gdb/std-regs.c

   1 /* Builtin frame register, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2002, 2005, 2007, 2008, 2009, 2010, 2011
   4    Free Software Foundation, Inc.
   5
   6    Contributed by Red Hat.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 #include "defs.h"
  24 #include "user-regs.h"
  25 #include "frame.h"
  26 #include "gdbtypes.h"
  27 #include "value.h"
  28 #include "gdb_string.h"
  29
  30
  31 static struct value *
  32 value_of_builtin_frame_fp_reg (struct frame_info *frame, const void *baton)
  33 {
  34   struct gdbarch *gdbarch = get_frame_arch (frame);
  35
  36   if (gdbarch_deprecated_fp_regnum (gdbarch) >= 0)
  37     /* NOTE: cagney/2003-04-24: Since the mere presence of "fp" in the
  38        register name table overrides this built-in $fp register, there
  39        is no real reason for this gdbarch_deprecated_fp_regnum trickery here.
  40        An architecture wanting to implement "$fp" as alias for a raw
  41        register can do so by adding "fp" to register name table (mind
  42        you, doing this is probably a dangerous thing).  */
  43     return value_of_register (gdbarch_deprecated_fp_regnum (gdbarch),
  44                               frame);
  45   else
  46     {
  47       struct type *data_ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
  48       struct value *val = allocate_value (data_ptr_type);
  49       gdb_byte *buf = value_contents_raw (val);
  50
  51       if (frame == NULL)
  52         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  53       else
  54         gdbarch_address_to_pointer (gdbarch, data_ptr_type,
  55                                     buf, get_frame_base_address (frame));
  56       return val;
  57     }
  58 }
  59
  60 static struct value *
  61 value_of_builtin_frame_pc_reg (struct frame_info *frame, const void *baton)
  62 {
  63   struct gdbarch *gdbarch = get_frame_arch (frame);
  64
  65   if (gdbarch_pc_regnum (gdbarch) >= 0)
  66     return value_of_register (gdbarch_pc_regnum (gdbarch), frame);
  67   else
  68     {
  69       struct type *func_ptr_type = builtin_type (gdbarch)->builtin_func_ptr;
  70       struct value *val = allocate_value (func_ptr_type);
  71       gdb_byte *buf = value_contents_raw (val);
  72
  73       if (frame == NULL)
  74         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  75       else
  76         gdbarch_address_to_pointer (gdbarch, func_ptr_type,
  77                                     buf, get_frame_pc (frame));
  78       return val;
  79     }
  80 }
  81
  82 static struct value *
  83 value_of_builtin_frame_sp_reg (struct frame_info *frame, const void *baton)
  84 {
  85   struct gdbarch *gdbarch = get_frame_arch (frame);
  86
  87   if (gdbarch_sp_regnum (gdbarch) >= 0)
  88     return value_of_register (gdbarch_sp_regnum (gdbarch), frame);
  89   error (_("Standard register ``$sp'' is not available for this target"));
  90 }
  91
  92 static struct value *
  93 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton)
  94 {
  95   struct gdbarch *gdbarch = get_frame_arch (frame);
  96
  97   if (gdbarch_ps_regnum (gdbarch) >= 0)
  98     return value_of_register (gdbarch_ps_regnum (gdbarch), frame);
  99   error (_("Standard register ``$ps'' is not available for this target"));
 100 }
 101
 102 extern initialize_file_ftype _initialize_frame_reg; /* -Wmissing-prototypes */
 103
 104 void
 105 _initialize_frame_reg (void)
 106 {
 107   /* Frame based $fp, $pc, $sp and $ps.  These only come into play
 108      when the target does not define its own version of these
 109      registers.  */
 110   user_reg_add_builtin ("fp", value_of_builtin_frame_fp_reg, NULL);
 111   user_reg_add_builtin ("pc", value_of_builtin_frame_pc_reg, NULL);
 112   user_reg_add_builtin ("sp", value_of_builtin_frame_sp_reg, NULL);
 113   user_reg_add_builtin ("ps", value_of_builtin_frame_ps_reg, NULL);
 114 }