gdb/core.c

   1 /* Work with core dump and executable files, for GDB.
   2    Copyright (C) 1986, 1987, 1989 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 This program is free software; you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation; either version 2 of the License, or
   9 (at your option) any later version.
  10
  11 This program is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with this program; if not, write to the Free Software
  18 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include <stdio.h>
  21 #include <errno.h>
  22 #include <signal.h>
  23 #include <fcntl.h>
  24 #include "defs.h"
  25 #include "param.h"
  26 #include "frame.h"  /* required by inferior.h */
  27 #include "inferior.h"
  28 #include "symtab.h"
  29 #include "command.h"
  30 #include "bfd.h"
  31 #include "target.h"
  32 #include "gdbcore.h"
  33
  34 extern int xfer_memory ();
  35 extern void child_attach (), child_create_inferior ();
  36
  37 extern int sys_nerr;
  38 extern char *sys_errlist[];
  39 extern char *sys_siglist[];
  40
  41 extern char registers[];
  42
  43 /* Hook for `exec_file_command' command to call.  */
  44
  45 void (*exec_file_display_hook) () = NULL;
  46
  47 /* Binary file diddling handle for the core file.  */
  48
  49 bfd *core_bfd = NULL;
  50
  51 /* Forward decl */
  52 extern struct target_ops core_ops;
  53
  54 \f
  55 /* Discard all vestiges of any previous core file
  56    and mark data and stack spaces as empty.  */
  57
  58 /* ARGSUSED */
  59 void
  60 core_close (quitting)
  61      int quitting;
  62 {
  63   if (core_bfd) {
  64     free (bfd_get_filename (core_bfd));
  65     bfd_close (core_bfd);
  66     core_bfd = NULL;
  67 #ifdef CLEAR_SOLIB
  68     CLEAR_SOLIB ();
  69 #endif
  70     if (core_ops.sections) {
  71       free (core_ops.sections);
  72       core_ops.sections = NULL;
  73       core_ops.sections_end = NULL;
  74     }
  75   }
  76 }
  77
  78 #ifdef SOLIB_ADD
  79 /* Stub function for catch_errors around shared library hacking. */
  80
  81 int
  82 solib_add_stub (from_tty)
  83      char *from_tty;
  84 {
  85     SOLIB_ADD (NULL, (int)from_tty, &core_ops);
  86     return 0;
  87 }
  88 #endif /* SOLIB_ADD */
  89
  90 /* This routine opens and sets up the core file bfd */
  91
  92 void
  93 core_open (filename, from_tty)
  94      char *filename;
  95      int from_tty;
  96 {
  97   const char *p;
  98   int siggy;
  99   struct cleanup *old_chain;
 100   char *temp;
 101   bfd *temp_bfd;
 102   int ontop;
 103   int scratch_chan;
 104
 105   target_preopen (from_tty);
 106   if (!filename)
 107     {
 108       error (core_bfd?
 109        "No core file specified.  (Use `detach' to stop debugging a core file.)"
 110      : "No core file specified.");
 111     }
 112
 113   filename = tilde_expand (filename);
 114   if (filename[0] != '/') {
 115     temp = concat (current_directory, "/", filename, NULL);
 116     free (filename);
 117     filename = temp;
 118   }
 119
 120   old_chain = make_cleanup (free, filename);
 121
 122   scratch_chan = open (filename, write_files? O_RDWR: O_RDONLY, 0);
 123   if (scratch_chan < 0)
 124     perror_with_name (filename);
 125
 126   temp_bfd = bfd_fdopenr (filename, NULL, scratch_chan);
 127   if (temp_bfd == NULL)
 128     {
 129       perror_with_name (filename);
 130     }
 131
 132   if (!bfd_check_format (temp_bfd, bfd_core))
 133     {
 134       make_cleanup (bfd_close, temp_bfd);       /* Do it after the err msg */
 135       error ("\"%s\" is not a core dump: %s", filename, bfd_errmsg(bfd_error));
 136     }
 137
 138   /* Looks semi-reasonable.  Toss the old core file and work on the new.  */
 139
 140   discard_cleanups (old_chain);         /* Don't free filename any more */
 141   unpush_target (&core_ops);
 142   core_bfd = temp_bfd;
 143   old_chain = make_cleanup (core_close, core_bfd);
 144
 145   validate_files ();
 146
 147   /* Find the data section */
 148   if (build_section_table (core_bfd, &core_ops.sections,
 149                            &core_ops.sections_end))
 150     error ("Can't find sections in `%s': %s", bfd_get_filename(core_bfd),
 151            bfd_errmsg (bfd_error));
 152
 153   ontop = !push_target (&core_ops);
 154   discard_cleanups (old_chain);
 155
 156   p = bfd_core_file_failing_command (core_bfd);
 157   if (p)
 158     printf ("Core was generated by `%s'.\n", p);
 159
 160   siggy = bfd_core_file_failing_signal (core_bfd);
 161   if (siggy > 0)
 162     printf ("Program terminated with signal %d, %s.\n", siggy,
 163             siggy < NSIG ? sys_siglist[siggy] : "(undocumented)");
 164
 165   if (ontop) {
 166     /* Fetch all registers from core file */
 167     target_fetch_registers (-1);
 168
 169     /* Add symbols and section mappings for any shared libraries */
 170 #ifdef SOLIB_ADD
 171     (void) catch_errors (solib_add_stub, (char *)from_tty, (char *)0);
 172 #endif
 173
 174     /* Now, set up the frame cache, and print the top of stack */
 175     set_current_frame (create_new_frame (read_register (FP_REGNUM),
 176                                          read_pc ()));
 177     select_frame (get_current_frame (), 0);
 178     print_stack_frame (selected_frame, selected_frame_level, 1);
 179   } else {
 180     printf (
 181 "Warning: you won't be able to access this core file until you terminate\n\
 182 your %s; do ``info files''\n", current_target->to_longname);
 183   }
 184 }
 185
 186 void
 187 core_detach (args, from_tty)
 188      char *args;
 189      int from_tty;
 190 {
 191   if (args)
 192     error ("Too many arguments");
 193   unpush_target (&core_ops);
 194   if (from_tty)
 195     printf ("No core file now.\n");
 196 }
 197
 198 /* Backward compatability with old way of specifying core files.  */
 199
 200 void
 201 core_file_command (filename, from_tty)
 202      char *filename;
 203      int from_tty;
 204 {
 205   dont_repeat ();                       /* Either way, seems bogus. */
 206   if (!filename)
 207     core_detach (filename, from_tty);
 208   else
 209     core_open (filename, from_tty);
 210 }
 211
 212 \f
 213 /* Call this to specify the hook for exec_file_command to call back.
 214    This is called from the x-window display code.  */
 215
 216 void
 217 specify_exec_file_hook (hook)
 218      void (*hook) ();
 219 {
 220   exec_file_display_hook = hook;
 221 }
 222
 223 /* The exec file must be closed before running an inferior.
 224    If it is needed again after the inferior dies, it must
 225    be reopened.  */
 226
 227 void
 228 close_exec_file ()
 229 {
 230 #ifdef FIXME
 231   if (exec_bfd)
 232     bfd_tempclose (exec_bfd);
 233 #endif
 234 }
 235
 236 void
 237 reopen_exec_file ()
 238 {
 239 #ifdef FIXME
 240   if (exec_bfd)
 241     bfd_reopen (exec_bfd);
 242 #endif
 243 }
 244 \f
 245 /* If we have both a core file and an exec file,
 246    print a warning if they don't go together.  */
 247
 248 void
 249 validate_files ()
 250 {
 251   if (exec_bfd && core_bfd)
 252     {
 253       if (!core_file_matches_executable_p (core_bfd, exec_bfd))
 254         printf ("Warning: core file may not match specified executable file.\n");
 255       else if (bfd_get_mtime(exec_bfd) > bfd_get_mtime(core_bfd))
 256         printf ("Warning: exec file is newer than core file.\n");
 257     }
 258 }
 259
 260 /* Return the name of the executable file as a string.
 261    ERR nonzero means get error if there is none specified;
 262    otherwise return 0 in that case.  */
 263
 264 char *
 265 get_exec_file (err)
 266      int err;
 267 {
 268   if (exec_bfd) return bfd_get_filename(exec_bfd);
 269   if (!err)     return NULL;
 270
 271   error ("No executable file specified.\n\
 272 Use the \"file\" or \"exec-file\" command.");
 273   return NULL;
 274 }
 275
 276 static void
 277 core_files_info (t)
 278   struct target_ops *t;
 279 {
 280   struct section_table *p;
 281
 282   printf_filtered ("\t`%s', ", bfd_get_filename(core_bfd));
 283   wrap_here ("        ");
 284   printf_filtered ("file type %s.\n", bfd_get_target(core_bfd));
 285
 286   for (p = t->sections; p < t->sections_end; p++) {
 287     printf_filtered ("\t%s", local_hex_string_custom (p->addr, "08"));
 288     printf_filtered (" - %s is %s",
 289         local_hex_string_custom (p->endaddr, "08"),
 290         bfd_section_name (p->bfd, p->sec_ptr));
 291     if (p->bfd != core_bfd) {
 292       printf_filtered (" in %s", bfd_get_filename (p->bfd));
 293     }
 294     printf_filtered ("\n");
 295   }
 296 }
 297 \f
 298 void
 299 memory_error (status, memaddr)
 300      int status;
 301      CORE_ADDR memaddr;
 302 {
 303
 304   if (status == EIO)
 305     {
 306       /* Actually, address between memaddr and memaddr + len
 307          was out of bounds. */
 308       error ("Cannot access memory at address %s.", local_hex_string(memaddr));
 309     }
 310   else
 311     {
 312       if (status >= sys_nerr || status < 0)
 313         error ("Error accessing memory address %s: unknown error (%d).",
 314                local_hex_string(memaddr), status);
 315       else
 316         error ("Error accessing memory address %s: %s.",
 317                local_hex_string(memaddr), sys_errlist[status]);
 318     }
 319 }
 320
 321 /* Same as target_read_memory, but report an error if can't read.  */
 322 void
 323 read_memory (memaddr, myaddr, len)
 324      CORE_ADDR memaddr;
 325      char *myaddr;
 326      int len;
 327 {
 328   int status;
 329   status = target_read_memory (memaddr, myaddr, len);
 330   if (status != 0)
 331     memory_error (status, memaddr);
 332 }
 333
 334 /* Same as target_write_memory, but report an error if can't write.  */
 335 void
 336 write_memory (memaddr, myaddr, len)
 337      CORE_ADDR memaddr;
 338      char *myaddr;
 339      int len;
 340 {
 341   int status;
 342
 343   status = target_write_memory (memaddr, myaddr, len);
 344   if (status != 0)
 345     memory_error (status, memaddr);
 346 }
 347
 348 /* Read an integer from debugged memory, given address and number of bytes.  */
 349
 350 long
 351 read_memory_integer (memaddr, len)
 352      CORE_ADDR memaddr;
 353      int len;
 354 {
 355   char cbuf;
 356   short sbuf;
 357   int ibuf;
 358   long lbuf;
 359
 360   if (len == sizeof (char))
 361     {
 362       read_memory (memaddr, &cbuf, len);
 363       return cbuf;
 364     }
 365   if (len == sizeof (short))
 366     {
 367       read_memory (memaddr, (char *)&sbuf, len);
 368       SWAP_TARGET_AND_HOST (&sbuf, sizeof (short));
 369       return sbuf;
 370     }
 371   if (len == sizeof (int))
 372     {
 373       read_memory (memaddr, (char *)&ibuf, len);
 374       SWAP_TARGET_AND_HOST (&ibuf, sizeof (int));
 375       return ibuf;
 376     }
 377   if (len == sizeof (lbuf))
 378     {
 379       read_memory (memaddr, (char *)&lbuf, len);
 380       SWAP_TARGET_AND_HOST (&lbuf, sizeof (lbuf));
 381       return lbuf;
 382     }
 383   error ("Cannot handle integers of %d bytes.", len);
 384   return -1;    /* for lint */
 385 }
 386 \f
 387 /* Get the registers out of a core file.  This is the machine-
 388    independent part.  Fetch_core_registers is the machine-dependent
 389    part, typically implemented in the xm-file for each architecture.  */
 390
 391 /* We just get all the registers, so we don't use regno.  */
 392 /* ARGSUSED */
 393 static void
 394 get_core_registers (regno)
 395      int regno;
 396 {
 397   sec_ptr reg_sec;
 398   unsigned size;
 399   char *the_regs;
 400
 401   reg_sec = bfd_get_section_by_name (core_bfd, ".reg");
 402   if (!reg_sec) goto cant;
 403   size = bfd_section_size (core_bfd, reg_sec);
 404   the_regs = alloca (size);
 405   if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size))
 406     {
 407       fetch_core_registers (the_regs, size, 0,
 408                             (unsigned) bfd_section_vma (abfd,reg_sec));
 409     }
 410   else
 411     {
 412 cant:
 413       fprintf (stderr, "Couldn't fetch registers from core file: %s\n",
 414                bfd_errmsg (bfd_error));
 415     }
 416
 417   /* Now do it again for the float registers, if they exist.  */
 418   reg_sec = bfd_get_section_by_name (core_bfd, ".reg2");
 419   if (reg_sec) {
 420     size = bfd_section_size (core_bfd, reg_sec);
 421     the_regs = alloca (size);
 422     if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0,
 423                                   size))
 424       {
 425         fetch_core_registers (the_regs, size, 2,
 426                               (unsigned) bfd_section_vma (abfd,reg_sec));
 427       }
 428     else
 429       {
 430         fprintf (stderr, "Couldn't fetch register set 2 from core file: %s\n",
 431                  bfd_errmsg (bfd_error));
 432       }
 433   }
 434   registers_fetched();
 435 }
 436 \f
 437 struct target_ops core_ops = {
 438         "core", "Local core dump file",
 439         "Use a core file as a target.  Specify the filename of the core file.",
 440         core_open, core_close,
 441         child_attach, core_detach, 0, 0, /* resume, wait */
 442         get_core_registers,
 443         0, 0, 0, 0, /* store_regs, prepare_to_store, conv_to, conv_from */
 444         xfer_memory, core_files_info,
 445         0, 0, /* core_insert_breakpoint, core_remove_breakpoint, */
 446         0, 0, 0, 0, 0, /* terminal stuff */
 447         0, 0, 0, 0, /* kill, load, call fn, lookup sym */
 448         child_create_inferior, 0, /* mourn_inferior */
 449         core_stratum, 0, /* next */
 450         0, 1, 1, 1, 0,  /* all mem, mem, stack, regs, exec */
 451         0, 0,                   /* section pointers */
 452         OPS_MAGIC,              /* Always the last thing */
 453 };
 454
 455 void
 456 _initialize_core()
 457 {
 458
 459   add_com ("core-file", class_files, core_file_command,
 460            "Use FILE as core dump for examining memory and registers.\n\
 461 No arg means have no core file.  This command has been superseded by the\n\
 462 `target core' and `detach' commands.");
 463   add_target (&core_ops);
 464 }