gdb/corefile.c

   1 /* Core dump and executable file functions above target vector, for GDB.
   2
   3    Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1996, 1997,
   4    1998, 1999, 2000, 2001, 2003 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 #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 the current target isn't exec. */
 159   if (exec_bfd == NULL || strcmp (target_shortname, "exec") != 0)
 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     {
 170       exec_open (filename, 0);
 171     }
 172 #endif
 173 }
 174 \f
 175 /* If we have both a core file and an exec file,
 176    print a warning if they don't go together.  */
 177
 178 void
 179 validate_files (void)
 180 {
 181   if (exec_bfd && core_bfd)
 182     {
 183       if (!core_file_matches_executable_p (core_bfd, exec_bfd))
 184         warning ("core file may not match specified executable file.");
 185       else if (bfd_get_mtime (exec_bfd) > bfd_get_mtime (core_bfd))
 186         warning ("exec file is newer than core file.");
 187     }
 188 }
 189
 190 /* Return the name of the executable file as a string.
 191    ERR nonzero means get error if there is none specified;
 192    otherwise return 0 in that case.  */
 193
 194 char *
 195 get_exec_file (int err)
 196 {
 197   if (exec_bfd)
 198     return bfd_get_filename (exec_bfd);
 199   if (!err)
 200     return NULL;
 201
 202   error ("No executable file specified.\n\
 203 Use the \"file\" or \"exec-file\" command.");
 204   return NULL;
 205 }
 206 \f
 207
 208 /* Report a memory error with error().  */
 209
 210 void
 211 memory_error (int status, CORE_ADDR memaddr)
 212 {
 213   struct ui_file *tmp_stream = mem_fileopen ();
 214   make_cleanup_ui_file_delete (tmp_stream);
 215
 216   if (status == EIO)
 217     {
 218       /* Actually, address between memaddr and memaddr + len
 219          was out of bounds. */
 220       fprintf_unfiltered (tmp_stream, "Cannot access memory at address ");
 221       print_address_numeric (memaddr, 1, tmp_stream);
 222     }
 223   else
 224     {
 225       fprintf_filtered (tmp_stream, "Error accessing memory address ");
 226       print_address_numeric (memaddr, 1, tmp_stream);
 227       fprintf_filtered (tmp_stream, ": %s.",
 228                        safe_strerror (status));
 229     }
 230
 231   error_stream (tmp_stream);
 232 }
 233
 234 /* Same as target_read_memory, but report an error if can't read.  */
 235 void
 236 read_memory (CORE_ADDR memaddr, char *myaddr, int len)
 237 {
 238   int status;
 239   status = target_read_memory (memaddr, myaddr, len);
 240   if (status != 0)
 241     memory_error (status, memaddr);
 242 }
 243
 244 /* Argument / return result struct for use with
 245    do_captured_read_memory_integer().  MEMADDR and LEN are filled in
 246    by gdb_read_memory_integer().  RESULT is the contents that were
 247    successfully read from MEMADDR of length LEN.  */
 248
 249 struct captured_read_memory_integer_arguments
 250 {
 251   CORE_ADDR memaddr;
 252   int len;
 253   LONGEST result;
 254 };
 255
 256 /* Helper function for gdb_read_memory_integer().  DATA must be a
 257    pointer to a captured_read_memory_integer_arguments struct.
 258    Return 1 if successful.  Note that the catch_errors() interface
 259    will return 0 if an error occurred while reading memory.  This
 260    choice of return code is so that we can distinguish between
 261    success and failure.  */
 262
 263 static int
 264 do_captured_read_memory_integer (void *data)
 265 {
 266   struct captured_read_memory_integer_arguments *args = (struct captured_read_memory_integer_arguments*) data;
 267   CORE_ADDR memaddr = args->memaddr;
 268   int len = args->len;
 269
 270   args->result = read_memory_integer (memaddr, len);
 271
 272   return 1;
 273 }
 274
 275 /* Read memory at MEMADDR of length LEN and put the contents in
 276    RETURN_VALUE.  Return 0 if MEMADDR couldn't be read and non-zero
 277    if successful.  */
 278
 279 int
 280 safe_read_memory_integer (CORE_ADDR memaddr, int len, LONGEST *return_value)
 281 {
 282   int status;
 283   struct captured_read_memory_integer_arguments args;
 284   args.memaddr = memaddr;
 285   args.len = len;
 286
 287   status = catch_errors (do_captured_read_memory_integer, &args,
 288                         "", RETURN_MASK_ALL);
 289   if (status)
 290     *return_value = args.result;
 291
 292   return status;
 293 }
 294
 295 LONGEST
 296 read_memory_integer (CORE_ADDR memaddr, int len)
 297 {
 298   char buf[sizeof (LONGEST)];
 299
 300   read_memory (memaddr, buf, len);
 301   return extract_signed_integer (buf, len);
 302 }
 303
 304 ULONGEST
 305 read_memory_unsigned_integer (CORE_ADDR memaddr, int len)
 306 {
 307   char buf[sizeof (ULONGEST)];
 308
 309   read_memory (memaddr, buf, len);
 310   return extract_unsigned_integer (buf, len);
 311 }
 312
 313 void
 314 read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len)
 315 {
 316   char *cp;
 317   int i;
 318   int cnt;
 319
 320   cp = buffer;
 321   while (1)
 322     {
 323       if (cp - buffer >= max_len)
 324         {
 325           buffer[max_len - 1] = '\0';
 326           break;
 327         }
 328       cnt = max_len - (cp - buffer);
 329       if (cnt > 8)
 330         cnt = 8;
 331       read_memory (memaddr + (int) (cp - buffer), cp, cnt);
 332       for (i = 0; i < cnt && *cp; i++, cp++)
 333         ;                       /* null body */
 334
 335       if (i < cnt && !*cp)
 336         break;
 337     }
 338 }
 339
 340 CORE_ADDR
 341 read_memory_typed_address (CORE_ADDR addr, struct type *type)
 342 {
 343   char *buf = alloca (TYPE_LENGTH (type));
 344   read_memory (addr, buf, TYPE_LENGTH (type));
 345   return extract_typed_address (buf, type);
 346 }
 347
 348 /* Same as target_write_memory, but report an error if can't write.  */
 349 void
 350 write_memory (CORE_ADDR memaddr, char *myaddr, int len)
 351 {
 352   int status;
 353
 354   status = target_write_memory (memaddr, myaddr, 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   char *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   char *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
 418 static void set_gnutarget_command (char *, int, struct cmd_list_element *);
 419
 420 static void
 421 set_gnutarget_command (char *ignore, int from_tty, struct cmd_list_element *c)
 422 {
 423   if (strcmp (gnutarget_string, "auto") == 0)
 424     gnutarget = NULL;
 425   else
 426     gnutarget = gnutarget_string;
 427 }
 428
 429 /* Set the gnutarget.  */
 430 void
 431 set_gnutarget (char *newtarget)
 432 {
 433   if (gnutarget_string != NULL)
 434     xfree (gnutarget_string);
 435   gnutarget_string = savestring (newtarget, strlen (newtarget));
 436   set_gnutarget_command (NULL, 0, NULL);
 437 }
 438
 439 void
 440 _initialize_core (void)
 441 {
 442   struct cmd_list_element *c;
 443   c = add_cmd ("core-file", class_files, core_file_command,
 444                "Use FILE as core dump for examining memory and registers.\n\
 445 No arg means have no core file.  This command has been superseded by the\n\
 446 `target core' and `detach' commands.", &cmdlist);
 447   set_cmd_completer (c, filename_completer);
 448
 449   c = add_set_cmd ("gnutarget", class_files, var_string_noescape,
 450                    (char *) &gnutarget_string,
 451                    "Set the current BFD target.\n\
 452 Use `set gnutarget auto' to specify automatic detection.",
 453                    &setlist);
 454   set_cmd_sfunc (c, set_gnutarget_command);
 455   deprecated_add_show_from_set (c, &showlist);
 456
 457   if (getenv ("GNUTARGET"))
 458     set_gnutarget (getenv ("GNUTARGET"));
 459   else
 460     set_gnutarget ("auto");
 461 }