Re: objdump prints PE relocations with --private-headers, not --reloc

[Pavel Roskin <proski at gnu dot org>]

On Thu, 30 Oct 2003, Ian Lance Taylor wrote:

> Note that relocations in an executable file should not normally be
> dumped by objdump -r (--reloc), they should be dumped by objdump -R
> (--dynamic-reloc).

OK, I've just tested in on GNU/Linux i686:

$ gcc -o hello hello.c
$ objdump -r hello

hello:     file format elf32-i386

$ objdump -R hello

hello:     file format elf32-i386

DYNAMIC RELOCATION RECORDS
OFFSET   TYPE              VALUE
08049508 R_386_GLOB_DAT    __gmon_start__
08049500 R_386_JUMP_SLOT   __libc_start_main
08049504 R_386_JUMP_SLOT   printf


$ gcc -o hello hello.c -Wl,--emit-reloc
$ objdump -r hello

hello:     file format elf32-i386

RELOCATION RECORDS FOR [.init]:
OFFSET   TYPE              VALUE
00000007 R_386_PC32        .text
0000000c R_386_PC32        .text
00000011 R_386_PC32        .text


RELOCATION RECORDS FOR [.text]:
OFFSET   TYPE              VALUE
0000000c R_386_32          __libc_csu_fini
00000011 R_386_32          __libc_csu_init
00000018 R_386_32          main
0000001d R_386_PC32        __libc_start_main@@GLIBC_2.0
00000031 R_386_GOTPC       _GLOBAL_OFFSET_TABLE_
00000037 R_386_GOT32       __gmon_start__
[dozens of lines skipped]

$ objdump -R hello

hello:     file format elf32-i386

DYNAMIC RELOCATION RECORDS
OFFSET   TYPE              VALUE
08049508 R_386_GLOB_DAT    __gmon_start__
08049500 R_386_JUMP_SLOT   __libc_start_main
08049504 R_386_JUMP_SLOT   printf


As you can see, use of --emit-reloc affects the output of "objdump -r",
but not "objdump -R".

What I'm interested in is the data from the .reloc section in PE files.
Normally the .reloc section is missing.  Regardless of whether the reloc
section is present, "objdump -r" and "objdump -R" don't print relocations:

$ /home/proski/src/binutils/binutils/objdump -r test-reloc.exe

test-reloc.exe:     file format pei-i386

$ /home/proski/src/binutils/binutils/objdump -R test-reloc.exe

test-reloc.exe:     file format pei-i386

/home/proski/src/binutils/binutils/objdump: test-reloc.exe: not a dynamic
object
/home/proski/src/binutils/binutils/objdump: test-reloc.exe: Invalid
operation

> Executable file relocation information is not the same as object file
> relocation information.  The latter is processed by the program linker,
> the former by the dynamic linker.  That's why we have different options
> in objdump to dump them.
>
> It would be appropriate for objdump -R to dump dynamic relocations for
> PE executables.

I'm confused by the fact that in case of ELF format, --emit-reloc affects
the symbols shown by "objdump -r", and --emit-reloc means "leave
relocations in the final executable".

Now, in case of PE files I also want to leave relocations in the final
executable, so I'm going to use --emit-reloc for that.  But you are
suggesting that the relocations created by --emit-reloc should be listed
by "objdump -R".  I don't see any logic here.

-- 
Regards,
Pavel Roskin