aboutsummaryrefslogtreecommitdiff
path: root/scripts/kconfig/symbol.c
blob: b664d6ed515ffe27e4a805734a5f51d839078da4 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
/*
 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
 * Released under the terms of the GNU GPL v2.0.
 */

#include <ctype.h>
#include <stdlib.h>
#include <string.h>
#include <regex.h>
#include <sys/utsname.h>

#include "lkc.h"

struct symbol symbol_yes = {
	.name = "y",
	.curr = { "y", yes },
	.flags = SYMBOL_CONST|SYMBOL_VALID,
}, symbol_mod = {
	.name = "m",
	.curr = { "m", mod },
	.flags = SYMBOL_CONST|SYMBOL_VALID,
}, symbol_no = {
	.name = "n",
	.curr = { "n", no },
	.flags = SYMBOL_CONST|SYMBOL_VALID,
}, symbol_empty = {
	.name = "",
	.curr = { "", no },
	.flags = SYMBOL_VALID,
};

struct symbol *sym_defconfig_list;
struct symbol *modules_sym;
tristate modules_val;

struct expr *sym_env_list;

static void sym_add_default(struct symbol *sym, const char *def)
{
	struct property *prop = prop_alloc(P_DEFAULT, sym);

	prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));
}

void sym_init(void)
{
	struct symbol *sym;
	struct utsname uts;
	static bool inited = false;

	if (inited)
		return;
	inited = true;

	uname(&uts);

	sym = sym_lookup("UNAME_RELEASE", 0);
	sym->type = S_STRING;
	sym->flags |= SYMBOL_AUTO;
	sym_add_default(sym, uts.release);
}

enum symbol_type sym_get_type(struct symbol *sym)
{
	enum symbol_type type = sym->type;

	if (type == S_TRISTATE) {
		if (sym_is_choice_value(sym) && sym->visible == yes)
			type = S_BOOLEAN;
		else if (modules_val == no)
			type = S_BOOLEAN;
	}
	return type;
}

const char *sym_type_name(enum symbol_type type)
{
	switch (type) {
	case S_BOOLEAN:
		return "boolean";
	case S_TRISTATE:
		return "tristate";
	case S_INT:
		return "integer";
	case S_HEX:
		return "hex";
	case S_STRING:
		return "string";
	case S_UNKNOWN:
		return "unknown";
	case S_OTHER:
		break;
	}
	return "???";
}

struct property *sym_get_choice_prop(struct symbol *sym)
{
	struct property *prop;

	for_all_choices(sym, prop)
		return prop;
	return NULL;
}

struct property *sym_get_env_prop(struct symbol *sym)
{
	struct property *prop;

	for_all_properties(sym, prop, P_ENV)
		return prop;
	return NULL;
}

struct property *sym_get_default_prop(struct symbol *sym)
{
	struct property *prop;

	for_all_defaults(sym, prop) {
		prop->visible.tri = expr_calc_value(prop->visible.expr);
		if (prop->visible.tri != no)
			return prop;
	}
	return NULL;
}

static struct property *sym_get_range_prop(struct symbol *sym)
{
	struct property *prop;

	for_all_properties(sym, prop, P_RANGE) {
		prop->visible.tri = expr_calc_value(prop->visible.expr);
		if (prop->visible.tri != no)
			return prop;
	}
	return NULL;
}

static long sym_get_range_val(struct symbol *sym, int base)
{
	sym_calc_value(sym);
	switch (sym->type) {
	case S_INT:
		base = 10;
		break;
	case S_HEX:
		base = 16;
		break;
	default:
		break;
	}
	return strtol(sym->curr.val, NULL, base);
}

static void sym_validate_range(struct symbol *sym)
{
	struct property *prop;
	long base, val, val2;
	char str[64];

	switch (sym->type) {
	case S_INT:
		base = 10;
		break;
	case S_HEX:
		base = 16;
		break;
	default:
		return;
	}
	prop = sym_get_range_prop(sym);
	if (!prop)
		return;
	val = strtol(sym->curr.val, NULL, base);
	val2 = sym_get_range_val(prop->expr->left.sym, base);
	if (val >= val2) {
		val2 = sym_get_range_val(prop->expr->right.sym, base);
		if (val <= val2)
			return;
	}
	if (sym->type == S_INT)
		sprintf(str, "%ld", val2);
	else
		sprintf(str, "0x%lx", val2);
	sym->curr.val = strdup(str);
}

static void sym_calc_visibility(struct symbol *sym)
{
	struct property *prop;
	tristate tri;

	/* any prompt visible? */
	tri = no;
	for_all_prompts(sym, prop) {
		prop->visible.tri = expr_calc_value(prop->visible.expr);
		tri = EXPR_OR(tri, prop->visible.tri);
	}
	if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
		tri = yes;
	if (sym->visible != tri) {
		sym->visible = tri;
		sym_set_changed(sym);
	}
	if (sym_is_choice_value(sym))
		return;
	/* defaulting to "yes" if no explicit "depends on" are given */
	tri = yes;
	if (sym->dir_dep.expr)
		tri = expr_calc_value(sym->dir_dep.expr);
	if (tri == mod)
		tri = yes;
	if (sym->dir_dep.tri != tri) {
		sym->dir_dep.tri = tri;
		sym_set_changed(sym);
	}
	tri = no;
	if (sym->rev_dep.expr)
		tri = expr_calc_value(sym->rev_dep.expr);
	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
		tri = yes;
	if (sym->rev_dep.tri != tri) {
		sym->rev_dep.tri = tri;
		sym_set_changed(sym);
	}
}

/*
 * Find the default symbol for a choice.
 * First try the default values for the choice symbol
 * Next locate the first visible choice value
 * Return NULL if none was found
 */
struct symbol *sym_choice_default(struct symbol *sym)
{
	struct symbol *def_sym;
	struct property *prop;
	struct expr *e;

	/* any of the defaults visible? */
	for_all_defaults(sym, prop) {
		prop->visible.tri = expr_calc_value(prop->visible.expr);
		if (prop->visible.tri == no)
			continue;
		def_sym = prop_get_symbol(prop);
		if (def_sym->visible != no)
			return def_sym;
	}

	/* just get the first visible value */
	prop = sym_get_choice_prop(sym);
	expr_list_for_each_sym(prop->expr, e, def_sym)
		if (def_sym->visible != no)
			return def_sym;

	/* failed to locate any defaults */
	return NULL;
}

static struct symbol *sym_calc_choice(struct symbol *sym)
{
	struct symbol *def_sym;
	struct property *prop;
	struct expr *e;
	int flags;

	/* first calculate all choice values' visibilities */
	flags = sym->flags;
	prop = sym_get_choice_prop(sym);
	expr_list_for_each_sym(prop->expr, e, def_sym) {
		sym_calc_visibility(def_sym);
		if (def_sym->visible != no)
			flags &= def_sym->flags;
	}

	sym->flags &= flags | ~SYMBOL_DEF_USER;

	/* is the user choice visible? */
	def_sym = sym->def[S_DEF_USER].val;
	if (def_sym && def_sym->visible != no)
		return def_sym;

	def_sym = sym_choice_default(sym);

	if (def_sym == NULL)
		/* no choice? reset tristate value */
		sym->curr.tri = no;

	return def_sym;
}

void sym_calc_value(struct symbol *sym)
{
	struct symbol_value newval, oldval;
	struct property *prop;
	struct expr *e;

	if (!sym)
		return;

	if (sym->flags & SYMBOL_VALID)
		return;

	if (sym_is_choice_value(sym) &&
	    sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
		sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
		prop = sym_get_choice_prop(sym);
		sym_calc_value(prop_get_symbol(prop));
	}

	sym->flags |= SYMBOL_VALID;

	oldval = sym->curr;

	switch (sym->type) {
	case S_INT:
	case S_HEX:
	case S_STRING:
		newval = symbol_empty.curr;
		break;
	case S_BOOLEAN:
	case S_TRISTATE:
		newval = symbol_no.curr;
		break;
	default:
		sym->curr.val = sym->name;
		sym->curr.tri = no;
		return;
	}
	if (!sym_is_choice_value(sym))
		sym->flags &= ~SYMBOL_WRITE;

	sym_calc_visibility(sym);

	/* set default if recursively called */
	sym->curr = newval;

	switch (sym_get_type(sym)) {
	case S_BOOLEAN:
	case S_TRISTATE:
		if (sym_is_choice_value(sym) && sym->visible == yes) {
			prop = sym_get_choice_prop(sym);
			newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
		} else {
			if (sym->visible != no) {
				/* if the symbol is visible use the user value
				 * if available, otherwise try the default value
				 */
				sym->flags |= SYMBOL_WRITE;
				if (sym_has_value(sym)) {
					newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
							      sym->visible);
					goto calc_newval;
				}
			}
			if (sym->rev_dep.tri != no)
				sym->flags |= SYMBOL_WRITE;
			if (!sym_is_choice(sym)) {
				prop = sym_get_default_prop(sym);
				if (prop) {
					sym->flags |= SYMBOL_WRITE;
					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
							      prop->visible.tri);
				}
			}
		calc_newval:
			if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
				struct expr *e;
				e = expr_simplify_unmet_dep(sym->rev_dep.expr,
				    sym->dir_dep.expr);
				fprintf(stderr, "warning: (");
				expr_fprint(e, stderr);
				fprintf(stderr, ") selects %s which has unmet direct dependencies (",
					sym->name);
				expr_fprint(sym->dir_dep.expr, stderr);
				fprintf(stderr, ")\n");
				expr_free(e);
			}
			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
		}
		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
			newval.tri = yes;
		break;
	case S_STRING:
	case S_HEX:
	case S_INT:
		if (sym->visible != no) {
			sym->flags |= SYMBOL_WRITE;
			if (sym_has_value(sym)) {
				newval.val = sym->def[S_DEF_USER].val;
				break;
			}
		}
		prop = sym_get_default_prop(sym);
		if (prop) {
			struct symbol *ds = prop_get_symbol(prop);
			if (ds) {
				sym->flags |= SYMBOL_WRITE;
				sym_calc_value(ds);
				newval.val = ds->curr.val;
			}
		}
		break;
	default:
		;
	}

	sym->curr = newval;
	if (sym_is_choice(sym) && newval.tri == yes)
		sym->curr.val = sym_calc_choice(sym);
	sym_validate_range(sym);

	if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
		sym_set_changed(sym);
		if (modules_sym == sym) {
			sym_set_all_changed();
			modules_val = modules_sym->curr.tri;
		}
	}

	if (sym_is_choice(sym)) {
		struct symbol *choice_sym;

		prop = sym_get_choice_prop(sym);
		expr_list_for_each_sym(prop->expr, e, choice_sym) {
			if ((sym->flags & SYMBOL_WRITE) &&
			    choice_sym->visible != no)
				choice_sym->flags |= SYMBOL_WRITE;
			if (sym->flags & SYMBOL_CHANGED)
				sym_set_changed(choice_sym);
		}
	}

	if (sym->flags & SYMBOL_AUTO)
		sym->flags &= ~SYMBOL_WRITE;

	if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
		set_all_choice_values(sym);
}

void sym_clear_all_valid(void)
{
	struct symbol *sym;
	int i;

	for_all_symbols(i, sym)
		sym->flags &= ~SYMBOL_VALID;
	sym_add_change_count(1);
	if (modules_sym)
		sym_calc_value(modules_sym);
}

void sym_set_changed(struct symbol *sym)
{
	struct property *prop;

	sym->flags |= SYMBOL_CHANGED;
	for (prop = sym->prop; prop; prop = prop->next) {
		if (prop->menu)
			prop->menu->flags |= MENU_CHANGED;
	}
}

void sym_set_all_changed(void)
{
	struct symbol *sym;
	int i;

	for_all_symbols(i, sym)
		sym_set_changed(sym);
}

bool sym_tristate_within_range(struct symbol *sym, tristate val)
{
	int type = sym_get_type(sym);

	if (sym->visible == no)
		return false;

	if (type != S_BOOLEAN && type != S_TRISTATE)
		return false;

	if (type == S_BOOLEAN && val == mod)
		return false;
	if (sym->visible <= sym->rev_dep.tri)
		return false;
	if (sym_is_choice_value(sym) && sym->visible == yes)
		return val == yes;
	return val >= sym->rev_dep.tri && val <= sym->visible;
}

bool sym_set_tristate_value(struct symbol *sym, tristate val)
{
	tristate oldval = sym_get_tristate_value(sym);

	if (oldval != val && !sym_tristate_within_range(sym, val))
		return false;

	if (!(sym->flags & SYMBOL_DEF_USER)) {
		sym->flags |= SYMBOL_DEF_USER;
		sym_set_changed(sym);
	}
	/*
	 * setting a choice value also resets the new flag of the choice
	 * symbol and all other choice values.
	 */
	if (sym_is_choice_value(sym) && val == yes) {
		struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
		struct property *prop;
		struct expr *e;

		cs->def[S_DEF_USER].val = sym;
		cs->flags |= SYMBOL_DEF_USER;
		prop = sym_get_choice_prop(cs);
		for (e = prop->expr; e; e = e->left.expr) {
			if (e->right.sym->visible != no)
				e->right.sym->flags |= SYMBOL_DEF_USER;
		}
	}

	sym->def[S_DEF_USER].tri = val;
	if (oldval != val)
		sym_clear_all_valid();

	return true;
}

tristate sym_toggle_tristate_value(struct symbol *sym)
{
	tristate oldval, newval;

	oldval = newval = sym_get_tristate_value(sym);
	do {
		switch (newval) {
		case no:
			newval = mod;
			break;
		case mod:
			newval = yes;
			break;
		case yes:
			newval = no;
			break;
		}
		if (sym_set_tristate_value(sym, newval))
			break;
	} while (oldval != newval);
	return newval;
}

bool sym_string_valid(struct symbol *sym, const char *str)
{
	signed char ch;

	switch (sym->type) {
	case S_STRING:
		return true;
	case S_INT:
		ch = *str++;
		if (ch == '-')
			ch = *str++;
		if (!isdigit(ch))
			return false;
		if (ch == '0' && *str != 0)
			return false;
		while ((ch = *str++)) {
			if (!isdigit(ch))
				return false;
		}
		return true;
	case S_HEX:
		if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
			str += 2;
		ch = *str++;
		do {
			if (!isxdigit(ch))
				return false;
		} while ((ch = *str++));
		return true;
	case S_BOOLEAN:
	case S_TRISTATE:
		switch (str[0]) {
		case 'y': case 'Y':
		case 'm': case 'M':
		case 'n': case 'N':
			return true;
		}
		return false;
	default:
		return false;
	}
}

bool sym_string_within_range(struct symbol *sym, const char *str)
{
	struct property *prop;
	long val;

	switch (sym->type) {
	case S_STRING:
		return sym_string_valid(sym, str);
	case S_INT:
		if (!sym_string_valid(sym, str))
			return false;
		prop = sym_get_range_prop(sym);
		if (!prop)
			return true;
		val = strtol(str, NULL, 10);
		return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
		       val <= sym_get_range_val(prop->expr->right.sym, 10);
	case S_HEX:
		if (!sym_string_valid(sym, str))
			return false;
		prop = sym_get_range_prop(sym);
		if (!prop)
			return true;
		val = strtol(str, NULL, 16);
		return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
		       val <= sym_get_range_val(prop->expr->right.sym, 16);
	case S_BOOLEAN:
	case S_TRISTATE:
		switch (str[0]) {
		case 'y': case 'Y':
			return sym_tristate_within_range(sym, yes);
		case 'm': case 'M':
			return sym_tristate_within_range(sym, mod);
		case 'n': case 'N':
			return sym_tristate_within_range(sym, no);
		}
		return false;
	default:
		return false;
	}
}

bool sym_set_string_value(struct symbol *sym, const char *newval)
{
	const char *oldval;
	char *val;
	int size;

	switch (sym->type) {
	case S_BOOLEAN:
	case S_TRISTATE:
		switch (newval[0]) {
		case 'y': case 'Y':
			return sym_set_tristate_value(sym, yes);
		case 'm': case 'M':
			return sym_set_tristate_value(sym, mod);
		case 'n': case 'N':
			return sym_set_tristate_value(sym, no);
		}
		return false;
	default:
		;
	}

	if (!sym_string_within_range(sym, newval))
		return false;

	if (!(sym->flags & SYMBOL_DEF_USER)) {
		sym->flags |= SYMBOL_DEF_USER;
		sym_set_changed(sym);
	}

	oldval = sym->def[S_DEF_USER].val;
	size = strlen(newval) + 1;
	if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
		size += 2;
		sym->def[S_DEF_USER].val = val = xmalloc(size);
		*val++ = '0';
		*val++ = 'x';
	} else if (!oldval || strcmp(oldval, newval))
		sym->def[S_DEF_USER].val = val = xmalloc(size);
	else
		return true;

	strcpy(val, newval);
	free((void *)oldval);
	sym_clear_all_valid();

	return true;
}

/*
 * Find the default value associated to a symbol.
 * For tristate symbol handle the modules=n case
 * in which case "m" becomes "y".
 * If the symbol does not have any default then fallback
 * to the fixed default values.
 */
const char *sym_get_string_default(struct symbol *sym)
{
	struct property *prop;
	struct symbol *ds;
	const char *str;
	tristate val;

	sym_calc_visibility(sym);
	sym_calc_value(modules_sym);
	val = symbol_no.curr.tri;
	str = symbol_empty.curr.val;

	/* If symbol has a default value look it up */
	prop = sym_get_default_prop(sym);
	if (prop != NULL) {
		switch (sym->type) {
		case S_BOOLEAN:
		case S_TRISTATE:
			/* The visibility may limit the value from yes => mod */
			val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
			break;
		default:
			/*
			 * The following fails to handle the situation
			 * where a default value is further limited by
			 * the valid range.
			 */
			ds = prop_get_symbol(prop);
			if (ds != NULL) {
				sym_calc_value(ds);
				str = (const char *)ds->curr.val;
			}
		}
	}

	/* Handle select statements */
	val = EXPR_OR(val, sym->rev_dep.tri);

	/* transpose mod to yes if modules are not enabled */
	if (val == mod)
		if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
			val = yes;

	/* transpose mod to yes if type is bool */
	if (sym->type == S_BOOLEAN && val == mod)
		val = yes;

	switch (sym->type) {
	case S_BOOLEAN:
	case S_TRISTATE:
		switch (val) {
		case no: return "n";
		case mod: return "m";
		case yes: return "y";
		}
	case S_INT:
	case S_HEX:
		return str;
	case S_STRING:
		return str;
	case S_OTHER:
	case S_UNKNOWN:
		break;
	}
	return "";
}

const char *sym_get_string_value(struct symbol *sym)
{
	tristate val;

	switch (sym->type) {
	case S_BOOLEAN:
	case S_TRISTATE:
		val = sym_get_tristate_value(sym);
		switch (val) {
		case no:
			return "n";
		case mod:
			sym_calc_value(modules_sym);
			return (modules_sym->curr.tri == no) ? "n" : "m";
		case yes:
			return "y";
		}
		break;
	default:
		;
	}
	return (const char *)sym->curr.val;
}

bool sym_is_changable(struct symbol *sym)
{
	return sym->visible > sym->rev_dep.tri;
}

static unsigned strhash(const char *s)
{
	/* fnv32 hash */
	unsigned hash = 2166136261U;
	for (; *s; s++)
		hash = (hash ^ *s) * 0x01000193;
	return hash;
}

struct symbol *sym_lookup(const char *name, int flags)
{
	struct symbol *symbol;
	char *new_name;
	int hash;

	if (name) {
		if (name[0] && !name[1]) {
			switch (name[0]) {
			case 'y': return &symbol_yes;
			case 'm': return &symbol_mod;
			case 'n': return &symbol_no;
			}
		}
		hash = strhash(name) % SYMBOL_HASHSIZE;

		for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
			if (symbol->name &&
			    !strcmp(symbol->name, name) &&
			    (flags ? symbol->flags & flags
				   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
				return symbol;
		}
		new_name = strdup(name);
	} else {
		new_name = NULL;
		hash = 0;
	}

	symbol = xmalloc(sizeof(*symbol));
	memset(symbol, 0, sizeof(*symbol));
	symbol->name = new_name;
	symbol->type = S_UNKNOWN;
	symbol->flags |= flags;

	symbol->next = symbol_hash[hash];
	symbol_hash[hash] = symbol;

	return symbol;
}

struct symbol *sym_find(const char *name)
{
	struct symbol *symbol = NULL;
	int hash = 0;

	if (!name)
		return NULL;

	if (name[0] && !name[1]) {
		switch (name[0]) {
		case 'y': return &symbol_yes;
		case 'm': return &symbol_mod;
		case 'n': return &symbol_no;
		}
	}
	hash = strhash(name) % SYMBOL_HASHSIZE;

	for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
		if (symbol->name &&
		    !strcmp(symbol->name, name) &&
		    !(symbol->flags & SYMBOL_CONST))
				break;
	}

	return symbol;
}

/*
 * Expand symbol's names embedded in the string given in argument. Symbols'
 * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
 * the empty string.
 */
const char *sym_expand_string_value(const char *in)
{
	const char *src;
	char *res;
	size_t reslen;

	reslen = strlen(in) + 1;
	res = xmalloc(reslen);
	res[0] = '\0';

	while ((src = strchr(in, '$'))) {
		char *p, name[SYMBOL_MAXLENGTH];
		const char *symval = "";
		struct symbol *sym;
		size_t newlen;

		strncat(res, in, src - in);
		src++;

		p = name;
		while (isalnum(*src) || *src == '_')
			*p++ = *src++;
		*p = '\0';

		sym = sym_find(name);
		if (sym != NULL) {
			sym_calc_value(sym);
			symval = sym_get_string_value(sym);
		}

		newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
		if (newlen > reslen) {
			reslen = newlen;
			res = realloc(res, reslen);
		}

		strcat(res, symval);
		in = src;
	}
	strcat(res, in);

	return res;
}

const char *sym_escape_string_value(const char *in)
{
	const char *p;
	size_t reslen;
	char *res;
	size_t l;

	reslen = strlen(in) + strlen("\"\"") + 1;

	p = in;
	for (;;) {
		l = strcspn(p, "\"\\");
		p += l;

		if (p[0] == '\0')
			break;

		reslen++;
		p++;
	}

	res = xmalloc(reslen);
	res[0] = '\0';

	strcat(res, "\"");

	p = in;
	for (;;) {
		l = strcspn(p, "\"\\");
		strncat(res, p, l);
		p += l;

		if (p[0] == '\0')
			break;

		strcat(res, "\\");
		strncat(res, p++, 1);
	}

	strcat(res, "\"");
	return res;
}

struct sym_match {
	struct symbol	*sym;
	off_t		so, eo;
};

/* Compare matched symbols as thus:
 * - first, symbols that match exactly
 * - then, alphabetical sort
 */
static int sym_rel_comp(const void *sym1, const void *sym2)
{
	struct sym_match *s1 = *(struct sym_match **)sym1;
	struct sym_match *s2 = *(struct sym_match **)sym2;
	int exact1, exact2;

	/* Exact match:
	 * - if matched length on symbol s1 is the length of that symbol,
	 *   then this symbol should come first;
	 * - if matched length on symbol s2 is the length of that symbol,
	 *   then this symbol should come first.
	 * Note: since the search can be a regexp, both symbols may match
	 * exactly; if this is the case, we can't decide which comes first,
	 * and we fallback to sorting alphabetically.
	 */
	exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
	exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
	if (exact1 && !exact2)
		return -1;
	if (!exact1 && exact2)
		return 1;

	/* As a fallback, sort symbols alphabetically */
	return strcmp(s1->sym->name, s2->sym->name);
}

struct symbol **sym_re_search(const char *pattern)
{
	struct symbol *sym, **sym_arr = NULL;
	struct sym_match **sym_match_arr = NULL;
	int i, cnt, size;
	regex_t re;
	regmatch_t match[1];

	cnt = size = 0;
	/* Skip if empty */
	if (strlen(pattern) == 0)
		return NULL;
	if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
		return NULL;

	for_all_symbols(i, sym) {
		struct sym_match *tmp_sym_match;
		if (sym->flags & SYMBOL_CONST || !sym->name)
			continue;
		if (regexec(&re, sym->name, 1, match, 0))
			continue;
		if (cnt + 1 >= size) {
			void *tmp;
			size += 16;
			tmp = realloc(sym_match_arr, size * sizeof(struct sym_match *));
			if (!tmp)
				goto sym_re_search_free;
			sym_match_arr = tmp;
		}
		sym_calc_value(sym);
		tmp_sym_match = (struct sym_match*)malloc(sizeof(struct sym_match));
		if (!tmp_sym_match)
			goto sym_re_search_free;
		tmp_sym_match->sym = sym;
		/* As regexec returned 0, we know we have a match, so
		 * we can use match[0].rm_[se]o without further checks
		 */
		tmp_sym_match->so = match[0].rm_so;
		tmp_sym_match->eo = match[0].rm_eo;
		sym_match_arr[cnt++] = tmp_sym_match;
	}
	if (sym_match_arr) {
		qsort(sym_match_arr, cnt, sizeof(struct sym_match*), sym_rel_comp);
		sym_arr = malloc((cnt+1) * sizeof(struct symbol));
		if (!sym_arr)
			goto sym_re_search_free;
		for (i = 0; i < cnt; i++)
			sym_arr[i] = sym_match_arr[i]->sym;
		sym_arr[cnt] = NULL;
	}
sym_re_search_free:
	if (sym_match_arr) {
		for (i = 0; i < cnt; i++)
			free(sym_match_arr[i]);
		free(sym_match_arr);
	}
	regfree(&re);

	return sym_arr;
}

/*
 * When we check for recursive dependencies we use a stack to save
 * current state so we can print out relevant info to user.
 * The entries are located on the call stack so no need to free memory.
 * Note inser() remove() must always match to properly clear the stack.
 */
static struct dep_stack {
	struct dep_stack *prev, *next;
	struct symbol *sym;
	struct property *prop;
	struct expr *expr;
} *check_top;

static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
{
	memset(stack, 0, sizeof(*stack));
	if (check_top)
		check_top->next = stack;
	stack->prev = check_top;
	stack->sym = sym;
	check_top = stack;
}

static void dep_stack_remove(void)
{
	check_top = check_top->prev;
	if (check_top)
		check_top->next = NULL;
}

/*
 * Called when we have detected a recursive dependency.
 * check_top point to the top of the stact so we use
 * the ->prev pointer to locate the bottom of the stack.
 */
static void sym_check_print_recursive(struct symbol *last_sym)
{
	struct dep_stack *stack;
	struct symbol *sym, *next_sym;
	struct menu *menu = NULL;
	struct property *prop;
	struct dep_stack cv_stack;

	if (sym_is_choice_value(last_sym)) {
		dep_stack_insert(&cv_stack, last_sym);
		last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
	}

	for (stack = check_top; stack != NULL; stack = stack->prev)
		if (stack->sym == last_sym)
			break;
	if (!stack) {
		fprintf(stderr, "unexpected recursive dependency error\n");
		return;
	}

	for (; stack; stack = stack->next) {
		sym = stack->sym;
		next_sym = stack->next ? stack->next->sym : last_sym;
		prop = stack->prop;
		if (prop == NULL)
			prop = stack->sym->prop;

		/* for choice values find the menu entry (used below) */
		if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
			for (prop = sym->prop; prop; prop = prop->next) {
				menu = prop->menu;
				if (prop->menu)
					break;
			}
		}
		if (stack->sym == last_sym)
			fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
				prop->file->name, prop->lineno);
		if (stack->expr) {
			fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
				prop->file->name, prop->lineno,
				sym->name ? sym->name : "<choice>",
				prop_get_type_name(prop->type),
				next_sym->name ? next_sym->name : "<choice>");
		} else if (stack->prop) {
			fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
				prop->file->name, prop->lineno,
				sym->name ? sym->name : "<choice>",
				next_sym->name ? next_sym->name : "<choice>");
		} else if (sym_is_choice(sym)) {
			fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
				menu->file->name, menu->lineno,
				sym->name ? sym->name : "<choice>",
				next_sym->name ? next_sym->name : "<choice>");
		} else if (sym_is_choice_value(sym)) {
			fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
				menu->file->name, menu->lineno,
				sym->name ? sym->name : "<choice>",
				next_sym->name ? next_sym->name : "<choice>");
		} else {
			fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
				prop->file->name, prop->lineno,
				sym->name ? sym->name : "<choice>",
				next_sym->name ? next_sym->name : "<choice>");
		}
	}

	if (check_top == &cv_stack)
		dep_stack_remove();
}

static struct symbol *sym_check_expr_deps(struct expr *e)
{
	struct symbol *sym;

	if (!e)
		return NULL;
	switch (e->type) {
	case E_OR:
	case E_AND:
		sym = sym_check_expr_deps(e->left.expr);
		if (sym)
			return sym;
		return sym_check_expr_deps(e->right.expr);
	case E_NOT:
		return sym_check_expr_deps(e->left.expr);
	case E_EQUAL:
	case E_UNEQUAL:
		sym = sym_check_deps(e->left.sym);
		if (sym)
			return sym;
		return sym_check_deps(e->right.sym);
	case E_SYMBOL:
		return sym_check_deps(e->left.sym);
	default:
		break;
	}
	printf("Oops! How to check %d?\n", e->type);
	return NULL;
}

/* return NULL when dependencies are OK */
static struct symbol *sym_check_sym_deps(struct symbol *sym)
{
	struct symbol *sym2;
	struct property *prop;
	struct dep_stack stack;

	dep_stack_insert(&stack, sym);

	sym2 = sym_check_expr_deps(sym->rev_dep.expr);
	if (sym2)
		goto out;

	for (prop = sym->prop; prop; prop = prop->next) {
		if (prop->type == P_CHOICE || prop->type == P_SELECT)
			continue;
		stack.prop = prop;
		sym2 = sym_check_expr_deps(prop->visible.expr);
		if (sym2)
			break;
		if (prop->type != P_DEFAULT || sym_is_choice(sym))
			continue;
		stack.expr = prop->expr;
		sym2 = sym_check_expr_deps(prop->expr);
		if (sym2)
			break;
		stack.expr = NULL;
	}

out:
	dep_stack_remove();

	return sym2;
}

static struct symbol *sym_check_choice_deps(struct symbol *choice)
{
	struct symbol *sym, *sym2;
	struct property *prop;
	struct expr *e;
	struct dep_stack stack;

	dep_stack_insert(&stack, choice);

	prop = sym_get_choice_prop(choice);
	expr_list_for_each_sym(prop->expr, e, sym)
		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);

	choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
	sym2 = sym_check_sym_deps(choice);
	choice->flags &= ~SYMBOL_CHECK;
	if (sym2)
		goto out;

	expr_list_for_each_sym(prop->expr, e, sym) {
		sym2 = sym_check_sym_deps(sym);
		if (sym2)
			break;
	}
out:
	expr_list_for_each_sym(prop->expr, e, sym)
		sym->flags &= ~SYMBOL_CHECK;

	if (sym2 && sym_is_choice_value(sym2) &&
	    prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
		sym2 = choice;

	dep_stack_remove();

	return sym2;
}

struct symbol *sym_check_deps(struct symbol *sym)
{
	struct symbol *sym2;
	struct property *prop;

	if (sym->flags & SYMBOL_CHECK) {
		sym_check_print_recursive(sym);
		return sym;
	}
	if (sym->flags & SYMBOL_CHECKED)
		return NULL;

	if (sym_is_choice_value(sym)) {
		struct dep_stack stack;

		/* for choice groups start the check with main choice symbol */
		dep_stack_insert(&stack, sym);
		prop = sym_get_choice_prop(sym);
		sym2 = sym_check_deps(prop_get_symbol(prop));
		dep_stack_remove();
	} else if (sym_is_choice(sym)) {
		sym2 = sym_check_choice_deps(sym);
	} else {
		sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
		sym2 = sym_check_sym_deps(sym);
		sym->flags &= ~SYMBOL_CHECK;
	}

	if (sym2 && sym2 == sym)
		sym2 = NULL;

	return sym2;
}

struct property *prop_alloc(enum prop_type type, struct symbol *sym)
{
	struct property *prop;
	struct property **propp;

	prop = xmalloc(sizeof(*prop));
	memset(prop, 0, sizeof(*prop));
	prop->type = type;
	prop->sym = sym;
	prop->file = current_file;
	prop->lineno = zconf_lineno();

	/* append property to the prop list of symbol */
	if (sym) {
		for (propp = &sym->prop; *propp; propp = &(*propp)->next)
			;
		*propp = prop;
	}

	return prop;
}

struct symbol *prop_get_symbol(struct property *prop)
{
	if (prop->expr && (prop->expr->type == E_SYMBOL ||
			   prop->expr->type == E_LIST))
		return prop->expr->left.sym;
	return NULL;
}

const char *prop_get_type_name(enum prop_type type)
{
	switch (type) {
	case P_PROMPT:
		return "prompt";
	case P_ENV:
		return "env";
	case P_COMMENT:
		return "comment";
	case P_MENU:
		return "menu";
	case P_DEFAULT:
		return "default";
	case P_CHOICE:
		return "choice";
	case P_SELECT:
		return "select";
	case P_RANGE:
		return "range";
	case P_SYMBOL:
		return "symbol";
	case P_UNKNOWN:
		break;
	}
	return "unknown";
}

static void prop_add_env(const char *env)
{
	struct symbol *sym, *sym2;
	struct property *prop;
	char *p;

	sym = current_entry->sym;
	sym->flags |= SYMBOL_AUTO;
	for_all_properties(sym, prop, P_ENV) {
		sym2 = prop_get_symbol(prop);
		if (strcmp(sym2->name, env))
			menu_warn(current_entry, "redefining environment symbol from %s",
				  sym2->name);
		return;
	}

	prop = prop_alloc(P_ENV, sym);
	prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));

	sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
	sym_env_list->right.sym = sym;

	p = getenv(env);
	if (p)
		sym_add_default(sym, p);
	else
		menu_warn(current_entry, "environment variable %s undefined", env);
}