1 //===- MachOObject.h - Mach-O Object File Wrapper ---------------*- C++ -*-===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 #ifndef LLVM_OBJECT_MACHOOBJECT_H
11 #define LLVM_OBJECT_MACHOOBJECT_H
14 #include "llvm/ADT/InMemoryStruct.h"
15 #include "llvm/ADT/OwningPtr.h"
16 #include "llvm/Object/MachOFormat.h"
24 /// \brief Wrapper object for manipulating Mach-O object files.
26 /// This class is designed to implement a full-featured, efficient, portable,
27 /// and robust Mach-O interface to Mach-O object files. It does not attempt to
28 /// smooth over rough edges in the Mach-O format or generalize access to object
29 /// independent features.
31 /// The class is designed around accessing the Mach-O object which is expected
32 /// to be fully loaded into memory.
34 /// This class is *not* suitable for concurrent use. For efficient operation,
35 /// the class uses APIs which rely on the ability to cache the results of
36 /// certain calls in internal objects which are not safe for concurrent
37 /// access. This allows the API to be zero-copy on the common paths.
39 // FIXME: It would be cool if we supported a "paged" MemoryBuffer
40 // implementation. This would allow us to implement a more sensible version of
41 // MemoryObject which can work like a MemoryBuffer, but be more efficient for
42 // objects which are in the current address space.
45 struct LoadCommandInfo {
46 /// The load command information.
47 macho::LoadCommand Command;
49 /// The offset to the start of the load command in memory.
54 OwningPtr<MemoryBuffer> Buffer;
56 /// Whether the object is little endian.
58 /// Whether the object is 64-bit.
60 /// Whether the object is swapped endianness from the host.
63 /// The cached information on the load commands.
64 LoadCommandInfo *LoadCommands;
65 mutable unsigned NumLoadedCommands;
67 /// The cached copy of the header.
69 macho::Header64Ext Header64Ext;
72 MachOObject(MemoryBuffer *Buffer, bool IsLittleEndian, bool Is64Bit);
77 /// \brief Load a Mach-O object from a MemoryBuffer object.
79 /// \param Buffer - The buffer to load the object from. This routine takes
80 /// exclusive ownership of the buffer (which is passed to the returned object
82 /// \param ErrorStr [out] - If given, will be set to a user readable error
83 /// message on failure.
84 /// \returns The loaded object, or null on error.
85 static MachOObject *LoadFromBuffer(MemoryBuffer *Buffer,
86 std::string *ErrorStr = 0);
88 /// @name File Information
91 bool isLittleEndian() const { return IsLittleEndian; }
92 bool isSwappedEndian() const { return IsSwappedEndian; }
93 bool is64Bit() const { return Is64Bit; }
95 unsigned getHeaderSize() const {
96 return Is64Bit ? macho::Header64Size : macho::Header32Size;
100 /// @name Object Header Access
103 const macho::Header &getHeader() const { return Header; }
104 const macho::Header64Ext &getHeader64Ext() const {
105 assert(is64Bit() && "Invalid access!");
110 /// @name Object Structure Access
113 /// \brief Retrieve the information for the given load command.
114 const LoadCommandInfo &getLoadCommandInfo(unsigned Index) const;
116 void ReadSegmentLoadCommand(
117 const LoadCommandInfo &LCI,
118 InMemoryStruct<macho::SegmentLoadCommand> &Res) const;
119 void ReadSegment64LoadCommand(
120 const LoadCommandInfo &LCI,
121 InMemoryStruct<macho::Segment64LoadCommand> &Res) const;
122 void ReadSymtabLoadCommand(
123 const LoadCommandInfo &LCI,
124 InMemoryStruct<macho::SymtabLoadCommand> &Res) const;
125 void ReadDysymtabLoadCommand(
126 const LoadCommandInfo &LCI,
127 InMemoryStruct<macho::DysymtabLoadCommand> &Res) const;
128 void ReadIndirectSymbolTableEntry(
129 const macho::DysymtabLoadCommand &DLC,
131 InMemoryStruct<macho::IndirectSymbolTableEntry> &Res) const;
133 const LoadCommandInfo &LCI,
135 InMemoryStruct<macho::Section> &Res) const;
137 const LoadCommandInfo &LCI,
139 InMemoryStruct<macho::Section64> &Res) const;
140 void ReadRelocationEntry(
141 uint64_t RelocationTableOffset, unsigned Index,
142 InMemoryStruct<macho::RelocationEntry> &Res) const;
147 } // end namespace object
148 } // end namespace llvm