aboutsummaryrefslogtreecommitdiff
path: root/gcc/cpphash.c
blob: 1d8a104460e406856ad571d4515fd9058b8497f0 (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
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
/* Part of CPP library.  (Macro handling.)
   Copyright (C) 1986, 87, 89, 92-95, 1996, 1998 Free Software Foundation, Inc.
   Written by Per Bothner, 1994.
   Based on CCCP program by Paul Rubin, June 1986
   Adapted to ANSI C, Richard Stallman, Jan 1987

This program 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.

This program 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 this program; if not, write to the Free Software
Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.

 In other words, you are welcome to use, share and improve this program.
 You are forbidden to forbid anyone else to use, share and improve
 what you give them.   Help stamp out software-hoarding!  */

#include "config.h"
#include "system.h"
#include "cpplib.h"
#include "cpphash.h"
#undef abort

static int comp_def_part	 PARAMS ((int, U_CHAR *, int, U_CHAR *,
					  int, int));
static int change_newlines	 PARAMS ((U_CHAR *, int));
static void push_macro_expansion PARAMS ((cpp_reader *,
					  U_CHAR *, int, HASHNODE *));
static int unsafe_chars		 PARAMS ((int, int));

#define SKIP_WHITE_SPACE(p) do { while (is_hor_space[*p]) p++; } while (0)
#define CPP_IS_MACRO_BUFFER(PBUF) ((PBUF)->data != NULL)
#define FORWARD(N) CPP_FORWARD (CPP_BUFFER (pfile), (N))

extern char *version_string;

/* The arglist structure is built by create_definition to tell
   collect_expansion where the argument names begin.  That
   is, for a define like "#define f(x,y,z) foo+x-bar*y", the arglist
   would contain pointers to the strings x, y, and z.
   collect_expansion would then build a DEFINITION node,
   with reflist nodes pointing to the places x, y, and z had
   appeared.  So the arglist is just convenience data passed
   between these two routines.  It is not kept around after
   the current #define has been processed and entered into the
   hash table.  */

struct arglist
{
  struct arglist *next;
  U_CHAR *name;
  int length;
  int argno;
  char rest_args;
};

/* This structure represents one parsed argument in a macro call.
   `raw' points to the argument text as written (`raw_length' is its length).
   `expanded' points to the argument's macro-expansion
   (its length is `expand_length').
   `stringified_length' is the length the argument would have
   if stringified.
   `use_count' is the number of times this macro arg is substituted
   into the macro.  If the actual use count exceeds 10, 
   the value stored is 10.  */

/* raw and expanded are relative to ARG_BASE */
#define ARG_BASE ((pfile)->token_buffer)

struct argdata
{
  /* Strings relative to pfile->token_buffer */
  long raw, expanded, stringified;
  int raw_length, expand_length;
  int stringified_length;
  char newlines;
  char use_count;
};


/* Return hash function on name.  must be compatible with the one
   computed a step at a time, elsewhere  */

int
hashf (name, len, hashsize)
     register const U_CHAR *name;
     register int len;
     int hashsize;
{
  register int r = 0;

  while (len--)
    r = HASHSTEP (r, *name++);

  return MAKE_POS (r) % hashsize;
}

/* Find the most recent hash node for name "name" (ending with first
   non-identifier char) installed by cpp_install

   If LEN is >= 0, it is the length of the name.
   Otherwise, compute the length by scanning the entire name.

   If HASH is >= 0, it is the precomputed hash code.
   Otherwise, compute the hash code.  */

HASHNODE *
cpp_lookup (pfile, name, len, hash)
     cpp_reader *pfile ATTRIBUTE_UNUSED;
     const U_CHAR *name;
     int len;
     int hash;
{
  register const U_CHAR *bp;
  register HASHNODE *bucket;

  if (len < 0)
    {
      for (bp = name; is_idchar[*bp]; bp++);
      len = bp - name;
    }

  if (hash < 0)
    hash = hashf (name, len, HASHSIZE);

  bucket = pfile->hashtab[hash];
  while (bucket)
    {
      if (bucket->length == len && strncmp (bucket->name, name, len) == 0)
	return bucket;
      bucket = bucket->next;
    }
  return (HASHNODE *) 0;
}

/*
 * Delete a hash node.  Some weirdness to free junk from macros.
 * More such weirdness will have to be added if you define more hash
 * types that need it.
 */

/* Note that the DEFINITION of a macro is removed from the hash table
   but its storage is not freed.  This would be a storage leak
   except that it is not reasonable to keep undefining and redefining
   large numbers of macros many times.
   In any case, this is necessary, because a macro can be #undef'd
   in the middle of reading the arguments to a call to it.
   If #undef freed the DEFINITION, that would crash.  */

void
delete_macro (hp)
     HASHNODE *hp;
{

  if (hp->prev != NULL)
    hp->prev->next = hp->next;
  if (hp->next != NULL)
    hp->next->prev = hp->prev;

  /* make sure that the bucket chain header that
     the deleted guy was on points to the right thing afterwards.  */
  if (hp == *hp->bucket_hdr)
    *hp->bucket_hdr = hp->next;

  if (hp->type == T_MACRO)
    {
      DEFINITION *d = hp->value.defn;
      struct reflist *ap, *nextap;

      for (ap = d->pattern; ap != NULL; ap = nextap)
	{
	  nextap = ap->next;
	  free (ap);
	}
      if (d->nargs >= 0)
	free (d->args.argnames);
      free (d);
    }

  free (hp);
}

/* Install a name in the main hash table, even if it is already there.
   Name stops with first non alphanumeric, except leading '#'.
   Caller must check against redefinition if that is desired.
   delete_macro () removes things installed by cpp_install () in fifo order.
   this is important because of the `defined' special symbol used
   in #if, and also if pushdef/popdef directives are ever implemented.

   If LEN is >= 0, it is the length of the name.
   Otherwise, compute the length by scanning the entire name.

   If HASH is >= 0, it is the precomputed hash code.
   Otherwise, compute the hash code.  */

HASHNODE *
cpp_install (pfile, name, len, type, value, hash)
     cpp_reader *pfile;
     U_CHAR *name;
     int len;
     enum node_type type;
     const char *value;
     int hash;
{
  register HASHNODE *hp;
  register int i, bucket;
  register U_CHAR *p;

  if (len < 0)
    {
      p = name;
      while (is_idchar[*p])
	p++;
      len = p - name;
    }

  if (hash < 0)
    hash = hashf (name, len, HASHSIZE);

  i = sizeof (HASHNODE) + len + 1;
  hp = (HASHNODE *) xmalloc (i);
  bucket = hash;
  hp->bucket_hdr = &pfile->hashtab[bucket];
  hp->next = pfile->hashtab[bucket];
  pfile->hashtab[bucket] = hp;
  hp->prev = NULL;
  if (hp->next != NULL)
    hp->next->prev = hp;
  hp->type = type;
  hp->length = len;
  hp->value.cpval = value;
  hp->name = ((U_CHAR *) hp) + sizeof (HASHNODE);
  bcopy (name, hp->name, len);
  hp->name[len] = 0;
  return hp;
}

static int
macro_cleanup (pbuf, pfile)
     cpp_buffer *pbuf;
     cpp_reader *pfile ATTRIBUTE_UNUSED;
{
  HASHNODE *macro = (HASHNODE *) pbuf->data;
  if (macro->type == T_DISABLED)
    macro->type = T_MACRO;
  if (macro->type != T_MACRO || pbuf->buf != macro->value.defn->expansion)
    free (pbuf->buf);
  return 0;
}


/* Read a replacement list for a macro with parameters.
   Build the DEFINITION structure.
   Reads characters of text starting at BUF until END.
   ARGLIST specifies the formal parameters to look for
   in the text of the definition; NARGS is the number of args
   in that list, or -1 for a macro name that wants no argument list.
   MACRONAME is the macro name itself (so we can avoid recursive expansion)
   and NAMELEN is its length in characters.
   
   Note that comments, backslash-newlines, and leading white space
   have already been deleted from the argument.  */

static DEFINITION *
collect_expansion (pfile, buf, limit, nargs, arglist)
     cpp_reader *pfile;
     U_CHAR *buf, *limit;
     int nargs;
     struct arglist *arglist;
{
  DEFINITION *defn;
  register U_CHAR *p, *lastp, *exp_p;
  struct reflist *endpat = NULL;
  /* Pointer to first nonspace after last ## seen.  */
  U_CHAR *concat = 0;
  /* Pointer to first nonspace after last single-# seen.  */
  U_CHAR *stringify = 0;
  int maxsize;
  int expected_delimiter = '\0';

  /* Scan thru the replacement list, ignoring comments and quoted
     strings, picking up on the macro calls.  It does a linear search
     thru the arg list on every potential symbol.  Profiling might say
     that something smarter should happen.  */

  if (limit < buf)
    {
      cpp_fatal (pfile, "internal error: limit < buf in collect_expansion");
      limit = buf; /* treat it like a null defn */
    }

  /* Find the beginning of the trailing whitespace.  */
  p = buf;
  while (p < limit && is_space[limit[-1]])
    limit--;

  /* Allocate space for the text in the macro definition.
     Leading and trailing whitespace chars need 2 bytes each.
     Each other input char may or may not need 1 byte,
     so this is an upper bound.  The extra 5 are for invented
     leading and trailing newline-marker and final null.  */
  maxsize = (sizeof (DEFINITION)
	     + (limit - p) + 5);
  defn = (DEFINITION *) xcalloc (1, maxsize);

  defn->nargs = nargs;
  exp_p = defn->expansion = (U_CHAR *) defn + sizeof (DEFINITION);
  lastp = exp_p;

  p = buf;

  /* Add one initial space escape-marker to prevent accidental
     token-pasting (often removed by macroexpand).  */
  *exp_p++ = '\r';
  *exp_p++ = ' ';

  if (limit - p >= 2 && p[0] == '#' && p[1] == '#')
    {
      cpp_error (pfile, "`##' at start of macro definition");
      p += 2;
    }

  /* Process the main body of the definition.  */
  while (p < limit)
    {
      int skipped_arg = 0;
      register U_CHAR c = *p++;

      *exp_p++ = c;

      if (!CPP_TRADITIONAL (pfile))
	{
	  switch (c)
	    {
	    case '\'':
	    case '\"':
	      if (expected_delimiter != '\0')
		{
		  if (c == expected_delimiter)
		    expected_delimiter = '\0';
		}
	      else
		expected_delimiter = c;
	      break;

	    case '\\':
	      if (p < limit && expected_delimiter)
		{
		  /* In a string, backslash goes through
		     and makes next char ordinary.  */
		  *exp_p++ = *p++;
		}
	      break;

	    case '#':
	      /* # is ordinary inside a string.  */
	      if (expected_delimiter)
		break;
	      if (p < limit && *p == '#')
		{
		  /* ##: concatenate preceding and following tokens.  */
		  /* Take out the first #, discard preceding whitespace.  */
		  exp_p--;
		  while (exp_p > lastp && is_hor_space[exp_p[-1]])
		    --exp_p;
		  /* Skip the second #.  */
		  p++;
		  /* Discard following whitespace.  */
		  SKIP_WHITE_SPACE (p);
		  concat = p;
		  if (p == limit)
		    cpp_error (pfile, "`##' at end of macro definition");
		}
	      else if (nargs >= 0)
		{
		  /* Single #: stringify following argument ref.
		     Don't leave the # in the expansion.  */
		  exp_p--;
		  SKIP_WHITE_SPACE (p);
		  if (p == limit || !is_idstart[*p]
		      || (*p == 'L' && p + 1 < limit && (p[1] == '\'' ||
							 p[1] == '"')))
		    cpp_error (pfile,
		"`#' operator is not followed by a macro argument name");
		  else
		    stringify = p;
		}
	      break;
	    }
	}
      else
	{
	  /* In -traditional mode, recognize arguments inside strings and
	     character constants, and ignore special properties of #.
	     Arguments inside strings are considered "stringified", but no
	     extra quote marks are supplied.  */
	  switch (c)
	    {
	    case '\'':
	    case '\"':
	      if (expected_delimiter != '\0')
		{
		  if (c == expected_delimiter)
		    expected_delimiter = '\0';
		}
	      else
		expected_delimiter = c;
	      break;

	    case '\\':
	      /* Backslash quotes delimiters and itself,
		 but not macro args.  */
	      if (expected_delimiter != 0 && p < limit
		  && (*p == expected_delimiter || *p == '\\'))
		{
		  *exp_p++ = *p++;
		  continue;
		}
	      break;

	    case '/':
	      if (expected_delimiter != '\0')
		/* No comments inside strings.  */
		break;
	      if (*p == '*')
		{
		  /* If we find a comment that wasn't removed by
		     handle_directive, this must be -traditional.
		     So replace the comment with nothing at all.  */
		  exp_p--;
		  p += 1;
		  while (p < limit && !(p[-2] == '*' && p[-1] == '/'))
		    p++;
#if 0
		  /* Mark this as a concatenation-point,
		     as if it had been ##.  */
		  concat = p;
#endif
		}
	      break;
	    }
	}

      /* Handle the start of a symbol.  */
      if (is_idchar[c] && nargs > 0)
	{
	  U_CHAR *id_beg = p - 1;
	  int id_len;

	  --exp_p;
	  while (p != limit && is_idchar[*p])
	    p++;
	  id_len = p - id_beg;

	  if (is_idstart[c]
	      && !(id_len == 1 && c == 'L' && (*p == '\'' || *p == '"')))
	    {
	      register struct arglist *arg;

	      for (arg = arglist; arg != NULL; arg = arg->next)
		{
		  struct reflist *tpat;

		  if (arg->name[0] == c
		      && arg->length == id_len
		      && strncmp (arg->name, id_beg, id_len) == 0)
		    {
		      if (expected_delimiter && CPP_OPTIONS
			(pfile)->warn_stringify)
			{
			  if (CPP_TRADITIONAL (pfile))
			    {
			      cpp_warning (pfile,
				       "macro argument `%.*s' is stringified.",
					   id_len, arg->name);
			    }
			  else
			    {
			      cpp_warning (pfile,
		    "macro arg `%.*s' would be stringified with -traditional.",
					   id_len, arg->name);
			    }
			}
		      /* If ANSI, don't actually substitute
			 inside a string.  */
		      if (!CPP_TRADITIONAL (pfile) && expected_delimiter)
			break;
		      /* make a pat node for this arg and append it
			 to the end of the pat list */
		      tpat = (struct reflist *)
			xmalloc (sizeof (struct reflist));
		      tpat->next = NULL;
		      tpat->raw_before = concat == id_beg;
		      tpat->raw_after = 0;
		      tpat->rest_args = arg->rest_args;
		      tpat->stringify = (CPP_TRADITIONAL (pfile)
					 ? expected_delimiter != '\0'
					 : stringify == id_beg);

		      if (endpat == NULL)
			defn->pattern = tpat;
		      else
			endpat->next = tpat;
		      endpat = tpat;

		      tpat->argno = arg->argno;
		      tpat->nchars = exp_p - lastp;
		      {
			register U_CHAR *p1 = p;
			SKIP_WHITE_SPACE (p1);
			if (p1 + 2 <= limit && p1[0] == '#' && p1[1] == '#')
			  tpat->raw_after = 1;
		      }
		      lastp = exp_p;
		      skipped_arg = 1;
		      break;
		    }
		}
	    }

	  /* If this was not a macro arg, copy it into the expansion.  */
	  if (!skipped_arg)
	    {
	      register U_CHAR *lim1 = p;
	      p = id_beg;
	      while (p != lim1)
		*exp_p++ = *p++;
	      if (stringify == id_beg)
		cpp_error (pfile,
		"`#' operator should be followed by a macro argument name");
	    }
	}
    }

  if (!CPP_TRADITIONAL (pfile) && expected_delimiter == 0)
    {
      /* If ANSI, put in a "\r " marker to prevent token pasting.
         But not if "inside a string" (which in ANSI mode
         happens only for -D option).  */
      *exp_p++ = '\r';
      *exp_p++ = ' ';
    }

  *exp_p = '\0';

  defn->length = exp_p - defn->expansion;

  /* Crash now if we overrun the allocated size.  */
  if (defn->length + 1 > maxsize)
    abort ();

#if 0
/* This isn't worth the time it takes.  */
  /* give back excess storage */
  defn->expansion = (U_CHAR *) xrealloc (defn->expansion, defn->length + 1);
#endif

  return defn;
}

/*
 * special extension string that can be added to the last macro argument to 
 * allow it to absorb the "rest" of the arguments when expanded.  Ex:
 * 		#define wow(a, b...)		process (b, a, b)
 *		{ wow (1, 2, 3); }	->	{ process (2, 3, 1, 2, 3); }
 *		{ wow (one, two); }	->	{ process (two, one, two); }
 * if this "rest_arg" is used with the concat token '##' and if it is not
 * supplied then the token attached to with ## will not be outputted.  Ex:
 * 		#define wow (a, b...)		process (b ## , a, ## b)
 *		{ wow (1, 2); }		->	{ process (2, 1, 2); }
 *		{ wow (one); }		->	{ process (one); {
 */
static char rest_extension[] = "...";
#define REST_EXTENSION_LENGTH	(sizeof (rest_extension) - 1)

/* Create a DEFINITION node from a #define directive.  Arguments are 
   as for do_define.  */

MACRODEF
create_definition (buf, limit, pfile, predefinition)
     U_CHAR *buf, *limit;
     cpp_reader *pfile;
     int predefinition;
{
  U_CHAR *bp;			/* temp ptr into input buffer */
  U_CHAR *symname;		/* remember where symbol name starts */
  int sym_length;		/* and how long it is */
  int rest_args = 0;
  long line, col;
  char *file = CPP_BUFFER (pfile) ? CPP_BUFFER (pfile)->nominal_fname : "";
  DEFINITION *defn;
  int arglengths = 0;		/* Accumulate lengths of arg names
				   plus number of args.  */
  MACRODEF mdef;
  cpp_buf_line_and_col (CPP_BUFFER (pfile), &line, &col);

  bp = buf;

  while (is_hor_space[*bp])
    bp++;

  symname = bp;			/* remember where it starts */

  sym_length = check_macro_name (pfile, bp, 0);
  bp += sym_length;

  /* Lossage will occur if identifiers or control keywords are broken
     across lines using backslash.  This is not the right place to take
     care of that.  */

  if (*bp == '(')
    {
      struct arglist *arg_ptrs = NULL;
      int argno = 0;

      bp++;			/* skip '(' */
      SKIP_WHITE_SPACE (bp);

      /* Loop over macro argument names.  */
      while (*bp != ')')
	{
	  struct arglist *temp;

	  temp = (struct arglist *) alloca (sizeof (struct arglist));
	  temp->name = bp;
	  temp->next = arg_ptrs;
	  temp->argno = argno++;
	  temp->rest_args = 0;
	  arg_ptrs = temp;

	  if (rest_args)
	    cpp_pedwarn (pfile, "another parameter follows `%s'",
			 rest_extension);

	  if (!is_idstart[*bp])
	    cpp_pedwarn (pfile, "invalid character in macro parameter name");

	  /* Find the end of the arg name.  */
	  while (is_idchar[*bp])
	    {
	      bp++;
	      /* do we have a "special" rest-args extension here? */
	      if ((size_t) (limit - bp) > REST_EXTENSION_LENGTH
		  && !strncmp (rest_extension, bp, REST_EXTENSION_LENGTH))
		{
		  rest_args = 1;
		  temp->rest_args = 1;
		  break;
		}
	    }
	  temp->length = bp - temp->name;
	  if (rest_args == 1)
	    bp += REST_EXTENSION_LENGTH;
	  arglengths += temp->length + 2;
	  SKIP_WHITE_SPACE (bp);
	  if (temp->length == 0 || (*bp != ',' && *bp != ')'))
	    {
	      cpp_error (pfile,
			 "badly punctuated parameter list in `#define'");
	      goto nope;
	    }
	  if (*bp == ',')
	    {
	      bp++;
	      SKIP_WHITE_SPACE (bp);
	    }
	  if (bp >= limit)
	    {
	      cpp_error (pfile, "unterminated parameter list in `#define'");
	      goto nope;
	    }
	  {
	    struct arglist *otemp;

	    for (otemp = temp->next; otemp != NULL; otemp = otemp->next)
	      if (temp->length == otemp->length
		  && strncmp (temp->name, otemp->name, temp->length) == 0)
		{
		  U_CHAR *name;

		  name = (U_CHAR *) alloca (temp->length + 1);
		  (void) strncpy (name, temp->name, temp->length);
		  name[temp->length] = '\0';
		  cpp_error (pfile,
			     "duplicate argument name `%s' in `#define'",
			     name);
		  goto nope;
		}
	  }
	}

      ++bp;			/* skip paren */
      SKIP_WHITE_SPACE (bp);
      /* now everything from bp before limit is the definition.  */
      defn = collect_expansion (pfile, bp, limit, argno, arg_ptrs);
      defn->rest_args = rest_args;

      /* Now set defn->args.argnames to the result of concatenating
         the argument names in reverse order
         with comma-space between them.  */
      defn->args.argnames = (U_CHAR *) xmalloc (arglengths + 1);
      {
	struct arglist *temp;
	int i = 0;
	for (temp = arg_ptrs; temp; temp = temp->next)
	  {
	    bcopy (temp->name, &defn->args.argnames[i], temp->length);
	    i += temp->length;
	    if (temp->next != 0)
	      {
		defn->args.argnames[i++] = ',';
		defn->args.argnames[i++] = ' ';
	      }
	  }
	defn->args.argnames[i] = 0;
      }
    }
  else
    {
      /* Simple expansion or empty definition.  */

      if (bp < limit)
	{
	  if (is_hor_space[*bp])
	    {
	      bp++;
	      SKIP_WHITE_SPACE (bp);
	    }
	  else
	    /* Per C9x, missing white space after the name in a #define
	       of an object-like macro is always a constraint violation. */
	    cpp_pedwarn (pfile,
			 "missing white space after `#define %.*s'",
			 sym_length, symname);
	}
      /* now everything from bp before limit is the definition.  */
      defn = collect_expansion (pfile, bp, limit, -1, NULL_PTR);
      defn->args.argnames = (U_CHAR *) "";
    }

  defn->line = line;
  defn->file = file;

  /* OP is null if this is a predefinition */
  defn->predefined = predefinition;
  mdef.defn = defn;
  mdef.symnam = symname;
  mdef.symlen = sym_length;

  return mdef;

nope:
  mdef.defn = 0;
  return mdef;
}

/*
 * Parse a macro argument and append the info on PFILE's token_buffer.
 * REST_ARGS means to absorb the rest of the args.
 * Return nonzero to indicate a syntax error.
 */

static enum cpp_token
macarg (pfile, rest_args)
     cpp_reader *pfile;
     int rest_args;
{
  int paren = 0;
  enum cpp_token token;
  char save_put_out_comments = CPP_OPTIONS (pfile)->put_out_comments;
  CPP_OPTIONS (pfile)->put_out_comments = 0;

  /* Try to parse as much of the argument as exists at this
     input stack level.  */
  pfile->no_macro_expand++;
  CPP_OPTIONS (pfile)->no_line_commands++;
  for (;;)
    {
      token = cpp_get_token (pfile);
      switch (token)
	{
	case CPP_EOF:
	  goto done;
	case CPP_POP:
	  /* If we've hit end of file, it's an error (reported by caller).
	     Ditto if it's the end of cpp_expand_to_buffer text.
	     If we've hit end of macro, just continue.  */
	  if (!CPP_IS_MACRO_BUFFER (CPP_BUFFER (pfile)))
	    goto done;
	  break;
	case CPP_LPAREN:
	  paren++;
	  break;
	case CPP_RPAREN:
	  if (--paren < 0)
	    goto found;
	  break;
	case CPP_COMMA:
	  /* if we've returned to lowest level and
	     we aren't absorbing all args */
	  if (paren == 0 && rest_args == 0)
	    goto found;
	  break;
	found:
	  /* Remove ',' or ')' from argument buffer.  */
	  CPP_ADJUST_WRITTEN (pfile, -1);
	  goto done;
	default:;
	}
    }

done:
  CPP_OPTIONS (pfile)->put_out_comments = save_put_out_comments;
  CPP_OPTIONS (pfile)->no_line_commands--;
  pfile->no_macro_expand--;

  return token;
}

/* Turn newlines to spaces in the string of length LENGTH at START,
   except inside of string constants.
   The string is copied into itself with its beginning staying fixed.  */

static int
change_newlines (start, length)
     U_CHAR *start;
     int length;
{
  register U_CHAR *ibp;
  register U_CHAR *obp;
  register U_CHAR *limit;
  register int c;

  ibp = start;
  limit = start + length;
  obp = start;

  while (ibp < limit)
    {
      *obp++ = c = *ibp++;
      switch (c)
	{

	case '\'':
	case '\"':
	  /* Notice and skip strings, so that we don't
	     delete newlines in them.  */
	  {
	    int quotec = c;
	    while (ibp < limit)
	      {
		*obp++ = c = *ibp++;
		if (c == quotec)
		  break;
		if (c == '\n' && quotec == '\'')
		  break;
	      }
	  }
	  break;
	}
    }

  return obp - start;
}


static struct tm *
timestamp (pfile)
     cpp_reader *pfile;
{
  if (!pfile->timebuf)
    {
      time_t t = time ((time_t *) 0);
      pfile->timebuf = localtime (&t);
    }
  return pfile->timebuf;
}

static char *monthnames[] =
{
  "Jan", "Feb", "Mar", "Apr", "May", "Jun",
  "Jul", "Aug", "Sep", "Oct", "Nov", "Dec",
};

/*
 * expand things like __FILE__.  Place the expansion into the output
 * buffer *without* rescanning.
 */

static void
special_symbol (hp, pfile)
     HASHNODE *hp;
     cpp_reader *pfile;
{
  const char *buf;
  int len;
  cpp_buffer *ip;

  switch (hp->type)
    {
    case T_FILE:
    case T_BASE_FILE:
      {
	ip = CPP_BUFFER (pfile);
	if (hp->type == T_BASE_FILE)
	  {
	    while (CPP_PREV_BUFFER (ip) != CPP_NULL_BUFFER (pfile))
	      ip = CPP_PREV_BUFFER (ip);
	  }
	else
	  {
	    ip = CPP_BUFFER (pfile);
	    while (!ip->nominal_fname && ip != CPP_NULL_BUFFER (pfile))
	      ip = CPP_PREV_BUFFER (ip);
	  }

	buf = ip->nominal_fname;

	if (!buf)
	  buf = "";
	CPP_RESERVE (pfile, 3 + 4 * strlen (buf));
	quote_string (pfile, buf);
	return;
      }

    case T_INCLUDE_LEVEL:
      {
	int true_indepth = 0;
	ip = CPP_BUFFER (pfile);
	for (; ip != CPP_NULL_BUFFER (pfile); ip = CPP_PREV_BUFFER (ip))
	  if (ip->fname != NULL)
	    true_indepth++;

	CPP_RESERVE (pfile, 10);
	sprintf (CPP_PWRITTEN (pfile), "%d", true_indepth);
	CPP_ADJUST_WRITTEN (pfile, strlen (CPP_PWRITTEN (pfile)));
	return;
      }

    case T_VERSION:
      len = strlen (version_string);
      CPP_RESERVE (pfile, 3 + len);
      CPP_PUTC_Q (pfile, '"');
      CPP_PUTS_Q (pfile, version_string, len);
      CPP_PUTC_Q (pfile, '"');
      CPP_NUL_TERMINATE_Q (pfile);
      return;

    case T_CONST:
      buf = hp->value.cpval;
      if (!buf)
	return;
      if (*buf == '\0')
	buf = "\r ";

      len = strlen (buf);
      CPP_RESERVE (pfile, len + 1);
      CPP_PUTS_Q (pfile, buf, len);
      CPP_NUL_TERMINATE_Q (pfile);
      return;

    case T_STDC:
      CPP_RESERVE (pfile, 2);
#ifdef STDC_0_IN_SYSTEM_HEADERS
      ip = CPP_BUFFER (pfile);
      while (!ip->nominal_fname && ip != CPP_NULL_BUFFER (pfile))
	ip = CPP_PREV_BUFFER (ip);
      if (ip->system_header_p
	  && !cpp_lookup (pfile, (U_CHAR *) "__STRICT_ANSI__", 15, -1))
	CPP_PUTC_Q (pfile, '0');
      else
#endif
	CPP_PUTC_Q (pfile, '1');
      CPP_NUL_TERMINATE_Q (pfile);
      return;

    case T_SPECLINE:
      {
	long line;
	cpp_buf_line_and_col (cpp_file_buffer (pfile), &line, NULL);

	CPP_RESERVE (pfile, 10);
	sprintf (CPP_PWRITTEN (pfile), "%ld", line);
	CPP_ADJUST_WRITTEN (pfile, strlen (CPP_PWRITTEN (pfile)));
	return;
      }

    case T_DATE:
    case T_TIME:
      {
	struct tm *timebuf;

	CPP_RESERVE (pfile, 20);
	timebuf = timestamp (pfile);
	if (hp->type == T_DATE)
	  sprintf (CPP_PWRITTEN (pfile), "\"%s %2d %4d\"",
		   monthnames[timebuf->tm_mon],
		   timebuf->tm_mday, timebuf->tm_year + 1900);
	else
	  sprintf (CPP_PWRITTEN (pfile), "\"%02d:%02d:%02d\"",
		   timebuf->tm_hour, timebuf->tm_min, timebuf->tm_sec);

	CPP_ADJUST_WRITTEN (pfile, strlen (CPP_PWRITTEN (pfile)));
	return;
      }

    default:
      cpp_fatal (pfile, "cpplib internal error: invalid special hash type");
      return;
    }
}

/* Expand a macro call.
   HP points to the symbol that is the macro being called.
   Put the result of expansion onto the input stack
   so that subsequent input by our caller will use it.

   If macro wants arguments, caller has already verified that
   an argument list follows; arguments come from the input stack.  */

void
macroexpand (pfile, hp)
     cpp_reader *pfile;
     HASHNODE *hp;
{
  int nargs;
  DEFINITION *defn;
  register U_CHAR *xbuf;
  long start_line, start_column;
  int xbuf_len;
  struct argdata *args;
  long old_written = CPP_WRITTEN (pfile);
#if 0
  int start_line = instack[indepth].lineno;
#endif
  int rest_args, rest_zero;
  register int i;

#if 0
  /* This macro is being used inside a #if, which means it must be */
  /* recorded as a precondition.  */
  if (pcp_inside_if && pcp_outfile && defn->predefined)
    dump_single_macro (hp, pcp_outfile);
#endif

  cpp_buf_line_and_col (cpp_file_buffer (pfile), &start_line, &start_column);

  /* Check for and handle special symbols. */
  if (hp->type != T_MACRO)
    {
      special_symbol (hp, pfile);
      xbuf_len = CPP_WRITTEN (pfile) - old_written;
      xbuf = (U_CHAR *) xmalloc (xbuf_len + 1);
      CPP_SET_WRITTEN (pfile, old_written);
      bcopy (CPP_PWRITTEN (pfile), xbuf, xbuf_len + 1);
      push_macro_expansion (pfile, xbuf, xbuf_len, hp);
      CPP_BUFFER (pfile)->has_escapes = 1;
      return;
    }

  defn = hp->value.defn;
  nargs = defn->nargs;
  pfile->output_escapes++;

  if (nargs >= 0)
    {
      enum cpp_token token = CPP_EOF;

      args = (struct argdata *) alloca ((nargs + 1) * sizeof (struct argdata));

      for (i = 0; i < nargs; i++)
	{
	  args[i].raw = args[i].expanded = 0;
	  args[i].raw_length = 0;
	  args[i].expand_length = args[i].stringified_length = -1;
	  args[i].use_count = 0;
	}

      /* Parse all the macro args that are supplied.  I counts them.
         The first NARGS args are stored in ARGS.
         The rest are discarded.  If rest_args is set then we assume
         macarg absorbed the rest of the args.  */
      i = 0;
      rest_args = 0;
      rest_args = 0;
      FORWARD (1);	/* Discard open-parenthesis before first arg.  */
      do
	{
	  if (rest_args)
	    continue;
	  if (i < nargs || (nargs == 0 && i == 0))
	    {
	      /* if we are working on last arg which absorbs rest of args... */
	      if (i == nargs - 1 && defn->rest_args)
		rest_args = 1;
	      args[i].raw = CPP_WRITTEN (pfile);
	      token = macarg (pfile, rest_args);
	      args[i].raw_length = CPP_WRITTEN (pfile) - args[i].raw;
	      args[i].newlines = 0;	/* FIXME */
	    }
	  else
	    token = macarg (pfile, 0);
	  if (token == CPP_EOF || token == CPP_POP)
	    {
	      cpp_error_with_line (pfile, start_line, start_column,
				   "unterminated macro call");
	      return;
	    }
	  i++;
	}
      while (token == CPP_COMMA);

      /* If we got one arg but it was just whitespace, call that 0 args.  */
      if (i == 1)
	{
	  register U_CHAR *bp = ARG_BASE + args[0].raw;
	  register U_CHAR *lim = bp + args[0].raw_length;
	  /* cpp.texi says for foo ( ) we provide one argument.
	     However, if foo wants just 0 arguments, treat this as 0.  */
	  if (nargs == 0)
	    while (bp != lim && is_space[*bp])
	      bp++;
	  if (bp == lim)
	    i = 0;
	}

      /* Don't output an error message if we have already output one for
         a parse error above.  */
      rest_zero = 0;
      if (nargs == 0 && i > 0)
	{
	  cpp_error (pfile, "arguments given to macro `%s'", hp->name);
	}
      else if (i < nargs)
	{
	  /* traditional C allows foo() if foo wants one argument.  */
	  if (nargs == 1 && i == 0 && CPP_TRADITIONAL (pfile))
	    ;
	  /* the rest args token is allowed to absorb 0 tokens */
	  else if (i == nargs - 1 && defn->rest_args)
	    rest_zero = 1;
	  else if (i == 0)
	    cpp_error (pfile, "macro `%s' used without args", hp->name);
	  else if (i == 1)
	    cpp_error (pfile, "macro `%s' used with just one arg", hp->name);
	  else
	    cpp_error (pfile, "macro `%s' used with only %d args",
		       hp->name, i);
	}
      else if (i > nargs)
	{
	  cpp_error (pfile,
		     "macro `%s' used with too many (%d) args", hp->name, i);
	}
    }

  /* If macro wants zero args, we parsed the arglist for checking only.
     Read directly from the macro definition.  */
  if (nargs <= 0)
    {
      xbuf = defn->expansion;
      xbuf_len = defn->length;
    }
  else
    {
      register U_CHAR *exp = defn->expansion;
      register int offset;	/* offset in expansion,
				   copied a piece at a time */
      register int totlen;	/* total amount of exp buffer filled so far */

      register struct reflist *ap, *last_ap;

      /* Macro really takes args.  Compute the expansion of this call.  */

      /* Compute length in characters of the macro's expansion.
         Also count number of times each arg is used.  */
      xbuf_len = defn->length;
      for (ap = defn->pattern; ap != NULL; ap = ap->next)
	{
	  if (ap->stringify)
	    {
	      register struct argdata *arg = &args[ap->argno];
	      /* Stringify if it hasn't already been */
	      if (arg->stringified_length < 0)
		{
		  int arglen = arg->raw_length;
		  int escaped = 0;
		  int in_string = 0;
		  int c;
		  /* Initially need_space is -1.  Otherwise, 1 means the
		     previous character was a space, but we suppressed it;
		     0 means the previous character was a non-space.  */
		  int need_space = -1;
		  i = 0;
		  arg->stringified = CPP_WRITTEN (pfile);
		  if (!CPP_TRADITIONAL (pfile))
		    CPP_PUTC (pfile, '\"');	/* insert beginning quote */
		  for (; i < arglen; i++)
		    {
		      c = (ARG_BASE + arg->raw)[i];

		      if (!in_string)
			{
			  /* Internal sequences of whitespace are
			     replaced by one space except within
			     a string or char token. */
			  if (is_space[c])
			    {
			      if (CPP_WRITTEN (pfile) > (unsigned) arg->stringified
				  && (CPP_PWRITTEN (pfile))[-1] == '\r')
				{
				  /* "\r " escape markers are removed */
				  CPP_ADJUST_WRITTEN (pfile, -1);
				  continue;
				}
			      if (need_space == 0)
				need_space = 1;
			      continue;
			    }
			  else if (need_space > 0)
			    CPP_PUTC (pfile, ' ');
			  need_space = 0;
			}

		      if (escaped)
			escaped = 0;
		      else
			{
			  if (c == '\\')
			    escaped = 1;
			  if (in_string)
			    {
			      if (c == in_string)
				in_string = 0;
			    }
			  else if (c == '\"' || c == '\'')
			    in_string = c;
			}

		      /* Escape these chars */
		      if (c == '\"' || (in_string && c == '\\'))
			CPP_PUTC (pfile, '\\');
		      if (ISPRINT (c))
			CPP_PUTC (pfile, c);
		      else
			{
			  CPP_RESERVE (pfile, 4);
			  sprintf ((char *) CPP_PWRITTEN (pfile), "\\%03o",
				   (unsigned int) c);
			  CPP_ADJUST_WRITTEN (pfile, 4);
			}
		    }
		  if (!CPP_TRADITIONAL (pfile))
		    CPP_PUTC (pfile, '\"');	/* insert ending quote */
		  arg->stringified_length
		    = CPP_WRITTEN (pfile) - arg->stringified;
		}
	      xbuf_len += args[ap->argno].stringified_length;
	    }
	  else if (ap->raw_before || ap->raw_after || CPP_TRADITIONAL (pfile))
	    /* Add 4 for two newline-space markers to prevent
	       token concatenation.  */
	    xbuf_len += args[ap->argno].raw_length + 4;
	  else
	    {
	      /* We have an ordinary (expanded) occurrence of the arg.
	         So compute its expansion, if we have not already.  */
	      if (args[ap->argno].expand_length < 0)
		{
		  args[ap->argno].expanded = CPP_WRITTEN (pfile);
		  cpp_expand_to_buffer (pfile,
					ARG_BASE + args[ap->argno].raw,
					args[ap->argno].raw_length);

		  args[ap->argno].expand_length
		    = CPP_WRITTEN (pfile) - args[ap->argno].expanded;
		}

	      /* Add 4 for two newline-space markers to prevent
	         token concatenation.  */
	      xbuf_len += args[ap->argno].expand_length + 4;
	    }
	  if (args[ap->argno].use_count < 10)
	    args[ap->argno].use_count++;
	}

      xbuf = (U_CHAR *) xmalloc (xbuf_len + 1);

      /* Generate in XBUF the complete expansion
         with arguments substituted in.
         TOTLEN is the total size generated so far.
         OFFSET is the index in the definition
         of where we are copying from.  */
      offset = totlen = 0;
      for (last_ap = NULL, ap = defn->pattern; ap != NULL;
	   last_ap = ap, ap = ap->next)
	{
	  register struct argdata *arg = &args[ap->argno];
	  int count_before = totlen;

	  /* Add chars to XBUF.  */
	  for (i = 0; i < ap->nchars; i++, offset++)
	    xbuf[totlen++] = exp[offset];

	  /* If followed by an empty rest arg with concatenation,
	     delete the last run of nonwhite chars.  */
	  if (rest_zero && totlen > count_before
	      && ((ap->rest_args && ap->raw_before)
		  || (last_ap != NULL && last_ap->rest_args
		      && last_ap->raw_after)))
	    {
	      /* Delete final whitespace.  */
	      while (totlen > count_before && is_space[xbuf[totlen - 1]])
		totlen--;

	      /* Delete the nonwhites before them.  */
	      while (totlen > count_before && !is_space[xbuf[totlen - 1]])
		totlen--;
	    }

	  if (ap->stringify != 0)
	    {
	      bcopy (ARG_BASE + arg->stringified,
		     xbuf + totlen, arg->stringified_length);
	      totlen += arg->stringified_length;
	    }
	  else if (ap->raw_before || ap->raw_after || CPP_TRADITIONAL (pfile))
	    {
	      U_CHAR *p1 = ARG_BASE + arg->raw;
	      U_CHAR *l1 = p1 + arg->raw_length;
	      if (ap->raw_before)
		{
		  while (p1 != l1 && is_space[*p1])
		    p1++;
		  while (p1 != l1 && is_idchar[*p1])
		    xbuf[totlen++] = *p1++;
		}
	      if (ap->raw_after)
		{
		  /* Arg is concatenated after: delete trailing whitespace,
		     whitespace markers, and no-reexpansion markers.  */
		  while (p1 != l1)
		    {
		      if (is_space[l1[-1]])
			l1--;
		      else if (l1[-1] == '\r')
			l1--;
		      else if (l1[-1] == '-')
			{
			  if (l1 != p1 + 1 && l1[-2] == '\r')
			    l1 -= 2;
			  else
			    break;
			}
		      else
			break;
		    }
		}

	      /* Delete any no-reexpansion marker that precedes
	         an identifier at the beginning of the argument. */
	      if (p1[0] == '\r' && p1[1] == '-')
		p1 += 2;

	      bcopy (p1, xbuf + totlen, l1 - p1);
	      totlen += l1 - p1;
	    }
	  else
	    {
	      U_CHAR *expanded = ARG_BASE + arg->expanded;
	      if (!ap->raw_before && totlen > 0 && arg->expand_length
		  && !CPP_TRADITIONAL (pfile)
		  && unsafe_chars (xbuf[totlen - 1], expanded[0]))
		{
		  xbuf[totlen++] = '\r';
		  xbuf[totlen++] = ' ';
		}

	      bcopy (expanded, xbuf + totlen, arg->expand_length);
	      totlen += arg->expand_length;

	      if (!ap->raw_after && totlen > 0 && offset < defn->length
		  && !CPP_TRADITIONAL (pfile)
		  && unsafe_chars (xbuf[totlen - 1], exp[offset]))
		{
		  xbuf[totlen++] = '\r';
		  xbuf[totlen++] = ' ';
		}

	      /* If a macro argument with newlines is used multiple times,
	         then only expand the newlines once.  This avoids creating
	         output lines which don't correspond to any input line,
	         which confuses gdb and gcov.  */
	      if (arg->use_count > 1 && arg->newlines > 0)
		{
		  /* Don't bother doing change_newlines for subsequent
		     uses of arg.  */
		  arg->use_count = 1;
		  arg->expand_length
		    = change_newlines (expanded, arg->expand_length);
		}
	    }

	  if (totlen > xbuf_len)
	    {
	      cpp_fatal (pfile, "internal_error: buffer overrun in macroexpand");
	      return;
	    }
	}

      /* if there is anything left of the definition
         after handling the arg list, copy that in too.  */

      for (i = offset; i < defn->length; i++)
	{
	  /* if we've reached the end of the macro */
	  if (exp[i] == ')')
	    rest_zero = 0;
	  if (!(rest_zero && last_ap != NULL && last_ap->rest_args
		&& last_ap->raw_after))
	    xbuf[totlen++] = exp[i];
	}

      xbuf[totlen] = 0;
      xbuf_len = totlen;

    }

  pfile->output_escapes--;

  /* Now put the expansion on the input stack
     so our caller will commence reading from it.  */
  push_macro_expansion (pfile, xbuf, xbuf_len, hp);
  CPP_BUFFER (pfile)->has_escapes = 1;

  /* Pop the space we've used in the token_buffer for argument expansion.  */
  CPP_SET_WRITTEN (pfile, old_written);

  /* Recursive macro use sometimes works traditionally.
     #define foo(x,y) bar (x (y,0), y)
     foo (foo, baz)  */

  if (!CPP_TRADITIONAL (pfile))
    hp->type = T_DISABLED;
}

/* Return 1 iff a token ending in C1 followed directly by a token C2
   could cause mis-tokenization.  */

static int
unsafe_chars (c1, c2)
     int c1, c2;
{
  switch (c1)
    {
    case '+':
    case '-':
      if (c2 == c1 || c2 == '=')
	return 1;
      goto letter;

    case '.':    case '0':    case '1':    case '2':    case '3':
    case '4':    case '5':    case '6':    case '7':    case '8':
    case '9':    case 'e':    case 'E':    case 'p':    case 'P':
      if (c2 == '-' || c2 == '+')
	return 1;		/* could extend a pre-processing number */
      goto letter;

    case 'L':
      if (c2 == '\'' || c2 == '\"')
	return 1;		/* Could turn into L"xxx" or L'xxx'.  */
      goto letter;

    case '_':  case 'a':  case 'b':  case 'c':  case 'd':  case 'f':
    case 'g':  case 'h':  case 'i':  case 'j':  case 'k':  case 'l':
    case 'm':  case 'n':  case 'o':  case 'q':  case 'r':  case 's':
    case 't':  case 'u':  case 'v':  case 'w':  case 'x':  case 'y':
    case 'z':  case 'A':  case 'B':  case 'C':  case 'D':  case 'F':
    case 'G':  case 'H':  case 'I':  case 'J':  case 'K':  case 'M':
    case 'N':  case 'O':  case 'Q':  case 'R':  case 'S':  case 'T':
    case 'U':  case 'V':  case 'W':  case 'X':  case 'Y':  case 'Z':
    letter:
    /* We're in the middle of either a name or a pre-processing number.  */
      return (is_idchar[c2] || c2 == '.');

    case '<':  case '>':  case '!':  case '%':  case '#':  case ':':
    case '^':  case '&':  case '|':  case '*':  case '/':  case '=':
      return (c2 == c1 || c2 == '=');
    }
  return 0;
}

static void
push_macro_expansion (pfile, xbuf, xbuf_len, hp)
     cpp_reader *pfile;
     register U_CHAR *xbuf;
     int xbuf_len;
     HASHNODE *hp;
{
  register cpp_buffer *mbuf = cpp_push_buffer (pfile, xbuf, xbuf_len);
  if (mbuf == NULL)
    return;
  mbuf->cleanup = macro_cleanup;
  mbuf->data = hp;

  /* The first chars of the expansion should be a "\r " added by
     collect_expansion.  This is to prevent accidental token-pasting
     between the text preceding the macro invocation, and the macro
     expansion text.

     We would like to avoid adding unneeded spaces (for the sake of
     tools that use cpp, such as imake).  In some common cases we can
     tell that it is safe to omit the space.

     The character before the macro invocation cannot have been an
     idchar (or else it would have been pasted with the idchars of
     the macro name).  Therefore, if the first non-space character
     of the expansion is an idchar, we do not need the extra space
     to prevent token pasting.

     Also, we don't need the extra space if the first char is '(',
     or some other (less common) characters.  */

  if (xbuf[0] == '\r' && xbuf[1] == ' '
      && (is_idchar[xbuf[2]] || xbuf[2] == '(' || xbuf[2] == '\''
	  || xbuf[2] == '\"'))
    mbuf->cur += 2;

  /* Likewise, avoid the extra space at the end of the macro expansion
     if this is safe.  We can do a better job here since we can know
     what the next char will be.  */
  if (xbuf_len >= 3
      && mbuf->rlimit[-2] == '\r'
      && mbuf->rlimit[-1] == ' ')
    {
      int c1 = mbuf->rlimit[-3];
      int c2 = CPP_BUF_PEEK (CPP_PREV_BUFFER (CPP_BUFFER (pfile)));
      if (c2 == EOF || !unsafe_chars (c1, c2))
	mbuf->rlimit -= 2;
    }
}

/* Return zero if two DEFINITIONs are isomorphic.  */

int
compare_defs (pfile, d1, d2)
     cpp_reader *pfile;
     DEFINITION *d1, *d2;
{
  register struct reflist *a1, *a2;
  register U_CHAR *p1 = d1->expansion;
  register U_CHAR *p2 = d2->expansion;
  int first = 1;

  if (d1->nargs != d2->nargs)
    return 1;
  if (CPP_PEDANTIC (pfile)
      && strcmp ((char *) d1->args.argnames, (char *) d2->args.argnames))
    return 1;
  for (a1 = d1->pattern, a2 = d2->pattern; a1 && a2;
       a1 = a1->next, a2 = a2->next)
    {
      if (!((a1->nchars == a2->nchars && !strncmp (p1, p2, a1->nchars))
	    || !comp_def_part (first, p1, a1->nchars, p2, a2->nchars, 0))
	  || a1->argno != a2->argno
	  || a1->stringify != a2->stringify
	  || a1->raw_before != a2->raw_before
	  || a1->raw_after != a2->raw_after)
	return 1;
      first = 0;
      p1 += a1->nchars;
      p2 += a2->nchars;
    }
  if (a1 != a2)
    return 1;

  return comp_def_part (first, p1, d1->length - (p1 - d1->expansion),
			p2, d2->length - (p2 - d2->expansion), 1);
}

/* Return 1 if two parts of two macro definitions are effectively different.
   One of the parts starts at BEG1 and has LEN1 chars;
   the other has LEN2 chars at BEG2.
   Any sequence of whitespace matches any other sequence of whitespace.
   FIRST means these parts are the first of a macro definition;
    so ignore leading whitespace entirely.
   LAST means these parts are the last of a macro definition;
    so ignore trailing whitespace entirely.  */

static int
comp_def_part (first, beg1, len1, beg2, len2, last)
     int first;
     U_CHAR *beg1, *beg2;
     int len1, len2;
     int last;
{
  register U_CHAR *end1 = beg1 + len1;
  register U_CHAR *end2 = beg2 + len2;
  if (first)
    {
      while (beg1 != end1 && is_space[*beg1])
	beg1++;
      while (beg2 != end2 && is_space[*beg2])
	beg2++;
    }
  if (last)
    {
      while (beg1 != end1 && is_space[end1[-1]])
	end1--;
      while (beg2 != end2 && is_space[end2[-1]])
	end2--;
    }
  while (beg1 != end1 && beg2 != end2)
    {
      if (is_space[*beg1] && is_space[*beg2])
	{
	  while (beg1 != end1 && is_space[*beg1])
	    beg1++;
	  while (beg2 != end2 && is_space[*beg2])
	    beg2++;
	}
      else if (*beg1 == *beg2)
	{
	  beg1++;
	  beg2++;
	}
      else
	break;
    }
  return (beg1 != end1) || (beg2 != end2);
}

/* Dump the definition of macro MACRO on stdout.  The format is suitable
   to be read back in again. */

void
dump_definition (pfile, macro)
     cpp_reader *pfile;
     MACRODEF macro;
{
  DEFINITION *defn = macro.defn;

  CPP_RESERVE (pfile, macro.symlen + sizeof "#define ");
  CPP_PUTS_Q (pfile, "#define ", sizeof "#define " -1);
  CPP_PUTS_Q (pfile, macro.symnam, macro.symlen);

  if (defn->nargs == -1)
    {
      CPP_PUTC_Q (pfile, ' ');

      /* The first and last two characters of a macro expansion are
	 always "\r "; this needs to be trimmed out.
	 So we need length-4 chars of space, plus one for the NUL.  */
      CPP_RESERVE (pfile, defn->length - 4 + 1);
      CPP_PUTS_Q (pfile, defn->expansion + 2, defn->length - 4);
      CPP_NUL_TERMINATE_Q (pfile);
    }
  else
    {
      struct reflist *r;
      unsigned char *argnames = xstrdup (defn->args.argnames);
      unsigned char **argv = alloca (defn->nargs * sizeof(char *));
      int *argl = alloca (defn->nargs * sizeof(int));
      unsigned char *x;
      int i;

      /* First extract the argument list. */
      x = argnames;
      i = defn->nargs;
      while (i--)
	{
	  argv[i] = x;
	  while (*x != ',' && *x != '\0') x++;
	  argl[i] = x - argv[i];
	  if (*x == ',')
	    {
	      *x = '\0';
	      x += 2;  /* skip the space after the comma */
	    }
	}
      
      /* Now print out the argument list. */
      CPP_PUTC_Q (pfile, '(');
      for (i = 0; i < defn->nargs; i++)
	{
	  CPP_RESERVE (pfile, argl[i] + 2);
	  CPP_PUTS_Q (pfile, argv[i], argl[i]);
	  if (i < defn->nargs-1)
	    CPP_PUTS_Q (pfile, ", ", 2);
	}

      if (defn->rest_args)
	CPP_PUTS (pfile, "...) ", 5);
      else
	CPP_PUTS (pfile, ") ", 2);

      /* Now the definition. */
      x = defn->expansion;
      for (r = defn->pattern; r; r = r->next)
      {
	i = r->nchars;
	if (*x == '\r') x += 2, i -= 2;
	/* i chars for macro text, plus the length of the macro
	   argument name, plus one for a stringify marker, plus two for
	   each concatenation marker. */
	CPP_RESERVE (pfile,
		     i + argl[r->argno] + r->stringify
		     + (r->raw_before + r->raw_after) * 2);

	if (i > 0) CPP_PUTS_Q (pfile, x, i);
	if (r->raw_before)
	  CPP_PUTS_Q (pfile, "##", 2);
	if (r->stringify)
	  CPP_PUTC_Q (pfile, '#');
	CPP_PUTS_Q (pfile, argv[r->argno], argl[r->argno]);
	if (r->raw_after && !(r->next && r->next->nchars == 0
			      && r->next->raw_before))
	  CPP_PUTS_Q (pfile, "##", 2);

	x += i;
      }

      i = defn->length - (x - defn->expansion) - 2;
      if (*x == '\r') x += 2, i -= 2;
      if (i > 0) CPP_PUTS (pfile, x, i);
      CPP_NUL_TERMINATE (pfile);
    }
}