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