gdb/std-regs.c

   1 /* Builtin frame register, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2002, 2005, 2007, 2008 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   struct gdbarch *gdbarch = get_frame_arch (frame);
  34   if (gdbarch_deprecated_fp_regnum (gdbarch) >= 0)
  35     /* NOTE: cagney/2003-04-24: Since the mere presence of "fp" in the
  36        register name table overrides this built-in $fp register, there
  37        is no real reason for this gdbarch_deprecated_fp_regnum trickery here.
  38        An architecture wanting to implement "$fp" as alias for a raw
  39        register can do so by adding "fp" to register name table (mind
  40        you, doing this is probably a dangerous thing).  */
  41     return value_of_register (gdbarch_deprecated_fp_regnum (gdbarch),
  42                               frame);
  43   else
  44     {
  45       struct type *data_ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
  46       struct value *val = allocate_value (data_ptr_type);
  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 (gdbarch, data_ptr_type,
  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   struct gdbarch *gdbarch = get_frame_arch (frame);
  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       if (frame == NULL)
  69         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  70       else
  71         gdbarch_address_to_pointer (gdbarch, func_ptr_type,
  72                                     buf, get_frame_pc (frame));
  73       return val;
  74     }
  75 }
  76
  77 static struct value *
  78 value_of_builtin_frame_sp_reg (struct frame_info *frame, const void *baton)
  79 {
  80   struct gdbarch *gdbarch = get_frame_arch (frame);
  81   if (gdbarch_sp_regnum (gdbarch) >= 0)
  82     return value_of_register (gdbarch_sp_regnum (gdbarch), frame);
  83   error (_("Standard register ``$sp'' is not available for this target"));
  84 }
  85
  86 static struct value *
  87 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton)
  88 {
  89   struct gdbarch *gdbarch = get_frame_arch (frame);
  90   if (gdbarch_ps_regnum (gdbarch) >= 0)
  91     return value_of_register (gdbarch_ps_regnum (gdbarch), frame);
  92   error (_("Standard register ``$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 }