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 (gdbarch_deprecated_fp_regnum (current_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 (current_gdbarch),
  43                               frame);
  44   else
  45     {
  46       struct value *val = allocate_value (builtin_type_void_data_ptr);
  47       gdb_byte *buf = value_contents_raw (val);
  48       if (frame == NULL)
  49         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  50       else
  51         gdbarch_address_to_pointer (current_gdbarch, builtin_type_void_data_ptr,
  52                                     buf, get_frame_base_address (frame));
  53       return val;
  54     }
  55 }
  56
  57 static struct value *
  58 value_of_builtin_frame_pc_reg (struct frame_info *frame, const void *baton)
  59 {
  60   if (gdbarch_pc_regnum (current_gdbarch) >= 0)
  61     return value_of_register (gdbarch_pc_regnum (current_gdbarch), frame);
  62   else
  63     {
  64       struct value *val = allocate_value (builtin_type_void_data_ptr);
  65       gdb_byte *buf = value_contents_raw (val);
  66       if (frame == NULL)
  67         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  68       else
  69         gdbarch_address_to_pointer (current_gdbarch, builtin_type_void_data_ptr,
  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   if (gdbarch_sp_regnum (current_gdbarch) >= 0)
  79     return value_of_register (gdbarch_sp_regnum (current_gdbarch), frame);
  80   error (_("Standard register ``$sp'' is not available for this target"));
  81 }
  82
  83 static struct value *
  84 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton)
  85 {
  86   if (gdbarch_ps_regnum (current_gdbarch) >= 0)
  87     return value_of_register (gdbarch_ps_regnum (current_gdbarch), frame);
  88   error (_("Standard register ``$ps'' is not available for this target"));
  89 }
  90
  91 extern initialize_file_ftype _initialize_frame_reg; /* -Wmissing-prototypes */
  92
  93 void
  94 _initialize_frame_reg (void)
  95 {
  96   /* Frame based $fp, $pc, $sp and $ps.  These only come into play
  97      when the target does not define its own version of these
  98      registers.  */
  99   user_reg_add_builtin ("fp", value_of_builtin_frame_fp_reg, NULL);
 100   user_reg_add_builtin ("pc", value_of_builtin_frame_pc_reg, NULL);
 101   user_reg_add_builtin ("sp", value_of_builtin_frame_sp_reg, NULL);
 102   user_reg_add_builtin ("ps", value_of_builtin_frame_ps_reg, NULL);
 103 }