gnu/dist/gdb6/gdb/hppabsd-tdep.c

   1 /* Target-dependent code for HP PA-RISC BSD's.
   2
   3    Copyright (C) 2004, 2005, 2006 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 2 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program; if not, write to the Free Software
  19    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  20    Boston, MA 02110-1301, USA.  */
  21
  22 #include "defs.h"
  23 #include "arch-utils.h"
  24 #include "symtab.h"
  25 #include "objfiles.h"
  26 #include "osabi.h"
  27 #include "regcache.h"
  28 #include "regset.h"
  29 #include "target.h"
  30 #include "value.h"
  31
  32 #include "gdb_assert.h"
  33 #include "gdb_string.h"
  34
  35 #include "elf/common.h"
  36
  37 #include "hppa-tdep.h"
  38 #include "solib-svr4.h"
  39
  40
  41 CORE_ADDR
  42 hppabsd_find_global_pointer (struct value *function)
  43 {
  44   CORE_ADDR faddr = value_as_address (function);
  45   struct obj_section *faddr_sec;
  46   gdb_byte buf[4];
  47
  48   /* Is this a plabel? If so, dereference it to get the Global Pointer
  49      value.  */
  50   if (faddr & 2)
  51     {
  52       if (target_read_memory ((faddr & ~3) + 4, buf, sizeof buf) == 0)
  53         return extract_unsigned_integer (buf, sizeof buf);
  54     }
  55
  56   /* If the address is in the .plt section, then the real function
  57      hasn't yet been fixed up by the linker so we cannot determine the
  58      Global Pointer for that function.  */
  59   if (in_plt_section (faddr, NULL))
  60     return 0;
  61
  62   faddr_sec = find_pc_section (faddr);
  63   if (faddr_sec != NULL)
  64     {
  65       struct obj_section *sec;
  66
  67       ALL_OBJFILE_OSECTIONS (faddr_sec->objfile, sec)
  68         {
  69           if (strcmp (sec->the_bfd_section->name, ".dynamic") == 0)
  70             break;
  71         }
  72
  73       if (sec < faddr_sec->objfile->sections_end)
  74         {
  75           CORE_ADDR addr = sec->addr;
  76
  77           while (addr < sec->endaddr)
  78             {
  79               gdb_byte buf[4];
  80               LONGEST tag;
  81
  82               if (target_read_memory (addr, buf, sizeof buf) != 0)
  83                 break;
  84
  85               tag = extract_signed_integer (buf, sizeof buf);
  86               if (tag == DT_PLTGOT)
  87                 {
  88                   CORE_ADDR pltgot;
  89
  90                   if (target_read_memory (addr + 4, buf, sizeof buf) != 0)
  91                     break;
  92
  93                   /* The NetBSD/OpenBSD ld.so doesn't relocate DT_PLTGOT, so
  94                      we have to do it ourselves.  */
  95                   pltgot = extract_unsigned_integer (buf, sizeof buf);
  96                   pltgot += ANOFFSET (sec->objfile->section_offsets,
  97                                       SECT_OFF_TEXT (sec->objfile));
  98
  99                   return pltgot;
 100                 }
 101
 102               if (tag == DT_NULL)
 103                 break;
 104
 105               addr += 8;
 106             }
 107         }
 108     }
 109
 110   return 0;
 111 }
 112 \f
 113
 114 void
 115 hppabsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 116 {
 117   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 118
 119   /* OpenBSD and NetBSD have a 64-bit 'long double'.  */
 120   set_gdbarch_long_double_bit (gdbarch, 64);
 121   set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);
 122
 123   /* OpenBSD and NetBSD use ELF.  */
 124   tdep->is_elf = 1;
 125   tdep->find_global_pointer = hppabsd_find_global_pointer;
 126   tdep->in_solib_call_trampoline = hppa_in_solib_call_trampoline;
 127   set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
 128
 129   /* OpenBSD and NetBSD use SVR4-style shared libraries.  */
 130   set_solib_svr4_fetch_link_map_offsets
 131     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 132 }