gdb/corelow.c

   1 /* Core dump and executable file functions below target vector, for GDB.
   2    Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1995
   3    Free Software Foundation, Inc.
   4
   5 This file is part of GDB.
   6
   7 This program is free software; you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation; either version 2 of the License, or
  10 (at your option) any later version.
  11
  12 This program is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with this program; if not, write to the Free Software
  19 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  20
  21 #include "defs.h"
  22 #include "gdb_string.h"
  23 #include <errno.h>
  24 #include <signal.h>
  25 #include <fcntl.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 #include "thread.h"
  34
  35 /* List of all available core_fns.  On gdb startup, each core file register
  36    reader calls add_core_fns() to register information on each core format it
  37    is prepared to read. */
  38
  39 static struct core_fns *core_file_fns = NULL;
  40
  41 static void core_files_info PARAMS ((struct target_ops *));
  42
  43 #ifdef SOLIB_ADD
  44 static int solib_add_stub PARAMS ((char *));
  45 #endif
  46
  47 static void core_open PARAMS ((char *, int));
  48
  49 static void core_detach PARAMS ((char *, int));
  50
  51 static void core_close PARAMS ((int));
  52
  53 static void get_core_registers PARAMS ((int));
  54
  55 /* Link a new core_fns into the global core_file_fns list.  Called on gdb
  56    startup by the _initialize routine in each core file register reader, to
  57    register information about each format the the reader is prepared to
  58    handle. */
  59
  60 void
  61 add_core_fns (cf)
  62      struct core_fns *cf;
  63 {
  64   cf -> next = core_file_fns;
  65   core_file_fns = cf;
  66 }
  67
  68
  69 /* Discard all vestiges of any previous core file and mark data and stack
  70    spaces as empty.  */
  71
  72 /* ARGSUSED */
  73 static void
  74 core_close (quitting)
  75      int quitting;
  76 {
  77   char *name;
  78
  79   inferior_pid = 0;             /* Avoid confusion from thread stuff */
  80
  81   if (core_bfd)
  82     {
  83       name = bfd_get_filename (core_bfd);
  84       if (!bfd_close (core_bfd))
  85         warning ("cannot close \"%s\": %s",
  86                  name, bfd_errmsg (bfd_get_error ()));
  87       free (name);
  88       core_bfd = NULL;
  89 #ifdef CLEAR_SOLIB
  90       CLEAR_SOLIB ();
  91 #endif
  92       if (core_ops.to_sections)
  93         {
  94           free ((PTR)core_ops.to_sections);
  95           core_ops.to_sections = NULL;
  96           core_ops.to_sections_end = NULL;
  97         }
  98     }
  99 }
 100
 101 #ifdef SOLIB_ADD
 102 /* Stub function for catch_errors around shared library hacking.  FROM_TTYP
 103    is really an int * which points to from_tty.  */
 104
 105 static int
 106 solib_add_stub (from_ttyp)
 107      char *from_ttyp;
 108 {
 109   SOLIB_ADD (NULL, *(int *)from_ttyp, &current_target);
 110   return 0;
 111 }
 112 #endif /* SOLIB_ADD */
 113
 114 /* Look for sections whose names start with `.reg/' so that we can extract the
 115    list of threads in a core file.  */
 116
 117 static void
 118 add_to_thread_list (abfd, asect, reg_sect_arg)
 119      bfd *abfd;
 120      asection *asect;
 121      PTR reg_sect_arg;
 122 {
 123   int thread_id;
 124   asection *reg_sect = (asection *) reg_sect_arg;
 125
 126   if (strncmp (bfd_section_name (abfd, asect), ".reg/", 5) != 0)
 127     return;
 128
 129   thread_id = atoi (bfd_section_name (abfd, asect) + 5);
 130
 131   add_thread (thread_id);
 132
 133 /* Warning, Will Robinson, looking at BFD private data! */
 134
 135   if (asect->filepos == reg_sect->filepos) /* Did we find .reg? */
 136     inferior_pid = thread_id;   /* Yes, make it current */
 137 }
 138
 139 /* This routine opens and sets up the core file bfd.  */
 140
 141 static void
 142 core_open (filename, from_tty)
 143      char *filename;
 144      int from_tty;
 145 {
 146   const char *p;
 147   int siggy;
 148   struct cleanup *old_chain;
 149   char *temp;
 150   bfd *temp_bfd;
 151   int ontop;
 152   int scratch_chan;
 153
 154   target_preopen (from_tty);
 155   if (!filename)
 156     {
 157       error (core_bfd ?
 158        "No core file specified.  (Use `detach' to stop debugging a core file.)"
 159      : "No core file specified.");
 160     }
 161
 162   filename = tilde_expand (filename);
 163   if (filename[0] != '/')
 164     {
 165       temp = concat (current_directory, "/", filename, NULL);
 166       free (filename);
 167       filename = temp;
 168     }
 169
 170   old_chain = make_cleanup (free, filename);
 171
 172   scratch_chan = open (filename, write_files ? O_RDWR : O_RDONLY, 0);
 173   if (scratch_chan < 0)
 174     perror_with_name (filename);
 175
 176   temp_bfd = bfd_fdopenr (filename, gnutarget, scratch_chan);
 177   if (temp_bfd == NULL)
 178     perror_with_name (filename);
 179
 180   if (!bfd_check_format (temp_bfd, bfd_core))
 181     {
 182       /* Do it after the err msg */
 183       /* FIXME: should be checking for errors from bfd_close (for one thing,
 184          on error it does not free all the storage associated with the
 185          bfd).  */
 186       make_cleanup (bfd_close, temp_bfd);
 187       error ("\"%s\" is not a core dump: %s",
 188              filename, bfd_errmsg (bfd_get_error ()));
 189     }
 190
 191   /* Looks semi-reasonable.  Toss the old core file and work on the new.  */
 192
 193   discard_cleanups (old_chain);         /* Don't free filename any more */
 194   unpush_target (&core_ops);
 195   core_bfd = temp_bfd;
 196   old_chain = make_cleanup (core_close, core_bfd);
 197
 198   validate_files ();
 199
 200   /* Find the data section */
 201   if (build_section_table (core_bfd, &core_ops.to_sections,
 202                            &core_ops.to_sections_end))
 203     error ("\"%s\": Can't find sections: %s",
 204            bfd_get_filename (core_bfd), bfd_errmsg (bfd_get_error ()));
 205
 206   ontop = !push_target (&core_ops);
 207   discard_cleanups (old_chain);
 208
 209   p = bfd_core_file_failing_command (core_bfd);
 210   if (p)
 211     printf_filtered ("Core was generated by `%s'.\n", p);
 212
 213   siggy = bfd_core_file_failing_signal (core_bfd);
 214   if (siggy > 0)
 215     printf_filtered ("Program terminated with signal %d, %s.\n", siggy,
 216                      safe_strsignal (siggy));
 217
 218   /* Build up thread list from BFD sections. */
 219
 220   init_thread_list ();
 221   bfd_map_over_sections (core_bfd, add_to_thread_list,
 222                          bfd_get_section_by_name (core_bfd, ".reg"));
 223
 224   if (ontop)
 225     {
 226       /* Fetch all registers from core file.  */
 227       target_fetch_registers (-1);
 228
 229       /* Add symbols and section mappings for any shared libraries.  */
 230 #ifdef SOLIB_ADD
 231       catch_errors (solib_add_stub, &from_tty, (char *)0,
 232                     RETURN_MASK_ALL);
 233 #endif
 234
 235       /* Now, set up the frame cache, and print the top of stack.  */
 236       flush_cached_frames ();
 237       select_frame (get_current_frame (), 0);
 238       print_stack_frame (selected_frame, selected_frame_level, 1);
 239     }
 240   else
 241     {
 242       warning (
 243 "you won't be able to access this core file until you terminate\n\
 244 your %s; do ``info files''", target_longname);
 245     }
 246 }
 247
 248 static void
 249 core_detach (args, from_tty)
 250      char *args;
 251      int from_tty;
 252 {
 253   if (args)
 254     error ("Too many arguments");
 255   unpush_target (&core_ops);
 256   reinit_frame_cache ();
 257   if (from_tty)
 258     printf_filtered ("No core file now.\n");
 259 }
 260
 261 /* Get the registers out of a core file.  This is the machine-
 262    independent part.  Fetch_core_registers is the machine-dependent
 263    part, typically implemented in the xm-file for each architecture.  */
 264
 265 /* We just get all the registers, so we don't use regno.  */
 266
 267 /* ARGSUSED */
 268 static void
 269 get_core_registers (regno)
 270      int regno;
 271 {
 272   sec_ptr reg_sec;
 273   unsigned size;
 274   char *the_regs;
 275   char secname[10];
 276   enum bfd_flavour our_flavour = bfd_get_flavour (core_bfd);
 277   struct core_fns *cf;
 278
 279   if (core_file_fns == NULL)
 280     {
 281       fprintf_filtered (gdb_stderr,
 282                         "Can't fetch registers from this type of core file\n");
 283       return;
 284     }
 285
 286   /* Thread support.  If inferior_pid is non-zero, then we have found a core
 287      file with threads (or multiple processes).  In that case, we need to
 288      use the appropriate register section, else we just use `.reg'. */
 289
 290   /* XXX - same thing needs to be done for floating-point (.reg2) sections. */
 291
 292   if (inferior_pid)
 293     sprintf (secname, ".reg/%d", inferior_pid);
 294   else
 295     strcpy (secname, ".reg");
 296
 297   reg_sec = bfd_get_section_by_name (core_bfd, secname);
 298   if (!reg_sec)
 299     goto cant;
 300   size = bfd_section_size (core_bfd, reg_sec);
 301   the_regs = alloca (size);
 302   /* Look for the core functions that match this flavor.  Default to the
 303      first one if nothing matches. */
 304   for (cf = core_file_fns; cf != NULL; cf = cf -> next)
 305     {
 306       if (our_flavour == cf -> core_flavour)
 307         {
 308           break;
 309         }
 310     }
 311   if (cf == NULL)
 312     {
 313       cf = core_file_fns;
 314     }
 315   if (cf != NULL &&
 316       bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size) &&
 317       cf -> core_read_registers != NULL)
 318     {
 319       (cf -> core_read_registers (the_regs, size, 0,
 320                                   (unsigned) bfd_section_vma (abfd,reg_sec)));
 321     }
 322   else
 323     {
 324 cant:
 325       fprintf_filtered (gdb_stderr,
 326                         "Couldn't fetch registers from core file: %s\n",
 327                         bfd_errmsg (bfd_get_error ()));
 328     }
 329
 330   /* Now do it again for the float registers, if they exist.  */
 331   reg_sec = bfd_get_section_by_name (core_bfd, ".reg2");
 332   if (reg_sec)
 333     {
 334       size = bfd_section_size (core_bfd, reg_sec);
 335       the_regs = alloca (size);
 336       if (cf != NULL &&
 337           bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size) &&
 338           cf -> core_read_registers != NULL)
 339         {
 340           (cf -> core_read_registers (the_regs, size, 2,
 341                                       (unsigned) bfd_section_vma (abfd,reg_sec)));
 342         }
 343       else
 344         {
 345           fprintf_filtered (gdb_stderr,
 346                             "Couldn't fetch register set 2 from core file: %s\n",
 347                             bfd_errmsg (bfd_get_error ()));
 348         }
 349     }
 350   registers_fetched ();
 351 }
 352
 353 static void
 354 core_files_info (t)
 355   struct target_ops *t;
 356 {
 357   print_section_info (t, core_bfd);
 358 }
 359 \f
 360 /* If mourn is being called in all the right places, this could be say
 361    `gdb internal error' (since generic_mourn calls breakpoint_init_inferior).  */
 362
 363 static int
 364 ignore (addr, contents)
 365      CORE_ADDR addr;
 366      char *contents;
 367 {
 368   return 0;
 369 }
 370
 371 struct target_ops core_ops = {
 372   "core",                       /* to_shortname */
 373   "Local core dump file",       /* to_longname */
 374   "Use a core file as a target.  Specify the filename of the core file.", /* to_doc */
 375   core_open,                    /* to_open */
 376   core_close,                   /* to_close */
 377   find_default_attach,          /* to_attach */
 378   core_detach,                  /* to_detach */
 379   0,                            /* to_resume */
 380   0,                            /* to_wait */
 381   get_core_registers,           /* to_fetch_registers */
 382   0,                            /* to_store_registers */
 383   0,                            /* to_prepare_to_store */
 384   xfer_memory,                  /* to_xfer_memory */
 385   core_files_info,              /* to_files_info */
 386   ignore,                       /* to_insert_breakpoint */
 387   ignore,                       /* to_remove_breakpoint */
 388   0,                            /* to_terminal_init */
 389   0,                            /* to_terminal_inferior */
 390   0,                            /* to_terminal_ours_for_output */
 391   0,                            /* to_terminal_ours */
 392   0,                            /* to_terminal_info */
 393   0,                            /* to_kill */
 394   0,                            /* to_load */
 395   0,                            /* to_lookup_symbol */
 396   find_default_create_inferior, /* to_create_inferior */
 397   0,                            /* to_mourn_inferior */
 398   0,                            /* to_can_run */
 399   0,                            /* to_notice_signals */
 400   0,                            /* to_thread_alive */
 401   0,                            /* to_stop */
 402   core_stratum,                 /* to_stratum */
 403   0,                            /* to_next */
 404   0,                            /* to_has_all_memory */
 405   1,                            /* to_has_memory */
 406   1,                            /* to_has_stack */
 407   1,                            /* to_has_registers */
 408   0,                            /* to_has_execution */
 409   0,                            /* to_sections */
 410   0,                            /* to_sections_end */
 411   OPS_MAGIC,                    /* to_magic */
 412 };
 413
 414 void
 415 _initialize_corelow()
 416 {
 417   add_target (&core_ops);
 418 }