freebsd-skq/contrib/gcc/config/ia64/unwind-aix.c
obrien c9ab9ae440 Enlist the FreeBSD-CURRENT users as testers of what is to become Gcc 3.1.0.
These bits are taken from the FSF anoncvs repo on 1-Feb-2002 08:20 PST.
2002-02-01 18:16:02 +00:00

121 lines
3.5 KiB
C

/* Implements unwind table entry lookup for AIX (cf. fde-glibc.c).
Copyright (C) 2001, 2002 Free Software Foundation, Inc.
Contributed by Timothy Wall <twall@redhat.com>
This file is part of GNU CC.
GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#include "tconfig.h"
#include "tsystem.h"
#include "unwind.h"
#include "unwind-ia64.h"
#include <dlfcn.h>
#include <link.h>
#include <sys/mman.h>
static struct unw_table_entry *
find_fde_for_dso (Elf64_Addr pc, rt_link_map *map,
unsigned long* pseg_base, unsigned long* pgp)
{
rt_segment *seg;
Elf64_Addr seg_base;
struct unw_table_entry *f_base;
size_t lo, hi;
/* See if PC falls into one of the loaded segments. */
for (seg = map->l_segments; seg; seg = (rt_segment *)seg->s_next)
{
if (pc >= seg->s_map_addr && pc < seg->s_map_addr + seg->s_mapsz)
break;
}
if (!seg)
return NULL;
/* Search for the entry within the unwind table. */
f_base = (struct unw_table_entry *) (map->l_unwind_table);
seg_base = (Elf64_Addr) seg->s_map_addr;
lo = 0;
hi = map->l_unwind_sz / sizeof (struct unw_table_entry);
while (lo < hi)
{
size_t mid = (lo + hi) / 2;
struct unw_table_entry *f = f_base + mid;
if (pc < f->start_offset + seg_base)
hi = mid;
else if (pc >= f->end_offset + seg_base)
lo = mid + 1;
else {
/* AIX executables are *always* dynamic. Look up GP for this
object. */
Elf64_Dyn *dyn = map->l_ld;
*pgp = 0;
for (; dyn->d_tag != DT_NULL ; dyn++)
{
if (dyn->d_tag == DT_PLTGOT)
{
*pgp = dyn->d_un.d_ptr;
break;
}
}
*pseg_base = seg_base;
return f;
}
}
return NULL;
}
/* Return a pointer to the unwind table entry for the function containing
PC. */
struct unw_table_entry *
_Unwind_FindTableEntry (void *pc, unsigned long *pseg_base, unsigned long *pgp)
{
extern rt_r_debug _r_debug;
struct unw_table_entry *ret;
rt_link_map *map = _r_debug.r_map; /* address of link map */
/* Check the main application first, hoping that most of the user's
code is there instead of in some library. */
ret = find_fde_for_dso ((Elf64_Addr)pc, map, pseg_base, pgp);
if (ret)
{
/* If we're in the main application, use the current GP value. */
register unsigned long gp __asm__("gp");
*pgp = gp;
return ret;
}
/* FIXME need a DSO lock mechanism for AIX here, to ensure shared
libraries aren't changed while we're examining them. */
for (map = _r_debug.r_map; map; map = map->l_next)
{
/* Skip the main application's entry. */
if (!map->l_name)
continue;
ret = find_fde_for_dso ((Elf64_Addr)pc, map, pseg_base, pgp);
if (ret)
break;
}
/* FIXME need a DSO unlock mechanism for AIX here. */
return ret;
}