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 #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 }