gdb/std-regs.c

   1 /* Builtin frame register, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2002-2014 Free Software Foundation, Inc.
   4
   5    Contributed by Red Hat.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 #include "defs.h"
  23 #include "user-regs.h"
  24 #include "frame.h"
  25 #include "gdbtypes.h"
  26 #include "value.h"
  27 #include <string.h>
  28
  29
  30 static struct value *
  31 value_of_builtin_frame_fp_reg (struct frame_info *frame, const void *baton)
  32 {
  33   struct gdbarch *gdbarch = get_frame_arch (frame);
  34
  35   if (gdbarch_deprecated_fp_regnum (gdbarch) >= 0)
  36     /* NOTE: cagney/2003-04-24: Since the mere presence of "fp" in the
  37        register name table overrides this built-in $fp register, there
  38        is no real reason for this gdbarch_deprecated_fp_regnum trickery here.
  39        An architecture wanting to implement "$fp" as alias for a raw
  40        register can do so by adding "fp" to register name table (mind
  41        you, doing this is probably a dangerous thing).  */
  42     return value_of_register (gdbarch_deprecated_fp_regnum (gdbarch),
  43                               frame);
  44   else
  45     {
  46       struct type *data_ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
  47       struct value *val = allocate_value (data_ptr_type);
  48       gdb_byte *buf = value_contents_raw (val);
  49
  50       gdbarch_address_to_pointer (gdbarch, data_ptr_type,
  51                                   buf, get_frame_base_address (frame));
  52       return val;
  53     }
  54 }
  55
  56 static struct value *
  57 value_of_builtin_frame_pc_reg (struct frame_info *frame, const void *baton)
  58 {
  59   struct gdbarch *gdbarch = get_frame_arch (frame);
  60
  61   if (gdbarch_pc_regnum (gdbarch) >= 0)
  62     return value_of_register (gdbarch_pc_regnum (gdbarch), frame);
  63   else
  64     {
  65       struct type *func_ptr_type = builtin_type (gdbarch)->builtin_func_ptr;
  66       struct value *val = allocate_value (func_ptr_type);
  67       gdb_byte *buf = value_contents_raw (val);
  68
  69       gdbarch_address_to_pointer (gdbarch, func_ptr_type,
  70                                   buf, get_frame_pc (frame));
  71       return val;
  72     }
  73 }
  74
  75 static struct value *
  76 value_of_builtin_frame_sp_reg (struct frame_info *frame, const void *baton)
  77 {
  78   struct gdbarch *gdbarch = get_frame_arch (frame);
  79
  80   if (gdbarch_sp_regnum (gdbarch) >= 0)
  81     return value_of_register (gdbarch_sp_regnum (gdbarch), frame);
  82   error (_("Standard register ``$sp'' is not available for this target"));
  83 }
  84
  85 static struct value *
  86 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton)
  87 {
  88   struct gdbarch *gdbarch = get_frame_arch (frame);
  89
  90   if (gdbarch_ps_regnum (gdbarch) >= 0)
  91     return value_of_register (gdbarch_ps_regnum (gdbarch), frame);
  92   error (_("Standard register ``$ps'' is not available for this target"));
  93 }
  94
  95 extern initialize_file_ftype _initialize_frame_reg; /* -Wmissing-prototypes */
  96
  97 void
  98 _initialize_frame_reg (void)
  99 {
 100   /* Frame based $fp, $pc, $sp and $ps.  These only come into play
 101      when the target does not define its own version of these
 102      registers.  */
 103   user_reg_add_builtin ("fp", value_of_builtin_frame_fp_reg, NULL);
 104   user_reg_add_builtin ("pc", value_of_builtin_frame_pc_reg, NULL);
 105   user_reg_add_builtin ("sp", value_of_builtin_frame_sp_reg, NULL);
 106   user_reg_add_builtin ("ps", value_of_builtin_frame_ps_reg, NULL);
 107 }