xref: /freebsd/contrib/bmake/meta.c (revision 963f5dc7a30624e95d72fb7f87b8892651164e46)
1 /*      $NetBSD: meta.c,v 1.185 2021/11/27 22:04:02 rillig Exp $ */
2 
3 /*
4  * Implement 'meta' mode.
5  * Adapted from John Birrell's patches to FreeBSD make.
6  * --sjg
7  */
8 /*
9  * Copyright (c) 2009-2016, Juniper Networks, Inc.
10  * Portions Copyright (c) 2009, John Birrell.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 #if defined(USE_META)
34 
35 #ifdef HAVE_CONFIG_H
36 # include "config.h"
37 #endif
38 #include <sys/stat.h>
39 #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 "dir.h"
51 #include "job.h"
52 
53 #ifdef USE_FILEMON
54 #include "filemon/filemon.h"
55 #endif
56 
57 static BuildMon Mybm;			/* for compat */
58 static StringList metaBailiwick = LST_INIT; /* our scope of control */
59 static char *metaBailiwickStr;		/* string storage for the list */
60 static StringList metaIgnorePaths = LST_INIT; /* paths we deliberately ignore */
61 static char *metaIgnorePathsStr;	/* string storage for the list */
62 
63 #ifndef MAKE_META_IGNORE_PATHS
64 #define MAKE_META_IGNORE_PATHS ".MAKE.META.IGNORE_PATHS"
65 #endif
66 #ifndef MAKE_META_IGNORE_PATTERNS
67 #define MAKE_META_IGNORE_PATTERNS ".MAKE.META.IGNORE_PATTERNS"
68 #endif
69 #ifndef MAKE_META_IGNORE_FILTER
70 #define MAKE_META_IGNORE_FILTER ".MAKE.META.IGNORE_FILTER"
71 #endif
72 
73 bool useMeta = false;
74 static bool useFilemon = false;
75 static bool writeMeta = false;
76 static bool metaMissing = false;	/* oodate if missing */
77 static bool filemonMissing = false;	/* oodate if missing */
78 static bool metaEnv = false;		/* don't save env unless asked */
79 static bool metaVerbose = false;
80 static bool metaIgnoreCMDs = false;	/* ignore CMDs in .meta files */
81 static bool metaIgnorePatterns = false; /* do we need to do pattern matches */
82 static bool metaIgnoreFilter = false;	/* do we have more complex filtering? */
83 static bool metaCurdirOk = false;	/* write .meta in .CURDIR Ok? */
84 static bool metaSilent = false;		/* if we have a .meta be SILENT */
85 
86 extern bool forceJobs;
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 #if !defined(HAVE_STRESEP)
102 char * stresep(char **, const char *, int);
103 #endif
104 
105 /*
106  * Filemon is a kernel module which snoops certain syscalls.
107  *
108  * C chdir
109  * E exec
110  * F [v]fork
111  * L [sym]link
112  * M rename
113  * R read
114  * W write
115  * S stat
116  *
117  * See meta_oodate below - we mainly care about 'E' and 'R'.
118  *
119  * We can still use meta mode without filemon, but
120  * the benefits are more limited.
121  */
122 #ifdef USE_FILEMON
123 
124 /*
125  * Open the filemon device.
126  */
127 static void
128 meta_open_filemon(BuildMon *pbm)
129 {
130     int dupfd;
131 
132     pbm->mon_fd = -1;
133     pbm->filemon = NULL;
134     if (!useFilemon || pbm->mfp == NULL)
135 	return;
136 
137     pbm->filemon = filemon_open();
138     if (pbm->filemon == NULL) {
139 	useFilemon = false;
140 	warn("Could not open filemon %s", filemon_path());
141 	return;
142     }
143 
144     /*
145      * We use a file outside of '.'
146      * to avoid a FreeBSD kernel bug where unlink invalidates
147      * cwd causing getcwd to do a lot more work.
148      * We only care about the descriptor.
149      */
150     if (!opts.compatMake)
151 	pbm->mon_fd = Job_TempFile("filemon.XXXXXX", NULL, 0);
152     else
153 	pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL, 0);
154     if ((dupfd = dup(pbm->mon_fd)) == -1) {
155 	Punt("Could not dup filemon output: %s", strerror(errno));
156     }
157     (void)fcntl(dupfd, F_SETFD, FD_CLOEXEC);
158     if (filemon_setfd(pbm->filemon, dupfd) == -1) {
159 	Punt("Could not set filemon file descriptor: %s", strerror(errno));
160     }
161     /* we don't need these once we exec */
162     (void)fcntl(pbm->mon_fd, F_SETFD, FD_CLOEXEC);
163 }
164 
165 /*
166  * Read the build monitor output file and write records to the target's
167  * metadata file.
168  */
169 static int
170 filemon_read(FILE *mfp, int fd)
171 {
172     char buf[BUFSIZ];
173     int error;
174 
175     /* Check if we're not writing to a meta data file.*/
176     if (mfp == NULL) {
177 	if (fd >= 0)
178 	    close(fd);			/* not interested */
179 	return 0;
180     }
181     /* rewind */
182     if (lseek(fd, (off_t)0, SEEK_SET) < 0) {
183 	error = errno;
184 	warn("Could not rewind filemon");
185 	fprintf(mfp, "\n");
186     } else {
187 	ssize_t n;
188 
189 	error = 0;
190 	fprintf(mfp, "\n-- filemon acquired metadata --\n");
191 
192 	while ((n = read(fd, buf, sizeof buf)) > 0) {
193 	    if ((ssize_t)fwrite(buf, 1, (size_t)n, mfp) < n)
194 		error = EIO;
195 	}
196     }
197     if (fflush(mfp) != 0)
198 	Punt("Cannot write filemon data to meta file: %s",
199 	    strerror(errno));
200     if (close(fd) < 0)
201 	error = errno;
202     return error;
203 }
204 #endif
205 
206 /*
207  * when realpath() fails,
208  * we use this, to clean up ./ and ../
209  */
210 static void
211 eat_dots(char *buf, size_t bufsz, int dots)
212 {
213     char *cp;
214     char *cp2;
215     const char *eat;
216     size_t eatlen;
217 
218     switch (dots) {
219     case 1:
220 	eat = "/./";
221 	eatlen = 2;
222 	break;
223     case 2:
224 	eat = "/../";
225 	eatlen = 3;
226 	break;
227     default:
228 	return;
229     }
230 
231     do {
232 	cp = strstr(buf, eat);
233 	if (cp != NULL) {
234 	    cp2 = cp + eatlen;
235 	    if (dots == 2 && cp > buf) {
236 		do {
237 		    cp--;
238 		} while (cp > buf && *cp != '/');
239 	    }
240 	    if (*cp == '/') {
241 		strlcpy(cp, cp2, bufsz - (size_t)(cp - buf));
242 	    } else {
243 		return;			/* can't happen? */
244 	    }
245 	}
246     } while (cp != NULL);
247 }
248 
249 static char *
250 meta_name(char *mname, size_t mnamelen,
251 	  const char *dname,
252 	  const char *tname,
253 	  const char *cwd)
254 {
255     char buf[MAXPATHLEN];
256     char *rp, *cp;
257     const char *tname_base;
258     char *tp;
259     char *dtp;
260     size_t ldname;
261 
262     /*
263      * Weed out relative paths from the target file name.
264      * We have to be careful though since if target is a
265      * symlink, the result will be unstable.
266      * So we use realpath() just to get the dirname, and leave the
267      * basename as given to us.
268      */
269     if ((tname_base = strrchr(tname, '/')) != NULL) {
270 	if (cached_realpath(tname, buf) != NULL) {
271 	    if ((rp = strrchr(buf, '/')) != NULL) {
272 		rp++;
273 		tname_base++;
274 		if (strcmp(tname_base, rp) != 0)
275 		    strlcpy(rp, tname_base, sizeof buf - (size_t)(rp - buf));
276 	    }
277 	    tname = buf;
278 	} else {
279 	    /*
280 	     * We likely have a directory which is about to be made.
281 	     * We pretend realpath() succeeded, to have a chance
282 	     * of generating the same meta file name that we will
283 	     * next time through.
284 	     */
285 	    if (tname[0] == '/') {
286 		strlcpy(buf, tname, sizeof buf);
287 	    } else {
288 		snprintf(buf, sizeof buf, "%s/%s", cwd, tname);
289 	    }
290 	    eat_dots(buf, sizeof buf, 1);	/* ./ */
291 	    eat_dots(buf, sizeof buf, 2);	/* ../ */
292 	    tname = buf;
293 	}
294     }
295     /* on some systems dirname may modify its arg */
296     tp = bmake_strdup(tname);
297     dtp = dirname(tp);
298     if (strcmp(dname, dtp) == 0)
299 	snprintf(mname, mnamelen, "%s.meta", tname);
300     else {
301 	ldname = strlen(dname);
302 	if (strncmp(dname, dtp, ldname) == 0 && dtp[ldname] == '/')
303 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, &tname[ldname+1]);
304 	else
305 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, tname);
306 
307 	/*
308 	 * Replace path separators in the file name after the
309 	 * current object directory path.
310 	 */
311 	cp = mname + strlen(dname) + 1;
312 
313 	while (*cp != '\0') {
314 	    if (*cp == '/')
315 		*cp = '_';
316 	    cp++;
317 	}
318     }
319     free(tp);
320     return mname;
321 }
322 
323 /*
324  * Return true if running ${.MAKE}
325  * Bypassed if target is flagged .MAKE
326  */
327 static bool
328 is_submake(const char *cmd, GNode *gn)
329 {
330     static const char *p_make = NULL;
331     static size_t p_len;
332     char *mp = NULL;
333     const char *cp, *cp2;
334     bool rc = false;
335 
336     if (p_make == NULL) {
337 	p_make = Var_Value(gn, ".MAKE").str;
338 	p_len = strlen(p_make);
339     }
340     cp = strchr(cmd, '$');
341     if (cp != NULL) {
342 	(void)Var_Subst(cmd, gn, VARE_WANTRES, &mp);
343 	/* TODO: handle errors */
344 	cmd = mp;
345     }
346     cp2 = strstr(cmd, p_make);
347     if (cp2 != NULL) {
348 	switch (cp2[p_len]) {
349 	case '\0':
350 	case ' ':
351 	case '\t':
352 	case '\n':
353 	    rc = true;
354 	    break;
355 	}
356 	if (cp2 > cmd && rc) {
357 	    switch (cp2[-1]) {
358 	    case ' ':
359 	    case '\t':
360 	    case '\n':
361 		break;
362 	    default:
363 		rc = false;		/* no match */
364 		break;
365 	    }
366 	}
367     }
368     free(mp);
369     return rc;
370 }
371 
372 static bool
373 any_is_submake(GNode *gn)
374 {
375     StringListNode *ln;
376 
377     for (ln = gn->commands.first; ln != NULL; ln = ln->next)
378 	if (is_submake(ln->datum, gn))
379 	    return true;
380     return false;
381 }
382 
383 static void
384 printCMD(const char *ucmd, FILE *fp, GNode *gn)
385 {
386     FStr xcmd = FStr_InitRefer(ucmd);
387 
388     if (strchr(ucmd, '$') != NULL) {
389     	char *expanded;
390 	(void)Var_Subst(ucmd, gn, VARE_WANTRES, &expanded);
391 	/* TODO: handle errors */
392 	xcmd = FStr_InitOwn(expanded);
393     }
394 
395     fprintf(fp, "CMD %s\n", xcmd.str);
396     FStr_Done(&xcmd);
397 }
398 
399 static void
400 printCMDs(GNode *gn, FILE *fp)
401 {
402     StringListNode *ln;
403 
404     for (ln = gn->commands.first; ln != NULL; ln = ln->next)
405 	printCMD(ln->datum, fp, gn);
406 }
407 
408 /*
409  * Certain node types never get a .meta file
410  */
411 #define SKIP_META_TYPE(_type) do { \
412     if ((gn->type & __CONCAT(OP_, _type))) { \
413 	if (verbose) { \
414 	    debug_printf("Skipping meta for %s: .%s\n", \
415 		    gn->name, __STRING(_type)); \
416 	} \
417 	return false; \
418     } \
419 } while (false)
420 
421 
422 /*
423  * Do we need/want a .meta file ?
424  */
425 static bool
426 meta_needed(GNode *gn, const char *dname,
427 	    char *objdir_realpath, bool verbose)
428 {
429     struct cached_stat cst;
430 
431     if (verbose)
432 	verbose = DEBUG(META);
433 
434     /* This may be a phony node which we don't want meta data for... */
435     /* Skip .meta for .BEGIN, .END, .ERROR etc as well. */
436     /* Or it may be explicitly flagged as .NOMETA */
437     SKIP_META_TYPE(NOMETA);
438     /* Unless it is explicitly flagged as .META */
439     if (!(gn->type & OP_META)) {
440 	SKIP_META_TYPE(PHONY);
441 	SKIP_META_TYPE(SPECIAL);
442 	SKIP_META_TYPE(MAKE);
443     }
444 
445     /* Check if there are no commands to execute. */
446     if (Lst_IsEmpty(&gn->commands)) {
447 	if (verbose)
448 	    debug_printf("Skipping meta for %s: no commands\n", gn->name);
449 	return false;
450     }
451     if ((gn->type & (OP_META|OP_SUBMAKE)) == OP_SUBMAKE) {
452 	/* OP_SUBMAKE is a bit too aggressive */
453 	if (any_is_submake(gn)) {
454 	    DEBUG1(META, "Skipping meta for %s: .SUBMAKE\n", gn->name);
455 	    return false;
456 	}
457     }
458 
459     /* The object directory may not exist. Check it.. */
460     if (cached_stat(dname, &cst) != 0) {
461 	if (verbose)
462 	    debug_printf("Skipping meta for %s: no .OBJDIR\n", gn->name);
463 	return false;
464     }
465 
466     /* make sure these are canonical */
467     if (cached_realpath(dname, objdir_realpath) != NULL)
468 	dname = objdir_realpath;
469 
470     /* If we aren't in the object directory, don't create a meta file. */
471     if (!metaCurdirOk && strcmp(curdir, dname) == 0) {
472 	if (verbose)
473 	    debug_printf("Skipping meta for %s: .OBJDIR == .CURDIR\n",
474 			 gn->name);
475 	return false;
476     }
477     return true;
478 }
479 
480 
481 static FILE *
482 meta_create(BuildMon *pbm, GNode *gn)
483 {
484     FILE *fp;
485     char buf[MAXPATHLEN];
486     char objdir_realpath[MAXPATHLEN];
487     char **ptr;
488     FStr dname;
489     const char *tname;
490     char *fname;
491     const char *cp;
492 
493     fp = NULL;
494 
495     dname = Var_Value(gn, ".OBJDIR");
496     tname = GNode_VarTarget(gn);
497 
498     /* if this succeeds objdir_realpath is realpath of dname */
499     if (!meta_needed(gn, dname.str, objdir_realpath, true))
500 	goto out;
501     dname.str = objdir_realpath;
502 
503     if (metaVerbose) {
504 	char *mp;
505 
506 	/* Describe the target we are building */
507 	(void)Var_Subst("${" MAKE_META_PREFIX "}", gn, VARE_WANTRES, &mp);
508 	/* TODO: handle errors */
509 	if (mp[0] != '\0')
510 	    fprintf(stdout, "%s\n", mp);
511 	free(mp);
512     }
513     /* Get the basename of the target */
514     cp = str_basename(tname);
515 
516     fflush(stdout);
517 
518     if (!writeMeta)
519 	/* Don't create meta data. */
520 	goto out;
521 
522     fname = meta_name(pbm->meta_fname, sizeof pbm->meta_fname,
523 		      dname.str, tname, objdir_realpath);
524 
525 #ifdef DEBUG_META_MODE
526     DEBUG1(META, "meta_create: %s\n", fname);
527 #endif
528 
529     if ((fp = fopen(fname, "w")) == NULL)
530 	Punt("Could not open meta file '%s': %s", fname, strerror(errno));
531 
532     fprintf(fp, "# Meta data file %s\n", fname);
533 
534     printCMDs(gn, fp);
535 
536     fprintf(fp, "CWD %s\n", getcwd(buf, sizeof buf));
537     fprintf(fp, "TARGET %s\n", tname);
538     cp = GNode_VarOodate(gn);
539     if (cp != NULL && *cp != '\0') {
540 	fprintf(fp, "OODATE %s\n", cp);
541     }
542     if (metaEnv) {
543 	for (ptr = environ; *ptr != NULL; ptr++)
544 	    fprintf(fp, "ENV %s\n", *ptr);
545     }
546 
547     fprintf(fp, "-- command output --\n");
548     if (fflush(fp) != 0)
549 	Punt("Cannot write expanded command to meta file: %s",
550 	    strerror(errno));
551 
552     Global_Append(".MAKE.META.FILES", fname);
553     Global_Append(".MAKE.META.CREATED", fname);
554 
555     gn->type |= OP_META;		/* in case anyone wants to know */
556     if (metaSilent) {
557 	    gn->type |= OP_SILENT;
558     }
559  out:
560     FStr_Done(&dname);
561 
562     return fp;
563 }
564 
565 static bool
566 boolValue(const char *s)
567 {
568     switch (*s) {
569     case '0':
570     case 'N':
571     case 'n':
572     case 'F':
573     case 'f':
574 	return false;
575     }
576     return true;
577 }
578 
579 /*
580  * Initialization we need before reading makefiles.
581  */
582 void
583 meta_init(void)
584 {
585 #ifdef USE_FILEMON
586 	/* this allows makefiles to test if we have filemon support */
587 	Global_Set(".MAKE.PATH_FILEMON", filemon_path());
588 #endif
589 }
590 
591 
592 #define get_mode_bf(bf, token) \
593     if ((cp = strstr(make_mode, token)) != NULL) \
594 	bf = boolValue(cp + sizeof (token) - 1)
595 
596 /*
597  * Initialization we need after reading makefiles.
598  */
599 void
600 meta_mode_init(const char *make_mode)
601 {
602     static bool once = false;
603     const char *cp;
604     FStr value;
605 
606     useMeta = true;
607     useFilemon = true;
608     writeMeta = true;
609 
610     if (make_mode != NULL) {
611 	if (strstr(make_mode, "env") != NULL)
612 	    metaEnv = true;
613 	if (strstr(make_mode, "verb") != NULL)
614 	    metaVerbose = true;
615 	if (strstr(make_mode, "read") != NULL)
616 	    writeMeta = false;
617 	if (strstr(make_mode, "nofilemon") != NULL)
618 	    useFilemon = false;
619 	if (strstr(make_mode, "ignore-cmd") != NULL)
620 	    metaIgnoreCMDs = true;
621 	if (useFilemon)
622 	    get_mode_bf(filemonMissing, "missing-filemon=");
623 	get_mode_bf(metaCurdirOk, "curdirok=");
624 	get_mode_bf(metaMissing, "missing-meta=");
625 	get_mode_bf(metaSilent, "silent=");
626     }
627     if (metaVerbose && !Var_Exists(SCOPE_GLOBAL, MAKE_META_PREFIX)) {
628 	/*
629 	 * The default value for MAKE_META_PREFIX
630 	 * prints the absolute path of the target.
631 	 * This works be cause :H will generate '.' if there is no /
632 	 * and :tA will resolve that to cwd.
633 	 */
634 	Global_Set(MAKE_META_PREFIX,
635 	    "Building ${.TARGET:H:tA}/${.TARGET:T}");
636     }
637     if (once)
638 	return;
639     once = true;
640     memset(&Mybm, 0, sizeof Mybm);
641     /*
642      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
643      */
644     (void)Var_Subst("${.MAKE.META.BAILIWICK:O:u:tA}",
645 		    SCOPE_GLOBAL, VARE_WANTRES, &metaBailiwickStr);
646     /* TODO: handle errors */
647     str2Lst_Append(&metaBailiwick, metaBailiwickStr);
648     /*
649      * We ignore any paths that start with ${.MAKE.META.IGNORE_PATHS}
650      */
651     Global_Append(MAKE_META_IGNORE_PATHS,
652 	       "/dev /etc /proc /tmp /var/run /var/tmp ${TMPDIR}");
653     (void)Var_Subst("${" MAKE_META_IGNORE_PATHS ":O:u:tA}",
654 		    SCOPE_GLOBAL, VARE_WANTRES, &metaIgnorePathsStr);
655     /* TODO: handle errors */
656     str2Lst_Append(&metaIgnorePaths, metaIgnorePathsStr);
657 
658     /*
659      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
660      */
661     value = Var_Value(SCOPE_GLOBAL, MAKE_META_IGNORE_PATTERNS);
662     if (value.str != NULL) {
663 	metaIgnorePatterns = true;
664 	FStr_Done(&value);
665     }
666     value = Var_Value(SCOPE_GLOBAL, MAKE_META_IGNORE_FILTER);
667     if (value.str != NULL) {
668 	metaIgnoreFilter = true;
669 	FStr_Done(&value);
670     }
671 }
672 
673 /*
674  * In each case below we allow for job==NULL
675  */
676 void
677 meta_job_start(Job *job, GNode *gn)
678 {
679     BuildMon *pbm;
680 
681     if (job != NULL) {
682 	pbm = &job->bm;
683     } else {
684 	pbm = &Mybm;
685     }
686     pbm->mfp = meta_create(pbm, gn);
687 #ifdef USE_FILEMON_ONCE
688     /* compat mode we open the filemon dev once per command */
689     if (job == NULL)
690 	return;
691 #endif
692 #ifdef USE_FILEMON
693     if (pbm->mfp != NULL && useFilemon) {
694 	meta_open_filemon(pbm);
695     } else {
696 	pbm->mon_fd = -1;
697 	pbm->filemon = NULL;
698     }
699 #endif
700 }
701 
702 /*
703  * The child calls this before doing anything.
704  * It does not disturb our state.
705  */
706 void
707 meta_job_child(Job *job)
708 {
709 #ifdef USE_FILEMON
710     BuildMon *pbm;
711 
712     if (job != NULL) {
713 	pbm = &job->bm;
714     } else {
715 	pbm = &Mybm;
716     }
717     if (pbm->mfp != NULL) {
718 	close(fileno(pbm->mfp));
719 	if (useFilemon && pbm->filemon != NULL) {
720 	    pid_t pid;
721 
722 	    pid = getpid();
723 	    if (filemon_setpid_child(pbm->filemon, pid) == -1) {
724 		Punt("Could not set filemon pid: %s", strerror(errno));
725 	    }
726 	}
727     }
728 #endif
729 }
730 
731 void
732 meta_job_parent(Job *job, pid_t pid)
733 {
734 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
735     BuildMon *pbm;
736 
737     if (job != NULL) {
738 	pbm = &job->bm;
739     } else {
740 	pbm = &Mybm;
741     }
742     if (useFilemon && pbm->filemon != NULL) {
743 	filemon_setpid_parent(pbm->filemon, pid);
744     }
745 #endif
746 }
747 
748 int
749 meta_job_fd(Job *job)
750 {
751 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
752     BuildMon *pbm;
753 
754     if (job != NULL) {
755 	pbm = &job->bm;
756     } else {
757 	pbm = &Mybm;
758     }
759     if (useFilemon && pbm->filemon != NULL) {
760 	return filemon_readfd(pbm->filemon);
761     }
762 #endif
763     return -1;
764 }
765 
766 int
767 meta_job_event(Job *job)
768 {
769 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
770     BuildMon *pbm;
771 
772     if (job != NULL) {
773 	pbm = &job->bm;
774     } else {
775 	pbm = &Mybm;
776     }
777     if (useFilemon && pbm->filemon != NULL) {
778 	return filemon_process(pbm->filemon);
779     }
780 #endif
781     return 0;
782 }
783 
784 void
785 meta_job_error(Job *job, GNode *gn, bool ignerr, int status)
786 {
787     char cwd[MAXPATHLEN];
788     BuildMon *pbm;
789 
790     if (job != NULL) {
791 	pbm = &job->bm;
792 	if (gn == NULL)
793 	    gn = job->node;
794     } else {
795 	pbm = &Mybm;
796     }
797     if (pbm->mfp != NULL) {
798 	fprintf(pbm->mfp, "\n*** Error code %d%s\n",
799 		status, ignerr ? "(ignored)" : "");
800     }
801     if (gn != NULL)
802 	Global_Set(".ERROR_TARGET", GNode_Path(gn));
803     getcwd(cwd, sizeof cwd);
804     Global_Set(".ERROR_CWD", cwd);
805     if (pbm->meta_fname[0] != '\0') {
806 	Global_Set(".ERROR_META_FILE", pbm->meta_fname);
807     }
808     meta_job_finish(job);
809 }
810 
811 void
812 meta_job_output(Job *job, char *cp, const char *nl)
813 {
814     BuildMon *pbm;
815 
816     if (job != NULL) {
817 	pbm = &job->bm;
818     } else {
819 	pbm = &Mybm;
820     }
821     if (pbm->mfp != NULL) {
822 	if (metaVerbose) {
823 	    static char *meta_prefix = NULL;
824 	    static size_t meta_prefix_len;
825 
826 	    if (meta_prefix == NULL) {
827 		char *cp2;
828 
829 		(void)Var_Subst("${" MAKE_META_PREFIX "}",
830 				SCOPE_GLOBAL, VARE_WANTRES, &meta_prefix);
831 		/* TODO: handle errors */
832 		if ((cp2 = strchr(meta_prefix, '$')) != NULL)
833 		    meta_prefix_len = (size_t)(cp2 - meta_prefix);
834 		else
835 		    meta_prefix_len = strlen(meta_prefix);
836 	    }
837 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
838 		cp = strchr(cp + 1, '\n');
839 		if (cp == NULL)
840 		    return;
841 		cp++;
842 	    }
843 	}
844 	fprintf(pbm->mfp, "%s%s", cp, nl);
845     }
846 }
847 
848 int
849 meta_cmd_finish(void *pbmp)
850 {
851     int error = 0;
852     BuildMon *pbm = pbmp;
853 #ifdef USE_FILEMON
854     int x;
855 #endif
856 
857     if (pbm == NULL)
858 	pbm = &Mybm;
859 
860 #ifdef USE_FILEMON
861     if (pbm->filemon != NULL) {
862 	while (filemon_process(pbm->filemon) > 0)
863 	    continue;
864 	if (filemon_close(pbm->filemon) == -1) {
865 	    error = errno;
866 	    Punt("filemon failed: %s", strerror(errno));
867 	}
868 	x = filemon_read(pbm->mfp, pbm->mon_fd);
869 	if (error == 0 && x != 0)
870 	    error = x;
871 	pbm->mon_fd = -1;
872 	pbm->filemon = NULL;
873 	return error;
874     }
875 #endif
876 
877     fprintf(pbm->mfp, "\n");	/* ensure end with newline */
878     return error;
879 }
880 
881 int
882 meta_job_finish(Job *job)
883 {
884     BuildMon *pbm;
885     int error = 0;
886     int x;
887 
888     if (job != NULL) {
889 	pbm = &job->bm;
890     } else {
891 	pbm = &Mybm;
892     }
893     if (pbm->mfp != NULL) {
894 	error = meta_cmd_finish(pbm);
895 	x = fclose(pbm->mfp);
896 	if (error == 0 && x != 0)
897 	    error = errno;
898 	pbm->mfp = NULL;
899 	pbm->meta_fname[0] = '\0';
900     }
901     return error;
902 }
903 
904 void
905 meta_finish(void)
906 {
907     Lst_Done(&metaBailiwick);
908     free(metaBailiwickStr);
909     Lst_Done(&metaIgnorePaths);
910     free(metaIgnorePathsStr);
911 }
912 
913 /*
914  * Fetch a full line from fp - growing bufp if needed
915  * Return length in bufp.
916  */
917 static int
918 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
919 {
920     char *buf = *bufp;
921     size_t bufsz = *szp;
922     struct stat fs;
923     int x;
924 
925     if (fgets(&buf[o], (int)bufsz - o, fp) != NULL) {
926     check_newline:
927 	x = o + (int)strlen(&buf[o]);
928 	if (buf[x - 1] == '\n')
929 	    return x;
930 	/*
931 	 * We need to grow the buffer.
932 	 * The meta file can give us a clue.
933 	 */
934 	if (fstat(fileno(fp), &fs) == 0) {
935 	    size_t newsz;
936 	    char *p;
937 
938 	    newsz = ROUNDUP(((size_t)fs.st_size / 2), BUFSIZ);
939 	    if (newsz <= bufsz)
940 		newsz = ROUNDUP((size_t)fs.st_size, BUFSIZ);
941 	    if (newsz <= bufsz)
942 		return x;		/* truncated */
943 	    DEBUG2(META, "growing buffer %u -> %u\n",
944 		   (unsigned)bufsz, (unsigned)newsz);
945 	    p = bmake_realloc(buf, newsz);
946 	    *bufp = buf = p;
947 	    *szp = bufsz = newsz;
948 	    /* fetch the rest */
949 	    if (fgets(&buf[x], (int)bufsz - x, fp) == NULL)
950 		return x;		/* truncated! */
951 	    goto check_newline;
952 	}
953     }
954     return 0;
955 }
956 
957 static bool
958 prefix_match(const char *prefix, const char *path)
959 {
960     size_t n = strlen(prefix);
961 
962     return strncmp(path, prefix, n) == 0;
963 }
964 
965 static bool
966 has_any_prefix(const char *path, StringList *prefixes)
967 {
968     StringListNode *ln;
969 
970     for (ln = prefixes->first; ln != NULL; ln = ln->next)
971 	if (prefix_match(ln->datum, path))
972 	    return true;
973     return false;
974 }
975 
976 /* See if the path equals prefix or starts with "prefix/". */
977 static bool
978 path_starts_with(const char *path, const char *prefix)
979 {
980     size_t n = strlen(prefix);
981 
982     if (strncmp(path, prefix, n) != 0)
983 	return false;
984     return path[n] == '\0' || path[n] == '/';
985 }
986 
987 static bool
988 meta_ignore(GNode *gn, const char *p)
989 {
990     char fname[MAXPATHLEN];
991 
992     if (p == NULL)
993 	return true;
994 
995     if (*p == '/') {
996 	cached_realpath(p, fname); /* clean it up */
997 	if (has_any_prefix(fname, &metaIgnorePaths)) {
998 #ifdef DEBUG_META_MODE
999 	    DEBUG1(META, "meta_oodate: ignoring path: %s\n", p);
1000 #endif
1001 	    return true;
1002 	}
1003     }
1004 
1005     if (metaIgnorePatterns) {
1006 	const char *expr;
1007 	char *pm;
1008 
1009 	/*
1010 	 * XXX: This variable is set on a target GNode but is not one of
1011 	 * the usual local variables.  It should be deleted afterwards.
1012 	 * Ideally it would not be created in the first place, just like
1013 	 * in a .for loop.
1014 	 */
1015 	Var_Set(gn, ".p.", p);
1016 	expr = "${" MAKE_META_IGNORE_PATTERNS ":@m@${.p.:M$m}@}";
1017 	(void)Var_Subst(expr, gn, VARE_WANTRES, &pm);
1018 	/* TODO: handle errors */
1019 	if (pm[0] != '\0') {
1020 #ifdef DEBUG_META_MODE
1021 	    DEBUG1(META, "meta_oodate: ignoring pattern: %s\n", p);
1022 #endif
1023 	    free(pm);
1024 	    return true;
1025 	}
1026 	free(pm);
1027     }
1028 
1029     if (metaIgnoreFilter) {
1030 	char *fm;
1031 
1032 	/* skip if filter result is empty */
1033 	snprintf(fname, sizeof fname,
1034 		 "${%s:L:${%s:ts:}}",
1035 		 p, MAKE_META_IGNORE_FILTER);
1036 	(void)Var_Subst(fname, gn, VARE_WANTRES, &fm);
1037 	/* TODO: handle errors */
1038 	if (*fm == '\0') {
1039 #ifdef DEBUG_META_MODE
1040 	    DEBUG1(META, "meta_oodate: ignoring filtered: %s\n", p);
1041 #endif
1042 	    free(fm);
1043 	    return true;
1044 	}
1045 	free(fm);
1046     }
1047     return false;
1048 }
1049 
1050 /*
1051  * When running with 'meta' functionality, a target can be out-of-date
1052  * if any of the references in its meta data file is more recent.
1053  * We have to track the latestdir on a per-process basis.
1054  */
1055 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
1056 #define LDIR_VNAME_FMT ".meta.%d.ldir"
1057 
1058 /*
1059  * It is possible that a .meta file is corrupted,
1060  * if we detect this we want to reproduce it.
1061  * Setting oodate true will have that effect.
1062  */
1063 #define CHECK_VALID_META(p) if (!(p != NULL && *p != '\0')) { \
1064     warnx("%s: %d: malformed", fname, lineno); \
1065     oodate = true; \
1066     continue; \
1067     }
1068 
1069 #define DEQUOTE(p) if (*p == '\'') {	\
1070     char *ep; \
1071     p++; \
1072     if ((ep = strchr(p, '\'')) != NULL) \
1073 	*ep = '\0'; \
1074     }
1075 
1076 static void
1077 append_if_new(StringList *list, const char *str)
1078 {
1079     StringListNode *ln;
1080 
1081     for (ln = list->first; ln != NULL; ln = ln->next)
1082 	if (strcmp(ln->datum, str) == 0)
1083 	    return;
1084     Lst_Append(list, bmake_strdup(str));
1085 }
1086 
1087 bool
1088 meta_oodate(GNode *gn, bool oodate)
1089 {
1090     static char *tmpdir = NULL;
1091     static char cwd[MAXPATHLEN];
1092     char lcwd_vname[64];
1093     char ldir_vname[64];
1094     char lcwd[MAXPATHLEN];
1095     char latestdir[MAXPATHLEN];
1096     char fname[MAXPATHLEN];
1097     char fname1[MAXPATHLEN];
1098     char fname2[MAXPATHLEN];
1099     char fname3[MAXPATHLEN];
1100     FStr dname;
1101     const char *tname;
1102     char *p;
1103     char *link_src;
1104     char *move_target;
1105     static size_t cwdlen = 0;
1106     static size_t tmplen = 0;
1107     FILE *fp;
1108     bool needOODATE = false;
1109     StringList missingFiles;
1110     bool have_filemon = false;
1111 
1112     if (oodate)
1113 	return oodate;		/* we're done */
1114 
1115     dname = Var_Value(gn, ".OBJDIR");
1116     tname = GNode_VarTarget(gn);
1117 
1118     /* if this succeeds fname3 is realpath of dname */
1119     if (!meta_needed(gn, dname.str, fname3, false))
1120 	goto oodate_out;
1121     dname.str = fname3;
1122 
1123     Lst_Init(&missingFiles);
1124 
1125     /*
1126      * We need to check if the target is out-of-date. This includes
1127      * checking if the expanded command has changed. This in turn
1128      * requires that all variables are set in the same way that they
1129      * would be if the target needs to be re-built.
1130      */
1131     GNode_SetLocalVars(gn);
1132 
1133     meta_name(fname, sizeof fname, dname.str, tname, dname.str);
1134 
1135 #ifdef DEBUG_META_MODE
1136     DEBUG1(META, "meta_oodate: %s\n", fname);
1137 #endif
1138 
1139     if ((fp = fopen(fname, "r")) != NULL) {
1140 	static char *buf = NULL;
1141 	static size_t bufsz;
1142 	int lineno = 0;
1143 	int lastpid = 0;
1144 	int pid;
1145 	int x;
1146 	StringListNode *cmdNode;
1147 	struct cached_stat cst;
1148 
1149 	if (buf == NULL) {
1150 	    bufsz = 8 * BUFSIZ;
1151 	    buf = bmake_malloc(bufsz);
1152 	}
1153 
1154 	if (cwdlen == 0) {
1155 	    if (getcwd(cwd, sizeof cwd) == NULL)
1156 		err(1, "Could not get current working directory");
1157 	    cwdlen = strlen(cwd);
1158 	}
1159 	strlcpy(lcwd, cwd, sizeof lcwd);
1160 	strlcpy(latestdir, cwd, sizeof latestdir);
1161 
1162 	if (tmpdir == NULL) {
1163 	    tmpdir = getTmpdir();
1164 	    tmplen = strlen(tmpdir);
1165 	}
1166 
1167 	/* we want to track all the .meta we read */
1168 	Global_Append(".MAKE.META.FILES", fname);
1169 
1170 	cmdNode = gn->commands.first;
1171 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1172 	    lineno++;
1173 	    if (buf[x - 1] == '\n')
1174 		buf[x - 1] = '\0';
1175 	    else {
1176 		warnx("%s: %d: line truncated at %u", fname, lineno, x);
1177 		oodate = true;
1178 		break;
1179 	    }
1180 	    link_src = NULL;
1181 	    move_target = NULL;
1182 	    /* Find the start of the build monitor section. */
1183 	    if (!have_filemon) {
1184 		if (strncmp(buf, "-- filemon", 10) == 0) {
1185 		    have_filemon = true;
1186 		    continue;
1187 		}
1188 		if (strncmp(buf, "# buildmon", 10) == 0) {
1189 		    have_filemon = true;
1190 		    continue;
1191 		}
1192 	    }
1193 
1194 	    /* Delimit the record type. */
1195 	    p = buf;
1196 #ifdef DEBUG_META_MODE
1197 	    DEBUG3(META, "%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 			FStr ldir;
1240 
1241 			if (lastpid > 0) {
1242 			    /* We need to remember these. */
1243 			    Global_SetExpand(lcwd_vname, lcwd);
1244 			    Global_SetExpand(ldir_vname, latestdir);
1245 			}
1246 			snprintf(lcwd_vname, sizeof lcwd_vname, LCWD_VNAME_FMT, pid);
1247 			snprintf(ldir_vname, sizeof ldir_vname, LDIR_VNAME_FMT, pid);
1248 			lastpid = pid;
1249 			ldir = Var_Value(SCOPE_GLOBAL, ldir_vname);
1250 			if (ldir.str != NULL) {
1251 			    strlcpy(latestdir, ldir.str, sizeof latestdir);
1252 			    FStr_Done(&ldir);
1253 			}
1254 			ldir = Var_Value(SCOPE_GLOBAL, lcwd_vname);
1255 			if (ldir.str != NULL) {
1256 			    strlcpy(lcwd, ldir.str, sizeof lcwd);
1257 			    FStr_Done(&ldir);
1258 			}
1259 		    }
1260 		    /* Skip past the pid. */
1261 		    if (strsep(&p, " ") == NULL)
1262 			continue;
1263 #ifdef DEBUG_META_MODE
1264 		    if (DEBUG(META))
1265 			debug_printf("%s: %d: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1266 				     fname, lineno,
1267 				     pid, buf[0], cwd, lcwd, latestdir);
1268 #endif
1269 		    break;
1270 		}
1271 
1272 		CHECK_VALID_META(p);
1273 
1274 		/* Process according to record type. */
1275 		switch (buf[0]) {
1276 		case 'X':		/* eXit */
1277 		    Var_DeleteExpand(SCOPE_GLOBAL, lcwd_vname);
1278 		    Var_DeleteExpand(SCOPE_GLOBAL, ldir_vname);
1279 		    lastpid = 0;	/* no need to save ldir_vname */
1280 		    break;
1281 
1282 		case 'F':		/* [v]Fork */
1283 		    {
1284 			char cldir[64];
1285 			int child;
1286 
1287 			child = atoi(p);
1288 			if (child > 0) {
1289 			    snprintf(cldir, sizeof cldir, LCWD_VNAME_FMT, child);
1290 			    Global_SetExpand(cldir, lcwd);
1291 			    snprintf(cldir, sizeof cldir, LDIR_VNAME_FMT, child);
1292 			    Global_SetExpand(cldir, latestdir);
1293 #ifdef DEBUG_META_MODE
1294 			    if (DEBUG(META))
1295 				debug_printf(
1296 					"%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 		    Global_SetExpand(lcwd_vname, lcwd);
1309 		    Global_SetExpand(ldir_vname, lcwd);
1310 #ifdef DEBUG_META_MODE
1311 		    DEBUG4(META, "%s: %d: cwd=%s ldir=%s\n",
1312 			   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 		    {
1323 			char *cp = p;	/* save this for a second */
1324 			/* now get target */
1325 			if (strsep(&p, " ") == NULL)
1326 			    continue;
1327 			CHECK_VALID_META(p);
1328 			move_target = p;
1329 			p = cp;
1330 		    }
1331 		    /* 'L' and 'M' put single quotes around the args */
1332 		    DEQUOTE(p);
1333 		    DEQUOTE(move_target);
1334 		    /* FALLTHROUGH */
1335 		case 'D':		/* unlink */
1336 		    if (*p == '/') {
1337 			/* remove any missingFiles entries that match p */
1338 			StringListNode *ln = missingFiles.first;
1339 			while (ln != NULL) {
1340 			    StringListNode *next = ln->next;
1341 			    if (path_starts_with(ln->datum, p)) {
1342 				free(ln->datum);
1343 				Lst_Remove(&missingFiles, ln);
1344 			    }
1345 			    ln = next;
1346 			}
1347 		    }
1348 		    if (buf[0] == 'M') {
1349 			/* the target of the mv is a file 'W'ritten */
1350 #ifdef DEBUG_META_MODE
1351 			DEBUG2(META, "meta_oodate: M %s -> %s\n",
1352 			       p, move_target);
1353 #endif
1354 			p = move_target;
1355 			goto check_write;
1356 		    }
1357 		    break;
1358 		case 'L':		/* Link */
1359 		    /*
1360 		     * For 'L'inks check
1361 		     * the src as for 'R'ead
1362 		     * and the target as for 'W'rite.
1363 		     */
1364 		    link_src = p;
1365 		    /* now get target */
1366 		    if (strsep(&p, " ") == NULL)
1367 			continue;
1368 		    CHECK_VALID_META(p);
1369 		    /* 'L' and 'M' put single quotes around the args */
1370 		    DEQUOTE(p);
1371 		    DEQUOTE(link_src);
1372 #ifdef DEBUG_META_MODE
1373 		    DEBUG2(META, "meta_oodate: L %s -> %s\n", link_src, p);
1374 #endif
1375 		    /* FALLTHROUGH */
1376 		case 'W':		/* Write */
1377 		check_write:
1378 		    /*
1379 		     * If a file we generated within our bailiwick
1380 		     * but outside of .OBJDIR is missing,
1381 		     * we need to do it again.
1382 		     */
1383 		    /* ignore non-absolute paths */
1384 		    if (*p != '/')
1385 			break;
1386 
1387 		    if (Lst_IsEmpty(&metaBailiwick))
1388 			break;
1389 
1390 		    /* ignore cwd - normal dependencies handle those */
1391 		    if (strncmp(p, cwd, cwdlen) == 0)
1392 			break;
1393 
1394 		    if (!has_any_prefix(p, &metaBailiwick))
1395 			break;
1396 
1397 		    /* tmpdir might be within */
1398 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1399 			break;
1400 
1401 		    /* ignore anything containing the string "tmp" */
1402 		    /* XXX: The arguments to strstr must be swapped. */
1403 		    if (strstr("tmp", p) != NULL)
1404 			break;
1405 
1406 		    if ((link_src != NULL && cached_lstat(p, &cst) < 0) ||
1407 			(link_src == NULL && cached_stat(p, &cst) < 0)) {
1408 			if (!meta_ignore(gn, p))
1409 			    append_if_new(&missingFiles, p);
1410 		    }
1411 		    break;
1412 		check_link_src:
1413 		    p = link_src;
1414 		    link_src = NULL;
1415 #ifdef DEBUG_META_MODE
1416 		    DEBUG1(META, "meta_oodate: L src %s\n", p);
1417 #endif
1418 		    /* FALLTHROUGH */
1419 		case 'R':		/* Read */
1420 		case 'E':		/* Exec */
1421 		    /*
1422 		     * Check for runtime files that can't
1423 		     * be part of the dependencies because
1424 		     * they are _expected_ to change.
1425 		     */
1426 		    if (meta_ignore(gn, p))
1427 			break;
1428 
1429 		    /*
1430 		     * The rest of the record is the file name.
1431 		     * Check if it's not an absolute path.
1432 		     */
1433 		    {
1434 			char *sdirs[4];
1435 			char **sdp;
1436 			int sdx = 0;
1437 			bool found = false;
1438 
1439 			if (*p == '/') {
1440 			    sdirs[sdx++] = p; /* done */
1441 			} else {
1442 			    if (strcmp(".", p) == 0)
1443 				continue; /* no point */
1444 
1445 			    /* Check vs latestdir */
1446 			    snprintf(fname1, sizeof fname1, "%s/%s", latestdir, p);
1447 			    sdirs[sdx++] = fname1;
1448 
1449 			    if (strcmp(latestdir, lcwd) != 0) {
1450 				/* Check vs lcwd */
1451 				snprintf(fname2, sizeof fname2, "%s/%s", lcwd, p);
1452 				sdirs[sdx++] = fname2;
1453 			    }
1454 			    if (strcmp(lcwd, cwd) != 0) {
1455 				/* Check vs cwd */
1456 				snprintf(fname3, sizeof fname3, "%s/%s", cwd, p);
1457 				sdirs[sdx++] = fname3;
1458 			    }
1459 			}
1460 			sdirs[sdx++] = NULL;
1461 
1462 			for (sdp = sdirs; *sdp != NULL && !found; sdp++) {
1463 #ifdef DEBUG_META_MODE
1464 			    DEBUG3(META, "%s: %d: looking for: %s\n",
1465 				   fname, lineno, *sdp);
1466 #endif
1467 			    if (cached_stat(*sdp, &cst) == 0) {
1468 				found = true;
1469 				p = *sdp;
1470 			    }
1471 			}
1472 			if (found) {
1473 #ifdef DEBUG_META_MODE
1474 			    DEBUG3(META, "%s: %d: found: %s\n",
1475 				   fname, lineno, p);
1476 #endif
1477 			    if (!S_ISDIR(cst.cst_mode) &&
1478 				cst.cst_mtime > gn->mtime) {
1479 				DEBUG3(META, "%s: %d: file '%s' is newer than the target...\n",
1480 				       fname, lineno, p);
1481 				oodate = true;
1482 			    } else if (S_ISDIR(cst.cst_mode)) {
1483 				/* Update the latest directory. */
1484 				cached_realpath(p, latestdir);
1485 			    }
1486 			} else if (errno == ENOENT && *p == '/' &&
1487 				   strncmp(p, cwd, cwdlen) != 0) {
1488 			    /*
1489 			     * A referenced file outside of CWD is missing.
1490 			     * We cannot catch every eventuality here...
1491 			     */
1492 			    append_if_new(&missingFiles, p);
1493 			}
1494 		    }
1495 		    if (buf[0] == 'E') {
1496 			/* previous latestdir is no longer relevant */
1497 			strlcpy(latestdir, lcwd, sizeof latestdir);
1498 		    }
1499 		    break;
1500 		default:
1501 		    break;
1502 		}
1503 		if (!oodate && buf[0] == 'L' && link_src != NULL)
1504 		    goto check_link_src;
1505 	    } else if (strcmp(buf, "CMD") == 0) {
1506 		/*
1507 		 * Compare the current command with the one in the
1508 		 * meta data file.
1509 		 */
1510 		if (cmdNode == NULL) {
1511 		    DEBUG2(META, "%s: %d: there were more build commands in the meta data file than there are now...\n",
1512 			   fname, lineno);
1513 		    oodate = true;
1514 		} else {
1515 		    const char *cp;
1516 		    char *cmd = cmdNode->datum;
1517 		    bool hasOODATE = false;
1518 
1519 		    if (strstr(cmd, "$?") != NULL)
1520 			hasOODATE = true;
1521 		    else if ((cp = strstr(cmd, ".OODATE")) != NULL) {
1522 			/* check for $[{(].OODATE[:)}] */
1523 			if (cp > cmd + 2 && cp[-2] == '$')
1524 			    hasOODATE = true;
1525 		    }
1526 		    if (hasOODATE) {
1527 			needOODATE = true;
1528 			DEBUG2(META, "%s: %d: cannot compare command using .OODATE\n",
1529 			       fname, lineno);
1530 		    }
1531 		    (void)Var_Subst(cmd, gn, VARE_UNDEFERR, &cmd);
1532 		    /* TODO: handle errors */
1533 
1534 		    if ((cp = strchr(cmd, '\n')) != NULL) {
1535 			int n;
1536 
1537 			/*
1538 			 * This command contains newlines, we need to
1539 			 * fetch more from the .meta file before we
1540 			 * attempt a comparison.
1541 			 */
1542 			/* first put the newline back at buf[x - 1] */
1543 			buf[x - 1] = '\n';
1544 			do {
1545 			    /* now fetch the next line */
1546 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1547 				break;
1548 			    x = n;
1549 			    lineno++;
1550 			    if (buf[x - 1] != '\n') {
1551 				warnx("%s: %d: line truncated at %u", fname, lineno, x);
1552 				break;
1553 			    }
1554 			    cp = strchr(cp + 1, '\n');
1555 			} while (cp != NULL);
1556 			if (buf[x - 1] == '\n')
1557 			    buf[x - 1] = '\0';
1558 		    }
1559 		    if (p != NULL &&
1560 			!hasOODATE &&
1561 			!(gn->type & OP_NOMETA_CMP) &&
1562 			(strcmp(p, cmd) != 0)) {
1563 			DEBUG4(META, "%s: %d: a build command has changed\n%s\nvs\n%s\n",
1564 			       fname, lineno, p, cmd);
1565 			if (!metaIgnoreCMDs)
1566 			    oodate = true;
1567 		    }
1568 		    free(cmd);
1569 		    cmdNode = cmdNode->next;
1570 		}
1571 	    } else if (strcmp(buf, "CWD") == 0) {
1572 		/*
1573 		 * Check if there are extra commands now
1574 		 * that weren't in the meta data file.
1575 		 */
1576 		if (!oodate && cmdNode != NULL) {
1577 		    DEBUG2(META, "%s: %d: there are extra build commands now that weren't in the meta data file\n",
1578 			   fname, lineno);
1579 		    oodate = true;
1580 		}
1581 		CHECK_VALID_META(p);
1582 		if (strcmp(p, cwd) != 0) {
1583 		    DEBUG4(META, "%s: %d: the current working directory has changed from '%s' to '%s'\n",
1584 			   fname, lineno, p, curdir);
1585 		    oodate = true;
1586 		}
1587 	    }
1588 	}
1589 
1590 	fclose(fp);
1591 	if (!Lst_IsEmpty(&missingFiles)) {
1592 	    DEBUG2(META, "%s: missing files: %s...\n",
1593 		   fname, (char *)missingFiles.first->datum);
1594 	    oodate = true;
1595 	}
1596 	if (!oodate && !have_filemon && filemonMissing) {
1597 	    DEBUG1(META, "%s: missing filemon data\n", fname);
1598 	    oodate = true;
1599 	}
1600     } else {
1601 	if (writeMeta && (metaMissing || (gn->type & OP_META))) {
1602 	    const char *cp = NULL;
1603 
1604 	    /* if target is in .CURDIR we do not need a meta file */
1605 	    if (gn->path != NULL && (cp = strrchr(gn->path, '/')) != NULL &&
1606 		(cp > gn->path)) {
1607 		if (strncmp(curdir, gn->path, (size_t)(cp - gn->path)) != 0) {
1608 		    cp = NULL;		/* not in .CURDIR */
1609 		}
1610 	    }
1611 	    if (cp == NULL) {
1612 		DEBUG1(META, "%s: required but missing\n", fname);
1613 		oodate = true;
1614 		needOODATE = true;	/* assume the worst */
1615 	    }
1616 	}
1617     }
1618 
1619     Lst_DoneCall(&missingFiles, free);
1620 
1621     if (oodate && needOODATE) {
1622 	/*
1623 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1624 	 * We have decided it is oodate, so .OODATE needs to be set.
1625 	 * All we can sanely do is set it to .ALLSRC.
1626 	 */
1627 	Var_Delete(gn, OODATE);
1628 	Var_Set(gn, OODATE, GNode_VarAllsrc(gn));
1629     }
1630 
1631  oodate_out:
1632     FStr_Done(&dname);
1633     return oodate;
1634 }
1635 
1636 /* support for compat mode */
1637 
1638 static int childPipe[2];
1639 
1640 void
1641 meta_compat_start(void)
1642 {
1643 #ifdef USE_FILEMON_ONCE
1644     /*
1645      * We need to re-open filemon for each cmd.
1646      */
1647     BuildMon *pbm = &Mybm;
1648 
1649     if (pbm->mfp != NULL && useFilemon) {
1650 	meta_open_filemon(pbm);
1651     } else {
1652 	pbm->mon_fd = -1;
1653 	pbm->filemon = NULL;
1654     }
1655 #endif
1656     if (pipe(childPipe) < 0)
1657 	Punt("Cannot create pipe: %s", strerror(errno));
1658     /* Set close-on-exec flag for both */
1659     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1660     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1661 }
1662 
1663 void
1664 meta_compat_child(void)
1665 {
1666     meta_job_child(NULL);
1667     if (dup2(childPipe[1], 1) < 0 || dup2(1, 2) < 0)
1668 	execDie("dup2", "pipe");
1669 }
1670 
1671 void
1672 meta_compat_parent(pid_t child)
1673 {
1674     int outfd, metafd, maxfd, nfds;
1675     char buf[BUFSIZ+1];
1676     fd_set readfds;
1677 
1678     meta_job_parent(NULL, child);
1679     close(childPipe[1]);			/* child side */
1680     outfd = childPipe[0];
1681 #ifdef USE_FILEMON
1682     metafd = Mybm.filemon != NULL ? filemon_readfd(Mybm.filemon) : -1;
1683 #else
1684     metafd = -1;
1685 #endif
1686     maxfd = -1;
1687     if (outfd > maxfd)
1688 	    maxfd = outfd;
1689     if (metafd > maxfd)
1690 	    maxfd = metafd;
1691 
1692     while (outfd != -1 || metafd != -1) {
1693 	FD_ZERO(&readfds);
1694 	if (outfd != -1) {
1695 	    FD_SET(outfd, &readfds);
1696 	}
1697 	if (metafd != -1) {
1698 	    FD_SET(metafd, &readfds);
1699 	}
1700 	nfds = select(maxfd + 1, &readfds, NULL, NULL, NULL);
1701 	if (nfds == -1) {
1702 	    if (errno == EINTR)
1703 		continue;
1704 	    err(1, "select");
1705 	}
1706 
1707 	if (outfd != -1 && FD_ISSET(outfd, &readfds) != 0) do {
1708 	    /* XXX this is not line-buffered */
1709 	    ssize_t nread = read(outfd, buf, sizeof buf - 1);
1710 	    if (nread == -1)
1711 		err(1, "read");
1712 	    if (nread == 0) {
1713 		close(outfd);
1714 		outfd = -1;
1715 		break;
1716 	    }
1717 	    fwrite(buf, 1, (size_t)nread, stdout);
1718 	    fflush(stdout);
1719 	    buf[nread] = '\0';
1720 	    meta_job_output(NULL, buf, "");
1721 	} while (false);
1722 	if (metafd != -1 && FD_ISSET(metafd, &readfds) != 0) {
1723 	    if (meta_job_event(NULL) <= 0)
1724 		metafd = -1;
1725 	}
1726     }
1727 }
1728 
1729 #endif /* USE_META */
1730