xref: /openbsd-src/usr.bin/make/engine.c (revision 91f110e064cd7c194e59e019b83bb7496c1c84d4)
1 /*	$OpenBSD: engine.c,v 1.47 2013/11/22 15:47:35 espie Exp $ */
2 /*
3  * Copyright (c) 2012 Marc Espie.
4  *
5  * Extensive code modifications for the OpenBSD project.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  *
16  * THIS SOFTWARE IS PROVIDED BY THE OPENBSD PROJECT AND CONTRIBUTORS
17  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
18  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
19  * A PARTICULAR PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OPENBSD
20  * PROJECT OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
21  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
22  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
26  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27  */
28 /*
29  * Copyright (c) 1988, 1989, 1990 The Regents of the University of California.
30  * Copyright (c) 1988, 1989 by Adam de Boor
31  * Copyright (c) 1989 by Berkeley Softworks
32  * All rights reserved.
33  *
34  * This code is derived from software contributed to Berkeley by
35  * Adam de Boor.
36  *
37  * Redistribution and use in source and binary forms, with or without
38  * modification, are permitted provided that the following conditions
39  * are met:
40  * 1. Redistributions of source code must retain the above copyright
41  *    notice, this list of conditions and the following disclaimer.
42  * 2. Redistributions in binary form must reproduce the above copyright
43  *    notice, this list of conditions and the following disclaimer in the
44  *    documentation and/or other materials provided with the distribution.
45  * 3. Neither the name of the University nor the names of its contributors
46  *    may be used to endorse or promote products derived from this software
47  *    without specific prior written permission.
48  *
49  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
50  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
51  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
52  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
53  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
54  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
55  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
56  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
57  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
58  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
59  * SUCH DAMAGE.
60  */
61 
62 #include <sys/types.h>
63 #include <sys/time.h>
64 #include <sys/wait.h>
65 #include <assert.h>
66 #include <ctype.h>
67 #include <errno.h>
68 #include <fcntl.h>
69 #include <limits.h>
70 #include <signal.h>
71 #include <stdint.h>
72 #include <stdio.h>
73 #include <stdlib.h>
74 #include <string.h>
75 #include <unistd.h>
76 #include "config.h"
77 #include "defines.h"
78 #include "dir.h"
79 #include "engine.h"
80 #include "arch.h"
81 #include "gnode.h"
82 #include "targ.h"
83 #include "var.h"
84 #include "extern.h"
85 #include "lst.h"
86 #include "timestamp.h"
87 #include "make.h"
88 #include "pathnames.h"
89 #include "error.h"
90 #include "str.h"
91 #include "memory.h"
92 #include "buf.h"
93 #include "job.h"
94 #include "lowparse.h"
95 
96 static void MakeTimeStamp(void *, void *);
97 static int rewrite_time(const char *);
98 static void setup_meta(void);
99 static void setup_engine(void);
100 static char **recheck_command_for_shell(char **);
101 static void list_parents(GNode *, FILE *);
102 
103 /* XXX due to a bug in make's logic, targets looking like *.a or -l*
104  * have been silently dropped when make couldn't figure them out.
105  * Now, we warn about them until all Makefile bugs have been fixed.
106  */
107 static bool
108 drop_silently(const char *s)
109 {
110 	size_t len;
111 
112 	if (s[0] == '-' && s[1] == 'l')
113 		return true;
114 
115 	len = strlen(s);
116 	if (len >=2 && s[len-2] == '.' && s[len-1] == 'a')
117 		return true;
118 	return false;
119 }
120 
121 bool
122 node_find_valid_commands(GNode *gn)
123 {
124 	/* Alter our type to tell if errors should be ignored or things
125 	 * should not be printed so setup_and_run_command knows what to do.
126 	 */
127 	if (Targ_Ignore(gn))
128 		gn->type |= OP_IGNORE;
129 	if (Targ_Silent(gn))
130 		gn->type |= OP_SILENT;
131 
132 	if (DEBUG(DOUBLE) && (gn->type & OP_DOUBLE))
133 		fprintf(stderr, "Warning: target %s had >1 lists of "
134 		    "shell commands (ignoring later ones)\n", gn->name);
135 	if (OP_NOP(gn->type) && Lst_IsEmpty(&gn->commands)) {
136 		if (drop_silently(gn->name)) {
137 			printf("Warning: target %s", gn->name);
138 			list_parents(gn, stdout);
139 			printf(" does not have any command (BUG)\n");
140 			return true;
141 		}
142 		/*
143 		 * No commands. Look for .DEFAULT rule from which we might infer
144 		 * commands
145 		 */
146 		if ((gn->type & OP_NODEFAULT) == 0 &&
147 		    (DEFAULT->type & OP_DUMMY) == 0 &&
148 		    !Lst_IsEmpty(&DEFAULT->commands)) {
149 			/*
150 			 * Make only looks for a .DEFAULT if the node was never
151 			 * the target of an operator, so that's what we do too.
152 			 * If a .DEFAULT was given, we substitute its commands
153 			 * for gn's commands and set the IMPSRC variable to be
154 			 * the target's name The DEFAULT node acts like a
155 			 * transformation rule, in that gn also inherits any
156 			 * attributes or sources attached to .DEFAULT itself.
157 			 */
158 			Make_HandleUse(DEFAULT, gn);
159 			Var(IMPSRC_INDEX, gn) = Var(TARGET_INDEX, gn);
160 		} else if (is_out_of_date(Dir_MTime(gn))) {
161 			/*
162 			 * The node wasn't the target of an operator we have no
163 			 * .DEFAULT rule to go on and the target doesn't
164 			 * already exist. There's nothing more we can do for
165 			 * this branch.
166 			 */
167 			 return false;
168 	    	}
169 	}
170 	return true;
171 }
172 
173 static void
174 list_parents(GNode *gn, FILE *out)
175 {
176 	LstNode ln;
177 	bool first = true;
178 
179 	for (ln = Lst_First(&gn->parents); ln != NULL; ln = Lst_Adv(ln)) {
180 		GNode *p = Lst_Datum(ln);
181 		if (!p->must_make)
182 			continue;
183 		if (first) {
184 			fprintf(out, " (prerequisite of:");
185 			first = false;
186 		}
187 		fprintf(out, " %s", p->name);
188 	}
189 	if (!first)
190 		fprintf(out, ")");
191 }
192 
193 void
194 node_failure(GNode *gn)
195 {
196 	/*
197 	 If the -k flag wasn't given, we stop in
198 	 * our tracks, otherwise we just don't update this
199 	 * node's parents so they never get examined.
200 	 */
201 	const char *diag;
202 	FILE *out;
203 
204 	if (gn->type & OP_OPTIONAL) {
205 		out = stdout;
206 		diag = "(ignored)";
207 	} else if (keepgoing) {
208 		out = stdout;
209 		diag = "(continuing)";
210 	} else {
211 		out = stderr;
212 		diag = "";
213 	}
214 	fprintf(out, "make: don't know how to make %s", gn->name);
215 	list_parents(gn, out);
216 	fprintf(out, "%s\n", diag);
217 	if (out == stdout)
218 		fflush(stdout);
219 	else {
220 		print_errors();
221 		Punt(NULL);
222 	}
223 }
224 
225 /* touch files the hard way, by writing stuff to them */
226 static int
227 rewrite_time(const char *name)
228 {
229 	int fd;
230 	char c;
231 
232 	fd = open(name, O_RDWR | O_CREAT, 0666);
233 	if (fd < 0)
234 		return -1;
235 	/*
236 	 * Read and write a byte to the file to change
237 	 * the modification time.
238 	 */
239 	if (read(fd, &c, 1) == 1) {
240 		(void)lseek(fd, 0, SEEK_SET);
241 		(void)write(fd, &c, 1);
242 	}
243 
244 	(void)close(fd);
245 	return 0;
246 }
247 
248 void
249 Job_Touch(GNode *gn)
250 {
251 	handle_all_signals();
252 	if (gn->type & (OP_JOIN|OP_USE|OP_EXEC|OP_OPTIONAL|OP_PHONY)) {
253 		/*
254 		 * .JOIN, .USE, and .OPTIONAL targets are "virtual" targets
255 		 * and, as such, shouldn't really be created.
256 		 * Likewise, .PHONY targets are not really files
257 		 */
258 		return;
259 	}
260 
261 	if (!(gn->type & OP_SILENT)) {
262 		(void)fprintf(stdout, "touch %s\n", gn->name);
263 		(void)fflush(stdout);
264 	}
265 
266 	if (noExecute) {
267 		return;
268 	}
269 
270 	if (gn->type & OP_ARCHV) {
271 		Arch_Touch(gn);
272 	} else {
273 		const char *file = gn->path != NULL ? gn->path : gn->name;
274 
275 		if (set_times(file) == -1){
276 			if (rewrite_time(file) == -1) {
277 				(void)fprintf(stdout,
278 				    "*** couldn't touch %s: %s", file,
279 				    strerror(errno));
280 				(void)fflush(stdout);
281 		    	}
282 		}
283 	}
284 }
285 
286 void
287 Make_TimeStamp(GNode *parent, GNode *child)
288 {
289 	if (is_strictly_before(parent->youngest->mtime, child->mtime)) {
290  		parent->youngest = child;
291 	}
292 }
293 
294 void
295 Make_HandleUse(GNode	*cgn,	/* The .USE node */
296     GNode	*pgn)	/* The target of the .USE node */
297 {
298 	GNode	*gn;	/* A child of the .USE node */
299 	LstNode	ln;	/* An element in the children list */
300 
301 
302 	assert(cgn->type & (OP_USE|OP_TRANSFORM));
303 
304 	if ((cgn->type & OP_USE) || Lst_IsEmpty(&pgn->commands)) {
305 		/* .USE or transformation and target has no commands
306 		 * -- append the child's commands to the parent.  */
307 		Lst_Concat(&pgn->commands, &cgn->commands);
308 	}
309 
310 	for (ln = Lst_First(&cgn->children); ln != NULL;
311 	    ln = Lst_Adv(ln)) {
312 		gn = (GNode *)Lst_Datum(ln);
313 
314 		if (Lst_AddNew(&pgn->children, gn)) {
315 			Lst_AtEnd(&gn->parents, pgn);
316 			pgn->unmade++;
317 		}
318 	}
319 
320 	if (DEBUG(DOUBLE) && (cgn->type & OP_DOUBLE))
321 		fprintf(stderr,
322 		    "Warning: .USE %s expanded in %s had >1 lists of "
323 		    "shell commands (ignoring later ones)\n",
324 		    cgn->name, pgn->name);
325 	pgn->type |= cgn->type & ~(OP_OPMASK|OP_USE|OP_TRANSFORM|OP_DOUBLE);
326 
327 	/*
328 	 * This child node is now "made", so we decrement the count of
329 	 * unmade children in the parent... We also remove the child
330 	 * from the parent's list to accurately reflect the number of
331 	 * decent children the parent has. This is used by Make_Run to
332 	 * decide whether to queue the parent or examine its children...
333 	 */
334 	if (cgn->type & OP_USE)
335 		pgn->unmade--;
336 }
337 
338 void
339 Make_DoAllVar(GNode *gn)
340 {
341 	GNode *child;
342 	LstNode ln;
343 	BUFFER allsrc, oodate;
344 	char *target;
345 	bool do_oodate;
346 	int oodate_count, allsrc_count = 0;
347 
348 	oodate_count = 0;
349 	allsrc_count = 0;
350 
351 	Var(OODATE_INDEX, gn) = "";
352 	Var(ALLSRC_INDEX, gn) = "";
353 
354 	for (ln = Lst_First(&gn->children); ln != NULL; ln = Lst_Adv(ln)) {
355 		child = (GNode *)Lst_Datum(ln);
356 		if ((child->type & (OP_EXEC|OP_USE|OP_INVISIBLE)) != 0)
357 			continue;
358 		if (OP_NOP(child->type) ||
359 		    (target = Var(TARGET_INDEX, child)) == NULL) {
360 			/*
361 			 * this node is only source; use the specific pathname
362 			 * for it
363 			 */
364 			target = child->path != NULL ? child->path :
365 			    child->name;
366 		}
367 
368 		/*
369 		 * It goes in the OODATE variable if the parent is younger than
370 		 * the child or if the child has been modified more recently
371 		 * than the start of the make.  This is to keep make from
372 		 * getting confused if something else updates the parent after
373 		 * the make starts (shouldn't happen, I know, but sometimes it
374 		 * does). In such a case, if we've updated the kid, the parent
375 		 * is likely to have a modification time later than that of the
376 		 * kid and anything that relies on the OODATE variable will be
377 		 * hosed.
378 		 */
379 		do_oodate = false;
380 		if (gn->type & OP_JOIN) {
381 			if (child->built_status == MADE)
382 				do_oodate = true;
383 		} else if (is_strictly_before(gn->mtime, child->mtime) ||
384 		   (!is_strictly_before(child->mtime, starttime) &&
385 		   child->built_status == MADE))
386 		   	do_oodate = true;
387 		if (do_oodate) {
388 			oodate_count++;
389 			if (oodate_count == 1)
390 				Var(OODATE_INDEX, gn) = target;
391 			else {
392 				if (oodate_count == 2) {
393 					Buf_Init(&oodate, 0);
394 					Buf_AddString(&oodate,
395 					    Var(OODATE_INDEX, gn));
396 				}
397 				Buf_AddSpace(&oodate);
398 				Buf_AddString(&oodate, target);
399 			}
400 		}
401 		allsrc_count++;
402 		if (allsrc_count == 1)
403 			Var(ALLSRC_INDEX, gn) = target;
404 		else {
405 			if (allsrc_count == 2) {
406 				Buf_Init(&allsrc, 0);
407 				Buf_AddString(&allsrc,
408 				    Var(ALLSRC_INDEX, gn));
409 			}
410 			Buf_AddSpace(&allsrc);
411 			Buf_AddString(&allsrc, target);
412 		}
413 	}
414 
415 	if (allsrc_count > 1)
416 		Var(ALLSRC_INDEX, gn) = Buf_Retrieve(&allsrc);
417 	if (oodate_count > 1)
418 		Var(OODATE_INDEX, gn) = Buf_Retrieve(&oodate);
419 
420 	if (gn->impliedsrc)
421 		Var(IMPSRC_INDEX, gn) = Var(TARGET_INDEX, gn->impliedsrc);
422 
423 	if (gn->type & OP_JOIN)
424 		Var(TARGET_INDEX, gn) = Var(ALLSRC_INDEX, gn);
425 }
426 
427 /* Wrapper to call Make_TimeStamp from a forEach loop.	*/
428 static void
429 MakeTimeStamp(void *parent, void *child)
430 {
431     Make_TimeStamp((GNode *)parent, (GNode *)child);
432 }
433 
434 bool
435 Make_OODate(GNode *gn)
436 {
437 	bool	    oodate;
438 
439 	/*
440 	 * Certain types of targets needn't even be sought as their datedness
441 	 * doesn't depend on their modification time...
442 	 */
443 	if ((gn->type & (OP_JOIN|OP_USE|OP_EXEC|OP_PHONY)) == 0) {
444 		(void)Dir_MTime(gn);
445 		if (DEBUG(MAKE)) {
446 			if (!is_out_of_date(gn->mtime))
447 				printf("modified %s...",
448 				    time_to_string(&gn->mtime));
449 			else
450 				printf("non-existent...");
451 		}
452 	}
453 
454 	/*
455 	 * A target is remade in one of the following circumstances:
456 	 * - its modification time is smaller than that of its youngest child
457 	 *   and it would actually be run (has commands or type OP_NOP)
458 	 * - it's the object of a force operator
459 	 * - it has no children, was on the lhs of an operator and doesn't
460 	 *   exist already.
461 	 *
462 	 */
463 	if (gn->type & OP_USE) {
464 		/*
465 		 * If the node is a USE node it is *never* out of date
466 		 * no matter *what*.
467 		 */
468 		if (DEBUG(MAKE))
469 			printf(".USE node...");
470 		oodate = false;
471 	} else if (gn->type & OP_JOIN) {
472 		/*
473 		 * A target with the .JOIN attribute is only considered
474 		 * out-of-date if any of its children was out-of-date.
475 		 */
476 		if (DEBUG(MAKE))
477 			printf(".JOIN node...");
478 		oodate = gn->childMade;
479 	} else if (gn->type & (OP_FORCE|OP_EXEC|OP_PHONY)) {
480 		/*
481 		 * A node which is the object of the force (!) operator or which
482 		 * has the .EXEC attribute is always considered out-of-date.
483 		 */
484 		if (DEBUG(MAKE)) {
485 			if (gn->type & OP_FORCE)
486 				printf("! operator...");
487 			else if (gn->type & OP_PHONY)
488 				printf(".PHONY node...");
489 			else
490 				printf(".EXEC node...");
491 		}
492 		oodate = true;
493 	} else if (is_strictly_before(gn->mtime, gn->youngest->mtime) ||
494 	   (gn == gn->youngest &&
495 	    (is_out_of_date(gn->mtime) || (gn->type & OP_DOUBLEDEP)))) {
496 		/*
497 		 * A node whose modification time is less than that of its
498 		 * youngest child or that has no children (gn->youngest == gn)
499 		 * and either doesn't exist (mtime == OUT_OF_DATE)
500 		 * or was the object of a :: operator is out-of-date.
501 		 */
502 		if (DEBUG(MAKE)) {
503 			if (is_strictly_before(gn->mtime, gn->youngest->mtime))
504 				printf("modified before source(%s)...",
505 				    gn->youngest->name);
506 			else if (is_out_of_date(gn->mtime))
507 				printf("non-existent and no sources...");
508 			else
509 				printf(":: operator and no sources...");
510 		}
511 		oodate = true;
512 	} else {
513 		oodate = false;
514 	}
515 
516 	/*
517 	 * If the target isn't out-of-date, the parents need to know its
518 	 * modification time. Note that targets that appear to be out-of-date
519 	 * but aren't, because they have no commands and aren't of type OP_NOP,
520 	 * have their mtime stay below their children's mtime to keep parents
521 	 * from thinking they're out-of-date.
522 	 */
523 	if (!oodate)
524 		Lst_ForEach(&gn->parents, MakeTimeStamp, gn);
525 
526 	return oodate;
527 }
528 
529 /* The following array is used to make a fast determination of which
530  * characters are interpreted specially by the shell.  If a command
531  * contains any of these characters, it is executed by the shell, not
532  * directly by us.  */
533 static char	    meta[256];
534 
535 void
536 setup_meta(void)
537 {
538 	char *p;
539 
540 	for (p = "#=|^(){};&<>*?[]:$`\\\n"; *p != '\0'; p++)
541 		meta[(unsigned char) *p] = 1;
542 	/* The null character serves as a sentinel in the string.  */
543 	meta[0] = 1;
544 }
545 
546 static char **
547 recheck_command_for_shell(char **av)
548 {
549 	char *runsh[] = {
550 		"!", "alias", "cd", "eval", "exit", "read", "set", "ulimit",
551 		"unalias", "unset", "wait", "umask", NULL
552 	};
553 
554 	char **p;
555 
556 	/* optimization: if exec cmd, we avoid the intermediate shell */
557 	if (strcmp(av[0], "exec") == 0)
558 		av++;
559 
560 	for (p = runsh; *p; p++)
561 		if (strcmp(av[0], *p) == 0)
562 			return NULL;
563 
564 	return av;
565 }
566 
567 static void
568 run_command(const char *cmd, bool errCheck)
569 {
570 	const char *p;
571 	char *shargv[4];
572 	char **todo;
573 
574 	shargv[0] = _PATH_BSHELL;
575 
576 	shargv[1] = errCheck ? "-ec" : "-c";
577 	shargv[2] = (char *)cmd;
578 	shargv[3] = NULL;
579 
580 	todo = shargv;
581 
582 
583 	/* Search for meta characters in the command. If there are no meta
584 	 * characters, there's no need to execute a shell to execute the
585 	 * command.  */
586 	for (p = cmd; !meta[(unsigned char)*p]; p++)
587 		continue;
588 	if (*p == '\0') {
589 		char *bp;
590 		char **av;
591 		int argc;
592 		/* No meta-characters, so probably no need to exec a shell.
593 		 * Break the command into words to form an argument vector
594 		 * we can execute.  */
595 		av = brk_string(cmd, &argc, &bp);
596 		av = recheck_command_for_shell(av);
597 		if (av != NULL)
598 			todo = av;
599 	}
600 	execvp(todo[0], todo);
601 
602 	if (errno == ENOENT)
603 		fprintf(stderr, "%s: not found\n", todo[0]);
604 	else
605 		perror(todo[0]);
606 	_exit(1);
607 }
608 
609 static Job myjob;
610 
611 void
612 job_attach_node(Job *job, GNode *node)
613 {
614 	job->node = node;
615 	job->node->built_status = BUILDING;
616 	job->next_cmd = Lst_First(&node->commands);
617 	job->exit_type = JOB_EXIT_OKAY;
618 	job->location = NULL;
619 	job->flags = 0;
620 }
621 
622 void
623 job_handle_status(Job *job, int status)
624 {
625 	bool silent;
626 	int dying;
627 
628 	/* if there's one job running and we don't keep going, no need
629 	 * to report right now.
630 	 */
631 	if ((job->flags & JOB_ERRCHECK) && !keepgoing && runningJobs == NULL)
632 		silent = !DEBUG(JOB);
633 	else
634 		silent = false;
635 
636 	debug_job_printf("Process %ld (%s) exited with status %d.\n",
637 	    (long)job->pid, job->node->name, status);
638 
639 	/* classify status */
640 	if (WIFEXITED(status)) {
641 		job->code = WEXITSTATUS(status);/* exited */
642 		if (job->code != 0) {
643 			/* if we're already dying from that signal, be silent */
644 			if (!silent && job->code > 128
645 			    && job->code <= 128 + _NSIG) {
646 				dying = check_dying_signal();
647 				silent = dying && job->code == dying + 128;
648 			}
649 			if (!silent)
650 				printf("*** Error %d", job->code);
651 			job->exit_type = JOB_EXIT_BAD;
652 		} else
653 			job->exit_type = JOB_EXIT_OKAY;
654 	} else {
655 		job->exit_type = JOB_SIGNALED;
656 		job->code = WTERMSIG(status);	/* signaled */
657 		/* if we're already dying from that signal, be silent */
658 		if (!silent) {
659 			dying = check_dying_signal();
660 			silent = dying && job->code == dying;
661 		}
662 		if (!silent)
663 			printf("*** Signal %d", job->code);
664 	}
665 
666 	/* if there is a problem, what's going on ? */
667 	if (job->exit_type != JOB_EXIT_OKAY) {
668 		if (!silent)
669 			printf(" in target '%s'", job->node->name);
670 		if (job->flags & JOB_ERRCHECK) {
671 			job->node->built_status = ERROR;
672 			/* compute expensive status if we really want it */
673 			if ((job->flags & JOB_SILENT) && job == &myjob)
674 				determine_expensive_job(job);
675 			if (!keepgoing) {
676 				if (!silent)
677 					printf("\n");
678 				job->next = errorJobs;
679 				errorJobs = job;
680 				/* XXX don't free the command */
681 				return;
682 			}
683 			printf(", line %lu of %s", job->location->lineno,
684 			    job->location->fname);
685 			if ((job->flags & (JOB_SILENT | JOB_IS_EXPENSIVE))
686 			    == JOB_SILENT)
687 				printf(": %s", job->cmd);
688 			/* Abort the current target,
689 			 * but let others continue.  */
690 			printf(" (continuing)\n");
691 		} else {
692 			/* Continue executing commands for
693 			 * this target.  If we return 0,
694 			 * this will happen...  */
695 			printf(" (ignored)\n");
696 			job->exit_type = JOB_EXIT_OKAY;
697 		}
698 	}
699 	free(job->cmd);
700 }
701 
702 int
703 run_gnode(GNode *gn)
704 {
705 	if (!gn || (gn->type & OP_DUMMY))
706 		return NOSUCHNODE;
707 
708 	gn->built_status = MADE;
709 
710 	job_attach_node(&myjob, gn);
711 	while (myjob.exit_type == JOB_EXIT_OKAY) {
712 		bool finished = job_run_next(&myjob);
713 		if (finished)
714 			break;
715 		handle_one_job(&myjob);
716 	}
717 
718 	return gn->built_status;
719 }
720 
721 
722 static void
723 setup_engine(void)
724 {
725 	static int already_setup = 0;
726 
727 	if (!already_setup) {
728 		setup_meta();
729 		already_setup = 1;
730 	}
731 }
732 
733 static bool
734 do_run_command(Job *job)
735 {
736 	bool silent;	/* Don't print command */
737 	bool doExecute;	/* Execute the command */
738 	bool errCheck;	/* Check errors */
739 	pid_t cpid; 	/* Child pid */
740 
741 	const char *cmd = job->cmd;
742 	silent = job->node->type & OP_SILENT;
743 	errCheck = !(job->node->type & OP_IGNORE);
744 	if (job->node->type & OP_MAKE)
745 		doExecute = true;
746 	else
747 		doExecute = !noExecute;
748 
749 	/* How can we execute a null command ? we warn the user that the
750 	 * command expanded to nothing (is this the right thing to do?).  */
751 	if (*cmd == '\0') {
752 		Error("%s expands to empty string", cmd);
753 		return false;
754 	}
755 
756 	for (;; cmd++) {
757 		if (*cmd == '@')
758 			silent = DEBUG(LOUD) ? false : true;
759 		else if (*cmd == '-')
760 			errCheck = false;
761 		else if (*cmd == '+')
762 			doExecute = true;
763 		else
764 			break;
765 	}
766 	while (ISSPACE(*cmd))
767 		cmd++;
768 	/* Print the command before fork if make -n or !silent*/
769 	if ( noExecute || !silent)
770 		printf("%s\n", cmd);
771 
772 	if (silent)
773 		job->flags |= JOB_SILENT;
774 	else
775 		job->flags &= ~JOB_SILENT;
776 
777 	/* If we're not supposed to execute any commands, this is as far as
778 	 * we go...  */
779 	if (!doExecute)
780 		return false;
781 	/* always flush for other stuff */
782 	fflush(stdout);
783 
784 	/* Fork and execute the single command. If the fork fails, we abort.  */
785 	switch (cpid = fork()) {
786 	case -1:
787 		Punt("Could not fork");
788 		/*NOTREACHED*/
789 	case 0:
790 		/* put a random delay unless we're the only job running
791 		 * and there's nothing left to do.
792 		 */
793 		if (random_delay)
794 			if (!(runningJobs == NULL && no_jobs_left()))
795 				usleep(arc4random_uniform(random_delay));
796 		run_command(cmd, errCheck);
797 		/*NOTREACHED*/
798 	default:
799 		job->pid = cpid;
800 		job->next = runningJobs;
801 		runningJobs = job;
802 		if (errCheck)
803 			job->flags |= JOB_ERRCHECK;
804 		else
805 			job->flags &= ~JOB_ERRCHECK;
806 		debug_job_printf("Running %ld (%s) %s\n", (long)job->pid,
807 		    job->node->name, (noExecute || !silent) ? "" : cmd);
808 		return true;
809 	}
810 }
811 
812 bool
813 job_run_next(Job *job)
814 {
815 	bool started;
816 	GNode *gn = job->node;
817 
818 	setup_engine();
819 	while (job->next_cmd != NULL) {
820 		struct command *command = Lst_Datum(job->next_cmd);
821 
822 		handle_all_signals();
823 		job->location = &command->location;
824 		Parse_SetLocation(job->location);
825 		job->cmd = Var_Subst(command->string, &gn->context, false);
826 		job->next_cmd = Lst_Adv(job->next_cmd);
827 		if (fatal_errors)
828 			Punt(NULL);
829 		started = do_run_command(job);
830 		if (started)
831 			return false;
832 		else
833 			free(job->cmd);
834 	}
835 	job->exit_type = JOB_EXIT_OKAY;
836 	return true;
837 }
838 
839