Disassemble Microsoft Visual Studio 2003 compiler output

Question

I\'m seeing what I think is strange behaviour from object files output by the Microsoft Visual Studio 2003 tools. The file utility tells me:

asmfil         


        

Answer 1

Edit based on the cl command line options being added to the question:

I think the problem is the use of the /GL option, which specifies that link-time code generation optimization will be done. from a doc page on that option:

obj files produced with /GL will not be available to such linker utilities as EDITBIN and DUMPBIN.

Using this option causes the compiler to generate .obj files that the linker can perform program-wide optimization on - apparently the file format is proprietary (maybe it's documented somewhere, but I suspect not).

The docs for /GL (also known as "whole program optimization", "link-time code generation", or LTCG) contain several warnings about interoperability of the .obj files or libraries containing such objects files.

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Original answer:

What exactly is in the C source for the .obj file you're trying to disassemble? I get the following using dumpbin /disasm test.obj for a simple 'hello world' program:

Microsoft (R) COFF/PE Dumper Version 8.00.50727.42
Copyright (C) Microsoft Corporation.  All rights reserved.


Dump of file test.obj

File Type: COFF OBJECT

_main:
  00000000: 55                 push        ebp
  00000001: 8B EC              mov         ebp,esp
  00000003: 6A 01              push        1
  00000005: 68 00 00 00 00     push        offset $SG4665
  0000000A: E8 00 00 00 00     call        _printf
  0000000F: 83 C4 08           add         esp,8
  00000012: 33 C0              xor         eax,eax
  00000014: 3B EC              cmp         ebp,esp
  00000016: E8 00 00 00 00     call        __RTC_CheckEsp
  0000001B: 5D                 pop         ebp
  0000001C: C3                 ret

  Summary

         7AC .debug$S
          30 .debug$T
          2F .drectve
           4 .rdata
           4 .rtc$IMZ
           4 .rtc$TMZ
          1D .text

Note: this is using an .obj file compiled by and a dumpbin provided by VS2005, but I can't imagine this stuff would have changed much from VS2003.