gdb/core.c

   1 /* Work with core dump and executable files, for GDB.
   2    Copyright 1986, 1987, 1989, 1991, 1992 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 "frame.h"  /* required by inferior.h */
  26 #include "inferior.h"
  27 #include "symtab.h"
  28 #include "command.h"
  29 #include "bfd.h"
  30 #include "target.h"
  31 #include "gdbcore.h"
  32
  33 #ifdef SOLIB_ADD
  34 static int
  35 solib_add_stub PARAMS ((char *));
  36 #endif
  37
  38 static void
  39 core_close PARAMS ((int));
  40
  41 static void
  42 core_open PARAMS ((char *, int));
  43
  44 static void
  45 core_detach PARAMS ((char *, int));
  46
  47 static void
  48 get_core_registers PARAMS ((int));
  49
  50 static void
  51 core_files_info PARAMS ((struct target_ops *));
  52
  53 extern int sys_nerr;
  54 extern char *sys_errlist[];
  55 extern char *sys_siglist[];
  56
  57 extern char registers[];
  58
  59 /* Hook for `exec_file_command' command to call.  */
  60
  61 void (*exec_file_display_hook) PARAMS ((char *)) = NULL;
  62
  63 /* Binary file diddling handle for the core file.  */
  64
  65 bfd *core_bfd = NULL;
  66
  67 /* Forward decl */
  68 extern struct target_ops core_ops;
  69
  70 \f
  71 /* Discard all vestiges of any previous core file
  72    and mark data and stack spaces as empty.  */
  73
  74 /* ARGSUSED */
  75 static void
  76 core_close (quitting)
  77      int quitting;
  78 {
  79   if (core_bfd) {
  80     free (bfd_get_filename (core_bfd));
  81     bfd_close (core_bfd);
  82     core_bfd = NULL;
  83 #ifdef CLEAR_SOLIB
  84     CLEAR_SOLIB ();
  85 #endif
  86     if (core_ops.to_sections) {
  87       free (core_ops.to_sections);
  88       core_ops.to_sections = NULL;
  89       core_ops.to_sections_end = NULL;
  90     }
  91   }
  92 }
  93
  94 #ifdef SOLIB_ADD
  95 /* Stub function for catch_errors around shared library hacking. */
  96
  97 static int
  98 solib_add_stub (from_tty)
  99      char *from_tty;
 100 {
 101     SOLIB_ADD (NULL, (int)from_tty, &core_ops);
 102     return 0;
 103 }
 104 #endif /* SOLIB_ADD */
 105
 106 /* This routine opens and sets up the core file bfd */
 107
 108 static void
 109 core_open (filename, from_tty)
 110      char *filename;
 111      int from_tty;
 112 {
 113   const char *p;
 114   int siggy;
 115   struct cleanup *old_chain;
 116   char *temp;
 117   bfd *temp_bfd;
 118   int ontop;
 119   int scratch_chan;
 120
 121   target_preopen (from_tty);
 122   if (!filename)
 123     {
 124       error (core_bfd?
 125        "No core file specified.  (Use `detach' to stop debugging a core file.)"
 126      : "No core file specified.");
 127     }
 128
 129   filename = tilde_expand (filename);
 130   if (filename[0] != '/') {
 131     temp = concat (current_directory, "/", filename, NULL);
 132     free (filename);
 133     filename = temp;
 134   }
 135
 136   old_chain = make_cleanup (free, filename);
 137
 138   scratch_chan = open (filename, write_files? O_RDWR: O_RDONLY, 0);
 139   if (scratch_chan < 0)
 140     perror_with_name (filename);
 141
 142   temp_bfd = bfd_fdopenr (filename, NULL, scratch_chan);
 143   if (temp_bfd == NULL)
 144     {
 145       perror_with_name (filename);
 146     }
 147
 148   if (!bfd_check_format (temp_bfd, bfd_core))
 149     {
 150       /* Do it after the err msg */
 151       make_cleanup (bfd_close, temp_bfd);
 152       error ("\"%s\" is not a core dump: %s", filename, bfd_errmsg(bfd_error));
 153     }
 154
 155   /* Looks semi-reasonable.  Toss the old core file and work on the new.  */
 156
 157   discard_cleanups (old_chain);         /* Don't free filename any more */
 158   unpush_target (&core_ops);
 159   core_bfd = temp_bfd;
 160   old_chain = make_cleanup (core_close, core_bfd);
 161
 162   validate_files ();
 163
 164   /* Find the data section */
 165   if (build_section_table (core_bfd, &core_ops.to_sections,
 166                            &core_ops.to_sections_end))
 167     error ("Can't find sections in `%s': %s", bfd_get_filename(core_bfd),
 168            bfd_errmsg (bfd_error));
 169
 170   ontop = !push_target (&core_ops);
 171   discard_cleanups (old_chain);
 172
 173   p = bfd_core_file_failing_command (core_bfd);
 174   if (p)
 175     printf ("Core was generated by `%s'.\n", p);
 176
 177   siggy = bfd_core_file_failing_signal (core_bfd);
 178   if (siggy > 0)
 179     printf ("Program terminated with signal %d, %s.\n", siggy,
 180             siggy < NSIG ? sys_siglist[siggy] : "(undocumented)");
 181
 182   if (ontop) {
 183     /* Fetch all registers from core file */
 184     target_fetch_registers (-1);
 185
 186     /* Add symbols and section mappings for any shared libraries */
 187 #ifdef SOLIB_ADD
 188     (void) catch_errors (solib_add_stub, (char *)from_tty, (char *)0);
 189 #endif
 190
 191     /* Now, set up the frame cache, and print the top of stack */
 192     set_current_frame (create_new_frame (read_register (FP_REGNUM),
 193                                          read_pc ()));
 194     select_frame (get_current_frame (), 0);
 195     print_stack_frame (selected_frame, selected_frame_level, 1);
 196   } else {
 197     printf (
 198 "Warning: you won't be able to access this core file until you terminate\n\
 199 your %s; do ``info files''\n", current_target->to_longname);
 200   }
 201 }
 202
 203 static void
 204 core_detach (args, from_tty)
 205      char *args;
 206      int from_tty;
 207 {
 208   if (args)
 209     error ("Too many arguments");
 210   unpush_target (&core_ops);
 211   if (from_tty)
 212     printf ("No core file now.\n");
 213 }
 214
 215 /* Backward compatability with old way of specifying core files.  */
 216
 217 void
 218 core_file_command (filename, from_tty)
 219      char *filename;
 220      int from_tty;
 221 {
 222   dont_repeat ();                       /* Either way, seems bogus. */
 223   if (!filename)
 224     core_detach (filename, from_tty);
 225   else
 226     core_open (filename, from_tty);
 227 }
 228
 229 \f
 230 /* Call this to specify the hook for exec_file_command to call back.
 231    This is called from the x-window display code.  */
 232
 233 void
 234 specify_exec_file_hook (hook)
 235      void (*hook) PARAMS ((char *));
 236 {
 237   exec_file_display_hook = hook;
 238 }
 239
 240 /* The exec file must be closed before running an inferior.
 241    If it is needed again after the inferior dies, it must
 242    be reopened.  */
 243
 244 void
 245 close_exec_file ()
 246 {
 247 #ifdef FIXME
 248   if (exec_bfd)
 249     bfd_tempclose (exec_bfd);
 250 #endif
 251 }
 252
 253 void
 254 reopen_exec_file ()
 255 {
 256 #ifdef FIXME
 257   if (exec_bfd)
 258     bfd_reopen (exec_bfd);
 259 #endif
 260 }
 261 \f
 262 /* If we have both a core file and an exec file,
 263    print a warning if they don't go together.  */
 264
 265 void
 266 validate_files ()
 267 {
 268   if (exec_bfd && core_bfd)
 269     {
 270       if (!core_file_matches_executable_p (core_bfd, exec_bfd))
 271         printf ("Warning: core file may not match specified executable file.\n");
 272       else if (bfd_get_mtime(exec_bfd) > bfd_get_mtime(core_bfd))
 273         printf ("Warning: exec file is newer than core file.\n");
 274     }
 275 }
 276
 277 /* Return the name of the executable file as a string.
 278    ERR nonzero means get error if there is none specified;
 279    otherwise return 0 in that case.  */
 280
 281 char *
 282 get_exec_file (err)
 283      int err;
 284 {
 285   if (exec_bfd) return bfd_get_filename(exec_bfd);
 286   if (!err)     return NULL;
 287
 288   error ("No executable file specified.\n\
 289 Use the \"file\" or \"exec-file\" command.");
 290   return NULL;
 291 }
 292
 293 static void
 294 core_files_info (t)
 295   struct target_ops *t;
 296 {
 297   print_section_info (t, core_bfd);
 298 }
 299 \f
 300 /* Report a memory error with error().  */
 301
 302 void
 303 memory_error (status, memaddr)
 304      int status;
 305      CORE_ADDR memaddr;
 306 {
 307
 308   if (status == EIO)
 309     {
 310       /* Actually, address between memaddr and memaddr + len
 311          was out of bounds. */
 312       error ("Cannot access memory at address %s.", local_hex_string(memaddr));
 313     }
 314   else
 315     {
 316       if (status >= sys_nerr || status < 0)
 317         error ("Error accessing memory address %s: unknown error (%d).",
 318                local_hex_string(memaddr), status);
 319       else
 320         error ("Error accessing memory address %s: %s.",
 321                local_hex_string(memaddr), sys_errlist[status]);
 322     }
 323 }
 324
 325 /* Same as target_read_memory, but report an error if can't read.  */
 326 void
 327 read_memory (memaddr, myaddr, len)
 328      CORE_ADDR memaddr;
 329      char *myaddr;
 330      int len;
 331 {
 332   int status;
 333   status = target_read_memory (memaddr, myaddr, len);
 334   if (status != 0)
 335     memory_error (status, memaddr);
 336 }
 337
 338 /* Same as target_write_memory, but report an error if can't write.  */
 339 void
 340 write_memory (memaddr, myaddr, len)
 341      CORE_ADDR memaddr;
 342      char *myaddr;
 343      int len;
 344 {
 345   int status;
 346
 347   status = target_write_memory (memaddr, myaddr, len);
 348   if (status != 0)
 349     memory_error (status, memaddr);
 350 }
 351
 352 /* Read an integer from debugged memory, given address and number of bytes.  */
 353
 354 long
 355 read_memory_integer (memaddr, len)
 356      CORE_ADDR memaddr;
 357      int len;
 358 {
 359   char cbuf;
 360   short sbuf;
 361   int ibuf;
 362   long lbuf;
 363
 364   if (len == sizeof (char))
 365     {
 366       read_memory (memaddr, &cbuf, len);
 367       return cbuf;
 368     }
 369   if (len == sizeof (short))
 370     {
 371       read_memory (memaddr, (char *)&sbuf, len);
 372       SWAP_TARGET_AND_HOST (&sbuf, sizeof (short));
 373       return sbuf;
 374     }
 375   if (len == sizeof (int))
 376     {
 377       read_memory (memaddr, (char *)&ibuf, len);
 378       SWAP_TARGET_AND_HOST (&ibuf, sizeof (int));
 379       return ibuf;
 380     }
 381   if (len == sizeof (lbuf))
 382     {
 383       read_memory (memaddr, (char *)&lbuf, len);
 384       SWAP_TARGET_AND_HOST (&lbuf, sizeof (lbuf));
 385       return lbuf;
 386     }
 387   error ("Cannot handle integers of %d bytes.", len);
 388   return -1;    /* for lint */
 389 }
 390 \f
 391 /* Get the registers out of a core file.  This is the machine-
 392    independent part.  Fetch_core_registers is the machine-dependent
 393    part, typically implemented in the xm-file for each architecture.  */
 394
 395 /* We just get all the registers, so we don't use regno.  */
 396 /* ARGSUSED */
 397 static void
 398 get_core_registers (regno)
 399      int regno;
 400 {
 401   sec_ptr reg_sec;
 402   unsigned size;
 403   char *the_regs;
 404
 405   reg_sec = bfd_get_section_by_name (core_bfd, ".reg");
 406   if (!reg_sec) goto cant;
 407   size = bfd_section_size (core_bfd, reg_sec);
 408   the_regs = alloca (size);
 409   if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size))
 410     {
 411       fetch_core_registers (the_regs, size, 0,
 412                             (unsigned) bfd_section_vma (abfd,reg_sec));
 413     }
 414   else
 415     {
 416 cant:
 417       fprintf (stderr, "Couldn't fetch registers from core file: %s\n",
 418                bfd_errmsg (bfd_error));
 419     }
 420
 421   /* Now do it again for the float registers, if they exist.  */
 422   reg_sec = bfd_get_section_by_name (core_bfd, ".reg2");
 423   if (reg_sec) {
 424     size = bfd_section_size (core_bfd, reg_sec);
 425     the_regs = alloca (size);
 426     if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0,
 427                                   size))
 428       {
 429         fetch_core_registers (the_regs, size, 2,
 430                               (unsigned) bfd_section_vma (abfd,reg_sec));
 431       }
 432     else
 433       {
 434         fprintf (stderr, "Couldn't fetch register set 2 from core file: %s\n",
 435                  bfd_errmsg (bfd_error));
 436       }
 437   }
 438   registers_fetched();
 439 }
 440 \f
 441 struct target_ops core_ops = {
 442         "core", "Local core dump file",
 443         "Use a core file as a target.  Specify the filename of the core file.",
 444         core_open, core_close,
 445         child_attach, core_detach, 0, 0, /* resume, wait */
 446         get_core_registers,
 447         0, 0, 0, 0, /* store_regs, prepare_to_store, conv_to, conv_from */
 448         xfer_memory, core_files_info,
 449         0, 0, /* core_insert_breakpoint, core_remove_breakpoint, */
 450         0, 0, 0, 0, 0, /* terminal stuff */
 451         0, 0, 0, /* kill, load, lookup sym */
 452         child_create_inferior, 0, /* mourn_inferior */
 453         core_stratum, 0, /* next */
 454         0, 1, 1, 1, 0,  /* all mem, mem, stack, regs, exec */
 455         0, 0,                   /* section pointers */
 456         OPS_MAGIC,              /* Always the last thing */
 457 };
 458
 459 void
 460 _initialize_core()
 461 {
 462
 463   add_com ("core-file", class_files, core_file_command,
 464            "Use FILE as core dump for examining memory and registers.\n\
 465 No arg means have no core file.  This command has been superseded by the\n\
 466 `target core' and `detach' commands.");
 467   add_target (&core_ops);
 468 }