Re: gcc and -fPIC

[Gerhard Wiesinger <lists@wiesinger.com>]

On Sat, 16 Oct 2004, Daniel Jacobowitz wrote:

> On Sat, Oct 16, 2004 at 02:09:24PM +0200, Andreas Schwab wrote:
>> Gerhard Wiesinger <lists@wiesinger.com> writes:
>>
>>> BTW: Is it possible to see the dynamic symbols in the disassembly? I don't
>>> see the call to operator delete[](void*) at location 8048592.
>>
>> Difficult, because the PLT entries have no symbols attached to them.
>> There is no information about which PLT entry belongs to which function.
>
> There's some code in HEAD to do this, written by Jakub.
>

Ok, I tried the HEAD version:
DYNAMIC SYMBOL TABLE:
080483d0      DF *UND*  0000002a  GLIBCPP_3.2 operator delete(void*)
080483e0      DF *UND*  000004d1  CXXABI_1.2  __gxx_personality_v0
080483f0      DF *UND*  000000f3  GLIBC_2.0   __libc_start_main
080486c0 g    DO .rodata        00000004  Base        _IO_stdin_used
08048400      DF *UND*  00000039  GLIBCPP_3.2 operator new[](unsigned int)
08048410      DF *UND*  00000026  GLIBCPP_3.2 operator delete[](void*)
00000000  w   D  *UND*  00000000              _Jv_RegisterClasses
08048420      DF *UND*  000000a3  GLIBCPP_3.2 operator new(unsigned int)
00000000  w   D  *UND*  00000000              __gmon_start__

08048410 <_ZdaPv@plt>:
  8048410:       ff 25 3c 98 04 08       jmp    *0x804983c
  8048416:       68 20 00 00 00          push   $0x20
  804841b:       e9 a0 ff ff ff          jmp    80483c0 <_init+0x18>


         delete x;
  8048578:       83 ec 0c                sub    $0xc,%esp
  804857b:       ff 75 f4                pushl  0xfffffff4(%ebp)
  804857e:       e8 4d fe ff ff          call   80483d0 <_ZdlPv@plt>
  8048583:       83 c4 10                add    $0x10,%esp
         delete [] xarray;
  8048586:       83 7d f0 00             cmpl   $0x0,0xfffffff0(%ebp)
  804858a:       74 0e                   je     804859a <main+0xba>
  804858c:       83 ec 0c                sub    $0xc,%esp
  804858f:       ff 75 f0                pushl  0xfffffff0(%ebp)
  8048592:       e8 79 fe ff ff          call   8048410 <_ZdaPv@plt>
  8048597:       83 c4 10                add    $0x10,%esp
}


I got some symbol output, but not the expected one.

But it shouldn't be to difficult to implement because the DYNAMIC SYMBOL 
table above has already the correct symbol.

Ciao,
Gerhard