[deliverable/binutils-gdb.git] / gdb / inftarg.c

/* Target-vector operations for controlling Unix child processes, for GDB.
   Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
   Contributed by Cygnus Support.

This file is part of GDB.

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  */

#include "defs.h"
#include "frame.h"  /* required by inferior.h */
#include "inferior.h"
#include "target.h"
#include "wait.h"
#include "gdbcore.h"
#include "command.h"
#include <signal.h>

static void
child_prepare_to_store PARAMS ((void));

#ifndef CHILD_WAIT
static int child_wait PARAMS ((int, struct target_waitstatus *));
#endif /* CHILD_WAIT */

static void child_open PARAMS ((char *, int));

static void
child_files_info PARAMS ((struct target_ops *));

static void
child_detach PARAMS ((char *, int));

static void
child_attach PARAMS ((char *, int));

static void
ptrace_me PARAMS ((void));

static void
ptrace_him PARAMS ((int));

static void child_create_inferior PARAMS ((char *, char *, char **));

static void
child_mourn_inferior PARAMS ((void));

static int
child_can_run PARAMS ((void));

extern char **environ;

/* Forward declaration */
extern struct target_ops child_ops;

#ifndef CHILD_WAIT

/* Wait for child to do something.  Return pid of child, or -1 in case
   of error; store status through argument pointer OURSTATUS.  */

static int
child_wait (pid, ourstatus)
     int pid;
     struct target_waitstatus *ourstatus;
{
  int save_errno;
  int status;

  do {
    if (attach_flag)
      set_sigint_trap();	/* Causes SIGINT to be passed on to the
				   attached process. */
    set_sigio_trap ();

    pid = wait (&status);
    save_errno = errno;

    clear_sigio_trap ();

    if (attach_flag)
      clear_sigint_trap();

    if (pid == -1)
      {
	if (save_errno == EINTR)
	  continue;
	fprintf_unfiltered (gdb_stderr, "Child process unexpectedly missing: %s.\n",
		 safe_strerror (save_errno));
	/* Claim it exited with unknown signal.  */
	ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
	ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
        return -1;
      }
  } while (pid != inferior_pid); /* Some other child died or stopped */
  store_waitstatus (ourstatus, status);
  return pid;
}
#endif /* CHILD_WAIT */

/* Attach to process PID, then initialize for debugging it.  */

static void
child_attach (args, from_tty)
     char *args;
     int from_tty;
{
  if (!args)
    error_no_arg ("process-id to attach");

#ifndef ATTACH_DETACH
  error ("Can't attach to a process on this machine.");
#else
  {
    char *exec_file;
    int pid;

    pid = atoi (args);

    if (pid == getpid())		/* Trying to masturbate? */
      error ("I refuse to debug myself!");

    if (from_tty)
      {
	exec_file = (char *) get_exec_file (0);

	if (exec_file)
	  printf_unfiltered ("Attaching to program `%s', %s\n", exec_file,
		  target_pid_to_str (pid));
	else
	  printf_unfiltered ("Attaching to %s\n", target_pid_to_str (pid));

	gdb_flush (gdb_stdout);
      }

    attach (pid);
    inferior_pid = pid;
    push_target (&child_ops);
  }
#endif  /* ATTACH_DETACH */
}


/* Take a program previously attached to and detaches it.
   The program resumes execution and will no longer stop
   on signals, etc.  We'd better not have left any breakpoints
   in the program or it'll die when it hits one.  For this
   to work, it may be necessary for the process to have been
   previously attached.  It *might* work if the program was
   started via the normal ptrace (PTRACE_TRACEME).  */

static void
child_detach (args, from_tty)
     char *args;
     int from_tty;
{
#ifdef ATTACH_DETACH
  {
    int siggnal = 0;

    if (from_tty)
      {
	char *exec_file = get_exec_file (0);
	if (exec_file == 0)
	  exec_file = "";
	printf_unfiltered ("Detaching from program: %s %s\n", exec_file,
		target_pid_to_str (inferior_pid));
	gdb_flush (gdb_stdout);
      }
    if (args)
      siggnal = atoi (args);

    detach (siggnal);
    inferior_pid = 0;
    unpush_target (&child_ops);
  }
#else
  error ("This version of Unix does not support detaching a process.");
#endif
}

/* Get ready to modify the registers array.  On machines which store
   individual registers, this doesn't need to do anything.  On machines
   which store all the registers in one fell swoop, this makes sure
   that registers contains all the registers from the program being
   debugged.  */

static void
child_prepare_to_store ()
{
#ifdef CHILD_PREPARE_TO_STORE
  CHILD_PREPARE_TO_STORE ();
#endif
}

/* Print status information about what we're accessing.  */

static void
child_files_info (ignore)
     struct target_ops *ignore;
{
  printf_unfiltered ("\tUsing the running image of %s %s.\n",
	  attach_flag? "attached": "child", target_pid_to_str (inferior_pid));
}

/* ARGSUSED */
static void
child_open (arg, from_tty)
     char *arg;
     int from_tty;
{
  error ("Use the \"run\" command to start a Unix child process.");
}

/* Stub function which causes the inferior that runs it, to be ptrace-able
   by its parent process.  */

static void
ptrace_me ()
{
  /* "Trace me, Dr. Memory!" */
  call_ptrace (0, 0, (PTRACE_ARG3_TYPE) 0, 0);
}

/* Stub function which causes the GDB that runs it, to start ptrace-ing
   the child process.  */

static void
ptrace_him (pid)
     int pid;
{
  push_target (&child_ops);

#ifdef START_INFERIOR_TRAPS_EXPECTED
  startup_inferior (START_INFERIOR_TRAPS_EXPECTED);
#else
  /* One trap to exec the shell, one to exec the program being debugged.  */
  startup_inferior (2);
#endif
}

/* Start an inferior Unix child process and sets inferior_pid to its pid.
   EXEC_FILE is the file to run.
   ALLARGS is a string containing the arguments to the program.
   ENV is the environment vector to pass.  Errors reported with error().  */

static void
child_create_inferior (exec_file, allargs, env)
     char *exec_file;
     char *allargs;
     char **env;
{
  fork_inferior (exec_file, allargs, env, ptrace_me, ptrace_him, NULL);
  /* We are at the first instruction we care about.  */
  /* Pedal to the metal... */
  proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0);
}

static void
child_mourn_inferior ()
{
  unpush_target (&child_ops);
  generic_mourn_inferior ();
}

static int
child_can_run ()
{
  return(1);
}
\f
struct target_ops child_ops = {
  "child",			/* to_shortname */
  "Unix child process",		/* to_longname */
  "Unix child process (started by the \"run\" command).",	/* to_doc */
  child_open,			/* to_open */
  0,				/* to_close */
  child_attach,			/* to_attach */
  child_detach, 		/* to_detach */
  child_resume,			/* to_resume */
  child_wait,			/* to_wait */
  fetch_inferior_registers,	/* to_fetch_registers */
  store_inferior_registers,	/* to_store_registers */
  child_prepare_to_store,	/* to_prepare_to_store */
  child_xfer_memory,		/* to_xfer_memory */
  child_files_info,		/* to_files_info */
  memory_insert_breakpoint,	/* to_insert_breakpoint */
  memory_remove_breakpoint,	/* to_remove_breakpoint */
  terminal_init_inferior,	/* to_terminal_init */
  terminal_inferior, 		/* to_terminal_inferior */
  terminal_ours_for_output,	/* to_terminal_ours_for_output */
  terminal_ours,		/* to_terminal_ours */
  child_terminal_info,		/* to_terminal_info */
  kill_inferior,		/* to_kill */
  0,				/* to_load */
  0,				/* to_lookup_symbol */
  child_create_inferior,	/* to_create_inferior */
  child_mourn_inferior,		/* to_mourn_inferior */
  child_can_run,		/* to_can_run */
  0, 				/* to_notice_signals */
  process_stratum,		/* to_stratum */
  0,				/* to_next */
  1,				/* to_has_all_memory */
  1,				/* to_has_memory */
  1,				/* to_has_stack */
  1,				/* to_has_registers */
  1,				/* to_has_execution */
  0,				/* sections */
  0,				/* sections_end */
  OPS_MAGIC			/* to_magic */
};

void
_initialize_inftarg ()
{
  add_target (&child_ops);
}
Commit	Line	Data
	1	/* Target-vector operations for controlling Unix child processes, for GDB.
	2	Copyright 1990, 1991, 1992 Free Software Foundation, Inc.
	3	Contributed by Cygnus Support.
	4
	5	This file is part of GDB.
	6
	7	This program is free software; you can redistribute it and/or modify
	8	it under the terms of the GNU General Public License as published by
	9	the Free Software Foundation; either version 2 of the License, or
	10	(at your option) any later version.
	11
	12	This program is distributed in the hope that it will be useful,
	13	but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	GNU General Public License for more details.
	16
	17	You should have received a copy of the GNU General Public License
	18	along with this program; if not, write to the Free Software
	19	Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. */
	20
	21	#include "defs.h"
	22	#include "frame.h" /* required by inferior.h */
	23	#include "inferior.h"
	24	#include "target.h"
	25	#include "wait.h"
	26	#include "gdbcore.h"
	27	#include "command.h"
	28	#include <signal.h>
	29
	30	static void
	31	child_prepare_to_store PARAMS ((void));
	32
	33	#ifndef CHILD_WAIT
	34	static int child_wait PARAMS ((int, struct target_waitstatus *));
	35	#endif /* CHILD_WAIT */
	36
	37	static void 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	static void
	46	child_attach PARAMS ((char *, int));
	47
	48	static void
	49	ptrace_me PARAMS ((void));
	50
	51	static void
	52	ptrace_him PARAMS ((int));
	53
	54	static void child_create_inferior PARAMS ((char , char , char **));
	55
	56	static void
	57	child_mourn_inferior PARAMS ((void));
	58
	59	static int
	60	child_can_run PARAMS ((void));
	61
	62	extern char **environ;
	63
	64	/* Forward declaration */
	65	extern struct target_ops child_ops;
	66
	67	#ifndef CHILD_WAIT
	68
	69	/* Wait for child to do something. Return pid of child, or -1 in case
	70	of error; store status through argument pointer OURSTATUS. */
	71
	72	static int
	73	child_wait (pid, ourstatus)
	74	int pid;
	75	struct target_waitstatus *ourstatus;
	76	{
	77	int save_errno;
	78	int status;
	79
	80	do {
	81	if (attach_flag)
	82	set_sigint_trap(); /* Causes SIGINT to be passed on to the
	83	attached process. */
	84	set_sigio_trap ();
	85
	86	pid = wait (&status);
	87	save_errno = errno;
	88
	89	clear_sigio_trap ();
	90
	91	if (attach_flag)
	92	clear_sigint_trap();
	93
	94	if (pid == -1)
	95	{
	96	if (save_errno == EINTR)
	97	continue;
	98	fprintf_unfiltered (gdb_stderr, "Child process unexpectedly missing: %s.\n",
	99	safe_strerror (save_errno));
	100	/* Claim it exited with unknown signal. */
	101	ourstatus->kind = TARGET_WAITKIND_SIGNALLED;
	102	ourstatus->value.sig = TARGET_SIGNAL_UNKNOWN;
	103	return -1;
	104	}
	105	} while (pid != inferior_pid); /* Some other child died or stopped */
	106	store_waitstatus (ourstatus, status);
	107	return pid;
	108	}
	109	#endif /* CHILD_WAIT */
	110
	111	/* Attach to process PID, then initialize for debugging it. */
	112
	113	static void
	114	child_attach (args, from_tty)
	115	char *args;
	116	int from_tty;
	117	{
	118	if (!args)
	119	error_no_arg ("process-id to attach");
	120
	121	#ifndef ATTACH_DETACH
	122	error ("Can't attach to a process on this machine.");
	123	#else
	124	{
	125	char *exec_file;
	126	int pid;
	127
	128	pid = atoi (args);
	129
	130	if (pid == getpid()) /* Trying to masturbate? */
	131	error ("I refuse to debug myself!");
	132
	133	if (from_tty)
	134	{
	135	exec_file = (char *) get_exec_file (0);
	136
	137	if (exec_file)
	138	printf_unfiltered ("Attaching to program `%s', %s\n", exec_file,
	139	target_pid_to_str (pid));
	140	else
	141	printf_unfiltered ("Attaching to %s\n", target_pid_to_str (pid));
	142
	143	gdb_flush (gdb_stdout);
	144	}
	145
	146	attach (pid);
	147	inferior_pid = pid;
	148	push_target (&child_ops);
	149	}
	150	#endif /* ATTACH_DETACH */
	151	}
	152
	153
	154	/* Take a program previously attached to and detaches it.
	155	The program resumes execution and will no longer stop
	156	on signals, etc. We'd better not have left any breakpoints
	157	in the program or it'll die when it hits one. For this
	158	to work, it may be necessary for the process to have been
	159	previously attached. It might work if the program was
	160	started via the normal ptrace (PTRACE_TRACEME). */
	161
	162	static void
	163	child_detach (args, from_tty)
	164	char *args;
	165	int from_tty;
	166	{
	167	#ifdef ATTACH_DETACH
	168	{
	169	int siggnal = 0;
	170
	171	if (from_tty)
	172	{
	173	char *exec_file = get_exec_file (0);
	174	if (exec_file == 0)
	175	exec_file = "";
	176	printf_unfiltered ("Detaching from program: %s %s\n", exec_file,
	177	target_pid_to_str (inferior_pid));
	178	gdb_flush (gdb_stdout);
	179	}
	180	if (args)
	181	siggnal = atoi (args);
	182
	183	detach (siggnal);
	184	inferior_pid = 0;
	185	unpush_target (&child_ops);
	186	}
	187	#else
	188	error ("This version of Unix does not support detaching a process.");
	189	#endif
	190	}
	191
	192	/* Get ready to modify the registers array. On machines which store
	193	individual registers, this doesn't need to do anything. On machines
	194	which store all the registers in one fell swoop, this makes sure
	195	that registers contains all the registers from the program being
	196	debugged. */
	197
	198	static void
	199	child_prepare_to_store ()
	200	{
	201	#ifdef CHILD_PREPARE_TO_STORE
	202	CHILD_PREPARE_TO_STORE ();
	203	#endif
	204	}
	205
	206	/* Print status information about what we're accessing. */
	207
	208	static void
	209	child_files_info (ignore)
	210	struct target_ops *ignore;
	211	{
	212	printf_unfiltered ("\tUsing the running image of %s %s.\n",
	213	attach_flag? "attached": "child", target_pid_to_str (inferior_pid));
	214	}
	215
	216	/* ARGSUSED */
	217	static void
	218	child_open (arg, from_tty)
	219	char *arg;
	220	int from_tty;
	221	{
	222	error ("Use the \"run\" command to start a Unix child process.");
	223	}
	224
	225	/* Stub function which causes the inferior that runs it, to be ptrace-able
	226	by its parent process. */
	227
	228	static void
	229	ptrace_me ()
	230	{
	231	/* "Trace me, Dr. Memory!" */
	232	call_ptrace (0, 0, (PTRACE_ARG3_TYPE) 0, 0);
	233	}
	234
	235	/* Stub function which causes the GDB that runs it, to start ptrace-ing
	236	the child process. */
	237
	238	static void
	239	ptrace_him (pid)
	240	int pid;
	241	{
	242	push_target (&child_ops);
	243
	244	#ifdef START_INFERIOR_TRAPS_EXPECTED
	245	startup_inferior (START_INFERIOR_TRAPS_EXPECTED);
	246	#else
	247	/* One trap to exec the shell, one to exec the program being debugged. */
	248	startup_inferior (2);
	249	#endif
	250	}
	251
	252	/* Start an inferior Unix child process and sets inferior_pid to its pid.
	253	EXEC_FILE is the file to run.
	254	ALLARGS is a string containing the arguments to the program.
	255	ENV is the environment vector to pass. Errors reported with error(). */
	256
	257	static void
	258	child_create_inferior (exec_file, allargs, env)
	259	char *exec_file;
	260	char *allargs;
	261	char **env;
	262	{
	263	fork_inferior (exec_file, allargs, env, ptrace_me, ptrace_him, NULL);
	264	/* We are at the first instruction we care about. */
	265	/* Pedal to the metal... */
	266	proceed ((CORE_ADDR) -1, TARGET_SIGNAL_0, 0);
	267	}
	268
	269	static void
	270	child_mourn_inferior ()
	271	{
	272	unpush_target (&child_ops);
	273	generic_mourn_inferior ();
	274	}
	275
	276	static int
	277	child_can_run ()
	278	{
	279	return(1);
	280	}
	281	\f
	282	struct target_ops child_ops = {
	283	"child", /* to_shortname */
	284	"Unix child process", /* to_longname */
	285	"Unix child process (started by the \"run\" command).", /* to_doc */
	286	child_open, /* to_open */
	287	0, /* to_close */
	288	child_attach, /* to_attach */
	289	child_detach, /* to_detach */
	290	child_resume, /* to_resume */
	291	child_wait, /* to_wait */
	292	fetch_inferior_registers, /* to_fetch_registers */
	293	store_inferior_registers, /* to_store_registers */
	294	child_prepare_to_store, /* to_prepare_to_store */
	295	child_xfer_memory, /* to_xfer_memory */
	296	child_files_info, /* to_files_info */
	297	memory_insert_breakpoint, /* to_insert_breakpoint */
	298	memory_remove_breakpoint, /* to_remove_breakpoint */
	299	terminal_init_inferior, /* to_terminal_init */
	300	terminal_inferior, /* to_terminal_inferior */
	301	terminal_ours_for_output, /* to_terminal_ours_for_output */
	302	terminal_ours, /* to_terminal_ours */
	303	child_terminal_info, /* to_terminal_info */
	304	kill_inferior, /* to_kill */
	305	0, /* to_load */
	306	0, /* to_lookup_symbol */
	307	child_create_inferior, /* to_create_inferior */
	308	child_mourn_inferior, /* to_mourn_inferior */
	309	child_can_run, /* to_can_run */
	310	0, /* to_notice_signals */
	311	process_stratum, /* to_stratum */
	312	0, /* to_next */
	313	1, /* to_has_all_memory */
	314	1, /* to_has_memory */
	315	1, /* to_has_stack */
	316	1, /* to_has_registers */
	317	1, /* to_has_execution */
	318	0, /* sections */
	319	0, /* sections_end */
	320	OPS_MAGIC /* to_magic */
	321	};
	322
	323	void
	324	_initialize_inftarg ()
	325	{
	326	add_target (&child_ops);
	327	}