xref: /freebsd/contrib/bmake/meta.c (revision 884d26c84cba3ffc3d4e626306098fcdfe6a0c2b)
1 /*      $NetBSD: meta.c,v 1.61 2016/06/07 00:40:00 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 
73 Boolean useMeta = FALSE;
74 static Boolean useFilemon = FALSE;
75 static Boolean writeMeta = FALSE;
76 static Boolean metaMissing = FALSE;	/* oodate if missing */
77 static Boolean filemonMissing = FALSE;	/* oodate if missing */
78 static Boolean metaEnv = FALSE;		/* don't save env unless asked */
79 static Boolean metaVerbose = FALSE;
80 static Boolean metaIgnoreCMDs = FALSE;	/* ignore CMDs in .meta files */
81 static Boolean metaIgnorePatterns = FALSE; /* do we need to do pattern matches */
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 
250     /*
251      * Weed out relative paths from the target file name.
252      * We have to be careful though since if target is a
253      * symlink, the result will be unstable.
254      * So we use realpath() just to get the dirname, and leave the
255      * basename as given to us.
256      */
257     if ((cp = strrchr(tname, '/'))) {
258 	if (cached_realpath(tname, buf)) {
259 	    if ((rp = strrchr(buf, '/'))) {
260 		rp++;
261 		cp++;
262 		if (strcmp(cp, rp) != 0)
263 		    strlcpy(rp, cp, sizeof(buf) - (rp - buf));
264 	    }
265 	    tname = buf;
266 	} else {
267 	    /*
268 	     * We likely have a directory which is about to be made.
269 	     * We pretend realpath() succeeded, to have a chance
270 	     * of generating the same meta file name that we will
271 	     * next time through.
272 	     */
273 	    if (tname[0] == '/') {
274 		strlcpy(buf, tname, sizeof(buf));
275 	    } else {
276 		snprintf(buf, sizeof(buf), "%s/%s", cwd, tname);
277 	    }
278 	    eat_dots(buf, sizeof(buf), 1);	/* ./ */
279 	    eat_dots(buf, sizeof(buf), 2);	/* ../ */
280 	    tname = buf;
281 	}
282     }
283     /* on some systems dirname may modify its arg */
284     tp = bmake_strdup(tname);
285     if (strcmp(dname, dirname(tp)) == 0)
286 	snprintf(mname, mnamelen, "%s.meta", tname);
287     else {
288 	snprintf(mname, mnamelen, "%s/%s.meta", dname, tname);
289 
290 	/*
291 	 * Replace path separators in the file name after the
292 	 * current object directory path.
293 	 */
294 	cp = mname + strlen(dname) + 1;
295 
296 	while (*cp != '\0') {
297 	    if (*cp == '/')
298 		*cp = '_';
299 	    cp++;
300 	}
301     }
302     free(tp);
303     return (mname);
304 }
305 
306 /*
307  * Return true if running ${.MAKE}
308  * Bypassed if target is flagged .MAKE
309  */
310 static int
311 is_submake(void *cmdp, void *gnp)
312 {
313     static char *p_make = NULL;
314     static int p_len;
315     char  *cmd = cmdp;
316     GNode *gn = gnp;
317     char *mp = NULL;
318     char *cp;
319     char *cp2;
320     int rc = 0;				/* keep looking */
321 
322     if (!p_make) {
323 	p_make = Var_Value(".MAKE", gn, &cp);
324 	p_len = strlen(p_make);
325     }
326     cp = strchr(cmd, '$');
327     if ((cp)) {
328 	mp = Var_Subst(NULL, cmd, gn, VARF_WANTRES);
329 	cmd = mp;
330     }
331     cp2 = strstr(cmd, p_make);
332     if ((cp2)) {
333 	switch (cp2[p_len]) {
334 	case '\0':
335 	case ' ':
336 	case '\t':
337 	case '\n':
338 	    rc = 1;
339 	    break;
340 	}
341 	if (cp2 > cmd && rc > 0) {
342 	    switch (cp2[-1]) {
343 	    case ' ':
344 	    case '\t':
345 	    case '\n':
346 		break;
347 	    default:
348 		rc = 0;			/* no match */
349 		break;
350 	    }
351 	}
352     }
353     free(mp);
354     return (rc);
355 }
356 
357 typedef struct meta_file_s {
358     FILE *fp;
359     GNode *gn;
360 } meta_file_t;
361 
362 static int
363 printCMD(void *cmdp, void *mfpp)
364 {
365     meta_file_t *mfp = mfpp;
366     char *cmd = cmdp;
367     char *cp = NULL;
368 
369     if (strchr(cmd, '$')) {
370 	cmd = cp = Var_Subst(NULL, cmd, mfp->gn, VARF_WANTRES);
371     }
372     fprintf(mfp->fp, "CMD %s\n", cmd);
373     free(cp);
374     return 0;
375 }
376 
377 /*
378  * Certain node types never get a .meta file
379  */
380 #define SKIP_META_TYPE(_type) do { \
381     if ((gn->type & __CONCAT(OP_, _type))) {	\
382 	if (verbose) { \
383 	    fprintf(debug_file, "Skipping meta for %s: .%s\n", \
384 		    gn->name, __STRING(_type));		       \
385 	} \
386 	return FALSE; \
387     } \
388 } while (0)
389 
390 
391 /*
392  * Do we need/want a .meta file ?
393  */
394 static Boolean
395 meta_needed(GNode *gn, const char *dname, const char *tname,
396 	     char *objdir, int verbose)
397 {
398     struct stat fs;
399 
400     if (verbose)
401 	verbose = DEBUG(META);
402 
403     /* This may be a phony node which we don't want meta data for... */
404     /* Skip .meta for .BEGIN, .END, .ERROR etc as well. */
405     /* Or it may be explicitly flagged as .NOMETA */
406     SKIP_META_TYPE(NOMETA);
407     /* Unless it is explicitly flagged as .META */
408     if (!(gn->type & OP_META)) {
409 	SKIP_META_TYPE(PHONY);
410 	SKIP_META_TYPE(SPECIAL);
411 	SKIP_META_TYPE(MAKE);
412     }
413 
414     /* Check if there are no commands to execute. */
415     if (Lst_IsEmpty(gn->commands)) {
416 	if (verbose)
417 	    fprintf(debug_file, "Skipping meta for %s: no commands\n",
418 		    gn->name);
419 	return FALSE;
420     }
421     if ((gn->type & (OP_META|OP_SUBMAKE)) == OP_SUBMAKE) {
422 	/* OP_SUBMAKE is a bit too aggressive */
423 	if (Lst_ForEach(gn->commands, is_submake, gn)) {
424 	    if (DEBUG(META))
425 		fprintf(debug_file, "Skipping meta for %s: .SUBMAKE\n",
426 			gn->name);
427 	    return FALSE;
428 	}
429     }
430 
431     /* The object directory may not exist. Check it.. */
432     if (cached_stat(dname, &fs) != 0) {
433 	if (verbose)
434 	    fprintf(debug_file, "Skipping meta for %s: no .OBJDIR\n",
435 		    gn->name);
436 	return FALSE;
437     }
438 
439     /* make sure these are canonical */
440     if (cached_realpath(dname, objdir))
441 	dname = objdir;
442 
443     /* If we aren't in the object directory, don't create a meta file. */
444     if (!metaCurdirOk && strcmp(curdir, dname) == 0) {
445 	if (verbose)
446 	    fprintf(debug_file, "Skipping meta for %s: .OBJDIR == .CURDIR\n",
447 		    gn->name);
448 	return FALSE;
449     }
450     return TRUE;
451 }
452 
453 
454 static FILE *
455 meta_create(BuildMon *pbm, GNode *gn)
456 {
457     meta_file_t mf;
458     char buf[MAXPATHLEN];
459     char objdir[MAXPATHLEN];
460     char **ptr;
461     const char *dname;
462     const char *tname;
463     char *fname;
464     const char *cp;
465     char *p[4];				/* >= possible uses */
466     int i;
467 
468     mf.fp = NULL;
469     i = 0;
470 
471     dname = Var_Value(".OBJDIR", gn, &p[i++]);
472     tname = Var_Value(TARGET, gn, &p[i++]);
473 
474     /* if this succeeds objdir is realpath of dname */
475     if (!meta_needed(gn, dname, tname, objdir, TRUE))
476 	goto out;
477     dname = objdir;
478 
479     if (metaVerbose) {
480 	char *mp;
481 
482 	/* Describe the target we are building */
483 	mp = Var_Subst(NULL, "${" MAKE_META_PREFIX "}", gn, VARF_WANTRES);
484 	if (*mp)
485 	    fprintf(stdout, "%s\n", mp);
486 	free(mp);
487     }
488     /* Get the basename of the target */
489     if ((cp = strrchr(tname, '/')) == NULL) {
490 	cp = tname;
491     } else {
492 	cp++;
493     }
494 
495     fflush(stdout);
496 
497     if (!writeMeta)
498 	/* Don't create meta data. */
499 	goto out;
500 
501     fname = meta_name(gn, pbm->meta_fname, sizeof(pbm->meta_fname),
502 		      dname, tname, objdir);
503 
504 #ifdef DEBUG_META_MODE
505     if (DEBUG(META))
506 	fprintf(debug_file, "meta_create: %s\n", fname);
507 #endif
508 
509     if ((mf.fp = fopen(fname, "w")) == NULL)
510 	err(1, "Could not open meta file '%s'", fname);
511 
512     fprintf(mf.fp, "# Meta data file %s\n", fname);
513 
514     mf.gn = gn;
515 
516     Lst_ForEach(gn->commands, printCMD, &mf);
517 
518     fprintf(mf.fp, "CWD %s\n", getcwd(buf, sizeof(buf)));
519     fprintf(mf.fp, "TARGET %s\n", tname);
520 
521     if (metaEnv) {
522 	for (ptr = environ; *ptr != NULL; ptr++)
523 	    fprintf(mf.fp, "ENV %s\n", *ptr);
524     }
525 
526     fprintf(mf.fp, "-- command output --\n");
527     fflush(mf.fp);
528 
529     Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
530     Var_Append(".MAKE.META.CREATED", fname, VAR_GLOBAL);
531 
532     gn->type |= OP_META;		/* in case anyone wants to know */
533     if (metaSilent) {
534 	    gn->type |= OP_SILENT;
535     }
536  out:
537     for (i--; i >= 0; i--) {
538 	free(p[i]);
539     }
540 
541     return (mf.fp);
542 }
543 
544 static Boolean
545 boolValue(char *s)
546 {
547     switch(*s) {
548     case '0':
549     case 'N':
550     case 'n':
551     case 'F':
552     case 'f':
553 	return FALSE;
554     }
555     return TRUE;
556 }
557 
558 /*
559  * Initialization we need before reading makefiles.
560  */
561 void
562 meta_init(void)
563 {
564 #ifdef USE_FILEMON
565 	/* this allows makefiles to test if we have filemon support */
566 	Var_Set(".MAKE.PATH_FILEMON", _PATH_FILEMON, VAR_GLOBAL, 0);
567 #endif
568 }
569 
570 
571 #define get_mode_bf(bf, token) \
572     if ((cp = strstr(make_mode, token))) \
573 	bf = boolValue(&cp[sizeof(token) - 1])
574 
575 /*
576  * Initialization we need after reading makefiles.
577  */
578 void
579 meta_mode_init(const char *make_mode)
580 {
581     static int once = 0;
582     char *cp;
583 
584     useMeta = TRUE;
585     useFilemon = TRUE;
586     writeMeta = TRUE;
587 
588     if (make_mode) {
589 	if (strstr(make_mode, "env"))
590 	    metaEnv = TRUE;
591 	if (strstr(make_mode, "verb"))
592 	    metaVerbose = TRUE;
593 	if (strstr(make_mode, "read"))
594 	    writeMeta = FALSE;
595 	if (strstr(make_mode, "nofilemon"))
596 	    useFilemon = FALSE;
597 	if (strstr(make_mode, "ignore-cmd"))
598 	    metaIgnoreCMDs = TRUE;
599 	if (useFilemon)
600 	    get_mode_bf(filemonMissing, "missing-filemon=");
601 	get_mode_bf(metaCurdirOk, "curdirok=");
602 	get_mode_bf(metaMissing, "missing-meta=");
603 	get_mode_bf(metaSilent, "silent=");
604     }
605     if (metaVerbose && !Var_Exists(MAKE_META_PREFIX, VAR_GLOBAL)) {
606 	/*
607 	 * The default value for MAKE_META_PREFIX
608 	 * prints the absolute path of the target.
609 	 * This works be cause :H will generate '.' if there is no /
610 	 * and :tA will resolve that to cwd.
611 	 */
612 	Var_Set(MAKE_META_PREFIX, "Building ${.TARGET:H:tA}/${.TARGET:T}", VAR_GLOBAL, 0);
613     }
614     if (once)
615 	return;
616     once = 1;
617     memset(&Mybm, 0, sizeof(Mybm));
618     /*
619      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
620      */
621     metaBailiwick = Lst_Init(FALSE);
622     metaBailiwickStr = Var_Subst(NULL, "${.MAKE.META.BAILIWICK:O:u:tA}",
623 	VAR_GLOBAL, VARF_WANTRES);
624     if (metaBailiwickStr) {
625 	str2Lst_Append(metaBailiwick, metaBailiwickStr, NULL);
626     }
627     /*
628      * We ignore any paths that start with ${.MAKE.META.IGNORE_PATHS}
629      */
630     metaIgnorePaths = Lst_Init(FALSE);
631     Var_Append(MAKE_META_IGNORE_PATHS,
632 	       "/dev /etc /proc /tmp /var/run /var/tmp ${TMPDIR}", VAR_GLOBAL);
633     metaIgnorePathsStr = Var_Subst(NULL,
634 		   "${" MAKE_META_IGNORE_PATHS ":O:u:tA}", VAR_GLOBAL,
635 		   VARF_WANTRES);
636     if (metaIgnorePathsStr) {
637 	str2Lst_Append(metaIgnorePaths, metaIgnorePathsStr, NULL);
638     }
639 
640     /*
641      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
642      */
643     cp = NULL;
644     if (Var_Value(MAKE_META_IGNORE_PATTERNS, VAR_GLOBAL, &cp)) {
645 	metaIgnorePatterns = TRUE;
646 	free(cp);
647     }
648 }
649 
650 /*
651  * In each case below we allow for job==NULL
652  */
653 void
654 meta_job_start(Job *job, GNode *gn)
655 {
656     BuildMon *pbm;
657 
658     if (job != NULL) {
659 	pbm = &job->bm;
660     } else {
661 	pbm = &Mybm;
662     }
663     pbm->mfp = meta_create(pbm, gn);
664 #ifdef USE_FILEMON_ONCE
665     /* compat mode we open the filemon dev once per command */
666     if (job == NULL)
667 	return;
668 #endif
669 #ifdef USE_FILEMON
670     if (pbm->mfp != NULL && useFilemon) {
671 	filemon_open(pbm);
672     } else {
673 	pbm->mon_fd = pbm->filemon_fd = -1;
674     }
675 #endif
676 }
677 
678 /*
679  * The child calls this before doing anything.
680  * It does not disturb our state.
681  */
682 void
683 meta_job_child(Job *job)
684 {
685 #ifdef USE_FILEMON
686     BuildMon *pbm;
687 
688     if (job != NULL) {
689 	pbm = &job->bm;
690     } else {
691 	pbm = &Mybm;
692     }
693     if (pbm->mfp != NULL) {
694 	close(fileno(pbm->mfp));
695 	if (useFilemon) {
696 	    pid_t pid;
697 
698 	    pid = getpid();
699 	    if (ioctl(pbm->filemon_fd, FILEMON_SET_PID, &pid) < 0) {
700 		err(1, "Could not set filemon pid!");
701 	    }
702 	}
703     }
704 #endif
705 }
706 
707 void
708 meta_job_error(Job *job, GNode *gn, int flags, int status)
709 {
710     char cwd[MAXPATHLEN];
711     BuildMon *pbm;
712 
713     if (job != NULL) {
714 	pbm = &job->bm;
715 	if (!gn)
716 	    gn = job->node;
717     } else {
718 	pbm = &Mybm;
719     }
720     if (pbm->mfp != NULL) {
721 	fprintf(pbm->mfp, "*** Error code %d%s\n",
722 		status,
723 		(flags & JOB_IGNERR) ?
724 		"(ignored)" : "");
725     }
726     if (gn) {
727 	Var_Set(".ERROR_TARGET", gn->path ? gn->path : gn->name, VAR_GLOBAL, 0);
728     }
729     getcwd(cwd, sizeof(cwd));
730     Var_Set(".ERROR_CWD", cwd, VAR_GLOBAL, 0);
731     if (pbm->meta_fname[0]) {
732 	Var_Set(".ERROR_META_FILE", pbm->meta_fname, VAR_GLOBAL, 0);
733     }
734     meta_job_finish(job);
735 }
736 
737 void
738 meta_job_output(Job *job, char *cp, const char *nl)
739 {
740     BuildMon *pbm;
741 
742     if (job != NULL) {
743 	pbm = &job->bm;
744     } else {
745 	pbm = &Mybm;
746     }
747     if (pbm->mfp != NULL) {
748 	if (metaVerbose) {
749 	    static char *meta_prefix = NULL;
750 	    static int meta_prefix_len;
751 
752 	    if (!meta_prefix) {
753 		char *cp2;
754 
755 		meta_prefix = Var_Subst(NULL, "${" MAKE_META_PREFIX "}",
756 					VAR_GLOBAL, VARF_WANTRES);
757 		if ((cp2 = strchr(meta_prefix, '$')))
758 		    meta_prefix_len = cp2 - meta_prefix;
759 		else
760 		    meta_prefix_len = strlen(meta_prefix);
761 	    }
762 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
763 		cp = strchr(cp+1, '\n');
764 		if (!cp++)
765 		    return;
766 	    }
767 	}
768 	fprintf(pbm->mfp, "%s%s", cp, nl);
769     }
770 }
771 
772 int
773 meta_cmd_finish(void *pbmp)
774 {
775     int error = 0;
776 #ifdef USE_FILEMON
777     BuildMon *pbm = pbmp;
778     int x;
779 
780     if (!pbm)
781 	pbm = &Mybm;
782 
783     if (pbm->filemon_fd >= 0) {
784 	if (close(pbm->filemon_fd) < 0)
785 	    error = errno;
786 	x = filemon_read(pbm->mfp, pbm->mon_fd);
787 	if (error == 0 && x != 0)
788 	    error = x;
789 	pbm->filemon_fd = pbm->mon_fd = -1;
790     }
791 #endif
792     return error;
793 }
794 
795 int
796 meta_job_finish(Job *job)
797 {
798     BuildMon *pbm;
799     int error = 0;
800     int x;
801 
802     if (job != NULL) {
803 	pbm = &job->bm;
804     } else {
805 	pbm = &Mybm;
806     }
807     if (pbm->mfp != NULL) {
808 	error = meta_cmd_finish(pbm);
809 	x = fclose(pbm->mfp);
810 	if (error == 0 && x != 0)
811 	    error = errno;
812 	pbm->mfp = NULL;
813 	pbm->meta_fname[0] = '\0';
814     }
815     return error;
816 }
817 
818 void
819 meta_finish(void)
820 {
821     Lst_Destroy(metaBailiwick, NULL);
822     free(metaBailiwickStr);
823     Lst_Destroy(metaIgnorePaths, NULL);
824     free(metaIgnorePathsStr);
825 }
826 
827 /*
828  * Fetch a full line from fp - growing bufp if needed
829  * Return length in bufp.
830  */
831 static int
832 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
833 {
834     char *buf = *bufp;
835     size_t bufsz = *szp;
836     struct stat fs;
837     int x;
838 
839     if (fgets(&buf[o], bufsz - o, fp) != NULL) {
840     check_newline:
841 	x = o + strlen(&buf[o]);
842 	if (buf[x - 1] == '\n')
843 	    return x;
844 	/*
845 	 * We need to grow the buffer.
846 	 * The meta file can give us a clue.
847 	 */
848 	if (fstat(fileno(fp), &fs) == 0) {
849 	    size_t newsz;
850 	    char *p;
851 
852 	    newsz = ROUNDUP((fs.st_size / 2), BUFSIZ);
853 	    if (newsz <= bufsz)
854 		newsz = ROUNDUP(fs.st_size, BUFSIZ);
855 	    if (DEBUG(META))
856 		fprintf(debug_file, "growing buffer %u -> %u\n",
857 			(unsigned)bufsz, (unsigned)newsz);
858 	    p = bmake_realloc(buf, newsz);
859 	    if (p) {
860 		*bufp = buf = p;
861 		*szp = bufsz = newsz;
862 		/* fetch the rest */
863 		if (!fgets(&buf[x], bufsz - x, fp))
864 		    return x;		/* truncated! */
865 		goto check_newline;
866 	    }
867 	}
868     }
869     return 0;
870 }
871 
872 static int
873 prefix_match(void *p, void *q)
874 {
875     const char *prefix = p;
876     const char *path = q;
877     size_t n = strlen(prefix);
878 
879     return (0 == strncmp(path, prefix, n));
880 }
881 
882 static int
883 string_match(const void *p, const void *q)
884 {
885     const char *p1 = p;
886     const char *p2 = q;
887 
888     return strcmp(p1, p2);
889 }
890 
891 
892 /*
893  * When running with 'meta' functionality, a target can be out-of-date
894  * if any of the references in its meta data file is more recent.
895  * We have to track the latestdir on a per-process basis.
896  */
897 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
898 #define LDIR_VNAME_FMT ".meta.%d.ldir"
899 
900 /*
901  * It is possible that a .meta file is corrupted,
902  * if we detect this we want to reproduce it.
903  * Setting oodate TRUE will have that effect.
904  */
905 #define CHECK_VALID_META(p) if (!(p && *p)) { \
906     warnx("%s: %d: malformed", fname, lineno); \
907     oodate = TRUE; \
908     continue; \
909     }
910 
911 #define DEQUOTE(p) if (*p == '\'') {	\
912     char *ep; \
913     p++; \
914     if ((ep = strchr(p, '\''))) \
915 	*ep = '\0'; \
916     }
917 
918 Boolean
919 meta_oodate(GNode *gn, Boolean oodate)
920 {
921     static char *tmpdir = NULL;
922     static char cwd[MAXPATHLEN];
923     char lcwd_vname[64];
924     char ldir_vname[64];
925     char lcwd[MAXPATHLEN];
926     char latestdir[MAXPATHLEN];
927     char fname[MAXPATHLEN];
928     char fname1[MAXPATHLEN];
929     char fname2[MAXPATHLEN];
930     char fname3[MAXPATHLEN];
931     const char *dname;
932     const char *tname;
933     char *p;
934     char *cp;
935     char *link_src;
936     char *move_target;
937     static size_t cwdlen = 0;
938     static size_t tmplen = 0;
939     FILE *fp;
940     Boolean needOODATE = FALSE;
941     Lst missingFiles;
942     char *pa[4];			/* >= possible uses */
943     int i;
944     int have_filemon = FALSE;
945 
946     if (oodate)
947 	return oodate;		/* we're done */
948 
949     i = 0;
950 
951     dname = Var_Value(".OBJDIR", gn, &pa[i++]);
952     tname = Var_Value(TARGET, gn, &pa[i++]);
953 
954     /* if this succeeds fname3 is realpath of dname */
955     if (!meta_needed(gn, dname, tname, fname3, FALSE))
956 	goto oodate_out;
957     dname = fname3;
958 
959     missingFiles = Lst_Init(FALSE);
960 
961     /*
962      * We need to check if the target is out-of-date. This includes
963      * checking if the expanded command has changed. This in turn
964      * requires that all variables are set in the same way that they
965      * would be if the target needs to be re-built.
966      */
967     Make_DoAllVar(gn);
968 
969     meta_name(gn, fname, sizeof(fname), dname, tname, dname);
970 
971 #ifdef DEBUG_META_MODE
972     if (DEBUG(META))
973 	fprintf(debug_file, "meta_oodate: %s\n", fname);
974 #endif
975 
976     if ((fp = fopen(fname, "r")) != NULL) {
977 	static char *buf = NULL;
978 	static size_t bufsz;
979 	int lineno = 0;
980 	int lastpid = 0;
981 	int pid;
982 	int x;
983 	LstNode ln;
984 	struct stat fs;
985 
986 	if (!buf) {
987 	    bufsz = 8 * BUFSIZ;
988 	    buf = bmake_malloc(bufsz);
989 	}
990 
991 	if (!cwdlen) {
992 	    if (getcwd(cwd, sizeof(cwd)) == NULL)
993 		err(1, "Could not get current working directory");
994 	    cwdlen = strlen(cwd);
995 	}
996 	strlcpy(lcwd, cwd, sizeof(lcwd));
997 	strlcpy(latestdir, cwd, sizeof(latestdir));
998 
999 	if (!tmpdir) {
1000 	    tmpdir = getTmpdir();
1001 	    tmplen = strlen(tmpdir);
1002 	}
1003 
1004 	/* we want to track all the .meta we read */
1005 	Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
1006 
1007 	ln = Lst_First(gn->commands);
1008 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1009 	    lineno++;
1010 	    if (buf[x - 1] == '\n')
1011 		buf[x - 1] = '\0';
1012 	    else {
1013 		warnx("%s: %d: line truncated at %u", fname, lineno, x);
1014 		oodate = TRUE;
1015 		break;
1016 	    }
1017 	    link_src = NULL;
1018 	    move_target = NULL;
1019 	    /* Find the start of the build monitor section. */
1020 	    if (!have_filemon) {
1021 		if (strncmp(buf, "-- filemon", 10) == 0) {
1022 		    have_filemon = TRUE;
1023 		    continue;
1024 		}
1025 		if (strncmp(buf, "# buildmon", 10) == 0) {
1026 		    have_filemon = TRUE;
1027 		    continue;
1028 		}
1029 	    }
1030 
1031 	    /* Delimit the record type. */
1032 	    p = buf;
1033 #ifdef DEBUG_META_MODE
1034 	    if (DEBUG(META))
1035 		fprintf(debug_file, "%s: %d: %s\n", fname, lineno, buf);
1036 #endif
1037 	    strsep(&p, " ");
1038 	    if (have_filemon) {
1039 		/*
1040 		 * We are in the 'filemon' output section.
1041 		 * Each record from filemon follows the general form:
1042 		 *
1043 		 * <key> <pid> <data>
1044 		 *
1045 		 * Where:
1046 		 * <key> is a single letter, denoting the syscall.
1047 		 * <pid> is the process that made the syscall.
1048 		 * <data> is the arguments (of interest).
1049 		 */
1050 		switch(buf[0]) {
1051 		case '#':		/* comment */
1052 		case 'V':		/* version */
1053 		    break;
1054 		default:
1055 		    /*
1056 		     * We need to track pathnames per-process.
1057 		     *
1058 		     * Each process run by make, starts off in the 'CWD'
1059 		     * recorded in the .meta file, if it chdirs ('C')
1060 		     * elsewhere we need to track that - but only for
1061 		     * that process.  If it forks ('F'), we initialize
1062 		     * the child to have the same cwd as its parent.
1063 		     *
1064 		     * We also need to track the 'latestdir' of
1065 		     * interest.  This is usually the same as cwd, but
1066 		     * not if a process is reading directories.
1067 		     *
1068 		     * Each time we spot a different process ('pid')
1069 		     * we save the current value of 'latestdir' in a
1070 		     * variable qualified by 'lastpid', and
1071 		     * re-initialize 'latestdir' to any pre-saved
1072 		     * value for the current 'pid' and 'CWD' if none.
1073 		     */
1074 		    CHECK_VALID_META(p);
1075 		    pid = atoi(p);
1076 		    if (pid > 0 && pid != lastpid) {
1077 			char *ldir;
1078 			char *tp;
1079 
1080 			if (lastpid > 0) {
1081 			    /* We need to remember these. */
1082 			    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1083 			    Var_Set(ldir_vname, latestdir, VAR_GLOBAL, 0);
1084 			}
1085 			snprintf(lcwd_vname, sizeof(lcwd_vname), LCWD_VNAME_FMT, pid);
1086 			snprintf(ldir_vname, sizeof(ldir_vname), LDIR_VNAME_FMT, pid);
1087 			lastpid = pid;
1088 			ldir = Var_Value(ldir_vname, VAR_GLOBAL, &tp);
1089 			if (ldir) {
1090 			    strlcpy(latestdir, ldir, sizeof(latestdir));
1091 			    free(tp);
1092 			}
1093 			ldir = Var_Value(lcwd_vname, VAR_GLOBAL, &tp);
1094 			if (ldir) {
1095 			    strlcpy(lcwd, ldir, sizeof(lcwd));
1096 			    free(tp);
1097 			}
1098 		    }
1099 		    /* Skip past the pid. */
1100 		    if (strsep(&p, " ") == NULL)
1101 			continue;
1102 #ifdef DEBUG_META_MODE
1103 		    if (DEBUG(META))
1104 			    fprintf(debug_file, "%s: %d: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1105 				    fname, lineno,
1106 				    pid, buf[0], cwd, lcwd, latestdir);
1107 #endif
1108 		    break;
1109 		}
1110 
1111 		CHECK_VALID_META(p);
1112 
1113 		/* Process according to record type. */
1114 		switch (buf[0]) {
1115 		case 'X':		/* eXit */
1116 		    Var_Delete(lcwd_vname, VAR_GLOBAL);
1117 		    Var_Delete(ldir_vname, VAR_GLOBAL);
1118 		    lastpid = 0;	/* no need to save ldir_vname */
1119 		    break;
1120 
1121 		case 'F':		/* [v]Fork */
1122 		    {
1123 			char cldir[64];
1124 			int child;
1125 
1126 			child = atoi(p);
1127 			if (child > 0) {
1128 			    snprintf(cldir, sizeof(cldir), LCWD_VNAME_FMT, child);
1129 			    Var_Set(cldir, lcwd, VAR_GLOBAL, 0);
1130 			    snprintf(cldir, sizeof(cldir), LDIR_VNAME_FMT, child);
1131 			    Var_Set(cldir, latestdir, VAR_GLOBAL, 0);
1132 #ifdef DEBUG_META_MODE
1133 			    if (DEBUG(META))
1134 				    fprintf(debug_file, "%s: %d: %d: cwd=%s lcwd=%s ldir=%s\n",
1135 					    fname, lineno,
1136 					    child, cwd, lcwd, latestdir);
1137 #endif
1138 			}
1139 		    }
1140 		    break;
1141 
1142 		case 'C':		/* Chdir */
1143 		    /* Update lcwd and latest directory. */
1144 		    strlcpy(latestdir, p, sizeof(latestdir));
1145 		    strlcpy(lcwd, p, sizeof(lcwd));
1146 		    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1147 		    Var_Set(ldir_vname, lcwd, VAR_GLOBAL, 0);
1148 #ifdef DEBUG_META_MODE
1149 		    if (DEBUG(META))
1150 			fprintf(debug_file, "%s: %d: cwd=%s ldir=%s\n", fname, lineno, cwd, lcwd);
1151 #endif
1152 		    break;
1153 
1154 		case 'M':		/* renaMe */
1155 		    /*
1156 		     * For 'M'oves we want to check
1157 		     * the src as for 'R'ead
1158 		     * and the target as for 'W'rite.
1159 		     */
1160 		    cp = p;		/* save this for a second */
1161 		    /* now get target */
1162 		    if (strsep(&p, " ") == NULL)
1163 			continue;
1164 		    CHECK_VALID_META(p);
1165 		    move_target = p;
1166 		    p = cp;
1167 		    /* 'L' and 'M' put single quotes around the args */
1168 		    DEQUOTE(p);
1169 		    DEQUOTE(move_target);
1170 		    /* FALLTHROUGH */
1171 		case 'D':		/* unlink */
1172 		    if (*p == '/' && !Lst_IsEmpty(missingFiles)) {
1173 			/* remove p from the missingFiles list if present */
1174 			if ((ln = Lst_Find(missingFiles, p, string_match)) != NULL) {
1175 			    char *tp = Lst_Datum(ln);
1176 			    Lst_Remove(missingFiles, ln);
1177 			    free(tp);
1178 			    ln = NULL;	/* we're done with it */
1179 			}
1180 		    }
1181 		    if (buf[0] == 'M') {
1182 			/* the target of the mv is a file 'W'ritten */
1183 #ifdef DEBUG_META_MODE
1184 			if (DEBUG(META))
1185 			    fprintf(debug_file, "meta_oodate: M %s -> %s\n",
1186 				    p, move_target);
1187 #endif
1188 			p = move_target;
1189 			goto check_write;
1190 		    }
1191 		    break;
1192 		case 'L':		/* Link */
1193 		    /*
1194 		     * For 'L'inks check
1195 		     * the src as for 'R'ead
1196 		     * and the target as for 'W'rite.
1197 		     */
1198 		    link_src = p;
1199 		    /* now get target */
1200 		    if (strsep(&p, " ") == NULL)
1201 			continue;
1202 		    CHECK_VALID_META(p);
1203 		    /* 'L' and 'M' put single quotes around the args */
1204 		    DEQUOTE(p);
1205 		    DEQUOTE(link_src);
1206 #ifdef DEBUG_META_MODE
1207 		    if (DEBUG(META))
1208 			fprintf(debug_file, "meta_oodate: L %s -> %s\n",
1209 				link_src, p);
1210 #endif
1211 		    /* FALLTHROUGH */
1212 		case 'W':		/* Write */
1213 		check_write:
1214 		    /*
1215 		     * If a file we generated within our bailiwick
1216 		     * but outside of .OBJDIR is missing,
1217 		     * we need to do it again.
1218 		     */
1219 		    /* ignore non-absolute paths */
1220 		    if (*p != '/')
1221 			break;
1222 
1223 		    if (Lst_IsEmpty(metaBailiwick))
1224 			break;
1225 
1226 		    /* ignore cwd - normal dependencies handle those */
1227 		    if (strncmp(p, cwd, cwdlen) == 0)
1228 			break;
1229 
1230 		    if (!Lst_ForEach(metaBailiwick, prefix_match, p))
1231 			break;
1232 
1233 		    /* tmpdir might be within */
1234 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1235 			break;
1236 
1237 		    /* ignore anything containing the string "tmp" */
1238 		    if ((strstr("tmp", p)))
1239 			break;
1240 
1241 		    if ((link_src != NULL && cached_lstat(p, &fs) < 0) ||
1242 			(link_src == NULL && cached_stat(p, &fs) < 0)) {
1243 			if (Lst_Find(missingFiles, p, string_match) == NULL)
1244 				Lst_AtEnd(missingFiles, bmake_strdup(p));
1245 		    }
1246 		    break;
1247 		check_link_src:
1248 		    p = link_src;
1249 		    link_src = NULL;
1250 #ifdef DEBUG_META_MODE
1251 		    if (DEBUG(META))
1252 			fprintf(debug_file, "meta_oodate: L src %s\n", p);
1253 #endif
1254 		    /* FALLTHROUGH */
1255 		case 'R':		/* Read */
1256 		case 'E':		/* Exec */
1257 		    /*
1258 		     * Check for runtime files that can't
1259 		     * be part of the dependencies because
1260 		     * they are _expected_ to change.
1261 		     */
1262 		    if (*p == '/') {
1263 			cached_realpath(p, fname1); /* clean it up */
1264 			if (Lst_ForEach(metaIgnorePaths, prefix_match, fname1)) {
1265 #ifdef DEBUG_META_MODE
1266 			    if (DEBUG(META))
1267 				fprintf(debug_file, "meta_oodate: ignoring path: %s\n",
1268 					p);
1269 #endif
1270 			    break;
1271 			}
1272 		    }
1273 
1274 		    if (metaIgnorePatterns) {
1275 			char *pm;
1276 
1277 			snprintf(fname1, sizeof(fname1),
1278 				 "${%s:@m@${%s:L:M$m}@}",
1279 				 MAKE_META_IGNORE_PATTERNS, p);
1280 			pm = Var_Subst(NULL, fname1, gn, VARF_WANTRES);
1281 			if (*pm) {
1282 #ifdef DEBUG_META_MODE
1283 			    if (DEBUG(META))
1284 				fprintf(debug_file, "meta_oodate: ignoring pattern: %s\n",
1285 					p);
1286 #endif
1287 			    free(pm);
1288 			    break;
1289 			}
1290 			free(pm);
1291 		    }
1292 
1293 		    /*
1294 		     * The rest of the record is the file name.
1295 		     * Check if it's not an absolute path.
1296 		     */
1297 		    {
1298 			char *sdirs[4];
1299 			char **sdp;
1300 			int sdx = 0;
1301 			int found = 0;
1302 
1303 			if (*p == '/') {
1304 			    sdirs[sdx++] = p; /* done */
1305 			} else {
1306 			    if (strcmp(".", p) == 0)
1307 				continue;  /* no point */
1308 
1309 			    /* Check vs latestdir */
1310 			    snprintf(fname1, sizeof(fname1), "%s/%s", latestdir, p);
1311 			    sdirs[sdx++] = fname1;
1312 
1313 			    if (strcmp(latestdir, lcwd) != 0) {
1314 				/* Check vs lcwd */
1315 				snprintf(fname2, sizeof(fname2), "%s/%s", lcwd, p);
1316 				sdirs[sdx++] = fname2;
1317 			    }
1318 			    if (strcmp(lcwd, cwd) != 0) {
1319 				/* Check vs cwd */
1320 				snprintf(fname3, sizeof(fname3), "%s/%s", cwd, p);
1321 				sdirs[sdx++] = fname3;
1322 			    }
1323 			}
1324 			sdirs[sdx++] = NULL;
1325 
1326 			for (sdp = sdirs; *sdp && !found; sdp++) {
1327 #ifdef DEBUG_META_MODE
1328 			    if (DEBUG(META))
1329 				fprintf(debug_file, "%s: %d: looking for: %s\n", fname, lineno, *sdp);
1330 #endif
1331 			    if (cached_stat(*sdp, &fs) == 0) {
1332 				found = 1;
1333 				p = *sdp;
1334 			    }
1335 			}
1336 			if (found) {
1337 #ifdef DEBUG_META_MODE
1338 			    if (DEBUG(META))
1339 				fprintf(debug_file, "%s: %d: found: %s\n", fname, lineno, p);
1340 #endif
1341 			    if (!S_ISDIR(fs.st_mode) &&
1342 				fs.st_mtime > gn->mtime) {
1343 				if (DEBUG(META))
1344 				    fprintf(debug_file, "%s: %d: file '%s' is newer than the target...\n", fname, lineno, p);
1345 				oodate = TRUE;
1346 			    } else if (S_ISDIR(fs.st_mode)) {
1347 				/* Update the latest directory. */
1348 				cached_realpath(p, latestdir);
1349 			    }
1350 			} else if (errno == ENOENT && *p == '/' &&
1351 				   strncmp(p, cwd, cwdlen) != 0) {
1352 			    /*
1353 			     * A referenced file outside of CWD is missing.
1354 			     * We cannot catch every eventuality here...
1355 			     */
1356 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1357 				    Lst_AtEnd(missingFiles, bmake_strdup(p));
1358 			}
1359 		    }
1360 		    if (buf[0] == 'E') {
1361 			/* previous latestdir is no longer relevant */
1362 			strlcpy(latestdir, lcwd, sizeof(latestdir));
1363 		    }
1364 		    break;
1365 		default:
1366 		    break;
1367 		}
1368 		if (!oodate && buf[0] == 'L' && link_src != NULL)
1369 		    goto check_link_src;
1370 	    } else if (strcmp(buf, "CMD") == 0) {
1371 		/*
1372 		 * Compare the current command with the one in the
1373 		 * meta data file.
1374 		 */
1375 		if (ln == NULL) {
1376 		    if (DEBUG(META))
1377 			fprintf(debug_file, "%s: %d: there were more build commands in the meta data file than there are now...\n", fname, lineno);
1378 		    oodate = TRUE;
1379 		} else {
1380 		    char *cmd = (char *)Lst_Datum(ln);
1381 		    Boolean hasOODATE = FALSE;
1382 
1383 		    if (strstr(cmd, "$?"))
1384 			hasOODATE = TRUE;
1385 		    else if ((cp = strstr(cmd, ".OODATE"))) {
1386 			/* check for $[{(].OODATE[:)}] */
1387 			if (cp > cmd + 2 && cp[-2] == '$')
1388 			    hasOODATE = TRUE;
1389 		    }
1390 		    if (hasOODATE) {
1391 			needOODATE = TRUE;
1392 			if (DEBUG(META))
1393 			    fprintf(debug_file, "%s: %d: cannot compare command using .OODATE\n", fname, lineno);
1394 		    }
1395 		    cmd = Var_Subst(NULL, cmd, gn, VARF_WANTRES|VARF_UNDEFERR);
1396 
1397 		    if ((cp = strchr(cmd, '\n'))) {
1398 			int n;
1399 
1400 			/*
1401 			 * This command contains newlines, we need to
1402 			 * fetch more from the .meta file before we
1403 			 * attempt a comparison.
1404 			 */
1405 			/* first put the newline back at buf[x - 1] */
1406 			buf[x - 1] = '\n';
1407 			do {
1408 			    /* now fetch the next line */
1409 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1410 				break;
1411 			    x = n;
1412 			    lineno++;
1413 			    if (buf[x - 1] != '\n') {
1414 				warnx("%s: %d: line truncated at %u", fname, lineno, x);
1415 				break;
1416 			    }
1417 			    cp = strchr(++cp, '\n');
1418 			} while (cp);
1419 			if (buf[x - 1] == '\n')
1420 			    buf[x - 1] = '\0';
1421 		    }
1422 		    if (!hasOODATE &&
1423 			!(gn->type & OP_NOMETA_CMP) &&
1424 			strcmp(p, cmd) != 0) {
1425 			if (DEBUG(META))
1426 			    fprintf(debug_file, "%s: %d: a build command has changed\n%s\nvs\n%s\n", fname, lineno, p, cmd);
1427 			if (!metaIgnoreCMDs)
1428 			    oodate = TRUE;
1429 		    }
1430 		    free(cmd);
1431 		    ln = Lst_Succ(ln);
1432 		}
1433 	    } else if (strcmp(buf, "CWD") == 0) {
1434 		/*
1435 		 * Check if there are extra commands now
1436 		 * that weren't in the meta data file.
1437 		 */
1438 		if (!oodate && ln != NULL) {
1439 		    if (DEBUG(META))
1440 			fprintf(debug_file, "%s: %d: there are extra build commands now that weren't in the meta data file\n", fname, lineno);
1441 		    oodate = TRUE;
1442 		}
1443 		if (strcmp(p, cwd) != 0) {
1444 		    if (DEBUG(META))
1445 			fprintf(debug_file, "%s: %d: the current working directory has changed from '%s' to '%s'\n", fname, lineno, p, curdir);
1446 		    oodate = TRUE;
1447 		}
1448 	    }
1449 	}
1450 
1451 	fclose(fp);
1452 	if (!Lst_IsEmpty(missingFiles)) {
1453 	    if (DEBUG(META))
1454 		fprintf(debug_file, "%s: missing files: %s...\n",
1455 			fname, (char *)Lst_Datum(Lst_First(missingFiles)));
1456 	    oodate = TRUE;
1457 	}
1458 	if (!oodate && !have_filemon && filemonMissing) {
1459 	    if (DEBUG(META))
1460 		fprintf(debug_file, "%s: missing filemon data\n", fname);
1461 	    oodate = TRUE;
1462 	}
1463     } else {
1464 	if (writeMeta && metaMissing) {
1465 	    cp = NULL;
1466 
1467 	    /* if target is in .CURDIR we do not need a meta file */
1468 	    if (gn->path && (cp = strrchr(gn->path, '/')) && cp > gn->path) {
1469 		if (strncmp(curdir, gn->path, (cp - gn->path)) != 0) {
1470 		    cp = NULL;		/* not in .CURDIR */
1471 		}
1472 	    }
1473 	    if (!cp) {
1474 		if (DEBUG(META))
1475 		    fprintf(debug_file, "%s: required but missing\n", fname);
1476 		oodate = TRUE;
1477 		needOODATE = TRUE;	/* assume the worst */
1478 	    }
1479 	}
1480     }
1481 
1482     Lst_Destroy(missingFiles, (FreeProc *)free);
1483 
1484     if (oodate && needOODATE) {
1485 	/*
1486 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1487 	 * We have decided it is oodate, so .OODATE needs to be set.
1488 	 * All we can sanely do is set it to .ALLSRC.
1489 	 */
1490 	Var_Delete(OODATE, gn);
1491 	Var_Set(OODATE, Var_Value(ALLSRC, gn, &cp), gn, 0);
1492 	free(cp);
1493     }
1494 
1495  oodate_out:
1496     for (i--; i >= 0; i--) {
1497 	free(pa[i]);
1498     }
1499     return oodate;
1500 }
1501 
1502 /* support for compat mode */
1503 
1504 static int childPipe[2];
1505 
1506 void
1507 meta_compat_start(void)
1508 {
1509 #ifdef USE_FILEMON_ONCE
1510     /*
1511      * We need to re-open filemon for each cmd.
1512      */
1513     BuildMon *pbm = &Mybm;
1514 
1515     if (pbm->mfp != NULL && useFilemon) {
1516 	filemon_open(pbm);
1517     } else {
1518 	pbm->mon_fd = pbm->filemon_fd = -1;
1519     }
1520 #endif
1521     if (pipe(childPipe) < 0)
1522 	Punt("Cannot create pipe: %s", strerror(errno));
1523     /* Set close-on-exec flag for both */
1524     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1525     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1526 }
1527 
1528 void
1529 meta_compat_child(void)
1530 {
1531     meta_job_child(NULL);
1532     if (dup2(childPipe[1], 1) < 0 ||
1533 	dup2(1, 2) < 0) {
1534 	execError("dup2", "pipe");
1535 	_exit(1);
1536     }
1537 }
1538 
1539 void
1540 meta_compat_parent(void)
1541 {
1542     FILE *fp;
1543     char buf[BUFSIZ];
1544 
1545     close(childPipe[1]);			/* child side */
1546     fp = fdopen(childPipe[0], "r");
1547     while (fgets(buf, sizeof(buf), fp)) {
1548 	meta_job_output(NULL, buf, "");
1549 	printf("%s", buf);
1550 	(void)fflush(stdout);
1551     }
1552     fclose(fp);
1553 }
1554 
1555 #endif	/* USE_META */
1556