xref: /freebsd/contrib/bmake/meta.c (revision 6e563a1b608438504d963c2d7c70e50d2e75af46)
1 /*      $NetBSD: meta.c,v 1.199 2022/03/04 23:17:16 sjg Exp $ */
2 
3 /*
4  * Implement 'meta' mode.
5  * Adapted from John Birrell's patches to FreeBSD make.
6  * --sjg
7  */
8 /*
9  * Copyright (c) 2009-2016, Juniper Networks, Inc.
10  * Portions Copyright (c) 2009, John Birrell.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 #if defined(USE_META)
34 
35 #ifdef HAVE_CONFIG_H
36 # include "config.h"
37 #endif
38 #include <sys/stat.h>
39 #ifdef HAVE_LIBGEN_H
40 #include <libgen.h>
41 #elif !defined(HAVE_DIRNAME)
42 char * dirname(char *);
43 #endif
44 #include <errno.h>
45 #if !defined(HAVE_CONFIG_H) || defined(HAVE_ERR_H)
46 #include <err.h>
47 #endif
48 
49 #include "make.h"
50 #include "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 #ifndef MAKE_META_CMP_FILTER
73 #define MAKE_META_CMP_FILTER ".MAKE.META.CMP_FILTER"
74 #endif
75 
76 bool useMeta = false;
77 static bool useFilemon = false;
78 static bool writeMeta = false;
79 static bool metaMissing = false;	/* oodate if missing */
80 static bool filemonMissing = false;	/* oodate if missing */
81 static bool metaEnv = false;		/* don't save env unless asked */
82 static bool metaVerbose = false;
83 static bool metaIgnoreCMDs = false;	/* ignore CMDs in .meta files */
84 static bool metaIgnorePatterns = false; /* do we need to do pattern matches */
85 static bool metaIgnoreFilter = false;	/* do we have more complex filtering? */
86 static bool metaCmpFilter = false;	/* do we have CMP_FILTER ? */
87 static bool metaCurdirOk = false;	/* write .meta in .CURDIR Ok? */
88 static bool metaSilent = false;		/* if we have a .meta be SILENT */
89 
90 extern bool forceJobs;
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 #if !defined(HAVE_STRESEP)
106 char * stresep(char **, const char *, int);
107 #endif
108 
109 /*
110  * Filemon is a kernel module which snoops certain syscalls.
111  *
112  * C chdir
113  * E exec
114  * F [v]fork
115  * L [sym]link
116  * M rename
117  * R read
118  * W write
119  * S stat
120  *
121  * See meta_oodate below - we mainly care about 'E' and 'R'.
122  *
123  * We can still use meta mode without filemon, but
124  * the benefits are more limited.
125  */
126 #ifdef USE_FILEMON
127 
128 /*
129  * Open the filemon device.
130  */
131 static void
132 meta_open_filemon(BuildMon *pbm)
133 {
134     int dupfd;
135 
136     pbm->mon_fd = -1;
137     pbm->filemon = NULL;
138     if (!useFilemon || pbm->mfp == NULL)
139 	return;
140 
141     pbm->filemon = filemon_open();
142     if (pbm->filemon == NULL) {
143 	useFilemon = false;
144 	warn("Could not open filemon %s", filemon_path());
145 	return;
146     }
147 
148     /*
149      * We use a file outside of '.'
150      * to avoid a FreeBSD kernel bug where unlink invalidates
151      * cwd causing getcwd to do a lot more work.
152      * We only care about the descriptor.
153      */
154     if (!opts.compatMake)
155 	pbm->mon_fd = Job_TempFile("filemon.XXXXXX", NULL, 0);
156     else
157 	pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL, 0);
158     if ((dupfd = dup(pbm->mon_fd)) == -1) {
159 	Punt("Could not dup filemon output: %s", strerror(errno));
160     }
161     (void)fcntl(dupfd, F_SETFD, FD_CLOEXEC);
162     if (filemon_setfd(pbm->filemon, dupfd) == -1) {
163 	Punt("Could not set filemon file descriptor: %s", strerror(errno));
164     }
165     /* we don't need these once we exec */
166     (void)fcntl(pbm->mon_fd, F_SETFD, FD_CLOEXEC);
167 }
168 
169 /*
170  * Read the build monitor output file and write records to the target's
171  * metadata file.
172  */
173 static int
174 filemon_read(FILE *mfp, int fd)
175 {
176     char buf[BUFSIZ];
177     int error;
178 
179     /* Check if we're not writing to a meta data file.*/
180     if (mfp == NULL) {
181 	if (fd >= 0)
182 	    close(fd);			/* not interested */
183 	return 0;
184     }
185     /* rewind */
186     if (lseek(fd, (off_t)0, SEEK_SET) < 0) {
187 	error = errno;
188 	warn("Could not rewind filemon");
189 	fprintf(mfp, "\n");
190     } else {
191 	ssize_t n;
192 
193 	error = 0;
194 	fprintf(mfp, "\n-- filemon acquired metadata --\n");
195 
196 	while ((n = read(fd, buf, sizeof buf)) > 0) {
197 	    if ((ssize_t)fwrite(buf, 1, (size_t)n, mfp) < n)
198 		error = EIO;
199 	}
200     }
201     if (fflush(mfp) != 0)
202 	Punt("Cannot write filemon data to meta file: %s",
203 	    strerror(errno));
204     if (close(fd) < 0)
205 	error = errno;
206     return error;
207 }
208 #endif
209 
210 /*
211  * when realpath() fails,
212  * we use this, to clean up ./ and ../
213  */
214 static void
215 eat_dots(char *buf)
216 {
217     char *p;
218 
219     while ((p = strstr(buf, "/./")) != NULL)
220 	memmove(p, p + 2, strlen(p + 2) + 1);
221 
222     while ((p = strstr(buf, "/../")) != NULL) {
223 	char *p2 = p + 3;
224 	if (p > buf) {
225 	    do {
226 		p--;
227 	    } while (p > buf && *p != '/');
228 	}
229 	if (*p == '/')
230 	    memmove(p, p2, strlen(p2) + 1);
231 	else
232 	    return;		/* can't happen? */
233     }
234 }
235 
236 static char *
237 meta_name(char *mname, size_t mnamelen,
238 	  const char *dname,
239 	  const char *tname,
240 	  const char *cwd)
241 {
242     char buf[MAXPATHLEN];
243     char *rp, *cp;
244     const char *tname_base;
245     char *tp;
246     char *dtp;
247     size_t ldname;
248 
249     /*
250      * Weed out relative paths from the target file name.
251      * We have to be careful though since if target is a
252      * symlink, the result will be unstable.
253      * So we use realpath() just to get the dirname, and leave the
254      * basename as given to us.
255      */
256     if ((tname_base = strrchr(tname, '/')) != NULL) {
257 	if (cached_realpath(tname, buf) != NULL) {
258 	    if ((rp = strrchr(buf, '/')) != NULL) {
259 		rp++;
260 		tname_base++;
261 		if (strcmp(tname_base, rp) != 0)
262 		    strlcpy(rp, tname_base, sizeof buf - (size_t)(rp - buf));
263 	    }
264 	    tname = buf;
265 	} else {
266 	    /*
267 	     * We likely have a directory which is about to be made.
268 	     * We pretend realpath() succeeded, to have a chance
269 	     * of generating the same meta file name that we will
270 	     * next time through.
271 	     */
272 	    if (tname[0] == '/') {
273 		strlcpy(buf, tname, sizeof buf);
274 	    } else {
275 		snprintf(buf, sizeof buf, "%s/%s", cwd, tname);
276 	    }
277 	    eat_dots(buf);
278 	    tname = buf;
279 	}
280     }
281     /* on some systems dirname may modify its arg */
282     tp = bmake_strdup(tname);
283     dtp = dirname(tp);
284     if (strcmp(dname, dtp) == 0)
285 	snprintf(mname, mnamelen, "%s.meta", tname);
286     else {
287 	ldname = strlen(dname);
288 	if (strncmp(dname, dtp, ldname) == 0 && dtp[ldname] == '/')
289 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, &tname[ldname+1]);
290 	else
291 	    snprintf(mname, mnamelen, "%s/%s.meta", dname, tname);
292 
293 	/*
294 	 * Replace path separators in the file name after the
295 	 * current object directory path.
296 	 */
297 	cp = mname + strlen(dname) + 1;
298 
299 	while (*cp != '\0') {
300 	    if (*cp == '/')
301 		*cp = '_';
302 	    cp++;
303 	}
304     }
305     free(tp);
306     return mname;
307 }
308 
309 /*
310  * Return true if running ${.MAKE}
311  * Bypassed if target is flagged .MAKE
312  */
313 static bool
314 is_submake(const char *cmd, GNode *gn)
315 {
316     static const char *p_make = NULL;
317     static size_t p_len;
318     char *mp = NULL;
319     const char *cp2;
320     bool rc = false;
321 
322     if (p_make == NULL) {
323 	p_make = Var_Value(gn, ".MAKE").str;
324 	p_len = strlen(p_make);
325     }
326     if (strchr(cmd, '$') != NULL) {
327 	(void)Var_Subst(cmd, gn, VARE_WANTRES, &mp);
328 	/* TODO: handle errors */
329 	cmd = mp;
330     }
331     cp2 = strstr(cmd, p_make);
332     if (cp2 != NULL) {
333 	switch (cp2[p_len]) {
334 	case '\0':
335 	case ' ':
336 	case '\t':
337 	case '\n':
338 	    rc = true;
339 	    break;
340 	}
341 	if (cp2 > cmd && rc) {
342 	    switch (cp2[-1]) {
343 	    case ' ':
344 	    case '\t':
345 	    case '\n':
346 		break;
347 	    default:
348 		rc = false;		/* no match */
349 		break;
350 	    }
351 	}
352     }
353     free(mp);
354     return rc;
355 }
356 
357 static bool
358 any_is_submake(GNode *gn)
359 {
360     StringListNode *ln;
361 
362     for (ln = gn->commands.first; ln != NULL; ln = ln->next)
363 	if (is_submake(ln->datum, gn))
364 	    return true;
365     return false;
366 }
367 
368 static void
369 printCMD(const char *ucmd, FILE *fp, GNode *gn)
370 {
371     FStr xcmd = FStr_InitRefer(ucmd);
372 
373     Var_Expand(&xcmd, gn, VARE_WANTRES);
374     fprintf(fp, "CMD %s\n", xcmd.str);
375     FStr_Done(&xcmd);
376 }
377 
378 static void
379 printCMDs(GNode *gn, FILE *fp)
380 {
381     StringListNode *ln;
382 
383     for (ln = gn->commands.first; ln != NULL; ln = ln->next)
384 	printCMD(ln->datum, fp, gn);
385 }
386 
387 /*
388  * Certain node types never get a .meta file
389  */
390 #define SKIP_META_TYPE(_type) do { \
391     if ((gn->type & __CONCAT(OP_, _type))) { \
392 	if (verbose) { \
393 	    debug_printf("Skipping meta for %s: .%s\n", \
394 		    gn->name, __STRING(_type)); \
395 	} \
396 	return false; \
397     } \
398 } while (false)
399 
400 
401 /*
402  * Do we need/want a .meta file ?
403  */
404 static bool
405 meta_needed(GNode *gn, const char *dname,
406 	    char *objdir_realpath, bool verbose)
407 {
408     struct cached_stat cst;
409 
410     if (verbose)
411 	verbose = DEBUG(META);
412 
413     /* This may be a phony node which we don't want meta data for... */
414     /* Skip .meta for .BEGIN, .END, .ERROR etc as well. */
415     /* Or it may be explicitly flagged as .NOMETA */
416     SKIP_META_TYPE(NOMETA);
417     /* Unless it is explicitly flagged as .META */
418     if (!(gn->type & OP_META)) {
419 	SKIP_META_TYPE(PHONY);
420 	SKIP_META_TYPE(SPECIAL);
421 	SKIP_META_TYPE(MAKE);
422     }
423 
424     /* Check if there are no commands to execute. */
425     if (Lst_IsEmpty(&gn->commands)) {
426 	if (verbose)
427 	    debug_printf("Skipping meta for %s: no commands\n", gn->name);
428 	return false;
429     }
430     if ((gn->type & (OP_META|OP_SUBMAKE)) == OP_SUBMAKE) {
431 	/* OP_SUBMAKE is a bit too aggressive */
432 	if (any_is_submake(gn)) {
433 	    DEBUG1(META, "Skipping meta for %s: .SUBMAKE\n", gn->name);
434 	    return false;
435 	}
436     }
437 
438     /* The object directory may not exist. Check it.. */
439     if (cached_stat(dname, &cst) != 0) {
440 	if (verbose)
441 	    debug_printf("Skipping meta for %s: no .OBJDIR\n", gn->name);
442 	return false;
443     }
444 
445     /* make sure these are canonical */
446     if (cached_realpath(dname, objdir_realpath) != NULL)
447 	dname = objdir_realpath;
448 
449     /* If we aren't in the object directory, don't create a meta file. */
450     if (!metaCurdirOk && strcmp(curdir, dname) == 0) {
451 	if (verbose)
452 	    debug_printf("Skipping meta for %s: .OBJDIR == .CURDIR\n",
453 			 gn->name);
454 	return false;
455     }
456     return true;
457 }
458 
459 
460 static FILE *
461 meta_create(BuildMon *pbm, GNode *gn)
462 {
463     FILE *fp;
464     char buf[MAXPATHLEN];
465     char objdir_realpath[MAXPATHLEN];
466     char **ptr;
467     FStr dname;
468     const char *tname;
469     char *fname;
470     const char *cp;
471 
472     fp = NULL;
473 
474     dname = Var_Value(gn, ".OBJDIR");
475     tname = GNode_VarTarget(gn);
476 
477     /* if this succeeds objdir_realpath is realpath of dname */
478     if (!meta_needed(gn, dname.str, objdir_realpath, true))
479 	goto out;
480     dname.str = objdir_realpath;
481 
482     if (metaVerbose) {
483 	char *mp;
484 
485 	/* Describe the target we are building */
486 	(void)Var_Subst("${" MAKE_META_PREFIX "}", gn, VARE_WANTRES, &mp);
487 	/* TODO: handle errors */
488 	if (mp[0] != '\0')
489 	    fprintf(stdout, "%s\n", mp);
490 	free(mp);
491     }
492     /* Get the basename of the target */
493     cp = str_basename(tname);
494 
495     fflush(stdout);
496 
497     if (!writeMeta)
498 	/* Don't create meta data. */
499 	goto out;
500 
501     fname = meta_name(pbm->meta_fname, sizeof pbm->meta_fname,
502 		      dname.str, tname, objdir_realpath);
503 
504 #ifdef DEBUG_META_MODE
505     DEBUG1(META, "meta_create: %s\n", fname);
506 #endif
507 
508     if ((fp = fopen(fname, "w")) == NULL)
509 	Punt("Could not open meta file '%s': %s", fname, strerror(errno));
510 
511     fprintf(fp, "# Meta data file %s\n", fname);
512 
513     printCMDs(gn, fp);
514 
515     fprintf(fp, "CWD %s\n", getcwd(buf, sizeof buf));
516     fprintf(fp, "TARGET %s\n", tname);
517     cp = GNode_VarOodate(gn);
518     if (cp != NULL && *cp != '\0') {
519 	fprintf(fp, "OODATE %s\n", cp);
520     }
521     if (metaEnv) {
522 	for (ptr = environ; *ptr != NULL; ptr++)
523 	    fprintf(fp, "ENV %s\n", *ptr);
524     }
525 
526     fprintf(fp, "-- command output --\n");
527     if (fflush(fp) != 0)
528 	Punt("Cannot write expanded command to meta file: %s",
529 	    strerror(errno));
530 
531     Global_Append(".MAKE.META.FILES", fname);
532     Global_Append(".MAKE.META.CREATED", fname);
533 
534     gn->type |= OP_META;		/* in case anyone wants to know */
535     if (metaSilent) {
536 	    gn->type |= OP_SILENT;
537     }
538  out:
539     FStr_Done(&dname);
540 
541     return fp;
542 }
543 
544 static bool
545 boolValue(const char *s)
546 {
547     switch (*s) {
548     case '0':
549     case 'N':
550     case 'n':
551     case 'F':
552     case 'f':
553 	return false;
554     }
555     return true;
556 }
557 
558 /*
559  * Initialization we need before reading makefiles.
560  */
561 void
562 meta_init(void)
563 {
564 #ifdef USE_FILEMON
565 	/* this allows makefiles to test if we have filemon support */
566 	Global_Set(".MAKE.PATH_FILEMON", filemon_path());
567 #endif
568 }
569 
570 
571 #define get_mode_bf(bf, token) \
572     if ((cp = strstr(make_mode, token)) != NULL) \
573 	bf = boolValue(cp + sizeof (token) - 1)
574 
575 /*
576  * Initialization we need after reading makefiles.
577  */
578 void
579 meta_mode_init(const char *make_mode)
580 {
581     static bool once = false;
582     const char *cp;
583 
584     useMeta = true;
585     useFilemon = true;
586     writeMeta = true;
587 
588     if (make_mode != NULL) {
589 	if (strstr(make_mode, "env") != NULL)
590 	    metaEnv = true;
591 	if (strstr(make_mode, "verb") != NULL)
592 	    metaVerbose = true;
593 	if (strstr(make_mode, "read") != NULL)
594 	    writeMeta = false;
595 	if (strstr(make_mode, "nofilemon") != NULL)
596 	    useFilemon = false;
597 	if (strstr(make_mode, "ignore-cmd") != NULL)
598 	    metaIgnoreCMDs = true;
599 	if (useFilemon)
600 	    get_mode_bf(filemonMissing, "missing-filemon=");
601 	get_mode_bf(metaCurdirOk, "curdirok=");
602 	get_mode_bf(metaMissing, "missing-meta=");
603 	get_mode_bf(metaSilent, "silent=");
604     }
605     if (metaVerbose && !Var_Exists(SCOPE_GLOBAL, MAKE_META_PREFIX)) {
606 	/*
607 	 * The default value for MAKE_META_PREFIX
608 	 * prints the absolute path of the target.
609 	 * This works be cause :H will generate '.' if there is no /
610 	 * and :tA will resolve that to cwd.
611 	 */
612 	Global_Set(MAKE_META_PREFIX,
613 	    "Building ${.TARGET:H:tA}/${.TARGET:T}");
614     }
615     if (once)
616 	return;
617     once = true;
618     memset(&Mybm, 0, sizeof Mybm);
619     /*
620      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
621      */
622     (void)Var_Subst("${.MAKE.META.BAILIWICK:O:u:tA}",
623 		    SCOPE_GLOBAL, VARE_WANTRES, &metaBailiwickStr);
624     /* TODO: handle errors */
625     str2Lst_Append(&metaBailiwick, metaBailiwickStr);
626     /*
627      * We ignore any paths that start with ${.MAKE.META.IGNORE_PATHS}
628      */
629     Global_Append(MAKE_META_IGNORE_PATHS,
630 	       "/dev /etc /proc /tmp /var/run /var/tmp ${TMPDIR}");
631     (void)Var_Subst("${" MAKE_META_IGNORE_PATHS ":O:u:tA}",
632 		    SCOPE_GLOBAL, VARE_WANTRES, &metaIgnorePathsStr);
633     /* TODO: handle errors */
634     str2Lst_Append(&metaIgnorePaths, metaIgnorePathsStr);
635 
636     /*
637      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
638      */
639     metaIgnorePatterns = Var_Exists(SCOPE_GLOBAL, MAKE_META_IGNORE_PATTERNS);
640     metaIgnoreFilter = Var_Exists(SCOPE_GLOBAL, MAKE_META_IGNORE_FILTER);
641     metaCmpFilter = Var_Exists(SCOPE_GLOBAL, MAKE_META_CMP_FILTER);
642 }
643 
644 /*
645  * In each case below we allow for job==NULL
646  */
647 void
648 meta_job_start(Job *job, GNode *gn)
649 {
650     BuildMon *pbm;
651 
652     if (job != NULL) {
653 	pbm = &job->bm;
654     } else {
655 	pbm = &Mybm;
656     }
657     pbm->mfp = meta_create(pbm, gn);
658 #ifdef USE_FILEMON_ONCE
659     /* compat mode we open the filemon dev once per command */
660     if (job == NULL)
661 	return;
662 #endif
663 #ifdef USE_FILEMON
664     if (pbm->mfp != NULL && useFilemon) {
665 	meta_open_filemon(pbm);
666     } else {
667 	pbm->mon_fd = -1;
668 	pbm->filemon = NULL;
669     }
670 #endif
671 }
672 
673 /*
674  * The child calls this before doing anything.
675  * It does not disturb our state.
676  */
677 void
678 meta_job_child(Job *job MAKE_ATTR_UNUSED)
679 {
680 #ifdef USE_FILEMON
681     BuildMon *pbm;
682 
683     if (job != NULL) {
684 	pbm = &job->bm;
685     } else {
686 	pbm = &Mybm;
687     }
688     if (pbm->mfp != NULL) {
689 	close(fileno(pbm->mfp));
690 	if (useFilemon && pbm->filemon != NULL) {
691 	    pid_t pid;
692 
693 	    pid = getpid();
694 	    if (filemon_setpid_child(pbm->filemon, pid) == -1) {
695 		Punt("Could not set filemon pid: %s", strerror(errno));
696 	    }
697 	}
698     }
699 #endif
700 }
701 
702 void
703 meta_job_parent(Job *job MAKE_ATTR_UNUSED, pid_t pid MAKE_ATTR_UNUSED)
704 {
705 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
706     BuildMon *pbm;
707 
708     if (job != NULL) {
709 	pbm = &job->bm;
710     } else {
711 	pbm = &Mybm;
712     }
713     if (useFilemon && pbm->filemon != NULL) {
714 	filemon_setpid_parent(pbm->filemon, pid);
715     }
716 #endif
717 }
718 
719 int
720 meta_job_fd(Job *job MAKE_ATTR_UNUSED)
721 {
722 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
723     BuildMon *pbm;
724 
725     if (job != NULL) {
726 	pbm = &job->bm;
727     } else {
728 	pbm = &Mybm;
729     }
730     if (useFilemon && pbm->filemon != NULL) {
731 	return filemon_readfd(pbm->filemon);
732     }
733 #endif
734     return -1;
735 }
736 
737 int
738 meta_job_event(Job *job MAKE_ATTR_UNUSED)
739 {
740 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
741     BuildMon *pbm;
742 
743     if (job != NULL) {
744 	pbm = &job->bm;
745     } else {
746 	pbm = &Mybm;
747     }
748     if (useFilemon && pbm->filemon != NULL) {
749 	return filemon_process(pbm->filemon);
750     }
751 #endif
752     return 0;
753 }
754 
755 void
756 meta_job_error(Job *job, GNode *gn, bool ignerr, int status)
757 {
758     char cwd[MAXPATHLEN];
759     BuildMon *pbm;
760 
761     if (job != NULL) {
762 	pbm = &job->bm;
763 	if (gn == NULL)
764 	    gn = job->node;
765     } else {
766 	pbm = &Mybm;
767     }
768     if (pbm->mfp != NULL) {
769 	fprintf(pbm->mfp, "\n*** Error code %d%s\n",
770 		status, ignerr ? "(ignored)" : "");
771     }
772     if (gn != NULL)
773 	Global_Set(".ERROR_TARGET", GNode_Path(gn));
774     getcwd(cwd, sizeof cwd);
775     Global_Set(".ERROR_CWD", cwd);
776     if (pbm->meta_fname[0] != '\0') {
777 	Global_Set(".ERROR_META_FILE", pbm->meta_fname);
778     }
779     meta_job_finish(job);
780 }
781 
782 void
783 meta_job_output(Job *job, char *cp, const char *nl)
784 {
785     BuildMon *pbm;
786 
787     if (job != NULL) {
788 	pbm = &job->bm;
789     } else {
790 	pbm = &Mybm;
791     }
792     if (pbm->mfp != NULL) {
793 	if (metaVerbose) {
794 	    static char *meta_prefix = NULL;
795 	    static size_t meta_prefix_len;
796 
797 	    if (meta_prefix == NULL) {
798 		char *cp2;
799 
800 		(void)Var_Subst("${" MAKE_META_PREFIX "}",
801 				SCOPE_GLOBAL, VARE_WANTRES, &meta_prefix);
802 		/* TODO: handle errors */
803 		if ((cp2 = strchr(meta_prefix, '$')) != NULL)
804 		    meta_prefix_len = (size_t)(cp2 - meta_prefix);
805 		else
806 		    meta_prefix_len = strlen(meta_prefix);
807 	    }
808 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
809 		cp = strchr(cp + 1, '\n');
810 		if (cp == NULL)
811 		    return;
812 		cp++;
813 	    }
814 	}
815 	fprintf(pbm->mfp, "%s%s", cp, nl);
816     }
817 }
818 
819 int
820 meta_cmd_finish(void *pbmp)
821 {
822     int error = 0;
823     BuildMon *pbm = pbmp;
824 #ifdef USE_FILEMON
825     int x;
826 #endif
827 
828     if (pbm == NULL)
829 	pbm = &Mybm;
830 
831 #ifdef USE_FILEMON
832     if (pbm->filemon != NULL) {
833 	while (filemon_process(pbm->filemon) > 0)
834 	    continue;
835 	if (filemon_close(pbm->filemon) == -1) {
836 	    error = errno;
837 	    Punt("filemon failed: %s", strerror(errno));
838 	}
839 	x = filemon_read(pbm->mfp, pbm->mon_fd);
840 	if (error == 0 && x != 0)
841 	    error = x;
842 	pbm->mon_fd = -1;
843 	pbm->filemon = NULL;
844 	return error;
845     }
846 #endif
847 
848     fprintf(pbm->mfp, "\n");	/* ensure end with newline */
849     return error;
850 }
851 
852 int
853 meta_job_finish(Job *job)
854 {
855     BuildMon *pbm;
856     int error = 0;
857     int x;
858 
859     if (job != NULL) {
860 	pbm = &job->bm;
861     } else {
862 	pbm = &Mybm;
863     }
864     if (pbm->mfp != NULL) {
865 	error = meta_cmd_finish(pbm);
866 	x = fclose(pbm->mfp);
867 	if (error == 0 && x != 0)
868 	    error = errno;
869 	pbm->mfp = NULL;
870 	pbm->meta_fname[0] = '\0';
871     }
872     return error;
873 }
874 
875 void
876 meta_finish(void)
877 {
878     Lst_Done(&metaBailiwick);
879     free(metaBailiwickStr);
880     Lst_Done(&metaIgnorePaths);
881     free(metaIgnorePathsStr);
882 }
883 
884 /*
885  * Fetch a full line from fp - growing bufp if needed
886  * Return length in bufp.
887  */
888 static int
889 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
890 {
891     char *buf = *bufp;
892     size_t bufsz = *szp;
893     struct stat fs;
894     int x;
895 
896     if (fgets(&buf[o], (int)bufsz - o, fp) != NULL) {
897     check_newline:
898 	x = o + (int)strlen(&buf[o]);
899 	if (buf[x - 1] == '\n')
900 	    return x;
901 	/*
902 	 * We need to grow the buffer.
903 	 * The meta file can give us a clue.
904 	 */
905 	if (fstat(fileno(fp), &fs) == 0) {
906 	    size_t newsz;
907 	    char *p;
908 
909 	    newsz = ROUNDUP(((size_t)fs.st_size / 2), BUFSIZ);
910 	    if (newsz <= bufsz)
911 		newsz = ROUNDUP((size_t)fs.st_size, BUFSIZ);
912 	    if (newsz <= bufsz)
913 		return x;		/* truncated */
914 	    DEBUG2(META, "growing buffer %u -> %u\n",
915 		   (unsigned)bufsz, (unsigned)newsz);
916 	    p = bmake_realloc(buf, newsz);
917 	    *bufp = buf = p;
918 	    *szp = bufsz = newsz;
919 	    /* fetch the rest */
920 	    if (fgets(&buf[x], (int)bufsz - x, fp) == NULL)
921 		return x;		/* truncated! */
922 	    goto check_newline;
923 	}
924     }
925     return 0;
926 }
927 
928 static bool
929 prefix_match(const char *prefix, const char *path)
930 {
931     size_t n = strlen(prefix);
932 
933     return strncmp(path, prefix, n) == 0;
934 }
935 
936 static bool
937 has_any_prefix(const char *path, StringList *prefixes)
938 {
939     StringListNode *ln;
940 
941     for (ln = prefixes->first; ln != NULL; ln = ln->next)
942 	if (prefix_match(ln->datum, path))
943 	    return true;
944     return false;
945 }
946 
947 /* See if the path equals prefix or starts with "prefix/". */
948 static bool
949 path_starts_with(const char *path, const char *prefix)
950 {
951     size_t n = strlen(prefix);
952 
953     if (strncmp(path, prefix, n) != 0)
954 	return false;
955     return path[n] == '\0' || path[n] == '/';
956 }
957 
958 static bool
959 meta_ignore(GNode *gn, const char *p)
960 {
961     char fname[MAXPATHLEN];
962 
963     if (p == NULL)
964 	return true;
965 
966     if (*p == '/') {
967 	cached_realpath(p, fname); /* clean it up */
968 	if (has_any_prefix(fname, &metaIgnorePaths)) {
969 #ifdef DEBUG_META_MODE
970 	    DEBUG1(META, "meta_oodate: ignoring path: %s\n", p);
971 #endif
972 	    return true;
973 	}
974     }
975 
976     if (metaIgnorePatterns) {
977 	const char *expr;
978 	char *pm;
979 
980 	/*
981 	 * XXX: This variable is set on a target GNode but is not one of
982 	 * the usual local variables.  It should be deleted afterwards.
983 	 * Ideally it would not be created in the first place, just like
984 	 * in a .for loop.
985 	 */
986 	Var_Set(gn, ".p.", p);
987 	expr = "${" MAKE_META_IGNORE_PATTERNS ":@m@${.p.:M$m}@}";
988 	(void)Var_Subst(expr, gn, VARE_WANTRES, &pm);
989 	/* TODO: handle errors */
990 	if (pm[0] != '\0') {
991 #ifdef DEBUG_META_MODE
992 	    DEBUG1(META, "meta_oodate: ignoring pattern: %s\n", p);
993 #endif
994 	    free(pm);
995 	    return true;
996 	}
997 	free(pm);
998     }
999 
1000     if (metaIgnoreFilter) {
1001 	char *fm;
1002 
1003 	/* skip if filter result is empty */
1004 	snprintf(fname, sizeof fname,
1005 		 "${%s:L:${%s:ts:}}",
1006 		 p, MAKE_META_IGNORE_FILTER);
1007 	(void)Var_Subst(fname, gn, VARE_WANTRES, &fm);
1008 	/* TODO: handle errors */
1009 	if (*fm == '\0') {
1010 #ifdef DEBUG_META_MODE
1011 	    DEBUG1(META, "meta_oodate: ignoring filtered: %s\n", p);
1012 #endif
1013 	    free(fm);
1014 	    return true;
1015 	}
1016 	free(fm);
1017     }
1018     return false;
1019 }
1020 
1021 /*
1022  * When running with 'meta' functionality, a target can be out-of-date
1023  * if any of the references in its meta data file is more recent.
1024  * We have to track the latestdir on a per-process basis.
1025  */
1026 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
1027 #define LDIR_VNAME_FMT ".meta.%d.ldir"
1028 
1029 /*
1030  * It is possible that a .meta file is corrupted,
1031  * if we detect this we want to reproduce it.
1032  * Setting oodate true will have that effect.
1033  */
1034 #define CHECK_VALID_META(p) if (!(p != NULL && *p != '\0')) { \
1035     warnx("%s: %u: malformed", fname, lineno); \
1036     oodate = true; \
1037     continue; \
1038     }
1039 
1040 #define DEQUOTE(p) if (*p == '\'') {	\
1041     char *ep; \
1042     p++; \
1043     if ((ep = strchr(p, '\'')) != NULL) \
1044 	*ep = '\0'; \
1045     }
1046 
1047 static void
1048 append_if_new(StringList *list, const char *str)
1049 {
1050     StringListNode *ln;
1051 
1052     for (ln = list->first; ln != NULL; ln = ln->next)
1053 	if (strcmp(ln->datum, str) == 0)
1054 	    return;
1055     Lst_Append(list, bmake_strdup(str));
1056 }
1057 
1058 /* A "reserved" variable to store the command to be filtered */
1059 #define META_CMD_FILTER_VAR ".MAKE.cmd_filtered"
1060 
1061 static char *
1062 meta_filter_cmd(GNode *gn, char *s)
1063 {
1064     Var_Set(gn, META_CMD_FILTER_VAR, s);
1065     Var_Subst("${" META_CMD_FILTER_VAR ":${" MAKE_META_CMP_FILTER ":ts:}}", gn, VARE_WANTRES, &s);
1066     return s;
1067 }
1068 
1069 static int
1070 meta_cmd_cmp(GNode *gn, char *a, char *b, bool filter)
1071 {
1072     int rc;
1073 
1074     rc = strcmp(a, b);
1075     if (rc == 0 || !filter)
1076 	return rc;
1077     a = meta_filter_cmd(gn, a);
1078     b = meta_filter_cmd(gn, b);
1079     rc = strcmp(a, b);
1080     free(a);
1081     free(b);
1082     Var_Delete(gn, META_CMD_FILTER_VAR);
1083     return rc;
1084 }
1085 
1086 bool
1087 meta_oodate(GNode *gn, bool oodate)
1088 {
1089     static char *tmpdir = NULL;
1090     static char cwd[MAXPATHLEN];
1091     char lcwd_vname[64];
1092     char ldir_vname[64];
1093     char lcwd[MAXPATHLEN];
1094     char latestdir[MAXPATHLEN];
1095     char fname[MAXPATHLEN];
1096     char fname1[MAXPATHLEN];
1097     char fname2[MAXPATHLEN];
1098     char fname3[MAXPATHLEN];
1099     FStr dname;
1100     const char *tname;
1101     char *p;
1102     char *link_src;
1103     char *move_target;
1104     static size_t cwdlen = 0;
1105     static size_t tmplen = 0;
1106     FILE *fp;
1107     bool needOODATE = false;
1108     StringList missingFiles;
1109     bool have_filemon = false;
1110     bool cmp_filter;
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 	unsigned 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 	cmp_filter = metaCmpFilter || Var_Exists(gn, MAKE_META_CMP_FILTER);
1171 
1172 	cmdNode = gn->commands.first;
1173 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1174 	    lineno++;
1175 	    if (buf[x - 1] == '\n')
1176 		buf[x - 1] = '\0';
1177 	    else {
1178 		warnx("%s: %u: line truncated at %u", fname, lineno, x);
1179 		oodate = true;
1180 		break;
1181 	    }
1182 	    link_src = NULL;
1183 	    move_target = NULL;
1184 	    /* Find the start of the build monitor section. */
1185 	    if (!have_filemon) {
1186 		if (strncmp(buf, "-- filemon", 10) == 0) {
1187 		    have_filemon = true;
1188 		    continue;
1189 		}
1190 		if (strncmp(buf, "# buildmon", 10) == 0) {
1191 		    have_filemon = true;
1192 		    continue;
1193 		}
1194 	    }
1195 
1196 	    /* Delimit the record type. */
1197 	    p = buf;
1198 #ifdef DEBUG_META_MODE
1199 	    DEBUG3(META, "%s: %u: %s\n", fname, lineno, buf);
1200 #endif
1201 	    strsep(&p, " ");
1202 	    if (have_filemon) {
1203 		/*
1204 		 * We are in the 'filemon' output section.
1205 		 * Each record from filemon follows the general form:
1206 		 *
1207 		 * <key> <pid> <data>
1208 		 *
1209 		 * Where:
1210 		 * <key> is a single letter, denoting the syscall.
1211 		 * <pid> is the process that made the syscall.
1212 		 * <data> is the arguments (of interest).
1213 		 */
1214 		switch(buf[0]) {
1215 		case '#':		/* comment */
1216 		case 'V':		/* version */
1217 		    break;
1218 		default:
1219 		    /*
1220 		     * We need to track pathnames per-process.
1221 		     *
1222 		     * Each process run by make starts off in the 'CWD'
1223 		     * recorded in the .meta file, if it chdirs ('C')
1224 		     * elsewhere we need to track that - but only for
1225 		     * that process.  If it forks ('F'), we initialize
1226 		     * the child to have the same cwd as its parent.
1227 		     *
1228 		     * We also need to track the 'latestdir' of
1229 		     * interest.  This is usually the same as cwd, but
1230 		     * not if a process is reading directories.
1231 		     *
1232 		     * Each time we spot a different process ('pid')
1233 		     * we save the current value of 'latestdir' in a
1234 		     * variable qualified by 'lastpid', and
1235 		     * re-initialize 'latestdir' to any pre-saved
1236 		     * value for the current 'pid' and 'CWD' if none.
1237 		     */
1238 		    CHECK_VALID_META(p);
1239 		    pid = atoi(p);
1240 		    if (pid > 0 && pid != lastpid) {
1241 			FStr ldir;
1242 
1243 			if (lastpid > 0) {
1244 			    /* We need to remember these. */
1245 			    Global_Set(lcwd_vname, lcwd);
1246 			    Global_Set(ldir_vname, latestdir);
1247 			}
1248 			snprintf(lcwd_vname, sizeof lcwd_vname, LCWD_VNAME_FMT, pid);
1249 			snprintf(ldir_vname, sizeof ldir_vname, LDIR_VNAME_FMT, pid);
1250 			lastpid = pid;
1251 			ldir = Var_Value(SCOPE_GLOBAL, ldir_vname);
1252 			if (ldir.str != NULL) {
1253 			    strlcpy(latestdir, ldir.str, sizeof latestdir);
1254 			    FStr_Done(&ldir);
1255 			}
1256 			ldir = Var_Value(SCOPE_GLOBAL, lcwd_vname);
1257 			if (ldir.str != NULL) {
1258 			    strlcpy(lcwd, ldir.str, sizeof lcwd);
1259 			    FStr_Done(&ldir);
1260 			}
1261 		    }
1262 		    /* Skip past the pid. */
1263 		    if (strsep(&p, " ") == NULL)
1264 			continue;
1265 #ifdef DEBUG_META_MODE
1266 		    if (DEBUG(META))
1267 			debug_printf("%s: %u: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1268 				     fname, lineno,
1269 				     pid, buf[0], cwd, lcwd, latestdir);
1270 #endif
1271 		    break;
1272 		}
1273 
1274 		CHECK_VALID_META(p);
1275 
1276 		/* Process according to record type. */
1277 		switch (buf[0]) {
1278 		case 'X':		/* eXit */
1279 		    Var_Delete(SCOPE_GLOBAL, lcwd_vname);
1280 		    Var_Delete(SCOPE_GLOBAL, ldir_vname);
1281 		    lastpid = 0;	/* no need to save ldir_vname */
1282 		    break;
1283 
1284 		case 'F':		/* [v]Fork */
1285 		    {
1286 			char cldir[64];
1287 			int child;
1288 
1289 			child = atoi(p);
1290 			if (child > 0) {
1291 			    snprintf(cldir, sizeof cldir, LCWD_VNAME_FMT, child);
1292 			    Global_Set(cldir, lcwd);
1293 			    snprintf(cldir, sizeof cldir, LDIR_VNAME_FMT, child);
1294 			    Global_Set(cldir, latestdir);
1295 #ifdef DEBUG_META_MODE
1296 			    if (DEBUG(META))
1297 				debug_printf(
1298 					"%s: %u: %d: cwd=%s lcwd=%s ldir=%s\n",
1299 					fname, lineno,
1300 					child, cwd, lcwd, latestdir);
1301 #endif
1302 			}
1303 		    }
1304 		    break;
1305 
1306 		case 'C':		/* Chdir */
1307 		    /* Update lcwd and latest directory. */
1308 		    strlcpy(latestdir, p, sizeof latestdir);
1309 		    strlcpy(lcwd, p, sizeof lcwd);
1310 		    Global_Set(lcwd_vname, lcwd);
1311 		    Global_Set(ldir_vname, lcwd);
1312 #ifdef DEBUG_META_MODE
1313 		    DEBUG4(META, "%s: %u: cwd=%s ldir=%s\n",
1314 			   fname, lineno, cwd, lcwd);
1315 #endif
1316 		    break;
1317 
1318 		case 'M':		/* renaMe */
1319 		    /*
1320 		     * For 'M'oves we want to check
1321 		     * the src as for 'R'ead
1322 		     * and the target as for 'W'rite.
1323 		     */
1324 		    {
1325 			char *cp = p;	/* save this for a second */
1326 			/* now get target */
1327 			if (strsep(&p, " ") == NULL)
1328 			    continue;
1329 			CHECK_VALID_META(p);
1330 			move_target = p;
1331 			p = cp;
1332 		    }
1333 		    /* 'L' and 'M' put single quotes around the args */
1334 		    DEQUOTE(p);
1335 		    DEQUOTE(move_target);
1336 		    /* FALLTHROUGH */
1337 		case 'D':		/* unlink */
1338 		    if (*p == '/') {
1339 			/* remove any missingFiles entries that match p */
1340 			StringListNode *ln = missingFiles.first;
1341 			while (ln != NULL) {
1342 			    StringListNode *next = ln->next;
1343 			    if (path_starts_with(ln->datum, p)) {
1344 				free(ln->datum);
1345 				Lst_Remove(&missingFiles, ln);
1346 			    }
1347 			    ln = next;
1348 			}
1349 		    }
1350 		    if (buf[0] == 'M') {
1351 			/* the target of the mv is a file 'W'ritten */
1352 #ifdef DEBUG_META_MODE
1353 			DEBUG2(META, "meta_oodate: M %s -> %s\n",
1354 			       p, move_target);
1355 #endif
1356 			p = move_target;
1357 			goto check_write;
1358 		    }
1359 		    break;
1360 		case 'L':		/* Link */
1361 		    /*
1362 		     * For 'L'inks check
1363 		     * the src as for 'R'ead
1364 		     * and the target as for 'W'rite.
1365 		     */
1366 		    link_src = p;
1367 		    /* now get target */
1368 		    if (strsep(&p, " ") == NULL)
1369 			continue;
1370 		    CHECK_VALID_META(p);
1371 		    /* 'L' and 'M' put single quotes around the args */
1372 		    DEQUOTE(p);
1373 		    DEQUOTE(link_src);
1374 #ifdef DEBUG_META_MODE
1375 		    DEBUG2(META, "meta_oodate: L %s -> %s\n", link_src, p);
1376 #endif
1377 		    /* FALLTHROUGH */
1378 		case 'W':		/* Write */
1379 		check_write:
1380 		    /*
1381 		     * If a file we generated within our bailiwick
1382 		     * but outside of .OBJDIR is missing,
1383 		     * we need to do it again.
1384 		     */
1385 		    /* ignore non-absolute paths */
1386 		    if (*p != '/')
1387 			break;
1388 
1389 		    if (Lst_IsEmpty(&metaBailiwick))
1390 			break;
1391 
1392 		    /* ignore cwd - normal dependencies handle those */
1393 		    if (strncmp(p, cwd, cwdlen) == 0)
1394 			break;
1395 
1396 		    if (!has_any_prefix(p, &metaBailiwick))
1397 			break;
1398 
1399 		    /* tmpdir might be within */
1400 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1401 			break;
1402 
1403 		    /* ignore anything containing the string "tmp" */
1404 		    /* XXX: The arguments to strstr must be swapped. */
1405 		    if (strstr("tmp", p) != NULL)
1406 			break;
1407 
1408 		    if ((link_src != NULL && cached_lstat(p, &cst) < 0) ||
1409 			(link_src == NULL && cached_stat(p, &cst) < 0)) {
1410 			if (!meta_ignore(gn, p))
1411 			    append_if_new(&missingFiles, p);
1412 		    }
1413 		    break;
1414 		check_link_src:
1415 		    p = link_src;
1416 		    link_src = NULL;
1417 #ifdef DEBUG_META_MODE
1418 		    DEBUG1(META, "meta_oodate: L src %s\n", p);
1419 #endif
1420 		    /* FALLTHROUGH */
1421 		case 'R':		/* Read */
1422 		case 'E':		/* Exec */
1423 		    /*
1424 		     * Check for runtime files that can't
1425 		     * be part of the dependencies because
1426 		     * they are _expected_ to change.
1427 		     */
1428 		    if (meta_ignore(gn, p))
1429 			break;
1430 
1431 		    /*
1432 		     * The rest of the record is the file name.
1433 		     * Check if it's not an absolute path.
1434 		     */
1435 		    {
1436 			char *sdirs[4];
1437 			char **sdp;
1438 			int sdx = 0;
1439 			bool found = false;
1440 
1441 			if (*p == '/') {
1442 			    sdirs[sdx++] = p; /* done */
1443 			} else {
1444 			    if (strcmp(".", p) == 0)
1445 				continue; /* no point */
1446 
1447 			    /* Check vs latestdir */
1448 			    snprintf(fname1, sizeof fname1, "%s/%s", latestdir, p);
1449 			    sdirs[sdx++] = fname1;
1450 
1451 			    if (strcmp(latestdir, lcwd) != 0) {
1452 				/* Check vs lcwd */
1453 				snprintf(fname2, sizeof fname2, "%s/%s", lcwd, p);
1454 				sdirs[sdx++] = fname2;
1455 			    }
1456 			    if (strcmp(lcwd, cwd) != 0) {
1457 				/* Check vs cwd */
1458 				snprintf(fname3, sizeof fname3, "%s/%s", cwd, p);
1459 				sdirs[sdx++] = fname3;
1460 			    }
1461 			}
1462 			sdirs[sdx++] = NULL;
1463 
1464 			for (sdp = sdirs; *sdp != NULL && !found; sdp++) {
1465 #ifdef DEBUG_META_MODE
1466 			    DEBUG3(META, "%s: %u: looking for: %s\n",
1467 				   fname, lineno, *sdp);
1468 #endif
1469 			    if (cached_stat(*sdp, &cst) == 0) {
1470 				found = true;
1471 				p = *sdp;
1472 			    }
1473 			}
1474 			if (found) {
1475 #ifdef DEBUG_META_MODE
1476 			    DEBUG3(META, "%s: %u: found: %s\n",
1477 				   fname, lineno, p);
1478 #endif
1479 			    if (!S_ISDIR(cst.cst_mode) &&
1480 				cst.cst_mtime > gn->mtime) {
1481 				DEBUG3(META, "%s: %u: file '%s' is newer than the target...\n",
1482 				       fname, lineno, p);
1483 				oodate = true;
1484 			    } else if (S_ISDIR(cst.cst_mode)) {
1485 				/* Update the latest directory. */
1486 				cached_realpath(p, latestdir);
1487 			    }
1488 			} else if (errno == ENOENT && *p == '/' &&
1489 				   strncmp(p, cwd, cwdlen) != 0) {
1490 			    /*
1491 			     * A referenced file outside of CWD is missing.
1492 			     * We cannot catch every eventuality here...
1493 			     */
1494 			    append_if_new(&missingFiles, p);
1495 			}
1496 		    }
1497 		    if (buf[0] == 'E') {
1498 			/* previous latestdir is no longer relevant */
1499 			strlcpy(latestdir, lcwd, sizeof latestdir);
1500 		    }
1501 		    break;
1502 		default:
1503 		    break;
1504 		}
1505 		if (!oodate && buf[0] == 'L' && link_src != NULL)
1506 		    goto check_link_src;
1507 	    } else if (strcmp(buf, "CMD") == 0) {
1508 		/*
1509 		 * Compare the current command with the one in the
1510 		 * meta data file.
1511 		 */
1512 		if (cmdNode == NULL) {
1513 		    DEBUG2(META, "%s: %u: there were more build commands in the meta data file than there are now...\n",
1514 			   fname, lineno);
1515 		    oodate = true;
1516 		} else {
1517 		    const char *cp;
1518 		    char *cmd = cmdNode->datum;
1519 		    bool hasOODATE = false;
1520 
1521 		    if (strstr(cmd, "$?") != NULL)
1522 			hasOODATE = true;
1523 		    else if ((cp = strstr(cmd, ".OODATE")) != NULL) {
1524 			/* check for $[{(].OODATE[:)}] */
1525 			if (cp > cmd + 2 && cp[-2] == '$')
1526 			    hasOODATE = true;
1527 		    }
1528 		    if (hasOODATE) {
1529 			needOODATE = true;
1530 			DEBUG2(META, "%s: %u: cannot compare command using .OODATE\n",
1531 			       fname, lineno);
1532 		    }
1533 		    (void)Var_Subst(cmd, gn, VARE_UNDEFERR, &cmd);
1534 		    /* TODO: handle errors */
1535 
1536 		    if ((cp = strchr(cmd, '\n')) != NULL) {
1537 			int n;
1538 
1539 			/*
1540 			 * This command contains newlines, we need to
1541 			 * fetch more from the .meta file before we
1542 			 * attempt a comparison.
1543 			 */
1544 			/* first put the newline back at buf[x - 1] */
1545 			buf[x - 1] = '\n';
1546 			do {
1547 			    /* now fetch the next line */
1548 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1549 				break;
1550 			    x = n;
1551 			    lineno++;
1552 			    if (buf[x - 1] != '\n') {
1553 				warnx("%s: %u: line truncated at %u", fname, lineno, x);
1554 				break;
1555 			    }
1556 			    cp = strchr(cp + 1, '\n');
1557 			} while (cp != NULL);
1558 			if (buf[x - 1] == '\n')
1559 			    buf[x - 1] = '\0';
1560 		    }
1561 		    if (p != NULL &&
1562 			!hasOODATE &&
1563 			!(gn->type & OP_NOMETA_CMP) &&
1564 			(meta_cmd_cmp(gn, p, cmd, cmp_filter) != 0)) {
1565 			DEBUG4(META, "%s: %u: a build command has changed\n%s\nvs\n%s\n",
1566 			       fname, lineno, p, cmd);
1567 			if (!metaIgnoreCMDs)
1568 			    oodate = true;
1569 		    }
1570 		    free(cmd);
1571 		    cmdNode = cmdNode->next;
1572 		}
1573 	    } else if (strcmp(buf, "CWD") == 0) {
1574 		/*
1575 		 * Check if there are extra commands now
1576 		 * that weren't in the meta data file.
1577 		 */
1578 		if (!oodate && cmdNode != NULL) {
1579 		    DEBUG2(META, "%s: %u: there are extra build commands now that weren't in the meta data file\n",
1580 			   fname, lineno);
1581 		    oodate = true;
1582 		}
1583 		CHECK_VALID_META(p);
1584 		if (strcmp(p, cwd) != 0) {
1585 		    DEBUG4(META, "%s: %u: the current working directory has changed from '%s' to '%s'\n",
1586 			   fname, lineno, p, curdir);
1587 		    oodate = true;
1588 		}
1589 	    }
1590 	}
1591 
1592 	fclose(fp);
1593 	if (!Lst_IsEmpty(&missingFiles)) {
1594 	    DEBUG2(META, "%s: missing files: %s...\n",
1595 		   fname, (char *)missingFiles.first->datum);
1596 	    oodate = true;
1597 	}
1598 	if (!oodate && !have_filemon && filemonMissing) {
1599 	    DEBUG1(META, "%s: missing filemon data\n", fname);
1600 	    oodate = true;
1601 	}
1602     } else {
1603 	if (writeMeta && (metaMissing || (gn->type & OP_META))) {
1604 	    const char *cp = NULL;
1605 
1606 	    /* if target is in .CURDIR we do not need a meta file */
1607 	    if (gn->path != NULL && (cp = strrchr(gn->path, '/')) != NULL &&
1608 		(cp > gn->path)) {
1609 		if (strncmp(curdir, gn->path, (size_t)(cp - gn->path)) != 0) {
1610 		    cp = NULL;		/* not in .CURDIR */
1611 		}
1612 	    }
1613 	    if (cp == NULL) {
1614 		DEBUG1(META, "%s: required but missing\n", fname);
1615 		oodate = true;
1616 		needOODATE = true;	/* assume the worst */
1617 	    }
1618 	}
1619     }
1620 
1621     Lst_DoneCall(&missingFiles, free);
1622 
1623     if (oodate && needOODATE) {
1624 	/*
1625 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1626 	 * We have decided it is oodate, so .OODATE needs to be set.
1627 	 * All we can sanely do is set it to .ALLSRC.
1628 	 */
1629 	Var_Delete(gn, OODATE);
1630 	Var_Set(gn, OODATE, GNode_VarAllsrc(gn));
1631     }
1632 
1633  oodate_out:
1634     FStr_Done(&dname);
1635     return oodate;
1636 }
1637 
1638 /* support for compat mode */
1639 
1640 static int childPipe[2];
1641 
1642 void
1643 meta_compat_start(void)
1644 {
1645 #ifdef USE_FILEMON_ONCE
1646     /*
1647      * We need to re-open filemon for each cmd.
1648      */
1649     BuildMon *pbm = &Mybm;
1650 
1651     if (pbm->mfp != NULL && useFilemon) {
1652 	meta_open_filemon(pbm);
1653     } else {
1654 	pbm->mon_fd = -1;
1655 	pbm->filemon = NULL;
1656     }
1657 #endif
1658     if (pipe(childPipe) < 0)
1659 	Punt("Cannot create pipe: %s", strerror(errno));
1660     /* Set close-on-exec flag for both */
1661     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1662     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1663 }
1664 
1665 void
1666 meta_compat_child(void)
1667 {
1668     meta_job_child(NULL);
1669     if (dup2(childPipe[1], 1) < 0 || dup2(1, 2) < 0)
1670 	execDie("dup2", "pipe");
1671 }
1672 
1673 void
1674 meta_compat_parent(pid_t child)
1675 {
1676     int outfd, metafd, maxfd, nfds;
1677     char buf[BUFSIZ+1];
1678     fd_set readfds;
1679 
1680     meta_job_parent(NULL, child);
1681     close(childPipe[1]);			/* child side */
1682     outfd = childPipe[0];
1683 #ifdef USE_FILEMON
1684     metafd = Mybm.filemon != NULL ? filemon_readfd(Mybm.filemon) : -1;
1685 #else
1686     metafd = -1;
1687 #endif
1688     maxfd = -1;
1689     if (outfd > maxfd)
1690 	    maxfd = outfd;
1691     if (metafd > maxfd)
1692 	    maxfd = metafd;
1693 
1694     while (outfd != -1 || metafd != -1) {
1695 	FD_ZERO(&readfds);
1696 	if (outfd != -1) {
1697 	    FD_SET(outfd, &readfds);
1698 	}
1699 	if (metafd != -1) {
1700 	    FD_SET(metafd, &readfds);
1701 	}
1702 	nfds = select(maxfd + 1, &readfds, NULL, NULL, NULL);
1703 	if (nfds == -1) {
1704 	    if (errno == EINTR)
1705 		continue;
1706 	    err(1, "select");
1707 	}
1708 
1709 	if (outfd != -1 && FD_ISSET(outfd, &readfds) != 0) do {
1710 	    /* XXX this is not line-buffered */
1711 	    ssize_t nread = read(outfd, buf, sizeof buf - 1);
1712 	    if (nread == -1)
1713 		err(1, "read");
1714 	    if (nread == 0) {
1715 		close(outfd);
1716 		outfd = -1;
1717 		break;
1718 	    }
1719 	    fwrite(buf, 1, (size_t)nread, stdout);
1720 	    fflush(stdout);
1721 	    buf[nread] = '\0';
1722 	    meta_job_output(NULL, buf, "");
1723 	} while (false);
1724 	if (metafd != -1 && FD_ISSET(metafd, &readfds) != 0) {
1725 	    if (meta_job_event(NULL) <= 0)
1726 		metafd = -1;
1727 	}
1728     }
1729 }
1730 
1731 #endif /* USE_META */
1732