gdb/hppabsd-tdep.c

   1 /* Target-dependent code for HP PA-RISC BSD's.
   2
   3    Copyright (C) 2004, 2005, 2006, 2007 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 /* Core file support.  */
  41
  42 /* Sizeof `struct reg' in <machine/reg.h>.  */
  43 #define HPPABSD_SIZEOF_GREGS    (34 * 4)
  44
  45 /* Supply register REGNUM from the buffer specified by GREGS and LEN
  46    in the general-purpose register set REGSET to register cache
  47    REGCACHE.  If REGNUM is -1, do this for all registers in REGSET.  */
  48
  49 static void
  50 hppabsd_supply_gregset (const struct regset *regset, struct regcache *regcache,
  51                      int regnum, const void *gregs, size_t len)
  52 {
  53   const gdb_byte *regs = gregs;
  54   size_t offset;
  55   int i;
  56
  57   gdb_assert (len >= HPPABSD_SIZEOF_GREGS);
  58
  59   for (i = HPPA_R1_REGNUM, offset = 4; i <= HPPA_R31_REGNUM; i++, offset += 4)
  60     {
  61       if (regnum == -1 || regnum == i)
  62         regcache_raw_supply (regcache, i, regs + offset);
  63     }
  64
  65   if (regnum == -1 || regnum == HPPA_SAR_REGNUM)
  66     regcache_raw_supply (regcache, HPPA_SAR_REGNUM, regs);
  67   if (regnum == -1 || regnum == HPPA_PCOQ_HEAD_REGNUM)
  68     regcache_raw_supply (regcache, HPPA_PCOQ_HEAD_REGNUM, regs + 32 * 4);
  69   if (regnum == -1 || regnum == HPPA_PCOQ_TAIL_REGNUM)
  70     regcache_raw_supply (regcache, HPPA_PCOQ_TAIL_REGNUM, regs + 33 * 4);
  71 }
  72
  73 /* OpenBSD/hppa register set.  */
  74
  75 static struct regset hppabsd_gregset =
  76 {
  77   NULL,
  78   hppabsd_supply_gregset
  79 };
  80
  81 /* Return the appropriate register set for the core section identified
  82    by SECT_NAME and SECT_SIZE.  */
  83
  84 static const struct regset *
  85 hppabsd_regset_from_core_section (struct gdbarch *gdbarch,
  86                                   const char *sect_name, size_t sect_size)
  87 {
  88   if (strcmp (sect_name, ".reg") == 0 && sect_size >= HPPABSD_SIZEOF_GREGS)
  89     return &hppabsd_gregset;
  90
  91   return NULL;
  92 }
  93 \f
  94
  95 CORE_ADDR
  96 hppabsd_find_global_pointer (struct value *function)
  97 {
  98   CORE_ADDR faddr = value_as_address (function);
  99   struct obj_section *faddr_sec;
 100   gdb_byte buf[4];
 101
 102   /* Is this a plabel? If so, dereference it to get the Global Pointer
 103      value.  */
 104   if (faddr & 2)
 105     {
 106       if (target_read_memory ((faddr & ~3) + 4, buf, sizeof buf) == 0)
 107         return extract_unsigned_integer (buf, sizeof buf);
 108     }
 109
 110   /* If the address is in the .plt section, then the real function
 111      hasn't yet been fixed up by the linker so we cannot determine the
 112      Global Pointer for that function.  */
 113   if (in_plt_section (faddr, NULL))
 114     return 0;
 115
 116   faddr_sec = find_pc_section (faddr);
 117   if (faddr_sec != NULL)
 118     {
 119       struct obj_section *sec;
 120
 121       ALL_OBJFILE_OSECTIONS (faddr_sec->objfile, sec)
 122         {
 123           if (strcmp (sec->the_bfd_section->name, ".dynamic") == 0)
 124             break;
 125         }
 126
 127       if (sec < faddr_sec->objfile->sections_end)
 128         {
 129           CORE_ADDR addr = sec->addr;
 130
 131           while (addr < sec->endaddr)
 132             {
 133               gdb_byte buf[4];
 134               LONGEST tag;
 135
 136               if (target_read_memory (addr, buf, sizeof buf) != 0)
 137                 break;
 138
 139               tag = extract_signed_integer (buf, sizeof buf);
 140               if (tag == DT_PLTGOT)
 141                 {
 142                   CORE_ADDR pltgot;
 143
 144                   if (target_read_memory (addr + 4, buf, sizeof buf) != 0)
 145                     break;
 146
 147                   /* The OpenBSD ld.so doesn't relocate DT_PLTGOT, so
 148                      we have to do it ourselves.  */
 149                   pltgot = extract_unsigned_integer (buf, sizeof buf);
 150                   pltgot += ANOFFSET (sec->objfile->section_offsets,
 151                                       SECT_OFF_TEXT (sec->objfile));
 152                   return pltgot;
 153                 }
 154
 155               if (tag == DT_NULL)
 156                 break;
 157
 158               addr += 8;
 159             }
 160         }
 161     }
 162
 163   return 0;
 164 }
 165 \f
 166
 167 static void
 168 hppabsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 169 {
 170   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 171
 172   /* OpenBSD and NetBSD have a 64-bit 'long double'.  */
 173   set_gdbarch_long_double_bit (gdbarch, 64);
 174   set_gdbarch_long_double_format (gdbarch, &floatformat_ieee_double_big);
 175
 176   /* Core file support.  */
 177   set_gdbarch_regset_from_core_section
 178     (gdbarch, hppabsd_regset_from_core_section);
 179
 180   /* OpenBSD and NetBSD use ELF.  */
 181   tdep->is_elf = 1;
 182   tdep->find_global_pointer = hppabsd_find_global_pointer;
 183   tdep->in_solib_call_trampoline = hppa_in_solib_call_trampoline;
 184   set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
 185
 186   /* OpenBSD and NetBSD use SVR4-style shared libraries.  */
 187   set_solib_svr4_fetch_link_map_offsets
 188     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 189 }
 190 \f
 191
 192 /* OpenBSD uses uses the traditional NetBSD core file format, even for
 193    ports that use ELF.  */
 194 #define GDB_OSABI_NETBSD_CORE GDB_OSABI_OPENBSD_ELF
 195
 196 static enum gdb_osabi
 197 hppabsd_core_osabi_sniffer (bfd *abfd)
 198 {
 199   if (strcmp (bfd_get_target (abfd), "netbsd-core") == 0)
 200     return GDB_OSABI_NETBSD_CORE;
 201
 202   return GDB_OSABI_UNKNOWN;
 203 }
 204 \f
 205
 206 /* Provide a prototype to silence -Wmissing-prototypes.  */
 207 void _initialize_hppabsd_tdep (void);
 208
 209 void
 210 _initialize_hppabsd_tdep (void)
 211 {
 212   /* BFD doesn't set a flavour for NetBSD style a.out core files.  */
 213   gdbarch_register_osabi_sniffer (bfd_arch_hppa, bfd_target_unknown_flavour,
 214                                   hppabsd_core_osabi_sniffer);
 215
 216   gdbarch_register_osabi (bfd_arch_hppa, 0, GDB_OSABI_NETBSD_ELF,
 217                           hppabsd_init_abi);
 218   gdbarch_register_osabi (bfd_arch_hppa, 0, GDB_OSABI_OPENBSD_ELF,
 219                           hppabsd_init_abi);
 220 }