Question

If I run objdump -d on a (linux amd64) .o file, function calls show up without the link time resolution done. Example:

  90:   66 89 44 24 1c          mov    %ax,0x1c(%rsp)
  95:   44 89 74 24 10          mov    %r14d,0x10(%rsp)
  9a:   e8 00 00 00 00          callq  9f <foo+0x9f>
  9f:   83 f8 ff                cmp    $0xffffffffffffffff,%eax
  a2:   74 5e                   je     102 <foo+0x102>

A branch within the function shows up properly, but the callq is just the stub put in for the linker (with four bytes of zeros available for the linker to put a proper address into).

Is there a way, without actually linking, to get an assembly listing that has the function names resolved? I don’t care about the address that will eventually be used, just the name of the function. That info has got to be in the .o file, since the linker must consume it to do its job.

I ask because the shared lib that the code in question goes into is about 140Mb, and it takes a long time to run objdump -d on that to get the asm dump with all the function calls resolved to their actual names.

Answer 1

Is there a way, without actually linking, to get an assembly listing that has the function names resolved?

Yes: use objdump -dr foo.o