1 //===-- gold-plugin.cpp - Plugin to gold for Link Time Optimization ------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This is a gold plugin for LLVM. It provides an LLVM implementation of the
11 // interface described in http://gcc.gnu.org/wiki/whopr/driver .
13 //===----------------------------------------------------------------------===//
15 #include "llvm/Config/config.h" // plugin-api.h requires HAVE_STDINT_H
16 #include "llvm/ADT/DenseSet.h"
17 #include "llvm/ADT/StringSet.h"
18 #include "llvm/Bitcode/ReaderWriter.h"
19 #include "llvm/CodeGen/Analysis.h"
20 #include "llvm/CodeGen/CommandFlags.h"
21 #include "llvm/IR/Constants.h"
22 #include "llvm/IR/LLVMContext.h"
23 #include "llvm/IR/Module.h"
24 #include "llvm/IR/Verifier.h"
25 #include "llvm/Linker/Linker.h"
26 #include "llvm/MC/SubtargetFeature.h"
27 #include "llvm/Object/IRObjectFile.h"
28 #include "llvm/PassManager.h"
29 #include "llvm/Support/FormattedStream.h"
30 #include "llvm/Support/Host.h"
31 #include "llvm/Support/MemoryBuffer.h"
32 #include "llvm/Support/TargetRegistry.h"
33 #include "llvm/Support/TargetSelect.h"
34 #include "llvm/Target/TargetLibraryInfo.h"
35 #include "llvm/Transforms/IPO.h"
36 #include "llvm/Transforms/IPO/PassManagerBuilder.h"
37 #include "llvm/Transforms/Utils/GlobalStatus.h"
38 #include "llvm/Transforms/Utils/ModuleUtils.h"
39 #include "llvm/Transforms/Utils/ValueMapper.h"
41 #include <plugin-api.h>
42 #include <system_error>
46 // FIXME: remove this declaration when we stop maintaining Ubuntu Quantal and
47 // Precise and Debian Wheezy (binutils 2.23 is required)
56 std::vector<ld_plugin_symbol> syms;
60 static ld_plugin_status discard_message(int level, const char *format, ...) {
61 // Die loudly. Recent versions of Gold pass ld_plugin_message as the first
62 // callback in the transfer vector. This should never be called.
66 static ld_plugin_get_input_file get_input_file = nullptr;
67 static ld_plugin_release_input_file release_input_file = nullptr;
68 static ld_plugin_add_symbols add_symbols = nullptr;
69 static ld_plugin_get_symbols get_symbols = nullptr;
70 static ld_plugin_add_input_file add_input_file = nullptr;
71 static ld_plugin_set_extra_library_path set_extra_library_path = nullptr;
72 static ld_plugin_get_view get_view = nullptr;
73 static ld_plugin_message message = discard_message;
74 static Reloc::Model RelocationModel = Reloc::Default;
75 static std::string output_name = "";
76 static std::list<claimed_file> Modules;
77 static std::vector<std::string> Cleanup;
78 static llvm::TargetOptions TargetOpts;
81 enum generate_bc { BC_NO, BC_ALSO, BC_ONLY };
82 static bool generate_api_file = false;
83 static generate_bc generate_bc_file = BC_NO;
84 static std::string bc_path;
85 static std::string obj_path;
86 static std::string extra_library_path;
87 static std::string triple;
88 static std::string mcpu;
89 // Additional options to pass into the code generator.
90 // Note: This array will contain all plugin options which are not claimed
91 // as plugin exclusive to pass to the code generator.
92 // For example, "generate-api-file" and "as"options are for the plugin
93 // use only and will not be passed.
94 static std::vector<const char *> extra;
96 static void process_plugin_option(const char* opt_)
100 llvm::StringRef opt = opt_;
102 if (opt == "generate-api-file") {
103 generate_api_file = true;
104 } else if (opt.startswith("mcpu=")) {
105 mcpu = opt.substr(strlen("mcpu="));
106 } else if (opt.startswith("extra-library-path=")) {
107 extra_library_path = opt.substr(strlen("extra_library_path="));
108 } else if (opt.startswith("mtriple=")) {
109 triple = opt.substr(strlen("mtriple="));
110 } else if (opt.startswith("obj-path=")) {
111 obj_path = opt.substr(strlen("obj-path="));
112 } else if (opt == "emit-llvm") {
113 generate_bc_file = BC_ONLY;
114 } else if (opt == "also-emit-llvm") {
115 generate_bc_file = BC_ALSO;
116 } else if (opt.startswith("also-emit-llvm=")) {
117 llvm::StringRef path = opt.substr(strlen("also-emit-llvm="));
118 generate_bc_file = BC_ALSO;
119 if (!bc_path.empty()) {
120 message(LDPL_WARNING, "Path to the output IL file specified twice. "
127 // Save this option to pass to the code generator.
128 // ParseCommandLineOptions() expects argv[0] to be program name. Lazily
131 extra.push_back("LLVMgold");
133 extra.push_back(opt_);
138 static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
140 static ld_plugin_status all_symbols_read_hook(void);
141 static ld_plugin_status cleanup_hook(void);
143 extern "C" ld_plugin_status onload(ld_plugin_tv *tv);
144 ld_plugin_status onload(ld_plugin_tv *tv) {
145 InitializeAllTargetInfos();
146 InitializeAllTargets();
147 InitializeAllTargetMCs();
148 InitializeAllAsmParsers();
149 InitializeAllAsmPrinters();
151 // We're given a pointer to the first transfer vector. We read through them
152 // until we find one where tv_tag == LDPT_NULL. The REGISTER_* tagged values
153 // contain pointers to functions that we need to call to register our own
154 // hooks. The others are addresses of functions we can use to call into gold
157 bool registeredClaimFile = false;
158 bool RegisteredAllSymbolsRead = false;
160 for (; tv->tv_tag != LDPT_NULL; ++tv) {
161 switch (tv->tv_tag) {
162 case LDPT_OUTPUT_NAME:
163 output_name = tv->tv_u.tv_string;
165 case LDPT_LINKER_OUTPUT:
166 switch (tv->tv_u.tv_val) {
168 case LDPO_DYN: // .so
169 case LDPO_PIE: // position independent executable
170 RelocationModel = Reloc::PIC_;
172 case LDPO_EXEC: // .exe
173 RelocationModel = Reloc::Static;
176 message(LDPL_ERROR, "Unknown output file type %d", tv->tv_u.tv_val);
181 options::process_plugin_option(tv->tv_u.tv_string);
183 case LDPT_REGISTER_CLAIM_FILE_HOOK: {
184 ld_plugin_register_claim_file callback;
185 callback = tv->tv_u.tv_register_claim_file;
187 if (callback(claim_file_hook) != LDPS_OK)
190 registeredClaimFile = true;
192 case LDPT_REGISTER_ALL_SYMBOLS_READ_HOOK: {
193 ld_plugin_register_all_symbols_read callback;
194 callback = tv->tv_u.tv_register_all_symbols_read;
196 if (callback(all_symbols_read_hook) != LDPS_OK)
199 RegisteredAllSymbolsRead = true;
201 case LDPT_REGISTER_CLEANUP_HOOK: {
202 ld_plugin_register_cleanup callback;
203 callback = tv->tv_u.tv_register_cleanup;
205 if (callback(cleanup_hook) != LDPS_OK)
208 case LDPT_GET_INPUT_FILE:
209 get_input_file = tv->tv_u.tv_get_input_file;
211 case LDPT_RELEASE_INPUT_FILE:
212 release_input_file = tv->tv_u.tv_release_input_file;
214 case LDPT_ADD_SYMBOLS:
215 add_symbols = tv->tv_u.tv_add_symbols;
217 case LDPT_GET_SYMBOLS_V2:
218 get_symbols = tv->tv_u.tv_get_symbols;
220 case LDPT_ADD_INPUT_FILE:
221 add_input_file = tv->tv_u.tv_add_input_file;
223 case LDPT_SET_EXTRA_LIBRARY_PATH:
224 set_extra_library_path = tv->tv_u.tv_set_extra_library_path;
227 get_view = tv->tv_u.tv_get_view;
230 message = tv->tv_u.tv_message;
237 if (!registeredClaimFile) {
238 message(LDPL_ERROR, "register_claim_file not passed to LLVMgold.");
242 message(LDPL_ERROR, "add_symbols not passed to LLVMgold.");
246 if (!RegisteredAllSymbolsRead)
249 if (!get_input_file) {
250 message(LDPL_ERROR, "get_input_file not passed to LLVMgold.");
253 if (!release_input_file) {
254 message(LDPL_ERROR, "relesase_input_file not passed to LLVMgold.");
261 static const GlobalObject *getBaseObject(const GlobalValue &GV) {
262 if (auto *GA = dyn_cast<GlobalAlias>(&GV))
263 return GA->getBaseObject();
264 return cast<GlobalObject>(&GV);
267 /// Called by gold to see whether this file is one that our plugin can handle.
268 /// We'll try to open it and register all the symbols with add_symbol if
270 static ld_plugin_status claim_file_hook(const ld_plugin_input_file *file,
273 MemoryBufferRef BufferRef;
274 std::unique_ptr<MemoryBuffer> Buffer;
277 if (get_view(file->handle, &view) != LDPS_OK) {
278 message(LDPL_ERROR, "Failed to get a view of %s", file->name);
281 BufferRef = MemoryBufferRef(StringRef((char *)view, file->filesize), "");
284 // Gold has found what might be IR part-way inside of a file, such as
287 offset = file->offset;
289 ErrorOr<std::unique_ptr<MemoryBuffer>> BufferOrErr =
290 MemoryBuffer::getOpenFileSlice(file->fd, file->name, file->filesize,
292 if (std::error_code EC = BufferOrErr.getError()) {
293 message(LDPL_ERROR, EC.message().c_str());
296 Buffer = std::move(BufferOrErr.get());
297 BufferRef = Buffer->getMemBufferRef();
300 ErrorOr<std::unique_ptr<object::IRObjectFile>> ObjOrErr =
301 object::IRObjectFile::createIRObjectFile(BufferRef, Context);
302 std::error_code EC = ObjOrErr.getError();
303 if (EC == BitcodeError::InvalidBitcodeSignature ||
304 EC == object::object_error::invalid_file_type ||
305 EC == object::object_error::bitcode_section_not_found)
311 message(LDPL_ERROR, "LLVM gold plugin has failed to create LTO module: %s",
312 EC.message().c_str());
315 std::unique_ptr<object::IRObjectFile> Obj = std::move(*ObjOrErr);
317 Modules.resize(Modules.size() + 1);
318 claimed_file &cf = Modules.back();
320 cf.handle = file->handle;
322 for (auto &Sym : Obj->symbols()) {
323 uint32_t Symflags = Sym.getFlags();
324 if (!(Symflags & object::BasicSymbolRef::SF_Global))
327 if (Symflags & object::BasicSymbolRef::SF_FormatSpecific)
330 cf.syms.push_back(ld_plugin_symbol());
331 ld_plugin_symbol &sym = cf.syms.back();
332 sym.version = nullptr;
334 SmallString<64> Name;
336 raw_svector_ostream OS(Name);
339 sym.name = strdup(Name.c_str());
341 const GlobalValue *GV = Obj->getSymbolGV(Sym.getRawDataRefImpl());
343 sym.visibility = LDPV_DEFAULT;
345 switch (GV->getVisibility()) {
346 case GlobalValue::DefaultVisibility:
347 sym.visibility = LDPV_DEFAULT;
349 case GlobalValue::HiddenVisibility:
350 sym.visibility = LDPV_HIDDEN;
352 case GlobalValue::ProtectedVisibility:
353 sym.visibility = LDPV_PROTECTED;
358 if (Symflags & object::BasicSymbolRef::SF_Undefined) {
359 sym.def = LDPK_UNDEF;
360 if (GV && GV->hasExternalWeakLinkage())
361 sym.def = LDPK_WEAKUNDEF;
365 assert(!GV->hasExternalWeakLinkage() &&
366 !GV->hasAvailableExternallyLinkage() && "Not a declaration!");
367 if (GV->hasCommonLinkage())
368 sym.def = LDPK_COMMON;
369 else if (GV->isWeakForLinker())
370 sym.def = LDPK_WEAKDEF;
375 sym.comdat_key = nullptr;
377 const GlobalObject *Base = getBaseObject(*GV);
379 message(LDPL_FATAL, "Unable to determine comdat of alias!");
380 const Comdat *C = Base->getComdat();
382 sym.comdat_key = strdup(C->getName().str().c_str());
383 else if (Base->hasWeakLinkage() || Base->hasLinkOnceLinkage())
384 sym.comdat_key = strdup(sym.name);
387 sym.resolution = LDPR_UNKNOWN;
390 if (!cf.syms.empty()) {
391 if (add_symbols(cf.handle, cf.syms.size(), &cf.syms[0]) != LDPS_OK) {
392 message(LDPL_ERROR, "Unable to add symbols!");
400 static void keepGlobalValue(GlobalValue &GV,
401 std::vector<GlobalAlias *> &KeptAliases) {
402 assert(!GV.hasLocalLinkage());
404 if (auto *GA = dyn_cast<GlobalAlias>(&GV))
405 KeptAliases.push_back(GA);
407 switch (GV.getLinkage()) {
410 case GlobalValue::LinkOnceAnyLinkage:
411 GV.setLinkage(GlobalValue::WeakAnyLinkage);
413 case GlobalValue::LinkOnceODRLinkage:
414 GV.setLinkage(GlobalValue::WeakODRLinkage);
418 assert(!GV.isDiscardableIfUnused());
421 static bool isDeclaration(const GlobalValue &V) {
422 if (V.hasAvailableExternallyLinkage())
425 if (V.isMaterializable())
428 return V.isDeclaration();
431 static void internalize(GlobalValue &GV) {
432 if (isDeclaration(GV))
433 return; // We get here if there is a matching asm definition.
434 if (!GV.hasLocalLinkage())
435 GV.setLinkage(GlobalValue::InternalLinkage);
438 static void drop(GlobalValue &GV) {
439 if (auto *F = dyn_cast<Function>(&GV)) {
441 F->setComdat(nullptr); // Should deleteBody do this?
445 if (auto *Var = dyn_cast<GlobalVariable>(&GV)) {
446 Var->setInitializer(nullptr);
448 GlobalValue::ExternalLinkage); // Should setInitializer do this?
449 Var->setComdat(nullptr); // and this?
453 auto &Alias = cast<GlobalAlias>(GV);
454 Module &M = *Alias.getParent();
455 PointerType &Ty = *cast<PointerType>(Alias.getType());
456 GlobalValue::LinkageTypes L = Alias.getLinkage();
458 new GlobalVariable(M, Ty.getElementType(), /*isConstant*/ false, L,
459 /*Initializer*/ nullptr);
460 Var->takeName(&Alias);
461 Alias.replaceAllUsesWith(Var);
462 Alias.eraseFromParent();
465 static const char *getResolutionName(ld_plugin_symbol_resolution R) {
471 case LDPR_PREVAILING_DEF:
472 return "PREVAILING_DEF";
473 case LDPR_PREVAILING_DEF_IRONLY:
474 return "PREVAILING_DEF_IRONLY";
475 case LDPR_PREEMPTED_REG:
476 return "PREEMPTED_REG";
477 case LDPR_PREEMPTED_IR:
478 return "PREEMPTED_IR";
479 case LDPR_RESOLVED_IR:
480 return "RESOLVED_IR";
481 case LDPR_RESOLVED_EXEC:
482 return "RESOLVED_EXEC";
483 case LDPR_RESOLVED_DYN:
484 return "RESOLVED_DYN";
485 case LDPR_PREVAILING_DEF_IRONLY_EXP:
486 return "PREVAILING_DEF_IRONLY_EXP";
488 llvm_unreachable("Unknown resolution");
491 static GlobalObject *makeInternalReplacement(GlobalObject *GO) {
492 Module *M = GO->getParent();
494 if (auto *F = dyn_cast<Function>(GO)) {
495 auto *NewF = Function::Create(F->getFunctionType(), F->getLinkage(),
498 ValueToValueMapTy VM;
499 Function::arg_iterator NewI = NewF->arg_begin();
500 for (auto &Arg : F->args()) {
501 NewI->setName(Arg.getName());
506 NewF->getBasicBlockList().splice(NewF->end(), F->getBasicBlockList());
507 for (auto &BB : *NewF) {
508 for (auto &Inst : BB)
509 RemapInstruction(&Inst, VM, RF_IgnoreMissingEntries);
515 auto *Var = cast<GlobalVariable>(GO);
516 Ret = new GlobalVariable(
517 *M, Var->getType()->getElementType(), Var->isConstant(),
518 Var->getLinkage(), Var->getInitializer(), Var->getName(),
519 nullptr, Var->getThreadLocalMode(), Var->getType()->getAddressSpace(),
520 Var->isExternallyInitialized());
521 Var->setInitializer(nullptr);
523 Ret->copyAttributesFrom(GO);
524 Ret->setLinkage(GlobalValue::InternalLinkage);
525 Ret->setComdat(GO->getComdat());
531 class LocalValueMaterializer : public ValueMaterializer {
532 DenseSet<GlobalValue *> &Dropped;
535 LocalValueMaterializer(DenseSet<GlobalValue *> &Dropped) : Dropped(Dropped) {}
536 Value *materializeValueFor(Value *V) override;
540 Value *LocalValueMaterializer::materializeValueFor(Value *V) {
541 auto *GV = dyn_cast<GlobalValue>(V);
544 if (!Dropped.count(GV))
546 assert(!isa<GlobalAlias>(GV) && "Found alias point to weak alias.");
547 return makeInternalReplacement(cast<GlobalObject>(GV));
550 static Constant *mapConstantToLocalCopy(Constant *C, ValueToValueMapTy &VM,
551 LocalValueMaterializer *Materializer) {
552 return MapValue(C, VM, RF_IgnoreMissingEntries, nullptr, Materializer);
555 static std::unique_ptr<Module>
556 getModuleForFile(LLVMContext &Context, claimed_file &F, raw_fd_ostream *ApiFile,
557 StringSet<> &Internalize, StringSet<> &Maybe) {
558 ld_plugin_input_file File;
559 if (get_input_file(F.handle, &File) != LDPS_OK)
560 message(LDPL_FATAL, "Failed to get file information");
562 if (get_symbols(F.handle, F.syms.size(), &F.syms[0]) != LDPS_OK)
563 message(LDPL_FATAL, "Failed to get symbol information");
566 if (get_view(F.handle, &View) != LDPS_OK)
567 message(LDPL_FATAL, "Failed to get a view of file");
569 llvm::ErrorOr<MemoryBufferRef> MBOrErr =
570 object::IRObjectFile::findBitcodeInMemBuffer(
571 MemoryBufferRef(StringRef((const char *)View, File.filesize), ""));
572 if (std::error_code EC = MBOrErr.getError())
573 message(LDPL_FATAL, "Could not read bitcode from file : %s",
574 EC.message().c_str());
576 std::unique_ptr<MemoryBuffer> Buffer =
577 MemoryBuffer::getMemBuffer(MBOrErr->getBuffer(), "", false);
579 if (release_input_file(F.handle) != LDPS_OK)
580 message(LDPL_FATAL, "Failed to release file information");
582 ErrorOr<Module *> MOrErr = getLazyBitcodeModule(std::move(Buffer), Context);
584 if (std::error_code EC = MOrErr.getError())
585 message(LDPL_FATAL, "Could not read bitcode from file : %s",
586 EC.message().c_str());
588 std::unique_ptr<Module> M(MOrErr.get());
590 SmallPtrSet<GlobalValue *, 8> Used;
591 collectUsedGlobalVariables(*M, Used, /*CompilerUsed*/ false);
593 DenseSet<GlobalValue *> Drop;
594 std::vector<GlobalAlias *> KeptAliases;
595 for (ld_plugin_symbol &Sym : F.syms) {
596 ld_plugin_symbol_resolution Resolution =
597 (ld_plugin_symbol_resolution)Sym.resolution;
599 if (options::generate_api_file)
600 *ApiFile << Sym.name << ' ' << getResolutionName(Resolution) << '\n';
602 GlobalValue *GV = M->getNamedValue(Sym.name);
604 continue; // Asm symbol.
606 if (Resolution != LDPR_PREVAILING_DEF_IRONLY && GV->hasCommonLinkage()) {
607 // Common linkage is special. There is no single symbol that wins the
608 // resolution. Instead we have to collect the maximum alignment and size.
609 // The IR linker does that for us if we just pass it every common GV.
610 // We still have to keep track of LDPR_PREVAILING_DEF_IRONLY so we
611 // internalize once the IR linker has done its job.
615 switch (Resolution) {
617 llvm_unreachable("Unexpected resolution");
619 case LDPR_RESOLVED_IR:
620 case LDPR_RESOLVED_EXEC:
621 case LDPR_RESOLVED_DYN:
623 assert(isDeclaration(*GV));
626 case LDPR_PREVAILING_DEF_IRONLY: {
627 keepGlobalValue(*GV, KeptAliases);
628 if (!Used.count(GV)) {
629 // Since we use the regular lib/Linker, we cannot just internalize GV
630 // now or it will not be copied to the merged module. Instead we force
631 // it to be copied and then internalize it.
632 Internalize.insert(Sym.name);
637 case LDPR_PREVAILING_DEF:
638 keepGlobalValue(*GV, KeptAliases);
641 case LDPR_PREEMPTED_IR:
642 // Gold might have selected a linkonce_odr and preempted a weak_odr.
643 // In that case we have to make sure we don't end up internalizing it.
644 if (!GV->isDiscardableIfUnused())
645 Maybe.erase(Sym.name);
648 case LDPR_PREEMPTED_REG:
652 case LDPR_PREVAILING_DEF_IRONLY_EXP: {
653 // We can only check for address uses after we merge the modules. The
654 // reason is that this GV might have a copy in another module
655 // and in that module the address might be significant, but that
656 // copy will be LDPR_PREEMPTED_IR.
657 if (GV->hasLinkOnceODRLinkage())
658 Maybe.insert(Sym.name);
659 keepGlobalValue(*GV, KeptAliases);
665 free(Sym.comdat_key);
667 Sym.comdat_key = nullptr;
671 // This is horrible. Given how lazy loading is implemented, dropping
672 // the body while there is a materializer present doesn't work, the
673 // linker will just read the body back.
674 M->materializeAllPermanently();
676 ValueToValueMapTy VM;
677 LocalValueMaterializer Materializer(Drop);
678 for (GlobalAlias *GA : KeptAliases) {
679 // Gold told us to keep GA. It is possible that a GV usied in the aliasee
680 // expression is being dropped. If that is the case, that GV must be copied.
681 Constant *Aliasee = GA->getAliasee();
682 Constant *Replacement = mapConstantToLocalCopy(Aliasee, VM, &Materializer);
683 if (Aliasee != Replacement)
684 GA->setAliasee(Replacement);
687 for (auto *GV : Drop)
693 static void runLTOPasses(Module &M, TargetMachine &TM) {
695 PassManagerBuilder PMB;
696 PMB.LibraryInfo = new TargetLibraryInfo(Triple(TM.getTargetTriple()));
697 PMB.Inliner = createFunctionInliningPass();
698 PMB.VerifyInput = true;
699 PMB.VerifyOutput = true;
700 PMB.populateLTOPassManager(passes, &TM);
704 static void codegen(Module &M) {
705 const std::string &TripleStr = M.getTargetTriple();
706 Triple TheTriple(TripleStr);
709 const Target *TheTarget = TargetRegistry::lookupTarget(TripleStr, ErrMsg);
711 message(LDPL_FATAL, "Target not found: %s", ErrMsg.c_str());
713 if (unsigned NumOpts = options::extra.size())
714 cl::ParseCommandLineOptions(NumOpts, &options::extra[0]);
716 SubtargetFeatures Features;
717 Features.getDefaultSubtargetFeatures(TheTriple);
718 for (const std::string &A : MAttrs)
719 Features.AddFeature(A);
721 TargetOptions Options = InitTargetOptionsFromCodeGenFlags();
722 std::unique_ptr<TargetMachine> TM(TheTarget->createTargetMachine(
723 TripleStr, options::mcpu, Features.getString(), Options, RelocationModel,
724 CodeModel::Default, CodeGenOpt::Aggressive));
726 runLTOPasses(M, *TM);
728 PassManager CodeGenPasses;
729 CodeGenPasses.add(new DataLayoutPass());
731 SmallString<128> Filename;
733 if (options::obj_path.empty()) {
735 sys::fs::createTemporaryFile("lto-llvm", "o", FD, Filename);
737 message(LDPL_FATAL, "Could not create temorary file: %s",
738 EC.message().c_str());
740 Filename = options::obj_path;
742 sys::fs::openFileForWrite(Filename.c_str(), FD, sys::fs::F_None);
744 message(LDPL_FATAL, "Could not open file: %s", EC.message().c_str());
748 raw_fd_ostream OS(FD, true);
749 formatted_raw_ostream FOS(OS);
751 if (TM->addPassesToEmitFile(CodeGenPasses, FOS,
752 TargetMachine::CGFT_ObjectFile))
753 message(LDPL_FATAL, "Failed to setup codegen");
754 CodeGenPasses.run(M);
757 if (add_input_file(Filename.c_str()) != LDPS_OK)
759 "Unable to add .o file to the link. File left behind in: %s",
762 if (options::obj_path.empty())
763 Cleanup.push_back(Filename.c_str());
766 /// gold informs us that all symbols have been read. At this point, we use
767 /// get_symbols to see if any of our definitions have been overridden by a
768 /// native object file. Then, perform optimization and codegen.
769 static ld_plugin_status allSymbolsReadHook(raw_fd_ostream *ApiFile) {
774 std::unique_ptr<Module> Combined(new Module("ld-temp.o", Context));
775 Linker L(Combined.get());
777 std::string DefaultTriple = sys::getDefaultTargetTriple();
779 StringSet<> Internalize;
781 for (claimed_file &F : Modules) {
782 std::unique_ptr<Module> M =
783 getModuleForFile(Context, F, ApiFile, Internalize, Maybe);
784 if (!options::triple.empty())
785 M->setTargetTriple(options::triple.c_str());
786 else if (M->getTargetTriple().empty()) {
787 M->setTargetTriple(DefaultTriple);
791 if (L.linkInModule(M.get(), &ErrMsg))
792 message(LDPL_FATAL, "Failed to link module: %s", ErrMsg.c_str());
795 for (const auto &Name : Internalize) {
796 GlobalValue *GV = Combined->getNamedValue(Name.first());
801 for (const auto &Name : Maybe) {
802 GlobalValue *GV = Combined->getNamedValue(Name.first());
805 GV->setLinkage(GlobalValue::LinkOnceODRLinkage);
806 if (canBeOmittedFromSymbolTable(GV))
810 if (options::generate_bc_file != options::BC_NO) {
812 if (options::generate_bc_file == options::BC_ONLY)
814 else if (!options::bc_path.empty())
815 path = options::bc_path;
817 path = output_name + ".bc";
820 raw_fd_ostream OS(path, EC, sys::fs::OpenFlags::F_None);
822 message(LDPL_FATAL, "Failed to write the output file.");
823 WriteBitcodeToFile(L.getModule(), OS);
825 if (options::generate_bc_file == options::BC_ONLY)
829 codegen(*L.getModule());
831 if (!options::extra_library_path.empty() &&
832 set_extra_library_path(options::extra_library_path.c_str()) != LDPS_OK)
833 message(LDPL_FATAL, "Unable to set the extra library path.");
838 static ld_plugin_status all_symbols_read_hook(void) {
839 ld_plugin_status Ret;
840 if (!options::generate_api_file) {
841 Ret = allSymbolsReadHook(nullptr);
844 raw_fd_ostream ApiFile("apifile.txt", EC, sys::fs::F_None);
846 message(LDPL_FATAL, "Unable to open apifile.txt for writing: %s",
847 EC.message().c_str());
848 Ret = allSymbolsReadHook(&ApiFile);
851 if (options::generate_bc_file == options::BC_ONLY)
857 static ld_plugin_status cleanup_hook(void) {
858 for (std::string &Name : Cleanup) {
859 std::error_code EC = sys::fs::remove(Name);
861 message(LDPL_ERROR, "Failed to delete '%s': %s", Name.c_str(),
862 EC.message().c_str());