xref: /netbsd-src/usr.bin/make/meta.c (revision cef8759bd76c1b621f8eab8faa6f208faabc2e15)
1 /*      $NetBSD: meta.c,v 1.92 2020/08/03 20:26:09 rillig 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 <libgen.h>
40 #include <errno.h>
41 #if !defined(HAVE_CONFIG_H) || defined(HAVE_ERR_H)
42 #include <err.h>
43 #endif
44 
45 #include "make.h"
46 #include "job.h"
47 
48 #ifdef USE_FILEMON
49 #include "filemon/filemon.h"
50 #endif
51 
52 static BuildMon Mybm;			/* for compat */
53 static Lst metaBailiwick;		/* our scope of control */
54 static char *metaBailiwickStr;		/* string storage for the list */
55 static Lst metaIgnorePaths;		/* paths we deliberately ignore */
56 static char *metaIgnorePathsStr;	/* string storage for the list */
57 
58 #ifndef MAKE_META_IGNORE_PATHS
59 #define MAKE_META_IGNORE_PATHS ".MAKE.META.IGNORE_PATHS"
60 #endif
61 #ifndef MAKE_META_IGNORE_PATTERNS
62 #define MAKE_META_IGNORE_PATTERNS ".MAKE.META.IGNORE_PATTERNS"
63 #endif
64 #ifndef MAKE_META_IGNORE_FILTER
65 #define MAKE_META_IGNORE_FILTER ".MAKE.META.IGNORE_FILTER"
66 #endif
67 
68 Boolean useMeta = FALSE;
69 static Boolean useFilemon = FALSE;
70 static Boolean writeMeta = FALSE;
71 static Boolean metaMissing = FALSE;	/* oodate if missing */
72 static Boolean filemonMissing = FALSE;	/* oodate if missing */
73 static Boolean metaEnv = FALSE;		/* don't save env unless asked */
74 static Boolean metaVerbose = FALSE;
75 static Boolean metaIgnoreCMDs = FALSE;	/* ignore CMDs in .meta files */
76 static Boolean metaIgnorePatterns = FALSE; /* do we need to do pattern matches */
77 static Boolean metaIgnoreFilter = FALSE;   /* do we have more complex filtering? */
78 static Boolean metaCurdirOk = FALSE;	/* write .meta in .CURDIR Ok? */
79 static Boolean metaSilent = FALSE;	/* if we have a .meta be SILENT */
80 
81 extern Boolean forceJobs;
82 extern Boolean comatMake;
83 extern char    **environ;
84 
85 #define	MAKE_META_PREFIX	".MAKE.META.PREFIX"
86 
87 #ifndef N2U
88 # define N2U(n, u)   (((n) + ((u) - 1)) / (u))
89 #endif
90 #ifndef ROUNDUP
91 # define ROUNDUP(n, u)   (N2U((n), (u)) * (u))
92 #endif
93 
94 #if !defined(HAVE_STRSEP)
95 # define strsep(s, d) stresep((s), (d), 0)
96 #endif
97 
98 /*
99  * Filemon is a kernel module which snoops certain syscalls.
100  *
101  * C chdir
102  * E exec
103  * F [v]fork
104  * L [sym]link
105  * M rename
106  * R read
107  * W write
108  * S stat
109  *
110  * See meta_oodate below - we mainly care about 'E' and 'R'.
111  *
112  * We can still use meta mode without filemon, but
113  * the benefits are more limited.
114  */
115 #ifdef USE_FILEMON
116 
117 /*
118  * Open the filemon device.
119  */
120 static void
121 meta_open_filemon(BuildMon *pbm)
122 {
123     int dupfd;
124 
125     pbm->mon_fd = -1;
126     pbm->filemon = NULL;
127     if (!useFilemon || !pbm->mfp)
128 	return;
129 
130     pbm->filemon = filemon_open();
131     if (pbm->filemon == NULL) {
132 	useFilemon = FALSE;
133 	warn("Could not open filemon %s", filemon_path());
134 	return;
135     }
136 
137     /*
138      * We use a file outside of '.'
139      * to avoid a FreeBSD kernel bug where unlink invalidates
140      * cwd causing getcwd to do a lot more work.
141      * We only care about the descriptor.
142      */
143     pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL);
144     if ((dupfd = dup(pbm->mon_fd)) == -1) {
145 	err(1, "Could not dup filemon output!");
146     }
147     (void)fcntl(dupfd, F_SETFD, FD_CLOEXEC);
148     if (filemon_setfd(pbm->filemon, dupfd) == -1) {
149 	err(1, "Could not set filemon file descriptor!");
150     }
151     /* we don't need these once we exec */
152     (void)fcntl(pbm->mon_fd, F_SETFD, FD_CLOEXEC);
153 }
154 
155 /*
156  * Read the build monitor output file and write records to the target's
157  * metadata file.
158  */
159 static int
160 filemon_read(FILE *mfp, int fd)
161 {
162     char buf[BUFSIZ];
163     int n;
164     int error;
165 
166     /* Check if we're not writing to a meta data file.*/
167     if (mfp == NULL) {
168 	if (fd >= 0)
169 	    close(fd);			/* not interested */
170 	return 0;
171     }
172     /* rewind */
173     if (lseek(fd, (off_t)0, SEEK_SET) < 0) {
174 	error = errno;
175 	warn("Could not rewind filemon");
176 	fprintf(mfp, "\n");
177     } else {
178 	error = 0;
179 	fprintf(mfp, "\n-- filemon acquired metadata --\n");
180 
181 	while ((n = read(fd, buf, sizeof(buf))) > 0) {
182 	    if ((int)fwrite(buf, 1, n, mfp) < n)
183 		error = EIO;
184 	}
185     }
186     fflush(mfp);
187     if (close(fd) < 0)
188 	error = errno;
189     return error;
190 }
191 #endif
192 
193 /*
194  * when realpath() fails,
195  * we use this, to clean up ./ and ../
196  */
197 static void
198 eat_dots(char *buf, size_t bufsz, int dots)
199 {
200     char *cp;
201     char *cp2;
202     const char *eat;
203     size_t eatlen;
204 
205     switch (dots) {
206     case 1:
207 	eat = "/./";
208 	eatlen = 2;
209 	break;
210     case 2:
211 	eat = "/../";
212 	eatlen = 3;
213 	break;
214     default:
215 	return;
216     }
217 
218     do {
219 	cp = strstr(buf, eat);
220 	if (cp) {
221 	    cp2 = cp + eatlen;
222 	    if (dots == 2 && cp > buf) {
223 		do {
224 		    cp--;
225 		} while (cp > buf && *cp != '/');
226 	    }
227 	    if (*cp == '/') {
228 		strlcpy(cp, cp2, bufsz - (cp - buf));
229 	    } else {
230 		return;			/* can't happen? */
231 	    }
232 	}
233     } while (cp);
234 }
235 
236 static char *
237 meta_name(struct GNode *gn, char *mname, size_t mnamelen,
238 	  const char *dname,
239 	  const char *tname,
240 	  const char *cwd)
241 {
242     char buf[MAXPATHLEN];
243     char *rp;
244     char *cp;
245     char *tp;
246     char *dtp;
247     size_t ldname;
248 
249     /*
250      * Weed out relative paths from the target file name.
251      * We have to be careful though since if target is a
252      * symlink, the result will be unstable.
253      * So we use realpath() just to get the dirname, and leave the
254      * basename as given to us.
255      */
256     if ((cp = strrchr(tname, '/'))) {
257 	if (cached_realpath(tname, buf)) {
258 	    if ((rp = strrchr(buf, '/'))) {
259 		rp++;
260 		cp++;
261 		if (strcmp(cp, rp) != 0)
262 		    strlcpy(rp, cp, sizeof(buf) - (rp - buf));
263 	    }
264 	    tname = buf;
265 	} else {
266 	    /*
267 	     * We likely have a directory which is about to be made.
268 	     * We pretend realpath() succeeded, to have a chance
269 	     * of generating the same meta file name that we will
270 	     * next time through.
271 	     */
272 	    if (tname[0] == '/') {
273 		strlcpy(buf, tname, sizeof(buf));
274 	    } else {
275 		snprintf(buf, sizeof(buf), "%s/%s", cwd, tname);
276 	    }
277 	    eat_dots(buf, sizeof(buf), 1);	/* ./ */
278 	    eat_dots(buf, sizeof(buf), 2);	/* ../ */
279 	    tname = buf;
280 	}
281     }
282     /* on some systems dirname may modify its arg */
283     tp = bmake_strdup(tname);
284     dtp = dirname(tp);
285     if (strcmp(dname, dtp) == 0)
286 	snprintf(mname, mnamelen, "%s.meta", tname);
287     else {
288 	ldname = strlen(dname);
289 	if (strncmp(dname, dtp, ldname) == 0 && dtp[ldname] == '/')
290 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, &tname[ldname+1]);
291 	else
292 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, tname);
293 
294 	/*
295 	 * Replace path separators in the file name after the
296 	 * current object directory path.
297 	 */
298 	cp = mname + strlen(dname) + 1;
299 
300 	while (*cp != '\0') {
301 	    if (*cp == '/')
302 		*cp = '_';
303 	    cp++;
304 	}
305     }
306     free(tp);
307     return mname;
308 }
309 
310 /*
311  * Return true if running ${.MAKE}
312  * Bypassed if target is flagged .MAKE
313  */
314 static int
315 is_submake(void *cmdp, void *gnp)
316 {
317     static const char *p_make = NULL;
318     static int p_len;
319     char  *cmd = cmdp;
320     GNode *gn = gnp;
321     char *mp = NULL;
322     char *cp;
323     char *cp2;
324     int rc = 0;				/* keep looking */
325 
326     if (!p_make) {
327 	p_make = Var_Value(".MAKE", gn, &cp);
328 	p_len = strlen(p_make);
329     }
330     cp = strchr(cmd, '$');
331     if ((cp)) {
332 	mp = Var_Subst(cmd, gn, VARE_WANTRES);
333 	cmd = mp;
334     }
335     cp2 = strstr(cmd, p_make);
336     if ((cp2)) {
337 	switch (cp2[p_len]) {
338 	case '\0':
339 	case ' ':
340 	case '\t':
341 	case '\n':
342 	    rc = 1;
343 	    break;
344 	}
345 	if (cp2 > cmd && rc > 0) {
346 	    switch (cp2[-1]) {
347 	    case ' ':
348 	    case '\t':
349 	    case '\n':
350 		break;
351 	    default:
352 		rc = 0;			/* no match */
353 		break;
354 	    }
355 	}
356     }
357     free(mp);
358     return rc;
359 }
360 
361 typedef struct meta_file_s {
362     FILE *fp;
363     GNode *gn;
364 } meta_file_t;
365 
366 static int
367 printCMD(void *cmdp, void *mfpp)
368 {
369     meta_file_t *mfp = mfpp;
370     char *cmd = cmdp;
371     char *cp = NULL;
372 
373     if (strchr(cmd, '$')) {
374 	cmd = cp = Var_Subst(cmd, mfp->gn, VARE_WANTRES);
375     }
376     fprintf(mfp->fp, "CMD %s\n", cmd);
377     free(cp);
378     return 0;
379 }
380 
381 /*
382  * Certain node types never get a .meta file
383  */
384 #define SKIP_META_TYPE(_type) do { \
385     if ((gn->type & __CONCAT(OP_, _type))) {	\
386 	if (verbose) { \
387 	    fprintf(debug_file, "Skipping meta for %s: .%s\n", \
388 		    gn->name, __STRING(_type));		       \
389 	} \
390 	return FALSE; \
391     } \
392 } while (0)
393 
394 
395 /*
396  * Do we need/want a .meta file ?
397  */
398 static Boolean
399 meta_needed(GNode *gn, const char *dname, const char *tname,
400 	     char *objdir, int verbose)
401 {
402     struct stat fs;
403 
404     if (verbose)
405 	verbose = DEBUG(META);
406 
407     /* This may be a phony node which we don't want meta data for... */
408     /* Skip .meta for .BEGIN, .END, .ERROR etc as well. */
409     /* Or it may be explicitly flagged as .NOMETA */
410     SKIP_META_TYPE(NOMETA);
411     /* Unless it is explicitly flagged as .META */
412     if (!(gn->type & OP_META)) {
413 	SKIP_META_TYPE(PHONY);
414 	SKIP_META_TYPE(SPECIAL);
415 	SKIP_META_TYPE(MAKE);
416     }
417 
418     /* Check if there are no commands to execute. */
419     if (Lst_IsEmpty(gn->commands)) {
420 	if (verbose)
421 	    fprintf(debug_file, "Skipping meta for %s: no commands\n",
422 		    gn->name);
423 	return FALSE;
424     }
425     if ((gn->type & (OP_META|OP_SUBMAKE)) == OP_SUBMAKE) {
426 	/* OP_SUBMAKE is a bit too aggressive */
427 	if (Lst_ForEach(gn->commands, is_submake, gn)) {
428 	    if (DEBUG(META))
429 		fprintf(debug_file, "Skipping meta for %s: .SUBMAKE\n",
430 			gn->name);
431 	    return FALSE;
432 	}
433     }
434 
435     /* The object directory may not exist. Check it.. */
436     if (cached_stat(dname, &fs) != 0) {
437 	if (verbose)
438 	    fprintf(debug_file, "Skipping meta for %s: no .OBJDIR\n",
439 		    gn->name);
440 	return FALSE;
441     }
442 
443     /* make sure these are canonical */
444     if (cached_realpath(dname, objdir))
445 	dname = objdir;
446 
447     /* If we aren't in the object directory, don't create a meta file. */
448     if (!metaCurdirOk && strcmp(curdir, dname) == 0) {
449 	if (verbose)
450 	    fprintf(debug_file, "Skipping meta for %s: .OBJDIR == .CURDIR\n",
451 		    gn->name);
452 	return FALSE;
453     }
454     return TRUE;
455 }
456 
457 
458 static FILE *
459 meta_create(BuildMon *pbm, GNode *gn)
460 {
461     meta_file_t mf;
462     char buf[MAXPATHLEN];
463     char objdir[MAXPATHLEN];
464     char **ptr;
465     const char *dname;
466     const char *tname;
467     char *fname;
468     const char *cp;
469     char *p[5];				/* >= possible uses */
470     int i;
471 
472     mf.fp = NULL;
473     i = 0;
474 
475     dname = Var_Value(".OBJDIR", gn, &p[i++]);
476     tname = Var_Value(TARGET, gn, &p[i++]);
477 
478     /* if this succeeds objdir is realpath of dname */
479     if (!meta_needed(gn, dname, tname, objdir, TRUE))
480 	goto out;
481     dname = objdir;
482 
483     if (metaVerbose) {
484 	char *mp;
485 
486 	/* Describe the target we are building */
487 	mp = Var_Subst("${" MAKE_META_PREFIX "}", gn, VARE_WANTRES);
488 	if (*mp)
489 	    fprintf(stdout, "%s\n", mp);
490 	free(mp);
491     }
492     /* Get the basename of the target */
493     if ((cp = strrchr(tname, '/')) == NULL) {
494 	cp = tname;
495     } else {
496 	cp++;
497     }
498 
499     fflush(stdout);
500 
501     if (!writeMeta)
502 	/* Don't create meta data. */
503 	goto out;
504 
505     fname = meta_name(gn, pbm->meta_fname, sizeof(pbm->meta_fname),
506 		      dname, tname, objdir);
507 
508 #ifdef DEBUG_META_MODE
509     if (DEBUG(META))
510 	fprintf(debug_file, "meta_create: %s\n", fname);
511 #endif
512 
513     if ((mf.fp = fopen(fname, "w")) == NULL)
514 	err(1, "Could not open meta file '%s'", fname);
515 
516     fprintf(mf.fp, "# Meta data file %s\n", fname);
517 
518     mf.gn = gn;
519 
520     Lst_ForEach(gn->commands, printCMD, &mf);
521 
522     fprintf(mf.fp, "CWD %s\n", getcwd(buf, sizeof(buf)));
523     fprintf(mf.fp, "TARGET %s\n", tname);
524     cp = Var_Value(".OODATE", gn, &p[i++]);
525     if (cp && *cp) {
526 	    fprintf(mf.fp, "OODATE %s\n", cp);
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 	bmake_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", filemon_path(), VAR_GLOBAL);
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);
620     }
621     if (once)
622 	return;
623     once = 1;
624     memset(&Mybm, 0, sizeof(Mybm));
625     /*
626      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
627      */
628     metaBailiwick = Lst_Init(FALSE);
629     metaBailiwickStr = Var_Subst("${.MAKE.META.BAILIWICK:O:u:tA}",
630 	VAR_GLOBAL, VARE_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 ${TMPDIR}", VAR_GLOBAL);
640     metaIgnorePathsStr = Var_Subst("${" MAKE_META_IGNORE_PATHS ":O:u:tA}",
641 				   VAR_GLOBAL, VARE_WANTRES);
642     if (metaIgnorePathsStr) {
643 	str2Lst_Append(metaIgnorePaths, metaIgnorePathsStr, NULL);
644     }
645 
646     /*
647      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
648      */
649     cp = NULL;
650     if (Var_Value(MAKE_META_IGNORE_PATTERNS, VAR_GLOBAL, &cp)) {
651 	metaIgnorePatterns = TRUE;
652 	bmake_free(cp);
653     }
654     cp = NULL;
655     if (Var_Value(MAKE_META_IGNORE_FILTER, VAR_GLOBAL, &cp)) {
656 	metaIgnoreFilter = TRUE;
657 	bmake_free(cp);
658     }
659 }
660 
661 /*
662  * In each case below we allow for job==NULL
663  */
664 void
665 meta_job_start(Job *job, GNode *gn)
666 {
667     BuildMon *pbm;
668 
669     if (job != NULL) {
670 	pbm = &job->bm;
671     } else {
672 	pbm = &Mybm;
673     }
674     pbm->mfp = meta_create(pbm, gn);
675 #ifdef USE_FILEMON_ONCE
676     /* compat mode we open the filemon dev once per command */
677     if (job == NULL)
678 	return;
679 #endif
680 #ifdef USE_FILEMON
681     if (pbm->mfp != NULL && useFilemon) {
682 	meta_open_filemon(pbm);
683     } else {
684 	pbm->mon_fd = -1;
685 	pbm->filemon = NULL;
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 && pbm->filemon) {
708 	    pid_t pid;
709 
710 	    pid = getpid();
711 	    if (filemon_setpid_child(pbm->filemon, pid) == -1) {
712 		err(1, "Could not set filemon pid!");
713 	    }
714 	}
715     }
716 #endif
717 }
718 
719 void
720 meta_job_parent(Job *job, pid_t pid)
721 {
722 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
723     BuildMon *pbm;
724 
725     if (job != NULL) {
726 	pbm = &job->bm;
727     } else {
728 	pbm = &Mybm;
729     }
730     if (useFilemon && pbm->filemon) {
731 	filemon_setpid_parent(pbm->filemon, pid);
732     }
733 #endif
734 }
735 
736 int
737 meta_job_fd(Job *job)
738 {
739 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
740     BuildMon *pbm;
741 
742     if (job != NULL) {
743 	pbm = &job->bm;
744     } else {
745 	pbm = &Mybm;
746     }
747     if (useFilemon && pbm->filemon) {
748 	return filemon_readfd(pbm->filemon);
749     }
750 #endif
751     return -1;
752 }
753 
754 int
755 meta_job_event(Job *job)
756 {
757 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
758     BuildMon *pbm;
759 
760     if (job != NULL) {
761 	pbm = &job->bm;
762     } else {
763 	pbm = &Mybm;
764     }
765     if (useFilemon && pbm->filemon) {
766 	return filemon_process(pbm->filemon);
767     }
768 #endif
769     return 0;
770 }
771 
772 void
773 meta_job_error(Job *job, GNode *gn, int flags, int status)
774 {
775     char cwd[MAXPATHLEN];
776     BuildMon *pbm;
777 
778     if (job != NULL) {
779 	pbm = &job->bm;
780 	if (!gn)
781 	    gn = job->node;
782     } else {
783 	pbm = &Mybm;
784     }
785     if (pbm->mfp != NULL) {
786 	fprintf(pbm->mfp, "\n*** Error code %d%s\n",
787 		status,
788 		(flags & JOB_IGNERR) ?
789 		"(ignored)" : "");
790     }
791     if (gn) {
792 	Var_Set(".ERROR_TARGET", gn->path ? gn->path : gn->name, VAR_GLOBAL);
793     }
794     getcwd(cwd, sizeof(cwd));
795     Var_Set(".ERROR_CWD", cwd, VAR_GLOBAL);
796     if (pbm->meta_fname[0]) {
797 	Var_Set(".ERROR_META_FILE", pbm->meta_fname, VAR_GLOBAL);
798     }
799     meta_job_finish(job);
800 }
801 
802 void
803 meta_job_output(Job *job, char *cp, const char *nl)
804 {
805     BuildMon *pbm;
806 
807     if (job != NULL) {
808 	pbm = &job->bm;
809     } else {
810 	pbm = &Mybm;
811     }
812     if (pbm->mfp != NULL) {
813 	if (metaVerbose) {
814 	    static char *meta_prefix = NULL;
815 	    static int meta_prefix_len;
816 
817 	    if (!meta_prefix) {
818 		char *cp2;
819 
820 		meta_prefix = Var_Subst("${" MAKE_META_PREFIX "}",
821 					VAR_GLOBAL, VARE_WANTRES);
822 		if ((cp2 = strchr(meta_prefix, '$')))
823 		    meta_prefix_len = cp2 - meta_prefix;
824 		else
825 		    meta_prefix_len = strlen(meta_prefix);
826 	    }
827 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
828 		cp = strchr(cp+1, '\n');
829 		if (!cp++)
830 		    return;
831 	    }
832 	}
833 	fprintf(pbm->mfp, "%s%s", cp, nl);
834     }
835 }
836 
837 int
838 meta_cmd_finish(void *pbmp)
839 {
840     int error = 0;
841     BuildMon *pbm = pbmp;
842 #ifdef USE_FILEMON
843     int x;
844 #endif
845 
846     if (!pbm)
847 	pbm = &Mybm;
848 
849 #ifdef USE_FILEMON
850     if (pbm->filemon) {
851 	while (filemon_process(pbm->filemon) > 0)
852 	    continue;
853 	if (filemon_close(pbm->filemon) == -1)
854 	    error = errno;
855 	x = filemon_read(pbm->mfp, pbm->mon_fd);
856 	if (error == 0 && x != 0)
857 	    error = x;
858 	pbm->mon_fd = -1;
859 	pbm->filemon = NULL;
860     } else
861 #endif
862 	fprintf(pbm->mfp, "\n");	/* ensure end with newline */
863     return error;
864 }
865 
866 int
867 meta_job_finish(Job *job)
868 {
869     BuildMon *pbm;
870     int error = 0;
871     int x;
872 
873     if (job != NULL) {
874 	pbm = &job->bm;
875     } else {
876 	pbm = &Mybm;
877     }
878     if (pbm->mfp != NULL) {
879 	error = meta_cmd_finish(pbm);
880 	x = fclose(pbm->mfp);
881 	if (error == 0 && x != 0)
882 	    error = errno;
883 	pbm->mfp = NULL;
884 	pbm->meta_fname[0] = '\0';
885     }
886     return error;
887 }
888 
889 void
890 meta_finish(void)
891 {
892     Lst_Destroy(metaBailiwick, NULL);
893     free(metaBailiwickStr);
894     Lst_Destroy(metaIgnorePaths, NULL);
895     free(metaIgnorePathsStr);
896 }
897 
898 /*
899  * Fetch a full line from fp - growing bufp if needed
900  * Return length in bufp.
901  */
902 static int
903 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
904 {
905     char *buf = *bufp;
906     size_t bufsz = *szp;
907     struct stat fs;
908     int x;
909 
910     if (fgets(&buf[o], bufsz - o, fp) != NULL) {
911     check_newline:
912 	x = o + strlen(&buf[o]);
913 	if (buf[x - 1] == '\n')
914 	    return x;
915 	/*
916 	 * We need to grow the buffer.
917 	 * The meta file can give us a clue.
918 	 */
919 	if (fstat(fileno(fp), &fs) == 0) {
920 	    size_t newsz;
921 	    char *p;
922 
923 	    newsz = ROUNDUP((fs.st_size / 2), BUFSIZ);
924 	    if (newsz <= bufsz)
925 		newsz = ROUNDUP(fs.st_size, BUFSIZ);
926 	    if (newsz <= bufsz)
927 		return x;		/* truncated */
928 	    if (DEBUG(META))
929 		fprintf(debug_file, "growing buffer %zu -> %zu\n",
930 			bufsz, newsz);
931 	    p = bmake_realloc(buf, newsz);
932 	    if (p) {
933 		*bufp = buf = p;
934 		*szp = bufsz = newsz;
935 		/* fetch the rest */
936 		if (!fgets(&buf[x], bufsz - x, fp))
937 		    return x;		/* truncated! */
938 		goto check_newline;
939 	    }
940 	}
941     }
942     return 0;
943 }
944 
945 /* Lst_ForEach wants 1 to stop search */
946 static int
947 prefix_match(void *p, void *q)
948 {
949     const char *prefix = p;
950     const char *path = q;
951     size_t n = strlen(prefix);
952 
953     return strncmp(path, prefix, n) == 0;
954 }
955 
956 /*
957  * looking for exact or prefix/ match to
958  * Lst_Find wants 0 to stop search
959  */
960 static int
961 path_match(const void *p, const void *q)
962 {
963     const char *prefix = q;
964     const char *path = p;
965     size_t n = strlen(prefix);
966     int rc;
967 
968     if ((rc = strncmp(path, prefix, n)) == 0) {
969 	switch (path[n]) {
970 	case '\0':
971 	case '/':
972 	    break;
973 	default:
974 	    rc = 1;
975 	    break;
976 	}
977     }
978     return rc;
979 }
980 
981 /* Lst_Find wants 0 to stop search */
982 static int
983 string_match(const void *p, const void *q)
984 {
985     const char *p1 = p;
986     const char *p2 = q;
987 
988     return strcmp(p1, p2);
989 }
990 
991 
992 static int
993 meta_ignore(GNode *gn, const char *p)
994 {
995     char fname[MAXPATHLEN];
996 
997     if (p == NULL)
998 	return TRUE;
999 
1000     if (*p == '/') {
1001 	cached_realpath(p, fname); /* clean it up */
1002 	if (Lst_ForEach(metaIgnorePaths, prefix_match, fname)) {
1003 #ifdef DEBUG_META_MODE
1004 	    if (DEBUG(META))
1005 		fprintf(debug_file, "meta_oodate: ignoring path: %s\n",
1006 			p);
1007 #endif
1008 	    return TRUE;
1009 	}
1010     }
1011 
1012     if (metaIgnorePatterns) {
1013         const char *expr;
1014         char *pm;
1015 
1016 	Var_Set(".p.", p, gn);
1017 	expr = "${" MAKE_META_IGNORE_PATTERNS ":@m@${.p.:M$m}@}";
1018 	pm = Var_Subst(expr, gn, VARE_WANTRES);
1019 	if (*pm) {
1020 #ifdef DEBUG_META_MODE
1021 	    if (DEBUG(META))
1022 		fprintf(debug_file, "meta_oodate: ignoring pattern: %s\n",
1023 			p);
1024 #endif
1025 	    free(pm);
1026 	    return TRUE;
1027 	}
1028 	free(pm);
1029     }
1030 
1031     if (metaIgnoreFilter) {
1032 	char *fm;
1033 
1034 	/* skip if filter result is empty */
1035 	snprintf(fname, sizeof(fname),
1036 		 "${%s:L:${%s:ts:}}",
1037 		 p, MAKE_META_IGNORE_FILTER);
1038 	fm = Var_Subst(fname, gn, VARE_WANTRES);
1039 	if (*fm == '\0') {
1040 #ifdef DEBUG_META_MODE
1041 	    if (DEBUG(META))
1042 		fprintf(debug_file, "meta_oodate: ignoring filtered: %s\n",
1043 			p);
1044 #endif
1045 	    free(fm);
1046 	    return TRUE;
1047 	}
1048 	free(fm);
1049     }
1050     return FALSE;
1051 }
1052 
1053 /*
1054  * When running with 'meta' functionality, a target can be out-of-date
1055  * if any of the references in its meta data file is more recent.
1056  * We have to track the latestdir on a per-process basis.
1057  */
1058 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
1059 #define LDIR_VNAME_FMT ".meta.%d.ldir"
1060 
1061 /*
1062  * It is possible that a .meta file is corrupted,
1063  * if we detect this we want to reproduce it.
1064  * Setting oodate TRUE will have that effect.
1065  */
1066 #define CHECK_VALID_META(p) if (!(p && *p)) { \
1067     warnx("%s: %d: malformed", fname, lineno); \
1068     oodate = TRUE; \
1069     continue; \
1070     }
1071 
1072 #define DEQUOTE(p) if (*p == '\'') {	\
1073     char *ep; \
1074     p++; \
1075     if ((ep = strchr(p, '\''))) \
1076 	*ep = '\0'; \
1077     }
1078 
1079 Boolean
1080 meta_oodate(GNode *gn, Boolean oodate)
1081 {
1082     static char *tmpdir = NULL;
1083     static char cwd[MAXPATHLEN];
1084     char lcwd_vname[64];
1085     char ldir_vname[64];
1086     char lcwd[MAXPATHLEN];
1087     char latestdir[MAXPATHLEN];
1088     char fname[MAXPATHLEN];
1089     char fname1[MAXPATHLEN];
1090     char fname2[MAXPATHLEN];
1091     char fname3[MAXPATHLEN];
1092     const char *dname;
1093     const char *tname;
1094     char *p;
1095     char *cp;
1096     char *link_src;
1097     char *move_target;
1098     static size_t cwdlen = 0;
1099     static size_t tmplen = 0;
1100     FILE *fp;
1101     Boolean needOODATE = FALSE;
1102     Lst missingFiles;
1103     char *pa[4];			/* >= possible uses */
1104     int i;
1105     int have_filemon = FALSE;
1106 
1107     if (oodate)
1108 	return oodate;		/* we're done */
1109 
1110     i = 0;
1111 
1112     dname = Var_Value(".OBJDIR", gn, &pa[i++]);
1113     tname = Var_Value(TARGET, gn, &pa[i++]);
1114 
1115     /* if this succeeds fname3 is realpath of dname */
1116     if (!meta_needed(gn, dname, tname, fname3, FALSE))
1117 	goto oodate_out;
1118     dname = fname3;
1119 
1120     missingFiles = Lst_Init(FALSE);
1121 
1122     /*
1123      * We need to check if the target is out-of-date. This includes
1124      * checking if the expanded command has changed. This in turn
1125      * requires that all variables are set in the same way that they
1126      * would be if the target needs to be re-built.
1127      */
1128     Make_DoAllVar(gn);
1129 
1130     meta_name(gn, fname, sizeof(fname), dname, tname, dname);
1131 
1132 #ifdef DEBUG_META_MODE
1133     if (DEBUG(META))
1134 	fprintf(debug_file, "meta_oodate: %s\n", fname);
1135 #endif
1136 
1137     if ((fp = fopen(fname, "r")) != NULL) {
1138 	static char *buf = NULL;
1139 	static size_t bufsz;
1140 	int lineno = 0;
1141 	int lastpid = 0;
1142 	int pid;
1143 	int x;
1144 	LstNode ln;
1145 	struct stat fs;
1146 
1147 	if (!buf) {
1148 	    bufsz = 8 * BUFSIZ;
1149 	    buf = bmake_malloc(bufsz);
1150 	}
1151 
1152 	if (!cwdlen) {
1153 	    if (getcwd(cwd, sizeof(cwd)) == NULL)
1154 		err(1, "Could not get current working directory");
1155 	    cwdlen = strlen(cwd);
1156 	}
1157 	strlcpy(lcwd, cwd, sizeof(lcwd));
1158 	strlcpy(latestdir, cwd, sizeof(latestdir));
1159 
1160 	if (!tmpdir) {
1161 	    tmpdir = getTmpdir();
1162 	    tmplen = strlen(tmpdir);
1163 	}
1164 
1165 	/* we want to track all the .meta we read */
1166 	Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
1167 
1168 	ln = Lst_First(gn->commands);
1169 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1170 	    lineno++;
1171 	    if (buf[x - 1] == '\n')
1172 		buf[x - 1] = '\0';
1173 	    else {
1174 		warnx("%s: %d: line truncated at %u", fname, lineno, x);
1175 		oodate = TRUE;
1176 		break;
1177 	    }
1178 	    link_src = NULL;
1179 	    move_target = NULL;
1180 	    /* Find the start of the build monitor section. */
1181 	    if (!have_filemon) {
1182 		if (strncmp(buf, "-- filemon", 10) == 0) {
1183 		    have_filemon = TRUE;
1184 		    continue;
1185 		}
1186 		if (strncmp(buf, "# buildmon", 10) == 0) {
1187 		    have_filemon = TRUE;
1188 		    continue;
1189 		}
1190 	    }
1191 
1192 	    /* Delimit the record type. */
1193 	    p = buf;
1194 #ifdef DEBUG_META_MODE
1195 	    if (DEBUG(META))
1196 		fprintf(debug_file, "%s: %d: %s\n", fname, lineno, buf);
1197 #endif
1198 	    strsep(&p, " ");
1199 	    if (have_filemon) {
1200 		/*
1201 		 * We are in the 'filemon' output section.
1202 		 * Each record from filemon follows the general form:
1203 		 *
1204 		 * <key> <pid> <data>
1205 		 *
1206 		 * Where:
1207 		 * <key> is a single letter, denoting the syscall.
1208 		 * <pid> is the process that made the syscall.
1209 		 * <data> is the arguments (of interest).
1210 		 */
1211 		switch(buf[0]) {
1212 		case '#':		/* comment */
1213 		case 'V':		/* version */
1214 		    break;
1215 		default:
1216 		    /*
1217 		     * We need to track pathnames per-process.
1218 		     *
1219 		     * Each process run by make, starts off in the 'CWD'
1220 		     * recorded in the .meta file, if it chdirs ('C')
1221 		     * elsewhere we need to track that - but only for
1222 		     * that process.  If it forks ('F'), we initialize
1223 		     * the child to have the same cwd as its parent.
1224 		     *
1225 		     * We also need to track the 'latestdir' of
1226 		     * interest.  This is usually the same as cwd, but
1227 		     * not if a process is reading directories.
1228 		     *
1229 		     * Each time we spot a different process ('pid')
1230 		     * we save the current value of 'latestdir' in a
1231 		     * variable qualified by 'lastpid', and
1232 		     * re-initialize 'latestdir' to any pre-saved
1233 		     * value for the current 'pid' and 'CWD' if none.
1234 		     */
1235 		    CHECK_VALID_META(p);
1236 		    pid = atoi(p);
1237 		    if (pid > 0 && pid != lastpid) {
1238 			const char *ldir;
1239 			char *tp;
1240 
1241 			if (lastpid > 0) {
1242 			    /* We need to remember these. */
1243 			    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL);
1244 			    Var_Set(ldir_vname, latestdir, VAR_GLOBAL);
1245 			}
1246 			snprintf(lcwd_vname, sizeof(lcwd_vname), LCWD_VNAME_FMT, pid);
1247 			snprintf(ldir_vname, sizeof(ldir_vname), LDIR_VNAME_FMT, pid);
1248 			lastpid = pid;
1249 			ldir = Var_Value(ldir_vname, VAR_GLOBAL, &tp);
1250 			if (ldir) {
1251 			    strlcpy(latestdir, ldir, sizeof(latestdir));
1252 			    bmake_free(tp);
1253 			}
1254 			ldir = Var_Value(lcwd_vname, VAR_GLOBAL, &tp);
1255 			if (ldir) {
1256 			    strlcpy(lcwd, ldir, sizeof(lcwd));
1257 			    bmake_free(tp);
1258 			}
1259 		    }
1260 		    /* Skip past the pid. */
1261 		    if (strsep(&p, " ") == NULL)
1262 			continue;
1263 #ifdef DEBUG_META_MODE
1264 		    if (DEBUG(META))
1265 			    fprintf(debug_file, "%s: %d: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1266 				    fname, lineno,
1267 				    pid, buf[0], cwd, lcwd, latestdir);
1268 #endif
1269 		    break;
1270 		}
1271 
1272 		CHECK_VALID_META(p);
1273 
1274 		/* Process according to record type. */
1275 		switch (buf[0]) {
1276 		case 'X':		/* eXit */
1277 		    Var_Delete(lcwd_vname, VAR_GLOBAL);
1278 		    Var_Delete(ldir_vname, VAR_GLOBAL);
1279 		    lastpid = 0;	/* no need to save ldir_vname */
1280 		    break;
1281 
1282 		case 'F':		/* [v]Fork */
1283 		    {
1284 			char cldir[64];
1285 			int child;
1286 
1287 			child = atoi(p);
1288 			if (child > 0) {
1289 			    snprintf(cldir, sizeof(cldir), LCWD_VNAME_FMT, child);
1290 			    Var_Set(cldir, lcwd, VAR_GLOBAL);
1291 			    snprintf(cldir, sizeof(cldir), LDIR_VNAME_FMT, child);
1292 			    Var_Set(cldir, latestdir, VAR_GLOBAL);
1293 #ifdef DEBUG_META_MODE
1294 			    if (DEBUG(META))
1295 				    fprintf(debug_file, "%s: %d: %d: cwd=%s lcwd=%s ldir=%s\n",
1296 					    fname, lineno,
1297 					    child, cwd, lcwd, latestdir);
1298 #endif
1299 			}
1300 		    }
1301 		    break;
1302 
1303 		case 'C':		/* Chdir */
1304 		    /* Update lcwd and latest directory. */
1305 		    strlcpy(latestdir, p, sizeof(latestdir));
1306 		    strlcpy(lcwd, p, sizeof(lcwd));
1307 		    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL);
1308 		    Var_Set(ldir_vname, lcwd, VAR_GLOBAL);
1309 #ifdef DEBUG_META_MODE
1310 		    if (DEBUG(META))
1311 			fprintf(debug_file, "%s: %d: cwd=%s ldir=%s\n", fname, lineno, cwd, lcwd);
1312 #endif
1313 		    break;
1314 
1315 		case 'M':		/* renaMe */
1316 		    /*
1317 		     * For 'M'oves we want to check
1318 		     * the src as for 'R'ead
1319 		     * and the target as for 'W'rite.
1320 		     */
1321 		    cp = p;		/* save this for a second */
1322 		    /* now get target */
1323 		    if (strsep(&p, " ") == NULL)
1324 			continue;
1325 		    CHECK_VALID_META(p);
1326 		    move_target = p;
1327 		    p = cp;
1328 		    /* 'L' and 'M' put single quotes around the args */
1329 		    DEQUOTE(p);
1330 		    DEQUOTE(move_target);
1331 		    /* FALLTHROUGH */
1332 		case 'D':		/* unlink */
1333 		    if (*p == '/' && !Lst_IsEmpty(missingFiles)) {
1334 			/* remove any missingFiles entries that match p */
1335 			if ((ln = Lst_Find(missingFiles, p,
1336 					   path_match)) != NULL) {
1337 			    LstNode nln;
1338 			    char *tp;
1339 
1340 			    do {
1341 				nln = Lst_FindFrom(missingFiles, Lst_Succ(ln),
1342 						   p, path_match);
1343 				tp = Lst_Datum(ln);
1344 				Lst_Remove(missingFiles, ln);
1345 				free(tp);
1346 			    } while ((ln = nln) != NULL);
1347 			}
1348 		    }
1349 		    if (buf[0] == 'M') {
1350 			/* the target of the mv is a file 'W'ritten */
1351 #ifdef DEBUG_META_MODE
1352 			if (DEBUG(META))
1353 			    fprintf(debug_file, "meta_oodate: M %s -> %s\n",
1354 				    p, move_target);
1355 #endif
1356 			p = move_target;
1357 			goto check_write;
1358 		    }
1359 		    break;
1360 		case 'L':		/* Link */
1361 		    /*
1362 		     * For 'L'inks check
1363 		     * the src as for 'R'ead
1364 		     * and the target as for 'W'rite.
1365 		     */
1366 		    link_src = p;
1367 		    /* now get target */
1368 		    if (strsep(&p, " ") == NULL)
1369 			continue;
1370 		    CHECK_VALID_META(p);
1371 		    /* 'L' and 'M' put single quotes around the args */
1372 		    DEQUOTE(p);
1373 		    DEQUOTE(link_src);
1374 #ifdef DEBUG_META_MODE
1375 		    if (DEBUG(META))
1376 			fprintf(debug_file, "meta_oodate: L %s -> %s\n",
1377 				link_src, p);
1378 #endif
1379 		    /* FALLTHROUGH */
1380 		case 'W':		/* Write */
1381 		check_write:
1382 		    /*
1383 		     * If a file we generated within our bailiwick
1384 		     * but outside of .OBJDIR is missing,
1385 		     * we need to do it again.
1386 		     */
1387 		    /* ignore non-absolute paths */
1388 		    if (*p != '/')
1389 			break;
1390 
1391 		    if (Lst_IsEmpty(metaBailiwick))
1392 			break;
1393 
1394 		    /* ignore cwd - normal dependencies handle those */
1395 		    if (strncmp(p, cwd, cwdlen) == 0)
1396 			break;
1397 
1398 		    if (!Lst_ForEach(metaBailiwick, prefix_match, p))
1399 			break;
1400 
1401 		    /* tmpdir might be within */
1402 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1403 			break;
1404 
1405 		    /* ignore anything containing the string "tmp" */
1406 		    if ((strstr("tmp", p)))
1407 			break;
1408 
1409 		    if ((link_src != NULL && cached_lstat(p, &fs) < 0) ||
1410 			(link_src == NULL && cached_stat(p, &fs) < 0)) {
1411 			if (!meta_ignore(gn, p)) {
1412 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1413 				Lst_AtEnd(missingFiles, bmake_strdup(p));
1414 			}
1415 		    }
1416 		    break;
1417 		check_link_src:
1418 		    p = link_src;
1419 		    link_src = NULL;
1420 #ifdef DEBUG_META_MODE
1421 		    if (DEBUG(META))
1422 			fprintf(debug_file, "meta_oodate: L src %s\n", p);
1423 #endif
1424 		    /* FALLTHROUGH */
1425 		case 'R':		/* Read */
1426 		case 'E':		/* Exec */
1427 		    /*
1428 		     * Check for runtime files that can't
1429 		     * be part of the dependencies because
1430 		     * they are _expected_ to change.
1431 		     */
1432 		    if (meta_ignore(gn, p))
1433 			break;
1434 
1435 		    /*
1436 		     * The rest of the record is the file name.
1437 		     * Check if it's not an absolute path.
1438 		     */
1439 		    {
1440 			char *sdirs[4];
1441 			char **sdp;
1442 			int sdx = 0;
1443 			int found = 0;
1444 
1445 			if (*p == '/') {
1446 			    sdirs[sdx++] = p; /* done */
1447 			} else {
1448 			    if (strcmp(".", p) == 0)
1449 				continue;  /* no point */
1450 
1451 			    /* Check vs latestdir */
1452 			    snprintf(fname1, sizeof(fname1), "%s/%s", latestdir, p);
1453 			    sdirs[sdx++] = fname1;
1454 
1455 			    if (strcmp(latestdir, lcwd) != 0) {
1456 				/* Check vs lcwd */
1457 				snprintf(fname2, sizeof(fname2), "%s/%s", lcwd, p);
1458 				sdirs[sdx++] = fname2;
1459 			    }
1460 			    if (strcmp(lcwd, cwd) != 0) {
1461 				/* Check vs cwd */
1462 				snprintf(fname3, sizeof(fname3), "%s/%s", cwd, p);
1463 				sdirs[sdx++] = fname3;
1464 			    }
1465 			}
1466 			sdirs[sdx++] = NULL;
1467 
1468 			for (sdp = sdirs; *sdp && !found; sdp++) {
1469 #ifdef DEBUG_META_MODE
1470 			    if (DEBUG(META))
1471 				fprintf(debug_file, "%s: %d: looking for: %s\n", fname, lineno, *sdp);
1472 #endif
1473 			    if (cached_stat(*sdp, &fs) == 0) {
1474 				found = 1;
1475 				p = *sdp;
1476 			    }
1477 			}
1478 			if (found) {
1479 #ifdef DEBUG_META_MODE
1480 			    if (DEBUG(META))
1481 				fprintf(debug_file, "%s: %d: found: %s\n", fname, lineno, p);
1482 #endif
1483 			    if (!S_ISDIR(fs.st_mode) &&
1484 				fs.st_mtime > gn->mtime) {
1485 				if (DEBUG(META))
1486 				    fprintf(debug_file, "%s: %d: file '%s' is newer than the target...\n", fname, lineno, p);
1487 				oodate = TRUE;
1488 			    } else if (S_ISDIR(fs.st_mode)) {
1489 				/* Update the latest directory. */
1490 				cached_realpath(p, latestdir);
1491 			    }
1492 			} else if (errno == ENOENT && *p == '/' &&
1493 				   strncmp(p, cwd, cwdlen) != 0) {
1494 			    /*
1495 			     * A referenced file outside of CWD is missing.
1496 			     * We cannot catch every eventuality here...
1497 			     */
1498 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1499 				    Lst_AtEnd(missingFiles, bmake_strdup(p));
1500 			}
1501 		    }
1502 		    if (buf[0] == 'E') {
1503 			/* previous latestdir is no longer relevant */
1504 			strlcpy(latestdir, lcwd, sizeof(latestdir));
1505 		    }
1506 		    break;
1507 		default:
1508 		    break;
1509 		}
1510 		if (!oodate && buf[0] == 'L' && link_src != NULL)
1511 		    goto check_link_src;
1512 	    } else if (strcmp(buf, "CMD") == 0) {
1513 		/*
1514 		 * Compare the current command with the one in the
1515 		 * meta data file.
1516 		 */
1517 		if (ln == NULL) {
1518 		    if (DEBUG(META))
1519 			fprintf(debug_file, "%s: %d: there were more build commands in the meta data file than there are now...\n", fname, lineno);
1520 		    oodate = TRUE;
1521 		} else {
1522 		    char *cmd = (char *)Lst_Datum(ln);
1523 		    Boolean hasOODATE = FALSE;
1524 
1525 		    if (strstr(cmd, "$?"))
1526 			hasOODATE = TRUE;
1527 		    else if ((cp = strstr(cmd, ".OODATE"))) {
1528 			/* check for $[{(].OODATE[:)}] */
1529 			if (cp > cmd + 2 && cp[-2] == '$')
1530 			    hasOODATE = TRUE;
1531 		    }
1532 		    if (hasOODATE) {
1533 			needOODATE = TRUE;
1534 			if (DEBUG(META))
1535 			    fprintf(debug_file, "%s: %d: cannot compare command using .OODATE\n", fname, lineno);
1536 		    }
1537 		    cmd = Var_Subst(cmd, gn, VARE_WANTRES|VARE_UNDEFERR);
1538 
1539 		    if ((cp = strchr(cmd, '\n'))) {
1540 			int n;
1541 
1542 			/*
1543 			 * This command contains newlines, we need to
1544 			 * fetch more from the .meta file before we
1545 			 * attempt a comparison.
1546 			 */
1547 			/* first put the newline back at buf[x - 1] */
1548 			buf[x - 1] = '\n';
1549 			do {
1550 			    /* now fetch the next line */
1551 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1552 				break;
1553 			    x = n;
1554 			    lineno++;
1555 			    if (buf[x - 1] != '\n') {
1556 				warnx("%s: %d: line truncated at %u", fname, lineno, x);
1557 				break;
1558 			    }
1559 			    cp = strchr(++cp, '\n');
1560 			} while (cp);
1561 			if (buf[x - 1] == '\n')
1562 			    buf[x - 1] = '\0';
1563 		    }
1564 		    if (p &&
1565 			!hasOODATE &&
1566 			!(gn->type & OP_NOMETA_CMP) &&
1567 			strcmp(p, cmd) != 0) {
1568 			if (DEBUG(META))
1569 			    fprintf(debug_file, "%s: %d: a build command has changed\n%s\nvs\n%s\n", fname, lineno, p, cmd);
1570 			if (!metaIgnoreCMDs)
1571 			    oodate = TRUE;
1572 		    }
1573 		    free(cmd);
1574 		    ln = Lst_Succ(ln);
1575 		}
1576 	    } else if (strcmp(buf, "CWD") == 0) {
1577 		/*
1578 		 * Check if there are extra commands now
1579 		 * that weren't in the meta data file.
1580 		 */
1581 		if (!oodate && ln != NULL) {
1582 		    if (DEBUG(META))
1583 			fprintf(debug_file, "%s: %d: there are extra build commands now that weren't in the meta data file\n", fname, lineno);
1584 		    oodate = TRUE;
1585 		}
1586 		CHECK_VALID_META(p);
1587 		if (strcmp(p, cwd) != 0) {
1588 		    if (DEBUG(META))
1589 			fprintf(debug_file, "%s: %d: the current working directory has changed from '%s' to '%s'\n", fname, lineno, p, curdir);
1590 		    oodate = TRUE;
1591 		}
1592 	    }
1593 	}
1594 
1595 	fclose(fp);
1596 	if (!Lst_IsEmpty(missingFiles)) {
1597 	    if (DEBUG(META))
1598 		fprintf(debug_file, "%s: missing files: %s...\n",
1599 			fname, (char *)Lst_Datum(Lst_First(missingFiles)));
1600 	    oodate = TRUE;
1601 	}
1602 	if (!oodate && !have_filemon && filemonMissing) {
1603 	    if (DEBUG(META))
1604 		fprintf(debug_file, "%s: missing filemon data\n", fname);
1605 	    oodate = TRUE;
1606 	}
1607     } else {
1608 	if (writeMeta && (metaMissing || (gn->type & OP_META))) {
1609 	    cp = NULL;
1610 
1611 	    /* if target is in .CURDIR we do not need a meta file */
1612 	    if (gn->path && (cp = strrchr(gn->path, '/')) && cp > gn->path) {
1613 		if (strncmp(curdir, gn->path, (cp - gn->path)) != 0) {
1614 		    cp = NULL;		/* not in .CURDIR */
1615 		}
1616 	    }
1617 	    if (!cp) {
1618 		if (DEBUG(META))
1619 		    fprintf(debug_file, "%s: required but missing\n", fname);
1620 		oodate = TRUE;
1621 		needOODATE = TRUE;	/* assume the worst */
1622 	    }
1623 	}
1624     }
1625 
1626     Lst_Destroy(missingFiles, (FreeProc *)free);
1627 
1628     if (oodate && needOODATE) {
1629 	/*
1630 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1631 	 * We have decided it is oodate, so .OODATE needs to be set.
1632 	 * All we can sanely do is set it to .ALLSRC.
1633 	 */
1634 	Var_Delete(OODATE, gn);
1635 	Var_Set(OODATE, Var_Value(ALLSRC, gn, &cp), gn);
1636 	bmake_free(cp);
1637     }
1638 
1639  oodate_out:
1640     for (i--; i >= 0; i--) {
1641 	bmake_free(pa[i]);
1642     }
1643     return oodate;
1644 }
1645 
1646 /* support for compat mode */
1647 
1648 static int childPipe[2];
1649 
1650 void
1651 meta_compat_start(void)
1652 {
1653 #ifdef USE_FILEMON_ONCE
1654     /*
1655      * We need to re-open filemon for each cmd.
1656      */
1657     BuildMon *pbm = &Mybm;
1658 
1659     if (pbm->mfp != NULL && useFilemon) {
1660 	meta_open_filemon(pbm);
1661     } else {
1662 	pbm->mon_fd = -1;
1663 	pbm->filemon = NULL;
1664     }
1665 #endif
1666     if (pipe(childPipe) < 0)
1667 	Punt("Cannot create pipe: %s", strerror(errno));
1668     /* Set close-on-exec flag for both */
1669     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1670     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1671 }
1672 
1673 void
1674 meta_compat_child(void)
1675 {
1676     meta_job_child(NULL);
1677     if (dup2(childPipe[1], 1) < 0 ||
1678 	dup2(1, 2) < 0) {
1679 	execError("dup2", "pipe");
1680 	_exit(1);
1681     }
1682 }
1683 
1684 void
1685 meta_compat_parent(pid_t child)
1686 {
1687     int outfd, metafd, maxfd, nfds;
1688     char buf[BUFSIZ+1];
1689     fd_set readfds;
1690 
1691     meta_job_parent(NULL, child);
1692     close(childPipe[1]);			/* child side */
1693     outfd = childPipe[0];
1694 #ifdef USE_FILEMON
1695     metafd = Mybm.filemon ? filemon_readfd(Mybm.filemon) : -1;
1696 #else
1697     metafd = -1;
1698 #endif
1699     maxfd = -1;
1700     if (outfd > maxfd)
1701 	    maxfd = outfd;
1702     if (metafd > maxfd)
1703 	    maxfd = metafd;
1704 
1705     while (outfd != -1 || metafd != -1) {
1706 	FD_ZERO(&readfds);
1707 	if (outfd != -1) {
1708 	    FD_SET(outfd, &readfds);
1709 	}
1710 	if (metafd != -1) {
1711 	    FD_SET(metafd, &readfds);
1712 	}
1713 	nfds = select(maxfd + 1, &readfds, NULL, NULL, NULL);
1714 	if (nfds == -1) {
1715 	    if (errno == EINTR)
1716 		continue;
1717 	    err(1, "select");
1718 	}
1719 
1720 	if (outfd != -1 && FD_ISSET(outfd, &readfds)) do {
1721 	    /* XXX this is not line-buffered */
1722 	    ssize_t nread = read(outfd, buf, sizeof(buf) - 1);
1723 	    if (nread == -1)
1724 		err(1, "read");
1725 	    if (nread == 0) {
1726 		close(outfd);
1727 		outfd = -1;
1728 		break;
1729 	    }
1730 	    fwrite(buf, 1, (size_t)nread, stdout);
1731 	    fflush(stdout);
1732 	    buf[nread] = '\0';
1733 	    meta_job_output(NULL, buf, "");
1734 	} while (0);
1735 	if (metafd != -1 && FD_ISSET(metafd, &readfds)) {
1736 	    if (meta_job_event(NULL) <= 0)
1737 		metafd = -1;
1738 	}
1739     }
1740 }
1741 
1742 #endif	/* USE_META */
1743