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