xref: /freebsd/contrib/bmake/meta.c (revision 3c5ba95ad12285ad37c182a4bfc1b240ec6d18a7)
1 /*      $NetBSD: meta.c,v 1.70 2018/02/13 19:37:30 sjg Exp $ */
2 
3 /*
4  * Implement 'meta' mode.
5  * Adapted from John Birrell's patches to FreeBSD make.
6  * --sjg
7  */
8 /*
9  * Copyright (c) 2009-2016, Juniper Networks, Inc.
10  * Portions Copyright (c) 2009, John Birrell.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 #if defined(USE_META)
34 
35 #ifdef HAVE_CONFIG_H
36 # include "config.h"
37 #endif
38 #include <sys/stat.h>
39 #include <sys/ioctl.h>
40 #ifdef HAVE_LIBGEN_H
41 #include <libgen.h>
42 #elif !defined(HAVE_DIRNAME)
43 char * dirname(char *);
44 #endif
45 #include <errno.h>
46 #if !defined(HAVE_CONFIG_H) || defined(HAVE_ERR_H)
47 #include <err.h>
48 #endif
49 
50 #include "make.h"
51 #include "job.h"
52 
53 #ifdef HAVE_FILEMON_H
54 # include <filemon.h>
55 #endif
56 #if !defined(USE_FILEMON) && defined(FILEMON_SET_FD)
57 # define USE_FILEMON
58 #endif
59 
60 static BuildMon Mybm;			/* for compat */
61 static Lst metaBailiwick;		/* our scope of control */
62 static char *metaBailiwickStr;		/* string storage for the list */
63 static Lst metaIgnorePaths;		/* paths we deliberately ignore */
64 static char *metaIgnorePathsStr;	/* string storage for the list */
65 
66 #ifndef MAKE_META_IGNORE_PATHS
67 #define MAKE_META_IGNORE_PATHS ".MAKE.META.IGNORE_PATHS"
68 #endif
69 #ifndef MAKE_META_IGNORE_PATTERNS
70 #define MAKE_META_IGNORE_PATTERNS ".MAKE.META.IGNORE_PATTERNS"
71 #endif
72 #ifndef MAKE_META_IGNORE_FILTER
73 #define MAKE_META_IGNORE_FILTER ".MAKE.META.IGNORE_FILTER"
74 #endif
75 
76 Boolean useMeta = FALSE;
77 static Boolean useFilemon = FALSE;
78 static Boolean writeMeta = FALSE;
79 static Boolean metaMissing = FALSE;	/* oodate if missing */
80 static Boolean filemonMissing = FALSE;	/* oodate if missing */
81 static Boolean metaEnv = FALSE;		/* don't save env unless asked */
82 static Boolean metaVerbose = FALSE;
83 static Boolean metaIgnoreCMDs = FALSE;	/* ignore CMDs in .meta files */
84 static Boolean metaIgnorePatterns = FALSE; /* do we need to do pattern matches */
85 static Boolean metaIgnoreFilter = FALSE;   /* do we have more complex filtering? */
86 static Boolean metaCurdirOk = FALSE;	/* write .meta in .CURDIR Ok? */
87 static Boolean metaSilent = FALSE;	/* if we have a .meta be SILENT */
88 
89 extern Boolean forceJobs;
90 extern Boolean comatMake;
91 extern char    **environ;
92 
93 #define	MAKE_META_PREFIX	".MAKE.META.PREFIX"
94 
95 #ifndef N2U
96 # define N2U(n, u)   (((n) + ((u) - 1)) / (u))
97 #endif
98 #ifndef ROUNDUP
99 # define ROUNDUP(n, u)   (N2U((n), (u)) * (u))
100 #endif
101 
102 #if !defined(HAVE_STRSEP)
103 # define strsep(s, d) stresep((s), (d), 0)
104 #endif
105 
106 /*
107  * Filemon is a kernel module which snoops certain syscalls.
108  *
109  * C chdir
110  * E exec
111  * F [v]fork
112  * L [sym]link
113  * M rename
114  * R read
115  * W write
116  * S stat
117  *
118  * See meta_oodate below - we mainly care about 'E' and 'R'.
119  *
120  * We can still use meta mode without filemon, but
121  * the benefits are more limited.
122  */
123 #ifdef USE_FILEMON
124 # ifndef _PATH_FILEMON
125 #   define _PATH_FILEMON "/dev/filemon"
126 # endif
127 
128 /*
129  * Open the filemon device.
130  */
131 static void
132 filemon_open(BuildMon *pbm)
133 {
134     int retry;
135 
136     pbm->mon_fd = pbm->filemon_fd = -1;
137     if (!useFilemon)
138 	return;
139 
140     for (retry = 5; retry >= 0; retry--) {
141 	if ((pbm->filemon_fd = open(_PATH_FILEMON, O_RDWR)) >= 0)
142 	    break;
143     }
144 
145     if (pbm->filemon_fd < 0) {
146 	useFilemon = FALSE;
147 	warn("Could not open %s", _PATH_FILEMON);
148 	return;
149     }
150 
151     /*
152      * We use a file outside of '.'
153      * to avoid a FreeBSD kernel bug where unlink invalidates
154      * cwd causing getcwd to do a lot more work.
155      * We only care about the descriptor.
156      */
157     pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL);
158     if (ioctl(pbm->filemon_fd, FILEMON_SET_FD, &pbm->mon_fd) < 0) {
159 	err(1, "Could not set filemon file descriptor!");
160     }
161     /* we don't need these once we exec */
162     (void)fcntl(pbm->mon_fd, F_SETFD, FD_CLOEXEC);
163     (void)fcntl(pbm->filemon_fd, F_SETFD, FD_CLOEXEC);
164 }
165 
166 /*
167  * Read the build monitor output file and write records to the target's
168  * metadata file.
169  */
170 static int
171 filemon_read(FILE *mfp, int fd)
172 {
173     char buf[BUFSIZ];
174     int n;
175     int error;
176 
177     /* Check if we're not writing to a meta data file.*/
178     if (mfp == NULL) {
179 	if (fd >= 0)
180 	    close(fd);			/* not interested */
181 	return 0;
182     }
183     /* rewind */
184     (void)lseek(fd, (off_t)0, SEEK_SET);
185 
186     error = 0;
187     fprintf(mfp, "\n-- filemon acquired metadata --\n");
188 
189     while ((n = read(fd, buf, sizeof(buf))) > 0) {
190 	if ((int)fwrite(buf, 1, n, mfp) < n)
191 	    error = EIO;
192     }
193     fflush(mfp);
194     if (close(fd) < 0)
195 	error = errno;
196     return error;
197 }
198 #endif
199 
200 /*
201  * when realpath() fails,
202  * we use this, to clean up ./ and ../
203  */
204 static void
205 eat_dots(char *buf, size_t bufsz, int dots)
206 {
207     char *cp;
208     char *cp2;
209     const char *eat;
210     size_t eatlen;
211 
212     switch (dots) {
213     case 1:
214 	eat = "/./";
215 	eatlen = 2;
216 	break;
217     case 2:
218 	eat = "/../";
219 	eatlen = 3;
220 	break;
221     default:
222 	return;
223     }
224 
225     do {
226 	cp = strstr(buf, eat);
227 	if (cp) {
228 	    cp2 = cp + eatlen;
229 	    if (dots == 2 && cp > buf) {
230 		do {
231 		    cp--;
232 		} while (cp > buf && *cp != '/');
233 	    }
234 	    if (*cp == '/') {
235 		strlcpy(cp, cp2, bufsz - (cp - buf));
236 	    } else {
237 		return;			/* can't happen? */
238 	    }
239 	}
240     } while (cp);
241 }
242 
243 static char *
244 meta_name(char *mname, size_t mnamelen,
245 	  const char *dname,
246 	  const char *tname,
247 	  const char *cwd)
248 {
249     char buf[MAXPATHLEN];
250     char *rp;
251     char *cp;
252     char *tp;
253     char *dtp;
254     size_t ldname;
255 
256     /*
257      * Weed out relative paths from the target file name.
258      * We have to be careful though since if target is a
259      * symlink, the result will be unstable.
260      * So we use realpath() just to get the dirname, and leave the
261      * basename as given to us.
262      */
263     if ((cp = strrchr(tname, '/'))) {
264 	if (cached_realpath(tname, buf)) {
265 	    if ((rp = strrchr(buf, '/'))) {
266 		rp++;
267 		cp++;
268 		if (strcmp(cp, rp) != 0)
269 		    strlcpy(rp, cp, sizeof(buf) - (rp - buf));
270 	    }
271 	    tname = buf;
272 	} else {
273 	    /*
274 	     * We likely have a directory which is about to be made.
275 	     * We pretend realpath() succeeded, to have a chance
276 	     * of generating the same meta file name that we will
277 	     * next time through.
278 	     */
279 	    if (tname[0] == '/') {
280 		strlcpy(buf, tname, sizeof(buf));
281 	    } else {
282 		snprintf(buf, sizeof(buf), "%s/%s", cwd, tname);
283 	    }
284 	    eat_dots(buf, sizeof(buf), 1);	/* ./ */
285 	    eat_dots(buf, sizeof(buf), 2);	/* ../ */
286 	    tname = buf;
287 	}
288     }
289     /* on some systems dirname may modify its arg */
290     tp = bmake_strdup(tname);
291     dtp = dirname(tp);
292     if (strcmp(dname, dtp) == 0)
293 	snprintf(mname, mnamelen, "%s.meta", tname);
294     else {
295 	ldname = strlen(dname);
296 	if (strncmp(dname, dtp, ldname) == 0 && dtp[ldname] == '/')
297 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, &tname[ldname+1]);
298 	else
299 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, tname);
300 
301 	/*
302 	 * Replace path separators in the file name after the
303 	 * current object directory path.
304 	 */
305 	cp = mname + strlen(dname) + 1;
306 
307 	while (*cp != '\0') {
308 	    if (*cp == '/')
309 		*cp = '_';
310 	    cp++;
311 	}
312     }
313     free(tp);
314     return (mname);
315 }
316 
317 /*
318  * Return true if running ${.MAKE}
319  * Bypassed if target is flagged .MAKE
320  */
321 static int
322 is_submake(void *cmdp, void *gnp)
323 {
324     static char *p_make = NULL;
325     static int p_len;
326     char  *cmd = cmdp;
327     GNode *gn = gnp;
328     char *mp = NULL;
329     char *cp;
330     char *cp2;
331     int rc = 0;				/* keep looking */
332 
333     if (!p_make) {
334 	p_make = Var_Value(".MAKE", gn, &cp);
335 	p_len = strlen(p_make);
336     }
337     cp = strchr(cmd, '$');
338     if ((cp)) {
339 	mp = Var_Subst(NULL, cmd, gn, VARF_WANTRES);
340 	cmd = mp;
341     }
342     cp2 = strstr(cmd, p_make);
343     if ((cp2)) {
344 	switch (cp2[p_len]) {
345 	case '\0':
346 	case ' ':
347 	case '\t':
348 	case '\n':
349 	    rc = 1;
350 	    break;
351 	}
352 	if (cp2 > cmd && rc > 0) {
353 	    switch (cp2[-1]) {
354 	    case ' ':
355 	    case '\t':
356 	    case '\n':
357 		break;
358 	    default:
359 		rc = 0;			/* no match */
360 		break;
361 	    }
362 	}
363     }
364     free(mp);
365     return (rc);
366 }
367 
368 typedef struct meta_file_s {
369     FILE *fp;
370     GNode *gn;
371 } meta_file_t;
372 
373 static int
374 printCMD(void *cmdp, void *mfpp)
375 {
376     meta_file_t *mfp = mfpp;
377     char *cmd = cmdp;
378     char *cp = NULL;
379 
380     if (strchr(cmd, '$')) {
381 	cmd = cp = Var_Subst(NULL, cmd, mfp->gn, VARF_WANTRES);
382     }
383     fprintf(mfp->fp, "CMD %s\n", cmd);
384     free(cp);
385     return 0;
386 }
387 
388 /*
389  * Certain node types never get a .meta file
390  */
391 #define SKIP_META_TYPE(_type) do { \
392     if ((gn->type & __CONCAT(OP_, _type))) {	\
393 	if (verbose) { \
394 	    fprintf(debug_file, "Skipping meta for %s: .%s\n", \
395 		    gn->name, __STRING(_type));		       \
396 	} \
397 	return FALSE; \
398     } \
399 } while (0)
400 
401 
402 /*
403  * Do we need/want a .meta file ?
404  */
405 static Boolean
406 meta_needed(GNode *gn, const char *dname,
407 	     char *objdir, int verbose)
408 {
409     struct stat fs;
410 
411     if (verbose)
412 	verbose = DEBUG(META);
413 
414     /* This may be a phony node which we don't want meta data for... */
415     /* Skip .meta for .BEGIN, .END, .ERROR etc as well. */
416     /* Or it may be explicitly flagged as .NOMETA */
417     SKIP_META_TYPE(NOMETA);
418     /* Unless it is explicitly flagged as .META */
419     if (!(gn->type & OP_META)) {
420 	SKIP_META_TYPE(PHONY);
421 	SKIP_META_TYPE(SPECIAL);
422 	SKIP_META_TYPE(MAKE);
423     }
424 
425     /* Check if there are no commands to execute. */
426     if (Lst_IsEmpty(gn->commands)) {
427 	if (verbose)
428 	    fprintf(debug_file, "Skipping meta for %s: no commands\n",
429 		    gn->name);
430 	return FALSE;
431     }
432     if ((gn->type & (OP_META|OP_SUBMAKE)) == OP_SUBMAKE) {
433 	/* OP_SUBMAKE is a bit too aggressive */
434 	if (Lst_ForEach(gn->commands, is_submake, gn)) {
435 	    if (DEBUG(META))
436 		fprintf(debug_file, "Skipping meta for %s: .SUBMAKE\n",
437 			gn->name);
438 	    return FALSE;
439 	}
440     }
441 
442     /* The object directory may not exist. Check it.. */
443     if (cached_stat(dname, &fs) != 0) {
444 	if (verbose)
445 	    fprintf(debug_file, "Skipping meta for %s: no .OBJDIR\n",
446 		    gn->name);
447 	return FALSE;
448     }
449 
450     /* make sure these are canonical */
451     if (cached_realpath(dname, objdir))
452 	dname = objdir;
453 
454     /* If we aren't in the object directory, don't create a meta file. */
455     if (!metaCurdirOk && strcmp(curdir, dname) == 0) {
456 	if (verbose)
457 	    fprintf(debug_file, "Skipping meta for %s: .OBJDIR == .CURDIR\n",
458 		    gn->name);
459 	return FALSE;
460     }
461     return TRUE;
462 }
463 
464 
465 static FILE *
466 meta_create(BuildMon *pbm, GNode *gn)
467 {
468     meta_file_t mf;
469     char buf[MAXPATHLEN];
470     char objdir[MAXPATHLEN];
471     char **ptr;
472     const char *dname;
473     const char *tname;
474     char *fname;
475     const char *cp;
476     char *p[4];				/* >= possible uses */
477     int i;
478 
479     mf.fp = NULL;
480     i = 0;
481 
482     dname = Var_Value(".OBJDIR", gn, &p[i++]);
483     tname = Var_Value(TARGET, gn, &p[i++]);
484 
485     /* if this succeeds objdir is realpath of dname */
486     if (!meta_needed(gn, dname, objdir, TRUE))
487 	goto out;
488     dname = objdir;
489 
490     if (metaVerbose) {
491 	char *mp;
492 
493 	/* Describe the target we are building */
494 	mp = Var_Subst(NULL, "${" MAKE_META_PREFIX "}", gn, VARF_WANTRES);
495 	if (*mp)
496 	    fprintf(stdout, "%s\n", mp);
497 	free(mp);
498     }
499     /* Get the basename of the target */
500     if ((cp = strrchr(tname, '/')) == NULL) {
501 	cp = tname;
502     } else {
503 	cp++;
504     }
505 
506     fflush(stdout);
507 
508     if (!writeMeta)
509 	/* Don't create meta data. */
510 	goto out;
511 
512     fname = meta_name(pbm->meta_fname, sizeof(pbm->meta_fname),
513 		      dname, tname, objdir);
514 
515 #ifdef DEBUG_META_MODE
516     if (DEBUG(META))
517 	fprintf(debug_file, "meta_create: %s\n", fname);
518 #endif
519 
520     if ((mf.fp = fopen(fname, "w")) == NULL)
521 	err(1, "Could not open meta file '%s'", fname);
522 
523     fprintf(mf.fp, "# Meta data file %s\n", fname);
524 
525     mf.gn = gn;
526 
527     Lst_ForEach(gn->commands, printCMD, &mf);
528 
529     fprintf(mf.fp, "CWD %s\n", getcwd(buf, sizeof(buf)));
530     fprintf(mf.fp, "TARGET %s\n", tname);
531 
532     if (metaEnv) {
533 	for (ptr = environ; *ptr != NULL; ptr++)
534 	    fprintf(mf.fp, "ENV %s\n", *ptr);
535     }
536 
537     fprintf(mf.fp, "-- command output --\n");
538     fflush(mf.fp);
539 
540     Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
541     Var_Append(".MAKE.META.CREATED", fname, VAR_GLOBAL);
542 
543     gn->type |= OP_META;		/* in case anyone wants to know */
544     if (metaSilent) {
545 	    gn->type |= OP_SILENT;
546     }
547  out:
548     for (i--; i >= 0; i--) {
549 	free(p[i]);
550     }
551 
552     return (mf.fp);
553 }
554 
555 static Boolean
556 boolValue(char *s)
557 {
558     switch(*s) {
559     case '0':
560     case 'N':
561     case 'n':
562     case 'F':
563     case 'f':
564 	return FALSE;
565     }
566     return TRUE;
567 }
568 
569 /*
570  * Initialization we need before reading makefiles.
571  */
572 void
573 meta_init(void)
574 {
575 #ifdef USE_FILEMON
576 	/* this allows makefiles to test if we have filemon support */
577 	Var_Set(".MAKE.PATH_FILEMON", _PATH_FILEMON, VAR_GLOBAL, 0);
578 #endif
579 }
580 
581 
582 #define get_mode_bf(bf, token) \
583     if ((cp = strstr(make_mode, token))) \
584 	bf = boolValue(&cp[sizeof(token) - 1])
585 
586 /*
587  * Initialization we need after reading makefiles.
588  */
589 void
590 meta_mode_init(const char *make_mode)
591 {
592     static int once = 0;
593     char *cp;
594 
595     useMeta = TRUE;
596     useFilemon = TRUE;
597     writeMeta = TRUE;
598 
599     if (make_mode) {
600 	if (strstr(make_mode, "env"))
601 	    metaEnv = TRUE;
602 	if (strstr(make_mode, "verb"))
603 	    metaVerbose = TRUE;
604 	if (strstr(make_mode, "read"))
605 	    writeMeta = FALSE;
606 	if (strstr(make_mode, "nofilemon"))
607 	    useFilemon = FALSE;
608 	if (strstr(make_mode, "ignore-cmd"))
609 	    metaIgnoreCMDs = TRUE;
610 	if (useFilemon)
611 	    get_mode_bf(filemonMissing, "missing-filemon=");
612 	get_mode_bf(metaCurdirOk, "curdirok=");
613 	get_mode_bf(metaMissing, "missing-meta=");
614 	get_mode_bf(metaSilent, "silent=");
615     }
616     if (metaVerbose && !Var_Exists(MAKE_META_PREFIX, VAR_GLOBAL)) {
617 	/*
618 	 * The default value for MAKE_META_PREFIX
619 	 * prints the absolute path of the target.
620 	 * This works be cause :H will generate '.' if there is no /
621 	 * and :tA will resolve that to cwd.
622 	 */
623 	Var_Set(MAKE_META_PREFIX, "Building ${.TARGET:H:tA}/${.TARGET:T}", VAR_GLOBAL, 0);
624     }
625     if (once)
626 	return;
627     once = 1;
628     memset(&Mybm, 0, sizeof(Mybm));
629     /*
630      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
631      */
632     metaBailiwick = Lst_Init(FALSE);
633     metaBailiwickStr = Var_Subst(NULL, "${.MAKE.META.BAILIWICK:O:u:tA}",
634 	VAR_GLOBAL, VARF_WANTRES);
635     if (metaBailiwickStr) {
636 	str2Lst_Append(metaBailiwick, metaBailiwickStr, NULL);
637     }
638     /*
639      * We ignore any paths that start with ${.MAKE.META.IGNORE_PATHS}
640      */
641     metaIgnorePaths = Lst_Init(FALSE);
642     Var_Append(MAKE_META_IGNORE_PATHS,
643 	       "/dev /etc /proc /tmp /var/run /var/tmp ${TMPDIR}", VAR_GLOBAL);
644     metaIgnorePathsStr = Var_Subst(NULL,
645 		   "${" MAKE_META_IGNORE_PATHS ":O:u:tA}", VAR_GLOBAL,
646 		   VARF_WANTRES);
647     if (metaIgnorePathsStr) {
648 	str2Lst_Append(metaIgnorePaths, metaIgnorePathsStr, NULL);
649     }
650 
651     /*
652      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
653      */
654     cp = NULL;
655     if (Var_Value(MAKE_META_IGNORE_PATTERNS, VAR_GLOBAL, &cp)) {
656 	metaIgnorePatterns = TRUE;
657 	free(cp);
658     }
659     cp = NULL;
660     if (Var_Value(MAKE_META_IGNORE_FILTER, VAR_GLOBAL, &cp)) {
661 	metaIgnoreFilter = TRUE;
662 	free(cp);
663     }
664 }
665 
666 /*
667  * In each case below we allow for job==NULL
668  */
669 void
670 meta_job_start(Job *job, GNode *gn)
671 {
672     BuildMon *pbm;
673 
674     if (job != NULL) {
675 	pbm = &job->bm;
676     } else {
677 	pbm = &Mybm;
678     }
679     pbm->mfp = meta_create(pbm, gn);
680 #ifdef USE_FILEMON_ONCE
681     /* compat mode we open the filemon dev once per command */
682     if (job == NULL)
683 	return;
684 #endif
685 #ifdef USE_FILEMON
686     if (pbm->mfp != NULL && useFilemon) {
687 	filemon_open(pbm);
688     } else {
689 	pbm->mon_fd = pbm->filemon_fd = -1;
690     }
691 #endif
692 }
693 
694 /*
695  * The child calls this before doing anything.
696  * It does not disturb our state.
697  */
698 void
699 meta_job_child(Job *job)
700 {
701 #ifdef USE_FILEMON
702     BuildMon *pbm;
703 
704     if (job != NULL) {
705 	pbm = &job->bm;
706     } else {
707 	pbm = &Mybm;
708     }
709     if (pbm->mfp != NULL) {
710 	close(fileno(pbm->mfp));
711 	if (useFilemon) {
712 	    pid_t pid;
713 
714 	    pid = getpid();
715 	    if (ioctl(pbm->filemon_fd, FILEMON_SET_PID, &pid) < 0) {
716 		err(1, "Could not set filemon pid!");
717 	    }
718 	}
719     }
720 #endif
721 }
722 
723 void
724 meta_job_error(Job *job, GNode *gn, int flags, int status)
725 {
726     char cwd[MAXPATHLEN];
727     BuildMon *pbm;
728 
729     if (job != NULL) {
730 	pbm = &job->bm;
731 	if (!gn)
732 	    gn = job->node;
733     } else {
734 	pbm = &Mybm;
735     }
736     if (pbm->mfp != NULL) {
737 	fprintf(pbm->mfp, "\n*** Error code %d%s\n",
738 		status,
739 		(flags & JOB_IGNERR) ?
740 		"(ignored)" : "");
741     }
742     if (gn) {
743 	Var_Set(".ERROR_TARGET", gn->path ? gn->path : gn->name, VAR_GLOBAL, 0);
744     }
745     getcwd(cwd, sizeof(cwd));
746     Var_Set(".ERROR_CWD", cwd, VAR_GLOBAL, 0);
747     if (pbm->meta_fname[0]) {
748 	Var_Set(".ERROR_META_FILE", pbm->meta_fname, VAR_GLOBAL, 0);
749     }
750     meta_job_finish(job);
751 }
752 
753 void
754 meta_job_output(Job *job, char *cp, const char *nl)
755 {
756     BuildMon *pbm;
757 
758     if (job != NULL) {
759 	pbm = &job->bm;
760     } else {
761 	pbm = &Mybm;
762     }
763     if (pbm->mfp != NULL) {
764 	if (metaVerbose) {
765 	    static char *meta_prefix = NULL;
766 	    static int meta_prefix_len;
767 
768 	    if (!meta_prefix) {
769 		char *cp2;
770 
771 		meta_prefix = Var_Subst(NULL, "${" MAKE_META_PREFIX "}",
772 					VAR_GLOBAL, VARF_WANTRES);
773 		if ((cp2 = strchr(meta_prefix, '$')))
774 		    meta_prefix_len = cp2 - meta_prefix;
775 		else
776 		    meta_prefix_len = strlen(meta_prefix);
777 	    }
778 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
779 		cp = strchr(cp+1, '\n');
780 		if (!cp++)
781 		    return;
782 	    }
783 	}
784 	fprintf(pbm->mfp, "%s%s", cp, nl);
785     }
786 }
787 
788 int
789 meta_cmd_finish(void *pbmp)
790 {
791     int error = 0;
792     BuildMon *pbm = pbmp;
793 #ifdef USE_FILEMON
794     int x;
795 #endif
796 
797     if (!pbm)
798 	pbm = &Mybm;
799 
800 #ifdef USE_FILEMON
801     if (pbm->filemon_fd >= 0) {
802 	if (close(pbm->filemon_fd) < 0)
803 	    error = errno;
804 	x = filemon_read(pbm->mfp, pbm->mon_fd);
805 	if (error == 0 && x != 0)
806 	    error = x;
807 	pbm->filemon_fd = pbm->mon_fd = -1;
808     } else
809 #endif
810 	fprintf(pbm->mfp, "\n");	/* ensure end with newline */
811     return error;
812 }
813 
814 int
815 meta_job_finish(Job *job)
816 {
817     BuildMon *pbm;
818     int error = 0;
819     int x;
820 
821     if (job != NULL) {
822 	pbm = &job->bm;
823     } else {
824 	pbm = &Mybm;
825     }
826     if (pbm->mfp != NULL) {
827 	error = meta_cmd_finish(pbm);
828 	x = fclose(pbm->mfp);
829 	if (error == 0 && x != 0)
830 	    error = errno;
831 	pbm->mfp = NULL;
832 	pbm->meta_fname[0] = '\0';
833     }
834     return error;
835 }
836 
837 void
838 meta_finish(void)
839 {
840     Lst_Destroy(metaBailiwick, NULL);
841     free(metaBailiwickStr);
842     Lst_Destroy(metaIgnorePaths, NULL);
843     free(metaIgnorePathsStr);
844 }
845 
846 /*
847  * Fetch a full line from fp - growing bufp if needed
848  * Return length in bufp.
849  */
850 static int
851 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
852 {
853     char *buf = *bufp;
854     size_t bufsz = *szp;
855     struct stat fs;
856     int x;
857 
858     if (fgets(&buf[o], bufsz - o, fp) != NULL) {
859     check_newline:
860 	x = o + strlen(&buf[o]);
861 	if (buf[x - 1] == '\n')
862 	    return x;
863 	/*
864 	 * We need to grow the buffer.
865 	 * The meta file can give us a clue.
866 	 */
867 	if (fstat(fileno(fp), &fs) == 0) {
868 	    size_t newsz;
869 	    char *p;
870 
871 	    newsz = ROUNDUP((fs.st_size / 2), BUFSIZ);
872 	    if (newsz <= bufsz)
873 		newsz = ROUNDUP(fs.st_size, BUFSIZ);
874 	    if (newsz <= bufsz)
875 		return x;		/* truncated */
876 	    if (DEBUG(META))
877 		fprintf(debug_file, "growing buffer %u -> %u\n",
878 			(unsigned)bufsz, (unsigned)newsz);
879 	    p = bmake_realloc(buf, newsz);
880 	    if (p) {
881 		*bufp = buf = p;
882 		*szp = bufsz = newsz;
883 		/* fetch the rest */
884 		if (!fgets(&buf[x], bufsz - x, fp))
885 		    return x;		/* truncated! */
886 		goto check_newline;
887 	    }
888 	}
889     }
890     return 0;
891 }
892 
893 /* Lst_ForEach wants 1 to stop search */
894 static int
895 prefix_match(void *p, void *q)
896 {
897     const char *prefix = p;
898     const char *path = q;
899     size_t n = strlen(prefix);
900 
901     return (0 == strncmp(path, prefix, n));
902 }
903 
904 /*
905  * looking for exact or prefix/ match to
906  * Lst_Find wants 0 to stop search
907  */
908 static int
909 path_match(const void *p, const void *q)
910 {
911     const char *prefix = q;
912     const char *path = p;
913     size_t n = strlen(prefix);
914     int rc;
915 
916     if ((rc = strncmp(path, prefix, n)) == 0) {
917 	switch (path[n]) {
918 	case '\0':
919 	case '/':
920 	    break;
921 	default:
922 	    rc = 1;
923 	    break;
924 	}
925     }
926     return rc;
927 }
928 
929 /* Lst_Find wants 0 to stop search */
930 static int
931 string_match(const void *p, const void *q)
932 {
933     const char *p1 = p;
934     const char *p2 = q;
935 
936     return strcmp(p1, p2);
937 }
938 
939 
940 static int
941 meta_ignore(GNode *gn, const char *p)
942 {
943     char fname[MAXPATHLEN];
944 
945     if (p == NULL)
946 	return TRUE;
947 
948     if (*p == '/') {
949 	cached_realpath(p, fname); /* clean it up */
950 	if (Lst_ForEach(metaIgnorePaths, prefix_match, fname)) {
951 #ifdef DEBUG_META_MODE
952 	    if (DEBUG(META))
953 		fprintf(debug_file, "meta_oodate: ignoring path: %s\n",
954 			p);
955 #endif
956 	    return TRUE;
957 	}
958     }
959 
960     if (metaIgnorePatterns) {
961 	char *pm;
962 
963 	Var_Set(".p.", p, gn, 0);
964 	pm = Var_Subst(NULL,
965 		       "${" MAKE_META_IGNORE_PATTERNS ":@m@${.p.:M$m}@}",
966 		       gn, VARF_WANTRES);
967 	if (*pm) {
968 #ifdef DEBUG_META_MODE
969 	    if (DEBUG(META))
970 		fprintf(debug_file, "meta_oodate: ignoring pattern: %s\n",
971 			p);
972 #endif
973 	    free(pm);
974 	    return TRUE;
975 	}
976 	free(pm);
977     }
978 
979     if (metaIgnoreFilter) {
980 	char *fm;
981 
982 	/* skip if filter result is empty */
983 	snprintf(fname, sizeof(fname),
984 		 "${%s:L:${%s:ts:}}",
985 		 p, MAKE_META_IGNORE_FILTER);
986 	fm = Var_Subst(NULL, fname, gn, VARF_WANTRES);
987 	if (*fm == '\0') {
988 #ifdef DEBUG_META_MODE
989 	    if (DEBUG(META))
990 		fprintf(debug_file, "meta_oodate: ignoring filtered: %s\n",
991 			p);
992 #endif
993 	    free(fm);
994 	    return TRUE;
995 	}
996 	free(fm);
997     }
998     return FALSE;
999 }
1000 
1001 /*
1002  * When running with 'meta' functionality, a target can be out-of-date
1003  * if any of the references in its meta data file is more recent.
1004  * We have to track the latestdir on a per-process basis.
1005  */
1006 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
1007 #define LDIR_VNAME_FMT ".meta.%d.ldir"
1008 
1009 /*
1010  * It is possible that a .meta file is corrupted,
1011  * if we detect this we want to reproduce it.
1012  * Setting oodate TRUE will have that effect.
1013  */
1014 #define CHECK_VALID_META(p) if (!(p && *p)) { \
1015     warnx("%s: %d: malformed", fname, lineno); \
1016     oodate = TRUE; \
1017     continue; \
1018     }
1019 
1020 #define DEQUOTE(p) if (*p == '\'') {	\
1021     char *ep; \
1022     p++; \
1023     if ((ep = strchr(p, '\''))) \
1024 	*ep = '\0'; \
1025     }
1026 
1027 Boolean
1028 meta_oodate(GNode *gn, Boolean oodate)
1029 {
1030     static char *tmpdir = NULL;
1031     static char cwd[MAXPATHLEN];
1032     char lcwd_vname[64];
1033     char ldir_vname[64];
1034     char lcwd[MAXPATHLEN];
1035     char latestdir[MAXPATHLEN];
1036     char fname[MAXPATHLEN];
1037     char fname1[MAXPATHLEN];
1038     char fname2[MAXPATHLEN];
1039     char fname3[MAXPATHLEN];
1040     const char *dname;
1041     const char *tname;
1042     char *p;
1043     char *cp;
1044     char *link_src;
1045     char *move_target;
1046     static size_t cwdlen = 0;
1047     static size_t tmplen = 0;
1048     FILE *fp;
1049     Boolean needOODATE = FALSE;
1050     Lst missingFiles;
1051     char *pa[4];			/* >= possible uses */
1052     int i;
1053     int have_filemon = FALSE;
1054 
1055     if (oodate)
1056 	return oodate;		/* we're done */
1057 
1058     i = 0;
1059 
1060     dname = Var_Value(".OBJDIR", gn, &pa[i++]);
1061     tname = Var_Value(TARGET, gn, &pa[i++]);
1062 
1063     /* if this succeeds fname3 is realpath of dname */
1064     if (!meta_needed(gn, dname, fname3, FALSE))
1065 	goto oodate_out;
1066     dname = fname3;
1067 
1068     missingFiles = Lst_Init(FALSE);
1069 
1070     /*
1071      * We need to check if the target is out-of-date. This includes
1072      * checking if the expanded command has changed. This in turn
1073      * requires that all variables are set in the same way that they
1074      * would be if the target needs to be re-built.
1075      */
1076     Make_DoAllVar(gn);
1077 
1078     meta_name(fname, sizeof(fname), dname, tname, dname);
1079 
1080 #ifdef DEBUG_META_MODE
1081     if (DEBUG(META))
1082 	fprintf(debug_file, "meta_oodate: %s\n", fname);
1083 #endif
1084 
1085     if ((fp = fopen(fname, "r")) != NULL) {
1086 	static char *buf = NULL;
1087 	static size_t bufsz;
1088 	int lineno = 0;
1089 	int lastpid = 0;
1090 	int pid;
1091 	int x;
1092 	LstNode ln;
1093 	struct stat fs;
1094 
1095 	if (!buf) {
1096 	    bufsz = 8 * BUFSIZ;
1097 	    buf = bmake_malloc(bufsz);
1098 	}
1099 
1100 	if (!cwdlen) {
1101 	    if (getcwd(cwd, sizeof(cwd)) == NULL)
1102 		err(1, "Could not get current working directory");
1103 	    cwdlen = strlen(cwd);
1104 	}
1105 	strlcpy(lcwd, cwd, sizeof(lcwd));
1106 	strlcpy(latestdir, cwd, sizeof(latestdir));
1107 
1108 	if (!tmpdir) {
1109 	    tmpdir = getTmpdir();
1110 	    tmplen = strlen(tmpdir);
1111 	}
1112 
1113 	/* we want to track all the .meta we read */
1114 	Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
1115 
1116 	ln = Lst_First(gn->commands);
1117 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1118 	    lineno++;
1119 	    if (buf[x - 1] == '\n')
1120 		buf[x - 1] = '\0';
1121 	    else {
1122 		warnx("%s: %d: line truncated at %u", fname, lineno, x);
1123 		oodate = TRUE;
1124 		break;
1125 	    }
1126 	    link_src = NULL;
1127 	    move_target = NULL;
1128 	    /* Find the start of the build monitor section. */
1129 	    if (!have_filemon) {
1130 		if (strncmp(buf, "-- filemon", 10) == 0) {
1131 		    have_filemon = TRUE;
1132 		    continue;
1133 		}
1134 		if (strncmp(buf, "# buildmon", 10) == 0) {
1135 		    have_filemon = TRUE;
1136 		    continue;
1137 		}
1138 	    }
1139 
1140 	    /* Delimit the record type. */
1141 	    p = buf;
1142 #ifdef DEBUG_META_MODE
1143 	    if (DEBUG(META))
1144 		fprintf(debug_file, "%s: %d: %s\n", fname, lineno, buf);
1145 #endif
1146 	    strsep(&p, " ");
1147 	    if (have_filemon) {
1148 		/*
1149 		 * We are in the 'filemon' output section.
1150 		 * Each record from filemon follows the general form:
1151 		 *
1152 		 * <key> <pid> <data>
1153 		 *
1154 		 * Where:
1155 		 * <key> is a single letter, denoting the syscall.
1156 		 * <pid> is the process that made the syscall.
1157 		 * <data> is the arguments (of interest).
1158 		 */
1159 		switch(buf[0]) {
1160 		case '#':		/* comment */
1161 		case 'V':		/* version */
1162 		    break;
1163 		default:
1164 		    /*
1165 		     * We need to track pathnames per-process.
1166 		     *
1167 		     * Each process run by make, starts off in the 'CWD'
1168 		     * recorded in the .meta file, if it chdirs ('C')
1169 		     * elsewhere we need to track that - but only for
1170 		     * that process.  If it forks ('F'), we initialize
1171 		     * the child to have the same cwd as its parent.
1172 		     *
1173 		     * We also need to track the 'latestdir' of
1174 		     * interest.  This is usually the same as cwd, but
1175 		     * not if a process is reading directories.
1176 		     *
1177 		     * Each time we spot a different process ('pid')
1178 		     * we save the current value of 'latestdir' in a
1179 		     * variable qualified by 'lastpid', and
1180 		     * re-initialize 'latestdir' to any pre-saved
1181 		     * value for the current 'pid' and 'CWD' if none.
1182 		     */
1183 		    CHECK_VALID_META(p);
1184 		    pid = atoi(p);
1185 		    if (pid > 0 && pid != lastpid) {
1186 			char *ldir;
1187 			char *tp;
1188 
1189 			if (lastpid > 0) {
1190 			    /* We need to remember these. */
1191 			    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1192 			    Var_Set(ldir_vname, latestdir, VAR_GLOBAL, 0);
1193 			}
1194 			snprintf(lcwd_vname, sizeof(lcwd_vname), LCWD_VNAME_FMT, pid);
1195 			snprintf(ldir_vname, sizeof(ldir_vname), LDIR_VNAME_FMT, pid);
1196 			lastpid = pid;
1197 			ldir = Var_Value(ldir_vname, VAR_GLOBAL, &tp);
1198 			if (ldir) {
1199 			    strlcpy(latestdir, ldir, sizeof(latestdir));
1200 			    free(tp);
1201 			}
1202 			ldir = Var_Value(lcwd_vname, VAR_GLOBAL, &tp);
1203 			if (ldir) {
1204 			    strlcpy(lcwd, ldir, sizeof(lcwd));
1205 			    free(tp);
1206 			}
1207 		    }
1208 		    /* Skip past the pid. */
1209 		    if (strsep(&p, " ") == NULL)
1210 			continue;
1211 #ifdef DEBUG_META_MODE
1212 		    if (DEBUG(META))
1213 			    fprintf(debug_file, "%s: %d: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1214 				    fname, lineno,
1215 				    pid, buf[0], cwd, lcwd, latestdir);
1216 #endif
1217 		    break;
1218 		}
1219 
1220 		CHECK_VALID_META(p);
1221 
1222 		/* Process according to record type. */
1223 		switch (buf[0]) {
1224 		case 'X':		/* eXit */
1225 		    Var_Delete(lcwd_vname, VAR_GLOBAL);
1226 		    Var_Delete(ldir_vname, VAR_GLOBAL);
1227 		    lastpid = 0;	/* no need to save ldir_vname */
1228 		    break;
1229 
1230 		case 'F':		/* [v]Fork */
1231 		    {
1232 			char cldir[64];
1233 			int child;
1234 
1235 			child = atoi(p);
1236 			if (child > 0) {
1237 			    snprintf(cldir, sizeof(cldir), LCWD_VNAME_FMT, child);
1238 			    Var_Set(cldir, lcwd, VAR_GLOBAL, 0);
1239 			    snprintf(cldir, sizeof(cldir), LDIR_VNAME_FMT, child);
1240 			    Var_Set(cldir, latestdir, VAR_GLOBAL, 0);
1241 #ifdef DEBUG_META_MODE
1242 			    if (DEBUG(META))
1243 				    fprintf(debug_file, "%s: %d: %d: cwd=%s lcwd=%s ldir=%s\n",
1244 					    fname, lineno,
1245 					    child, cwd, lcwd, latestdir);
1246 #endif
1247 			}
1248 		    }
1249 		    break;
1250 
1251 		case 'C':		/* Chdir */
1252 		    /* Update lcwd and latest directory. */
1253 		    strlcpy(latestdir, p, sizeof(latestdir));
1254 		    strlcpy(lcwd, p, sizeof(lcwd));
1255 		    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1256 		    Var_Set(ldir_vname, lcwd, VAR_GLOBAL, 0);
1257 #ifdef DEBUG_META_MODE
1258 		    if (DEBUG(META))
1259 			fprintf(debug_file, "%s: %d: cwd=%s ldir=%s\n", fname, lineno, cwd, lcwd);
1260 #endif
1261 		    break;
1262 
1263 		case 'M':		/* renaMe */
1264 		    /*
1265 		     * For 'M'oves we want to check
1266 		     * the src as for 'R'ead
1267 		     * and the target as for 'W'rite.
1268 		     */
1269 		    cp = p;		/* save this for a second */
1270 		    /* now get target */
1271 		    if (strsep(&p, " ") == NULL)
1272 			continue;
1273 		    CHECK_VALID_META(p);
1274 		    move_target = p;
1275 		    p = cp;
1276 		    /* 'L' and 'M' put single quotes around the args */
1277 		    DEQUOTE(p);
1278 		    DEQUOTE(move_target);
1279 		    /* FALLTHROUGH */
1280 		case 'D':		/* unlink */
1281 		    if (*p == '/' && !Lst_IsEmpty(missingFiles)) {
1282 			/* remove any missingFiles entries that match p */
1283 			if ((ln = Lst_Find(missingFiles, p,
1284 					   path_match)) != NULL) {
1285 			    LstNode nln;
1286 			    char *tp;
1287 
1288 			    do {
1289 				nln = Lst_FindFrom(missingFiles, Lst_Succ(ln),
1290 						   p, path_match);
1291 				tp = Lst_Datum(ln);
1292 				Lst_Remove(missingFiles, ln);
1293 				free(tp);
1294 			    } while ((ln = nln) != NULL);
1295 			}
1296 		    }
1297 		    if (buf[0] == 'M') {
1298 			/* the target of the mv is a file 'W'ritten */
1299 #ifdef DEBUG_META_MODE
1300 			if (DEBUG(META))
1301 			    fprintf(debug_file, "meta_oodate: M %s -> %s\n",
1302 				    p, move_target);
1303 #endif
1304 			p = move_target;
1305 			goto check_write;
1306 		    }
1307 		    break;
1308 		case 'L':		/* Link */
1309 		    /*
1310 		     * For 'L'inks check
1311 		     * the src as for 'R'ead
1312 		     * and the target as for 'W'rite.
1313 		     */
1314 		    link_src = p;
1315 		    /* now get target */
1316 		    if (strsep(&p, " ") == NULL)
1317 			continue;
1318 		    CHECK_VALID_META(p);
1319 		    /* 'L' and 'M' put single quotes around the args */
1320 		    DEQUOTE(p);
1321 		    DEQUOTE(link_src);
1322 #ifdef DEBUG_META_MODE
1323 		    if (DEBUG(META))
1324 			fprintf(debug_file, "meta_oodate: L %s -> %s\n",
1325 				link_src, p);
1326 #endif
1327 		    /* FALLTHROUGH */
1328 		case 'W':		/* Write */
1329 		check_write:
1330 		    /*
1331 		     * If a file we generated within our bailiwick
1332 		     * but outside of .OBJDIR is missing,
1333 		     * we need to do it again.
1334 		     */
1335 		    /* ignore non-absolute paths */
1336 		    if (*p != '/')
1337 			break;
1338 
1339 		    if (Lst_IsEmpty(metaBailiwick))
1340 			break;
1341 
1342 		    /* ignore cwd - normal dependencies handle those */
1343 		    if (strncmp(p, cwd, cwdlen) == 0)
1344 			break;
1345 
1346 		    if (!Lst_ForEach(metaBailiwick, prefix_match, p))
1347 			break;
1348 
1349 		    /* tmpdir might be within */
1350 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1351 			break;
1352 
1353 		    /* ignore anything containing the string "tmp" */
1354 		    if ((strstr("tmp", p)))
1355 			break;
1356 
1357 		    if ((link_src != NULL && cached_lstat(p, &fs) < 0) ||
1358 			(link_src == NULL && cached_stat(p, &fs) < 0)) {
1359 			if (!meta_ignore(gn, p)) {
1360 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1361 				Lst_AtEnd(missingFiles, bmake_strdup(p));
1362 			}
1363 		    }
1364 		    break;
1365 		check_link_src:
1366 		    p = link_src;
1367 		    link_src = NULL;
1368 #ifdef DEBUG_META_MODE
1369 		    if (DEBUG(META))
1370 			fprintf(debug_file, "meta_oodate: L src %s\n", p);
1371 #endif
1372 		    /* FALLTHROUGH */
1373 		case 'R':		/* Read */
1374 		case 'E':		/* Exec */
1375 		    /*
1376 		     * Check for runtime files that can't
1377 		     * be part of the dependencies because
1378 		     * they are _expected_ to change.
1379 		     */
1380 		    if (meta_ignore(gn, p))
1381 			break;
1382 
1383 		    /*
1384 		     * The rest of the record is the file name.
1385 		     * Check if it's not an absolute path.
1386 		     */
1387 		    {
1388 			char *sdirs[4];
1389 			char **sdp;
1390 			int sdx = 0;
1391 			int found = 0;
1392 
1393 			if (*p == '/') {
1394 			    sdirs[sdx++] = p; /* done */
1395 			} else {
1396 			    if (strcmp(".", p) == 0)
1397 				continue;  /* no point */
1398 
1399 			    /* Check vs latestdir */
1400 			    snprintf(fname1, sizeof(fname1), "%s/%s", latestdir, p);
1401 			    sdirs[sdx++] = fname1;
1402 
1403 			    if (strcmp(latestdir, lcwd) != 0) {
1404 				/* Check vs lcwd */
1405 				snprintf(fname2, sizeof(fname2), "%s/%s", lcwd, p);
1406 				sdirs[sdx++] = fname2;
1407 			    }
1408 			    if (strcmp(lcwd, cwd) != 0) {
1409 				/* Check vs cwd */
1410 				snprintf(fname3, sizeof(fname3), "%s/%s", cwd, p);
1411 				sdirs[sdx++] = fname3;
1412 			    }
1413 			}
1414 			sdirs[sdx++] = NULL;
1415 
1416 			for (sdp = sdirs; *sdp && !found; sdp++) {
1417 #ifdef DEBUG_META_MODE
1418 			    if (DEBUG(META))
1419 				fprintf(debug_file, "%s: %d: looking for: %s\n", fname, lineno, *sdp);
1420 #endif
1421 			    if (cached_stat(*sdp, &fs) == 0) {
1422 				found = 1;
1423 				p = *sdp;
1424 			    }
1425 			}
1426 			if (found) {
1427 #ifdef DEBUG_META_MODE
1428 			    if (DEBUG(META))
1429 				fprintf(debug_file, "%s: %d: found: %s\n", fname, lineno, p);
1430 #endif
1431 			    if (!S_ISDIR(fs.st_mode) &&
1432 				fs.st_mtime > gn->mtime) {
1433 				if (DEBUG(META))
1434 				    fprintf(debug_file, "%s: %d: file '%s' is newer than the target...\n", fname, lineno, p);
1435 				oodate = TRUE;
1436 			    } else if (S_ISDIR(fs.st_mode)) {
1437 				/* Update the latest directory. */
1438 				cached_realpath(p, latestdir);
1439 			    }
1440 			} else if (errno == ENOENT && *p == '/' &&
1441 				   strncmp(p, cwd, cwdlen) != 0) {
1442 			    /*
1443 			     * A referenced file outside of CWD is missing.
1444 			     * We cannot catch every eventuality here...
1445 			     */
1446 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1447 				    Lst_AtEnd(missingFiles, bmake_strdup(p));
1448 			}
1449 		    }
1450 		    if (buf[0] == 'E') {
1451 			/* previous latestdir is no longer relevant */
1452 			strlcpy(latestdir, lcwd, sizeof(latestdir));
1453 		    }
1454 		    break;
1455 		default:
1456 		    break;
1457 		}
1458 		if (!oodate && buf[0] == 'L' && link_src != NULL)
1459 		    goto check_link_src;
1460 	    } else if (strcmp(buf, "CMD") == 0) {
1461 		/*
1462 		 * Compare the current command with the one in the
1463 		 * meta data file.
1464 		 */
1465 		if (ln == NULL) {
1466 		    if (DEBUG(META))
1467 			fprintf(debug_file, "%s: %d: there were more build commands in the meta data file than there are now...\n", fname, lineno);
1468 		    oodate = TRUE;
1469 		} else {
1470 		    char *cmd = (char *)Lst_Datum(ln);
1471 		    Boolean hasOODATE = FALSE;
1472 
1473 		    if (strstr(cmd, "$?"))
1474 			hasOODATE = TRUE;
1475 		    else if ((cp = strstr(cmd, ".OODATE"))) {
1476 			/* check for $[{(].OODATE[:)}] */
1477 			if (cp > cmd + 2 && cp[-2] == '$')
1478 			    hasOODATE = TRUE;
1479 		    }
1480 		    if (hasOODATE) {
1481 			needOODATE = TRUE;
1482 			if (DEBUG(META))
1483 			    fprintf(debug_file, "%s: %d: cannot compare command using .OODATE\n", fname, lineno);
1484 		    }
1485 		    cmd = Var_Subst(NULL, cmd, gn, VARF_WANTRES|VARF_UNDEFERR);
1486 
1487 		    if ((cp = strchr(cmd, '\n'))) {
1488 			int n;
1489 
1490 			/*
1491 			 * This command contains newlines, we need to
1492 			 * fetch more from the .meta file before we
1493 			 * attempt a comparison.
1494 			 */
1495 			/* first put the newline back at buf[x - 1] */
1496 			buf[x - 1] = '\n';
1497 			do {
1498 			    /* now fetch the next line */
1499 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1500 				break;
1501 			    x = n;
1502 			    lineno++;
1503 			    if (buf[x - 1] != '\n') {
1504 				warnx("%s: %d: line truncated at %u", fname, lineno, x);
1505 				break;
1506 			    }
1507 			    cp = strchr(++cp, '\n');
1508 			} while (cp);
1509 			if (buf[x - 1] == '\n')
1510 			    buf[x - 1] = '\0';
1511 		    }
1512 		    if (!hasOODATE &&
1513 			!(gn->type & OP_NOMETA_CMP) &&
1514 			strcmp(p, cmd) != 0) {
1515 			if (DEBUG(META))
1516 			    fprintf(debug_file, "%s: %d: a build command has changed\n%s\nvs\n%s\n", fname, lineno, p, cmd);
1517 			if (!metaIgnoreCMDs)
1518 			    oodate = TRUE;
1519 		    }
1520 		    free(cmd);
1521 		    ln = Lst_Succ(ln);
1522 		}
1523 	    } else if (strcmp(buf, "CWD") == 0) {
1524 		/*
1525 		 * Check if there are extra commands now
1526 		 * that weren't in the meta data file.
1527 		 */
1528 		if (!oodate && ln != NULL) {
1529 		    if (DEBUG(META))
1530 			fprintf(debug_file, "%s: %d: there are extra build commands now that weren't in the meta data file\n", fname, lineno);
1531 		    oodate = TRUE;
1532 		}
1533 		if (strcmp(p, cwd) != 0) {
1534 		    if (DEBUG(META))
1535 			fprintf(debug_file, "%s: %d: the current working directory has changed from '%s' to '%s'\n", fname, lineno, p, curdir);
1536 		    oodate = TRUE;
1537 		}
1538 	    }
1539 	}
1540 
1541 	fclose(fp);
1542 	if (!Lst_IsEmpty(missingFiles)) {
1543 	    if (DEBUG(META))
1544 		fprintf(debug_file, "%s: missing files: %s...\n",
1545 			fname, (char *)Lst_Datum(Lst_First(missingFiles)));
1546 	    oodate = TRUE;
1547 	}
1548 	if (!oodate && !have_filemon && filemonMissing) {
1549 	    if (DEBUG(META))
1550 		fprintf(debug_file, "%s: missing filemon data\n", fname);
1551 	    oodate = TRUE;
1552 	}
1553     } else {
1554 	if (writeMeta && metaMissing) {
1555 	    cp = NULL;
1556 
1557 	    /* if target is in .CURDIR we do not need a meta file */
1558 	    if (gn->path && (cp = strrchr(gn->path, '/')) && cp > gn->path) {
1559 		if (strncmp(curdir, gn->path, (cp - gn->path)) != 0) {
1560 		    cp = NULL;		/* not in .CURDIR */
1561 		}
1562 	    }
1563 	    if (!cp) {
1564 		if (DEBUG(META))
1565 		    fprintf(debug_file, "%s: required but missing\n", fname);
1566 		oodate = TRUE;
1567 		needOODATE = TRUE;	/* assume the worst */
1568 	    }
1569 	}
1570     }
1571 
1572     Lst_Destroy(missingFiles, (FreeProc *)free);
1573 
1574     if (oodate && needOODATE) {
1575 	/*
1576 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1577 	 * We have decided it is oodate, so .OODATE needs to be set.
1578 	 * All we can sanely do is set it to .ALLSRC.
1579 	 */
1580 	Var_Delete(OODATE, gn);
1581 	Var_Set(OODATE, Var_Value(ALLSRC, gn, &cp), gn, 0);
1582 	free(cp);
1583     }
1584 
1585  oodate_out:
1586     for (i--; i >= 0; i--) {
1587 	free(pa[i]);
1588     }
1589     return oodate;
1590 }
1591 
1592 /* support for compat mode */
1593 
1594 static int childPipe[2];
1595 
1596 void
1597 meta_compat_start(void)
1598 {
1599 #ifdef USE_FILEMON_ONCE
1600     /*
1601      * We need to re-open filemon for each cmd.
1602      */
1603     BuildMon *pbm = &Mybm;
1604 
1605     if (pbm->mfp != NULL && useFilemon) {
1606 	filemon_open(pbm);
1607     } else {
1608 	pbm->mon_fd = pbm->filemon_fd = -1;
1609     }
1610 #endif
1611     if (pipe(childPipe) < 0)
1612 	Punt("Cannot create pipe: %s", strerror(errno));
1613     /* Set close-on-exec flag for both */
1614     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1615     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1616 }
1617 
1618 void
1619 meta_compat_child(void)
1620 {
1621     meta_job_child(NULL);
1622     if (dup2(childPipe[1], 1) < 0 ||
1623 	dup2(1, 2) < 0) {
1624 	execError("dup2", "pipe");
1625 	_exit(1);
1626     }
1627 }
1628 
1629 void
1630 meta_compat_parent(void)
1631 {
1632     FILE *fp;
1633     char buf[BUFSIZ];
1634 
1635     close(childPipe[1]);			/* child side */
1636     fp = fdopen(childPipe[0], "r");
1637     while (fgets(buf, sizeof(buf), fp)) {
1638 	meta_job_output(NULL, buf, "");
1639 	printf("%s", buf);
1640 	fflush(stdout);
1641     }
1642     fclose(fp);
1643 }
1644 
1645 #endif	/* USE_META */
1646