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_YES|SYMBOL_VALID,
  19 }, symbol_mod = {
  20         .name = "m",
  21         .curr = { "m", mod },
  22         .flags = SYMBOL_MOD|SYMBOL_VALID,
  23 }, symbol_no = {
  24         .name = "n",
  25         .curr = { "n", no },
  26         .flags = SYMBOL_NO|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("KERNELRELEASE", 0);
  65         sym->type = S_STRING;
  66         sym->flags |= SYMBOL_AUTO;
  67         p = getenv("KERNELRELEASE");
  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->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->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->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->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->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->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->user.val = val = malloc(size);
 604                 *val++ = '0';
 605                 *val++ = 'x';
 606         } else if (!oldval || strcmp(oldval, newval))
 607                 sym->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 }