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 /* Read an integer from debugged memory, given address and number of bytes.  */
 264
 265 struct captured_read_memory_integer_arguments
 266 {
 267   CORE_ADDR memaddr;
 268   int len;
 269   LONGEST result;
 270 };
 271
 272 static int
 273 do_captured_read_memory_integer (void *data)
 274 {
 275   struct captured_read_memory_integer_arguments *args = (struct captured_read_memory_integer_arguments*) data;
 276   CORE_ADDR memaddr = args->memaddr;
 277   int len = args->len;
 278
 279   args->result = read_memory_integer (memaddr, len);
 280
 281   return 0;
 282 }
 283
 284 int
 285 safe_read_memory_integer (CORE_ADDR memaddr, int len, LONGEST *return_value)
 286 {
 287   int status;
 288   struct captured_read_memory_integer_arguments args;
 289   args.memaddr = memaddr;
 290   args.len = len;
 291
 292   status = catch_errors (do_captured_read_memory_integer, &args,
 293                         "", RETURN_MASK_ALL);
 294   if (!status)
 295     *return_value = args.result;
 296
 297   return status;
 298 }
 299
 300 LONGEST
 301 read_memory_integer (CORE_ADDR memaddr, int len)
 302 {
 303   char buf[sizeof (LONGEST)];
 304
 305   read_memory (memaddr, buf, len);
 306   return extract_signed_integer (buf, len);
 307 }
 308
 309 ULONGEST
 310 read_memory_unsigned_integer (CORE_ADDR memaddr, int len)
 311 {
 312   char buf[sizeof (ULONGEST)];
 313
 314   read_memory (memaddr, buf, len);
 315   return extract_unsigned_integer (buf, len);
 316 }
 317
 318 void
 319 read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len)
 320 {
 321   register char *cp;
 322   register int i;
 323   int cnt;
 324
 325   cp = buffer;
 326   while (1)
 327     {
 328       if (cp - buffer >= max_len)
 329         {
 330           buffer[max_len - 1] = '\0';
 331           break;
 332         }
 333       cnt = max_len - (cp - buffer);
 334       if (cnt > 8)
 335         cnt = 8;
 336       read_memory (memaddr + (int) (cp - buffer), cp, cnt);
 337       for (i = 0; i < cnt && *cp; i++, cp++)
 338         ;                       /* null body */
 339
 340       if (i < cnt && !*cp)
 341         break;
 342     }
 343 }
 344
 345 /* Same as target_write_memory, but report an error if can't write.  */
 346 void
 347 write_memory (CORE_ADDR memaddr, char *myaddr, int len)
 348 {
 349   int status;
 350
 351   status = target_write_memory (memaddr, myaddr, len);
 352   if (status != 0)
 353     memory_error (status, memaddr);
 354 }
 355
 356 /* Store VALUE at ADDR in the inferior as a LEN-byte unsigned integer.  */
 357 void
 358 write_memory_unsigned_integer (CORE_ADDR addr, int len, ULONGEST value)
 359 {
 360   char *buf = alloca (len);
 361   store_unsigned_integer (buf, len, value);
 362   write_memory (addr, buf, len);
 363 }
 364
 365 /* Store VALUE at ADDR in the inferior as a LEN-byte signed integer.  */
 366 void
 367 write_memory_signed_integer (CORE_ADDR addr, int len, LONGEST value)
 368 {
 369   char *buf = alloca (len);
 370   store_signed_integer (buf, len, value);
 371   write_memory (addr, buf, len);
 372 }
 373
 374 \f
 375
 376 #if 0
 377 /* Enable after 4.12.  It is not tested.  */
 378
 379 /* Search code.  Targets can just make this their search function, or
 380    if the protocol has a less general search function, they can call this
 381    in the cases it can't handle.  */
 382 void
 383 generic_search (int len, char *data, char *mask, CORE_ADDR startaddr,
 384                 int increment, CORE_ADDR lorange, CORE_ADDR hirange,
 385                 CORE_ADDR *addr_found, char *data_found)
 386 {
 387   int i;
 388   CORE_ADDR curaddr = startaddr;
 389
 390   while (curaddr >= lorange && curaddr < hirange)
 391     {
 392       read_memory (curaddr, data_found, len);
 393       for (i = 0; i < len; ++i)
 394         if ((data_found[i] & mask[i]) != data[i])
 395           goto try_again;
 396       /* It matches.  */
 397       *addr_found = curaddr;
 398       return;
 399
 400     try_again:
 401       curaddr += increment;
 402     }
 403   *addr_found = (CORE_ADDR) 0;
 404   return;
 405 }
 406 #endif /* 0 */
 407 \f
 408 /* The current default bfd target.  Points to storage allocated for
 409    gnutarget_string.  */
 410 char *gnutarget;
 411
 412 /* Same thing, except it is "auto" not NULL for the default case.  */
 413 static char *gnutarget_string;
 414
 415 static void set_gnutarget_command (char *, int, struct cmd_list_element *);
 416
 417 static void
 418 set_gnutarget_command (char *ignore, int from_tty, struct cmd_list_element *c)
 419 {
 420   if (STREQ (gnutarget_string, "auto"))
 421     gnutarget = NULL;
 422   else
 423     gnutarget = gnutarget_string;
 424 }
 425
 426 /* Set the gnutarget.  */
 427 void
 428 set_gnutarget (char *newtarget)
 429 {
 430   if (gnutarget_string != NULL)
 431     xfree (gnutarget_string);
 432   gnutarget_string = savestring (newtarget, strlen (newtarget));
 433   set_gnutarget_command (NULL, 0, NULL);
 434 }
 435
 436 void
 437 _initialize_core (void)
 438 {
 439   struct cmd_list_element *c;
 440   c = add_cmd ("core-file", class_files, core_file_command,
 441                "Use FILE as core dump for examining memory and registers.\n\
 442 No arg means have no core file.  This command has been superseded by the\n\
 443 `target core' and `detach' commands.", &cmdlist);
 444   set_cmd_completer (c, filename_completer);
 445
 446   c = add_set_cmd ("gnutarget", class_files, var_string_noescape,
 447                    (char *) &gnutarget_string,
 448                    "Set the current BFD target.\n\
 449 Use `set gnutarget auto' to specify automatic detection.",
 450                    &setlist);
 451   set_cmd_sfunc (c, set_gnutarget_command);
 452   add_show_from_set (c, &showlist);
 453
 454   if (getenv ("GNUTARGET"))
 455     set_gnutarget (getenv ("GNUTARGET"));
 456   else
 457     set_gnutarget ("auto");
 458 }