gdb/corelow.c

   1 /* Core dump and executable file functions below target vector, for GDB.
   2    Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994
   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., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  20
  21 #include "defs.h"
  22 #include <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 static void core_files_info PARAMS ((struct target_ops *));
  36
  37 #ifdef SOLIB_ADD
  38 static int solib_add_stub PARAMS ((char *));
  39 #endif
  40
  41 static void core_close PARAMS ((int));
  42
  43 static void get_core_registers PARAMS ((int));
  44
  45 /* Discard all vestiges of any previous core file and mark data and stack
  46    spaces as empty.  */
  47
  48 /* ARGSUSED */
  49 static void
  50 core_close (quitting)
  51      int quitting;
  52 {
  53   char *name;
  54
  55   inferior_pid = 0;             /* Avoid confusion from thread stuff */
  56
  57   if (core_bfd)
  58     {
  59       name = bfd_get_filename (core_bfd);
  60       if (!bfd_close (core_bfd))
  61         warning ("cannot close \"%s\": %s",
  62                  name, bfd_errmsg (bfd_get_error ()));
  63       free (name);
  64       core_bfd = NULL;
  65 #ifdef CLEAR_SOLIB
  66       CLEAR_SOLIB ();
  67 #endif
  68       if (core_ops.to_sections)
  69         {
  70           free ((PTR)core_ops.to_sections);
  71           core_ops.to_sections = NULL;
  72           core_ops.to_sections_end = NULL;
  73         }
  74     }
  75 }
  76
  77 #ifdef SOLIB_ADD
  78 /* Stub function for catch_errors around shared library hacking.  FROM_TTYP
  79    is really an int * which points to from_tty.  */
  80
  81 static int
  82 solib_add_stub (from_ttyp)
  83      char *from_ttyp;
  84 {
  85   SOLIB_ADD (NULL, *(int *)from_ttyp, &current_target);
  86   return 0;
  87 }
  88 #endif /* SOLIB_ADD */
  89
  90 /* Look for sections whose names start with `.reg/' so that we can extract the
  91    list of threads in a core file.  */
  92
  93 static void
  94 add_to_thread_list (abfd, asect, reg_sect_arg)
  95      bfd *abfd;
  96      asection *asect;
  97      PTR reg_sect_arg;
  98 {
  99   int thread_id;
 100   asection *reg_sect = (asection *) reg_sect_arg;
 101
 102   if (strncmp (bfd_section_name (abfd, asect), ".reg/", 5) != 0)
 103     return;
 104
 105   thread_id = atoi (bfd_section_name (abfd, asect) + 5);
 106
 107   add_thread (thread_id);
 108
 109 /* Warning, Will Robinson, looking at BFD private data! */
 110
 111   if (asect->filepos == reg_sect->filepos) /* Did we find .reg? */
 112     inferior_pid = thread_id;   /* Yes, make it current */
 113 }
 114
 115 /* This routine opens and sets up the core file bfd.  */
 116
 117 void
 118 core_open (filename, from_tty)
 119      char *filename;
 120      int from_tty;
 121 {
 122   const char *p;
 123   int siggy;
 124   struct cleanup *old_chain;
 125   char *temp;
 126   bfd *temp_bfd;
 127   int ontop;
 128   int scratch_chan;
 129
 130   target_preopen (from_tty);
 131   if (!filename)
 132     {
 133       error (core_bfd ?
 134        "No core file specified.  (Use `detach' to stop debugging a core file.)"
 135      : "No core file specified.");
 136     }
 137
 138   filename = tilde_expand (filename);
 139   if (filename[0] != '/')
 140     {
 141       temp = concat (current_directory, "/", filename, NULL);
 142       free (filename);
 143       filename = temp;
 144     }
 145
 146   old_chain = make_cleanup (free, filename);
 147
 148   scratch_chan = open (filename, write_files ? O_RDWR : O_RDONLY, 0);
 149   if (scratch_chan < 0)
 150     perror_with_name (filename);
 151
 152   temp_bfd = bfd_fdopenr (filename, gnutarget, scratch_chan);
 153   if (temp_bfd == NULL)
 154     perror_with_name (filename);
 155
 156   if (!bfd_check_format (temp_bfd, bfd_core))
 157     {
 158       /* Do it after the err msg */
 159       /* FIXME: should be checking for errors from bfd_close (for one thing,
 160          on error it does not free all the storage associated with the
 161          bfd).  */
 162       make_cleanup (bfd_close, temp_bfd);
 163       error ("\"%s\" is not a core dump: %s",
 164              filename, bfd_errmsg (bfd_get_error ()));
 165     }
 166
 167   /* Looks semi-reasonable.  Toss the old core file and work on the new.  */
 168
 169   discard_cleanups (old_chain);         /* Don't free filename any more */
 170   unpush_target (&core_ops);
 171   core_bfd = temp_bfd;
 172   old_chain = make_cleanup (core_close, core_bfd);
 173
 174   validate_files ();
 175
 176   /* Find the data section */
 177   if (build_section_table (core_bfd, &core_ops.to_sections,
 178                            &core_ops.to_sections_end))
 179     error ("\"%s\": Can't find sections: %s",
 180            bfd_get_filename (core_bfd), bfd_errmsg (bfd_get_error ()));
 181
 182   ontop = !push_target (&core_ops);
 183   discard_cleanups (old_chain);
 184
 185   p = bfd_core_file_failing_command (core_bfd);
 186   if (p)
 187     printf_filtered ("Core was generated by `%s'.\n", p);
 188
 189   siggy = bfd_core_file_failing_signal (core_bfd);
 190   if (siggy > 0)
 191     printf_filtered ("Program terminated with signal %d, %s.\n", siggy,
 192                      safe_strsignal (siggy));
 193
 194   /* Build up thread list from BFD sections. */
 195
 196   init_thread_list ();
 197   bfd_map_over_sections (core_bfd, add_to_thread_list,
 198                          bfd_get_section_by_name (core_bfd, ".reg"));
 199
 200   if (ontop)
 201     {
 202       /* Fetch all registers from core file.  */
 203       target_fetch_registers (-1);
 204
 205       /* Add symbols and section mappings for any shared libraries.  */
 206 #ifdef SOLIB_ADD
 207       catch_errors (solib_add_stub, &from_tty, (char *)0,
 208                     RETURN_MASK_ALL);
 209
 210       /* solib_add_stub usually modifies current_target.to_sections, which
 211          has to be reflected in core_ops to enable proper freeing of
 212          the to_sections vector in core_close and correct section
 213          mapping in xfer_memory and core_files_info.  */
 214       core_ops.to_sections = current_target.to_sections;
 215       core_ops.to_sections_end = current_target.to_sections_end;
 216 #endif
 217
 218       /* Now, set up the frame cache, and print the top of stack.  */
 219       flush_cached_frames ();
 220       select_frame (get_current_frame (), 0);
 221       print_stack_frame (selected_frame, selected_frame_level, 1);
 222     }
 223   else
 224     {
 225       warning (
 226 "you won't be able to access this core file until you terminate\n\
 227 your %s; do ``info files''", target_longname);
 228     }
 229 }
 230
 231 void
 232 core_detach (args, from_tty)
 233      char *args;
 234      int from_tty;
 235 {
 236   if (args)
 237     error ("Too many arguments");
 238   unpush_target (&core_ops);
 239   reinit_frame_cache ();
 240   if (from_tty)
 241     printf_filtered ("No core file now.\n");
 242 }
 243
 244 /* Get the registers out of a core file.  This is the machine-
 245    independent part.  Fetch_core_registers is the machine-dependent
 246    part, typically implemented in the xm-file for each architecture.  */
 247
 248 /* We just get all the registers, so we don't use regno.  */
 249
 250 /* ARGSUSED */
 251 static void
 252 get_core_registers (regno)
 253      int regno;
 254 {
 255   sec_ptr reg_sec;
 256   unsigned size;
 257   char *the_regs;
 258   char secname[10];
 259
 260   /* Thread support.  If inferior_pid is non-zero, then we have found a core
 261      file with threads (or multiple processes).  In that case, we need to
 262      use the appropriate register section, else we just use `.reg'. */
 263
 264   /* XXX - same thing needs to be done for floating-point (.reg2) sections. */
 265
 266   if (inferior_pid)
 267     sprintf (secname, ".reg/%d", inferior_pid);
 268   else
 269     strcpy (secname, ".reg");
 270
 271   reg_sec = bfd_get_section_by_name (core_bfd, secname);
 272   if (!reg_sec)
 273     goto cant;
 274   size = bfd_section_size (core_bfd, reg_sec);
 275   the_regs = alloca (size);
 276   if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size))
 277     {
 278       fetch_core_registers (the_regs, size, 0,
 279                             (unsigned) bfd_section_vma (abfd,reg_sec));
 280     }
 281   else
 282     {
 283 cant:
 284       fprintf_filtered (gdb_stderr,
 285                         "Couldn't fetch registers from core file: %s\n",
 286                         bfd_errmsg (bfd_get_error ()));
 287     }
 288
 289   /* Now do it again for the float registers, if they exist.  */
 290   reg_sec = bfd_get_section_by_name (core_bfd, ".reg2");
 291   if (reg_sec)
 292     {
 293       size = bfd_section_size (core_bfd, reg_sec);
 294       the_regs = alloca (size);
 295       if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0,
 296                                     size))
 297         {
 298           fetch_core_registers (the_regs, size, 2,
 299                                 (unsigned) bfd_section_vma (abfd,reg_sec));
 300         }
 301       else
 302         {
 303           fprintf_filtered (gdb_stderr,
 304                             "Couldn't fetch register set 2 from core file: %s\n",
 305                             bfd_errmsg (bfd_get_error ()));
 306         }
 307     }
 308   registers_fetched ();
 309 }
 310
 311 static void
 312 core_files_info (t)
 313   struct target_ops *t;
 314 {
 315   print_section_info (t, core_bfd);
 316 }
 317 \f
 318 /* If mourn is being called in all the right places, this could be say
 319    `gdb internal error' (since generic_mourn calls breakpoint_init_inferior).  */
 320
 321 static int
 322 ignore (addr, contents)
 323      CORE_ADDR addr;
 324      char *contents;
 325 {
 326   return 0;
 327 }
 328
 329 struct target_ops core_ops = {
 330   "core",                       /* to_shortname */
 331   "Local core dump file",       /* to_longname */
 332   "Use a core file as a target.  Specify the filename of the core file.", /* to_doc */
 333   core_open,                    /* to_open */
 334   core_close,                   /* to_close */
 335   find_default_attach,          /* to_attach */
 336   core_detach,                  /* to_detach */
 337   0,                            /* to_resume */
 338   0,                            /* to_wait */
 339   get_core_registers,           /* to_fetch_registers */
 340   0,                            /* to_store_registers */
 341   0,                            /* to_prepare_to_store */
 342   xfer_memory,                  /* to_xfer_memory */
 343   core_files_info,              /* to_files_info */
 344   ignore,                       /* to_insert_breakpoint */
 345   ignore,                       /* to_remove_breakpoint */
 346   0,                            /* to_terminal_init */
 347   0,                            /* to_terminal_inferior */
 348   0,                            /* to_terminal_ours_for_output */
 349   0,                            /* to_terminal_ours */
 350   0,                            /* to_terminal_info */
 351   0,                            /* to_kill */
 352   0,                            /* to_load */
 353   0,                            /* to_lookup_symbol */
 354   find_default_create_inferior, /* to_create_inferior */
 355   0,                            /* to_mourn_inferior */
 356   0,                            /* to_can_run */
 357   0,                            /* to_notice_signals */
 358   0,                            /* to_stop */
 359   core_stratum,                 /* to_stratum */
 360   0,                            /* to_next */
 361   0,                            /* to_has_all_memory */
 362   1,                            /* to_has_memory */
 363   1,                            /* to_has_stack */
 364   1,                            /* to_has_registers */
 365   0,                            /* to_has_execution */
 366   0,                            /* to_sections */
 367   0,                            /* to_sections_end */
 368   OPS_MAGIC,                    /* to_magic */
 369 };
 370
 371 void
 372 _initialize_corelow()
 373 {
 374   add_target (&core_ops);
 375 }