kconfig: simplify symbol-search code
[carl9170fw.git] / config / symbol.c
1 /*
2  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
3  * Released under the terms of the GNU GPL v2.0.
4  */
5
6 #include <ctype.h>
7 #include <stdlib.h>
8 #include <string.h>
9 #include <regex.h>
10 #include <sys/utsname.h>
11
12 #include "lkc.h"
13
14 struct symbol symbol_yes = {
15         .name = "y",
16         .curr = { "y", yes },
17         .flags = SYMBOL_CONST|SYMBOL_VALID,
18 }, symbol_mod = {
19         .name = "m",
20         .curr = { "m", mod },
21         .flags = SYMBOL_CONST|SYMBOL_VALID,
22 }, symbol_no = {
23         .name = "n",
24         .curr = { "n", no },
25         .flags = SYMBOL_CONST|SYMBOL_VALID,
26 }, symbol_empty = {
27         .name = "",
28         .curr = { "", no },
29         .flags = SYMBOL_VALID,
30 };
31
32 struct symbol *sym_defconfig_list;
33 struct symbol *modules_sym;
34 tristate modules_val;
35
36 struct expr *sym_env_list;
37
38 static void sym_add_default(struct symbol *sym, const char *def)
39 {
40         struct property *prop = prop_alloc(P_DEFAULT, sym);
41
42         prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));
43 }
44
45 void sym_init(void)
46 {
47         struct symbol *sym;
48         struct utsname uts;
49         static bool inited = false;
50
51         if (inited)
52                 return;
53         inited = true;
54
55         uname(&uts);
56
57         sym = sym_lookup("UNAME_RELEASE", 0);
58         sym->type = S_STRING;
59         sym->flags |= SYMBOL_AUTO;
60         sym_add_default(sym, uts.release);
61 }
62
63 enum symbol_type sym_get_type(struct symbol *sym)
64 {
65         enum symbol_type type = sym->type;
66
67         if (type == S_TRISTATE) {
68                 if (sym_is_choice_value(sym) && sym->visible == yes)
69                         type = S_BOOLEAN;
70                 else if (modules_val == no)
71                         type = S_BOOLEAN;
72         }
73         return type;
74 }
75
76 const char *sym_type_name(enum symbol_type type)
77 {
78         switch (type) {
79         case S_BOOLEAN:
80                 return "boolean";
81         case S_TRISTATE:
82                 return "tristate";
83         case S_INT:
84                 return "integer";
85         case S_HEX:
86                 return "hex";
87         case S_STRING:
88                 return "string";
89         case S_UNKNOWN:
90                 return "unknown";
91         case S_OTHER:
92                 break;
93         }
94         return "???";
95 }
96
97 struct property *sym_get_choice_prop(struct symbol *sym)
98 {
99         struct property *prop;
100
101         for_all_choices(sym, prop)
102                 return prop;
103         return NULL;
104 }
105
106 struct property *sym_get_env_prop(struct symbol *sym)
107 {
108         struct property *prop;
109
110         for_all_properties(sym, prop, P_ENV)
111                 return prop;
112         return NULL;
113 }
114
115 struct property *sym_get_default_prop(struct symbol *sym)
116 {
117         struct property *prop;
118
119         for_all_defaults(sym, prop) {
120                 prop->visible.tri = expr_calc_value(prop->visible.expr);
121                 if (prop->visible.tri != no)
122                         return prop;
123         }
124         return NULL;
125 }
126
127 static struct property *sym_get_range_prop(struct symbol *sym)
128 {
129         struct property *prop;
130
131         for_all_properties(sym, prop, P_RANGE) {
132                 prop->visible.tri = expr_calc_value(prop->visible.expr);
133                 if (prop->visible.tri != no)
134                         return prop;
135         }
136         return NULL;
137 }
138
139 static long sym_get_range_val(struct symbol *sym, int base)
140 {
141         sym_calc_value(sym);
142         switch (sym->type) {
143         case S_INT:
144                 base = 10;
145                 break;
146         case S_HEX:
147                 base = 16;
148                 break;
149         default:
150                 break;
151         }
152         return strtol(sym->curr.val, NULL, base);
153 }
154
155 static void sym_validate_range(struct symbol *sym)
156 {
157         struct property *prop;
158         long base, val, val2;
159         char str[64];
160
161         switch (sym->type) {
162         case S_INT:
163                 base = 10;
164                 break;
165         case S_HEX:
166                 base = 16;
167                 break;
168         default:
169                 return;
170         }
171         prop = sym_get_range_prop(sym);
172         if (!prop)
173                 return;
174         val = strtol(sym->curr.val, NULL, base);
175         val2 = sym_get_range_val(prop->expr->left.sym, base);
176         if (val >= val2) {
177                 val2 = sym_get_range_val(prop->expr->right.sym, base);
178                 if (val <= val2)
179                         return;
180         }
181         if (sym->type == S_INT)
182                 sprintf(str, "%ld", val2);
183         else
184                 sprintf(str, "0x%lx", val2);
185         sym->curr.val = strdup(str);
186 }
187
188 static void sym_calc_visibility(struct symbol *sym)
189 {
190         struct property *prop;
191         tristate tri;
192
193         /* any prompt visible? */
194         tri = no;
195         for_all_prompts(sym, prop) {
196                 prop->visible.tri = expr_calc_value(prop->visible.expr);
197                 tri = EXPR_OR(tri, prop->visible.tri);
198         }
199         if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
200                 tri = yes;
201         if (sym->visible != tri) {
202                 sym->visible = tri;
203                 sym_set_changed(sym);
204         }
205         if (sym_is_choice_value(sym))
206                 return;
207         /* defaulting to "yes" if no explicit "depends on" are given */
208         tri = yes;
209         if (sym->dir_dep.expr)
210                 tri = expr_calc_value(sym->dir_dep.expr);
211         if (tri == mod)
212                 tri = yes;
213         if (sym->dir_dep.tri != tri) {
214                 sym->dir_dep.tri = tri;
215                 sym_set_changed(sym);
216         }
217         tri = no;
218         if (sym->rev_dep.expr)
219                 tri = expr_calc_value(sym->rev_dep.expr);
220         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
221                 tri = yes;
222         if (sym->rev_dep.tri != tri) {
223                 sym->rev_dep.tri = tri;
224                 sym_set_changed(sym);
225         }
226 }
227
228 /*
229  * Find the default symbol for a choice.
230  * First try the default values for the choice symbol
231  * Next locate the first visible choice value
232  * Return NULL if none was found
233  */
234 struct symbol *sym_choice_default(struct symbol *sym)
235 {
236         struct symbol *def_sym;
237         struct property *prop;
238         struct expr *e;
239
240         /* any of the defaults visible? */
241         for_all_defaults(sym, prop) {
242                 prop->visible.tri = expr_calc_value(prop->visible.expr);
243                 if (prop->visible.tri == no)
244                         continue;
245                 def_sym = prop_get_symbol(prop);
246                 if (def_sym->visible != no)
247                         return def_sym;
248         }
249
250         /* just get the first visible value */
251         prop = sym_get_choice_prop(sym);
252         expr_list_for_each_sym(prop->expr, e, def_sym)
253                 if (def_sym->visible != no)
254                         return def_sym;
255
256         /* failed to locate any defaults */
257         return NULL;
258 }
259
260 static struct symbol *sym_calc_choice(struct symbol *sym)
261 {
262         struct symbol *def_sym;
263         struct property *prop;
264         struct expr *e;
265         int flags;
266
267         /* first calculate all choice values' visibilities */
268         flags = sym->flags;
269         prop = sym_get_choice_prop(sym);
270         expr_list_for_each_sym(prop->expr, e, def_sym) {
271                 sym_calc_visibility(def_sym);
272                 if (def_sym->visible != no)
273                         flags &= def_sym->flags;
274         }
275
276         sym->flags &= flags | ~SYMBOL_DEF_USER;
277
278         /* is the user choice visible? */
279         def_sym = sym->def[S_DEF_USER].val;
280         if (def_sym && def_sym->visible != no)
281                 return def_sym;
282
283         def_sym = sym_choice_default(sym);
284
285         if (def_sym == NULL)
286                 /* no choice? reset tristate value */
287                 sym->curr.tri = no;
288
289         return def_sym;
290 }
291
292 void sym_calc_value(struct symbol *sym)
293 {
294         struct symbol_value newval, oldval;
295         struct property *prop;
296         struct expr *e;
297
298         if (!sym)
299                 return;
300
301         if (sym->flags & SYMBOL_VALID)
302                 return;
303
304         if (sym_is_choice_value(sym) &&
305             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
306                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
307                 prop = sym_get_choice_prop(sym);
308                 sym_calc_value(prop_get_symbol(prop));
309         }
310
311         sym->flags |= SYMBOL_VALID;
312
313         oldval = sym->curr;
314
315         switch (sym->type) {
316         case S_INT:
317         case S_HEX:
318         case S_STRING:
319                 newval = symbol_empty.curr;
320                 break;
321         case S_BOOLEAN:
322         case S_TRISTATE:
323                 newval = symbol_no.curr;
324                 break;
325         default:
326                 sym->curr.val = sym->name;
327                 sym->curr.tri = no;
328                 return;
329         }
330         if (!sym_is_choice_value(sym))
331                 sym->flags &= ~SYMBOL_WRITE;
332
333         sym_calc_visibility(sym);
334
335         /* set default if recursively called */
336         sym->curr = newval;
337
338         switch (sym_get_type(sym)) {
339         case S_BOOLEAN:
340         case S_TRISTATE:
341                 if (sym_is_choice_value(sym) && sym->visible == yes) {
342                         prop = sym_get_choice_prop(sym);
343                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
344                 } else {
345                         if (sym->visible != no) {
346                                 /* if the symbol is visible use the user value
347                                  * if available, otherwise try the default value
348                                  */
349                                 sym->flags |= SYMBOL_WRITE;
350                                 if (sym_has_value(sym)) {
351                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
352                                                               sym->visible);
353                                         goto calc_newval;
354                                 }
355                         }
356                         if (sym->rev_dep.tri != no)
357                                 sym->flags |= SYMBOL_WRITE;
358                         if (!sym_is_choice(sym)) {
359                                 prop = sym_get_default_prop(sym);
360                                 if (prop) {
361                                         sym->flags |= SYMBOL_WRITE;
362                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
363                                                               prop->visible.tri);
364                                 }
365                         }
366                 calc_newval:
367                         if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
368                                 struct expr *e;
369                                 e = expr_simplify_unmet_dep(sym->rev_dep.expr,
370                                     sym->dir_dep.expr);
371                                 fprintf(stderr, "warning: (");
372                                 expr_fprint(e, stderr);
373                                 fprintf(stderr, ") selects %s which has unmet direct dependencies (",
374                                         sym->name);
375                                 expr_fprint(sym->dir_dep.expr, stderr);
376                                 fprintf(stderr, ")\n");
377                                 expr_free(e);
378                         }
379                         newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
380                 }
381                 if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
382                         newval.tri = yes;
383                 break;
384         case S_STRING:
385         case S_HEX:
386         case S_INT:
387                 if (sym->visible != no) {
388                         sym->flags |= SYMBOL_WRITE;
389                         if (sym_has_value(sym)) {
390                                 newval.val = sym->def[S_DEF_USER].val;
391                                 break;
392                         }
393                 }
394                 prop = sym_get_default_prop(sym);
395                 if (prop) {
396                         struct symbol *ds = prop_get_symbol(prop);
397                         if (ds) {
398                                 sym->flags |= SYMBOL_WRITE;
399                                 sym_calc_value(ds);
400                                 newval.val = ds->curr.val;
401                         }
402                 }
403                 break;
404         default:
405                 ;
406         }
407
408         sym->curr = newval;
409         if (sym_is_choice(sym) && newval.tri == yes)
410                 sym->curr.val = sym_calc_choice(sym);
411         sym_validate_range(sym);
412
413         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
414                 sym_set_changed(sym);
415                 if (modules_sym == sym) {
416                         sym_set_all_changed();
417                         modules_val = modules_sym->curr.tri;
418                 }
419         }
420
421         if (sym_is_choice(sym)) {
422                 struct symbol *choice_sym;
423
424                 prop = sym_get_choice_prop(sym);
425                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
426                         if ((sym->flags & SYMBOL_WRITE) &&
427                             choice_sym->visible != no)
428                                 choice_sym->flags |= SYMBOL_WRITE;
429                         if (sym->flags & SYMBOL_CHANGED)
430                                 sym_set_changed(choice_sym);
431                 }
432         }
433
434         if (sym->flags & SYMBOL_AUTO)
435                 sym->flags &= ~SYMBOL_WRITE;
436
437         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
438                 set_all_choice_values(sym);
439 }
440
441 void sym_clear_all_valid(void)
442 {
443         struct symbol *sym;
444         int i;
445
446         for_all_symbols(i, sym)
447                 sym->flags &= ~SYMBOL_VALID;
448         sym_add_change_count(1);
449         if (modules_sym)
450                 sym_calc_value(modules_sym);
451 }
452
453 void sym_set_changed(struct symbol *sym)
454 {
455         struct property *prop;
456
457         sym->flags |= SYMBOL_CHANGED;
458         for (prop = sym->prop; prop; prop = prop->next) {
459                 if (prop->menu)
460                         prop->menu->flags |= MENU_CHANGED;
461         }
462 }
463
464 void sym_set_all_changed(void)
465 {
466         struct symbol *sym;
467         int i;
468
469         for_all_symbols(i, sym)
470                 sym_set_changed(sym);
471 }
472
473 bool sym_tristate_within_range(struct symbol *sym, tristate val)
474 {
475         int type = sym_get_type(sym);
476
477         if (sym->visible == no)
478                 return false;
479
480         if (type != S_BOOLEAN && type != S_TRISTATE)
481                 return false;
482
483         if (type == S_BOOLEAN && val == mod)
484                 return false;
485         if (sym->visible <= sym->rev_dep.tri)
486                 return false;
487         if (sym_is_choice_value(sym) && sym->visible == yes)
488                 return val == yes;
489         return val >= sym->rev_dep.tri && val <= sym->visible;
490 }
491
492 bool sym_set_tristate_value(struct symbol *sym, tristate val)
493 {
494         tristate oldval = sym_get_tristate_value(sym);
495
496         if (oldval != val && !sym_tristate_within_range(sym, val))
497                 return false;
498
499         if (!(sym->flags & SYMBOL_DEF_USER)) {
500                 sym->flags |= SYMBOL_DEF_USER;
501                 sym_set_changed(sym);
502         }
503         /*
504          * setting a choice value also resets the new flag of the choice
505          * symbol and all other choice values.
506          */
507         if (sym_is_choice_value(sym) && val == yes) {
508                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
509                 struct property *prop;
510                 struct expr *e;
511
512                 cs->def[S_DEF_USER].val = sym;
513                 cs->flags |= SYMBOL_DEF_USER;
514                 prop = sym_get_choice_prop(cs);
515                 for (e = prop->expr; e; e = e->left.expr) {
516                         if (e->right.sym->visible != no)
517                                 e->right.sym->flags |= SYMBOL_DEF_USER;
518                 }
519         }
520
521         sym->def[S_DEF_USER].tri = val;
522         if (oldval != val)
523                 sym_clear_all_valid();
524
525         return true;
526 }
527
528 tristate sym_toggle_tristate_value(struct symbol *sym)
529 {
530         tristate oldval, newval;
531
532         oldval = newval = sym_get_tristate_value(sym);
533         do {
534                 switch (newval) {
535                 case no:
536                         newval = mod;
537                         break;
538                 case mod:
539                         newval = yes;
540                         break;
541                 case yes:
542                         newval = no;
543                         break;
544                 }
545                 if (sym_set_tristate_value(sym, newval))
546                         break;
547         } while (oldval != newval);
548         return newval;
549 }
550
551 bool sym_string_valid(struct symbol *sym, const char *str)
552 {
553         signed char ch;
554
555         switch (sym->type) {
556         case S_STRING:
557                 return true;
558         case S_INT:
559                 ch = *str++;
560                 if (ch == '-')
561                         ch = *str++;
562                 if (!isdigit(ch))
563                         return false;
564                 if (ch == '0' && *str != 0)
565                         return false;
566                 while ((ch = *str++)) {
567                         if (!isdigit(ch))
568                                 return false;
569                 }
570                 return true;
571         case S_HEX:
572                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
573                         str += 2;
574                 ch = *str++;
575                 do {
576                         if (!isxdigit(ch))
577                                 return false;
578                 } while ((ch = *str++));
579                 return true;
580         case S_BOOLEAN:
581         case S_TRISTATE:
582                 switch (str[0]) {
583                 case 'y': case 'Y':
584                 case 'm': case 'M':
585                 case 'n': case 'N':
586                         return true;
587                 }
588                 return false;
589         default:
590                 return false;
591         }
592 }
593
594 bool sym_string_within_range(struct symbol *sym, const char *str)
595 {
596         struct property *prop;
597         long val;
598
599         switch (sym->type) {
600         case S_STRING:
601                 return sym_string_valid(sym, str);
602         case S_INT:
603                 if (!sym_string_valid(sym, str))
604                         return false;
605                 prop = sym_get_range_prop(sym);
606                 if (!prop)
607                         return true;
608                 val = strtol(str, NULL, 10);
609                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
610                        val <= sym_get_range_val(prop->expr->right.sym, 10);
611         case S_HEX:
612                 if (!sym_string_valid(sym, str))
613                         return false;
614                 prop = sym_get_range_prop(sym);
615                 if (!prop)
616                         return true;
617                 val = strtol(str, NULL, 16);
618                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
619                        val <= sym_get_range_val(prop->expr->right.sym, 16);
620         case S_BOOLEAN:
621         case S_TRISTATE:
622                 switch (str[0]) {
623                 case 'y': case 'Y':
624                         return sym_tristate_within_range(sym, yes);
625                 case 'm': case 'M':
626                         return sym_tristate_within_range(sym, mod);
627                 case 'n': case 'N':
628                         return sym_tristate_within_range(sym, no);
629                 }
630                 return false;
631         default:
632                 return false;
633         }
634 }
635
636 bool sym_set_string_value(struct symbol *sym, const char *newval)
637 {
638         const char *oldval;
639         char *val;
640         int size;
641
642         switch (sym->type) {
643         case S_BOOLEAN:
644         case S_TRISTATE:
645                 switch (newval[0]) {
646                 case 'y': case 'Y':
647                         return sym_set_tristate_value(sym, yes);
648                 case 'm': case 'M':
649                         return sym_set_tristate_value(sym, mod);
650                 case 'n': case 'N':
651                         return sym_set_tristate_value(sym, no);
652                 }
653                 return false;
654         default:
655                 ;
656         }
657
658         if (!sym_string_within_range(sym, newval))
659                 return false;
660
661         if (!(sym->flags & SYMBOL_DEF_USER)) {
662                 sym->flags |= SYMBOL_DEF_USER;
663                 sym_set_changed(sym);
664         }
665
666         oldval = sym->def[S_DEF_USER].val;
667         size = strlen(newval) + 1;
668         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
669                 size += 2;
670                 sym->def[S_DEF_USER].val = val = xmalloc(size);
671                 *val++ = '0';
672                 *val++ = 'x';
673         } else if (!oldval || strcmp(oldval, newval))
674                 sym->def[S_DEF_USER].val = val = xmalloc(size);
675         else
676                 return true;
677
678         strcpy(val, newval);
679         free((void *)oldval);
680         sym_clear_all_valid();
681
682         return true;
683 }
684
685 /*
686  * Find the default value associated to a symbol.
687  * For tristate symbol handle the modules=n case
688  * in which case "m" becomes "y".
689  * If the symbol does not have any default then fallback
690  * to the fixed default values.
691  */
692 const char *sym_get_string_default(struct symbol *sym)
693 {
694         struct property *prop;
695         struct symbol *ds;
696         const char *str;
697         tristate val;
698
699         sym_calc_visibility(sym);
700         sym_calc_value(modules_sym);
701         val = symbol_no.curr.tri;
702         str = symbol_empty.curr.val;
703
704         /* If symbol has a default value look it up */
705         prop = sym_get_default_prop(sym);
706         if (prop != NULL) {
707                 switch (sym->type) {
708                 case S_BOOLEAN:
709                 case S_TRISTATE:
710                         /* The visibility may limit the value from yes => mod */
711                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
712                         break;
713                 default:
714                         /*
715                          * The following fails to handle the situation
716                          * where a default value is further limited by
717                          * the valid range.
718                          */
719                         ds = prop_get_symbol(prop);
720                         if (ds != NULL) {
721                                 sym_calc_value(ds);
722                                 str = (const char *)ds->curr.val;
723                         }
724                 }
725         }
726
727         /* Handle select statements */
728         val = EXPR_OR(val, sym->rev_dep.tri);
729
730         /* transpose mod to yes if modules are not enabled */
731         if (val == mod)
732                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
733                         val = yes;
734
735         /* transpose mod to yes if type is bool */
736         if (sym->type == S_BOOLEAN && val == mod)
737                 val = yes;
738
739         switch (sym->type) {
740         case S_BOOLEAN:
741         case S_TRISTATE:
742                 switch (val) {
743                 case no: return "n";
744                 case mod: return "m";
745                 case yes: return "y";
746                 }
747         case S_INT:
748         case S_HEX:
749                 return str;
750         case S_STRING:
751                 return str;
752         case S_OTHER:
753         case S_UNKNOWN:
754                 break;
755         }
756         return "";
757 }
758
759 const char *sym_get_string_value(struct symbol *sym)
760 {
761         tristate val;
762
763         switch (sym->type) {
764         case S_BOOLEAN:
765         case S_TRISTATE:
766                 val = sym_get_tristate_value(sym);
767                 switch (val) {
768                 case no:
769                         return "n";
770                 case mod:
771                         sym_calc_value(modules_sym);
772                         return (modules_sym->curr.tri == no) ? "n" : "m";
773                 case yes:
774                         return "y";
775                 }
776                 break;
777         default:
778                 ;
779         }
780         return (const char *)sym->curr.val;
781 }
782
783 bool sym_is_changable(struct symbol *sym)
784 {
785         return sym->visible > sym->rev_dep.tri;
786 }
787
788 static unsigned strhash(const char *s)
789 {
790         /* fnv32 hash */
791         unsigned hash = 2166136261U;
792         for (; *s; s++)
793                 hash = (hash ^ *s) * 0x01000193;
794         return hash;
795 }
796
797 struct symbol *sym_lookup(const char *name, int flags)
798 {
799         struct symbol *symbol;
800         char *new_name;
801         int hash;
802
803         if (name) {
804                 if (name[0] && !name[1]) {
805                         switch (name[0]) {
806                         case 'y': return &symbol_yes;
807                         case 'm': return &symbol_mod;
808                         case 'n': return &symbol_no;
809                         }
810                 }
811                 hash = strhash(name) % SYMBOL_HASHSIZE;
812
813                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
814                         if (symbol->name &&
815                             !strcmp(symbol->name, name) &&
816                             (flags ? symbol->flags & flags
817                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
818                                 return symbol;
819                 }
820                 new_name = strdup(name);
821         } else {
822                 new_name = NULL;
823                 hash = 0;
824         }
825
826         symbol = xmalloc(sizeof(*symbol));
827         memset(symbol, 0, sizeof(*symbol));
828         symbol->name = new_name;
829         symbol->type = S_UNKNOWN;
830         symbol->flags |= flags;
831
832         symbol->next = symbol_hash[hash];
833         symbol_hash[hash] = symbol;
834
835         return symbol;
836 }
837
838 struct symbol *sym_find(const char *name)
839 {
840         struct symbol *symbol = NULL;
841         int hash = 0;
842
843         if (!name)
844                 return NULL;
845
846         if (name[0] && !name[1]) {
847                 switch (name[0]) {
848                 case 'y': return &symbol_yes;
849                 case 'm': return &symbol_mod;
850                 case 'n': return &symbol_no;
851                 }
852         }
853         hash = strhash(name) % SYMBOL_HASHSIZE;
854
855         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
856                 if (symbol->name &&
857                     !strcmp(symbol->name, name) &&
858                     !(symbol->flags & SYMBOL_CONST))
859                                 break;
860         }
861
862         return symbol;
863 }
864
865 /*
866  * Expand symbol's names embedded in the string given in argument. Symbols'
867  * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
868  * the empty string.
869  */
870 const char *sym_expand_string_value(const char *in)
871 {
872         const char *src;
873         char *res;
874         size_t reslen;
875
876         reslen = strlen(in) + 1;
877         res = xmalloc(reslen);
878         res[0] = '\0';
879
880         while ((src = strchr(in, '$'))) {
881                 char *p, name[SYMBOL_MAXLENGTH];
882                 const char *symval = "";
883                 struct symbol *sym;
884                 size_t newlen;
885
886                 strncat(res, in, src - in);
887                 src++;
888
889                 p = name;
890                 while (isalnum(*src) || *src == '_')
891                         *p++ = *src++;
892                 *p = '\0';
893
894                 sym = sym_find(name);
895                 if (sym != NULL) {
896                         sym_calc_value(sym);
897                         symval = sym_get_string_value(sym);
898                 }
899
900                 newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
901                 if (newlen > reslen) {
902                         reslen = newlen;
903                         res = realloc(res, reslen);
904                 }
905
906                 strcat(res, symval);
907                 in = src;
908         }
909         strcat(res, in);
910
911         return res;
912 }
913
914 const char *sym_escape_string_value(const char *in)
915 {
916         const char *p;
917         size_t reslen;
918         char *res;
919         size_t l;
920
921         reslen = strlen(in) + strlen("\"\"") + 1;
922
923         p = in;
924         for (;;) {
925                 l = strcspn(p, "\"\\");
926                 p += l;
927
928                 if (p[0] == '\0')
929                         break;
930
931                 reslen++;
932                 p++;
933         }
934
935         res = xmalloc(reslen);
936         res[0] = '\0';
937
938         strcat(res, "\"");
939
940         p = in;
941         for (;;) {
942                 l = strcspn(p, "\"\\");
943                 strncat(res, p, l);
944                 p += l;
945
946                 if (p[0] == '\0')
947                         break;
948
949                 strcat(res, "\\");
950                 strncat(res, p++, 1);
951         }
952
953         strcat(res, "\"");
954         return res;
955 }
956
957 struct sym_match {
958         struct symbol   *sym;
959         off_t           so, eo;
960 };
961
962 /* Compare matched symbols as thus:
963  * - first, symbols that match exactly
964  * - then, alphabetical sort
965  */
966 static int sym_rel_comp(const void *sym1, const void *sym2)
967 {
968         const struct sym_match *s1 = sym1;
969         const struct sym_match *s2 = sym2;
970         int exact1, exact2;
971
972         /* Exact match:
973          * - if matched length on symbol s1 is the length of that symbol,
974          *   then this symbol should come first;
975          * - if matched length on symbol s2 is the length of that symbol,
976          *   then this symbol should come first.
977          * Note: since the search can be a regexp, both symbols may match
978          * exactly; if this is the case, we can't decide which comes first,
979          * and we fallback to sorting alphabetically.
980          */
981         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
982         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
983         if (exact1 && !exact2)
984                 return -1;
985         if (!exact1 && exact2)
986                 return 1;
987
988         /* As a fallback, sort symbols alphabetically */
989         return strcmp(s1->sym->name, s2->sym->name);
990 }
991
992 struct symbol **sym_re_search(const char *pattern)
993 {
994         struct symbol *sym, **sym_arr = NULL;
995         struct sym_match *sym_match_arr = NULL;
996         int i, cnt, size;
997         regex_t re;
998         regmatch_t match[1];
999
1000         cnt = size = 0;
1001         /* Skip if empty */
1002         if (strlen(pattern) == 0)
1003                 return NULL;
1004         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
1005                 return NULL;
1006
1007         for_all_symbols(i, sym) {
1008                 if (sym->flags & SYMBOL_CONST || !sym->name)
1009                         continue;
1010                 if (regexec(&re, sym->name, 1, match, 0))
1011                         continue;
1012                 if (cnt >= size) {
1013                         void *tmp;
1014                         size += 16;
1015                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
1016                         if (!tmp)
1017                                 goto sym_re_search_free;
1018                         sym_match_arr = tmp;
1019                 }
1020                 sym_calc_value(sym);
1021                 /* As regexec returned 0, we know we have a match, so
1022                  * we can use match[0].rm_[se]o without further checks
1023                  */
1024                 sym_match_arr[cnt].so = match[0].rm_so;
1025                 sym_match_arr[cnt].eo = match[0].rm_eo;
1026                 sym_match_arr[cnt++].sym = sym;
1027         }
1028         if (sym_match_arr) {
1029                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
1030                 sym_arr = malloc((cnt+1) * sizeof(struct symbol));
1031                 if (!sym_arr)
1032                         goto sym_re_search_free;
1033                 for (i = 0; i < cnt; i++)
1034                         sym_arr[i] = sym_match_arr[i].sym;
1035                 sym_arr[cnt] = NULL;
1036         }
1037 sym_re_search_free:
1038         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
1039         free(sym_match_arr);
1040         regfree(&re);
1041
1042         return sym_arr;
1043 }
1044
1045 /*
1046  * When we check for recursive dependencies we use a stack to save
1047  * current state so we can print out relevant info to user.
1048  * The entries are located on the call stack so no need to free memory.
1049  * Note inser() remove() must always match to properly clear the stack.
1050  */
1051 static struct dep_stack {
1052         struct dep_stack *prev, *next;
1053         struct symbol *sym;
1054         struct property *prop;
1055         struct expr *expr;
1056 } *check_top;
1057
1058 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1059 {
1060         memset(stack, 0, sizeof(*stack));
1061         if (check_top)
1062                 check_top->next = stack;
1063         stack->prev = check_top;
1064         stack->sym = sym;
1065         check_top = stack;
1066 }
1067
1068 static void dep_stack_remove(void)
1069 {
1070         check_top = check_top->prev;
1071         if (check_top)
1072                 check_top->next = NULL;
1073 }
1074
1075 /*
1076  * Called when we have detected a recursive dependency.
1077  * check_top point to the top of the stact so we use
1078  * the ->prev pointer to locate the bottom of the stack.
1079  */
1080 static void sym_check_print_recursive(struct symbol *last_sym)
1081 {
1082         struct dep_stack *stack;
1083         struct symbol *sym, *next_sym;
1084         struct menu *menu = NULL;
1085         struct property *prop;
1086         struct dep_stack cv_stack;
1087
1088         if (sym_is_choice_value(last_sym)) {
1089                 dep_stack_insert(&cv_stack, last_sym);
1090                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1091         }
1092
1093         for (stack = check_top; stack != NULL; stack = stack->prev)
1094                 if (stack->sym == last_sym)
1095                         break;
1096         if (!stack) {
1097                 fprintf(stderr, "unexpected recursive dependency error\n");
1098                 return;
1099         }
1100
1101         for (; stack; stack = stack->next) {
1102                 sym = stack->sym;
1103                 next_sym = stack->next ? stack->next->sym : last_sym;
1104                 prop = stack->prop;
1105                 if (prop == NULL)
1106                         prop = stack->sym->prop;
1107
1108                 /* for choice values find the menu entry (used below) */
1109                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1110                         for (prop = sym->prop; prop; prop = prop->next) {
1111                                 menu = prop->menu;
1112                                 if (prop->menu)
1113                                         break;
1114                         }
1115                 }
1116                 if (stack->sym == last_sym)
1117                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1118                                 prop->file->name, prop->lineno);
1119                 if (stack->expr) {
1120                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1121                                 prop->file->name, prop->lineno,
1122                                 sym->name ? sym->name : "<choice>",
1123                                 prop_get_type_name(prop->type),
1124                                 next_sym->name ? next_sym->name : "<choice>");
1125                 } else if (stack->prop) {
1126                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1127                                 prop->file->name, prop->lineno,
1128                                 sym->name ? sym->name : "<choice>",
1129                                 next_sym->name ? next_sym->name : "<choice>");
1130                 } else if (sym_is_choice(sym)) {
1131                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1132                                 menu->file->name, menu->lineno,
1133                                 sym->name ? sym->name : "<choice>",
1134                                 next_sym->name ? next_sym->name : "<choice>");
1135                 } else if (sym_is_choice_value(sym)) {
1136                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1137                                 menu->file->name, menu->lineno,
1138                                 sym->name ? sym->name : "<choice>",
1139                                 next_sym->name ? next_sym->name : "<choice>");
1140                 } else {
1141                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1142                                 prop->file->name, prop->lineno,
1143                                 sym->name ? sym->name : "<choice>",
1144                                 next_sym->name ? next_sym->name : "<choice>");
1145                 }
1146         }
1147
1148         if (check_top == &cv_stack)
1149                 dep_stack_remove();
1150 }
1151
1152 static struct symbol *sym_check_expr_deps(struct expr *e)
1153 {
1154         struct symbol *sym;
1155
1156         if (!e)
1157                 return NULL;
1158         switch (e->type) {
1159         case E_OR:
1160         case E_AND:
1161                 sym = sym_check_expr_deps(e->left.expr);
1162                 if (sym)
1163                         return sym;
1164                 return sym_check_expr_deps(e->right.expr);
1165         case E_NOT:
1166                 return sym_check_expr_deps(e->left.expr);
1167         case E_EQUAL:
1168         case E_UNEQUAL:
1169                 sym = sym_check_deps(e->left.sym);
1170                 if (sym)
1171                         return sym;
1172                 return sym_check_deps(e->right.sym);
1173         case E_SYMBOL:
1174                 return sym_check_deps(e->left.sym);
1175         default:
1176                 break;
1177         }
1178         printf("Oops! How to check %d?\n", e->type);
1179         return NULL;
1180 }
1181
1182 /* return NULL when dependencies are OK */
1183 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1184 {
1185         struct symbol *sym2;
1186         struct property *prop;
1187         struct dep_stack stack;
1188
1189         dep_stack_insert(&stack, sym);
1190
1191         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1192         if (sym2)
1193                 goto out;
1194
1195         for (prop = sym->prop; prop; prop = prop->next) {
1196                 if (prop->type == P_CHOICE || prop->type == P_SELECT)
1197                         continue;
1198                 stack.prop = prop;
1199                 sym2 = sym_check_expr_deps(prop->visible.expr);
1200                 if (sym2)
1201                         break;
1202                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1203                         continue;
1204                 stack.expr = prop->expr;
1205                 sym2 = sym_check_expr_deps(prop->expr);
1206                 if (sym2)
1207                         break;
1208                 stack.expr = NULL;
1209         }
1210
1211 out:
1212         dep_stack_remove();
1213
1214         return sym2;
1215 }
1216
1217 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1218 {
1219         struct symbol *sym, *sym2;
1220         struct property *prop;
1221         struct expr *e;
1222         struct dep_stack stack;
1223
1224         dep_stack_insert(&stack, choice);
1225
1226         prop = sym_get_choice_prop(choice);
1227         expr_list_for_each_sym(prop->expr, e, sym)
1228                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1229
1230         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1231         sym2 = sym_check_sym_deps(choice);
1232         choice->flags &= ~SYMBOL_CHECK;
1233         if (sym2)
1234                 goto out;
1235
1236         expr_list_for_each_sym(prop->expr, e, sym) {
1237                 sym2 = sym_check_sym_deps(sym);
1238                 if (sym2)
1239                         break;
1240         }
1241 out:
1242         expr_list_for_each_sym(prop->expr, e, sym)
1243                 sym->flags &= ~SYMBOL_CHECK;
1244
1245         if (sym2 && sym_is_choice_value(sym2) &&
1246             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1247                 sym2 = choice;
1248
1249         dep_stack_remove();
1250
1251         return sym2;
1252 }
1253
1254 struct symbol *sym_check_deps(struct symbol *sym)
1255 {
1256         struct symbol *sym2;
1257         struct property *prop;
1258
1259         if (sym->flags & SYMBOL_CHECK) {
1260                 sym_check_print_recursive(sym);
1261                 return sym;
1262         }
1263         if (sym->flags & SYMBOL_CHECKED)
1264                 return NULL;
1265
1266         if (sym_is_choice_value(sym)) {
1267                 struct dep_stack stack;
1268
1269                 /* for choice groups start the check with main choice symbol */
1270                 dep_stack_insert(&stack, sym);
1271                 prop = sym_get_choice_prop(sym);
1272                 sym2 = sym_check_deps(prop_get_symbol(prop));
1273                 dep_stack_remove();
1274         } else if (sym_is_choice(sym)) {
1275                 sym2 = sym_check_choice_deps(sym);
1276         } else {
1277                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1278                 sym2 = sym_check_sym_deps(sym);
1279                 sym->flags &= ~SYMBOL_CHECK;
1280         }
1281
1282         if (sym2 && sym2 == sym)
1283                 sym2 = NULL;
1284
1285         return sym2;
1286 }
1287
1288 struct property *prop_alloc(enum prop_type type, struct symbol *sym)
1289 {
1290         struct property *prop;
1291         struct property **propp;
1292
1293         prop = xmalloc(sizeof(*prop));
1294         memset(prop, 0, sizeof(*prop));
1295         prop->type = type;
1296         prop->sym = sym;
1297         prop->file = current_file;
1298         prop->lineno = zconf_lineno();
1299
1300         /* append property to the prop list of symbol */
1301         if (sym) {
1302                 for (propp = &sym->prop; *propp; propp = &(*propp)->next)
1303                         ;
1304                 *propp = prop;
1305         }
1306
1307         return prop;
1308 }
1309
1310 struct symbol *prop_get_symbol(struct property *prop)
1311 {
1312         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1313                            prop->expr->type == E_LIST))
1314                 return prop->expr->left.sym;
1315         return NULL;
1316 }
1317
1318 const char *prop_get_type_name(enum prop_type type)
1319 {
1320         switch (type) {
1321         case P_PROMPT:
1322                 return "prompt";
1323         case P_ENV:
1324                 return "env";
1325         case P_COMMENT:
1326                 return "comment";
1327         case P_MENU:
1328                 return "menu";
1329         case P_DEFAULT:
1330                 return "default";
1331         case P_CHOICE:
1332                 return "choice";
1333         case P_SELECT:
1334                 return "select";
1335         case P_RANGE:
1336                 return "range";
1337         case P_SYMBOL:
1338                 return "symbol";
1339         case P_UNKNOWN:
1340                 break;
1341         }
1342         return "unknown";
1343 }
1344
1345 static void prop_add_env(const char *env)
1346 {
1347         struct symbol *sym, *sym2;
1348         struct property *prop;
1349         char *p;
1350
1351         sym = current_entry->sym;
1352         sym->flags |= SYMBOL_AUTO;
1353         for_all_properties(sym, prop, P_ENV) {
1354                 sym2 = prop_get_symbol(prop);
1355                 if (strcmp(sym2->name, env))
1356                         menu_warn(current_entry, "redefining environment symbol from %s",
1357                                   sym2->name);
1358                 return;
1359         }
1360
1361         prop = prop_alloc(P_ENV, sym);
1362         prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
1363
1364         sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
1365         sym_env_list->right.sym = sym;
1366
1367         p = getenv(env);
1368         if (p)
1369                 sym_add_default(sym, p);
1370         else
1371                 menu_warn(current_entry, "environment variable %s undefined", env);
1372 }