Re: next snapshot in preparation for m4 1.4.12

[Tom G. Christensen]

On Tue, Sep 02, 2008 at 01:20:43PM -0600, Eric Blake wrote:
> I wonder if switching to libsigsegv's version will solve it.  In the
> meantime, I would be curious to see the disassembly of recurse, to see if
> anything obvious appears as to why p==0 rather than a valid stack address
> before the final stack frame.  In gdb, you can get this with 'disas recurse'.
>
(gdb) run
Starting program:
/usr/people/tgc/buildpkg/m4/src/m4-1.4.11.42-864d/tests/test-c-stack

Program received signal SIGSEGV, Segmentation fault.
0x400d70 in recurse (p=0x0) at test-c-stack.c:46
46      {
(gdb) disas recurse
Dump of assembler code for function recurse:
0x400d60 <recurse>:     lui     $gp,0xfc0
0x400d64 <recurse+4>:   addiu   $gp,$gp,29504
0x400d68 <recurse+8>:   addu    $gp,$gp,$t9
0x400d6c <recurse+12>:  addiu   $sp,$sp,-536
0x400d70 <recurse+16>:  sw      $ra,28($sp)
0x400d74 <recurse+20>:  sw      $gp,24($sp)
0x400d78 <recurse+24>:  sw      $a0,536($sp)
0x400d7c <recurse+28>:  li      $t6,1
0x400d80 <recurse+32>:  addiu   $t7,$sp,36
0x400d84 <recurse+36>:  sb      $t6,0($t7)
0x400d88 <recurse+40>:  lw      $t9,-32748($gp)
0x400d8c <recurse+44>:  addiu   $a0,$sp,36
0x400d90 <recurse+48>:  addiu   $t9,$t9,3424
0x400d94 <recurse+52>:  jalr    $t9
0x400d98 <recurse+56>:  nop
0x400d9c <recurse+60>:  lw      $t8,536($sp)
0x400da0 <recurse+64>:  lw      $gp,24($sp)
0x400da4 <recurse+68>:  lbu     $t9,0($t8)
0x400da8 <recurse+72>:  b       0x400db8 <recurse+88>
0x400dac <recurse+76>:  addu    $v0,$v0,$t9
0x400db0 <recurse+80>:  b       0x400db8 <recurse+88>
0x400db4 <recurse+84>:  nop
0x400db8 <recurse+88>:  lw      $ra,28($sp)
0x400dbc <recurse+92>:  addiu   $sp,$sp,536
0x400dc0 <recurse+96>:  jr      $ra
0x400dc4 <recurse+100>: nop
End of assembler dump.
(gdb) quit

-tgc