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 /* Argument / return result struct for use with
 264    do_captured_read_memory_integer().  MEMADDR and LEN are filled in
 265    by gdb_read_memory_integer().  RESULT is the contents that were
 266    successfully read from MEMADDR of length LEN.  */
 267
 268 struct captured_read_memory_integer_arguments
 269 {
 270   CORE_ADDR memaddr;
 271   int len;
 272   LONGEST result;
 273 };
 274
 275 /* Helper function for gdb_read_memory_integer().  DATA must be a
 276    pointer to a captured_read_memory_integer_arguments struct.
 277    Return 1 if successful.  Note that the catch_errors() interface
 278    will return 0 if an error occurred while reading memory.  This
 279    choice of return code is so that we can distinguish between
 280    success and failure.  */
 281
 282 static int
 283 do_captured_read_memory_integer (void *data)
 284 {
 285   struct captured_read_memory_integer_arguments *args = (struct captured_read_memory_integer_arguments*) data;
 286   CORE_ADDR memaddr = args->memaddr;
 287   int len = args->len;
 288
 289   args->result = read_memory_integer (memaddr, len);
 290
 291   return 1;
 292 }
 293
 294 /* Read memory at MEMADDR of length LEN and put the contents in
 295    RETURN_VALUE.  Return 0 if MEMADDR couldn't be read and non-zero
 296    if successful.  */
 297
 298 int
 299 safe_read_memory_integer (CORE_ADDR memaddr, int len, LONGEST *return_value)
 300 {
 301   int status;
 302   struct captured_read_memory_integer_arguments args;
 303   args.memaddr = memaddr;
 304   args.len = len;
 305
 306   status = catch_errors (do_captured_read_memory_integer, &args,
 307                         "", RETURN_MASK_ALL);
 308   if (status)
 309     *return_value = args.result;
 310
 311   return status;
 312 }
 313
 314 LONGEST
 315 read_memory_integer (CORE_ADDR memaddr, int len)
 316 {
 317   char buf[sizeof (LONGEST)];
 318
 319   read_memory (memaddr, buf, len);
 320   return extract_signed_integer (buf, len);
 321 }
 322
 323 ULONGEST
 324 read_memory_unsigned_integer (CORE_ADDR memaddr, int len)
 325 {
 326   char buf[sizeof (ULONGEST)];
 327
 328   read_memory (memaddr, buf, len);
 329   return extract_unsigned_integer (buf, len);
 330 }
 331
 332 void
 333 read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len)
 334 {
 335   register char *cp;
 336   register int i;
 337   int cnt;
 338
 339   cp = buffer;
 340   while (1)
 341     {
 342       if (cp - buffer >= max_len)
 343         {
 344           buffer[max_len - 1] = '\0';
 345           break;
 346         }
 347       cnt = max_len - (cp - buffer);
 348       if (cnt > 8)
 349         cnt = 8;
 350       read_memory (memaddr + (int) (cp - buffer), cp, cnt);
 351       for (i = 0; i < cnt && *cp; i++, cp++)
 352         ;                       /* null body */
 353
 354       if (i < cnt && !*cp)
 355         break;
 356     }
 357 }
 358
 359 /* Same as target_write_memory, but report an error if can't write.  */
 360 void
 361 write_memory (CORE_ADDR memaddr, char *myaddr, int len)
 362 {
 363   int status;
 364
 365   status = target_write_memory (memaddr, myaddr, len);
 366   if (status != 0)
 367     memory_error (status, memaddr);
 368 }
 369
 370 /* Store VALUE at ADDR in the inferior as a LEN-byte unsigned integer.  */
 371 void
 372 write_memory_unsigned_integer (CORE_ADDR addr, int len, ULONGEST value)
 373 {
 374   char *buf = alloca (len);
 375   store_unsigned_integer (buf, len, value);
 376   write_memory (addr, buf, len);
 377 }
 378
 379 /* Store VALUE at ADDR in the inferior as a LEN-byte signed integer.  */
 380 void
 381 write_memory_signed_integer (CORE_ADDR addr, int len, LONGEST value)
 382 {
 383   char *buf = alloca (len);
 384   store_signed_integer (buf, len, value);
 385   write_memory (addr, buf, len);
 386 }
 387
 388 \f
 389
 390 #if 0
 391 /* Enable after 4.12.  It is not tested.  */
 392
 393 /* Search code.  Targets can just make this their search function, or
 394    if the protocol has a less general search function, they can call this
 395    in the cases it can't handle.  */
 396 void
 397 generic_search (int len, char *data, char *mask, CORE_ADDR startaddr,
 398                 int increment, CORE_ADDR lorange, CORE_ADDR hirange,
 399                 CORE_ADDR *addr_found, char *data_found)
 400 {
 401   int i;
 402   CORE_ADDR curaddr = startaddr;
 403
 404   while (curaddr >= lorange && curaddr < hirange)
 405     {
 406       read_memory (curaddr, data_found, len);
 407       for (i = 0; i < len; ++i)
 408         if ((data_found[i] & mask[i]) != data[i])
 409           goto try_again;
 410       /* It matches.  */
 411       *addr_found = curaddr;
 412       return;
 413
 414     try_again:
 415       curaddr += increment;
 416     }
 417   *addr_found = (CORE_ADDR) 0;
 418   return;
 419 }
 420 #endif /* 0 */
 421 \f
 422 /* The current default bfd target.  Points to storage allocated for
 423    gnutarget_string.  */
 424 char *gnutarget;
 425
 426 /* Same thing, except it is "auto" not NULL for the default case.  */
 427 static char *gnutarget_string;
 428
 429 static void set_gnutarget_command (char *, int, struct cmd_list_element *);
 430
 431 static void
 432 set_gnutarget_command (char *ignore, int from_tty, struct cmd_list_element *c)
 433 {
 434   if (STREQ (gnutarget_string, "auto"))
 435     gnutarget = NULL;
 436   else
 437     gnutarget = gnutarget_string;
 438 }
 439
 440 /* Set the gnutarget.  */
 441 void
 442 set_gnutarget (char *newtarget)
 443 {
 444   if (gnutarget_string != NULL)
 445     xfree (gnutarget_string);
 446   gnutarget_string = savestring (newtarget, strlen (newtarget));
 447   set_gnutarget_command (NULL, 0, NULL);
 448 }
 449
 450 void
 451 _initialize_core (void)
 452 {
 453   struct cmd_list_element *c;
 454   c = add_cmd ("core-file", class_files, core_file_command,
 455                "Use FILE as core dump for examining memory and registers.\n\
 456 No arg means have no core file.  This command has been superseded by the\n\
 457 `target core' and `detach' commands.", &cmdlist);
 458   set_cmd_completer (c, filename_completer);
 459
 460   c = add_set_cmd ("gnutarget", class_files, var_string_noescape,
 461                    (char *) &gnutarget_string,
 462                    "Set the current BFD target.\n\
 463 Use `set gnutarget auto' to specify automatic detection.",
 464                    &setlist);
 465   set_cmd_sfunc (c, set_gnutarget_command);
 466   add_show_from_set (c, &showlist);
 467
 468   if (getenv ("GNUTARGET"))
 469     set_gnutarget (getenv ("GNUTARGET"));
 470   else
 471     set_gnutarget ("auto");
 472 }