//===-lto.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-c/lto.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/StringExtras.h" #include "llvm/Bitcode/BitcodeReader.h" #include "llvm/CodeGen/CommandFlags.h" #include "llvm/IR/DiagnosticInfo.h" #include "llvm/IR/DiagnosticPrinter.h" #include "llvm/IR/LLVMContext.h" #include "llvm/LTO/LTO.h" #include "llvm/LTO/legacy/LTOCodeGenerator.h" #include "llvm/LTO/legacy/LTOModule.h" #include "llvm/LTO/legacy/ThinLTOCodeGenerator.h" #include "llvm/Support/MemoryBuffer.h" #include "llvm/Support/Signals.h" #include "llvm/Support/TargetSelect.h" #include "llvm/Support/raw_ostream.h" using namespace llvm; static codegen::RegisterCodeGenFlags CGF; // extra command-line flags needed for LTOCodeGenerator static cl::opt OptLevel("O", cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] " "(default = '-O2')"), cl::Prefix, cl::ZeroOrMore, cl::init('2')); static cl::opt EnableFreestanding( "lto-freestanding", cl::init(false), cl::desc("Enable Freestanding (disable builtins / TLI) during LTO")); #ifdef NDEBUG static bool VerifyByDefault = false; #else static bool VerifyByDefault = true; #endif static cl::opt DisableVerify( "disable-llvm-verifier", cl::init(!VerifyByDefault), cl::desc("Don't run the LLVM verifier during the optimization pipeline")); // Holds most recent error string. // *** Not thread safe *** static std::string sLastErrorString; // Holds the initialization state of the LTO module. // *** Not thread safe *** static bool initialized = false; // Represent the state of parsing command line debug options. static enum class OptParsingState { NotParsed, // Initial state. Early, // After lto_set_debug_options is called. Done // After maybeParseOptions is called. } optionParsingState = OptParsingState::NotParsed; static LLVMContext *LTOContext = nullptr; struct LTOToolDiagnosticHandler : public DiagnosticHandler { bool handleDiagnostics(const DiagnosticInfo &DI) override { if (DI.getSeverity() != DS_Error) { DiagnosticPrinterRawOStream DP(errs()); DI.print(DP); errs() << '\n'; return true; } sLastErrorString = ""; { raw_string_ostream Stream(sLastErrorString); DiagnosticPrinterRawOStream DP(Stream); DI.print(DP); } return true; } }; // Initialize the configured targets if they have not been initialized. static void lto_initialize() { if (!initialized) { #ifdef _WIN32 // Dialog box on crash disabling doesn't work across DLL boundaries, so do // it here. llvm::sys::DisableSystemDialogsOnCrash(); #endif InitializeAllTargetInfos(); InitializeAllTargets(); InitializeAllTargetMCs(); InitializeAllAsmParsers(); InitializeAllAsmPrinters(); InitializeAllDisassemblers(); static LLVMContext Context; LTOContext = &Context; LTOContext->setDiagnosticHandler( std::make_unique(), true); initialized = true; } } namespace { static void handleLibLTODiagnostic(lto_codegen_diagnostic_severity_t Severity, const char *Msg, void *) { sLastErrorString = Msg; } // This derived class owns the native object file. This helps implement the // libLTO API semantics, which require that the code generator owns the object // file. struct LibLTOCodeGenerator : LTOCodeGenerator { LibLTOCodeGenerator() : LTOCodeGenerator(*LTOContext) { init(); } LibLTOCodeGenerator(std::unique_ptr Context) : LTOCodeGenerator(*Context), OwnedContext(std::move(Context)) { init(); } // Reset the module first in case MergedModule is created in OwnedContext. // Module must be destructed before its context gets destructed. ~LibLTOCodeGenerator() { resetMergedModule(); } void init() { setDiagnosticHandler(handleLibLTODiagnostic, nullptr); } std::unique_ptr NativeObjectFile; std::unique_ptr OwnedContext; }; } DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LibLTOCodeGenerator, lto_code_gen_t) DEFINE_SIMPLE_CONVERSION_FUNCTIONS(ThinLTOCodeGenerator, thinlto_code_gen_t) DEFINE_SIMPLE_CONVERSION_FUNCTIONS(LTOModule, lto_module_t) // Convert the subtarget features into a string to pass to LTOCodeGenerator. static void lto_add_attrs(lto_code_gen_t cg) { LTOCodeGenerator *CG = unwrap(cg); CG->setAttrs(codegen::getMAttrs()); if (OptLevel < '0' || OptLevel > '3') report_fatal_error("Optimization level must be between 0 and 3"); CG->setOptLevel(OptLevel - '0'); CG->setFreestanding(EnableFreestanding); CG->setDisableVerify(DisableVerify); } extern const char* lto_get_version() { return LTOCodeGenerator::getVersionString(); } const char* lto_get_error_message() { return sLastErrorString.c_str(); } bool lto_module_is_object_file(const char* path) { return LTOModule::isBitcodeFile(StringRef(path)); } bool lto_module_is_object_file_for_target(const char* path, const char* target_triplet_prefix) { ErrorOr> Buffer = MemoryBuffer::getFile(path); if (!Buffer) return false; return LTOModule::isBitcodeForTarget(Buffer->get(), StringRef(target_triplet_prefix)); } bool lto_module_has_objc_category(const void *mem, size_t length) { std::unique_ptr Buffer(LTOModule::makeBuffer(mem, length)); if (!Buffer) return false; LLVMContext Ctx; ErrorOr Result = expectedToErrorOrAndEmitErrors( Ctx, llvm::isBitcodeContainingObjCCategory(*Buffer)); return Result && *Result; } bool lto_module_is_object_file_in_memory(const void* mem, size_t length) { return LTOModule::isBitcodeFile(mem, length); } bool lto_module_is_object_file_in_memory_for_target(const void* mem, size_t length, const char* target_triplet_prefix) { std::unique_ptr buffer(LTOModule::makeBuffer(mem, length)); if (!buffer) return false; return LTOModule::isBitcodeForTarget(buffer.get(), StringRef(target_triplet_prefix)); } lto_module_t lto_module_create(const char* path) { lto_initialize(); llvm::TargetOptions Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple()); ErrorOr> M = LTOModule::createFromFile(*LTOContext, StringRef(path), Options); if (!M) return nullptr; return wrap(M->release()); } lto_module_t lto_module_create_from_fd(int fd, const char *path, size_t size) { lto_initialize(); llvm::TargetOptions Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple()); ErrorOr> M = LTOModule::createFromOpenFile( *LTOContext, fd, StringRef(path), size, Options); if (!M) return nullptr; return wrap(M->release()); } lto_module_t lto_module_create_from_fd_at_offset(int fd, const char *path, size_t file_size, size_t map_size, off_t offset) { lto_initialize(); llvm::TargetOptions Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple()); ErrorOr> M = LTOModule::createFromOpenFileSlice( *LTOContext, fd, StringRef(path), map_size, offset, Options); if (!M) return nullptr; return wrap(M->release()); } lto_module_t lto_module_create_from_memory(const void* mem, size_t length) { lto_initialize(); llvm::TargetOptions Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple()); ErrorOr> M = LTOModule::createFromBuffer(*LTOContext, mem, length, Options); if (!M) return nullptr; return wrap(M->release()); } lto_module_t lto_module_create_from_memory_with_path(const void* mem, size_t length, const char *path) { lto_initialize(); llvm::TargetOptions Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple()); ErrorOr> M = LTOModule::createFromBuffer( *LTOContext, mem, length, Options, StringRef(path)); if (!M) return nullptr; return wrap(M->release()); } lto_module_t lto_module_create_in_local_context(const void *mem, size_t length, const char *path) { lto_initialize(); llvm::TargetOptions Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple()); // Create a local context. Ownership will be transferred to LTOModule. std::unique_ptr Context = std::make_unique(); Context->setDiagnosticHandler(std::make_unique(), true); ErrorOr> M = LTOModule::createInLocalContext( std::move(Context), mem, length, Options, StringRef(path)); if (!M) return nullptr; return wrap(M->release()); } lto_module_t lto_module_create_in_codegen_context(const void *mem, size_t length, const char *path, lto_code_gen_t cg) { lto_initialize(); llvm::TargetOptions Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple()); ErrorOr> M = LTOModule::createFromBuffer( unwrap(cg)->getContext(), mem, length, Options, StringRef(path)); return wrap(M->release()); } void lto_module_dispose(lto_module_t mod) { delete unwrap(mod); } const char* lto_module_get_target_triple(lto_module_t mod) { return unwrap(mod)->getTargetTriple().c_str(); } void lto_module_set_target_triple(lto_module_t mod, const char *triple) { return unwrap(mod)->setTargetTriple(StringRef(triple)); } unsigned int lto_module_get_num_symbols(lto_module_t mod) { return unwrap(mod)->getSymbolCount(); } const char* lto_module_get_symbol_name(lto_module_t mod, unsigned int index) { return unwrap(mod)->getSymbolName(index).data(); } lto_symbol_attributes lto_module_get_symbol_attribute(lto_module_t mod, unsigned int index) { return unwrap(mod)->getSymbolAttributes(index); } const char* lto_module_get_linkeropts(lto_module_t mod) { return unwrap(mod)->getLinkerOpts().data(); } lto_bool_t lto_module_get_macho_cputype(lto_module_t mod, unsigned int *out_cputype, unsigned int *out_cpusubtype) { LTOModule *M = unwrap(mod); Expected CPUType = M->getMachOCPUType(); if (!CPUType) { sLastErrorString = toString(CPUType.takeError()); return true; } *out_cputype = *CPUType; Expected CPUSubType = M->getMachOCPUSubType(); if (!CPUSubType) { sLastErrorString = toString(CPUSubType.takeError()); return true; } *out_cpusubtype = *CPUSubType; return false; } void lto_codegen_set_diagnostic_handler(lto_code_gen_t cg, lto_diagnostic_handler_t diag_handler, void *ctxt) { unwrap(cg)->setDiagnosticHandler(diag_handler, ctxt); } static lto_code_gen_t createCodeGen(bool InLocalContext) { lto_initialize(); TargetOptions Options = codegen::InitTargetOptionsFromCodeGenFlags(Triple()); LibLTOCodeGenerator *CodeGen = InLocalContext ? new LibLTOCodeGenerator(std::make_unique()) : new LibLTOCodeGenerator(); CodeGen->setTargetOptions(Options); return wrap(CodeGen); } lto_code_gen_t lto_codegen_create(void) { return createCodeGen(/* InLocalContext */ false); } lto_code_gen_t lto_codegen_create_in_local_context(void) { return createCodeGen(/* InLocalContext */ true); } void lto_codegen_dispose(lto_code_gen_t cg) { delete unwrap(cg); } bool lto_codegen_add_module(lto_code_gen_t cg, lto_module_t mod) { return !unwrap(cg)->addModule(unwrap(mod)); } void lto_codegen_set_module(lto_code_gen_t cg, lto_module_t mod) { unwrap(cg)->setModule(std::unique_ptr(unwrap(mod))); } bool lto_codegen_set_debug_model(lto_code_gen_t cg, lto_debug_model debug) { unwrap(cg)->setDebugInfo(debug); return false; } bool lto_codegen_set_pic_model(lto_code_gen_t cg, lto_codegen_model model) { switch (model) { case LTO_CODEGEN_PIC_MODEL_STATIC: unwrap(cg)->setCodePICModel(Reloc::Static); return false; case LTO_CODEGEN_PIC_MODEL_DYNAMIC: unwrap(cg)->setCodePICModel(Reloc::PIC_); return false; case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC: unwrap(cg)->setCodePICModel(Reloc::DynamicNoPIC); return false; case LTO_CODEGEN_PIC_MODEL_DEFAULT: unwrap(cg)->setCodePICModel(None); return false; } sLastErrorString = "Unknown PIC model"; return true; } void lto_codegen_set_cpu(lto_code_gen_t cg, const char *cpu) { return unwrap(cg)->setCpu(cpu); } void lto_codegen_set_assembler_path(lto_code_gen_t cg, const char *path) { // In here only for backwards compatibility. We use MC now. } void lto_codegen_set_assembler_args(lto_code_gen_t cg, const char **args, int nargs) { // In here only for backwards compatibility. We use MC now. } void lto_codegen_add_must_preserve_symbol(lto_code_gen_t cg, const char *symbol) { unwrap(cg)->addMustPreserveSymbol(symbol); } static void maybeParseOptions(lto_code_gen_t cg) { if (optionParsingState != OptParsingState::Done) { // Parse options if any were set by the lto_codegen_debug_options* function. unwrap(cg)->parseCodeGenDebugOptions(); lto_add_attrs(cg); optionParsingState = OptParsingState::Done; } } bool lto_codegen_write_merged_modules(lto_code_gen_t cg, const char *path) { maybeParseOptions(cg); return !unwrap(cg)->writeMergedModules(path); } const void *lto_codegen_compile(lto_code_gen_t cg, size_t *length) { maybeParseOptions(cg); LibLTOCodeGenerator *CG = unwrap(cg); CG->NativeObjectFile = CG->compile(); if (!CG->NativeObjectFile) return nullptr; *length = CG->NativeObjectFile->getBufferSize(); return CG->NativeObjectFile->getBufferStart(); } bool lto_codegen_optimize(lto_code_gen_t cg) { maybeParseOptions(cg); return !unwrap(cg)->optimize(); } const void *lto_codegen_compile_optimized(lto_code_gen_t cg, size_t *length) { maybeParseOptions(cg); LibLTOCodeGenerator *CG = unwrap(cg); CG->NativeObjectFile = CG->compileOptimized(); if (!CG->NativeObjectFile) return nullptr; *length = CG->NativeObjectFile->getBufferSize(); return CG->NativeObjectFile->getBufferStart(); } bool lto_codegen_compile_to_file(lto_code_gen_t cg, const char **name) { maybeParseOptions(cg); return !unwrap(cg)->compile_to_file(name); } void lto_set_debug_options(const char *const *options, int number) { assert(optionParsingState == OptParsingState::NotParsed && "option processing already happened"); // Need to put each suboption in a null-terminated string before passing to // parseCommandLineOptions(). std::vector Options; for (int i = 0; i < number; ++i) Options.push_back(options[i]); llvm::parseCommandLineOptions(Options); optionParsingState = OptParsingState::Early; } void lto_codegen_debug_options(lto_code_gen_t cg, const char *opt) { assert(optionParsingState != OptParsingState::Early && "early option processing already happened"); SmallVector Options; for (std::pair o = getToken(opt); !o.first.empty(); o = getToken(o.second)) Options.push_back(o.first); unwrap(cg)->setCodeGenDebugOptions(Options); } void lto_codegen_debug_options_array(lto_code_gen_t cg, const char *const *options, int number) { assert(optionParsingState != OptParsingState::Early && "early option processing already happened"); SmallVector Options; for (int i = 0; i < number; ++i) Options.push_back(options[i]); unwrap(cg)->setCodeGenDebugOptions(makeArrayRef(Options)); } unsigned int lto_api_version() { return LTO_API_VERSION; } void lto_codegen_set_should_internalize(lto_code_gen_t cg, bool ShouldInternalize) { unwrap(cg)->setShouldInternalize(ShouldInternalize); } void lto_codegen_set_should_embed_uselists(lto_code_gen_t cg, lto_bool_t ShouldEmbedUselists) { unwrap(cg)->setShouldEmbedUselists(ShouldEmbedUselists); } lto_bool_t lto_module_has_ctor_dtor(lto_module_t mod) { return unwrap(mod)->hasCtorDtor(); } // ThinLTO API below thinlto_code_gen_t thinlto_create_codegen(void) { lto_initialize(); ThinLTOCodeGenerator *CodeGen = new ThinLTOCodeGenerator(); CodeGen->setTargetOptions( codegen::InitTargetOptionsFromCodeGenFlags(Triple())); CodeGen->setFreestanding(EnableFreestanding); if (OptLevel.getNumOccurrences()) { if (OptLevel < '0' || OptLevel > '3') report_fatal_error("Optimization level must be between 0 and 3"); CodeGen->setOptLevel(OptLevel - '0'); switch (OptLevel) { case '0': CodeGen->setCodeGenOptLevel(CodeGenOpt::None); break; case '1': CodeGen->setCodeGenOptLevel(CodeGenOpt::Less); break; case '2': CodeGen->setCodeGenOptLevel(CodeGenOpt::Default); break; case '3': CodeGen->setCodeGenOptLevel(CodeGenOpt::Aggressive); break; } } return wrap(CodeGen); } void thinlto_codegen_dispose(thinlto_code_gen_t cg) { delete unwrap(cg); } void thinlto_codegen_add_module(thinlto_code_gen_t cg, const char *Identifier, const char *Data, int Length) { unwrap(cg)->addModule(Identifier, StringRef(Data, Length)); } void thinlto_codegen_process(thinlto_code_gen_t cg) { unwrap(cg)->run(); } unsigned int thinlto_module_get_num_objects(thinlto_code_gen_t cg) { return unwrap(cg)->getProducedBinaries().size(); } LTOObjectBuffer thinlto_module_get_object(thinlto_code_gen_t cg, unsigned int index) { assert(index < unwrap(cg)->getProducedBinaries().size() && "Index overflow"); auto &MemBuffer = unwrap(cg)->getProducedBinaries()[index]; return LTOObjectBuffer{MemBuffer->getBufferStart(), MemBuffer->getBufferSize()}; } unsigned int thinlto_module_get_num_object_files(thinlto_code_gen_t cg) { return unwrap(cg)->getProducedBinaryFiles().size(); } const char *thinlto_module_get_object_file(thinlto_code_gen_t cg, unsigned int index) { assert(index < unwrap(cg)->getProducedBinaryFiles().size() && "Index overflow"); return unwrap(cg)->getProducedBinaryFiles()[index].c_str(); } void thinlto_codegen_disable_codegen(thinlto_code_gen_t cg, lto_bool_t disable) { unwrap(cg)->disableCodeGen(disable); } void thinlto_codegen_set_codegen_only(thinlto_code_gen_t cg, lto_bool_t CodeGenOnly) { unwrap(cg)->setCodeGenOnly(CodeGenOnly); } void thinlto_debug_options(const char *const *options, int number) { // if options were requested, set them if (number && options) { std::vector CodegenArgv(1, "libLTO"); append_range(CodegenArgv, ArrayRef(options, number)); cl::ParseCommandLineOptions(CodegenArgv.size(), CodegenArgv.data()); } } lto_bool_t lto_module_is_thinlto(lto_module_t mod) { return unwrap(mod)->isThinLTO(); } void thinlto_codegen_add_must_preserve_symbol(thinlto_code_gen_t cg, const char *Name, int Length) { unwrap(cg)->preserveSymbol(StringRef(Name, Length)); } void thinlto_codegen_add_cross_referenced_symbol(thinlto_code_gen_t cg, const char *Name, int Length) { unwrap(cg)->crossReferenceSymbol(StringRef(Name, Length)); } void thinlto_codegen_set_cpu(thinlto_code_gen_t cg, const char *cpu) { return unwrap(cg)->setCpu(cpu); } void thinlto_codegen_set_cache_dir(thinlto_code_gen_t cg, const char *cache_dir) { return unwrap(cg)->setCacheDir(cache_dir); } void thinlto_codegen_set_cache_pruning_interval(thinlto_code_gen_t cg, int interval) { return unwrap(cg)->setCachePruningInterval(interval); } void thinlto_codegen_set_cache_entry_expiration(thinlto_code_gen_t cg, unsigned expiration) { return unwrap(cg)->setCacheEntryExpiration(expiration); } void thinlto_codegen_set_final_cache_size_relative_to_available_space( thinlto_code_gen_t cg, unsigned Percentage) { return unwrap(cg)->setMaxCacheSizeRelativeToAvailableSpace(Percentage); } void thinlto_codegen_set_cache_size_bytes( thinlto_code_gen_t cg, unsigned MaxSizeBytes) { return unwrap(cg)->setCacheMaxSizeBytes(MaxSizeBytes); } void thinlto_codegen_set_cache_size_megabytes( thinlto_code_gen_t cg, unsigned MaxSizeMegabytes) { uint64_t MaxSizeBytes = MaxSizeMegabytes; MaxSizeBytes *= 1024 * 1024; return unwrap(cg)->setCacheMaxSizeBytes(MaxSizeBytes); } void thinlto_codegen_set_cache_size_files( thinlto_code_gen_t cg, unsigned MaxSizeFiles) { return unwrap(cg)->setCacheMaxSizeFiles(MaxSizeFiles); } void thinlto_codegen_set_savetemps_dir(thinlto_code_gen_t cg, const char *save_temps_dir) { return unwrap(cg)->setSaveTempsDir(save_temps_dir); } void thinlto_set_generated_objects_dir(thinlto_code_gen_t cg, const char *save_temps_dir) { unwrap(cg)->setGeneratedObjectsDirectory(save_temps_dir); } lto_bool_t thinlto_codegen_set_pic_model(thinlto_code_gen_t cg, lto_codegen_model model) { switch (model) { case LTO_CODEGEN_PIC_MODEL_STATIC: unwrap(cg)->setCodePICModel(Reloc::Static); return false; case LTO_CODEGEN_PIC_MODEL_DYNAMIC: unwrap(cg)->setCodePICModel(Reloc::PIC_); return false; case LTO_CODEGEN_PIC_MODEL_DYNAMIC_NO_PIC: unwrap(cg)->setCodePICModel(Reloc::DynamicNoPIC); return false; case LTO_CODEGEN_PIC_MODEL_DEFAULT: unwrap(cg)->setCodePICModel(None); return false; } sLastErrorString = "Unknown PIC model"; return true; } DEFINE_SIMPLE_CONVERSION_FUNCTIONS(lto::InputFile, lto_input_t) lto_input_t lto_input_create(const void *buffer, size_t buffer_size, const char *path) { return wrap(LTOModule::createInputFile(buffer, buffer_size, path, sLastErrorString)); } void lto_input_dispose(lto_input_t input) { delete unwrap(input); } extern unsigned lto_input_get_num_dependent_libraries(lto_input_t input) { return LTOModule::getDependentLibraryCount(unwrap(input)); } extern const char *lto_input_get_dependent_library(lto_input_t input, size_t index, size_t *size) { return LTOModule::getDependentLibrary(unwrap(input), index, size); } extern const char *const *lto_runtime_lib_symbols_list(size_t *size) { auto symbols = lto::LTO::getRuntimeLibcallSymbols(); *size = symbols.size(); return symbols.data(); }