gdb/inftarg.c

   1 /* Subroutines for handling an "inferior" (child) process as a target
   2    for debugging, in GDB.
   3    Copyright 1990, 1991 Free Software Foundation, Inc.
   4    Contributed by Cygnus Support.
   5
   6 This file is part of GDB.
   7
   8 This program is free software; you can redistribute it and/or modify
   9 it under the terms of the GNU General Public License as published by
  10 the Free Software Foundation; either version 2 of the License, or
  11 (at your option) any later version.
  12
  13 This program is distributed in the hope that it will be useful,
  14 but WITHOUT ANY WARRANTY; without even the implied warranty of
  15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16 GNU General Public License for more details.
  17
  18 You should have received a copy of the GNU General Public License
  19 along with this program; if not, write to the Free Software
  20 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */
  21
  22 #include "defs.h"
  23 #include "frame.h"  /* required by inferior.h */
  24 #include "inferior.h"
  25 #include "target.h"
  26 #include "wait.h"
  27 #include "gdbcore.h"
  28 #include "ieee-float.h"         /* Required by REGISTER_CONVERT_TO_XXX */
  29
  30 static void
  31 child_prepare_to_store PARAMS ((void));
  32
  33 static int
  34 child_wait PARAMS ((int *));
  35
  36 static void
  37 child_open PARAMS ((char *, int));
  38
  39 static void
  40 child_files_info PARAMS ((struct target_ops *));
  41
  42 static void
  43 child_detach PARAMS ((char *, int));
  44
  45 /* Forward declaration */
  46 extern struct target_ops child_ops;
  47
  48 /* Wait for child to do something.  Return pid of child, or -1 in case
  49    of error; store status through argument pointer STATUS.  */
  50
  51 static int
  52 child_wait (status)
  53      int *status;
  54 {
  55   int pid;
  56
  57   do {
  58 #ifdef USE_PROC_FS
  59     pid = proc_wait (status);
  60 #else
  61     pid = wait (status);
  62 #endif
  63     if (pid == -1)              /* No more children to wait for */
  64       {
  65         fprintf (stderr, "Child process unexpectedly missing.\n");
  66         *status = 42;   /* Claim it exited with signal 42 */
  67         return -1;
  68       }
  69   } while (pid != inferior_pid); /* Some other child died or stopped */
  70   return pid;
  71 }
  72
  73
  74 /*
  75  * child_detach()
  76  * takes a program previously attached to and detaches it.
  77  * The program resumes execution and will no longer stop
  78  * on signals, etc.  We better not have left any breakpoints
  79  * in the program or it'll die when it hits one.  For this
  80  * to work, it may be necessary for the process to have been
  81  * previously attached.  It *might* work if the program was
  82  * started via the normal ptrace (PTRACE_TRACEME).
  83  */
  84
  85 static void
  86 child_detach (args, from_tty)
  87      char *args;
  88      int from_tty;
  89 {
  90   int siggnal = 0;
  91
  92 #ifdef ATTACH_DETACH
  93   if (from_tty)
  94     {
  95       char *exec_file = get_exec_file (0);
  96       if (exec_file == 0)
  97         exec_file = "";
  98       printf ("Detaching program: %s pid %d\n",
  99               exec_file, inferior_pid);
 100       fflush (stdout);
 101     }
 102   if (args)
 103     siggnal = atoi (args);
 104
 105   detach (siggnal);
 106   inferior_pid = 0;
 107   unpush_target (&child_ops);           /* Pop out of handling an inferior */
 108 #else
 109     error ("This version of Unix does not support detaching a process.");
 110 #endif
 111 }
 112
 113 /* Get ready to modify the registers array.  On machines which store
 114    individual registers, this doesn't need to do anything.  On machines
 115    which store all the registers in one fell swoop, this makes sure
 116    that registers contains all the registers from the program being
 117    debugged.  */
 118
 119 static void
 120 child_prepare_to_store ()
 121 {
 122 #ifdef CHILD_PREPARE_TO_STORE
 123   CHILD_PREPARE_TO_STORE ();
 124 #endif
 125 }
 126
 127 /* Print status information about what we're accessing.  */
 128
 129 static void
 130 child_files_info (ignore)
 131      struct target_ops *ignore;
 132 {
 133   printf ("\tUsing the running image of %s process %d.\n",
 134           attach_flag? "attached": "child", inferior_pid);
 135 }
 136
 137 /* ARGSUSED */
 138 static void
 139 child_open (arg, from_tty)
 140      char *arg;
 141      int from_tty;
 142 {
 143   error ("Use the \"run\" command to start a Unix child process.");
 144 }
 145
 146 struct target_ops child_ops = {
 147   "child",                      /* to_shortname */
 148   "Unix child process",         /* to_longname */
 149   "Unix child process (started by the \"run\" command).",       /* to_doc */
 150   child_open,                   /* to_open */
 151   0,                            /* to_close */
 152   child_attach,                 /* to_attach */
 153   child_detach,                 /* to_detach */
 154   child_resume,                 /* to_resume */
 155   child_wait,                   /* to_wait */
 156   fetch_inferior_registers,     /* to_fetch_registers */
 157   store_inferior_registers,     /* to_store_registers */
 158   child_prepare_to_store,       /* to_prepare_to_store */
 159   child_xfer_memory,            /* to_xfer_memory */
 160   child_files_info,             /* to_files_info */
 161   memory_insert_breakpoint,     /* to_insert_breakpoint */
 162   memory_remove_breakpoint,     /* to_remove_breakpoint */
 163   terminal_init_inferior,       /* to_terminal_init */
 164   terminal_inferior,            /* to_terminal_inferior */
 165   terminal_ours_for_output,     /* to_terminal_ours_for_output */
 166   terminal_ours,                /* to_terminal_ours */
 167   child_terminal_info,          /* to_terminal_info */
 168   kill_inferior,                /* to_kill */
 169   0,                            /* to_load */
 170   0,                            /* to_lookup_symbol */
 171   child_create_inferior,        /* to_create_inferior */
 172   child_mourn_inferior,         /* to_mourn_inferior */
 173   process_stratum,              /* to_stratum */
 174   0,                            /* to_next */
 175   1,                            /* to_has_all_memory */
 176   1,                            /* to_has_memory */
 177   1,                            /* to_has_stack */
 178   1,                            /* to_has_registers */
 179   1,                            /* to_has_execution */
 180   0,                            /* sections */
 181   0,                            /* sections_end */
 182   OPS_MAGIC                     /* to_magic */
 183 };
 184
 185 void
 186 _initialize_inftarg ()
 187 {
 188   add_target (&child_ops);
 189 }