gdb/hppabsd-tdep.c

   1 /* Target-dependent code for HP PA-RISC BSD's.
   2
   3    Copyright (C) 2004-2016 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 3 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, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "objfiles.h"
  22 #include "target.h"
  23 #include "value.h"
  24
  25 #include "elf/common.h"
  26
  27 #include "hppa-tdep.h"
  28 #include "hppabsd-tdep.h"
  29 #include "dwarf2-frame.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))
  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 static void
 109 hppabsd_dwarf2_frame_init_reg (struct gdbarch *gdbarch, int regnum,
 110                                struct dwarf2_frame_state_reg *reg,
 111                                struct frame_info *this_frame)
 112 {
 113   if (regnum == HPPA_PCOQ_HEAD_REGNUM)
 114     reg->how = DWARF2_FRAME_REG_RA;
 115   else if (regnum == HPPA_SP_REGNUM)
 116     reg->how = DWARF2_FRAME_REG_CFA;
 117 }
 118
 119 void
 120 hppabsd_init_abi (struct gdbarch_info info, struct gdbarch *gdbarch)
 121 {
 122   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
 123
 124   /* OpenBSD and NetBSD have a 64-bit 'long double'.  */
 125   set_gdbarch_long_double_bit (gdbarch, 64);
 126   set_gdbarch_long_double_format (gdbarch, floatformats_ieee_double);
 127
 128   /* OpenBSD and NetBSD use ELF.  */
 129   tdep->is_elf = 1;
 130   tdep->find_global_pointer = hppabsd_find_global_pointer;
 131   tdep->in_solib_call_trampoline = hppa_in_solib_call_trampoline;
 132   set_gdbarch_skip_trampoline_code (gdbarch, hppa_skip_trampoline_code);
 133
 134   /* OpenBSD and NetBSD use SVR4-style shared libraries.  */
 135   set_solib_svr4_fetch_link_map_offsets
 136     (gdbarch, svr4_ilp32_fetch_link_map_offsets);
 137
 138   /* Hook in the DWARF CFI frame unwinder.  */
 139   dwarf2_frame_set_init_reg (gdbarch, hppabsd_dwarf2_frame_init_reg);
 140   dwarf2_append_unwinders (gdbarch);
 141 }