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//===-LTOModule.h - LLVM Link Time Optimizer ------------------------------===//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// This file declares the LTOModule class.
#include "llvm-c/lto.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/StringSet.h"
#include "llvm/IR/Module.h"
#include "llvm/LTO/LTO.h"
#include "llvm/Object/IRObjectFile.h"
#include "llvm/Object/ModuleSymbolTable.h"
#include "llvm/Target/TargetMachine.h"
#include <string>
#include <vector>
// Forward references to llvm classes.
namespace llvm {
class Function;
class GlobalValue;
class MemoryBuffer;
class TargetOptions;
class Value;
/// C++ class which implements the opaque lto_module_t type.
struct LTOModule {
struct NameAndAttributes {
StringRef name;
uint32_t attributes = 0;
bool isFunction = 0;
const GlobalValue *symbol = 0;
std::unique_ptr<LLVMContext> OwnedContext;
std::string LinkerOpts;
std::string DependentLibraries;
std::unique_ptr<Module> Mod;
MemoryBufferRef MBRef;
ModuleSymbolTable SymTab;
std::unique_ptr<TargetMachine> _target;
std::vector<NameAndAttributes> _symbols;
// _defines and _undefines only needed to disambiguate tentative definitions
StringSet<> _defines;
StringMap<NameAndAttributes> _undefines;
std::vector<StringRef> _asm_undefines;
LTOModule(std::unique_ptr<Module> M, MemoryBufferRef MBRef,
TargetMachine *TM);
/// Returns 'true' if the file or memory contents is LLVM bitcode.
static bool isBitcodeFile(const void *mem, size_t length);
static bool isBitcodeFile(StringRef path);
/// Returns 'true' if the Module is produced for ThinLTO.
bool isThinLTO();
/// Returns 'true' if the memory buffer is LLVM bitcode for the specified
/// triple.
static bool isBitcodeForTarget(MemoryBuffer *memBuffer,
StringRef triplePrefix);
/// Returns a string representing the producer identification stored in the
/// bitcode, or "" if the bitcode does not contains any.
static std::string getProducerString(MemoryBuffer *Buffer);
/// Create a MemoryBuffer from a memory range with an optional name.
static std::unique_ptr<MemoryBuffer>
makeBuffer(const void *mem, size_t length, StringRef name = "");
/// Create an LTOModule. N.B. These methods take ownership of the buffer. The
/// caller must have initialized the Targets, the TargetMCs, the AsmPrinters,
/// and the AsmParsers by calling:
/// InitializeAllTargets();
/// InitializeAllTargetMCs();
/// InitializeAllAsmPrinters();
/// InitializeAllAsmParsers();
static ErrorOr<std::unique_ptr<LTOModule>>
createFromFile(LLVMContext &Context, StringRef path,
const TargetOptions &options);
static ErrorOr<std::unique_ptr<LTOModule>>
createFromOpenFile(LLVMContext &Context, int fd, StringRef path, size_t size,
const TargetOptions &options);
static ErrorOr<std::unique_ptr<LTOModule>>
createFromOpenFileSlice(LLVMContext &Context, int fd, StringRef path,
size_t map_size, off_t offset,
const TargetOptions &options);
static ErrorOr<std::unique_ptr<LTOModule>>
createFromBuffer(LLVMContext &Context, const void *mem, size_t length,
const TargetOptions &options, StringRef path = "");
static ErrorOr<std::unique_ptr<LTOModule>>
createInLocalContext(std::unique_ptr<LLVMContext> Context, const void *mem,
size_t length, const TargetOptions &options,
StringRef path);
const Module &getModule() const { return *Mod; }
Module &getModule() { return *Mod; }
std::unique_ptr<Module> takeModule() { return std::move(Mod); }
/// Return the Module's target triple.
const std::string &getTargetTriple() {
return getModule().getTargetTriple();
/// Set the Module's target triple.
void setTargetTriple(StringRef Triple) {
/// Get the number of symbols
uint32_t getSymbolCount() {
return _symbols.size();
/// Get the attributes for a symbol at the specified index.
lto_symbol_attributes getSymbolAttributes(uint32_t index) {
if (index < _symbols.size())
return lto_symbol_attributes(_symbols[index].attributes);
return lto_symbol_attributes(0);
/// Get the name of the symbol at the specified index.
StringRef getSymbolName(uint32_t index) {
if (index < _symbols.size())
return _symbols[index].name;
return StringRef();
const GlobalValue *getSymbolGV(uint32_t index) {
if (index < _symbols.size())
return _symbols[index].symbol;
return nullptr;
StringRef getLinkerOpts() { return LinkerOpts; }
const std::vector<StringRef> &getAsmUndefinedRefs() { return _asm_undefines; }
static lto::InputFile *createInputFile(const void *buffer, size_t buffer_size,
const char *path, std::string &out_error);
static size_t getDependentLibraryCount(lto::InputFile *input);
static const char *getDependentLibrary(lto::InputFile *input, size_t index, size_t *size);
/// Parse metadata from the module
// FIXME: it only parses "llvm.linker.options" metadata at the moment
// FIXME: can't access metadata in lazily loaded modules
void parseMetadata();
/// Parse the symbols from the module and model-level ASM and add them to
/// either the defined or undefined lists.
void parseSymbols();
/// Add a symbol which isn't defined just yet to a list to be resolved later.
void addPotentialUndefinedSymbol(ModuleSymbolTable::Symbol Sym,
bool isFunc);
/// Add a defined symbol to the list.
void addDefinedSymbol(StringRef Name, const GlobalValue *def,
bool isFunction);
/// Add a data symbol as defined to the list.
void addDefinedDataSymbol(ModuleSymbolTable::Symbol Sym);
void addDefinedDataSymbol(StringRef Name, const GlobalValue *v);
/// Add a function symbol as defined to the list.
void addDefinedFunctionSymbol(ModuleSymbolTable::Symbol Sym);
void addDefinedFunctionSymbol(StringRef Name, const Function *F);
/// Add a global symbol from module-level ASM to the defined list.
void addAsmGlobalSymbol(StringRef, lto_symbol_attributes scope);
/// Add a global symbol from module-level ASM to the undefined list.
void addAsmGlobalSymbolUndef(StringRef);
/// Parse i386/ppc ObjC class data structure.
void addObjCClass(const GlobalVariable *clgv);
/// Parse i386/ppc ObjC category data structure.
void addObjCCategory(const GlobalVariable *clgv);
/// Parse i386/ppc ObjC class list data structure.
void addObjCClassRef(const GlobalVariable *clgv);
/// Get string that the data pointer points to.
bool objcClassNameFromExpression(const Constant *c, std::string &name);
/// Create an LTOModule (private version).
static ErrorOr<std::unique_ptr<LTOModule>>
makeLTOModule(MemoryBufferRef Buffer, const TargetOptions &options,
LLVMContext &Context, bool ShouldBeLazy);