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