gdb/gould-xdep.c

   1 /* Low level interface to ptrace, for GDB when running under Unix.
   2    Copyright (C) 1986, 1987, 1989, 1991 Free Software Foundation, Inc.
   3
   4 This file is part of GDB.
   5
   6 GDB 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 1, or (at your option)
   9 any later version.
  10
  11 GDB 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 GDB; see the file COPYING.  If not, write to
  18 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  19
  20 #include <stdio.h>
  21 #include "defs.h"
  22 #include "param.h"
  23 #include "frame.h"
  24 #include "inferior.h"
  25
  26 #include <sys/param.h>
  27 #include <sys/dir.h>
  28 #include <signal.h>
  29 #include <sys/user.h>
  30 #include <sys/ioctl.h>
  31 #include <fcntl.h>
  32
  33 #include "gdbcore.h"
  34
  35 #include <sys/file.h>
  36 #include <sys/stat.h>
  37 \f
  38 /* Work with core dump and executable files, for GDB.
  39    This code would be in core.c if it weren't machine-dependent. */
  40
  41 void
  42 core_file_command (filename, from_tty)
  43      char *filename;
  44      int from_tty;
  45 {
  46   int val;
  47   extern char registers[];
  48
  49   /* Discard all vestiges of any previous core file
  50      and mark data and stack spaces as empty.  */
  51
  52   if (corefile)
  53     free (corefile);
  54   corefile = 0;
  55
  56   if (corechan >= 0)
  57     close (corechan);
  58   corechan = -1;
  59
  60   data_start = 0;
  61   data_end = 0;
  62   stack_start = STACK_END_ADDR;
  63   stack_end = STACK_END_ADDR;
  64
  65   /* Now, if a new core file was specified, open it and digest it.  */
  66
  67   if (filename)
  68     {
  69       filename = tilde_expand (filename);
  70       make_cleanup (free, filename);
  71
  72       if (have_inferior_p ())
  73         error ("To look at a core file, you must kill the inferior with \"kill\".");
  74       corechan = open (filename, O_RDONLY, 0);
  75       if (corechan < 0)
  76         perror_with_name (filename);
  77       /* 4.2-style (and perhaps also sysV-style) core dump file.  */
  78       {
  79         struct user u;
  80         int reg_offset;
  81
  82         val = myread (corechan, &u, sizeof u);
  83         if (val < 0)
  84           perror_with_name (filename);
  85         data_start = exec_data_start;
  86
  87         data_end = data_start + NBPG * u.u_dsize;
  88         stack_start = stack_end - NBPG * u.u_ssize;
  89         data_offset = NBPG * UPAGES;
  90         stack_offset = NBPG * (UPAGES + u.u_dsize);
  91         reg_offset = (int) u.u_ar0 - KERNEL_U_ADDR;
  92
  93         /* I don't know where to find this info.
  94            So, for now, mark it as not available.  */
  95         core_aouthdr.a_magic = 0;
  96
  97         /* Read the register values out of the core file and store
  98            them where `read_register' will find them.  */
  99
 100         {
 101           register int regno;
 102
 103           for (regno = 0; regno < NUM_REGS; regno++)
 104             {
 105               char buf[MAX_REGISTER_RAW_SIZE];
 106
 107               val = lseek (corechan, register_addr (regno, reg_offset), 0);
 108               if (val < 0)
 109                 perror_with_name (filename);
 110
 111               val = myread (corechan, buf, sizeof buf);
 112               if (val < 0)
 113                 perror_with_name (filename);
 114               supply_register (regno, buf);
 115             }
 116         }
 117       }
 118       if (filename[0] == '/')
 119         corefile = savestring (filename, strlen (filename));
 120       else
 121         {
 122           corefile = concat (current_directory, "/", filename);
 123         }
 124
 125       set_current_frame ( create_new_frame (read_register (FP_REGNUM),
 126                                             read_pc ()));
 127       select_frame (get_current_frame (), 0);
 128       validate_files ();
 129     }
 130   else if (from_tty)
 131     printf ("No core file now.\n");
 132 }