4ea0050dcb16ff54b24a0661317eb9c972bd914b
[linux-2.6.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 int sym_change_count;
34 struct symbol *modules_sym;
35 tristate modules_val;
36
37 void sym_add_default(struct symbol *sym, const char *def)
38 {
39         struct property *prop = prop_alloc(P_DEFAULT, sym);
40
41         prop->expr = expr_alloc_symbol(sym_lookup(def, 1));
42 }
43
44 void sym_init(void)
45 {
46         struct symbol *sym;
47         struct utsname uts;
48         char *p;
49         static bool inited = false;
50
51         if (inited)
52                 return;
53         inited = true;
54
55         uname(&uts);
56
57         sym = sym_lookup("ARCH", 0);
58         sym->type = S_STRING;
59         sym->flags |= SYMBOL_AUTO;
60         p = getenv("ARCH");
61         if (p)
62                 sym_add_default(sym, p);
63
64         sym = sym_lookup("KERNELVERSION", 0);
65         sym->type = S_STRING;
66         sym->flags |= SYMBOL_AUTO;
67         p = getenv("KERNELVERSION");
68         if (p)
69                 sym_add_default(sym, p);
70
71         sym = sym_lookup("UNAME_RELEASE", 0);
72         sym->type = S_STRING;
73         sym->flags |= SYMBOL_AUTO;
74         sym_add_default(sym, uts.release);
75 }
76
77 enum symbol_type sym_get_type(struct symbol *sym)
78 {
79         enum symbol_type type = sym->type;
80
81         if (type == S_TRISTATE) {
82                 if (sym_is_choice_value(sym) && sym->visible == yes)
83                         type = S_BOOLEAN;
84                 else if (modules_val == no)
85                         type = S_BOOLEAN;
86         }
87         return type;
88 }
89
90 const char *sym_type_name(enum symbol_type type)
91 {
92         switch (type) {
93         case S_BOOLEAN:
94                 return "boolean";
95         case S_TRISTATE:
96                 return "tristate";
97         case S_INT:
98                 return "integer";
99         case S_HEX:
100                 return "hex";
101         case S_STRING:
102                 return "string";
103         case S_UNKNOWN:
104                 return "unknown";
105         case S_OTHER:
106                 break;
107         }
108         return "???";
109 }
110
111 struct property *sym_get_choice_prop(struct symbol *sym)
112 {
113         struct property *prop;
114
115         for_all_choices(sym, prop)
116                 return prop;
117         return NULL;
118 }
119
120 struct property *sym_get_default_prop(struct symbol *sym)
121 {
122         struct property *prop;
123
124         for_all_defaults(sym, prop) {
125                 prop->visible.tri = expr_calc_value(prop->visible.expr);
126                 if (prop->visible.tri != no)
127                         return prop;
128         }
129         return NULL;
130 }
131
132 struct property *sym_get_range_prop(struct symbol *sym)
133 {
134         struct property *prop;
135
136         for_all_properties(sym, prop, P_RANGE) {
137                 prop->visible.tri = expr_calc_value(prop->visible.expr);
138                 if (prop->visible.tri != no)
139                         return prop;
140         }
141         return NULL;
142 }
143
144 static int sym_get_range_val(struct symbol *sym, int base)
145 {
146         sym_calc_value(sym);
147         switch (sym->type) {
148         case S_INT:
149                 base = 10;
150                 break;
151         case S_HEX:
152                 base = 16;
153                 break;
154         default:
155                 break;
156         }
157         return strtol(sym->curr.val, NULL, base);
158 }
159
160 static void sym_validate_range(struct symbol *sym)
161 {
162         struct property *prop;
163         int base, val, val2;
164         char str[64];
165
166         switch (sym->type) {
167         case S_INT:
168                 base = 10;
169                 break;
170         case S_HEX:
171                 base = 16;
172                 break;
173         default:
174                 return;
175         }
176         prop = sym_get_range_prop(sym);
177         if (!prop)
178                 return;
179         val = strtol(sym->curr.val, NULL, base);
180         val2 = sym_get_range_val(prop->expr->left.sym, base);
181         if (val >= val2) {
182                 val2 = sym_get_range_val(prop->expr->right.sym, base);
183                 if (val <= val2)
184                         return;
185         }
186         if (sym->type == S_INT)
187                 sprintf(str, "%d", val2);
188         else
189                 sprintf(str, "0x%x", val2);
190         sym->curr.val = strdup(str);
191 }
192
193 static void sym_calc_visibility(struct symbol *sym)
194 {
195         struct property *prop;
196         tristate tri;
197
198         /* any prompt visible? */
199         tri = no;
200         for_all_prompts(sym, prop) {
201                 prop->visible.tri = expr_calc_value(prop->visible.expr);
202                 tri = E_OR(tri, prop->visible.tri);
203         }
204         if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
205                 tri = yes;
206         if (sym->visible != tri) {
207                 sym->visible = tri;
208                 sym_set_changed(sym);
209         }
210         if (sym_is_choice_value(sym))
211                 return;
212         tri = no;
213         if (sym->rev_dep.expr)
214                 tri = expr_calc_value(sym->rev_dep.expr);
215         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
216                 tri = yes;
217         if (sym->rev_dep.tri != tri) {
218                 sym->rev_dep.tri = tri;
219                 sym_set_changed(sym);
220         }
221 }
222
223 static struct symbol *sym_calc_choice(struct symbol *sym)
224 {
225         struct symbol *def_sym;
226         struct property *prop;
227         struct expr *e;
228
229         /* is the user choice visible? */
230         def_sym = sym->def[S_DEF_USER].val;
231         if (def_sym) {
232                 sym_calc_visibility(def_sym);
233                 if (def_sym->visible != no)
234                         return def_sym;
235         }
236
237         /* any of the defaults visible? */
238         for_all_defaults(sym, prop) {
239                 prop->visible.tri = expr_calc_value(prop->visible.expr);
240                 if (prop->visible.tri == no)
241                         continue;
242                 def_sym = prop_get_symbol(prop);
243                 sym_calc_visibility(def_sym);
244                 if (def_sym->visible != no)
245                         return def_sym;
246         }
247
248         /* just get the first visible value */
249         prop = sym_get_choice_prop(sym);
250         for (e = prop->expr; e; e = e->left.expr) {
251                 def_sym = e->right.sym;
252                 sym_calc_visibility(def_sym);
253                 if (def_sym->visible != no)
254                         return def_sym;
255         }
256
257         /* no choice? reset tristate value */
258         sym->curr.tri = no;
259         return NULL;
260 }
261
262 void sym_calc_value(struct symbol *sym)
263 {
264         struct symbol_value newval, oldval;
265         struct property *prop;
266         struct expr *e;
267
268         if (!sym)
269                 return;
270
271         if (sym->flags & SYMBOL_VALID)
272                 return;
273         sym->flags |= SYMBOL_VALID;
274
275         oldval = sym->curr;
276
277         switch (sym->type) {
278         case S_INT:
279         case S_HEX:
280         case S_STRING:
281                 newval = symbol_empty.curr;
282                 break;
283         case S_BOOLEAN:
284         case S_TRISTATE:
285                 newval = symbol_no.curr;
286                 break;
287         default:
288                 sym->curr.val = sym->name;
289                 sym->curr.tri = no;
290                 return;
291         }
292         if (!sym_is_choice_value(sym))
293                 sym->flags &= ~SYMBOL_WRITE;
294
295         sym_calc_visibility(sym);
296
297         /* set default if recursively called */
298         sym->curr = newval;
299
300         switch (sym_get_type(sym)) {
301         case S_BOOLEAN:
302         case S_TRISTATE:
303                 if (sym_is_choice_value(sym) && sym->visible == yes) {
304                         prop = sym_get_choice_prop(sym);
305                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
306                 } else if (E_OR(sym->visible, sym->rev_dep.tri) != no) {
307                         sym->flags |= SYMBOL_WRITE;
308                         if (sym_has_value(sym))
309                                 newval.tri = sym->def[S_DEF_USER].tri;
310                         else if (!sym_is_choice(sym)) {
311                                 prop = sym_get_default_prop(sym);
312                                 if (prop)
313                                         newval.tri = expr_calc_value(prop->expr);
314                         }
315                         newval.tri = E_OR(E_AND(newval.tri, sym->visible), sym->rev_dep.tri);
316                 } else if (!sym_is_choice(sym)) {
317                         prop = sym_get_default_prop(sym);
318                         if (prop) {
319                                 sym->flags |= SYMBOL_WRITE;
320                                 newval.tri = expr_calc_value(prop->expr);
321                         }
322                 }
323                 if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
324                         newval.tri = yes;
325                 break;
326         case S_STRING:
327         case S_HEX:
328         case S_INT:
329                 if (sym->visible != no) {
330                         sym->flags |= SYMBOL_WRITE;
331                         if (sym_has_value(sym)) {
332                                 newval.val = sym->def[S_DEF_USER].val;
333                                 break;
334                         }
335                 }
336                 prop = sym_get_default_prop(sym);
337                 if (prop) {
338                         struct symbol *ds = prop_get_symbol(prop);
339                         if (ds) {
340                                 sym->flags |= SYMBOL_WRITE;
341                                 sym_calc_value(ds);
342                                 newval.val = ds->curr.val;
343                         }
344                 }
345                 break;
346         default:
347                 ;
348         }
349
350         sym->curr = newval;
351         if (sym_is_choice(sym) && newval.tri == yes)
352                 sym->curr.val = sym_calc_choice(sym);
353         sym_validate_range(sym);
354
355         if (memcmp(&oldval, &sym->curr, sizeof(oldval)))
356                 sym_set_changed(sym);
357         if (modules_sym == sym)
358                 modules_val = modules_sym->curr.tri;
359
360         if (sym_is_choice(sym)) {
361                 int flags = sym->flags & (SYMBOL_CHANGED | SYMBOL_WRITE);
362                 prop = sym_get_choice_prop(sym);
363                 for (e = prop->expr; e; e = e->left.expr) {
364                         e->right.sym->flags |= flags;
365                         if (flags & SYMBOL_CHANGED)
366                                 sym_set_changed(e->right.sym);
367                 }
368         }
369 }
370
371 void sym_clear_all_valid(void)
372 {
373         struct symbol *sym;
374         int i;
375
376         for_all_symbols(i, sym)
377                 sym->flags &= ~SYMBOL_VALID;
378         sym_change_count++;
379         if (modules_sym)
380                 sym_calc_value(modules_sym);
381 }
382
383 void sym_set_changed(struct symbol *sym)
384 {
385         struct property *prop;
386
387         sym->flags |= SYMBOL_CHANGED;
388         for (prop = sym->prop; prop; prop = prop->next) {
389                 if (prop->menu)
390                         prop->menu->flags |= MENU_CHANGED;
391         }
392 }
393
394 void sym_set_all_changed(void)
395 {
396         struct symbol *sym;
397         int i;
398
399         for_all_symbols(i, sym)
400                 sym_set_changed(sym);
401 }
402
403 bool sym_tristate_within_range(struct symbol *sym, tristate val)
404 {
405         int type = sym_get_type(sym);
406
407         if (sym->visible == no)
408                 return false;
409
410         if (type != S_BOOLEAN && type != S_TRISTATE)
411                 return false;
412
413         if (type == S_BOOLEAN && val == mod)
414                 return false;
415         if (sym->visible <= sym->rev_dep.tri)
416                 return false;
417         if (sym_is_choice_value(sym) && sym->visible == yes)
418                 return val == yes;
419         return val >= sym->rev_dep.tri && val <= sym->visible;
420 }
421
422 bool sym_set_tristate_value(struct symbol *sym, tristate val)
423 {
424         tristate oldval = sym_get_tristate_value(sym);
425
426         if (oldval != val && !sym_tristate_within_range(sym, val))
427                 return false;
428
429         if (sym->flags & SYMBOL_NEW) {
430                 sym->flags &= ~SYMBOL_NEW;
431                 sym_set_changed(sym);
432         }
433         /*
434          * setting a choice value also resets the new flag of the choice
435          * symbol and all other choice values.
436          */
437         if (sym_is_choice_value(sym) && val == yes) {
438                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
439                 struct property *prop;
440                 struct expr *e;
441
442                 cs->def[S_DEF_USER].val = sym;
443                 cs->flags &= ~SYMBOL_NEW;
444                 prop = sym_get_choice_prop(cs);
445                 for (e = prop->expr; e; e = e->left.expr) {
446                         if (e->right.sym->visible != no)
447                                 e->right.sym->flags &= ~SYMBOL_NEW;
448                 }
449         }
450
451         sym->def[S_DEF_USER].tri = val;
452         if (oldval != val) {
453                 sym_clear_all_valid();
454                 if (sym == modules_sym)
455                         sym_set_all_changed();
456         }
457
458         return true;
459 }
460
461 tristate sym_toggle_tristate_value(struct symbol *sym)
462 {
463         tristate oldval, newval;
464
465         oldval = newval = sym_get_tristate_value(sym);
466         do {
467                 switch (newval) {
468                 case no:
469                         newval = mod;
470                         break;
471                 case mod:
472                         newval = yes;
473                         break;
474                 case yes:
475                         newval = no;
476                         break;
477                 }
478                 if (sym_set_tristate_value(sym, newval))
479                         break;
480         } while (oldval != newval);
481         return newval;
482 }
483
484 bool sym_string_valid(struct symbol *sym, const char *str)
485 {
486         signed char ch;
487
488         switch (sym->type) {
489         case S_STRING:
490                 return true;
491         case S_INT:
492                 ch = *str++;
493                 if (ch == '-')
494                         ch = *str++;
495                 if (!isdigit(ch))
496                         return false;
497                 if (ch == '0' && *str != 0)
498                         return false;
499                 while ((ch = *str++)) {
500                         if (!isdigit(ch))
501                                 return false;
502                 }
503                 return true;
504         case S_HEX:
505                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
506                         str += 2;
507                 ch = *str++;
508                 do {
509                         if (!isxdigit(ch))
510                                 return false;
511                 } while ((ch = *str++));
512                 return true;
513         case S_BOOLEAN:
514         case S_TRISTATE:
515                 switch (str[0]) {
516                 case 'y': case 'Y':
517                 case 'm': case 'M':
518                 case 'n': case 'N':
519                         return true;
520                 }
521                 return false;
522         default:
523                 return false;
524         }
525 }
526
527 bool sym_string_within_range(struct symbol *sym, const char *str)
528 {
529         struct property *prop;
530         int val;
531
532         switch (sym->type) {
533         case S_STRING:
534                 return sym_string_valid(sym, str);
535         case S_INT:
536                 if (!sym_string_valid(sym, str))
537                         return false;
538                 prop = sym_get_range_prop(sym);
539                 if (!prop)
540                         return true;
541                 val = strtol(str, NULL, 10);
542                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
543                        val <= sym_get_range_val(prop->expr->right.sym, 10);
544         case S_HEX:
545                 if (!sym_string_valid(sym, str))
546                         return false;
547                 prop = sym_get_range_prop(sym);
548                 if (!prop)
549                         return true;
550                 val = strtol(str, NULL, 16);
551                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
552                        val <= sym_get_range_val(prop->expr->right.sym, 16);
553         case S_BOOLEAN:
554         case S_TRISTATE:
555                 switch (str[0]) {
556                 case 'y': case 'Y':
557                         return sym_tristate_within_range(sym, yes);
558                 case 'm': case 'M':
559                         return sym_tristate_within_range(sym, mod);
560                 case 'n': case 'N':
561                         return sym_tristate_within_range(sym, no);
562                 }
563                 return false;
564         default:
565                 return false;
566         }
567 }
568
569 bool sym_set_string_value(struct symbol *sym, const char *newval)
570 {
571         const char *oldval;
572         char *val;
573         int size;
574
575         switch (sym->type) {
576         case S_BOOLEAN:
577         case S_TRISTATE:
578                 switch (newval[0]) {
579                 case 'y': case 'Y':
580                         return sym_set_tristate_value(sym, yes);
581                 case 'm': case 'M':
582                         return sym_set_tristate_value(sym, mod);
583                 case 'n': case 'N':
584                         return sym_set_tristate_value(sym, no);
585                 }
586                 return false;
587         default:
588                 ;
589         }
590
591         if (!sym_string_within_range(sym, newval))
592                 return false;
593
594         if (sym->flags & SYMBOL_NEW) {
595                 sym->flags &= ~SYMBOL_NEW;
596                 sym_set_changed(sym);
597         }
598
599         oldval = sym->def[S_DEF_USER].val;
600         size = strlen(newval) + 1;
601         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
602                 size += 2;
603                 sym->def[S_DEF_USER].val = val = malloc(size);
604                 *val++ = '0';
605                 *val++ = 'x';
606         } else if (!oldval || strcmp(oldval, newval))
607                 sym->def[S_DEF_USER].val = val = malloc(size);
608         else
609                 return true;
610
611         strcpy(val, newval);
612         free((void *)oldval);
613         sym_clear_all_valid();
614
615         return true;
616 }
617
618 const char *sym_get_string_value(struct symbol *sym)
619 {
620         tristate val;
621
622         switch (sym->type) {
623         case S_BOOLEAN:
624         case S_TRISTATE:
625                 val = sym_get_tristate_value(sym);
626                 switch (val) {
627                 case no:
628                         return "n";
629                 case mod:
630                         return "m";
631                 case yes:
632                         return "y";
633                 }
634                 break;
635         default:
636                 ;
637         }
638         return (const char *)sym->curr.val;
639 }
640
641 bool sym_is_changable(struct symbol *sym)
642 {
643         return sym->visible > sym->rev_dep.tri;
644 }
645
646 struct symbol *sym_lookup(const char *name, int isconst)
647 {
648         struct symbol *symbol;
649         const char *ptr;
650         char *new_name;
651         int hash = 0;
652
653         if (name) {
654                 if (name[0] && !name[1]) {
655                         switch (name[0]) {
656                         case 'y': return &symbol_yes;
657                         case 'm': return &symbol_mod;
658                         case 'n': return &symbol_no;
659                         }
660                 }
661                 for (ptr = name; *ptr; ptr++)
662                         hash += *ptr;
663                 hash &= 0xff;
664
665                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
666                         if (!strcmp(symbol->name, name)) {
667                                 if ((isconst && symbol->flags & SYMBOL_CONST) ||
668                                     (!isconst && !(symbol->flags & SYMBOL_CONST)))
669                                         return symbol;
670                         }
671                 }
672                 new_name = strdup(name);
673         } else {
674                 new_name = NULL;
675                 hash = 256;
676         }
677
678         symbol = malloc(sizeof(*symbol));
679         memset(symbol, 0, sizeof(*symbol));
680         symbol->name = new_name;
681         symbol->type = S_UNKNOWN;
682         symbol->flags = SYMBOL_NEW;
683         if (isconst)
684                 symbol->flags |= SYMBOL_CONST;
685
686         symbol->next = symbol_hash[hash];
687         symbol_hash[hash] = symbol;
688
689         return symbol;
690 }
691
692 struct symbol *sym_find(const char *name)
693 {
694         struct symbol *symbol = NULL;
695         const char *ptr;
696         int hash = 0;
697
698         if (!name)
699                 return NULL;
700
701         if (name[0] && !name[1]) {
702                 switch (name[0]) {
703                 case 'y': return &symbol_yes;
704                 case 'm': return &symbol_mod;
705                 case 'n': return &symbol_no;
706                 }
707         }
708         for (ptr = name; *ptr; ptr++)
709                 hash += *ptr;
710         hash &= 0xff;
711
712         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
713                 if (!strcmp(symbol->name, name) &&
714                     !(symbol->flags & SYMBOL_CONST))
715                                 break;
716         }
717
718         return symbol;
719 }
720
721 struct symbol **sym_re_search(const char *pattern)
722 {
723         struct symbol *sym, **sym_arr = NULL;
724         int i, cnt, size;
725         regex_t re;
726
727         cnt = size = 0;
728         /* Skip if empty */
729         if (strlen(pattern) == 0)
730                 return NULL;
731         if (regcomp(&re, pattern, REG_EXTENDED|REG_NOSUB|REG_ICASE))
732                 return NULL;
733
734         for_all_symbols(i, sym) {
735                 if (sym->flags & SYMBOL_CONST || !sym->name)
736                         continue;
737                 if (regexec(&re, sym->name, 0, NULL, 0))
738                         continue;
739                 if (cnt + 1 >= size) {
740                         void *tmp = sym_arr;
741                         size += 16;
742                         sym_arr = realloc(sym_arr, size * sizeof(struct symbol *));
743                         if (!sym_arr) {
744                                 free(tmp);
745                                 return NULL;
746                         }
747                 }
748                 sym_arr[cnt++] = sym;
749         }
750         if (sym_arr)
751                 sym_arr[cnt] = NULL;
752         regfree(&re);
753
754         return sym_arr;
755 }
756
757
758 struct symbol *sym_check_deps(struct symbol *sym);
759
760 static struct symbol *sym_check_expr_deps(struct expr *e)
761 {
762         struct symbol *sym;
763
764         if (!e)
765                 return NULL;
766         switch (e->type) {
767         case E_OR:
768         case E_AND:
769                 sym = sym_check_expr_deps(e->left.expr);
770                 if (sym)
771                         return sym;
772                 return sym_check_expr_deps(e->right.expr);
773         case E_NOT:
774                 return sym_check_expr_deps(e->left.expr);
775         case E_EQUAL:
776         case E_UNEQUAL:
777                 sym = sym_check_deps(e->left.sym);
778                 if (sym)
779                         return sym;
780                 return sym_check_deps(e->right.sym);
781         case E_SYMBOL:
782                 return sym_check_deps(e->left.sym);
783         default:
784                 break;
785         }
786         printf("Oops! How to check %d?\n", e->type);
787         return NULL;
788 }
789
790 struct symbol *sym_check_deps(struct symbol *sym)
791 {
792         struct symbol *sym2;
793         struct property *prop;
794
795         if (sym->flags & SYMBOL_CHECK) {
796                 printf("Warning! Found recursive dependency: %s", sym->name);
797                 return sym;
798         }
799         if (sym->flags & SYMBOL_CHECKED)
800                 return NULL;
801
802         sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
803         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
804         if (sym2)
805                 goto out;
806
807         for (prop = sym->prop; prop; prop = prop->next) {
808                 if (prop->type == P_CHOICE || prop->type == P_SELECT)
809                         continue;
810                 sym2 = sym_check_expr_deps(prop->visible.expr);
811                 if (sym2)
812                         goto out;
813                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
814                         continue;
815                 sym2 = sym_check_expr_deps(prop->expr);
816                 if (sym2)
817                         goto out;
818         }
819 out:
820         if (sym2) {
821                 printf(" %s", sym->name);
822                 if (sym2 == sym) {
823                         printf("\n");
824                         sym2 = NULL;
825                 }
826         }
827         sym->flags &= ~SYMBOL_CHECK;
828         return sym2;
829 }
830
831 struct property *prop_alloc(enum prop_type type, struct symbol *sym)
832 {
833         struct property *prop;
834         struct property **propp;
835
836         prop = malloc(sizeof(*prop));
837         memset(prop, 0, sizeof(*prop));
838         prop->type = type;
839         prop->sym = sym;
840         prop->file = current_file;
841         prop->lineno = zconf_lineno();
842
843         /* append property to the prop list of symbol */
844         if (sym) {
845                 for (propp = &sym->prop; *propp; propp = &(*propp)->next)
846                         ;
847                 *propp = prop;
848         }
849
850         return prop;
851 }
852
853 struct symbol *prop_get_symbol(struct property *prop)
854 {
855         if (prop->expr && (prop->expr->type == E_SYMBOL ||
856                            prop->expr->type == E_CHOICE))
857                 return prop->expr->left.sym;
858         return NULL;
859 }
860
861 const char *prop_get_type_name(enum prop_type type)
862 {
863         switch (type) {
864         case P_PROMPT:
865                 return "prompt";
866         case P_COMMENT:
867                 return "comment";
868         case P_MENU:
869                 return "menu";
870         case P_DEFAULT:
871                 return "default";
872         case P_CHOICE:
873                 return "choice";
874         case P_SELECT:
875                 return "select";
876         case P_RANGE:
877                 return "range";
878         case P_UNKNOWN:
879                 break;
880         }
881         return "unknown";
882 }