gdb/gdbserver/regcache.c

   1 /* Register support routines for the remote server for GDB.
   2    Copyright (C) 2001, 2002, 2004, 2005, 2007, 2008
   3    Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "server.h"
  21 #include "regdef.h"
  22
  23 #include <stdlib.h>
  24 #include <string.h>
  25
  26 /* The private data for the register cache.  Note that we have one
  27    per inferior; this is primarily for simplicity, as the performance
  28    benefit is minimal.  */
  29
  30 struct inferior_regcache_data
  31 {
  32   int registers_valid;
  33   unsigned char *registers;
  34 };
  35
  36 static int register_bytes;
  37
  38 static struct reg *reg_defs;
  39 static int num_registers;
  40
  41 const char **gdbserver_expedite_regs;
  42
  43 static struct inferior_regcache_data *
  44 get_regcache (struct thread_info *inf, int fetch)
  45 {
  46   struct inferior_regcache_data *regcache;
  47
  48   regcache = (struct inferior_regcache_data *) inferior_regcache_data (inf);
  49
  50   if (regcache == NULL)
  51     fatal ("no register cache");
  52
  53   /* FIXME - fetch registers for INF */
  54   if (fetch && regcache->registers_valid == 0)
  55     {
  56       fetch_inferior_registers (0);
  57       regcache->registers_valid = 1;
  58     }
  59
  60   return regcache;
  61 }
  62
  63 void
  64 regcache_invalidate_one (struct inferior_list_entry *entry)
  65 {
  66   struct thread_info *thread = (struct thread_info *) entry;
  67   struct inferior_regcache_data *regcache;
  68
  69   regcache = (struct inferior_regcache_data *) inferior_regcache_data (thread);
  70
  71   if (regcache->registers_valid)
  72     {
  73       struct thread_info *saved_inferior = current_inferior;
  74
  75       current_inferior = thread;
  76       store_inferior_registers (-1);
  77       current_inferior = saved_inferior;
  78     }
  79
  80   regcache->registers_valid = 0;
  81 }
  82
  83 void
  84 regcache_invalidate ()
  85 {
  86   for_each_inferior (&all_threads, regcache_invalidate_one);
  87 }
  88
  89 void *
  90 new_register_cache (void)
  91 {
  92   struct inferior_regcache_data *regcache;
  93
  94   regcache = malloc (sizeof (*regcache));
  95
  96   /* Make sure to zero-initialize the register cache when it is created,
  97      in case there are registers the target never fetches.  This way they'll
  98      read as zero instead of garbage.  */
  99   regcache->registers = calloc (1, register_bytes);
 100   if (regcache->registers == NULL)
 101     fatal ("Could not allocate register cache.");
 102
 103   regcache->registers_valid = 0;
 104
 105   return regcache;
 106 }
 107
 108 void
 109 free_register_cache (void *regcache_p)
 110 {
 111   struct inferior_regcache_data *regcache
 112     = (struct inferior_regcache_data *) regcache_p;
 113
 114   free (regcache->registers);
 115   free (regcache);
 116 }
 117
 118 static void
 119 realloc_register_cache (struct inferior_list_entry *thread_p)
 120 {
 121   struct thread_info *thread = (struct thread_info *) thread_p;
 122
 123   free_register_cache (inferior_regcache_data (thread));
 124   set_inferior_regcache_data (thread, new_register_cache ());
 125 }
 126
 127 void
 128 set_register_cache (struct reg *regs, int n)
 129 {
 130   int offset, i;
 131
 132   reg_defs = regs;
 133   num_registers = n;
 134
 135   offset = 0;
 136   for (i = 0; i < n; i++)
 137     {
 138       regs[i].offset = offset;
 139       offset += regs[i].size;
 140     }
 141
 142   register_bytes = offset / 8;
 143
 144   /* Make sure PBUFSIZ is large enough to hold a full register packet.  */
 145   if (2 * register_bytes + 32 > PBUFSIZ)
 146     fatal ("Register packet size exceeds PBUFSIZ.");
 147
 148   /* Re-allocate all pre-existing register caches.  */
 149   for_each_inferior (&all_threads, realloc_register_cache);
 150 }
 151
 152 void
 153 registers_to_string (char *buf)
 154 {
 155   unsigned char *registers = get_regcache (current_inferior, 1)->registers;
 156
 157   convert_int_to_ascii (registers, buf, register_bytes);
 158 }
 159
 160 void
 161 registers_from_string (char *buf)
 162 {
 163   int len = strlen (buf);
 164   unsigned char *registers = get_regcache (current_inferior, 1)->registers;
 165
 166   if (len != register_bytes * 2)
 167     {
 168       warning ("Wrong sized register packet (expected %d bytes, got %d)", 2*register_bytes, len);
 169       if (len > register_bytes * 2)
 170         len = register_bytes * 2;
 171     }
 172   convert_ascii_to_int (buf, registers, len / 2);
 173 }
 174
 175 struct reg *
 176 find_register_by_name (const char *name)
 177 {
 178   int i;
 179
 180   for (i = 0; i < num_registers; i++)
 181     if (!strcmp (name, reg_defs[i].name))
 182       return &reg_defs[i];
 183   fatal ("Unknown register %s requested", name);
 184   return 0;
 185 }
 186
 187 int
 188 find_regno (const char *name)
 189 {
 190   int i;
 191
 192   for (i = 0; i < num_registers; i++)
 193     if (!strcmp (name, reg_defs[i].name))
 194       return i;
 195   fatal ("Unknown register %s requested", name);
 196   return -1;
 197 }
 198
 199 struct reg *
 200 find_register_by_number (int n)
 201 {
 202   return &reg_defs[n];
 203 }
 204
 205 int
 206 register_size (int n)
 207 {
 208   return reg_defs[n].size / 8;
 209 }
 210
 211 static unsigned char *
 212 register_data (int n, int fetch)
 213 {
 214   unsigned char *registers
 215     = get_regcache (current_inferior, fetch)->registers;
 216
 217   return registers + (reg_defs[n].offset / 8);
 218 }
 219
 220 void
 221 supply_register (int n, const void *buf)
 222 {
 223   memcpy (register_data (n, 0), buf, register_size (n));
 224 }
 225
 226 void
 227 supply_register_by_name (const char *name, const void *buf)
 228 {
 229   supply_register (find_regno (name), buf);
 230 }
 231
 232 void
 233 collect_register (int n, void *buf)
 234 {
 235   memcpy (buf, register_data (n, 1), register_size (n));
 236 }
 237
 238 void
 239 collect_register_as_string (int n, char *buf)
 240 {
 241   convert_int_to_ascii (register_data (n, 1), buf, register_size (n));
 242 }
 243
 244 void
 245 collect_register_by_name (const char *name, void *buf)
 246 {
 247   collect_register (find_regno (name), buf);
 248 }