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