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