/*	$OpenPackages$ */
/*	$OpenBSD: compat.c,v 1.45 2001/12/02 00:13:16 espie Exp $	*/
/*	$NetBSD: compat.c,v 1.14 1996/11/06 17:59:01 christos Exp $	*/

/*
 * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
 * Copyright (c) 1988, 1989 by Adam de Boor
 * Copyright (c) 1989 by Berkeley Softworks
 * All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Adam de Boor.
 *
 * 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, 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.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``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 REGENTS OR CONTRIBUTORS 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.
 */

#include <sys/types.h>
#include <sys/stat.h>
#include <sys/wait.h>
#include <ctype.h>
#include <errno.h>
#include <limits.h>
#include <signal.h>
#include <stddef.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "config.h"
#include "defines.h"
#include "dir.h"
#include "job.h"
#include "compat.h"
#include "suff.h"
#include "var.h"
#include "targ.h"
#include "error.h"
#include "str.h"
#include "extern.h"
#include "memory.h"
#include "gnode.h"
#include "make.h"
#include "timestamp.h"
#include "lst.h"
#include "pathnames.h"

/* The following array is used to make a fast determination of which
 * characters are interpreted specially by the shell.  If a command
 * contains any of these characters, it is executed by the shell, not
 * directly by us.  */

static char	    meta[256];

static GNode	    *ENDNode;
static void CompatInterrupt(int);
static int CompatRunCommand(void *, void *);
static void CompatMake(void *, void *);
static int shellneed(char **);

static volatile sig_atomic_t interrupted;

static void 
CompatInterrupt(signo)
    int signo;
{
    if (interrupted != SIGINT)
	interrupted = signo;
}

/*-
 *-----------------------------------------------------------------------
 * shellneed --
 *
 * Results:
 *	Returns 1 if a specified set of arguments
 *	must be executed by the shell,
 *	0 if it can be run via execve, and -1 if the command can be
 *	handled internally
 *
 * Side Effects:
 *	May modify the process umask
 *-----------------------------------------------------------------------
 */
static int
shellneed(av)
	char **av;
{
	char *runsh[] = {
		"alias", "cd", "eval", "exec", "exit", "read", "set", "ulimit",
		"unalias", "unset", "wait",
		NULL
	};

	char **p;

	/* FIXME most of these ARE actual no-ops */
	for (p = runsh; *p; p++)
		if (strcmp(av[0], *p) == 0)
			return 1;

	if (strcmp(av[0], "umask") == 0) {
		long umi;
		char *ep = NULL;
		mode_t um;

		if (av[1] != NULL) {
			umi = strtol(av[1], &ep, 8);
			if (ep == NULL)
				return 1;
			um = umi;
		}
		else {
			um = umask(0);
			printf("%o\n", um);
		}
		(void)umask(um);
		return -1;
	}

	return 0;
}

/*-
 *-----------------------------------------------------------------------
 * CompatRunCommand --
 *	Execute the next command for a target. If the command returns an
 *	error, the node's made field is set to ERROR and creation stops.
 *
 * Results:
 *	0 in case of error, 1 if ok.
 *
 * Side Effects:
 *	The node's 'made' field may be set to ERROR.
 *-----------------------------------------------------------------------
 */
static int
CompatRunCommand(cmdp, gnp)
    void *	  cmdp; 	/* Command to execute */
    void *	  gnp;		/* Node from which the command came */
{
    char	  *cmdStart;	/* Start of expanded command */
    char *cp, *bp = NULL;
    bool	  silent,	/* Don't print command */
		  errCheck,	/* Check errors */
		  doExecute;	/* Execute the command */
    int 	  reason;	/* Reason for child's death */
    int 	  status;	/* Description of child's death */
    int 	  cpid; 	/* Child actually found */
    int		  stat; 	/* Status of fork */
    LstNode	  cmdNode;	/* Node where current command is located */
    char	  **av; 	/* Argument vector for thing to exec */
    int 	  argc; 	/* Number of arguments in av or 0 if not
				 * dynamically allocated */
    bool	  local;	/* true if command should be executed
				 * locally */
    char	  *cmd = (char *)cmdp;
    GNode	  *gn = (GNode *)gnp;
    static char *shargv[4] = { _PATH_BSHELL };

    /* Avoid clobbered variable warnings by forcing the compiler
     * to ``unregister'' variables.  */
#if __GNUC__
    (void)&av;
    (void)&errCheck;
#endif
    silent = gn->type & OP_SILENT;
    errCheck = !(gn->type & OP_IGNORE);
    doExecute = !noExecute;

    cmdNode = Lst_Member(&gn->commands, cmd);
    cmdStart = Var_Subst(cmd, &gn->context, false);

    /* brk_string will return an argv with a NULL in av[0], thus causing
     * execvp to choke and die horribly. Besides, how can we execute a null
     * command? In any case, we warn the user that the command expanded to
     * nothing (is this the right thing to do?).  */

    if (*cmdStart == '\0') {
	free(cmdStart);
	Error("%s expands to empty string", cmd);
	return 1;
    } else
	cmd = cmdStart;
    Lst_Replace(cmdNode, cmdStart);

    if ((gn->type & OP_SAVE_CMDS) && (gn != ENDNode)) {
	Lst_AtEnd(&ENDNode->commands, cmdStart);
	return 1;
    } else if (strcmp(cmdStart, "...") == 0) {
	gn->type |= OP_SAVE_CMDS;
	return 1;
    }

    for (;; cmd++) {
	if (*cmd == '@')
	    silent = DEBUG(LOUD) ? false : true;
	else if (*cmd == '-')
	    errCheck = false;
	else if (*cmd == '+')
	    doExecute = true;
	else
	    break;
    }

    while (isspace(*cmd))
	cmd++;

    /* Search for meta characters in the command. If there are no meta
     * characters, there's no need to execute a shell to execute the
     * command.  */
    for (cp = cmd; !meta[(unsigned char)*cp]; cp++) {
	continue;
    }

    /* Print the command before echoing if we're not supposed to be quiet for
     * this one. We also print the command if -n given.  */
    if (!silent || noExecute) {
	printf("%s\n", cmd);
	fflush(stdout);
    }

    /* If we're not supposed to execute any commands, this is as far as
     * we go...  */
    if (!doExecute)
	return 1;

    if (*cp != '\0') {
	/* If *cp isn't the null character, we hit a "meta" character and
	 * need to pass the command off to the shell. We give the shell the
	 * -e flag as well as -c if it's supposed to exit when it hits an
	 * error.  */

	shargv[1] = errCheck ? "-ec" : "-c";
	shargv[2] = cmd;
	shargv[3] = NULL;
	av = shargv;
	argc = 0;
    } else {
	/* No meta-characters, so probably no need to exec a shell.
	 * Break the command into words to form an argument vector
	 * we can execute.  */
	av = brk_string(cmd, &argc, &bp);
	switch (shellneed(av)) {
	case -1: /* handled internally */
		free(bp);
		free(av);
		return 1;
	case 1:
		shargv[1] = errCheck ? "-ec" : "-c";
		shargv[2] = cmd;
		shargv[3] = NULL;
		free(av);
		free(bp);
		bp = NULL;
		av = shargv;
		argc = 0;
		break;
	default: /* nothing needed */
		break;
	}
    }

    local = true;

    /* Fork and execute the single command. If the fork fails, we abort.  */
    cpid = vfork();
    if (cpid == -1)
	Fatal("Could not fork");
    if (cpid == 0) {
	if (local) {
	    execvp(av[0], av);
	    if (errno == ENOENT)
		fprintf(stderr, "%s: not found\n", av[0]);
	    else
		perror(av[0]);
	} else
	    (void)execv(av[0], av);
	_exit(1);
    }
    if (bp) {
	free(av);
	free(bp);
    }
    free(cmdStart);
    Lst_Replace(cmdNode, NULL);

    /* The child is off and running. Now all we can do is wait...  */
    while (1) {

	while ((stat = wait(&reason)) != cpid) {
	    if (stat == -1 && errno != EINTR)
		break;
	}

	if (interrupted)
	    break;

	if (stat != -1) {
	    if (WIFSTOPPED(reason))
		status = WSTOPSIG(reason);		/* stopped */
	    else if (WIFEXITED(reason)) {
		status = WEXITSTATUS(reason);		/* exited */
		if (status != 0)
		    printf("*** Error code %d", status);
	    } else {
		status = WTERMSIG(reason);		/* signaled */
		printf("*** Signal %d", status);
	    }


	    if (!WIFEXITED(reason) || status != 0) {
		if (errCheck) {
		    gn->made = ERROR;
		    if (keepgoing)
			/* Abort the current target, but let others
			 * continue.  */
			printf(" (continuing)\n");
		} else {
		    /* Continue executing commands for this target.
		     * If we return 0, this will happen...  */
		    printf(" (ignored)\n");
		    status = 0;
		}
	    }
	    return !status;
	} else
	    Fatal("error in wait: %d", stat);
	    /*NOTREACHED*/
    }

    /* This is reached only if interrupted */
    if (!Targ_Precious(gn)) {
	char	  *file = Varq_Value(TARGET_INDEX, gn);

	if (!noExecute && eunlink(file) != -1)
	    Error("*** %s removed\n", file);
    }
    if (interrupted == SIGINT) {
    	GNode *i = Targ_FindNode(".INTERRUPT", TARG_NOCREATE);
	signal(SIGINT, SIG_IGN);
	signal(SIGTERM, SIG_IGN);
	signal(SIGHUP, SIG_IGN);
	signal(SIGQUIT, SIG_IGN);
	interrupted = 0;
	if (i != NULL)
	    Lst_Find(&i->commands, CompatRunCommand, i);
	exit(SIGINT);
    }
    exit(interrupted);
}

/*-
 *-----------------------------------------------------------------------
 * CompatMake --
 *	Make a target.
 *
 * Side Effects:
 *	If an error is detected and not being ignored, the process exits.
 *-----------------------------------------------------------------------
 */
static void
CompatMake(gnp, pgnp)
    void *	gnp;	    /* The node to make */
    void *	pgnp;	    /* Parent to abort if necessary */
{
    GNode *gn = (GNode *)gnp;
    GNode *pgn = (GNode *)pgnp;

    if (pgn->type & OP_MADE) {
	(void)Dir_MTime(gn);
	gn->made = UPTODATE;
    }

    if (gn->type & OP_USE) {
	Make_HandleUse(gn, pgn);
    } else if (gn->made == UNMADE) {
	/* First mark ourselves to be made, then apply whatever transformations
	 * the suffix module thinks are necessary. Once that's done, we can
	 * descend and make all our children. If any of them has an error
	 * but the -k flag was given, our 'make' field will be set false again.
	 * This is our signal to not attempt to do anything but abort our
	 * parent as well.  */
	gn->make = true;
	gn->made = BEINGMADE;
	Suff_FindDeps(gn);
	Lst_ForEach(&gn->children, CompatMake, gn);
	if (!gn->make) {
	    gn->made = ABORTED;
	    pgn->make = false;
	    return;
	}

	if (Lst_Member(&gn->iParents, pgn) != NULL) {
	    Varq_Set(IMPSRC_INDEX, Varq_Value(TARGET_INDEX, gn), pgn);
	}

	/* All the children were made ok. Now cmtime contains the modification
	 * time of the newest child, we need to find out if we exist and when
	 * we were modified last. The criteria for datedness are defined by the
	 * Make_OODate function.  */
	if (DEBUG(MAKE))
	    printf("Examining %s...", gn->name);
	if (! Make_OODate(gn)) {
	    gn->made = UPTODATE;
	    if (DEBUG(MAKE))
		printf("up-to-date.\n");
	    return;
	} else if (DEBUG(MAKE))
	    printf("out-of-date.\n");

	/* If the user is just seeing if something is out-of-date, exit now
	 * to tell him/her "yes".  */
	if (queryFlag)
	    exit(-1);

	/* We need to be re-made. We also have to make sure we've got a $?
	 * variable. To be nice, we also define the $> variable using
	 * Make_DoAllVar().  */
	Make_DoAllVar(gn);

	/* Alter our type to tell if errors should be ignored or things
	 * should not be printed so CompatRunCommand knows what to do.	*/
	if (Targ_Ignore(gn))
	    gn->type |= OP_IGNORE;
	if (Targ_Silent(gn))
	    gn->type |= OP_SILENT;

	if (Job_CheckCommands(gn, Fatal)) {
	    /* Our commands are ok, but we still have to worry about the -t
	     * flag...	*/
	    if (!touchFlag)
		Lst_Find(&gn->commands, CompatRunCommand, gn);
	    else
		Job_Touch(gn, gn->type & OP_SILENT);
	} else
	    gn->made = ERROR;

	if (gn->made != ERROR) {
	    /* If the node was made successfully, mark it so, update
	     * its modification time and timestamp all its parents. Note
	     * that for .ZEROTIME targets, the timestamping isn't done.
	     * This is to keep its state from affecting that of its parent.  */
	    gn->made = MADE;
#ifndef RECHECK
	    /* We can't re-stat the thing, but we can at least take care of
	     * rules where a target depends on a source that actually creates
	     * the target, but only if it has changed, e.g.
	     *
	     * parse.h : parse.o
	     *
	     * parse.o : parse.y
	     *		yacc -d parse.y
	     *		cc -c y.tab.c
	     *		mv y.tab.o parse.o
	     *		cmp -s y.tab.h parse.h || mv y.tab.h parse.h
	     *
	     * In this case, if the definitions produced by yacc haven't
	     * changed from before, parse.h won't have been updated and
	     * gn->mtime will reflect the current modification time for
	     * parse.h. This is something of a kludge, I admit, but it's a
	     * useful one..
	     *
	     * XXX: People like to use a rule like
	     *
	     * FRC:
	     *
	     * To force things that depend on FRC to be made, so we have to
	     * check for gn->children being empty as well...  */
	    if (!Lst_IsEmpty(&gn->commands) || Lst_IsEmpty(&gn->children))
		gn->mtime = now;
#else
	    /* This is what Make does and it's actually a good thing, as it
	     * allows rules like
	     *
	     *	cmp -s y.tab.h parse.h || cp y.tab.h parse.h
	     *
	     * to function as intended. Unfortunately, thanks to the stateless
	     * nature of NFS (and the speed of this program), there are times
	     * when the modification time of a file created on a remote
	     * machine will not be modified before the stat() implied by
	     * the Dir_MTime occurs, thus leading us to believe that the file
	     * is unchanged, wreaking havoc with files that depend on this one.
	     *
	     * I have decided it is better to make too much than to make too
	     * little, so this stuff is commented out unless you're sure it's
	     * ok.
	     * -- ardeb 1/12/88
	     */
	    if (noExecute || is_out_of_date(Dir_MTime(gn)))
		gn->mtime = now;
	    if (is_strictly_before(gn->mtime, gn->cmtime))
		gn->mtime = gn->cmtime;
	    if (DEBUG(MAKE))
		printf("update time: %s\n", Targ_FmtTime(gn->mtime));
#endif
	    if (!(gn->type & OP_EXEC)) {
		pgn->childMade = true;
		Make_TimeStamp(pgn, gn);
	    }
	} else if (keepgoing)
	    pgn->make = false;
	else {

	    if (gn->lineno)
		printf("\n\nStop in %s (line %lu of %s).\n",
			Var_Value(".CURDIR"),
			(unsigned long)gn->lineno,
			gn->fname);
	    else
		printf("\n\nStop in %s.\n", Var_Value(".CURDIR"));
	    exit(1);
	}
    } else if (gn->made == ERROR)
	/* Already had an error when making this beastie. Tell the parent
	 * to abort.  */
	pgn->make = false;
    else {
	if (Lst_Member(&gn->iParents, pgn) != NULL) {
	    Varq_Set(IMPSRC_INDEX, Varq_Value(TARGET_INDEX, gn), pgn);
	}
	switch (gn->made) {
	    case BEINGMADE:
		Error("Graph cycles through %s\n", gn->name);
		gn->made = ERROR;
		pgn->make = false;
		break;
	    case MADE:
		if ((gn->type & OP_EXEC) == 0) {
		    pgn->childMade = true;
		    Make_TimeStamp(pgn, gn);
		}
		break;
	    case UPTODATE:
		if ((gn->type & OP_EXEC) == 0)
		    Make_TimeStamp(pgn, gn);
		break;
	    default:
		break;
	}
    }
}

void
Compat_Run(targs)
    Lst 	  targs;    /* List of target nodes to re-create */
{
    char	  *cp;	    /* Pointer to string of shell meta-characters */
    GNode	  *gn = NULL;/* Current root target */
    int 	  errors;   /* Number of targets not remade due to errors */

    signal(SIGINT, CompatInterrupt);
    signal(SIGTERM, CompatInterrupt);
    signal(SIGHUP, CompatInterrupt);
    signal(SIGQUIT, CompatInterrupt);

    for (cp = "#=|^(){};&<>*?[]:$`\\\n"; *cp != '\0'; cp++)
	meta[(unsigned char) *cp] = 1;
    /* The null character serves as a sentinel in the string.  */
    meta[0] = 1;

    ENDNode = Targ_FindNode(".END", TARG_CREATE);
    /* If the user has defined a .BEGIN target, execute the commands attached
     * to it.  */
    if (!queryFlag) {
	gn = Targ_FindNode(".BEGIN", TARG_NOCREATE);
	if (gn != NULL) {
	    Lst_Find(&gn->commands, CompatRunCommand, gn);
	    if (gn->made == ERROR) {
		printf("\n\nStop.\n");
		exit(1);
	    }
	}
    }

    /* For each entry in the list of targets to create, call CompatMake on
     * it to create the thing. CompatMake will leave the 'made' field of gn
     * in one of several states:
     *	    UPTODATE	    gn was already up-to-date
     *	    MADE	    gn was recreated successfully
     *	    ERROR	    An error occurred while gn was being created
     *	    ABORTED	    gn was not remade because one of its inferiors
     *			    could not be made due to errors.  */
    errors = 0;
    while ((gn = (GNode *)Lst_DeQueue(targs)) != NULL) {
	CompatMake(gn, gn);

	if (gn->made == UPTODATE)
	    printf("`%s' is up to date.\n", gn->name);
	else if (gn->made == ABORTED) {
	    printf("`%s' not remade because of errors.\n", gn->name);
	    errors += 1;
	}
    }

    /* If the user has defined a .END target, run its commands.  */
    if (errors == 0)
	Lst_Find(&ENDNode->commands, CompatRunCommand, ENDNode);
}