gdb/std-regs.c

   1 /* Builtin frame register, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2002-2019 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 static struct value *
  28 value_of_builtin_frame_fp_reg (struct frame_info *frame, const void *baton)
  29 {
  30   struct gdbarch *gdbarch = get_frame_arch (frame);
  31
  32   if (gdbarch_deprecated_fp_regnum (gdbarch) >= 0)
  33     /* NOTE: cagney/2003-04-24: Since the mere presence of "fp" in the
  34        register name table overrides this built-in $fp register, there
  35        is no real reason for this gdbarch_deprecated_fp_regnum trickery here.
  36        An architecture wanting to implement "$fp" as alias for a raw
  37        register can do so by adding "fp" to register name table (mind
  38        you, doing this is probably a dangerous thing).  */
  39     return value_of_register (gdbarch_deprecated_fp_regnum (gdbarch),
  40                               frame);
  41   else
  42     {
  43       struct type *data_ptr_type = builtin_type (gdbarch)->builtin_data_ptr;
  44       struct value *val = allocate_value (data_ptr_type);
  45       gdb_byte *buf = value_contents_raw (val);
  46
  47       gdbarch_address_to_pointer (gdbarch, data_ptr_type,
  48                                   buf, get_frame_base_address (frame));
  49       return val;
  50     }
  51 }
  52
  53 static struct value *
  54 value_of_builtin_frame_pc_reg (struct frame_info *frame, const void *baton)
  55 {
  56   struct gdbarch *gdbarch = get_frame_arch (frame);
  57
  58   if (gdbarch_pc_regnum (gdbarch) >= 0)
  59     return value_of_register (gdbarch_pc_regnum (gdbarch), frame);
  60   else
  61     {
  62       struct type *func_ptr_type = builtin_type (gdbarch)->builtin_func_ptr;
  63       struct value *val = allocate_value (func_ptr_type);
  64       gdb_byte *buf = value_contents_raw (val);
  65
  66       gdbarch_address_to_pointer (gdbarch, func_ptr_type,
  67                                   buf, get_frame_pc (frame));
  68       return val;
  69     }
  70 }
  71
  72 static struct value *
  73 value_of_builtin_frame_sp_reg (struct frame_info *frame, const void *baton)
  74 {
  75   struct gdbarch *gdbarch = get_frame_arch (frame);
  76
  77   if (gdbarch_sp_regnum (gdbarch) >= 0)
  78     return value_of_register (gdbarch_sp_regnum (gdbarch), frame);
  79   error (_("Standard register ``$sp'' is not available for this target"));
  80 }
  81
  82 static struct value *
  83 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton)
  84 {
  85   struct gdbarch *gdbarch = get_frame_arch (frame);
  86
  87   if (gdbarch_ps_regnum (gdbarch) >= 0)
  88     return value_of_register (gdbarch_ps_regnum (gdbarch), frame);
  89   error (_("Standard register ``$ps'' is not available for this target"));
  90 }
  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 }