File: configure.ac

package info (click to toggle)
glibc 2.24-11+deb9u4
  • links: PTS, VCS
  • area: main
  • in suites: stretch, stretch-proposed-updates
  • size: 225,852 kB
  • sloc: ansic: 996,505; asm: 261,827; sh: 10,484; makefile: 9,856; cpp: 4,169; python: 3,971; perl: 2,254; awk: 1,753; pascal: 1,521; yacc: 291; sed: 80
file content (1860 lines) | stat: -rw-r--r-- 55,792 bytes parent folder | download | duplicates (4)
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
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
dnl Process this file with autoconf to produce a configure script.
dnl Note we do not use AC_PREREQ here!  See aclocal.m4 for what we use instead.
AC_INIT([GNU C Library], [(see version.h)], [http://sourceware.org/bugzilla/], [glibc])
AC_CONFIG_SRCDIR([include/features.h])
AC_CONFIG_HEADERS([config.h])
AC_CONFIG_AUX_DIR([scripts])

ACX_PKGVERSION([GNU libc])
ACX_BUGURL([http://www.gnu.org/software/libc/bugs.html])
AC_DEFINE_UNQUOTED([PKGVERSION], ["$PKGVERSION"],
		   [Package description])
AC_DEFINE_UNQUOTED([REPORT_BUGS_TO], ["$REPORT_BUGS_TO"],
		   [Bug reporting address])

# Glibc should not depend on any header files
AC_DEFUN([_AC_INCLUDES_DEFAULT_REQUIREMENTS],
  [m4_divert_text([DEFAULTS],
    [ac_includes_default='/* none */'])])

# We require GCC, and by default use its preprocessor.  Override AC_PROG_CPP
# here to work around the Autoconf issue discussed in
# <http://sourceware.org/ml/libc-alpha/2013-01/msg00721.html>.
AC_DEFUN([AC_PROG_CPP],
[AC_REQUIRE([AC_PROG_CC])dnl
AC_ARG_VAR([CPP],      [C preprocessor])dnl
_AC_ARG_VAR_CPPFLAGS()dnl
# On Suns, sometimes $CPP names a directory.
if test -n "$CPP" && test -d "$CPP"; then
  CPP=
fi
if test -z "$CPP"; then
  CPP="$CC -E"
fi
AC_SUBST(CPP)dnl
])# AC_PROG_CPP

# We require GCC.  Override _AC_PROG_CC_C89 here to work around the Autoconf
# issue discussed in
# <http://sourceware.org/ml/libc-alpha/2013-01/msg00757.html>.
AC_DEFUN([_AC_PROG_CC_C89], [[$1]])

dnl This is here so we can set $subdirs directly based on configure fragments.
AC_CONFIG_SUBDIRS()

AC_CANONICAL_HOST

AC_PROG_CC
if test $host != $build; then
  AC_CHECK_PROGS(BUILD_CC, gcc cc)
fi
AC_SUBST(cross_compiling)
AC_PROG_CPP
AC_CHECK_TOOL(READELF, readelf, false)

# We need the C++ compiler only for testing.
AC_PROG_CXX
# It's useless to us if it can't link programs (e.g. missing -lstdc++).
AC_CACHE_CHECK([whether $CXX can link programs], libc_cv_cxx_link_ok, [dnl
AC_LANG_PUSH([C++])
# Default, dynamic case.
AC_LINK_IFELSE([AC_LANG_PROGRAM([], [])],
	       [libc_cv_cxx_link_ok=yes],
	       [libc_cv_cxx_link_ok=no])
# Static case.
old_LDFLAGS="$LDFLAGS"
LDFLAGS="$LDFLAGS -static"
AC_LINK_IFELSE([AC_LANG_SOURCE([
#include <iostream>

int
main()
{
  std::cout << "Hello, world!";
  return 0;
}
])],
	       [],
	       [libc_cv_cxx_link_ok=no])
LDFLAGS="$old_LDFLAGS"
AC_LANG_POP([C++])])
AS_IF([test $libc_cv_cxx_link_ok != yes], [CXX=])

if test "`cd $srcdir; pwd -P`" = "`pwd -P`"; then
  AC_MSG_ERROR([you must configure in a separate build directory])
fi

# This will get text that should go into config.make.
config_vars=

# Check for a --with-gd argument and set libgd-LDFLAGS in config.make.
AC_ARG_WITH([gd],
	    AC_HELP_STRING([--with-gd=DIR],
			   [find libgd include dir and library with prefix DIR]),
	    [dnl
case "$with_gd" in
yes|''|no) ;;
*) libgd_include="-I$withval/include"
   libgd_ldflags="-L$withval/lib" ;;
esac
])
AC_ARG_WITH([gd-include],
	    AC_HELP_STRING([--with-gd-include=DIR],
			   [find libgd include files in DIR]),
	    [dnl
case "$with_gd_include" in
''|no) ;;
*) libgd_include="-I$withval" ;;
esac
])
AC_ARG_WITH([gd-lib],
	    AC_HELP_STRING([--with-gd-lib=DIR],
			   [find libgd library files in DIR]),
	    [dnl
case "$with_gd_lib" in
''|no) ;;
*) libgd_ldflags="-L$withval" ;;
esac
])

if test -n "$libgd_include"; then
  config_vars="$config_vars
CFLAGS-memusagestat.c = $libgd_include"
fi
if test -n "$libgd_ldflags"; then
  config_vars="$config_vars
libgd-LDFLAGS = $libgd_ldflags"
fi

dnl Arguments to specify presence of other packages/features.
AC_ARG_WITH([fp],
	    AC_HELP_STRING([--with-fp],
			   [if using floating-point hardware @<:@default=yes@:>@]),
	    [with_fp=$withval],
	    [with_fp=yes])
AC_SUBST(with_fp)
AC_ARG_WITH([binutils],
	    AC_HELP_STRING([--with-binutils=PATH],
			   [specify location of binutils (as and ld)]),
	    [path_binutils=$withval],
	    [path_binutils=''])
AC_ARG_WITH([selinux],
	    AC_HELP_STRING([--with-selinux],
			   [if building with SELinux support]),
	    [with_selinux=$withval],
	    [with_selinux=auto])

AC_ARG_WITH([headers],
	    AC_HELP_STRING([--with-headers=PATH],
			   [location of system headers to use
			    (for example /usr/src/linux/include)
			    @<:@default=compiler default@:>@]),
	    [sysheaders=$withval],
	    [sysheaders=''])
AC_SUBST(sysheaders)

AC_SUBST(use_default_link)
AC_ARG_WITH([default-link],
	    AC_HELP_STRING([--with-default-link],
			   [do not use explicit linker scripts]),
	    [use_default_link=$withval],
	    [use_default_link=default])

AC_ARG_ENABLE([sanity-checks],
	      AC_HELP_STRING([--disable-sanity-checks],
			     [really do not use threads (should not be used except in special situations) @<:@default=yes@:>@]),
	      [enable_sanity=$enableval],
	      [enable_sanity=yes])

AC_ARG_ENABLE([shared],
	      AC_HELP_STRING([--enable-shared],
			     [build shared library @<:@default=yes if GNU ld@:>@]),
	      [shared=$enableval],
	      [shared=yes])
AC_ARG_ENABLE([profile],
	      AC_HELP_STRING([--enable-profile],
			     [build profiled library @<:@default=no@:>@]),
	      [profile=$enableval],
	      [profile=no])
AC_ARG_ENABLE([timezone-tools],
	      AC_HELP_STRING([--disable-timezone-tools],
			     [do not install timezone tools @<:@default=install@:>@]),
	      [enable_timezone_tools=$enableval],
	      [enable_timezone_tools=yes])
AC_SUBST(enable_timezone_tools)

AC_ARG_ENABLE([hardcoded-path-in-tests],
	      AC_HELP_STRING([--enable-hardcoded-path-in-tests],
			     [hardcode newly built glibc path in tests @<:@default=no@:>@]),
	      [hardcoded_path_in_tests=$enableval],
	      [hardcoded_path_in_tests=no])
AC_SUBST(hardcoded_path_in_tests)

AC_ARG_ENABLE([stackguard-randomization],
	      AC_HELP_STRING([--enable-stackguard-randomization],
			     [initialize __stack_chk_guard canary with a random number at program start]),
	      [enable_stackguard_randomize=$enableval],
	      [enable_stackguard_randomize=no])
if test "$enable_stackguard_randomize" = yes; then
  AC_DEFINE(ENABLE_STACKGUARD_RANDOMIZE)
fi

AC_ARG_ENABLE([lock-elision],
	      AC_HELP_STRING([--enable-lock-elision[=yes/no]],
			     [Enable lock elision for pthread mutexes by default]),
	      [enable_lock_elision=$enableval],
	      [enable_lock_elision=no])
AC_SUBST(enable_lock_elision)
if test "$enable_lock_elision" = yes ; then
  AC_DEFINE(ENABLE_LOCK_ELISION)
fi

dnl Generic infrastructure for drop-in additions to libc.
AC_ARG_ENABLE([add-ons],
	      AC_HELP_STRING([--enable-add-ons@<:@=DIRS...@:>@],
			     [configure and build add-ons in DIR1,DIR2,...
			      search for add-ons if no parameter given]),
			     , [enable_add_ons=yes])

AC_ARG_ENABLE([hidden-plt],
	      AC_HELP_STRING([--disable-hidden-plt],
			     [do not hide internal function calls to avoid PLT]),
	      [hidden=$enableval],
	      [hidden=yes])
if test "x$hidden" = xno; then
  AC_DEFINE(NO_HIDDEN)
fi

AC_ARG_ENABLE([bind-now],
	      AC_HELP_STRING([--enable-bind-now],
			     [disable lazy relocations in DSOs]),
	      [bindnow=$enableval],
	      [bindnow=no])
AC_SUBST(bindnow)
if test "x$bindnow" = xyes; then
  AC_DEFINE(BIND_NOW)
fi

dnl On some platforms we cannot use dynamic loading.  We must provide
dnl static NSS modules.
AC_ARG_ENABLE([static-nss],
	      AC_HELP_STRING([--enable-static-nss],
			     [build static NSS modules @<:@default=no@:>@]),
	      [static_nss=$enableval],
	      [static_nss=no])
dnl Enable static NSS also if we build no shared objects.
if test x"$static_nss" = xyes || test x"$shared" = xno; then
  static_nss=yes
  AC_DEFINE(DO_STATIC_NSS)
fi

AC_ARG_ENABLE([force-install],
	      AC_HELP_STRING([--disable-force-install],
			     [don't force installation of files from this package, even if they are older than the installed files]),
	      [force_install=$enableval],
	      [force_install=yes])
AC_SUBST(force_install)

AC_ARG_ENABLE([maintainer-mode],
	      AC_HELP_STRING([--enable-maintainer-mode],
			     [enable make rules and dependencies not useful (and sometimes confusing) to the casual installer]),
	      [maintainer=$enableval],
	      [maintainer=no])

dnl On some platforms we allow dropping compatibility with all kernel
dnl versions.
AC_ARG_ENABLE([kernel],
	      AC_HELP_STRING([--enable-kernel=VERSION],
			     [compile for compatibility with kernel not older than VERSION]),
	      [minimum_kernel=$enableval],
	      [])
dnl Prevent unreasonable values.
if test "$minimum_kernel" = yes || test "$minimum_kernel" = no; then
  # Better nothing than this.
  minimum_kernel=""
else
  if test "$minimum_kernel" = current; then
    minimum_kernel=`uname -r 2>/dev/null` || minimum_kernel=
  fi
fi

dnl For the development we sometimes want gcc to issue even more warnings.
dnl This is not the default since many of the extra warnings are not
dnl appropriate.
AC_ARG_ENABLE([all-warnings],
	      AC_HELP_STRING([--enable-all-warnings],
			     [enable all useful warnings gcc can issue]),
	      [all_warnings=$enableval],
	      [])
AC_SUBST(all_warnings)

AC_ARG_ENABLE([werror],
	      AC_HELP_STRING([--disable-werror],
			     [do not build with -Werror]),
	      [enable_werror=$enableval],
	      [enable_werror=yes])
AC_SUBST(enable_werror)

AC_ARG_ENABLE([multi-arch],
	      AC_HELP_STRING([--enable-multi-arch],
			     [enable single DSO with optimizations for multiple architectures]),
	      [multi_arch=$enableval],
	      [multi_arch=default])

AC_ARG_ENABLE([nss-crypt],
	      AC_HELP_STRING([--enable-nss-crypt],
			     [enable libcrypt to use nss]),
	      [nss_crypt=$enableval],
	      [nss_crypt=no])
if test x$nss_crypt = xyes; then
  nss_includes=-I$(nss-config --includedir 2>/dev/null)
  if test $? -ne 0; then
    AC_MSG_ERROR([cannot find include directory with nss-config])
  fi
  old_CFLAGS="$CFLAGS"
  CFLAGS="$CFLAGS $nss_includes"
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([typedef int PRBool;
#include <hasht.h>
#include <nsslowhash.h>
void f (void) { NSSLOW_Init (); }])],
	     libc_cv_nss_crypt=yes,
	     AC_MSG_ERROR([
cannot find NSS headers with lowlevel hash function interfaces]))
  old_LIBS="$LIBS"
  LIBS="$LIBS -lfreebl3"
  AC_LINK_IFELSE([AC_LANG_PROGRAM([typedef int PRBool;
#include <hasht.h>
#include <nsslowhash.h>],
				  [NSSLOW_Init();])],
		 libc_cv_nss_crypt=yes,
		 AC_MSG_ERROR([
cannot link program using lowlevel NSS hash functions]))
  CFLAGS="$old_CFLAGS"
  LIBS="$old_LIBS"
else
  libc_cv_nss_crypt=no
fi
AC_SUBST(libc_cv_nss_crypt)


AC_ARG_ENABLE([obsolete-rpc],
              AC_HELP_STRING([--enable-obsolete-rpc],
                             [build and install the obsolete RPC code for link-time usage]),
              [link_obsolete_rpc=$enableval],
              [link_obsolete_rpc=no])
AC_SUBST(link_obsolete_rpc)

if test "$link_obsolete_rpc" = yes; then
  AC_DEFINE(LINK_OBSOLETE_RPC)
fi

AC_ARG_ENABLE([systemtap],
              [AS_HELP_STRING([--enable-systemtap],
	       [enable systemtap static probe points @<:@default=no@:>@])],
              [systemtap=$enableval],
	      [systemtap=no])
if test "x$systemtap" != xno; then
  AC_CACHE_CHECK([for systemtap static probe support], libc_cv_sdt, [dnl
  old_CFLAGS="$CFLAGS"
  CFLAGS="-std=gnu11 $CFLAGS"
  AC_COMPILE_IFELSE([AC_LANG_SOURCE([[#include <sys/sdt.h>
void foo (int i, void *p)
{
  asm ("" STAP_PROBE_ASM (foo, bar, STAP_PROBE_ASM_TEMPLATE (2)) ""
       :: STAP_PROBE_ASM_OPERANDS (2, i, p));
}]])], [libc_cv_sdt=yes], [libc_cv_sdt=no])
  CFLAGS="$old_CFLAGS"])
  if test $libc_cv_sdt = yes; then
    AC_DEFINE([USE_STAP_PROBE])
  elif test "x$systemtap" != xauto; then
    AC_MSG_FAILURE([systemtap support needs sys/sdt.h with asm support])
  fi
fi

AC_ARG_ENABLE([build-nscd],
	      [AS_HELP_STRING([--disable-build-nscd],
	       [disable building and installing the nscd daemon])],
	      [build_nscd=$enableval],
	      [build_nscd=default])
AC_SUBST(build_nscd)

# Note the use of $use_nscd is near the bottom of the file.
AC_ARG_ENABLE([nscd],
	      [AS_HELP_STRING([--disable-nscd],
	       [library functions will not contact the nscd daemon])],
	      [use_nscd=$enableval],
	      [use_nscd=yes])

AC_ARG_ENABLE([pt_chown],
	      [AS_HELP_STRING([--enable-pt_chown],
	       [Enable building and installing pt_chown])],
	      [build_pt_chown=$enableval],
	      [build_pt_chown=no])
AC_SUBST(build_pt_chown)
if test "$build_pt_chown" = yes; then
  AC_DEFINE(HAVE_PT_CHOWN)
fi

# The abi-tags file uses a fairly simplistic model for name recognition that
# can't distinguish i486-pc-linux-gnu fully from i486-pc-gnu.  So we mutate a
# $host_os of `gnu*' here to be `gnu-gnu*' just so that it can tell.
# This doesn't get used much beyond that, so it's fairly safe.
case "$host_os" in
linux*)
  ;;
gnu*)
  host_os=`echo $host_os | sed -e 's/gnu/gnu-gnu/'`
  ;;
esac

AC_ARG_ENABLE([mathvec],
	      [AS_HELP_STRING([--enable-mathvec],
	      [Enable building and installing mathvec @<:@default depends on architecture@:>@])],
	      [build_mathvec=$enableval],
	      [build_mathvec=notset])

# The abi-tags file uses a fairly simplistic model for name recognition that
# can't distinguish i486-pc-linux-gnu fully from i486-pc-gnu.  So we mutate a
# $host_os of `gnu*' here to be `gnu-gnu*' just so that it can tell.
# This doesn't get used much beyond that, so it's fairly safe.
case "$host_os" in
linux*)
  ;;
gnu*)
  host_os=`echo $host_os | sed -e 's/gnu/gnu-gnu/'`
  ;;
esac

# We keep the original values in `$config_*' and never modify them, so we
# can write them unchanged into config.make.  Everything else uses
# $machine, $vendor, and $os, and changes them whenever convenient.
config_machine=$host_cpu config_vendor=$host_vendor config_os=$host_os

# Don't allow vendor == "unknown"
test "$config_vendor" = unknown && config_vendor=
config_os="`echo $config_os | sed 's/^unknown-//'`"

# Some configurations imply other options.
elf=yes

# The configure fragment of an add-on port can modify these to supplement
# or override the table in the case statement below.  No fragment should
# ever change the config_* variables, however.
machine=$config_machine
vendor=$config_vendor
os=$config_os
base_os=''

submachine=
AC_ARG_WITH([cpu],
	    AS_HELP_STRING([--with-cpu=CPU], [select code for CPU variant]),
	    [dnl
  case "$withval" in
  yes|'') AC_MSG_ERROR([--with-cpu requires an argument]) ;;
  no) ;;
  *) submachine="$withval" ;;
  esac
])

# An preconfigure script can set this when it wants to disable the sanity
# check below.
libc_config_ok=no

dnl Let sysdeps/*/preconfigure act here, like they can in add-ons.
LIBC_PRECONFIGURE([$srcdir], [for sysdeps])

dnl Having this here, though empty, makes sure that if add-ons' fragments
dnl do AC_CONFIG_SUBDIRS([some-dir]), which just sets $subdirs, then
dnl our AC_OUTPUT will actually use it.
AC_CONFIG_SUBDIRS()

case "$enable_add_ons" in
''|no) add_ons= ;;
yes|'*')
 add_ons=`cd $srcdir && ls -d 2> /dev/null */configure */sysdeps |
	  sed 's@/[[^/]]*$@@' | sort | uniq`
	 add_ons_automatic=yes
	 ;;
*) add_ons=`echo "$enable_add_ons" | sed 's/,/ /g'`
       add_ons_automatic=no ;;
esac

configured_add_ons=
add_ons_sfx=
add_ons_pfx=
if test x"$add_ons" != x; then
  for f in $add_ons; do
    # Some sanity checks
    case "$f" in
    crypt)
      AC_MSG_ERROR([
*** It seems that you're using an old \`crypt' add-on.  crypt is now
*** part of glibc and using the old add-on will not work with this
*** release.  Start again with fresh sources and without the old
*** \`crypt' add-on.])
    ;;
    localedata)
      AC_MSG_ERROR([
*** It seems that you're using an old \`localedata' add-on.  localedata
*** is now part of glibc and using the old add-on will not work with
*** this release.  Start again with fresh sources and without the old
*** \`localedata' add-on.])
    ;;
    esac
  done

  # Now source each add-on's configure fragment.
  # The fragments can use $srcdir/$libc_add_on to find themselves,
  # and test $add_ons_automatic to see if they were explicitly requested.
  # A fragment can clear (or even change) $libc_add_on to affect
  # whether it goes into the list to be actually used in the build.
  use_add_ons=
  for libc_add_on in $add_ons; do
    # Test whether such a directory really exists.
    # It can be absolute, or relative to $srcdir, or relative to the build dir.
    case "$libc_add_on" in
    /*)
      libc_add_on_srcdir=$libc_add_on
      ;;
    *)
      test -d "$srcdir/$libc_add_on" || {
	if test -d "$libc_add_on"; then
	  libc_add_on="`pwd`/$libc_add_on"
	else
	  AC_MSG_ERROR(add-on directory \"$libc_add_on\" does not exist)
	fi
      }
      libc_add_on_srcdir=$srcdir/$libc_add_on
      ;;
    esac

    libc_add_on_frag=$libc_add_on_srcdir/configure
    libc_add_on_canonical=
    libc_add_on_config_subdirs=
    if test -r "$libc_add_on_frag"; then
      AC_MSG_NOTICE(running configure fragment for add-on $libc_add_on)
      libc_add_on_canonical=unknown
      libc_add_on_subdirs=
      . "$libc_add_on_frag"
      test -z "$libc_add_on" || {
	configured_add_ons="$configured_add_ons $libc_add_on"
	if test "x$libc_add_on_canonical" = xunknown; then
	  AC_MSG_ERROR(fragment must set \$libc_add_on_canonical)
	fi
	for d in $libc_add_on_subdirs; do
	  case "$libc_add_on" in
	  /*) subdir_srcdir="$libc_add_on" ;;
	  *) subdir_srcdir="\$(..)$libc_add_on" ;;
	  esac
	  case "$d" in
	  .)
	    d="${libc_add_on_canonical:-$libc_add_on}"
	    ;;
	  /*)
	    subdir_srcdir="$d"
	    ;;
	  *)
	    subdir_srcdir="$subdir_srcdir/$d"
	    ;;
	  esac
	  d=`echo "$d" | sed 's@/*$@@;s@^.*/@@'`
	  add_on_subdirs="$add_on_subdirs $d"
	  test "$subdir_srcdir" = "\$(..)$d" || config_vars="$config_vars
$d-srcdir = $subdir_srcdir"
	done
	for d in $libc_add_on_config_subdirs; do
	  case "$d" in
	  /*) AC_MSG_ERROR(dnl
fragment uses absolute path in \$libc_add_on_config_subdirs) ;;
	  esac
	  if test ! -d "$libc_add_on_srcdir/$d"; then
	    AC_MSG_ERROR(fragment wants to configure missing directory $d)
	  fi
	  case "$libc_add_on" in
	  /*) AC_MSG_ERROR(dnl
relative path required for add-on using \$libc_add_on_config_subdirs) ;;
	  esac
	  subdirs="$subdirs $libc_add_on/$d"
	done
      }
    fi
    if test -n "$libc_add_on"; then
      LIBC_PRECONFIGURE([$libc_add_on_srcdir], [add-on $libc_add_on for])
      use_add_ons="$use_add_ons $libc_add_on"
      add_ons_pfx="$add_ons_pfx $libc_add_on/"
      test -z "$libc_add_on_canonical" ||
      add_ons_sfx="$add_ons_sfx /$libc_add_on_canonical"
    fi
  done
  # Use echo to strip excess whitespace.
  add_ons="`echo $use_add_ons`"
fi
AC_SUBST(add_ons)
AC_SUBST(add_on_subdirs)


###
### By using the undocumented --enable-hacker-mode option for configure
### one can skip this test to make the configuration not fail for unsupported
### platforms.
###
if test -z "$enable_hacker_mode" && test x"$libc_config_ok" != xyes; then
  case "$machine-$host_os" in
  *-linux* | *-gnu* | *-kfreebsd*)
    ;;
  *)
    AC_MSG_ERROR([
*** The GNU C library is currently unavailable for this platform.
*** If you are interested in seeing glibc on this platform visit
*** the "How to submit a new port" in the wiki:
***   https://sourceware.org/glibc/wiki/#Development
*** and join the community!])
    ;;
  esac
fi

# Set base_machine if not set by a preconfigure fragment.
test -n "$base_machine" || base_machine=$machine
AC_SUBST(base_machine)

# For the multi-arch option we need support in the assembler & linker.
AC_CACHE_CHECK([for assembler and linker STT_GNU_IFUNC support],
	       libc_cv_ld_gnu_indirect_function, [dnl
cat > conftest.S <<EOF
.type foo,%gnu_indirect_function
foo:
.globl _start
_start:
.globl __start
__start:
.data
#ifdef _LP64
.quad foo
#else
.long foo
#endif
EOF
libc_cv_ld_gnu_indirect_function=no
if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
	    -nostartfiles -nostdlib \
	    -o conftest conftest.S 1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD; then
  # Do a link to see if the backend supports IFUNC relocs.
  $READELF -r conftest 1>&AS_MESSAGE_LOG_FD
  LC_ALL=C $READELF -r conftest | grep 'no relocations' >/dev/null || {
    libc_cv_ld_gnu_indirect_function=yes
  }
fi
rm -f conftest*])

if test x"$libc_cv_ld_gnu_indirect_function" != xyes; then
  if test x"$multi_arch" = xyes; then
    AC_MSG_ERROR([--enable-multi-arch support requires assembler and linker support])
  else
    multi_arch=no
  fi
fi
multi_arch_d=
if test x"$multi_arch" != xno; then
  multi_arch_d=/multiarch
fi

# Compute the list of sysdep directories for this configuration.
# This can take a while to compute.
sysdep_dir=$srcdir/sysdeps
AC_MSG_CHECKING(sysdep dirs)
dnl We need to use [ and ] for other purposes for a while now.
changequote(,)dnl
# Make sco3.2v4 become sco3.2.4 and sunos4.1.1_U1 become sunos4.1.1.U1.
os="`echo $os | sed 's/\([0-9A-Z]\)[v_]\([0-9A-Z]\)/\1.\2/g'`"

test "x$base_os" != x || case "$os" in
gnu*)
  base_os=mach/hurd ;;
linux*)
  base_os=unix/sysv ;;
k*bsd*)
  base_os=unix/bsd/bsd4.4 ;;
esac

# For sunos4.1.1, try sunos4.1.1, then sunos4.1, then sunos4, then sunos.
tail=$os
ostry=$os
while o=`echo $tail | sed 's/\.[^.]*$//'`; test $o != $tail; do
  ostry="$ostry /$o"
  tail=$o
done
o=`echo $tail | sed 's/[0-9]*$//'`
if test $o != $tail; then
  ostry="$ostry /$o"
fi
# For linux-gnu, try linux-gnu, then linux.
o=`echo $tail | sed 's/-.*$//'`
if test $o != $tail; then
  ostry="$ostry /$o"
fi

# For unix/sysv/sysv4, try unix/sysv/sysv4, then unix/sysv, then unix.
base=
tail=$base_os
while b=`echo $tail | sed 's@^\(.*\)/\([^/]*\)$@& \1@'`; test -n "$b"; do
  set $b
  base="$base /$1"
  tail="$2"
done

# For sparc/sparc32, try sparc/sparc32 and then sparc.
mach=
tail=$machine${submachine:+/$submachine}
while m=`echo $tail | sed 's@^\(.*\)/\([^/]*\)$@& \1@'`; test -n "$m"; do
  set $m
  # Prepend the machine's FPU directory unless --without-fp.
  if test "$with_fp" = yes; then
    maybe_fpu=/fpu
  else
    maybe_fpu=/nofpu
  fi
  # For each machine term, try it with and then without /multiarch.
  for try_fpu in $maybe_fpu ''; do
    for try_multi in $multi_arch_d ''; do
      mach="$mach /$1$try_fpu$try_multi"
    done
  done
  tail="$2"
done

dnl We are done with glob and regexp uses of [ and ]; return to autoconf.
changequote([,])dnl

# Find what sysdep directories exist.
sysnames_add_ons=
sysnames=
for b in $base ''; do
  for m0 in $mach ''; do
    for v in /$vendor ''; do
      test "$v" = / && continue
      for o in /$ostry ''; do
	test "$o" = / && continue
	for m in $mach ''; do
	  for d in $add_ons_pfx ''; do
	    for a in $add_ons_sfx ''; do
	      try_suffix="$m0$b$v$o$m"
	      if test -n "$try_suffix"; then
		try_srcdir="${srcdir}/"
		case "$d" in
		/*) try_srcdir= ;;
		esac
		try="${d}sysdeps$try_suffix$a"
		test -n "$enable_debug_configure" &&
		echo "$0 [DEBUG]: try $try" >&2
		if test -d "$try_srcdir$try"; then
		  sysnames="$sysnames $try"
		  { test -n "$o" || test -n "$b"; } && os_used=t
		  { test -n "$m" || test -n "$m0"; } && machine_used=t
		  case x${m0:-$m} in
		  x*/$submachine) submachine_used=t ;;
		  esac
		  if test -n "$d"; then
		    case "$sysnames_add_ons" in
		    *" $d "*) ;;
		    *|'') sysnames_add_ons="$sysnames_add_ons $d" ;;
		    esac
		  fi
		fi
	      fi
	    done
	  done
	done
      done
    done
  done
done

# If the assembler supports gnu_indirect_function symbol type and the
# architecture supports multi-arch, we enable multi-arch by default.
case $sysnames_add_ons$sysnames in
*"$multi_arch_d"*)
  ;;
*)
  test x"$multi_arch" = xdefault && multi_arch=no
  ;;
esac
if test x"$multi_arch" != xno; then
  AC_DEFINE(USE_MULTIARCH)
fi
AC_SUBST(multi_arch)

if test -z "$os_used" && test "$os" != none; then
  AC_MSG_ERROR(Operating system $os is not supported.)
fi
if test -z "$machine_used" && test "$machine" != none; then
  AC_MSG_ERROR(The $machine is not supported.)
fi
if test -z "$submachine_used" && test -n "$submachine"; then
  AC_MSG_ERROR(The $submachine subspecies of $host_cpu is not supported.)
fi
AC_SUBST(submachine)

# We have now validated the configuration.

# Expand the list of system names into a full list of directories
# from each element's parent name and Implies file (if present).
set $sysnames
names=
while test $# -gt 0; do
  name=$1
  shift

  case " $names " in *" $name "*)
    # Already in the list.
    continue
  esac

  # Report each name as we discover it, so there is no long pause in output.
  echo $ECHO_N "$name $ECHO_C" >&AS_MESSAGE_FD

  name_base=`echo $name | sed -e 's@\(.*sysdeps\)/.*@\1@'`

  case $name in
    /*) xsrcdir= ;;
    *)  xsrcdir=$srcdir/ ;;
  esac
  test -n "$enable_debug_configure" &&
  echo "[DEBUG]: name/Implies $xsrcdir$name/Implies" >&2

  for implies_file in Implies Implies-before Implies-after; do
    implies_type=`echo $implies_file | sed s/-/_/`
    eval ${implies_type}=
    if test -f $xsrcdir$name/$implies_file; then
      # Collect more names from the `Implies' file (removing comments).
      implied_candidate="`sed 's/#.*$//' < $xsrcdir$name/$implies_file`"
      for x in $implied_candidate; do
	found=no
	if test -d $xsrcdir$name_base/$x; then
	  eval "${implies_type}=\"\$${implies_type} \$name_base/\$x\""
	  found=yes
	fi
	for d in $add_ons_pfx ''; do
	  try="${d}sysdeps/$x"
	  case $d in
	   /*) try_srcdir= ;;
	   *) try_srcdir=$srcdir/ ;;
	  esac
	  test -n "$enable_debug_configure" &&
	   echo "[DEBUG]: $name $implies_file $x try($d) {$try_srcdir}$try" >&2
	  if test $try != $xsrcdir$name_base/$x && test -d $try_srcdir$try;
	  then
	    eval "${implies_type}=\"\$${implies_type} \$try\""
	    found=yes
	    case "$sysnames_add_ons" in
	    *" $d "*) ;;
	    *|'') sysnames_add_ons="$sysnames_add_ons $d" ;;
	    esac
	  fi
	done
	if test $found = no; then
	  AC_MSG_WARN($name/$implies_file specifies nonexistent $x)
	fi
      done
    fi
  done

  # Add NAME to the list of names.
  names="$names $name"

  # Find the parent of NAME, using the empty string if it has none.
changequote(,)dnl
  parent="`echo $name | sed -n -e 's=/[^/]*$==' -e '/sysdeps$/q' -e p`"
changequote([,])dnl

  test -n "$enable_debug_configure" &&
    echo "[DEBUG]: $name Implies='$Implies' rest='$*' parent='$parent' \
Implies_before='$Implies_before' Implies_after='$Implies_after'" >&2

  # Add the names implied by NAME, and NAME's parent (if it has one), to
  # the list of names to be processed (the argument list).  We prepend the
  # implied names to the list and append the parent.  We want implied
  # directories to come before further directories inferred from the
  # configuration components; this ensures that for sysv4, unix/common
  # (implied by unix/sysv/sysv4) comes before unix/sysv (in ostry (here $*)
  # after sysv4).
  sysnames="`echo $Implies $* $Implies_before $parent $Implies_after`"
  test -n "$sysnames" && set $sysnames
done

# Add the default directories.
default_sysnames="sysdeps/generic"
sysnames="$names $default_sysnames"
AC_SUBST(sysnames)
# The other names were emitted during the scan.
AC_MSG_RESULT($default_sysnames)

# Collect the list of add-ons that supply partial sysdeps trees.
sysdeps_add_ons=
for add_on in $add_ons; do
  case "$add_on" in
  /*) xsrcdir= ;;
  *) xsrcdir="$srcdir/" ;;
  esac

  test -d "$xsrcdir$add_on/sysdeps" || {
    case "$configured_add_ons " in
    *" $add_on "*) ;;
    *|'')
      AC_MSG_ERROR(add-on $add_on has no configure fragment or sysdeps tree)
      ;;
    esac
    continue
  }

  sysdeps_add_ons="$sysdeps_add_ons $add_on"
  case "$sysnames_add_ons" in
  *" $add_on/ "*) ;;
  *|'')
    AC_MSG_WARN(add-on $add_on contributed no sysdeps directories)
    continue ;;
  esac

  found=no
  for d in $sysnames; do
    case "$d" in
    $add_on/sysdeps/*) ;;
    *) continue ;;
    esac
    (cd "$xsrcdir$d" && for f in *[[!~]]; do
       case "$f" in
       sys|bits)
	 for ff in $f/*.h; do
	   test -d "$ff" || { test -e "$ff" && exit 88; }
	 done
	 ;;
       *)
	 test -d "$f" || { test -e "$f" && exit 88; }
	 ;;
       esac
     done)
    if test $? -eq 88; then
      found=yes
      break
    fi
  done
  if test $found = no; then
    AC_MSG_WARN(add-on $add_on contributed no useful sysdeps directories)
  fi
done
AC_SUBST(sysdeps_add_ons)


### Locate tools.

AC_PROG_INSTALL
if test "$INSTALL" = "${srcdir}/scripts/install-sh -c"; then
  # The makefiles need to use a different form to find it in $srcdir.
  INSTALL='\$(..)./scripts/install-sh -c'
fi
AC_PROG_LN_S

LIBC_PROG_BINUTILS

# Accept binutils 2.22 or newer.
AC_CHECK_PROG_VER(AS, $AS, --version,
		  [GNU assembler.* \([0-9]*\.[0-9.]*\)],
		  [2.1[0-9][0-9]*|2.2[2-9]*|2.[3-9][0-9]*|[3-9].*|[1-9][0-9]*],
		  AS=: critic_missing="$critic_missing as")
AC_CHECK_PROG_VER(LD, $LD, --version,
		  [GNU ld.* \([0-9][0-9]*\.[0-9.]*\)],
		  [2.1[0-9][0-9]*|2.2[2-9]*|2.[3-9][0-9]*|[3-9].*|[1-9][0-9]*],
		  LD=: critic_missing="$critic_missing ld")

# These programs are version sensitive.
AC_CHECK_TOOL_PREFIX
AC_CHECK_PROG_VER(MAKE, gnumake gmake make, --version,
  [GNU Make[^0-9]*\([0-9][0-9.]*\)],
  [3.79* | 3.[89]* | [4-9].* | [1-9][0-9]*], critic_missing="$critic_missing make")

AC_CHECK_PROG_VER(MSGFMT, gnumsgfmt gmsgfmt msgfmt, --version,
  [GNU gettext.* \([0-9]*\.[0-9.]*\)],
  [0.10.3[6-9]* | 0.10.[4-9][0-9]* | 0.1[1-9]* | 0.[2-9][0-9]* | [1-9].*],
  MSGFMT=: aux_missing="$aux_missing msgfmt")
AC_CHECK_PROG_VER(MAKEINFO, makeinfo, --version,
  [GNU texinfo.* \([0-9][0-9.]*\)],
  [4.[7-9]*|4.[1-9][0-9]*|[5-9].*],
  MAKEINFO=: aux_missing="$aux_missing makeinfo")
AC_CHECK_PROG_VER(SED, sed, --version,
  [GNU sed[^0-9]* \([0-9]*\.[0-9.]*\)],
  [3.0[2-9]*|3.[1-9]*|[4-9]*],
  SED=: aux_missing="$aux_missing sed")
AC_CHECK_PROG_VER(AWK, gawk, --version,
  [GNU Awk[^0-9]*\([0-9][0-9.]*\)],
  [3.1.[2-9]*|3.[2-9]*|[4-9]*], critic_missing="$critic_missing gawk")

AC_CACHE_CHECK([if $CC is sufficient to build libc], libc_cv_compiler_ok, [
AC_TRY_COMPILE([], [
#if !defined __GNUC__ || __GNUC__ < 4 || (__GNUC__ == 4 && __GNUC_MINOR__ < 7)
#error insufficient compiler
#endif],
	       [libc_cv_compiler_ok=yes],
	       [libc_cv_compiler_ok=no])])
AS_IF([test $libc_cv_compiler_ok != yes],
      [critic_missing="$critic_missing compiler"])

AC_CHECK_TOOL(NM, nm, false)

if test "x$maintainer" = "xyes"; then
  AC_CHECK_PROGS(AUTOCONF, autoconf, no)
  case "x$AUTOCONF" in
  xno|x|x:) AUTOCONF=no ;;
  *)
    AC_CACHE_CHECK(dnl
  whether $AUTOCONF${ACFLAGS:+ }$ACFLAGS works, libc_cv_autoconf_works, [dnl
    if (cd $srcdir; $AUTOCONF $ACFLAGS configure.ac > /dev/null 2>&1); then
      libc_cv_autoconf_works=yes
    else
      libc_cv_autoconf_works=no
    fi])
    test $libc_cv_autoconf_works = yes || AUTOCONF=no
    ;;
  esac
  if test "x$AUTOCONF" = xno; then
    aux_missing="$aux_missing autoconf"
  fi
else
  AUTOCONF=no
fi

test -n "$critic_missing" && AC_MSG_ERROR([
*** These critical programs are missing or too old:$critic_missing
*** Check the INSTALL file for required versions.])

test -n "$aux_missing" && AC_MSG_WARN([
*** These auxiliary programs are missing or incompatible versions:$aux_missing
*** some features will be disabled.
*** Check the INSTALL file for required versions.])

# if using special system headers, find out the compiler's sekrit
# header directory and add that to the list.  NOTE: Only does the right
# thing on a system that doesn't need fixincludes.  (Not presently a problem.)
if test -n "$sysheaders"; then
  SYSINCLUDES=-nostdinc
  for d in include include-fixed; do
    i=`$CC -print-file-name="$d"` && test "x$i" != x && test "x$i" != "x$d" &&
    SYSINCLUDES="$SYSINCLUDES -isystem $i"
  done
  SYSINCLUDES="$SYSINCLUDES \
-isystem `echo $sysheaders | sed 's/:/ -isystem /g'`"
  if test -n "$CXX"; then
    CXX_SYSINCLUDES=
    for cxxheaders in `$CXX -v -S -x c++ /dev/null -o /dev/null 2>&1 \
    | sed -n -e '1,/#include/d' -e 's/^ \(\/.*\/[cg]++\)/\1/p'`; do
      test "x$cxxheaders" != x &&
      CXX_SYSINCLUDES="$CXX_SYSINCLUDES -isystem $cxxheaders"
    done
  fi
fi
AC_SUBST(SYSINCLUDES)
AC_SUBST(CXX_SYSINCLUDES)

# Test if LD_LIBRARY_PATH contains the notation for the current directory
# since this would lead to problems installing/building glibc.
# LD_LIBRARY_PATH contains the current directory if one of the following
# is true:
# - one of the terminals (":" and ";") is the first or last sign
# - two terminals occur directly after each other
# - the path contains an element with a dot in it
AC_MSG_CHECKING(LD_LIBRARY_PATH variable)
changequote(,)dnl
case ${LD_LIBRARY_PATH} in
  [:\;]* | *[:\;] | *[:\;][:\;]* |  *[:\;]. | .[:\;]*| . | *[:\;].[:\;]* )
    ld_library_path_setting="contains current directory"
    ;;
  *)
    ld_library_path_setting="ok"
    ;;
esac
changequote([,])dnl
AC_MSG_RESULT($ld_library_path_setting)
if test "$ld_library_path_setting" != "ok"; then
AC_MSG_ERROR([
*** LD_LIBRARY_PATH shouldn't contain the current directory when
*** building glibc. Please change the environment variable
*** and run configure again.])
fi

AC_PATH_PROG(BASH_SHELL, bash, no)

AC_PATH_PROG(PERL, perl, no)
if test "$PERL" != no &&
   (eval `$PERL -V:apiversion`; test `expr "$apiversion" \< 5` -ne 0); then
  PERL=no
fi
AC_PATH_PROG(INSTALL_INFO, install-info, no,
	     $PATH:/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin)
AC_CHECK_PROG_VER(BISON, bison, --version,
		  [bison (GNU Bison) \([0-9]*\.[0-9.]*\)],
		  [2.7*|[3-9].*|[1-9][0-9]*],
		  BISON=no)

AC_CACHE_CHECK(for .set assembler directive, libc_cv_asm_set_directive, [dnl
cat > conftest.s <<EOF
.text
foo:
.set glibc_conftest_frobozz,foo
.globl glibc_conftest_frobozz
EOF
# The alpha-dec-osf1 assembler gives only a warning for `.set'
# (but it doesn't work), so we must do a linking check to be sure.
cat > conftest1.c <<\EOF
extern int glibc_conftest_frobozz;
void _start() { glibc_conftest_frobozz = 1; }
EOF
if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
	    -nostartfiles -nostdlib \
	    -o conftest conftest.s conftest1.c 1>&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD; then
  libc_cv_asm_set_directive=yes
else
  libc_cv_asm_set_directive=no
fi
rm -f conftest*])
if test $libc_cv_asm_set_directive = yes; then
  AC_DEFINE(HAVE_ASM_SET_DIRECTIVE)
fi

AC_CACHE_CHECK(linker support for protected data symbol,
	       libc_cv_protected_data,
	       [cat > conftest.c <<EOF
		int bar __attribute__ ((visibility ("protected"))) = 1;
EOF
		libc_cv_protected_data=no
		if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles -fPIC -shared conftest.c -o conftest.so); then
		  cat > conftest.c <<EOF
		  extern int bar;
		  int main (void) { return bar; }
EOF
		  if AC_TRY_COMMAND(${CC-cc} -nostdlib -nostartfiles conftest.c -o conftest conftest.so); then
		    libc_cv_protected_data=yes
		  fi
		fi
		rm -f conftest.*
	       ])
AC_SUBST(libc_cv_protected_data)

AC_CACHE_CHECK(for broken __attribute__((alias())),
	       libc_cv_broken_alias_attribute,
	       [cat > conftest.c <<EOF
	       extern int foo (int x) __asm ("xyzzy");
	       int bar (int x) { return x; }
	       extern __typeof (bar) foo __attribute ((weak, alias ("bar")));
	       extern int dfoo;
	       extern __typeof (dfoo) dfoo __asm ("abccb");
	       int dfoo = 1;
EOF
	       libc_cv_broken_alias_attribute=yes
	       if AC_TRY_COMMAND(${CC-cc} -Werror -S conftest.c -o conftest.s 1>&AS_MESSAGE_LOG_FD); then
		 if grep 'xyzzy' conftest.s >/dev/null &&
		    grep 'abccb' conftest.s >/dev/null; then
		   libc_cv_broken_alias_attribute=no
		 fi
	       fi
	       rm -f conftest.c conftest.s
	       ])
if test $libc_cv_broken_alias_attribute = yes; then
  AC_MSG_ERROR(working alias attribute support required)
fi

AC_CACHE_CHECK(whether to put _rtld_local into .sdata section,
	       libc_cv_have_sdata_section,
	       [echo "int i;" > conftest.c
		libc_cv_have_sdata_section=no
		if ${CC-cc} $LDFLAGS -fPIC -shared -Wl,--verbose conftest.c -o conftest.so 2>&1 \
		   | grep '\.sdata' >/dev/null; then
		  libc_cv_have_sdata_section=yes
		fi
		rm -f conftest.c conftest.so
	       ])
if test $libc_cv_have_sdata_section = yes; then
  AC_DEFINE(HAVE_SDATA_SECTION)
fi

AC_CACHE_CHECK(whether to use .ctors/.dtors header and trailer,
	       libc_cv_ctors_header, [dnl
  libc_cv_ctors_header=yes
  LIBC_TRY_LINK_STATIC([
__attribute__ ((constructor)) void ctor (void) { asm (""); }
__attribute__ ((destructor))  void dtor (void) { asm (""); }
],
	      [dnl
      AS_IF([$READELF -WS conftest$ac_exeext | $AWK '
	{ gsub(/\@<:@ */, "@<:@") }
	$2 == ".ctors" || $2 == ".dtors" {
	  size = strtonum("0x" $6)
	  align = strtonum("0x" $NF)
	  seen@<:@$2@:>@ = 1
	  stub@<:@$2@:>@ = size == align * 2
	}
	END {
	  ctors_ok = !seen@<:@".ctors"@:>@ || stub@<:@".ctors"@:>@
	  dtors_ok = !seen@<:@".dtors"@:>@ || stub@<:@".dtors"@:>@
	  exit ((ctors_ok && dtors_ok) ? 0 : 1)
	}
      '], [libc_cv_ctors_header=no])
    ], [dnl
      AC_MSG_ERROR([missing __attribute__ ((constructor)) support??])
    ])
])
if test $libc_cv_ctors_header = no; then
  AC_DEFINE(NO_CTORS_DTORS_SECTIONS)
fi

AC_CACHE_CHECK(for libunwind-support in compiler,
	       libc_cv_cc_with_libunwind, [
  cat > conftest.c <<EOF
int main (void) { return 0; }
EOF
  if ${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS -static -o conftest \
     conftest.c -v 2>&1 >/dev/null | grep ' -lunwind ' >/dev/null; then
    libc_cv_cc_with_libunwind=yes
  else
    libc_cv_cc_with_libunwind=no
  fi
  rm -f conftest*])
AC_SUBST(libc_cv_cc_with_libunwind)
if test $libc_cv_cc_with_libunwind = yes; then
  AC_DEFINE(HAVE_CC_WITH_LIBUNWIND)
fi

ASFLAGS_config=
AC_CACHE_CHECK(whether --noexecstack is desirable for .S files,
	       libc_cv_as_noexecstack, [dnl
cat > conftest.c <<EOF
void foo (void) { }
EOF
if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS
		   -S -o conftest.s conftest.c 1>&AS_MESSAGE_LOG_FD]) \
   && grep .note.GNU-stack conftest.s >/dev/null \
   && AC_TRY_COMMAND([${CC-cc} $ASFLAGS -Wa,--noexecstack
		      -c -o conftest.o conftest.s 1>&AS_MESSAGE_LOG_FD])
then
  libc_cv_as_noexecstack=yes
else
  libc_cv_as_noexecstack=no
fi
rm -f conftest*])
if test $libc_cv_as_noexecstack = yes; then
  ASFLAGS_config="$ASFLAGS_config -Wa,--noexecstack"
fi
AC_SUBST(ASFLAGS_config)

AC_CACHE_CHECK(for -z combreloc,
	       libc_cv_z_combreloc, [dnl
cat > conftest.c <<EOF
extern int bar (int);
extern int mumble;
int foo (void) { return bar (mumble); }
EOF
if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS
			-fPIC -shared -o conftest.so conftest.c
			-nostdlib -nostartfiles
			-Wl,-z,combreloc 1>&AS_MESSAGE_LOG_FD])
then
dnl The following test is a bit weak.  We must use a tool which can test
dnl cross-platform since the gcc used can be a cross compiler.  Without
dnl introducing new options this is not easily doable.  Instead use a tool
dnl which always is cross-platform: readelf.  To detect whether -z combreloc
dnl look for a section named .rel.dyn.
  if $READELF -S conftest.so | grep '\.rel\(a\|\)\.dyn' > /dev/null; then
    libc_cv_z_combreloc=yes
  else
    libc_cv_z_combreloc=no
  fi
else
  libc_cv_z_combreloc=no
fi
rm -f conftest*])
if test "$libc_cv_z_combreloc" = yes; then
  AC_DEFINE(HAVE_Z_COMBRELOC)
fi
AC_SUBST(libc_cv_z_combreloc)

LIBC_LINKER_FEATURE([-z execstack], [-Wl,-z,execstack],
		    [libc_cv_z_execstack=yes], [libc_cv_z_execstack=no])
AC_SUBST(libc_cv_z_execstack)

AC_CACHE_CHECK(for -fpie, libc_cv_fpie, [dnl
LIBC_TRY_CC_OPTION([-fpie], [libc_cv_fpie=yes], [libc_cv_fpie=no])
])

AC_SUBST(libc_cv_fpie)

AC_CACHE_CHECK(for --hash-style option,
	       libc_cv_hashstyle, [dnl
cat > conftest.c <<EOF
int _start (void) { return 42; }
EOF
if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS
			    -fPIC -shared -o conftest.so conftest.c
			    -Wl,--hash-style=both -nostdlib 1>&AS_MESSAGE_LOG_FD])
then
  libc_cv_hashstyle=yes
else
  libc_cv_hashstyle=no
fi
rm -f conftest*])
AC_SUBST(libc_cv_hashstyle)

# The linker's default -shared behavior is good enough if it
# does these things that our custom linker scripts ensure that
# all allocated NOTE sections come first.
if test "$use_default_link" = default; then
  AC_CACHE_CHECK([for sufficient default -shared layout],
		  libc_cv_use_default_link, [dnl
  libc_cv_use_default_link=no
  cat > conftest.s <<\EOF
	  .section .note.a,"a",%note
	  .balign 4
	  .long 4,4,9
	  .string "GNU"
	  .string "foo"
	  .section .note.b,"a",%note
	  .balign 4
	  .long 4,4,9
	  .string "GNU"
	  .string "bar"
EOF
  if AC_TRY_COMMAND([dnl
  ${CC-cc} $ASFLAGS -shared -o conftest.so conftest.s 1>&AS_MESSAGE_LOG_FD]) &&
       ac_try=`$READELF -S conftest.so | sed -n \
	 ['${x;p;}
	  s/^ *\[ *[1-9][0-9]*\]  *\([^ ][^ ]*\)  *\([^ ][^ ]*\) .*$/\2 \1/
	  t a
	  b
	  : a
	  H']`
  then
    libc_seen_a=no libc_seen_b=no
    set -- $ac_try
    while test $# -ge 2 -a "$1" = NOTE; do
      case "$2" in
      .note.a) libc_seen_a=yes ;;
      .note.b) libc_seen_b=yes ;;
      esac
      shift 2
    done
    case "$libc_seen_a$libc_seen_b" in
    yesyes)
      libc_cv_use_default_link=yes
      ;;
    *)
      echo >&AS_MESSAGE_LOG_FD "\
$libc_seen_a$libc_seen_b from:
$ac_try"
      ;;
    esac
  fi
  rm -f conftest*])
  use_default_link=$libc_cv_use_default_link
fi

AC_CACHE_CHECK(for GLOB_DAT reloc,
	       libc_cv_has_glob_dat, [dnl
cat > conftest.c <<EOF
extern int mumble;
int foo (void) { return mumble; }
EOF
if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS
			-fPIC -shared -o conftest.so conftest.c
			-nostdlib -nostartfiles
			1>&AS_MESSAGE_LOG_FD])
then
dnl look for GLOB_DAT relocation.
  if $READELF -rW conftest.so | grep '_GLOB_DAT' > /dev/null; then
    libc_cv_has_glob_dat=yes
  else
    libc_cv_has_glob_dat=no
  fi
else
  libc_cv_has_glob_dat=no
fi
rm -f conftest*])
AC_SUBST(libc_cv_has_glob_dat)

AC_CACHE_CHECK(linker output format, libc_cv_output_format, [dnl
if libc_cv_output_format=`
${CC-cc} -nostartfiles -nostdlib -Wl,--print-output-format 2>&AS_MESSAGE_LOG_FD`
then
  :
else
  libc_cv_output_format=
fi
test -n "$libc_cv_output_format" || libc_cv_output_format=unknown])
AC_SUBST(libc_cv_output_format)

AC_CACHE_CHECK(for -fno-toplevel-reorder -fno-section-anchors, libc_cv_fno_toplevel_reorder, [dnl
cat > conftest.c <<EOF
int foo;
EOF
if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -S -fno-toplevel-reorder -fno-section-anchors
			    conftest.c 1>&AS_MESSAGE_LOG_FD])
then
  libc_cv_fno_toplevel_reorder=yes
else
  libc_cv_fno_toplevel_reorder=no
fi
rm -f conftest*])
if test $libc_cv_fno_toplevel_reorder = yes; then
  fno_unit_at_a_time="-fno-toplevel-reorder -fno-section-anchors"
else
  fno_unit_at_a_time=-fno-unit-at-a-time
fi
AC_SUBST(fno_unit_at_a_time)

AC_CACHE_CHECK(for -fstack-protector, libc_cv_ssp, [dnl
LIBC_TRY_CC_OPTION([$CFLAGS $CPPFLAGS -Werror -fstack-protector],
		   [libc_cv_ssp=yes],
		   [libc_cv_ssp=no])
])

AC_CACHE_CHECK(for -fstack-protector-strong, libc_cv_ssp_strong, [dnl
LIBC_TRY_CC_OPTION([$CFLAGS $CPPFLAGS -Werror -fstack-protector-strong],
		   [libc_cv_ssp_strong=yes],
		   [libc_cv_ssp_strong=no])
])

stack_protector=
if test "$libc_cv_ssp_strong" = "yes"; then
  stack_protector="-fstack-protector-strong"
elif test "$libc_cv_ssp" = "yes"; then
  stack_protector="-fstack-protector"
fi
AC_SUBST(stack_protector)

AC_CACHE_CHECK([for -mtls-dialect=gnu2], libc_cv_mtls_dialect_gnu2,
[dnl
cat > conftest.c <<EOF
__thread int i;
void foo (void)
{
  i = 10;
}
EOF
if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -S -fPIC -mtls-dialect=gnu2
		   conftest.c 1>&AS_MESSAGE_LOG_FD])
then
  libc_cv_mtls_dialect_gnu2=yes
else
  libc_cv_mtls_dialect_gnu2=no
fi
rm -f conftest*])
AC_SUBST(libc_cv_mtls_dialect_gnu2)
LIBC_CONFIG_VAR([have-mtls-dialect-gnu2], [$libc_cv_mtls_dialect_gnu2])

AC_CACHE_CHECK(whether cc puts quotes around section names,
	       libc_cv_have_section_quotes,
	       [cat > conftest.c <<EOF
		static const int foo
		__attribute__ ((section ("bar"))) = 1;
EOF
		if ${CC-cc} -S conftest.c -o conftest.s; then
		  if grep '\.section.*"bar"' conftest.s >/dev/null; then
		    libc_cv_have_section_quotes=yes
		  else
		    libc_cv_have_section_quotes=no
		  fi
		else
		  libc_cv_have_section_quotes=unknown
		fi
		rm -f conftest.{c,s}
		])
if test $libc_cv_have_section_quotes = yes; then
  AC_DEFINE(HAVE_SECTION_QUOTES)
fi

AC_CACHE_CHECK(for __builtin_memset, libc_cv_gcc_builtin_memset, [dnl
cat > conftest.c <<\EOF
void zero (void *x)
{
  __builtin_memset (x, 0, 1000);
}
EOF
dnl
if AC_TRY_COMMAND([${CC-cc} -O3 -S conftest.c -o - | fgrep "memset" > /dev/null]);
then
  libc_cv_gcc_builtin_memset=no
else
  libc_cv_gcc_builtin_memset=yes
fi
rm -f conftest* ])
if test "$libc_cv_gcc_builtin_memset" = yes ; then
  AC_DEFINE(HAVE_BUILTIN_MEMSET)
fi

AC_CACHE_CHECK(for redirection of built-in functions, libc_cv_gcc_builtin_redirection, [dnl
cat > conftest.c <<\EOF
extern char *strstr (const char *, const char *) __asm ("my_strstr");
char *foo (const char *a, const char *b)
{
  return __builtin_strstr (a, b);
}
EOF
dnl
if AC_TRY_COMMAND([${CC-cc} -O3 -S conftest.c -o - | fgrep "my_strstr" > /dev/null]);
then
  libc_cv_gcc_builtin_redirection=yes
else
  libc_cv_gcc_builtin_redirection=no
fi
rm -f conftest* ])
if test "$libc_cv_gcc_builtin_redirection" = no; then
  AC_MSG_ERROR([support for the symbol redirection needed])
fi

dnl Determine how to disable generation of FMA instructions.
AC_CACHE_CHECK([for compiler option to disable generation of FMA instructions],
	       libc_cv_cc_nofma, [dnl
libc_cv_cc_nofma=
for opt in -ffp-contract=off -mno-fused-madd; do
  LIBC_TRY_CC_OPTION([$opt], [libc_cv_cc_nofma=$opt; break])
done])
AC_SUBST(libc_cv_cc_nofma)

if test -n "$submachine"; then
  AC_CACHE_CHECK([for compiler option for CPU variant],
		 libc_cv_cc_submachine, [dnl
  libc_cv_cc_submachine=no
  for opt in "-march=$submachine" "-mcpu=$submachine"; do
    LIBC_TRY_CC_OPTION([$opt], [
      libc_cv_cc_submachine="$opt"
      break], [])
  done])
  if test "x$libc_cv_cc_submachine" = xno; then
    AC_MSG_ERROR([${CC-cc} does not support $submachine])
  fi
fi
AC_SUBST(libc_cv_cc_submachine)

AC_CACHE_CHECK(if $CC accepts -fno-tree-loop-distribute-patterns with \
__attribute__ ((__optimize__)), libc_cv_cc_loop_to_function, [dnl
cat > conftest.c <<EOF
void
__attribute__ ((__optimize__ ("-fno-tree-loop-distribute-patterns")))
foo (void) {}
EOF
libc_cv_cc_loop_to_function=no
if AC_TRY_COMMAND([${CC-cc} $CFLAGS $CPPFLAGS -c conftest.c])
then
  libc_cv_cc_loop_to_function=yes
fi
rm -f conftest*])
if test $libc_cv_cc_loop_to_function = yes; then
  AC_DEFINE(HAVE_CC_INHIBIT_LOOP_TO_LIBCALL)
fi
AC_SUBST(libc_cv_cc_loop_to_function)

dnl Check whether we have the gd library available.
AC_MSG_CHECKING(for libgd)
if test "$with_gd" != "no"; then
  old_CFLAGS="$CFLAGS"
  CFLAGS="$CFLAGS $libgd_include"
  old_LDFLAGS="$LDFLAGS"
  LDFLAGS="$LDFLAGS $libgd_ldflags"
  old_LIBS="$LIBS"
  LIBS="$LIBS -lgd -lpng -lz -lm"
  AC_TRY_LINK([#include <gd.h>], [gdImagePng (0, 0)], LIBGD=yes, LIBGD=no)
  CFLAGS="$old_CFLAGS"
  LDFLAGS="$old_LDFLAGS"
  LIBS="$old_LIBS"
else
  LIBGD=no
fi
AC_MSG_RESULT($LIBGD)
AC_SUBST(LIBGD)

# SELinux detection
if test x$with_selinux = xno ; then
  have_selinux=no;
else
  # See if we have the SELinux library
  AC_CHECK_LIB(selinux, is_selinux_enabled,
	       have_selinux=yes, have_selinux=no)
  if test x$with_selinux = xyes ; then
    if test x$have_selinux = xno ; then
      AC_MSG_ERROR([SELinux explicitly required, but SELinux library not found])
    fi
  fi
fi
# Check if we're building with SELinux support.
if test "x$have_selinux" = xyes; then
  AC_DEFINE(HAVE_SELINUX, 1, [SELinux support])

  # See if we have the libaudit library
  AC_CHECK_LIB(audit, audit_log_user_avc_message,
	       have_libaudit=yes, have_libaudit=no)
  if test "x$have_libaudit" = xyes; then
    AC_DEFINE(HAVE_LIBAUDIT, 1, [SELinux libaudit support])
  fi
  AC_SUBST(have_libaudit)

  # See if we have the libcap library
  AC_CHECK_LIB(cap, cap_init, have_libcap=yes, have_libcap=no)
  if test "x$have_libcap" = xyes; then
    AC_DEFINE(HAVE_LIBCAP, 1, [SELinux libcap support])
  fi
  AC_SUBST(have_libcap)
fi
AC_SUBST(have_selinux)

CPPUNDEFS=
dnl Check for silly hacked compilers predefining _FORTIFY_SOURCE.
dnl Since we are building the implementations of the fortified functions here,
dnl having the macro defined interacts very badly.
AC_CACHE_CHECK([for _FORTIFY_SOURCE predefine], libc_cv_predef_fortify_source,
[AC_TRY_COMPILE([], [
#ifdef _FORTIFY_SOURCE
# error bogon
#endif],
		[libc_cv_predef_fortify_source=no],
		[libc_cv_predef_fortify_source=yes])])
if test $libc_cv_predef_fortify_source = yes; then
  CPPUNDEFS="${CPPUNDEFS:+$CPPUNDEFS }-U_FORTIFY_SOURCE"
fi
AC_SUBST(CPPUNDEFS)

dnl Check for silly hacked compilers inserting -fstack-protector.
dnl This breaks badly for the early startup code we compile, since
dnl the compiled code can refer to a magic machine-dependent location
dnl for the canary value before we have sufficient setup for that to
dnl work.  It's also questionable to build all of libc with this flag
dnl even when you're doing that for most applications you build, since
dnl libc's code is so heavily-used and performance-sensitive.  If we
dnl ever really want to make that work, it should be enabled explicitly
dnl in the libc build, not inherited from implicit compiler settings.
AC_CACHE_CHECK([whether $CC implicitly enables -fstack-protector],
	       libc_cv_predef_stack_protector, [
AC_TRY_COMPILE([extern void foobar (char *);],
	       [char large_array[2048]; foobar (large_array);], [
libc_undefs=`$NM -u conftest.o |
  LC_ALL=C $AWK '$1 == "U" { print $2 | "sort -u"; next } { exit(1) }' \
    2>&AS_MESSAGE_LOG_FD` || {
  AC_MSG_ERROR([confusing output from $NM -u])
}
echo >&AS_MESSAGE_LOG_FD "libc_undefs='$libc_undefs'"
# On some architectures, there are architecture-specific undefined
# symbols (resolved by the linker), so filter out unknown symbols.
# This will fail to produce the correct result if the compiler
# defaults to -fstack-protector but this produces an undefined symbol
# other than __stack_chk_fail or __stack_chk_fail_local. However,
# compilers like that have not been encountered in practice.
libc_undefs=`echo "$libc_undefs" | \
  egrep '^(foobar|__stack_chk_fail|__stack_chk_fail_local)$'`
case "$libc_undefs" in
foobar) libc_cv_predef_stack_protector=no ;;
'__stack_chk_fail
foobar'|'__stack_chk_fail_local
foobar') libc_cv_predef_stack_protector=yes ;;
*) AC_MSG_ERROR([unexpected symbols in test: $libc_undefs]) ;;
esac],
	       [AC_MSG_ERROR([test compilation failed])])
])
libc_extra_cflags=
if test $libc_cv_predef_stack_protector = yes; then
  libc_extra_cflags="$libc_extra_cflags -fno-stack-protector"
fi
libc_extra_cppflags=

# Some linkers on some architectures support __ehdr_start but with
# bugs.  Make sure usage of it does not create relocations in the
# output (as the linker should resolve them all for us).
AC_CACHE_CHECK([whether the linker provides working __ehdr_start],
	       libc_cv_ehdr_start, [
old_CFLAGS="$CFLAGS"
old_LDFLAGS="$LDFLAGS"
old_LIBS="$LIBS"
CFLAGS="$CFLAGS -fPIC"
LDFLAGS="$LDFLAGS -nostdlib -nostartfiles -shared"
LIBS=
AC_LINK_IFELSE([AC_LANG_SOURCE([
typedef struct {
  char foo;
  long val;
} Ehdr;
extern const Ehdr __ehdr_start __attribute__ ((visibility ("hidden")));
long ehdr (void) { return __ehdr_start.val; }
])],
	       [if $READELF -r conftest | fgrep __ehdr_start >/dev/null; then
		  libc_cv_ehdr_start=broken
		else
		  libc_cv_ehdr_start=yes
		fi], [libc_cv_ehdr_start=no])
CFLAGS="$old_CFLAGS"
LDFLAGS="$old_LDFLAGS"
LIBS="$old_LIBS"
])
if test "$libc_cv_ehdr_start" = yes; then
  AC_DEFINE([HAVE_EHDR_START])
elif test "$libc_cv_ehdr_start" = broken; then
  AC_MSG_WARN([linker is broken -- you should upgrade])
fi

AC_CACHE_CHECK(for __builtin_trap with no external dependencies,
	       libc_cv_builtin_trap, [dnl
libc_cv_builtin_trap=no
AC_TRY_COMPILE([], [__builtin_trap ()], [
libc_undefs=`$NM -u conftest.o |
  LC_ALL=C $AWK '$1 == "U" { print $2 | "sort -u"; next } { exit(1) }' \
    2>&AS_MESSAGE_LOG_FD` || {
  AC_MSG_ERROR([confusing output from $NM -u])
}
echo >&AS_MESSAGE_LOG_FD "libc_undefs='$libc_undefs'"
if test -z "$libc_undefs"; then
  libc_cv_builtin_trap=yes
fi])])
if test $libc_cv_builtin_trap = yes; then
  AC_DEFINE([HAVE_BUILTIN_TRAP])
fi

dnl C++ feature tests.
AC_LANG_PUSH([C++])

AC_CACHE_CHECK([whether the C++ compiler supports thread_local],
	       libc_cv_cxx_thread_local, [
old_CXXFLAGS="$CXXFLAGS"
CXXFLAGS="$CXXFLAGS -std=gnu++11"
AC_COMPILE_IFELSE([AC_LANG_SOURCE([
#include <thread>

// Compiler support.
struct S
{
  S ();
  ~S ();
};
thread_local S s;
S * get () { return &s; }

// libstdc++ support.
#ifndef _GLIBCXX_HAVE___CXA_THREAD_ATEXIT_IMPL
#error __cxa_thread_atexit_impl not supported
#endif
])],
	       [libc_cv_cxx_thread_local=yes],
	       [libc_cv_cxx_thread_local=no])
CXXFLAGS="$old_CXXFLAGS"
])
AC_SUBST(libc_cv_cxx_thread_local)

AC_LANG_POP([C++])
dnl End of C++ feature tests.

### End of automated tests.
### Now run sysdeps configure fragments.

# They also can set these variables.
use_ldconfig=no
ldd_rewrite_script=no
libc_cv_sysconfdir=$sysconfdir
libc_cv_localstatedir=$localstatedir
libc_cv_gcc_unwind_find_fde=no
libc_cv_idn=no

# Iterate over all the sysdep directories we will use, running their
# configure fragments.
for dir in $sysnames; do
  case $dir in
    /*) dest=$dir ;;
    *)  dest=$srcdir/$dir ;;
  esac
  if test -r $dest/configure; then
    AC_MSG_RESULT(running configure fragment for $dir)
    . $dest/configure
  fi
done

if test x"$build_mathvec" = xnotset; then
  build_mathvec=no
fi
LIBC_CONFIG_VAR([build-mathvec], [$build_mathvec])

AC_SUBST(libc_extra_cflags)
AC_SUBST(libc_extra_cppflags)

if test x$libc_cv_gcc_unwind_find_fde = xyes; then
  AC_DEFINE(EXPORT_UNWIND_FIND_FDE)
fi
AC_SUBST(libc_cv_gcc_unwind_find_fde)

# A sysdeps configure fragment can reset this if IFUNC is not actually
# usable even though the assembler knows how to generate the symbol type.
if test x"$libc_cv_ld_gnu_indirect_function" = xyes; then
  AC_DEFINE(HAVE_IFUNC)
fi

# This is far from the AC_ARG_ENABLE that sets it so that a sysdeps
# configure fragment can override the value to prevent this AC_DEFINE.
AC_SUBST(use_nscd)
if test "x$use_nscd" != xno; then
  AC_DEFINE([USE_NSCD])
fi
if test "x$build_nscd" = xdefault; then
  build_nscd=$use_nscd
fi

AC_SUBST(libc_cv_slibdir)
AC_SUBST(libc_cv_rtlddir)
AC_SUBST(libc_cv_complocaledir)
AC_SUBST(libc_cv_sysconfdir)
AC_SUBST(libc_cv_localstatedir)
AC_SUBST(libc_cv_rootsbindir)

if test x$use_ldconfig = xyes; then
  AC_DEFINE(USE_LDCONFIG)
fi
AC_SUBST(use_ldconfig)
AC_SUBST(ldd_rewrite_script)

AC_SUBST(static)
AC_SUBST(shared)

AC_CACHE_CHECK([whether -fPIC is default], libc_cv_pic_default,
[libc_cv_pic_default=yes
cat > conftest.c <<EOF
#if defined __PIC__ || defined __pic__ || defined PIC || defined pic
# error PIC is default.
#endif
EOF
if eval "${CC-cc} -S conftest.c 2>&AS_MESSAGE_LOG_FD 1>&AS_MESSAGE_LOG_FD"; then
  libc_cv_pic_default=no
fi
rm -f conftest.*])
AC_SUBST(libc_cv_pic_default)

AC_CACHE_CHECK([whether -fPIE is default], libc_cv_pie_default,
[libc_cv_pie_default=yes
cat > conftest.c <<EOF
#if defined __PIE__ || defined __pie__ || defined PIE || defined pie
# error PIE is default.
#endif
EOF
if eval "${CC-cc} -S conftest.c 2>&AS_MESSAGE_LOG_FD 1>&AS_MESSAGE_LOG_FD"; then
  libc_cv_pie_default=no
fi
rm -f conftest.*])
AC_SUBST(libc_cv_pie_default)

AC_SUBST(profile)
AC_SUBST(static_nss)

AC_SUBST(DEFINES)

dnl See sysdeps/mach/configure.ac for this variable.
AC_SUBST(mach_interface_list)

VERSION=`sed -n -e 's/^#define VERSION "\([^"]*\)"/\1/p' < $srcdir/version.h`
RELEASE=`sed -n -e 's/^#define RELEASE "\([^"]*\)"/\1/p' < $srcdir/version.h`
AC_SUBST(VERSION)
AC_SUBST(RELEASE)

AC_CONFIG_FILES([config.make Makefile])
AC_CONFIG_COMMANDS([default],[[
case $CONFIG_FILES in *config.make*)
echo "$config_vars" >> config.make;;
esac
test -d bits || mkdir bits]],[[config_vars='$config_vars']])
AC_OUTPUT