summaryrefslogtreecommitdiff
path: root/remake.c
blob: 72c4d78a4447be79219343cc364a0bdaf456c5d3 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
/* Basic dependency engine for GNU Make.
Copyright (C) 1988, 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999,
2002 Free Software Foundation, Inc.
This file is part of GNU Make.

GNU Make is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Make is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Make; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#include "make.h"
#include "filedef.h"
#include "job.h"
#include "commands.h"
#include "dep.h"
#include "variable.h"
#include "debug.h"

#include <assert.h>

#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#else
#include <sys/file.h>
#endif

#ifdef VMS
#include <starlet.h>
#endif
#ifdef WINDOWS32
#include <io.h>
#endif

extern int try_implicit_rule PARAMS ((struct file *file, unsigned int depth));


/* The test for circular dependencies is based on the 'updating' bit in
   `struct file'.  However, double colon targets have seperate `struct
   file's; make sure we always use the base of the double colon chain. */

#define start_updating(_f)  (((_f)->double_colon ? (_f)->double_colon : (_f))\
                             ->updating = 1)
#define finish_updating(_f) (((_f)->double_colon ? (_f)->double_colon : (_f))\
                             ->updating = 0)
#define is_updating(_f)     (((_f)->double_colon ? (_f)->double_colon : (_f))\
                             ->updating)


/* Incremented when a command is started (under -n, when one would be).  */
unsigned int commands_started = 0;

/* Current value for pruning the scan of the goal chain (toggle 0/1).  */
static unsigned int considered;

static int update_file PARAMS ((struct file *file, unsigned int depth));
static int update_file_1 PARAMS ((struct file *file, unsigned int depth));
static int check_dep PARAMS ((struct file *file, unsigned int depth, FILE_TIMESTAMP this_mtime, int *must_make_ptr));
static int touch_file PARAMS ((struct file *file));
static void remake_file PARAMS ((struct file *file));
static FILE_TIMESTAMP name_mtime PARAMS ((char *name));
static int library_search PARAMS ((char **lib, FILE_TIMESTAMP *mtime_ptr));


/* Remake all the goals in the `struct dep' chain GOALS.  Return -1 if nothing
   was done, 0 if all goals were updated successfully, or 1 if a goal failed.
   If MAKEFILES is nonzero, these goals are makefiles, so -t, -q, and -n should
   be disabled for them unless they were also command-line targets, and we
   should only make one goal at a time and return as soon as one goal whose
   `changed' member is nonzero is successfully made.  */

int
update_goal_chain (goals, makefiles)
     register struct dep *goals;
     int makefiles;
{
  int t = touch_flag, q = question_flag, n = just_print_flag;
  unsigned int j = job_slots;
  int status = -1;

#define	MTIME(file) (makefiles ? file_mtime_no_search (file) \
		     : file_mtime (file))

  /* Duplicate the chain so we can remove things from it.  */

  goals = copy_dep_chain (goals);

  {
    /* Clear the `changed' flag of each goal in the chain.
       We will use the flag below to notice when any commands
       have actually been run for a target.  When no commands
       have been run, we give an "up to date" diagnostic.  */

    struct dep *g;
    for (g = goals; g != 0; g = g->next)
      g->changed = 0;
  }

  /* All files start with the considered bit 0, so the global value is 1.  */
  considered = 1;

  /* Update all the goals until they are all finished.  */

  while (goals != 0)
    {
      register struct dep *g, *lastgoal;

      /* Start jobs that are waiting for the load to go down.  */

      start_waiting_jobs ();

      /* Wait for a child to die.  */

      reap_children (1, 0);

      lastgoal = 0;
      g = goals;
      while (g != 0)
	{
	  /* Iterate over all double-colon entries for this file.  */
	  struct file *file;
	  int stop = 0, any_not_updated = 0;

	  for (file = g->file->double_colon ? g->file->double_colon : g->file;
	       file != NULL;
	       file = file->prev)
	    {
	      unsigned int ocommands_started;
	      int x;
	      check_renamed (file);
	      if (makefiles)
		{
		  if (file->cmd_target)
		    {
		      touch_flag = t;
		      question_flag = q;
		      just_print_flag = n;
		    }
		  else
		    touch_flag = question_flag = just_print_flag = 0;
		}

	      /* Save the old value of `commands_started' so we can compare
		 later.  It will be incremented when any commands are
		 actually run.  */
	      ocommands_started = commands_started;

	      x = update_file (file, makefiles ? 1 : 0);
	      check_renamed (file);

	      /* Set the goal's `changed' flag if any commands were started
		 by calling update_file above.  We check this flag below to
		 decide when to give an "up to date" diagnostic.  */
	      g->changed += commands_started - ocommands_started;

              /* If we updated a file and STATUS was not already 1, set it to
                 1 if updating failed, or to 0 if updating succeeded.  Leave
                 STATUS as it is if no updating was done.  */

	      stop = 0;
	      if ((x != 0 || file->updated) && status < 1)
                {
                  if (file->update_status != 0)
                    {
                      /* Updating failed, or -q triggered.  The STATUS value
                         tells our caller which.  */
                      status = file->update_status;
                      /* If -q just triggered, stop immediately.  It doesn't
                         matter how much more we run, since we already know
                         the answer to return.  */
                      stop = (!keep_going_flag && !question_flag
                              && !makefiles);
                    }
                  else
                    {
                      FILE_TIMESTAMP mtime = MTIME (file);
                      check_renamed (file);

                      if (file->updated && g->changed &&
                           mtime != file->mtime_before_update)
                        {
                          /* Updating was done.  If this is a makefile and
                             just_print_flag or question_flag is set (meaning
                             -n or -q was given and this file was specified
                             as a command-line target), don't change STATUS.
                             If STATUS is changed, we will get re-exec'd, and
                             enter an infinite loop.  */
                          if (!makefiles
                              || (!just_print_flag && !question_flag))
                            status = 0;
                          if (makefiles && file->dontcare)
                            /* This is a default makefile; stop remaking.  */
                            stop = 1;
                        }
                    }
                }

	      /* Keep track if any double-colon entry is not finished.
                 When they are all finished, the goal is finished.  */
	      any_not_updated |= !file->updated;

	      if (stop)
		break;
	    }

	  /* Reset FILE since it is null at the end of the loop.  */
	  file = g->file;

	  if (stop || !any_not_updated)
	    {
	      /* If we have found nothing whatever to do for the goal,
		 print a message saying nothing needs doing.  */

	      if (!makefiles
		  /* If the update_status is zero, we updated successfully
		     or not at all.  G->changed will have been set above if
		     any commands were actually started for this goal.  */
		  && file->update_status == 0 && !g->changed
		  /* Never give a message under -s or -q.  */
		  && !silent_flag && !question_flag)
		message (1, ((file->phony || file->cmds == 0)
			     ? _("Nothing to be done for `%s'.")
			     : _("`%s' is up to date.")),
			 file->name);

	      /* This goal is finished.  Remove it from the chain.  */
	      if (lastgoal == 0)
		goals = g->next;
	      else
		lastgoal->next = g->next;

	      /* Free the storage.  */
	      free ((char *) g);

	      g = lastgoal == 0 ? goals : lastgoal->next;

	      if (stop)
		break;
	    }
	  else
	    {
	      lastgoal = g;
	      g = g->next;
	    }
	}

      /* If we reached the end of the dependency graph toggle the considered
         flag for the next pass.  */
      if (g == 0)
        considered = !considered;
    }

  if (makefiles)
    {
      touch_flag = t;
      question_flag = q;
      just_print_flag = n;
      job_slots = j;
    }
  return status;
}

/* If FILE is not up to date, execute the commands for it.
   Return 0 if successful, 1 if unsuccessful;
   but with some flag settings, just call `exit' if unsuccessful.

   DEPTH is the depth in recursions of this function.
   We increment it during the consideration of our dependencies,
   then decrement it again after finding out whether this file
   is out of date.

   If there are multiple double-colon entries for FILE,
   each is considered in turn.  */

static int
update_file (file, depth)
     struct file *file;
     unsigned int depth;
{
  register int status = 0;
  register struct file *f;

  f = file->double_colon ? file->double_colon : file;

  /* Prune the dependency graph: if we've already been here on _this_
     pass through the dependency graph, we don't have to go any further.
     We won't reap_children until we start the next pass, so no state
     change is possible below here until then.  */
  if (f->considered == considered)
    {
      DBF (DB_VERBOSE, _("Pruning file `%s'.\n"));
      return f->command_state == cs_finished ? f->update_status : 0;
    }

  /* This loop runs until we start commands for a double colon rule, or until
     the chain is exhausted. */
  for (; f != 0; f = f->prev)
    {
      f->considered = considered;

      status |= update_file_1 (f, depth);
      check_renamed (f);

      if (status != 0 && !keep_going_flag)
	break;

      if (f->command_state == cs_running
          || f->command_state == cs_deps_running)
        {
	  /* Don't run the other :: rules for this
	     file until this rule is finished.  */
          status = 0;
          break;
        }
    }

  /* Process the remaining rules in the double colon chain so they're marked
     considered.  Start their prerequisites, too.  */
  for (; f != 0 ; f = f->prev)
    {
      struct dep *d;

      f->considered = considered;

      for (d = f->deps; d != 0; d = d->next)
        status |= update_file (d->file, depth + 1);
    }

  return status;
}

/* Consider a single `struct file' and update it as appropriate.  */

static int
update_file_1 (file, depth)
     struct file *file;
     unsigned int depth;
{
  register FILE_TIMESTAMP this_mtime;
  int noexist, must_make, deps_changed;
  int dep_status = 0;
  register struct dep *d, *lastd;
  int running = 0;

  DBF (DB_VERBOSE, _("Considering target file `%s'.\n"));

  if (file->updated)
    {
      if (file->update_status > 0)
	{
	  DBF (DB_VERBOSE,
               _("Recently tried and failed to update file `%s'.\n"));
	  return file->update_status;
	}

      DBF (DB_VERBOSE, _("File `%s' was considered already.\n"));
      return 0;
    }

  switch (file->command_state)
    {
    case cs_not_started:
    case cs_deps_running:
      break;
    case cs_running:
      DBF (DB_VERBOSE, _("Still updating file `%s'.\n"));
      return 0;
    case cs_finished:
      DBF (DB_VERBOSE, _("Finished updating file `%s'.\n"));
      return file->update_status;
    default:
      abort ();
    }

  ++depth;

  /* Notice recursive update of the same file.  */
  start_updating (file);

  /* Looking at the file's modtime beforehand allows the possibility
     that its name may be changed by a VPATH search, and thus it may
     not need an implicit rule.  If this were not done, the file
     might get implicit commands that apply to its initial name, only
     to have that name replaced with another found by VPATH search.  */

  this_mtime = file_mtime (file);
  check_renamed (file);
  noexist = this_mtime == NONEXISTENT_MTIME;
  if (noexist)
    DBF (DB_BASIC, _("File `%s' does not exist.\n"));
  else if (ORDINARY_MTIME_MIN <= this_mtime && this_mtime <= ORDINARY_MTIME_MAX
	   && file->low_resolution_time)
    {
      /* Avoid spurious rebuilds due to low resolution time stamps.  */
      int ns = FILE_TIMESTAMP_NS (this_mtime);
      if (ns != 0)
	error (NILF, _("*** Warning: .LOW_RESOLUTION_TIME file `%s' has a high resolution time stamp"),
	       file->name);
      this_mtime += FILE_TIMESTAMPS_PER_S - 1 - ns;
    }

  must_make = noexist;

  /* If file was specified as a target with no commands,
     come up with some default commands.  */

  if (!file->phony && file->cmds == 0 && !file->tried_implicit)
    {
      if (try_implicit_rule (file, depth))
	DBF (DB_IMPLICIT, _("Found an implicit rule for `%s'.\n"));
      else
	DBF (DB_IMPLICIT, _("No implicit rule found for `%s'.\n"));
      file->tried_implicit = 1;
    }
  if (file->cmds == 0 && !file->is_target
      && default_file != 0 && default_file->cmds != 0)
    {
      DBF (DB_IMPLICIT, _("Using default commands for `%s'.\n"));
      file->cmds = default_file->cmds;
    }

  /* Update all non-intermediate files we depend on, if necessary,
     and see whether any of them is more recent than this file.  */

  lastd = 0;
  d = file->deps;
  while (d != 0)
    {
      FILE_TIMESTAMP mtime;
      int maybe_make;

      check_renamed (d->file);

      mtime = file_mtime (d->file);
      check_renamed (d->file);

      if (is_updating (d->file))
	{
	  error (NILF, _("Circular %s <- %s dependency dropped."),
		 file->name, d->file->name);
	  /* We cannot free D here because our the caller will still have
	     a reference to it when we were called recursively via
	     check_dep below.  */
	  if (lastd == 0)
	    file->deps = d->next;
	  else
	    lastd->next = d->next;
	  d = d->next;
	  continue;
	}

      d->file->parent = file;
      maybe_make = must_make;
      dep_status |= check_dep (d->file, depth, this_mtime, &maybe_make);
      if (! d->ignore_mtime)
        must_make = maybe_make;

      check_renamed (d->file);

      {
	register struct file *f = d->file;
	if (f->double_colon)
	  f = f->double_colon;
	do
	  {
	    running |= (f->command_state == cs_running
			|| f->command_state == cs_deps_running);
	    f = f->prev;
	  }
	while (f != 0);
      }

      if (dep_status != 0 && !keep_going_flag)
	break;

      if (!running)
	d->changed = file_mtime (d->file) != mtime;

      lastd = d;
      d = d->next;
    }

  /* Now we know whether this target needs updating.
     If it does, update all the intermediate files we depend on.  */

  if (must_make || always_make_flag)
    {
      for (d = file->deps; d != 0; d = d->next)
	if (d->file->intermediate)
	  {
	    FILE_TIMESTAMP mtime = file_mtime (d->file);
	    check_renamed (d->file);
	    d->file->parent = file;
	    dep_status |= update_file (d->file, depth);
	    check_renamed (d->file);

	    {
	      register struct file *f = d->file;
	      if (f->double_colon)
		f = f->double_colon;
	      do
		{
		  running |= (f->command_state == cs_running
			      || f->command_state == cs_deps_running);
		  f = f->prev;
		}
	      while (f != 0);
	    }

	    if (dep_status != 0 && !keep_going_flag)
	      break;

	    if (!running)
	      d->changed = ((file->phony && file->cmds != 0)
			    || file_mtime (d->file) != mtime);
	  }
    }

  finish_updating (file);

  DBF (DB_VERBOSE, _("Finished prerequisites of target file `%s'.\n"));

  if (running)
    {
      set_command_state (file, cs_deps_running);
      --depth;
      DBF (DB_VERBOSE, _("The prerequisites of `%s' are being made.\n"));
      return 0;
    }

  /* If any dependency failed, give up now.  */

  if (dep_status != 0)
    {
      file->update_status = dep_status;
      notice_finished_file (file);

      --depth;

      DBF (DB_VERBOSE, _("Giving up on target file `%s'.\n"));

      if (depth == 0 && keep_going_flag
	  && !just_print_flag && !question_flag)
	error (NILF,
               _("Target `%s' not remade because of errors."), file->name);

      return dep_status;
    }

  if (file->command_state == cs_deps_running)
    /* The commands for some deps were running on the last iteration, but
       they have finished now.  Reset the command_state to not_started to
       simplify later bookkeeping.  It is important that we do this only
       when the prior state was cs_deps_running, because that prior state
       was definitely propagated to FILE's also_make's by set_command_state
       (called above), but in another state an also_make may have
       independently changed to finished state, and we would confuse that
       file's bookkeeping (updated, but not_started is bogus state).  */
    set_command_state (file, cs_not_started);

  /* Now record which prerequisites are more
     recent than this file, so we can define $?.  */

  deps_changed = 0;
  for (d = file->deps; d != 0; d = d->next)
    {
      FILE_TIMESTAMP d_mtime = file_mtime (d->file);
      check_renamed (d->file);

      if (! d->ignore_mtime)
        {
#if 1
          /* %%% In version 4, remove this code completely to
	   implement not remaking deps if their deps are newer
	   than their parents.  */
          if (d_mtime == NONEXISTENT_MTIME && !d->file->intermediate)
            /* We must remake if this dep does not
               exist and is not intermediate.  */
            must_make = 1;
#endif

          /* Set DEPS_CHANGED if this dep actually changed.  */
          deps_changed |= d->changed;
        }

      /* Set D->changed if either this dep actually changed,
	 or its dependent, FILE, is older or does not exist.  */
      d->changed |= noexist || d_mtime > this_mtime;

      if (!noexist && ISDB (DB_BASIC|DB_VERBOSE))
	{
          const char *fmt = 0;

          if (d->ignore_mtime)
            {
              if (ISDB (DB_VERBOSE))
                fmt = _("Prerequisite `%s' is order-only for target `%s'.\n");
            }
          else if (d_mtime == NONEXISTENT_MTIME)
            {
              if (ISDB (DB_BASIC))
                fmt = _("Prerequisite `%s' of target `%s' does not exist.\n");
            }
	  else if (d->changed)
            {
              if (ISDB (DB_BASIC))
                fmt = _("Prerequisite `%s' is newer than target `%s'.\n");
            }
          else if (ISDB (DB_VERBOSE))
            fmt = _("Prerequisite `%s' is older than target `%s'.\n");

          if (fmt)
            {
              print_spaces (depth);
              printf (fmt, dep_name (d), file->name);
              fflush (stdout);
            }
	}
    }

  /* Here depth returns to the value it had when we were called.  */
  depth--;

  if (file->double_colon && file->deps == 0)
    {
      must_make = 1;
      DBF (DB_BASIC,
           _("Target `%s' is double-colon and has no prerequisites.\n"));
    }
  else if (!noexist && file->is_target && !deps_changed && file->cmds == 0
           && !always_make_flag)
    {
      must_make = 0;
      DBF (DB_VERBOSE,
           _("No commands for `%s' and no prerequisites actually changed.\n"));
    }
  else if (!must_make && file->cmds != 0 && always_make_flag)
    {
      must_make = 1;
      DBF (DB_VERBOSE, _("Making `%s' due to always-make flag.\n"));
    }

  if (!must_make)
    {
      if (ISDB (DB_VERBOSE))
        {
          print_spaces (depth);
          printf (_("No need to remake target `%s'"), file->name);
          if (!streq (file->name, file->hname))
              printf (_("; using VPATH name `%s'"), file->hname);
          puts (".");
          fflush (stdout);
        }

      notice_finished_file (file);

      /* Since we don't need to remake the file, convert it to use the
         VPATH filename if we found one.  hfile will be either the
         local name if no VPATH or the VPATH name if one was found.  */

      while (file)
        {
          file->name = file->hname;
          file = file->prev;
        }

      return 0;
    }

  DBF (DB_BASIC, _("Must remake target `%s'.\n"));

  /* It needs to be remade.  If it's VPATH and not reset via GPATH, toss the
     VPATH.  */
  if (!streq(file->name, file->hname))
    {
      DB (DB_BASIC, (_("  Ignoring VPATH name `%s'.\n"), file->hname));
      file->ignore_vpath = 1;
    }

  /* Now, take appropriate actions to remake the file.  */
  remake_file (file);

  if (file->command_state != cs_finished)
    {
      DBF (DB_VERBOSE, _("Commands of `%s' are being run.\n"));
      return 0;
    }

  switch (file->update_status)
    {
    case 2:
      DBF (DB_BASIC, _("Failed to remake target file `%s'.\n"));
      break;
    case 0:
      DBF (DB_BASIC, _("Successfully remade target file `%s'.\n"));
      break;
    case 1:
      DBF (DB_BASIC, _("Target file `%s' needs remade under -q.\n"));
      break;
    default:
      assert (file->update_status >= 0 && file->update_status <= 2);
      break;
    }

  file->updated = 1;
  return file->update_status;
}

/* Set FILE's `updated' flag and re-check its mtime and the mtime's of all
   files listed in its `also_make' member.  Under -t, this function also
   touches FILE.

   On return, FILE->update_status will no longer be -1 if it was.  */

void
notice_finished_file (file)
     register struct file *file;
{
  struct dep *d;
  int ran = file->command_state == cs_running;
  int touched = 0;

  file->command_state = cs_finished;
  file->updated = 1;

  if (touch_flag
      /* The update status will be:
	 	-1	if this target was not remade;
		0	if 0 or more commands (+ or ${MAKE}) were run and won;
		1	if some commands were run and lost.
	 We touch the target if it has commands which either were not run
	 or won when they ran (i.e. status is 0).  */
      && file->update_status == 0)
    {
      if (file->cmds != 0 && file->cmds->any_recurse)
	{
	  /* If all the command lines were recursive,
	     we don't want to do the touching.  */
	  unsigned int i;
	  for (i = 0; i < file->cmds->ncommand_lines; ++i)
	    if (!(file->cmds->lines_flags[i] & COMMANDS_RECURSE))
	      goto have_nonrecursing;
	}
      else
	{
	have_nonrecursing:
	  if (file->phony)
	    file->update_status = 0;
	  else
            {
              /* Should set file's modification date and do nothing else.  */
              file->update_status = touch_file (file);

              /* Pretend we ran a real touch command, to suppress the
                 "`foo' is up to date" message.  */
              commands_started++;

              /* Request for the timestamp to be updated (and distributed
                 to the double-colon entries). Simply setting ran=1 would
                 almost have done the trick, but messes up with the also_make
                 updating logic below.  */
              touched = 1;
            }
	}
    }

  if (file->mtime_before_update == UNKNOWN_MTIME)
    file->mtime_before_update = file->last_mtime;

  if ((ran && !file->phony) || touched)
    {
      struct file *f;
      int i = 0;

      /* If -n, -t, or -q and all the commands are recursive, we ran them so
         really check the target's mtime again.  Otherwise, assume the target
         would have been updated. */

      if (question_flag || just_print_flag || touch_flag)
        {
          for (i = file->cmds->ncommand_lines; i > 0; --i)
            if (! (file->cmds->lines_flags[i-1] & COMMANDS_RECURSE))
              break;
        }

      /* If there were no commands at all, it's always new. */

      else if (file->is_target && file->cmds == 0)
	i = 1;

      file->last_mtime = i == 0 ? UNKNOWN_MTIME : NEW_MTIME;

      /* Propagate the change of modification time to all the double-colon
	 entries for this file.  */
      for (f = file->double_colon; f != 0; f = f->prev)
	f->last_mtime = file->last_mtime;
    }

  if (ran && file->update_status != -1)
    /* We actually tried to update FILE, which has
       updated its also_make's as well (if it worked).
       If it didn't work, it wouldn't work again for them.
       So mark them as updated with the same status.  */
    for (d = file->also_make; d != 0; d = d->next)
      {
	d->file->command_state = cs_finished;
	d->file->updated = 1;
	d->file->update_status = file->update_status;

	if (ran && !d->file->phony)
	  /* Fetch the new modification time.
	     We do this instead of just invalidating the cached time
	     so that a vpath_search can happen.  Otherwise, it would
	     never be done because the target is already updated.  */
	  (void) f_mtime (d->file, 0);
      }
  else if (file->update_status == -1)
    /* Nothing was done for FILE, but it needed nothing done.
       So mark it now as "succeeded".  */
    file->update_status = 0;
}

/* Check whether another file (whose mtime is THIS_MTIME)
   needs updating on account of a dependency which is file FILE.
   If it does, store 1 in *MUST_MAKE_PTR.
   In the process, update any non-intermediate files
   that FILE depends on (including FILE itself).
   Return nonzero if any updating failed.  */

static int
check_dep (file, depth, this_mtime, must_make_ptr)
     struct file *file;
     unsigned int depth;
     FILE_TIMESTAMP this_mtime;
     int *must_make_ptr;
{
  struct dep *d;
  int dep_status = 0;

  ++depth;
  start_updating (file);

  if (!file->intermediate)
    /* If this is a non-intermediate file, update it and record
       whether it is newer than THIS_MTIME.  */
    {
      FILE_TIMESTAMP mtime;
      dep_status = update_file (file, depth);
      check_renamed (file);
      mtime = file_mtime (file);
      check_renamed (file);
      if (mtime == NONEXISTENT_MTIME || mtime > this_mtime)
	*must_make_ptr = 1;
    }
  else
    {
      /* FILE is an intermediate file.  */
      FILE_TIMESTAMP mtime;

      if (!file->phony && file->cmds == 0 && !file->tried_implicit)
	{
	  if (try_implicit_rule (file, depth))
	    DBF (DB_IMPLICIT, _("Found an implicit rule for `%s'.\n"));
	  else
	    DBF (DB_IMPLICIT, _("No implicit rule found for `%s'.\n"));
	  file->tried_implicit = 1;
	}
      if (file->cmds == 0 && !file->is_target
	  && default_file != 0 && default_file->cmds != 0)
	{
	  DBF (DB_IMPLICIT, _("Using default commands for `%s'.\n"));
	  file->cmds = default_file->cmds;
	}

      /* If the intermediate file actually exists
	 and is newer, then we should remake from it.  */
      check_renamed (file);
      mtime = file_mtime (file);
      check_renamed (file);
      if (mtime != NONEXISTENT_MTIME && mtime > this_mtime)
	*must_make_ptr = 1;
	  /* Otherwise, update all non-intermediate files we depend on,
	     if necessary, and see whether any of them is more
	     recent than the file on whose behalf we are checking.  */
      else
	{
	  struct dep *lastd;

	  lastd = 0;
	  d = file->deps;
	  while (d != 0)
	    {
              int maybe_make;

	      if (is_updating (d->file))
		{
		  error (NILF, _("Circular %s <- %s dependency dropped."),
			 file->name, d->file->name);
		  if (lastd == 0)
		    {
		      file->deps = d->next;
		      free ((char *) d);
		      d = file->deps;
		    }
		  else
		    {
		      lastd->next = d->next;
		      free ((char *) d);
		      d = lastd->next;
		    }
		  continue;
		}

	      d->file->parent = file;
              maybe_make = *must_make_ptr;
	      dep_status |= check_dep (d->file, depth, this_mtime,
                                       &maybe_make);
              if (! d->ignore_mtime)
                *must_make_ptr = maybe_make;
	      check_renamed (d->file);
	      if (dep_status != 0 && !keep_going_flag)
		break;

	      if (d->file->command_state == cs_running
		  || d->file->command_state == cs_deps_running)
		/* Record that some of FILE's deps are still being made.
		   This tells the upper levels to wait on processing it until
		   the commands are finished.  */
		set_command_state (file, cs_deps_running);

	      lastd = d;
	      d = d->next;
	    }
	}
    }

  finish_updating (file);
  return dep_status;
}

/* Touch FILE.  Return zero if successful, one if not.  */

#define TOUCH_ERROR(call) return (perror_with_name (call, file->name), 1)

static int
touch_file (file)
     register struct file *file;
{
  if (!silent_flag)
    message (0, "touch %s", file->name);

#ifndef	NO_ARCHIVES
  if (ar_name (file->name))
    return ar_touch (file->name);
  else
#endif
    {
      int fd = open (file->name, O_RDWR | O_CREAT, 0666);

      if (fd < 0)
	TOUCH_ERROR ("touch: open: ");
      else
	{
	  struct stat statbuf;
	  char buf;

	  if (fstat (fd, &statbuf) < 0)
	    TOUCH_ERROR ("touch: fstat: ");
	  /* Rewrite character 0 same as it already is.  */
	  if (read (fd, &buf, 1) < 0)
	    TOUCH_ERROR ("touch: read: ");
	  if (lseek (fd, 0L, 0) < 0L)
	    TOUCH_ERROR ("touch: lseek: ");
	  if (write (fd, &buf, 1) < 0)
	    TOUCH_ERROR ("touch: write: ");
	  /* If file length was 0, we just
	     changed it, so change it back.  */
	  if (statbuf.st_size == 0)
	    {
	      (void) close (fd);
	      fd = open (file->name, O_RDWR | O_TRUNC, 0666);
	      if (fd < 0)
		TOUCH_ERROR ("touch: open: ");
	    }
	  (void) close (fd);
	}
    }

  return 0;
}

/* Having checked and updated the dependencies of FILE,
   do whatever is appropriate to remake FILE itself.
   Return the status from executing FILE's commands.  */

static void
remake_file (file)
     struct file *file;
{
  if (file->cmds == 0)
    {
      if (file->phony)
	/* Phony target.  Pretend it succeeded.  */
	file->update_status = 0;
      else if (file->is_target)
	/* This is a nonexistent target file we cannot make.
	   Pretend it was successfully remade.  */
	file->update_status = 0;
      else
        {
          const char *msg_noparent
            = _("%sNo rule to make target `%s'%s");
          const char *msg_parent
            = _("%sNo rule to make target `%s', needed by `%s'%s");

          /* This is a dependency file we cannot remake.  Fail.  */
          if (!keep_going_flag && !file->dontcare)
            {
              if (file->parent == 0)
                fatal (NILF, msg_noparent, "", file->name, "");

              fatal (NILF, msg_parent, "", file->name, file->parent->name, "");
            }

          if (!file->dontcare)
            {
              if (file->parent == 0)
                error (NILF, msg_noparent, "*** ", file->name, ".");
              else
                error (NILF, msg_parent, "*** ",
                       file->name, file->parent->name, ".");
            }
          file->update_status = 2;
        }
    }
  else
    {
      chop_commands (file->cmds);

      /* The normal case: start some commands.  */
      if (!touch_flag || file->cmds->any_recurse)
	{
	  execute_file_commands (file);
	  return;
	}

      /* This tells notice_finished_file it is ok to touch the file.  */
      file->update_status = 0;
    }

  /* This does the touching under -t.  */
  notice_finished_file (file);
}

/* Return the mtime of a file, given a `struct file'.
   Caches the time in the struct file to avoid excess stat calls.

   If the file is not found, and SEARCH is nonzero, VPATH searching and
   replacement is done.  If that fails, a library (-lLIBNAME) is tried and
   the library's actual name (/lib/libLIBNAME.a, etc.) is substituted into
   FILE.  */

FILE_TIMESTAMP
f_mtime (file, search)
     register struct file *file;
     int search;
{
  FILE_TIMESTAMP mtime;

  /* File's mtime is not known; must get it from the system.  */

#ifndef	NO_ARCHIVES
  if (ar_name (file->name))
    {
      /* This file is an archive-member reference.  */

      char *arname, *memname;
      struct file *arfile;
      int arname_used = 0;
      time_t member_date;

      /* Find the archive's name.  */
      ar_parse_name (file->name, &arname, &memname);

      /* Find the modification time of the archive itself.
	 Also allow for its name to be changed via VPATH search.  */
      arfile = lookup_file (arname);
      if (arfile == 0)
	{
	  arfile = enter_file (arname);
	  arname_used = 1;
	}
      mtime = f_mtime (arfile, search);
      check_renamed (arfile);
      if (search && strcmp (arfile->hname, arname))
	{
	  /* The archive's name has changed.
	     Change the archive-member reference accordingly.  */

          char *name;
	  unsigned int arlen, memlen;

	  if (!arname_used)
	    {
	      free (arname);
	      arname_used = 1;
	    }

	  arname = arfile->hname;
	  arlen = strlen (arname);
	  memlen = strlen (memname);

	  /* free (file->name); */

	  name = (char *) xmalloc (arlen + 1 + memlen + 2);
	  bcopy (arname, name, arlen);
	  name[arlen] = '(';
	  bcopy (memname, name + arlen + 1, memlen);
	  name[arlen + 1 + memlen] = ')';
	  name[arlen + 1 + memlen + 1] = '\0';

          /* If the archive was found with GPATH, make the change permanent;
             otherwise defer it until later.  */
          if (arfile->name == arfile->hname)
            rename_file (file, name);
          else
            rehash_file (file, name);
          check_renamed (file);
	}

      if (!arname_used)
	free (arname);
      free (memname);

      file->low_resolution_time = 1;

      if (mtime == NONEXISTENT_MTIME)
	/* The archive doesn't exist, so its members don't exist either.  */
	return NONEXISTENT_MTIME;

      member_date = ar_member_date (file->hname);
      mtime = (member_date == (time_t) -1
               ? NONEXISTENT_MTIME
               : file_timestamp_cons (file->hname, member_date, 0));
    }
  else
#endif
    {
      mtime = name_mtime (file->name);

      if (mtime == NONEXISTENT_MTIME && search && !file->ignore_vpath)
	{
	  /* If name_mtime failed, search VPATH.  */
	  char *name = file->name;
	  if (vpath_search (&name, &mtime)
	      /* Last resort, is it a library (-lxxx)?  */
	      || (name[0] == '-' && name[1] == 'l'
		  && library_search (&name, &mtime)))
	    {
	      if (mtime != UNKNOWN_MTIME)
		/* vpath_search and library_search store UNKNOWN_MTIME
		   if they didn't need to do a stat call for their work.  */
		file->last_mtime = mtime;

              /* If we found it in VPATH, see if it's in GPATH too; if so,
                 change the name right now; if not, defer until after the
                 dependencies are updated. */
              if (gpath_search (name, strlen(name) - strlen(file->name) - 1))
                {
                  rename_file (file, name);
                  check_renamed (file);
                  return file_mtime (file);
                }

	      rehash_file (file, name);
	      check_renamed (file);
	      mtime = name_mtime (name);
	    }
	}
    }

  {
    /* Files can have bogus timestamps that nothing newly made will be
       "newer" than.  Updating their dependents could just result in loops.
       So notify the user of the anomaly with a warning.

       We only need to do this once, for now. */

    if (!clock_skew_detected
	&& mtime != NONEXISTENT_MTIME
	&& !file->updated)
      {
	static FILE_TIMESTAMP adjusted_now;

	FILE_TIMESTAMP adjusted_mtime = mtime;

#if defined(WINDOWS32) || defined(__MSDOS__)
	/* Experimentation has shown that FAT filesystems can set file times
	   up to 3 seconds into the future!  Play it safe.  */

#define FAT_ADJ_OFFSET  (FILE_TIMESTAMP) 3

	FILE_TIMESTAMP adjustment = FAT_ADJ_OFFSET << FILE_TIMESTAMP_LO_BITS;
	if (ORDINARY_MTIME_MIN + adjustment <= adjusted_mtime)
	  adjusted_mtime -= adjustment;
#endif

	/* If the file's time appears to be in the future, update our
	   concept of the present and try once more.  */
	if (adjusted_now < adjusted_mtime)
	  {
	    int resolution;
	    FILE_TIMESTAMP now = file_timestamp_now (&resolution);
	    adjusted_now = now + (resolution - 1);
	    if (adjusted_now < adjusted_mtime)
	      {
#ifdef NO_FLOAT
		error (NILF, _("Warning: File `%s' has modification time in the future"),
                       file->name);
#else
		double from_now =
		  (FILE_TIMESTAMP_S (mtime) - FILE_TIMESTAMP_S (now)
		   + ((FILE_TIMESTAMP_NS (mtime) - FILE_TIMESTAMP_NS (now))
		      / 1e9));
		error (NILF, _("Warning: File `%s' has modification time %.2g s in the future"),
		       file->name, from_now);
#endif
		clock_skew_detected = 1;
	      }
          }
      }
  }

  /* Store the mtime into all the entries for this file.  */
  if (file->double_colon)
    file = file->double_colon;

  do
    {
      /* If this file is not implicit but it is intermediate then it was
	 made so by the .INTERMEDIATE target.  If this file has never
	 been built by us but was found now, it existed before make
	 started.  So, turn off the intermediate bit so make doesn't
	 delete it, since it didn't create it.  */
      if (mtime != NONEXISTENT_MTIME && file->command_state == cs_not_started
	  && file->command_state == cs_not_started
	  && !file->tried_implicit && file->intermediate)
	file->intermediate = 0;

      file->last_mtime = mtime;
      file = file->prev;
    }
  while (file != 0);

  return mtime;
}


/* Return the mtime of the file or archive-member reference NAME.  */

static FILE_TIMESTAMP
name_mtime (name)
     register char *name;
{
  struct stat st;

  if (stat (name, &st) != 0)
    {
      if (errno != ENOENT && errno != ENOTDIR)
        perror_with_name ("stat:", name);
      return NONEXISTENT_MTIME;
    }

  return FILE_TIMESTAMP_STAT_MODTIME (name, st);
}


/* Search for a library file specified as -lLIBNAME, searching for a
   suitable library file in the system library directories and the VPATH
   directories.  */

static int
library_search (lib, mtime_ptr)
     char **lib;
     FILE_TIMESTAMP *mtime_ptr;
{
  static char *dirs[] =
    {
#ifndef _AMIGA
      "/lib",
      "/usr/lib",
#endif
#if defined(WINDOWS32) && !defined(LIBDIR)
/*
 * This is completely up to the user at product install time. Just define
 * a placeholder.
 */
#define LIBDIR "."
#endif
      LIBDIR,			/* Defined by configuration.  */
      0
    };

  static char *libpatterns = NULL;

  char *libname = &(*lib)[2];	/* Name without the `-l'.  */
  FILE_TIMESTAMP mtime;

  /* Loop variables for the libpatterns value.  */
  char *p, *p2;
  unsigned int len;

  char *file, **dp;

  /* If we don't have libpatterns, get it.  */
  if (!libpatterns)
    {
      int save = warn_undefined_variables_flag;
      warn_undefined_variables_flag = 0;

      libpatterns = xstrdup (variable_expand ("$(strip $(.LIBPATTERNS))"));

      warn_undefined_variables_flag = save;
    }

  /* Loop through all the patterns in .LIBPATTERNS, and search on each one.  */
  p2 = libpatterns;
  while ((p = find_next_token (&p2, &len)) != 0)
    {
      static char *buf = NULL;
      static int buflen = 0;
      static int libdir_maxlen = -1;
      char *libbuf = variable_expand ("");

      /* Expand the pattern using LIBNAME as a replacement.  */
      {
	char c = p[len];
	char *p3, *p4;

	p[len] = '\0';
	p3 = find_percent (p);
	if (!p3)
	  {
	    /* Give a warning if there is no pattern, then remove the
	       pattern so it's ignored next time.  */
	    error (NILF, _(".LIBPATTERNS element `%s' is not a pattern"), p);
	    for (; len; --len, ++p)
	      *p = ' ';
	    *p = c;
	    continue;
	  }
	p4 = variable_buffer_output (libbuf, p, p3-p);
	p4 = variable_buffer_output (p4, libname, strlen (libname));
	p4 = variable_buffer_output (p4, p3+1, len - (p3-p));
	p[len] = c;
      }

      /* Look first for `libNAME.a' in the current directory.  */
      mtime = name_mtime (libbuf);
      if (mtime != NONEXISTENT_MTIME)
	{
	  *lib = xstrdup (libbuf);
	  if (mtime_ptr != 0)
	    *mtime_ptr = mtime;
	  return 1;
	}

      /* Now try VPATH search on that.  */

      file = libbuf;
      if (vpath_search (&file, mtime_ptr))
	{
	  *lib = file;
	  return 1;
	}

      /* Now try the standard set of directories.  */

      if (!buflen)
	{
	  for (dp = dirs; *dp != 0; ++dp)
	    {
	      int l = strlen (*dp);
	      if (l > libdir_maxlen)
		libdir_maxlen = l;
	    }
	  buflen = strlen (libbuf);
	  buf = xmalloc(libdir_maxlen + buflen + 2);
	}
      else if (buflen < strlen (libbuf))
	{
	  buflen = strlen (libbuf);
	  buf = xrealloc (buf, libdir_maxlen + buflen + 2);
	}

      for (dp = dirs; *dp != 0; ++dp)
	{
	  sprintf (buf, "%s/%s", *dp, libbuf);
	  mtime = name_mtime (buf);
	  if (mtime != NONEXISTENT_MTIME)
	    {
	      *lib = xstrdup (buf);
	      if (mtime_ptr != 0)
		*mtime_ptr = mtime;
	      return 1;
	    }
	}
    }

  return 0;
}