gdb/corelow.c

   1 /* Core dump and executable file functions below target vector, 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 #include "thread.h"
  32
  33 static void
  34 core_files_info PARAMS ((struct target_ops *));
  35
  36 #ifdef SOLIB_ADD
  37 static int
  38 solib_add_stub PARAMS ((char *));
  39 #endif
  40
  41 static void
  42 core_close PARAMS ((int));
  43
  44 static void
  45 get_core_registers PARAMS ((int));
  46
  47 /* Discard all vestiges of any previous core file
  48    and mark data and stack spaces as empty.  */
  49
  50 /* ARGSUSED */
  51 static void
  52 core_close (quitting)
  53      int quitting;
  54 {
  55   inferior_pid = 0;             /* Avoid confusion from thread stuff */
  56
  57   if (core_bfd) {
  58     free (bfd_get_filename (core_bfd));
  59     bfd_close (core_bfd);
  60     core_bfd = NULL;
  61 #ifdef CLEAR_SOLIB
  62     CLEAR_SOLIB ();
  63 #endif
  64     if (core_ops.to_sections) {
  65       free ((PTR)core_ops.to_sections);
  66       core_ops.to_sections = NULL;
  67       core_ops.to_sections_end = NULL;
  68     }
  69   }
  70 }
  71
  72 #ifdef SOLIB_ADD
  73 /* Stub function for catch_errors around shared library hacking.  FROM_TTYP
  74    is really an int * which points to from_tty.  */
  75
  76 static int
  77 solib_add_stub (from_ttyp)
  78      char *from_ttyp;
  79 {
  80     SOLIB_ADD (NULL, *(int *)from_ttyp, &core_ops);
  81     return 0;
  82 }
  83 #endif /* SOLIB_ADD */
  84
  85 /* Look for sections whose names start with `.reg/' so that we can extract the
  86    list of threads in a core file.  */
  87
  88 static void
  89 add_to_thread_list (abfd, asect, reg_sect_arg)
  90      bfd *abfd;
  91      asection *asect;
  92      PTR reg_sect_arg;
  93 {
  94   int thread_id;
  95   asection *reg_sect = (asection *) reg_sect_arg;
  96
  97   if (strncmp (bfd_section_name (abfd, asect), ".reg/", 5) != 0)
  98     return;
  99
 100   thread_id = atoi (bfd_section_name (abfd, asect) + 5);
 101
 102   add_thread (thread_id);
 103
 104 /* Warning, Will Robinson, looking at BFD private data! */
 105
 106   if (asect->filepos == reg_sect->filepos) /* Did we find .reg? */
 107     inferior_pid = thread_id;   /* Yes, make it current */
 108 }
 109
 110 /* This routine opens and sets up the core file bfd */
 111
 112 void
 113 core_open (filename, from_tty)
 114      char *filename;
 115      int from_tty;
 116 {
 117   const char *p;
 118   int siggy;
 119   struct cleanup *old_chain;
 120   char *temp;
 121   bfd *temp_bfd;
 122   int ontop;
 123   int scratch_chan;
 124
 125   target_preopen (from_tty);
 126   if (!filename)
 127     {
 128       error (core_bfd?
 129        "No core file specified.  (Use `detach' to stop debugging a core file.)"
 130      : "No core file specified.");
 131     }
 132
 133   filename = tilde_expand (filename);
 134   if (filename[0] != '/') {
 135     temp = concat (current_directory, "/", filename, NULL);
 136     free (filename);
 137     filename = temp;
 138   }
 139
 140   old_chain = make_cleanup (free, filename);
 141
 142   scratch_chan = open (filename, write_files? O_RDWR: O_RDONLY, 0);
 143   if (scratch_chan < 0)
 144     perror_with_name (filename);
 145
 146   temp_bfd = bfd_fdopenr (filename, gnutarget, scratch_chan);
 147   if (temp_bfd == NULL)
 148     {
 149       perror_with_name (filename);
 150     }
 151
 152   if (!bfd_check_format (temp_bfd, bfd_core))
 153     {
 154       /* Do it after the err msg */
 155       make_cleanup (bfd_close, temp_bfd);
 156       error ("\"%s\" is not a core dump: %s", filename, bfd_errmsg(bfd_error));
 157     }
 158
 159   /* Looks semi-reasonable.  Toss the old core file and work on the new.  */
 160
 161   discard_cleanups (old_chain);         /* Don't free filename any more */
 162   unpush_target (&core_ops);
 163   core_bfd = temp_bfd;
 164   old_chain = make_cleanup (core_close, core_bfd);
 165
 166   validate_files ();
 167
 168   /* Find the data section */
 169   if (build_section_table (core_bfd, &core_ops.to_sections,
 170                            &core_ops.to_sections_end))
 171     error ("Can't find sections in `%s': %s", bfd_get_filename(core_bfd),
 172            bfd_errmsg (bfd_error));
 173
 174   ontop = !push_target (&core_ops);
 175   discard_cleanups (old_chain);
 176
 177   p = bfd_core_file_failing_command (core_bfd);
 178   if (p)
 179     printf_filtered ("Core was generated by `%s'.\n", p);
 180
 181   siggy = bfd_core_file_failing_signal (core_bfd);
 182   if (siggy > 0)
 183     printf_filtered ("Program terminated with signal %d, %s.\n", siggy,
 184             safe_strsignal (siggy));
 185
 186   /* Build up thread list from BFD sections. */
 187
 188   init_thread_list ();
 189   bfd_map_over_sections (core_bfd, add_to_thread_list,
 190                          bfd_get_section_by_name (core_bfd, ".reg"));
 191
 192   if (ontop) {
 193     /* Fetch all registers from core file */
 194     target_fetch_registers (-1);
 195
 196     /* Add symbols and section mappings for any shared libraries */
 197 #ifdef SOLIB_ADD
 198     catch_errors (solib_add_stub, &from_tty, (char *)0,
 199                   RETURN_MASK_ALL);
 200 #endif
 201
 202     /* Now, set up the frame cache, and print the top of stack */
 203     set_current_frame (create_new_frame (read_fp (),
 204                                          read_pc ()));
 205     select_frame (get_current_frame (), 0);
 206     print_stack_frame (selected_frame, selected_frame_level, 1);
 207   } else {
 208     warning (
 209 "you won't be able to access this core file until you terminate\n\
 210 your %s; do ``info files''", current_target->to_longname);
 211   }
 212 }
 213
 214 void
 215 core_detach (args, from_tty)
 216      char *args;
 217      int from_tty;
 218 {
 219   if (args)
 220     error ("Too many arguments");
 221   unpush_target (&core_ops);
 222   reinit_frame_cache ();
 223   if (from_tty)
 224     printf_filtered ("No core file now.\n");
 225 }
 226
 227 /* Get the registers out of a core file.  This is the machine-
 228    independent part.  Fetch_core_registers is the machine-dependent
 229    part, typically implemented in the xm-file for each architecture.  */
 230
 231 /* We just get all the registers, so we don't use regno.  */
 232 /* ARGSUSED */
 233 static void
 234 get_core_registers (regno)
 235      int regno;
 236 {
 237   sec_ptr reg_sec;
 238   unsigned size;
 239   char *the_regs;
 240   char secname[10];
 241
 242   /* Thread support.  If inferior_pid is non-zero, then we have found a core
 243      file with threads (or multiple processes).  In that case, we need to
 244      use the appropriate register section, else we just use `.reg'. */
 245
 246   /* XXX - same thing needs to be done for floating-point (.reg2) sections. */
 247
 248   if (inferior_pid)
 249     sprintf (secname, ".reg/%d", inferior_pid);
 250   else
 251     strcpy (secname, ".reg");
 252
 253   reg_sec = bfd_get_section_by_name (core_bfd, secname);
 254   if (!reg_sec) goto cant;
 255   size = bfd_section_size (core_bfd, reg_sec);
 256   the_regs = alloca (size);
 257   if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size))
 258     {
 259       fetch_core_registers (the_regs, size, 0,
 260                             (unsigned) bfd_section_vma (abfd,reg_sec));
 261     }
 262   else
 263     {
 264 cant:
 265       fprintf_filtered (gdb_stderr, "Couldn't fetch registers from core file: %s\n",
 266                bfd_errmsg (bfd_error));
 267     }
 268
 269   /* Now do it again for the float registers, if they exist.  */
 270   reg_sec = bfd_get_section_by_name (core_bfd, ".reg2");
 271   if (reg_sec) {
 272     size = bfd_section_size (core_bfd, reg_sec);
 273     the_regs = alloca (size);
 274     if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0,
 275                                   size))
 276       {
 277         fetch_core_registers (the_regs, size, 2,
 278                               (unsigned) bfd_section_vma (abfd,reg_sec));
 279       }
 280     else
 281       {
 282         fprintf_filtered (gdb_stderr, "Couldn't fetch register set 2 from core file: %s\n",
 283                  bfd_errmsg (bfd_error));
 284       }
 285   }
 286   registers_fetched();
 287 }
 288
 289 static void
 290 core_files_info (t)
 291   struct target_ops *t;
 292 {
 293   print_section_info (t, core_bfd);
 294 }
 295 \f
 296 /* If mourn is being called in all the right places, this could be say
 297    `gdb internal error' (since generic_mourn calls breakpoint_init_inferior).  */
 298
 299 static int
 300 ignore (addr, contents)
 301      CORE_ADDR addr;
 302      char *contents;
 303 {
 304   return 0;
 305 }
 306
 307 struct target_ops core_ops = {
 308         "core", "Local core dump file",
 309         "Use a core file as a target.  Specify the filename of the core file.",
 310         core_open, core_close,
 311         find_default_attach, core_detach, 0, 0, /* resume, wait */
 312         get_core_registers,
 313         0, 0, /* store_regs, prepare_to_store */
 314         xfer_memory, core_files_info,
 315         ignore, ignore, /* core_insert_breakpoint, core_remove_breakpoint, */
 316         0, 0, 0, 0, 0, /* terminal stuff */
 317         0, 0, 0, /* kill, load, lookup sym */
 318         find_default_create_inferior, 0, /* mourn_inferior */
 319         0, /* can_run */
 320         0, /* notice_signals */
 321         core_stratum, 0, /* next */
 322         0, 1, 1, 1, 0,  /* all mem, mem, stack, regs, exec */
 323         0, 0,                   /* section pointers */
 324         OPS_MAGIC,              /* Always the last thing */
 325 };
 326
 327 void
 328 _initialize_corelow()
 329 {
 330   add_target (&core_ops);
 331 }