/*
 * Copyright (c) 2002, The Tendra Project <http://www.ten15.org/>
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice unmodified, this list of conditions, and the following
 *    disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 *
 *    		 Crown Copyright (c) 1997
 *
 *    This TenDRA(r) Computer Program is subject to Copyright
 *    owned by the United Kingdom Secretary of State for Defence
 *    acting through the Defence Evaluation and Research Agency
 *    (DERA).  It is made available to Recipients with a
 *    royalty-free licence for its use, reproduction, transfer
 *    to other parties and amendment for any purpose not excluding
 *    product development provided that any such use et cetera
 *    shall be deemed to be acceptance of the following conditions:-
 *
 *        (1) Its Recipients shall ensure that this Notice is
 *        reproduced upon any copies or amended versions of it;
 *
 *        (2) Any amended version of it shall be clearly marked to
 *        show both the nature of and the organisation responsible
 *        for the relevant amendment or amendments;
 *
 *        (3) Its onward transfer from a recipient to another
 *        party shall be deemed to be that party's acceptance of
 *        these conditions;
 *
 *        (4) DERA gives no warranty or assurance as to its
 *        quality or suitability for any purpose and DERA accepts
 *        no liability whatsoever in relation to any use to which
 *        it may be put.
 *
 * $TenDRA: tendra/src/tools/tcc/execute.c,v 1.12 2005/10/16 08:43:21 stefanf Exp $
 */


#include "config.h"
#include "cstring.h"
#include "fmm.h"
#include "msgcat.h"
#include "tenapp.h"

#include "external.h"
#include "filename.h"
#include "list.h"
#include "archive.h"
#include "execute.h"
#include "flags.h"
#include "main.h"
#include "utility.h"


/*
 *    CURRENT COMMAND
 *
 *    The current command is a variable sized array of strings, command.
 *    A complete command is terminated by a null string.
 */

static char **command = null;
static int command_size = 0;
static int cmd_no = 0;


/*
 *    DELAY SIGNAL HANDLING
 *
 *    Because the producer occasionally dies with a signal after it has
 *    output some useful errors it is beneficial to run the tot even
 *    after the signal has been caught. These globals and the functions
 *    below for using them tell the execute function to delay calling the
 *    signal handler until after the tot is called.
 */

static char *last_signaled_cmd = null;
static int last_signal = 0;
static int delay_signal_handling = 0;

void
enable_delayed_signal(void)
{
	delay_signal_handling = 1;
	return;
}

void
disable_delayed_signal(void)
{
	delay_signal_handling = 0;
	return;
}

void
process_delayed_signal(void)
{
	if (last_signal != 0) {
		last_command = last_signaled_cmd;
		tenapp_signal (last_signal);
	}
	return;
}


/*
 *    ADD A STRING TO THE CURRENT COMMAND
 *
 *    This routine adds the string s to the command array.  If s is null
 *    then the array counter is reset to the beginning.  The array counter
 *    is not advanced for empty strings.
 */

void
cmd_string(char *s)
{
	if (cmd_no >= command_size) {
		command_size += 1000;
		command = xrealloc (command, command_size * sizeof(*command));
	}
	command [cmd_no] = s;
	if (s == null) {
		cmd_no = 0;
	} else if (*s) {
		cmd_no++;
	}
	return;
}


/*
 *    ADD A FILENAME TO THE CURRENT COMMAND
 *
 *    This routine adds the names of the files given by p to the command
 *    array.
 */

void
cmd_filename(filename *p)
{
	for (; p != null; p = p->next) cmd_string (p->name);
	return;
}


/*
 *    ADD A LIST TO THE CURRENT COMMAND
 *
 *    This routine adds the list of strings given by p to the command array.
 */

void
cmd_list(list *p)
{
	for (; p != null; p = p->next) cmd_string (p->item);
	return;
}


/*
 *    OVERALL COMPILATION STATUS
 *
 *    This flag is true is an execution error occurs.
 */

boolean exec_error = 0;

void
reset_exec_error(void)
{
	exec_error = 0;
	return;
}


/*
 *    LAST RETURN VALUE
 *
 *    The return value (zero indicating success) of the last command
 *    executed is stored.
 */

int last_return = 0;


/*
 *    THE CURRENT PROCESS
 *
 *    When a process is active, its pid is stored as running_pid.  The
 *    value -1 is used to indicate that no process is active.
 */

#if FS_FORK
static long running_pid = -1;
#endif


/*
 *    KILL ANY STRAY PROCESSES
 *
 *    Occasionally a runaway process may occur.  This routine is intended
 *    to deal with these by sending the signal SIGTERM to the process.
 *    This routine is POSIX compliant.
 */

void
kill_stray(void)
{
#if FS_FORK
	if (running_pid == -1) return;
	IGNORE kill ((pid_t) running_pid, SIGTERM);
	running_pid = -1;
#endif
	return;
}


/*
 *    LIST OF FILES TO BE REMOVED BY REMOVE_JUNK
 *
 *    This gives the list of the files which are to be removed if an
 *    error occurs.
 */

static filename *junk = null;


/*
 *    REMOVE ANY INCOMPLETE OUTPUT FILES
 *
 *    Any files which are being created when an error occurs should be
 *    removed.
 */

void
remove_junk(void)
{
	if (!dry_run && !flag_keep_err) {
		filename *p;
		for (p = junk; p != null; p = p->next) {
			if (p->storage == OUTPUT_FILE) IGNORE remove (p->name);
		}
	}
	junk = null;
	return;
}


/*
 *    PRINT COMMAND INTO BUFFER
 *
 *    This routine prints the current command into a buffer and returns
 *    a pointer to the result.
 */

static void
print_cmd(char *b)
{
	char **s;
	for (s = command; *s != null; s++) {
		*b = ' ';
		IGNORE strcpy (b + 1, *s);
		b += strlen (b);
	}
	return;
}


/*
 *    EXECUTE THE CURRENT COMMAND
 *
 *    This routine executes the command given by the command array.  It
 *    returns either output, the list of all output files, if successful,
 *    or null, otherwise.  The routine is POSIX compliant.  It uses fork
 *    and execv from unistd.h to fork a process and various routines from
 *    sys/wait.h to analyse the result.  The interface with sys/wait.h
 *    has been abstracted to also allow the BSD implementation.
 */

filename *
execute(filename *input, filename *output)
{
	char *cmd;
	int err = 0;
	boolean filled_buff = 0;
	char buff [buffer_size];

	cmd_string ((char *) null);
	cmd = command [0];
	if (cmd == null) {
		MSG_empty_command ();
		return (null);
	}
	last_command = cmd;
	last_return = 0;
	junk = output;

	if (taciturn) {
		/* Print input files if in taciturn mode */
		filename *p;
		for (p = input; p != null; p = p->next) {
			if (p->storage == INPUT_FILE) {
				comment (1, "%s:\n", p->name);
			}
		}
	}

	if (verbose) {
		/* Print command if in verbose mode */
		print_cmd (buff);
		filled_buff = 1;
		comment (1, "%s\n", buff + 1);
	}

	if (cmd && strneq (cmd, "builtin/", 8)) {
		/* Check built in commands */
		cmd += 8;
		switch (*cmd) {
		case 'b' : {
			if (streq (cmd, "build_archive")) {
				err = build_archive (command [1], command + 2);
				goto execute_error;
			}
			break;
		}
		case 'c' : {
			if (streq (cmd, "cat")) {
				err = cat_file (command [1]);
				goto execute_error;
			}
			break;
		}
		case 'm' : {
			if (streq (cmd, "mkdir")) {
				err = make_dir (command [1]);
				goto execute_error;
			}
			if (streq (cmd, "move")) {
				err = move_file (command [1], command [2]);
				goto execute_error;
			}
			break;
		}
		case 'r' : {
			if (streq (cmd, "remove")) {
				err = remove_file (command [1]);
				goto execute_error;
			}
			break;
		}
		case 's' : {
			if (streq (cmd, "split_archive")) {
				err = split_archive (command [1], &output);
				goto execute_error;
			}
			break;
		}
		case 't' : {
			if (streq (cmd, "touch")) {
				err = touch_file (command [1], command [2]);
				goto execute_error;
			}
			break;
		}
		case 'u' : {
			if (streq (cmd, "undef")) {
				cmd = command [1];
				if (dry_run) {
					MSG_tool_is_not_available_w (cmd);
				} else {
					MSG_tool_is_not_available_i (cmd);
					err = 1;
				}
				goto execute_error;
			}
			break;
		}
		}
		MSG_built_in_command_not_implemented (cmd);
		err = 1;

	} else if (!dry_run) {
		/* Call system commands */
#if FS_FORK
		{
			pid_t pid = fork ();
			if (pid == (pid_t) -1) {
				MSG_cant_fork_process ();
				err = 1;
			} else {
				if (pid) {
					wait_type status;
					running_pid = (long) pid;
					while (process_wait (&status) != pid) /* empty */;
					running_pid = -1;
					if (process_exited (status)) {
						err = process_exit_value (status);
						/* This only returns if there was no
						 * remembered signal.
						 */
						process_delayed_signal ();
					} else {
						if (process_signaled (status)) {
							/* delay_signal_handling is a global that
							 * tells us that it is ok to let the next
							 * call to execute report that the command
							 * received a signal.  This supports the
							 * way that the producer is called.
							 */
							int sig = process_signal_value (status);
							if (delay_signal_handling && last_signal == 0) {
								last_signaled_cmd = string_copy (cmd);
								last_signal = sig;
							} else {
								tenapp_signal (sig);
							}
						}
						err = 1;
					}
					goto execute_error;
				}
				/* print tool chain commands sent to execv */
				if (tool_chain) {
					char **curr = command;
					IGNORE printf ("\n%s \\\n", *curr++);
					while (*curr) {
						IGNORE printf ("\t%s", *curr++);
						if (*curr)
							IGNORE printf (" \\");
						IGNORE printf ("\n");
					}
				}
				/* print environment values sent to execv */
				if (tool_chain_environ) {
					char **curr = environment;
					IGNORE printf ("\n\tEnvironment dump");
					if (!tool_chain)
						IGNORE printf (" for cmd %s", cmd);
					IGNORE printf ("\n");
					while (*curr){
						IGNORE printf ("\t%s\n", *curr);
						curr++;
					}
				}
				IGNORE execve (cmd, command, environment);
				running_pid = -1;
				MSG_cant_execute (cmd);
				exit (2);
			}
		}
#else
		{
			wait_type status;
			if (!filled_buff) {
				print_cmd (buff);
				filled_buff = 1;
			}
			err = system (buff + 1);
			process_return (status, err);
			if (process_exited (status)) {
				err = process_exit_value (status);
				process_delayed_signal ();
			} else {
				if (process_signaled (status)) {
					/* delay_signal_handling is a global that tells us
					 *		       that it is ok to let the next call to execute
					 *		       report that the command received a signal.
					 *		       This supports the way that the producer is called. */
					int sig = process_signal_value (status);
					if (delay_signal_handling && last_signal == 0) {
						last_signaled_cmd = string_copy (cmd);
						last_signal = sig;
					} else {
						tenapp_signal (sig);
					}
				}
				err = 1;
			}
		}
#endif
	}

	/* Deal with errors */
	execute_error : {
		disable_delayed_signal ();
		last_return = err;
		if (tidy_up) {
			/* Remove unneeded files */
			filename *p;
			for (p = input; p != null; p = p->next) {
				if (p->storage == TEMP_FILE && p->type != BINARY_OBJ) {
					IGNORE remove (p->name);
				}
			}
		}
		if (err) {
			exec_error = 1;
			exit_status = EXIT_FAILURE;
			if (show_errors) {
				/* Show when the error occurred */
				if (!filled_buff) print_cmd (buff);
				MSG_error_in (buff + 1);
			}
			remove_junk ();
			return (null);
		}
		junk = null;
		return (output);
	}
}