xref: /netbsd-src/usr.bin/make/meta.c (revision 404ee5b9334f618040b6cdef96a0ff35a6fc4636)
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 #include <libgen.h>
41 #include <errno.h>
42 #if !defined(HAVE_CONFIG_H) || defined(HAVE_ERR_H)
43 #include <err.h>
44 #endif
45 
46 #include "make.h"
47 #include "job.h"
48 
49 #ifdef HAVE_FILEMON_H
50 # include <filemon.h>
51 #endif
52 #if !defined(USE_FILEMON) && defined(FILEMON_SET_FD)
53 # define USE_FILEMON
54 #endif
55 
56 static BuildMon Mybm;			/* for compat */
57 static Lst metaBailiwick;		/* our scope of control */
58 static char *metaBailiwickStr;		/* string storage for the list */
59 static Lst metaIgnorePaths;		/* paths we deliberately ignore */
60 static char *metaIgnorePathsStr;	/* string storage for the list */
61 
62 #ifndef MAKE_META_IGNORE_PATHS
63 #define MAKE_META_IGNORE_PATHS ".MAKE.META.IGNORE_PATHS"
64 #endif
65 #ifndef MAKE_META_IGNORE_PATTERNS
66 #define MAKE_META_IGNORE_PATTERNS ".MAKE.META.IGNORE_PATTERNS"
67 #endif
68 #ifndef MAKE_META_IGNORE_FILTER
69 #define MAKE_META_IGNORE_FILTER ".MAKE.META.IGNORE_FILTER"
70 #endif
71 
72 Boolean useMeta = FALSE;
73 static Boolean useFilemon = FALSE;
74 static Boolean writeMeta = FALSE;
75 static Boolean metaMissing = FALSE;	/* oodate if missing */
76 static Boolean filemonMissing = FALSE;	/* oodate if missing */
77 static Boolean metaEnv = FALSE;		/* don't save env unless asked */
78 static Boolean metaVerbose = FALSE;
79 static Boolean metaIgnoreCMDs = FALSE;	/* ignore CMDs in .meta files */
80 static Boolean metaIgnorePatterns = FALSE; /* do we need to do pattern matches */
81 static Boolean metaIgnoreFilter = FALSE;   /* do we have more complex filtering? */
82 static Boolean metaCurdirOk = FALSE;	/* write .meta in .CURDIR Ok? */
83 static Boolean metaSilent = FALSE;	/* if we have a .meta be SILENT */
84 
85 extern Boolean forceJobs;
86 extern Boolean comatMake;
87 extern char    **environ;
88 
89 #define	MAKE_META_PREFIX	".MAKE.META.PREFIX"
90 
91 #ifndef N2U
92 # define N2U(n, u)   (((n) + ((u) - 1)) / (u))
93 #endif
94 #ifndef ROUNDUP
95 # define ROUNDUP(n, u)   (N2U((n), (u)) * (u))
96 #endif
97 
98 #if !defined(HAVE_STRSEP)
99 # define strsep(s, d) stresep((s), (d), 0)
100 #endif
101 
102 /*
103  * Filemon is a kernel module which snoops certain syscalls.
104  *
105  * C chdir
106  * E exec
107  * F [v]fork
108  * L [sym]link
109  * M rename
110  * R read
111  * W write
112  * S stat
113  *
114  * See meta_oodate below - we mainly care about 'E' and 'R'.
115  *
116  * We can still use meta mode without filemon, but
117  * the benefits are more limited.
118  */
119 #ifdef USE_FILEMON
120 # ifndef _PATH_FILEMON
121 #   define _PATH_FILEMON "/dev/filemon"
122 # endif
123 
124 /*
125  * Open the filemon device.
126  */
127 static void
128 filemon_open(BuildMon *pbm)
129 {
130     int retry;
131 
132     pbm->mon_fd = pbm->filemon_fd = -1;
133     if (!useFilemon)
134 	return;
135 
136     for (retry = 5; retry >= 0; retry--) {
137 	if ((pbm->filemon_fd = open(_PATH_FILEMON, O_RDWR)) >= 0)
138 	    break;
139     }
140 
141     if (pbm->filemon_fd < 0) {
142 	useFilemon = FALSE;
143 	warn("Could not open %s", _PATH_FILEMON);
144 	return;
145     }
146 
147     /*
148      * We use a file outside of '.'
149      * to avoid a FreeBSD kernel bug where unlink invalidates
150      * cwd causing getcwd to do a lot more work.
151      * We only care about the descriptor.
152      */
153     pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL);
154     if (ioctl(pbm->filemon_fd, FILEMON_SET_FD, &pbm->mon_fd) < 0) {
155 	err(1, "Could not set filemon file descriptor!");
156     }
157     /* we don't need these once we exec */
158     (void)fcntl(pbm->mon_fd, F_SETFD, FD_CLOEXEC);
159     (void)fcntl(pbm->filemon_fd, F_SETFD, FD_CLOEXEC);
160 }
161 
162 /*
163  * Read the build monitor output file and write records to the target's
164  * metadata file.
165  */
166 static int
167 filemon_read(FILE *mfp, int fd)
168 {
169     char buf[BUFSIZ];
170     int n;
171     int error;
172 
173     /* Check if we're not writing to a meta data file.*/
174     if (mfp == NULL) {
175 	if (fd >= 0)
176 	    close(fd);			/* not interested */
177 	return 0;
178     }
179     /* rewind */
180     (void)lseek(fd, (off_t)0, SEEK_SET);
181 
182     error = 0;
183     fprintf(mfp, "\n-- filemon acquired metadata --\n");
184 
185     while ((n = read(fd, buf, sizeof(buf))) > 0) {
186 	if ((int)fwrite(buf, 1, n, mfp) < n)
187 	    error = EIO;
188     }
189     fflush(mfp);
190     if (close(fd) < 0)
191 	error = errno;
192     return error;
193 }
194 #endif
195 
196 /*
197  * when realpath() fails,
198  * we use this, to clean up ./ and ../
199  */
200 static void
201 eat_dots(char *buf, size_t bufsz, int dots)
202 {
203     char *cp;
204     char *cp2;
205     const char *eat;
206     size_t eatlen;
207 
208     switch (dots) {
209     case 1:
210 	eat = "/./";
211 	eatlen = 2;
212 	break;
213     case 2:
214 	eat = "/../";
215 	eatlen = 3;
216 	break;
217     default:
218 	return;
219     }
220 
221     do {
222 	cp = strstr(buf, eat);
223 	if (cp) {
224 	    cp2 = cp + eatlen;
225 	    if (dots == 2 && cp > buf) {
226 		do {
227 		    cp--;
228 		} while (cp > buf && *cp != '/');
229 	    }
230 	    if (*cp == '/') {
231 		strlcpy(cp, cp2, bufsz - (cp - buf));
232 	    } else {
233 		return;			/* can't happen? */
234 	    }
235 	}
236     } while (cp);
237 }
238 
239 static char *
240 meta_name(struct GNode *gn, char *mname, size_t mnamelen,
241 	  const char *dname,
242 	  const char *tname,
243 	  const char *cwd)
244 {
245     char buf[MAXPATHLEN];
246     char *rp;
247     char *cp;
248     char *tp;
249     char *dtp;
250     size_t ldname;
251 
252     /*
253      * Weed out relative paths from the target file name.
254      * We have to be careful though since if target is a
255      * symlink, the result will be unstable.
256      * So we use realpath() just to get the dirname, and leave the
257      * basename as given to us.
258      */
259     if ((cp = strrchr(tname, '/'))) {
260 	if (cached_realpath(tname, buf)) {
261 	    if ((rp = strrchr(buf, '/'))) {
262 		rp++;
263 		cp++;
264 		if (strcmp(cp, rp) != 0)
265 		    strlcpy(rp, cp, sizeof(buf) - (rp - buf));
266 	    }
267 	    tname = buf;
268 	} else {
269 	    /*
270 	     * We likely have a directory which is about to be made.
271 	     * We pretend realpath() succeeded, to have a chance
272 	     * of generating the same meta file name that we will
273 	     * next time through.
274 	     */
275 	    if (tname[0] == '/') {
276 		strlcpy(buf, tname, sizeof(buf));
277 	    } else {
278 		snprintf(buf, sizeof(buf), "%s/%s", cwd, tname);
279 	    }
280 	    eat_dots(buf, sizeof(buf), 1);	/* ./ */
281 	    eat_dots(buf, sizeof(buf), 2);	/* ../ */
282 	    tname = buf;
283 	}
284     }
285     /* on some systems dirname may modify its arg */
286     tp = bmake_strdup(tname);
287     dtp = dirname(tp);
288     if (strcmp(dname, dtp) == 0)
289 	snprintf(mname, mnamelen, "%s.meta", tname);
290     else {
291 	ldname = strlen(dname);
292 	if (strncmp(dname, dtp, ldname) == 0 && dtp[ldname] == '/')
293 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, &tname[ldname+1]);
294 	else
295 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, tname);
296 
297 	/*
298 	 * Replace path separators in the file name after the
299 	 * current object directory path.
300 	 */
301 	cp = mname + strlen(dname) + 1;
302 
303 	while (*cp != '\0') {
304 	    if (*cp == '/')
305 		*cp = '_';
306 	    cp++;
307 	}
308     }
309     free(tp);
310     return (mname);
311 }
312 
313 /*
314  * Return true if running ${.MAKE}
315  * Bypassed if target is flagged .MAKE
316  */
317 static int
318 is_submake(void *cmdp, void *gnp)
319 {
320     static char *p_make = NULL;
321     static int p_len;
322     char  *cmd = cmdp;
323     GNode *gn = gnp;
324     char *mp = NULL;
325     char *cp;
326     char *cp2;
327     int rc = 0;				/* keep looking */
328 
329     if (!p_make) {
330 	p_make = Var_Value(".MAKE", gn, &cp);
331 	p_len = strlen(p_make);
332     }
333     cp = strchr(cmd, '$');
334     if ((cp)) {
335 	mp = Var_Subst(NULL, cmd, gn, VARF_WANTRES);
336 	cmd = mp;
337     }
338     cp2 = strstr(cmd, p_make);
339     if ((cp2)) {
340 	switch (cp2[p_len]) {
341 	case '\0':
342 	case ' ':
343 	case '\t':
344 	case '\n':
345 	    rc = 1;
346 	    break;
347 	}
348 	if (cp2 > cmd && rc > 0) {
349 	    switch (cp2[-1]) {
350 	    case ' ':
351 	    case '\t':
352 	    case '\n':
353 		break;
354 	    default:
355 		rc = 0;			/* no match */
356 		break;
357 	    }
358 	}
359     }
360     free(mp);
361     return (rc);
362 }
363 
364 typedef struct meta_file_s {
365     FILE *fp;
366     GNode *gn;
367 } meta_file_t;
368 
369 static int
370 printCMD(void *cmdp, void *mfpp)
371 {
372     meta_file_t *mfp = mfpp;
373     char *cmd = cmdp;
374     char *cp = NULL;
375 
376     if (strchr(cmd, '$')) {
377 	cmd = cp = Var_Subst(NULL, cmd, mfp->gn, VARF_WANTRES);
378     }
379     fprintf(mfp->fp, "CMD %s\n", cmd);
380     free(cp);
381     return 0;
382 }
383 
384 /*
385  * Certain node types never get a .meta file
386  */
387 #define SKIP_META_TYPE(_type) do { \
388     if ((gn->type & __CONCAT(OP_, _type))) {	\
389 	if (verbose) { \
390 	    fprintf(debug_file, "Skipping meta for %s: .%s\n", \
391 		    gn->name, __STRING(_type));		       \
392 	} \
393 	return FALSE; \
394     } \
395 } while (0)
396 
397 
398 /*
399  * Do we need/want a .meta file ?
400  */
401 static Boolean
402 meta_needed(GNode *gn, const char *dname, const char *tname,
403 	     char *objdir, int verbose)
404 {
405     struct stat fs;
406 
407     if (verbose)
408 	verbose = DEBUG(META);
409 
410     /* This may be a phony node which we don't want meta data for... */
411     /* Skip .meta for .BEGIN, .END, .ERROR etc as well. */
412     /* Or it may be explicitly flagged as .NOMETA */
413     SKIP_META_TYPE(NOMETA);
414     /* Unless it is explicitly flagged as .META */
415     if (!(gn->type & OP_META)) {
416 	SKIP_META_TYPE(PHONY);
417 	SKIP_META_TYPE(SPECIAL);
418 	SKIP_META_TYPE(MAKE);
419     }
420 
421     /* Check if there are no commands to execute. */
422     if (Lst_IsEmpty(gn->commands)) {
423 	if (verbose)
424 	    fprintf(debug_file, "Skipping meta for %s: no commands\n",
425 		    gn->name);
426 	return FALSE;
427     }
428     if ((gn->type & (OP_META|OP_SUBMAKE)) == OP_SUBMAKE) {
429 	/* OP_SUBMAKE is a bit too aggressive */
430 	if (Lst_ForEach(gn->commands, is_submake, gn)) {
431 	    if (DEBUG(META))
432 		fprintf(debug_file, "Skipping meta for %s: .SUBMAKE\n",
433 			gn->name);
434 	    return FALSE;
435 	}
436     }
437 
438     /* The object directory may not exist. Check it.. */
439     if (cached_stat(dname, &fs) != 0) {
440 	if (verbose)
441 	    fprintf(debug_file, "Skipping meta for %s: no .OBJDIR\n",
442 		    gn->name);
443 	return FALSE;
444     }
445 
446     /* make sure these are canonical */
447     if (cached_realpath(dname, objdir))
448 	dname = objdir;
449 
450     /* If we aren't in the object directory, don't create a meta file. */
451     if (!metaCurdirOk && strcmp(curdir, dname) == 0) {
452 	if (verbose)
453 	    fprintf(debug_file, "Skipping meta for %s: .OBJDIR == .CURDIR\n",
454 		    gn->name);
455 	return FALSE;
456     }
457     return TRUE;
458 }
459 
460 
461 static FILE *
462 meta_create(BuildMon *pbm, GNode *gn)
463 {
464     meta_file_t mf;
465     char buf[MAXPATHLEN];
466     char objdir[MAXPATHLEN];
467     char **ptr;
468     const char *dname;
469     const char *tname;
470     char *fname;
471     const char *cp;
472     char *p[4];				/* >= possible uses */
473     int i;
474 
475     mf.fp = NULL;
476     i = 0;
477 
478     dname = Var_Value(".OBJDIR", gn, &p[i++]);
479     tname = Var_Value(TARGET, gn, &p[i++]);
480 
481     /* if this succeeds objdir is realpath of dname */
482     if (!meta_needed(gn, dname, tname, objdir, TRUE))
483 	goto out;
484     dname = objdir;
485 
486     if (metaVerbose) {
487 	char *mp;
488 
489 	/* Describe the target we are building */
490 	mp = Var_Subst(NULL, "${" MAKE_META_PREFIX "}", gn, VARF_WANTRES);
491 	if (*mp)
492 	    fprintf(stdout, "%s\n", mp);
493 	free(mp);
494     }
495     /* Get the basename of the target */
496     if ((cp = strrchr(tname, '/')) == NULL) {
497 	cp = tname;
498     } else {
499 	cp++;
500     }
501 
502     fflush(stdout);
503 
504     if (!writeMeta)
505 	/* Don't create meta data. */
506 	goto out;
507 
508     fname = meta_name(gn, pbm->meta_fname, sizeof(pbm->meta_fname),
509 		      dname, tname, objdir);
510 
511 #ifdef DEBUG_META_MODE
512     if (DEBUG(META))
513 	fprintf(debug_file, "meta_create: %s\n", fname);
514 #endif
515 
516     if ((mf.fp = fopen(fname, "w")) == NULL)
517 	err(1, "Could not open meta file '%s'", fname);
518 
519     fprintf(mf.fp, "# Meta data file %s\n", fname);
520 
521     mf.gn = gn;
522 
523     Lst_ForEach(gn->commands, printCMD, &mf);
524 
525     fprintf(mf.fp, "CWD %s\n", getcwd(buf, sizeof(buf)));
526     fprintf(mf.fp, "TARGET %s\n", tname);
527 
528     if (metaEnv) {
529 	for (ptr = environ; *ptr != NULL; ptr++)
530 	    fprintf(mf.fp, "ENV %s\n", *ptr);
531     }
532 
533     fprintf(mf.fp, "-- command output --\n");
534     fflush(mf.fp);
535 
536     Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
537     Var_Append(".MAKE.META.CREATED", fname, VAR_GLOBAL);
538 
539     gn->type |= OP_META;		/* in case anyone wants to know */
540     if (metaSilent) {
541 	    gn->type |= OP_SILENT;
542     }
543  out:
544     for (i--; i >= 0; i--) {
545 	free(p[i]);
546     }
547 
548     return (mf.fp);
549 }
550 
551 static Boolean
552 boolValue(char *s)
553 {
554     switch(*s) {
555     case '0':
556     case 'N':
557     case 'n':
558     case 'F':
559     case 'f':
560 	return FALSE;
561     }
562     return TRUE;
563 }
564 
565 /*
566  * Initialization we need before reading makefiles.
567  */
568 void
569 meta_init(void)
570 {
571 #ifdef USE_FILEMON
572 	/* this allows makefiles to test if we have filemon support */
573 	Var_Set(".MAKE.PATH_FILEMON", _PATH_FILEMON, VAR_GLOBAL, 0);
574 #endif
575 }
576 
577 
578 #define get_mode_bf(bf, token) \
579     if ((cp = strstr(make_mode, token))) \
580 	bf = boolValue(&cp[sizeof(token) - 1])
581 
582 /*
583  * Initialization we need after reading makefiles.
584  */
585 void
586 meta_mode_init(const char *make_mode)
587 {
588     static int once = 0;
589     char *cp;
590 
591     useMeta = TRUE;
592     useFilemon = TRUE;
593     writeMeta = TRUE;
594 
595     if (make_mode) {
596 	if (strstr(make_mode, "env"))
597 	    metaEnv = TRUE;
598 	if (strstr(make_mode, "verb"))
599 	    metaVerbose = TRUE;
600 	if (strstr(make_mode, "read"))
601 	    writeMeta = FALSE;
602 	if (strstr(make_mode, "nofilemon"))
603 	    useFilemon = FALSE;
604 	if (strstr(make_mode, "ignore-cmd"))
605 	    metaIgnoreCMDs = TRUE;
606 	if (useFilemon)
607 	    get_mode_bf(filemonMissing, "missing-filemon=");
608 	get_mode_bf(metaCurdirOk, "curdirok=");
609 	get_mode_bf(metaMissing, "missing-meta=");
610 	get_mode_bf(metaSilent, "silent=");
611     }
612     if (metaVerbose && !Var_Exists(MAKE_META_PREFIX, VAR_GLOBAL)) {
613 	/*
614 	 * The default value for MAKE_META_PREFIX
615 	 * prints the absolute path of the target.
616 	 * This works be cause :H will generate '.' if there is no /
617 	 * and :tA will resolve that to cwd.
618 	 */
619 	Var_Set(MAKE_META_PREFIX, "Building ${.TARGET:H:tA}/${.TARGET:T}", VAR_GLOBAL, 0);
620     }
621     if (once)
622 	return;
623     once = 1;
624     memset(&Mybm, 0, sizeof(Mybm));
625     /*
626      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
627      */
628     metaBailiwick = Lst_Init(FALSE);
629     metaBailiwickStr = Var_Subst(NULL, "${.MAKE.META.BAILIWICK:O:u:tA}",
630 	VAR_GLOBAL, VARF_WANTRES);
631     if (metaBailiwickStr) {
632 	str2Lst_Append(metaBailiwick, metaBailiwickStr, NULL);
633     }
634     /*
635      * We ignore any paths that start with ${.MAKE.META.IGNORE_PATHS}
636      */
637     metaIgnorePaths = Lst_Init(FALSE);
638     Var_Append(MAKE_META_IGNORE_PATHS,
639 	       "/dev /etc /proc /tmp /var/run /var/tmp ${TMPDIR}", VAR_GLOBAL);
640     metaIgnorePathsStr = Var_Subst(NULL,
641 		   "${" MAKE_META_IGNORE_PATHS ":O:u:tA}", VAR_GLOBAL,
642 		   VARF_WANTRES);
643     if (metaIgnorePathsStr) {
644 	str2Lst_Append(metaIgnorePaths, metaIgnorePathsStr, NULL);
645     }
646 
647     /*
648      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
649      */
650     cp = NULL;
651     if (Var_Value(MAKE_META_IGNORE_PATTERNS, VAR_GLOBAL, &cp)) {
652 	metaIgnorePatterns = TRUE;
653 	free(cp);
654     }
655     cp = NULL;
656     if (Var_Value(MAKE_META_IGNORE_FILTER, VAR_GLOBAL, &cp)) {
657 	metaIgnoreFilter = TRUE;
658 	free(cp);
659     }
660 }
661 
662 /*
663  * In each case below we allow for job==NULL
664  */
665 void
666 meta_job_start(Job *job, GNode *gn)
667 {
668     BuildMon *pbm;
669 
670     if (job != NULL) {
671 	pbm = &job->bm;
672     } else {
673 	pbm = &Mybm;
674     }
675     pbm->mfp = meta_create(pbm, gn);
676 #ifdef USE_FILEMON_ONCE
677     /* compat mode we open the filemon dev once per command */
678     if (job == NULL)
679 	return;
680 #endif
681 #ifdef USE_FILEMON
682     if (pbm->mfp != NULL && useFilemon) {
683 	filemon_open(pbm);
684     } else {
685 	pbm->mon_fd = pbm->filemon_fd = -1;
686     }
687 #endif
688 }
689 
690 /*
691  * The child calls this before doing anything.
692  * It does not disturb our state.
693  */
694 void
695 meta_job_child(Job *job)
696 {
697 #ifdef USE_FILEMON
698     BuildMon *pbm;
699 
700     if (job != NULL) {
701 	pbm = &job->bm;
702     } else {
703 	pbm = &Mybm;
704     }
705     if (pbm->mfp != NULL) {
706 	close(fileno(pbm->mfp));
707 	if (useFilemon) {
708 	    pid_t pid;
709 
710 	    pid = getpid();
711 	    if (ioctl(pbm->filemon_fd, FILEMON_SET_PID, &pid) < 0) {
712 		err(1, "Could not set filemon pid!");
713 	    }
714 	}
715     }
716 #endif
717 }
718 
719 void
720 meta_job_error(Job *job, GNode *gn, int flags, int status)
721 {
722     char cwd[MAXPATHLEN];
723     BuildMon *pbm;
724 
725     if (job != NULL) {
726 	pbm = &job->bm;
727 	if (!gn)
728 	    gn = job->node;
729     } else {
730 	pbm = &Mybm;
731     }
732     if (pbm->mfp != NULL) {
733 	fprintf(pbm->mfp, "\n*** Error code %d%s\n",
734 		status,
735 		(flags & JOB_IGNERR) ?
736 		"(ignored)" : "");
737     }
738     if (gn) {
739 	Var_Set(".ERROR_TARGET", gn->path ? gn->path : gn->name, VAR_GLOBAL, 0);
740     }
741     getcwd(cwd, sizeof(cwd));
742     Var_Set(".ERROR_CWD", cwd, VAR_GLOBAL, 0);
743     if (pbm->meta_fname[0]) {
744 	Var_Set(".ERROR_META_FILE", pbm->meta_fname, VAR_GLOBAL, 0);
745     }
746     meta_job_finish(job);
747 }
748 
749 void
750 meta_job_output(Job *job, char *cp, const char *nl)
751 {
752     BuildMon *pbm;
753 
754     if (job != NULL) {
755 	pbm = &job->bm;
756     } else {
757 	pbm = &Mybm;
758     }
759     if (pbm->mfp != NULL) {
760 	if (metaVerbose) {
761 	    static char *meta_prefix = NULL;
762 	    static int meta_prefix_len;
763 
764 	    if (!meta_prefix) {
765 		char *cp2;
766 
767 		meta_prefix = Var_Subst(NULL, "${" MAKE_META_PREFIX "}",
768 					VAR_GLOBAL, VARF_WANTRES);
769 		if ((cp2 = strchr(meta_prefix, '$')))
770 		    meta_prefix_len = cp2 - meta_prefix;
771 		else
772 		    meta_prefix_len = strlen(meta_prefix);
773 	    }
774 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
775 		cp = strchr(cp+1, '\n');
776 		if (!cp++)
777 		    return;
778 	    }
779 	}
780 	fprintf(pbm->mfp, "%s%s", cp, nl);
781     }
782 }
783 
784 int
785 meta_cmd_finish(void *pbmp)
786 {
787     int error = 0;
788     BuildMon *pbm = pbmp;
789 #ifdef USE_FILEMON
790     int x;
791 #endif
792 
793     if (!pbm)
794 	pbm = &Mybm;
795 
796 #ifdef USE_FILEMON
797     if (pbm->filemon_fd >= 0) {
798 	if (close(pbm->filemon_fd) < 0)
799 	    error = errno;
800 	x = filemon_read(pbm->mfp, pbm->mon_fd);
801 	if (error == 0 && x != 0)
802 	    error = x;
803 	pbm->filemon_fd = pbm->mon_fd = -1;
804     } else
805 #endif
806 	fprintf(pbm->mfp, "\n");	/* ensure end with newline */
807     return error;
808 }
809 
810 int
811 meta_job_finish(Job *job)
812 {
813     BuildMon *pbm;
814     int error = 0;
815     int x;
816 
817     if (job != NULL) {
818 	pbm = &job->bm;
819     } else {
820 	pbm = &Mybm;
821     }
822     if (pbm->mfp != NULL) {
823 	error = meta_cmd_finish(pbm);
824 	x = fclose(pbm->mfp);
825 	if (error == 0 && x != 0)
826 	    error = errno;
827 	pbm->mfp = NULL;
828 	pbm->meta_fname[0] = '\0';
829     }
830     return error;
831 }
832 
833 void
834 meta_finish(void)
835 {
836     Lst_Destroy(metaBailiwick, NULL);
837     free(metaBailiwickStr);
838     Lst_Destroy(metaIgnorePaths, NULL);
839     free(metaIgnorePathsStr);
840 }
841 
842 /*
843  * Fetch a full line from fp - growing bufp if needed
844  * Return length in bufp.
845  */
846 static int
847 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
848 {
849     char *buf = *bufp;
850     size_t bufsz = *szp;
851     struct stat fs;
852     int x;
853 
854     if (fgets(&buf[o], bufsz - o, fp) != NULL) {
855     check_newline:
856 	x = o + strlen(&buf[o]);
857 	if (buf[x - 1] == '\n')
858 	    return x;
859 	/*
860 	 * We need to grow the buffer.
861 	 * The meta file can give us a clue.
862 	 */
863 	if (fstat(fileno(fp), &fs) == 0) {
864 	    size_t newsz;
865 	    char *p;
866 
867 	    newsz = ROUNDUP((fs.st_size / 2), BUFSIZ);
868 	    if (newsz <= bufsz)
869 		newsz = ROUNDUP(fs.st_size, BUFSIZ);
870 	    if (newsz <= bufsz)
871 		return x;		/* truncated */
872 	    if (DEBUG(META))
873 		fprintf(debug_file, "growing buffer %zu -> %zu\n",
874 			bufsz, newsz);
875 	    p = bmake_realloc(buf, newsz);
876 	    if (p) {
877 		*bufp = buf = p;
878 		*szp = bufsz = newsz;
879 		/* fetch the rest */
880 		if (!fgets(&buf[x], bufsz - x, fp))
881 		    return x;		/* truncated! */
882 		goto check_newline;
883 	    }
884 	}
885     }
886     return 0;
887 }
888 
889 /* Lst_ForEach wants 1 to stop search */
890 static int
891 prefix_match(void *p, void *q)
892 {
893     const char *prefix = p;
894     const char *path = q;
895     size_t n = strlen(prefix);
896 
897     return (0 == strncmp(path, prefix, n));
898 }
899 
900 /*
901  * looking for exact or prefix/ match to
902  * Lst_Find wants 0 to stop search
903  */
904 static int
905 path_match(const void *p, const void *q)
906 {
907     const char *prefix = q;
908     const char *path = p;
909     size_t n = strlen(prefix);
910     int rc;
911 
912     if ((rc = strncmp(path, prefix, n)) == 0) {
913 	switch (path[n]) {
914 	case '\0':
915 	case '/':
916 	    break;
917 	default:
918 	    rc = 1;
919 	    break;
920 	}
921     }
922     return rc;
923 }
924 
925 /* Lst_Find wants 0 to stop search */
926 static int
927 string_match(const void *p, const void *q)
928 {
929     const char *p1 = p;
930     const char *p2 = q;
931 
932     return strcmp(p1, p2);
933 }
934 
935 
936 static int
937 meta_ignore(GNode *gn, const char *p)
938 {
939     char fname[MAXPATHLEN];
940 
941     if (p == NULL)
942 	return TRUE;
943 
944     if (*p == '/') {
945 	cached_realpath(p, fname); /* clean it up */
946 	if (Lst_ForEach(metaIgnorePaths, prefix_match, fname)) {
947 #ifdef DEBUG_META_MODE
948 	    if (DEBUG(META))
949 		fprintf(debug_file, "meta_oodate: ignoring path: %s\n",
950 			p);
951 #endif
952 	    return TRUE;
953 	}
954     }
955 
956     if (metaIgnorePatterns) {
957 	char *pm;
958 
959 	Var_Set(".p.", p, gn, 0);
960 	pm = Var_Subst(NULL,
961 		       "${" MAKE_META_IGNORE_PATTERNS ":@m@${.p.:M$m}@}",
962 		       gn, VARF_WANTRES);
963 	if (*pm) {
964 #ifdef DEBUG_META_MODE
965 	    if (DEBUG(META))
966 		fprintf(debug_file, "meta_oodate: ignoring pattern: %s\n",
967 			p);
968 #endif
969 	    free(pm);
970 	    return TRUE;
971 	}
972 	free(pm);
973     }
974 
975     if (metaIgnoreFilter) {
976 	char *fm;
977 
978 	/* skip if filter result is empty */
979 	snprintf(fname, sizeof(fname),
980 		 "${%s:L:${%s:ts:}}",
981 		 p, MAKE_META_IGNORE_FILTER);
982 	fm = Var_Subst(NULL, fname, gn, VARF_WANTRES);
983 	if (*fm == '\0') {
984 #ifdef DEBUG_META_MODE
985 	    if (DEBUG(META))
986 		fprintf(debug_file, "meta_oodate: ignoring filtered: %s\n",
987 			p);
988 #endif
989 	    free(fm);
990 	    return TRUE;
991 	}
992 	free(fm);
993     }
994     return FALSE;
995 }
996 
997 /*
998  * When running with 'meta' functionality, a target can be out-of-date
999  * if any of the references in its meta data file is more recent.
1000  * We have to track the latestdir on a per-process basis.
1001  */
1002 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
1003 #define LDIR_VNAME_FMT ".meta.%d.ldir"
1004 
1005 /*
1006  * It is possible that a .meta file is corrupted,
1007  * if we detect this we want to reproduce it.
1008  * Setting oodate TRUE will have that effect.
1009  */
1010 #define CHECK_VALID_META(p) if (!(p && *p)) { \
1011     warnx("%s: %d: malformed", fname, lineno); \
1012     oodate = TRUE; \
1013     continue; \
1014     }
1015 
1016 #define DEQUOTE(p) if (*p == '\'') {	\
1017     char *ep; \
1018     p++; \
1019     if ((ep = strchr(p, '\''))) \
1020 	*ep = '\0'; \
1021     }
1022 
1023 Boolean
1024 meta_oodate(GNode *gn, Boolean oodate)
1025 {
1026     static char *tmpdir = NULL;
1027     static char cwd[MAXPATHLEN];
1028     char lcwd_vname[64];
1029     char ldir_vname[64];
1030     char lcwd[MAXPATHLEN];
1031     char latestdir[MAXPATHLEN];
1032     char fname[MAXPATHLEN];
1033     char fname1[MAXPATHLEN];
1034     char fname2[MAXPATHLEN];
1035     char fname3[MAXPATHLEN];
1036     const char *dname;
1037     const char *tname;
1038     char *p;
1039     char *cp;
1040     char *link_src;
1041     char *move_target;
1042     static size_t cwdlen = 0;
1043     static size_t tmplen = 0;
1044     FILE *fp;
1045     Boolean needOODATE = FALSE;
1046     Lst missingFiles;
1047     char *pa[4];			/* >= possible uses */
1048     int i;
1049     int have_filemon = FALSE;
1050 
1051     if (oodate)
1052 	return oodate;		/* we're done */
1053 
1054     i = 0;
1055 
1056     dname = Var_Value(".OBJDIR", gn, &pa[i++]);
1057     tname = Var_Value(TARGET, gn, &pa[i++]);
1058 
1059     /* if this succeeds fname3 is realpath of dname */
1060     if (!meta_needed(gn, dname, tname, fname3, FALSE))
1061 	goto oodate_out;
1062     dname = fname3;
1063 
1064     missingFiles = Lst_Init(FALSE);
1065 
1066     /*
1067      * We need to check if the target is out-of-date. This includes
1068      * checking if the expanded command has changed. This in turn
1069      * requires that all variables are set in the same way that they
1070      * would be if the target needs to be re-built.
1071      */
1072     Make_DoAllVar(gn);
1073 
1074     meta_name(gn, fname, sizeof(fname), dname, tname, dname);
1075 
1076 #ifdef DEBUG_META_MODE
1077     if (DEBUG(META))
1078 	fprintf(debug_file, "meta_oodate: %s\n", fname);
1079 #endif
1080 
1081     if ((fp = fopen(fname, "r")) != NULL) {
1082 	static char *buf = NULL;
1083 	static size_t bufsz;
1084 	int lineno = 0;
1085 	int lastpid = 0;
1086 	int pid;
1087 	int x;
1088 	LstNode ln;
1089 	struct stat fs;
1090 
1091 	if (!buf) {
1092 	    bufsz = 8 * BUFSIZ;
1093 	    buf = bmake_malloc(bufsz);
1094 	}
1095 
1096 	if (!cwdlen) {
1097 	    if (getcwd(cwd, sizeof(cwd)) == NULL)
1098 		err(1, "Could not get current working directory");
1099 	    cwdlen = strlen(cwd);
1100 	}
1101 	strlcpy(lcwd, cwd, sizeof(lcwd));
1102 	strlcpy(latestdir, cwd, sizeof(latestdir));
1103 
1104 	if (!tmpdir) {
1105 	    tmpdir = getTmpdir();
1106 	    tmplen = strlen(tmpdir);
1107 	}
1108 
1109 	/* we want to track all the .meta we read */
1110 	Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
1111 
1112 	ln = Lst_First(gn->commands);
1113 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1114 	    lineno++;
1115 	    if (buf[x - 1] == '\n')
1116 		buf[x - 1] = '\0';
1117 	    else {
1118 		warnx("%s: %d: line truncated at %u", fname, lineno, x);
1119 		oodate = TRUE;
1120 		break;
1121 	    }
1122 	    link_src = NULL;
1123 	    move_target = NULL;
1124 	    /* Find the start of the build monitor section. */
1125 	    if (!have_filemon) {
1126 		if (strncmp(buf, "-- filemon", 10) == 0) {
1127 		    have_filemon = TRUE;
1128 		    continue;
1129 		}
1130 		if (strncmp(buf, "# buildmon", 10) == 0) {
1131 		    have_filemon = TRUE;
1132 		    continue;
1133 		}
1134 	    }
1135 
1136 	    /* Delimit the record type. */
1137 	    p = buf;
1138 #ifdef DEBUG_META_MODE
1139 	    if (DEBUG(META))
1140 		fprintf(debug_file, "%s: %d: %s\n", fname, lineno, buf);
1141 #endif
1142 	    strsep(&p, " ");
1143 	    if (have_filemon) {
1144 		/*
1145 		 * We are in the 'filemon' output section.
1146 		 * Each record from filemon follows the general form:
1147 		 *
1148 		 * <key> <pid> <data>
1149 		 *
1150 		 * Where:
1151 		 * <key> is a single letter, denoting the syscall.
1152 		 * <pid> is the process that made the syscall.
1153 		 * <data> is the arguments (of interest).
1154 		 */
1155 		switch(buf[0]) {
1156 		case '#':		/* comment */
1157 		case 'V':		/* version */
1158 		    break;
1159 		default:
1160 		    /*
1161 		     * We need to track pathnames per-process.
1162 		     *
1163 		     * Each process run by make, starts off in the 'CWD'
1164 		     * recorded in the .meta file, if it chdirs ('C')
1165 		     * elsewhere we need to track that - but only for
1166 		     * that process.  If it forks ('F'), we initialize
1167 		     * the child to have the same cwd as its parent.
1168 		     *
1169 		     * We also need to track the 'latestdir' of
1170 		     * interest.  This is usually the same as cwd, but
1171 		     * not if a process is reading directories.
1172 		     *
1173 		     * Each time we spot a different process ('pid')
1174 		     * we save the current value of 'latestdir' in a
1175 		     * variable qualified by 'lastpid', and
1176 		     * re-initialize 'latestdir' to any pre-saved
1177 		     * value for the current 'pid' and 'CWD' if none.
1178 		     */
1179 		    CHECK_VALID_META(p);
1180 		    pid = atoi(p);
1181 		    if (pid > 0 && pid != lastpid) {
1182 			char *ldir;
1183 			char *tp;
1184 
1185 			if (lastpid > 0) {
1186 			    /* We need to remember these. */
1187 			    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1188 			    Var_Set(ldir_vname, latestdir, VAR_GLOBAL, 0);
1189 			}
1190 			snprintf(lcwd_vname, sizeof(lcwd_vname), LCWD_VNAME_FMT, pid);
1191 			snprintf(ldir_vname, sizeof(ldir_vname), LDIR_VNAME_FMT, pid);
1192 			lastpid = pid;
1193 			ldir = Var_Value(ldir_vname, VAR_GLOBAL, &tp);
1194 			if (ldir) {
1195 			    strlcpy(latestdir, ldir, sizeof(latestdir));
1196 			    free(tp);
1197 			}
1198 			ldir = Var_Value(lcwd_vname, VAR_GLOBAL, &tp);
1199 			if (ldir) {
1200 			    strlcpy(lcwd, ldir, sizeof(lcwd));
1201 			    free(tp);
1202 			}
1203 		    }
1204 		    /* Skip past the pid. */
1205 		    if (strsep(&p, " ") == NULL)
1206 			continue;
1207 #ifdef DEBUG_META_MODE
1208 		    if (DEBUG(META))
1209 			    fprintf(debug_file, "%s: %d: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1210 				    fname, lineno,
1211 				    pid, buf[0], cwd, lcwd, latestdir);
1212 #endif
1213 		    break;
1214 		}
1215 
1216 		CHECK_VALID_META(p);
1217 
1218 		/* Process according to record type. */
1219 		switch (buf[0]) {
1220 		case 'X':		/* eXit */
1221 		    Var_Delete(lcwd_vname, VAR_GLOBAL);
1222 		    Var_Delete(ldir_vname, VAR_GLOBAL);
1223 		    lastpid = 0;	/* no need to save ldir_vname */
1224 		    break;
1225 
1226 		case 'F':		/* [v]Fork */
1227 		    {
1228 			char cldir[64];
1229 			int child;
1230 
1231 			child = atoi(p);
1232 			if (child > 0) {
1233 			    snprintf(cldir, sizeof(cldir), LCWD_VNAME_FMT, child);
1234 			    Var_Set(cldir, lcwd, VAR_GLOBAL, 0);
1235 			    snprintf(cldir, sizeof(cldir), LDIR_VNAME_FMT, child);
1236 			    Var_Set(cldir, latestdir, VAR_GLOBAL, 0);
1237 #ifdef DEBUG_META_MODE
1238 			    if (DEBUG(META))
1239 				    fprintf(debug_file, "%s: %d: %d: cwd=%s lcwd=%s ldir=%s\n",
1240 					    fname, lineno,
1241 					    child, cwd, lcwd, latestdir);
1242 #endif
1243 			}
1244 		    }
1245 		    break;
1246 
1247 		case 'C':		/* Chdir */
1248 		    /* Update lcwd and latest directory. */
1249 		    strlcpy(latestdir, p, sizeof(latestdir));
1250 		    strlcpy(lcwd, p, sizeof(lcwd));
1251 		    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1252 		    Var_Set(ldir_vname, lcwd, VAR_GLOBAL, 0);
1253 #ifdef DEBUG_META_MODE
1254 		    if (DEBUG(META))
1255 			fprintf(debug_file, "%s: %d: cwd=%s ldir=%s\n", fname, lineno, cwd, lcwd);
1256 #endif
1257 		    break;
1258 
1259 		case 'M':		/* renaMe */
1260 		    /*
1261 		     * For 'M'oves we want to check
1262 		     * the src as for 'R'ead
1263 		     * and the target as for 'W'rite.
1264 		     */
1265 		    cp = p;		/* save this for a second */
1266 		    /* now get target */
1267 		    if (strsep(&p, " ") == NULL)
1268 			continue;
1269 		    CHECK_VALID_META(p);
1270 		    move_target = p;
1271 		    p = cp;
1272 		    /* 'L' and 'M' put single quotes around the args */
1273 		    DEQUOTE(p);
1274 		    DEQUOTE(move_target);
1275 		    /* FALLTHROUGH */
1276 		case 'D':		/* unlink */
1277 		    if (*p == '/' && !Lst_IsEmpty(missingFiles)) {
1278 			/* remove any missingFiles entries that match p */
1279 			if ((ln = Lst_Find(missingFiles, p,
1280 					   path_match)) != NULL) {
1281 			    LstNode nln;
1282 			    char *tp;
1283 
1284 			    do {
1285 				nln = Lst_FindFrom(missingFiles, Lst_Succ(ln),
1286 						   p, path_match);
1287 				tp = Lst_Datum(ln);
1288 				Lst_Remove(missingFiles, ln);
1289 				free(tp);
1290 			    } while ((ln = nln) != NULL);
1291 			}
1292 		    }
1293 		    if (buf[0] == 'M') {
1294 			/* the target of the mv is a file 'W'ritten */
1295 #ifdef DEBUG_META_MODE
1296 			if (DEBUG(META))
1297 			    fprintf(debug_file, "meta_oodate: M %s -> %s\n",
1298 				    p, move_target);
1299 #endif
1300 			p = move_target;
1301 			goto check_write;
1302 		    }
1303 		    break;
1304 		case 'L':		/* Link */
1305 		    /*
1306 		     * For 'L'inks check
1307 		     * the src as for 'R'ead
1308 		     * and the target as for 'W'rite.
1309 		     */
1310 		    link_src = p;
1311 		    /* now get target */
1312 		    if (strsep(&p, " ") == NULL)
1313 			continue;
1314 		    CHECK_VALID_META(p);
1315 		    /* 'L' and 'M' put single quotes around the args */
1316 		    DEQUOTE(p);
1317 		    DEQUOTE(link_src);
1318 #ifdef DEBUG_META_MODE
1319 		    if (DEBUG(META))
1320 			fprintf(debug_file, "meta_oodate: L %s -> %s\n",
1321 				link_src, p);
1322 #endif
1323 		    /* FALLTHROUGH */
1324 		case 'W':		/* Write */
1325 		check_write:
1326 		    /*
1327 		     * If a file we generated within our bailiwick
1328 		     * but outside of .OBJDIR is missing,
1329 		     * we need to do it again.
1330 		     */
1331 		    /* ignore non-absolute paths */
1332 		    if (*p != '/')
1333 			break;
1334 
1335 		    if (Lst_IsEmpty(metaBailiwick))
1336 			break;
1337 
1338 		    /* ignore cwd - normal dependencies handle those */
1339 		    if (strncmp(p, cwd, cwdlen) == 0)
1340 			break;
1341 
1342 		    if (!Lst_ForEach(metaBailiwick, prefix_match, p))
1343 			break;
1344 
1345 		    /* tmpdir might be within */
1346 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1347 			break;
1348 
1349 		    /* ignore anything containing the string "tmp" */
1350 		    if ((strstr("tmp", p)))
1351 			break;
1352 
1353 		    if ((link_src != NULL && cached_lstat(p, &fs) < 0) ||
1354 			(link_src == NULL && cached_stat(p, &fs) < 0)) {
1355 			if (!meta_ignore(gn, p)) {
1356 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1357 				Lst_AtEnd(missingFiles, bmake_strdup(p));
1358 			}
1359 		    }
1360 		    break;
1361 		check_link_src:
1362 		    p = link_src;
1363 		    link_src = NULL;
1364 #ifdef DEBUG_META_MODE
1365 		    if (DEBUG(META))
1366 			fprintf(debug_file, "meta_oodate: L src %s\n", p);
1367 #endif
1368 		    /* FALLTHROUGH */
1369 		case 'R':		/* Read */
1370 		case 'E':		/* Exec */
1371 		    /*
1372 		     * Check for runtime files that can't
1373 		     * be part of the dependencies because
1374 		     * they are _expected_ to change.
1375 		     */
1376 		    if (meta_ignore(gn, p))
1377 			break;
1378 
1379 		    /*
1380 		     * The rest of the record is the file name.
1381 		     * Check if it's not an absolute path.
1382 		     */
1383 		    {
1384 			char *sdirs[4];
1385 			char **sdp;
1386 			int sdx = 0;
1387 			int found = 0;
1388 
1389 			if (*p == '/') {
1390 			    sdirs[sdx++] = p; /* done */
1391 			} else {
1392 			    if (strcmp(".", p) == 0)
1393 				continue;  /* no point */
1394 
1395 			    /* Check vs latestdir */
1396 			    snprintf(fname1, sizeof(fname1), "%s/%s", latestdir, p);
1397 			    sdirs[sdx++] = fname1;
1398 
1399 			    if (strcmp(latestdir, lcwd) != 0) {
1400 				/* Check vs lcwd */
1401 				snprintf(fname2, sizeof(fname2), "%s/%s", lcwd, p);
1402 				sdirs[sdx++] = fname2;
1403 			    }
1404 			    if (strcmp(lcwd, cwd) != 0) {
1405 				/* Check vs cwd */
1406 				snprintf(fname3, sizeof(fname3), "%s/%s", cwd, p);
1407 				sdirs[sdx++] = fname3;
1408 			    }
1409 			}
1410 			sdirs[sdx++] = NULL;
1411 
1412 			for (sdp = sdirs; *sdp && !found; sdp++) {
1413 #ifdef DEBUG_META_MODE
1414 			    if (DEBUG(META))
1415 				fprintf(debug_file, "%s: %d: looking for: %s\n", fname, lineno, *sdp);
1416 #endif
1417 			    if (cached_stat(*sdp, &fs) == 0) {
1418 				found = 1;
1419 				p = *sdp;
1420 			    }
1421 			}
1422 			if (found) {
1423 #ifdef DEBUG_META_MODE
1424 			    if (DEBUG(META))
1425 				fprintf(debug_file, "%s: %d: found: %s\n", fname, lineno, p);
1426 #endif
1427 			    if (!S_ISDIR(fs.st_mode) &&
1428 				fs.st_mtime > gn->mtime) {
1429 				if (DEBUG(META))
1430 				    fprintf(debug_file, "%s: %d: file '%s' is newer than the target...\n", fname, lineno, p);
1431 				oodate = TRUE;
1432 			    } else if (S_ISDIR(fs.st_mode)) {
1433 				/* Update the latest directory. */
1434 				cached_realpath(p, latestdir);
1435 			    }
1436 			} else if (errno == ENOENT && *p == '/' &&
1437 				   strncmp(p, cwd, cwdlen) != 0) {
1438 			    /*
1439 			     * A referenced file outside of CWD is missing.
1440 			     * We cannot catch every eventuality here...
1441 			     */
1442 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1443 				    Lst_AtEnd(missingFiles, bmake_strdup(p));
1444 			}
1445 		    }
1446 		    if (buf[0] == 'E') {
1447 			/* previous latestdir is no longer relevant */
1448 			strlcpy(latestdir, lcwd, sizeof(latestdir));
1449 		    }
1450 		    break;
1451 		default:
1452 		    break;
1453 		}
1454 		if (!oodate && buf[0] == 'L' && link_src != NULL)
1455 		    goto check_link_src;
1456 	    } else if (strcmp(buf, "CMD") == 0) {
1457 		/*
1458 		 * Compare the current command with the one in the
1459 		 * meta data file.
1460 		 */
1461 		if (ln == NULL) {
1462 		    if (DEBUG(META))
1463 			fprintf(debug_file, "%s: %d: there were more build commands in the meta data file than there are now...\n", fname, lineno);
1464 		    oodate = TRUE;
1465 		} else {
1466 		    char *cmd = (char *)Lst_Datum(ln);
1467 		    Boolean hasOODATE = FALSE;
1468 
1469 		    if (strstr(cmd, "$?"))
1470 			hasOODATE = TRUE;
1471 		    else if ((cp = strstr(cmd, ".OODATE"))) {
1472 			/* check for $[{(].OODATE[:)}] */
1473 			if (cp > cmd + 2 && cp[-2] == '$')
1474 			    hasOODATE = TRUE;
1475 		    }
1476 		    if (hasOODATE) {
1477 			needOODATE = TRUE;
1478 			if (DEBUG(META))
1479 			    fprintf(debug_file, "%s: %d: cannot compare command using .OODATE\n", fname, lineno);
1480 		    }
1481 		    cmd = Var_Subst(NULL, cmd, gn, VARF_WANTRES|VARF_UNDEFERR);
1482 
1483 		    if ((cp = strchr(cmd, '\n'))) {
1484 			int n;
1485 
1486 			/*
1487 			 * This command contains newlines, we need to
1488 			 * fetch more from the .meta file before we
1489 			 * attempt a comparison.
1490 			 */
1491 			/* first put the newline back at buf[x - 1] */
1492 			buf[x - 1] = '\n';
1493 			do {
1494 			    /* now fetch the next line */
1495 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1496 				break;
1497 			    x = n;
1498 			    lineno++;
1499 			    if (buf[x - 1] != '\n') {
1500 				warnx("%s: %d: line truncated at %u", fname, lineno, x);
1501 				break;
1502 			    }
1503 			    cp = strchr(++cp, '\n');
1504 			} while (cp);
1505 			if (buf[x - 1] == '\n')
1506 			    buf[x - 1] = '\0';
1507 		    }
1508 		    if (!hasOODATE &&
1509 			!(gn->type & OP_NOMETA_CMP) &&
1510 			strcmp(p, cmd) != 0) {
1511 			if (DEBUG(META))
1512 			    fprintf(debug_file, "%s: %d: a build command has changed\n%s\nvs\n%s\n", fname, lineno, p, cmd);
1513 			if (!metaIgnoreCMDs)
1514 			    oodate = TRUE;
1515 		    }
1516 		    free(cmd);
1517 		    ln = Lst_Succ(ln);
1518 		}
1519 	    } else if (strcmp(buf, "CWD") == 0) {
1520 		/*
1521 		 * Check if there are extra commands now
1522 		 * that weren't in the meta data file.
1523 		 */
1524 		if (!oodate && ln != NULL) {
1525 		    if (DEBUG(META))
1526 			fprintf(debug_file, "%s: %d: there are extra build commands now that weren't in the meta data file\n", fname, lineno);
1527 		    oodate = TRUE;
1528 		}
1529 		if (strcmp(p, cwd) != 0) {
1530 		    if (DEBUG(META))
1531 			fprintf(debug_file, "%s: %d: the current working directory has changed from '%s' to '%s'\n", fname, lineno, p, curdir);
1532 		    oodate = TRUE;
1533 		}
1534 	    }
1535 	}
1536 
1537 	fclose(fp);
1538 	if (!Lst_IsEmpty(missingFiles)) {
1539 	    if (DEBUG(META))
1540 		fprintf(debug_file, "%s: missing files: %s...\n",
1541 			fname, (char *)Lst_Datum(Lst_First(missingFiles)));
1542 	    oodate = TRUE;
1543 	}
1544 	if (!oodate && !have_filemon && filemonMissing) {
1545 	    if (DEBUG(META))
1546 		fprintf(debug_file, "%s: missing filemon data\n", fname);
1547 	    oodate = TRUE;
1548 	}
1549     } else {
1550 	if (writeMeta && metaMissing) {
1551 	    cp = NULL;
1552 
1553 	    /* if target is in .CURDIR we do not need a meta file */
1554 	    if (gn->path && (cp = strrchr(gn->path, '/')) && cp > gn->path) {
1555 		if (strncmp(curdir, gn->path, (cp - gn->path)) != 0) {
1556 		    cp = NULL;		/* not in .CURDIR */
1557 		}
1558 	    }
1559 	    if (!cp) {
1560 		if (DEBUG(META))
1561 		    fprintf(debug_file, "%s: required but missing\n", fname);
1562 		oodate = TRUE;
1563 		needOODATE = TRUE;	/* assume the worst */
1564 	    }
1565 	}
1566     }
1567 
1568     Lst_Destroy(missingFiles, (FreeProc *)free);
1569 
1570     if (oodate && needOODATE) {
1571 	/*
1572 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1573 	 * We have decided it is oodate, so .OODATE needs to be set.
1574 	 * All we can sanely do is set it to .ALLSRC.
1575 	 */
1576 	Var_Delete(OODATE, gn);
1577 	Var_Set(OODATE, Var_Value(ALLSRC, gn, &cp), gn, 0);
1578 	free(cp);
1579     }
1580 
1581  oodate_out:
1582     for (i--; i >= 0; i--) {
1583 	free(pa[i]);
1584     }
1585     return oodate;
1586 }
1587 
1588 /* support for compat mode */
1589 
1590 static int childPipe[2];
1591 
1592 void
1593 meta_compat_start(void)
1594 {
1595 #ifdef USE_FILEMON_ONCE
1596     /*
1597      * We need to re-open filemon for each cmd.
1598      */
1599     BuildMon *pbm = &Mybm;
1600 
1601     if (pbm->mfp != NULL && useFilemon) {
1602 	filemon_open(pbm);
1603     } else {
1604 	pbm->mon_fd = pbm->filemon_fd = -1;
1605     }
1606 #endif
1607     if (pipe(childPipe) < 0)
1608 	Punt("Cannot create pipe: %s", strerror(errno));
1609     /* Set close-on-exec flag for both */
1610     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1611     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1612 }
1613 
1614 void
1615 meta_compat_child(void)
1616 {
1617     meta_job_child(NULL);
1618     if (dup2(childPipe[1], 1) < 0 ||
1619 	dup2(1, 2) < 0) {
1620 	execError("dup2", "pipe");
1621 	_exit(1);
1622     }
1623 }
1624 
1625 void
1626 meta_compat_parent(void)
1627 {
1628     FILE *fp;
1629     char buf[BUFSIZ];
1630 
1631     close(childPipe[1]);			/* child side */
1632     fp = fdopen(childPipe[0], "r");
1633     while (fgets(buf, sizeof(buf), fp)) {
1634 	meta_job_output(NULL, buf, "");
1635 	printf("%s", buf);
1636 	fflush(stdout);
1637     }
1638     fclose(fp);
1639 }
1640 
1641 #endif	/* USE_META */
1642