LTOModule.cpp revision 353358
1259698Sdim//===-- LTOModule.cpp - LLVM Link Time Optimizer --------------------------===// 2259698Sdim// 3353358Sdim// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4353358Sdim// See https://llvm.org/LICENSE.txt for license information. 5353358Sdim// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6259698Sdim// 7259698Sdim//===----------------------------------------------------------------------===// 8259698Sdim// 9259698Sdim// This file implements the Link Time Optimization library. This library is 10259698Sdim// intended to be used by linker to optimize code at link time. 11259698Sdim// 12259698Sdim//===----------------------------------------------------------------------===// 13259698Sdim 14309124Sdim#include "llvm/LTO/legacy/LTOModule.h" 15259698Sdim#include "llvm/ADT/Triple.h" 16314564Sdim#include "llvm/Bitcode/BitcodeReader.h" 17327952Sdim#include "llvm/CodeGen/TargetSubtargetInfo.h" 18259698Sdim#include "llvm/IR/Constants.h" 19259698Sdim#include "llvm/IR/LLVMContext.h" 20321369Sdim#include "llvm/IR/Mangler.h" 21276479Sdim#include "llvm/IR/Metadata.h" 22259698Sdim#include "llvm/IR/Module.h" 23259698Sdim#include "llvm/MC/MCExpr.h" 24259698Sdim#include "llvm/MC/MCInst.h" 25259698Sdim#include "llvm/MC/MCParser/MCAsmParser.h" 26276479Sdim#include "llvm/MC/MCSection.h" 27259698Sdim#include "llvm/MC/MCSubtargetInfo.h" 28259698Sdim#include "llvm/MC/MCSymbol.h" 29259698Sdim#include "llvm/MC/SubtargetFeature.h" 30280031Sdim#include "llvm/Object/IRObjectFile.h" 31280031Sdim#include "llvm/Object/ObjectFile.h" 32276479Sdim#include "llvm/Support/FileSystem.h" 33259698Sdim#include "llvm/Support/Host.h" 34259698Sdim#include "llvm/Support/MemoryBuffer.h" 35259698Sdim#include "llvm/Support/Path.h" 36259698Sdim#include "llvm/Support/SourceMgr.h" 37259698Sdim#include "llvm/Support/TargetRegistry.h" 38259698Sdim#include "llvm/Support/TargetSelect.h" 39341825Sdim#include "llvm/Target/TargetLoweringObjectFile.h" 40259698Sdim#include "llvm/Transforms/Utils/GlobalStatus.h" 41276479Sdim#include <system_error> 42259698Sdimusing namespace llvm; 43280031Sdimusing namespace llvm::object; 44259698Sdim 45314564SdimLTOModule::LTOModule(std::unique_ptr<Module> M, MemoryBufferRef MBRef, 46276479Sdim llvm::TargetMachine *TM) 47314564Sdim : Mod(std::move(M)), MBRef(MBRef), _target(TM) { 48314564Sdim SymTab.addModule(Mod.get()); 49314564Sdim} 50259698Sdim 51280031SdimLTOModule::~LTOModule() {} 52280031Sdim 53259698Sdim/// isBitcodeFile - Returns 'true' if the file (or memory contents) is LLVM 54259698Sdim/// bitcode. 55280031Sdimbool LTOModule::isBitcodeFile(const void *Mem, size_t Length) { 56327952Sdim Expected<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer( 57280031Sdim MemoryBufferRef(StringRef((const char *)Mem, Length), "<mem>")); 58341825Sdim return !errorToBool(BCData.takeError()); 59259698Sdim} 60259698Sdim 61314564Sdimbool LTOModule::isBitcodeFile(StringRef Path) { 62280031Sdim ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr = 63280031Sdim MemoryBuffer::getFile(Path); 64280031Sdim if (!BufferOrErr) 65259698Sdim return false; 66280031Sdim 67327952Sdim Expected<MemoryBufferRef> BCData = IRObjectFile::findBitcodeInMemBuffer( 68280031Sdim BufferOrErr.get()->getMemBufferRef()); 69341825Sdim return !errorToBool(BCData.takeError()); 70259698Sdim} 71259698Sdim 72309124Sdimbool LTOModule::isThinLTO() { 73321369Sdim Expected<BitcodeLTOInfo> Result = getBitcodeLTOInfo(MBRef); 74314564Sdim if (!Result) { 75344779Sdim logAllUnhandledErrors(Result.takeError(), errs()); 76314564Sdim return false; 77314564Sdim } 78321369Sdim return Result->IsThinLTO; 79309124Sdim} 80309124Sdim 81280031Sdimbool LTOModule::isBitcodeForTarget(MemoryBuffer *Buffer, 82280031Sdim StringRef TriplePrefix) { 83327952Sdim Expected<MemoryBufferRef> BCOrErr = 84280031Sdim IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef()); 85341825Sdim if (errorToBool(BCOrErr.takeError())) 86280031Sdim return false; 87280031Sdim LLVMContext Context; 88314564Sdim ErrorOr<std::string> TripleOrErr = 89314564Sdim expectedToErrorOrAndEmitErrors(Context, getBitcodeTargetTriple(*BCOrErr)); 90314564Sdim if (!TripleOrErr) 91314564Sdim return false; 92314564Sdim return StringRef(*TripleOrErr).startswith(TriplePrefix); 93259698Sdim} 94259698Sdim 95296417Sdimstd::string LTOModule::getProducerString(MemoryBuffer *Buffer) { 96327952Sdim Expected<MemoryBufferRef> BCOrErr = 97296417Sdim IRObjectFile::findBitcodeInMemBuffer(Buffer->getMemBufferRef()); 98341825Sdim if (errorToBool(BCOrErr.takeError())) 99296417Sdim return ""; 100296417Sdim LLVMContext Context; 101314564Sdim ErrorOr<std::string> ProducerOrErr = expectedToErrorOrAndEmitErrors( 102314564Sdim Context, getBitcodeProducerString(*BCOrErr)); 103314564Sdim if (!ProducerOrErr) 104314564Sdim return ""; 105314564Sdim return *ProducerOrErr; 106296417Sdim} 107296417Sdim 108296417SdimErrorOr<std::unique_ptr<LTOModule>> 109314564SdimLTOModule::createFromFile(LLVMContext &Context, StringRef path, 110309124Sdim const TargetOptions &options) { 111276479Sdim ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr = 112276479Sdim MemoryBuffer::getFile(path); 113309124Sdim if (std::error_code EC = BufferOrErr.getError()) { 114309124Sdim Context.emitError(EC.message()); 115296417Sdim return EC; 116309124Sdim } 117280031Sdim std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get()); 118309124Sdim return makeLTOModule(Buffer->getMemBufferRef(), options, Context, 119309124Sdim /* ShouldBeLazy*/ false); 120259698Sdim} 121259698Sdim 122296417SdimErrorOr<std::unique_ptr<LTOModule>> 123314564SdimLTOModule::createFromOpenFile(LLVMContext &Context, int fd, StringRef path, 124309124Sdim size_t size, const TargetOptions &options) { 125296417Sdim return createFromOpenFileSlice(Context, fd, path, size, 0, options); 126259698Sdim} 127259698Sdim 128296417SdimErrorOr<std::unique_ptr<LTOModule>> 129314564SdimLTOModule::createFromOpenFileSlice(LLVMContext &Context, int fd, StringRef path, 130314564Sdim size_t map_size, off_t offset, 131314564Sdim const TargetOptions &options) { 132276479Sdim ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr = 133353358Sdim MemoryBuffer::getOpenFileSlice(sys::fs::convertFDToNativeFile(fd), path, 134353358Sdim map_size, offset); 135309124Sdim if (std::error_code EC = BufferOrErr.getError()) { 136309124Sdim Context.emitError(EC.message()); 137296417Sdim return EC; 138309124Sdim } 139280031Sdim std::unique_ptr<MemoryBuffer> Buffer = std::move(BufferOrErr.get()); 140309124Sdim return makeLTOModule(Buffer->getMemBufferRef(), options, Context, 141309124Sdim /* ShouldBeLazy */ false); 142259698Sdim} 143259698Sdim 144296417SdimErrorOr<std::unique_ptr<LTOModule>> 145296417SdimLTOModule::createFromBuffer(LLVMContext &Context, const void *mem, 146309124Sdim size_t length, const TargetOptions &options, 147296417Sdim StringRef path) { 148309124Sdim StringRef Data((const char *)mem, length); 149309124Sdim MemoryBufferRef Buffer(Data, path); 150309124Sdim return makeLTOModule(Buffer, options, Context, /* ShouldBeLazy */ false); 151259698Sdim} 152259698Sdim 153296417SdimErrorOr<std::unique_ptr<LTOModule>> 154309124SdimLTOModule::createInLocalContext(std::unique_ptr<LLVMContext> Context, 155309124Sdim const void *mem, size_t length, 156309124Sdim const TargetOptions &options, StringRef path) { 157280031Sdim StringRef Data((const char *)mem, length); 158280031Sdim MemoryBufferRef Buffer(Data, path); 159309124Sdim // If we own a context, we know this is being used only for symbol extraction, 160309124Sdim // not linking. Be lazy in that case. 161309124Sdim ErrorOr<std::unique_ptr<LTOModule>> Ret = 162309124Sdim makeLTOModule(Buffer, options, *Context, /* ShouldBeLazy */ true); 163309124Sdim if (Ret) 164309124Sdim (*Ret)->OwnedContext = std::move(Context); 165309124Sdim return Ret; 166280031Sdim} 167280031Sdim 168296417Sdimstatic ErrorOr<std::unique_ptr<Module>> 169296417SdimparseBitcodeFileImpl(MemoryBufferRef Buffer, LLVMContext &Context, 170296417Sdim bool ShouldBeLazy) { 171280031Sdim // Find the buffer. 172327952Sdim Expected<MemoryBufferRef> MBOrErr = 173280031Sdim IRObjectFile::findBitcodeInMemBuffer(Buffer); 174327952Sdim if (Error E = MBOrErr.takeError()) { 175327952Sdim std::error_code EC = errorToErrorCode(std::move(E)); 176309124Sdim Context.emitError(EC.message()); 177296417Sdim return EC; 178309124Sdim } 179259698Sdim 180280031Sdim if (!ShouldBeLazy) { 181280031Sdim // Parse the full file. 182314564Sdim return expectedToErrorOrAndEmitErrors(Context, 183314564Sdim parseBitcodeFile(*MBOrErr, Context)); 184280031Sdim } 185280031Sdim 186280031Sdim // Parse lazily. 187314564Sdim return expectedToErrorOrAndEmitErrors( 188314564Sdim Context, 189314564Sdim getLazyBitcodeModule(*MBOrErr, Context, true /*ShouldLazyLoadMetadata*/)); 190280031Sdim} 191280031Sdim 192296417SdimErrorOr<std::unique_ptr<LTOModule>> 193309124SdimLTOModule::makeLTOModule(MemoryBufferRef Buffer, const TargetOptions &options, 194309124Sdim LLVMContext &Context, bool ShouldBeLazy) { 195296417Sdim ErrorOr<std::unique_ptr<Module>> MOrErr = 196309124Sdim parseBitcodeFileImpl(Buffer, Context, ShouldBeLazy); 197296417Sdim if (std::error_code EC = MOrErr.getError()) 198296417Sdim return EC; 199296417Sdim std::unique_ptr<Module> &M = *MOrErr; 200280031Sdim 201276479Sdim std::string TripleStr = M->getTargetTriple(); 202259698Sdim if (TripleStr.empty()) 203259698Sdim TripleStr = sys::getDefaultTargetTriple(); 204259698Sdim llvm::Triple Triple(TripleStr); 205259698Sdim 206259698Sdim // find machine architecture for this module 207296417Sdim std::string errMsg; 208259698Sdim const Target *march = TargetRegistry::lookupTarget(TripleStr, errMsg); 209259698Sdim if (!march) 210341825Sdim return make_error_code(object::object_error::arch_not_found); 211259698Sdim 212259698Sdim // construct LTOModule, hand over ownership of module and target 213259698Sdim SubtargetFeatures Features; 214259698Sdim Features.getDefaultSubtargetFeatures(Triple); 215259698Sdim std::string FeatureStr = Features.getString(); 216259698Sdim // Set a default CPU for Darwin triples. 217259698Sdim std::string CPU; 218259698Sdim if (Triple.isOSDarwin()) { 219259698Sdim if (Triple.getArch() == llvm::Triple::x86_64) 220259698Sdim CPU = "core2"; 221259698Sdim else if (Triple.getArch() == llvm::Triple::x86) 222259698Sdim CPU = "yonah"; 223280031Sdim else if (Triple.getArch() == llvm::Triple::aarch64) 224276479Sdim CPU = "cyclone"; 225259698Sdim } 226259698Sdim 227309124Sdim TargetMachine *target = 228309124Sdim march->createTargetMachine(TripleStr, CPU, FeatureStr, options, None); 229259698Sdim 230314564Sdim std::unique_ptr<LTOModule> Ret(new LTOModule(std::move(M), Buffer, target)); 231296417Sdim Ret->parseSymbols(); 232276479Sdim Ret->parseMetadata(); 233276479Sdim 234296417Sdim return std::move(Ret); 235259698Sdim} 236259698Sdim 237276479Sdim/// Create a MemoryBuffer from a memory range with an optional name. 238280031Sdimstd::unique_ptr<MemoryBuffer> 239280031SdimLTOModule::makeBuffer(const void *mem, size_t length, StringRef name) { 240259698Sdim const char *startPtr = (const char*)mem; 241276479Sdim return MemoryBuffer::getMemBuffer(StringRef(startPtr, length), name, false); 242259698Sdim} 243259698Sdim 244259698Sdim/// objcClassNameFromExpression - Get string that the data pointer points to. 245259698Sdimbool 246259698SdimLTOModule::objcClassNameFromExpression(const Constant *c, std::string &name) { 247259698Sdim if (const ConstantExpr *ce = dyn_cast<ConstantExpr>(c)) { 248259698Sdim Constant *op = ce->getOperand(0); 249259698Sdim if (GlobalVariable *gvn = dyn_cast<GlobalVariable>(op)) { 250259698Sdim Constant *cn = gvn->getInitializer(); 251259698Sdim if (ConstantDataArray *ca = dyn_cast<ConstantDataArray>(cn)) { 252259698Sdim if (ca->isCString()) { 253288943Sdim name = (".objc_class_name_" + ca->getAsCString()).str(); 254259698Sdim return true; 255259698Sdim } 256259698Sdim } 257259698Sdim } 258259698Sdim } 259259698Sdim return false; 260259698Sdim} 261259698Sdim 262259698Sdim/// addObjCClass - Parse i386/ppc ObjC class data structure. 263259698Sdimvoid LTOModule::addObjCClass(const GlobalVariable *clgv) { 264259698Sdim const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer()); 265259698Sdim if (!c) return; 266259698Sdim 267259698Sdim // second slot in __OBJC,__class is pointer to superclass name 268259698Sdim std::string superclassName; 269259698Sdim if (objcClassNameFromExpression(c->getOperand(1), superclassName)) { 270280031Sdim auto IterBool = 271280031Sdim _undefines.insert(std::make_pair(superclassName, NameAndAttributes())); 272280031Sdim if (IterBool.second) { 273280031Sdim NameAndAttributes &info = IterBool.first->second; 274314564Sdim info.name = IterBool.first->first(); 275259698Sdim info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED; 276259698Sdim info.isFunction = false; 277259698Sdim info.symbol = clgv; 278259698Sdim } 279259698Sdim } 280259698Sdim 281259698Sdim // third slot in __OBJC,__class is pointer to class name 282259698Sdim std::string className; 283259698Sdim if (objcClassNameFromExpression(c->getOperand(2), className)) { 284280031Sdim auto Iter = _defines.insert(className).first; 285259698Sdim 286259698Sdim NameAndAttributes info; 287314564Sdim info.name = Iter->first(); 288259698Sdim info.attributes = LTO_SYMBOL_PERMISSIONS_DATA | 289259698Sdim LTO_SYMBOL_DEFINITION_REGULAR | LTO_SYMBOL_SCOPE_DEFAULT; 290259698Sdim info.isFunction = false; 291259698Sdim info.symbol = clgv; 292259698Sdim _symbols.push_back(info); 293259698Sdim } 294259698Sdim} 295259698Sdim 296259698Sdim/// addObjCCategory - Parse i386/ppc ObjC category data structure. 297259698Sdimvoid LTOModule::addObjCCategory(const GlobalVariable *clgv) { 298259698Sdim const ConstantStruct *c = dyn_cast<ConstantStruct>(clgv->getInitializer()); 299259698Sdim if (!c) return; 300259698Sdim 301259698Sdim // second slot in __OBJC,__category is pointer to target class name 302259698Sdim std::string targetclassName; 303259698Sdim if (!objcClassNameFromExpression(c->getOperand(1), targetclassName)) 304259698Sdim return; 305259698Sdim 306280031Sdim auto IterBool = 307280031Sdim _undefines.insert(std::make_pair(targetclassName, NameAndAttributes())); 308259698Sdim 309280031Sdim if (!IterBool.second) 310259698Sdim return; 311259698Sdim 312280031Sdim NameAndAttributes &info = IterBool.first->second; 313314564Sdim info.name = IterBool.first->first(); 314259698Sdim info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED; 315259698Sdim info.isFunction = false; 316259698Sdim info.symbol = clgv; 317259698Sdim} 318259698Sdim 319259698Sdim/// addObjCClassRef - Parse i386/ppc ObjC class list data structure. 320259698Sdimvoid LTOModule::addObjCClassRef(const GlobalVariable *clgv) { 321259698Sdim std::string targetclassName; 322259698Sdim if (!objcClassNameFromExpression(clgv->getInitializer(), targetclassName)) 323259698Sdim return; 324259698Sdim 325280031Sdim auto IterBool = 326280031Sdim _undefines.insert(std::make_pair(targetclassName, NameAndAttributes())); 327280031Sdim 328280031Sdim if (!IterBool.second) 329259698Sdim return; 330259698Sdim 331280031Sdim NameAndAttributes &info = IterBool.first->second; 332314564Sdim info.name = IterBool.first->first(); 333259698Sdim info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED; 334259698Sdim info.isFunction = false; 335259698Sdim info.symbol = clgv; 336259698Sdim} 337259698Sdim 338314564Sdimvoid LTOModule::addDefinedDataSymbol(ModuleSymbolTable::Symbol Sym) { 339276479Sdim SmallString<64> Buffer; 340276479Sdim { 341276479Sdim raw_svector_ostream OS(Buffer); 342314564Sdim SymTab.printSymbolName(OS, Sym); 343314564Sdim Buffer.c_str(); 344276479Sdim } 345276479Sdim 346314564Sdim const GlobalValue *V = Sym.get<GlobalValue *>(); 347314564Sdim addDefinedDataSymbol(Buffer, V); 348276479Sdim} 349276479Sdim 350314564Sdimvoid LTOModule::addDefinedDataSymbol(StringRef Name, const GlobalValue *v) { 351259698Sdim // Add to list of defined symbols. 352276479Sdim addDefinedSymbol(Name, v, false); 353259698Sdim 354259698Sdim if (!v->hasSection() /* || !isTargetDarwin */) 355259698Sdim return; 356259698Sdim 357259698Sdim // Special case i386/ppc ObjC data structures in magic sections: 358259698Sdim // The issue is that the old ObjC object format did some strange 359259698Sdim // contortions to avoid real linker symbols. For instance, the 360259698Sdim // ObjC class data structure is allocated statically in the executable 361259698Sdim // that defines that class. That data structures contains a pointer to 362259698Sdim // its superclass. But instead of just initializing that part of the 363259698Sdim // struct to the address of its superclass, and letting the static and 364259698Sdim // dynamic linkers do the rest, the runtime works by having that field 365259698Sdim // instead point to a C-string that is the name of the superclass. 366259698Sdim // At runtime the objc initialization updates that pointer and sets 367259698Sdim // it to point to the actual super class. As far as the linker 368259698Sdim // knows it is just a pointer to a string. But then someone wanted the 369259698Sdim // linker to issue errors at build time if the superclass was not found. 370259698Sdim // So they figured out a way in mach-o object format to use an absolute 371259698Sdim // symbols (.objc_class_name_Foo = 0) and a floating reference 372259698Sdim // (.reference .objc_class_name_Bar) to cause the linker into erroring when 373259698Sdim // a class was missing. 374259698Sdim // The following synthesizes the implicit .objc_* symbols for the linker 375259698Sdim // from the ObjC data structures generated by the front end. 376259698Sdim 377259698Sdim // special case if this data blob is an ObjC class definition 378327952Sdim if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(v)) { 379327952Sdim StringRef Section = GV->getSection(); 380327952Sdim if (Section.startswith("__OBJC,__class,")) { 381327952Sdim addObjCClass(GV); 382259698Sdim } 383259698Sdim 384327952Sdim // special case if this data blob is an ObjC category definition 385327952Sdim else if (Section.startswith("__OBJC,__category,")) { 386327952Sdim addObjCCategory(GV); 387259698Sdim } 388259698Sdim 389327952Sdim // special case if this data blob is the list of referenced classes 390327952Sdim else if (Section.startswith("__OBJC,__cls_refs,")) { 391327952Sdim addObjCClassRef(GV); 392259698Sdim } 393259698Sdim } 394259698Sdim} 395259698Sdim 396314564Sdimvoid LTOModule::addDefinedFunctionSymbol(ModuleSymbolTable::Symbol Sym) { 397276479Sdim SmallString<64> Buffer; 398276479Sdim { 399276479Sdim raw_svector_ostream OS(Buffer); 400314564Sdim SymTab.printSymbolName(OS, Sym); 401314564Sdim Buffer.c_str(); 402276479Sdim } 403276479Sdim 404314564Sdim const Function *F = cast<Function>(Sym.get<GlobalValue *>()); 405314564Sdim addDefinedFunctionSymbol(Buffer, F); 406276479Sdim} 407276479Sdim 408314564Sdimvoid LTOModule::addDefinedFunctionSymbol(StringRef Name, const Function *F) { 409259698Sdim // add to list of defined symbols 410276479Sdim addDefinedSymbol(Name, F, true); 411259698Sdim} 412259698Sdim 413314564Sdimvoid LTOModule::addDefinedSymbol(StringRef Name, const GlobalValue *def, 414276479Sdim bool isFunction) { 415259698Sdim // set alignment part log2() can have rounding errors 416259698Sdim uint32_t align = def->getAlignment(); 417276479Sdim uint32_t attr = align ? countTrailingZeros(align) : 0; 418259698Sdim 419259698Sdim // set permissions part 420259698Sdim if (isFunction) { 421259698Sdim attr |= LTO_SYMBOL_PERMISSIONS_CODE; 422259698Sdim } else { 423259698Sdim const GlobalVariable *gv = dyn_cast<GlobalVariable>(def); 424259698Sdim if (gv && gv->isConstant()) 425259698Sdim attr |= LTO_SYMBOL_PERMISSIONS_RODATA; 426259698Sdim else 427259698Sdim attr |= LTO_SYMBOL_PERMISSIONS_DATA; 428259698Sdim } 429259698Sdim 430259698Sdim // set definition part 431276479Sdim if (def->hasWeakLinkage() || def->hasLinkOnceLinkage()) 432259698Sdim attr |= LTO_SYMBOL_DEFINITION_WEAK; 433259698Sdim else if (def->hasCommonLinkage()) 434259698Sdim attr |= LTO_SYMBOL_DEFINITION_TENTATIVE; 435259698Sdim else 436259698Sdim attr |= LTO_SYMBOL_DEFINITION_REGULAR; 437259698Sdim 438259698Sdim // set scope part 439276479Sdim if (def->hasLocalLinkage()) 440276479Sdim // Ignore visibility if linkage is local. 441276479Sdim attr |= LTO_SYMBOL_SCOPE_INTERNAL; 442276479Sdim else if (def->hasHiddenVisibility()) 443259698Sdim attr |= LTO_SYMBOL_SCOPE_HIDDEN; 444259698Sdim else if (def->hasProtectedVisibility()) 445259698Sdim attr |= LTO_SYMBOL_SCOPE_PROTECTED; 446341825Sdim else if (def->canBeOmittedFromSymbolTable()) 447259698Sdim attr |= LTO_SYMBOL_SCOPE_DEFAULT_CAN_BE_HIDDEN; 448276479Sdim else 449259698Sdim attr |= LTO_SYMBOL_SCOPE_DEFAULT; 450259698Sdim 451288943Sdim if (def->hasComdat()) 452288943Sdim attr |= LTO_SYMBOL_COMDAT; 453288943Sdim 454288943Sdim if (isa<GlobalAlias>(def)) 455288943Sdim attr |= LTO_SYMBOL_ALIAS; 456288943Sdim 457280031Sdim auto Iter = _defines.insert(Name).first; 458259698Sdim 459259698Sdim // fill information structure 460259698Sdim NameAndAttributes info; 461280031Sdim StringRef NameRef = Iter->first(); 462314564Sdim info.name = NameRef; 463314564Sdim assert(NameRef.data()[NameRef.size()] == '\0'); 464259698Sdim info.attributes = attr; 465259698Sdim info.isFunction = isFunction; 466259698Sdim info.symbol = def; 467259698Sdim 468259698Sdim // add to table of symbols 469259698Sdim _symbols.push_back(info); 470259698Sdim} 471259698Sdim 472259698Sdim/// addAsmGlobalSymbol - Add a global symbol from module-level ASM to the 473259698Sdim/// defined list. 474314564Sdimvoid LTOModule::addAsmGlobalSymbol(StringRef name, 475259698Sdim lto_symbol_attributes scope) { 476280031Sdim auto IterBool = _defines.insert(name); 477259698Sdim 478259698Sdim // only add new define if not already defined 479280031Sdim if (!IterBool.second) 480259698Sdim return; 481259698Sdim 482314564Sdim NameAndAttributes &info = _undefines[IterBool.first->first()]; 483259698Sdim 484276479Sdim if (info.symbol == nullptr) { 485259698Sdim // FIXME: This is trying to take care of module ASM like this: 486259698Sdim // 487259698Sdim // module asm ".zerofill __FOO, __foo, _bar_baz_qux, 0" 488259698Sdim // 489259698Sdim // but is gross and its mother dresses it funny. Have the ASM parser give us 490259698Sdim // more details for this type of situation so that we're not guessing so 491259698Sdim // much. 492259698Sdim 493259698Sdim // fill information structure 494314564Sdim info.name = IterBool.first->first(); 495259698Sdim info.attributes = 496259698Sdim LTO_SYMBOL_PERMISSIONS_DATA | LTO_SYMBOL_DEFINITION_REGULAR | scope; 497259698Sdim info.isFunction = false; 498276479Sdim info.symbol = nullptr; 499259698Sdim 500259698Sdim // add to table of symbols 501259698Sdim _symbols.push_back(info); 502259698Sdim return; 503259698Sdim } 504259698Sdim 505259698Sdim if (info.isFunction) 506276479Sdim addDefinedFunctionSymbol(info.name, cast<Function>(info.symbol)); 507259698Sdim else 508276479Sdim addDefinedDataSymbol(info.name, info.symbol); 509259698Sdim 510259698Sdim _symbols.back().attributes &= ~LTO_SYMBOL_SCOPE_MASK; 511259698Sdim _symbols.back().attributes |= scope; 512259698Sdim} 513259698Sdim 514259698Sdim/// addAsmGlobalSymbolUndef - Add a global symbol from module-level ASM to the 515259698Sdim/// undefined list. 516314564Sdimvoid LTOModule::addAsmGlobalSymbolUndef(StringRef name) { 517280031Sdim auto IterBool = _undefines.insert(std::make_pair(name, NameAndAttributes())); 518259698Sdim 519314564Sdim _asm_undefines.push_back(IterBool.first->first()); 520259698Sdim 521259698Sdim // we already have the symbol 522280031Sdim if (!IterBool.second) 523259698Sdim return; 524259698Sdim 525276479Sdim uint32_t attr = LTO_SYMBOL_DEFINITION_UNDEFINED; 526259698Sdim attr |= LTO_SYMBOL_SCOPE_DEFAULT; 527280031Sdim NameAndAttributes &info = IterBool.first->second; 528314564Sdim info.name = IterBool.first->first(); 529259698Sdim info.attributes = attr; 530259698Sdim info.isFunction = false; 531276479Sdim info.symbol = nullptr; 532259698Sdim} 533259698Sdim 534276479Sdim/// Add a symbol which isn't defined just yet to a list to be resolved later. 535314564Sdimvoid LTOModule::addPotentialUndefinedSymbol(ModuleSymbolTable::Symbol Sym, 536276479Sdim bool isFunc) { 537259698Sdim SmallString<64> name; 538276479Sdim { 539276479Sdim raw_svector_ostream OS(name); 540314564Sdim SymTab.printSymbolName(OS, Sym); 541314564Sdim name.c_str(); 542276479Sdim } 543259698Sdim 544280031Sdim auto IterBool = _undefines.insert(std::make_pair(name, NameAndAttributes())); 545259698Sdim 546259698Sdim // we already have the symbol 547280031Sdim if (!IterBool.second) 548259698Sdim return; 549259698Sdim 550280031Sdim NameAndAttributes &info = IterBool.first->second; 551259698Sdim 552314564Sdim info.name = IterBool.first->first(); 553259698Sdim 554314564Sdim const GlobalValue *decl = Sym.dyn_cast<GlobalValue *>(); 555276479Sdim 556259698Sdim if (decl->hasExternalWeakLinkage()) 557259698Sdim info.attributes = LTO_SYMBOL_DEFINITION_WEAKUNDEF; 558259698Sdim else 559259698Sdim info.attributes = LTO_SYMBOL_DEFINITION_UNDEFINED; 560259698Sdim 561259698Sdim info.isFunction = isFunc; 562259698Sdim info.symbol = decl; 563259698Sdim} 564259698Sdim 565296417Sdimvoid LTOModule::parseSymbols() { 566314564Sdim for (auto Sym : SymTab.symbols()) { 567314564Sdim auto *GV = Sym.dyn_cast<GlobalValue *>(); 568314564Sdim uint32_t Flags = SymTab.getSymbolFlags(Sym); 569276479Sdim if (Flags & object::BasicSymbolRef::SF_FormatSpecific) 570276479Sdim continue; 571259698Sdim 572276479Sdim bool IsUndefined = Flags & object::BasicSymbolRef::SF_Undefined; 573259698Sdim 574276479Sdim if (!GV) { 575276479Sdim SmallString<64> Buffer; 576276479Sdim { 577276479Sdim raw_svector_ostream OS(Buffer); 578314564Sdim SymTab.printSymbolName(OS, Sym); 579314564Sdim Buffer.c_str(); 580259698Sdim } 581314564Sdim StringRef Name(Buffer); 582259698Sdim 583276479Sdim if (IsUndefined) 584276479Sdim addAsmGlobalSymbolUndef(Name); 585276479Sdim else if (Flags & object::BasicSymbolRef::SF_Global) 586276479Sdim addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_DEFAULT); 587276479Sdim else 588276479Sdim addAsmGlobalSymbol(Name, LTO_SYMBOL_SCOPE_INTERNAL); 589276479Sdim continue; 590259698Sdim } 591259698Sdim 592276479Sdim auto *F = dyn_cast<Function>(GV); 593276479Sdim if (IsUndefined) { 594276479Sdim addPotentialUndefinedSymbol(Sym, F != nullptr); 595276479Sdim continue; 596259698Sdim } 597259698Sdim 598276479Sdim if (F) { 599276479Sdim addDefinedFunctionSymbol(Sym); 600276479Sdim continue; 601259698Sdim } 602259698Sdim 603276479Sdim if (isa<GlobalVariable>(GV)) { 604276479Sdim addDefinedDataSymbol(Sym); 605276479Sdim continue; 606259698Sdim } 607259698Sdim 608276479Sdim assert(isa<GlobalAlias>(GV)); 609276479Sdim addDefinedDataSymbol(Sym); 610259698Sdim } 611259698Sdim 612259698Sdim // make symbols for all undefines 613259698Sdim for (StringMap<NameAndAttributes>::iterator u =_undefines.begin(), 614259698Sdim e = _undefines.end(); u != e; ++u) { 615259698Sdim // If this symbol also has a definition, then don't make an undefine because 616259698Sdim // it is a tentative definition. 617259698Sdim if (_defines.count(u->getKey())) continue; 618259698Sdim NameAndAttributes info = u->getValue(); 619259698Sdim _symbols.push_back(info); 620259698Sdim } 621259698Sdim} 622276479Sdim 623276479Sdim/// parseMetadata - Parse metadata from the module 624276479Sdimvoid LTOModule::parseMetadata() { 625288943Sdim raw_string_ostream OS(LinkerOpts); 626288943Sdim 627276479Sdim // Linker Options 628321369Sdim if (NamedMDNode *LinkerOptions = 629321369Sdim getModule().getNamedMetadata("llvm.linker.options")) { 630276479Sdim for (unsigned i = 0, e = LinkerOptions->getNumOperands(); i != e; ++i) { 631321369Sdim MDNode *MDOptions = LinkerOptions->getOperand(i); 632276479Sdim for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) { 633276479Sdim MDString *MDOption = cast<MDString>(MDOptions->getOperand(ii)); 634288943Sdim OS << " " << MDOption->getString(); 635276479Sdim } 636276479Sdim } 637276479Sdim } 638276479Sdim 639321369Sdim // Globals - we only need to do this for COFF. 640321369Sdim const Triple TT(_target->getTargetTriple()); 641321369Sdim if (!TT.isOSBinFormatCOFF()) 642321369Sdim return; 643321369Sdim Mangler M; 644288943Sdim for (const NameAndAttributes &Sym : _symbols) { 645288943Sdim if (!Sym.symbol) 646288943Sdim continue; 647321369Sdim emitLinkerFlagsForGlobalCOFF(OS, Sym.symbol, TT, M); 648288943Sdim } 649353358Sdim} 650288943Sdim 651353358Sdimlto::InputFile *LTOModule::createInputFile(const void *buffer, 652353358Sdim size_t buffer_size, const char *path, 653353358Sdim std::string &outErr) { 654353358Sdim StringRef Data((const char *)buffer, buffer_size); 655353358Sdim MemoryBufferRef BufferRef(Data, path); 656353358Sdim 657353358Sdim Expected<std::unique_ptr<lto::InputFile>> ObjOrErr = 658353358Sdim lto::InputFile::create(BufferRef); 659353358Sdim 660353358Sdim if (ObjOrErr) 661353358Sdim return ObjOrErr->release(); 662353358Sdim 663353358Sdim outErr = std::string(path) + 664353358Sdim ": Could not read LTO input file: " + toString(ObjOrErr.takeError()); 665353358Sdim return nullptr; 666276479Sdim} 667353358Sdim 668353358Sdimsize_t LTOModule::getDependentLibraryCount(lto::InputFile *input) { 669353358Sdim return input->getDependentLibraries().size(); 670353358Sdim} 671353358Sdim 672353358Sdimconst char *LTOModule::getDependentLibrary(lto::InputFile *input, size_t index, 673353358Sdim size_t *size) { 674353358Sdim StringRef S = input->getDependentLibraries()[index]; 675353358Sdim *size = S.size(); 676353358Sdim return S.data(); 677353358Sdim} 678