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//===-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<char>
OptLevel("O",
cl::desc("Optimization level. [-O0, -O1, -O2, or -O3] "
"(default = '-O2')"),
cl::Prefix,
cl::ZeroOrMore,
cl::init('2'));
static cl::opt<bool> 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<bool> 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;
// Holds the command-line option parsing state of the LTO module.
static bool parsedOptions = false;
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<LTOToolDiagnosticHandler>(), 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<LLVMContext> 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<MemoryBuffer> NativeObjectFile;
std::unique_ptr<LLVMContext> 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<std::unique_ptr<MemoryBuffer>> 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<MemoryBuffer> Buffer(LTOModule::makeBuffer(mem, length));
if (!Buffer)
return false;
LLVMContext Ctx;
ErrorOr<bool> 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<MemoryBuffer> 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<std::unique_ptr<LTOModule>> 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<std::unique_ptr<LTOModule>> 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<std::unique_ptr<LTOModule>> 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<std::unique_ptr<LTOModule>> 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<std::unique_ptr<LTOModule>> 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<LLVMContext> Context = std::make_unique<LLVMContext>();
Context->setDiagnosticHandler(std::make_unique<LTOToolDiagnosticHandler>(),
true);
ErrorOr<std::unique_ptr<LTOModule>> 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<std::unique_ptr<LTOModule>> 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<uint32_t> CPUType = M->getMachOCPUType();
if (!CPUType) {
sLastErrorString = toString(CPUType.takeError());
return true;
}
*out_cputype = *CPUType;
Expected<uint32_t> 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<LLVMContext>())
: 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<LTOModule>(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 (!parsedOptions) {
unwrap(cg)->parseCodeGenDebugOptions();
lto_add_attrs(cg);
parsedOptions = true;
}
}
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_codegen_debug_options(lto_code_gen_t cg, const char *opt) {
SmallVector<StringRef, 4> Options;
for (std::pair<StringRef, StringRef> 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) {
SmallVector<StringRef, 4> 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);
}
// 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<const char *> CodegenArgv(1, "libLTO");
append_range(CodegenArgv, ArrayRef<const char *>(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();
}