xref: /freebsd/contrib/bmake/meta.c (revision 6e660824a82f590542932de52f128db584029893)
1 /*      $NetBSD: meta.c,v 1.30 2013/05/16 21:56:56 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) 2009-2010, Juniper Networks, Inc.
10  * Portions Copyright (c) 2009, John Birrell.
11  *
12  * Redistribution and use in source and binary forms, with or without
13  * modification, are permitted provided that the following conditions
14  * are met:
15  * 1. Redistributions of source code must retain the above copyright
16  *    notice, this list of conditions and the following disclaimer.
17  * 2. Redistributions in binary form must reproduce the above copyright
18  *    notice, this list of conditions and the following disclaimer in the
19  *    documentation and/or other materials provided with the distribution.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
22  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
23  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
24  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
25  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
26  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
27  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
28  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
29  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
30  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
31  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
32  */
33 #if defined(USE_META)
34 
35 #ifdef HAVE_CONFIG_H
36 # include "config.h"
37 #endif
38 #include <sys/stat.h>
39 #include <sys/ioctl.h>
40 #include <fcntl.h>
41 #include <libgen.h>
42 #include <errno.h>
43 #if !defined(HAVE_CONFIG_H) || defined(HAVE_ERR_H)
44 #include <err.h>
45 #endif
46 
47 #include "make.h"
48 #include "job.h"
49 
50 #ifdef HAVE_FILEMON_H
51 # include <filemon.h>
52 #endif
53 #if !defined(USE_FILEMON) && defined(FILEMON_SET_FD)
54 # define USE_FILEMON
55 #endif
56 
57 static BuildMon Mybm;			/* for compat */
58 static Lst metaBailiwick;			/* our scope of control */
59 
60 Boolean useMeta = FALSE;
61 static Boolean useFilemon = FALSE;
62 static Boolean writeMeta = FALSE;
63 static Boolean metaEnv = FALSE;		/* don't save env unless asked */
64 static Boolean metaVerbose = FALSE;
65 static Boolean metaIgnoreCMDs = FALSE;	/* ignore CMDs in .meta files */
66 static Boolean metaCurdirOk = FALSE;	/* write .meta in .CURDIR Ok? */
67 static Boolean metaSilent = FALSE;	/* if we have a .meta be SILENT */
68 
69 extern Boolean forceJobs;
70 extern Boolean comatMake;
71 extern char    **environ;
72 
73 #define	MAKE_META_PREFIX	".MAKE.META.PREFIX"
74 
75 #ifndef N2U
76 # define N2U(n, u)   (((n) + ((u) - 1)) / (u))
77 #endif
78 #ifndef ROUNDUP
79 # define ROUNDUP(n, u)   (N2U((n), (u)) * (u))
80 #endif
81 
82 #if !defined(HAVE_STRSEP)
83 # define strsep(s, d) stresep((s), (d), 0)
84 #endif
85 
86 /*
87  * Filemon is a kernel module which snoops certain syscalls.
88  *
89  * C chdir
90  * E exec
91  * F [v]fork
92  * L [sym]link
93  * M rename
94  * R read
95  * W write
96  * S stat
97  *
98  * See meta_oodate below - we mainly care about 'E' and 'R'.
99  *
100  * We can still use meta mode without filemon, but
101  * the benefits are more limited.
102  */
103 #ifdef USE_FILEMON
104 # ifndef _PATH_FILEMON
105 #   define _PATH_FILEMON "/dev/filemon"
106 # endif
107 
108 /*
109  * Open the filemon device.
110  */
111 static void
112 filemon_open(BuildMon *pbm)
113 {
114     int retry;
115 
116     pbm->mon_fd = pbm->filemon_fd = -1;
117     if (!useFilemon)
118 	return;
119 
120     for (retry = 5; retry >= 0; retry--) {
121 	if ((pbm->filemon_fd = open(_PATH_FILEMON, O_RDWR)) >= 0)
122 	    break;
123     }
124 
125     if (pbm->filemon_fd < 0) {
126 	useFilemon = FALSE;
127 	warn("Could not open %s", _PATH_FILEMON);
128 	return;
129     }
130 
131     /*
132      * We use a file outside of '.'
133      * to avoid a FreeBSD kernel bug where unlink invalidates
134      * cwd causing getcwd to do a lot more work.
135      * We only care about the descriptor.
136      */
137     pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL);
138     if (ioctl(pbm->filemon_fd, FILEMON_SET_FD, &pbm->mon_fd) < 0) {
139 	err(1, "Could not set filemon file descriptor!");
140     }
141     /* we don't need these once we exec */
142     (void)fcntl(pbm->mon_fd, F_SETFD, 1);
143     (void)fcntl(pbm->filemon_fd, F_SETFD, 1);
144 }
145 
146 /*
147  * Read the build monitor output file and write records to the target's
148  * metadata file.
149  */
150 static void
151 filemon_read(FILE *mfp, int fd)
152 {
153     FILE *fp;
154     char buf[BUFSIZ];
155 
156     /* Check if we're not writing to a meta data file.*/
157     if (mfp == NULL) {
158 	if (fd >= 0)
159 	    close(fd);			/* not interested */
160 	return;
161     }
162     /* rewind */
163     (void)lseek(fd, (off_t)0, SEEK_SET);
164     if ((fp = fdopen(fd, "r")) == NULL)
165 	err(1, "Could not read build monitor file '%d'", fd);
166 
167     fprintf(mfp, "-- filemon acquired metadata --\n");
168 
169     while (fgets(buf, sizeof(buf), fp)) {
170 	fprintf(mfp, "%s", buf);
171     }
172     fflush(mfp);
173     clearerr(fp);
174     fclose(fp);
175 }
176 #endif
177 
178 /*
179  * when realpath() fails,
180  * we use this, to clean up ./ and ../
181  */
182 static void
183 eat_dots(char *buf, size_t bufsz, int dots)
184 {
185     char *cp;
186     char *cp2;
187     const char *eat;
188     size_t eatlen;
189 
190     switch (dots) {
191     case 1:
192 	eat = "/./";
193 	eatlen = 2;
194 	break;
195     case 2:
196 	eat = "/../";
197 	eatlen = 3;
198 	break;
199     default:
200 	return;
201     }
202 
203     do {
204 	cp = strstr(buf, eat);
205 	if (cp) {
206 	    cp2 = cp + eatlen;
207 	    if (dots == 2 && cp > buf) {
208 		do {
209 		    cp--;
210 		} while (cp > buf && *cp != '/');
211 	    }
212 	    if (*cp == '/') {
213 		strlcpy(cp, cp2, bufsz - (cp - buf));
214 	    } else {
215 		return;			/* can't happen? */
216 	    }
217 	}
218     } while (cp);
219 }
220 
221 static char *
222 meta_name(struct GNode *gn, char *mname, size_t mnamelen,
223 	  const char *dname,
224 	  const char *tname)
225 {
226     char buf[MAXPATHLEN];
227     char cwd[MAXPATHLEN];
228     char *rp;
229     char *cp;
230     char *tp;
231     char *p[4];				/* >= number of possible uses */
232     int i;
233 
234     i = 0;
235     if (!dname)
236 	dname = Var_Value(".OBJDIR", gn, &p[i++]);
237     if (!tname)
238 	tname = Var_Value(TARGET, gn, &p[i++]);
239 
240     if (realpath(dname, cwd))
241 	dname = cwd;
242 
243     /*
244      * Weed out relative paths from the target file name.
245      * We have to be careful though since if target is a
246      * symlink, the result will be unstable.
247      * So we use realpath() just to get the dirname, and leave the
248      * basename as given to us.
249      */
250     if ((cp = strrchr(tname, '/'))) {
251 	if (realpath(tname, buf)) {
252 	    if ((rp = strrchr(buf, '/'))) {
253 		rp++;
254 		cp++;
255 		if (strcmp(cp, rp) != 0)
256 		    strlcpy(rp, cp, sizeof(buf) - (rp - buf));
257 	    }
258 	    tname = buf;
259 	} else {
260 	    /*
261 	     * We likely have a directory which is about to be made.
262 	     * We pretend realpath() succeeded, to have a chance
263 	     * of generating the same meta file name that we will
264 	     * next time through.
265 	     */
266 	    if (tname[0] == '/') {
267 		strlcpy(buf, tname, sizeof(buf));
268 	    } else {
269 		snprintf(buf, sizeof(buf), "%s/%s", cwd, tname);
270 	    }
271 	    eat_dots(buf, sizeof(buf), 1);	/* ./ */
272 	    eat_dots(buf, sizeof(buf), 2);	/* ../ */
273 	    tname = buf;
274 	}
275     }
276     /* on some systems dirname may modify its arg */
277     tp = bmake_strdup(tname);
278     if (strcmp(dname, dirname(tp)) == 0)
279 	snprintf(mname, mnamelen, "%s.meta", tname);
280     else {
281 	snprintf(mname, mnamelen, "%s/%s.meta", dname, tname);
282 
283 	/*
284 	 * Replace path separators in the file name after the
285 	 * current object directory path.
286 	 */
287 	cp = mname + strlen(dname) + 1;
288 
289 	while (*cp != '\0') {
290 	    if (*cp == '/')
291 		*cp = '_';
292 	    cp++;
293 	}
294     }
295     free(tp);
296     for (i--; i >= 0; i--) {
297 	if (p[i])
298 	    free(p[i]);
299     }
300     return (mname);
301 }
302 
303 /*
304  * Return true if running ${.MAKE}
305  * Bypassed if target is flagged .MAKE
306  */
307 static int
308 is_submake(void *cmdp, void *gnp)
309 {
310     static char *p_make = NULL;
311     static int p_len;
312     char  *cmd = cmdp;
313     GNode *gn = gnp;
314     char *mp = NULL;
315     char *cp;
316     char *cp2;
317     int rc = 0;				/* keep looking */
318 
319     if (!p_make) {
320 	p_make = Var_Value(".MAKE", gn, &cp);
321 	p_len = strlen(p_make);
322     }
323     cp = strchr(cmd, '$');
324     if ((cp)) {
325 	mp = Var_Subst(NULL, cmd, gn, FALSE);
326 	cmd = mp;
327     }
328     cp2 = strstr(cmd, p_make);
329     if ((cp2)) {
330 	switch (cp2[p_len]) {
331 	case '\0':
332 	case ' ':
333 	case '\t':
334 	case '\n':
335 	    rc = 1;
336 	    break;
337 	}
338 	if (cp2 > cmd && rc > 0) {
339 	    switch (cp2[-1]) {
340 	    case ' ':
341 	    case '\t':
342 	    case '\n':
343 		break;
344 	    default:
345 		rc = 0;			/* no match */
346 		break;
347 	    }
348 	}
349     }
350     if (mp)
351 	free(mp);
352     return (rc);
353 }
354 
355 typedef struct meta_file_s {
356     FILE *fp;
357     GNode *gn;
358 } meta_file_t;
359 
360 static int
361 printCMD(void *cmdp, void *mfpp)
362 {
363     meta_file_t *mfp = mfpp;
364     char *cmd = cmdp;
365     char *cp = NULL;
366 
367     if (strchr(cmd, '$')) {
368 	cmd = cp = Var_Subst(NULL, cmd, mfp->gn, FALSE);
369     }
370     fprintf(mfp->fp, "CMD %s\n", cmd);
371     if (cp)
372 	free(cp);
373     return 0;
374 }
375 
376 /*
377  * Certain node types never get a .meta file
378  */
379 #define SKIP_META_TYPE(_type) do { \
380     if ((gn->type & __CONCAT(OP_, _type))) {	\
381 	if (DEBUG(META)) { \
382 	    fprintf(debug_file, "Skipping meta for %s: .%s\n", \
383 		    gn->name, __STRING(_type));		       \
384 	} \
385 	return (NULL); \
386     } \
387 } while (0)
388 
389 static FILE *
390 meta_create(BuildMon *pbm, GNode *gn)
391 {
392     meta_file_t mf;
393     char buf[MAXPATHLEN];
394     char objdir[MAXPATHLEN];
395     char **ptr;
396     const char *dname;
397     const char *tname;
398     char *fname;
399     const char *cp;
400     char *p[4];				/* >= possible uses */
401     int i;
402     struct stat fs;
403 
404 
405     /* This may be a phony node which we don't want meta data for... */
406     /* Skip .meta for .BEGIN, .END, .ERROR etc as well. */
407     /* Or it may be explicitly flagged as .NOMETA */
408     SKIP_META_TYPE(NOMETA);
409     /* Unless it is explicitly flagged as .META */
410     if (!(gn->type & OP_META)) {
411 	SKIP_META_TYPE(PHONY);
412 	SKIP_META_TYPE(SPECIAL);
413 	SKIP_META_TYPE(MAKE);
414     }
415 
416     mf.fp = NULL;
417 
418     i = 0;
419 
420     dname = Var_Value(".OBJDIR", gn, &p[i++]);
421     tname = Var_Value(TARGET, gn, &p[i++]);
422 
423     /* The object directory may not exist. Check it.. */
424     if (stat(dname, &fs) != 0) {
425 	if (DEBUG(META))
426 	    fprintf(debug_file, "Skipping meta for %s: no .OBJDIR\n",
427 		    gn->name);
428 	goto out;
429     }
430     /* Check if there are no commands to execute. */
431     if (Lst_IsEmpty(gn->commands)) {
432 	if (DEBUG(META))
433 	    fprintf(debug_file, "Skipping meta for %s: no commands\n",
434 		    gn->name);
435 	goto out;
436     }
437 
438     /* make sure these are canonical */
439     if (realpath(dname, objdir))
440 	dname = objdir;
441 
442     /* If we aren't in the object directory, don't create a meta file. */
443     if (!metaCurdirOk && strcmp(curdir, dname) == 0) {
444 	if (DEBUG(META))
445 	    fprintf(debug_file, "Skipping meta for %s: .OBJDIR == .CURDIR\n",
446 		    gn->name);
447 	goto out;
448     }
449     if (!(gn->type & OP_META)) {
450 	/* We do not generate .meta files for sub-makes */
451 	if (Lst_ForEach(gn->commands, is_submake, gn)) {
452 	    if (DEBUG(META))
453 		fprintf(debug_file, "Skipping meta for %s: .MAKE\n",
454 			gn->name);
455 	    goto out;
456 	}
457     }
458 
459     if (metaVerbose) {
460 	char *mp;
461 
462 	/* Describe the target we are building */
463 	mp = Var_Subst(NULL, "${" MAKE_META_PREFIX "}", gn, 0);
464 	if (*mp)
465 	    fprintf(stdout, "%s\n", mp);
466 	free(mp);
467     }
468     /* Get the basename of the target */
469     if ((cp = strrchr(tname, '/')) == NULL) {
470 	cp = tname;
471     } else {
472 	cp++;
473     }
474 
475     fflush(stdout);
476 
477     if (strcmp(cp, makeDependfile) == 0)
478 	goto out;
479 
480     if (!writeMeta)
481 	/* Don't create meta data. */
482 	goto out;
483 
484     fname = meta_name(gn, pbm->meta_fname, sizeof(pbm->meta_fname),
485 		      dname, tname);
486 
487 #ifdef DEBUG_META_MODE
488     if (DEBUG(META))
489 	fprintf(debug_file, "meta_create: %s\n", fname);
490 #endif
491 
492     if ((mf.fp = fopen(fname, "w")) == NULL)
493 	err(1, "Could not open meta file '%s'", fname);
494 
495     fprintf(mf.fp, "# Meta data file %s\n", fname);
496 
497     mf.gn = gn;
498 
499     Lst_ForEach(gn->commands, printCMD, &mf);
500 
501     fprintf(mf.fp, "CWD %s\n", getcwd(buf, sizeof(buf)));
502     fprintf(mf.fp, "TARGET %s\n", tname);
503 
504     if (metaEnv) {
505 	for (ptr = environ; *ptr != NULL; ptr++)
506 	    fprintf(mf.fp, "ENV %s\n", *ptr);
507     }
508 
509     fprintf(mf.fp, "-- command output --\n");
510     fflush(mf.fp);
511 
512     Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
513     Var_Append(".MAKE.META.CREATED", fname, VAR_GLOBAL);
514 
515     gn->type |= OP_META;		/* in case anyone wants to know */
516     if (metaSilent) {
517 	    gn->type |= OP_SILENT;
518     }
519  out:
520     for (i--; i >= 0; i--) {
521 	if (p[i])
522 	    free(p[i]);
523     }
524 
525     return (mf.fp);
526 }
527 
528 static Boolean
529 boolValue(char *s)
530 {
531     switch(*s) {
532     case '0':
533     case 'N':
534     case 'n':
535     case 'F':
536     case 'f':
537 	return FALSE;
538     }
539     return TRUE;
540 }
541 
542 /*
543  * Initialization we need before reading makefiles.
544  */
545 void
546 meta_init(void)
547 {
548 #ifdef USE_FILEMON
549 	/* this allows makefiles to test if we have filemon support */
550 	Var_Set(".MAKE.PATH_FILEMON", _PATH_FILEMON, VAR_GLOBAL, 0);
551 #endif
552 }
553 
554 
555 /*
556  * Initialization we need after reading makefiles.
557  */
558 void
559 meta_mode_init(const char *make_mode)
560 {
561     static int once = 0;
562     char *cp;
563 
564     useMeta = TRUE;
565     useFilemon = TRUE;
566     writeMeta = TRUE;
567 
568     if (make_mode) {
569 	if (strstr(make_mode, "env"))
570 	    metaEnv = TRUE;
571 	if (strstr(make_mode, "verb"))
572 	    metaVerbose = TRUE;
573 	if (strstr(make_mode, "read"))
574 	    writeMeta = FALSE;
575 	if (strstr(make_mode, "nofilemon"))
576 	    useFilemon = FALSE;
577 	if ((cp = strstr(make_mode, "curdirok="))) {
578 	    metaCurdirOk = boolValue(&cp[9]);
579 	}
580 	if ((cp = strstr(make_mode, "silent="))) {
581 	    metaSilent = boolValue(&cp[7]);
582 	}
583 	if (strstr(make_mode, "ignore-cmd"))
584 	    metaIgnoreCMDs = TRUE;
585 	/* for backwards compatability */
586 	Var_Set(".MAKE.META_CREATED", "${.MAKE.META.CREATED}", VAR_GLOBAL, 0);
587 	Var_Set(".MAKE.META_FILES", "${.MAKE.META.FILES}", VAR_GLOBAL, 0);
588     }
589     if (metaVerbose && !Var_Exists(MAKE_META_PREFIX, VAR_GLOBAL)) {
590 	/*
591 	 * The default value for MAKE_META_PREFIX
592 	 * prints the absolute path of the target.
593 	 * This works be cause :H will generate '.' if there is no /
594 	 * and :tA will resolve that to cwd.
595 	 */
596 	Var_Set(MAKE_META_PREFIX, "Building ${.TARGET:H:tA}/${.TARGET:T}", VAR_GLOBAL, 0);
597     }
598     if (once)
599 	return;
600     once = 1;
601     memset(&Mybm, 0, sizeof(Mybm));
602     /*
603      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
604      */
605     metaBailiwick = Lst_Init(FALSE);
606     cp = Var_Subst(NULL, "${.MAKE.META.BAILIWICK:O:u:tA}", VAR_GLOBAL, 0);
607     if (cp) {
608 	str2Lst_Append(metaBailiwick, cp, NULL);
609     }
610 }
611 
612 /*
613  * In each case below we allow for job==NULL
614  */
615 void
616 meta_job_start(Job *job, GNode *gn)
617 {
618     BuildMon *pbm;
619 
620     if (job != NULL) {
621 	pbm = &job->bm;
622     } else {
623 	pbm = &Mybm;
624     }
625     pbm->mfp = meta_create(pbm, gn);
626 #ifdef USE_FILEMON_ONCE
627     /* compat mode we open the filemon dev once per command */
628     if (job == NULL)
629 	return;
630 #endif
631 #ifdef USE_FILEMON
632     if (pbm->mfp != NULL && useFilemon) {
633 	filemon_open(pbm);
634     } else {
635 	pbm->mon_fd = pbm->filemon_fd = -1;
636     }
637 #endif
638 }
639 
640 /*
641  * The child calls this before doing anything.
642  * It does not disturb our state.
643  */
644 void
645 meta_job_child(Job *job)
646 {
647 #ifdef USE_FILEMON
648     BuildMon *pbm;
649     pid_t pid;
650 
651     if (job != NULL) {
652 	pbm = &job->bm;
653     } else {
654 	pbm = &Mybm;
655     }
656     pid = getpid();
657     if (pbm->mfp != NULL && useFilemon) {
658 	if (ioctl(pbm->filemon_fd, FILEMON_SET_PID, &pid) < 0) {
659 	    err(1, "Could not set filemon pid!");
660 	}
661     }
662 #endif
663 }
664 
665 void
666 meta_job_error(Job *job, GNode *gn, int flags, int status)
667 {
668     char cwd[MAXPATHLEN];
669     BuildMon *pbm;
670 
671     if (job != NULL) {
672 	pbm = &job->bm;
673     } else {
674 	if (!gn)
675 	    gn = job->node;
676 	pbm = &Mybm;
677     }
678     if (pbm->mfp != NULL) {
679 	fprintf(pbm->mfp, "*** Error code %d%s\n",
680 		status,
681 		(flags & JOB_IGNERR) ?
682 		"(ignored)" : "");
683     }
684     if (gn) {
685 	Var_Set(".ERROR_TARGET", gn->path ? gn->path : gn->name, VAR_GLOBAL, 0);
686     }
687     getcwd(cwd, sizeof(cwd));
688     Var_Set(".ERROR_CWD", cwd, VAR_GLOBAL, 0);
689     if (pbm && pbm->meta_fname[0]) {
690 	Var_Set(".ERROR_META_FILE", pbm->meta_fname, VAR_GLOBAL, 0);
691     }
692     meta_job_finish(job);
693 }
694 
695 void
696 meta_job_output(Job *job, char *cp, const char *nl)
697 {
698     BuildMon *pbm;
699 
700     if (job != NULL) {
701 	pbm = &job->bm;
702     } else {
703 	pbm = &Mybm;
704     }
705     if (pbm->mfp != NULL) {
706 	if (metaVerbose) {
707 	    static char *meta_prefix = NULL;
708 	    static int meta_prefix_len;
709 
710 	    if (!meta_prefix) {
711 		char *cp2;
712 
713 		meta_prefix = Var_Subst(NULL, "${" MAKE_META_PREFIX "}", VAR_GLOBAL, 0);
714 		if ((cp2 = strchr(meta_prefix, '$')))
715 		    meta_prefix_len = cp2 - meta_prefix;
716 		else
717 		    meta_prefix_len = strlen(meta_prefix);
718 	    }
719 	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
720 		cp = strchr(cp+1, '\n');
721 		if (!cp++)
722 		    return;
723 	    }
724 	}
725 	fprintf(pbm->mfp, "%s%s", cp, nl);
726     }
727 }
728 
729 void
730 meta_cmd_finish(void *pbmp)
731 {
732 #ifdef USE_FILEMON
733     BuildMon *pbm = pbmp;
734 
735     if (!pbm)
736 	pbm = &Mybm;
737 
738     if (pbm->filemon_fd >= 0) {
739 	close(pbm->filemon_fd);
740 	filemon_read(pbm->mfp, pbm->mon_fd);
741 	pbm->filemon_fd = pbm->mon_fd = -1;
742     }
743 #endif
744 }
745 
746 void
747 meta_job_finish(Job *job)
748 {
749     BuildMon *pbm;
750 
751     if (job != NULL) {
752 	pbm = &job->bm;
753     } else {
754 	pbm = &Mybm;
755     }
756     if (pbm->mfp != NULL) {
757 	meta_cmd_finish(pbm);
758 	fclose(pbm->mfp);
759 	pbm->mfp = NULL;
760 	pbm->meta_fname[0] = '\0';
761     }
762 }
763 
764 /*
765  * Fetch a full line from fp - growing bufp if needed
766  * Return length in bufp.
767  */
768 static int
769 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
770 {
771     char *buf = *bufp;
772     size_t bufsz = *szp;
773     struct stat fs;
774     int x;
775 
776     if (fgets(&buf[o], bufsz - o, fp) != NULL) {
777     check_newline:
778 	x = o + strlen(&buf[o]);
779 	if (buf[x - 1] == '\n')
780 	    return x;
781 	/*
782 	 * We need to grow the buffer.
783 	 * The meta file can give us a clue.
784 	 */
785 	if (fstat(fileno(fp), &fs) == 0) {
786 	    size_t newsz;
787 	    char *p;
788 
789 	    newsz = ROUNDUP((fs.st_size / 2), BUFSIZ);
790 	    if (newsz <= bufsz)
791 		newsz = ROUNDUP(fs.st_size, BUFSIZ);
792 	    if (DEBUG(META))
793 		fprintf(debug_file, "growing buffer %u -> %u\n",
794 			(unsigned)bufsz, (unsigned)newsz);
795 	    p = bmake_realloc(buf, newsz);
796 	    if (p) {
797 		*bufp = buf = p;
798 		*szp = bufsz = newsz;
799 		/* fetch the rest */
800 		if (!fgets(&buf[x], bufsz - x, fp))
801 		    return x;		/* truncated! */
802 		goto check_newline;
803 	    }
804 	}
805     }
806     return 0;
807 }
808 
809 static int
810 prefix_match(void *p, void *q)
811 {
812     const char *prefix = p;
813     const char *path = q;
814     size_t n = strlen(prefix);
815 
816     return (0 == strncmp(path, prefix, n));
817 }
818 
819 static int
820 string_match(const void *p, const void *q)
821 {
822     const char *p1 = p;
823     const char *p2 = q;
824 
825     return strcmp(p1, p2);
826 }
827 
828 
829 /*
830  * When running with 'meta' functionality, a target can be out-of-date
831  * if any of the references in it's meta data file is more recent.
832  * We have to track the latestdir on a per-process basis.
833  */
834 #define LDIR_VNAME_FMT ".meta.%d.ldir"
835 
836 /*
837  * It is possible that a .meta file is corrupted,
838  * if we detect this we want to reproduce it.
839  * Setting oodate TRUE will have that effect.
840  */
841 #define CHECK_VALID_META(p) if (!(p && *p)) { \
842     warnx("%s: %d: malformed", fname, lineno); \
843     oodate = TRUE; \
844     continue; \
845     }
846 
847 Boolean
848 meta_oodate(GNode *gn, Boolean oodate)
849 {
850     static char *tmpdir = NULL;
851     static char cwd[MAXPATHLEN];
852     char ldir_vname[64];
853     char latestdir[MAXPATHLEN];
854     char fname[MAXPATHLEN];
855     char fname1[MAXPATHLEN];
856     char fname2[MAXPATHLEN];
857     char *p;
858     char *cp;
859     static size_t cwdlen = 0;
860     static size_t tmplen = 0;
861     FILE *fp;
862     Boolean needOODATE = FALSE;
863     Lst missingFiles;
864 
865     if (oodate)
866 	return oodate;		/* we're done */
867 
868     missingFiles = Lst_Init(FALSE);
869 
870     /*
871      * We need to check if the target is out-of-date. This includes
872      * checking if the expanded command has changed. This in turn
873      * requires that all variables are set in the same way that they
874      * would be if the target needs to be re-built.
875      */
876     Make_DoAllVar(gn);
877 
878     meta_name(gn, fname, sizeof(fname), NULL, NULL);
879 
880 #ifdef DEBUG_META_MODE
881     if (DEBUG(META))
882 	fprintf(debug_file, "meta_oodate: %s\n", fname);
883 #endif
884 
885     if ((fp = fopen(fname, "r")) != NULL) {
886 	static char *buf = NULL;
887 	static size_t bufsz;
888 	int lineno = 0;
889 	int lastpid = 0;
890 	int pid;
891 	int f = 0;
892 	int x;
893 	LstNode ln;
894 	struct stat fs;
895 
896 	if (!buf) {
897 	    bufsz = 8 * BUFSIZ;
898 	    buf = bmake_malloc(bufsz);
899 	}
900 
901 	if (!cwdlen) {
902 	    if (getcwd(cwd, sizeof(cwd)) == NULL)
903 		err(1, "Could not get current working directory");
904 	    cwdlen = strlen(cwd);
905 	}
906 
907 	if (!tmpdir) {
908 	    tmpdir = getTmpdir();
909 	    tmplen = strlen(tmpdir);
910 	}
911 
912 	/* we want to track all the .meta we read */
913 	Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
914 
915 	ln = Lst_First(gn->commands);
916 	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
917 	    lineno++;
918 	    if (buf[x - 1] == '\n')
919 		buf[x - 1] = '\0';
920 	    else {
921 		warnx("%s: %d: line truncated at %u", fname, lineno, x);
922 		oodate = TRUE;
923 		break;
924 	    }
925 	    /* Find the start of the build monitor section. */
926 	    if (!f) {
927 		if (strncmp(buf, "-- filemon", 10) == 0) {
928 		    f = 1;
929 		    continue;
930 		}
931 		if (strncmp(buf, "# buildmon", 10) == 0) {
932 		    f = 1;
933 		    continue;
934 		}
935 	    }
936 
937 	    /* Delimit the record type. */
938 	    p = buf;
939 #ifdef DEBUG_META_MODE
940 	    if (DEBUG(META))
941 		fprintf(debug_file, "%s: %d: %s\n", fname, lineno, buf);
942 #endif
943 	    strsep(&p, " ");
944 	    if (f) {
945 		/*
946 		 * We are in the 'filemon' output section.
947 		 * Each record from filemon follows the general form:
948 		 *
949 		 * <key> <pid> <data>
950 		 *
951 		 * Where:
952 		 * <key> is a single letter, denoting the syscall.
953 		 * <pid> is the process that made the syscall.
954 		 * <data> is the arguments (of interest).
955 		 */
956 		switch(buf[0]) {
957 		case '#':		/* comment */
958 		case 'V':		/* version */
959 		    break;
960 		default:
961 		    /*
962 		     * We need to track pathnames per-process.
963 		     *
964 		     * Each process run by make, starts off in the 'CWD'
965 		     * recorded in the .meta file, if it chdirs ('C')
966 		     * elsewhere we need to track that - but only for
967 		     * that process.  If it forks ('F'), we initialize
968 		     * the child to have the same cwd as its parent.
969 		     *
970 		     * We also need to track the 'latestdir' of
971 		     * interest.  This is usually the same as cwd, but
972 		     * not if a process is reading directories.
973 		     *
974 		     * Each time we spot a different process ('pid')
975 		     * we save the current value of 'latestdir' in a
976 		     * variable qualified by 'lastpid', and
977 		     * re-initialize 'latestdir' to any pre-saved
978 		     * value for the current 'pid' and 'CWD' if none.
979 		     */
980 		    CHECK_VALID_META(p);
981 		    pid = atoi(p);
982 		    if (pid > 0 && pid != lastpid) {
983 			char *ldir;
984 			char *tp;
985 
986 			if (lastpid > 0) {
987 			    /* We need to remember this. */
988 			    Var_Set(ldir_vname, latestdir, VAR_GLOBAL, 0);
989 			}
990 			snprintf(ldir_vname, sizeof(ldir_vname), LDIR_VNAME_FMT, pid);
991 			lastpid = pid;
992 			ldir = Var_Value(ldir_vname, VAR_GLOBAL, &tp);
993 			if (ldir) {
994 			    strlcpy(latestdir, ldir, sizeof(latestdir));
995 			    if (tp)
996 				free(tp);
997 			} else
998 			    strlcpy(latestdir, cwd, sizeof(latestdir));
999 		    }
1000 		    /* Skip past the pid. */
1001 		    if (strsep(&p, " ") == NULL)
1002 			continue;
1003 #ifdef DEBUG_META_MODE
1004 		    if (DEBUG(META))
1005 			fprintf(debug_file, "%s: %d: cwd=%s ldir=%s\n", fname, lineno, cwd, latestdir);
1006 #endif
1007 		    break;
1008 		}
1009 
1010 		CHECK_VALID_META(p);
1011 
1012 		/* Process according to record type. */
1013 		switch (buf[0]) {
1014 		case 'X':		/* eXit */
1015 		    Var_Delete(ldir_vname, VAR_GLOBAL);
1016 		    lastpid = 0;	/* no need to save ldir_vname */
1017 		    break;
1018 
1019 		case 'F':		/* [v]Fork */
1020 		    {
1021 			char cldir[64];
1022 			int child;
1023 
1024 			child = atoi(p);
1025 			if (child > 0) {
1026 			    snprintf(cldir, sizeof(cldir), LDIR_VNAME_FMT, child);
1027 			    Var_Set(cldir, latestdir, VAR_GLOBAL, 0);
1028 			}
1029 		    }
1030 		    break;
1031 
1032 		case 'C':		/* Chdir */
1033 		    /* Update the latest directory. */
1034 		    strlcpy(latestdir, p, sizeof(latestdir));
1035 		    break;
1036 
1037 		case 'M':		/* renaMe */
1038 		    if (Lst_IsEmpty(missingFiles))
1039 			break;
1040 		    /* 'L' and 'M' put single quotes around the args */
1041 		    if (*p == '\'') {
1042 			char *ep;
1043 
1044 			p++;
1045 			if ((ep = strchr(p, '\'')))
1046 			    *ep = '\0';
1047 		    }
1048 		    /* FALLTHROUGH */
1049 		case 'D':		/* unlink */
1050 		    if (*p == '/' && !Lst_IsEmpty(missingFiles)) {
1051 			/* remove p from the missingFiles list if present */
1052 			if ((ln = Lst_Find(missingFiles, p, string_match)) != NULL) {
1053 			    char *tp = Lst_Datum(ln);
1054 			    Lst_Remove(missingFiles, ln);
1055 			    free(tp);
1056 			    ln = NULL;	/* we're done with it */
1057 			}
1058 		    }
1059 		    break;
1060 		case 'L':		/* Link */
1061 		    /* we want the target */
1062 		    if (strsep(&p, " ") == NULL)
1063 			continue;
1064 		    CHECK_VALID_META(p);
1065 		    /* 'L' and 'M' put single quotes around the args */
1066 		    if (*p == '\'') {
1067 			char *ep;
1068 
1069 			p++;
1070 			if ((ep = strchr(p, '\'')))
1071 			    *ep = '\0';
1072 		    }
1073 		    /* FALLTHROUGH */
1074 		case 'W':		/* Write */
1075 		    /*
1076 		     * If a file we generated within our bailiwick
1077 		     * but outside of .OBJDIR is missing,
1078 		     * we need to do it again.
1079 		     */
1080 		    /* ignore non-absolute paths */
1081 		    if (*p != '/')
1082 			break;
1083 
1084 		    if (Lst_IsEmpty(metaBailiwick))
1085 			break;
1086 
1087 		    /* ignore cwd - normal dependencies handle those */
1088 		    if (strncmp(p, cwd, cwdlen) == 0)
1089 			break;
1090 
1091 		    if (!Lst_ForEach(metaBailiwick, prefix_match, p))
1092 			break;
1093 
1094 		    /* tmpdir might be within */
1095 		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1096 			break;
1097 
1098 		    /* ignore anything containing the string "tmp" */
1099 		    if ((strstr("tmp", p)))
1100 			break;
1101 
1102 		    if (stat(p, &fs) < 0) {
1103 			Lst_AtEnd(missingFiles, bmake_strdup(p));
1104 		    }
1105 		    break;
1106 		case 'R':		/* Read */
1107 		case 'E':		/* Exec */
1108 		    /*
1109 		     * Check for runtime files that can't
1110 		     * be part of the dependencies because
1111 		     * they are _expected_ to change.
1112 		     */
1113 		    if (strncmp(p, "/tmp/", 5) == 0 ||
1114 			(tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0))
1115 			break;
1116 
1117 		    if (strncmp(p, "/var/", 5) == 0)
1118 			break;
1119 
1120 		    /* Ignore device files. */
1121 		    if (strncmp(p, "/dev/", 5) == 0)
1122 			break;
1123 
1124 		    /* Ignore /etc/ files. */
1125 		    if (strncmp(p, "/etc/", 5) == 0)
1126 			break;
1127 
1128 		    if ((cp = strrchr(p, '/'))) {
1129 			cp++;
1130 			/*
1131 			 * We don't normally expect to see this,
1132 			 * but we do expect it to change.
1133 			 */
1134 			if (strcmp(cp, makeDependfile) == 0)
1135 			    break;
1136 		    }
1137 
1138 		    /*
1139 		     * The rest of the record is the file name.
1140 		     * Check if it's not an absolute path.
1141 		     */
1142 		    {
1143 			char *sdirs[4];
1144 			char **sdp;
1145 			int sdx = 0;
1146 			int found = 0;
1147 
1148 			if (*p == '/') {
1149 			    sdirs[sdx++] = p; /* done */
1150 			} else {
1151 			    if (strcmp(".", p) == 0)
1152 				continue;  /* no point */
1153 
1154 			    /* Check vs latestdir */
1155 			    snprintf(fname1, sizeof(fname1), "%s/%s", latestdir, p);
1156 			    sdirs[sdx++] = fname1;
1157 
1158 			    if (strcmp(latestdir, cwd) != 0) {
1159 				/* Check vs cwd */
1160 				snprintf(fname2, sizeof(fname2), "%s/%s", cwd, p);
1161 				sdirs[sdx++] = fname2;
1162 			    }
1163 			}
1164 			sdirs[sdx++] = NULL;
1165 
1166 			for (sdp = sdirs; *sdp && !found; sdp++) {
1167 #ifdef DEBUG_META_MODE
1168 			    if (DEBUG(META))
1169 				fprintf(debug_file, "%s: %d: looking for: %s\n", fname, lineno, *sdp);
1170 #endif
1171 			    if (stat(*sdp, &fs) == 0) {
1172 				found = 1;
1173 				p = *sdp;
1174 			    }
1175 			}
1176 			if (found) {
1177 #ifdef DEBUG_META_MODE
1178 			    if (DEBUG(META))
1179 				fprintf(debug_file, "%s: %d: found: %s\n", fname, lineno, p);
1180 #endif
1181 			    if (!S_ISDIR(fs.st_mode) &&
1182 				fs.st_mtime > gn->mtime) {
1183 				if (DEBUG(META))
1184 				    fprintf(debug_file, "%s: %d: file '%s' is newer than the target...\n", fname, lineno, p);
1185 				oodate = TRUE;
1186 			    } else if (S_ISDIR(fs.st_mode)) {
1187 				/* Update the latest directory. */
1188 				realpath(p, latestdir);
1189 			    }
1190 			} else if (errno == ENOENT && *p == '/' &&
1191 				   strncmp(p, cwd, cwdlen) != 0) {
1192 			    /*
1193 			     * A referenced file outside of CWD is missing.
1194 			     * We cannot catch every eventuality here...
1195 			     */
1196 			    if (DEBUG(META))
1197 				fprintf(debug_file, "%s: %d: file '%s' may have moved?...\n", fname, lineno, p);
1198 			    oodate = TRUE;
1199 			}
1200 		    }
1201 		    break;
1202 		default:
1203 		    break;
1204 		}
1205 	    } else if (strcmp(buf, "CMD") == 0) {
1206 		/*
1207 		 * Compare the current command with the one in the
1208 		 * meta data file.
1209 		 */
1210 		if (ln == NULL) {
1211 		    if (DEBUG(META))
1212 			fprintf(debug_file, "%s: %d: there were more build commands in the meta data file than there are now...\n", fname, lineno);
1213 		    oodate = TRUE;
1214 		} else {
1215 		    char *cmd = (char *)Lst_Datum(ln);
1216 		    Boolean hasOODATE = FALSE;
1217 
1218 		    if (strstr(cmd, "$?"))
1219 			hasOODATE = TRUE;
1220 		    else if ((cp = strstr(cmd, ".OODATE"))) {
1221 			/* check for $[{(].OODATE[:)}] */
1222 			if (cp > cmd + 2 && cp[-2] == '$')
1223 			    hasOODATE = TRUE;
1224 		    }
1225 		    if (hasOODATE) {
1226 			needOODATE = TRUE;
1227 			if (DEBUG(META))
1228 			    fprintf(debug_file, "%s: %d: cannot compare command using .OODATE\n", fname, lineno);
1229 		    }
1230 		    cmd = Var_Subst(NULL, cmd, gn, TRUE);
1231 
1232 		    if ((cp = strchr(cmd, '\n'))) {
1233 			int n;
1234 
1235 			/*
1236 			 * This command contains newlines, we need to
1237 			 * fetch more from the .meta file before we
1238 			 * attempt a comparison.
1239 			 */
1240 			/* first put the newline back at buf[x - 1] */
1241 			buf[x - 1] = '\n';
1242 			do {
1243 			    /* now fetch the next line */
1244 			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1245 				break;
1246 			    x = n;
1247 			    lineno++;
1248 			    if (buf[x - 1] != '\n') {
1249 				warnx("%s: %d: line truncated at %u", fname, lineno, x);
1250 				break;
1251 			    }
1252 			    cp = strchr(++cp, '\n');
1253 			} while (cp);
1254 			if (buf[x - 1] == '\n')
1255 			    buf[x - 1] = '\0';
1256 		    }
1257 		    if (!hasOODATE &&
1258 			!(gn->type & OP_NOMETA_CMP) &&
1259 			strcmp(p, cmd) != 0) {
1260 			if (DEBUG(META))
1261 			    fprintf(debug_file, "%s: %d: a build command has changed\n%s\nvs\n%s\n", fname, lineno, p, cmd);
1262 			if (!metaIgnoreCMDs)
1263 			    oodate = TRUE;
1264 		    }
1265 		    free(cmd);
1266 		    ln = Lst_Succ(ln);
1267 		}
1268 	    } else if (strcmp(buf, "CWD") == 0) {
1269 		/*
1270 		 * Check if there are extra commands now
1271 		 * that weren't in the meta data file.
1272 		 */
1273 		if (!oodate && ln != NULL) {
1274 		    if (DEBUG(META))
1275 			fprintf(debug_file, "%s: %d: there are extra build commands now that weren't in the meta data file\n", fname, lineno);
1276 		    oodate = TRUE;
1277 		}
1278 		if (strcmp(p, cwd) != 0) {
1279 		    if (DEBUG(META))
1280 			fprintf(debug_file, "%s: %d: the current working directory has changed from '%s' to '%s'\n", fname, lineno, p, curdir);
1281 		    oodate = TRUE;
1282 		}
1283 	    }
1284 	}
1285 
1286 	fclose(fp);
1287 	if (!Lst_IsEmpty(missingFiles)) {
1288 	    if (DEBUG(META))
1289 		fprintf(debug_file, "%s: missing files: %s...\n",
1290 			fname, (char *)Lst_Datum(Lst_First(missingFiles)));
1291 	    oodate = TRUE;
1292 	    Lst_Destroy(missingFiles, (FreeProc *)free);
1293 	}
1294     } else {
1295 	if ((gn->type & OP_META)) {
1296 	    if (DEBUG(META))
1297 		fprintf(debug_file, "%s: required but missing\n", fname);
1298 	    oodate = TRUE;
1299 	}
1300     }
1301     if (oodate && needOODATE) {
1302 	/*
1303 	 * Target uses .OODATE which is empty; or we wouldn't be here.
1304 	 * We have decided it is oodate, so .OODATE needs to be set.
1305 	 * All we can sanely do is set it to .ALLSRC.
1306 	 */
1307 	Var_Delete(OODATE, gn);
1308 	Var_Set(OODATE, Var_Value(ALLSRC, gn, &cp), gn, 0);
1309 	if (cp)
1310 	    free(cp);
1311     }
1312     return oodate;
1313 }
1314 
1315 /* support for compat mode */
1316 
1317 static int childPipe[2];
1318 
1319 void
1320 meta_compat_start(void)
1321 {
1322 #ifdef USE_FILEMON_ONCE
1323     /*
1324      * We need to re-open filemon for each cmd.
1325      */
1326     BuildMon *pbm = &Mybm;
1327 
1328     if (pbm->mfp != NULL && useFilemon) {
1329 	filemon_open(pbm);
1330     } else {
1331 	pbm->mon_fd = pbm->filemon_fd = -1;
1332     }
1333 #endif
1334     if (pipe(childPipe) < 0)
1335 	Punt("Cannot create pipe: %s", strerror(errno));
1336     /* Set close-on-exec flag for both */
1337     (void)fcntl(childPipe[0], F_SETFD, 1);
1338     (void)fcntl(childPipe[1], F_SETFD, 1);
1339 }
1340 
1341 void
1342 meta_compat_child(void)
1343 {
1344     meta_job_child(NULL);
1345     if (dup2(childPipe[1], 1) < 0 ||
1346 	dup2(1, 2) < 0) {
1347 	execError("dup2", "pipe");
1348 	_exit(1);
1349     }
1350 }
1351 
1352 void
1353 meta_compat_parent(void)
1354 {
1355     FILE *fp;
1356     char buf[BUFSIZ];
1357 
1358     close(childPipe[1]);			/* child side */
1359     fp = fdopen(childPipe[0], "r");
1360     while (fgets(buf, sizeof(buf), fp)) {
1361 	meta_job_output(NULL, buf, "");
1362 	printf("%s", buf);
1363     }
1364     fclose(fp);
1365 }
1366 
1367 #endif	/* USE_META */
1368