1 /*-
2  * Copyright (c) 1988, 1989, 1990, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1989 by Berkeley Softworks
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to Berkeley by
8  * Adam de Boor.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  * 3. All advertising materials mentioning features or use of this software
19  *    must display the following acknowledgement:
20  *	This product includes software developed by the University of
21  *	California, Berkeley and its contributors.
22  * 4. Neither the name of the University nor the names of its contributors
23  *    may be used to endorse or promote products derived from this software
24  *    without specific prior written permission.
25  *
26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36  * SUCH DAMAGE.
37  *
38  * @(#)make.c	8.1 (Berkeley) 6/6/93
39  */
40 
41 #include <sys/cdefs.h>
42 __FBSDID("$FreeBSD: stable/10/usr.bin/make/make.c 200630 2009-12-17 12:42:45Z stas $");
43 
44 /*
45  * make.c
46  *	The functions which perform the examination of targets and
47  *	their suitability for creation
48  *
49  * Interface:
50  *	Make_Run	Initialize things for the module and recreate
51  *			whatever needs recreating. Returns TRUE if
52  *			work was (or would have been) done and FALSE
53  *			otherwise.
54  *
55  *	Make_Update	Update all parents of a given child. Performs
56  *			various bookkeeping chores like the updating
57  *			of the cmtime field of the parent, filling
58  *			of the IMPSRC context variable, etc. It will
59  *			place the parent on the toBeMade queue if it should be.
60  *
61  *	Make_TimeStamp	Function to set the parent's cmtime field
62  *			based on a child's modification time.
63  *
64  *	Make_DoAllVar	Set up the various local variables for a
65  *			target, including the .ALLSRC variable, making
66  *			sure that any variable that needs to exist
67  *			at the very least has the empty value.
68  *
69  *	Make_OODate	Determine if a target is out-of-date.
70  *
71  *	Make_HandleUse	See if a child is a .USE node for a parent
72  *			and perform the .USE actions if so.
73  */
74 
75 #include "arch.h"
76 #include "config.h"
77 #include "dir.h"
78 #include "globals.h"
79 #include "GNode.h"
80 #include "job.h"
81 #include "make.h"
82 #include "parse.h"
83 #include "suff.h"
84 #include "targ.h"
85 #include "util.h"
86 #include "var.h"
87 
88 /* The current fringe of the graph. These are nodes which await examination
89  * by MakeOODate. It is added to by Make_Update and subtracted from by
90  * MakeStartJobs */
91 static Lst toBeMade = Lst_Initializer(toBeMade);
92 
93 /*
94  * Number of nodes to be processed. If this is non-zero when Job_Empty()
95  * returns TRUE, there's a cycle in the graph.
96  */
97 static int numNodes;
98 
99 static Boolean MakeStartJobs(void);
100 
101 /**
102  * Make_TimeStamp
103  *	Set the cmtime field of a parent node based on the mtime stamp in its
104  *	child. Called from MakeOODate via LST_FOREACH.
105  *
106  * Results:
107  *	Always returns 0.
108  *
109  * Side Effects:
110  *	The cmtime of the parent node will be changed if the mtime
111  *	field of the child is greater than it.
112  */
113 int
Make_TimeStamp(GNode * pgn,GNode * cgn)114 Make_TimeStamp(GNode *pgn, GNode *cgn)
115 {
116 
117 	if (cgn->mtime > pgn->cmtime) {
118 		pgn->cmtime = cgn->mtime;
119 		pgn->cmtime_gn = cgn;
120 	}
121 	return (0);
122 }
123 
124 /**
125  * Make_OODate
126  *	See if a given node is out of date with respect to its sources.
127  *	Used by Make_Run when deciding which nodes to place on the
128  *	toBeMade queue initially and by Make_Update to screen out USE and
129  *	EXEC nodes. In the latter case, however, any other sort of node
130  *	must be considered out-of-date since at least one of its children
131  *	will have been recreated.
132  *
133  * Results:
134  *	TRUE if the node is out of date. FALSE otherwise.
135  *
136  * Side Effects:
137  *	The mtime field of the node and the cmtime field of its parents
138  *	will/may be changed.
139  */
140 Boolean
Make_OODate(GNode * gn)141 Make_OODate(GNode *gn)
142 {
143 	Boolean	oodate;
144 	LstNode	*ln;
145 
146 	/*
147 	 * Certain types of targets needn't even be sought as their datedness
148 	 * doesn't depend on their modification time...
149 	 */
150 	if ((gn->type & (OP_JOIN | OP_USE | OP_EXEC)) == 0) {
151 		Dir_MTime(gn);
152 		if (gn->mtime != 0) {
153 			DEBUGF(MAKE, ("modified %s...",
154 			    Targ_FmtTime(gn->mtime)));
155 		} else {
156 			DEBUGF(MAKE, ("non-existent..."));
157 		}
158 	}
159 
160 	/*
161 	 * A target is remade in one of the following circumstances:
162 	 *	its modification time is smaller than that of its youngest child
163 	 *	    and it would actually be run (has commands or type OP_NOP)
164 	 *	it's the object of a force operator
165 	 *	it has no children, was on the lhs of an operator and doesn't
166 	 *	    exist already.
167 	 *
168 	 * Libraries are only considered out-of-date if the archive module says
169 	 * they are.
170 	 *
171 	 * These weird rules are brought to you by Backward-Compatibility and
172 	 * the strange people who wrote 'Make'.
173 	 */
174 	if (gn->type & OP_USE) {
175 		/*
176 		 * If the node is a USE node it is *never* out of date
177 		 * no matter *what*.
178 		 */
179 		DEBUGF(MAKE, (".USE node..."));
180 		oodate = FALSE;
181 
182 	} else if (gn->type & OP_LIB) {
183 		DEBUGF(MAKE, ("library..."));
184 
185 		/*
186 		 * always out of date if no children and :: target
187 		 */
188 		oodate = Arch_LibOODate(gn) ||
189 		    ((gn->cmtime == 0) && (gn->type & OP_DOUBLEDEP));
190 
191 	} else if (gn->type & OP_JOIN) {
192 		/*
193 		 * A target with the .JOIN attribute is only considered
194 		 * out-of-date if any of its children was out-of-date.
195 		 */
196 		DEBUGF(MAKE, (".JOIN node..."));
197 		oodate = gn->childMade;
198 
199 	} else if (gn->type & (OP_FORCE|OP_EXEC|OP_PHONY)) {
200 		/*
201 		 * A node which is the object of the force (!) operator or
202 		 * which has the .EXEC attribute is always considered
203 		 * out-of-date.
204 		 */
205 		if (gn->type & OP_FORCE) {
206 			DEBUGF(MAKE, ("! operator..."));
207 		} else if (gn->type & OP_PHONY) {
208 			DEBUGF(MAKE, (".PHONY node..."));
209 		} else {
210 			DEBUGF(MAKE, (".EXEC node..."));
211 		}
212 
213 		if (remakingMakefiles) {
214 			DEBUGF(MAKE, ("skipping (remaking makefiles)..."));
215 			oodate = FALSE;
216 		} else {
217 			oodate = TRUE;
218 		}
219 	} else if (gn->mtime < gn->cmtime ||
220 	    (gn->cmtime == 0 && (gn->mtime == 0 || (gn->type & OP_DOUBLEDEP)))) {
221 		/*
222 		 * A node whose modification time is less than that of its
223 		 * youngest child or that has no children (cmtime == 0) and
224 		 * either doesn't exist (mtime == 0) or was the object of a
225 		 * :: operator is out-of-date. Why? Because that's the way
226 		 * Make does it.
227 		 */
228 		if (gn->mtime < gn->cmtime) {
229 			DEBUGF(MAKE, ("modified before source (%s)...",
230 			    gn->cmtime_gn ? gn->cmtime_gn->path : "???"));
231 			oodate = TRUE;
232 		} else if (gn->mtime == 0) {
233 			DEBUGF(MAKE, ("non-existent and no sources..."));
234 			if (remakingMakefiles && Lst_IsEmpty(&gn->commands)) {
235 				DEBUGF(MAKE, ("skipping (no commands and remaking makefiles)..."));
236 				oodate = FALSE;
237 			} else {
238 				oodate = TRUE;
239 			}
240 		} else {
241 			DEBUGF(MAKE, (":: operator and no sources..."));
242 			if (remakingMakefiles) {
243 				DEBUGF(MAKE, ("skipping (remaking makefiles)..."));
244 				oodate = FALSE;
245 			} else {
246 				oodate = TRUE;
247 			}
248 		}
249 	} else
250 		oodate = FALSE;
251 
252 	/*
253 	 * If the target isn't out-of-date, the parents need to know its
254 	 * modification time. Note that targets that appear to be out-of-date
255 	 * but aren't, because they have no commands and aren't of type OP_NOP,
256 	 * have their mtime stay below their children's mtime to keep parents
257 	 * from thinking they're out-of-date.
258 	 */
259 	if (!oodate) {
260 		LST_FOREACH(ln, &gn->parents)
261 			if (Make_TimeStamp(Lst_Datum(ln), gn))
262 				break;
263 	}
264 
265 	return (oodate);
266 }
267 
268 /**
269  * Make_HandleUse
270  *	Function called by Make_Run and SuffApplyTransform on the downward
271  *	pass to handle .USE and transformation nodes. A callback function
272  *	for LST_FOREACH, it implements the .USE and transformation
273  *	functionality by copying the node's commands, type flags
274  *	and children to the parent node. Should be called before the
275  *	children are enqueued to be looked at.
276  *
277  *	A .USE node is much like an explicit transformation rule, except
278  *	its commands are always added to the target node, even if the
279  *	target already has commands.
280  *
281  * Results:
282  *	returns 0.
283  *
284  * Side Effects:
285  *	Children and commands may be added to the parent and the parent's
286  *	type may be changed.
287  *
288  *-----------------------------------------------------------------------
289  */
290 int
Make_HandleUse(GNode * cgn,GNode * pgn)291 Make_HandleUse(GNode *cgn, GNode *pgn)
292 {
293 	GNode	*gn;	/* A child of the .USE node */
294 	LstNode	*ln;	/* An element in the children list */
295 
296 	if (cgn->type & (OP_USE | OP_TRANSFORM)) {
297 		if ((cgn->type & OP_USE) || Lst_IsEmpty(&pgn->commands)) {
298 			/*
299 			 * .USE or transformation and target has no commands --
300 			 * append the child's commands to the parent.
301 			 */
302 			Lst_Concat(&pgn->commands, &cgn->commands, LST_CONCNEW);
303 		}
304 
305 		for (ln = Lst_First(&cgn->children); ln != NULL;
306 		    ln = Lst_Succ(ln)) {
307 			gn = Lst_Datum(ln);
308 
309 			if (Lst_Member(&pgn->children, gn) == NULL) {
310 				Lst_AtEnd(&pgn->children, gn);
311 				Lst_AtEnd(&gn->parents, pgn);
312 				pgn->unmade += 1;
313 			}
314 		}
315 
316 		pgn->type |= cgn->type & ~(OP_OPMASK | OP_USE | OP_TRANSFORM);
317 
318 		/*
319 		 * This child node is now "made", so we decrement the count of
320 		 * unmade children in the parent... We also remove the child
321 		 * from the parent's list to accurately reflect the number of
322 		 * decent children the parent has. This is used by Make_Run to
323 		 * decide whether to queue the parent or examine its children...
324 		 */
325 		if (cgn->type & OP_USE) {
326 			pgn->unmade--;
327 		}
328 	}
329 	return (0);
330 }
331 
332 /**
333  * Make_Update
334  *	Perform update on the parents of a node. Used by JobFinish once
335  *	a node has been dealt with and by MakeStartJobs if it finds an
336  *	up-to-date node.
337  *
338  * Results:
339  *	Always returns 0
340  *
341  * Side Effects:
342  *	The unmade field of pgn is decremented and pgn may be placed on
343  *	the toBeMade queue if this field becomes 0.
344  *
345  * 	If the child was made, the parent's childMade field will be set true
346  *	and its cmtime set to now.
347  *
348  *	If the child wasn't made, the cmtime field of the parent will be
349  *	altered if the child's mtime is big enough.
350  *
351  *	Finally, if the child is the implied source for the parent, the
352  *	parent's IMPSRC variable is set appropriately.
353  */
354 void
Make_Update(GNode * cgn)355 Make_Update(GNode *cgn)
356 {
357 	GNode		*pgn;	/* the parent node */
358 	const char	*cname;	/* the child's name */
359 	LstNode		*ln;	/* Element in parents and iParents lists */
360 	const char	*cpref;
361 
362 	cname = Var_Value(TARGET, cgn);
363 
364 	/*
365 	 * If the child was actually made, see what its modification time is
366 	 * now -- some rules won't actually update the file. If the file still
367 	 * doesn't exist, make its mtime now.
368 	 */
369 	if (cgn->made != UPTODATE) {
370 #ifndef RECHECK
371 		/*
372 		 * We can't re-stat the thing, but we can at least take care
373 		 * of rules where a target depends on a source that actually
374 		 * creates the target, but only if it has changed, e.g.
375 		 *
376 		 * parse.h : parse.o
377 		 *
378 		 * parse.o : parse.y
379 		 *  	yacc -d parse.y
380 		 *  	cc -c y.tab.c
381 		 *  	mv y.tab.o parse.o
382 		 *  	cmp -s y.tab.h parse.h || mv y.tab.h parse.h
383 		 *
384 		 * In this case, if the definitions produced by yacc haven't
385 		 * changed from before, parse.h won't have been updated and
386 		 * cgn->mtime will reflect the current modification time for
387 		 * parse.h. This is something of a kludge, I admit, but it's a
388 		 * useful one..
389 		 * XXX: People like to use a rule like
390 		 *
391 		 * FRC:
392 		 *
393 		 * To force things that depend on FRC to be made, so we have to
394 		 * check for gn->children being empty as well...
395 		 */
396 		if (!Lst_IsEmpty(&cgn->commands) ||
397 		    Lst_IsEmpty(&cgn->children)) {
398 			cgn->mtime = now;
399 		}
400 	#else
401 		/*
402 		 * This is what Make does and it's actually a good thing, as it
403 		 * allows rules like
404 		 *
405 		 *	cmp -s y.tab.h parse.h || cp y.tab.h parse.h
406 		 *
407 		 * to function as intended. Unfortunately, thanks to the
408 		 * stateless nature of NFS (by which I mean the loose coupling
409 		 * of two clients using the same file from a common server),
410 		 * there are times when the modification time of a file created
411 		 * on a remote machine will not be modified before the local
412 		 * stat() implied by the Dir_MTime occurs, thus leading us to
413 		 * believe that the file is unchanged, wreaking havoc with
414 		 * files that depend on this one.
415 		 *
416 		 * I have decided it is better to make too much than to make too
417 		 * little, so this stuff is commented out unless you're sure
418 		 * it's ok.
419 		 * -- ardeb 1/12/88
420 		 */
421 		/*
422 		 * Christos, 4/9/92: If we are  saving commands pretend that
423 		 * the target is made now. Otherwise archives with ... rules
424 		 * don't work!
425 		 */
426 		if (noExecute || (cgn->type & OP_SAVE_CMDS) ||
427 		    Dir_MTime(cgn) == 0) {
428 			cgn->mtime = now;
429 		}
430 		DEBUGF(MAKE, ("update time: %s\n", Targ_FmtTime(cgn->mtime)));
431 #endif
432 	}
433 
434 	for (ln = Lst_First(&cgn->parents); ln != NULL; ln = Lst_Succ(ln)) {
435 		pgn = Lst_Datum(ln);
436 		if (pgn->make) {
437 			pgn->unmade -= 1;
438 
439 			if (!(cgn->type & (OP_EXEC | OP_USE))) {
440 				if (cgn->made == MADE)
441 					pgn->childMade = TRUE;
442 				Make_TimeStamp(pgn, cgn);
443 			}
444 			if (pgn->unmade == 0) {
445 				/*
446 				 * Queue the node up -- any unmade predecessors
447 				 * will be dealt with in MakeStartJobs.
448 				 */
449 				Lst_EnQueue(&toBeMade, pgn);
450 			} else if (pgn->unmade < 0) {
451 				Error("Graph cycles through %s", pgn->name);
452 			}
453 		}
454 	}
455 
456 	/*
457 	 * Deal with successor nodes. If any is marked for making and has an
458 	 * unmade count of 0, has not been made and isn't in the examination
459 	 * queue, it means we need to place it in the queue as it restrained
460 	 * itself before.
461 	 */
462 	for (ln = Lst_First(&cgn->successors); ln != NULL; ln = Lst_Succ(ln)) {
463 		GNode	*succ = Lst_Datum(ln);
464 
465 		if (succ->make && succ->unmade == 0 && succ->made == UNMADE &&
466 		    Lst_Member(&toBeMade, succ) == NULL) {
467 			Lst_EnQueue(&toBeMade, succ);
468 		}
469 	}
470 
471 	/*
472 	 * Set the .PREFIX and .IMPSRC variables for all the implied parents
473 	 * of this node.
474 	 */
475 	cpref = Var_Value(PREFIX, cgn);
476 	for (ln = Lst_First(&cgn->iParents); ln != NULL; ln = Lst_Succ(ln)) {
477 		pgn = Lst_Datum(ln);
478 		if (pgn->make) {
479 			Var_Set(IMPSRC, cname, pgn);
480 			Var_Set(PREFIX, cpref, pgn);
481 		}
482 	}
483 }
484 
485 /**
486  * Make_DoAllVar
487  *	Set up the ALLSRC and OODATE variables. Sad to say, it must be
488  *	done separately, rather than while traversing the graph. This is
489  *	because Make defined OODATE to contain all sources whose modification
490  *	times were later than that of the target, *not* those sources that
491  *	were out-of-date. Since in both compatibility and native modes,
492  *	the modification time of the parent isn't found until the child
493  *	has been dealt with, we have to wait until now to fill in the
494  *	variable. As for ALLSRC, the ordering is important and not
495  *	guaranteed when in native mode, so it must be set here, too.
496  *
497  * Side Effects:
498  *	The ALLSRC and OODATE variables of the given node is filled in.
499  *	If the node is a .JOIN node, its TARGET variable will be set to
500  * 	match its ALLSRC variable.
501  */
502 void
Make_DoAllVar(GNode * gn)503 Make_DoAllVar(GNode *gn)
504 {
505 	LstNode		*ln;
506 	GNode		*cgn;
507 	const char	*child;
508 
509 	LST_FOREACH(ln, &gn->children) {
510 		/*
511 		 * Add the child's name to the ALLSRC and OODATE variables of
512 		 * the given node. The child is added only if it has not been
513 		 * given the .EXEC, .USE or .INVISIBLE attributes. .EXEC and
514 		 * .USE children are very rarely going to be files, so...
515 		 *
516 		 * A child is added to the OODATE variable if its modification
517 		 * time is later than that of its parent, as defined by Make,
518 		 * except if the parent is a .JOIN node. In that case, it is
519 		 * only added to the OODATE variable if it was actually made
520 		 * (since .JOIN nodes don't have modification times, the
521 		 * comparison is rather unfair...).
522 		 */
523 		cgn = Lst_Datum(ln);
524 
525 		if ((cgn->type & (OP_EXEC | OP_USE | OP_INVISIBLE)) == 0) {
526 			if (OP_NOP(cgn->type)) {
527 				/*
528 				 * this node is only source; use the specific
529 				 * pathname for it
530 				 */
531 				child = cgn->path ? cgn->path : cgn->name;
532 			} else
533 				child = Var_Value(TARGET, cgn);
534 			Var_Append(ALLSRC, child, gn);
535 			if (gn->type & OP_JOIN) {
536 				if (cgn->made == MADE) {
537 					Var_Append(OODATE, child, gn);
538 				}
539 			} else if (gn->mtime < cgn->mtime ||
540 			    (cgn->mtime >= now && cgn->made == MADE)) {
541 				/*
542 				 * It goes in the OODATE variable if the parent
543 				 * is younger than the child or if the child has
544 				 * been modified more recently than the start of
545 				 * the make. This is to keep pmake from getting
546 				 * confused if something else updates the parent
547 				 * after the make starts (shouldn't happen, I
548 				 * know, but sometimes it does). In such a case,
549 				 * if we've updated the kid, the parent is
550 				 * likely to have a modification time later than
551 				 * that of the kid and anything that relies on
552 				 * the OODATE variable will be hosed.
553 				 *
554 				 * XXX: This will cause all made children to
555 				 * go in the OODATE variable, even if they're
556 				 * not touched, if RECHECK isn't defined, since
557 				 * cgn->mtime is set to now in Make_Update.
558 				 * According to some people, this is good...
559 				 */
560 				Var_Append(OODATE, child, gn);
561 			}
562 		}
563 	}
564 
565 	if (!Var_Exists (OODATE, gn)) {
566 		Var_Set(OODATE, "", gn);
567 	}
568 	if (!Var_Exists (ALLSRC, gn)) {
569 		Var_Set(ALLSRC, "", gn);
570 	}
571 
572 	if (gn->type & OP_JOIN) {
573 		Var_Set(TARGET, Var_Value(ALLSRC, gn), gn);
574 	}
575 }
576 
577 /**
578  * MakeStartJobs
579  *	Start as many jobs as possible.
580  *
581  * Results:
582  *	If the query flag was given to pmake, no job will be started,
583  *	but as soon as an out-of-date target is found, this function
584  *	returns TRUE. At all other times, this function returns FALSE.
585  *
586  * Side Effects:
587  *	Nodes are removed from the toBeMade queue and job table slots
588  *	are filled.
589  */
590 static Boolean
MakeStartJobs(void)591 MakeStartJobs(void)
592 {
593 	GNode	*gn;
594 
595 	while (!Lst_IsEmpty(&toBeMade) && !Job_Full()) {
596 		gn = Lst_DeQueue(&toBeMade);
597 		DEBUGF(MAKE, ("Examining %s...", gn->name));
598 
599 		/*
600 		 * Make sure any and all predecessors that are going to be made,
601 		 * have been.
602 		 */
603 		if (!Lst_IsEmpty(&gn->preds)) {
604 			LstNode *ln;
605 
606 			for (ln = Lst_First(&gn->preds); ln != NULL;
607 			    ln = Lst_Succ(ln)){
608 				GNode	*pgn = Lst_Datum(ln);
609 
610 				if (pgn->make && pgn->made == UNMADE) {
611 					DEBUGF(MAKE, ("predecessor %s not made "
612 					    "yet.\n", pgn->name));
613 					break;
614 				}
615 			}
616 			/*
617 			 * If ln isn't NULL, there's a predecessor as yet
618 			 * unmade, so we just drop this node on the floor.
619 			 * When the node in question has been made, it will
620 			 * notice this node as being ready to make but as yet
621 			 * unmade and will place the node on the queue.
622 			 */
623 			if (ln != NULL) {
624 				continue;
625 			}
626 		}
627 
628 		numNodes--;
629 		if (Make_OODate(gn)) {
630 			DEBUGF(MAKE, ("out-of-date\n"));
631 			if (queryFlag) {
632 				return (TRUE);
633 			}
634 			Make_DoAllVar(gn);
635 			Job_Make(gn);
636 		} else {
637 			DEBUGF(MAKE, ("up-to-date\n"));
638 			gn->made = UPTODATE;
639 			if (gn->type & OP_JOIN) {
640 				/*
641 				 * Even for an up-to-date .JOIN node, we need
642 				 * it to have its context variables so
643 				 * references to it get the correct value for
644 				 * .TARGET when building up the context
645 				 * variables of its parent(s)...
646 				 */
647 				Make_DoAllVar(gn);
648 			}
649 
650 			Make_Update(gn);
651 		}
652 	}
653 	return (FALSE);
654 }
655 
656 /**
657  * MakePrintStatus
658  *	Print the status of a top-level node, viz. it being up-to-date
659  *	already or not created due to an error in a lower level.
660  *	Callback function for Make_Run via LST_FOREACH.  If gn->unmade is
661  *	nonzero and that is meant to imply a cycle in the graph, then
662  *	cycle is TRUE.
663  *
664  * Side Effects:
665  *	A message may be printed.
666  */
667 static void
MakePrintStatus(GNode * gn,Boolean cycle)668 MakePrintStatus(GNode *gn, Boolean cycle)
669 {
670 	LstNode	*ln;
671 
672 	if (gn->made == UPTODATE) {
673 		printf("`%s' is up to date.\n", gn->name);
674 
675 	} else if (gn->unmade != 0) {
676 		if (cycle) {
677 			/*
678 			 * If printing cycles and came to one that has unmade
679 			 * children, print out the cycle by recursing on its
680 			 * children. Note a cycle like:
681 			 *	a : b
682 			 *	b : c
683 			 *	c : b
684 			 * will cause this to erroneously complain about a
685 			 * being in the cycle, but this is a good approximation.
686 			 */
687 			if (gn->made == CYCLE) {
688 				Error("Graph cycles through `%s'", gn->name);
689 				gn->made = ENDCYCLE;
690 				LST_FOREACH(ln, &gn->children)
691 					MakePrintStatus(Lst_Datum(ln), TRUE);
692 				gn->made = UNMADE;
693 			} else if (gn->made != ENDCYCLE) {
694 				gn->made = CYCLE;
695 				LST_FOREACH(ln, &gn->children)
696 					MakePrintStatus(Lst_Datum(ln), TRUE);
697 			}
698 		} else {
699 			printf("`%s' not remade because of errors.\n",
700 			    gn->name);
701 		}
702 	}
703 }
704 
705 /**
706  * Make_Run
707  *	Initialize the nodes to remake and the list of nodes which are
708  *	ready to be made by doing a breadth-first traversal of the graph
709  *	starting from the nodes in the given list. Once this traversal
710  *	is finished, all the 'leaves' of the graph are in the toBeMade
711  *	queue.
712  *	Using this queue and the Job module, work back up the graph,
713  *	calling on MakeStartJobs to keep the job table as full as
714  *	possible.
715  *
716  * Results:
717  *	TRUE if work was done. FALSE otherwise.
718  *
719  * Side Effects:
720  *	The make field of all nodes involved in the creation of the given
721  *	targets is set to 1. The toBeMade list is set to contain all the
722  *	'leaves' of these subgraphs.
723  */
724 Boolean
Make_Run(Lst * targs)725 Make_Run(Lst *targs)
726 {
727 	GNode	*gn;		/* a temporary pointer */
728 	GNode	*cgn;
729 	Lst	examine;	/* List of targets to examine */
730 	LstNode	*ln;
731 
732 	Lst_Init(&examine);
733 	Lst_Duplicate(&examine, targs, NOCOPY);
734 	numNodes = 0;
735 
736 	/*
737 	 * Make an initial downward pass over the graph, marking nodes to be
738 	 * made as we go down. We call Suff_FindDeps to find where a node is and
739 	 * to get some children for it if it has none and also has no commands.
740 	 * If the node is a leaf, we stick it on the toBeMade queue to
741 	 * be looked at in a minute, otherwise we add its children to our queue
742 	 * and go on about our business.
743 	 */
744 	while (!Lst_IsEmpty(&examine)) {
745 		gn = Lst_DeQueue(&examine);
746 
747 		if (!gn->make) {
748 			gn->make = TRUE;
749 			numNodes++;
750 
751 			/*
752 			 * Apply any .USE rules before looking for implicit
753 			 * dependencies to make sure everything has commands
754 			 * that should...
755 			 */
756 			LST_FOREACH(ln, &gn->children)
757 				if (Make_HandleUse(Lst_Datum(ln), gn))
758 					break;
759 
760 			Suff_FindDeps(gn);
761 
762 			if (gn->unmade != 0) {
763 				LST_FOREACH(ln, &gn->children) {
764 					cgn = Lst_Datum(ln);
765 					if (!cgn->make && !(cgn->type & OP_USE))
766 						Lst_EnQueue(&examine, cgn);
767 				}
768 			} else {
769 				Lst_EnQueue(&toBeMade, gn);
770 			}
771 		}
772 	}
773 
774 	if (queryFlag) {
775 		/*
776 		 * We wouldn't do any work unless we could start some jobs in
777 		 * the next loop... (we won't actually start any, of course,
778 		 * this is just to see if any of the targets was out of date)
779 		 */
780 		return (MakeStartJobs());
781 
782 	} else {
783 		/*
784 		 * Initialization. At the moment, no jobs are running and
785 		 * until some get started, nothing will happen since the
786 		 * remaining upward traversal of the graph is performed by the
787 		 * routines in job.c upon the finishing of a job. So we fill
788 		 * the Job table as much as we can before going into our loop.
789 		 */
790 		MakeStartJobs();
791 	}
792 
793 	/*
794 	 * Main Loop: The idea here is that the ending of jobs will take
795 	 * care of the maintenance of data structures and the waiting for output
796 	 * will cause us to be idle most of the time while our children run as
797 	 * much as possible. Because the job table is kept as full as possible,
798 	 * the only time when it will be empty is when all the jobs which need
799 	 * running have been run, so that is the end condition of this loop.
800 	 * Note that the Job module will exit if there were any errors unless
801 	 * the keepgoing flag was given.
802 	 */
803 	while (!Job_Empty()) {
804 		Job_CatchOutput(!Lst_IsEmpty(&toBeMade));
805 		Job_CatchChildren(!usePipes);
806 		MakeStartJobs();
807 	}
808 
809 	Job_Finish();
810 
811 	/*
812 	 * Print the final status of each target. E.g. if it wasn't made
813 	 * because some inferior reported an error.
814 	 */
815 	LST_FOREACH(ln, targs)
816 		MakePrintStatus(Lst_Datum(ln), (makeErrors == 0) && (numNodes != 0));
817 
818 	return (TRUE);
819 }
820