gdb/core.c

   1 /* Work with core dump and executable files, for GDB.
   2    Copyright 1986, 1987, 1989, 1991 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 extern int xfer_memory ();
  34 extern void child_attach (), child_create_inferior ();
  35
  36 extern int sys_nerr;
  37 extern char *sys_errlist[];
  38 extern char *sys_siglist[];
  39
  40 extern char registers[];
  41
  42 /* Hook for `exec_file_command' command to call.  */
  43
  44 void (*exec_file_display_hook) () = NULL;
  45
  46 /* Binary file diddling handle for the core file.  */
  47
  48 bfd *core_bfd = NULL;
  49
  50 /* Forward decl */
  51 extern struct target_ops core_ops;
  52
  53 \f
  54 /* Discard all vestiges of any previous core file
  55    and mark data and stack spaces as empty.  */
  56
  57 /* ARGSUSED */
  58 void
  59 core_close (quitting)
  60      int quitting;
  61 {
  62   if (core_bfd) {
  63     free (bfd_get_filename (core_bfd));
  64     bfd_close (core_bfd);
  65     core_bfd = NULL;
  66 #ifdef CLEAR_SOLIB
  67     CLEAR_SOLIB ();
  68 #endif
  69     if (core_ops.sections) {
  70       free (core_ops.sections);
  71       core_ops.sections = NULL;
  72       core_ops.sections_end = NULL;
  73     }
  74   }
  75 }
  76
  77 #ifdef SOLIB_ADD
  78 /* Stub function for catch_errors around shared library hacking. */
  79
  80 int
  81 solib_add_stub (from_tty)
  82      char *from_tty;
  83 {
  84     SOLIB_ADD (NULL, (int)from_tty, &core_ops);
  85     return 0;
  86 }
  87 #endif /* SOLIB_ADD */
  88
  89 /* This routine opens and sets up the core file bfd */
  90
  91 void
  92 core_open (filename, from_tty)
  93      char *filename;
  94      int from_tty;
  95 {
  96   const char *p;
  97   int siggy;
  98   struct cleanup *old_chain;
  99   char *temp;
 100   bfd *temp_bfd;
 101   int ontop;
 102   int scratch_chan;
 103
 104   target_preopen (from_tty);
 105   if (!filename)
 106     {
 107       error (core_bfd?
 108        "No core file specified.  (Use `detach' to stop debugging a core file.)"
 109      : "No core file specified.");
 110     }
 111
 112   filename = tilde_expand (filename);
 113   if (filename[0] != '/') {
 114     temp = concat (current_directory, "/", filename, NULL);
 115     free (filename);
 116     filename = temp;
 117   }
 118
 119   old_chain = make_cleanup (free, filename);
 120
 121   scratch_chan = open (filename, write_files? O_RDWR: O_RDONLY, 0);
 122   if (scratch_chan < 0)
 123     perror_with_name (filename);
 124
 125   temp_bfd = bfd_fdopenr (filename, NULL, scratch_chan);
 126   if (temp_bfd == NULL)
 127     {
 128       perror_with_name (filename);
 129     }
 130
 131   if (!bfd_check_format (temp_bfd, bfd_core))
 132     {
 133       make_cleanup (bfd_close, temp_bfd);       /* Do it after the err msg */
 134       error ("\"%s\" is not a core dump: %s", filename, bfd_errmsg(bfd_error));
 135     }
 136
 137   /* Looks semi-reasonable.  Toss the old core file and work on the new.  */
 138
 139   discard_cleanups (old_chain);         /* Don't free filename any more */
 140   unpush_target (&core_ops);
 141   core_bfd = temp_bfd;
 142   old_chain = make_cleanup (core_close, core_bfd);
 143
 144   validate_files ();
 145
 146   /* Find the data section */
 147   if (build_section_table (core_bfd, &core_ops.sections,
 148                            &core_ops.sections_end))
 149     error ("Can't find sections in `%s': %s", bfd_get_filename(core_bfd),
 150            bfd_errmsg (bfd_error));
 151
 152   ontop = !push_target (&core_ops);
 153   discard_cleanups (old_chain);
 154
 155   p = bfd_core_file_failing_command (core_bfd);
 156   if (p)
 157     printf ("Core was generated by `%s'.\n", p);
 158
 159   siggy = bfd_core_file_failing_signal (core_bfd);
 160   if (siggy > 0)
 161     printf ("Program terminated with signal %d, %s.\n", siggy,
 162             siggy < NSIG ? sys_siglist[siggy] : "(undocumented)");
 163
 164   if (ontop) {
 165     /* Fetch all registers from core file */
 166     target_fetch_registers (-1);
 167
 168     /* Add symbols and section mappings for any shared libraries */
 169 #ifdef SOLIB_ADD
 170     (void) catch_errors (solib_add_stub, (char *)from_tty, (char *)0);
 171 #endif
 172
 173     /* Now, set up the frame cache, and print the top of stack */
 174     set_current_frame (create_new_frame (read_register (FP_REGNUM),
 175                                          read_pc ()));
 176     select_frame (get_current_frame (), 0);
 177     print_stack_frame (selected_frame, selected_frame_level, 1);
 178   } else {
 179     printf (
 180 "Warning: you won't be able to access this core file until you terminate\n\
 181 your %s; do ``info files''\n", current_target->to_longname);
 182   }
 183 }
 184
 185 void
 186 core_detach (args, from_tty)
 187      char *args;
 188      int from_tty;
 189 {
 190   if (args)
 191     error ("Too many arguments");
 192   unpush_target (&core_ops);
 193   if (from_tty)
 194     printf ("No core file now.\n");
 195 }
 196
 197 /* Backward compatability with old way of specifying core files.  */
 198
 199 void
 200 core_file_command (filename, from_tty)
 201      char *filename;
 202      int from_tty;
 203 {
 204   dont_repeat ();                       /* Either way, seems bogus. */
 205   if (!filename)
 206     core_detach (filename, from_tty);
 207   else
 208     core_open (filename, from_tty);
 209 }
 210
 211 \f
 212 /* Call this to specify the hook for exec_file_command to call back.
 213    This is called from the x-window display code.  */
 214
 215 void
 216 specify_exec_file_hook (hook)
 217      void (*hook) ();
 218 {
 219   exec_file_display_hook = hook;
 220 }
 221
 222 /* The exec file must be closed before running an inferior.
 223    If it is needed again after the inferior dies, it must
 224    be reopened.  */
 225
 226 void
 227 close_exec_file ()
 228 {
 229 #ifdef FIXME
 230   if (exec_bfd)
 231     bfd_tempclose (exec_bfd);
 232 #endif
 233 }
 234
 235 void
 236 reopen_exec_file ()
 237 {
 238 #ifdef FIXME
 239   if (exec_bfd)
 240     bfd_reopen (exec_bfd);
 241 #endif
 242 }
 243 \f
 244 /* If we have both a core file and an exec file,
 245    print a warning if they don't go together.  */
 246
 247 void
 248 validate_files ()
 249 {
 250   if (exec_bfd && core_bfd)
 251     {
 252       if (!core_file_matches_executable_p (core_bfd, exec_bfd))
 253         printf ("Warning: core file may not match specified executable file.\n");
 254       else if (bfd_get_mtime(exec_bfd) > bfd_get_mtime(core_bfd))
 255         printf ("Warning: exec file is newer than core file.\n");
 256     }
 257 }
 258
 259 /* Return the name of the executable file as a string.
 260    ERR nonzero means get error if there is none specified;
 261    otherwise return 0 in that case.  */
 262
 263 char *
 264 get_exec_file (err)
 265      int err;
 266 {
 267   if (exec_bfd) return bfd_get_filename(exec_bfd);
 268   if (!err)     return NULL;
 269
 270   error ("No executable file specified.\n\
 271 Use the \"file\" or \"exec-file\" command.");
 272   return NULL;
 273 }
 274
 275 static void
 276 core_files_info (t)
 277   struct target_ops *t;
 278 {
 279   struct section_table *p;
 280
 281   printf_filtered ("\t`%s', ", bfd_get_filename(core_bfd));
 282   wrap_here ("        ");
 283   printf_filtered ("file type %s.\n", bfd_get_target(core_bfd));
 284
 285   for (p = t->sections; p < t->sections_end; p++) {
 286     printf_filtered ("\t%s", local_hex_string_custom (p->addr, "08"));
 287     printf_filtered (" - %s is %s",
 288         local_hex_string_custom (p->endaddr, "08"),
 289         bfd_section_name (p->bfd, p->sec_ptr));
 290     if (p->bfd != core_bfd) {
 291       printf_filtered (" in %s", bfd_get_filename (p->bfd));
 292     }
 293     printf_filtered ("\n");
 294   }
 295 }
 296 \f
 297 void
 298 memory_error (status, memaddr)
 299      int status;
 300      CORE_ADDR memaddr;
 301 {
 302
 303   if (status == EIO)
 304     {
 305       /* Actually, address between memaddr and memaddr + len
 306          was out of bounds. */
 307       error ("Cannot access memory at address %s.", local_hex_string(memaddr));
 308     }
 309   else
 310     {
 311       if (status >= sys_nerr || status < 0)
 312         error ("Error accessing memory address %s: unknown error (%d).",
 313                local_hex_string(memaddr), status);
 314       else
 315         error ("Error accessing memory address %s: %s.",
 316                local_hex_string(memaddr), sys_errlist[status]);
 317     }
 318 }
 319
 320 /* Same as target_read_memory, but report an error if can't read.  */
 321 void
 322 read_memory (memaddr, myaddr, len)
 323      CORE_ADDR memaddr;
 324      char *myaddr;
 325      int len;
 326 {
 327   int status;
 328   status = target_read_memory (memaddr, myaddr, len);
 329   if (status != 0)
 330     memory_error (status, memaddr);
 331 }
 332
 333 /* Same as target_write_memory, but report an error if can't write.  */
 334 void
 335 write_memory (memaddr, myaddr, len)
 336      CORE_ADDR memaddr;
 337      char *myaddr;
 338      int len;
 339 {
 340   int status;
 341
 342   status = target_write_memory (memaddr, myaddr, len);
 343   if (status != 0)
 344     memory_error (status, memaddr);
 345 }
 346
 347 /* Read an integer from debugged memory, given address and number of bytes.  */
 348
 349 long
 350 read_memory_integer (memaddr, len)
 351      CORE_ADDR memaddr;
 352      int len;
 353 {
 354   char cbuf;
 355   short sbuf;
 356   int ibuf;
 357   long lbuf;
 358
 359   if (len == sizeof (char))
 360     {
 361       read_memory (memaddr, &cbuf, len);
 362       return cbuf;
 363     }
 364   if (len == sizeof (short))
 365     {
 366       read_memory (memaddr, (char *)&sbuf, len);
 367       SWAP_TARGET_AND_HOST (&sbuf, sizeof (short));
 368       return sbuf;
 369     }
 370   if (len == sizeof (int))
 371     {
 372       read_memory (memaddr, (char *)&ibuf, len);
 373       SWAP_TARGET_AND_HOST (&ibuf, sizeof (int));
 374       return ibuf;
 375     }
 376   if (len == sizeof (lbuf))
 377     {
 378       read_memory (memaddr, (char *)&lbuf, len);
 379       SWAP_TARGET_AND_HOST (&lbuf, sizeof (lbuf));
 380       return lbuf;
 381     }
 382   error ("Cannot handle integers of %d bytes.", len);
 383   return -1;    /* for lint */
 384 }
 385 \f
 386 /* Get the registers out of a core file.  This is the machine-
 387    independent part.  Fetch_core_registers is the machine-dependent
 388    part, typically implemented in the xm-file for each architecture.  */
 389
 390 /* We just get all the registers, so we don't use regno.  */
 391 /* ARGSUSED */
 392 static void
 393 get_core_registers (regno)
 394      int regno;
 395 {
 396   sec_ptr reg_sec;
 397   unsigned size;
 398   char *the_regs;
 399
 400   reg_sec = bfd_get_section_by_name (core_bfd, ".reg");
 401   if (!reg_sec) goto cant;
 402   size = bfd_section_size (core_bfd, reg_sec);
 403   the_regs = alloca (size);
 404   if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size))
 405     {
 406       fetch_core_registers (the_regs, size, 0,
 407                             (unsigned) bfd_section_vma (abfd,reg_sec));
 408     }
 409   else
 410     {
 411 cant:
 412       fprintf (stderr, "Couldn't fetch registers from core file: %s\n",
 413                bfd_errmsg (bfd_error));
 414     }
 415
 416   /* Now do it again for the float registers, if they exist.  */
 417   reg_sec = bfd_get_section_by_name (core_bfd, ".reg2");
 418   if (reg_sec) {
 419     size = bfd_section_size (core_bfd, reg_sec);
 420     the_regs = alloca (size);
 421     if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0,
 422                                   size))
 423       {
 424         fetch_core_registers (the_regs, size, 2,
 425                               (unsigned) bfd_section_vma (abfd,reg_sec));
 426       }
 427     else
 428       {
 429         fprintf (stderr, "Couldn't fetch register set 2 from core file: %s\n",
 430                  bfd_errmsg (bfd_error));
 431       }
 432   }
 433   registers_fetched();
 434 }
 435 \f
 436 struct target_ops core_ops = {
 437         "core", "Local core dump file",
 438         "Use a core file as a target.  Specify the filename of the core file.",
 439         core_open, core_close,
 440         child_attach, core_detach, 0, 0, /* resume, wait */
 441         get_core_registers,
 442         0, 0, 0, 0, /* store_regs, prepare_to_store, conv_to, conv_from */
 443         xfer_memory, core_files_info,
 444         0, 0, /* core_insert_breakpoint, core_remove_breakpoint, */
 445         0, 0, 0, 0, 0, /* terminal stuff */
 446         0, 0, 0, 0, /* kill, load, call fn, lookup sym */
 447         child_create_inferior, 0, /* mourn_inferior */
 448         core_stratum, 0, /* next */
 449         0, 1, 1, 1, 0,  /* all mem, mem, stack, regs, exec */
 450         0, 0,                   /* section pointers */
 451         OPS_MAGIC,              /* Always the last thing */
 452 };
 453
 454 void
 455 _initialize_core()
 456 {
 457
 458   add_com ("core-file", class_files, core_file_command,
 459            "Use FILE as core dump for examining memory and registers.\n\
 460 No arg means have no core file.  This command has been superseded by the\n\
 461 `target core' and `detach' commands.");
 462   add_target (&core_ops);
 463 }