xref: /freebsd/contrib/bmake/meta.c (revision cbd30a72ca196976c1c700400ecd424baa1b9c16)
1 /*      $NetBSD: meta.c,v 1.67 2016/08/17 15:52:42 sjg Exp $ */
2 
3 /*
4  * Implement 'meta' mode.
5  * Adapted from John Birrell's patches to FreeBSD make.
6  * --sjg
7  */
8 /*
9  * Copyright (c) 2009-2016, Juniper Networks, Inc.
10  * Portions Copyright (c) 2009, John Birrell.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 #if defined(USE_META)
34 
35 #ifdef HAVE_CONFIG_H
36 # include "config.h"
37 #endif
38 #include <sys/stat.h>
39 #include <sys/ioctl.h>
40 #ifdef HAVE_LIBGEN_H
41 #include <libgen.h>
42 #elif !defined(HAVE_DIRNAME)
43 char * dirname(char *);
44 #endif
45 #include <errno.h>
46 #if !defined(HAVE_CONFIG_H) || defined(HAVE_ERR_H)
47 #include <err.h>
48 #endif
49 
50 #include "make.h"
51 #include "job.h"
52 
53 #ifdef HAVE_FILEMON_H
54 # include <filemon.h>
55 #endif
56 #if !defined(USE_FILEMON) && defined(FILEMON_SET_FD)
57 # define USE_FILEMON
58 #endif
59 
60 static BuildMon Mybm;			/* for compat */
61 static Lst metaBailiwick;		/* our scope of control */
62 static char *metaBailiwickStr;		/* string storage for the list */
63 static Lst metaIgnorePaths;		/* paths we deliberately ignore */
64 static char *metaIgnorePathsStr;	/* string storage for the list */
65 
66 #ifndef MAKE_META_IGNORE_PATHS
67 #define MAKE_META_IGNORE_PATHS ".MAKE.META.IGNORE_PATHS"
68 #endif
69 #ifndef MAKE_META_IGNORE_PATTERNS
70 #define MAKE_META_IGNORE_PATTERNS ".MAKE.META.IGNORE_PATTERNS"
71 #endif
72 #ifndef MAKE_META_IGNORE_FILTER
73 #define MAKE_META_IGNORE_FILTER ".MAKE.META.IGNORE_FILTER"
74 #endif
75 
76 Boolean useMeta = FALSE;
77 static Boolean useFilemon = FALSE;
78 static Boolean writeMeta = FALSE;
79 static Boolean metaMissing = FALSE;	/* oodate if missing */
80 static Boolean filemonMissing = FALSE;	/* oodate if missing */
81 static Boolean metaEnv = FALSE;		/* don't save env unless asked */
82 static Boolean metaVerbose = FALSE;
83 static Boolean metaIgnoreCMDs = FALSE;	/* ignore CMDs in .meta files */
84 static Boolean metaIgnorePatterns = FALSE; /* do we need to do pattern matches */
85 static Boolean metaIgnoreFilter = FALSE;   /* do we have more complex filtering? */
86 static Boolean metaCurdirOk = FALSE;	/* write .meta in .CURDIR Ok? */
87 static Boolean metaSilent = FALSE;	/* if we have a .meta be SILENT */
88 
89 extern Boolean forceJobs;
90 extern Boolean comatMake;
91 extern char    **environ;
92 
93 #define	MAKE_META_PREFIX	".MAKE.META.PREFIX"
94 
95 #ifndef N2U
96 # define N2U(n, u)   (((n) + ((u) - 1)) / (u))
97 #endif
98 #ifndef ROUNDUP
99 # define ROUNDUP(n, u)   (N2U((n), (u)) * (u))
100 #endif
101 
102 #if !defined(HAVE_STRSEP)
103 # define strsep(s, d) stresep((s), (d), 0)
104 #endif
105 
106 /*
107  * Filemon is a kernel module which snoops certain syscalls.
108  *
109  * C chdir
110  * E exec
111  * F [v]fork
112  * L [sym]link
113  * M rename
114  * R read
115  * W write
116  * S stat
117  *
118  * See meta_oodate below - we mainly care about 'E' and 'R'.
119  *
120  * We can still use meta mode without filemon, but
121  * the benefits are more limited.
122  */
123 #ifdef USE_FILEMON
124 # ifndef _PATH_FILEMON
125 #   define _PATH_FILEMON "/dev/filemon"
126 # endif
127 
128 /*
129  * Open the filemon device.
130  */
131 static void
132 filemon_open(BuildMon *pbm)
133 {
134     int retry;
135 
136     pbm->mon_fd = pbm->filemon_fd = -1;
137     if (!useFilemon)
138 	return;
139 
140     for (retry = 5; retry >= 0; retry--) {
141 	if ((pbm->filemon_fd = open(_PATH_FILEMON, O_RDWR)) >= 0)
142 	    break;
143     }
144 
145     if (pbm->filemon_fd < 0) {
146 	useFilemon = FALSE;
147 	warn("Could not open %s", _PATH_FILEMON);
148 	return;
149     }
150 
151     /*
152      * We use a file outside of '.'
153      * to avoid a FreeBSD kernel bug where unlink invalidates
154      * cwd causing getcwd to do a lot more work.
155      * We only care about the descriptor.
156      */
157     pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL);
158     if (ioctl(pbm->filemon_fd, FILEMON_SET_FD, &pbm->mon_fd) < 0) {
159 	err(1, "Could not set filemon file descriptor!");
160     }
161     /* we don't need these once we exec */
162     (void)fcntl(pbm->mon_fd, F_SETFD, FD_CLOEXEC);
163     (void)fcntl(pbm->filemon_fd, F_SETFD, FD_CLOEXEC);
164 }
165 
166 /*
167  * Read the build monitor output file and write records to the target's
168  * metadata file.
169  */
170 static int
171 filemon_read(FILE *mfp, int fd)
172 {
173     char buf[BUFSIZ];
174     int n;
175     int error;
176 
177     /* Check if we're not writing to a meta data file.*/
178     if (mfp == NULL) {
179 	if (fd >= 0)
180 	    close(fd);			/* not interested */
181 	return 0;
182     }
183     /* rewind */
184     (void)lseek(fd, (off_t)0, SEEK_SET);
185 
186     error = 0;
187     fprintf(mfp, "\n-- filemon acquired metadata --\n");
188 
189     while ((n = read(fd, buf, sizeof(buf))) > 0) {
190 	if ((int)fwrite(buf, 1, n, mfp) < n)
191 	    error = EIO;
192     }
193     fflush(mfp);
194     if (close(fd) < 0)
195 	error = errno;
196     return error;
197 }
198 #endif
199 
200 /*
201  * when realpath() fails,
202  * we use this, to clean up ./ and ../
203  */
204 static void
205 eat_dots(char *buf, size_t bufsz, int dots)
206 {
207     char *cp;
208     char *cp2;
209     const char *eat;
210     size_t eatlen;
211 
212     switch (dots) {
213     case 1:
214 	eat = "/./";
215 	eatlen = 2;
216 	break;
217     case 2:
218 	eat = "/../";
219 	eatlen = 3;
220 	break;
221     default:
222 	return;
223     }
224 
225     do {
226 	cp = strstr(buf, eat);
227 	if (cp) {
228 	    cp2 = cp + eatlen;
229 	    if (dots == 2 && cp > buf) {
230 		do {
231 		    cp--;
232 		} while (cp > buf && *cp != '/');
233 	    }
234 	    if (*cp == '/') {
235 		strlcpy(cp, cp2, bufsz - (cp - buf));
236 	    } else {
237 		return;			/* can't happen? */
238 	    }
239 	}
240     } while (cp);
241 }
242 
243 static char *
244 meta_name(char *mname, size_t mnamelen,
245 	  const char *dname,
246 	  const char *tname,
247 	  const char *cwd)
248 {
249     char buf[MAXPATHLEN];
250     char *rp;
251     char *cp;
252     char *tp;
253 
254     /*
255      * Weed out relative paths from the target file name.
256      * We have to be careful though since if target is a
257      * symlink, the result will be unstable.
258      * So we use realpath() just to get the dirname, and leave the
259      * basename as given to us.
260      */
261     if ((cp = strrchr(tname, '/'))) {
262 	if (cached_realpath(tname, buf)) {
263 	    if ((rp = strrchr(buf, '/'))) {
264 		rp++;
265 		cp++;
266 		if (strcmp(cp, rp) != 0)
267 		    strlcpy(rp, cp, sizeof(buf) - (rp - buf));
268 	    }
269 	    tname = buf;
270 	} else {
271 	    /*
272 	     * We likely have a directory which is about to be made.
273 	     * We pretend realpath() succeeded, to have a chance
274 	     * of generating the same meta file name that we will
275 	     * next time through.
276 	     */
277 	    if (tname[0] == '/') {
278 		strlcpy(buf, tname, sizeof(buf));
279 	    } else {
280 		snprintf(buf, sizeof(buf), "%s/%s", cwd, tname);
281 	    }
282 	    eat_dots(buf, sizeof(buf), 1);	/* ./ */
283 	    eat_dots(buf, sizeof(buf), 2);	/* ../ */
284 	    tname = buf;
285 	}
286     }
287     /* on some systems dirname may modify its arg */
288     tp = bmake_strdup(tname);
289     if (strcmp(dname, dirname(tp)) == 0)
290 	snprintf(mname, mnamelen, "%s.meta", tname);
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[4];				/* >= 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 
525     if (metaEnv) {
526 	for (ptr = environ; *ptr != NULL; ptr++)
527 	    fprintf(mf.fp, "ENV %s\n", *ptr);
528     }
529 
530     fprintf(mf.fp, "-- command output --\n");
531     fflush(mf.fp);
532 
533     Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
534     Var_Append(".MAKE.META.CREATED", fname, VAR_GLOBAL);
535 
536     gn->type |= OP_META;		/* in case anyone wants to know */
537     if (metaSilent) {
538 	    gn->type |= OP_SILENT;
539     }
540  out:
541     for (i--; i >= 0; i--) {
542 	free(p[i]);
543     }
544 
545     return (mf.fp);
546 }
547 
548 static Boolean
549 boolValue(char *s)
550 {
551     switch(*s) {
552     case '0':
553     case 'N':
554     case 'n':
555     case 'F':
556     case 'f':
557 	return FALSE;
558     }
559     return TRUE;
560 }
561 
562 /*
563  * Initialization we need before reading makefiles.
564  */
565 void
566 meta_init(void)
567 {
568 #ifdef USE_FILEMON
569 	/* this allows makefiles to test if we have filemon support */
570 	Var_Set(".MAKE.PATH_FILEMON", _PATH_FILEMON, VAR_GLOBAL, 0);
571 #endif
572 }
573 
574 
575 #define get_mode_bf(bf, token) \
576     if ((cp = strstr(make_mode, token))) \
577 	bf = boolValue(&cp[sizeof(token) - 1])
578 
579 /*
580  * Initialization we need after reading makefiles.
581  */
582 void
583 meta_mode_init(const char *make_mode)
584 {
585     static int once = 0;
586     char *cp;
587 
588     useMeta = TRUE;
589     useFilemon = TRUE;
590     writeMeta = TRUE;
591 
592     if (make_mode) {
593 	if (strstr(make_mode, "env"))
594 	    metaEnv = TRUE;
595 	if (strstr(make_mode, "verb"))
596 	    metaVerbose = TRUE;
597 	if (strstr(make_mode, "read"))
598 	    writeMeta = FALSE;
599 	if (strstr(make_mode, "nofilemon"))
600 	    useFilemon = FALSE;
601 	if (strstr(make_mode, "ignore-cmd"))
602 	    metaIgnoreCMDs = TRUE;
603 	if (useFilemon)
604 	    get_mode_bf(filemonMissing, "missing-filemon=");
605 	get_mode_bf(metaCurdirOk, "curdirok=");
606 	get_mode_bf(metaMissing, "missing-meta=");
607 	get_mode_bf(metaSilent, "silent=");
608     }
609     if (metaVerbose && !Var_Exists(MAKE_META_PREFIX, VAR_GLOBAL)) {
610 	/*
611 	 * The default value for MAKE_META_PREFIX
612 	 * prints the absolute path of the target.
613 	 * This works be cause :H will generate '.' if there is no /
614 	 * and :tA will resolve that to cwd.
615 	 */
616 	Var_Set(MAKE_META_PREFIX, "Building ${.TARGET:H:tA}/${.TARGET:T}", VAR_GLOBAL, 0);
617     }
618     if (once)
619 	return;
620     once = 1;
621     memset(&Mybm, 0, sizeof(Mybm));
622     /*
623      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
624      */
625     metaBailiwick = Lst_Init(FALSE);
626     metaBailiwickStr = Var_Subst(NULL, "${.MAKE.META.BAILIWICK:O:u:tA}",
627 	VAR_GLOBAL, VARF_WANTRES);
628     if (metaBailiwickStr) {
629 	str2Lst_Append(metaBailiwick, metaBailiwickStr, NULL);
630     }
631     /*
632      * We ignore any paths that start with ${.MAKE.META.IGNORE_PATHS}
633      */
634     metaIgnorePaths = Lst_Init(FALSE);
635     Var_Append(MAKE_META_IGNORE_PATHS,
636 	       "/dev /etc /proc /tmp /var/run /var/tmp ${TMPDIR}", VAR_GLOBAL);
637     metaIgnorePathsStr = Var_Subst(NULL,
638 		   "${" MAKE_META_IGNORE_PATHS ":O:u:tA}", VAR_GLOBAL,
639 		   VARF_WANTRES);
640     if (metaIgnorePathsStr) {
641 	str2Lst_Append(metaIgnorePaths, metaIgnorePathsStr, NULL);
642     }
643 
644     /*
645      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
646      */
647     cp = NULL;
648     if (Var_Value(MAKE_META_IGNORE_PATTERNS, VAR_GLOBAL, &cp)) {
649 	metaIgnorePatterns = TRUE;
650 	free(cp);
651     }
652     cp = NULL;
653     if (Var_Value(MAKE_META_IGNORE_FILTER, VAR_GLOBAL, &cp)) {
654 	metaIgnoreFilter = TRUE;
655 	free(cp);
656     }
657 }
658 
659 /*
660  * In each case below we allow for job==NULL
661  */
662 void
663 meta_job_start(Job *job, GNode *gn)
664 {
665     BuildMon *pbm;
666 
667     if (job != NULL) {
668 	pbm = &job->bm;
669     } else {
670 	pbm = &Mybm;
671     }
672     pbm->mfp = meta_create(pbm, gn);
673 #ifdef USE_FILEMON_ONCE
674     /* compat mode we open the filemon dev once per command */
675     if (job == NULL)
676 	return;
677 #endif
678 #ifdef USE_FILEMON
679     if (pbm->mfp != NULL && useFilemon) {
680 	filemon_open(pbm);
681     } else {
682 	pbm->mon_fd = pbm->filemon_fd = -1;
683     }
684 #endif
685 }
686 
687 /*
688  * The child calls this before doing anything.
689  * It does not disturb our state.
690  */
691 void
692 meta_job_child(Job *job)
693 {
694 #ifdef USE_FILEMON
695     BuildMon *pbm;
696 
697     if (job != NULL) {
698 	pbm = &job->bm;
699     } else {
700 	pbm = &Mybm;
701     }
702     if (pbm->mfp != NULL) {
703 	close(fileno(pbm->mfp));
704 	if (useFilemon) {
705 	    pid_t pid;
706 
707 	    pid = getpid();
708 	    if (ioctl(pbm->filemon_fd, FILEMON_SET_PID, &pid) < 0) {
709 		err(1, "Could not set filemon pid!");
710 	    }
711 	}
712     }
713 #endif
714 }
715 
716 void
717 meta_job_error(Job *job, GNode *gn, int flags, int status)
718 {
719     char cwd[MAXPATHLEN];
720     BuildMon *pbm;
721 
722     if (job != NULL) {
723 	pbm = &job->bm;
724 	if (!gn)
725 	    gn = job->node;
726     } else {
727 	pbm = &Mybm;
728     }
729     if (pbm->mfp != NULL) {
730 	fprintf(pbm->mfp, "*** Error code %d%s\n",
731 		status,
732 		(flags & JOB_IGNERR) ?
733 		"(ignored)" : "");
734     }
735     if (gn) {
736 	Var_Set(".ERROR_TARGET", gn->path ? gn->path : gn->name, VAR_GLOBAL, 0);
737     }
738     getcwd(cwd, sizeof(cwd));
739     Var_Set(".ERROR_CWD", cwd, VAR_GLOBAL, 0);
740     if (pbm->meta_fname[0]) {
741 	Var_Set(".ERROR_META_FILE", pbm->meta_fname, VAR_GLOBAL, 0);
742     }
743     meta_job_finish(job);
744 }
745 
746 void
747 meta_job_output(Job *job, char *cp, const char *nl)
748 {
749     BuildMon *pbm;
750 
751     if (job != NULL) {
752 	pbm = &job->bm;
753     } else {
754 	pbm = &Mybm;
755     }
756     if (pbm->mfp != NULL) {
757 	if (metaVerbose) {
758 	    static char *meta_prefix = NULL;
759 	    static int meta_prefix_len;
760 
761 	    if (!meta_prefix) {
762 		char *cp2;
763 
764 		meta_prefix = Var_Subst(NULL, "${" MAKE_META_PREFIX "}",
765 					VAR_GLOBAL, VARF_WANTRES);
766 		if ((cp2 = strchr(meta_prefix, '$')))
767 		    meta_prefix_len = cp2 - meta_prefix;
768 		else
769 		    meta_prefix_len = strlen(meta_prefix);
770 	    }
771 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
772 		cp = strchr(cp+1, '\n');
773 		if (!cp++)
774 		    return;
775 	    }
776 	}
777 	fprintf(pbm->mfp, "%s%s", cp, nl);
778     }
779 }
780 
781 int
782 meta_cmd_finish(void *pbmp)
783 {
784     int error = 0;
785 #ifdef USE_FILEMON
786     BuildMon *pbm = pbmp;
787     int x;
788 
789     if (!pbm)
790 	pbm = &Mybm;
791 
792     if (pbm->filemon_fd >= 0) {
793 	if (close(pbm->filemon_fd) < 0)
794 	    error = errno;
795 	x = filemon_read(pbm->mfp, pbm->mon_fd);
796 	if (error == 0 && x != 0)
797 	    error = x;
798 	pbm->filemon_fd = pbm->mon_fd = -1;
799     }
800 #endif
801     return error;
802 }
803 
804 int
805 meta_job_finish(Job *job)
806 {
807     BuildMon *pbm;
808     int error = 0;
809     int x;
810 
811     if (job != NULL) {
812 	pbm = &job->bm;
813     } else {
814 	pbm = &Mybm;
815     }
816     if (pbm->mfp != NULL) {
817 	error = meta_cmd_finish(pbm);
818 	x = fclose(pbm->mfp);
819 	if (error == 0 && x != 0)
820 	    error = errno;
821 	pbm->mfp = NULL;
822 	pbm->meta_fname[0] = '\0';
823     }
824     return error;
825 }
826 
827 void
828 meta_finish(void)
829 {
830     Lst_Destroy(metaBailiwick, NULL);
831     free(metaBailiwickStr);
832     Lst_Destroy(metaIgnorePaths, NULL);
833     free(metaIgnorePathsStr);
834 }
835 
836 /*
837  * Fetch a full line from fp - growing bufp if needed
838  * Return length in bufp.
839  */
840 static int
841 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
842 {
843     char *buf = *bufp;
844     size_t bufsz = *szp;
845     struct stat fs;
846     int x;
847 
848     if (fgets(&buf[o], bufsz - o, fp) != NULL) {
849     check_newline:
850 	x = o + strlen(&buf[o]);
851 	if (buf[x - 1] == '\n')
852 	    return x;
853 	/*
854 	 * We need to grow the buffer.
855 	 * The meta file can give us a clue.
856 	 */
857 	if (fstat(fileno(fp), &fs) == 0) {
858 	    size_t newsz;
859 	    char *p;
860 
861 	    newsz = ROUNDUP((fs.st_size / 2), BUFSIZ);
862 	    if (newsz <= bufsz)
863 		newsz = ROUNDUP(fs.st_size, BUFSIZ);
864 	    if (DEBUG(META))
865 		fprintf(debug_file, "growing buffer %u -> %u\n",
866 			(unsigned)bufsz, (unsigned)newsz);
867 	    p = bmake_realloc(buf, newsz);
868 	    if (p) {
869 		*bufp = buf = p;
870 		*szp = bufsz = newsz;
871 		/* fetch the rest */
872 		if (!fgets(&buf[x], bufsz - x, fp))
873 		    return x;		/* truncated! */
874 		goto check_newline;
875 	    }
876 	}
877     }
878     return 0;
879 }
880 
881 /* Lst_ForEach wants 1 to stop search */
882 static int
883 prefix_match(void *p, void *q)
884 {
885     const char *prefix = p;
886     const char *path = q;
887     size_t n = strlen(prefix);
888 
889     return (0 == strncmp(path, prefix, n));
890 }
891 
892 /*
893  * looking for exact or prefix/ match to
894  * Lst_Find wants 0 to stop search
895  */
896 static int
897 path_match(const void *p, const void *q)
898 {
899     const char *prefix = q;
900     const char *path = p;
901     size_t n = strlen(prefix);
902     int rc;
903 
904     if ((rc = strncmp(path, prefix, n)) == 0) {
905 	switch (path[n]) {
906 	case '\0':
907 	case '/':
908 	    break;
909 	default:
910 	    rc = 1;
911 	    break;
912 	}
913     }
914     return rc;
915 }
916 
917 /* Lst_Find wants 0 to stop search */
918 static int
919 string_match(const void *p, const void *q)
920 {
921     const char *p1 = p;
922     const char *p2 = q;
923 
924     return strcmp(p1, p2);
925 }
926 
927 
928 static int
929 meta_ignore(GNode *gn, const char *p)
930 {
931     char fname[MAXPATHLEN];
932 
933     if (p == NULL)
934 	return TRUE;
935 
936     if (*p == '/') {
937 	cached_realpath(p, fname); /* clean it up */
938 	if (Lst_ForEach(metaIgnorePaths, prefix_match, fname)) {
939 #ifdef DEBUG_META_MODE
940 	    if (DEBUG(META))
941 		fprintf(debug_file, "meta_oodate: ignoring path: %s\n",
942 			p);
943 #endif
944 	    return TRUE;
945 	}
946     }
947 
948     if (metaIgnorePatterns) {
949 	char *pm;
950 
951 	snprintf(fname, sizeof(fname),
952 		 "${%s:@m@${%s:L:M$m}@}",
953 		 MAKE_META_IGNORE_PATTERNS, p);
954 	pm = Var_Subst(NULL, fname, gn, VARF_WANTRES);
955 	if (*pm) {
956 #ifdef DEBUG_META_MODE
957 	    if (DEBUG(META))
958 		fprintf(debug_file, "meta_oodate: ignoring pattern: %s\n",
959 			p);
960 #endif
961 	    free(pm);
962 	    return TRUE;
963 	}
964 	free(pm);
965     }
966 
967     if (metaIgnoreFilter) {
968 	char *fm;
969 
970 	/* skip if filter result is empty */
971 	snprintf(fname, sizeof(fname),
972 		 "${%s:L:${%s:ts:}}",
973 		 p, MAKE_META_IGNORE_FILTER);
974 	fm = Var_Subst(NULL, fname, gn, VARF_WANTRES);
975 	if (*fm == '\0') {
976 #ifdef DEBUG_META_MODE
977 	    if (DEBUG(META))
978 		fprintf(debug_file, "meta_oodate: ignoring filtered: %s\n",
979 			p);
980 #endif
981 	    free(fm);
982 	    return TRUE;
983 	}
984 	free(fm);
985     }
986     return FALSE;
987 }
988 
989 /*
990  * When running with 'meta' functionality, a target can be out-of-date
991  * if any of the references in its meta data file is more recent.
992  * We have to track the latestdir on a per-process basis.
993  */
994 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
995 #define LDIR_VNAME_FMT ".meta.%d.ldir"
996 
997 /*
998  * It is possible that a .meta file is corrupted,
999  * if we detect this we want to reproduce it.
1000  * Setting oodate TRUE will have that effect.
1001  */
1002 #define CHECK_VALID_META(p) if (!(p && *p)) { \
1003     warnx("%s: %d: malformed", fname, lineno); \
1004     oodate = TRUE; \
1005     continue; \
1006     }
1007 
1008 #define DEQUOTE(p) if (*p == '\'') {	\
1009     char *ep; \
1010     p++; \
1011     if ((ep = strchr(p, '\''))) \
1012 	*ep = '\0'; \
1013     }
1014 
1015 Boolean
1016 meta_oodate(GNode *gn, Boolean oodate)
1017 {
1018     static char *tmpdir = NULL;
1019     static char cwd[MAXPATHLEN];
1020     char lcwd_vname[64];
1021     char ldir_vname[64];
1022     char lcwd[MAXPATHLEN];
1023     char latestdir[MAXPATHLEN];
1024     char fname[MAXPATHLEN];
1025     char fname1[MAXPATHLEN];
1026     char fname2[MAXPATHLEN];
1027     char fname3[MAXPATHLEN];
1028     const char *dname;
1029     const char *tname;
1030     char *p;
1031     char *cp;
1032     char *link_src;
1033     char *move_target;
1034     static size_t cwdlen = 0;
1035     static size_t tmplen = 0;
1036     FILE *fp;
1037     Boolean needOODATE = FALSE;
1038     Lst missingFiles;
1039     char *pa[4];			/* >= possible uses */
1040     int i;
1041     int have_filemon = FALSE;
1042 
1043     if (oodate)
1044 	return oodate;		/* we're done */
1045 
1046     i = 0;
1047 
1048     dname = Var_Value(".OBJDIR", gn, &pa[i++]);
1049     tname = Var_Value(TARGET, gn, &pa[i++]);
1050 
1051     /* if this succeeds fname3 is realpath of dname */
1052     if (!meta_needed(gn, dname, fname3, FALSE))
1053 	goto oodate_out;
1054     dname = fname3;
1055 
1056     missingFiles = Lst_Init(FALSE);
1057 
1058     /*
1059      * We need to check if the target is out-of-date. This includes
1060      * checking if the expanded command has changed. This in turn
1061      * requires that all variables are set in the same way that they
1062      * would be if the target needs to be re-built.
1063      */
1064     Make_DoAllVar(gn);
1065 
1066     meta_name(fname, sizeof(fname), dname, tname, dname);
1067 
1068 #ifdef DEBUG_META_MODE
1069     if (DEBUG(META))
1070 	fprintf(debug_file, "meta_oodate: %s\n", fname);
1071 #endif
1072 
1073     if ((fp = fopen(fname, "r")) != NULL) {
1074 	static char *buf = NULL;
1075 	static size_t bufsz;
1076 	int lineno = 0;
1077 	int lastpid = 0;
1078 	int pid;
1079 	int x;
1080 	LstNode ln;
1081 	struct stat fs;
1082 
1083 	if (!buf) {
1084 	    bufsz = 8 * BUFSIZ;
1085 	    buf = bmake_malloc(bufsz);
1086 	}
1087 
1088 	if (!cwdlen) {
1089 	    if (getcwd(cwd, sizeof(cwd)) == NULL)
1090 		err(1, "Could not get current working directory");
1091 	    cwdlen = strlen(cwd);
1092 	}
1093 	strlcpy(lcwd, cwd, sizeof(lcwd));
1094 	strlcpy(latestdir, cwd, sizeof(latestdir));
1095 
1096 	if (!tmpdir) {
1097 	    tmpdir = getTmpdir();
1098 	    tmplen = strlen(tmpdir);
1099 	}
1100 
1101 	/* we want to track all the .meta we read */
1102 	Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
1103 
1104 	ln = Lst_First(gn->commands);
1105 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1106 	    lineno++;
1107 	    if (buf[x - 1] == '\n')
1108 		buf[x - 1] = '\0';
1109 	    else {
1110 		warnx("%s: %d: line truncated at %u", fname, lineno, x);
1111 		oodate = TRUE;
1112 		break;
1113 	    }
1114 	    link_src = NULL;
1115 	    move_target = NULL;
1116 	    /* Find the start of the build monitor section. */
1117 	    if (!have_filemon) {
1118 		if (strncmp(buf, "-- filemon", 10) == 0) {
1119 		    have_filemon = TRUE;
1120 		    continue;
1121 		}
1122 		if (strncmp(buf, "# buildmon", 10) == 0) {
1123 		    have_filemon = TRUE;
1124 		    continue;
1125 		}
1126 	    }
1127 
1128 	    /* Delimit the record type. */
1129 	    p = buf;
1130 #ifdef DEBUG_META_MODE
1131 	    if (DEBUG(META))
1132 		fprintf(debug_file, "%s: %d: %s\n", fname, lineno, buf);
1133 #endif
1134 	    strsep(&p, " ");
1135 	    if (have_filemon) {
1136 		/*
1137 		 * We are in the 'filemon' output section.
1138 		 * Each record from filemon follows the general form:
1139 		 *
1140 		 * <key> <pid> <data>
1141 		 *
1142 		 * Where:
1143 		 * <key> is a single letter, denoting the syscall.
1144 		 * <pid> is the process that made the syscall.
1145 		 * <data> is the arguments (of interest).
1146 		 */
1147 		switch(buf[0]) {
1148 		case '#':		/* comment */
1149 		case 'V':		/* version */
1150 		    break;
1151 		default:
1152 		    /*
1153 		     * We need to track pathnames per-process.
1154 		     *
1155 		     * Each process run by make, starts off in the 'CWD'
1156 		     * recorded in the .meta file, if it chdirs ('C')
1157 		     * elsewhere we need to track that - but only for
1158 		     * that process.  If it forks ('F'), we initialize
1159 		     * the child to have the same cwd as its parent.
1160 		     *
1161 		     * We also need to track the 'latestdir' of
1162 		     * interest.  This is usually the same as cwd, but
1163 		     * not if a process is reading directories.
1164 		     *
1165 		     * Each time we spot a different process ('pid')
1166 		     * we save the current value of 'latestdir' in a
1167 		     * variable qualified by 'lastpid', and
1168 		     * re-initialize 'latestdir' to any pre-saved
1169 		     * value for the current 'pid' and 'CWD' if none.
1170 		     */
1171 		    CHECK_VALID_META(p);
1172 		    pid = atoi(p);
1173 		    if (pid > 0 && pid != lastpid) {
1174 			char *ldir;
1175 			char *tp;
1176 
1177 			if (lastpid > 0) {
1178 			    /* We need to remember these. */
1179 			    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1180 			    Var_Set(ldir_vname, latestdir, VAR_GLOBAL, 0);
1181 			}
1182 			snprintf(lcwd_vname, sizeof(lcwd_vname), LCWD_VNAME_FMT, pid);
1183 			snprintf(ldir_vname, sizeof(ldir_vname), LDIR_VNAME_FMT, pid);
1184 			lastpid = pid;
1185 			ldir = Var_Value(ldir_vname, VAR_GLOBAL, &tp);
1186 			if (ldir) {
1187 			    strlcpy(latestdir, ldir, sizeof(latestdir));
1188 			    free(tp);
1189 			}
1190 			ldir = Var_Value(lcwd_vname, VAR_GLOBAL, &tp);
1191 			if (ldir) {
1192 			    strlcpy(lcwd, ldir, sizeof(lcwd));
1193 			    free(tp);
1194 			}
1195 		    }
1196 		    /* Skip past the pid. */
1197 		    if (strsep(&p, " ") == NULL)
1198 			continue;
1199 #ifdef DEBUG_META_MODE
1200 		    if (DEBUG(META))
1201 			    fprintf(debug_file, "%s: %d: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1202 				    fname, lineno,
1203 				    pid, buf[0], cwd, lcwd, latestdir);
1204 #endif
1205 		    break;
1206 		}
1207 
1208 		CHECK_VALID_META(p);
1209 
1210 		/* Process according to record type. */
1211 		switch (buf[0]) {
1212 		case 'X':		/* eXit */
1213 		    Var_Delete(lcwd_vname, VAR_GLOBAL);
1214 		    Var_Delete(ldir_vname, VAR_GLOBAL);
1215 		    lastpid = 0;	/* no need to save ldir_vname */
1216 		    break;
1217 
1218 		case 'F':		/* [v]Fork */
1219 		    {
1220 			char cldir[64];
1221 			int child;
1222 
1223 			child = atoi(p);
1224 			if (child > 0) {
1225 			    snprintf(cldir, sizeof(cldir), LCWD_VNAME_FMT, child);
1226 			    Var_Set(cldir, lcwd, VAR_GLOBAL, 0);
1227 			    snprintf(cldir, sizeof(cldir), LDIR_VNAME_FMT, child);
1228 			    Var_Set(cldir, latestdir, VAR_GLOBAL, 0);
1229 #ifdef DEBUG_META_MODE
1230 			    if (DEBUG(META))
1231 				    fprintf(debug_file, "%s: %d: %d: cwd=%s lcwd=%s ldir=%s\n",
1232 					    fname, lineno,
1233 					    child, cwd, lcwd, latestdir);
1234 #endif
1235 			}
1236 		    }
1237 		    break;
1238 
1239 		case 'C':		/* Chdir */
1240 		    /* Update lcwd and latest directory. */
1241 		    strlcpy(latestdir, p, sizeof(latestdir));
1242 		    strlcpy(lcwd, p, sizeof(lcwd));
1243 		    Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1244 		    Var_Set(ldir_vname, lcwd, VAR_GLOBAL, 0);
1245 #ifdef DEBUG_META_MODE
1246 		    if (DEBUG(META))
1247 			fprintf(debug_file, "%s: %d: cwd=%s ldir=%s\n", fname, lineno, cwd, lcwd);
1248 #endif
1249 		    break;
1250 
1251 		case 'M':		/* renaMe */
1252 		    /*
1253 		     * For 'M'oves we want to check
1254 		     * the src as for 'R'ead
1255 		     * and the target as for 'W'rite.
1256 		     */
1257 		    cp = p;		/* save this for a second */
1258 		    /* now get target */
1259 		    if (strsep(&p, " ") == NULL)
1260 			continue;
1261 		    CHECK_VALID_META(p);
1262 		    move_target = p;
1263 		    p = cp;
1264 		    /* 'L' and 'M' put single quotes around the args */
1265 		    DEQUOTE(p);
1266 		    DEQUOTE(move_target);
1267 		    /* FALLTHROUGH */
1268 		case 'D':		/* unlink */
1269 		    if (*p == '/' && !Lst_IsEmpty(missingFiles)) {
1270 			/* remove any missingFiles entries that match p */
1271 			if ((ln = Lst_Find(missingFiles, p,
1272 					   path_match)) != NULL) {
1273 			    LstNode nln;
1274 			    char *tp;
1275 
1276 			    do {
1277 				nln = Lst_FindFrom(missingFiles, Lst_Succ(ln),
1278 						   p, path_match);
1279 				tp = Lst_Datum(ln);
1280 				Lst_Remove(missingFiles, ln);
1281 				free(tp);
1282 			    } while ((ln = nln) != NULL);
1283 			}
1284 		    }
1285 		    if (buf[0] == 'M') {
1286 			/* the target of the mv is a file 'W'ritten */
1287 #ifdef DEBUG_META_MODE
1288 			if (DEBUG(META))
1289 			    fprintf(debug_file, "meta_oodate: M %s -> %s\n",
1290 				    p, move_target);
1291 #endif
1292 			p = move_target;
1293 			goto check_write;
1294 		    }
1295 		    break;
1296 		case 'L':		/* Link */
1297 		    /*
1298 		     * For 'L'inks check
1299 		     * the src as for 'R'ead
1300 		     * and the target as for 'W'rite.
1301 		     */
1302 		    link_src = p;
1303 		    /* now get target */
1304 		    if (strsep(&p, " ") == NULL)
1305 			continue;
1306 		    CHECK_VALID_META(p);
1307 		    /* 'L' and 'M' put single quotes around the args */
1308 		    DEQUOTE(p);
1309 		    DEQUOTE(link_src);
1310 #ifdef DEBUG_META_MODE
1311 		    if (DEBUG(META))
1312 			fprintf(debug_file, "meta_oodate: L %s -> %s\n",
1313 				link_src, p);
1314 #endif
1315 		    /* FALLTHROUGH */
1316 		case 'W':		/* Write */
1317 		check_write:
1318 		    /*
1319 		     * If a file we generated within our bailiwick
1320 		     * but outside of .OBJDIR is missing,
1321 		     * we need to do it again.
1322 		     */
1323 		    /* ignore non-absolute paths */
1324 		    if (*p != '/')
1325 			break;
1326 
1327 		    if (Lst_IsEmpty(metaBailiwick))
1328 			break;
1329 
1330 		    /* ignore cwd - normal dependencies handle those */
1331 		    if (strncmp(p, cwd, cwdlen) == 0)
1332 			break;
1333 
1334 		    if (!Lst_ForEach(metaBailiwick, prefix_match, p))
1335 			break;
1336 
1337 		    /* tmpdir might be within */
1338 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1339 			break;
1340 
1341 		    /* ignore anything containing the string "tmp" */
1342 		    if ((strstr("tmp", p)))
1343 			break;
1344 
1345 		    if ((link_src != NULL && cached_lstat(p, &fs) < 0) ||
1346 			(link_src == NULL && cached_stat(p, &fs) < 0)) {
1347 			if (!meta_ignore(gn, p)) {
1348 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1349 				Lst_AtEnd(missingFiles, bmake_strdup(p));
1350 			}
1351 		    }
1352 		    break;
1353 		check_link_src:
1354 		    p = link_src;
1355 		    link_src = NULL;
1356 #ifdef DEBUG_META_MODE
1357 		    if (DEBUG(META))
1358 			fprintf(debug_file, "meta_oodate: L src %s\n", p);
1359 #endif
1360 		    /* FALLTHROUGH */
1361 		case 'R':		/* Read */
1362 		case 'E':		/* Exec */
1363 		    /*
1364 		     * Check for runtime files that can't
1365 		     * be part of the dependencies because
1366 		     * they are _expected_ to change.
1367 		     */
1368 		    if (meta_ignore(gn, p))
1369 			break;
1370 
1371 		    /*
1372 		     * The rest of the record is the file name.
1373 		     * Check if it's not an absolute path.
1374 		     */
1375 		    {
1376 			char *sdirs[4];
1377 			char **sdp;
1378 			int sdx = 0;
1379 			int found = 0;
1380 
1381 			if (*p == '/') {
1382 			    sdirs[sdx++] = p; /* done */
1383 			} else {
1384 			    if (strcmp(".", p) == 0)
1385 				continue;  /* no point */
1386 
1387 			    /* Check vs latestdir */
1388 			    snprintf(fname1, sizeof(fname1), "%s/%s", latestdir, p);
1389 			    sdirs[sdx++] = fname1;
1390 
1391 			    if (strcmp(latestdir, lcwd) != 0) {
1392 				/* Check vs lcwd */
1393 				snprintf(fname2, sizeof(fname2), "%s/%s", lcwd, p);
1394 				sdirs[sdx++] = fname2;
1395 			    }
1396 			    if (strcmp(lcwd, cwd) != 0) {
1397 				/* Check vs cwd */
1398 				snprintf(fname3, sizeof(fname3), "%s/%s", cwd, p);
1399 				sdirs[sdx++] = fname3;
1400 			    }
1401 			}
1402 			sdirs[sdx++] = NULL;
1403 
1404 			for (sdp = sdirs; *sdp && !found; sdp++) {
1405 #ifdef DEBUG_META_MODE
1406 			    if (DEBUG(META))
1407 				fprintf(debug_file, "%s: %d: looking for: %s\n", fname, lineno, *sdp);
1408 #endif
1409 			    if (cached_stat(*sdp, &fs) == 0) {
1410 				found = 1;
1411 				p = *sdp;
1412 			    }
1413 			}
1414 			if (found) {
1415 #ifdef DEBUG_META_MODE
1416 			    if (DEBUG(META))
1417 				fprintf(debug_file, "%s: %d: found: %s\n", fname, lineno, p);
1418 #endif
1419 			    if (!S_ISDIR(fs.st_mode) &&
1420 				fs.st_mtime > gn->mtime) {
1421 				if (DEBUG(META))
1422 				    fprintf(debug_file, "%s: %d: file '%s' is newer than the target...\n", fname, lineno, p);
1423 				oodate = TRUE;
1424 			    } else if (S_ISDIR(fs.st_mode)) {
1425 				/* Update the latest directory. */
1426 				cached_realpath(p, latestdir);
1427 			    }
1428 			} else if (errno == ENOENT && *p == '/' &&
1429 				   strncmp(p, cwd, cwdlen) != 0) {
1430 			    /*
1431 			     * A referenced file outside of CWD is missing.
1432 			     * We cannot catch every eventuality here...
1433 			     */
1434 			    if (Lst_Find(missingFiles, p, string_match) == NULL)
1435 				    Lst_AtEnd(missingFiles, bmake_strdup(p));
1436 			}
1437 		    }
1438 		    if (buf[0] == 'E') {
1439 			/* previous latestdir is no longer relevant */
1440 			strlcpy(latestdir, lcwd, sizeof(latestdir));
1441 		    }
1442 		    break;
1443 		default:
1444 		    break;
1445 		}
1446 		if (!oodate && buf[0] == 'L' && link_src != NULL)
1447 		    goto check_link_src;
1448 	    } else if (strcmp(buf, "CMD") == 0) {
1449 		/*
1450 		 * Compare the current command with the one in the
1451 		 * meta data file.
1452 		 */
1453 		if (ln == NULL) {
1454 		    if (DEBUG(META))
1455 			fprintf(debug_file, "%s: %d: there were more build commands in the meta data file than there are now...\n", fname, lineno);
1456 		    oodate = TRUE;
1457 		} else {
1458 		    char *cmd = (char *)Lst_Datum(ln);
1459 		    Boolean hasOODATE = FALSE;
1460 
1461 		    if (strstr(cmd, "$?"))
1462 			hasOODATE = TRUE;
1463 		    else if ((cp = strstr(cmd, ".OODATE"))) {
1464 			/* check for $[{(].OODATE[:)}] */
1465 			if (cp > cmd + 2 && cp[-2] == '$')
1466 			    hasOODATE = TRUE;
1467 		    }
1468 		    if (hasOODATE) {
1469 			needOODATE = TRUE;
1470 			if (DEBUG(META))
1471 			    fprintf(debug_file, "%s: %d: cannot compare command using .OODATE\n", fname, lineno);
1472 		    }
1473 		    cmd = Var_Subst(NULL, cmd, gn, VARF_WANTRES|VARF_UNDEFERR);
1474 
1475 		    if ((cp = strchr(cmd, '\n'))) {
1476 			int n;
1477 
1478 			/*
1479 			 * This command contains newlines, we need to
1480 			 * fetch more from the .meta file before we
1481 			 * attempt a comparison.
1482 			 */
1483 			/* first put the newline back at buf[x - 1] */
1484 			buf[x - 1] = '\n';
1485 			do {
1486 			    /* now fetch the next line */
1487 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1488 				break;
1489 			    x = n;
1490 			    lineno++;
1491 			    if (buf[x - 1] != '\n') {
1492 				warnx("%s: %d: line truncated at %u", fname, lineno, x);
1493 				break;
1494 			    }
1495 			    cp = strchr(++cp, '\n');
1496 			} while (cp);
1497 			if (buf[x - 1] == '\n')
1498 			    buf[x - 1] = '\0';
1499 		    }
1500 		    if (!hasOODATE &&
1501 			!(gn->type & OP_NOMETA_CMP) &&
1502 			strcmp(p, cmd) != 0) {
1503 			if (DEBUG(META))
1504 			    fprintf(debug_file, "%s: %d: a build command has changed\n%s\nvs\n%s\n", fname, lineno, p, cmd);
1505 			if (!metaIgnoreCMDs)
1506 			    oodate = TRUE;
1507 		    }
1508 		    free(cmd);
1509 		    ln = Lst_Succ(ln);
1510 		}
1511 	    } else if (strcmp(buf, "CWD") == 0) {
1512 		/*
1513 		 * Check if there are extra commands now
1514 		 * that weren't in the meta data file.
1515 		 */
1516 		if (!oodate && ln != NULL) {
1517 		    if (DEBUG(META))
1518 			fprintf(debug_file, "%s: %d: there are extra build commands now that weren't in the meta data file\n", fname, lineno);
1519 		    oodate = TRUE;
1520 		}
1521 		if (strcmp(p, cwd) != 0) {
1522 		    if (DEBUG(META))
1523 			fprintf(debug_file, "%s: %d: the current working directory has changed from '%s' to '%s'\n", fname, lineno, p, curdir);
1524 		    oodate = TRUE;
1525 		}
1526 	    }
1527 	}
1528 
1529 	fclose(fp);
1530 	if (!Lst_IsEmpty(missingFiles)) {
1531 	    if (DEBUG(META))
1532 		fprintf(debug_file, "%s: missing files: %s...\n",
1533 			fname, (char *)Lst_Datum(Lst_First(missingFiles)));
1534 	    oodate = TRUE;
1535 	}
1536 	if (!oodate && !have_filemon && filemonMissing) {
1537 	    if (DEBUG(META))
1538 		fprintf(debug_file, "%s: missing filemon data\n", fname);
1539 	    oodate = TRUE;
1540 	}
1541     } else {
1542 	if (writeMeta && metaMissing) {
1543 	    cp = NULL;
1544 
1545 	    /* if target is in .CURDIR we do not need a meta file */
1546 	    if (gn->path && (cp = strrchr(gn->path, '/')) && cp > gn->path) {
1547 		if (strncmp(curdir, gn->path, (cp - gn->path)) != 0) {
1548 		    cp = NULL;		/* not in .CURDIR */
1549 		}
1550 	    }
1551 	    if (!cp) {
1552 		if (DEBUG(META))
1553 		    fprintf(debug_file, "%s: required but missing\n", fname);
1554 		oodate = TRUE;
1555 		needOODATE = TRUE;	/* assume the worst */
1556 	    }
1557 	}
1558     }
1559 
1560     Lst_Destroy(missingFiles, (FreeProc *)free);
1561 
1562     if (oodate && needOODATE) {
1563 	/*
1564 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1565 	 * We have decided it is oodate, so .OODATE needs to be set.
1566 	 * All we can sanely do is set it to .ALLSRC.
1567 	 */
1568 	Var_Delete(OODATE, gn);
1569 	Var_Set(OODATE, Var_Value(ALLSRC, gn, &cp), gn, 0);
1570 	free(cp);
1571     }
1572 
1573  oodate_out:
1574     for (i--; i >= 0; i--) {
1575 	free(pa[i]);
1576     }
1577     return oodate;
1578 }
1579 
1580 /* support for compat mode */
1581 
1582 static int childPipe[2];
1583 
1584 void
1585 meta_compat_start(void)
1586 {
1587 #ifdef USE_FILEMON_ONCE
1588     /*
1589      * We need to re-open filemon for each cmd.
1590      */
1591     BuildMon *pbm = &Mybm;
1592 
1593     if (pbm->mfp != NULL && useFilemon) {
1594 	filemon_open(pbm);
1595     } else {
1596 	pbm->mon_fd = pbm->filemon_fd = -1;
1597     }
1598 #endif
1599     if (pipe(childPipe) < 0)
1600 	Punt("Cannot create pipe: %s", strerror(errno));
1601     /* Set close-on-exec flag for both */
1602     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1603     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1604 }
1605 
1606 void
1607 meta_compat_child(void)
1608 {
1609     meta_job_child(NULL);
1610     if (dup2(childPipe[1], 1) < 0 ||
1611 	dup2(1, 2) < 0) {
1612 	execError("dup2", "pipe");
1613 	_exit(1);
1614     }
1615 }
1616 
1617 void
1618 meta_compat_parent(void)
1619 {
1620     FILE *fp;
1621     char buf[BUFSIZ];
1622 
1623     close(childPipe[1]);			/* child side */
1624     fp = fdopen(childPipe[0], "r");
1625     while (fgets(buf, sizeof(buf), fp)) {
1626 	meta_job_output(NULL, buf, "");
1627 	printf("%s", buf);
1628 	fflush(stdout);
1629     }
1630     fclose(fp);
1631 }
1632 
1633 #endif	/* USE_META */
1634