contrib/bmake/meta.c

   1 /*      $NetBSD: meta.c,v 1.67 2016/08/17 15:52:42 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 <sys/ioctl.h>
  40 #ifdef HAVE_LIBGEN_H
  41 #include <libgen.h>
  42 #elif !defined(HAVE_DIRNAME)
  43 char * dirname(char *);
  44 #endif
  45 #include <errno.h>
  46 #if !defined(HAVE_CONFIG_H) || defined(HAVE_ERR_H)
  47 #include <err.h>
  48 #endif
  49
  50 #include "make.h"
  51 #include "job.h"
  52
  53 #ifdef HAVE_FILEMON_H
  54 # include <filemon.h>
  55 #endif
  56 #if !defined(USE_FILEMON) && defined(FILEMON_SET_FD)
  57 # define USE_FILEMON
  58 #endif
  59
  60 static BuildMon Mybm;                   /* for compat */
  61 static Lst metaBailiwick;               /* our scope of control */
  62 static char *metaBailiwickStr;          /* string storage for the list */
  63 static Lst metaIgnorePaths;             /* paths we deliberately ignore */
  64 static char *metaIgnorePathsStr;        /* string storage for the list */
  65
  66 #ifndef MAKE_META_IGNORE_PATHS
  67 #define MAKE_META_IGNORE_PATHS ".MAKE.META.IGNORE_PATHS"
  68 #endif
  69 #ifndef MAKE_META_IGNORE_PATTERNS
  70 #define MAKE_META_IGNORE_PATTERNS ".MAKE.META.IGNORE_PATTERNS"
  71 #endif
  72 #ifndef MAKE_META_IGNORE_FILTER
  73 #define MAKE_META_IGNORE_FILTER ".MAKE.META.IGNORE_FILTER"
  74 #endif
  75
  76 Boolean useMeta = FALSE;
  77 static Boolean useFilemon = FALSE;
  78 static Boolean writeMeta = FALSE;
  79 static Boolean metaMissing = FALSE;     /* oodate if missing */
  80 static Boolean filemonMissing = FALSE;  /* oodate if missing */
  81 static Boolean metaEnv = FALSE;         /* don't save env unless asked */
  82 static Boolean metaVerbose = FALSE;
  83 static Boolean metaIgnoreCMDs = FALSE;  /* ignore CMDs in .meta files */
  84 static Boolean metaIgnorePatterns = FALSE; /* do we need to do pattern matches */
  85 static Boolean metaIgnoreFilter = FALSE;   /* do we have more complex filtering? */
  86 static Boolean metaCurdirOk = FALSE;    /* write .meta in .CURDIR Ok? */
  87 static Boolean metaSilent = FALSE;      /* if we have a .meta be SILENT */
  88
  89 extern Boolean forceJobs;
  90 extern Boolean comatMake;
  91 extern char    **environ;
  92
  93 #define MAKE_META_PREFIX        ".MAKE.META.PREFIX"
  94
  95 #ifndef N2U
  96 # define N2U(n, u)   (((n) + ((u) - 1)) / (u))
  97 #endif
  98 #ifndef ROUNDUP
  99 # define ROUNDUP(n, u)   (N2U((n), (u)) * (u))
 100 #endif
 101
 102 #if !defined(HAVE_STRSEP)
 103 # define strsep(s, d) stresep((s), (d), 0)
 104 #endif
 105
 106 /*
 107  * Filemon is a kernel module which snoops certain syscalls.
 108  *
 109  * C chdir
 110  * E exec
 111  * F [v]fork
 112  * L [sym]link
 113  * M rename
 114  * R read
 115  * W write
 116  * S stat
 117  *
 118  * See meta_oodate below - we mainly care about 'E' and 'R'.
 119  *
 120  * We can still use meta mode without filemon, but
 121  * the benefits are more limited.
 122  */
 123 #ifdef USE_FILEMON
 124 # ifndef _PATH_FILEMON
 125 #   define _PATH_FILEMON "/dev/filemon"
 126 # endif
 127
 128 /*
 129  * Open the filemon device.
 130  */
 131 static void
 132 filemon_open(BuildMon *pbm)
 133 {
 134     int retry;
 135
 136     pbm->mon_fd = pbm->filemon_fd = -1;
 137     if (!useFilemon)
 138         return;
 139
 140     for (retry = 5; retry >= 0; retry--) {
 141         if ((pbm->filemon_fd = open(_PATH_FILEMON, O_RDWR)) >= 0)
 142             break;
 143     }
 144
 145     if (pbm->filemon_fd < 0) {
 146         useFilemon = FALSE;
 147         warn("Could not open %s", _PATH_FILEMON);
 148         return;
 149     }
 150
 151     /*
 152      * We use a file outside of '.'
 153      * to avoid a FreeBSD kernel bug where unlink invalidates
 154      * cwd causing getcwd to do a lot more work.
 155      * We only care about the descriptor.
 156      */
 157     pbm->mon_fd = mkTempFile("filemon.XXXXXX", NULL);
 158     if (ioctl(pbm->filemon_fd, FILEMON_SET_FD, &pbm->mon_fd) < 0) {
 159         err(1, "Could not set filemon file descriptor!");
 160     }
 161     /* we don't need these once we exec */
 162     (void)fcntl(pbm->mon_fd, F_SETFD, FD_CLOEXEC);
 163     (void)fcntl(pbm->filemon_fd, F_SETFD, FD_CLOEXEC);
 164 }
 165
 166 /*
 167  * Read the build monitor output file and write records to the target's
 168  * metadata file.
 169  */
 170 static int
 171 filemon_read(FILE *mfp, int fd)
 172 {
 173     char buf[BUFSIZ];
 174     int n;
 175     int error;
 176
 177     /* Check if we're not writing to a meta data file.*/
 178     if (mfp == NULL) {
 179         if (fd >= 0)
 180             close(fd);                  /* not interested */
 181         return 0;
 182     }
 183     /* rewind */
 184     (void)lseek(fd, (off_t)0, SEEK_SET);
 185
 186     error = 0;
 187     fprintf(mfp, "\n-- filemon acquired metadata --\n");
 188
 189     while ((n = read(fd, buf, sizeof(buf))) > 0) {
 190         if ((int)fwrite(buf, 1, n, mfp) < n)
 191             error = EIO;
 192     }
 193     fflush(mfp);
 194     if (close(fd) < 0)
 195         error = errno;
 196     return error;
 197 }
 198 #endif
 199
 200 /*
 201  * when realpath() fails,
 202  * we use this, to clean up ./ and ../
 203  */
 204 static void
 205 eat_dots(char *buf, size_t bufsz, int dots)
 206 {
 207     char *cp;
 208     char *cp2;
 209     const char *eat;
 210     size_t eatlen;
 211
 212     switch (dots) {
 213     case 1:
 214         eat = "/./";
 215         eatlen = 2;
 216         break;
 217     case 2:
 218         eat = "/../";
 219         eatlen = 3;
 220         break;
 221     default:
 222         return;
 223     }
 224
 225     do {
 226         cp = strstr(buf, eat);
 227         if (cp) {
 228             cp2 = cp + eatlen;
 229             if (dots == 2 && cp > buf) {
 230                 do {
 231                     cp--;
 232                 } while (cp > buf && *cp != '/');
 233             }
 234             if (*cp == '/') {
 235                 strlcpy(cp, cp2, bufsz - (cp - buf));
 236             } else {
 237                 return;                 /* can't happen? */
 238             }
 239         }
 240     } while (cp);
 241 }
 242
 243 static char *
 244 meta_name(struct GNode __unused *gn, char *mname, size_t mnamelen,
 245           const char *dname,
 246           const char *tname,
 247           const char *cwd)
 248 {
 249     char buf[MAXPATHLEN];
 250     char *rp;
 251     char *cp;
 252     char *tp;
 253
 254     /*
 255      * Weed out relative paths from the target file name.
 256      * We have to be careful though since if target is a
 257      * symlink, the result will be unstable.
 258      * So we use realpath() just to get the dirname, and leave the
 259      * basename as given to us.
 260      */
 261     if ((cp = strrchr(tname, '/'))) {
 262         if (cached_realpath(tname, buf)) {
 263             if ((rp = strrchr(buf, '/'))) {
 264                 rp++;
 265                 cp++;
 266                 if (strcmp(cp, rp) != 0)
 267                     strlcpy(rp, cp, sizeof(buf) - (rp - buf));
 268             }
 269             tname = buf;
 270         } else {
 271             /*
 272              * We likely have a directory which is about to be made.
 273              * We pretend realpath() succeeded, to have a chance
 274              * of generating the same meta file name that we will
 275              * next time through.
 276              */
 277             if (tname[0] == '/') {
 278                 strlcpy(buf, tname, sizeof(buf));
 279             } else {
 280                 snprintf(buf, sizeof(buf), "%s/%s", cwd, tname);
 281             }
 282             eat_dots(buf, sizeof(buf), 1);      /* ./ */
 283             eat_dots(buf, sizeof(buf), 2);      /* ../ */
 284             tname = buf;
 285         }
 286     }
 287     /* on some systems dirname may modify its arg */
 288     tp = bmake_strdup(tname);
 289     if (strcmp(dname, dirname(tp)) == 0)
 290         snprintf(mname, mnamelen, "%s.meta", tname);
 291     else {
 292         snprintf(mname, mnamelen, "%s/%s.meta", dname, tname);
 293
 294         /*
 295          * Replace path separators in the file name after the
 296          * current object directory path.
 297          */
 298         cp = mname + strlen(dname) + 1;
 299
 300         while (*cp != '\0') {
 301             if (*cp == '/')
 302                 *cp = '_';
 303             cp++;
 304         }
 305     }
 306     free(tp);
 307     return (mname);
 308 }
 309
 310 /*
 311  * Return true if running ${.MAKE}
 312  * Bypassed if target is flagged .MAKE
 313  */
 314 static int
 315 is_submake(void *cmdp, void *gnp)
 316 {
 317     static char *p_make = NULL;
 318     static int p_len;
 319     char  *cmd = cmdp;
 320     GNode *gn = gnp;
 321     char *mp = NULL;
 322     char *cp;
 323     char *cp2;
 324     int rc = 0;                         /* keep looking */
 325
 326     if (!p_make) {
 327         p_make = Var_Value(".MAKE", gn, &cp);
 328         p_len = strlen(p_make);
 329     }
 330     cp = strchr(cmd, '$');
 331     if ((cp)) {
 332         mp = Var_Subst(NULL, cmd, gn, VARF_WANTRES);
 333         cmd = mp;
 334     }
 335     cp2 = strstr(cmd, p_make);
 336     if ((cp2)) {
 337         switch (cp2[p_len]) {
 338         case '\0':
 339         case ' ':
 340         case '\t':
 341         case '\n':
 342             rc = 1;
 343             break;
 344         }
 345         if (cp2 > cmd && rc > 0) {
 346             switch (cp2[-1]) {
 347             case ' ':
 348             case '\t':
 349             case '\n':
 350                 break;
 351             default:
 352                 rc = 0;                 /* no match */
 353                 break;
 354             }
 355         }
 356     }
 357     free(mp);
 358     return (rc);
 359 }
 360
 361 typedef struct meta_file_s {
 362     FILE *fp;
 363     GNode *gn;
 364 } meta_file_t;
 365
 366 static int
 367 printCMD(void *cmdp, void *mfpp)
 368 {
 369     meta_file_t *mfp = mfpp;
 370     char *cmd = cmdp;
 371     char *cp = NULL;
 372
 373     if (strchr(cmd, '$')) {
 374         cmd = cp = Var_Subst(NULL, cmd, mfp->gn, VARF_WANTRES);
 375     }
 376     fprintf(mfp->fp, "CMD %s\n", cmd);
 377     free(cp);
 378     return 0;
 379 }
 380
 381 /*
 382  * Certain node types never get a .meta file
 383  */
 384 #define SKIP_META_TYPE(_type) do { \
 385     if ((gn->type & __CONCAT(OP_, _type))) {    \
 386         if (verbose) { \
 387             fprintf(debug_file, "Skipping meta for %s: .%s\n", \
 388                     gn->name, __STRING(_type));                \
 389         } \
 390         return FALSE; \
 391     } \
 392 } while (0)
 393
 394
 395 /*
 396  * Do we need/want a .meta file ?
 397  */
 398 static Boolean
 399 meta_needed(GNode *gn, const char *dname, const char __unused *tname,
 400              char *objdir, int verbose)
 401 {
 402     struct stat fs;
 403
 404     if (verbose)
 405         verbose = DEBUG(META);
 406
 407     /* This may be a phony node which we don't want meta data for... */
 408     /* Skip .meta for .BEGIN, .END, .ERROR etc as well. */
 409     /* Or it may be explicitly flagged as .NOMETA */
 410     SKIP_META_TYPE(NOMETA);
 411     /* Unless it is explicitly flagged as .META */
 412     if (!(gn->type & OP_META)) {
 413         SKIP_META_TYPE(PHONY);
 414         SKIP_META_TYPE(SPECIAL);
 415         SKIP_META_TYPE(MAKE);
 416     }
 417
 418     /* Check if there are no commands to execute. */
 419     if (Lst_IsEmpty(gn->commands)) {
 420         if (verbose)
 421             fprintf(debug_file, "Skipping meta for %s: no commands\n",
 422                     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 (Lst_ForEach(gn->commands, is_submake, gn)) {
 428             if (DEBUG(META))
 429                 fprintf(debug_file, "Skipping meta for %s: .SUBMAKE\n",
 430                         gn->name);
 431             return FALSE;
 432         }
 433     }
 434
 435     /* The object directory may not exist. Check it.. */
 436     if (cached_stat(dname, &fs) != 0) {
 437         if (verbose)
 438             fprintf(debug_file, "Skipping meta for %s: no .OBJDIR\n",
 439                     gn->name);
 440         return FALSE;
 441     }
 442
 443     /* make sure these are canonical */
 444     if (cached_realpath(dname, objdir))
 445         dname = objdir;
 446
 447     /* If we aren't in the object directory, don't create a meta file. */
 448     if (!metaCurdirOk && strcmp(curdir, dname) == 0) {
 449         if (verbose)
 450             fprintf(debug_file, "Skipping meta for %s: .OBJDIR == .CURDIR\n",
 451                     gn->name);
 452         return FALSE;
 453     }
 454     return TRUE;
 455 }
 456
 457
 458 static FILE *
 459 meta_create(BuildMon *pbm, GNode *gn)
 460 {
 461     meta_file_t mf;
 462     char buf[MAXPATHLEN];
 463     char objdir[MAXPATHLEN];
 464     char **ptr;
 465     const char *dname;
 466     const char *tname;
 467     char *fname;
 468     const char *cp;
 469     char *p[4];                         /* >= possible uses */
 470     int i;
 471
 472     mf.fp = NULL;
 473     i = 0;
 474
 475     dname = Var_Value(".OBJDIR", gn, &p[i++]);
 476     tname = Var_Value(TARGET, gn, &p[i++]);
 477
 478     /* if this succeeds objdir is realpath of dname */
 479     if (!meta_needed(gn, dname, tname, objdir, TRUE))
 480         goto out;
 481     dname = objdir;
 482
 483     if (metaVerbose) {
 484         char *mp;
 485
 486         /* Describe the target we are building */
 487         mp = Var_Subst(NULL, "${" MAKE_META_PREFIX "}", gn, VARF_WANTRES);
 488         if (*mp)
 489             fprintf(stdout, "%s\n", mp);
 490         free(mp);
 491     }
 492     /* Get the basename of the target */
 493     if ((cp = strrchr(tname, '/')) == NULL) {
 494         cp = tname;
 495     } else {
 496         cp++;
 497     }
 498
 499     fflush(stdout);
 500
 501     if (!writeMeta)
 502         /* Don't create meta data. */
 503         goto out;
 504
 505     fname = meta_name(gn, pbm->meta_fname, sizeof(pbm->meta_fname),
 506                       dname, tname, objdir);
 507
 508 #ifdef DEBUG_META_MODE
 509     if (DEBUG(META))
 510         fprintf(debug_file, "meta_create: %s\n", fname);
 511 #endif
 512
 513     if ((mf.fp = fopen(fname, "w")) == NULL)
 514         err(1, "Could not open meta file '%s'", fname);
 515
 516     fprintf(mf.fp, "# Meta data file %s\n", fname);
 517
 518     mf.gn = gn;
 519
 520     Lst_ForEach(gn->commands, printCMD, &mf);
 521
 522     fprintf(mf.fp, "CWD %s\n", getcwd(buf, sizeof(buf)));
 523     fprintf(mf.fp, "TARGET %s\n", tname);
 524
 525     if (metaEnv) {
 526         for (ptr = environ; *ptr != NULL; ptr++)
 527             fprintf(mf.fp, "ENV %s\n", *ptr);
 528     }
 529
 530     fprintf(mf.fp, "-- command output --\n");
 531     fflush(mf.fp);
 532
 533     Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
 534     Var_Append(".MAKE.META.CREATED", fname, VAR_GLOBAL);
 535
 536     gn->type |= OP_META;                /* in case anyone wants to know */
 537     if (metaSilent) {
 538             gn->type |= OP_SILENT;
 539     }
 540  out:
 541     for (i--; i >= 0; i--) {
 542         free(p[i]);
 543     }
 544
 545     return (mf.fp);
 546 }
 547
 548 static Boolean
 549 boolValue(char *s)
 550 {
 551     switch(*s) {
 552     case '0':
 553     case 'N':
 554     case 'n':
 555     case 'F':
 556     case 'f':
 557         return FALSE;
 558     }
 559     return TRUE;
 560 }
 561
 562 /*
 563  * Initialization we need before reading makefiles.
 564  */
 565 void
 566 meta_init(void)
 567 {
 568 #ifdef USE_FILEMON
 569         /* this allows makefiles to test if we have filemon support */
 570         Var_Set(".MAKE.PATH_FILEMON", _PATH_FILEMON, VAR_GLOBAL, 0);
 571 #endif
 572 }
 573
 574
 575 #define get_mode_bf(bf, token) \
 576     if ((cp = strstr(make_mode, token))) \
 577         bf = boolValue(&cp[sizeof(token) - 1])
 578
 579 /*
 580  * Initialization we need after reading makefiles.
 581  */
 582 void
 583 meta_mode_init(const char *make_mode)
 584 {
 585     static int once = 0;
 586     char *cp;
 587
 588     useMeta = TRUE;
 589     useFilemon = TRUE;
 590     writeMeta = TRUE;
 591
 592     if (make_mode) {
 593         if (strstr(make_mode, "env"))
 594             metaEnv = TRUE;
 595         if (strstr(make_mode, "verb"))
 596             metaVerbose = TRUE;
 597         if (strstr(make_mode, "read"))
 598             writeMeta = FALSE;
 599         if (strstr(make_mode, "nofilemon"))
 600             useFilemon = FALSE;
 601         if (strstr(make_mode, "ignore-cmd"))
 602             metaIgnoreCMDs = TRUE;
 603         if (useFilemon)
 604             get_mode_bf(filemonMissing, "missing-filemon=");
 605         get_mode_bf(metaCurdirOk, "curdirok=");
 606         get_mode_bf(metaMissing, "missing-meta=");
 607         get_mode_bf(metaSilent, "silent=");
 608     }
 609     if (metaVerbose && !Var_Exists(MAKE_META_PREFIX, VAR_GLOBAL)) {
 610         /*
 611          * The default value for MAKE_META_PREFIX
 612          * prints the absolute path of the target.
 613          * This works be cause :H will generate '.' if there is no /
 614          * and :tA will resolve that to cwd.
 615          */
 616         Var_Set(MAKE_META_PREFIX, "Building ${.TARGET:H:tA}/${.TARGET:T}", VAR_GLOBAL, 0);
 617     }
 618     if (once)
 619         return;
 620     once = 1;
 621     memset(&Mybm, 0, sizeof(Mybm));
 622     /*
 623      * We consider ourselves master of all within ${.MAKE.META.BAILIWICK}
 624      */
 625     metaBailiwick = Lst_Init(FALSE);
 626     metaBailiwickStr = Var_Subst(NULL, "${.MAKE.META.BAILIWICK:O:u:tA}",
 627         VAR_GLOBAL, VARF_WANTRES);
 628     if (metaBailiwickStr) {
 629         str2Lst_Append(metaBailiwick, metaBailiwickStr, NULL);
 630     }
 631     /*
 632      * We ignore any paths that start with ${.MAKE.META.IGNORE_PATHS}
 633      */
 634     metaIgnorePaths = Lst_Init(FALSE);
 635     Var_Append(MAKE_META_IGNORE_PATHS,
 636                "/dev /etc /proc /tmp /var/run /var/tmp ${TMPDIR}", VAR_GLOBAL);
 637     metaIgnorePathsStr = Var_Subst(NULL,
 638                    "${" MAKE_META_IGNORE_PATHS ":O:u:tA}", VAR_GLOBAL,
 639                    VARF_WANTRES);
 640     if (metaIgnorePathsStr) {
 641         str2Lst_Append(metaIgnorePaths, metaIgnorePathsStr, NULL);
 642     }
 643
 644     /*
 645      * We ignore any paths that match ${.MAKE.META.IGNORE_PATTERNS}
 646      */
 647     cp = NULL;
 648     if (Var_Value(MAKE_META_IGNORE_PATTERNS, VAR_GLOBAL, &cp)) {
 649         metaIgnorePatterns = TRUE;
 650         free(cp);
 651     }
 652     cp = NULL;
 653     if (Var_Value(MAKE_META_IGNORE_FILTER, VAR_GLOBAL, &cp)) {
 654         metaIgnoreFilter = TRUE;
 655         free(cp);
 656     }
 657 }
 658
 659 /*
 660  * In each case below we allow for job==NULL
 661  */
 662 void
 663 meta_job_start(Job *job, GNode *gn)
 664 {
 665     BuildMon *pbm;
 666
 667     if (job != NULL) {
 668         pbm = &job->bm;
 669     } else {
 670         pbm = &Mybm;
 671     }
 672     pbm->mfp = meta_create(pbm, gn);
 673 #ifdef USE_FILEMON_ONCE
 674     /* compat mode we open the filemon dev once per command */
 675     if (job == NULL)
 676         return;
 677 #endif
 678 #ifdef USE_FILEMON
 679     if (pbm->mfp != NULL && useFilemon) {
 680         filemon_open(pbm);
 681     } else {
 682         pbm->mon_fd = pbm->filemon_fd = -1;
 683     }
 684 #endif
 685 }
 686
 687 /*
 688  * The child calls this before doing anything.
 689  * It does not disturb our state.
 690  */
 691 void
 692 meta_job_child(Job __unused *job)
 693 {
 694 #ifdef USE_FILEMON
 695     BuildMon *pbm;
 696
 697     if (job != NULL) {
 698         pbm = &job->bm;
 699     } else {
 700         pbm = &Mybm;
 701     }
 702     if (pbm->mfp != NULL) {
 703         close(fileno(pbm->mfp));
 704         if (useFilemon) {
 705             pid_t pid;
 706
 707             pid = getpid();
 708             if (ioctl(pbm->filemon_fd, FILEMON_SET_PID, &pid) < 0) {
 709                 err(1, "Could not set filemon pid!");
 710             }
 711         }
 712     }
 713 #endif
 714 }
 715
 716 void
 717 meta_job_error(Job *job, GNode *gn, int flags, int status)
 718 {
 719     char cwd[MAXPATHLEN];
 720     BuildMon *pbm;
 721
 722     if (job != NULL) {
 723         pbm = &job->bm;
 724         if (!gn)
 725             gn = job->node;
 726     } else {
 727         pbm = &Mybm;
 728     }
 729     if (pbm->mfp != NULL) {
 730         fprintf(pbm->mfp, "*** Error code %d%s\n",
 731                 status,
 732                 (flags & JOB_IGNERR) ?
 733                 "(ignored)" : "");
 734     }
 735     if (gn) {
 736         Var_Set(".ERROR_TARGET", gn->path ? gn->path : gn->name, VAR_GLOBAL, 0);
 737     }
 738     getcwd(cwd, sizeof(cwd));
 739     Var_Set(".ERROR_CWD", cwd, VAR_GLOBAL, 0);
 740     if (pbm->meta_fname[0]) {
 741         Var_Set(".ERROR_META_FILE", pbm->meta_fname, VAR_GLOBAL, 0);
 742     }
 743     meta_job_finish(job);
 744 }
 745
 746 void
 747 meta_job_output(Job *job, char *cp, const char *nl)
 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         if (metaVerbose) {
 758             static char *meta_prefix = NULL;
 759             static int meta_prefix_len;
 760
 761             if (!meta_prefix) {
 762                 char *cp2;
 763
 764                 meta_prefix = Var_Subst(NULL, "${" MAKE_META_PREFIX "}",
 765                                         VAR_GLOBAL, VARF_WANTRES);
 766                 if ((cp2 = strchr(meta_prefix, '$')))
 767                     meta_prefix_len = cp2 - meta_prefix;
 768                 else
 769                     meta_prefix_len = strlen(meta_prefix);
 770             }
 771             if (strncmp(cp, meta_prefix, meta_prefix_len) == 0) {
 772                 cp = strchr(cp+1, '\n');
 773                 if (!cp++)
 774                     return;
 775             }
 776         }
 777         fprintf(pbm->mfp, "%s%s", cp, nl);
 778     }
 779 }
 780
 781 int
 782 meta_cmd_finish(void __unused *pbmp)
 783 {
 784     int error = 0;
 785 #ifdef USE_FILEMON
 786     BuildMon *pbm = pbmp;
 787     int x;
 788
 789     if (!pbm)
 790         pbm = &Mybm;
 791
 792     if (pbm->filemon_fd >= 0) {
 793         if (close(pbm->filemon_fd) < 0)
 794             error = errno;
 795         x = filemon_read(pbm->mfp, pbm->mon_fd);
 796         if (error == 0 && x != 0)
 797             error = x;
 798         pbm->filemon_fd = pbm->mon_fd = -1;
 799     }
 800 #endif
 801     return error;
 802 }
 803
 804 int
 805 meta_job_finish(Job *job)
 806 {
 807     BuildMon *pbm;
 808     int error = 0;
 809     int x;
 810
 811     if (job != NULL) {
 812         pbm = &job->bm;
 813     } else {
 814         pbm = &Mybm;
 815     }
 816     if (pbm->mfp != NULL) {
 817         error = meta_cmd_finish(pbm);
 818         x = fclose(pbm->mfp);
 819         if (error == 0 && x != 0)
 820             error = errno;
 821         pbm->mfp = NULL;
 822         pbm->meta_fname[0] = '\0';
 823     }
 824     return error;
 825 }
 826
 827 void
 828 meta_finish(void)
 829 {
 830     Lst_Destroy(metaBailiwick, NULL);
 831     free(metaBailiwickStr);
 832     Lst_Destroy(metaIgnorePaths, NULL);
 833     free(metaIgnorePathsStr);
 834 }
 835
 836 /*
 837  * Fetch a full line from fp - growing bufp if needed
 838  * Return length in bufp.
 839  */
 840 static int
 841 fgetLine(char **bufp, size_t *szp, int o, FILE *fp)
 842 {
 843     char *buf = *bufp;
 844     size_t bufsz = *szp;
 845     struct stat fs;
 846     int x;
 847
 848     if (fgets(&buf[o], bufsz - o, fp) != NULL) {
 849     check_newline:
 850         x = o + strlen(&buf[o]);
 851         if (buf[x - 1] == '\n')
 852             return x;
 853         /*
 854          * We need to grow the buffer.
 855          * The meta file can give us a clue.
 856          */
 857         if (fstat(fileno(fp), &fs) == 0) {
 858             size_t newsz;
 859             char *p;
 860
 861             newsz = ROUNDUP((fs.st_size / 2), BUFSIZ);
 862             if (newsz <= bufsz)
 863                 newsz = ROUNDUP(fs.st_size, BUFSIZ);
 864             if (DEBUG(META))
 865                 fprintf(debug_file, "growing buffer %u -> %u\n",
 866                         (unsigned)bufsz, (unsigned)newsz);
 867             p = bmake_realloc(buf, newsz);
 868             if (p) {
 869                 *bufp = buf = p;
 870                 *szp = bufsz = newsz;
 871                 /* fetch the rest */
 872                 if (!fgets(&buf[x], bufsz - x, fp))
 873                     return x;           /* truncated! */
 874                 goto check_newline;
 875             }
 876         }
 877     }
 878     return 0;
 879 }
 880
 881 /* Lst_ForEach wants 1 to stop search */
 882 static int
 883 prefix_match(void *p, void *q)
 884 {
 885     const char *prefix = p;
 886     const char *path = q;
 887     size_t n = strlen(prefix);
 888
 889     return (0 == strncmp(path, prefix, n));
 890 }
 891
 892 /*
 893  * looking for exact or prefix/ match to
 894  * Lst_Find wants 0 to stop search
 895  */
 896 static int
 897 path_match(const void *p, const void *q)
 898 {
 899     const char *prefix = q;
 900     const char *path = p;
 901     size_t n = strlen(prefix);
 902     int rc;
 903
 904     if ((rc = strncmp(path, prefix, n)) == 0) {
 905         switch (path[n]) {
 906         case '\0':
 907         case '/':
 908             break;
 909         default:
 910             rc = 1;
 911             break;
 912         }
 913     }
 914     return rc;
 915 }
 916
 917 /* Lst_Find wants 0 to stop search */
 918 static int
 919 string_match(const void *p, const void *q)
 920 {
 921     const char *p1 = p;
 922     const char *p2 = q;
 923
 924     return strcmp(p1, p2);
 925 }
 926
 927
 928 static int
 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 (Lst_ForEach(metaIgnorePaths, prefix_match, fname)) {
 939 #ifdef DEBUG_META_MODE
 940             if (DEBUG(META))
 941                 fprintf(debug_file, "meta_oodate: ignoring path: %s\n",
 942                         p);
 943 #endif
 944             return TRUE;
 945         }
 946     }
 947
 948     if (metaIgnorePatterns) {
 949         char *pm;
 950
 951         snprintf(fname, sizeof(fname),
 952                  "${%s:@m@${%s:L:M$m}@}",
 953                  MAKE_META_IGNORE_PATTERNS, p);
 954         pm = Var_Subst(NULL, fname, gn, VARF_WANTRES);
 955         if (*pm) {
 956 #ifdef DEBUG_META_MODE
 957             if (DEBUG(META))
 958                 fprintf(debug_file, "meta_oodate: ignoring pattern: %s\n",
 959                         p);
 960 #endif
 961             free(pm);
 962             return TRUE;
 963         }
 964         free(pm);
 965     }
 966
 967     if (metaIgnoreFilter) {
 968         char *fm;
 969
 970         /* skip if filter result is empty */
 971         snprintf(fname, sizeof(fname),
 972                  "${%s:L:${%s:ts:}}",
 973                  p, MAKE_META_IGNORE_FILTER);
 974         fm = Var_Subst(NULL, fname, gn, VARF_WANTRES);
 975         if (*fm == '\0') {
 976 #ifdef DEBUG_META_MODE
 977             if (DEBUG(META))
 978                 fprintf(debug_file, "meta_oodate: ignoring filtered: %s\n",
 979                         p);
 980 #endif
 981             free(fm);
 982             return TRUE;
 983         }
 984         free(fm);
 985     }
 986     return FALSE;
 987 }
 988
 989 /*
 990  * When running with 'meta' functionality, a target can be out-of-date
 991  * if any of the references in its meta data file is more recent.
 992  * We have to track the latestdir on a per-process basis.
 993  */
 994 #define LCWD_VNAME_FMT ".meta.%d.lcwd"
 995 #define LDIR_VNAME_FMT ".meta.%d.ldir"
 996
 997 /*
 998  * It is possible that a .meta file is corrupted,
 999  * if we detect this we want to reproduce it.
1000  * Setting oodate TRUE will have that effect.
1001  */
1002 #define CHECK_VALID_META(p) if (!(p && *p)) { \
1003     warnx("%s: %d: malformed", fname, lineno); \
1004     oodate = TRUE; \
1005     continue; \
1006     }
1007
1008 #define DEQUOTE(p) if (*p == '\'') {    \
1009     char *ep; \
1010     p++; \
1011     if ((ep = strchr(p, '\''))) \
1012         *ep = '\0'; \
1013     }
1014
1015 Boolean
1016 meta_oodate(GNode *gn, Boolean oodate)
1017 {
1018     static char *tmpdir = NULL;
1019     static char cwd[MAXPATHLEN];
1020     char lcwd_vname[64];
1021     char ldir_vname[64];
1022     char lcwd[MAXPATHLEN];
1023     char latestdir[MAXPATHLEN];
1024     char fname[MAXPATHLEN];
1025     char fname1[MAXPATHLEN];
1026     char fname2[MAXPATHLEN];
1027     char fname3[MAXPATHLEN];
1028     const char *dname;
1029     const char *tname;
1030     char *p;
1031     char *cp;
1032     char *link_src;
1033     char *move_target;
1034     static size_t cwdlen = 0;
1035     static size_t tmplen = 0;
1036     FILE *fp;
1037     Boolean needOODATE = FALSE;
1038     Lst missingFiles;
1039     char *pa[4];                        /* >= possible uses */
1040     int i;
1041     int have_filemon = FALSE;
1042
1043     if (oodate)
1044         return oodate;          /* we're done */
1045
1046     i = 0;
1047
1048     dname = Var_Value(".OBJDIR", gn, &pa[i++]);
1049     tname = Var_Value(TARGET, gn, &pa[i++]);
1050
1051     /* if this succeeds fname3 is realpath of dname */
1052     if (!meta_needed(gn, dname, tname, fname3, FALSE))
1053         goto oodate_out;
1054     dname = fname3;
1055
1056     missingFiles = Lst_Init(FALSE);
1057
1058     /*
1059      * We need to check if the target is out-of-date. This includes
1060      * checking if the expanded command has changed. This in turn
1061      * requires that all variables are set in the same way that they
1062      * would be if the target needs to be re-built.
1063      */
1064     Make_DoAllVar(gn);
1065
1066     meta_name(gn, fname, sizeof(fname), dname, tname, dname);
1067
1068 #ifdef DEBUG_META_MODE
1069     if (DEBUG(META))
1070         fprintf(debug_file, "meta_oodate: %s\n", fname);
1071 #endif
1072
1073     if ((fp = fopen(fname, "r")) != NULL) {
1074         static char *buf = NULL;
1075         static size_t bufsz;
1076         int lineno = 0;
1077         int lastpid = 0;
1078         int pid;
1079         int x;
1080         LstNode ln;
1081         struct stat fs;
1082
1083         if (!buf) {
1084             bufsz = 8 * BUFSIZ;
1085             buf = bmake_malloc(bufsz);
1086         }
1087
1088         if (!cwdlen) {
1089             if (getcwd(cwd, sizeof(cwd)) == NULL)
1090                 err(1, "Could not get current working directory");
1091             cwdlen = strlen(cwd);
1092         }
1093         strlcpy(lcwd, cwd, sizeof(lcwd));
1094         strlcpy(latestdir, cwd, sizeof(latestdir));
1095
1096         if (!tmpdir) {
1097             tmpdir = getTmpdir();
1098             tmplen = strlen(tmpdir);
1099         }
1100
1101         /* we want to track all the .meta we read */
1102         Var_Append(".MAKE.META.FILES", fname, VAR_GLOBAL);
1103
1104         ln = Lst_First(gn->commands);
1105         while (!oodate && (x = fgetLine(&buf, &bufsz, 0, fp)) > 0) {
1106             lineno++;
1107             if (buf[x - 1] == '\n')
1108                 buf[x - 1] = '\0';
1109             else {
1110                 warnx("%s: %d: line truncated at %u", fname, lineno, x);
1111                 oodate = TRUE;
1112                 break;
1113             }
1114             link_src = NULL;
1115             move_target = NULL;
1116             /* Find the start of the build monitor section. */
1117             if (!have_filemon) {
1118                 if (strncmp(buf, "-- filemon", 10) == 0) {
1119                     have_filemon = TRUE;
1120                     continue;
1121                 }
1122                 if (strncmp(buf, "# buildmon", 10) == 0) {
1123                     have_filemon = TRUE;
1124                     continue;
1125                 }
1126             }
1127
1128             /* Delimit the record type. */
1129             p = buf;
1130 #ifdef DEBUG_META_MODE
1131             if (DEBUG(META))
1132                 fprintf(debug_file, "%s: %d: %s\n", fname, lineno, buf);
1133 #endif
1134             strsep(&p, " ");
1135             if (have_filemon) {
1136                 /*
1137                  * We are in the 'filemon' output section.
1138                  * Each record from filemon follows the general form:
1139                  *
1140                  * <key> <pid> <data>
1141                  *
1142                  * Where:
1143                  * <key> is a single letter, denoting the syscall.
1144                  * <pid> is the process that made the syscall.
1145                  * <data> is the arguments (of interest).
1146                  */
1147                 switch(buf[0]) {
1148                 case '#':               /* comment */
1149                 case 'V':               /* version */
1150                     break;
1151                 default:
1152                     /*
1153                      * We need to track pathnames per-process.
1154                      *
1155                      * Each process run by make, starts off in the 'CWD'
1156                      * recorded in the .meta file, if it chdirs ('C')
1157                      * elsewhere we need to track that - but only for
1158                      * that process.  If it forks ('F'), we initialize
1159                      * the child to have the same cwd as its parent.
1160                      *
1161                      * We also need to track the 'latestdir' of
1162                      * interest.  This is usually the same as cwd, but
1163                      * not if a process is reading directories.
1164                      *
1165                      * Each time we spot a different process ('pid')
1166                      * we save the current value of 'latestdir' in a
1167                      * variable qualified by 'lastpid', and
1168                      * re-initialize 'latestdir' to any pre-saved
1169                      * value for the current 'pid' and 'CWD' if none.
1170                      */
1171                     CHECK_VALID_META(p);
1172                     pid = atoi(p);
1173                     if (pid > 0 && pid != lastpid) {
1174                         char *ldir;
1175                         char *tp;
1176
1177                         if (lastpid > 0) {
1178                             /* We need to remember these. */
1179                             Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1180                             Var_Set(ldir_vname, latestdir, VAR_GLOBAL, 0);
1181                         }
1182                         snprintf(lcwd_vname, sizeof(lcwd_vname), LCWD_VNAME_FMT, pid);
1183                         snprintf(ldir_vname, sizeof(ldir_vname), LDIR_VNAME_FMT, pid);
1184                         lastpid = pid;
1185                         ldir = Var_Value(ldir_vname, VAR_GLOBAL, &tp);
1186                         if (ldir) {
1187                             strlcpy(latestdir, ldir, sizeof(latestdir));
1188                             free(tp);
1189                         }
1190                         ldir = Var_Value(lcwd_vname, VAR_GLOBAL, &tp);
1191                         if (ldir) {
1192                             strlcpy(lcwd, ldir, sizeof(lcwd));
1193                             free(tp);
1194                         }
1195                     }
1196                     /* Skip past the pid. */
1197                     if (strsep(&p, " ") == NULL)
1198                         continue;
1199 #ifdef DEBUG_META_MODE
1200                     if (DEBUG(META))
1201                             fprintf(debug_file, "%s: %d: %d: %c: cwd=%s lcwd=%s ldir=%s\n",
1202                                     fname, lineno,
1203                                     pid, buf[0], cwd, lcwd, latestdir);
1204 #endif
1205                     break;
1206                 }
1207
1208                 CHECK_VALID_META(p);
1209
1210                 /* Process according to record type. */
1211                 switch (buf[0]) {
1212                 case 'X':               /* eXit */
1213                     Var_Delete(lcwd_vname, VAR_GLOBAL);
1214                     Var_Delete(ldir_vname, VAR_GLOBAL);
1215                     lastpid = 0;        /* no need to save ldir_vname */
1216                     break;
1217
1218                 case 'F':               /* [v]Fork */
1219                     {
1220                         char cldir[64];
1221                         int child;
1222
1223                         child = atoi(p);
1224                         if (child > 0) {
1225                             snprintf(cldir, sizeof(cldir), LCWD_VNAME_FMT, child);
1226                             Var_Set(cldir, lcwd, VAR_GLOBAL, 0);
1227                             snprintf(cldir, sizeof(cldir), LDIR_VNAME_FMT, child);
1228                             Var_Set(cldir, latestdir, VAR_GLOBAL, 0);
1229 #ifdef DEBUG_META_MODE
1230                             if (DEBUG(META))
1231                                     fprintf(debug_file, "%s: %d: %d: cwd=%s lcwd=%s ldir=%s\n",
1232                                             fname, lineno,
1233                                             child, cwd, lcwd, latestdir);
1234 #endif
1235                         }
1236                     }
1237                     break;
1238
1239                 case 'C':               /* Chdir */
1240                     /* Update lcwd and latest directory. */
1241                     strlcpy(latestdir, p, sizeof(latestdir));
1242                     strlcpy(lcwd, p, sizeof(lcwd));
1243                     Var_Set(lcwd_vname, lcwd, VAR_GLOBAL, 0);
1244                     Var_Set(ldir_vname, lcwd, VAR_GLOBAL, 0);
1245 #ifdef DEBUG_META_MODE
1246                     if (DEBUG(META))
1247                         fprintf(debug_file, "%s: %d: cwd=%s ldir=%s\n", fname, lineno, cwd, lcwd);
1248 #endif
1249                     break;
1250
1251                 case 'M':               /* renaMe */
1252                     /*
1253                      * For 'M'oves we want to check
1254                      * the src as for 'R'ead
1255                      * and the target as for 'W'rite.
1256                      */
1257                     cp = p;             /* save this for a second */
1258                     /* now get target */
1259                     if (strsep(&p, " ") == NULL)
1260                         continue;
1261                     CHECK_VALID_META(p);
1262                     move_target = p;
1263                     p = cp;
1264                     /* 'L' and 'M' put single quotes around the args */
1265                     DEQUOTE(p);
1266                     DEQUOTE(move_target);
1267                     /* FALLTHROUGH */
1268                 case 'D':               /* unlink */
1269                     if (*p == '/' && !Lst_IsEmpty(missingFiles)) {
1270                         /* remove any missingFiles entries that match p */
1271                         if ((ln = Lst_Find(missingFiles, p,
1272                                            path_match)) != NULL) {
1273                             LstNode nln;
1274                             char *tp;
1275
1276                             do {
1277                                 nln = Lst_FindFrom(missingFiles, Lst_Succ(ln),
1278                                                    p, path_match);
1279                                 tp = Lst_Datum(ln);
1280                                 Lst_Remove(missingFiles, ln);
1281                                 free(tp);
1282                             } while ((ln = nln) != NULL);
1283                         }
1284                     }
1285                     if (buf[0] == 'M') {
1286                         /* the target of the mv is a file 'W'ritten */
1287 #ifdef DEBUG_META_MODE
1288                         if (DEBUG(META))
1289                             fprintf(debug_file, "meta_oodate: M %s -> %s\n",
1290                                     p, move_target);
1291 #endif
1292                         p = move_target;
1293                         goto check_write;
1294                     }
1295                     break;
1296                 case 'L':               /* Link */
1297                     /*
1298                      * For 'L'inks check
1299                      * the src as for 'R'ead
1300                      * and the target as for 'W'rite.
1301                      */
1302                     link_src = p;
1303                     /* now get target */
1304                     if (strsep(&p, " ") == NULL)
1305                         continue;
1306                     CHECK_VALID_META(p);
1307                     /* 'L' and 'M' put single quotes around the args */
1308                     DEQUOTE(p);
1309                     DEQUOTE(link_src);
1310 #ifdef DEBUG_META_MODE
1311                     if (DEBUG(META))
1312                         fprintf(debug_file, "meta_oodate: L %s -> %s\n",
1313                                 link_src, p);
1314 #endif
1315                     /* FALLTHROUGH */
1316                 case 'W':               /* Write */
1317                 check_write:
1318                     /*
1319                      * If a file we generated within our bailiwick
1320                      * but outside of .OBJDIR is missing,
1321                      * we need to do it again.
1322                      */
1323                     /* ignore non-absolute paths */
1324                     if (*p != '/')
1325                         break;
1326
1327                     if (Lst_IsEmpty(metaBailiwick))
1328                         break;
1329
1330                     /* ignore cwd - normal dependencies handle those */
1331                     if (strncmp(p, cwd, cwdlen) == 0)
1332                         break;
1333
1334                     if (!Lst_ForEach(metaBailiwick, prefix_match, p))
1335                         break;
1336
1337                     /* tmpdir might be within */
1338                     if (tmplen > 0 && strncmp(p, tmpdir, tmplen) == 0)
1339                         break;
1340
1341                     /* ignore anything containing the string "tmp" */
1342                     if ((strstr("tmp", p)))
1343                         break;
1344
1345                     if ((link_src != NULL && cached_lstat(p, &fs) < 0) ||
1346                         (link_src == NULL && cached_stat(p, &fs) < 0)) {
1347                         if (!meta_ignore(gn, p)) {
1348                             if (Lst_Find(missingFiles, p, string_match) == NULL)
1349                                 Lst_AtEnd(missingFiles, bmake_strdup(p));
1350                         }
1351                     }
1352                     break;
1353                 check_link_src:
1354                     p = link_src;
1355                     link_src = NULL;
1356 #ifdef DEBUG_META_MODE
1357                     if (DEBUG(META))
1358                         fprintf(debug_file, "meta_oodate: L src %s\n", p);
1359 #endif
1360                     /* FALLTHROUGH */
1361                 case 'R':               /* Read */
1362                 case 'E':               /* Exec */
1363                     /*
1364                      * Check for runtime files that can't
1365                      * be part of the dependencies because
1366                      * they are _expected_ to change.
1367                      */
1368                     if (meta_ignore(gn, p))
1369                         break;
1370
1371                     /*
1372                      * The rest of the record is the file name.
1373                      * Check if it's not an absolute path.
1374                      */
1375                     {
1376                         char *sdirs[4];
1377                         char **sdp;
1378                         int sdx = 0;
1379                         int found = 0;
1380
1381                         if (*p == '/') {
1382                             sdirs[sdx++] = p; /* done */
1383                         } else {
1384                             if (strcmp(".", p) == 0)
1385                                 continue;  /* no point */
1386
1387                             /* Check vs latestdir */
1388                             snprintf(fname1, sizeof(fname1), "%s/%s", latestdir, p);
1389                             sdirs[sdx++] = fname1;
1390
1391                             if (strcmp(latestdir, lcwd) != 0) {
1392                                 /* Check vs lcwd */
1393                                 snprintf(fname2, sizeof(fname2), "%s/%s", lcwd, p);
1394                                 sdirs[sdx++] = fname2;
1395                             }
1396                             if (strcmp(lcwd, cwd) != 0) {
1397                                 /* Check vs cwd */
1398                                 snprintf(fname3, sizeof(fname3), "%s/%s", cwd, p);
1399                                 sdirs[sdx++] = fname3;
1400                             }
1401                         }
1402                         sdirs[sdx++] = NULL;
1403
1404                         for (sdp = sdirs; *sdp && !found; sdp++) {
1405 #ifdef DEBUG_META_MODE
1406                             if (DEBUG(META))
1407                                 fprintf(debug_file, "%s: %d: looking for: %s\n", fname, lineno, *sdp);
1408 #endif
1409                             if (cached_stat(*sdp, &fs) == 0) {
1410                                 found = 1;
1411                                 p = *sdp;
1412                             }
1413                         }
1414                         if (found) {
1415 #ifdef DEBUG_META_MODE
1416                             if (DEBUG(META))
1417                                 fprintf(debug_file, "%s: %d: found: %s\n", fname, lineno, p);
1418 #endif
1419                             if (!S_ISDIR(fs.st_mode) &&
1420                                 fs.st_mtime > gn->mtime) {
1421                                 if (DEBUG(META))
1422                                     fprintf(debug_file, "%s: %d: file '%s' is newer than the target...\n", fname, lineno, p);
1423                                 oodate = TRUE;
1424                             } else if (S_ISDIR(fs.st_mode)) {
1425                                 /* Update the latest directory. */
1426                                 cached_realpath(p, latestdir);
1427                             }
1428                         } else if (errno == ENOENT && *p == '/' &&
1429                                    strncmp(p, cwd, cwdlen) != 0) {
1430                             /*
1431                              * A referenced file outside of CWD is missing.
1432                              * We cannot catch every eventuality here...
1433                              */
1434                             if (Lst_Find(missingFiles, p, string_match) == NULL)
1435                                     Lst_AtEnd(missingFiles, bmake_strdup(p));
1436                         }
1437                     }
1438                     if (buf[0] == 'E') {
1439                         /* previous latestdir is no longer relevant */
1440                         strlcpy(latestdir, lcwd, sizeof(latestdir));
1441                     }
1442                     break;
1443                 default:
1444                     break;
1445                 }
1446                 if (!oodate && buf[0] == 'L' && link_src != NULL)
1447                     goto check_link_src;
1448             } else if (strcmp(buf, "CMD") == 0) {
1449                 /*
1450                  * Compare the current command with the one in the
1451                  * meta data file.
1452                  */
1453                 if (ln == NULL) {
1454                     if (DEBUG(META))
1455                         fprintf(debug_file, "%s: %d: there were more build commands in the meta data file than there are now...\n", fname, lineno);
1456                     oodate = TRUE;
1457                 } else {
1458                     char *cmd = (char *)Lst_Datum(ln);
1459                     Boolean hasOODATE = FALSE;
1460
1461                     if (strstr(cmd, "$?"))
1462                         hasOODATE = TRUE;
1463                     else if ((cp = strstr(cmd, ".OODATE"))) {
1464                         /* check for $[{(].OODATE[:)}] */
1465                         if (cp > cmd + 2 && cp[-2] == '$')
1466                             hasOODATE = TRUE;
1467                     }
1468                     if (hasOODATE) {
1469                         needOODATE = TRUE;
1470                         if (DEBUG(META))
1471                             fprintf(debug_file, "%s: %d: cannot compare command using .OODATE\n", fname, lineno);
1472                     }
1473                     cmd = Var_Subst(NULL, cmd, gn, VARF_WANTRES|VARF_UNDEFERR);
1474
1475                     if ((cp = strchr(cmd, '\n'))) {
1476                         int n;
1477
1478                         /*
1479                          * This command contains newlines, we need to
1480                          * fetch more from the .meta file before we
1481                          * attempt a comparison.
1482                          */
1483                         /* first put the newline back at buf[x - 1] */
1484                         buf[x - 1] = '\n';
1485                         do {
1486                             /* now fetch the next line */
1487                             if ((n = fgetLine(&buf, &bufsz, x, fp)) <= 0)
1488                                 break;
1489                             x = n;
1490                             lineno++;
1491                             if (buf[x - 1] != '\n') {
1492                                 warnx("%s: %d: line truncated at %u", fname, lineno, x);
1493                                 break;
1494                             }
1495                             cp = strchr(++cp, '\n');
1496                         } while (cp);
1497                         if (buf[x - 1] == '\n')
1498                             buf[x - 1] = '\0';
1499                     }
1500                     if (!hasOODATE &&
1501                         !(gn->type & OP_NOMETA_CMP) &&
1502                         strcmp(p, cmd) != 0) {
1503                         if (DEBUG(META))
1504                             fprintf(debug_file, "%s: %d: a build command has changed\n%s\nvs\n%s\n", fname, lineno, p, cmd);
1505                         if (!metaIgnoreCMDs)
1506                             oodate = TRUE;
1507                     }
1508                     free(cmd);
1509                     ln = Lst_Succ(ln);
1510                 }
1511             } else if (strcmp(buf, "CWD") == 0) {
1512                 /*
1513                  * Check if there are extra commands now
1514                  * that weren't in the meta data file.
1515                  */
1516                 if (!oodate && ln != NULL) {
1517                     if (DEBUG(META))
1518                         fprintf(debug_file, "%s: %d: there are extra build commands now that weren't in the meta data file\n", fname, lineno);
1519                     oodate = TRUE;
1520                 }
1521                 if (strcmp(p, cwd) != 0) {
1522                     if (DEBUG(META))
1523                         fprintf(debug_file, "%s: %d: the current working directory has changed from '%s' to '%s'\n", fname, lineno, p, curdir);
1524                     oodate = TRUE;
1525                 }
1526             }
1527         }
1528
1529         fclose(fp);
1530         if (!Lst_IsEmpty(missingFiles)) {
1531             if (DEBUG(META))
1532                 fprintf(debug_file, "%s: missing files: %s...\n",
1533                         fname, (char *)Lst_Datum(Lst_First(missingFiles)));
1534             oodate = TRUE;
1535         }
1536         if (!oodate && !have_filemon && filemonMissing) {
1537             if (DEBUG(META))
1538                 fprintf(debug_file, "%s: missing filemon data\n", fname);
1539             oodate = TRUE;
1540         }
1541     } else {
1542         if (writeMeta && metaMissing) {
1543             cp = NULL;
1544
1545             /* if target is in .CURDIR we do not need a meta file */
1546             if (gn->path && (cp = strrchr(gn->path, '/')) && cp > gn->path) {
1547                 if (strncmp(curdir, gn->path, (cp - gn->path)) != 0) {
1548                     cp = NULL;          /* not in .CURDIR */
1549                 }
1550             }
1551             if (!cp) {
1552                 if (DEBUG(META))
1553                     fprintf(debug_file, "%s: required but missing\n", fname);
1554                 oodate = TRUE;
1555                 needOODATE = TRUE;      /* assume the worst */
1556             }
1557         }
1558     }
1559
1560     Lst_Destroy(missingFiles, (FreeProc *)free);
1561
1562     if (oodate && needOODATE) {
1563         /*
1564          * Target uses .OODATE which is empty; or we wouldn't be here.
1565          * We have decided it is oodate, so .OODATE needs to be set.
1566          * All we can sanely do is set it to .ALLSRC.
1567          */
1568         Var_Delete(OODATE, gn);
1569         Var_Set(OODATE, Var_Value(ALLSRC, gn, &cp), gn, 0);
1570         free(cp);
1571     }
1572
1573  oodate_out:
1574     for (i--; i >= 0; i--) {
1575         free(pa[i]);
1576     }
1577     return oodate;
1578 }
1579
1580 /* support for compat mode */
1581
1582 static int childPipe[2];
1583
1584 void
1585 meta_compat_start(void)
1586 {
1587 #ifdef USE_FILEMON_ONCE
1588     /*
1589      * We need to re-open filemon for each cmd.
1590      */
1591     BuildMon *pbm = &Mybm;
1592
1593     if (pbm->mfp != NULL && useFilemon) {
1594         filemon_open(pbm);
1595     } else {
1596         pbm->mon_fd = pbm->filemon_fd = -1;
1597     }
1598 #endif
1599     if (pipe(childPipe) < 0)
1600         Punt("Cannot create pipe: %s", strerror(errno));
1601     /* Set close-on-exec flag for both */
1602     (void)fcntl(childPipe[0], F_SETFD, FD_CLOEXEC);
1603     (void)fcntl(childPipe[1], F_SETFD, FD_CLOEXEC);
1604 }
1605
1606 void
1607 meta_compat_child(void)
1608 {
1609     meta_job_child(NULL);
1610     if (dup2(childPipe[1], 1) < 0 ||
1611         dup2(1, 2) < 0) {
1612         execError("dup2", "pipe");
1613         _exit(1);
1614     }
1615 }
1616
1617 void
1618 meta_compat_parent(void)
1619 {
1620     FILE *fp;
1621     char buf[BUFSIZ];
1622
1623     close(childPipe[1]);                        /* child side */
1624     fp = fdopen(childPipe[0], "r");
1625     while (fgets(buf, sizeof(buf), fp)) {
1626         meta_job_output(NULL, buf, "");
1627         printf("%s", buf);
1628         fflush(stdout);
1629     }
1630     fclose(fp);
1631 }
1632
1633 #endif  /* USE_META */