gdb/hppabsd-tdep.c

   1 /* Target-dependent code for HP PA-RISC BSD's.
   2
   3    Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 3 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "objfiles.h"
  23 #include "target.h"
  24 #include "value.h"
  25
  26 #include "elf/common.h"
  27
  28 #include "hppa-tdep.h"
  29 #include "solib-svr4.h"
  30
  31 CORE_ADDR
  32 hppabsd_find_global_pointer (struct gdbarch *gdbarch, struct value *function)
  33 {
  34   CORE_ADDR faddr = value_as_address (function);
  35   struct obj_section *faddr_sec;
  36   gdb_byte buf[4];
  37
  38   /* Is this a plabel? If so, dereference it to get the Global Pointer
  39      value.  */
  40   if (faddr & 2)
  41     {
  42       if (target_read_memory ((faddr & ~3) + 4, buf, sizeof buf) == 0)
  43         return extract_unsigned_integer (buf, sizeof buf);
  44     }
  45
  46   /* If the address is in the .plt section, then the real function
  47      hasn't yet been fixed up by the linker so we cannot determine the
  48      Global Pointer for that function.  */
  49   if (in_plt_section (faddr, NULL))
  50     return 0;
  51
  52   faddr_sec = find_pc_section (faddr);
  53   if (faddr_sec != NULL)
  54     {
  55       struct obj_section *sec;
  56
  57       ALL_OBJFILE_OSECTIONS (faddr_sec->objfile, sec)
  58         {
  59           if (strcmp (sec->the_bfd_section->name, ".dynamic") == 0)
  60             break;
  61         }
  62
  63       if (sec < faddr_sec->objfile->sections_end)
  64         {
  65           CORE_ADDR addr = obj_section_addr (sec);
  66           CORE_ADDR endaddr = obj_section_endaddr (sec);
  67
  68           while (addr < endaddr)
  69             {
  70               gdb_byte buf[4];
  71               LONGEST tag;
  72
  73               if (target_read_memory (addr, buf, sizeof buf) != 0)
  74                 break;
  75
  76               tag = extract_signed_integer (buf, sizeof buf);
  77               if (tag == DT_PLTGOT)
  78                 {
  79                   CORE_ADDR pltgot;
  80
  81                   if (target_read_memory (addr + 4, buf, sizeof buf) != 0)
  82                     break;
  83
  84                   /* The NetBSD/OpenBSD ld.so doesn't relocate DT_PLTGOT, so
  85                      we have to do it ourselves.  */
  86                   pltgot = extract_unsigned_integer (buf, sizeof buf);
  87                   pltgot += ANOFFSET (sec->objfile->section_offsets,
  88                                       SECT_OFF_TEXT (sec->objfile));
  89
  90                   return pltgot;
  91                 }
  92
  93               if (tag == DT_NULL)
  94                 break;
  95
  96               addr += 8;
  97             }
  98         }
  99     }
 100
 101   return 0;
 102 }
 103 \f
 104
 105 void
 106 hppabsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 107 {
 108   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 109
 110   /* OpenBSD and NetBSD have a 64-bit 'long double'.  */
 111   set_gdbarch_long_double_bit (gdbarch, 64);
 112   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 113
 114   /* OpenBSD and NetBSD use ELF.  */
 115   tdep->is_elf = 1;
 116   tdep->find_global_pointer = hppabsd_find_global_pointer;
 117   tdep->in_solib_call_trampoline = hppa_in_solib_call_trampoline;
 118   set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
 119
 120   /* OpenBSD and NetBSD use SVR4-style shared libraries.  */
 121   set_solib_svr4_fetch_link_map_offsets
 122     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 123 }