gdb/std-regs.c

   1 /* Builtin frame register, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2002, 2005, 2007 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 "gdb_string.h"
  28
  29
  30 static struct value *
  31 value_of_builtin_frame_fp_reg (struct frame_info *frame, const void *baton)
  32 {
  33   if (gdbarch_deprecated_fp_regnum (current_gdbarch) >= 0)
  34     /* NOTE: cagney/2003-04-24: Since the mere presence of "fp" in the
  35        register name table overrides this built-in $fp register, there
  36        is no real reason for this gdbarch_deprecated_fp_regnum trickery here.
  37        An architecture wanting to implement "$fp" as alias for a raw
  38        register can do so by adding "fp" to register name table (mind
  39        you, doing this is probably a dangerous thing).  */
  40     return value_of_register (gdbarch_deprecated_fp_regnum (current_gdbarch),
  41                               frame);
  42   else
  43     {
  44       struct value *val = allocate_value (builtin_type_void_data_ptr);
  45       gdb_byte *buf = value_contents_raw (val);
  46       if (frame == NULL)
  47         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  48       else
  49         gdbarch_address_to_pointer (current_gdbarch, builtin_type_void_data_ptr,
  50                                     buf, get_frame_base_address (frame));
  51       return val;
  52     }
  53 }
  54
  55 static struct value *
  56 value_of_builtin_frame_pc_reg (struct frame_info *frame, const void *baton)
  57 {
  58   if (gdbarch_pc_regnum (current_gdbarch) >= 0)
  59     return value_of_register (gdbarch_pc_regnum (current_gdbarch), frame);
  60   else
  61     {
  62       struct value *val = allocate_value (builtin_type_void_data_ptr);
  63       gdb_byte *buf = value_contents_raw (val);
  64       if (frame == NULL)
  65         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  66       else
  67         gdbarch_address_to_pointer (current_gdbarch, builtin_type_void_data_ptr,
  68                                      buf, get_frame_pc (frame));
  69       return val;
  70     }
  71 }
  72
  73 static struct value *
  74 value_of_builtin_frame_sp_reg (struct frame_info *frame, const void *baton)
  75 {
  76   if (gdbarch_sp_regnum (current_gdbarch) >= 0)
  77     return value_of_register (gdbarch_sp_regnum (current_gdbarch), frame);
  78   error (_("Standard register ``$sp'' is not available for this target"));
  79 }
  80
  81 static struct value *
  82 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton)
  83 {
  84   if (gdbarch_ps_regnum (current_gdbarch) >= 0)
  85     return value_of_register (gdbarch_ps_regnum (current_gdbarch), frame);
  86   error (_("Standard register ``$ps'' is not available for this target"));
  87 }
  88
  89 extern initialize_file_ftype _initialize_frame_reg; /* -Wmissing-prototypes */
  90
  91 void
  92 _initialize_frame_reg (void)
  93 {
  94   /* Frame based $fp, $pc, $sp and $ps.  These only come into play
  95      when the target does not define its own version of these
  96      registers.  */
  97   user_reg_add_builtin ("fp", value_of_builtin_frame_fp_reg, NULL);
  98   user_reg_add_builtin ("pc", value_of_builtin_frame_pc_reg, NULL);
  99   user_reg_add_builtin ("sp", value_of_builtin_frame_sp_reg, NULL);
 100   user_reg_add_builtin ("ps", value_of_builtin_frame_ps_reg, NULL);
 101 }