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