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//===- MachOObject.h - Mach-O Object File Wrapper ---------------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_OBJECT_MACHOOBJECT_H
#define LLVM_OBJECT_MACHOOBJECT_H
#include <string>
#include "llvm/ADT/InMemoryStruct.h"
#include "llvm/ADT/OwningPtr.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Object/MachOFormat.h"
namespace llvm {
class MemoryBuffer;
namespace object {
/// \brief Wrapper object for manipulating Mach-O object files.
///
/// This class is designed to implement a full-featured, efficient, portable,
/// and robust Mach-O interface to Mach-O object files. It does not attempt to
/// smooth over rough edges in the Mach-O format or generalize access to object
/// independent features.
///
/// The class is designed around accessing the Mach-O object which is expected
/// to be fully loaded into memory.
///
/// This class is *not* suitable for concurrent use. For efficient operation,
/// the class uses APIs which rely on the ability to cache the results of
/// certain calls in internal objects which are not safe for concurrent
/// access. This allows the API to be zero-copy on the common paths.
//
// FIXME: It would be cool if we supported a "paged" MemoryBuffer
// implementation. This would allow us to implement a more sensible version of
// MemoryObject which can work like a MemoryBuffer, but be more efficient for
// objects which are in the current address space.
class MachOObject {
public:
struct LoadCommandInfo {
/// The load command information.
macho::LoadCommand Command;
/// The offset to the start of the load command in memory.
uint64_t Offset;
};
private:
OwningPtr<MemoryBuffer> Buffer;
/// Whether the object is little endian.
bool IsLittleEndian;
/// Whether the object is 64-bit.
bool Is64Bit;
/// Whether the object is swapped endianness from the host.
bool IsSwappedEndian;
/// Whether the string table has been registered.
bool HasStringTable;
/// The cached information on the load commands.
LoadCommandInfo *LoadCommands;
mutable unsigned NumLoadedCommands;
/// The cached copy of the header.
macho::Header Header;
macho::Header64Ext Header64Ext;
/// Cache string table information.
StringRef StringTable;
private:
MachOObject(MemoryBuffer *Buffer, bool IsLittleEndian, bool Is64Bit);
public:
~MachOObject();
/// \brief Load a Mach-O object from a MemoryBuffer object.
///
/// \param Buffer - The buffer to load the object from. This routine takes
/// exclusive ownership of the buffer (which is passed to the returned object
/// on success).
/// \param ErrorStr [out] - If given, will be set to a user readable error
/// message on failure.
/// \returns The loaded object, or null on error.
static MachOObject *LoadFromBuffer(MemoryBuffer *Buffer,
std::string *ErrorStr = 0);
/// @name File Information
/// @{
bool isLittleEndian() const { return IsLittleEndian; }
bool isSwappedEndian() const { return IsSwappedEndian; }
bool is64Bit() const { return Is64Bit; }
unsigned getHeaderSize() const {
return Is64Bit ? macho::Header64Size : macho::Header32Size;
}
StringRef getData(size_t Offset, size_t Size) const;
/// @}
/// @name String Table Data
/// @{
StringRef getStringTableData() const {
assert(HasStringTable && "String table has not been registered!");
return StringTable;
}
StringRef getStringAtIndex(unsigned Index) const {
size_t End = getStringTableData().find('\0', Index);
return getStringTableData().slice(Index, End);
}
void RegisterStringTable(macho::SymtabLoadCommand &SLC);
/// @}
/// @name Object Header Access
/// @{
const macho::Header &getHeader() const { return Header; }
const macho::Header64Ext &getHeader64Ext() const {
assert(is64Bit() && "Invalid access!");
return Header64Ext;
}
/// @}
/// @name Object Structure Access
/// @{
/// \brief Retrieve the information for the given load command.
const LoadCommandInfo &getLoadCommandInfo(unsigned Index) const;
void ReadSegmentLoadCommand(
const LoadCommandInfo &LCI,
InMemoryStruct<macho::SegmentLoadCommand> &Res) const;
void ReadSegment64LoadCommand(
const LoadCommandInfo &LCI,
InMemoryStruct<macho::Segment64LoadCommand> &Res) const;
void ReadSymtabLoadCommand(
const LoadCommandInfo &LCI,
InMemoryStruct<macho::SymtabLoadCommand> &Res) const;
void ReadDysymtabLoadCommand(
const LoadCommandInfo &LCI,
InMemoryStruct<macho::DysymtabLoadCommand> &Res) const;
void ReadIndirectSymbolTableEntry(
const macho::DysymtabLoadCommand &DLC,
unsigned Index,
InMemoryStruct<macho::IndirectSymbolTableEntry> &Res) const;
void ReadSection(
const LoadCommandInfo &LCI,
unsigned Index,
InMemoryStruct<macho::Section> &Res) const;
void ReadSection64(
const LoadCommandInfo &LCI,
unsigned Index,
InMemoryStruct<macho::Section64> &Res) const;
void ReadRelocationEntry(
uint64_t RelocationTableOffset, unsigned Index,
InMemoryStruct<macho::RelocationEntry> &Res) const;
void ReadSymbolTableEntry(
uint64_t SymbolTableOffset, unsigned Index,
InMemoryStruct<macho::SymbolTableEntry> &Res) const;
void ReadSymbol64TableEntry(
uint64_t SymbolTableOffset, unsigned Index,
InMemoryStruct<macho::Symbol64TableEntry> &Res) const;
/// @}
};
} // end namespace object
} // end namespace llvm
#endif
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