gdb/std-regs.c

   1 /* Builtin frame register, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2002-2021 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 "gdbarch.h"
  28
  29 static struct value *
  30 value_of_builtin_frame_fp_reg (struct frame_info *frame, const void *baton)
  31 {
  32   struct gdbarch *gdbarch = get_frame_arch (frame);
  33
  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
  49       gdbarch_address_to_pointer (gdbarch, data_ptr_type,
  50                                   buf, get_frame_base_address (frame));
  51       return val;
  52     }
  53 }
  54
  55 static struct value *
  56 value_of_builtin_frame_pc_reg (struct frame_info *frame, const void *baton)
  57 {
  58   struct gdbarch *gdbarch = get_frame_arch (frame);
  59
  60   if (gdbarch_pc_regnum (gdbarch) >= 0)
  61     return value_of_register (gdbarch_pc_regnum (gdbarch), frame);
  62   else
  63     {
  64       struct type *func_ptr_type = builtin_type (gdbarch)->builtin_func_ptr;
  65       struct value *val = allocate_value (func_ptr_type);
  66       gdb_byte *buf = value_contents_raw (val);
  67
  68       gdbarch_address_to_pointer (gdbarch, func_ptr_type,
  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   struct gdbarch *gdbarch = get_frame_arch (frame);
  78
  79   if (gdbarch_sp_regnum (gdbarch) >= 0)
  80     return value_of_register (gdbarch_sp_regnum (gdbarch), frame);
  81   error (_("Standard register ``$sp'' is not available for this target"));
  82 }
  83
  84 static struct value *
  85 value_of_builtin_frame_ps_reg (struct frame_info *frame, const void *baton)
  86 {
  87   struct gdbarch *gdbarch = get_frame_arch (frame);
  88
  89   if (gdbarch_ps_regnum (gdbarch) >= 0)
  90     return value_of_register (gdbarch_ps_regnum (gdbarch), frame);
  91   error (_("Standard register ``$ps'' is not available for this target"));
  92 }
  93
  94 void _initialize_frame_reg ();
  95 void
  96 _initialize_frame_reg ()
  97 {
  98   /* Frame based $fp, $pc, $sp and $ps.  These only come into play
  99      when the target does not define its own version of these
 100      registers.  */
 101   user_reg_add_builtin ("fp", value_of_builtin_frame_fp_reg, NULL);
 102   user_reg_add_builtin ("pc", value_of_builtin_frame_pc_reg, NULL);
 103   user_reg_add_builtin ("sp", value_of_builtin_frame_sp_reg, NULL);
 104   user_reg_add_builtin ("ps", value_of_builtin_frame_ps_reg, NULL);
 105 }