gdb/corefile.c

   1 /* Core dump and executable file functions above target vector, for GDB.
   2    Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1996, 1997, 1998,
   3    1999, 2000, 2001
   4    Free Software Foundation, Inc.
   5
   6    This file is part of GDB.
   7
   8    This program is free software; you can redistribute it and/or modify
   9    it under the terms of the GNU General Public License as published by
  10    the Free Software Foundation; either version 2 of the License, or
  11    (at your option) any later version.
  12
  13    This program is distributed in the hope that it will be useful,
  14    but WITHOUT ANY WARRANTY; without even the implied warranty of
  15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16    GNU General Public License for more details.
  17
  18    You should have received a copy of the GNU General Public License
  19    along with this program; if not, write to the Free Software
  20    Foundation, Inc., 59 Temple Place - Suite 330,
  21    Boston, MA 02111-1307, USA.  */
  22
  23 #include "defs.h"
  24 #include "gdb_string.h"
  25 #include <errno.h>
  26 #include <signal.h>
  27 #include <fcntl.h>
  28 #include "inferior.h"
  29 #include "symtab.h"
  30 #include "command.h"
  31 #include "gdbcmd.h"
  32 #include "bfd.h"
  33 #include "target.h"
  34 #include "gdbcore.h"
  35 #include "dis-asm.h"
  36 #include "gdb_stat.h"
  37 #include "completer.h"
  38
  39 /* Local function declarations.  */
  40
  41 extern void _initialize_core (void);
  42 static void call_extra_exec_file_hooks (char *filename);
  43
  44 /* You can have any number of hooks for `exec_file_command' command to call.
  45    If there's only one hook, it is set in exec_file_display hook.
  46    If there are two or more hooks, they are set in exec_file_extra_hooks[],
  47    and exec_file_display_hook is set to a function that calls all of them.
  48    This extra complexity is needed to preserve compatibility with
  49    old code that assumed that only one hook could be set, and which called
  50    exec_file_display_hook directly.  */
  51
  52 typedef void (*hook_type) (char *);
  53
  54 hook_type exec_file_display_hook;       /* the original hook */
  55 static hook_type *exec_file_extra_hooks;        /* array of additional hooks */
  56 static int exec_file_hook_count = 0;    /* size of array */
  57
  58 /* Binary file diddling handle for the core file.  */
  59
  60 bfd *core_bfd = NULL;
  61 \f
  62
  63 /* Backward compatability with old way of specifying core files.  */
  64
  65 void
  66 core_file_command (char *filename, int from_tty)
  67 {
  68   struct target_ops *t;
  69
  70   dont_repeat ();               /* Either way, seems bogus. */
  71
  72   t = find_core_target ();
  73   if (t == NULL)
  74     error ("GDB can't read core files on this machine.");
  75
  76   if (!filename)
  77     (t->to_detach) (filename, from_tty);
  78   else
  79     (t->to_open) (filename, from_tty);
  80 }
  81 \f
  82
  83 /* If there are two or more functions that wish to hook into exec_file_command,
  84  * this function will call all of the hook functions. */
  85
  86 static void
  87 call_extra_exec_file_hooks (char *filename)
  88 {
  89   int i;
  90
  91   for (i = 0; i < exec_file_hook_count; i++)
  92     (*exec_file_extra_hooks[i]) (filename);
  93 }
  94
  95 /* Call this to specify the hook for exec_file_command to call back.
  96    This is called from the x-window display code.  */
  97
  98 void
  99 specify_exec_file_hook (void (*hook) (char *))
 100 {
 101   hook_type *new_array;
 102
 103   if (exec_file_display_hook != NULL)
 104     {
 105       /* There's already a hook installed.  Arrange to have both it
 106        * and the subsequent hooks called. */
 107       if (exec_file_hook_count == 0)
 108         {
 109           /* If this is the first extra hook, initialize the hook array. */
 110           exec_file_extra_hooks = (hook_type *) xmalloc (sizeof (hook_type));
 111           exec_file_extra_hooks[0] = exec_file_display_hook;
 112           exec_file_display_hook = call_extra_exec_file_hooks;
 113           exec_file_hook_count = 1;
 114         }
 115
 116       /* Grow the hook array by one and add the new hook to the end.
 117          Yes, it's inefficient to grow it by one each time but since
 118          this is hardly ever called it's not a big deal.  */
 119       exec_file_hook_count++;
 120       new_array =
 121         (hook_type *) xrealloc (exec_file_extra_hooks,
 122                                 exec_file_hook_count * sizeof (hook_type));
 123       exec_file_extra_hooks = new_array;
 124       exec_file_extra_hooks[exec_file_hook_count - 1] = hook;
 125     }
 126   else
 127     exec_file_display_hook = hook;
 128 }
 129
 130 /* The exec file must be closed before running an inferior.
 131    If it is needed again after the inferior dies, it must
 132    be reopened.  */
 133
 134 void
 135 close_exec_file (void)
 136 {
 137 #if 0                           /* FIXME */
 138   if (exec_bfd)
 139     bfd_tempclose (exec_bfd);
 140 #endif
 141 }
 142
 143 void
 144 reopen_exec_file (void)
 145 {
 146 #if 0                           /* FIXME */
 147   if (exec_bfd)
 148     bfd_reopen (exec_bfd);
 149 #else
 150   char *filename;
 151   int res;
 152   struct stat st;
 153   long mtime;
 154
 155   /* Don't do anything if the current target isn't exec. */
 156   if (exec_bfd == NULL || strcmp (target_shortname, "exec") != 0)
 157     return;
 158
 159   /* If the timestamp of the exec file has changed, reopen it. */
 160   filename = xstrdup (bfd_get_filename (exec_bfd));
 161   make_cleanup (xfree, filename);
 162   mtime = bfd_get_mtime (exec_bfd);
 163   res = stat (filename, &st);
 164
 165   if (mtime && mtime != st.st_mtime)
 166     {
 167       exec_open (filename, 0);
 168     }
 169 #endif
 170 }
 171 \f
 172 /* If we have both a core file and an exec file,
 173    print a warning if they don't go together.  */
 174
 175 void
 176 validate_files (void)
 177 {
 178   if (exec_bfd && core_bfd)
 179     {
 180       if (!core_file_matches_executable_p (core_bfd, exec_bfd))
 181         warning ("core file may not match specified executable file.");
 182       else if (bfd_get_mtime (exec_bfd) > bfd_get_mtime (core_bfd))
 183         warning ("exec file is newer than core file.");
 184     }
 185 }
 186
 187 /* Return the name of the executable file as a string.
 188    ERR nonzero means get error if there is none specified;
 189    otherwise return 0 in that case.  */
 190
 191 char *
 192 get_exec_file (int err)
 193 {
 194   if (exec_bfd)
 195     return bfd_get_filename (exec_bfd);
 196   if (!err)
 197     return NULL;
 198
 199   error ("No executable file specified.\n\
 200 Use the \"file\" or \"exec-file\" command.");
 201   return NULL;
 202 }
 203 \f
 204
 205 /* Report a memory error with error().  */
 206
 207 void
 208 memory_error (int status, CORE_ADDR memaddr)
 209 {
 210   struct ui_file *tmp_stream = mem_fileopen ();
 211   make_cleanup_ui_file_delete (tmp_stream);
 212
 213   if (status == EIO)
 214     {
 215       /* Actually, address between memaddr and memaddr + len
 216          was out of bounds. */
 217       fprintf_unfiltered (tmp_stream, "Cannot access memory at address ");
 218       print_address_numeric (memaddr, 1, tmp_stream);
 219     }
 220   else
 221     {
 222       fprintf_filtered (tmp_stream, "Error accessing memory address ");
 223       print_address_numeric (memaddr, 1, tmp_stream);
 224       fprintf_filtered (tmp_stream, ": %s.",
 225                        safe_strerror (status));
 226     }
 227
 228   error_stream (tmp_stream);
 229 }
 230
 231 /* Same as target_read_memory, but report an error if can't read.  */
 232 void
 233 read_memory (CORE_ADDR memaddr, char *myaddr, int len)
 234 {
 235   int status;
 236   status = target_read_memory (memaddr, myaddr, len);
 237   if (status != 0)
 238     memory_error (status, memaddr);
 239 }
 240
 241 /* Like target_read_memory, but slightly different parameters.  */
 242 int
 243 dis_asm_read_memory (bfd_vma memaddr, bfd_byte *myaddr, unsigned int len,
 244                      disassemble_info *info)
 245 {
 246   return target_read_memory (memaddr, (char *) myaddr, len);
 247 }
 248
 249 /* Like memory_error with slightly different parameters.  */
 250 void
 251 dis_asm_memory_error (int status, bfd_vma memaddr, disassemble_info *info)
 252 {
 253   memory_error (status, memaddr);
 254 }
 255
 256 /* Like print_address with slightly different parameters.  */
 257 void
 258 dis_asm_print_address (bfd_vma addr, struct disassemble_info *info)
 259 {
 260   print_address (addr, info->stream);
 261 }
 262
 263 /* Same as target_write_memory, but report an error if can't write.  */
 264 void
 265 write_memory (CORE_ADDR memaddr, char *myaddr, int len)
 266 {
 267   int status;
 268
 269   status = target_write_memory (memaddr, myaddr, len);
 270   if (status != 0)
 271     memory_error (status, memaddr);
 272 }
 273
 274 /* Read an integer from debugged memory, given address and number of bytes.  */
 275
 276 LONGEST
 277 read_memory_integer (CORE_ADDR memaddr, int len)
 278 {
 279   char buf[sizeof (LONGEST)];
 280
 281   read_memory (memaddr, buf, len);
 282   return extract_signed_integer (buf, len);
 283 }
 284
 285 ULONGEST
 286 read_memory_unsigned_integer (CORE_ADDR memaddr, int len)
 287 {
 288   char buf[sizeof (ULONGEST)];
 289
 290   read_memory (memaddr, buf, len);
 291   return extract_unsigned_integer (buf, len);
 292 }
 293
 294 void
 295 read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len)
 296 {
 297   register char *cp;
 298   register int i;
 299   int cnt;
 300
 301   cp = buffer;
 302   while (1)
 303     {
 304       if (cp - buffer >= max_len)
 305         {
 306           buffer[max_len - 1] = '\0';
 307           break;
 308         }
 309       cnt = max_len - (cp - buffer);
 310       if (cnt > 8)
 311         cnt = 8;
 312       read_memory (memaddr + (int) (cp - buffer), cp, cnt);
 313       for (i = 0; i < cnt && *cp; i++, cp++)
 314         ;                       /* null body */
 315
 316       if (i < cnt && !*cp)
 317         break;
 318     }
 319 }
 320 \f
 321
 322 #if 0
 323 /* Enable after 4.12.  It is not tested.  */
 324
 325 /* Search code.  Targets can just make this their search function, or
 326    if the protocol has a less general search function, they can call this
 327    in the cases it can't handle.  */
 328 void
 329 generic_search (int len, char *data, char *mask, CORE_ADDR startaddr,
 330                 int increment, CORE_ADDR lorange, CORE_ADDR hirange,
 331                 CORE_ADDR *addr_found, char *data_found)
 332 {
 333   int i;
 334   CORE_ADDR curaddr = startaddr;
 335
 336   while (curaddr >= lorange && curaddr < hirange)
 337     {
 338       read_memory (curaddr, data_found, len);
 339       for (i = 0; i < len; ++i)
 340         if ((data_found[i] & mask[i]) != data[i])
 341           goto try_again;
 342       /* It matches.  */
 343       *addr_found = curaddr;
 344       return;
 345
 346     try_again:
 347       curaddr += increment;
 348     }
 349   *addr_found = (CORE_ADDR) 0;
 350   return;
 351 }
 352 #endif /* 0 */
 353 \f
 354 /* The current default bfd target.  Points to storage allocated for
 355    gnutarget_string.  */
 356 char *gnutarget;
 357
 358 /* Same thing, except it is "auto" not NULL for the default case.  */
 359 static char *gnutarget_string;
 360
 361 static void set_gnutarget_command (char *, int, struct cmd_list_element *);
 362
 363 static void
 364 set_gnutarget_command (char *ignore, int from_tty, struct cmd_list_element *c)
 365 {
 366   if (STREQ (gnutarget_string, "auto"))
 367     gnutarget = NULL;
 368   else
 369     gnutarget = gnutarget_string;
 370 }
 371
 372 /* Set the gnutarget.  */
 373 void
 374 set_gnutarget (char *newtarget)
 375 {
 376   if (gnutarget_string != NULL)
 377     xfree (gnutarget_string);
 378   gnutarget_string = savestring (newtarget, strlen (newtarget));
 379   set_gnutarget_command (NULL, 0, NULL);
 380 }
 381
 382 void
 383 _initialize_core (void)
 384 {
 385   struct cmd_list_element *c;
 386   c = add_cmd ("core-file", class_files, core_file_command,
 387                "Use FILE as core dump for examining memory and registers.\n\
 388 No arg means have no core file.  This command has been superseded by the\n\
 389 `target core' and `detach' commands.", &cmdlist);
 390   c->completer = filename_completer;
 391
 392   c = add_set_cmd ("gnutarget", class_files, var_string_noescape,
 393                    (char *) &gnutarget_string,
 394                    "Set the current BFD target.\n\
 395 Use `set gnutarget auto' to specify automatic detection.",
 396                    &setlist);
 397   c->function.sfunc = set_gnutarget_command;
 398   add_show_from_set (c, &showlist);
 399
 400   if (getenv ("GNUTARGET"))
 401     set_gnutarget (getenv ("GNUTARGET"));
 402   else
 403     set_gnutarget ("auto");
 404 }