aboutsummaryrefslogtreecommitdiff
path: root/configure.ac
blob: 36ceeef302dcaa6599631732589eca1a8e8cd2e4 (plain) (blame)
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
#                                               -*- Autoconf -*-
# SPDX-License-Identifier: 0BSD

###############################################################################
#
# Process this file with autoconf to produce a configure script.
#
# Author: Lasse Collin
#
###############################################################################

# NOTE: Don't add useless checks. autoscan detects this and that, but don't
# let it confuse you. For example, we don't care about checking for behavior
# of malloc(), stat(), or lstat(), since we don't use those functions in
# a way that would cause the problems the autoconf macros check.

AC_PREREQ([2.69])

AC_INIT([XZ Utils], m4_esyscmd([/bin/sh build-aux/version.sh]),
	[xz@tukaani.org], [xz], [https://xz.tukaani.org/xz-utils/])
AC_CONFIG_SRCDIR([src/liblzma/common/common.h])
AC_CONFIG_AUX_DIR([build-aux])
AC_CONFIG_MACRO_DIR([m4])
AC_CONFIG_HEADERS([config.h])

echo
echo "$PACKAGE_STRING"

echo
echo "System type:"
# This is needed to know if assembler optimizations can be used.
AC_CANONICAL_HOST

# We do some special things on Windows (32-bit or 64-bit) builds.
case $host_os in
	mingw* | cygwin | msys) is_w32=yes ;;
	*)                      is_w32=no ;;
esac
AM_CONDITIONAL([COND_W32], [test "$is_w32" = yes])

# We need to use $EXEEXT with $(LN_S) when creating symlinks to
# executables. Cygwin is an exception to this, since it is recommended
# that symlinks don't have the .exe suffix. To make this work, we
# define LN_EXEEXT.
#
# MSYS2 is treated the same way as Cygwin. It uses plain "msys" like
# the original MSYS when building MSYS/MSYS2-binaries. Hopefully this
# doesn't break things for the original MSYS developers. Note that this
# doesn't affect normal MSYS/MSYS2 users building non-MSYS/MSYS2 binaries
# since in that case the $host_os is usually mingw32.
case $host_os in
	cygwin | msys)  LN_EXEEXT= ;;
	*)              LN_EXEEXT='$(EXEEXT)' ;;
esac
AC_SUBST([LN_EXEEXT])

echo
echo "Configure options:"
AM_CFLAGS=


#############
# Debugging #
#############

AC_MSG_CHECKING([if debugging code should be compiled])
AC_ARG_ENABLE([debug], AS_HELP_STRING([--enable-debug], [Enable debugging code.]),
	[], enable_debug=no)
if test "x$enable_debug" = xyes; then
	AC_MSG_RESULT([yes])
else
	AC_DEFINE([NDEBUG], [1], [Define to 1 to disable debugging code.])
	AC_MSG_RESULT([no])
fi


###########
# Filters #
###########

m4_define([SUPPORTED_FILTERS], [lzma1,lzma2,delta,x86,powerpc,ia64,arm,armthumb,arm64,sparc,riscv])dnl
m4_define([SIMPLE_FILTERS], [x86,powerpc,ia64,arm,armthumb,arm64,sparc,riscv])
m4_define([LZ_FILTERS], [lzma1,lzma2])

m4_foreach([NAME], [SUPPORTED_FILTERS],
[enable_filter_[]NAME=no
enable_encoder_[]NAME=no
enable_decoder_[]NAME=no
])dnl

AC_MSG_CHECKING([which encoders to build])
AC_ARG_ENABLE([encoders], AS_HELP_STRING([--enable-encoders=LIST],
		[Comma-separated list of encoders to build. Default=all.
		Available encoders:]
			m4_translit(m4_defn([SUPPORTED_FILTERS]), [,], [ ])),
	[], [enable_encoders=SUPPORTED_FILTERS])
enable_encoders=`echo "$enable_encoders" | sed 's/,/ /g'`
if test "x$enable_encoders" = xno || test "x$enable_encoders" = x; then
	enable_encoders=no
	AC_MSG_RESULT([(none)])
else
	for arg in $enable_encoders
	do
		case $arg in m4_foreach([NAME], [SUPPORTED_FILTERS], [
			NAME)
				enable_filter_[]NAME=yes
				enable_encoder_[]NAME=yes
				AC_DEFINE(HAVE_ENCODER_[]m4_toupper(NAME), [1],
				[Define to 1 if] NAME [encoder is enabled.])
				;;])
			*)
				AC_MSG_RESULT([])
				AC_MSG_ERROR([unknown filter: $arg])
				;;
		esac
	done
	AC_DEFINE([HAVE_ENCODERS], [1],
		[Define to 1 if any of HAVE_ENCODER_foo have been defined.])
	AC_MSG_RESULT([$enable_encoders])
fi

AC_MSG_CHECKING([which decoders to build])
AC_ARG_ENABLE([decoders], AS_HELP_STRING([--enable-decoders=LIST],
		[Comma-separated list of decoders to build. Default=all.
		Available decoders are the same as available encoders.]),
	[], [enable_decoders=SUPPORTED_FILTERS])
enable_decoders=`echo "$enable_decoders" | sed 's/,/ /g'`
if test "x$enable_decoders" = xno || test "x$enable_decoders" = x; then
	enable_decoders=no
	AC_MSG_RESULT([(none)])
else
	for arg in $enable_decoders
	do
		case $arg in m4_foreach([NAME], [SUPPORTED_FILTERS], [
			NAME)
				enable_filter_[]NAME=yes
				enable_decoder_[]NAME=yes
				AC_DEFINE(HAVE_DECODER_[]m4_toupper(NAME), [1],
				[Define to 1 if] NAME [decoder is enabled.])
				;;])
			*)
				AC_MSG_RESULT([])
				AC_MSG_ERROR([unknown filter: $arg])
				;;
		esac
	done
	AC_DEFINE([HAVE_DECODERS], [1],
		[Define to 1 if any of HAVE_DECODER_foo have been defined.])
	AC_MSG_RESULT([$enable_decoders])
fi

if test "x$enable_encoder_lzma2$enable_encoder_lzma1" = xyesno \
		|| test "x$enable_decoder_lzma2$enable_decoder_lzma1" = xyesno; then
	AC_MSG_ERROR([LZMA2 requires that LZMA1 is also enabled.])
fi

AM_CONDITIONAL(COND_MAIN_ENCODER, test "x$enable_encoders" != xno)
AM_CONDITIONAL(COND_MAIN_DECODER, test "x$enable_decoders" != xno)

m4_foreach([NAME], [SUPPORTED_FILTERS],
[AM_CONDITIONAL(COND_FILTER_[]m4_toupper(NAME), test "x$enable_filter_[]NAME" = xyes)
AM_CONDITIONAL(COND_ENCODER_[]m4_toupper(NAME), test "x$enable_encoder_[]NAME" = xyes)
AM_CONDITIONAL(COND_DECODER_[]m4_toupper(NAME), test "x$enable_decoder_[]NAME" = xyes)
])dnl

# The so called "simple filters" share common code.
enable_filter_simple=no
enable_encoder_simple=no
enable_decoder_simple=no
m4_foreach([NAME], [SIMPLE_FILTERS],
[test "x$enable_filter_[]NAME" = xyes && enable_filter_simple=yes
test "x$enable_encoder_[]NAME" = xyes && enable_encoder_simple=yes
test "x$enable_decoder_[]NAME" = xyes && enable_decoder_simple=yes
])dnl
AM_CONDITIONAL(COND_FILTER_SIMPLE, test "x$enable_filter_simple" = xyes)
AM_CONDITIONAL(COND_ENCODER_SIMPLE, test "x$enable_encoder_simple" = xyes)
AM_CONDITIONAL(COND_DECODER_SIMPLE, test "x$enable_decoder_simple" = xyes)

# LZ-based filters share common code.
enable_filter_lz=no
enable_encoder_lz=no
enable_decoder_lz=no
m4_foreach([NAME], [LZ_FILTERS],
[test "x$enable_filter_[]NAME" = xyes && enable_filter_lz=yes
test "x$enable_encoder_[]NAME" = xyes && enable_encoder_lz=yes
test "x$enable_decoder_[]NAME" = xyes && enable_decoder_lz=yes
])dnl
AM_CONDITIONAL(COND_FILTER_LZ, test "x$enable_filter_lz" = xyes)
AM_CONDITIONAL(COND_ENCODER_LZ, test "x$enable_encoder_lz" = xyes)
AM_CONDITIONAL(COND_DECODER_LZ, test "x$enable_decoder_lz" = xyes)


#################
# Match finders #
#################

m4_define([SUPPORTED_MATCH_FINDERS], [hc3,hc4,bt2,bt3,bt4])

m4_foreach([NAME], [SUPPORTED_MATCH_FINDERS],
[enable_match_finder_[]NAME=no
])

AC_MSG_CHECKING([which match finders to build])
AC_ARG_ENABLE([match-finders], AS_HELP_STRING([--enable-match-finders=LIST],
		[Comma-separated list of match finders to build. Default=all.
		At least one match finder is required for encoding with
		the LZMA1 and LZMA2 filters. Available match finders:]
		m4_translit(m4_defn([SUPPORTED_MATCH_FINDERS]), [,], [ ])), [],
	[enable_match_finders=SUPPORTED_MATCH_FINDERS])
enable_match_finders=`echo "$enable_match_finders" | sed 's/,/ /g'`
if test "x$enable_encoder_lz" = xyes ; then
	if test -z "$enable_match_finders"; then
		AC_MSG_ERROR([At least one match finder is required for an LZ-based encoder.])
	fi

	for arg in $enable_match_finders
		do
		case $arg in m4_foreach([NAME], [SUPPORTED_MATCH_FINDERS], [
			NAME)
				enable_match_finder_[]NAME=yes
				AC_DEFINE(HAVE_MF_[]m4_toupper(NAME), [1],
				[Define to 1 to enable] NAME [match finder.])
				;;])
			*)
				AC_MSG_RESULT([])
				AC_MSG_ERROR([unknown match finder: $arg])
				;;
		esac
	done
	AC_MSG_RESULT([$enable_match_finders])
else
	AC_MSG_RESULT([(none because not building any LZ-based encoder)])
fi


####################
# Integrity checks #
####################

m4_define([SUPPORTED_CHECKS], [crc32,crc64,sha256])

m4_foreach([NAME], [SUPPORTED_CHECKS],
[enable_check_[]NAME=no
])dnl

AC_MSG_CHECKING([which integrity checks to build])
AC_ARG_ENABLE([checks], AS_HELP_STRING([--enable-checks=LIST],
		[Comma-separated list of integrity checks to build.
		Default=all. Available integrity checks:]
		m4_translit(m4_defn([SUPPORTED_CHECKS]), [,], [ ])),
	[], [enable_checks=SUPPORTED_CHECKS])
enable_checks=`echo "$enable_checks" | sed 's/,/ /g'`
if test "x$enable_checks" = xno || test "x$enable_checks" = x; then
	AC_MSG_RESULT([(none)])
else
	for arg in $enable_checks
	do
		case $arg in m4_foreach([NAME], [SUPPORTED_CHECKS], [
			NAME)
				enable_check_[]NAME=yes
				AC_DEFINE(HAVE_CHECK_[]m4_toupper(NAME), [1],
				[Define to 1 if] NAME
				[integrity check is enabled.])
				;;])
			*)
				AC_MSG_RESULT([])
				AC_MSG_ERROR([unknown integrity check: $arg])
				;;
		esac
	done
	AC_MSG_RESULT([$enable_checks])
fi
if test "x$enable_check_crc32" = xno ; then
	AC_MSG_ERROR([For now, the CRC32 check must always be enabled.])
fi

m4_foreach([NAME], [SUPPORTED_CHECKS],
[AM_CONDITIONAL(COND_CHECK_[]m4_toupper(NAME), test "x$enable_check_[]NAME" = xyes)
])dnl

AC_MSG_CHECKING([if external SHA-256 should be used])
AC_ARG_ENABLE([external-sha256], AS_HELP_STRING([--enable-external-sha256],
		[Use SHA-256 code from the operating system.
		See INSTALL for possible subtle problems.]),
		[], [enable_external_sha256=no])
if test "x$enable_check_sha256" != "xyes"; then
	enable_external_sha256=no
fi
if test "x$enable_external_sha256" = xyes; then
	AC_MSG_RESULT([yes])
else
	AC_MSG_RESULT([no])
fi


#############
# MicroLZMA #
#############

AC_MSG_CHECKING([if MicroLZMA support should be built])
AC_ARG_ENABLE([microlzma], AS_HELP_STRING([--disable-microlzma],
		[Do not build MicroLZMA encoder and decoder.
		It is needed by specific applications only,
		for example, erofs-utils.]),
	[], [enable_microlzma=yes])
case $enable_microlzma in
	yes | no)
		AC_MSG_RESULT([$enable_microlzma])
		;;
	*)
		AC_MSG_RESULT([])
		AC_MSG_ERROR([--enable-microlzma accepts only 'yes' or 'no'.])
		;;
esac
AM_CONDITIONAL(COND_MICROLZMA, test "x$enable_microlzma" = xyes)


#############################
# .lz (lzip) format support #
#############################

AC_MSG_CHECKING([if .lz (lzip) decompression support should be built])
AC_ARG_ENABLE([lzip-decoder], AS_HELP_STRING([--disable-lzip-decoder],
		[Disable decompression support for .lz (lzip) files.]),
	[], [enable_lzip_decoder=yes])
if test "x$enable_decoder_lzma1" != xyes; then
	enable_lzip_decoder=no
	AC_MSG_RESULT([no because LZMA1 decoder is disabled])
elif test "x$enable_lzip_decoder" = xyes; then
	AC_DEFINE([HAVE_LZIP_DECODER], [1],
		[Define to 1 if .lz (lzip) decompression support is enabled.])
	AC_MSG_RESULT([yes])
else
	AC_MSG_RESULT([no])
fi
AM_CONDITIONAL(COND_LZIP_DECODER, test "x$enable_lzip_decoder" = xyes)


###########################
# Assembler optimizations #
###########################

AC_MSG_CHECKING([if assembler optimizations should be used])
AC_ARG_ENABLE([assembler], AS_HELP_STRING([--disable-assembler],
		[Do not use assembler optimizations even if such exist
		for the architecture.]),
	[], [enable_assembler=yes])
if test "x$enable_assembler" = xyes; then
	enable_assembler=no
	case $host_os in
		# Darwin should work too but only if not creating universal
		# binaries. Solaris x86 could work too but I cannot test.
		linux* | *bsd* | mingw* | cygwin | msys | *djgpp*)
			case $host_cpu in
				i?86)   enable_assembler=x86 ;;
			esac
			;;
	esac
fi
case $enable_assembler in
	x86 | no)
		AC_MSG_RESULT([$enable_assembler])
		;;
	*)
		AC_MSG_RESULT([])
		AC_MSG_ERROR([--enable-assembler accepts only 'yes', 'no', or 'x86' (32-bit).])
		;;
esac
AM_CONDITIONAL(COND_ASM_X86, test "x$enable_assembler" = xx86)


#############
# CLMUL CRC #
#############

AC_ARG_ENABLE([clmul-crc], AS_HELP_STRING([--disable-clmul-crc],
		[Do not use carryless multiplication for CRC calculation
		even if support for it is detected.]),
	[], [enable_clmul_crc=yes])


############################
# ARM64 CRC32 Instructions #
############################

AC_ARG_ENABLE([arm64-crc32], AS_HELP_STRING([--disable-arm64-crc32],
		[Do not use ARM64 CRC32 instructions even if support for it
		is detected.]),
	[], [enable_arm64_crc32=yes])


#####################
# Size optimization #
#####################

AC_MSG_CHECKING([if small size is preferred over speed])
AC_ARG_ENABLE([small], AS_HELP_STRING([--enable-small],
		[Make liblzma smaller and a little slower.
		This is disabled by default to optimize for speed.]),
	[], [enable_small=no])
if test "x$enable_small" = xyes; then
	AC_DEFINE([HAVE_SMALL], [1], [Define to 1 if optimizing for size.])
elif test "x$enable_small" != xno; then
	AC_MSG_RESULT([])
	AC_MSG_ERROR([--enable-small accepts only 'yes' or 'no'])
fi
AC_MSG_RESULT([$enable_small])
AM_CONDITIONAL(COND_SMALL, test "x$enable_small" = xyes)


#############
# Threading #
#############

AC_MSG_CHECKING([if threading support is wanted])
AC_ARG_ENABLE([threads], AS_HELP_STRING([--enable-threads=METHOD],
		[Supported METHODS are 'yes', 'no', 'posix', 'win95', and
		'vista'. The default is 'yes'. Using 'no' together with
		--enable-small makes liblzma thread unsafe.]),
	[], [enable_threads=yes])

if test "x$enable_threads" = xyes; then
	case $host_os in
		mingw*)
			case $host_cpu in
				i?86)   enable_threads=win95 ;;
				*)      enable_threads=vista ;;
			esac
			;;
		*)
			enable_threads=posix
			;;
	esac
fi

case $enable_threads in
	posix | win95 | vista)
		AC_MSG_RESULT([yes, $enable_threads])
		;;
	no)
		AC_MSG_RESULT([no])
		;;
	*)
		AC_MSG_RESULT([])
		AC_MSG_ERROR([--enable-threads only accepts 'yes', 'no', 'posix', 'win95', or 'vista'])
		;;
esac

# We use the actual result a little later.


#########################
# Assumed amount of RAM #
#########################

# We use 128 MiB as default, because it will allow decompressing files
# created with "xz -9". It would be slightly safer to guess a lower value,
# but most systems, on which we don't have any way to determine the amount
# of RAM, will probably have at least 128 MiB of RAM.
AC_MSG_CHECKING([how much RAM to assume if the real amount is unknown])
AC_ARG_ENABLE([assume-ram], AS_HELP_STRING([--enable-assume-ram=SIZE],
		[If and only if the real amount of RAM cannot be determined,
		assume SIZE MiB. The default is 128 MiB. This affects the
		default memory usage limit.]),
	[], [enable_assume_ram=128])
assume_ram_check=`echo "$enable_assume_ram" | tr -d 0123456789`
if test -z "$enable_assume_ram" || test -n "$assume_ram_check"; then
	AC_MSG_RESULT([])
	AC_MSG_ERROR([--enable-assume-ram accepts only an integer argument])
fi
AC_MSG_RESULT([$enable_assume_ram MiB])
AC_DEFINE_UNQUOTED([ASSUME_RAM], [$enable_assume_ram],
		[How many MiB of RAM to assume if the real amount cannot
		be determined.])


#########################
# Components to install #
#########################

AC_ARG_ENABLE([xz], [AS_HELP_STRING([--disable-xz],
		[do not build the xz tool])],
	[], [enable_xz=yes])
AM_CONDITIONAL([COND_XZ], [test x$enable_xz != xno])

AC_ARG_ENABLE([xzdec], [AS_HELP_STRING([--disable-xzdec],
		[do not build xzdec])],
	[], [enable_xzdec=yes])
test "x$enable_decoders" = xno && enable_xzdec=no
AM_CONDITIONAL([COND_XZDEC], [test x$enable_xzdec != xno])

AC_ARG_ENABLE([lzmadec], [AS_HELP_STRING([--disable-lzmadec],
		[do not build lzmadec
		(it exists primarily for LZMA Utils compatibility)])],
	[], [enable_lzmadec=yes])
test "x$enable_decoder_lzma1" = xno && enable_lzmadec=no
AM_CONDITIONAL([COND_LZMADEC], [test x$enable_lzmadec != xno])

AC_ARG_ENABLE([lzmainfo], [AS_HELP_STRING([--disable-lzmainfo],
		[do not build lzmainfo
		(it exists primarily for LZMA Utils compatibility)])],
	[], [enable_lzmainfo=yes])
test "x$enable_decoder_lzma1" = xno && enable_lzmainfo=no
AM_CONDITIONAL([COND_LZMAINFO], [test x$enable_lzmainfo != xno])

AC_ARG_ENABLE([lzma-links], [AS_HELP_STRING([--disable-lzma-links],
		[do not create symlinks for LZMA Utils compatibility])],
	[], [enable_lzma_links=yes])
AM_CONDITIONAL([COND_LZMALINKS], [test x$enable_lzma_links != xno])

AC_ARG_ENABLE([scripts], [AS_HELP_STRING([--disable-scripts],
		[do not install the scripts xzdiff, xzgrep, xzless, xzmore,
		and their symlinks])],
	[], [enable_scripts=yes])
AM_CONDITIONAL([COND_SCRIPTS], [test x$enable_scripts != xno])

AC_ARG_ENABLE([doc], [AS_HELP_STRING([--disable-doc],
		[do not install documentation files to docdir
		(man pages will still be installed)])],
	[], [enable_doc=yes])
AM_CONDITIONAL([COND_DOC], [test x$enable_doc != xno])


##############
# Sandboxing #
##############

AC_MSG_CHECKING([if sandboxing should be used])
AC_ARG_ENABLE([sandbox], [AS_HELP_STRING([--enable-sandbox=METHOD],
		[Sandboxing METHOD can be
		'auto', 'no', 'capsicum', 'pledge', or 'landlock'.
		The default is 'auto' which enables sandboxing if
		a supported sandboxing method is found.])],
	[], [enable_sandbox=auto])
case $enable_xzdec-$enable_xz-$enable_sandbox in
	no-no-*)
		enable_sandbox=no
		AC_MSG_RESULT([no, --disable-xz and --disable-xzdec was used])
		;;
	*-*-auto)
		AC_MSG_RESULT([maybe (autodetect)])
		;;
	*-*-no | *-*-capsicum | *-*-pledge | *-*-landlock)
		AC_MSG_RESULT([$enable_sandbox])
		;;
	*)
		AC_MSG_RESULT([])
		AC_MSG_ERROR([--enable-sandbox only accepts 'auto', 'no', 'capsicum', 'pledge', or 'landlock'.])
		;;
esac


###########################
# PATH prefix for scripts #
###########################

# The scripts can add a prefix to the search PATH so that POSIX tools
# or the xz binary is always in the PATH.
AC_ARG_ENABLE([path-for-scripts],
	[AS_HELP_STRING([--enable-path-for-scripts=PREFIX],
		[If PREFIX isn't empty, PATH=PREFIX:$PATH will be set in
		the beginning of the scripts (xzgrep and others).
		The default is empty except on Solaris the default is
		/usr/xpg4/bin.])],
	[], [
		case $host_os in
			solaris*) enable_path_for_scripts=/usr/xpg4/bin ;;
			*)        enable_path_for_scripts= ;;
		esac
	])
if test -n "$enable_path_for_scripts" && test "x$enable_path_for_scripts" != xno ; then
	enable_path_for_scripts="PATH=$enable_path_for_scripts:\$PATH"
else
	enable_path_for_scripts=
fi
AC_SUBST([enable_path_for_scripts])


###############################################################################
# Checks for programs.
###############################################################################

echo
case $host_os in
	solaris*)
		# The gnulib POSIX shell macro below may pick a shell that
		# doesn't work with xzgrep. Workaround by picking a shell
		# that is known to work.
		if test -z "$gl_cv_posix_shell" && test -x /usr/xpg4/bin/sh; then
			gl_cv_posix_shell=/usr/xpg4/bin/sh
		fi
		;;
esac
gl_POSIX_SHELL
if test -z "$POSIX_SHELL" && test "x$enable_scripts" = xyes ; then
	AC_MSG_ERROR([No POSIX conforming shell (sh) was found.])
fi

echo
echo "Initializing Automake:"

# We don't use "subdir-objects" yet because it breaks "make distclean" when
# dependencies are enabled (as of Automake 1.14.1) due to this bug:
# https://debbugs.gnu.org/cgi/bugreport.cgi?bug=17354
# The -Wno-unsupported is used to silence warnings about missing
# "subdir-objects".
AM_INIT_AUTOMAKE([1.12 foreign tar-v7 filename-length-max=99 -Wno-unsupported])
AC_PROG_LN_S

dnl # Autoconf >= 2.70 warns that AC_PROG_CC_C99 is obsolete. However,
dnl # we have to keep using AC_PROG_CC_C99 instead of AC_PROG_CC
dnl # as long as we try to be compatible with Autoconf 2.69.
AC_PROG_CC_C99
if test x$ac_cv_prog_cc_c99 = xno ; then
	AC_MSG_ERROR([No C99 compiler was found.])
fi

AM_PROG_CC_C_O
AM_PROG_AS
AC_USE_SYSTEM_EXTENSIONS

AS_CASE([$enable_threads],
	[posix], [
		echo
		echo "POSIX threading support:"
		AX_PTHREAD([:]) dnl We don't need the HAVE_PTHREAD macro.
		LIBS="$LIBS $PTHREAD_LIBS"
		AM_CFLAGS="$AM_CFLAGS $PTHREAD_CFLAGS"

		dnl NOTE: PTHREAD_CC is ignored. It would be useful on AIX,
		dnl but it's tricky to get it right together with
		dnl AC_PROG_CC_C99. Thus, this is handled by telling the
		dnl user in INSTALL to set the correct CC manually.

		AC_DEFINE([MYTHREAD_POSIX], [1],
			[Define to 1 when using POSIX threads (pthreads).])

		# This is nice to have but not mandatory.
		OLD_CFLAGS=$CFLAGS
		CFLAGS="$CFLAGS $PTHREAD_CFLAGS"
		AC_CHECK_FUNCS([pthread_condattr_setclock])
		CFLAGS=$OLD_CFLAGS
	],
	[win95], [
		AC_DEFINE([MYTHREAD_WIN95], [1], [Define to 1 when using
			Windows 95 (and thus XP) compatible threads.
			This avoids use of features that were added in
			Windows Vista.])
	],
	[vista], [
		AC_DEFINE([MYTHREAD_VISTA], [1], [Define to 1 when using
			Windows Vista compatible threads. This uses
			features that are not available on Windows XP.])
	]
)
AM_CONDITIONAL([COND_THREADS], [test "x$enable_threads" != xno])

echo
echo "Initializing Libtool:"
LT_PREREQ([2.4])
LT_INIT([win32-dll])
LT_LANG([Windows Resource])

# This is a bit wrong since it is possible to request that only some libs
# are built as shared. Using that feature isn't so common though, and this
# breaks only on Windows (at least for now) if the user enables only some
# libs as shared.
AM_CONDITIONAL([COND_SHARED], [test "x$enable_shared" != xno])

#####################
# Symbol versioning #
#####################

# NOTE: This checks if we are building shared or static library
# and if --with-pic or --without-pic was used. Thus this check
# must be after Libtool initialization.
AC_MSG_CHECKING([if library symbol versioning should be used])
AC_ARG_ENABLE([symbol-versions], [AS_HELP_STRING([--enable-symbol-versions],
		[Use symbol versioning for liblzma. Enabled by default on
		GNU/Linux, other GNU-based systems, and FreeBSD.])],
	[], [enable_symbol_versions=auto])
if test "x$enable_symbol_versions" = xauto; then
	case $host_os in
		# NOTE: Even if one omits -gnu on GNU/Linux (e.g.
		# i486-slackware-linux), configure will (via config.sub)
		# append -gnu (e.g. i486-slackware-linux-gnu), and this
		# test will work correctly.
		gnu* | *-gnu* | freebsd*)
			enable_symbol_versions=yes
			;;
		*)
			enable_symbol_versions=no
			;;
	esac
fi

# There are two variants for symbol versioning.
# See src/liblzma/validate_map.sh for details.
#
# On GNU/Linux, extra symbols are added in the C code. These extra symbols
# must not be put into a static library as they can cause problems (and
# even if they didn't cause problems, they would be useless). On other
# systems symbol versioning may be used too but there is no problem as only
# a linker script is specified in src/liblzma/Makefile.am and that isn't
# used when creating a static library.
#
# Libtool always uses -DPIC when building shared libraries by default and
# doesn't use it for static libs by default. This can be overridden with
# --with-pic and --without-pic though. As long as neither --with-pic nor
# --without-pic is used then we can use #ifdef PIC to detect if the file is
# being built for a shared library.
if test "x$enable_symbol_versions" = xno ; then
	enable_symbol_versions=no
	AC_MSG_RESULT([no])
elif test "x$enable_shared" = xno ; then
	enable_symbol_versions=no
	AC_MSG_RESULT([no (not building a shared library)])
else
	case "$host_cpu-$host_os" in
		microblaze*)
			# GCC 12 on MicroBlaze doesn't support __symver__
			# attribute. It's simplest and safest to use the
			# generic version on that platform since then only
			# the linker script is needed. The RHEL/CentOS 7
			# compatibility symbols don't matter on MicroBlaze.
			enable_symbol_versions=generic
			;;
		*-linux*)
			case "$pic_mode-$enable_static" in
				default-*)
					# Use symvers if PIC is defined.
					have_symbol_versions_linux=2
					;;
				*-no)
					# Not building static library.
					# Use symvers unconditionally.
					have_symbol_versions_linux=1
					;;
				*)
					AC_MSG_RESULT([])
					AC_MSG_ERROR([
    On GNU/Linux, building both shared and static library at the same time
    is not supported if --with-pic or --without-pic is used.
    Use either --disable-shared or --disable-static to build one type
    of library at a time. If both types are needed, build one at a time,
    possibly picking only src/liblzma/.libs/liblzma.a from the static build.])
					;;
			esac
			enable_symbol_versions=linux
			AC_DEFINE_UNQUOTED([HAVE_SYMBOL_VERSIONS_LINUX],
				[$have_symbol_versions_linux],
				[Define to 1 to if GNU/Linux-specific details
				are unconditionally wanted for symbol
				versioning. Define to 2 to if these are wanted
				only if also PIC is defined (allows building
				both shared and static liblzma at the same
				time with Libtool if neither --with-pic nor
				--without-pic is used). This define must be
				used together with liblzma_linux.map.])
			;;
		*)
			enable_symbol_versions=generic
			;;
	esac
	AC_MSG_RESULT([yes ($enable_symbol_versions)])
fi

AM_CONDITIONAL([COND_SYMVERS_LINUX],
	[test "x$enable_symbol_versions" = xlinux])
AM_CONDITIONAL([COND_SYMVERS_GENERIC],
	[test "x$enable_symbol_versions" = xgeneric])


###############################################################################
# Checks for libraries.
###############################################################################

dnl Support for _REQUIRE_VERSION was added in gettext 0.19.6. If both
dnl _REQUIRE_VERSION and _VERSION are present, the _VERSION is ignored.
dnl We use both for compatibility with other programs in the Autotools family.
echo
echo "Initializing gettext:"
AM_GNU_GETTEXT_REQUIRE_VERSION([0.19.6])
AM_GNU_GETTEXT_VERSION([0.19.6])
AM_GNU_GETTEXT([external])


###############################################################################
# Checks for header files.
###############################################################################

echo
echo "System headers and functions:"

# There is currently no workarounds in this package if some of
# these headers are missing.
AC_CHECK_HEADERS([fcntl.h limits.h sys/time.h],
	[],
	[AC_MSG_ERROR([Required header file(s) are missing.])])

# immintrin.h allows the use of the intrinsic functions if they are available.
# cpuid.h may be used for detecting x86 processor features at runtime.
AC_CHECK_HEADERS([immintrin.h cpuid.h])


###############################################################################
# Checks for typedefs, structures, and compiler characteristics.
###############################################################################

AC_HEADER_STDBOOL

AC_TYPE_UINT8_T
AC_TYPE_UINT16_T
AC_TYPE_INT32_T
AC_TYPE_UINT32_T
AC_TYPE_INT64_T
AC_TYPE_UINT64_T
AC_TYPE_UINTPTR_T

AC_CHECK_SIZEOF([size_t])

# The command line tool can copy high resolution timestamps if such
# information is available in struct stat. Otherwise one second accuracy
# is used.
AC_CHECK_MEMBERS([
	struct stat.st_atim.tv_nsec,
	struct stat.st_atimespec.tv_nsec,
	struct stat.st_atimensec,
	struct stat.st_uatime,
	struct stat.st_atim.st__tim.tv_nsec])

AC_SYS_LARGEFILE
AC_C_BIGENDIAN

# __attribute__((__constructor__)) can be used for one-time initializations.
# Use -Werror because some compilers accept unknown attributes and just
# give a warning.
#
# FIXME? Unfortunately -Werror can cause trouble if CFLAGS contains options
# that produce warnings for unrelated reasons. For example, GCC and Clang
# support -Wunused-macros which will warn about "#define _GNU_SOURCE 1"
# which will be among the #defines that Autoconf inserts to the beginning of
# the test program. There seems to be no nice way to prevent Autoconf from
# inserting the any defines to the test program.
AC_MSG_CHECKING([if __attribute__((__constructor__)) can be used])
have_func_attribute_constructor=no
OLD_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -Werror"
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
	__attribute__((__constructor__))
	static void my_constructor_func(void) { return; }
]])], [
	AC_DEFINE([HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR], [1],
		[Define to 1 if __attribute__((__constructor__))
		is supported for functions.])
	have_func_attribute_constructor=yes
	AC_MSG_RESULT([yes])
], [
	AC_MSG_RESULT([no])
])
CFLAGS="$OLD_CFLAGS"

# The Win95 threading lacks a thread-safe one-time initialization function.
# The one-time initialization is needed for crc32_small.c and crc64_small.c
# create the CRC tables. So if small mode is enabled, the threading mode is
# win95, and the compiler does not support attribute constructor, then we
# would end up with a multithreaded build that is thread-unsafe. As a
# result this configuration is not allowed.
if test "x$enable_small$enable_threads$have_func_attribute_constructor" \
		= xyeswin95no; then
	AC_MSG_ERROR([
    --enable-threads=win95 and --enable-small cannot be used
    at the same time with a compiler that doesn't support
    __attribute__((__constructor__))])
fi

# __attribute__((__ifunc__())) can be used to choose between different
# implementations of the same function at runtime. This is slightly more
# efficient than using __attribute__((__constructor__)) and setting
# a function pointer.
AC_ARG_ENABLE([ifunc], [AS_HELP_STRING([--enable-ifunc],
		[Use __attribute__((__ifunc__())). Enabled by default on
		GNU/Linux (glibc) and FreeBSD.])],
	[], [enable_ifunc=auto])

# When enable_ifunc is 'auto', allow the use of __attribute__((__ifunc__()))
# if compiler support is detected and we are building for GNU/Linux (glibc)
# or FreeBSD. uClibc and musl don't support ifunc in their dynamic linkers
# but some compilers still accept the attribute when compiling for these
# C libraries, which results in broken binaries. That's why we need to
# check which libc is being used.
if test "x$enable_ifunc" = xauto ; then
	OLD_CFLAGS="$CFLAGS"
	CFLAGS="$CFLAGS -Werror"
	AC_MSG_CHECKING([if __attribute__((__ifunc__())) can be used])
	AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
		/*
		 * Force a compilation error when not using glibc on Linux
		 * or if we are not using FreeBSD. uClibc will define
		 * __GLIBC__ but does not support ifunc, so we must have
		 * an extra check to disable with uClibc.
		 */
		#if defined(__linux__)
		#	include <features.h>
		#	if !defined(__GLIBC__) || defined(__UCLIBC__)
				compile error
		#	endif
		#elif !defined(__FreeBSD__)
			compile error
		#endif

		static void func(void) { return; }
		static void (*resolve_func (void)) (void) { return func; }
		void func_ifunc (void)
				__attribute__((__ifunc__("resolve_func")));
		/*
		 * 'clang -Wall' incorrectly warns that resolve_func is
		 * unused (-Wunused-function). Correct assembly output is
		 * still produced. This problem exists at least in Clang
		 * versions 4 to 17. The following silences the bogus warning:
		 */
		void make_clang_quiet(void);
		void make_clang_quiet(void) { resolve_func()(); }
	]])], [
		enable_ifunc=yes
	], [
		enable_ifunc=no
	])

	AC_MSG_RESULT([$enable_ifunc])

	CFLAGS="$OLD_CFLAGS"
fi

if test "x$enable_ifunc" = xyes ; then
	AC_DEFINE([HAVE_FUNC_ATTRIBUTE_IFUNC], [1],
			[Define to 1 if __attribute__((__ifunc__()))
			is supported for functions.])

	# ifunc explicitly does not work with -fsanitize=address.
	# If configured, it will result in a liblzma build that will fail
	# when liblzma is loaded at runtime (when the ifunc resolver
	# executes).
	AS_CASE([$CFLAGS], [*-fsanitize=*], [AC_MSG_ERROR([
    CFLAGS contains '-fsanitize=' which is incompatible with ifunc.
    Use --disable-ifunc when using '-fsanitize'.])])
fi


###############################################################################
# Checks for library functions.
###############################################################################

# Gnulib replacements as needed
gl_GETOPT

# If clock_gettime() is available, liblzma with pthreads may use it, and
# xz may use it even when threading support is disabled. In XZ Utils 5.4.x
# and older, configure checked for clock_gettime() only when using pthreads.
# This way non-threaded builds of liblzma didn't get a useless dependency on
# librt which further had a dependency on libpthread. Avoiding these was
# useful when a small build was needed, for example, for initramfs use.
#
# The above reasoning is thoroughly obsolete: On GNU/Linux, librt hasn't
# been needed for clock_gettime() since glibc 2.17 (2012-12-25).
# Solaris 10 needs librt but Solaris 11 doesn't anymore.
AC_SEARCH_LIBS([clock_gettime], [rt])
AC_CHECK_FUNCS([clock_gettime])
AC_CHECK_DECL([CLOCK_MONOTONIC], [AC_DEFINE([HAVE_CLOCK_MONOTONIC], [1],
	[Define to 1 if 'CLOCK_MONOTONIC' is declared in <time.h>.])], [],
	[[#include <time.h>]])

# Find the best function to set timestamps.
AC_CHECK_FUNCS([futimens futimes futimesat utimes _futime utime], [break])

# This is nice to have but not mandatory.
AC_CHECK_FUNCS([posix_fadvise])

TUKLIB_PROGNAME
TUKLIB_INTEGER
TUKLIB_PHYSMEM
TUKLIB_CPUCORES
TUKLIB_MBSTR

# If requested, check for system-provided SHA-256. At least the following
# implementations are supported:
#
# OS       Headers                     Library  Type           Function
# FreeBSD  sys/types.h + sha256.h      libmd    SHA256_CTX     SHA256_Init
# NetBSD   sys/types.h + sha2.h                 SHA256_CTX     SHA256_Init
# OpenBSD  sys/types.h + sha2.h                 SHA2_CTX       SHA256Init
# Solaris  sys/types.h + sha2.h        libmd    SHA256_CTX     SHA256Init
# MINIX 3  sys/types.h + sha2.h                 SHA256_CTX     SHA256_Init
# Darwin   CommonCrypto/CommonDigest.h          CC_SHA256_CTX  CC_SHA256_Init
#
# Note that Darwin's CC_SHA256_Update takes buffer size as uint32_t instead
# of size_t.
#
sha256_header_found=no
sha256_type_found=no
sha256_func_found=no
AS_IF([test "x$enable_external_sha256" = "xyes"], [
	# Test for Common Crypto before others, because Darwin has sha256.h
	# too and we don't want to use that, because on older versions it
	# uses OpenSSL functions, whose SHA256_Init is not guaranteed to
	# succeed.
	AC_CHECK_HEADERS(
		[CommonCrypto/CommonDigest.h sha256.h sha2.h],
		[sha256_header_found=yes ; break])
	if test "x$sha256_header_found" = xyes; then
		AC_CHECK_TYPES([CC_SHA256_CTX, SHA256_CTX, SHA2_CTX],
			[sha256_type_found=yes], [],
			[[#ifdef HAVE_SYS_TYPES_H
			  # include <sys/types.h>
			  #endif
			  #ifdef HAVE_COMMONCRYPTO_COMMONDIGEST_H
			  # include <CommonCrypto/CommonDigest.h>
			  #endif
			  #ifdef HAVE_SHA256_H
			  # include <sha256.h>
			  #endif
			  #ifdef HAVE_SHA2_H
			  # include <sha2.h>
			  #endif]])
		if test "x$sha256_type_found" = xyes ; then
			AC_SEARCH_LIBS([SHA256Init], [md])
			AC_SEARCH_LIBS([SHA256_Init], [md])
			AC_CHECK_FUNCS([CC_SHA256_Init SHA256Init SHA256_Init],
				[sha256_func_found=yes ; break])
		fi
	fi
])
AM_CONDITIONAL([COND_INTERNAL_SHA256], [test "x$sha256_func_found" = xno])
if test "x$enable_external_sha256$sha256_func_found" = xyesno; then
	AC_MSG_ERROR([--enable-external-sha256 was specified but no supported external SHA-256 implementation was found])
fi

# Check for SSE2 intrinsics. There is no run-time detection for SSE2 so if
# compiler options enable SSE2 then SSE2 support is required by the binaries.
# The compile-time check for SSE2 is done with #ifdefs because some compilers
# (ICC, MSVC) allow SSE2 intrinsics even when SSE2 isn't enabled.
AC_CHECK_DECL([_mm_movemask_epi8],
	[AC_DEFINE([HAVE__MM_MOVEMASK_EPI8], [1],
		[Define to 1 if _mm_movemask_epi8 is available.])],
	[],
[#ifdef HAVE_IMMINTRIN_H
#include <immintrin.h>
#endif])

# For faster CRC on 32/64-bit x86 and E2K (see also crc64_fast.c):
#
#   - Check for the CLMUL intrinsic _mm_clmulepi64_si128 in <immintrin.h>.
#     Check also for _mm_set_epi64x for consistency with CMake build
#     where it's needed to disable CLMUL with VS2013.
#
#   - Check that __attribute__((__target__("ssse3,sse4.1,pclmul"))) works
#     together with _mm_clmulepi64_si128 from <immintrin.h>. The attribute
#     was added in GCC 4.4 but some GCC 4.x versions don't allow intrinsics
#     with it. Exception: it must be not be used with EDG-based compilers
#     like ICC and the compiler on E2K.
#
# If everything above is supported, runtime detection will be used to keep the
# binaries working on systems that don't support the required extensions.
AC_MSG_CHECKING([if _mm_clmulepi64_si128 is usable])
AS_IF([test "x$enable_clmul_crc" = xno], [
	AC_MSG_RESULT([no, --disable-clmul-crc was used])
], [
	AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <immintrin.h>

// CLMUL works on older E2K instruction set but it is slow due to emulation.
#if defined(__e2k__) && __iset__ < 6
#	error
#endif

// Intel's old compiler (ICC) can define __GNUC__ but the attribute must not
// be used with it. The new Clang-based ICX needs the attribute.
// Checking for !defined(__EDG__) catches ICC and other EDG-based compilers.
#if (defined(__GNUC__) || defined(__clang__)) && !defined(__EDG__)
__attribute__((__target__("ssse3,sse4.1,pclmul")))
#endif
__m128i my_clmul(__m128i a)
{
	const __m128i b = _mm_set_epi64x(1, 2);
	return _mm_clmulepi64_si128(a, b, 0);
}
	]])], [
		AC_DEFINE([HAVE_USABLE_CLMUL], [1],
			[Define to 1 if _mm_set_epi64x and
			_mm_clmulepi64_si128 are usable.
			See configure.ac for details.])
		enable_clmul_crc=yes
	], [
		enable_clmul_crc=no
	])
	AC_MSG_RESULT([$enable_clmul_crc])
])

# ARM64 C Language Extensions define CRC32 functions in arm_acle.h.
# These are supported by at least GCC and Clang which both need
# __attribute__((__target__("+crc"))), unless the needed compiler flags
# are used to support the CRC instruction.
AC_MSG_CHECKING([if ARM64 CRC32 instruction is usable])
AS_IF([test "x$enable_arm64_crc32" = xno], [
	AC_MSG_RESULT([no, --disable-arm64-crc32 was used])
], [
	AC_COMPILE_IFELSE([AC_LANG_SOURCE([[
#include <arm_acle.h>
#include <stdint.h>

#if (defined(__GNUC__) || defined(__clang__)) && !defined(__EDG__)
__attribute__((__target__("+crc")))
#endif
uint32_t my_crc(uint32_t a, uint64_t b)
{
	return __crc32d(a, b);
}
	]])], [
		AC_DEFINE([HAVE_ARM64_CRC32], [1],
			[Define to 1 if ARM64 CRC32 instruction is supported.
			See configure.ac for details.])
		enable_arm64_crc32=yes
	], [
		enable_arm64_crc32=no
	])
	AC_MSG_RESULT([$enable_arm64_crc32])
])

# Check for ARM64 CRC32 instruction runtime detection.
# getauxval() is supported on Linux, elf_aux_info() on FreeBSD, and
# sysctlbyname("hw.optional.armv8_crc32", ...) is supported on Darwin
# (macOS, iOS, etc.). Note that sysctlbyname() is supported on FreeBSD,
# NetBSD, and possibly others too but the string is specific to Apple OSes.
# The C code is responsible for checking defined(__APPLE__) before using
# sysctlbyname("hw.optional.armv8_crc32", ...).
AS_IF([test "x$enable_arm64_crc32" = xyes], [
	AC_CHECK_FUNCS([getauxval elf_aux_info sysctlbyname])
])


# Check for sandbox support. If one is found, set enable_sandbox=found.
#
# About -fsanitize: Of our three sandbox methods, only Landlock is
# incompatible with -fsanitize. FreeBSD 13.2 with Capsicum was tested with
# -fsanitize=address,undefined and had no issues. OpenBSD (as of version
# 7.4) has minimal support for process instrumentation. OpenBSD does not
# distribute the additional libraries needed (libasan, libubsan, etc.) with
# GCC or Clang needed for runtime sanitization support and instead only
# support -fsanitize-minimal-runtime for minimal undefined behavior
# sanitization. This minimal support is compatible with our use of the
# Pledge sandbox. So only Landlock will result in a build that cannot
# compress or decompress a single file to standard out.
AS_CASE([$enable_sandbox],
	[auto | capsicum], [
		AC_CHECK_FUNCS([cap_rights_limit], [enable_sandbox=found])
	]
)
AS_CASE([$enable_sandbox],
	[auto | pledge], [
		AC_CHECK_FUNCS([pledge], [enable_sandbox=found])
	]
)
AS_CASE([$enable_sandbox],
	[auto | landlock], [
		AC_CHECK_HEADERS([linux/landlock.h], [
			enable_sandbox=found

			AS_CASE([$CFLAGS], [*-fsanitize=*], [AC_MSG_ERROR([
    CFLAGS contains '-fsanitize=' which is incompatible with the Landlock
    sandboxing. Use --disable-sandbox when using '-fsanitize'.])])
		])
	]
)

# If a specific sandboxing method was explicitly requested and it wasn't
# found, give an error.
case $enable_sandbox in
	auto | no | found)
		;;
	*)
		AC_MSG_ERROR([$enable_sandbox support not found])
		;;
esac


###############################################################################
# If using GCC, set some additional AM_CFLAGS:
###############################################################################

if test "$GCC" = yes ; then
	echo
	echo "GCC extensions:"
fi

# Always do the visibility check but don't set AM_CFLAGS on Windows.
# This way things get set properly even on Windows.
gl_VISIBILITY
if test -n "$CFLAG_VISIBILITY" && test "$is_w32" = no; then
	AM_CFLAGS="$AM_CFLAGS $CFLAG_VISIBILITY"
fi

AS_IF([test "$GCC" = yes], [
	# Enable as much warnings as possible. These commented warnings won't
	# work for this package though:
	#   * -Wunreachable-code breaks several assert(0) cases, which are
	#     backed up with "return LZMA_PROG_ERROR".
	#   * -Wcast-qual would break various things where we need a non-const
	#     pointer although we don't modify anything through it.
	#   * -Winline, -Wdisabled-optimization, -Wunsafe-loop-optimizations
	#     don't seem so useful here; at least the last one gives some
	#     warnings which are not bugs.
	#   * -Wconversion still shows too many warnings.
	#
	# The flags before the empty line are for GCC and many of them
	# are supported by Clang too. The flags after the empty line are
	# for Clang.
	for NEW_FLAG in \
			-Wall \
			-Wextra \
			-Wvla \
			-Wformat=2 \
			-Winit-self \
			-Wmissing-include-dirs \
			-Wshift-overflow=2 \
			-Wstrict-overflow=3 \
			-Walloc-zero \
			-Wduplicated-cond \
			-Wfloat-equal \
			-Wundef \
			-Wshadow \
			-Wpointer-arith \
			-Wbad-function-cast \
			-Wwrite-strings \
			-Wdate-time \
			-Wsign-conversion \
			-Wfloat-conversion \
			-Wlogical-op \
			-Waggregate-return \
			-Wstrict-prototypes \
			-Wold-style-definition \
			-Wmissing-prototypes \
			-Wmissing-declarations \
			-Wredundant-decls \
			\
			-Wc99-compat \
			-Wc11-extensions \
			-Wc2x-compat \
			-Wc2x-extensions \
			-Wpre-c2x-compat \
			-Warray-bounds-pointer-arithmetic \
			-Wassign-enum \
			-Wconditional-uninitialized \
			-Wdocumentation \
			-Wduplicate-enum \
			-Wempty-translation-unit \
			-Wflexible-array-extensions \
			-Wmissing-variable-declarations \
			-Wnewline-eof \
			-Wshift-sign-overflow \
			-Wstring-conversion
	do
		AC_MSG_CHECKING([if $CC accepts $NEW_FLAG])
		OLD_CFLAGS="$CFLAGS"
		CFLAGS="$CFLAGS $NEW_FLAG -Werror"
		AC_COMPILE_IFELSE([AC_LANG_SOURCE(
				[[void foo(void); void foo(void) { }]])], [
			AM_CFLAGS="$AM_CFLAGS $NEW_FLAG"
			AC_MSG_RESULT([yes])
		], [
			AC_MSG_RESULT([no])
		])
		CFLAGS="$OLD_CFLAGS"
	done

	AC_ARG_ENABLE([werror],
		AS_HELP_STRING([--enable-werror], [Enable -Werror to abort
			compilation on all compiler warnings.]),
		[], [enable_werror=no])
	if test "x$enable_werror" = "xyes"; then
		AM_CFLAGS="$AM_CFLAGS -Werror"
	fi
])


###############################################################################
# Create the makefiles and config.h
###############################################################################

echo

# Don't build the lib directory at all if we don't need any replacement
# functions.
AM_CONDITIONAL([COND_GNULIB], test -n "$LIBOBJS")

# Add default AM_CFLAGS.
AC_SUBST([AM_CFLAGS])

# This is needed for src/scripts.
xz=`echo xz | sed "$program_transform_name"`
AC_SUBST([xz])

AC_CONFIG_FILES([
	Makefile
	po/Makefile.in
	lib/Makefile
	src/Makefile
	src/liblzma/Makefile
	src/liblzma/api/Makefile
	src/xz/Makefile
	src/xzdec/Makefile
	src/lzmainfo/Makefile
	src/scripts/Makefile
	tests/Makefile
	debug/Makefile
])
AC_CONFIG_FILES([src/scripts/xzdiff], [chmod +x src/scripts/xzdiff])
AC_CONFIG_FILES([src/scripts/xzgrep], [chmod +x src/scripts/xzgrep])
AC_CONFIG_FILES([src/scripts/xzmore], [chmod +x src/scripts/xzmore])
AC_CONFIG_FILES([src/scripts/xzless], [chmod +x src/scripts/xzless])

AC_OUTPUT

# Some warnings
if test x$tuklib_cv_physmem_method = xunknown; then
	echo
	echo "WARNING:"
	echo "No supported method to detect the amount of RAM."
	echo "Consider using --enable-assume-ram (if you didn't already)"
	echo "or make a patch to add support for this operating system."
fi

if test x$tuklib_cv_cpucores_method = xunknown; then
	echo
	echo "WARNING:"
	echo "No supported method to detect the number of CPU cores."
fi

if test "x$enable_threads$enable_small$have_func_attribute_constructor" \
		= xnoyesno; then
	echo
	echo "NOTE:"
	echo "liblzma will be thread-unsafe due to the combination"
	echo "of --disable-threads --enable-small when using a compiler"
	echo "that doesn't support __attribute__((__constructor__))."
fi