meta.c revision 238152 
1/*      $NetBSD: meta.c,v 1.25 2012/06/27 17:22:58 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
57static BuildMon Mybm;			/* for compat */
58static Lst metaBailiwick;			/* our scope of control */
59
60Boolean useMeta = FALSE;
61static Boolean useFilemon = FALSE;
62static Boolean writeMeta = FALSE;
63static Boolean metaEnv = FALSE;		/* don't save env unless asked */
64static Boolean metaVerbose = FALSE;
65static Boolean metaIgnoreCMDs = FALSE;	/* ignore CMDs in .meta files */
66static Boolean metaCurdirOk = FALSE;	/* write .meta in .CURDIR Ok? */
67static Boolean metaSilent = FALSE;	/* if we have a .meta be SILENT */
68
69extern Boolean forceJobs;
70extern Boolean comatMake;
71extern 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 */
111static void
112filemon_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 */
150static void
151filemon_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 */
182static void
183eat_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
221static char *
222meta_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 ${.MAKE}
305 * Bypassed if target is flagged .MAKE
306 */
307static int
308is_submake(void *cmdp, void *gnp)
309{
310    static char *p_make = NULL;
311    static int p_len;
312    char  *cmd = cmdp;
313    GNode *gn = gnp;
314    char *mp = NULL;
315    char *cp;
316    char *cp2;
317    int rc = 0;				/* keep looking */
318
319    if (!p_make) {
320	p_make = Var_Value(".MAKE", gn, &cp);
321	p_len = strlen(p_make);
322    }
323    cp = strchr(cmd, '$');
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
355typedef struct meta_file_s {
356    FILE *fp;
357    GNode *gn;
358} meta_file_t;
359
360static int
361printCMD(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
389static FILE *
390meta_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
528static Boolean
529boolValue(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
542void
543meta_init(const char *make_mode)
544{
545    static int once = 0;
546    char *cp;
547
548    useMeta = TRUE;
549    useFilemon = TRUE;
550    writeMeta = TRUE;
551
552    if (make_mode) {
553	if (strstr(make_mode, "env"))
554	    metaEnv = TRUE;
555	if (strstr(make_mode, "verb"))
556	    metaVerbose = TRUE;
557	if (strstr(make_mode, "read"))
558	    writeMeta = FALSE;
559	if (strstr(make_mode, "nofilemon"))
560	    useFilemon = FALSE;
561	if ((cp = strstr(make_mode, "curdirok="))) {
562	    metaCurdirOk = boolValue(&cp[9]);
563	}
564	if ((cp = strstr(make_mode, "silent="))) {
565	    metaSilent = boolValue(&cp[7]);
566	}
567	if (strstr(make_mode, "ignore-cmd"))
568	    metaIgnoreCMDs = TRUE;
569	/* for backwards compatability */
570	Var_Set(".MAKE.META_CREATED", "${.MAKE.META.CREATED}", VAR_GLOBAL, 0);
571	Var_Set(".MAKE.META_FILES", "${.MAKE.META.FILES}", VAR_GLOBAL, 0);
572    }
573    if (metaVerbose && !Var_Exists(MAKE_META_PREFIX, VAR_GLOBAL)) {
574	/*
575	 * The default value for MAKE_META_PREFIX
576	 * prints the absolute path of the target.
577	 * This works be cause :H will generate '.' if there is no /
578	 * and :tA will resolve that to cwd.
579	 */
580	Var_Set(MAKE_META_PREFIX, "Building ${.TARGET:H:tA}/${.TARGET:T}", VAR_GLOBAL, 0);
581    }
582    if (once)
583	return;
584    once = 1;
585    memset(&Mybm, 0, sizeof(Mybm));
586    /*
587     * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
588     */
589    metaBailiwick = Lst_Init(FALSE);
590    cp = Var_Subst(NULL, "${.MAKE.META.BAILIWICK:O:u:tA}", VAR_GLOBAL, 0);
591    if (cp) {
592	str2Lst_Append(metaBailiwick, cp, NULL);
593    }
594}
595
596/*
597 * In each case below we allow for job==NULL
598 */
599void
600meta_job_start(Job *job, GNode *gn)
601{
602    BuildMon *pbm;
603
604    if (job != NULL) {
605	pbm = &job->bm;
606    } else {
607	pbm = &Mybm;
608    }
609    pbm->mfp = meta_create(pbm, gn);
610#ifdef USE_FILEMON_ONCE
611    /* compat mode we open the filemon dev once per command */
612    if (job == NULL)
613	return;
614#endif
615#ifdef USE_FILEMON
616    if (pbm->mfp != NULL && useFilemon) {
617	filemon_open(pbm);
618    } else {
619	pbm->mon_fd = pbm->filemon_fd = -1;
620    }
621#endif
622}
623
624/*
625 * The child calls this before doing anything.
626 * It does not disturb our state.
627 */
628void
629meta_job_child(Job *job)
630{
631#ifdef USE_FILEMON
632    BuildMon *pbm;
633    pid_t pid;
634
635    if (job != NULL) {
636	pbm = &job->bm;
637    } else {
638	pbm = &Mybm;
639    }
640    pid = getpid();
641    if (pbm->mfp != NULL && useFilemon) {
642	if (ioctl(pbm->filemon_fd, FILEMON_SET_PID, &pid) < 0) {
643	    err(1, "Could not set filemon pid!");
644	}
645    }
646#endif
647}
648
649void
650meta_job_error(Job *job, GNode *gn, int flags, int status)
651{
652    char cwd[MAXPATHLEN];
653    BuildMon *pbm;
654
655    if (job != NULL) {
656	pbm = &job->bm;
657    } else {
658	if (!gn)
659	    gn = job->node;
660	pbm = &Mybm;
661    }
662    if (pbm->mfp != NULL) {
663	fprintf(pbm->mfp, "*** Error code %d%s\n",
664		status,
665		(flags & JOB_IGNERR) ?
666		"(ignored)" : "");
667    }
668    if (gn) {
669	Var_Set(".ERROR_TARGET", gn->path ? gn->path : gn->name, VAR_GLOBAL, 0);
670    }
671    getcwd(cwd, sizeof(cwd));
672    Var_Set(".ERROR_CWD", cwd, VAR_GLOBAL, 0);
673    if (pbm && pbm->meta_fname[0]) {
674	Var_Set(".ERROR_META_FILE", pbm->meta_fname, VAR_GLOBAL, 0);
675    }
676    meta_job_finish(job);
677}
678
679void
680meta_job_output(Job *job, char *cp, const char *nl)
681{
682    BuildMon *pbm;
683
684    if (job != NULL) {
685	pbm = &job->bm;
686    } else {
687	pbm = &Mybm;
688    }
689    if (pbm->mfp != NULL) {
690	if (metaVerbose) {
691	    static char *meta_prefix = NULL;
692	    static int meta_prefix_len;
693
694	    if (!meta_prefix) {
695		char *cp2;
696
697		meta_prefix = Var_Subst(NULL, "${" MAKE_META_PREFIX "}", VAR_GLOBAL, 0);
698		if ((cp2 = strchr(meta_prefix, '$')))
699		    meta_prefix_len = cp2 - meta_prefix;
700		else
701		    meta_prefix_len = strlen(meta_prefix);
702	    }
703	    if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
704		cp = strchr(cp+1, '\n');
705		if (!cp++)
706		    return;
707	    }
708	}
709	fprintf(pbm->mfp, "%s%s", cp, nl);
710    }
711}
712
713void
714meta_cmd_finish(void *pbmp)
715{
716#ifdef USE_FILEMON
717    BuildMon *pbm = pbmp;
718
719    if (!pbm)
720	pbm = &Mybm;
721
722    if (pbm->filemon_fd >= 0) {
723	close(pbm->filemon_fd);
724	filemon_read(pbm->mfp, pbm->mon_fd);
725	pbm->filemon_fd = pbm->mon_fd = -1;
726    }
727#endif
728}
729
730void
731meta_job_finish(Job *job)
732{
733    BuildMon *pbm;
734
735    if (job != NULL) {
736	pbm = &job->bm;
737    } else {
738	pbm = &Mybm;
739    }
740    if (pbm->mfp != NULL) {
741	meta_cmd_finish(pbm);
742	fclose(pbm->mfp);
743	pbm->mfp = NULL;
744	pbm->meta_fname[0] = '\0';
745    }
746}
747
748/*
749 * Fetch a full line from fp - growing bufp if needed
750 * Return length in bufp.
751 */
752static int
753fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
754{
755    char *buf = *bufp;
756    size_t bufsz = *szp;
757    struct stat fs;
758    int x;
759
760    if (fgets(&buf[o], bufsz - o, fp) != NULL) {
761    check_newline:
762	x = o + strlen(&buf[o]);
763	if (buf[x - 1] == '\n')
764	    return x;
765	/*
766	 * We need to grow the buffer.
767	 * The meta file can give us a clue.
768	 */
769	if (fstat(fileno(fp), &fs) == 0) {
770	    size_t newsz;
771	    char *p;
772
773	    newsz = ROUNDUP((fs.st_size / 2), BUFSIZ);
774	    if (newsz <= bufsz)
775		newsz = ROUNDUP(fs.st_size, BUFSIZ);
776	    if (DEBUG(META))
777		fprintf(debug_file, "growing buffer %u -> %u\n",
778			(unsigned)bufsz, (unsigned)newsz);
779	    p = bmake_realloc(buf, newsz);
780	    if (p) {
781		*bufp = buf = p;
782		*szp = bufsz = newsz;
783		/* fetch the rest */
784		if (!fgets(&buf[x], bufsz - x, fp))
785		    return x;		/* truncated! */
786		goto check_newline;
787	    }
788	}
789    }
790    return 0;
791}
792
793static int
794prefix_match(void *p, void *q)
795{
796    const char *prefix = p;
797    const char *path = q;
798    size_t n = strlen(prefix);
799
800    return (0 == strncmp(path, prefix, n));
801}
802
803static int
804string_match(const void *p, const void *q)
805{
806    const char *p1 = p;
807    const char *p2 = q;
808
809    return strcmp(p1, p2);
810}
811
812
813/*
814 * When running with 'meta' functionality, a target can be out-of-date
815 * if any of the references in it's meta data file is more recent.
816 * We have to track the latestdir on a per-process basis.
817 */
818#define LDIR_VNAME_FMT ".meta.%d.ldir"
819
820/*
821 * It is possible that a .meta file is corrupted,
822 * if we detect this we want to reproduce it.
823 * Setting oodate TRUE will have that effect.
824 */
825#define CHECK_VALID_META(p) if (!(p && *p)) { \
826    warnx("%s: %d: malformed", fname, lineno); \
827    oodate = TRUE; \
828    continue; \
829    }
830
831Boolean
832meta_oodate(GNode *gn, Boolean oodate)
833{
834    static char *tmpdir = NULL;
835    static char cwd[MAXPATHLEN];
836    char ldir_vname[64];
837    char latestdir[MAXPATHLEN];
838    char fname[MAXPATHLEN];
839    char fname1[MAXPATHLEN];
840    char fname2[MAXPATHLEN];
841    char *p;
842    char *cp;
843    static size_t cwdlen = 0;
844    static size_t tmplen = 0;
845    FILE *fp;
846    Boolean ignoreOODATE = FALSE;
847    Lst missingFiles;
848
849    if (oodate)
850	return oodate;		/* we're done */
851
852    missingFiles = Lst_Init(FALSE);
853
854    /*
855     * We need to check if the target is out-of-date. This includes
856     * checking if the expanded command has changed. This in turn
857     * requires that all variables are set in the same way that they
858     * would be if the target needs to be re-built.
859     */
860    Make_DoAllVar(gn);
861
862    meta_name(gn, fname, sizeof(fname), NULL, NULL);
863
864#ifdef DEBUG_META_MODE
865    if (DEBUG(META))
866	fprintf(debug_file, "meta_oodate: %s\n", fname);
867#endif
868
869    if ((fp = fopen(fname, "r")) != NULL) {
870	static char *buf = NULL;
871	static size_t bufsz;
872	int lineno = 0;
873	int lastpid = 0;
874	int pid;
875	int f = 0;
876	int x;
877	LstNode ln;
878	struct stat fs;
879
880	if (!buf) {
881	    bufsz = 8 * BUFSIZ;
882	    buf = bmake_malloc(bufsz);
883	}
884
885	if (!cwdlen) {
886	    if (getcwd(cwd, sizeof(cwd)) == NULL)
887		err(1, "Could not get current working directory");
888	    cwdlen = strlen(cwd);
889	}
890
891	if (!tmpdir) {
892	    tmpdir = getTmpdir();
893	    tmplen = strlen(tmpdir);
894	}
895
896	/* we want to track all the .meta we read */
897	Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
898
899	ln = Lst_First(gn->commands);
900	while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
901	    lineno++;
902	    if (buf[x - 1] == '\n')
903		buf[x - 1] = '\0';
904	    else {
905		warnx("%s: %d: line truncated at %u", fname, lineno, x);
906		oodate = TRUE;
907		break;
908	    }
909	    /* Find the start of the build monitor section. */
910	    if (!f) {
911		if (strncmp(buf, "-- filemon", 10) == 0) {
912		    f = 1;
913		    continue;
914		}
915		if (strncmp(buf, "# buildmon", 10) == 0) {
916		    f = 1;
917		    continue;
918		}
919	    }
920
921	    /* Delimit the record type. */
922	    p = buf;
923#ifdef DEBUG_META_MODE
924	    if (DEBUG(META))
925		fprintf(debug_file, "%s: %d: %s\n", fname, lineno, buf);
926#endif
927	    strsep(&p, " ");
928	    if (f) {
929		/*
930		 * We are in the 'filemon' output section.
931		 * Each record from filemon follows the general form:
932		 *
933		 * <key> <pid> <data>
934		 *
935		 * Where:
936		 * <key> is a single letter, denoting the syscall.
937		 * <pid> is the process that made the syscall.
938		 * <data> is the arguments (of interest).
939		 */
940		switch(buf[0]) {
941		case '#':		/* comment */
942		case 'V':		/* version */
943		    break;
944		default:
945		    /*
946		     * We need to track pathnames per-process.
947		     *
948		     * Each process run by make, starts off in the 'CWD'
949		     * recorded in the .meta file, if it chdirs ('C')
950		     * elsewhere we need to track that - but only for
951		     * that process.  If it forks ('F'), we initialize
952		     * the child to have the same cwd as its parent.
953		     *
954		     * We also need to track the 'latestdir' of
955		     * interest.  This is usually the same as cwd, but
956		     * not if a process is reading directories.
957		     *
958		     * Each time we spot a different process ('pid')
959		     * we save the current value of 'latestdir' in a
960		     * variable qualified by 'lastpid', and
961		     * re-initialize 'latestdir' to any pre-saved
962		     * value for the current 'pid' and 'CWD' if none.
963		     */
964		    CHECK_VALID_META(p);
965		    pid = atoi(p);
966		    if (pid > 0 && pid != lastpid) {
967			char *ldir;
968			char *tp;
969
970			if (lastpid > 0) {
971			    /* We need to remember this. */
972			    Var_Set(ldir_vname, latestdir, VAR_GLOBAL, 0);
973			}
974			snprintf(ldir_vname, sizeof(ldir_vname), LDIR_VNAME_FMT, pid);
975			lastpid = pid;
976			ldir = Var_Value(ldir_vname, VAR_GLOBAL, &tp);
977			if (ldir) {
978			    strlcpy(latestdir, ldir, sizeof(latestdir));
979			    if (tp)
980				free(tp);
981			} else
982			    strlcpy(latestdir, cwd, sizeof(latestdir));
983		    }
984		    /* Skip past the pid. */
985		    if (strsep(&p, " ") == NULL)
986			continue;
987#ifdef DEBUG_META_MODE
988		    if (DEBUG(META))
989			fprintf(debug_file, "%s: %d: cwd=%s ldir=%s\n", fname, lineno, cwd, latestdir);
990#endif
991		    break;
992		}
993
994		CHECK_VALID_META(p);
995
996		/* Process according to record type. */
997		switch (buf[0]) {
998		case 'X':		/* eXit */
999		    Var_Delete(ldir_vname, VAR_GLOBAL);
1000		    lastpid = 0;	/* no need to save ldir_vname */
1001		    break;
1002
1003		case 'F':		/* [v]Fork */
1004		    {
1005			char cldir[64];
1006			int child;
1007
1008			child = atoi(p);
1009			if (child > 0) {
1010			    snprintf(cldir, sizeof(cldir), LDIR_VNAME_FMT, child);
1011			    Var_Set(cldir, latestdir, VAR_GLOBAL, 0);
1012			}
1013		    }
1014		    break;
1015
1016		case 'C':		/* Chdir */
1017		    /* Update the latest directory. */
1018		    strlcpy(latestdir, p, sizeof(latestdir));
1019		    break;
1020
1021		case 'M':		/* renaMe */
1022		    if (Lst_IsEmpty(missingFiles))
1023			break;
1024		    /* 'L' and 'M' put single quotes around the args */
1025		    if (*p == '\'') {
1026			char *ep;
1027
1028			p++;
1029			if ((ep = strchr(p, '\'')))
1030			    *ep = '\0';
1031		    }
1032		    /* FALLTHROUGH */
1033		case 'D':		/* unlink */
1034		    if (*p == '/' && !Lst_IsEmpty(missingFiles)) {
1035			/* remove p from the missingFiles list if present */
1036			if ((ln = Lst_Find(missingFiles, p, string_match)) != NULL) {
1037			    char *tp = Lst_Datum(ln);
1038			    Lst_Remove(missingFiles, ln);
1039			    free(tp);
1040			}
1041		    }
1042		    break;
1043		case 'L':		/* Link */
1044		    /* we want the target */
1045		    if (strsep(&p, " ") == NULL)
1046			continue;
1047		    CHECK_VALID_META(p);
1048		    /* 'L' and 'M' put single quotes around the args */
1049		    if (*p == '\'') {
1050			char *ep;
1051
1052			p++;
1053			if ((ep = strchr(p, '\'')))
1054			    *ep = '\0';
1055		    }
1056		    /* FALLTHROUGH */
1057		case 'W':		/* Write */
1058		    /*
1059		     * If a file we generated within our bailiwick
1060		     * but outside of .OBJDIR is missing,
1061		     * we need to do it again.
1062		     */
1063		    /* ignore non-absolute paths */
1064		    if (*p != '/')
1065			break;
1066
1067		    if (Lst_IsEmpty(metaBailiwick))
1068			break;
1069
1070		    /* ignore cwd - normal dependencies handle those */
1071		    if (strncmp(p, cwd, cwdlen) == 0)
1072			break;
1073
1074		    if (!Lst_ForEach(metaBailiwick, prefix_match, p))
1075			break;
1076
1077		    /* tmpdir might be within */
1078		    if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1079			break;
1080
1081		    /* ignore anything containing the string "tmp" */
1082		    if ((strstr("tmp", p)))
1083			break;
1084
1085		    if (stat(p, &fs) < 0) {
1086			Lst_AtEnd(missingFiles, bmake_strdup(p));
1087		    }
1088		    break;
1089		case 'R':		/* Read */
1090		case 'E':		/* Exec */
1091		    /*
1092		     * Check for runtime files that can't
1093		     * be part of the dependencies because
1094		     * they are _expected_ to change.
1095		     */
1096		    if (strncmp(p, "/tmp/", 5) == 0 ||
1097			(tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0))
1098			break;
1099
1100		    if (strncmp(p, "/var/", 5) == 0)
1101			break;
1102
1103		    /* Ignore device files. */
1104		    if (strncmp(p, "/dev/", 5) == 0)
1105			break;
1106
1107		    /* Ignore /etc/ files. */
1108		    if (strncmp(p, "/etc/", 5) == 0)
1109			break;
1110
1111		    if ((cp = strrchr(p, '/'))) {
1112			cp++;
1113			/*
1114			 * We don't normally expect to see this,
1115			 * but we do expect it to change.
1116			 */
1117			if (strcmp(cp, makeDependfile) == 0)
1118			    break;
1119		    }
1120
1121		    /*
1122		     * The rest of the record is the file name.
1123		     * Check if it's not an absolute path.
1124		     */
1125		    {
1126			char *sdirs[4];
1127			char **sdp;
1128			int sdx = 0;
1129			int found = 0;
1130
1131			if (*p == '/') {
1132			    sdirs[sdx++] = p; /* done */
1133			} else {
1134			    if (strcmp(".", p) == 0)
1135				continue;  /* no point */
1136
1137			    /* Check vs latestdir */
1138			    snprintf(fname1, sizeof(fname1), "%s/%s", latestdir, p);
1139			    sdirs[sdx++] = fname1;
1140
1141			    if (strcmp(latestdir, cwd) != 0) {
1142				/* Check vs cwd */
1143				snprintf(fname2, sizeof(fname2), "%s/%s", cwd, p);
1144				sdirs[sdx++] = fname2;
1145			    }
1146			}
1147			sdirs[sdx++] = NULL;
1148
1149			for (sdp = sdirs; *sdp && !found; sdp++) {
1150#ifdef DEBUG_META_MODE
1151			    if (DEBUG(META))
1152				fprintf(debug_file, "%s: %d: looking for: %s\n", fname, lineno, *sdp);
1153#endif
1154			    if (stat(*sdp, &fs) == 0) {
1155				found = 1;
1156				p = *sdp;
1157			    }
1158			}
1159			if (found) {
1160#ifdef DEBUG_META_MODE
1161			    if (DEBUG(META))
1162				fprintf(debug_file, "%s: %d: found: %s\n", fname, lineno, p);
1163#endif
1164			    if (!S_ISDIR(fs.st_mode) &&
1165				fs.st_mtime > gn->mtime) {
1166				if (DEBUG(META))
1167				    fprintf(debug_file, "%s: %d: file '%s' is newer than the target...\n", fname, lineno, p);
1168				oodate = TRUE;
1169			    } else if (S_ISDIR(fs.st_mode)) {
1170				/* Update the latest directory. */
1171				realpath(p, latestdir);
1172			    }
1173			} else if (errno == ENOENT && *p == '/' &&
1174				   strncmp(p, cwd, cwdlen) != 0) {
1175			    /*
1176			     * A referenced file outside of CWD is missing.
1177			     * We cannot catch every eventuality here...
1178			     */
1179			    if (DEBUG(META))
1180				fprintf(debug_file, "%s: %d: file '%s' may have moved?...\n", fname, lineno, p);
1181			    oodate = TRUE;
1182			}
1183		    }
1184		    break;
1185		default:
1186		    break;
1187		}
1188	    } else if (strcmp(buf, "CMD") == 0) {
1189		/*
1190		 * Compare the current command with the one in the
1191		 * meta data file.
1192		 */
1193		if (ln == NULL) {
1194		    if (DEBUG(META))
1195			fprintf(debug_file, "%s: %d: there were more build commands in the meta data file than there are now...\n", fname, lineno);
1196		    oodate = TRUE;
1197		} else {
1198		    char *cmd = (char *)Lst_Datum(ln);
1199
1200		    if (!ignoreOODATE) {
1201			if (strstr(cmd, "$?"))
1202			    ignoreOODATE = TRUE;
1203			else if ((cp = strstr(cmd, ".OODATE"))) {
1204			    /* check for $[{(].OODATE[)}] */
1205			    if (cp > cmd + 2 && cp[-2] == '$')
1206				ignoreOODATE = TRUE;
1207			}
1208			if (ignoreOODATE && DEBUG(META))
1209			    fprintf(debug_file, "%s: %d: cannot compare commands using .OODATE\n", fname, lineno);
1210		    }
1211		    cmd = Var_Subst(NULL, cmd, gn, TRUE);
1212
1213		    if ((cp = strchr(cmd, '\n'))) {
1214			int n;
1215
1216			/*
1217			 * This command contains newlines, we need to
1218			 * fetch more from the .meta file before we
1219			 * attempt a comparison.
1220			 */
1221			/* first put the newline back at buf[x - 1] */
1222			buf[x - 1] = '\n';
1223			do {
1224			    /* now fetch the next line */
1225			    if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1226				break;
1227			    x = n;
1228			    lineno++;
1229			    if (buf[x - 1] != '\n') {
1230				warnx("%s: %d: line truncated at %u", fname, lineno, x);
1231				break;
1232			    }
1233			    cp = strchr(++cp, '\n');
1234			} while (cp);
1235			if (buf[x - 1] == '\n')
1236			    buf[x - 1] = '\0';
1237		    }
1238		    if (!ignoreOODATE &&
1239			!(gn->type & OP_NOMETA_CMP) &&
1240			strcmp(p, cmd) != 0) {
1241			if (DEBUG(META))
1242			    fprintf(debug_file, "%s: %d: a build command has changed\n%s\nvs\n%s\n", fname, lineno, p, cmd);
1243			if (!metaIgnoreCMDs)
1244			    oodate = TRUE;
1245		    }
1246		    free(cmd);
1247		    ln = Lst_Succ(ln);
1248		}
1249	    } else if (strcmp(buf, "CWD") == 0) {
1250		/*
1251		 * Check if there are extra commands now
1252		 * that weren't in the meta data file.
1253		 */
1254		if (!oodate && ln != NULL) {
1255		    if (DEBUG(META))
1256			fprintf(debug_file, "%s: %d: there are extra build commands now that weren't in the meta data file\n", fname, lineno);
1257		    oodate = TRUE;
1258		}
1259		if (strcmp(p, cwd) != 0) {
1260		    if (DEBUG(META))
1261			fprintf(debug_file, "%s: %d: the current working directory has changed from '%s' to '%s'\n", fname, lineno, p, curdir);
1262		    oodate = TRUE;
1263		}
1264	    }
1265	}
1266
1267	fclose(fp);
1268	if (!Lst_IsEmpty(missingFiles)) {
1269	    if (DEBUG(META))
1270		fprintf(debug_file, "%s: missing files: %s...\n",
1271			fname, (char *)Lst_Datum(Lst_First(missingFiles)));
1272	    oodate = TRUE;
1273	    Lst_Destroy(missingFiles, (FreeProc *)free);
1274	}
1275    } else {
1276	if ((gn->type & OP_META)) {
1277	    if (DEBUG(META))
1278		fprintf(debug_file, "%s: required but missing\n", fname);
1279	    oodate = TRUE;
1280	}
1281    }
1282    if (oodate && ignoreOODATE) {
1283	/*
1284	 * Target uses .OODATE, so we need to re-compute it.
1285	 * We need to clean up what Make_DoAllVar() did.
1286	 */
1287	Var_Delete(ALLSRC, gn);
1288	Var_Delete(OODATE, gn);
1289	gn->flags &= ~DONE_ALLSRC;
1290    }
1291    return oodate;
1292}
1293
1294/* support for compat mode */
1295
1296static int childPipe[2];
1297
1298void
1299meta_compat_start(void)
1300{
1301#ifdef USE_FILEMON_ONCE
1302    /*
1303     * We need to re-open filemon for each cmd.
1304     */
1305    BuildMon *pbm = &Mybm;
1306
1307    if (pbm->mfp != NULL && useFilemon) {
1308	filemon_open(pbm);
1309    } else {
1310	pbm->mon_fd = pbm->filemon_fd = -1;
1311    }
1312#endif
1313    if (pipe(childPipe) < 0)
1314	Punt("Cannot create pipe: %s", strerror(errno));
1315    /* Set close-on-exec flag for both */
1316    (void)fcntl(childPipe[0], F_SETFD, 1);
1317    (void)fcntl(childPipe[1], F_SETFD, 1);
1318}
1319
1320void
1321meta_compat_child(void)
1322{
1323    meta_job_child(NULL);
1324    if (dup2(childPipe[1], 1) < 0 ||
1325	dup2(1, 2) < 0) {
1326	execError("dup2", "pipe");
1327	_exit(1);
1328    }
1329}
1330
1331void
1332meta_compat_parent(void)
1333{
1334    FILE *fp;
1335    char buf[BUFSIZ];
1336
1337    close(childPipe[1]);			/* child side */
1338    fp = fdopen(childPipe[0], "r");
1339    while (fgets(buf, sizeof(buf), fp)) {
1340	meta_job_output(NULL, buf, "");
1341	printf("%s", buf);
1342    }
1343    fclose(fp);
1344}
1345
1346#endif	/* USE_META */
1347