Re: Special names tha ld needs to recognize for hppa64-hp-hpux11.X

["John David Anglin" <dave at hiauly1 dot hia dot nrc dot ca>]

>  "John David Anglin" writes:
> 
>  > bash-2.05$ gcc -g -static -o main main.c
>  > bash-2.05$ ./main
>  > Segmentation fault (core dumped)
>  > 
>  > The problem is this code in the exitcu.o module:
>  > 
>  >    8:   2b 60 00 00     addil 0,dp,%r1
>  > 			8: R_PARISC_LTOFF_FPTR21L       do_exitcu
>  >    c:   50 3a 00 00     ldd 0(r1),r26
>  > 			c: R_PARISC_LTOFF_FPTR14DR      do_exitcu
>  > 
>  > When linked with gnu ld, r26 ends up with actual address of "do_exitcu".
>  > However, r26 should contain the address of the .opd entry for "do_exitcu".  
> Hmmm, what is the scope of do_exitcu?  global or file-local?

It's local.

Symbols from exitcu.o:

[Index]    Value                  Size    Type  Bind  O Shndx    Name

[3]      |                     0|     180|FUNC |LOCAL|0|   .text|do_exitcu

> I vaguely recall that the behavior of these are different; specifically
> the .dlt entry isn't supposed to point to a .opd entry (since we don't
> have .opd entries for static functions).

That's definitely strange as the HP compiler is definitely passing a
pointer to an .opd entry for do_excite when it calls ___stdio_unsup_1.
The GNU linked code seg faults on the bve,l call to do_exitcu which
occurs here:

 36c:   50 a2 00 20     ldd 10(r5),rp
 370:   50 bb 00 30     ldd 18(r5),dp
 374:   35 9a 00 00     ldo 0(r12),r26
 378:   e8 40 f0 00     bve,l (rp),%r2

It seems that the HP compiler and linker use an .opd entry for an indirect
call to a static function in a different module.  This little test program
shows the difference between what cc +DA2.0W and gcc are doing:

extern void f (void (*)(void));
static void g (void) { }
main ()
{
  f (g);
}

cc +DA2.0W -c:

  18:   2b 60 00 00     addil 0,dp,%r1
			18: R_PARISC_LTOFF_FPTR21L      g
  1c:   50 3a 00 00     ldd 0(r1),r26
			1c: R_PARISC_LTOFF_FPTR14DR     g
  20:   e8 00 a0 00     b,l 28 <main+0x28>,%r2
			20: R_PARISC_PCREL22F   f
  24:   37 dd 3f a1     ldo -30(sp),ret1

gcc:

  40:   2b 60 00 00     addil 0,dp,%r1
			40: R_PARISC_DLTIND21L  L$C0000
  44:   50 21 00 00     ldd 0(r1),r1
			44: R_PARISC_DLTIND14R  L$C0000
  48:   0c 20 10 da     ldd 0(sr0,r1),r26
  4c:   37 dd 3f e1     ldo -10(sp),ret1
  50:   e8 00 a0 00     b,l 58 <main+0x40>,%r2
			50: R_PARISC_PCREL22F   f
  54:   08 00 02 40     nop

Dave
-- 
J. David Anglin                                  dave.anglin@nrc.ca
National Research Council of Canada              (613) 990-0752 (FAX: 952-6605)