Subversion Repositories QNX 8.QNX8 LLVM/Clang compiler suite

//===-LTOModule.h - 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 declares the LTOModule class.

//

//===----------------------------------------------------------------------===//

#ifndef LLVM_LTO_LEGACY_LTOMODULE_H

#define LLVM_LTO_LEGACY_LTOMODULE_H

#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 {

private:

  struct NameAndAttributes {

    StringRef name;

    uint32_t           attributes = 0;

    bool               isFunction = false;

    const GlobalValue *symbol = nullptr;

  };

  std::unique_ptr<LLVMContext> OwnedContext;

  std::string LinkerOpts;

  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);

public:

  ~LTOModule();

  /// 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) {

    getModule().setTargetTriple(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);

  Expected<uint32_t> getMachOCPUType() const;

  Expected<uint32_t> getMachOCPUSubType() const;

  /// Returns true if the module has either the @llvm.global_ctors or the

  /// @llvm.global_dtors symbol. Otherwise returns false.

  bool hasCtorDtor() const;

private:

  /// 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);

};

}

#endif