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 "hppabsd-tdep.h"
  30 #include "solib-svr4.h"
  31
  32 static CORE_ADDR
  33 hppabsd_find_global_pointer (struct gdbarch *gdbarch, struct value *function)
  34 {
  35   enum bfd_endian byte_order = gdbarch_byte_order (gdbarch);
  36   CORE_ADDR faddr = value_as_address (function);
  37   struct obj_section *faddr_sec;
  38   gdb_byte buf[4];
  39
  40   /* Is this a plabel? If so, dereference it to get the Global Pointer
  41      value.  */
  42   if (faddr & 2)
  43     {
  44       if (target_read_memory ((faddr & ~3) + 4, buf, sizeof buf) == 0)
  45         return extract_unsigned_integer (buf, sizeof buf, byte_order);
  46     }
  47
  48   /* If the address is in the .plt section, then the real function
  49      hasn't yet been fixed up by the linker so we cannot determine the
  50      Global Pointer for that function.  */
  51   if (in_plt_section (faddr, NULL))
  52     return 0;
  53
  54   faddr_sec = find_pc_section (faddr);
  55   if (faddr_sec != NULL)
  56     {
  57       struct obj_section *sec;
  58
  59       ALL_OBJFILE_OSECTIONS (faddr_sec->objfile, sec)
  60         {
  61           if (strcmp (sec->the_bfd_section->name, ".dynamic") == 0)
  62             break;
  63         }
  64
  65       if (sec < faddr_sec->objfile->sections_end)
  66         {
  67           CORE_ADDR addr = obj_section_addr (sec);
  68           CORE_ADDR endaddr = obj_section_endaddr (sec);
  69
  70           while (addr < endaddr)
  71             {
  72               gdb_byte buf[4];
  73               LONGEST tag;
  74
  75               if (target_read_memory (addr, buf, sizeof buf) != 0)
  76                 break;
  77
  78               tag = extract_signed_integer (buf, sizeof buf, byte_order);
  79               if (tag == DT_PLTGOT)
  80                 {
  81                   CORE_ADDR pltgot;
  82
  83                   if (target_read_memory (addr + 4, buf, sizeof buf) != 0)
  84                     break;
  85
  86                   /* The NetBSD/OpenBSD ld.so doesn't relocate DT_PLTGOT, so
  87                      we have to do it ourselves.  */
  88                   pltgot = extract_unsigned_integer (buf, sizeof buf,
  89                                                      byte_order);
  90                   pltgot += ANOFFSET (sec->objfile->section_offsets,
  91                                       SECT_OFF_TEXT (sec->objfile));
  92
  93                   return pltgot;
  94                 }
  95
  96               if (tag == DT_NULL)
  97                 break;
  98
  99               addr += 8;
 100             }
 101         }
 102     }
 103
 104   return 0;
 105 }
 106 \f
 107
 108 void
 109 hppabsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 110 {
 111   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 112
 113   /* OpenBSD and NetBSD have a 64-bit 'long double'.  */
 114   set_gdbarch_long_double_bit (gdbarch, 64);
 115   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 116
 117   /* OpenBSD and NetBSD use ELF.  */
 118   tdep->is_elf = 1;
 119   tdep->find_global_pointer = hppabsd_find_global_pointer;
 120   tdep->in_solib_call_trampoline = hppa_in_solib_call_trampoline;
 121   set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
 122
 123   /* OpenBSD and NetBSD use SVR4-style shared libraries.  */
 124   set_solib_svr4_fetch_link_map_offsets
 125     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 126 }