gdb/alphafbsd-tdep.c

   1 /* Target-dependent code for FreeBSD/alpha.
   2
   3    Copyright (C) 2001-2016 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 "value.h"
  22 #include "osabi.h"
  23
  24 #include "alpha-tdep.h"
  25 #include "solib-svr4.h"
  26
  27 static int
  28 alphafbsd_return_in_memory (struct type *type)
  29 {
  30   enum type_code code;
  31   int i;
  32
  33   /* All aggregate types that won't fit in a register must be returned
  34      in memory.  */
  35   if (TYPE_LENGTH (type) > ALPHA_REGISTER_SIZE)
  36     return 1;
  37
  38   /* The only aggregate types that can be returned in a register are
  39      structs and unions.  Arrays must be returned in memory.  */
  40   code = TYPE_CODE (type);
  41   if (code != TYPE_CODE_STRUCT && code != TYPE_CODE_UNION)
  42     return 1;
  43
  44   /* We need to check if this struct/union is "integer" like.  For
  45      this to be true, the offset of each adressable subfield must be
  46      zero.  Note that bit fields are not addressable.  */
  47   for (i = 0; i < TYPE_NFIELDS (type); i++)
  48     {
  49       /* If the field bitsize is non-zero, it isn't adressable.  */
  50       if (TYPE_FIELD_BITPOS (type, i) != 0
  51           && TYPE_FIELD_BITSIZE (type, i) == 0)
  52         return 1;
  53     }
  54
  55   return 0;
  56 }
  57 \f
  58
  59 /* Support for signal handlers.  */
  60
  61 /* Return whether PC is in a BSD sigtramp routine.  */
  62
  63 CORE_ADDR alphafbsd_sigtramp_start = 0x11ffff68;
  64 CORE_ADDR alphafbsd_sigtramp_end = 0x11ffffe0;
  65
  66 static int
  67 alphafbsd_pc_in_sigtramp (struct gdbarch *gdbarch,
  68                           CORE_ADDR pc, const char *func_name)
  69 {
  70   return (pc >= alphafbsd_sigtramp_start && pc < alphafbsd_sigtramp_end);
  71 }
  72
  73 static LONGEST
  74 alphafbsd_sigtramp_offset (struct gdbarch *gdbarch, 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   /* FIXME: Should activate generic FreeBSD support here with
  97      fbsd_init_abi(), but this requires a valid
  98      'iterate_over_regset_sections' gdbarch method and
  99      'collect_regset' functions for each regset.  */
 100
 101   /* Hook into the DWARF CFI frame unwinder.  */
 102   alpha_dwarf2_init_abi (info, gdbarch);
 103
 104   /* Hook into the MDEBUG frame unwinder.  */
 105   alpha_mdebug_init_abi (info, gdbarch);
 106
 107   /* FreeBSD/alpha has SVR4-style shared libraries.  */
 108   set_solib_svr4_fetch_link_map_offsets
 109     (gdbarch, svr4_lp64_fetch_link_map_offsets);
 110
 111   tdep->dynamic_sigtramp_offset = alphafbsd_sigtramp_offset;
 112   tdep->sigcontext_addr = alphafbsd_sigcontext_addr;
 113   tdep->pc_in_sigtramp = alphafbsd_pc_in_sigtramp;
 114   tdep->return_in_memory = alphafbsd_return_in_memory;
 115   tdep->sc_pc_offset = 288;
 116   tdep->sc_regs_offset = 24;
 117   tdep->sc_fpregs_offset = 320;
 118
 119   tdep->jb_pc = 2;
 120   tdep->jb_elt_size = 8;
 121 }
 122 \f
 123
 124 /* Provide a prototype to silence -Wmissing-prototypes.  */
 125 void _initialize_alphafbsd_tdep (void);
 126
 127 void
 128 _initialize_alphafbsd_tdep (void)
 129 {
 130   gdbarch_register_osabi (bfd_arch_alpha, 0, GDB_OSABI_FREEBSD_ELF,
 131                           alphafbsd_init_abi);
 132 }