xref: /freebsd/contrib/bmake/meta.c (revision 2938ecc85c29202824e83d65af5c3a4fb7b3e5fb)
1 /*      $NetBSD: meta.c,v 1.81 2020/04/03 03:32:28 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 #ifdef HAVE_LIBGEN_H
40 #include <libgen.h>
41 #elif !defined(HAVE_DIRNAME)
42 char * dirname(char *);
43 #endif
44 #include <errno.h>
45 #if !defined(HAVE_CONFIG_H) || defined(HAVE_ERR_H)
46 #include <err.h>
47 #endif
48 
49 #include "make.h"
50 #include "job.h"
51 
52 #ifdef USE_FILEMON
53 #include "filemon/filemon.h"
54 #endif
55 
56 static BuildMon Mybm;			/* for compat */
57 static Lst metaBailiwick;		/* our scope of control */
58 static char *metaBailiwickStr;		/* string storage for the list */
59 static Lst metaIgnorePaths;		/* paths we deliberately ignore */
60 static char *metaIgnorePathsStr;	/* string storage for the list */
61 
62 #ifndef MAKE_META_IGNORE_PATHS
63 #define MAKE_META_IGNORE_PATHS ".MAKE.META.IGNORE_PATHS"
64 #endif
65 #ifndef MAKE_META_IGNORE_PATTERNS
66 #define MAKE_META_IGNORE_PATTERNS ".MAKE.META.IGNORE_PATTERNS"
67 #endif
68 #ifndef MAKE_META_IGNORE_FILTER
69 #define MAKE_META_IGNORE_FILTER ".MAKE.META.IGNORE_FILTER"
70 #endif
71 
72 Boolean useMeta = FALSE;
73 static Boolean useFilemon = FALSE;
74 static Boolean writeMeta = FALSE;
75 static Boolean metaMissing = FALSE;	/* oodate if missing */
76 static Boolean filemonMissing = FALSE;	/* oodate if missing */
77 static Boolean metaEnv = FALSE;		/* don't save env unless asked */
78 static Boolean metaVerbose = FALSE;
79 static Boolean metaIgnoreCMDs = FALSE;	/* ignore CMDs in .meta files */
80 static Boolean metaIgnorePatterns = FALSE; /* do we need to do pattern matches */
81 static Boolean metaIgnoreFilter = FALSE;   /* do we have more complex filtering? */
82 static Boolean metaCurdirOk = FALSE;	/* write .meta in .CURDIR Ok? */
83 static Boolean metaSilent = FALSE;	/* if we have a .meta be SILENT */
84 
85 extern Boolean forceJobs;
86 extern Boolean comatMake;
87 extern char    **environ;
88 
89 #define	MAKE_META_PREFIX	".MAKE.META.PREFIX"
90 
91 #ifndef N2U
92 # define N2U(n, u)   (((n) + ((u) - 1)) / (u))
93 #endif
94 #ifndef ROUNDUP
95 # define ROUNDUP(n, u)   (N2U((n), (u)) * (u))
96 #endif
97 
98 #if !defined(HAVE_STRSEP)
99 # define strsep(s, d) stresep((s), (d), 0)
100 #endif
101 
102 /*
103  * Filemon is a kernel module which snoops certain syscalls.
104  *
105  * C chdir
106  * E exec
107  * F [v]fork
108  * L [sym]link
109  * M rename
110  * R read
111  * W write
112  * S stat
113  *
114  * See meta_oodate below - we mainly care about 'E' and 'R'.
115  *
116  * We can still use meta mode without filemon, but
117  * the benefits are more limited.
118  */
119 #ifdef USE_FILEMON
120 
121 /*
122  * Open the filemon device.
123  */
124 static void
125 meta_open_filemon(BuildMon *pbm)
126 {
127     int dupfd;
128 
129     pbm->mon_fd = -1;
130     pbm->filemon = NULL;
131     if (!useFilemon || !pbm->mfp)
132 	return;
133 
134     pbm->filemon = filemon_open();
135     if (pbm->filemon == NULL) {
136 	useFilemon = FALSE;
137 	warn("Could not open filemon %s", filemon_path());
138 	return;
139     }
140 
141     /*
142      * We use a file outside of '.'
143      * to avoid a FreeBSD kernel bug where unlink invalidates
144      * cwd causing getcwd to do a lot more work.
145      * We only care about the descriptor.
146      */
147     pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL);
148     if ((dupfd = dup(pbm->mon_fd)) == -1) {
149 	err(1, "Could not dup filemon output!");
150     }
151     (void)fcntl(dupfd, F_SETFD, FD_CLOEXEC);
152     if (filemon_setfd(pbm->filemon, dupfd) == -1) {
153 	err(1, "Could not set filemon file descriptor!");
154     }
155     /* we don't need these once we exec */
156     (void)fcntl(pbm->mon_fd, F_SETFD, FD_CLOEXEC);
157 }
158 
159 /*
160  * Read the build monitor output file and write records to the target's
161  * metadata file.
162  */
163 static int
164 filemon_read(FILE *mfp, int fd)
165 {
166     char buf[BUFSIZ];
167     int n;
168     int error;
169 
170     /* Check if we're not writing to a meta data file.*/
171     if (mfp == NULL) {
172 	if (fd >= 0)
173 	    close(fd);			/* not interested */
174 	return 0;
175     }
176     /* rewind */
177     (void)lseek(fd, (off_t)0, SEEK_SET);
178 
179     error = 0;
180     fprintf(mfp, "\n-- filemon acquired metadata --\n");
181 
182     while ((n = read(fd, buf, sizeof(buf))) > 0) {
183 	if ((int)fwrite(buf, 1, n, mfp) < n)
184 	    error = EIO;
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(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 ${.MAKE}
312  * Bypassed if target is flagged .MAKE
313  */
314 static int
315 is_submake(void *cmdp, void *gnp)
316 {
317     static char *p_make = NULL;
318     static int p_len;
319     char  *cmd = cmdp;
320     GNode *gn = gnp;
321     char *mp = NULL;
322     char *cp;
323     char *cp2;
324     int rc = 0;				/* keep looking */
325 
326     if (!p_make) {
327 	p_make = Var_Value(".MAKE", gn, &cp);
328 	p_len = strlen(p_make);
329     }
330     cp = strchr(cmd, '$');
331     if ((cp)) {
332 	mp = Var_Subst(NULL, cmd, gn, VARF_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(NULL, cmd, mfp->gn, VARF_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,
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, 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(NULL, "${" MAKE_META_PREFIX "}", gn, VARF_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(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 	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, 0);
574 #endif
575 }
576 
577 
578 #define get_mode_bf(bf, token) \
579     if ((cp = strstr(make_mode, token))) \
580 	bf = boolValue(&cp[sizeof(token) - 1])
581 
582 /*
583  * Initialization we need after reading makefiles.
584  */
585 void
586 meta_mode_init(const char *make_mode)
587 {
588     static int once = 0;
589     char *cp;
590 
591     useMeta = TRUE;
592     useFilemon = TRUE;
593     writeMeta = TRUE;
594 
595     if (make_mode) {
596 	if (strstr(make_mode, "env"))
597 	    metaEnv = TRUE;
598 	if (strstr(make_mode, "verb"))
599 	    metaVerbose = TRUE;
600 	if (strstr(make_mode, "read"))
601 	    writeMeta = FALSE;
602 	if (strstr(make_mode, "nofilemon"))
603 	    useFilemon = FALSE;
604 	if (strstr(make_mode, "ignore-cmd"))
605 	    metaIgnoreCMDs = TRUE;
606 	if (useFilemon)
607 	    get_mode_bf(filemonMissing, "missing-filemon=");
608 	get_mode_bf(metaCurdirOk, "curdirok=");
609 	get_mode_bf(metaMissing, "missing-meta=");
610 	get_mode_bf(metaSilent, "silent=");
611     }
612     if (metaVerbose && !Var_Exists(MAKE_META_PREFIX, VAR_GLOBAL)) {
613 	/*
614 	 * The default value for MAKE_META_PREFIX
615 	 * prints the absolute path of the target.
616 	 * This works be cause :H will generate '.' if there is no /
617 	 * and :tA will resolve that to cwd.
618 	 */
619 	Var_Set(MAKE_META_PREFIX, "Building ${.TARGET:H:tA}/${.TARGET:T}", VAR_GLOBAL, 0);
620     }
621     if (once)
622 	return;
623     once = 1;
624     memset(&Mybm, 0, sizeof(Mybm));
625     /*
626      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
627      */
628     metaBailiwick = Lst_Init(FALSE);
629     metaBailiwickStr = Var_Subst(NULL, "${.MAKE.META.BAILIWICK:O:u:tA}",
630 	VAR_GLOBAL, VARF_WANTRES);
631     if (metaBailiwickStr) {
632 	str2Lst_Append(metaBailiwick, metaBailiwickStr, NULL);
633     }
634     /*
635      * We ignore any paths that start with ${.MAKE.META.IGNORE_PATHS}
636      */
637     metaIgnorePaths = Lst_Init(FALSE);
638     Var_Append(MAKE_META_IGNORE_PATHS,
639 	       "/dev /etc /proc /tmp /var/run /var/tmp ${TMPDIR}", VAR_GLOBAL);
640     metaIgnorePathsStr = Var_Subst(NULL,
641 		   "${" MAKE_META_IGNORE_PATHS ":O:u:tA}", VAR_GLOBAL,
642 		   VARF_WANTRES);
643     if (metaIgnorePathsStr) {
644 	str2Lst_Append(metaIgnorePaths, metaIgnorePathsStr, NULL);
645     }
646 
647     /*
648      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
649      */
650     cp = NULL;
651     if (Var_Value(MAKE_META_IGNORE_PATTERNS, VAR_GLOBAL, &cp)) {
652 	metaIgnorePatterns = TRUE;
653 	free(cp);
654     }
655     cp = NULL;
656     if (Var_Value(MAKE_META_IGNORE_FILTER, VAR_GLOBAL, &cp)) {
657 	metaIgnoreFilter = TRUE;
658 	free(cp);
659     }
660 }
661 
662 /*
663  * In each case below we allow for job==NULL
664  */
665 void
666 meta_job_start(Job *job, GNode *gn)
667 {
668     BuildMon *pbm;
669 
670     if (job != NULL) {
671 	pbm = &job->bm;
672     } else {
673 	pbm = &Mybm;
674     }
675     pbm->mfp = meta_create(pbm, gn);
676 #ifdef USE_FILEMON_ONCE
677     /* compat mode we open the filemon dev once per command */
678     if (job == NULL)
679 	return;
680 #endif
681 #ifdef USE_FILEMON
682     if (pbm->mfp != NULL && useFilemon) {
683 	meta_open_filemon(pbm);
684     } else {
685 	pbm->mon_fd = -1;
686 	pbm->filemon = NULL;
687     }
688 #endif
689 }
690 
691 /*
692  * The child calls this before doing anything.
693  * It does not disturb our state.
694  */
695 void
696 meta_job_child(Job *job)
697 {
698 #ifdef USE_FILEMON
699     BuildMon *pbm;
700 
701     if (job != NULL) {
702 	pbm = &job->bm;
703     } else {
704 	pbm = &Mybm;
705     }
706     if (pbm->mfp != NULL) {
707 	close(fileno(pbm->mfp));
708 	if (useFilemon && pbm->filemon) {
709 	    pid_t pid;
710 
711 	    pid = getpid();
712 	    if (filemon_setpid_child(pbm->filemon, pid) == -1) {
713 		err(1, "Could not set filemon pid!");
714 	    }
715 	}
716     }
717 #endif
718 }
719 
720 void
721 meta_job_parent(Job *job, pid_t pid)
722 {
723 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
724     BuildMon *pbm;
725 
726     if (job != NULL) {
727 	pbm = &job->bm;
728     } else {
729 	pbm = &Mybm;
730     }
731     if (useFilemon && pbm->filemon) {
732 	filemon_setpid_parent(pbm->filemon, pid);
733     }
734 #endif
735 }
736 
737 int
738 meta_job_fd(Job *job)
739 {
740 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
741     BuildMon *pbm;
742 
743     if (job != NULL) {
744 	pbm = &job->bm;
745     } else {
746 	pbm = &Mybm;
747     }
748     if (useFilemon && pbm->filemon) {
749 	return filemon_readfd(pbm->filemon);
750     }
751 #endif
752     return -1;
753 }
754 
755 int
756 meta_job_event(Job *job)
757 {
758 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
759     BuildMon *pbm;
760 
761     if (job != NULL) {
762 	pbm = &job->bm;
763     } else {
764 	pbm = &Mybm;
765     }
766     if (useFilemon && pbm->filemon) {
767 	return filemon_process(pbm->filemon);
768     }
769 #endif
770     return 0;
771 }
772 
773 void
774 meta_job_error(Job *job, GNode *gn, int flags, int status)
775 {
776     char cwd[MAXPATHLEN];
777     BuildMon *pbm;
778 
779     if (job != NULL) {
780 	pbm = &job->bm;
781 	if (!gn)
782 	    gn = job->node;
783     } else {
784 	pbm = &Mybm;
785     }
786     if (pbm->mfp != NULL) {
787 	fprintf(pbm->mfp, "\n*** Error code %d%s\n",
788 		status,
789 		(flags & JOB_IGNERR) ?
790 		"(ignored)" : "");
791     }
792     if (gn) {
793 	Var_Set(".ERROR_TARGET", gn->path ? gn->path : gn->name, VAR_GLOBAL, 0);
794     }
795     getcwd(cwd, sizeof(cwd));
796     Var_Set(".ERROR_CWD", cwd, VAR_GLOBAL, 0);
797     if (pbm->meta_fname[0]) {
798 	Var_Set(".ERROR_META_FILE", pbm->meta_fname, VAR_GLOBAL, 0);
799     }
800     meta_job_finish(job);
801 }
802 
803 void
804 meta_job_output(Job *job, char *cp, const char *nl)
805 {
806     BuildMon *pbm;
807 
808     if (job != NULL) {
809 	pbm = &job->bm;
810     } else {
811 	pbm = &Mybm;
812     }
813     if (pbm->mfp != NULL) {
814 	if (metaVerbose) {
815 	    static char *meta_prefix = NULL;
816 	    static int meta_prefix_len;
817 
818 	    if (!meta_prefix) {
819 		char *cp2;
820 
821 		meta_prefix = Var_Subst(NULL, "${" MAKE_META_PREFIX "}",
822 					VAR_GLOBAL, VARF_WANTRES);
823 		if ((cp2 = strchr(meta_prefix, '$')))
824 		    meta_prefix_len = cp2 - meta_prefix;
825 		else
826 		    meta_prefix_len = strlen(meta_prefix);
827 	    }
828 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
829 		cp = strchr(cp+1, '\n');
830 		if (!cp++)
831 		    return;
832 	    }
833 	}
834 	fprintf(pbm->mfp, "%s%s", cp, nl);
835     }
836 }
837 
838 int
839 meta_cmd_finish(void *pbmp)
840 {
841     int error = 0;
842     BuildMon *pbm = pbmp;
843 #ifdef USE_FILEMON
844     int x;
845 #endif
846 
847     if (!pbm)
848 	pbm = &Mybm;
849 
850 #ifdef USE_FILEMON
851     if (pbm->filemon) {
852 	while (filemon_process(pbm->filemon) > 0)
853 	    continue;
854 	if (filemon_close(pbm->filemon) == -1)
855 	    error = errno;
856 	x = filemon_read(pbm->mfp, pbm->mon_fd);
857 	if (error == 0 && x != 0)
858 	    error = x;
859 	pbm->mon_fd = -1;
860 	pbm->filemon = NULL;
861     } else
862 #endif
863 	fprintf(pbm->mfp, "\n");	/* ensure end with newline */
864     return error;
865 }
866 
867 int
868 meta_job_finish(Job *job)
869 {
870     BuildMon *pbm;
871     int error = 0;
872     int x;
873 
874     if (job != NULL) {
875 	pbm = &job->bm;
876     } else {
877 	pbm = &Mybm;
878     }
879     if (pbm->mfp != NULL) {
880 	error = meta_cmd_finish(pbm);
881 	x = fclose(pbm->mfp);
882 	if (error == 0 && x != 0)
883 	    error = errno;
884 	pbm->mfp = NULL;
885 	pbm->meta_fname[0] = '\0';
886     }
887     return error;
888 }
889 
890 void
891 meta_finish(void)
892 {
893     Lst_Destroy(metaBailiwick, NULL);
894     free(metaBailiwickStr);
895     Lst_Destroy(metaIgnorePaths, NULL);
896     free(metaIgnorePathsStr);
897 }
898 
899 /*
900  * Fetch a full line from fp - growing bufp if needed
901  * Return length in bufp.
902  */
903 static int
904 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
905 {
906     char *buf = *bufp;
907     size_t bufsz = *szp;
908     struct stat fs;
909     int x;
910 
911     if (fgets(&buf[o], bufsz - o, fp) != NULL) {
912     check_newline:
913 	x = o + strlen(&buf[o]);
914 	if (buf[x - 1] == '\n')
915 	    return x;
916 	/*
917 	 * We need to grow the buffer.
918 	 * The meta file can give us a clue.
919 	 */
920 	if (fstat(fileno(fp), &fs) == 0) {
921 	    size_t newsz;
922 	    char *p;
923 
924 	    newsz = ROUNDUP((fs.st_size / 2), BUFSIZ);
925 	    if (newsz <= bufsz)
926 		newsz = ROUNDUP(fs.st_size, BUFSIZ);
927 	    if (newsz <= bufsz)
928 		return x;		/* truncated */
929 	    if (DEBUG(META))
930 		fprintf(debug_file, "growing buffer %u -> %u\n",
931 			(unsigned)bufsz, (unsigned)newsz);
932 	    p = bmake_realloc(buf, newsz);
933 	    if (p) {
934 		*bufp = buf = p;
935 		*szp = bufsz = newsz;
936 		/* fetch the rest */
937 		if (!fgets(&buf[x], bufsz - x, fp))
938 		    return x;		/* truncated! */
939 		goto check_newline;
940 	    }
941 	}
942     }
943     return 0;
944 }
945 
946 /* Lst_ForEach wants 1 to stop search */
947 static int
948 prefix_match(void *p, void *q)
949 {
950     const char *prefix = p;
951     const char *path = q;
952     size_t n = strlen(prefix);
953 
954     return (0 == strncmp(path, prefix, n));
955 }
956 
957 /*
958  * looking for exact or prefix/ match to
959  * Lst_Find wants 0 to stop search
960  */
961 static int
962 path_match(const void *p, const void *q)
963 {
964     const char *prefix = q;
965     const char *path = p;
966     size_t n = strlen(prefix);
967     int rc;
968 
969     if ((rc = strncmp(path, prefix, n)) == 0) {
970 	switch (path[n]) {
971 	case '\0':
972 	case '/':
973 	    break;
974 	default:
975 	    rc = 1;
976 	    break;
977 	}
978     }
979     return rc;
980 }
981 
982 /* Lst_Find wants 0 to stop search */
983 static int
984 string_match(const void *p, const void *q)
985 {
986     const char *p1 = p;
987     const char *p2 = q;
988 
989     return strcmp(p1, p2);
990 }
991 
992 
993 static int
994 meta_ignore(GNode *gn, const char *p)
995 {
996     char fname[MAXPATHLEN];
997 
998     if (p == NULL)
999 	return TRUE;
1000 
1001     if (*p == '/') {
1002 	cached_realpath(p, fname); /* clean it up */
1003 	if (Lst_ForEach(metaIgnorePaths, prefix_match, fname)) {
1004 #ifdef DEBUG_META_MODE
1005 	    if (DEBUG(META))
1006 		fprintf(debug_file, "meta_oodate: ignoring path: %s\n",
1007 			p);
1008 #endif
1009 	    return TRUE;
1010 	}
1011     }
1012 
1013     if (metaIgnorePatterns) {
1014 	char *pm;
1015 
1016 	Var_Set(".p.", p, gn, 0);
1017 	pm = Var_Subst(NULL,
1018 		       "${" MAKE_META_IGNORE_PATTERNS ":@m@${.p.:M$m}@}",
1019 		       gn, VARF_WANTRES);
1020 	if (*pm) {
1021 #ifdef DEBUG_META_MODE
1022 	    if (DEBUG(META))
1023 		fprintf(debug_file, "meta_oodate: ignoring pattern: %s\n",
1024 			p);
1025 #endif
1026 	    free(pm);
1027 	    return TRUE;
1028 	}
1029 	free(pm);
1030     }
1031 
1032     if (metaIgnoreFilter) {
1033 	char *fm;
1034 
1035 	/* skip if filter result is empty */
1036 	snprintf(fname, sizeof(fname),
1037 		 "${%s:L:${%s:ts:}}",
1038 		 p, MAKE_META_IGNORE_FILTER);
1039 	fm = Var_Subst(NULL, fname, gn, VARF_WANTRES);
1040 	if (*fm == '\0') {
1041 #ifdef DEBUG_META_MODE
1042 	    if (DEBUG(META))
1043 		fprintf(debug_file, "meta_oodate: ignoring filtered: %s\n",
1044 			p);
1045 #endif
1046 	    free(fm);
1047 	    return TRUE;
1048 	}
1049 	free(fm);
1050     }
1051     return FALSE;
1052 }
1053 
1054 /*
1055  * When running with 'meta' functionality, a target can be out-of-date
1056  * if any of the references in its meta data file is more recent.
1057  * We have to track the latestdir on a per-process basis.
1058  */
1059 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
1060 #define LDIR_VNAME_FMT ".meta.%d.ldir"
1061 
1062 /*
1063  * It is possible that a .meta file is corrupted,
1064  * if we detect this we want to reproduce it.
1065  * Setting oodate TRUE will have that effect.
1066  */
1067 #define CHECK_VALID_META(p) if (!(p && *p)) { \
1068     warnx("%s: %d: malformed", fname, lineno); \
1069     oodate = TRUE; \
1070     continue; \
1071     }
1072 
1073 #define DEQUOTE(p) if (*p == '\'') {	\
1074     char *ep; \
1075     p++; \
1076     if ((ep = strchr(p, '\''))) \
1077 	*ep = '\0'; \
1078     }
1079 
1080 Boolean
1081 meta_oodate(GNode *gn, Boolean oodate)
1082 {
1083     static char *tmpdir = NULL;
1084     static char cwd[MAXPATHLEN];
1085     char lcwd_vname[64];
1086     char ldir_vname[64];
1087     char lcwd[MAXPATHLEN];
1088     char latestdir[MAXPATHLEN];
1089     char fname[MAXPATHLEN];
1090     char fname1[MAXPATHLEN];
1091     char fname2[MAXPATHLEN];
1092     char fname3[MAXPATHLEN];
1093     const char *dname;
1094     const char *tname;
1095     char *p;
1096     char *cp;
1097     char *link_src;
1098     char *move_target;
1099     static size_t cwdlen = 0;
1100     static size_t tmplen = 0;
1101     FILE *fp;
1102     Boolean needOODATE = FALSE;
1103     Lst missingFiles;
1104     char *pa[4];			/* >= possible uses */
1105     int i;
1106     int have_filemon = FALSE;
1107 
1108     if (oodate)
1109 	return oodate;		/* we're done */
1110 
1111     i = 0;
1112 
1113     dname = Var_Value(".OBJDIR", gn, &pa[i++]);
1114     tname = Var_Value(TARGET, gn, &pa[i++]);
1115 
1116     /* if this succeeds fname3 is realpath of dname */
1117     if (!meta_needed(gn, dname, fname3, FALSE))
1118 	goto oodate_out;
1119     dname = fname3;
1120 
1121     missingFiles = Lst_Init(FALSE);
1122 
1123     /*
1124      * We need to check if the target is out-of-date. This includes
1125      * checking if the expanded command has changed. This in turn
1126      * requires that all variables are set in the same way that they
1127      * would be if the target needs to be re-built.
1128      */
1129     Make_DoAllVar(gn);
1130 
1131     meta_name(fname, sizeof(fname), dname, tname, dname);
1132 
1133 #ifdef DEBUG_META_MODE
1134     if (DEBUG(META))
1135 	fprintf(debug_file, "meta_oodate: %s\n", fname);
1136 #endif
1137 
1138     if ((fp = fopen(fname, "r")) != NULL) {
1139 	static char *buf = NULL;
1140 	static size_t bufsz;
1141 	int lineno = 0;
1142 	int lastpid = 0;
1143 	int pid;
1144 	int x;
1145 	LstNode ln;
1146 	struct stat fs;
1147 
1148 	if (!buf) {
1149 	    bufsz = 8 * BUFSIZ;
1150 	    buf = bmake_malloc(bufsz);
1151 	}
1152 
1153 	if (!cwdlen) {
1154 	    if (getcwd(cwd, sizeof(cwd)) == NULL)
1155 		err(1, "Could not get current working directory");
1156 	    cwdlen = strlen(cwd);
1157 	}
1158 	strlcpy(lcwd, cwd, sizeof(lcwd));
1159 	strlcpy(latestdir, cwd, sizeof(latestdir));
1160 
1161 	if (!tmpdir) {
1162 	    tmpdir = getTmpdir();
1163 	    tmplen = strlen(tmpdir);
1164 	}
1165 
1166 	/* we want to track all the .meta we read */
1167 	Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
1168 
1169 	ln = Lst_First(gn->commands);
1170 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1171 	    lineno++;
1172 	    if (buf[x - 1] == '\n')
1173 		buf[x - 1] = '\0';
1174 	    else {
1175 		warnx("%s: %d: line truncated at %u", fname, lineno, x);
1176 		oodate = TRUE;
1177 		break;
1178 	    }
1179 	    link_src = NULL;
1180 	    move_target = NULL;
1181 	    /* Find the start of the build monitor section. */
1182 	    if (!have_filemon) {
1183 		if (strncmp(buf, "-- filemon", 10) == 0) {
1184 		    have_filemon = TRUE;
1185 		    continue;
1186 		}
1187 		if (strncmp(buf, "# buildmon", 10) == 0) {
1188 		    have_filemon = TRUE;
1189 		    continue;
1190 		}
1191 	    }
1192 
1193 	    /* Delimit the record type. */
1194 	    p = buf;
1195 #ifdef DEBUG_META_MODE
1196 	    if (DEBUG(META))
1197 		fprintf(debug_file, "%s: %d: %s\n", fname, lineno, buf);
1198 #endif
1199 	    strsep(&p, " ");
1200 	    if (have_filemon) {
1201 		/*
1202 		 * We are in the 'filemon' output section.
1203 		 * Each record from filemon follows the general form:
1204 		 *
1205 		 * <key> <pid> <data>
1206 		 *
1207 		 * Where:
1208 		 * <key> is a single letter, denoting the syscall.
1209 		 * <pid> is the process that made the syscall.
1210 		 * <data> is the arguments (of interest).
1211 		 */
1212 		switch(buf[0]) {
1213 		case '#':		/* comment */
1214 		case 'V':		/* version */
1215 		    break;
1216 		default:
1217 		    /*
1218 		     * We need to track pathnames per-process.
1219 		     *
1220 		     * Each process run by make, starts off in the 'CWD'
1221 		     * recorded in the .meta file, if it chdirs ('C')
1222 		     * elsewhere we need to track that - but only for
1223 		     * that process.  If it forks ('F'), we initialize
1224 		     * the child to have the same cwd as its parent.
1225 		     *
1226 		     * We also need to track the 'latestdir' of
1227 		     * interest.  This is usually the same as cwd, but
1228 		     * not if a process is reading directories.
1229 		     *
1230 		     * Each time we spot a different process ('pid')
1231 		     * we save the current value of 'latestdir' in a
1232 		     * variable qualified by 'lastpid', and
1233 		     * re-initialize 'latestdir' to any pre-saved
1234 		     * value for the current 'pid' and 'CWD' if none.
1235 		     */
1236 		    CHECK_VALID_META(p);
1237 		    pid = atoi(p);
1238 		    if (pid > 0 && pid != lastpid) {
1239 			char *ldir;
1240 			char *tp;
1241 
1242 			if (lastpid > 0) {
1243 			    /* We need to remember these. */
1244 			    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1245 			    Var_Set(ldir_vname, latestdir, VAR_GLOBAL, 0);
1246 			}
1247 			snprintf(lcwd_vname, sizeof(lcwd_vname), LCWD_VNAME_FMT, pid);
1248 			snprintf(ldir_vname, sizeof(ldir_vname), LDIR_VNAME_FMT, pid);
1249 			lastpid = pid;
1250 			ldir = Var_Value(ldir_vname, VAR_GLOBAL, &tp);
1251 			if (ldir) {
1252 			    strlcpy(latestdir, ldir, sizeof(latestdir));
1253 			    free(tp);
1254 			}
1255 			ldir = Var_Value(lcwd_vname, VAR_GLOBAL, &tp);
1256 			if (ldir) {
1257 			    strlcpy(lcwd, ldir, sizeof(lcwd));
1258 			    free(tp);
1259 			}
1260 		    }
1261 		    /* Skip past the pid. */
1262 		    if (strsep(&p, " ") == NULL)
1263 			continue;
1264 #ifdef DEBUG_META_MODE
1265 		    if (DEBUG(META))
1266 			    fprintf(debug_file, "%s: %d: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1267 				    fname, lineno,
1268 				    pid, buf[0], cwd, lcwd, latestdir);
1269 #endif
1270 		    break;
1271 		}
1272 
1273 		CHECK_VALID_META(p);
1274 
1275 		/* Process according to record type. */
1276 		switch (buf[0]) {
1277 		case 'X':		/* eXit */
1278 		    Var_Delete(lcwd_vname, VAR_GLOBAL);
1279 		    Var_Delete(ldir_vname, VAR_GLOBAL);
1280 		    lastpid = 0;	/* no need to save ldir_vname */
1281 		    break;
1282 
1283 		case 'F':		/* [v]Fork */
1284 		    {
1285 			char cldir[64];
1286 			int child;
1287 
1288 			child = atoi(p);
1289 			if (child > 0) {
1290 			    snprintf(cldir, sizeof(cldir), LCWD_VNAME_FMT, child);
1291 			    Var_Set(cldir, lcwd, VAR_GLOBAL, 0);
1292 			    snprintf(cldir, sizeof(cldir), LDIR_VNAME_FMT, child);
1293 			    Var_Set(cldir, latestdir, VAR_GLOBAL, 0);
1294 #ifdef DEBUG_META_MODE
1295 			    if (DEBUG(META))
1296 				    fprintf(debug_file, "%s: %d: %d: cwd=%s lcwd=%s ldir=%s\n",
1297 					    fname, lineno,
1298 					    child, cwd, lcwd, latestdir);
1299 #endif
1300 			}
1301 		    }
1302 		    break;
1303 
1304 		case 'C':		/* Chdir */
1305 		    /* Update lcwd and latest directory. */
1306 		    strlcpy(latestdir, p, sizeof(latestdir));
1307 		    strlcpy(lcwd, p, sizeof(lcwd));
1308 		    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1309 		    Var_Set(ldir_vname, lcwd, VAR_GLOBAL, 0);
1310 #ifdef DEBUG_META_MODE
1311 		    if (DEBUG(META))
1312 			fprintf(debug_file, "%s: %d: cwd=%s ldir=%s\n", fname, lineno, cwd, lcwd);
1313 #endif
1314 		    break;
1315 
1316 		case 'M':		/* renaMe */
1317 		    /*
1318 		     * For 'M'oves we want to check
1319 		     * the src as for 'R'ead
1320 		     * and the target as for 'W'rite.
1321 		     */
1322 		    cp = p;		/* save this for a second */
1323 		    /* now get target */
1324 		    if (strsep(&p, " ") == NULL)
1325 			continue;
1326 		    CHECK_VALID_META(p);
1327 		    move_target = p;
1328 		    p = cp;
1329 		    /* 'L' and 'M' put single quotes around the args */
1330 		    DEQUOTE(p);
1331 		    DEQUOTE(move_target);
1332 		    /* FALLTHROUGH */
1333 		case 'D':		/* unlink */
1334 		    if (*p == '/' && !Lst_IsEmpty(missingFiles)) {
1335 			/* remove any missingFiles entries that match p */
1336 			if ((ln = Lst_Find(missingFiles, p,
1337 					   path_match)) != NULL) {
1338 			    LstNode nln;
1339 			    char *tp;
1340 
1341 			    do {
1342 				nln = Lst_FindFrom(missingFiles, Lst_Succ(ln),
1343 						   p, path_match);
1344 				tp = Lst_Datum(ln);
1345 				Lst_Remove(missingFiles, ln);
1346 				free(tp);
1347 			    } while ((ln = nln) != NULL);
1348 			}
1349 		    }
1350 		    if (buf[0] == 'M') {
1351 			/* the target of the mv is a file 'W'ritten */
1352 #ifdef DEBUG_META_MODE
1353 			if (DEBUG(META))
1354 			    fprintf(debug_file, "meta_oodate: M %s -> %s\n",
1355 				    p, move_target);
1356 #endif
1357 			p = move_target;
1358 			goto check_write;
1359 		    }
1360 		    break;
1361 		case 'L':		/* Link */
1362 		    /*
1363 		     * For 'L'inks check
1364 		     * the src as for 'R'ead
1365 		     * and the target as for 'W'rite.
1366 		     */
1367 		    link_src = p;
1368 		    /* now get target */
1369 		    if (strsep(&p, " ") == NULL)
1370 			continue;
1371 		    CHECK_VALID_META(p);
1372 		    /* 'L' and 'M' put single quotes around the args */
1373 		    DEQUOTE(p);
1374 		    DEQUOTE(link_src);
1375 #ifdef DEBUG_META_MODE
1376 		    if (DEBUG(META))
1377 			fprintf(debug_file, "meta_oodate: L %s -> %s\n",
1378 				link_src, p);
1379 #endif
1380 		    /* FALLTHROUGH */
1381 		case 'W':		/* Write */
1382 		check_write:
1383 		    /*
1384 		     * If a file we generated within our bailiwick
1385 		     * but outside of .OBJDIR is missing,
1386 		     * we need to do it again.
1387 		     */
1388 		    /* ignore non-absolute paths */
1389 		    if (*p != '/')
1390 			break;
1391 
1392 		    if (Lst_IsEmpty(metaBailiwick))
1393 			break;
1394 
1395 		    /* ignore cwd - normal dependencies handle those */
1396 		    if (strncmp(p, cwd, cwdlen) == 0)
1397 			break;
1398 
1399 		    if (!Lst_ForEach(metaBailiwick, prefix_match, p))
1400 			break;
1401 
1402 		    /* tmpdir might be within */
1403 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1404 			break;
1405 
1406 		    /* ignore anything containing the string "tmp" */
1407 		    if ((strstr("tmp", p)))
1408 			break;
1409 
1410 		    if ((link_src != NULL && cached_lstat(p, &fs) < 0) ||
1411 			(link_src == NULL && cached_stat(p, &fs) < 0)) {
1412 			if (!meta_ignore(gn, p)) {
1413 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1414 				Lst_AtEnd(missingFiles, bmake_strdup(p));
1415 			}
1416 		    }
1417 		    break;
1418 		check_link_src:
1419 		    p = link_src;
1420 		    link_src = NULL;
1421 #ifdef DEBUG_META_MODE
1422 		    if (DEBUG(META))
1423 			fprintf(debug_file, "meta_oodate: L src %s\n", p);
1424 #endif
1425 		    /* FALLTHROUGH */
1426 		case 'R':		/* Read */
1427 		case 'E':		/* Exec */
1428 		    /*
1429 		     * Check for runtime files that can't
1430 		     * be part of the dependencies because
1431 		     * they are _expected_ to change.
1432 		     */
1433 		    if (meta_ignore(gn, p))
1434 			break;
1435 
1436 		    /*
1437 		     * The rest of the record is the file name.
1438 		     * Check if it's not an absolute path.
1439 		     */
1440 		    {
1441 			char *sdirs[4];
1442 			char **sdp;
1443 			int sdx = 0;
1444 			int found = 0;
1445 
1446 			if (*p == '/') {
1447 			    sdirs[sdx++] = p; /* done */
1448 			} else {
1449 			    if (strcmp(".", p) == 0)
1450 				continue;  /* no point */
1451 
1452 			    /* Check vs latestdir */
1453 			    snprintf(fname1, sizeof(fname1), "%s/%s", latestdir, p);
1454 			    sdirs[sdx++] = fname1;
1455 
1456 			    if (strcmp(latestdir, lcwd) != 0) {
1457 				/* Check vs lcwd */
1458 				snprintf(fname2, sizeof(fname2), "%s/%s", lcwd, p);
1459 				sdirs[sdx++] = fname2;
1460 			    }
1461 			    if (strcmp(lcwd, cwd) != 0) {
1462 				/* Check vs cwd */
1463 				snprintf(fname3, sizeof(fname3), "%s/%s", cwd, p);
1464 				sdirs[sdx++] = fname3;
1465 			    }
1466 			}
1467 			sdirs[sdx++] = NULL;
1468 
1469 			for (sdp = sdirs; *sdp && !found; sdp++) {
1470 #ifdef DEBUG_META_MODE
1471 			    if (DEBUG(META))
1472 				fprintf(debug_file, "%s: %d: looking for: %s\n", fname, lineno, *sdp);
1473 #endif
1474 			    if (cached_stat(*sdp, &fs) == 0) {
1475 				found = 1;
1476 				p = *sdp;
1477 			    }
1478 			}
1479 			if (found) {
1480 #ifdef DEBUG_META_MODE
1481 			    if (DEBUG(META))
1482 				fprintf(debug_file, "%s: %d: found: %s\n", fname, lineno, p);
1483 #endif
1484 			    if (!S_ISDIR(fs.st_mode) &&
1485 				fs.st_mtime > gn->mtime) {
1486 				if (DEBUG(META))
1487 				    fprintf(debug_file, "%s: %d: file '%s' is newer than the target...\n", fname, lineno, p);
1488 				oodate = TRUE;
1489 			    } else if (S_ISDIR(fs.st_mode)) {
1490 				/* Update the latest directory. */
1491 				cached_realpath(p, latestdir);
1492 			    }
1493 			} else if (errno == ENOENT && *p == '/' &&
1494 				   strncmp(p, cwd, cwdlen) != 0) {
1495 			    /*
1496 			     * A referenced file outside of CWD is missing.
1497 			     * We cannot catch every eventuality here...
1498 			     */
1499 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1500 				    Lst_AtEnd(missingFiles, bmake_strdup(p));
1501 			}
1502 		    }
1503 		    if (buf[0] == 'E') {
1504 			/* previous latestdir is no longer relevant */
1505 			strlcpy(latestdir, lcwd, sizeof(latestdir));
1506 		    }
1507 		    break;
1508 		default:
1509 		    break;
1510 		}
1511 		if (!oodate && buf[0] == 'L' && link_src != NULL)
1512 		    goto check_link_src;
1513 	    } else if (strcmp(buf, "CMD") == 0) {
1514 		/*
1515 		 * Compare the current command with the one in the
1516 		 * meta data file.
1517 		 */
1518 		if (ln == NULL) {
1519 		    if (DEBUG(META))
1520 			fprintf(debug_file, "%s: %d: there were more build commands in the meta data file than there are now...\n", fname, lineno);
1521 		    oodate = TRUE;
1522 		} else {
1523 		    char *cmd = (char *)Lst_Datum(ln);
1524 		    Boolean hasOODATE = FALSE;
1525 
1526 		    if (strstr(cmd, "$?"))
1527 			hasOODATE = TRUE;
1528 		    else if ((cp = strstr(cmd, ".OODATE"))) {
1529 			/* check for $[{(].OODATE[:)}] */
1530 			if (cp > cmd + 2 && cp[-2] == '$')
1531 			    hasOODATE = TRUE;
1532 		    }
1533 		    if (hasOODATE) {
1534 			needOODATE = TRUE;
1535 			if (DEBUG(META))
1536 			    fprintf(debug_file, "%s: %d: cannot compare command using .OODATE\n", fname, lineno);
1537 		    }
1538 		    cmd = Var_Subst(NULL, cmd, gn, VARF_WANTRES|VARF_UNDEFERR);
1539 
1540 		    if ((cp = strchr(cmd, '\n'))) {
1541 			int n;
1542 
1543 			/*
1544 			 * This command contains newlines, we need to
1545 			 * fetch more from the .meta file before we
1546 			 * attempt a comparison.
1547 			 */
1548 			/* first put the newline back at buf[x - 1] */
1549 			buf[x - 1] = '\n';
1550 			do {
1551 			    /* now fetch the next line */
1552 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1553 				break;
1554 			    x = n;
1555 			    lineno++;
1556 			    if (buf[x - 1] != '\n') {
1557 				warnx("%s: %d: line truncated at %u", fname, lineno, x);
1558 				break;
1559 			    }
1560 			    cp = strchr(++cp, '\n');
1561 			} while (cp);
1562 			if (buf[x - 1] == '\n')
1563 			    buf[x - 1] = '\0';
1564 		    }
1565 		    if (p &&
1566 			!hasOODATE &&
1567 			!(gn->type & OP_NOMETA_CMP) &&
1568 			strcmp(p, cmd) != 0) {
1569 			if (DEBUG(META))
1570 			    fprintf(debug_file, "%s: %d: a build command has changed\n%s\nvs\n%s\n", fname, lineno, p, cmd);
1571 			if (!metaIgnoreCMDs)
1572 			    oodate = TRUE;
1573 		    }
1574 		    free(cmd);
1575 		    ln = Lst_Succ(ln);
1576 		}
1577 	    } else if (strcmp(buf, "CWD") == 0) {
1578 		/*
1579 		 * Check if there are extra commands now
1580 		 * that weren't in the meta data file.
1581 		 */
1582 		if (!oodate && ln != NULL) {
1583 		    if (DEBUG(META))
1584 			fprintf(debug_file, "%s: %d: there are extra build commands now that weren't in the meta data file\n", fname, lineno);
1585 		    oodate = TRUE;
1586 		}
1587 		CHECK_VALID_META(p);
1588 		if (strcmp(p, cwd) != 0) {
1589 		    if (DEBUG(META))
1590 			fprintf(debug_file, "%s: %d: the current working directory has changed from '%s' to '%s'\n", fname, lineno, p, curdir);
1591 		    oodate = TRUE;
1592 		}
1593 	    }
1594 	}
1595 
1596 	fclose(fp);
1597 	if (!Lst_IsEmpty(missingFiles)) {
1598 	    if (DEBUG(META))
1599 		fprintf(debug_file, "%s: missing files: %s...\n",
1600 			fname, (char *)Lst_Datum(Lst_First(missingFiles)));
1601 	    oodate = TRUE;
1602 	}
1603 	if (!oodate && !have_filemon && filemonMissing) {
1604 	    if (DEBUG(META))
1605 		fprintf(debug_file, "%s: missing filemon data\n", fname);
1606 	    oodate = TRUE;
1607 	}
1608     } else {
1609 	if (writeMeta && metaMissing) {
1610 	    cp = NULL;
1611 
1612 	    /* if target is in .CURDIR we do not need a meta file */
1613 	    if (gn->path && (cp = strrchr(gn->path, '/')) && cp > gn->path) {
1614 		if (strncmp(curdir, gn->path, (cp - gn->path)) != 0) {
1615 		    cp = NULL;		/* not in .CURDIR */
1616 		}
1617 	    }
1618 	    if (!cp) {
1619 		if (DEBUG(META))
1620 		    fprintf(debug_file, "%s: required but missing\n", fname);
1621 		oodate = TRUE;
1622 		needOODATE = TRUE;	/* assume the worst */
1623 	    }
1624 	}
1625     }
1626 
1627     Lst_Destroy(missingFiles, (FreeProc *)free);
1628 
1629     if (oodate && needOODATE) {
1630 	/*
1631 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1632 	 * We have decided it is oodate, so .OODATE needs to be set.
1633 	 * All we can sanely do is set it to .ALLSRC.
1634 	 */
1635 	Var_Delete(OODATE, gn);
1636 	Var_Set(OODATE, Var_Value(ALLSRC, gn, &cp), gn, 0);
1637 	free(cp);
1638     }
1639 
1640  oodate_out:
1641     for (i--; i >= 0; i--) {
1642 	free(pa[i]);
1643     }
1644     return oodate;
1645 }
1646 
1647 /* support for compat mode */
1648 
1649 static int childPipe[2];
1650 
1651 void
1652 meta_compat_start(void)
1653 {
1654 #ifdef USE_FILEMON_ONCE
1655     /*
1656      * We need to re-open filemon for each cmd.
1657      */
1658     BuildMon *pbm = &Mybm;
1659 
1660     if (pbm->mfp != NULL && useFilemon) {
1661 	meta_open_filemon(pbm);
1662     } else {
1663 	pbm->mon_fd = -1;
1664 	pbm->filemon = NULL;
1665     }
1666 #endif
1667     if (pipe(childPipe) < 0)
1668 	Punt("Cannot create pipe: %s", strerror(errno));
1669     /* Set close-on-exec flag for both */
1670     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1671     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1672 }
1673 
1674 void
1675 meta_compat_child(void)
1676 {
1677     meta_job_child(NULL);
1678     if (dup2(childPipe[1], 1) < 0 ||
1679 	dup2(1, 2) < 0) {
1680 	execError("dup2", "pipe");
1681 	_exit(1);
1682     }
1683 }
1684 
1685 void
1686 meta_compat_parent(pid_t child)
1687 {
1688     int outfd, metafd, maxfd, nfds;
1689     char buf[BUFSIZ+1];
1690     fd_set readfds;
1691 
1692     meta_job_parent(NULL, child);
1693     close(childPipe[1]);			/* child side */
1694     outfd = childPipe[0];
1695 #ifdef USE_FILEMON
1696     metafd = Mybm.filemon ? filemon_readfd(Mybm.filemon) : -1;
1697 #else
1698     metafd = -1;
1699 #endif
1700     maxfd = -1;
1701     if (outfd > maxfd)
1702 	    maxfd = outfd;
1703     if (metafd > maxfd)
1704 	    maxfd = metafd;
1705 
1706     while (outfd != -1 || metafd != -1) {
1707 	FD_ZERO(&readfds);
1708 	if (outfd != -1) {
1709 	    FD_SET(outfd, &readfds);
1710 	}
1711 	if (metafd != -1) {
1712 	    FD_SET(metafd, &readfds);
1713 	}
1714 	nfds = select(maxfd + 1, &readfds, NULL, NULL, NULL);
1715 	if (nfds == -1) {
1716 	    if (errno == EINTR)
1717 		continue;
1718 	    err(1, "select");
1719 	}
1720 
1721 	if (outfd != -1 && FD_ISSET(outfd, &readfds)) do {
1722 	    /* XXX this is not line-buffered */
1723 	    ssize_t nread = read(outfd, buf, sizeof(buf) - 1);
1724 	    if (nread == -1)
1725 		err(1, "read");
1726 	    if (nread == 0) {
1727 		close(outfd);
1728 		outfd = -1;
1729 		break;
1730 	    }
1731 	    fwrite(buf, 1, (size_t)nread, stdout);
1732 	    fflush(stdout);
1733 	    buf[nread] = '\0';
1734 	    meta_job_output(NULL, buf, "");
1735 	} while (0);
1736 	if (metafd != -1 && FD_ISSET(metafd, &readfds)) {
1737 	    if (meta_job_event(NULL) <= 0)
1738 		metafd = -1;
1739 	}
1740     }
1741 }
1742 
1743 #endif	/* USE_META */
1744