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