xref: /netbsd-src/usr.bin/make/meta.c (revision 7d62b00eb9ad855ffcd7da46b41e23feb5476fac)
1 /*      $NetBSD: meta.c,v 1.204 2023/02/28 06:04:28 sjg Exp $ */
2 
3 /*
4  * Implement 'meta' mode.
5  * Adapted from John Birrell's patches to FreeBSD make.
6  * --sjg
7  */
8 /*
9  * Copyright (c) 2009-2016, Juniper Networks, Inc.
10  * Portions Copyright (c) 2009, John Birrell.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 #if defined(USE_META)
34 
35 #ifdef HAVE_CONFIG_H
36 # include "config.h"
37 #endif
38 #include <sys/stat.h>
39 #include <libgen.h>
40 #include <errno.h>
41 #if !defined(HAVE_CONFIG_H) || defined(HAVE_ERR_H)
42 #include <err.h>
43 #endif
44 
45 #include "make.h"
46 #include "dir.h"
47 #include "job.h"
48 
49 #ifdef USE_FILEMON
50 #include "filemon/filemon.h"
51 #endif
52 
53 static BuildMon Mybm;			/* for compat */
54 static StringList metaBailiwick = LST_INIT; /* our scope of control */
55 static char *metaBailiwickStr;		/* string storage for the list */
56 static StringList metaIgnorePaths = LST_INIT; /* paths we deliberately ignore */
57 static char *metaIgnorePathsStr;	/* string storage for the list */
58 
59 #ifndef MAKE_META_IGNORE_PATHS
60 #define MAKE_META_IGNORE_PATHS ".MAKE.META.IGNORE_PATHS"
61 #endif
62 #ifndef MAKE_META_IGNORE_PATTERNS
63 #define MAKE_META_IGNORE_PATTERNS ".MAKE.META.IGNORE_PATTERNS"
64 #endif
65 #ifndef MAKE_META_IGNORE_FILTER
66 #define MAKE_META_IGNORE_FILTER ".MAKE.META.IGNORE_FILTER"
67 #endif
68 #ifndef MAKE_META_CMP_FILTER
69 #define MAKE_META_CMP_FILTER ".MAKE.META.CMP_FILTER"
70 #endif
71 
72 bool useMeta = false;
73 static bool useFilemon = false;
74 static bool writeMeta = false;
75 static bool metaMissing = false;	/* oodate if missing */
76 static bool filemonMissing = false;	/* oodate if missing */
77 static bool metaEnv = false;		/* don't save env unless asked */
78 static bool metaVerbose = false;
79 static bool metaIgnoreCMDs = false;	/* ignore CMDs in .meta files */
80 static bool metaIgnorePatterns = false; /* do we need to do pattern matches */
81 static bool metaIgnoreFilter = false;	/* do we have more complex filtering? */
82 static bool metaCmpFilter = false;	/* do we have CMP_FILTER ? */
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 
102 /*
103  * Filemon is a kernel module which snoops certain syscalls.
104  *
105  * C chdir
106  * E exec
107  * F [v]fork
108  * L [sym]link
109  * M rename
110  * R read
111  * W write
112  * S stat
113  *
114  * See meta_oodate below - we mainly care about 'E' and 'R'.
115  *
116  * We can still use meta mode without filemon, but
117  * the benefits are more limited.
118  */
119 #ifdef USE_FILEMON
120 
121 /*
122  * Open the filemon device.
123  */
124 static void
125 meta_open_filemon(BuildMon *pbm)
126 {
127     int dupfd;
128 
129     pbm->mon_fd = -1;
130     pbm->filemon = NULL;
131     if (!useFilemon || pbm->mfp == NULL)
132 	return;
133 
134     pbm->filemon = filemon_open();
135     if (pbm->filemon == NULL) {
136 	useFilemon = false;
137 	warn("Could not open filemon %s", filemon_path());
138 	return;
139     }
140 
141     /*
142      * We use a file outside of '.'
143      * to avoid a FreeBSD kernel bug where unlink invalidates
144      * cwd causing getcwd to do a lot more work.
145      * We only care about the descriptor.
146      */
147     if (!opts.compatMake)
148 	pbm->mon_fd = Job_TempFile("filemon.XXXXXX", NULL, 0);
149     else
150 	pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL, 0);
151     if ((dupfd = dup(pbm->mon_fd)) == -1) {
152 	Punt("Could not dup filemon output: %s", strerror(errno));
153     }
154     (void)fcntl(dupfd, F_SETFD, FD_CLOEXEC);
155     if (filemon_setfd(pbm->filemon, dupfd) == -1) {
156 	Punt("Could not set filemon file descriptor: %s", strerror(errno));
157     }
158     /* we don't need these once we exec */
159     (void)fcntl(pbm->mon_fd, F_SETFD, FD_CLOEXEC);
160 }
161 
162 /*
163  * Read the build monitor output file and write records to the target's
164  * metadata file.
165  */
166 static int
167 filemon_read(FILE *mfp, int fd)
168 {
169     char buf[BUFSIZ];
170     int error;
171 
172     /* Check if we're not writing to a meta data file.*/
173     if (mfp == NULL) {
174 	if (fd >= 0)
175 	    close(fd);			/* not interested */
176 	return 0;
177     }
178     /* rewind */
179     if (lseek(fd, (off_t)0, SEEK_SET) < 0) {
180 	error = errno;
181 	warn("Could not rewind filemon");
182 	fprintf(mfp, "\n");
183     } else {
184 	ssize_t n;
185 
186 	error = 0;
187 	fprintf(mfp, "\n-- filemon acquired metadata --\n");
188 
189 	while ((n = read(fd, buf, sizeof buf)) > 0) {
190 	    if ((ssize_t)fwrite(buf, 1, (size_t)n, mfp) < n)
191 		error = EIO;
192 	}
193     }
194     if (fflush(mfp) != 0)
195 	Punt("Cannot write filemon data to meta file: %s",
196 	    strerror(errno));
197     if (close(fd) < 0)
198 	error = errno;
199     return error;
200 }
201 #endif
202 
203 /*
204  * when realpath() fails,
205  * we use this, to clean up ./ and ../
206  */
207 static void
208 eat_dots(char *buf)
209 {
210     char *p;
211 
212     while ((p = strstr(buf, "/./")) != NULL)
213 	memmove(p, p + 2, strlen(p + 2) + 1);
214 
215     while ((p = strstr(buf, "/../")) != NULL) {
216 	char *p2 = p + 3;
217 	if (p > buf) {
218 	    do {
219 		p--;
220 	    } while (p > buf && *p != '/');
221 	}
222 	if (*p == '/')
223 	    memmove(p, p2, strlen(p2) + 1);
224 	else
225 	    return;		/* can't happen? */
226     }
227 }
228 
229 static char *
230 meta_name(char *mname, size_t mnamelen,
231 	  const char *dname,
232 	  const char *tname,
233 	  const char *cwd)
234 {
235     char buf[MAXPATHLEN];
236     char *rp, *cp;
237     const char *tname_base;
238     char *tp;
239     char *dtp;
240     size_t ldname;
241 
242     /*
243      * Weed out relative paths from the target file name.
244      * We have to be careful though since if target is a
245      * symlink, the result will be unstable.
246      * So we use realpath() just to get the dirname, and leave the
247      * basename as given to us.
248      */
249     if ((tname_base = strrchr(tname, '/')) != NULL) {
250 	if (cached_realpath(tname, buf) != NULL) {
251 	    if ((rp = strrchr(buf, '/')) != NULL) {
252 		rp++;
253 		tname_base++;
254 		if (strcmp(tname_base, rp) != 0)
255 		    strlcpy(rp, tname_base, sizeof buf - (size_t)(rp - buf));
256 	    }
257 	    tname = buf;
258 	} else {
259 	    /*
260 	     * We likely have a directory which is about to be made.
261 	     * We pretend realpath() succeeded, to have a chance
262 	     * of generating the same meta file name that we will
263 	     * next time through.
264 	     */
265 	    if (tname[0] == '/') {
266 		strlcpy(buf, tname, sizeof buf);
267 	    } else {
268 		snprintf(buf, sizeof buf, "%s/%s", cwd, tname);
269 	    }
270 	    eat_dots(buf);
271 	    tname = buf;
272 	}
273     }
274     /* on some systems dirname may modify its arg */
275     tp = bmake_strdup(tname);
276     dtp = dirname(tp);
277     if (strcmp(dname, dtp) == 0) {
278 	if (snprintf(mname, mnamelen, "%s.meta", tname) >= (int)mnamelen)
279 	    mname[mnamelen - 1] = '\0';
280     } else {
281 	int x;
282 
283 	ldname = strlen(dname);
284 	if (strncmp(dname, dtp, ldname) == 0 && dtp[ldname] == '/')
285 	    x = snprintf(mname, mnamelen, "%s/%s.meta", dname, &tname[ldname+1]);
286 	else
287 	    x = snprintf(mname, mnamelen, "%s/%s.meta", dname, tname);
288 	if (x >= (int)mnamelen)
289 	    mname[mnamelen - 1] = '\0';
290 	/*
291 	 * Replace path separators in the file name after the
292 	 * current object directory path.
293 	 */
294 	cp = mname + strlen(dname) + 1;
295 
296 	while (*cp != '\0') {
297 	    if (*cp == '/')
298 		*cp = '_';
299 	    cp++;
300 	}
301     }
302     free(tp);
303     return mname;
304 }
305 
306 /*
307  * Return true if running ${.MAKE}
308  * Bypassed if target is flagged .MAKE
309  */
310 static bool
311 is_submake(const char *cmd, GNode *gn)
312 {
313     static const char *p_make = NULL;
314     static size_t p_len;
315     char *mp = NULL;
316     const char *cp2;
317     bool rc = false;
318 
319     if (p_make == NULL) {
320 	p_make = Var_Value(gn, ".MAKE").str;
321 	p_len = strlen(p_make);
322     }
323     if (strchr(cmd, '$') != NULL) {
324 	mp = Var_Subst(cmd, gn, VARE_WANTRES);
325 	/* TODO: handle errors */
326 	cmd = mp;
327     }
328     cp2 = strstr(cmd, p_make);
329     if (cp2 != NULL) {
330 	switch (cp2[p_len]) {
331 	case '\0':
332 	case ' ':
333 	case '\t':
334 	case '\n':
335 	    rc = true;
336 	    break;
337 	}
338 	if (cp2 > cmd && rc) {
339 	    switch (cp2[-1]) {
340 	    case ' ':
341 	    case '\t':
342 	    case '\n':
343 		break;
344 	    default:
345 		rc = false;		/* no match */
346 		break;
347 	    }
348 	}
349     }
350     free(mp);
351     return rc;
352 }
353 
354 static bool
355 any_is_submake(GNode *gn)
356 {
357     StringListNode *ln;
358 
359     for (ln = gn->commands.first; ln != NULL; ln = ln->next)
360 	if (is_submake(ln->datum, gn))
361 	    return true;
362     return false;
363 }
364 
365 static void
366 printCMD(const char *ucmd, FILE *fp, GNode *gn)
367 {
368     FStr xcmd = FStr_InitRefer(ucmd);
369 
370     Var_Expand(&xcmd, gn, VARE_WANTRES);
371     fprintf(fp, "CMD %s\n", xcmd.str);
372     FStr_Done(&xcmd);
373 }
374 
375 static void
376 printCMDs(GNode *gn, FILE *fp)
377 {
378     StringListNode *ln;
379 
380     for (ln = gn->commands.first; ln != NULL; ln = ln->next)
381 	printCMD(ln->datum, fp, gn);
382 }
383 
384 /*
385  * Certain node types never get a .meta file
386  */
387 #define SKIP_META_TYPE(flag, str) do { \
388     if ((gn->type & (flag))) { \
389 	if (verbose) \
390 	    debug_printf("Skipping meta for %s: .%s\n", gn->name, str); \
391 	return false; \
392     } \
393 } while (false)
394 
395 
396 /*
397  * Do we need/want a .meta file ?
398  */
399 static bool
400 meta_needed(GNode *gn, const char *dname,
401 	    char *objdir_realpath, bool verbose)
402 {
403     struct cached_stat cst;
404 
405     if (verbose)
406 	verbose = DEBUG(META);
407 
408     /* This may be a phony node which we don't want meta data for... */
409     /* Skip .meta for .BEGIN, .END, .ERROR etc as well. */
410     /* Or it may be explicitly flagged as .NOMETA */
411     SKIP_META_TYPE(OP_NOMETA, "NOMETA");
412     /* Unless it is explicitly flagged as .META */
413     if (!(gn->type & OP_META)) {
414 	SKIP_META_TYPE(OP_PHONY, "PHONY");
415 	SKIP_META_TYPE(OP_SPECIAL, "SPECIAL");
416 	SKIP_META_TYPE(OP_MAKE, "MAKE");
417     }
418 
419     /* Check if there are no commands to execute. */
420     if (Lst_IsEmpty(&gn->commands)) {
421 	if (verbose)
422 	    debug_printf("Skipping meta for %s: no commands\n", gn->name);
423 	return false;
424     }
425     if ((gn->type & (OP_META|OP_SUBMAKE)) == OP_SUBMAKE) {
426 	/* OP_SUBMAKE is a bit too aggressive */
427 	if (any_is_submake(gn)) {
428 	    DEBUG1(META, "Skipping meta for %s: .SUBMAKE\n", gn->name);
429 	    return false;
430 	}
431     }
432 
433     /* The object directory may not exist. Check it.. */
434     if (cached_stat(dname, &cst) != 0) {
435 	if (verbose)
436 	    debug_printf("Skipping meta for %s: no .OBJDIR\n", gn->name);
437 	return false;
438     }
439 
440     /* make sure these are canonical */
441     if (cached_realpath(dname, objdir_realpath) != NULL)
442 	dname = objdir_realpath;
443 
444     /* If we aren't in the object directory, don't create a meta file. */
445     if (!metaCurdirOk && strcmp(curdir, dname) == 0) {
446 	if (verbose)
447 	    debug_printf("Skipping meta for %s: .OBJDIR == .CURDIR\n",
448 			 gn->name);
449 	return false;
450     }
451     return true;
452 }
453 
454 
455 static FILE *
456 meta_create(BuildMon *pbm, GNode *gn)
457 {
458     FILE *fp;
459     char buf[MAXPATHLEN];
460     char objdir_realpath[MAXPATHLEN];
461     char **ptr;
462     FStr dname;
463     const char *tname;
464     char *fname;
465     const char *cp;
466 
467     fp = NULL;
468 
469     dname = Var_Value(gn, ".OBJDIR");
470     tname = GNode_VarTarget(gn);
471 
472     /* if this succeeds objdir_realpath is realpath of dname */
473     if (!meta_needed(gn, dname.str, objdir_realpath, true))
474 	goto out;
475     dname.str = objdir_realpath;
476 
477     if (metaVerbose) {
478 	/* Describe the target we are building */
479 	char *mp = Var_Subst("${" MAKE_META_PREFIX "}", gn, VARE_WANTRES);
480 	/* TODO: handle errors */
481 	if (mp[0] != '\0')
482 	    fprintf(stdout, "%s\n", mp);
483 	free(mp);
484     }
485     /* Get the basename of the target */
486     cp = str_basename(tname);
487 
488     fflush(stdout);
489 
490     if (!writeMeta)
491 	/* Don't create meta data. */
492 	goto out;
493 
494     fname = meta_name(pbm->meta_fname, sizeof pbm->meta_fname,
495 		      dname.str, tname, objdir_realpath);
496 
497 #ifdef DEBUG_META_MODE
498     DEBUG1(META, "meta_create: %s\n", fname);
499 #endif
500 
501     if ((fp = fopen(fname, "w")) == NULL)
502 	Punt("Could not open meta file '%s': %s", fname, strerror(errno));
503 
504     fprintf(fp, "# Meta data file %s\n", fname);
505 
506     printCMDs(gn, fp);
507 
508     fprintf(fp, "CWD %s\n", getcwd(buf, sizeof buf));
509     fprintf(fp, "TARGET %s\n", tname);
510     cp = GNode_VarOodate(gn);
511     if (cp != NULL && *cp != '\0') {
512 	fprintf(fp, "OODATE %s\n", cp);
513     }
514     if (metaEnv) {
515 	for (ptr = environ; *ptr != NULL; ptr++)
516 	    fprintf(fp, "ENV %s\n", *ptr);
517     }
518 
519     fprintf(fp, "-- command output --\n");
520     if (fflush(fp) != 0)
521 	Punt("Cannot write expanded command to meta file: %s",
522 	    strerror(errno));
523 
524     Global_Append(".MAKE.META.FILES", fname);
525     Global_Append(".MAKE.META.CREATED", fname);
526 
527     gn->type |= OP_META;		/* in case anyone wants to know */
528     if (metaSilent) {
529 	    gn->type |= OP_SILENT;
530     }
531  out:
532     FStr_Done(&dname);
533 
534     return fp;
535 }
536 
537 static bool
538 boolValue(const char *s)
539 {
540     switch (*s) {
541     case '0':
542     case 'N':
543     case 'n':
544     case 'F':
545     case 'f':
546 	return false;
547     }
548     return true;
549 }
550 
551 /*
552  * Initialization we need before reading makefiles.
553  */
554 void
555 meta_init(void)
556 {
557 #ifdef USE_FILEMON
558 	/* this allows makefiles to test if we have filemon support */
559 	Global_Set(".MAKE.PATH_FILEMON", filemon_path());
560 #endif
561 }
562 
563 
564 #define get_mode_bf(bf, token) \
565     if ((cp = strstr(make_mode, token)) != NULL) \
566 	bf = boolValue(cp + sizeof (token) - 1)
567 
568 /*
569  * Initialization we need after reading makefiles.
570  */
571 void
572 meta_mode_init(const char *make_mode)
573 {
574     static bool once = false;
575     const char *cp;
576 
577     useMeta = true;
578     useFilemon = true;
579     writeMeta = true;
580 
581     if (make_mode != NULL) {
582 	if (strstr(make_mode, "env") != NULL)
583 	    metaEnv = true;
584 	if (strstr(make_mode, "verb") != NULL)
585 	    metaVerbose = true;
586 	if (strstr(make_mode, "read") != NULL)
587 	    writeMeta = false;
588 	if (strstr(make_mode, "nofilemon") != NULL)
589 	    useFilemon = false;
590 	if (strstr(make_mode, "ignore-cmd") != NULL)
591 	    metaIgnoreCMDs = true;
592 	if (useFilemon)
593 	    get_mode_bf(filemonMissing, "missing-filemon=");
594 	get_mode_bf(metaCurdirOk, "curdirok=");
595 	get_mode_bf(metaMissing, "missing-meta=");
596 	get_mode_bf(metaSilent, "silent=");
597     }
598     if (metaVerbose && !Var_Exists(SCOPE_GLOBAL, MAKE_META_PREFIX)) {
599 	/*
600 	 * The default value for MAKE_META_PREFIX
601 	 * prints the absolute path of the target.
602 	 * This works be cause :H will generate '.' if there is no /
603 	 * and :tA will resolve that to cwd.
604 	 */
605 	Global_Set(MAKE_META_PREFIX,
606 	    "Building ${.TARGET:H:tA}/${.TARGET:T}");
607     }
608     if (once)
609 	return;
610     once = true;
611     memset(&Mybm, 0, sizeof Mybm);
612     /*
613      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
614      */
615     metaBailiwickStr = Var_Subst("${.MAKE.META.BAILIWICK:O:u:tA}",
616 				 SCOPE_GLOBAL, VARE_WANTRES);
617     /* TODO: handle errors */
618     str2Lst_Append(&metaBailiwick, metaBailiwickStr);
619     /*
620      * We ignore any paths that start with ${.MAKE.META.IGNORE_PATHS}
621      */
622     Global_Append(MAKE_META_IGNORE_PATHS,
623 	       "/dev /etc /proc /tmp /var/run /var/tmp ${TMPDIR}");
624     metaIgnorePathsStr = Var_Subst("${" MAKE_META_IGNORE_PATHS ":O:u:tA}",
625 				   SCOPE_GLOBAL, VARE_WANTRES);
626     /* TODO: handle errors */
627     str2Lst_Append(&metaIgnorePaths, metaIgnorePathsStr);
628 
629     /*
630      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
631      */
632     metaIgnorePatterns = Var_Exists(SCOPE_GLOBAL, MAKE_META_IGNORE_PATTERNS);
633     metaIgnoreFilter = Var_Exists(SCOPE_GLOBAL, MAKE_META_IGNORE_FILTER);
634     metaCmpFilter = Var_Exists(SCOPE_GLOBAL, MAKE_META_CMP_FILTER);
635 }
636 
637 MAKE_INLINE BuildMon *
638 BM(Job *job)
639 {
640 
641 	return ((job != NULL) ? &job->bm : &Mybm);
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     pbm = BM(job);
653     pbm->mfp = meta_create(pbm, gn);
654 #ifdef USE_FILEMON_ONCE
655     /* compat mode we open the filemon dev once per command */
656     if (job == NULL)
657 	return;
658 #endif
659 #ifdef USE_FILEMON
660     if (pbm->mfp != NULL && useFilemon) {
661 	meta_open_filemon(pbm);
662     } else {
663 	pbm->mon_fd = -1;
664 	pbm->filemon = NULL;
665     }
666 #endif
667 }
668 
669 /*
670  * The child calls this before doing anything.
671  * It does not disturb our state.
672  */
673 void
674 meta_job_child(Job *job MAKE_ATTR_UNUSED)
675 {
676 #ifdef USE_FILEMON
677     BuildMon *pbm;
678 
679     pbm = BM(job);
680     if (pbm->mfp != NULL) {
681 	close(fileno(pbm->mfp));
682 	if (useFilemon && pbm->filemon != NULL) {
683 	    pid_t pid;
684 
685 	    pid = getpid();
686 	    if (filemon_setpid_child(pbm->filemon, pid) == -1) {
687 		Punt("Could not set filemon pid: %s", strerror(errno));
688 	    }
689 	}
690     }
691 #endif
692 }
693 
694 void
695 meta_job_parent(Job *job MAKE_ATTR_UNUSED, pid_t pid MAKE_ATTR_UNUSED)
696 {
697 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
698     BuildMon *pbm;
699 
700     pbm = BM(job);
701     if (useFilemon && pbm->filemon != NULL) {
702 	filemon_setpid_parent(pbm->filemon, pid);
703     }
704 #endif
705 }
706 
707 int
708 meta_job_fd(Job *job MAKE_ATTR_UNUSED)
709 {
710 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
711     BuildMon *pbm;
712 
713     pbm = BM(job);
714     if (useFilemon && pbm->filemon != NULL) {
715 	return filemon_readfd(pbm->filemon);
716     }
717 #endif
718     return -1;
719 }
720 
721 int
722 meta_job_event(Job *job MAKE_ATTR_UNUSED)
723 {
724 #if defined(USE_FILEMON) && !defined(USE_FILEMON_DEV)
725     BuildMon *pbm;
726 
727     pbm = BM(job);
728     if (useFilemon && pbm->filemon != NULL) {
729 	return filemon_process(pbm->filemon);
730     }
731 #endif
732     return 0;
733 }
734 
735 void
736 meta_job_error(Job *job, GNode *gn, bool ignerr, int status)
737 {
738     char cwd[MAXPATHLEN];
739     BuildMon *pbm;
740 
741     pbm = BM(job);
742     if (job != NULL && gn == NULL)
743 	    gn = job->node;
744     if (pbm->mfp != NULL) {
745 	fprintf(pbm->mfp, "\n*** Error code %d%s\n",
746 		status, ignerr ? "(ignored)" : "");
747     }
748     if (gn != NULL)
749 	Global_Set(".ERROR_TARGET", GNode_Path(gn));
750     if (getcwd(cwd, sizeof cwd) == NULL)
751 	Punt("Cannot get cwd: %s", strerror(errno));
752 
753     Global_Set(".ERROR_CWD", cwd);
754     if (pbm->meta_fname[0] != '\0') {
755 	Global_Set(".ERROR_META_FILE", pbm->meta_fname);
756     }
757     meta_job_finish(job);
758 }
759 
760 void
761 meta_job_output(Job *job, char *cp, const char *nl)
762 {
763     BuildMon *pbm;
764 
765     pbm = BM(job);
766     if (pbm->mfp != NULL) {
767 	if (metaVerbose) {
768 	    static char *meta_prefix = NULL;
769 	    static size_t meta_prefix_len;
770 
771 	    if (meta_prefix == NULL) {
772 		char *cp2;
773 
774 		meta_prefix = Var_Subst("${" MAKE_META_PREFIX "}",
775 					SCOPE_GLOBAL, VARE_WANTRES);
776 		/* TODO: handle errors */
777 		if ((cp2 = strchr(meta_prefix, '$')) != NULL)
778 		    meta_prefix_len = (size_t)(cp2 - meta_prefix);
779 		else
780 		    meta_prefix_len = strlen(meta_prefix);
781 	    }
782 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
783 		cp = strchr(cp + 1, '\n');
784 		if (cp == NULL)
785 		    return;
786 		cp++;
787 	    }
788 	}
789 	fprintf(pbm->mfp, "%s%s", cp, nl);
790     }
791 }
792 
793 int
794 meta_cmd_finish(void *pbmp)
795 {
796     int error = 0;
797     BuildMon *pbm = pbmp;
798 #ifdef USE_FILEMON
799     int x;
800 #endif
801 
802     if (pbm == NULL)
803 	pbm = &Mybm;
804 
805 #ifdef USE_FILEMON
806     if (pbm->filemon != NULL) {
807 	while (filemon_process(pbm->filemon) > 0)
808 	    continue;
809 	if (filemon_close(pbm->filemon) == -1) {
810 	    error = errno;
811 	    Punt("filemon failed: %s", strerror(errno));
812 	}
813 	x = filemon_read(pbm->mfp, pbm->mon_fd);
814 	if (error == 0 && x != 0)
815 	    error = x;
816 	pbm->mon_fd = -1;
817 	pbm->filemon = NULL;
818 	return error;
819     }
820 #endif
821 
822     fprintf(pbm->mfp, "\n");	/* ensure end with newline */
823     return error;
824 }
825 
826 int
827 meta_job_finish(Job *job)
828 {
829     BuildMon *pbm;
830     int error = 0;
831     int x;
832 
833     pbm = BM(job);
834     if (pbm->mfp != NULL) {
835 	error = meta_cmd_finish(pbm);
836 	x = fclose(pbm->mfp);
837 	if (error == 0 && x != 0)
838 	    error = errno;
839 	pbm->mfp = NULL;
840 	pbm->meta_fname[0] = '\0';
841     }
842     return error;
843 }
844 
845 void
846 meta_finish(void)
847 {
848     Lst_Done(&metaBailiwick);
849     free(metaBailiwickStr);
850     Lst_Done(&metaIgnorePaths);
851     free(metaIgnorePathsStr);
852 }
853 
854 /*
855  * Fetch a full line from fp - growing bufp if needed
856  * Return length in bufp.
857  */
858 static int
859 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
860 {
861     char *buf = *bufp;
862     size_t bufsz = *szp;
863     struct stat fs;
864     int x;
865 
866     if (fgets(&buf[o], (int)bufsz - o, fp) != NULL) {
867     check_newline:
868 	x = o + (int)strlen(&buf[o]);
869 	if (buf[x - 1] == '\n')
870 	    return x;
871 	/*
872 	 * We need to grow the buffer.
873 	 * The meta file can give us a clue.
874 	 */
875 	if (fstat(fileno(fp), &fs) == 0) {
876 	    size_t newsz;
877 	    char *p;
878 
879 	    newsz = ROUNDUP(((size_t)fs.st_size / 2), BUFSIZ);
880 	    if (newsz <= bufsz)
881 		newsz = ROUNDUP((size_t)fs.st_size, BUFSIZ);
882 	    if (newsz <= bufsz)
883 		return x;		/* truncated */
884 	    DEBUG2(META, "growing buffer %u -> %u\n",
885 		   (unsigned)bufsz, (unsigned)newsz);
886 	    p = bmake_realloc(buf, newsz);
887 	    *bufp = buf = p;
888 	    *szp = bufsz = newsz;
889 	    /* fetch the rest */
890 	    if (fgets(&buf[x], (int)bufsz - x, fp) == NULL)
891 		return x;		/* truncated! */
892 	    goto check_newline;
893 	}
894     }
895     return 0;
896 }
897 
898 static bool
899 prefix_match(const char *prefix, const char *path)
900 {
901     size_t n = strlen(prefix);
902 
903     return strncmp(path, prefix, n) == 0;
904 }
905 
906 static bool
907 has_any_prefix(const char *path, StringList *prefixes)
908 {
909     StringListNode *ln;
910 
911     for (ln = prefixes->first; ln != NULL; ln = ln->next)
912 	if (prefix_match(ln->datum, path))
913 	    return true;
914     return false;
915 }
916 
917 /* See if the path equals prefix or starts with "prefix/". */
918 static bool
919 path_starts_with(const char *path, const char *prefix)
920 {
921     size_t n = strlen(prefix);
922 
923     if (strncmp(path, prefix, n) != 0)
924 	return false;
925     return path[n] == '\0' || path[n] == '/';
926 }
927 
928 static bool
929 meta_ignore(GNode *gn, const char *p)
930 {
931     char fname[MAXPATHLEN];
932 
933     if (p == NULL)
934 	return true;
935 
936     if (*p == '/') {
937 	cached_realpath(p, fname); /* clean it up */
938 	if (has_any_prefix(fname, &metaIgnorePaths)) {
939 #ifdef DEBUG_META_MODE
940 	    DEBUG1(META, "meta_oodate: ignoring path: %s\n", p);
941 #endif
942 	    return true;
943 	}
944     }
945 
946     if (metaIgnorePatterns) {
947 	const char *expr;
948 	char *pm;
949 
950 	/*
951 	 * XXX: This variable is set on a target GNode but is not one of
952 	 * the usual local variables.  It should be deleted afterwards.
953 	 * Ideally it would not be created in the first place, just like
954 	 * in a .for loop.
955 	 */
956 	Var_Set(gn, ".p.", p);
957 	expr = "${" MAKE_META_IGNORE_PATTERNS ":@m@${.p.:M$m}@}";
958 	pm = Var_Subst(expr, gn, VARE_WANTRES);
959 	/* TODO: handle errors */
960 	if (pm[0] != '\0') {
961 #ifdef DEBUG_META_MODE
962 	    DEBUG1(META, "meta_oodate: ignoring pattern: %s\n", p);
963 #endif
964 	    free(pm);
965 	    return true;
966 	}
967 	free(pm);
968     }
969 
970     if (metaIgnoreFilter) {
971 	char *fm;
972 
973 	/* skip if filter result is empty */
974 	snprintf(fname, sizeof fname,
975 		 "${%s:L:${%s:ts:}}",
976 		 p, MAKE_META_IGNORE_FILTER);
977 	fm = Var_Subst(fname, gn, VARE_WANTRES);
978 	/* TODO: handle errors */
979 	if (*fm == '\0') {
980 #ifdef DEBUG_META_MODE
981 	    DEBUG1(META, "meta_oodate: ignoring filtered: %s\n", p);
982 #endif
983 	    free(fm);
984 	    return true;
985 	}
986 	free(fm);
987     }
988     return false;
989 }
990 
991 /*
992  * When running with 'meta' functionality, a target can be out-of-date
993  * if any of the references in its meta data file is more recent.
994  * We have to track the latestdir on a per-process basis.
995  */
996 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
997 #define LDIR_VNAME_FMT ".meta.%d.ldir"
998 
999 /*
1000  * It is possible that a .meta file is corrupted,
1001  * if we detect this we want to reproduce it.
1002  * Setting oodate true will have that effect.
1003  */
1004 #define CHECK_VALID_META(p) if (!(p != NULL && *p != '\0')) { \
1005     warnx("%s: %u: malformed", fname, lineno); \
1006     oodate = true; \
1007     continue; \
1008     }
1009 
1010 #define DEQUOTE(p) if (*p == '\'') {	\
1011     char *ep; \
1012     p++; \
1013     if ((ep = strchr(p, '\'')) != NULL) \
1014 	*ep = '\0'; \
1015     }
1016 
1017 static void
1018 append_if_new(StringList *list, const char *str)
1019 {
1020     StringListNode *ln;
1021 
1022     for (ln = list->first; ln != NULL; ln = ln->next)
1023 	if (strcmp(ln->datum, str) == 0)
1024 	    return;
1025     Lst_Append(list, bmake_strdup(str));
1026 }
1027 
1028 /* A "reserved" variable to store the command to be filtered */
1029 #define META_CMD_FILTER_VAR ".MAKE.cmd_filtered"
1030 
1031 static char *
1032 meta_filter_cmd(GNode *gn, char *s)
1033 {
1034     Var_Set(gn, META_CMD_FILTER_VAR, s);
1035     s = Var_Subst(
1036 	"${" META_CMD_FILTER_VAR ":${" MAKE_META_CMP_FILTER ":ts:}}",
1037 	gn, VARE_WANTRES);
1038     return s;
1039 }
1040 
1041 static int
1042 meta_cmd_cmp(GNode *gn, char *a, char *b, bool filter)
1043 {
1044     int rc;
1045 
1046     rc = strcmp(a, b);
1047     if (rc == 0 || !filter)
1048 	return rc;
1049     a = meta_filter_cmd(gn, a);
1050     b = meta_filter_cmd(gn, b);
1051     rc = strcmp(a, b);
1052     free(a);
1053     free(b);
1054     Var_Delete(gn, META_CMD_FILTER_VAR);
1055     return rc;
1056 }
1057 
1058 bool
1059 meta_oodate(GNode *gn, bool oodate)
1060 {
1061     static char *tmpdir = NULL;
1062     static char cwd[MAXPATHLEN];
1063     char lcwd_vname[64];
1064     char ldir_vname[64];
1065     char lcwd[MAXPATHLEN];
1066     char latestdir[MAXPATHLEN];
1067     char fname[MAXPATHLEN];
1068     char fname1[MAXPATHLEN];
1069     char fname2[MAXPATHLEN];
1070     char fname3[MAXPATHLEN];
1071     FStr dname;
1072     const char *tname;
1073     char *p;
1074     char *link_src;
1075     char *move_target;
1076     static size_t cwdlen = 0;
1077     static size_t tmplen = 0;
1078     FILE *fp;
1079     bool needOODATE = false;
1080     StringList missingFiles;
1081     bool have_filemon = false;
1082     bool cmp_filter;
1083 
1084     if (oodate)
1085 	return oodate;		/* we're done */
1086 
1087     dname = Var_Value(gn, ".OBJDIR");
1088     tname = GNode_VarTarget(gn);
1089 
1090     /* if this succeeds fname3 is realpath of dname */
1091     if (!meta_needed(gn, dname.str, fname3, false))
1092 	goto oodate_out;
1093     dname.str = fname3;
1094 
1095     Lst_Init(&missingFiles);
1096 
1097     /*
1098      * We need to check if the target is out-of-date. This includes
1099      * checking if the expanded command has changed. This in turn
1100      * requires that all variables are set in the same way that they
1101      * would be if the target needs to be re-built.
1102      */
1103     GNode_SetLocalVars(gn);
1104 
1105     meta_name(fname, sizeof fname, dname.str, tname, dname.str);
1106 
1107 #ifdef DEBUG_META_MODE
1108     DEBUG1(META, "meta_oodate: %s\n", fname);
1109 #endif
1110 
1111     if ((fp = fopen(fname, "r")) != NULL) {
1112 	static char *buf = NULL;
1113 	static size_t bufsz;
1114 	unsigned lineno = 0;
1115 	int lastpid = 0;
1116 	int pid;
1117 	int x;
1118 	StringListNode *cmdNode;
1119 	struct cached_stat cst;
1120 
1121 	if (buf == NULL) {
1122 	    bufsz = 8 * BUFSIZ;
1123 	    buf = bmake_malloc(bufsz);
1124 	}
1125 
1126 	if (cwdlen == 0) {
1127 	    if (getcwd(cwd, sizeof cwd) == NULL)
1128 		err(1, "Could not get current working directory");
1129 	    cwdlen = strlen(cwd);
1130 	}
1131 	strlcpy(lcwd, cwd, sizeof lcwd);
1132 	strlcpy(latestdir, cwd, sizeof latestdir);
1133 
1134 	if (tmpdir == NULL) {
1135 	    tmpdir = getTmpdir();
1136 	    tmplen = strlen(tmpdir);
1137 	}
1138 
1139 	/* we want to track all the .meta we read */
1140 	Global_Append(".MAKE.META.FILES", fname);
1141 
1142 	cmp_filter = metaCmpFilter || Var_Exists(gn, MAKE_META_CMP_FILTER);
1143 
1144 	cmdNode = gn->commands.first;
1145 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1146 	    lineno++;
1147 	    if (buf[x - 1] == '\n')
1148 		buf[x - 1] = '\0';
1149 	    else {
1150 		warnx("%s: %u: line truncated at %u", fname, lineno, x);
1151 		oodate = true;
1152 		break;
1153 	    }
1154 	    link_src = NULL;
1155 	    move_target = NULL;
1156 	    /* Find the start of the build monitor section. */
1157 	    if (!have_filemon) {
1158 		if (strncmp(buf, "-- filemon", 10) == 0) {
1159 		    have_filemon = true;
1160 		    continue;
1161 		}
1162 		if (strncmp(buf, "# buildmon", 10) == 0) {
1163 		    have_filemon = true;
1164 		    continue;
1165 		}
1166 	    }
1167 
1168 	    /* Delimit the record type. */
1169 	    p = buf;
1170 #ifdef DEBUG_META_MODE
1171 	    DEBUG3(META, "%s: %u: %s\n", fname, lineno, buf);
1172 #endif
1173 	    strsep(&p, " ");
1174 	    if (have_filemon) {
1175 		/*
1176 		 * We are in the 'filemon' output section.
1177 		 * Each record from filemon follows the general form:
1178 		 *
1179 		 * <key> <pid> <data>
1180 		 *
1181 		 * Where:
1182 		 * <key> is a single letter, denoting the syscall.
1183 		 * <pid> is the process that made the syscall.
1184 		 * <data> is the arguments (of interest).
1185 		 */
1186 		switch(buf[0]) {
1187 		case '#':		/* comment */
1188 		case 'V':		/* version */
1189 		    break;
1190 		default:
1191 		    /*
1192 		     * We need to track pathnames per-process.
1193 		     *
1194 		     * Each process run by make starts off in the 'CWD'
1195 		     * recorded in the .meta file, if it chdirs ('C')
1196 		     * elsewhere we need to track that - but only for
1197 		     * that process.  If it forks ('F'), we initialize
1198 		     * the child to have the same cwd as its parent.
1199 		     *
1200 		     * We also need to track the 'latestdir' of
1201 		     * interest.  This is usually the same as cwd, but
1202 		     * not if a process is reading directories.
1203 		     *
1204 		     * Each time we spot a different process ('pid')
1205 		     * we save the current value of 'latestdir' in a
1206 		     * variable qualified by 'lastpid', and
1207 		     * re-initialize 'latestdir' to any pre-saved
1208 		     * value for the current 'pid' and 'CWD' if none.
1209 		     */
1210 		    CHECK_VALID_META(p);
1211 		    pid = atoi(p);
1212 		    if (pid > 0 && pid != lastpid) {
1213 			FStr ldir;
1214 
1215 			if (lastpid > 0) {
1216 			    /* We need to remember these. */
1217 			    Global_Set(lcwd_vname, lcwd);
1218 			    Global_Set(ldir_vname, latestdir);
1219 			}
1220 			snprintf(lcwd_vname, sizeof lcwd_vname, LCWD_VNAME_FMT, pid);
1221 			snprintf(ldir_vname, sizeof ldir_vname, LDIR_VNAME_FMT, pid);
1222 			lastpid = pid;
1223 			ldir = Var_Value(SCOPE_GLOBAL, ldir_vname);
1224 			if (ldir.str != NULL) {
1225 			    strlcpy(latestdir, ldir.str, sizeof latestdir);
1226 			    FStr_Done(&ldir);
1227 			}
1228 			ldir = Var_Value(SCOPE_GLOBAL, lcwd_vname);
1229 			if (ldir.str != NULL) {
1230 			    strlcpy(lcwd, ldir.str, sizeof lcwd);
1231 			    FStr_Done(&ldir);
1232 			}
1233 		    }
1234 		    /* Skip past the pid. */
1235 		    if (strsep(&p, " ") == NULL)
1236 			continue;
1237 #ifdef DEBUG_META_MODE
1238 		    if (DEBUG(META))
1239 			debug_printf("%s: %u: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1240 				     fname, lineno,
1241 				     pid, buf[0], cwd, lcwd, latestdir);
1242 #endif
1243 		    break;
1244 		}
1245 
1246 		CHECK_VALID_META(p);
1247 
1248 		/* Process according to record type. */
1249 		switch (buf[0]) {
1250 		case 'X':		/* eXit */
1251 		    Var_Delete(SCOPE_GLOBAL, lcwd_vname);
1252 		    Var_Delete(SCOPE_GLOBAL, ldir_vname);
1253 		    lastpid = 0;	/* no need to save ldir_vname */
1254 		    break;
1255 
1256 		case 'F':		/* [v]Fork */
1257 		    {
1258 			char cldir[64];
1259 			int child;
1260 
1261 			child = atoi(p);
1262 			if (child > 0) {
1263 			    snprintf(cldir, sizeof cldir, LCWD_VNAME_FMT, child);
1264 			    Global_Set(cldir, lcwd);
1265 			    snprintf(cldir, sizeof cldir, LDIR_VNAME_FMT, child);
1266 			    Global_Set(cldir, latestdir);
1267 #ifdef DEBUG_META_MODE
1268 			    if (DEBUG(META))
1269 				debug_printf(
1270 					"%s: %u: %d: cwd=%s lcwd=%s ldir=%s\n",
1271 					fname, lineno,
1272 					child, cwd, lcwd, latestdir);
1273 #endif
1274 			}
1275 		    }
1276 		    break;
1277 
1278 		case 'C':		/* Chdir */
1279 		    /* Update lcwd and latest directory. */
1280 		    strlcpy(latestdir, p, sizeof latestdir);
1281 		    strlcpy(lcwd, p, sizeof lcwd);
1282 		    Global_Set(lcwd_vname, lcwd);
1283 		    Global_Set(ldir_vname, lcwd);
1284 #ifdef DEBUG_META_MODE
1285 		    DEBUG4(META, "%s: %u: cwd=%s ldir=%s\n",
1286 			   fname, lineno, cwd, lcwd);
1287 #endif
1288 		    break;
1289 
1290 		case 'M':		/* renaMe */
1291 		    /*
1292 		     * For 'M'oves we want to check
1293 		     * the src as for 'R'ead
1294 		     * and the target as for 'W'rite.
1295 		     */
1296 		    {
1297 			char *cp = p;	/* save this for a second */
1298 			/* now get target */
1299 			if (strsep(&p, " ") == NULL)
1300 			    continue;
1301 			CHECK_VALID_META(p);
1302 			move_target = p;
1303 			p = cp;
1304 		    }
1305 		    /* 'L' and 'M' put single quotes around the args */
1306 		    DEQUOTE(p);
1307 		    DEQUOTE(move_target);
1308 		    /* FALLTHROUGH */
1309 		case 'D':		/* unlink */
1310 		    if (*p == '/') {
1311 			/* remove any missingFiles entries that match p */
1312 			StringListNode *ln = missingFiles.first;
1313 			while (ln != NULL) {
1314 			    StringListNode *next = ln->next;
1315 			    if (path_starts_with(ln->datum, p)) {
1316 				free(ln->datum);
1317 				Lst_Remove(&missingFiles, ln);
1318 			    }
1319 			    ln = next;
1320 			}
1321 		    }
1322 		    if (buf[0] == 'M') {
1323 			/* the target of the mv is a file 'W'ritten */
1324 #ifdef DEBUG_META_MODE
1325 			DEBUG2(META, "meta_oodate: M %s -> %s\n",
1326 			       p, move_target);
1327 #endif
1328 			p = move_target;
1329 			goto check_write;
1330 		    }
1331 		    break;
1332 		case 'L':		/* Link */
1333 		    /*
1334 		     * For 'L'inks check
1335 		     * the src as for 'R'ead
1336 		     * and the target as for 'W'rite.
1337 		     */
1338 		    link_src = p;
1339 		    /* now get target */
1340 		    if (strsep(&p, " ") == NULL)
1341 			continue;
1342 		    CHECK_VALID_META(p);
1343 		    /* 'L' and 'M' put single quotes around the args */
1344 		    DEQUOTE(p);
1345 		    DEQUOTE(link_src);
1346 #ifdef DEBUG_META_MODE
1347 		    DEBUG2(META, "meta_oodate: L %s -> %s\n", link_src, p);
1348 #endif
1349 		    /* FALLTHROUGH */
1350 		case 'W':		/* Write */
1351 		check_write:
1352 		    /*
1353 		     * If a file we generated within our bailiwick
1354 		     * but outside of .OBJDIR is missing,
1355 		     * we need to do it again.
1356 		     */
1357 		    /* ignore non-absolute paths */
1358 		    if (*p != '/')
1359 			break;
1360 
1361 		    if (Lst_IsEmpty(&metaBailiwick))
1362 			break;
1363 
1364 		    /* ignore cwd - normal dependencies handle those */
1365 		    if (strncmp(p, cwd, cwdlen) == 0)
1366 			break;
1367 
1368 		    if (!has_any_prefix(p, &metaBailiwick))
1369 			break;
1370 
1371 		    /* tmpdir might be within */
1372 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1373 			break;
1374 
1375 		    /* ignore anything containing the string "tmp" */
1376 		    /* XXX: The arguments to strstr must be swapped. */
1377 		    if (strstr("tmp", p) != NULL)
1378 			break;
1379 
1380 		    if ((link_src != NULL && cached_lstat(p, &cst) < 0) ||
1381 			(link_src == NULL && cached_stat(p, &cst) < 0)) {
1382 			if (!meta_ignore(gn, p))
1383 			    append_if_new(&missingFiles, p);
1384 		    }
1385 		    break;
1386 		check_link_src:
1387 		    p = link_src;
1388 		    link_src = NULL;
1389 #ifdef DEBUG_META_MODE
1390 		    DEBUG1(META, "meta_oodate: L src %s\n", p);
1391 #endif
1392 		    /* FALLTHROUGH */
1393 		case 'R':		/* Read */
1394 		case 'E':		/* Exec */
1395 		    /*
1396 		     * Check for runtime files that can't
1397 		     * be part of the dependencies because
1398 		     * they are _expected_ to change.
1399 		     */
1400 		    if (meta_ignore(gn, p))
1401 			break;
1402 
1403 		    /*
1404 		     * The rest of the record is the file name.
1405 		     * Check if it's not an absolute path.
1406 		     */
1407 		    {
1408 			char *sdirs[4];
1409 			char **sdp;
1410 			int sdx = 0;
1411 			bool found = false;
1412 
1413 			if (*p == '/') {
1414 			    sdirs[sdx++] = p; /* done */
1415 			} else {
1416 			    if (strcmp(".", p) == 0)
1417 				continue; /* no point */
1418 
1419 			    /* Check vs latestdir */
1420 			    if (snprintf(fname1, sizeof fname1, "%s/%s", latestdir, p) < (int)(sizeof fname1))
1421 				sdirs[sdx++] = fname1;
1422 
1423 			    if (strcmp(latestdir, lcwd) != 0) {
1424 				/* Check vs lcwd */
1425 				if (snprintf(fname2, sizeof fname2, "%s/%s", lcwd, p) < (int)(sizeof fname2))
1426 				    sdirs[sdx++] = fname2;
1427 			    }
1428 			    if (strcmp(lcwd, cwd) != 0) {
1429 				/* Check vs cwd */
1430 				if (snprintf(fname3, sizeof fname3, "%s/%s", cwd, p) < (int)(sizeof fname3))
1431 				    sdirs[sdx++] = fname3;
1432 			    }
1433 			}
1434 			sdirs[sdx++] = NULL;
1435 
1436 			for (sdp = sdirs; *sdp != NULL && !found; sdp++) {
1437 #ifdef DEBUG_META_MODE
1438 			    DEBUG3(META, "%s: %u: looking for: %s\n",
1439 				   fname, lineno, *sdp);
1440 #endif
1441 			    if (cached_stat(*sdp, &cst) == 0) {
1442 				found = true;
1443 				p = *sdp;
1444 			    }
1445 			}
1446 			if (found) {
1447 #ifdef DEBUG_META_MODE
1448 			    DEBUG3(META, "%s: %u: found: %s\n",
1449 				   fname, lineno, p);
1450 #endif
1451 			    if (!S_ISDIR(cst.cst_mode) &&
1452 				cst.cst_mtime > gn->mtime) {
1453 				DEBUG3(META, "%s: %u: file '%s' is newer than the target...\n",
1454 				       fname, lineno, p);
1455 				oodate = true;
1456 			    } else if (S_ISDIR(cst.cst_mode)) {
1457 				/* Update the latest directory. */
1458 				cached_realpath(p, latestdir);
1459 			    }
1460 			} else if (errno == ENOENT && *p == '/' &&
1461 				   strncmp(p, cwd, cwdlen) != 0) {
1462 			    /*
1463 			     * A referenced file outside of CWD is missing.
1464 			     * We cannot catch every eventuality here...
1465 			     */
1466 			    append_if_new(&missingFiles, p);
1467 			}
1468 		    }
1469 		    if (buf[0] == 'E') {
1470 			/* previous latestdir is no longer relevant */
1471 			strlcpy(latestdir, lcwd, sizeof latestdir);
1472 		    }
1473 		    break;
1474 		default:
1475 		    break;
1476 		}
1477 		if (!oodate && buf[0] == 'L' && link_src != NULL)
1478 		    goto check_link_src;
1479 	    } else if (strcmp(buf, "CMD") == 0) {
1480 		/*
1481 		 * Compare the current command with the one in the
1482 		 * meta data file.
1483 		 */
1484 		if (cmdNode == NULL) {
1485 		    DEBUG2(META, "%s: %u: there were more build commands in the meta data file than there are now...\n",
1486 			   fname, lineno);
1487 		    oodate = true;
1488 		} else {
1489 		    const char *cp;
1490 		    char *cmd = cmdNode->datum;
1491 		    bool hasOODATE = false;
1492 
1493 		    if (strstr(cmd, "$?") != NULL)
1494 			hasOODATE = true;
1495 		    else if ((cp = strstr(cmd, ".OODATE")) != NULL) {
1496 			/* check for $[{(].OODATE[:)}] */
1497 			if (cp > cmd + 2 && cp[-2] == '$')
1498 			    hasOODATE = true;
1499 		    }
1500 		    if (hasOODATE) {
1501 			needOODATE = true;
1502 			DEBUG2(META, "%s: %u: cannot compare command using .OODATE\n",
1503 			       fname, lineno);
1504 		    }
1505 		    cmd = Var_Subst(cmd, gn, VARE_UNDEFERR);
1506 		    /* TODO: handle errors */
1507 
1508 		    if ((cp = strchr(cmd, '\n')) != NULL) {
1509 			int n;
1510 
1511 			/*
1512 			 * This command contains newlines, we need to
1513 			 * fetch more from the .meta file before we
1514 			 * attempt a comparison.
1515 			 */
1516 			/* first put the newline back at buf[x - 1] */
1517 			buf[x - 1] = '\n';
1518 			do {
1519 			    /* now fetch the next line */
1520 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1521 				break;
1522 			    x = n;
1523 			    lineno++;
1524 			    if (buf[x - 1] != '\n') {
1525 				warnx("%s: %u: line truncated at %u", fname, lineno, x);
1526 				break;
1527 			    }
1528 			    cp = strchr(cp + 1, '\n');
1529 			} while (cp != NULL);
1530 			if (buf[x - 1] == '\n')
1531 			    buf[x - 1] = '\0';
1532 		    }
1533 		    if (p != NULL &&
1534 			!hasOODATE &&
1535 			!(gn->type & OP_NOMETA_CMP) &&
1536 			(meta_cmd_cmp(gn, p, cmd, cmp_filter) != 0)) {
1537 			DEBUG4(META, "%s: %u: a build command has changed\n%s\nvs\n%s\n",
1538 			       fname, lineno, p, cmd);
1539 			if (!metaIgnoreCMDs)
1540 			    oodate = true;
1541 		    }
1542 		    free(cmd);
1543 		    cmdNode = cmdNode->next;
1544 		}
1545 	    } else if (strcmp(buf, "CWD") == 0) {
1546 		/*
1547 		 * Check if there are extra commands now
1548 		 * that weren't in the meta data file.
1549 		 */
1550 		if (!oodate && cmdNode != NULL) {
1551 		    DEBUG2(META, "%s: %u: there are extra build commands now that weren't in the meta data file\n",
1552 			   fname, lineno);
1553 		    oodate = true;
1554 		}
1555 		CHECK_VALID_META(p);
1556 		if (strcmp(p, cwd) != 0) {
1557 		    DEBUG4(META, "%s: %u: the current working directory has changed from '%s' to '%s'\n",
1558 			   fname, lineno, p, curdir);
1559 		    oodate = true;
1560 		}
1561 	    }
1562 	}
1563 
1564 	fclose(fp);
1565 	if (!Lst_IsEmpty(&missingFiles)) {
1566 	    DEBUG2(META, "%s: missing files: %s...\n",
1567 		   fname, (char *)missingFiles.first->datum);
1568 	    oodate = true;
1569 	}
1570 	if (!oodate && !have_filemon && filemonMissing) {
1571 	    DEBUG1(META, "%s: missing filemon data\n", fname);
1572 	    oodate = true;
1573 	}
1574     } else {
1575 	if (writeMeta && (metaMissing || (gn->type & OP_META))) {
1576 	    const char *cp = NULL;
1577 
1578 	    /* if target is in .CURDIR we do not need a meta file */
1579 	    if (gn->path != NULL && (cp = strrchr(gn->path, '/')) != NULL &&
1580 		(cp > gn->path)) {
1581 		if (strncmp(curdir, gn->path, (size_t)(cp - gn->path)) != 0) {
1582 		    cp = NULL;		/* not in .CURDIR */
1583 		}
1584 	    }
1585 	    if (cp == NULL) {
1586 		DEBUG1(META, "%s: required but missing\n", fname);
1587 		oodate = true;
1588 		needOODATE = true;	/* assume the worst */
1589 	    }
1590 	}
1591     }
1592 
1593     Lst_DoneCall(&missingFiles, free);
1594 
1595     if (oodate && needOODATE) {
1596 	/*
1597 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1598 	 * We have decided it is oodate, so .OODATE needs to be set.
1599 	 * All we can sanely do is set it to .ALLSRC.
1600 	 */
1601 	Var_Delete(gn, OODATE);
1602 	Var_Set(gn, OODATE, GNode_VarAllsrc(gn));
1603     }
1604 
1605  oodate_out:
1606     FStr_Done(&dname);
1607     return oodate;
1608 }
1609 
1610 /* support for compat mode */
1611 
1612 static int childPipe[2];
1613 
1614 void
1615 meta_compat_start(void)
1616 {
1617 #ifdef USE_FILEMON_ONCE
1618     /*
1619      * We need to re-open filemon for each cmd.
1620      */
1621     BuildMon *pbm = &Mybm;
1622 
1623     if (pbm->mfp != NULL && useFilemon) {
1624 	meta_open_filemon(pbm);
1625     } else {
1626 	pbm->mon_fd = -1;
1627 	pbm->filemon = NULL;
1628     }
1629 #endif
1630     if (pipe(childPipe) < 0)
1631 	Punt("Cannot create pipe: %s", strerror(errno));
1632     /* Set close-on-exec flag for both */
1633     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1634     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1635 }
1636 
1637 void
1638 meta_compat_child(void)
1639 {
1640     meta_job_child(NULL);
1641     if (dup2(childPipe[1], 1) < 0 || dup2(1, 2) < 0)
1642 	execDie("dup2", "pipe");
1643 }
1644 
1645 void
1646 meta_compat_parent(pid_t child)
1647 {
1648     int outfd, metafd, maxfd, nfds;
1649     char buf[BUFSIZ+1];
1650     fd_set readfds;
1651 
1652     meta_job_parent(NULL, child);
1653     close(childPipe[1]);			/* child side */
1654     outfd = childPipe[0];
1655 #ifdef USE_FILEMON
1656     metafd = Mybm.filemon != NULL ? filemon_readfd(Mybm.filemon) : -1;
1657 #else
1658     metafd = -1;
1659 #endif
1660     maxfd = -1;
1661     if (outfd > maxfd)
1662 	    maxfd = outfd;
1663     if (metafd > maxfd)
1664 	    maxfd = metafd;
1665 
1666     while (outfd != -1 || metafd != -1) {
1667 	FD_ZERO(&readfds);
1668 	if (outfd != -1) {
1669 	    FD_SET(outfd, &readfds);
1670 	}
1671 	if (metafd != -1) {
1672 	    FD_SET(metafd, &readfds);
1673 	}
1674 	nfds = select(maxfd + 1, &readfds, NULL, NULL, NULL);
1675 	if (nfds == -1) {
1676 	    if (errno == EINTR)
1677 		continue;
1678 	    err(1, "select");
1679 	}
1680 
1681 	if (outfd != -1 && FD_ISSET(outfd, &readfds) != 0) do {
1682 	    /* XXX this is not line-buffered */
1683 	    ssize_t nread = read(outfd, buf, sizeof buf - 1);
1684 	    if (nread == -1)
1685 		err(1, "read");
1686 	    if (nread == 0) {
1687 		close(outfd);
1688 		outfd = -1;
1689 		break;
1690 	    }
1691 	    fwrite(buf, 1, (size_t)nread, stdout);
1692 	    fflush(stdout);
1693 	    buf[nread] = '\0';
1694 	    meta_job_output(NULL, buf, "");
1695 	} while (false);
1696 	if (metafd != -1 && FD_ISSET(metafd, &readfds) != 0) {
1697 	    if (meta_job_event(NULL) <= 0)
1698 		metafd = -1;
1699 	}
1700     }
1701 }
1702 
1703 #endif /* USE_META */
1704