triple::aarch64 || |
| Triple.getArch() == llvm::Triple::aarch64_32) |
| CPU = "cyclone"; |
| } |
| |
| TargetMachine *target = march->createTargetMachine(TripleStr, CPU, FeatureStr, |
| options, std::nullopt); |
| |
| std::unique_ptr<LTOModule> Ret(new LTOModule(std::move(M), Buffer, target)); |
| Ret->parseSymbols(); |
| Ret->parseMetadata(); |
| |
| return std::move(Ret); |
| } |
| |
| /// Create a MemoryBuffer from a memory range with an optional name. |
| std::unique_ptr<MemoryBuffer> |
| LTOModule::makeBuffer(const void *mem, size_t length, StringRef name) { |
| const char *startPtr = (const char*)mem; |
| return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), name, false); |
| } |
| |
| /// objcClassNameFromExpression - Get string that the data pointer points to. |
| bool |
| LTOModule::objcClassNameFromExpression(const Constant *c, std::string &name) { |
| if (const ConstantExpr *ce = dyn_cast<ConstantExpr>(c)) { |
| Constant *op = ce->getOperand(0); |
| if (GlobalVariable *gvn = dyn_cast<GlobalVariable>(op)) { |
| Constant *cn = gvn->getInitializer(); |
| if (ConstantDataArray *ca = dyn_cast<ConstantDataArray>(cn)) { |
| if (ca->isCString()) { |
| name = (".objc_class_name_" + ca->getAsCString()).str(); |
| return true; |
| } |
| } |
| } |
| } |
| return false; |
| } |
| |
| /// addObjCClass - Parse i386/ppc ObjC class data structure. |
| void LTOModule::addObjCClass(const GlobalVariable *clgv) { |
| const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer()); |
| if (!c) return; |
| |
| // second slot in __OBJC,__class is pointer to superclass name |
| std::string superclassName; |
| if (objcClassNameFromExpression(c->getOperand(1), superclassName)) { |
| auto IterBool = |
| _undefines.insert(std::make_pair(superclassName, NameAndAttributes())); |
| if (IterBool.second) { |
| NameAndAttributes &info = IterBool.first->second; |
| info.name = IterBool.first->first(); |
| info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED; |
| info.isFunction = false; |
| info.symbol = clgv; |
| } |
| } |
| |
| // third slot in __OBJC,__class is pointer to class name |
| std::string className; |
| if (objcClassNameFromExpression(c->getOperand(2), className)) { |
| auto Iter = _defines.insert(className).first; |
| |
| NameAndAttributes info; |
| info.name = Iter->first(); |
| info.attributes = LTO_SYMBOL_PERMISSIONS_DATA | |
| LTO_SYMBOL_DEFINITION_REGULAR | LTO_SYMBOL_SCOPE_DEFAULT; |
| info.isFunction = false; |
| info.symbol = clgv; |
| _symbols.push_back(info); |
| } |
| } |
| |
| /// addObjCCategory - Parse i386/ppc ObjC category data structure. |
| void LTOModule::addObjCCategory(const GlobalVariable *clgv) { |
| const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer()); |
| if (!c) return; |
| |
| // second slot in __OBJC,__category is pointer to target class name |
| std::string targetclassName; |
| if (!objcClassNameFromExpression(c->getOperand(1), targetclassName)) |
| return; |
| |
| auto IterBool = |
| _undefines.insert(std::make_pair(targetclassName, NameAndAttributes())); |
| |
| if (!IterBool.second) |
| return; |
| |
| NameAndAttributes &info = IterBool.first->second; |
| info.name = IterBool.first->first(); |
| info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED; |
| info.isFunction = false; |
| info.symbol = clgv; |
| } |
| |
| /// addObjCClassRef - Parse i386/ppc ObjC class list data structure. |
| void LTOModule::addObjCClassRef(const GlobalVariable *clgv) { |
| std::string targetclassName; |
| if (!objcClassNameFromExpression(clgv->getInitializer(), targetclassName)) |
| return; |
| |
| auto IterBool = |
| _undefines.insert(std::make_pair(targetclassName, NameAndAttributes())); |
| |
| if (!IterBool.second) |
| return; |
| |
| NameAndAttributes &info = IterBool.first->second; |
| info.name = IterBool.first->first(); |
| info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED; |
| info.isFunction = false; |
| info.symbol = clgv; |
| } |
| |
| void LTOModule::addDefinedDataSymbol(ModuleSymbolTable::Symbol Sym) { |
| SmallString<64> Buffer; |
| { |
| raw_svector_ostream OS(Buffer); |
| SymTab.printSymbolName(OS, Sym); |
| Buffer.c_str(); |
| } |
| |
| const GlobalValue *V = cast<GlobalValue *>(Sym); |
| addDefinedDataSymbol(Buffer, V); |
| } |
| |
| void LTOModule::addDefinedDataSymbol(StringRef Name, const GlobalValue *v) { |
| // Add to list of defined symbols. |
| addDefinedSymbol(Name, v, false); |
| |
| if (!v->hasSection() /* || !isTargetDarwin */) |
| return; |
| |
| // Special case i386/ppc ObjC data structures in magic sections: |
| // The issue is that the old ObjC object format did some strange |
| // contortions to avoid real linker symbols. For instance, the |
| // ObjC class data structure is allocated statically in the executable |
| // that defines that class. That data structures contains a pointer to |
| // its superclass. But instead of just initializing that part of the |
| // struct to the address of its superclass, and letting the static and |
| // dynamic linkers do the rest, the runtime works by having that field |
| // instead point to a C-string that is the name of the superclass. |
| // At runtime the objc initialization updates that pointer and sets |
| // it to point to the actual super class. As far as the linker |
| // knows it is just a pointer to a string. But then someone wanted the |
| // linker to issue errors at build time if the superclass was not found. |
| // So they figured out a way in mach-o object format to use an absolute |
| // symbols (.objc_class_name_Foo = 0) and a floating reference |
| // (.reference .objc_class_name_Bar) to cause the linker into erroring when |
| // a class was missing. |
| // The following synthesizes the implicit .objc_* symbols for the linker |
| // from the ObjC data structures generated by the front end. |
| |
| // special case if this data blob is an ObjC class definition |
| if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(v)) { |
| StringRef Section = GV->getSection(); |
| if (Section.startswith("__OBJC,__class,")) { |
| addObjCClass(GV); |
| } |
| |
| // special case if this data blob is an ObjC category definition |
| else if (Section.startswith("__OBJC,__category,")) { |
| addObjCCategory(GV); |
| } |
| |
| // special case if this data blob is the list of referenced classes |
| else if (Section.startswith("__OBJC,__cls_refs,")) { |
| addObjCClassRef(GV); |
| } |
| } |
| } |
| |
| void LTOModule::addDefinedFunctionSymbol(ModuleSymbolTable::Symbol Sym) { |
| SmallString<64> Buffer; |
| { |
| raw_svector_ostream OS(Buffer); |
| SymTab.printSymbolName(OS, Sym); |
| Buffer.c_str(); |
| } |
| |
| const Function *F = cast<Function>(cast<GlobalValue *>(Sym)); |
| addDefinedFunctionSymbol(Buffer, F); |
| } |
| |
| void LTOModule::addDefinedFunctionSymbol(StringRef Name, const Function *F) { |
| // add to list of defined symbols |
| addDefinedSymbol(Name, F, true); |
| } |
| |
| void LTOModule::addDefinedSymbol(StringRef Name, const GlobalValue *def, |
| bool isFunction) { |
| const GlobalObject *go = dyn_cast<GlobalObject>(def); |
| uint32_t attr = go ? Log2(go->getAlign().valueOrOne()) : 0; |
| |
| // set permissions part |
| if (isFunction) { |
| attr |= LTO_SYMBOL_PERMISSIONS_CODE; |
| } else { |
| const GlobalVariable *gv = dyn_cast<GlobalVariable>(def); |
| if (gv && gv->isConstant()) |
| attr |= LTO_SYMBOL_PERMISSIONS_RODATA; |
| else |
| attr |= LTO_SYMBOL_PERMISSIONS_DATA; |
| } |
| |
| // set definition part |
| if (def->hasWeakLinkage() || def->hasLinkOnceLinkage()) |
| attr |= LTO_SYMBOL_DEFINITION_WEAK; |
| else if (def->hasCommonLinkage()) |
| attr |= LTO_SYMBOL_DEFINITION_TENTATIVE; |
| else |
| attr |= LTO_SYMBOL_DEFINITION_REGULAR; |
| |
| // set scope part |
| if (def->hasLocalLinkage()) |
| // Ignore visibility if linkage is local. |
| attr |= LTO_SYMBOL_SCOPE_INTERNAL; |
| else if (def->hasHiddenVisibility()) |
| attr |= LTO_SYMBOL_SCOPE_HIDDEN; |
| else if (def->hasProtectedVisibility()) |
| attr |= LTO_SYMBOL_SCOPE_PROTECTED; |
| else if (def->canBeOmittedFromSymbolTable()) |
| attr |= LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN; |
| else |
| attr |= LTO_SYMBOL_SCOPE_DEFAULT; |
| |
| if (def->hasComdat()) |
| attr |= LTO_SYMBOL_COMDAT; |
| |
| if (isa<GlobalAlias>(def)) |
| attr |= LTO_SYMBOL_ALIAS; |
| |
| auto Iter = _defines.insert(Name).first; |
| |
| // fill information structure |
| NameAndAttributes info; |
| StringRef NameRef = Iter->first(); |
| info.name = NameRef; |
| assert(NameRef.data()[NameRef.size()] == '\0'); |
| info.attributes = attr; |
| info.isFunction = isFunction; |
| info.symbol = def; |
| |
| // add to table of symbols |
| _symbols.push_back(info); |
| } |
| |
| /// addAsmGlobalSymbol - Add a global symbol from module-level ASM to the |
| /// defined list. |
| void LTOModule::addAsmGlobalSymbol(StringRef name, |
| lto_symbol_attributes scope) { |
| auto IterBool = _defines.insert(name); |
| |
| // only add new define if not already defined |
| if (!IterBool.second) |
| return; |
| |
| NameAndAttributes &info = _undefines[IterBool.first->first()]; |
| |
| if (info.symbol == nullptr) { |
| // FIXME: This is trying to take care of module ASM like this: |
| // |
| // module asm ".zerofill __FOO, __foo, _bar_baz_qux, 0" |
| // |
| // but is gross and its mother dresses it funny. Have the ASM parser give us |
| // more details for this type of situation so that we're not guessing so |
| // much. |
| |
| // fill information structure |
| info.name = IterBool.first->first(); |
| info.attributes = |
| LTO_SYMBOL_PERMISSIONS_DATA | LTO_SYMBOL_DEFINITION_REGULAR | scope; |
| info.isFunction = false; |
| info.symbol = nullptr; |
| |
| // add to table of symbols |
| _symbols.push_back(info); |
| return; |
| } |
| |
| if (info.isFunction) |
| addDefinedFunctionSymbol(info.name, cast<Function>(info.symbol)); |
| else |
| addDefinedDataSymbol(info.name, info.symbol); |
| |
| _symbols.back().attributes &= ~LTO_SYMBOL_SCOPE_MASK; |
| _symbols.back().attributes |= scope; |
| } |
| |
| /// addAsmGlobalSymbolUndef - Add a global symbol from module-level ASM to the |
| /// undefined list. |
| void LTOModule::addAsmGlobalSymbolUndef(StringRef name) { |
| auto IterBool = _undefines.insert(std::make_pair(name, NameAndAttributes())); |
| |
| _asm_undefines.push_back(IterBool.first->first()); |
| |
| // we already have the symbol |
| if (!IterBool.second) |
| return; |
| |
| uint32_t attr = LTO_SYMBOL_DEFINITION_UNDEFINED; |
| attr |= LTO_SYMBOL_SCOPE_DEFAULT; |
| NameAndAttributes &info = IterBool.first->second; |
| info.name = IterBool.first->first(); |
| info.attributes = attr; |
| info.isFunction = false; |
| info.symbol = nullptr; |
| } |
| |
| /// Add a symbol which isn't defined just yet to a list to be resolved later. |
| void LTOModule::addPotentialUndefinedSymbol(ModuleSymbolTable::Symbol Sym, |
| bool isFunc) { |
| SmallString<64> name; |
| { |
| raw_svector_ostream OS(name); |
| SymTab.printSymbolName(OS, Sym); |
| name.c_str(); |
| } |
| |
| auto IterBool = |
| _undefines.insert(std::make_pair(name.str(), NameAndAttributes())); |
| |
| // we already have the symbol |
| if (!IterBool.second) |
| return; |
| |
| NameAndAttributes &info = IterBool.first->second; |
| |
| info.name = IterBool.first->first(); |
| |
| const GlobalValue *decl = dyn_cast_if_present<GlobalValue *>(Sym); |
| |
| if (decl->hasExternalWeakLinkage()) |
| info.attributes = LTO_SYMBOL_DEFINITION_WEAKUNDEF; |
| else |
| info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED; |
| |
| info.isFunction = isFunc; |
| info.symbol = decl; |
| } |
| |
| void LTOModule::parseSymbols() { |
| for (auto Sym : SymTab.symbols()) { |
| auto *GV = dyn_cast_if_present<GlobalValue *>(Sym); |
| uint32_t Flags = SymTab.getSymbolFlags(Sym); |
| if (Flags & object::BasicSymbolRef::SF_FormatSpecific) |
| continue; |
| |
| bool IsUndefined = Flags & object::BasicSymbolRef::SF_Undefined; |
| |
| if (!GV) { |
| SmallString<64> Buffer; |
| { |
| raw_svector_ostream OS(Buffer); |
| SymTab.printSymbolName(OS, Sym); |
| Buffer.c_str(); |
| } |
| StringRef Name = Buffer; |
| |
| if (IsUndefined) |
| addAsmGlobalSymbolUndef(Name); |
| else if (Flags & object::BasicSymbolRef::SF_Global) |
| addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_DEFAULT); |
| else |
| addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_INTERNAL); |
| continue; |
| } |
| |
| auto *F = dyn_cast<Function>(GV); |
| if (IsUndefined) { |
| addPotentialUndefinedSymbol(Sym, F != nullptr); |
| continue; |
| } |
| |
| if (F) { |
| addDefinedFunctionSymbol(Sym); |
| continue; |
| } |
| |
| if (isa<GlobalVariable>(GV)) { |
| addDefinedDataSymbol(Sym); |
| continue; |
| } |
| |
| assert(isa<GlobalAlias>(GV)); |
| addDefinedDataSymbol(Sym); |
| } |
| |
| // make symbols for all undefines |
| for (StringMap<NameAndAttributes>::iterator u =_undefines.begin(), |
| e = _undefines.end(); u != e; ++u) { |
| // If this symbol also has a definition, then don't make an undefine because |
| // it is a tentative definition. |
| if (_defines.count(u->getKey())) continue; |
| NameAndAttributes info = u->getValue(); |
| _symbols.push_back(info); |
| } |
| } |
| |
| /// parseMetadata - Parse metadata from the module |
| void LTOModule::parseMetadata() { |
| raw_string_ostream OS(LinkerOpts); |
| |
| // Linker Options |
| if (NamedMDNode *LinkerOptions = |
| getModule().getNamedMetadata("llvm.linker.options")) { |
| for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) { |
| MDNode *MDOptions = LinkerOptions->getOperand(i); |
| for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) { |
| MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii)); |
| OS << " " << MDOption->getString(); |
| } |
| } |
| } |
| |
| // Globals - we only need to do this for COFF. |
| const Triple TT(_target->getTargetTriple()); |
| if (!TT.isOSBinFormatCOFF()) |
| return; |
| Mangler M; |
| for (const NameAndAttributes &Sym : _symbols) { |
| if (!Sym.symbol) |
| continue; |
| emitLinkerFlagsForGlobalCOFF(OS, Sym.symbol, TT, M); |
| } |
| } |
| |
| lto::InputFile *LTOModule::createInputFile(const void *buffer, |
| size_t buffer_size, const char *path, |
| std::string &outErr) { |
| StringRef Data((const char *)buffer, buffer_size); |
| MemoryBufferRef BufferRef(Data, path); |
| |
| Expected<std::unique_ptr<lto::InputFile>> ObjOrErr = |
| lto::InputFile::create(BufferRef); |
| |
| if (ObjOrErr) |
| return ObjOrErr->release(); |
| |
| outErr = std::string(path) + |
| ": Could not read LTO input file: " + toString(ObjOrErr.takeError()); |
| return nullptr; |
| } |
| |
| size_t LTOModule::getDependentLibraryCount(lto::InputFile *input) { |
| return input->getDependentLibraries().size(); |
| } |
| |
| const char *LTOModule::getDependentLibrary(lto::InputFile *input, size_t index, |
| size_t *size) { |
| StringRef S = input->getDependentLibraries()[index]; |
| *size = S.size(); |
| return S.data(); |
| } |
| |
| Expected<uint32_t> LTOModule::getMachOCPUType() const { |
| return MachO::getCPUType(Triple(Mod->getTargetTriple())); |
| } |
| |
| Expected<uint32_t> LTOModule::getMachOCPUSubType() const { |
| return MachO::getCPUSubType(Triple(Mod->getTargetTriple())); |
| } |
| |
| bool LTOModule::hasCtorDtor() const { |
| for (auto Sym : SymTab.symbols()) { |
| if (auto *GV = dyn_cast_if_present<GlobalValue *>(Sym)) { |
| StringRef Name = GV->getName(); |
| if (Name.consume_front("llvm.global_")) { |
| if (Name.equals("ctors") || Name.equals("dtors")) |
| return true; |
| } |
| } |
| } |
| return false; |
| } |