kconfig/symbol.c: handle choice_values that depend on 'm' symbols
[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 static 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 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 strtoll(sym->curr.val, NULL, base);
153 }
154
155 static void sym_validate_range(struct symbol *sym)
156 {
157         struct property *prop;
158         int base;
159         long long 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 = strtoll(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, "%lld", val2);
184         else
185                 sprintf(str, "0x%llx", val2);
186         sym->curr.val = strdup(str);
187 }
188
189 static void sym_set_changed(struct symbol *sym)
190 {
191         struct property *prop;
192
193         sym->flags |= SYMBOL_CHANGED;
194         for (prop = sym->prop; prop; prop = prop->next) {
195                 if (prop->menu)
196                         prop->menu->flags |= MENU_CHANGED;
197         }
198 }
199
200 static void sym_set_all_changed(void)
201 {
202         struct symbol *sym;
203         int i;
204
205         for_all_symbols(i, sym)
206                 sym_set_changed(sym);
207 }
208
209 static void sym_calc_visibility(struct symbol *sym)
210 {
211         struct property *prop;
212         struct symbol *choice_sym = NULL;
213         tristate tri;
214
215         /* any prompt visible? */
216         tri = no;
217
218         if (sym_is_choice_value(sym))
219                 choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
220
221         for_all_prompts(sym, prop) {
222                 prop->visible.tri = expr_calc_value(prop->visible.expr);
223                 /*
224                  * Tristate choice_values with visibility 'mod' are
225                  * not visible if the corresponding choice's value is
226                  * 'yes'.
227                  */
228                 if (choice_sym && sym->type == S_TRISTATE &&
229                     prop->visible.tri == mod && choice_sym->curr.tri == yes)
230                         prop->visible.tri = no;
231
232                 tri = EXPR_OR(tri, prop->visible.tri);
233         }
234         if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
235                 tri = yes;
236         if (sym->visible != tri) {
237                 sym->visible = tri;
238                 sym_set_changed(sym);
239         }
240         if (sym_is_choice_value(sym))
241                 return;
242         /* defaulting to "yes" if no explicit "depends on" are given */
243         tri = yes;
244         if (sym->dir_dep.expr)
245                 tri = expr_calc_value(sym->dir_dep.expr);
246         if (tri == mod)
247                 tri = yes;
248         if (sym->dir_dep.tri != tri) {
249                 sym->dir_dep.tri = tri;
250                 sym_set_changed(sym);
251         }
252         tri = no;
253         if (sym->rev_dep.expr)
254                 tri = expr_calc_value(sym->rev_dep.expr);
255         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
256                 tri = yes;
257         if (sym->rev_dep.tri != tri) {
258                 sym->rev_dep.tri = tri;
259                 sym_set_changed(sym);
260         }
261 }
262
263 /*
264  * Find the default symbol for a choice.
265  * First try the default values for the choice symbol
266  * Next locate the first visible choice value
267  * Return NULL if none was found
268  */
269 struct symbol *sym_choice_default(struct symbol *sym)
270 {
271         struct symbol *def_sym;
272         struct property *prop;
273         struct expr *e;
274
275         /* any of the defaults visible? */
276         for_all_defaults(sym, prop) {
277                 prop->visible.tri = expr_calc_value(prop->visible.expr);
278                 if (prop->visible.tri == no)
279                         continue;
280                 def_sym = prop_get_symbol(prop);
281                 if (def_sym->visible != no)
282                         return def_sym;
283         }
284
285         /* just get the first visible value */
286         prop = sym_get_choice_prop(sym);
287         expr_list_for_each_sym(prop->expr, e, def_sym)
288                 if (def_sym->visible != no)
289                         return def_sym;
290
291         /* failed to locate any defaults */
292         return NULL;
293 }
294
295 static struct symbol *sym_calc_choice(struct symbol *sym)
296 {
297         struct symbol *def_sym;
298         struct property *prop;
299         struct expr *e;
300         int flags;
301
302         /* first calculate all choice values' visibilities */
303         flags = sym->flags;
304         prop = sym_get_choice_prop(sym);
305         expr_list_for_each_sym(prop->expr, e, def_sym) {
306                 sym_calc_visibility(def_sym);
307                 if (def_sym->visible != no)
308                         flags &= def_sym->flags;
309         }
310
311         sym->flags &= flags | ~SYMBOL_DEF_USER;
312
313         /* is the user choice visible? */
314         def_sym = sym->def[S_DEF_USER].val;
315         if (def_sym && def_sym->visible != no)
316                 return def_sym;
317
318         def_sym = sym_choice_default(sym);
319
320         if (def_sym == NULL)
321                 /* no choice? reset tristate value */
322                 sym->curr.tri = no;
323
324         return def_sym;
325 }
326
327 void sym_calc_value(struct symbol *sym)
328 {
329         struct symbol_value newval, oldval;
330         struct property *prop;
331         struct expr *e;
332
333         if (!sym)
334                 return;
335
336         if (sym->flags & SYMBOL_VALID)
337                 return;
338
339         if (sym_is_choice_value(sym) &&
340             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
341                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
342                 prop = sym_get_choice_prop(sym);
343                 sym_calc_value(prop_get_symbol(prop));
344         }
345
346         sym->flags |= SYMBOL_VALID;
347
348         oldval = sym->curr;
349
350         switch (sym->type) {
351         case S_INT:
352         case S_HEX:
353         case S_STRING:
354                 newval = symbol_empty.curr;
355                 break;
356         case S_BOOLEAN:
357         case S_TRISTATE:
358                 newval = symbol_no.curr;
359                 break;
360         default:
361                 sym->curr.val = sym->name;
362                 sym->curr.tri = no;
363                 return;
364         }
365         if (!sym_is_choice_value(sym))
366                 sym->flags &= ~SYMBOL_WRITE;
367
368         sym_calc_visibility(sym);
369
370         /* set default if recursively called */
371         sym->curr = newval;
372
373         switch (sym_get_type(sym)) {
374         case S_BOOLEAN:
375         case S_TRISTATE:
376                 if (sym_is_choice_value(sym) && sym->visible == yes) {
377                         prop = sym_get_choice_prop(sym);
378                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
379                 } else {
380                         if (sym->visible != no) {
381                                 /* if the symbol is visible use the user value
382                                  * if available, otherwise try the default value
383                                  */
384                                 sym->flags |= SYMBOL_WRITE;
385                                 if (sym_has_value(sym)) {
386                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
387                                                               sym->visible);
388                                         goto calc_newval;
389                                 }
390                         }
391                         if (sym->rev_dep.tri != no)
392                                 sym->flags |= SYMBOL_WRITE;
393                         if (!sym_is_choice(sym)) {
394                                 prop = sym_get_default_prop(sym);
395                                 if (prop) {
396                                         sym->flags |= SYMBOL_WRITE;
397                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
398                                                               prop->visible.tri);
399                                 }
400                         }
401                 calc_newval:
402                         if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
403                                 struct expr *e;
404                                 e = expr_simplify_unmet_dep(sym->rev_dep.expr,
405                                     sym->dir_dep.expr);
406                                 fprintf(stderr, "warning: (");
407                                 expr_fprint(e, stderr);
408                                 fprintf(stderr, ") selects %s which has unmet direct dependencies (",
409                                         sym->name);
410                                 expr_fprint(sym->dir_dep.expr, stderr);
411                                 fprintf(stderr, ")\n");
412                                 expr_free(e);
413                         }
414                         newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
415                 }
416                 if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
417                         newval.tri = yes;
418                 break;
419         case S_STRING:
420         case S_HEX:
421         case S_INT:
422                 if (sym->visible != no) {
423                         sym->flags |= SYMBOL_WRITE;
424                         if (sym_has_value(sym)) {
425                                 newval.val = sym->def[S_DEF_USER].val;
426                                 break;
427                         }
428                 }
429                 prop = sym_get_default_prop(sym);
430                 if (prop) {
431                         struct symbol *ds = prop_get_symbol(prop);
432                         if (ds) {
433                                 sym->flags |= SYMBOL_WRITE;
434                                 sym_calc_value(ds);
435                                 newval.val = ds->curr.val;
436                         }
437                 }
438                 break;
439         default:
440                 ;
441         }
442
443         sym->curr = newval;
444         if (sym_is_choice(sym) && newval.tri == yes)
445                 sym->curr.val = sym_calc_choice(sym);
446         sym_validate_range(sym);
447
448         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
449                 sym_set_changed(sym);
450                 if (modules_sym == sym) {
451                         sym_set_all_changed();
452                         modules_val = modules_sym->curr.tri;
453                 }
454         }
455
456         if (sym_is_choice(sym)) {
457                 struct symbol *choice_sym;
458
459                 prop = sym_get_choice_prop(sym);
460                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
461                         if ((sym->flags & SYMBOL_WRITE) &&
462                             choice_sym->visible != no)
463                                 choice_sym->flags |= SYMBOL_WRITE;
464                         if (sym->flags & SYMBOL_CHANGED)
465                                 sym_set_changed(choice_sym);
466                 }
467         }
468
469         if (sym->flags & SYMBOL_AUTO)
470                 sym->flags &= ~SYMBOL_WRITE;
471
472         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
473                 set_all_choice_values(sym);
474 }
475
476 void sym_clear_all_valid(void)
477 {
478         struct symbol *sym;
479         int i;
480
481         for_all_symbols(i, sym)
482                 sym->flags &= ~SYMBOL_VALID;
483         sym_add_change_count(1);
484         sym_calc_value(modules_sym);
485 }
486
487 bool sym_tristate_within_range(struct symbol *sym, tristate val)
488 {
489         int type = sym_get_type(sym);
490
491         if (sym->visible == no)
492                 return false;
493
494         if (type != S_BOOLEAN && type != S_TRISTATE)
495                 return false;
496
497         if (type == S_BOOLEAN && val == mod)
498                 return false;
499         if (sym->visible <= sym->rev_dep.tri)
500                 return false;
501         if (sym_is_choice_value(sym) && sym->visible == yes)
502                 return val == yes;
503         return val >= sym->rev_dep.tri && val <= sym->visible;
504 }
505
506 bool sym_set_tristate_value(struct symbol *sym, tristate val)
507 {
508         tristate oldval = sym_get_tristate_value(sym);
509
510         if (oldval != val && !sym_tristate_within_range(sym, val))
511                 return false;
512
513         if (!(sym->flags & SYMBOL_DEF_USER)) {
514                 sym->flags |= SYMBOL_DEF_USER;
515                 sym_set_changed(sym);
516         }
517         /*
518          * setting a choice value also resets the new flag of the choice
519          * symbol and all other choice values.
520          */
521         if (sym_is_choice_value(sym) && val == yes) {
522                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
523                 struct property *prop;
524                 struct expr *e;
525
526                 cs->def[S_DEF_USER].val = sym;
527                 cs->flags |= SYMBOL_DEF_USER;
528                 prop = sym_get_choice_prop(cs);
529                 for (e = prop->expr; e; e = e->left.expr) {
530                         if (e->right.sym->visible != no)
531                                 e->right.sym->flags |= SYMBOL_DEF_USER;
532                 }
533         }
534
535         sym->def[S_DEF_USER].tri = val;
536         if (oldval != val)
537                 sym_clear_all_valid();
538
539         return true;
540 }
541
542 tristate sym_toggle_tristate_value(struct symbol *sym)
543 {
544         tristate oldval, newval;
545
546         oldval = newval = sym_get_tristate_value(sym);
547         do {
548                 switch (newval) {
549                 case no:
550                         newval = mod;
551                         break;
552                 case mod:
553                         newval = yes;
554                         break;
555                 case yes:
556                         newval = no;
557                         break;
558                 }
559                 if (sym_set_tristate_value(sym, newval))
560                         break;
561         } while (oldval != newval);
562         return newval;
563 }
564
565 bool sym_string_valid(struct symbol *sym, const char *str)
566 {
567         signed char ch;
568
569         switch (sym->type) {
570         case S_STRING:
571                 return true;
572         case S_INT:
573                 ch = *str++;
574                 if (ch == '-')
575                         ch = *str++;
576                 if (!isdigit(ch))
577                         return false;
578                 if (ch == '0' && *str != 0)
579                         return false;
580                 while ((ch = *str++)) {
581                         if (!isdigit(ch))
582                                 return false;
583                 }
584                 return true;
585         case S_HEX:
586                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
587                         str += 2;
588                 ch = *str++;
589                 do {
590                         if (!isxdigit(ch))
591                                 return false;
592                 } while ((ch = *str++));
593                 return true;
594         case S_BOOLEAN:
595         case S_TRISTATE:
596                 switch (str[0]) {
597                 case 'y': case 'Y':
598                 case 'm': case 'M':
599                 case 'n': case 'N':
600                         return true;
601                 }
602                 return false;
603         default:
604                 return false;
605         }
606 }
607
608 bool sym_string_within_range(struct symbol *sym, const char *str)
609 {
610         struct property *prop;
611         long long val;
612
613         switch (sym->type) {
614         case S_STRING:
615                 return sym_string_valid(sym, str);
616         case S_INT:
617                 if (!sym_string_valid(sym, str))
618                         return false;
619                 prop = sym_get_range_prop(sym);
620                 if (!prop)
621                         return true;
622                 val = strtoll(str, NULL, 10);
623                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
624                        val <= sym_get_range_val(prop->expr->right.sym, 10);
625         case S_HEX:
626                 if (!sym_string_valid(sym, str))
627                         return false;
628                 prop = sym_get_range_prop(sym);
629                 if (!prop)
630                         return true;
631                 val = strtoll(str, NULL, 16);
632                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
633                        val <= sym_get_range_val(prop->expr->right.sym, 16);
634         case S_BOOLEAN:
635         case S_TRISTATE:
636                 switch (str[0]) {
637                 case 'y': case 'Y':
638                         return sym_tristate_within_range(sym, yes);
639                 case 'm': case 'M':
640                         return sym_tristate_within_range(sym, mod);
641                 case 'n': case 'N':
642                         return sym_tristate_within_range(sym, no);
643                 }
644                 return false;
645         default:
646                 return false;
647         }
648 }
649
650 bool sym_set_string_value(struct symbol *sym, const char *newval)
651 {
652         const char *oldval;
653         char *val;
654         int size;
655
656         switch (sym->type) {
657         case S_BOOLEAN:
658         case S_TRISTATE:
659                 switch (newval[0]) {
660                 case 'y': case 'Y':
661                         return sym_set_tristate_value(sym, yes);
662                 case 'm': case 'M':
663                         return sym_set_tristate_value(sym, mod);
664                 case 'n': case 'N':
665                         return sym_set_tristate_value(sym, no);
666                 }
667                 return false;
668         default:
669                 ;
670         }
671
672         if (!sym_string_within_range(sym, newval))
673                 return false;
674
675         if (!(sym->flags & SYMBOL_DEF_USER)) {
676                 sym->flags |= SYMBOL_DEF_USER;
677                 sym_set_changed(sym);
678         }
679
680         oldval = sym->def[S_DEF_USER].val;
681         size = strlen(newval) + 1;
682         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
683                 size += 2;
684                 sym->def[S_DEF_USER].val = val = xmalloc(size);
685                 *val++ = '0';
686                 *val++ = 'x';
687         } else if (!oldval || strcmp(oldval, newval))
688                 sym->def[S_DEF_USER].val = val = xmalloc(size);
689         else
690                 return true;
691
692         strcpy(val, newval);
693         free((void *)oldval);
694         sym_clear_all_valid();
695
696         return true;
697 }
698
699 /*
700  * Find the default value associated to a symbol.
701  * For tristate symbol handle the modules=n case
702  * in which case "m" becomes "y".
703  * If the symbol does not have any default then fallback
704  * to the fixed default values.
705  */
706 const char *sym_get_string_default(struct symbol *sym)
707 {
708         struct property *prop;
709         struct symbol *ds;
710         const char *str;
711         tristate val;
712
713         sym_calc_visibility(sym);
714         sym_calc_value(modules_sym);
715         val = symbol_no.curr.tri;
716         str = symbol_empty.curr.val;
717
718         /* If symbol has a default value look it up */
719         prop = sym_get_default_prop(sym);
720         if (prop != NULL) {
721                 switch (sym->type) {
722                 case S_BOOLEAN:
723                 case S_TRISTATE:
724                         /* The visibility may limit the value from yes => mod */
725                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
726                         break;
727                 default:
728                         /*
729                          * The following fails to handle the situation
730                          * where a default value is further limited by
731                          * the valid range.
732                          */
733                         ds = prop_get_symbol(prop);
734                         if (ds != NULL) {
735                                 sym_calc_value(ds);
736                                 str = (const char *)ds->curr.val;
737                         }
738                 }
739         }
740
741         /* Handle select statements */
742         val = EXPR_OR(val, sym->rev_dep.tri);
743
744         /* transpose mod to yes if modules are not enabled */
745         if (val == mod)
746                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
747                         val = yes;
748
749         /* transpose mod to yes if type is bool */
750         if (sym->type == S_BOOLEAN && val == mod)
751                 val = yes;
752
753         switch (sym->type) {
754         case S_BOOLEAN:
755         case S_TRISTATE:
756                 switch (val) {
757                 case no: return "n";
758                 case mod: return "m";
759                 case yes: return "y";
760                 }
761         case S_INT:
762         case S_HEX:
763                 return str;
764         case S_STRING:
765                 return str;
766         case S_OTHER:
767         case S_UNKNOWN:
768                 break;
769         }
770         return "";
771 }
772
773 const char *sym_get_string_value(struct symbol *sym)
774 {
775         tristate val;
776
777         switch (sym->type) {
778         case S_BOOLEAN:
779         case S_TRISTATE:
780                 val = sym_get_tristate_value(sym);
781                 switch (val) {
782                 case no:
783                         return "n";
784                 case mod:
785                         sym_calc_value(modules_sym);
786                         return (modules_sym->curr.tri == no) ? "n" : "m";
787                 case yes:
788                         return "y";
789                 }
790                 break;
791         default:
792                 ;
793         }
794         return (const char *)sym->curr.val;
795 }
796
797 bool sym_is_changable(struct symbol *sym)
798 {
799         return sym->visible > sym->rev_dep.tri;
800 }
801
802 static unsigned strhash(const char *s)
803 {
804         /* fnv32 hash */
805         unsigned hash = 2166136261U;
806         for (; *s; s++)
807                 hash = (hash ^ *s) * 0x01000193;
808         return hash;
809 }
810
811 struct symbol *sym_lookup(const char *name, int flags)
812 {
813         struct symbol *symbol;
814         char *new_name;
815         int hash;
816
817         if (name) {
818                 if (name[0] && !name[1]) {
819                         switch (name[0]) {
820                         case 'y': return &symbol_yes;
821                         case 'm': return &symbol_mod;
822                         case 'n': return &symbol_no;
823                         }
824                 }
825                 hash = strhash(name) % SYMBOL_HASHSIZE;
826
827                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
828                         if (symbol->name &&
829                             !strcmp(symbol->name, name) &&
830                             (flags ? symbol->flags & flags
831                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
832                                 return symbol;
833                 }
834                 new_name = strdup(name);
835         } else {
836                 new_name = NULL;
837                 hash = 0;
838         }
839
840         symbol = xmalloc(sizeof(*symbol));
841         memset(symbol, 0, sizeof(*symbol));
842         symbol->name = new_name;
843         symbol->type = S_UNKNOWN;
844         symbol->flags |= flags;
845
846         symbol->next = symbol_hash[hash];
847         symbol_hash[hash] = symbol;
848
849         return symbol;
850 }
851
852 struct symbol *sym_find(const char *name)
853 {
854         struct symbol *symbol = NULL;
855         int hash = 0;
856
857         if (!name)
858                 return NULL;
859
860         if (name[0] && !name[1]) {
861                 switch (name[0]) {
862                 case 'y': return &symbol_yes;
863                 case 'm': return &symbol_mod;
864                 case 'n': return &symbol_no;
865                 }
866         }
867         hash = strhash(name) % SYMBOL_HASHSIZE;
868
869         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
870                 if (symbol->name &&
871                     !strcmp(symbol->name, name) &&
872                     !(symbol->flags & SYMBOL_CONST))
873                                 break;
874         }
875
876         return symbol;
877 }
878
879 /*
880  * Expand symbol's names embedded in the string given in argument. Symbols'
881  * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
882  * the empty string.
883  */
884 const char *sym_expand_string_value(const char *in)
885 {
886         const char *src;
887         char *res;
888         size_t reslen;
889
890         reslen = strlen(in) + 1;
891         res = xmalloc(reslen);
892         res[0] = '\0';
893
894         while ((src = strchr(in, '$'))) {
895                 char *p, name[SYMBOL_MAXLENGTH];
896                 const char *symval = "";
897                 struct symbol *sym;
898                 size_t newlen;
899
900                 strncat(res, in, src - in);
901                 src++;
902
903                 p = name;
904                 while (isalnum(*src) || *src == '_')
905                         *p++ = *src++;
906                 *p = '\0';
907
908                 sym = sym_find(name);
909                 if (sym != NULL) {
910                         sym_calc_value(sym);
911                         symval = sym_get_string_value(sym);
912                 }
913
914                 newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
915                 if (newlen > reslen) {
916                         reslen = newlen;
917                         res = realloc(res, reslen);
918                 }
919
920                 strcat(res, symval);
921                 in = src;
922         }
923         strcat(res, in);
924
925         return res;
926 }
927
928 const char *sym_escape_string_value(const char *in)
929 {
930         const char *p;
931         size_t reslen;
932         char *res;
933         size_t l;
934
935         reslen = strlen(in) + strlen("\"\"") + 1;
936
937         p = in;
938         for (;;) {
939                 l = strcspn(p, "\"\\");
940                 p += l;
941
942                 if (p[0] == '\0')
943                         break;
944
945                 reslen++;
946                 p++;
947         }
948
949         res = xmalloc(reslen);
950         res[0] = '\0';
951
952         strcat(res, "\"");
953
954         p = in;
955         for (;;) {
956                 l = strcspn(p, "\"\\");
957                 strncat(res, p, l);
958                 p += l;
959
960                 if (p[0] == '\0')
961                         break;
962
963                 strcat(res, "\\");
964                 strncat(res, p++, 1);
965         }
966
967         strcat(res, "\"");
968         return res;
969 }
970
971 struct sym_match {
972         struct symbol   *sym;
973         off_t           so, eo;
974 };
975
976 /* Compare matched symbols as thus:
977  * - first, symbols that match exactly
978  * - then, alphabetical sort
979  */
980 static int sym_rel_comp(const void *sym1, const void *sym2)
981 {
982         const struct sym_match *s1 = sym1;
983         const struct sym_match *s2 = sym2;
984         int exact1, exact2;
985
986         /* Exact match:
987          * - if matched length on symbol s1 is the length of that symbol,
988          *   then this symbol should come first;
989          * - if matched length on symbol s2 is the length of that symbol,
990          *   then this symbol should come first.
991          * Note: since the search can be a regexp, both symbols may match
992          * exactly; if this is the case, we can't decide which comes first,
993          * and we fallback to sorting alphabetically.
994          */
995         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
996         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
997         if (exact1 && !exact2)
998                 return -1;
999         if (!exact1 && exact2)
1000                 return 1;
1001
1002         /* As a fallback, sort symbols alphabetically */
1003         return strcmp(s1->sym->name, s2->sym->name);
1004 }
1005
1006 struct symbol **sym_re_search(const char *pattern)
1007 {
1008         struct symbol *sym, **sym_arr = NULL;
1009         struct sym_match *sym_match_arr = NULL;
1010         int i, cnt, size;
1011         regex_t re;
1012         regmatch_t match[1];
1013
1014         cnt = size = 0;
1015         /* Skip if empty */
1016         if (strlen(pattern) == 0)
1017                 return NULL;
1018         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
1019                 return NULL;
1020
1021         for_all_symbols(i, sym) {
1022                 if (sym->flags & SYMBOL_CONST || !sym->name)
1023                         continue;
1024                 if (regexec(&re, sym->name, 1, match, 0))
1025                         continue;
1026                 if (cnt >= size) {
1027                         void *tmp;
1028                         size += 16;
1029                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
1030                         if (!tmp)
1031                                 goto sym_re_search_free;
1032                         sym_match_arr = tmp;
1033                 }
1034                 sym_calc_value(sym);
1035                 /* As regexec returned 0, we know we have a match, so
1036                  * we can use match[0].rm_[se]o without further checks
1037                  */
1038                 sym_match_arr[cnt].so = match[0].rm_so;
1039                 sym_match_arr[cnt].eo = match[0].rm_eo;
1040                 sym_match_arr[cnt++].sym = sym;
1041         }
1042         if (sym_match_arr) {
1043                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
1044                 sym_arr = malloc((cnt+1) * sizeof(struct symbol));
1045                 if (!sym_arr)
1046                         goto sym_re_search_free;
1047                 for (i = 0; i < cnt; i++)
1048                         sym_arr[i] = sym_match_arr[i].sym;
1049                 sym_arr[cnt] = NULL;
1050         }
1051 sym_re_search_free:
1052         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
1053         free(sym_match_arr);
1054         regfree(&re);
1055
1056         return sym_arr;
1057 }
1058
1059 /*
1060  * When we check for recursive dependencies we use a stack to save
1061  * current state so we can print out relevant info to user.
1062  * The entries are located on the call stack so no need to free memory.
1063  * Note insert() remove() must always match to properly clear the stack.
1064  */
1065 static struct dep_stack {
1066         struct dep_stack *prev, *next;
1067         struct symbol *sym;
1068         struct property *prop;
1069         struct expr *expr;
1070 } *check_top;
1071
1072 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1073 {
1074         memset(stack, 0, sizeof(*stack));
1075         if (check_top)
1076                 check_top->next = stack;
1077         stack->prev = check_top;
1078         stack->sym = sym;
1079         check_top = stack;
1080 }
1081
1082 static void dep_stack_remove(void)
1083 {
1084         check_top = check_top->prev;
1085         if (check_top)
1086                 check_top->next = NULL;
1087 }
1088
1089 /*
1090  * Called when we have detected a recursive dependency.
1091  * check_top point to the top of the stact so we use
1092  * the ->prev pointer to locate the bottom of the stack.
1093  */
1094 static void sym_check_print_recursive(struct symbol *last_sym)
1095 {
1096         struct dep_stack *stack;
1097         struct symbol *sym, *next_sym;
1098         struct menu *menu = NULL;
1099         struct property *prop;
1100         struct dep_stack cv_stack;
1101
1102         if (sym_is_choice_value(last_sym)) {
1103                 dep_stack_insert(&cv_stack, last_sym);
1104                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1105         }
1106
1107         for (stack = check_top; stack != NULL; stack = stack->prev)
1108                 if (stack->sym == last_sym)
1109                         break;
1110         if (!stack) {
1111                 fprintf(stderr, "unexpected recursive dependency error\n");
1112                 return;
1113         }
1114
1115         for (; stack; stack = stack->next) {
1116                 sym = stack->sym;
1117                 next_sym = stack->next ? stack->next->sym : last_sym;
1118                 prop = stack->prop;
1119                 if (prop == NULL)
1120                         prop = stack->sym->prop;
1121
1122                 /* for choice values find the menu entry (used below) */
1123                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1124                         for (prop = sym->prop; prop; prop = prop->next) {
1125                                 menu = prop->menu;
1126                                 if (prop->menu)
1127                                         break;
1128                         }
1129                 }
1130                 if (stack->sym == last_sym)
1131                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1132                                 prop->file->name, prop->lineno);
1133                         fprintf(stderr, "For a resolution refer to Documentation/kbuild/kconfig-language.txt\n");
1134                         fprintf(stderr, "subsection \"Kconfig recursive dependency limitations\"\n");
1135                 if (stack->expr) {
1136                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1137                                 prop->file->name, prop->lineno,
1138                                 sym->name ? sym->name : "<choice>",
1139                                 prop_get_type_name(prop->type),
1140                                 next_sym->name ? next_sym->name : "<choice>");
1141                 } else if (stack->prop) {
1142                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1143                                 prop->file->name, prop->lineno,
1144                                 sym->name ? sym->name : "<choice>",
1145                                 next_sym->name ? next_sym->name : "<choice>");
1146                 } else if (sym_is_choice(sym)) {
1147                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1148                                 menu->file->name, menu->lineno,
1149                                 sym->name ? sym->name : "<choice>",
1150                                 next_sym->name ? next_sym->name : "<choice>");
1151                 } else if (sym_is_choice_value(sym)) {
1152                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1153                                 menu->file->name, menu->lineno,
1154                                 sym->name ? sym->name : "<choice>",
1155                                 next_sym->name ? next_sym->name : "<choice>");
1156                 } else {
1157                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1158                                 prop->file->name, prop->lineno,
1159                                 sym->name ? sym->name : "<choice>",
1160                                 next_sym->name ? next_sym->name : "<choice>");
1161                 }
1162         }
1163
1164         if (check_top == &cv_stack)
1165                 dep_stack_remove();
1166 }
1167
1168 static struct symbol *sym_check_expr_deps(struct expr *e)
1169 {
1170         struct symbol *sym;
1171
1172         if (!e)
1173                 return NULL;
1174         switch (e->type) {
1175         case E_OR:
1176         case E_AND:
1177                 sym = sym_check_expr_deps(e->left.expr);
1178                 if (sym)
1179                         return sym;
1180                 return sym_check_expr_deps(e->right.expr);
1181         case E_NOT:
1182                 return sym_check_expr_deps(e->left.expr);
1183         case E_EQUAL:
1184         case E_GEQ:
1185         case E_GTH:
1186         case E_LEQ:
1187         case E_LTH:
1188         case E_UNEQUAL:
1189                 sym = sym_check_deps(e->left.sym);
1190                 if (sym)
1191                         return sym;
1192                 return sym_check_deps(e->right.sym);
1193         case E_SYMBOL:
1194                 return sym_check_deps(e->left.sym);
1195         default:
1196                 break;
1197         }
1198         printf("Oops! How to check %d?\n", e->type);
1199         return NULL;
1200 }
1201
1202 /* return NULL when dependencies are OK */
1203 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1204 {
1205         struct symbol *sym2;
1206         struct property *prop;
1207         struct dep_stack stack;
1208
1209         dep_stack_insert(&stack, sym);
1210
1211         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1212         if (sym2)
1213                 goto out;
1214
1215         for (prop = sym->prop; prop; prop = prop->next) {
1216                 if (prop->type == P_CHOICE || prop->type == P_SELECT)
1217                         continue;
1218                 stack.prop = prop;
1219                 sym2 = sym_check_expr_deps(prop->visible.expr);
1220                 if (sym2)
1221                         break;
1222                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1223                         continue;
1224                 stack.expr = prop->expr;
1225                 sym2 = sym_check_expr_deps(prop->expr);
1226                 if (sym2)
1227                         break;
1228                 stack.expr = NULL;
1229         }
1230
1231 out:
1232         dep_stack_remove();
1233
1234         return sym2;
1235 }
1236
1237 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1238 {
1239         struct symbol *sym, *sym2;
1240         struct property *prop;
1241         struct expr *e;
1242         struct dep_stack stack;
1243
1244         dep_stack_insert(&stack, choice);
1245
1246         prop = sym_get_choice_prop(choice);
1247         expr_list_for_each_sym(prop->expr, e, sym)
1248                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1249
1250         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1251         sym2 = sym_check_sym_deps(choice);
1252         choice->flags &= ~SYMBOL_CHECK;
1253         if (sym2)
1254                 goto out;
1255
1256         expr_list_for_each_sym(prop->expr, e, sym) {
1257                 sym2 = sym_check_sym_deps(sym);
1258                 if (sym2)
1259                         break;
1260         }
1261 out:
1262         expr_list_for_each_sym(prop->expr, e, sym)
1263                 sym->flags &= ~SYMBOL_CHECK;
1264
1265         if (sym2 && sym_is_choice_value(sym2) &&
1266             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1267                 sym2 = choice;
1268
1269         dep_stack_remove();
1270
1271         return sym2;
1272 }
1273
1274 struct symbol *sym_check_deps(struct symbol *sym)
1275 {
1276         struct symbol *sym2;
1277         struct property *prop;
1278
1279         if (sym->flags & SYMBOL_CHECK) {
1280                 sym_check_print_recursive(sym);
1281                 return sym;
1282         }
1283         if (sym->flags & SYMBOL_CHECKED)
1284                 return NULL;
1285
1286         if (sym_is_choice_value(sym)) {
1287                 struct dep_stack stack;
1288
1289                 /* for choice groups start the check with main choice symbol */
1290                 dep_stack_insert(&stack, sym);
1291                 prop = sym_get_choice_prop(sym);
1292                 sym2 = sym_check_deps(prop_get_symbol(prop));
1293                 dep_stack_remove();
1294         } else if (sym_is_choice(sym)) {
1295                 sym2 = sym_check_choice_deps(sym);
1296         } else {
1297                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1298                 sym2 = sym_check_sym_deps(sym);
1299                 sym->flags &= ~SYMBOL_CHECK;
1300         }
1301
1302         if (sym2 && sym2 == sym)
1303                 sym2 = NULL;
1304
1305         return sym2;
1306 }
1307
1308 struct property *prop_alloc(enum prop_type type, struct symbol *sym)
1309 {
1310         struct property *prop;
1311         struct property **propp;
1312
1313         prop = xmalloc(sizeof(*prop));
1314         memset(prop, 0, sizeof(*prop));
1315         prop->type = type;
1316         prop->sym = sym;
1317         prop->file = current_file;
1318         prop->lineno = zconf_lineno();
1319
1320         /* append property to the prop list of symbol */
1321         if (sym) {
1322                 for (propp = &sym->prop; *propp; propp = &(*propp)->next)
1323                         ;
1324                 *propp = prop;
1325         }
1326
1327         return prop;
1328 }
1329
1330 struct symbol *prop_get_symbol(struct property *prop)
1331 {
1332         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1333                            prop->expr->type == E_LIST))
1334                 return prop->expr->left.sym;
1335         return NULL;
1336 }
1337
1338 const char *prop_get_type_name(enum prop_type type)
1339 {
1340         switch (type) {
1341         case P_PROMPT:
1342                 return "prompt";
1343         case P_ENV:
1344                 return "env";
1345         case P_COMMENT:
1346                 return "comment";
1347         case P_MENU:
1348                 return "menu";
1349         case P_DEFAULT:
1350                 return "default";
1351         case P_CHOICE:
1352                 return "choice";
1353         case P_SELECT:
1354                 return "select";
1355         case P_RANGE:
1356                 return "range";
1357         case P_SYMBOL:
1358                 return "symbol";
1359         case P_UNKNOWN:
1360                 break;
1361         }
1362         return "unknown";
1363 }
1364
1365 static void prop_add_env(const char *env)
1366 {
1367         struct symbol *sym, *sym2;
1368         struct property *prop;
1369         char *p;
1370
1371         sym = current_entry->sym;
1372         sym->flags |= SYMBOL_AUTO;
1373         for_all_properties(sym, prop, P_ENV) {
1374                 sym2 = prop_get_symbol(prop);
1375                 if (strcmp(sym2->name, env))
1376                         menu_warn(current_entry, "redefining environment symbol from %s",
1377                                   sym2->name);
1378                 return;
1379         }
1380
1381         prop = prop_alloc(P_ENV, sym);
1382         prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
1383
1384         sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
1385         sym_env_list->right.sym = sym;
1386
1387         p = getenv(env);
1388         if (p)
1389                 sym_add_default(sym, p);
1390         else
1391                 menu_warn(current_entry, "environment variable %s undefined", env);
1392 }