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   re_enable_breakpoints_in_shlibs ();
 111   return 0;
 112 }
 113 #endif /* SOLIB_ADD */
 114
 115 /* Look for sections whose names start with `.reg/' so that we can extract the
 116    list of threads in a core file.  */
 117
 118 static void
 119 add_to_thread_list (abfd, asect, reg_sect_arg)
 120      bfd *abfd;
 121      asection *asect;
 122      PTR reg_sect_arg;
 123 {
 124   int thread_id;
 125   asection *reg_sect = (asection *) reg_sect_arg;
 126
 127   if (strncmp (bfd_section_name (abfd, asect), ".reg/", 5) != 0)
 128     return;
 129
 130   thread_id = atoi (bfd_section_name (abfd, asect) + 5);
 131
 132   add_thread (thread_id);
 133
 134 /* Warning, Will Robinson, looking at BFD private data! */
 135
 136   if (reg_sect != NULL
 137       && asect->filepos == reg_sect->filepos) /* Did we find .reg? */
 138     inferior_pid = thread_id;   /* Yes, make it current */
 139 }
 140
 141 /* This routine opens and sets up the core file bfd.  */
 142
 143 static void
 144 core_open (filename, from_tty)
 145      char *filename;
 146      int from_tty;
 147 {
 148   const char *p;
 149   int siggy;
 150   struct cleanup *old_chain;
 151   char *temp;
 152   bfd *temp_bfd;
 153   int ontop;
 154   int scratch_chan;
 155
 156   target_preopen (from_tty);
 157   if (!filename)
 158     {
 159       error (core_bfd ?
 160        "No core file specified.  (Use `detach' to stop debugging a core file.)"
 161      : "No core file specified.");
 162     }
 163
 164   filename = tilde_expand (filename);
 165   if (filename[0] != '/')
 166     {
 167       temp = concat (current_directory, "/", filename, NULL);
 168       free (filename);
 169       filename = temp;
 170     }
 171
 172   old_chain = make_cleanup (free, filename);
 173
 174   scratch_chan = open (filename, write_files ? O_RDWR : O_RDONLY, 0);
 175   if (scratch_chan < 0)
 176     perror_with_name (filename);
 177
 178   temp_bfd = bfd_fdopenr (filename, gnutarget, scratch_chan);
 179   if (temp_bfd == NULL)
 180     perror_with_name (filename);
 181
 182   if (!bfd_check_format (temp_bfd, bfd_core))
 183     {
 184       /* Do it after the err msg */
 185       /* FIXME: should be checking for errors from bfd_close (for one thing,
 186          on error it does not free all the storage associated with the
 187          bfd).  */
 188       make_cleanup (bfd_close, temp_bfd);
 189       error ("\"%s\" is not a core dump: %s",
 190              filename, bfd_errmsg (bfd_get_error ()));
 191     }
 192
 193   /* Looks semi-reasonable.  Toss the old core file and work on the new.  */
 194
 195   discard_cleanups (old_chain);         /* Don't free filename any more */
 196   unpush_target (&core_ops);
 197   core_bfd = temp_bfd;
 198   old_chain = make_cleanup (core_close, core_bfd);
 199
 200   validate_files ();
 201
 202   /* Find the data section */
 203   if (build_section_table (core_bfd, &core_ops.to_sections,
 204                            &core_ops.to_sections_end))
 205     error ("\"%s\": Can't find sections: %s",
 206            bfd_get_filename (core_bfd), bfd_errmsg (bfd_get_error ()));
 207
 208   ontop = !push_target (&core_ops);
 209   discard_cleanups (old_chain);
 210
 211   p = bfd_core_file_failing_command (core_bfd);
 212   if (p)
 213     printf_filtered ("Core was generated by `%s'.\n", p);
 214
 215   siggy = bfd_core_file_failing_signal (core_bfd);
 216   if (siggy > 0)
 217     printf_filtered ("Program terminated with signal %d, %s.\n", siggy,
 218                      safe_strsignal (siggy));
 219
 220   /* Build up thread list from BFD sections. */
 221
 222   init_thread_list ();
 223   bfd_map_over_sections (core_bfd, add_to_thread_list,
 224                          bfd_get_section_by_name (core_bfd, ".reg"));
 225
 226   if (ontop)
 227     {
 228       /* Fetch all registers from core file.  */
 229       target_fetch_registers (-1);
 230
 231       /* Add symbols and section mappings for any shared libraries.  */
 232 #ifdef SOLIB_ADD
 233       catch_errors (solib_add_stub, &from_tty, (char *)0,
 234                     RETURN_MASK_ALL);
 235 #endif
 236
 237       /* Now, set up the frame cache, and print the top of stack.  */
 238       flush_cached_frames ();
 239       select_frame (get_current_frame (), 0);
 240       print_stack_frame (selected_frame, selected_frame_level, 1);
 241     }
 242   else
 243     {
 244       warning (
 245 "you won't be able to access this core file until you terminate\n\
 246 your %s; do ``info files''", target_longname);
 247     }
 248 }
 249
 250 static void
 251 core_detach (args, from_tty)
 252      char *args;
 253      int from_tty;
 254 {
 255   if (args)
 256     error ("Too many arguments");
 257   unpush_target (&core_ops);
 258   reinit_frame_cache ();
 259   if (from_tty)
 260     printf_filtered ("No core file now.\n");
 261 }
 262
 263 /* Get the registers out of a core file.  This is the machine-
 264    independent part.  Fetch_core_registers is the machine-dependent
 265    part, typically implemented in the xm-file for each architecture.  */
 266
 267 /* We just get all the registers, so we don't use regno.  */
 268
 269 /* ARGSUSED */
 270 static void
 271 get_core_registers (regno)
 272      int regno;
 273 {
 274   sec_ptr reg_sec;
 275   unsigned size;
 276   char *the_regs;
 277   char secname[10];
 278   enum bfd_flavour our_flavour = bfd_get_flavour (core_bfd);
 279   struct core_fns *cf;
 280
 281   if (core_file_fns == NULL)
 282     {
 283       fprintf_filtered (gdb_stderr,
 284                         "Can't fetch registers from this type of core file\n");
 285       return;
 286     }
 287
 288   /* Thread support.  If inferior_pid is non-zero, then we have found a core
 289      file with threads (or multiple processes).  In that case, we need to
 290      use the appropriate register section, else we just use `.reg'. */
 291
 292   /* XXX - same thing needs to be done for floating-point (.reg2) sections. */
 293
 294   if (inferior_pid)
 295     sprintf (secname, ".reg/%d", inferior_pid);
 296   else
 297     strcpy (secname, ".reg");
 298
 299   reg_sec = bfd_get_section_by_name (core_bfd, secname);
 300   if (!reg_sec)
 301     goto cant;
 302   size = bfd_section_size (core_bfd, reg_sec);
 303   the_regs = alloca (size);
 304   /* Look for the core functions that match this flavor.  Default to the
 305      first one if nothing matches. */
 306   for (cf = core_file_fns; cf != NULL; cf = cf -> next)
 307     {
 308       if (our_flavour == cf -> core_flavour)
 309         {
 310           break;
 311         }
 312     }
 313   if (cf == NULL)
 314     {
 315       cf = core_file_fns;
 316     }
 317   if (cf != NULL &&
 318       bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size) &&
 319       cf -> core_read_registers != NULL)
 320     {
 321       (cf -> core_read_registers (the_regs, size, 0,
 322                                   (unsigned) bfd_section_vma (abfd,reg_sec)));
 323     }
 324   else
 325     {
 326 cant:
 327       fprintf_filtered (gdb_stderr,
 328                         "Couldn't fetch registers from core file: %s\n",
 329                         bfd_errmsg (bfd_get_error ()));
 330     }
 331
 332   /* Now do it again for the float registers, if they exist.  */
 333   reg_sec = bfd_get_section_by_name (core_bfd, ".reg2");
 334   if (reg_sec)
 335     {
 336       size = bfd_section_size (core_bfd, reg_sec);
 337       the_regs = alloca (size);
 338       if (cf != NULL &&
 339           bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size) &&
 340           cf -> core_read_registers != NULL)
 341         {
 342           (cf -> core_read_registers (the_regs, size, 2,
 343                                       (unsigned) bfd_section_vma (abfd,reg_sec)));
 344         }
 345       else
 346         {
 347           fprintf_filtered (gdb_stderr,
 348                             "Couldn't fetch register set 2 from core file: %s\n",
 349                             bfd_errmsg (bfd_get_error ()));
 350         }
 351     }
 352   registers_fetched ();
 353 }
 354
 355 static void
 356 core_files_info (t)
 357   struct target_ops *t;
 358 {
 359   print_section_info (t, core_bfd);
 360 }
 361 \f
 362 /* If mourn is being called in all the right places, this could be say
 363    `gdb internal error' (since generic_mourn calls breakpoint_init_inferior).  */
 364
 365 static int
 366 ignore (addr, contents)
 367      CORE_ADDR addr;
 368      char *contents;
 369 {
 370   return 0;
 371 }
 372
 373 struct target_ops core_ops = {
 374   "core",                       /* to_shortname */
 375   "Local core dump file",       /* to_longname */
 376   "Use a core file as a target.  Specify the filename of the core file.", /* to_doc */
 377   core_open,                    /* to_open */
 378   core_close,                   /* to_close */
 379   find_default_attach,          /* to_attach */
 380   core_detach,                  /* to_detach */
 381   0,                            /* to_resume */
 382   0,                            /* to_wait */
 383   get_core_registers,           /* to_fetch_registers */
 384   0,                            /* to_store_registers */
 385   0,                            /* to_prepare_to_store */
 386   xfer_memory,                  /* to_xfer_memory */
 387   core_files_info,              /* to_files_info */
 388   ignore,                       /* to_insert_breakpoint */
 389   ignore,                       /* to_remove_breakpoint */
 390   0,                            /* to_terminal_init */
 391   0,                            /* to_terminal_inferior */
 392   0,                            /* to_terminal_ours_for_output */
 393   0,                            /* to_terminal_ours */
 394   0,                            /* to_terminal_info */
 395   0,                            /* to_kill */
 396   0,                            /* to_load */
 397   0,                            /* to_lookup_symbol */
 398   find_default_create_inferior, /* to_create_inferior */
 399   0,                            /* to_mourn_inferior */
 400   0,                            /* to_can_run */
 401   0,                            /* to_notice_signals */
 402   0,                            /* to_thread_alive */
 403   0,                            /* to_stop */
 404   core_stratum,                 /* to_stratum */
 405   0,                            /* to_next */
 406   0,                            /* to_has_all_memory */
 407   1,                            /* to_has_memory */
 408   1,                            /* to_has_stack */
 409   1,                            /* to_has_registers */
 410   0,                            /* to_has_execution */
 411   0,                            /* to_sections */
 412   0,                            /* to_sections_end */
 413   OPS_MAGIC,                    /* to_magic */
 414 };
 415
 416 void
 417 _initialize_corelow()
 418 {
 419   add_target (&core_ops);
 420 }