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   if (core_bfd) {
  55     free (bfd_get_filename (core_bfd));
  56     bfd_close (core_bfd);
  57     core_bfd = NULL;
  58 #ifdef CLEAR_SOLIB
  59     CLEAR_SOLIB ();
  60 #endif
  61     if (core_ops.to_sections) {
  62       free ((PTR)core_ops.to_sections);
  63       core_ops.to_sections = NULL;
  64       core_ops.to_sections_end = NULL;
  65     }
  66   }
  67 }
  68
  69 #ifdef SOLIB_ADD
  70 /* Stub function for catch_errors around shared library hacking. */
  71
  72 static int
  73 solib_add_stub (from_tty)
  74      char *from_tty;
  75 {
  76     SOLIB_ADD (NULL, (int)from_tty, &core_ops);
  77     return 0;
  78 }
  79 #endif /* SOLIB_ADD */
  80
  81 /* This routine opens and sets up the core file bfd */
  82
  83 void
  84 core_open (filename, from_tty)
  85      char *filename;
  86      int from_tty;
  87 {
  88   const char *p;
  89   int siggy;
  90   struct cleanup *old_chain;
  91   char *temp;
  92   bfd *temp_bfd;
  93   int ontop;
  94   int scratch_chan;
  95
  96   target_preopen (from_tty);
  97   if (!filename)
  98     {
  99       error (core_bfd?
 100        "No core file specified.  (Use `detach' to stop debugging a core file.)"
 101      : "No core file specified.");
 102     }
 103
 104   filename = tilde_expand (filename);
 105   if (filename[0] != '/') {
 106     temp = concat (current_directory, "/", filename, NULL);
 107     free (filename);
 108     filename = temp;
 109   }
 110
 111   old_chain = make_cleanup (free, filename);
 112
 113   scratch_chan = open (filename, write_files? O_RDWR: O_RDONLY, 0);
 114   if (scratch_chan < 0)
 115     perror_with_name (filename);
 116
 117   temp_bfd = bfd_fdopenr (filename, NULL, scratch_chan);
 118   if (temp_bfd == NULL)
 119     {
 120       perror_with_name (filename);
 121     }
 122
 123   if (!bfd_check_format (temp_bfd, bfd_core))
 124     {
 125       /* Do it after the err msg */
 126       make_cleanup (bfd_close, temp_bfd);
 127       error ("\"%s\" is not a core dump: %s", filename, bfd_errmsg(bfd_error));
 128     }
 129
 130   /* Looks semi-reasonable.  Toss the old core file and work on the new.  */
 131
 132   discard_cleanups (old_chain);         /* Don't free filename any more */
 133   unpush_target (&core_ops);
 134   core_bfd = temp_bfd;
 135   old_chain = make_cleanup (core_close, core_bfd);
 136
 137   validate_files ();
 138
 139   /* Find the data section */
 140   if (build_section_table (core_bfd, &core_ops.to_sections,
 141                            &core_ops.to_sections_end))
 142     error ("Can't find sections in `%s': %s", bfd_get_filename(core_bfd),
 143            bfd_errmsg (bfd_error));
 144
 145   ontop = !push_target (&core_ops);
 146   discard_cleanups (old_chain);
 147
 148   p = bfd_core_file_failing_command (core_bfd);
 149   if (p)
 150     printf_filtered ("Core was generated by `%s'.\n", p);
 151
 152   siggy = bfd_core_file_failing_signal (core_bfd);
 153   if (siggy > 0)
 154     printf_filtered ("Program terminated with signal %d, %s.\n", siggy,
 155             safe_strsignal (siggy));
 156
 157   if (ontop) {
 158     /* Fetch all registers from core file */
 159     target_fetch_registers (-1);
 160
 161     /* Add symbols and section mappings for any shared libraries */
 162 #ifdef SOLIB_ADD
 163     catch_errors (solib_add_stub, (char *)from_tty, (char *)0);
 164 #endif
 165
 166     /* Now, set up the frame cache, and print the top of stack */
 167     set_current_frame (create_new_frame (read_register (FP_REGNUM),
 168                                          read_pc ()));
 169     select_frame (get_current_frame (), 0);
 170     print_stack_frame (selected_frame, selected_frame_level, 1);
 171   } else {
 172     warning (
 173 "you won't be able to access this core file until you terminate\n\
 174 your %s; do ``info files''", current_target->to_longname);
 175   }
 176 }
 177
 178 void
 179 core_detach (args, from_tty)
 180      char *args;
 181      int from_tty;
 182 {
 183   if (args)
 184     error ("Too many arguments");
 185   unpush_target (&core_ops);
 186   if (from_tty)
 187     printf_filtered ("No core file now.\n");
 188 }
 189
 190 /* Get the registers out of a core file.  This is the machine-
 191    independent part.  Fetch_core_registers is the machine-dependent
 192    part, typically implemented in the xm-file for each architecture.  */
 193
 194 /* We just get all the registers, so we don't use regno.  */
 195 /* ARGSUSED */
 196 static void
 197 get_core_registers (regno)
 198      int regno;
 199 {
 200   sec_ptr reg_sec;
 201   unsigned size;
 202   char *the_regs;
 203
 204   reg_sec = bfd_get_section_by_name (core_bfd, ".reg");
 205   if (!reg_sec) goto cant;
 206   size = bfd_section_size (core_bfd, reg_sec);
 207   the_regs = alloca (size);
 208   if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0, size))
 209     {
 210       fetch_core_registers (the_regs, size, 0,
 211                             (unsigned) bfd_section_vma (abfd,reg_sec));
 212     }
 213   else
 214     {
 215 cant:
 216       fprintf_filtered (stderr, "Couldn't fetch registers from core file: %s\n",
 217                bfd_errmsg (bfd_error));
 218     }
 219
 220   /* Now do it again for the float registers, if they exist.  */
 221   reg_sec = bfd_get_section_by_name (core_bfd, ".reg2");
 222   if (reg_sec) {
 223     size = bfd_section_size (core_bfd, reg_sec);
 224     the_regs = alloca (size);
 225     if (bfd_get_section_contents (core_bfd, reg_sec, the_regs, (file_ptr)0,
 226                                   size))
 227       {
 228         fetch_core_registers (the_regs, size, 2,
 229                               (unsigned) bfd_section_vma (abfd,reg_sec));
 230       }
 231     else
 232       {
 233         fprintf_filtered (stderr, "Couldn't fetch register set 2 from core file: %s\n",
 234                  bfd_errmsg (bfd_error));
 235       }
 236   }
 237   registers_fetched();
 238 }
 239
 240 static void
 241 core_files_info (t)
 242   struct target_ops *t;
 243 {
 244   print_section_info (t, core_bfd);
 245 }
 246 \f
 247 struct target_ops core_ops = {
 248         "core", "Local core dump file",
 249         "Use a core file as a target.  Specify the filename of the core file.",
 250         core_open, core_close,
 251         find_default_attach, core_detach, 0, 0, /* resume, wait */
 252         get_core_registers,
 253         0, 0, /* store_regs, prepare_to_store */
 254         xfer_memory, core_files_info,
 255         0, 0, /* core_insert_breakpoint, core_remove_breakpoint, */
 256         0, 0, 0, 0, 0, /* terminal stuff */
 257         0, 0, 0, /* kill, load, lookup sym */
 258         find_default_create_inferior, 0, /* mourn_inferior */
 259         0, /* can_run */
 260         0, /* notice_signals */
 261         core_stratum, 0, /* next */
 262         0, 1, 1, 1, 0,  /* all mem, mem, stack, regs, exec */
 263         0, 0,                   /* section pointers */
 264         OPS_MAGIC,              /* Always the last thing */
 265 };
 266
 267 void
 268 _initialize_corelow()
 269 {
 270   add_target (&core_ops);
 271 }