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, 1998,
   4    1999, 2000, 2001, 2003, 2006, 2007, 2008 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 3 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, see <http://www.gnu.org/licenses/>.  */
  20
  21 #include "defs.h"
  22 #include "gdb_string.h"
  23 #include <errno.h>
  24 #include <signal.h>
  25 #include <fcntl.h>
  26 #include "inferior.h"
  27 #include "symtab.h"
  28 #include "command.h"
  29 #include "gdbcmd.h"
  30 #include "bfd.h"
  31 #include "target.h"
  32 #include "gdbcore.h"
  33 #include "dis-asm.h"
  34 #include "gdb_stat.h"
  35 #include "completer.h"
  36 #include "exceptions.h"
  37
  38 /* Local function declarations.  */
  39
  40 extern void _initialize_core (void);
  41 static void call_extra_exec_file_hooks (char *filename);
  42
  43 /* You can have any number of hooks for `exec_file_command' command to
  44    call.  If there's only one hook, it is set in exec_file_display
  45    hook.  If there are two or more hooks, they are set in
  46    exec_file_extra_hooks[], and deprecated_exec_file_display_hook is
  47    set to a function that calls all of them.  This extra complexity is
  48    needed to preserve compatibility with old code that assumed that
  49    only one hook could be set, and which called
  50    deprecated_exec_file_display_hook directly.  */
  51
  52 typedef void (*hook_type) (char *);
  53
  54 hook_type deprecated_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
  84    exec_file_command, this function will call all of the hook
  85    functions.  */
  86
  87 static void
  88 call_extra_exec_file_hooks (char *filename)
  89 {
  90   int i;
  91
  92   for (i = 0; i < exec_file_hook_count; i++)
  93     (*exec_file_extra_hooks[i]) (filename);
  94 }
  95
  96 /* Call this to specify the hook for exec_file_command to call back.
  97    This is called from the x-window display code.  */
  98
  99 void
 100 specify_exec_file_hook (void (*hook) (char *))
 101 {
 102   hook_type *new_array;
 103
 104   if (deprecated_exec_file_display_hook != NULL)
 105     {
 106       /* There's already a hook installed.  Arrange to have both it
 107        * and the subsequent hooks called. */
 108       if (exec_file_hook_count == 0)
 109         {
 110           /* If this is the first extra hook, initialize the hook array.  */
 111           exec_file_extra_hooks = (hook_type *) xmalloc (sizeof (hook_type));
 112           exec_file_extra_hooks[0] = deprecated_exec_file_display_hook;
 113           deprecated_exec_file_display_hook = call_extra_exec_file_hooks;
 114           exec_file_hook_count = 1;
 115         }
 116
 117       /* Grow the hook array by one and add the new hook to the end.
 118          Yes, it's inefficient to grow it by one each time but since
 119          this is hardly ever called it's not a big deal.  */
 120       exec_file_hook_count++;
 121       new_array =
 122         (hook_type *) xrealloc (exec_file_extra_hooks,
 123                                 exec_file_hook_count * sizeof (hook_type));
 124       exec_file_extra_hooks = new_array;
 125       exec_file_extra_hooks[exec_file_hook_count - 1] = hook;
 126     }
 127   else
 128     deprecated_exec_file_display_hook = hook;
 129 }
 130
 131 /* The exec file must be closed before running an inferior.
 132    If it is needed again after the inferior dies, it must
 133    be reopened.  */
 134
 135 void
 136 close_exec_file (void)
 137 {
 138 #if 0                           /* FIXME */
 139   if (exec_bfd)
 140     bfd_tempclose (exec_bfd);
 141 #endif
 142 }
 143
 144 void
 145 reopen_exec_file (void)
 146 {
 147 #if 0                           /* FIXME */
 148   if (exec_bfd)
 149     bfd_reopen (exec_bfd);
 150 #else
 151   char *filename;
 152   int res;
 153   struct stat st;
 154   long mtime;
 155
 156   /* Don't do anything if there isn't an exec file. */
 157   if (exec_bfd == NULL)
 158     return;
 159
 160   /* If the timestamp of the exec file has changed, reopen it. */
 161   filename = xstrdup (bfd_get_filename (exec_bfd));
 162   make_cleanup (xfree, filename);
 163   mtime = bfd_get_mtime (exec_bfd);
 164   res = stat (filename, &st);
 165
 166   if (mtime && mtime != st.st_mtime)
 167     exec_file_attach (filename, 0);
 168 #endif
 169 }
 170 \f
 171 /* If we have both a core file and an exec file,
 172    print a warning if they don't go together.  */
 173
 174 void
 175 validate_files (void)
 176 {
 177   if (exec_bfd && core_bfd)
 178     {
 179       if (!core_file_matches_executable_p (core_bfd, exec_bfd))
 180         warning (_("core file may not match specified executable file."));
 181       else if (bfd_get_mtime (exec_bfd) > bfd_get_mtime (core_bfd))
 182         warning (_("exec file is newer than core file."));
 183     }
 184 }
 185
 186 /* Return the name of the executable file as a string.
 187    ERR nonzero means get error if there is none specified;
 188    otherwise return 0 in that case.  */
 189
 190 char *
 191 get_exec_file (int err)
 192 {
 193   if (exec_bfd)
 194     return bfd_get_filename (exec_bfd);
 195   if (!err)
 196     return NULL;
 197
 198   error (_("No executable file specified.\n\
 199 Use the \"file\" or \"exec-file\" command."));
 200   return NULL;
 201 }
 202 \f
 203
 204 /* Report a memory error with error().  */
 205
 206 void
 207 memory_error (int status, CORE_ADDR memaddr)
 208 {
 209   struct ui_file *tmp_stream = mem_fileopen ();
 210   make_cleanup_ui_file_delete (tmp_stream);
 211
 212   if (status == EIO)
 213     {
 214       /* Actually, address between memaddr and memaddr + len
 215          was out of bounds. */
 216       fprintf_unfiltered (tmp_stream, "Cannot access memory at address ");
 217       fputs_filtered (paddress (memaddr), tmp_stream);
 218     }
 219   else
 220     {
 221       fprintf_filtered (tmp_stream, "Error accessing memory address ");
 222       fputs_filtered (paddress (memaddr), tmp_stream);
 223       fprintf_filtered (tmp_stream, ": %s.",
 224                        safe_strerror (status));
 225     }
 226
 227   error_stream (tmp_stream);
 228 }
 229
 230 /* Same as target_read_memory, but report an error if can't read.  */
 231 void
 232 read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len)
 233 {
 234   int status;
 235   status = target_read_memory (memaddr, myaddr, len);
 236   if (status != 0)
 237     memory_error (status, memaddr);
 238 }
 239
 240 /* Argument / return result struct for use with
 241    do_captured_read_memory_integer().  MEMADDR and LEN are filled in
 242    by gdb_read_memory_integer().  RESULT is the contents that were
 243    successfully read from MEMADDR of length LEN.  */
 244
 245 struct captured_read_memory_integer_arguments
 246 {
 247   CORE_ADDR memaddr;
 248   int len;
 249   LONGEST result;
 250 };
 251
 252 /* Helper function for gdb_read_memory_integer().  DATA must be a
 253    pointer to a captured_read_memory_integer_arguments struct.
 254    Return 1 if successful.  Note that the catch_errors() interface
 255    will return 0 if an error occurred while reading memory.  This
 256    choice of return code is so that we can distinguish between
 257    success and failure.  */
 258
 259 static int
 260 do_captured_read_memory_integer (void *data)
 261 {
 262   struct captured_read_memory_integer_arguments *args = (struct captured_read_memory_integer_arguments*) data;
 263   CORE_ADDR memaddr = args->memaddr;
 264   int len = args->len;
 265
 266   args->result = read_memory_integer (memaddr, len);
 267
 268   return 1;
 269 }
 270
 271 /* Read memory at MEMADDR of length LEN and put the contents in
 272    RETURN_VALUE.  Return 0 if MEMADDR couldn't be read and non-zero
 273    if successful.  */
 274
 275 int
 276 safe_read_memory_integer (CORE_ADDR memaddr, int len, LONGEST *return_value)
 277 {
 278   int status;
 279   struct captured_read_memory_integer_arguments args;
 280   args.memaddr = memaddr;
 281   args.len = len;
 282
 283   status = catch_errors (do_captured_read_memory_integer, &args,
 284                         "", RETURN_MASK_ALL);
 285   if (status)
 286     *return_value = args.result;
 287
 288   return status;
 289 }
 290
 291 LONGEST
 292 read_memory_integer (CORE_ADDR memaddr, int len)
 293 {
 294   gdb_byte buf[sizeof (LONGEST)];
 295
 296   read_memory (memaddr, buf, len);
 297   return extract_signed_integer (buf, len);
 298 }
 299
 300 ULONGEST
 301 read_memory_unsigned_integer (CORE_ADDR memaddr, int len)
 302 {
 303   gdb_byte buf[sizeof (ULONGEST)];
 304
 305   read_memory (memaddr, buf, len);
 306   return extract_unsigned_integer (buf, len);
 307 }
 308
 309 void
 310 read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len)
 311 {
 312   char *cp;
 313   int i;
 314   int cnt;
 315
 316   cp = buffer;
 317   while (1)
 318     {
 319       if (cp - buffer >= max_len)
 320         {
 321           buffer[max_len - 1] = '\0';
 322           break;
 323         }
 324       cnt = max_len - (cp - buffer);
 325       if (cnt > 8)
 326         cnt = 8;
 327       read_memory (memaddr + (int) (cp - buffer), cp, cnt);
 328       for (i = 0; i < cnt && *cp; i++, cp++)
 329         ;                       /* null body */
 330
 331       if (i < cnt && !*cp)
 332         break;
 333     }
 334 }
 335
 336 CORE_ADDR
 337 read_memory_typed_address (CORE_ADDR addr, struct type *type)
 338 {
 339   gdb_byte *buf = alloca (TYPE_LENGTH (type));
 340   read_memory (addr, buf, TYPE_LENGTH (type));
 341   return extract_typed_address (buf, type);
 342 }
 343
 344 /* Same as target_write_memory, but report an error if can't write.  */
 345 void
 346 write_memory (CORE_ADDR memaddr, const bfd_byte *myaddr, int len)
 347 {
 348   int status;
 349   gdb_byte *bytes = alloca (len);
 350
 351   memcpy (bytes, myaddr, len);
 352   status = target_write_memory (memaddr, bytes, len);
 353   if (status != 0)
 354     memory_error (status, memaddr);
 355 }
 356
 357 /* Store VALUE at ADDR in the inferior as a LEN-byte unsigned integer.  */
 358 void
 359 write_memory_unsigned_integer (CORE_ADDR addr, int len, ULONGEST value)
 360 {
 361   gdb_byte *buf = alloca (len);
 362   store_unsigned_integer (buf, len, value);
 363   write_memory (addr, buf, len);
 364 }
 365
 366 /* Store VALUE at ADDR in the inferior as a LEN-byte signed integer.  */
 367 void
 368 write_memory_signed_integer (CORE_ADDR addr, int len, LONGEST value)
 369 {
 370   gdb_byte *buf = alloca (len);
 371   store_signed_integer (buf, len, value);
 372   write_memory (addr, buf, len);
 373 }
 374
 375 \f
 376
 377 #if 0
 378 /* Enable after 4.12.  It is not tested.  */
 379
 380 /* Search code.  Targets can just make this their search function, or
 381    if the protocol has a less general search function, they can call this
 382    in the cases it can't handle.  */
 383 void
 384 generic_search (int len, char *data, char *mask, CORE_ADDR startaddr,
 385                 int increment, CORE_ADDR lorange, CORE_ADDR hirange,
 386                 CORE_ADDR *addr_found, char *data_found)
 387 {
 388   int i;
 389   CORE_ADDR curaddr = startaddr;
 390
 391   while (curaddr >= lorange && curaddr < hirange)
 392     {
 393       read_memory (curaddr, data_found, len);
 394       for (i = 0; i < len; ++i)
 395         if ((data_found[i] & mask[i]) != data[i])
 396           goto try_again;
 397       /* It matches.  */
 398       *addr_found = curaddr;
 399       return;
 400
 401     try_again:
 402       curaddr += increment;
 403     }
 404   *addr_found = (CORE_ADDR) 0;
 405   return;
 406 }
 407 #endif /* 0 */
 408 \f
 409 /* The current default bfd target.  Points to storage allocated for
 410    gnutarget_string.  */
 411 char *gnutarget;
 412
 413 /* Same thing, except it is "auto" not NULL for the default case.  */
 414 static char *gnutarget_string;
 415 static void
 416 show_gnutarget_string (struct ui_file *file, int from_tty,
 417                        struct cmd_list_element *c, const char *value)
 418 {
 419   fprintf_filtered (file, _("The current BFD target is \"%s\".\n"), value);
 420 }
 421
 422 static void set_gnutarget_command (char *, int, struct cmd_list_element *);
 423
 424 static void
 425 set_gnutarget_command (char *ignore, int from_tty, struct cmd_list_element *c)
 426 {
 427   if (strcmp (gnutarget_string, "auto") == 0)
 428     gnutarget = NULL;
 429   else
 430     gnutarget = gnutarget_string;
 431 }
 432
 433 /* Set the gnutarget.  */
 434 void
 435 set_gnutarget (char *newtarget)
 436 {
 437   if (gnutarget_string != NULL)
 438     xfree (gnutarget_string);
 439   gnutarget_string = savestring (newtarget, strlen (newtarget));
 440   set_gnutarget_command (NULL, 0, NULL);
 441 }
 442
 443 void
 444 _initialize_core (void)
 445 {
 446   struct cmd_list_element *c;
 447   c = add_cmd ("core-file", class_files, core_file_command, _("\
 448 Use FILE as core dump for examining memory and registers.\n\
 449 No arg means have no core file.  This command has been superseded by the\n\
 450 `target core' and `detach' commands."), &cmdlist);
 451   set_cmd_completer (c, filename_completer);
 452
 453
 454   add_setshow_string_noescape_cmd ("gnutarget", class_files,
 455                                    &gnutarget_string, _("(\
 456 Set the current BFD target."), _("\
 457 Show the current BFD target."), _("\
 458 Use `set gnutarget auto' to specify automatic detection."),
 459                                    set_gnutarget_command,
 460                                    show_gnutarget_string,
 461                                    &setlist, &showlist);
 462
 463   if (getenv ("GNUTARGET"))
 464     set_gnutarget (getenv ("GNUTARGET"));
 465   else
 466     set_gnutarget ("auto");
 467 }