xref: /openbsd-src/usr.bin/make/engine.c (revision f2da64fbbbf1b03f09f390ab01267c93dfd77c4c)
1 /*	$OpenBSD: engine.c,v 1.50 2015/01/23 13:18:40 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(stderr,
278 				    "*** couldn't touch %s: %s", file,
279 				    strerror(errno));
280 		    	}
281 		}
282 	}
283 }
284 
285 void
286 Make_TimeStamp(GNode *parent, GNode *child)
287 {
288 	if (is_strictly_before(parent->youngest->mtime, child->mtime)) {
289  		parent->youngest = child;
290 	}
291 }
292 
293 void
294 Make_HandleUse(GNode	*cgn,	/* The .USE node */
295     GNode	*pgn)	/* The target of the .USE node */
296 {
297 	GNode	*gn;	/* A child of the .USE node */
298 	LstNode	ln;	/* An element in the children list */
299 
300 
301 	assert(cgn->type & (OP_USE|OP_TRANSFORM));
302 
303 	if ((cgn->type & OP_USE) || Lst_IsEmpty(&pgn->commands)) {
304 		/* .USE or transformation and target has no commands
305 		 * -- append the child's commands to the parent.  */
306 		Lst_Concat(&pgn->commands, &cgn->commands);
307 	}
308 
309 	for (ln = Lst_First(&cgn->children); ln != NULL;
310 	    ln = Lst_Adv(ln)) {
311 		gn = (GNode *)Lst_Datum(ln);
312 
313 		if (Lst_AddNew(&pgn->children, gn)) {
314 			Lst_AtEnd(&gn->parents, pgn);
315 			pgn->unmade++;
316 		}
317 	}
318 
319 	if (DEBUG(DOUBLE) && (cgn->type & OP_DOUBLE))
320 		fprintf(stderr,
321 		    "Warning: .USE %s expanded in %s had >1 lists of "
322 		    "shell commands (ignoring later ones)\n",
323 		    cgn->name, pgn->name);
324 	pgn->type |= cgn->type & ~(OP_OPMASK|OP_USE|OP_TRANSFORM|OP_DOUBLE);
325 
326 	/*
327 	 * This child node is now "made", so we decrement the count of
328 	 * unmade children in the parent... We also remove the child
329 	 * from the parent's list to accurately reflect the number of
330 	 * decent children the parent has. This is used by Make_Run to
331 	 * decide whether to queue the parent or examine its children...
332 	 */
333 	if (cgn->type & OP_USE)
334 		pgn->unmade--;
335 }
336 
337 void
338 Make_DoAllVar(GNode *gn)
339 {
340 	GNode *child;
341 	LstNode ln;
342 	BUFFER allsrc, oodate;
343 	char *target;
344 	bool do_oodate;
345 	int oodate_count, allsrc_count = 0;
346 
347 	oodate_count = 0;
348 	allsrc_count = 0;
349 
350 	Var(OODATE_INDEX, gn) = "";
351 	Var(ALLSRC_INDEX, gn) = "";
352 
353 	for (ln = Lst_First(&gn->children); ln != NULL; ln = Lst_Adv(ln)) {
354 		child = (GNode *)Lst_Datum(ln);
355 		if ((child->type & (OP_EXEC|OP_USE|OP_INVISIBLE)) != 0)
356 			continue;
357 		if (OP_NOP(child->type) ||
358 		    (target = Var(TARGET_INDEX, child)) == NULL) {
359 			/*
360 			 * this node is only source; use the specific pathname
361 			 * for it
362 			 */
363 			target = child->path != NULL ? child->path :
364 			    child->name;
365 		}
366 
367 		/*
368 		 * It goes in the OODATE variable if the parent is younger than
369 		 * the child or if the child has been modified more recently
370 		 * than the start of the make.  This is to keep make from
371 		 * getting confused if something else updates the parent after
372 		 * the make starts (shouldn't happen, I know, but sometimes it
373 		 * does). In such a case, if we've updated the kid, the parent
374 		 * is likely to have a modification time later than that of the
375 		 * kid and anything that relies on the OODATE variable will be
376 		 * hosed.
377 		 */
378 		do_oodate = false;
379 		if (gn->type & OP_JOIN) {
380 			if (child->built_status == MADE)
381 				do_oodate = true;
382 		} else if (is_strictly_before(gn->mtime, child->mtime) ||
383 		   (!is_strictly_before(child->mtime, starttime) &&
384 		   child->built_status == MADE))
385 		   	do_oodate = true;
386 		if (do_oodate) {
387 			oodate_count++;
388 			if (oodate_count == 1)
389 				Var(OODATE_INDEX, gn) = target;
390 			else {
391 				if (oodate_count == 2) {
392 					Buf_Init(&oodate, 0);
393 					Buf_AddString(&oodate,
394 					    Var(OODATE_INDEX, gn));
395 				}
396 				Buf_AddSpace(&oodate);
397 				Buf_AddString(&oodate, target);
398 			}
399 		}
400 		allsrc_count++;
401 		if (allsrc_count == 1)
402 			Var(ALLSRC_INDEX, gn) = target;
403 		else {
404 			if (allsrc_count == 2) {
405 				Buf_Init(&allsrc, 0);
406 				Buf_AddString(&allsrc,
407 				    Var(ALLSRC_INDEX, gn));
408 			}
409 			Buf_AddSpace(&allsrc);
410 			Buf_AddString(&allsrc, target);
411 		}
412 	}
413 
414 	if (allsrc_count > 1)
415 		Var(ALLSRC_INDEX, gn) = Buf_Retrieve(&allsrc);
416 	if (oodate_count > 1)
417 		Var(OODATE_INDEX, gn) = Buf_Retrieve(&oodate);
418 
419 	if (gn->impliedsrc)
420 		Var(IMPSRC_INDEX, gn) = Var(TARGET_INDEX, gn->impliedsrc);
421 
422 	if (gn->type & OP_JOIN)
423 		Var(TARGET_INDEX, gn) = Var(ALLSRC_INDEX, gn);
424 }
425 
426 /* Wrapper to call Make_TimeStamp from a forEach loop.	*/
427 static void
428 MakeTimeStamp(void *parent, void *child)
429 {
430     Make_TimeStamp(parent, child);
431 }
432 
433 bool
434 Make_OODate(GNode *gn)
435 {
436 	bool	    oodate;
437 
438 	/*
439 	 * Certain types of targets needn't even be sought as their datedness
440 	 * doesn't depend on their modification time...
441 	 */
442 	if ((gn->type & (OP_JOIN|OP_USE|OP_EXEC|OP_PHONY)) == 0) {
443 		(void)Dir_MTime(gn);
444 		if (DEBUG(MAKE)) {
445 			if (!is_out_of_date(gn->mtime))
446 				printf("modified %s...",
447 				    time_to_string(&gn->mtime));
448 			else
449 				printf("non-existent...");
450 		}
451 	}
452 
453 	/*
454 	 * A target is remade in one of the following circumstances:
455 	 * - its modification time is smaller than that of its youngest child
456 	 *   and it would actually be run (has commands or type OP_NOP)
457 	 * - it's the object of a force operator
458 	 * - it has no children, was on the lhs of an operator and doesn't
459 	 *   exist already.
460 	 *
461 	 */
462 	if (gn->type & OP_USE) {
463 		/*
464 		 * If the node is a USE node it is *never* out of date
465 		 * no matter *what*.
466 		 */
467 		if (DEBUG(MAKE))
468 			printf(".USE node...");
469 		oodate = false;
470 	} else if (gn->type & OP_JOIN) {
471 		/*
472 		 * A target with the .JOIN attribute is only considered
473 		 * out-of-date if any of its children was out-of-date.
474 		 */
475 		if (DEBUG(MAKE))
476 			printf(".JOIN node...");
477 		oodate = gn->childMade;
478 	} else if (gn->type & (OP_FORCE|OP_EXEC|OP_PHONY)) {
479 		/*
480 		 * A node which is the object of the force (!) operator or which
481 		 * has the .EXEC attribute is always considered out-of-date.
482 		 */
483 		if (DEBUG(MAKE)) {
484 			if (gn->type & OP_FORCE)
485 				printf("! operator...");
486 			else if (gn->type & OP_PHONY)
487 				printf(".PHONY node...");
488 			else
489 				printf(".EXEC node...");
490 		}
491 		oodate = true;
492 	} else if (is_strictly_before(gn->mtime, gn->youngest->mtime) ||
493 	   (gn == gn->youngest &&
494 	    (is_out_of_date(gn->mtime) || (gn->type & OP_DOUBLEDEP)))) {
495 		/*
496 		 * A node whose modification time is less than that of its
497 		 * youngest child or that has no children (gn->youngest == gn)
498 		 * and either doesn't exist (mtime == OUT_OF_DATE)
499 		 * or was the object of a :: operator is out-of-date.
500 		 */
501 		if (DEBUG(MAKE)) {
502 			if (is_strictly_before(gn->mtime, gn->youngest->mtime))
503 				printf("modified before source(%s)...",
504 				    gn->youngest->name);
505 			else if (is_out_of_date(gn->mtime))
506 				printf("non-existent and no sources...");
507 			else
508 				printf(":: operator and no sources...");
509 		}
510 		oodate = true;
511 	} else {
512 		oodate = false;
513 	}
514 
515 	/*
516 	 * If the target isn't out-of-date, the parents need to know its
517 	 * modification time. Note that targets that appear to be out-of-date
518 	 * but aren't, because they have no commands and aren't of type OP_NOP,
519 	 * have their mtime stay below their children's mtime to keep parents
520 	 * from thinking they're out-of-date.
521 	 */
522 	if (!oodate)
523 		Lst_ForEach(&gn->parents, MakeTimeStamp, gn);
524 
525 	return oodate;
526 }
527 
528 /* The following array is used to make a fast determination of which
529  * characters are interpreted specially by the shell.  If a command
530  * contains any of these characters, it is executed by the shell, not
531  * directly by us.  */
532 static char	    meta[256];
533 
534 void
535 setup_meta(void)
536 {
537 	char *p;
538 
539 	for (p = "#=|^(){};&<>*?[]:$`\\\n~"; *p != '\0'; p++)
540 		meta[(unsigned char) *p] = 1;
541 	/* The null character serves as a sentinel in the string.  */
542 	meta[0] = 1;
543 }
544 
545 static char **
546 recheck_command_for_shell(char **av)
547 {
548 	char *runsh[] = {
549 		"!", "alias", "cd", "eval", "exit", "read", "set", "ulimit",
550 		"unalias", "unset", "wait", "umask", NULL
551 	};
552 
553 	char **p;
554 
555 	/* optimization: if exec cmd, we avoid the intermediate shell */
556 	if (strcmp(av[0], "exec") == 0)
557 		av++;
558 
559 	for (p = runsh; *p; p++)
560 		if (strcmp(av[0], *p) == 0)
561 			return NULL;
562 
563 	return av;
564 }
565 
566 static void
567 run_command(const char *cmd, bool errCheck)
568 {
569 	const char *p;
570 	char *shargv[4];
571 	char **todo;
572 
573 	shargv[0] = _PATH_BSHELL;
574 
575 	shargv[1] = errCheck ? "-ec" : "-c";
576 	shargv[2] = (char *)cmd;
577 	shargv[3] = NULL;
578 
579 	todo = shargv;
580 
581 
582 	/* Search for meta characters in the command. If there are no meta
583 	 * characters, there's no need to execute a shell to execute the
584 	 * command.  */
585 	for (p = cmd; !meta[(unsigned char)*p]; p++)
586 		continue;
587 	if (*p == '\0') {
588 		char *bp;
589 		char **av;
590 		int argc;
591 		/* No meta-characters, so probably no need to exec a shell.
592 		 * Break the command into words to form an argument vector
593 		 * we can execute.  */
594 		av = brk_string(cmd, &argc, &bp);
595 		av = recheck_command_for_shell(av);
596 		if (av != NULL)
597 			todo = av;
598 	}
599 	execvp(todo[0], todo);
600 
601 	if (errno == ENOENT)
602 		fprintf(stderr, "%s: not found\n", todo[0]);
603 	else
604 		perror(todo[0]);
605 	_exit(1);
606 }
607 
608 static Job myjob;
609 
610 void
611 job_attach_node(Job *job, GNode *node)
612 {
613 	job->node = node;
614 	job->node->built_status = BUILDING;
615 	job->next_cmd = Lst_First(&node->commands);
616 	job->exit_type = JOB_EXIT_OKAY;
617 	job->location = NULL;
618 	job->flags = 0;
619 }
620 
621 void
622 job_handle_status(Job *job, int status)
623 {
624 	bool silent;
625 	int dying;
626 
627 	/* if there's one job running and we don't keep going, no need
628 	 * to report right now.
629 	 */
630 	if ((job->flags & JOB_ERRCHECK) && !keepgoing && runningJobs == NULL)
631 		silent = !DEBUG(JOB);
632 	else
633 		silent = false;
634 
635 	debug_job_printf("Process %ld (%s) exited with status %d.\n",
636 	    (long)job->pid, job->node->name, status);
637 
638 	/* classify status */
639 	if (WIFEXITED(status)) {
640 		job->code = WEXITSTATUS(status);/* exited */
641 		if (job->code != 0) {
642 			/* if we're already dying from that signal, be silent */
643 			if (!silent && job->code > 128
644 			    && job->code <= 128 + _NSIG) {
645 				dying = check_dying_signal();
646 				silent = dying && job->code == dying + 128;
647 			}
648 			if (!silent)
649 				printf("*** Error %d", job->code);
650 			job->exit_type = JOB_EXIT_BAD;
651 		} else
652 			job->exit_type = JOB_EXIT_OKAY;
653 	} else {
654 		job->exit_type = JOB_SIGNALED;
655 		job->code = WTERMSIG(status);	/* signaled */
656 		/* if we're already dying from that signal, be silent */
657 		if (!silent) {
658 			dying = check_dying_signal();
659 			silent = dying && job->code == dying;
660 		}
661 		if (!silent)
662 			printf("*** Signal %d", job->code);
663 	}
664 
665 	/* if there is a problem, what's going on ? */
666 	if (job->exit_type != JOB_EXIT_OKAY) {
667 		if (!silent)
668 			printf(" in target '%s'", job->node->name);
669 		if (job->flags & JOB_ERRCHECK) {
670 			job->node->built_status = ERROR;
671 			/* compute expensive status if we really want it */
672 			if ((job->flags & JOB_SILENT) && job == &myjob)
673 				determine_expensive_job(job);
674 			if (!keepgoing) {
675 				if (!silent)
676 					printf("\n");
677 				job->next = errorJobs;
678 				errorJobs = job;
679 				/* XXX don't free the command */
680 				return;
681 			}
682 			printf(", line %lu of %s", job->location->lineno,
683 			    job->location->fname);
684 			if ((job->flags & (JOB_SILENT | JOB_IS_EXPENSIVE))
685 			    == JOB_SILENT)
686 				printf(": %s", job->cmd);
687 			/* Abort the current target,
688 			 * but let others continue.  */
689 			printf(" (continuing)\n");
690 		} else {
691 			/* Continue executing commands for
692 			 * this target.  If we return 0,
693 			 * this will happen...  */
694 			printf(" (ignored)\n");
695 			job->exit_type = JOB_EXIT_OKAY;
696 		}
697 	}
698 	free(job->cmd);
699 }
700 
701 int
702 run_gnode(GNode *gn)
703 {
704 	if (!gn || (gn->type & OP_DUMMY))
705 		return NOSUCHNODE;
706 
707 	gn->built_status = MADE;
708 
709 	job_attach_node(&myjob, gn);
710 	while (myjob.exit_type == JOB_EXIT_OKAY) {
711 		bool finished = job_run_next(&myjob);
712 		if (finished)
713 			break;
714 		handle_one_job(&myjob);
715 	}
716 
717 	return gn->built_status;
718 }
719 
720 
721 static void
722 setup_engine(void)
723 {
724 	static int already_setup = 0;
725 
726 	if (!already_setup) {
727 		setup_meta();
728 		already_setup = 1;
729 	}
730 }
731 
732 static bool
733 do_run_command(Job *job)
734 {
735 	bool silent;	/* Don't print command */
736 	bool doExecute;	/* Execute the command */
737 	bool errCheck;	/* Check errors */
738 	pid_t cpid; 	/* Child pid */
739 
740 	const char *cmd = job->cmd;
741 	silent = job->node->type & OP_SILENT;
742 	errCheck = !(job->node->type & OP_IGNORE);
743 	if (job->node->type & OP_MAKE)
744 		doExecute = true;
745 	else
746 		doExecute = !noExecute;
747 
748 	/* How can we execute a null command ? we warn the user that the
749 	 * command expanded to nothing (is this the right thing to do?).  */
750 	if (*cmd == '\0') {
751 		Error("%s expands to empty string", cmd);
752 		return false;
753 	}
754 
755 	for (;; cmd++) {
756 		if (*cmd == '@')
757 			silent = DEBUG(LOUD) ? false : true;
758 		else if (*cmd == '-')
759 			errCheck = false;
760 		else if (*cmd == '+')
761 			doExecute = true;
762 		else
763 			break;
764 	}
765 	while (ISSPACE(*cmd))
766 		cmd++;
767 	/* Print the command before fork if make -n or !silent*/
768 	if ( noExecute || !silent)
769 		printf("%s\n", cmd);
770 
771 	if (silent)
772 		job->flags |= JOB_SILENT;
773 	else
774 		job->flags &= ~JOB_SILENT;
775 
776 	/* If we're not supposed to execute any commands, this is as far as
777 	 * we go...  */
778 	if (!doExecute)
779 		return false;
780 	/* always flush for other stuff */
781 	fflush(stdout);
782 
783 	/* Fork and execute the single command. If the fork fails, we abort.  */
784 	switch (cpid = fork()) {
785 	case -1:
786 		Punt("Could not fork");
787 		/*NOTREACHED*/
788 	case 0:
789 		/* put a random delay unless we're the only job running
790 		 * and there's nothing left to do.
791 		 */
792 		if (random_delay)
793 			if (!(runningJobs == NULL && no_jobs_left()))
794 				usleep(arc4random_uniform(random_delay));
795 		run_command(cmd, errCheck);
796 		/*NOTREACHED*/
797 	default:
798 		job->pid = cpid;
799 		job->next = runningJobs;
800 		runningJobs = job;
801 		if (errCheck)
802 			job->flags |= JOB_ERRCHECK;
803 		else
804 			job->flags &= ~JOB_ERRCHECK;
805 		debug_job_printf("Running %ld (%s) %s\n", (long)job->pid,
806 		    job->node->name, (noExecute || !silent) ? "" : cmd);
807 		return true;
808 	}
809 }
810 
811 bool
812 job_run_next(Job *job)
813 {
814 	bool started;
815 	GNode *gn = job->node;
816 
817 	setup_engine();
818 	while (job->next_cmd != NULL) {
819 		struct command *command = Lst_Datum(job->next_cmd);
820 
821 		handle_all_signals();
822 		job->location = &command->location;
823 		Parse_SetLocation(job->location);
824 		job->cmd = Var_Subst(command->string, &gn->context, false);
825 		job->next_cmd = Lst_Adv(job->next_cmd);
826 		if (fatal_errors)
827 			Punt(NULL);
828 		started = do_run_command(job);
829 		if (started)
830 			return false;
831 		else
832 			free(job->cmd);
833 	}
834 	job->exit_type = JOB_EXIT_OKAY;
835 	return true;
836 }
837 
838