gdb/alphafbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/alpha.
   2
   3    Copyright (C) 2001, 2002, 2003, 2006, 2007, 2008
   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 "value.h"
  23 #include "osabi.h"
  24
  25 #include "alpha-tdep.h"
  26 #include "solib-svr4.h"
  27
  28 static int
  29 alphafbsd_return_in_memory (struct type *type)
  30 {
  31   enum type_code code;
  32   int i;
  33
  34   /* All aggregate types that won't fit in a register must be returned
  35      in memory.  */
  36   if (TYPE_LENGTH (type) > ALPHA_REGISTER_SIZE)
  37     return 1;
  38
  39   /* The only aggregate types that can be returned in a register are
  40      structs and unions.  Arrays must be returned in memory.  */
  41   code = TYPE_CODE (type);
  42   if (code != TYPE_CODE_STRUCT && code != TYPE_CODE_UNION)
  43     return 1;
  44
  45   /* We need to check if this struct/union is "integer" like.  For
  46      this to be true, the offset of each adressable subfield must be
  47      zero.  Note that bit fields are not addressable.  */
  48   for (i = 0; i < TYPE_NFIELDS (type); i++)
  49     {
  50       /* If the field bitsize is non-zero, it isn't adressable.  */
  51       if (TYPE_FIELD_BITPOS (type, i) != 0
  52           && TYPE_FIELD_BITSIZE (type, i) == 0)
  53         return 1;
  54     }
  55
  56   return 0;
  57 }
  58 \f
  59
  60 /* Support for signal handlers.  */
  61
  62 /* Return whether PC is in a BSD sigtramp routine.  */
  63
  64 CORE_ADDR alphafbsd_sigtramp_start = 0x11ffff68;
  65 CORE_ADDR alphafbsd_sigtramp_end = 0x11ffffe0;
  66
  67 static int
  68 alphafbsd_pc_in_sigtramp (CORE_ADDR pc, char *func_name)
  69 {
  70   return (pc >= alphafbsd_sigtramp_start && pc < alphafbsd_sigtramp_end);
  71 }
  72
  73 static LONGEST
  74 alphafbsd_sigtramp_offset (CORE_ADDR pc)
  75 {
  76   return pc - alphafbsd_sigtramp_start;
  77 }
  78
  79 /* Assuming THIS_FRAME is the frame of a BSD sigtramp routine,
  80    return the address of the associated sigcontext structure.  */
  81
  82 static CORE_ADDR
  83 alphafbsd_sigcontext_addr (struct frame_info *this_frame)
  84 {
  85   return get_frame_register_unsigned (this_frame, ALPHA_SP_REGNUM) + 24;
  86 }
  87
  88 /* FreeBSD 5.0-RELEASE or later.  */
  89
  90 static void
  91 alphafbsd_init_abi (struct gdbarch_info info,
  92                     struct gdbarch *gdbarch)
  93 {
  94   struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch);
  95
  96   /* Hook into the DWARF CFI frame unwinder.  */
  97   alpha_dwarf2_init_abi (info, gdbarch);
  98
  99   /* Hook into the MDEBUG frame unwinder.  */
 100   alpha_mdebug_init_abi (info, gdbarch);
 101
 102   /* FreeBSD/alpha has SVR4-style shared libraries.  */
 103   set_solib_svr4_fetch_link_map_offsets
 104     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 105
 106   tdep->dynamic_sigtramp_offset = alphafbsd_sigtramp_offset;
 107   tdep->sigcontext_addr = alphafbsd_sigcontext_addr;
 108   tdep->pc_in_sigtramp = alphafbsd_pc_in_sigtramp;
 109   tdep->return_in_memory = alphafbsd_return_in_memory;
 110   tdep->sc_pc_offset = 288;
 111   tdep->sc_regs_offset = 24;
 112   tdep->sc_fpregs_offset = 320;
 113
 114   tdep->jb_pc = 2;
 115   tdep->jb_elt_size = 8;
 116 }
 117 \f
 118
 119 /* Provide a prototype to silence -Wmissing-prototypes.  */
 120 void _initialize_alphafbsd_tdep (void);
 121
 122 void
 123 _initialize_alphafbsd_tdep (void)
 124 {
 125   gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_FREEBSD_ELF,
 126                           alphafbsd_init_abi);
 127 }