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 GDB 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 1, or (at your option)
  11 any later version.
  12
  13 GDB 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 GDB; see the file COPYING.  If not, write to
  20 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.  */
  21
  22 #include <stdio.h>
  23 #include "defs.h"
  24 #include "param.h"
  25 #include "frame.h"  /* required by inferior.h */
  26 #include "inferior.h"
  27 #include "target.h"
  28 #include "wait.h"
  29 #include "gdbcore.h"
  30 #include "ieee-float.h"         /* Required by REGISTER_CONVERT_TO_XXX */
  31
  32 extern int fetch_inferior_registers();
  33 extern int store_inferior_registers();
  34 extern int child_xfer_memory();
  35 extern int memory_insert_breakpoint(), memory_remove_breakpoint();
  36 extern void terminal_init_inferior(), terminal_ours(), terminal_inferior();
  37 extern void terminal_ours_for_output(), child_terminal_info();
  38 extern void kill_inferior(), add_syms_addr_command();
  39 extern struct value *call_function_by_hand();
  40 extern void child_resume();
  41 extern void child_create_inferior();
  42 extern void child_mourn_inferior();
  43 extern void child_attach ();
  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 int
  52 child_wait (status)
  53      int *status;
  54 {
  55   int pid;
  56
  57   do {
  58     pid = wait (status);
  59     if (pid == -1)              /* No more children to wait for */
  60       {
  61         fprintf (stderr, "Child process unexpectedly missing.\n");
  62         *status = 42;   /* Claim it exited with signal 42 */
  63         return -1;
  64       }
  65   } while (pid != inferior_pid); /* Some other child died or stopped */
  66   return pid;
  67 }
  68
  69
  70 /*
  71  * child_detach()
  72  * takes a program previously attached to and detaches it.
  73  * The program resumes execution and will no longer stop
  74  * on signals, etc.  We better not have left any breakpoints
  75  * in the program or it'll die when it hits one.  For this
  76  * to work, it may be necessary for the process to have been
  77  * previously attached.  It *might* work if the program was
  78  * started via the normal ptrace (PTRACE_TRACEME).
  79  */
  80
  81 static void
  82 child_detach (args, from_tty)
  83      char *args;
  84      int from_tty;
  85 {
  86   int siggnal = 0;
  87
  88 #ifdef ATTACH_DETACH
  89   if (from_tty)
  90     {
  91       char *exec_file = get_exec_file (0);
  92       if (exec_file == 0)
  93         exec_file = "";
  94       printf ("Detaching program: %s pid %d\n",
  95               exec_file, inferior_pid);
  96       fflush (stdout);
  97     }
  98   if (args)
  99     siggnal = atoi (args);
 100
 101   detach (siggnal);
 102   inferior_pid = 0;
 103   unpush_target (&child_ops);           /* Pop out of handling an inferior */
 104 #else
 105     error ("This version of Unix does not support detaching a process.");
 106 #endif
 107 }
 108
 109 /* Get ready to modify the registers array.  On machines which store
 110    individual registers, this doesn't need to do anything.  On machines
 111    which store all the registers in one fell swoop, this makes sure
 112    that registers contains all the registers from the program being
 113    debugged.  */
 114
 115 void
 116 child_prepare_to_store ()
 117 {
 118 #ifdef CHILD_PREPARE_TO_STORE
 119   CHILD_PREPARE_TO_STORE ();
 120 #endif
 121 }
 122
 123 /* Convert data from raw format for register REGNUM
 124    to virtual format for register REGNUM.  */
 125
 126 /* Some machines won't need to use regnum.  */
 127 /* ARGSUSED */
 128 void
 129 host_convert_to_virtual (regnum, from, to)
 130      int regnum;
 131      char *from;
 132      char *to;
 133 {
 134   REGISTER_CONVERT_TO_VIRTUAL (regnum, from, to);
 135 }
 136
 137 /* Convert data from virtual format for register REGNUM
 138    to raw format for register REGNUM.  */
 139
 140 /* ARGSUSED */
 141 void
 142 host_convert_from_virtual (regnum, from, to)
 143      int regnum;
 144      char *from;
 145      char *to;
 146 {
 147   REGISTER_CONVERT_TO_RAW (regnum, from, to);
 148 }
 149
 150 /* Print status information about what we're accessing.  */
 151
 152 static void
 153 child_files_info ()
 154 {
 155   printf ("\tUsing the running image of %s process %d.\n",
 156           attach_flag? "attached": "child", inferior_pid);
 157 }
 158
 159 /* ARGSUSED */
 160 static void
 161 child_open (arg, from_tty)
 162      char *arg;
 163      int from_tty;
 164 {
 165   error ("Use the \"run\" command to start a Unix child process.");
 166 }
 167
 168 struct target_ops child_ops = {
 169         "child", "Unix child process",
 170         "Unix child process (started by the \"run\" command).",
 171         child_open, 0,  /* open, close */
 172         child_attach, child_detach,
 173         child_resume,
 174         child_wait,
 175         fetch_inferior_registers, store_inferior_registers,
 176         child_prepare_to_store,
 177         host_convert_to_virtual, host_convert_from_virtual,
 178         child_xfer_memory, child_files_info,
 179         memory_insert_breakpoint, memory_remove_breakpoint,
 180         terminal_init_inferior, terminal_inferior,
 181         terminal_ours_for_output, terminal_ours, child_terminal_info,
 182         kill_inferior, 0, add_syms_addr_command,  /* load */
 183         call_function_by_hand,
 184         0, /* lookup_symbol */
 185         child_create_inferior, child_mourn_inferior,
 186         process_stratum, 0, /* next */
 187         1, 1, 1, 1, 1,  /* all mem, mem, stack, regs, exec */
 188         OPS_MAGIC,              /* Always the last thing */
 189 };
 190
 191 void
 192 _initialize_inftarg ()
 193 {
 194   add_target (&child_ops);
 195 }