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 2 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, write to the Free Software
  21    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22    Boston, MA 02110-1301, USA.  */
  23
  24 #include "defs.h"
  25 #include "user-regs.h"
  26 #include "frame.h"
  27 #include "gdbtypes.h"
  28 #include "value.h"
  29 #include "gdb_string.h"
  30
  31
  32 static struct value *
  33 value_of_builtin_frame_fp_reg (struct frame_info *frame, const void *baton)
  34 {
  35   if (DEPRECATED_FP_REGNUM >= 0)
  36     /* NOTE: cagney/2003-04-24: Since the mere presence of "fp" in the
  37        register name table overrides this built-in $fp register, there
  38        is no real reason for this DEPRECATED_FP_REGNUM trickery here.
  39        An architecture wanting to implement "$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 (DEPRECATED_FP_REGNUM, frame);
  43   else
  44     {
  45       struct value *val = allocate_value (builtin_type_void_data_ptr);
  46       gdb_byte *buf = value_contents_raw (val);
  47       if (frame == NULL)
  48         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  49       else
  50         gdbarch_address_to_pointer (current_gdbarch, builtin_type_void_data_ptr,
  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   if (gdbarch_pc_regnum (current_gdbarch) >= 0)
  60     return value_of_register (gdbarch_pc_regnum (current_gdbarch), frame);
  61   else
  62     {
  63       struct value *val = allocate_value (builtin_type_void_data_ptr);
  64       gdb_byte *buf = value_contents_raw (val);
  65       if (frame == NULL)
  66         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  67       else
  68         gdbarch_address_to_pointer (current_gdbarch, builtin_type_void_data_ptr,
  69                                      buf, get_frame_pc (frame));
  70       return val;
  71     }
  72 }
  73
  74 static struct value *
  75 value_of_builtin_frame_sp_reg (struct frame_info *frame, const void *baton)
  76 {
  77   if (gdbarch_sp_regnum (current_gdbarch) >= 0)
  78     return value_of_register (gdbarch_sp_regnum (current_gdbarch), frame);
  79   error (_("Standard register ``$sp'' is not available for this target"));
  80 }
  81
  82 static struct value *
  83 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton)
  84 {
  85   if (gdbarch_ps_regnum (current_gdbarch) >= 0)
  86     return value_of_register (gdbarch_ps_regnum (current_gdbarch), frame);
  87   error (_("Standard register ``$ps'' is not available for this target"));
  88 }
  89
  90 extern initialize_file_ftype _initialize_frame_reg; /* -Wmissing-prototypes */
  91
  92 void
  93 _initialize_frame_reg (void)
  94 {
  95   /* Frame based $fp, $pc, $sp and $ps.  These only come into play
  96      when the target does not define its own version of these
  97      registers.  */
  98   user_reg_add_builtin ("fp", value_of_builtin_frame_fp_reg, NULL);
  99   user_reg_add_builtin ("pc", value_of_builtin_frame_pc_reg, NULL);
 100   user_reg_add_builtin ("sp", value_of_builtin_frame_sp_reg, NULL);
 101   user_reg_add_builtin ("ps", value_of_builtin_frame_ps_reg, NULL);
 102 }