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
  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 call.
  44    If there's only one hook, it is set in exec_file_display hook.
  45    If there are two or more hooks, they are set in exec_file_extra_hooks[],
  46    and exec_file_display_hook is set to a function that calls all of them.
  47    This extra complexity is needed to preserve compatibility with
  48    old code that assumed that only one hook could be set, and which called
  49    exec_file_display_hook directly.  */
  50
  51 typedef void (*hook_type) (char *);
  52
  53 hook_type exec_file_display_hook;       /* the original hook */
  54 static hook_type *exec_file_extra_hooks;        /* array of additional hooks */
  55 static int exec_file_hook_count = 0;    /* size of array */
  56
  57 /* Binary file diddling handle for the core file.  */
  58
  59 bfd *core_bfd = NULL;
  60 \f
  61
  62 /* Backward compatability with old way of specifying core files.  */
  63
  64 void
  65 core_file_command (char *filename, int from_tty)
  66 {
  67   struct target_ops *t;
  68
  69   dont_repeat ();               /* Either way, seems bogus. */
  70
  71   t = find_core_target ();
  72   if (t == NULL)
  73     error ("GDB can't read core files on this machine.");
  74
  75   if (!filename)
  76     (t->to_detach) (filename, from_tty);
  77   else
  78     (t->to_open) (filename, from_tty);
  79 }
  80 \f
  81
  82 /* If there are two or more functions that wish to hook into exec_file_command,
  83  * this function will call all of the hook functions. */
  84
  85 static void
  86 call_extra_exec_file_hooks (char *filename)
  87 {
  88   int i;
  89
  90   for (i = 0; i < exec_file_hook_count; i++)
  91     (*exec_file_extra_hooks[i]) (filename);
  92 }
  93
  94 /* Call this to specify the hook for exec_file_command to call back.
  95    This is called from the x-window display code.  */
  96
  97 void
  98 specify_exec_file_hook (void (*hook) (char *))
  99 {
 100   hook_type *new_array;
 101
 102   if (exec_file_display_hook != NULL)
 103     {
 104       /* There's already a hook installed.  Arrange to have both it
 105        * and the subsequent hooks called. */
 106       if (exec_file_hook_count == 0)
 107         {
 108           /* If this is the first extra hook, initialize the hook array. */
 109           exec_file_extra_hooks = (hook_type *) xmalloc (sizeof (hook_type));
 110           exec_file_extra_hooks[0] = exec_file_display_hook;
 111           exec_file_display_hook = call_extra_exec_file_hooks;
 112           exec_file_hook_count = 1;
 113         }
 114
 115       /* Grow the hook array by one and add the new hook to the end.
 116          Yes, it's inefficient to grow it by one each time but since
 117          this is hardly ever called it's not a big deal.  */
 118       exec_file_hook_count++;
 119       new_array =
 120         (hook_type *) xrealloc (exec_file_extra_hooks,
 121                                 exec_file_hook_count * sizeof (hook_type));
 122       exec_file_extra_hooks = new_array;
 123       exec_file_extra_hooks[exec_file_hook_count - 1] = hook;
 124     }
 125   else
 126     exec_file_display_hook = hook;
 127 }
 128
 129 /* The exec file must be closed before running an inferior.
 130    If it is needed again after the inferior dies, it must
 131    be reopened.  */
 132
 133 void
 134 close_exec_file (void)
 135 {
 136 #if 0                           /* FIXME */
 137   if (exec_bfd)
 138     bfd_tempclose (exec_bfd);
 139 #endif
 140 }
 141
 142 void
 143 reopen_exec_file (void)
 144 {
 145 #if 0                           /* FIXME */
 146   if (exec_bfd)
 147     bfd_reopen (exec_bfd);
 148 #else
 149   char *filename;
 150   int res;
 151   struct stat st;
 152   long mtime;
 153
 154   /* Don't do anything if the current target isn't exec. */
 155   if (exec_bfd == NULL || strcmp (target_shortname, "exec") != 0)
 156     return;
 157
 158   /* If the timestamp of the exec file has changed, reopen it. */
 159   filename = xstrdup (bfd_get_filename (exec_bfd));
 160   make_cleanup (xfree, filename);
 161   mtime = bfd_get_mtime (exec_bfd);
 162   res = stat (filename, &st);
 163
 164   if (mtime && mtime != st.st_mtime)
 165     {
 166       exec_open (filename, 0);
 167     }
 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       print_address_numeric (memaddr, 1, tmp_stream);
 218     }
 219   else
 220     {
 221       fprintf_filtered (tmp_stream, "Error accessing memory address ");
 222       print_address_numeric (memaddr, 1, 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, char *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 /* Like target_read_memory, but slightly different parameters.  */
 241 int
 242 dis_asm_read_memory (bfd_vma memaddr, bfd_byte *myaddr, unsigned int len,
 243                      disassemble_info *info)
 244 {
 245   return target_read_memory (memaddr, (char *) myaddr, len);
 246 }
 247
 248 /* Like memory_error with slightly different parameters.  */
 249 void
 250 dis_asm_memory_error (int status, bfd_vma memaddr, disassemble_info *info)
 251 {
 252   memory_error (status, memaddr);
 253 }
 254
 255 /* Like print_address with slightly different parameters.  */
 256 void
 257 dis_asm_print_address (bfd_vma addr, struct disassemble_info *info)
 258 {
 259   print_address (addr, info->stream);
 260 }
 261
 262 /* Same as target_write_memory, but report an error if can't write.  */
 263 void
 264 write_memory (CORE_ADDR memaddr, char *myaddr, int len)
 265 {
 266   int status;
 267
 268   status = target_write_memory (memaddr, myaddr, len);
 269   if (status != 0)
 270     memory_error (status, memaddr);
 271 }
 272
 273 /* Read an integer from debugged memory, given address and number of bytes.  */
 274
 275 LONGEST
 276 read_memory_integer (CORE_ADDR memaddr, int len)
 277 {
 278   char buf[sizeof (LONGEST)];
 279
 280   read_memory (memaddr, buf, len);
 281   return extract_signed_integer (buf, len);
 282 }
 283
 284 ULONGEST
 285 read_memory_unsigned_integer (CORE_ADDR memaddr, int len)
 286 {
 287   char buf[sizeof (ULONGEST)];
 288
 289   read_memory (memaddr, buf, len);
 290   return extract_unsigned_integer (buf, len);
 291 }
 292
 293 void
 294 read_memory_string (CORE_ADDR memaddr, char *buffer, int max_len)
 295 {
 296   register char *cp;
 297   register int i;
 298   int cnt;
 299
 300   cp = buffer;
 301   while (1)
 302     {
 303       if (cp - buffer >= max_len)
 304         {
 305           buffer[max_len - 1] = '\0';
 306           break;
 307         }
 308       cnt = max_len - (cp - buffer);
 309       if (cnt > 8)
 310         cnt = 8;
 311       read_memory (memaddr + (int) (cp - buffer), cp, cnt);
 312       for (i = 0; i < cnt && *cp; i++, cp++)
 313         ;                       /* null body */
 314
 315       if (i < cnt && !*cp)
 316         break;
 317     }
 318 }
 319 \f
 320
 321 #if 0
 322 /* Enable after 4.12.  It is not tested.  */
 323
 324 /* Search code.  Targets can just make this their search function, or
 325    if the protocol has a less general search function, they can call this
 326    in the cases it can't handle.  */
 327 void
 328 generic_search (int len, char *data, char *mask, CORE_ADDR startaddr,
 329                 int increment, CORE_ADDR lorange, CORE_ADDR hirange,
 330                 CORE_ADDR *addr_found, char *data_found)
 331 {
 332   int i;
 333   CORE_ADDR curaddr = startaddr;
 334
 335   while (curaddr >= lorange && curaddr < hirange)
 336     {
 337       read_memory (curaddr, data_found, len);
 338       for (i = 0; i < len; ++i)
 339         if ((data_found[i] & mask[i]) != data[i])
 340           goto try_again;
 341       /* It matches.  */
 342       *addr_found = curaddr;
 343       return;
 344
 345     try_again:
 346       curaddr += increment;
 347     }
 348   *addr_found = (CORE_ADDR) 0;
 349   return;
 350 }
 351 #endif /* 0 */
 352 \f
 353 /* The current default bfd target.  Points to storage allocated for
 354    gnutarget_string.  */
 355 char *gnutarget;
 356
 357 /* Same thing, except it is "auto" not NULL for the default case.  */
 358 static char *gnutarget_string;
 359
 360 static void set_gnutarget_command (char *, int, struct cmd_list_element *);
 361
 362 static void
 363 set_gnutarget_command (char *ignore, int from_tty, struct cmd_list_element *c)
 364 {
 365   if (STREQ (gnutarget_string, "auto"))
 366     gnutarget = NULL;
 367   else
 368     gnutarget = gnutarget_string;
 369 }
 370
 371 /* Set the gnutarget.  */
 372 void
 373 set_gnutarget (char *newtarget)
 374 {
 375   if (gnutarget_string != NULL)
 376     xfree (gnutarget_string);
 377   gnutarget_string = savestring (newtarget, strlen (newtarget));
 378   set_gnutarget_command (NULL, 0, NULL);
 379 }
 380
 381 void
 382 _initialize_core (void)
 383 {
 384   struct cmd_list_element *c;
 385   c = add_cmd ("core-file", class_files, core_file_command,
 386                "Use FILE as core dump for examining memory and registers.\n\
 387 No arg means have no core file.  This command has been superseded by the\n\
 388 `target core' and `detach' commands.", &cmdlist);
 389   c->completer = filename_completer;
 390
 391   c = add_set_cmd ("gnutarget", class_files, var_string_noescape,
 392                    (char *) &gnutarget_string,
 393                    "Set the current BFD target.\n\
 394 Use `set gnutarget auto' to specify automatic detection.",
 395                    &setlist);
 396   c->function.sfunc = set_gnutarget_command;
 397   add_show_from_set (c, &showlist);
 398
 399   if (getenv ("GNUTARGET"))
 400     set_gnutarget (getenv ("GNUTARGET"));
 401   else
 402     set_gnutarget ("auto");
 403 }