cmacosfunctionsymbols

readelf-like tool for Mac OS X?


Is there a tool for reading Mac OS X binaries that would print information about relocation tables and symbol offsets similar to this readelf output?

readelf -r app

Relocation section '.rel.dyn' at offset 0x5ec contains 2 entries:
 Offset     Info    Type            Sym.Value  Sym. Name
08049d58  00001706 R_386_GLOB_DAT    00000000   __gmon_start__
08049d60  00000305 R_386_COPY        08049d60   _ZSt4cout

Relocation section '.rel.plt' at offset 0x5fc contains 13 entries:
 Offset     Info    Type            Sym.Value  Sym. Name
08049d24  00000107 R_386_JUMP_SLOT   0804868c   print
08049d28  00000207 R_386_JUMP_SLOT   0804869c   _ZNSt8ios_base4InitC1E
08049d2c  00000507 R_386_JUMP_SLOT   080486ac   _ZStlsISt11char_traits
08049d30  00000607 R_386_JUMP_SLOT   080486bc   _ZNSolsEPFRSoS_E
08049d34  00000707 R_386_JUMP_SLOT   08048664   _init
08049d38  00000807 R_386_JUMP_SLOT   080486dc   sleep
08049d3c  00000907 R_386_JUMP_SLOT   080486ec   _ZNKSsixEj
08049d40  00000b07 R_386_JUMP_SLOT   080486fc   _ZNKSs4sizeEv
08049d44  00000c07 R_386_JUMP_SLOT   0804870c   __libc_start_main
08049d48  00000d07 R_386_JUMP_SLOT   08048ae4   _fini
08049d4c  00001307 R_386_JUMP_SLOT   0804872c   _ZSt4endlIcSt11char_tr
08049d50  00001507 R_386_JUMP_SLOT   0804873c   __gxx_personality_v0
08049d54  00001607 R_386_JUMP_SLOT   0804874c   _ZNSt8ios_base4InitD1E

In this example, print is a function loaded from a shared library (I wrote) at runtime. readelf is able to display information about its location inside the app binary.


Solution

  • Using Macports:

    1. Install macports.
    2. Using macports port install binutils
    3. gobjdump -p /path/to/app

    Using Homebrew:

    1. Install Homebrew
    2. Do brew update && brew install binutils
    3. /usr/local/path/to/gobjdump -p /path/to/app # or follow instructions to add it to your PATH

    There are, of course, many other command-line options. Note that the binutils port cautions that installing it may cause other ports to fail to build. Having it around to port install/look at something/port uninstall can still be handy.

    It's rather amazing that there isn't already some native tool to do this.