gnu/dist/gdb6/gdb/std-regs.c

   1 /* Builtin frame register, for GDB, the GNU debugger.
   2
   3    Copyright (C) 2002, 2005 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 /* Types that describe the various builtin registers.  */
  32
  33 static struct type *builtin_type_frame_reg;
  34
  35 /* Constructors for those types.  */
  36
  37 static void
  38 build_builtin_type_frame_reg (void)
  39 {
  40   /* $frame.  */
  41   if (builtin_type_frame_reg == NULL)
  42     {
  43 #if 0
  44       struct frame
  45       {
  46         void *base;
  47       };
  48 #endif
  49       builtin_type_frame_reg = init_composite_type ("frame", TYPE_CODE_STRUCT);
  50       append_composite_type_field (builtin_type_frame_reg, "base",
  51                                    builtin_type_void_data_ptr);
  52     }
  53 }
  54
  55 static struct value *
  56 value_of_builtin_frame_reg (struct frame_info *frame)
  57 {
  58   struct value *val;
  59   gdb_byte *buf;
  60   build_builtin_type_frame_reg ();
  61   val = allocate_value (builtin_type_frame_reg);
  62   VALUE_LVAL (val) = not_lval;
  63   buf = value_contents_raw (val);
  64   memset (buf, 0, TYPE_LENGTH (value_type (val)));
  65   /* frame.base.  */
  66   if (frame != NULL)
  67     ADDRESS_TO_POINTER (builtin_type_void_data_ptr, buf,
  68                         get_frame_base (frame));
  69   buf += TYPE_LENGTH (builtin_type_void_data_ptr);
  70   /* frame.XXX.  */
  71   return val;
  72 }
  73
  74 static struct value *
  75 value_of_builtin_frame_fp_reg (struct frame_info *frame)
  76 {
  77   if (DEPRECATED_FP_REGNUM >= 0)
  78     /* NOTE: cagney/2003-04-24: Since the mere presence of "fp" in the
  79        register name table overrides this built-in $fp register, there
  80        is no real reason for this DEPRECATED_FP_REGNUM trickery here.
  81        An architecture wanting to implement "$fp" as alias for a raw
  82        register can do so by adding "fp" to register name table (mind
  83        you, doing this is probably a dangerous thing).  */
  84     return value_of_register (DEPRECATED_FP_REGNUM, frame);
  85   else
  86     {
  87       struct value *val = allocate_value (builtin_type_void_data_ptr);
  88       gdb_byte *buf = value_contents_raw (val);
  89       if (frame == NULL)
  90         memset (buf, 0, TYPE_LENGTH (value_type (val)));
  91       else
  92         ADDRESS_TO_POINTER (builtin_type_void_data_ptr, buf,
  93                             get_frame_base_address (frame));
  94       return val;
  95     }
  96 }
  97
  98 static struct value *
  99 value_of_builtin_frame_pc_reg (struct frame_info *frame)
 100 {
 101   if (PC_REGNUM >= 0)
 102     return value_of_register (PC_REGNUM, frame);
 103   else
 104     {
 105       struct value *val = allocate_value (builtin_type_void_data_ptr);
 106       gdb_byte *buf = value_contents_raw (val);
 107       if (frame == NULL)
 108         memset (buf, 0, TYPE_LENGTH (value_type (val)));
 109       else
 110         ADDRESS_TO_POINTER (builtin_type_void_data_ptr, buf,
 111                             get_frame_pc (frame));
 112       return val;
 113     }
 114 }
 115
 116 static struct value *
 117 value_of_builtin_frame_sp_reg (struct frame_info *frame)
 118 {
 119 #ifdef SP_REGNUM
 120   if (SP_REGNUM >= 0)
 121     return value_of_register (SP_REGNUM, frame);
 122 #endif
 123   error (_("Standard register ``$sp'' is not available for this target"));
 124 }
 125
 126 static struct value *
 127 value_of_builtin_frame_ps_reg (struct frame_info *frame)
 128 {
 129 #ifdef PS_REGNUM
 130   if (PS_REGNUM >= 0)
 131     return value_of_register (PS_REGNUM, frame);
 132 #endif
 133   error (_("Standard register ``$ps'' is not available for this target"));
 134 }
 135
 136 extern initialize_file_ftype _initialize_frame_reg; /* -Wmissing-prototypes */
 137
 138 void
 139 _initialize_frame_reg (void)
 140 {
 141   /* FIXME: cagney/2002-02-08: At present the local builtin types
 142      can't be initialized using _initialize*() or gdbarch.  Due mainly
 143      to non-multi-arch targets, GDB initializes things piece meal and,
 144      as a consequence can leave these types NULL.  */
 145   DEPRECATED_REGISTER_GDBARCH_SWAP (builtin_type_frame_reg);
 146
 147   /* Frame based $fp, $pc, $sp and $ps.  These only come into play
 148      when the target does not define its own version of these
 149      registers.  */
 150   user_reg_add_builtin ("fp", value_of_builtin_frame_fp_reg);
 151   user_reg_add_builtin ("pc", value_of_builtin_frame_pc_reg);
 152   user_reg_add_builtin ("sp", value_of_builtin_frame_sp_reg);
 153   user_reg_add_builtin ("ps", value_of_builtin_frame_ps_reg);
 154
 155   /* NOTE: cagney/2002-04-05: For moment leave the $frame / $gdbframe
 156      / $gdb.frame disabled.  It isn't yet clear which of the many
 157      options is the best.  */
 158   if (0)
 159     user_reg_add_builtin ("frame", value_of_builtin_frame_reg);
 160 }