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 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., 51 Franklin Street, Fifth Floor,
  21    Boston, MA 02110-1301, 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 #include "exceptions.h"
  39
  40 /* Local function declarations.  */
  41
  42 extern void _initialize_core (void);
  43 static void call_extra_exec_file_hooks (char *filename);
  44
  45 /* You can have any number of hooks for `exec_file_command' command to
  46    call.  If there's only one hook, it is set in exec_file_display
  47    hook.  If there are two or more hooks, they are set in
  48    exec_file_extra_hooks[], and deprecated_exec_file_display_hook is
  49    set to a function that calls all of them.  This extra complexity is
  50    needed to preserve compatibility with old code that assumed that
  51    only one hook could be set, and which called
  52    deprecated_exec_file_display_hook directly.  */
  53
  54 typedef void (*hook_type) (char *);
  55
  56 hook_type deprecated_exec_file_display_hook;    /* the original hook */
  57 static hook_type *exec_file_extra_hooks;        /* array of additional hooks */
  58 static int exec_file_hook_count = 0;    /* size of array */
  59
  60 /* Binary file diddling handle for the core file.  */
  61
  62 bfd *core_bfd = NULL;
  63 \f
  64
  65 /* Backward compatability with old way of specifying core files.  */
  66
  67 void
  68 core_file_command (char *filename, int from_tty)
  69 {
  70   struct target_ops *t;
  71
  72   dont_repeat ();               /* Either way, seems bogus. */
  73
  74   t = find_core_target ();
  75   if (t == NULL)
  76     error (_("GDB can't read core files on this machine."));
  77
  78   if (!filename)
  79     (t->to_detach) (filename, from_tty);
  80   else
  81     (t->to_open) (filename, from_tty);
  82 }
  83 \f
  84
  85 /* If there are two or more functions that wish to hook into
  86    exec_file_command, this function will call all of the hook
  87    functions.  */
  88
  89 static void
  90 call_extra_exec_file_hooks (char *filename)
  91 {
  92   int i;
  93
  94   for (i = 0; i < exec_file_hook_count; i++)
  95     (*exec_file_extra_hooks[i]) (filename);
  96 }
  97
  98 /* Call this to specify the hook for exec_file_command to call back.
  99    This is called from the x-window display code.  */
 100
 101 void
 102 specify_exec_file_hook (void (*hook) (char *))
 103 {
 104   hook_type *new_array;
 105
 106   if (deprecated_exec_file_display_hook != NULL)
 107     {
 108       /* There's already a hook installed.  Arrange to have both it
 109        * and the subsequent hooks called. */
 110       if (exec_file_hook_count == 0)
 111         {
 112           /* If this is the first extra hook, initialize the hook array.  */
 113           exec_file_extra_hooks = (hook_type *) xmalloc (sizeof (hook_type));
 114           exec_file_extra_hooks[0] = deprecated_exec_file_display_hook;
 115           deprecated_exec_file_display_hook = call_extra_exec_file_hooks;
 116           exec_file_hook_count = 1;
 117         }
 118
 119       /* Grow the hook array by one and add the new hook to the end.
 120          Yes, it's inefficient to grow it by one each time but since
 121          this is hardly ever called it's not a big deal.  */
 122       exec_file_hook_count++;
 123       new_array =
 124         (hook_type *) xrealloc (exec_file_extra_hooks,
 125                                 exec_file_hook_count * sizeof (hook_type));
 126       exec_file_extra_hooks = new_array;
 127       exec_file_extra_hooks[exec_file_hook_count - 1] = hook;
 128     }
 129   else
 130     deprecated_exec_file_display_hook = hook;
 131 }
 132
 133 /* The exec file must be closed before running an inferior.
 134    If it is needed again after the inferior dies, it must
 135    be reopened.  */
 136
 137 void
 138 close_exec_file (void)
 139 {
 140 #if 0                           /* FIXME */
 141   if (exec_bfd)
 142     bfd_tempclose (exec_bfd);
 143 #endif
 144 }
 145
 146 void
 147 reopen_exec_file (void)
 148 {
 149 #if 0                           /* FIXME */
 150   if (exec_bfd)
 151     bfd_reopen (exec_bfd);
 152 #else
 153   char *filename;
 154   int res;
 155   struct stat st;
 156   long mtime;
 157
 158   /* Don't do anything if there isn't an exec file. */
 159   if (exec_bfd == NULL)
 160     return;
 161
 162   /* If the timestamp of the exec file has changed, reopen it. */
 163   filename = xstrdup (bfd_get_filename (exec_bfd));
 164   make_cleanup (xfree, filename);
 165   mtime = bfd_get_mtime (exec_bfd);
 166   res = stat (filename, &st);
 167
 168   if (mtime && mtime != st.st_mtime)
 169     exec_file_attach (filename, 0);
 170 #endif
 171 }
 172 \f
 173 /* If we have both a core file and an exec file,
 174    print a warning if they don't go together.  */
 175
 176 void
 177 validate_files (void)
 178 {
 179   if (exec_bfd && core_bfd)
 180     {
 181       if (!core_file_matches_executable_p (core_bfd, exec_bfd))
 182         warning (_("core file may not match specified executable file."));
 183       else if (bfd_get_mtime (exec_bfd) > bfd_get_mtime (core_bfd))
 184         warning (_("exec file is newer than core file."));
 185     }
 186 }
 187
 188 /* Return the name of the executable file as a string.
 189    ERR nonzero means get error if there is none specified;
 190    otherwise return 0 in that case.  */
 191
 192 char *
 193 get_exec_file (int err)
 194 {
 195   if (exec_bfd)
 196     return bfd_get_filename (exec_bfd);
 197   if (!err)
 198     return NULL;
 199
 200   error (_("No executable file specified.\n\
 201 Use the \"file\" or \"exec-file\" command."));
 202   return NULL;
 203 }
 204 \f
 205
 206 /* Report a memory error with error().  */
 207
 208 void
 209 memory_error (int status, CORE_ADDR memaddr)
 210 {
 211   struct ui_file *tmp_stream = mem_fileopen ();
 212   make_cleanup_ui_file_delete (tmp_stream);
 213
 214   if (status == EIO)
 215     {
 216       /* Actually, address between memaddr and memaddr + len
 217          was out of bounds. */
 218       fprintf_unfiltered (tmp_stream, "Cannot access memory at address ");
 219       deprecated_print_address_numeric (memaddr, 1, tmp_stream);
 220     }
 221   else
 222     {
 223       fprintf_filtered (tmp_stream, "Error accessing memory address ");
 224       deprecated_print_address_numeric (memaddr, 1, tmp_stream);
 225       fprintf_filtered (tmp_stream, ": %s.",
 226                        safe_strerror (status));
 227     }
 228
 229   error_stream (tmp_stream);
 230 }
 231
 232 /* Same as target_read_memory, but report an error if can't read.  */
 233 void
 234 read_memory (CORE_ADDR memaddr, gdb_byte *myaddr, int len)
 235 {
 236   int status;
 237   status = target_read_memory (memaddr, myaddr, len);
 238   if (status != 0)
 239     memory_error (status, memaddr);
 240 }
 241
 242 /* Argument / return result struct for use with
 243    do_captured_read_memory_integer().  MEMADDR and LEN are filled in
 244    by gdb_read_memory_integer().  RESULT is the contents that were
 245    successfully read from MEMADDR of length LEN.  */
 246
 247 struct captured_read_memory_integer_arguments
 248 {
 249   CORE_ADDR memaddr;
 250   int len;
 251   LONGEST result;
 252 };
 253
 254 /* Helper function for gdb_read_memory_integer().  DATA must be a
 255    pointer to a captured_read_memory_integer_arguments struct.
 256    Return 1 if successful.  Note that the catch_errors() interface
 257    will return 0 if an error occurred while reading memory.  This
 258    choice of return code is so that we can distinguish between
 259    success and failure.  */
 260
 261 static int
 262 do_captured_read_memory_integer (void *data)
 263 {
 264   struct captured_read_memory_integer_arguments *args = (struct captured_read_memory_integer_arguments*) data;
 265   CORE_ADDR memaddr = args->memaddr;
 266   int len = args->len;
 267
 268   args->result = read_memory_integer (memaddr, len);
 269
 270   return 1;
 271 }
 272
 273 /* Read memory at MEMADDR of length LEN and put the contents in
 274    RETURN_VALUE.  Return 0 if MEMADDR couldn't be read and non-zero
 275    if successful.  */
 276
 277 int
 278 safe_read_memory_integer (CORE_ADDR memaddr, int len, LONGEST *return_value)
 279 {
 280   int status;
 281   struct captured_read_memory_integer_arguments args;
 282   args.memaddr = memaddr;
 283   args.len = len;
 284
 285   status = catch_errors (do_captured_read_memory_integer, &args,
 286                         "", RETURN_MASK_ALL);
 287   if (status)
 288     *return_value = args.result;
 289
 290   return status;
 291 }
 292
 293 LONGEST
 294 read_memory_integer (CORE_ADDR memaddr, int len)
 295 {
 296   gdb_byte buf[sizeof (LONGEST)];
 297
 298   read_memory (memaddr, buf, len);
 299   return extract_signed_integer (buf, len);
 300 }
 301
 302 ULONGEST
 303 read_memory_unsigned_integer (CORE_ADDR memaddr, int len)
 304 {
 305   gdb_byte buf[sizeof (ULONGEST)];
 306
 307   read_memory (memaddr, buf, len);
 308   return extract_unsigned_integer (buf, len);
 309 }
 310
 311 void
 312 read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len)
 313 {
 314   char *cp;
 315   int i;
 316   int cnt;
 317
 318   cp = buffer;
 319   while (1)
 320     {
 321       if (cp - buffer >= max_len)
 322         {
 323           buffer[max_len - 1] = '\0';
 324           break;
 325         }
 326       cnt = max_len - (cp - buffer);
 327       if (cnt > 8)
 328         cnt = 8;
 329       read_memory (memaddr + (int) (cp - buffer), cp, cnt);
 330       for (i = 0; i < cnt && *cp; i++, cp++)
 331         ;                       /* null body */
 332
 333       if (i < cnt && !*cp)
 334         break;
 335     }
 336 }
 337
 338 CORE_ADDR
 339 read_memory_typed_address (CORE_ADDR addr, struct type *type)
 340 {
 341   gdb_byte *buf = alloca (TYPE_LENGTH (type));
 342   read_memory (addr, buf, TYPE_LENGTH (type));
 343   return extract_typed_address (buf, type);
 344 }
 345
 346 /* Same as target_write_memory, but report an error if can't write.  */
 347 void
 348 write_memory (CORE_ADDR memaddr, const bfd_byte *myaddr, int len)
 349 {
 350   int status;
 351   gdb_byte *bytes = alloca (len);
 352
 353   memcpy (bytes, myaddr, len);
 354   status = target_write_memory (memaddr, bytes, len);
 355   if (status != 0)
 356     memory_error (status, memaddr);
 357 }
 358
 359 /* Store VALUE at ADDR in the inferior as a LEN-byte unsigned integer.  */
 360 void
 361 write_memory_unsigned_integer (CORE_ADDR addr, int len, ULONGEST value)
 362 {
 363   gdb_byte *buf = alloca (len);
 364   store_unsigned_integer (buf, len, value);
 365   write_memory (addr, buf, len);
 366 }
 367
 368 /* Store VALUE at ADDR in the inferior as a LEN-byte signed integer.  */
 369 void
 370 write_memory_signed_integer (CORE_ADDR addr, int len, LONGEST value)
 371 {
 372   gdb_byte *buf = alloca (len);
 373   store_signed_integer (buf, len, value);
 374   write_memory (addr, buf, len);
 375 }
 376
 377 \f
 378
 379 #if 0
 380 /* Enable after 4.12.  It is not tested.  */
 381
 382 /* Search code.  Targets can just make this their search function, or
 383    if the protocol has a less general search function, they can call this
 384    in the cases it can't handle.  */
 385 void
 386 generic_search (int len, char *data, char *mask, CORE_ADDR startaddr,
 387                 int increment, CORE_ADDR lorange, CORE_ADDR hirange,
 388                 CORE_ADDR *addr_found, char *data_found)
 389 {
 390   int i;
 391   CORE_ADDR curaddr = startaddr;
 392
 393   while (curaddr >= lorange && curaddr < hirange)
 394     {
 395       read_memory (curaddr, data_found, len);
 396       for (i = 0; i < len; ++i)
 397         if ((data_found[i] & mask[i]) != data[i])
 398           goto try_again;
 399       /* It matches.  */
 400       *addr_found = curaddr;
 401       return;
 402
 403     try_again:
 404       curaddr += increment;
 405     }
 406   *addr_found = (CORE_ADDR) 0;
 407   return;
 408 }
 409 #endif /* 0 */
 410 \f
 411 /* The current default bfd target.  Points to storage allocated for
 412    gnutarget_string.  */
 413 char *gnutarget;
 414
 415 /* Same thing, except it is "auto" not NULL for the default case.  */
 416 static char *gnutarget_string;
 417 static void
 418 show_gnutarget_string (struct ui_file *file, int from_tty,
 419                        struct cmd_list_element *c, const char *value)
 420 {
 421   fprintf_filtered (file, _("The current BFD target is \"%s\".\n"), value);
 422 }
 423
 424 static void set_gnutarget_command (char *, int, struct cmd_list_element *);
 425
 426 static void
 427 set_gnutarget_command (char *ignore, int from_tty, struct cmd_list_element *c)
 428 {
 429   if (strcmp (gnutarget_string, "auto") == 0)
 430     gnutarget = NULL;
 431   else
 432     gnutarget = gnutarget_string;
 433 }
 434
 435 /* Set the gnutarget.  */
 436 void
 437 set_gnutarget (char *newtarget)
 438 {
 439   if (gnutarget_string != NULL)
 440     xfree (gnutarget_string);
 441   gnutarget_string = savestring (newtarget, strlen (newtarget));
 442   set_gnutarget_command (NULL, 0, NULL);
 443 }
 444
 445 void
 446 _initialize_core (void)
 447 {
 448   struct cmd_list_element *c;
 449   c = add_cmd ("core-file", class_files, core_file_command, _("\
 450 Use FILE as core dump for examining memory and registers.\n\
 451 No arg means have no core file.  This command has been superseded by the\n\
 452 `target core' and `detach' commands."), &cmdlist);
 453   set_cmd_completer (c, filename_completer);
 454
 455
 456   add_setshow_string_noescape_cmd ("gnutarget", class_files,
 457                                    &gnutarget_string, _("(\
 458 Set the current BFD target."), _("\
 459 Show the current BFD target."), _("\
 460 Use `set gnutarget auto' to specify automatic detection."),
 461                                    set_gnutarget_command,
 462                                    show_gnutarget_string,
 463                                    &setlist, &showlist);
 464
 465   if (getenv ("GNUTARGET"))
 466     set_gnutarget (getenv ("GNUTARGET"));
 467   else
 468     set_gnutarget ("auto");
 469 }