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