gdb/corefile.c

   1 /* Core dump and executable file functions above target vector, for GDB.
   2
   3    Copyright (C) 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1996, 1997,
   4    1998, 1999, 2000, 2001, 2003, 2006
   5    Free Software Foundation, Inc.
   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 "gdb_string.h"
  26 #include <errno.h>
  27 #include <signal.h>
  28 #include <fcntl.h>
  29 #include "inferior.h"
  30 #include "symtab.h"
  31 #include "command.h"
  32 #include "gdbcmd.h"
  33 #include "bfd.h"
  34 #include "target.h"
  35 #include "gdbcore.h"
  36 #include "dis-asm.h"
  37 #include "gdb_stat.h"
  38 #include "completer.h"
  39 #include "exceptions.h"
  40
  41 /* Local function declarations.  */
  42
  43 extern void _initialize_core (void);
  44 static void call_extra_exec_file_hooks (char *filename);
  45
  46 /* You can have any number of hooks for `exec_file_command' command to
  47    call.  If there's only one hook, it is set in exec_file_display
  48    hook.  If there are two or more hooks, they are set in
  49    exec_file_extra_hooks[], and deprecated_exec_file_display_hook is
  50    set to a function that calls all of them.  This extra complexity is
  51    needed to preserve compatibility with old code that assumed that
  52    only one hook could be set, and which called
  53    deprecated_exec_file_display_hook directly.  */
  54
  55 typedef void (*hook_type) (char *);
  56
  57 hook_type deprecated_exec_file_display_hook;    /* the original hook */
  58 static hook_type *exec_file_extra_hooks;        /* array of additional hooks */
  59 static int exec_file_hook_count = 0;    /* size of array */
  60
  61 /* Binary file diddling handle for the core file.  */
  62
  63 bfd *core_bfd = NULL;
  64 \f
  65
  66 /* Backward compatability with old way of specifying core files.  */
  67
  68 void
  69 core_file_command (char *filename, int from_tty)
  70 {
  71   struct target_ops *t;
  72
  73   dont_repeat ();               /* Either way, seems bogus. */
  74
  75   t = find_core_target ();
  76   if (t == NULL)
  77     error (_("GDB can't read core files on this machine."));
  78
  79   if (!filename)
  80     (t->to_detach) (filename, from_tty);
  81   else
  82     (t->to_open) (filename, from_tty);
  83 }
  84 \f
  85
  86 /* If there are two or more functions that wish to hook into
  87    exec_file_command, this function will call all of the hook
  88    functions.  */
  89
  90 static void
  91 call_extra_exec_file_hooks (char *filename)
  92 {
  93   int i;
  94
  95   for (i = 0; i < exec_file_hook_count; i++)
  96     (*exec_file_extra_hooks[i]) (filename);
  97 }
  98
  99 /* Call this to specify the hook for exec_file_command to call back.
 100    This is called from the x-window display code.  */
 101
 102 void
 103 specify_exec_file_hook (void (*hook) (char *))
 104 {
 105   hook_type *new_array;
 106
 107   if (deprecated_exec_file_display_hook != NULL)
 108     {
 109       /* There's already a hook installed.  Arrange to have both it
 110        * and the subsequent hooks called. */
 111       if (exec_file_hook_count == 0)
 112         {
 113           /* If this is the first extra hook, initialize the hook array.  */
 114           exec_file_extra_hooks = (hook_type *) xmalloc (sizeof (hook_type));
 115           exec_file_extra_hooks[0] = deprecated_exec_file_display_hook;
 116           deprecated_exec_file_display_hook = call_extra_exec_file_hooks;
 117           exec_file_hook_count = 1;
 118         }
 119
 120       /* Grow the hook array by one and add the new hook to the end.
 121          Yes, it's inefficient to grow it by one each time but since
 122          this is hardly ever called it's not a big deal.  */
 123       exec_file_hook_count++;
 124       new_array =
 125         (hook_type *) xrealloc (exec_file_extra_hooks,
 126                                 exec_file_hook_count * sizeof (hook_type));
 127       exec_file_extra_hooks = new_array;
 128       exec_file_extra_hooks[exec_file_hook_count - 1] = hook;
 129     }
 130   else
 131     deprecated_exec_file_display_hook = hook;
 132 }
 133
 134 /* The exec file must be closed before running an inferior.
 135    If it is needed again after the inferior dies, it must
 136    be reopened.  */
 137
 138 void
 139 close_exec_file (void)
 140 {
 141 #if 0                           /* FIXME */
 142   if (exec_bfd)
 143     bfd_tempclose (exec_bfd);
 144 #endif
 145 }
 146
 147 void
 148 reopen_exec_file (void)
 149 {
 150 #if 0                           /* FIXME */
 151   if (exec_bfd)
 152     bfd_reopen (exec_bfd);
 153 #else
 154   char *filename;
 155   int res;
 156   struct stat st;
 157   long mtime;
 158
 159   /* Don't do anything if there isn't an exec file. */
 160   if (exec_bfd == NULL)
 161     return;
 162
 163   /* If the timestamp of the exec file has changed, reopen it. */
 164   filename = xstrdup (bfd_get_filename (exec_bfd));
 165   make_cleanup (xfree, filename);
 166   mtime = bfd_get_mtime (exec_bfd);
 167   res = stat (filename, &st);
 168
 169   if (mtime && mtime != st.st_mtime)
 170     exec_file_attach (filename, 0);
 171 #endif
 172 }
 173 \f
 174 /* If we have both a core file and an exec file,
 175    print a warning if they don't go together.  */
 176
 177 void
 178 validate_files (void)
 179 {
 180   if (exec_bfd && core_bfd)
 181     {
 182       if (!core_file_matches_executable_p (core_bfd, exec_bfd))
 183         warning (_("core file may not match specified executable file."));
 184       else if (bfd_get_mtime (exec_bfd) > bfd_get_mtime (core_bfd))
 185         warning (_("exec file is newer than core file."));
 186     }
 187 }
 188
 189 /* Return the name of the executable file as a string.
 190    ERR nonzero means get error if there is none specified;
 191    otherwise return 0 in that case.  */
 192
 193 char *
 194 get_exec_file (int err)
 195 {
 196   if (exec_bfd)
 197     return bfd_get_filename (exec_bfd);
 198   if (!err)
 199     return NULL;
 200
 201   error (_("No executable file specified.\n\
 202 Use the \"file\" or \"exec-file\" command."));
 203   return NULL;
 204 }
 205 \f
 206
 207 /* Report a memory error with error().  */
 208
 209 void
 210 memory_error (int status, CORE_ADDR memaddr)
 211 {
 212   struct ui_file *tmp_stream = mem_fileopen ();
 213   make_cleanup_ui_file_delete (tmp_stream);
 214
 215   if (status == EIO)
 216     {
 217       /* Actually, address between memaddr and memaddr + len
 218          was out of bounds. */
 219       fprintf_unfiltered (tmp_stream, "Cannot access memory at address ");
 220       deprecated_print_address_numeric (memaddr, 1, tmp_stream);
 221     }
 222   else
 223     {
 224       fprintf_filtered (tmp_stream, "Error accessing memory address ");
 225       deprecated_print_address_numeric (memaddr, 1, tmp_stream);
 226       fprintf_filtered (tmp_stream, ": %s.",
 227                        safe_strerror (status));
 228     }
 229
 230   error_stream (tmp_stream);
 231 }
 232
 233 /* Same as target_read_memory, but report an error if can't read.  */
 234 void
 235 read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len)
 236 {
 237   int status;
 238   status = target_read_memory (memaddr, myaddr, len);
 239   if (status != 0)
 240     memory_error (status, memaddr);
 241 }
 242
 243 /* Argument / return result struct for use with
 244    do_captured_read_memory_integer().  MEMADDR and LEN are filled in
 245    by gdb_read_memory_integer().  RESULT is the contents that were
 246    successfully read from MEMADDR of length LEN.  */
 247
 248 struct captured_read_memory_integer_arguments
 249 {
 250   CORE_ADDR memaddr;
 251   int len;
 252   LONGEST result;
 253 };
 254
 255 /* Helper function for gdb_read_memory_integer().  DATA must be a
 256    pointer to a captured_read_memory_integer_arguments struct.
 257    Return 1 if successful.  Note that the catch_errors() interface
 258    will return 0 if an error occurred while reading memory.  This
 259    choice of return code is so that we can distinguish between
 260    success and failure.  */
 261
 262 static int
 263 do_captured_read_memory_integer (void *data)
 264 {
 265   struct captured_read_memory_integer_arguments *args = (struct captured_read_memory_integer_arguments*) data;
 266   CORE_ADDR memaddr = args->memaddr;
 267   int len = args->len;
 268
 269   args->result = read_memory_integer (memaddr, len);
 270
 271   return 1;
 272 }
 273
 274 /* Read memory at MEMADDR of length LEN and put the contents in
 275    RETURN_VALUE.  Return 0 if MEMADDR couldn't be read and non-zero
 276    if successful.  */
 277
 278 int
 279 safe_read_memory_integer (CORE_ADDR memaddr, int len, LONGEST *return_value)
 280 {
 281   int status;
 282   struct captured_read_memory_integer_arguments args;
 283   args.memaddr = memaddr;
 284   args.len = len;
 285
 286   status = catch_errors (do_captured_read_memory_integer, &args,
 287                         "", RETURN_MASK_ALL);
 288   if (status)
 289     *return_value = args.result;
 290
 291   return status;
 292 }
 293
 294 LONGEST
 295 read_memory_integer (CORE_ADDR memaddr, int len)
 296 {
 297   gdb_byte buf[sizeof (LONGEST)];
 298
 299   read_memory (memaddr, buf, len);
 300   return extract_signed_integer (buf, len);
 301 }
 302
 303 ULONGEST
 304 read_memory_unsigned_integer (CORE_ADDR memaddr, int len)
 305 {
 306   gdb_byte buf[sizeof (ULONGEST)];
 307
 308   read_memory (memaddr, buf, len);
 309   return extract_unsigned_integer (buf, len);
 310 }
 311
 312 void
 313 read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len)
 314 {
 315   char *cp;
 316   int i;
 317   int cnt;
 318
 319   cp = buffer;
 320   while (1)
 321     {
 322       if (cp - buffer >= max_len)
 323         {
 324           buffer[max_len - 1] = '\0';
 325           break;
 326         }
 327       cnt = max_len - (cp - buffer);
 328       if (cnt > 8)
 329         cnt = 8;
 330       read_memory (memaddr + (int) (cp - buffer), cp, cnt);
 331       for (i = 0; i < cnt && *cp; i++, cp++)
 332         ;                       /* null body */
 333
 334       if (i < cnt && !*cp)
 335         break;
 336     }
 337 }
 338
 339 CORE_ADDR
 340 read_memory_typed_address (CORE_ADDR addr, struct type *type)
 341 {
 342   gdb_byte *buf = alloca (TYPE_LENGTH (type));
 343   read_memory (addr, buf, TYPE_LENGTH (type));
 344   return extract_typed_address (buf, type);
 345 }
 346
 347 /* Same as target_write_memory, but report an error if can't write.  */
 348 void
 349 write_memory (CORE_ADDR memaddr, const bfd_byte *myaddr, int len)
 350 {
 351   int status;
 352   gdb_byte *bytes = alloca (len);
 353
 354   memcpy (bytes, myaddr, len);
 355   status = target_write_memory (memaddr, bytes, len);
 356   if (status != 0)
 357     memory_error (status, memaddr);
 358 }
 359
 360 /* Store VALUE at ADDR in the inferior as a LEN-byte unsigned integer.  */
 361 void
 362 write_memory_unsigned_integer (CORE_ADDR addr, int len, ULONGEST value)
 363 {
 364   gdb_byte *buf = alloca (len);
 365   store_unsigned_integer (buf, len, value);
 366   write_memory (addr, buf, len);
 367 }
 368
 369 /* Store VALUE at ADDR in the inferior as a LEN-byte signed integer.  */
 370 void
 371 write_memory_signed_integer (CORE_ADDR addr, int len, LONGEST value)
 372 {
 373   gdb_byte *buf = alloca (len);
 374   store_signed_integer (buf, len, value);
 375   write_memory (addr, buf, len);
 376 }
 377
 378 \f
 379
 380 #if 0
 381 /* Enable after 4.12.  It is not tested.  */
 382
 383 /* Search code.  Targets can just make this their search function, or
 384    if the protocol has a less general search function, they can call this
 385    in the cases it can't handle.  */
 386 void
 387 generic_search (int len, char *data, char *mask, CORE_ADDR startaddr,
 388                 int increment, CORE_ADDR lorange, CORE_ADDR hirange,
 389                 CORE_ADDR *addr_found, char *data_found)
 390 {
 391   int i;
 392   CORE_ADDR curaddr = startaddr;
 393
 394   while (curaddr >= lorange && curaddr < hirange)
 395     {
 396       read_memory (curaddr, data_found, len);
 397       for (i = 0; i < len; ++i)
 398         if ((data_found[i] & mask[i]) != data[i])
 399           goto try_again;
 400       /* It matches.  */
 401       *addr_found = curaddr;
 402       return;
 403
 404     try_again:
 405       curaddr += increment;
 406     }
 407   *addr_found = (CORE_ADDR) 0;
 408   return;
 409 }
 410 #endif /* 0 */
 411 \f
 412 /* The current default bfd target.  Points to storage allocated for
 413    gnutarget_string.  */
 414 char *gnutarget;
 415
 416 /* Same thing, except it is "auto" not NULL for the default case.  */
 417 static char *gnutarget_string;
 418 static void
 419 show_gnutarget_string (struct ui_file *file, int from_tty,
 420                        struct cmd_list_element *c, const char *value)
 421 {
 422   fprintf_filtered (file, _("The current BFD target is \"%s\".\n"), value);
 423 }
 424
 425 static void set_gnutarget_command (char *, int, struct cmd_list_element *);
 426
 427 static void
 428 set_gnutarget_command (char *ignore, int from_tty, struct cmd_list_element *c)
 429 {
 430   if (strcmp (gnutarget_string, "auto") == 0)
 431     gnutarget = NULL;
 432   else
 433     gnutarget = gnutarget_string;
 434 }
 435
 436 /* Set the gnutarget.  */
 437 void
 438 set_gnutarget (char *newtarget)
 439 {
 440   if (gnutarget_string != NULL)
 441     xfree (gnutarget_string);
 442   gnutarget_string = savestring (newtarget, strlen (newtarget));
 443   set_gnutarget_command (NULL, 0, NULL);
 444 }
 445
 446 void
 447 _initialize_core (void)
 448 {
 449   struct cmd_list_element *c;
 450   c = add_cmd ("core-file", class_files, core_file_command, _("\
 451 Use FILE as core dump for examining memory and registers.\n\
 452 No arg means have no core file.  This command has been superseded by the\n\
 453 `target core' and `detach' commands."), &cmdlist);
 454   set_cmd_completer (c, filename_completer);
 455
 456
 457   add_setshow_string_noescape_cmd ("gnutarget", class_files,
 458                                    &gnutarget_string, _("(\
 459 Set the current BFD target."), _("\
 460 Show the current BFD target."), _("\
 461 Use `set gnutarget auto' to specify automatic detection."),
 462                                    set_gnutarget_command,
 463                                    show_gnutarget_string,
 464                                    &setlist, &showlist);
 465
 466   if (getenv ("GNUTARGET"))
 467     set_gnutarget (getenv ("GNUTARGET"));
 468   else
 469     set_gnutarget ("auto");
 470 }