Re: What about add a interface to output the assembly codes follow inferior execution

[teawater <teawater at gmail dot com>]

Hi Doug and Daniel,

Thanks for your reply.

I think I didn't talk clear of my idea.
When exec-disassemble is on,
If the $pc doesn't have the line message, gdb will output the assembly
code for $pc.
If the $pc has the line message, gdb will output the assembly codes of
this line.

For example:
(gdb) set exec-disassemble on
(gdb) n
26              printf ("a = %d b = %d c = %d\n", a, b, c);
 80483fe:       8b 15 84 96 04 08       mov    0x8049684,%edx
 8048404:       8b 45 f4                mov    -0xc(%ebp),%eax
 8048407:       89 44 24 0c             mov    %eax,0xc(%esp)
 804840b:       8b 45 f8                mov    -0x8(%ebp),%eax
 804840e:       89 44 24 08             mov    %eax,0x8(%esp)
 8048412:       89 54 24 04             mov    %edx,0x4(%esp)
 8048416:       c7 04 24 58 85 04 08    movl   $0x8048558,(%esp)
 804841d:       e8 b6 fe ff ff          call   80482d8 <printf@plt>
This assembly codes is for line 26 printf ("a = %d b = %d c = %d\n", a, b, c);

(gdb) n
21	       int     c = 1;
80483c8:	c7 45 f4 01 00 00 00 	movl   $0x1,-0xc(%ebp)
This assembly codes is for line 21 int     c = 1;

It will make user clear what instructions will be execute in next line.



The "disp/8i $pc" just can output 8 instructions, even if the next
line just have 1 instruction.
For example:
(gdb) n
21	       int     c = 1;
1: x/8i $pc
0x80483c8 <main+24>:	movl   $0x1,-0xc(%ebp)
0x80483cf <main+31>:	mov    0x8049684,%edx
0x80483d5 <main+37>:	mov    -0xc(%ebp),%eax
0x80483d8 <main+40>:	mov    %eax,0xc(%esp)
0x80483dc <main+44>:	mov    -0x8(%ebp),%eax
0x80483df <main+47>:	mov    %eax,0x8(%esp)
0x80483e3 <main+51>:	mov    %edx,0x4(%esp)
0x80483e7 <main+55>:	movl   $0x8048558,(%esp)
Just 1 line for line 21.


Thanks,
Hui



On Wed, Mar 4, 2009 at 01:04, Daniel Jacobowitz <drow@false.org> wrote:
> On Tue, Mar 03, 2009 at 08:41:53AM -0800, Doug Evans wrote:
>> Are you looking for behaviour different than what "disp/8i $pc" would give you?
>
> I often run with display/i $pc. ?But I think the 'auto' setting is a
> nice idea; it's when I don't have source code that this is most useful.
>
> --
> Daniel Jacobowitz
> CodeSourcery
>