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