tools/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         tri = no;
 262         if (sym->implied.expr && sym->dir_dep.tri != no)
 263                 tri = expr_calc_value(sym->implied.expr);
 264         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 265                 tri = yes;
 266         if (sym->implied.tri != tri) {
 267                 sym->implied.tri = tri;
 268                 sym_set_changed(sym);
 269         }
 270 }
 271
 272 /*
 273  * Find the default symbol for a choice.
 274  * First try the default values for the choice symbol
 275  * Next locate the first visible choice value
 276  * Return NULL if none was found
 277  */
 278 struct symbol *sym_choice_default(struct symbol *sym)
 279 {
 280         struct symbol *def_sym;
 281         struct property *prop;
 282         struct expr *e;
 283
 284         /* any of the defaults visible? */
 285         for_all_defaults(sym, prop) {
 286                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 287                 if (prop->visible.tri == no)
 288                         continue;
 289                 def_sym = prop_get_symbol(prop);
 290                 if (def_sym->visible != no)
 291                         return def_sym;
 292         }
 293
 294         /* just get the first visible value */
 295         prop = sym_get_choice_prop(sym);
 296         expr_list_for_each_sym(prop->expr, e, def_sym)
 297                 if (def_sym->visible != no)
 298                         return def_sym;
 299
 300         /* failed to locate any defaults */
 301         return NULL;
 302 }
 303
 304 static struct symbol *sym_calc_choice(struct symbol *sym)
 305 {
 306         struct symbol *def_sym;
 307         struct property *prop;
 308         struct expr *e;
 309         int flags;
 310
 311         /* first calculate all choice values' visibilities */
 312         flags = sym->flags;
 313         prop = sym_get_choice_prop(sym);
 314         expr_list_for_each_sym(prop->expr, e, def_sym) {
 315                 sym_calc_visibility(def_sym);
 316                 if (def_sym->visible != no)
 317                         flags &= def_sym->flags;
 318         }
 319
 320         sym->flags &= flags | ~SYMBOL_DEF_USER;
 321
 322         /* is the user choice visible? */
 323         def_sym = sym->def[S_DEF_USER].val;
 324         if (def_sym && def_sym->visible != no)
 325                 return def_sym;
 326
 327         def_sym = sym_choice_default(sym);
 328
 329         if (def_sym == NULL)
 330                 /* no choice? reset tristate value */
 331                 sym->curr.tri = no;
 332
 333         return def_sym;
 334 }
 335
 336 void sym_calc_value(struct symbol *sym)
 337 {
 338         struct symbol_value newval, oldval;
 339         struct property *prop;
 340         struct expr *e;
 341
 342         if (!sym)
 343                 return;
 344
 345         if (sym->flags & SYMBOL_VALID)
 346                 return;
 347
 348         if (sym_is_choice_value(sym) &&
 349             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 350                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 351                 prop = sym_get_choice_prop(sym);
 352                 sym_calc_value(prop_get_symbol(prop));
 353         }
 354
 355         sym->flags |= SYMBOL_VALID;
 356
 357         oldval = sym->curr;
 358
 359         switch (sym->type) {
 360         case S_INT:
 361         case S_HEX:
 362         case S_STRING:
 363                 newval = symbol_empty.curr;
 364                 break;
 365         case S_BOOLEAN:
 366         case S_TRISTATE:
 367                 newval = symbol_no.curr;
 368                 break;
 369         default:
 370                 sym->curr.val = sym->name;
 371                 sym->curr.tri = no;
 372                 return;
 373         }
 374         if (!sym_is_choice_value(sym))
 375                 sym->flags &= ~SYMBOL_WRITE;
 376
 377         sym_calc_visibility(sym);
 378
 379         /* set default if recursively called */
 380         sym->curr = newval;
 381
 382         switch (sym_get_type(sym)) {
 383         case S_BOOLEAN:
 384         case S_TRISTATE:
 385                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 386                         prop = sym_get_choice_prop(sym);
 387                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 388                 } else {
 389                         if (sym->visible != no) {
 390                                 /* if the symbol is visible use the user value
 391                                  * if available, otherwise try the default value
 392                                  */
 393                                 sym->flags |= SYMBOL_WRITE;
 394                                 if (sym_has_value(sym)) {
 395                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 396                                                               sym->visible);
 397                                         goto calc_newval;
 398                                 }
 399                         }
 400                         if (sym->rev_dep.tri != no)
 401                                 sym->flags |= SYMBOL_WRITE;
 402                         if (!sym_is_choice(sym)) {
 403                                 prop = sym_get_default_prop(sym);
 404                                 if (prop) {
 405                                         sym->flags |= SYMBOL_WRITE;
 406                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 407                                                               prop->visible.tri);
 408                                 }
 409                                 if (sym->implied.tri != no) {
 410                                         sym->flags |= SYMBOL_WRITE;
 411                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 412                                 }
 413                         }
 414                 calc_newval:
 415                         if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
 416                                 struct expr *e;
 417                                 e = expr_simplify_unmet_dep(sym->rev_dep.expr,
 418                                     sym->dir_dep.expr);
 419                                 fprintf(stderr, "warning: (");
 420                                 expr_fprint(e, stderr);
 421                                 fprintf(stderr, ") selects %s which has unmet direct dependencies (",
 422                                         sym->name);
 423                                 expr_fprint(sym->dir_dep.expr, stderr);
 424                                 fprintf(stderr, ")\n");
 425                                 expr_free(e);
 426                         }
 427                         newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 428                 }
 429                 if (newval.tri == mod &&
 430                     (sym_get_type(sym) == S_BOOLEAN || sym->implied.tri == yes))
 431                         newval.tri = yes;
 432                 break;
 433         case S_STRING:
 434         case S_HEX:
 435         case S_INT:
 436                 if (sym->visible != no) {
 437                         sym->flags |= SYMBOL_WRITE;
 438                         if (sym_has_value(sym)) {
 439                                 newval.val = sym->def[S_DEF_USER].val;
 440                                 break;
 441                         }
 442                 }
 443                 prop = sym_get_default_prop(sym);
 444                 if (prop) {
 445                         struct symbol *ds = prop_get_symbol(prop);
 446                         if (ds) {
 447                                 sym->flags |= SYMBOL_WRITE;
 448                                 sym_calc_value(ds);
 449                                 newval.val = ds->curr.val;
 450                         }
 451                 }
 452                 break;
 453         default:
 454                 ;
 455         }
 456
 457         sym->curr = newval;
 458         if (sym_is_choice(sym) && newval.tri == yes)
 459                 sym->curr.val = sym_calc_choice(sym);
 460         sym_validate_range(sym);
 461
 462         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 463                 sym_set_changed(sym);
 464                 if (modules_sym == sym) {
 465                         sym_set_all_changed();
 466                         modules_val = modules_sym->curr.tri;
 467                 }
 468         }
 469
 470         if (sym_is_choice(sym)) {
 471                 struct symbol *choice_sym;
 472
 473                 prop = sym_get_choice_prop(sym);
 474                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 475                         if ((sym->flags & SYMBOL_WRITE) &&
 476                             choice_sym->visible != no)
 477                                 choice_sym->flags |= SYMBOL_WRITE;
 478                         if (sym->flags & SYMBOL_CHANGED)
 479                                 sym_set_changed(choice_sym);
 480                 }
 481         }
 482
 483         if (sym->flags & SYMBOL_AUTO)
 484                 sym->flags &= ~SYMBOL_WRITE;
 485
 486         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 487                 set_all_choice_values(sym);
 488 }
 489
 490 void sym_clear_all_valid(void)
 491 {
 492         struct symbol *sym;
 493         int i;
 494
 495         for_all_symbols(i, sym)
 496                 sym->flags &= ~SYMBOL_VALID;
 497         sym_add_change_count(1);
 498         sym_calc_value(modules_sym);
 499 }
 500
 501 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 502 {
 503         int type = sym_get_type(sym);
 504
 505         if (sym->visible == no)
 506                 return false;
 507
 508         if (type != S_BOOLEAN && type != S_TRISTATE)
 509                 return false;
 510
 511         if (type == S_BOOLEAN && val == mod)
 512                 return false;
 513         if (sym->visible <= sym->rev_dep.tri)
 514                 return false;
 515         if (sym->implied.tri == yes && val == mod)
 516                 return false;
 517         if (sym_is_choice_value(sym) && sym->visible == yes)
 518                 return val == yes;
 519         return val >= sym->rev_dep.tri && val <= sym->visible;
 520 }
 521
 522 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 523 {
 524         tristate oldval = sym_get_tristate_value(sym);
 525
 526         if (oldval != val && !sym_tristate_within_range(sym, val))
 527                 return false;
 528
 529         if (!(sym->flags & SYMBOL_DEF_USER)) {
 530                 sym->flags |= SYMBOL_DEF_USER;
 531                 sym_set_changed(sym);
 532         }
 533         /*
 534          * setting a choice value also resets the new flag of the choice
 535          * symbol and all other choice values.
 536          */
 537         if (sym_is_choice_value(sym) && val == yes) {
 538                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 539                 struct property *prop;
 540                 struct expr *e;
 541
 542                 cs->def[S_DEF_USER].val = sym;
 543                 cs->flags |= SYMBOL_DEF_USER;
 544                 prop = sym_get_choice_prop(cs);
 545                 for (e = prop->expr; e; e = e->left.expr) {
 546                         if (e->right.sym->visible != no)
 547                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 548                 }
 549         }
 550
 551         sym->def[S_DEF_USER].tri = val;
 552         if (oldval != val)
 553                 sym_clear_all_valid();
 554
 555         return true;
 556 }
 557
 558 tristate sym_toggle_tristate_value(struct symbol *sym)
 559 {
 560         tristate oldval, newval;
 561
 562         oldval = newval = sym_get_tristate_value(sym);
 563         do {
 564                 switch (newval) {
 565                 case no:
 566                         newval = mod;
 567                         break;
 568                 case mod:
 569                         newval = yes;
 570                         break;
 571                 case yes:
 572                         newval = no;
 573                         break;
 574                 }
 575                 if (sym_set_tristate_value(sym, newval))
 576                         break;
 577         } while (oldval != newval);
 578         return newval;
 579 }
 580
 581 bool sym_string_valid(struct symbol *sym, const char *str)
 582 {
 583         signed char ch;
 584
 585         switch (sym->type) {
 586         case S_STRING:
 587                 return true;
 588         case S_INT:
 589                 ch = *str++;
 590                 if (ch == '-')
 591                         ch = *str++;
 592                 if (!isdigit(ch))
 593                         return false;
 594                 if (ch == '0' && *str != 0)
 595                         return false;
 596                 while ((ch = *str++)) {
 597                         if (!isdigit(ch))
 598                                 return false;
 599                 }
 600                 return true;
 601         case S_HEX:
 602                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 603                         str += 2;
 604                 ch = *str++;
 605                 do {
 606                         if (!isxdigit(ch))
 607                                 return false;
 608                 } while ((ch = *str++));
 609                 return true;
 610         case S_BOOLEAN:
 611         case S_TRISTATE:
 612                 switch (str[0]) {
 613                 case 'y': case 'Y':
 614                 case 'm': case 'M':
 615                 case 'n': case 'N':
 616                         return true;
 617                 }
 618                 return false;
 619         default:
 620                 return false;
 621         }
 622 }
 623
 624 bool sym_string_within_range(struct symbol *sym, const char *str)
 625 {
 626         struct property *prop;
 627         long long val;
 628
 629         switch (sym->type) {
 630         case S_STRING:
 631                 return sym_string_valid(sym, str);
 632         case S_INT:
 633                 if (!sym_string_valid(sym, str))
 634                         return false;
 635                 prop = sym_get_range_prop(sym);
 636                 if (!prop)
 637                         return true;
 638                 val = strtoll(str, NULL, 10);
 639                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 640                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 641         case S_HEX:
 642                 if (!sym_string_valid(sym, str))
 643                         return false;
 644                 prop = sym_get_range_prop(sym);
 645                 if (!prop)
 646                         return true;
 647                 val = strtoll(str, NULL, 16);
 648                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 649                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 650         case S_BOOLEAN:
 651         case S_TRISTATE:
 652                 switch (str[0]) {
 653                 case 'y': case 'Y':
 654                         return sym_tristate_within_range(sym, yes);
 655                 case 'm': case 'M':
 656                         return sym_tristate_within_range(sym, mod);
 657                 case 'n': case 'N':
 658                         return sym_tristate_within_range(sym, no);
 659                 }
 660                 return false;
 661         default:
 662                 return false;
 663         }
 664 }
 665
 666 bool sym_set_string_value(struct symbol *sym, const char *newval)
 667 {
 668         const char *oldval;
 669         char *val;
 670         int size;
 671
 672         switch (sym->type) {
 673         case S_BOOLEAN:
 674         case S_TRISTATE:
 675                 switch (newval[0]) {
 676                 case 'y': case 'Y':
 677                         return sym_set_tristate_value(sym, yes);
 678                 case 'm': case 'M':
 679                         return sym_set_tristate_value(sym, mod);
 680                 case 'n': case 'N':
 681                         return sym_set_tristate_value(sym, no);
 682                 }
 683                 return false;
 684         default:
 685                 ;
 686         }
 687
 688         if (!sym_string_within_range(sym, newval))
 689                 return false;
 690
 691         if (!(sym->flags & SYMBOL_DEF_USER)) {
 692                 sym->flags |= SYMBOL_DEF_USER;
 693                 sym_set_changed(sym);
 694         }
 695
 696         oldval = sym->def[S_DEF_USER].val;
 697         size = strlen(newval) + 1;
 698         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 699                 size += 2;
 700                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 701                 *val++ = '0';
 702                 *val++ = 'x';
 703         } else if (!oldval || strcmp(oldval, newval))
 704                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 705         else
 706                 return true;
 707
 708         strcpy(val, newval);
 709         free((void *)oldval);
 710         sym_clear_all_valid();
 711
 712         return true;
 713 }
 714
 715 /*
 716  * Find the default value associated to a symbol.
 717  * For tristate symbol handle the modules=n case
 718  * in which case "m" becomes "y".
 719  * If the symbol does not have any default then fallback
 720  * to the fixed default values.
 721  */
 722 const char *sym_get_string_default(struct symbol *sym)
 723 {
 724         struct property *prop;
 725         struct symbol *ds;
 726         const char *str;
 727         tristate val;
 728
 729         sym_calc_visibility(sym);
 730         sym_calc_value(modules_sym);
 731         val = symbol_no.curr.tri;
 732         str = symbol_empty.curr.val;
 733
 734         /* If symbol has a default value look it up */
 735         prop = sym_get_default_prop(sym);
 736         if (prop != NULL) {
 737                 switch (sym->type) {
 738                 case S_BOOLEAN:
 739                 case S_TRISTATE:
 740                         /* The visibility may limit the value from yes => mod */
 741                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 742                         break;
 743                 default:
 744                         /*
 745                          * The following fails to handle the situation
 746                          * where a default value is further limited by
 747                          * the valid range.
 748                          */
 749                         ds = prop_get_symbol(prop);
 750                         if (ds != NULL) {
 751                                 sym_calc_value(ds);
 752                                 str = (const char *)ds->curr.val;
 753                         }
 754                 }
 755         }
 756
 757         /* Handle select statements */
 758         val = EXPR_OR(val, sym->rev_dep.tri);
 759
 760         /* transpose mod to yes if modules are not enabled */
 761         if (val == mod)
 762                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 763                         val = yes;
 764
 765         /* transpose mod to yes if type is bool */
 766         if (sym->type == S_BOOLEAN && val == mod)
 767                 val = yes;
 768
 769         /* adjust the default value if this symbol is implied by another */
 770         if (val < sym->implied.tri)
 771                 val = sym->implied.tri;
 772
 773         switch (sym->type) {
 774         case S_BOOLEAN:
 775         case S_TRISTATE:
 776                 switch (val) {
 777                 case no: return "n";
 778                 case mod: return "m";
 779                 case yes: return "y";
 780                 }
 781         case S_INT:
 782         case S_HEX:
 783                 return str;
 784         case S_STRING:
 785                 return str;
 786         case S_OTHER:
 787         case S_UNKNOWN:
 788                 break;
 789         }
 790         return "";
 791 }
 792
 793 const char *sym_get_string_value(struct symbol *sym)
 794 {
 795         tristate val;
 796
 797         switch (sym->type) {
 798         case S_BOOLEAN:
 799         case S_TRISTATE:
 800                 val = sym_get_tristate_value(sym);
 801                 switch (val) {
 802                 case no:
 803                         return "n";
 804                 case mod:
 805                         sym_calc_value(modules_sym);
 806                         return (modules_sym->curr.tri == no) ? "n" : "m";
 807                 case yes:
 808                         return "y";
 809                 }
 810                 break;
 811         default:
 812                 ;
 813         }
 814         return (const char *)sym->curr.val;
 815 }
 816
 817 bool sym_is_changable(struct symbol *sym)
 818 {
 819         return sym->visible > sym->rev_dep.tri;
 820 }
 821
 822 static unsigned strhash(const char *s)
 823 {
 824         /* fnv32 hash */
 825         unsigned hash = 2166136261U;
 826         for (; *s; s++)
 827                 hash = (hash ^ *s) * 0x01000193;
 828         return hash;
 829 }
 830
 831 struct symbol *sym_lookup(const char *name, int flags)
 832 {
 833         struct symbol *symbol;
 834         char *new_name;
 835         int hash;
 836
 837         if (name) {
 838                 if (name[0] && !name[1]) {
 839                         switch (name[0]) {
 840                         case 'y': return &symbol_yes;
 841                         case 'm': return &symbol_mod;
 842                         case 'n': return &symbol_no;
 843                         }
 844                 }
 845                 hash = strhash(name) % SYMBOL_HASHSIZE;
 846
 847                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 848                         if (symbol->name &&
 849                             !strcmp(symbol->name, name) &&
 850                             (flags ? symbol->flags & flags
 851                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 852                                 return symbol;
 853                 }
 854                 new_name = strdup(name);
 855         } else {
 856                 new_name = NULL;
 857                 hash = 0;
 858         }
 859
 860         symbol = xmalloc(sizeof(*symbol));
 861         memset(symbol, 0, sizeof(*symbol));
 862         symbol->name = new_name;
 863         symbol->type = S_UNKNOWN;
 864         symbol->flags |= flags;
 865
 866         symbol->next = symbol_hash[hash];
 867         symbol_hash[hash] = symbol;
 868
 869         return symbol;
 870 }
 871
 872 struct symbol *sym_find(const char *name)
 873 {
 874         struct symbol *symbol = NULL;
 875         int hash = 0;
 876
 877         if (!name)
 878                 return NULL;
 879
 880         if (name[0] && !name[1]) {
 881                 switch (name[0]) {
 882                 case 'y': return &symbol_yes;
 883                 case 'm': return &symbol_mod;
 884                 case 'n': return &symbol_no;
 885                 }
 886         }
 887         hash = strhash(name) % SYMBOL_HASHSIZE;
 888
 889         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 890                 if (symbol->name &&
 891                     !strcmp(symbol->name, name) &&
 892                     !(symbol->flags & SYMBOL_CONST))
 893                                 break;
 894         }
 895
 896         return symbol;
 897 }
 898
 899 /*
 900  * Expand symbol's names embedded in the string given in argument. Symbols'
 901  * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
 902  * the empty string.
 903  */
 904 const char *sym_expand_string_value(const char *in)
 905 {
 906         const char *src;
 907         char *res;
 908         size_t reslen;
 909
 910         reslen = strlen(in) + 1;
 911         res = xmalloc(reslen);
 912         res[0] = '\0';
 913
 914         while ((src = strchr(in, '$'))) {
 915                 char *p, name[SYMBOL_MAXLENGTH];
 916                 const char *symval = "";
 917                 struct symbol *sym;
 918                 size_t newlen;
 919
 920                 strncat(res, in, src - in);
 921                 src++;
 922
 923                 p = name;
 924                 while (isalnum(*src) || *src == '_')
 925                         *p++ = *src++;
 926                 *p = '\0';
 927
 928                 sym = sym_find(name);
 929                 if (sym != NULL) {
 930                         sym_calc_value(sym);
 931                         symval = sym_get_string_value(sym);
 932                 }
 933
 934                 newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
 935                 if (newlen > reslen) {
 936                         reslen = newlen;
 937                         res = realloc(res, reslen);
 938                 }
 939
 940                 strcat(res, symval);
 941                 in = src;
 942         }
 943         strcat(res, in);
 944
 945         return res;
 946 }
 947
 948 const char *sym_escape_string_value(const char *in)
 949 {
 950         const char *p;
 951         size_t reslen;
 952         char *res;
 953         size_t l;
 954
 955         reslen = strlen(in) + strlen("\"\"") + 1;
 956
 957         p = in;
 958         for (;;) {
 959                 l = strcspn(p, "\"\\");
 960                 p += l;
 961
 962                 if (p[0] == '\0')
 963                         break;
 964
 965                 reslen++;
 966                 p++;
 967         }
 968
 969         res = xmalloc(reslen);
 970         res[0] = '\0';
 971
 972         strcat(res, "\"");
 973
 974         p = in;
 975         for (;;) {
 976                 l = strcspn(p, "\"\\");
 977                 strncat(res, p, l);
 978                 p += l;
 979
 980                 if (p[0] == '\0')
 981                         break;
 982
 983                 strcat(res, "\\");
 984                 strncat(res, p++, 1);
 985         }
 986
 987         strcat(res, "\"");
 988         return res;
 989 }
 990
 991 struct sym_match {
 992         struct symbol   *sym;
 993         off_t           so, eo;
 994 };
 995
 996 /* Compare matched symbols as thus:
 997  * - first, symbols that match exactly
 998  * - then, alphabetical sort
 999  */
1000 static int sym_rel_comp(const void *sym1, const void *sym2)
1001 {
1002         const struct sym_match *s1 = sym1;
1003         const struct sym_match *s2 = sym2;
1004         int exact1, exact2;
1005
1006         /* Exact match:
1007          * - if matched length on symbol s1 is the length of that symbol,
1008          *   then this symbol should come first;
1009          * - if matched length on symbol s2 is the length of that symbol,
1010          *   then this symbol should come first.
1011          * Note: since the search can be a regexp, both symbols may match
1012          * exactly; if this is the case, we can't decide which comes first,
1013          * and we fallback to sorting alphabetically.
1014          */
1015         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
1016         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
1017         if (exact1 && !exact2)
1018                 return -1;
1019         if (!exact1 && exact2)
1020                 return 1;
1021
1022         /* As a fallback, sort symbols alphabetically */
1023         return strcmp(s1->sym->name, s2->sym->name);
1024 }
1025
1026 struct symbol **sym_re_search(const char *pattern)
1027 {
1028         struct symbol *sym, **sym_arr = NULL;
1029         struct sym_match *sym_match_arr = NULL;
1030         int i, cnt, size;
1031         regex_t re;
1032         regmatch_t match[1];
1033
1034         cnt = size = 0;
1035         /* Skip if empty */
1036         if (strlen(pattern) == 0)
1037                 return NULL;
1038         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
1039                 return NULL;
1040
1041         for_all_symbols(i, sym) {
1042                 if (sym->flags & SYMBOL_CONST || !sym->name)
1043                         continue;
1044                 if (regexec(&re, sym->name, 1, match, 0))
1045                         continue;
1046                 if (cnt >= size) {
1047                         void *tmp;
1048                         size += 16;
1049                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
1050                         if (!tmp)
1051                                 goto sym_re_search_free;
1052                         sym_match_arr = tmp;
1053                 }
1054                 sym_calc_value(sym);
1055                 /* As regexec returned 0, we know we have a match, so
1056                  * we can use match[0].rm_[se]o without further checks
1057                  */
1058                 sym_match_arr[cnt].so = match[0].rm_so;
1059                 sym_match_arr[cnt].eo = match[0].rm_eo;
1060                 sym_match_arr[cnt++].sym = sym;
1061         }
1062         if (sym_match_arr) {
1063                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
1064                 sym_arr = malloc((cnt+1) * sizeof(struct symbol));
1065                 if (!sym_arr)
1066                         goto sym_re_search_free;
1067                 for (i = 0; i < cnt; i++)
1068                         sym_arr[i] = sym_match_arr[i].sym;
1069                 sym_arr[cnt] = NULL;
1070         }
1071 sym_re_search_free:
1072         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
1073         free(sym_match_arr);
1074         regfree(&re);
1075
1076         return sym_arr;
1077 }
1078
1079 /*
1080  * When we check for recursive dependencies we use a stack to save
1081  * current state so we can print out relevant info to user.
1082  * The entries are located on the call stack so no need to free memory.
1083  * Note insert() remove() must always match to properly clear the stack.
1084  */
1085 static struct dep_stack {
1086         struct dep_stack *prev, *next;
1087         struct symbol *sym;
1088         struct property *prop;
1089         struct expr *expr;
1090 } *check_top;
1091
1092 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1093 {
1094         memset(stack, 0, sizeof(*stack));
1095         if (check_top)
1096                 check_top->next = stack;
1097         stack->prev = check_top;
1098         stack->sym = sym;
1099         check_top = stack;
1100 }
1101
1102 static void dep_stack_remove(void)
1103 {
1104         check_top = check_top->prev;
1105         if (check_top)
1106                 check_top->next = NULL;
1107 }
1108
1109 /*
1110  * Called when we have detected a recursive dependency.
1111  * check_top point to the top of the stact so we use
1112  * the ->prev pointer to locate the bottom of the stack.
1113  */
1114 static void sym_check_print_recursive(struct symbol *last_sym)
1115 {
1116         struct dep_stack *stack;
1117         struct symbol *sym, *next_sym;
1118         struct menu *menu = NULL;
1119         struct property *prop;
1120         struct dep_stack cv_stack;
1121
1122         if (sym_is_choice_value(last_sym)) {
1123                 dep_stack_insert(&cv_stack, last_sym);
1124                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1125         }
1126
1127         for (stack = check_top; stack != NULL; stack = stack->prev)
1128                 if (stack->sym == last_sym)
1129                         break;
1130         if (!stack) {
1131                 fprintf(stderr, "unexpected recursive dependency error\n");
1132                 return;
1133         }
1134
1135         for (; stack; stack = stack->next) {
1136                 sym = stack->sym;
1137                 next_sym = stack->next ? stack->next->sym : last_sym;
1138                 prop = stack->prop;
1139                 if (prop == NULL)
1140                         prop = stack->sym->prop;
1141
1142                 /* for choice values find the menu entry (used below) */
1143                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1144                         for (prop = sym->prop; prop; prop = prop->next) {
1145                                 menu = prop->menu;
1146                                 if (prop->menu)
1147                                         break;
1148                         }
1149                 }
1150                 if (stack->sym == last_sym) {
1151                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1152                                 prop->file->name, prop->lineno);
1153                         fprintf(stderr, "For a resolution refer to Documentation/kbuild/kconfig-language.txt\n");
1154                         fprintf(stderr, "subsection \"Kconfig recursive dependency limitations\"\n");
1155                 }
1156                 if (stack->expr) {
1157                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1158                                 prop->file->name, prop->lineno,
1159                                 sym->name ? sym->name : "<choice>",
1160                                 prop_get_type_name(prop->type),
1161                                 next_sym->name ? next_sym->name : "<choice>");
1162                 } else if (stack->prop) {
1163                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1164                                 prop->file->name, prop->lineno,
1165                                 sym->name ? sym->name : "<choice>",
1166                                 next_sym->name ? next_sym->name : "<choice>");
1167                 } else if (sym_is_choice(sym)) {
1168                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1169                                 menu->file->name, menu->lineno,
1170                                 sym->name ? sym->name : "<choice>",
1171                                 next_sym->name ? next_sym->name : "<choice>");
1172                 } else if (sym_is_choice_value(sym)) {
1173                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1174                                 menu->file->name, menu->lineno,
1175                                 sym->name ? sym->name : "<choice>",
1176                                 next_sym->name ? next_sym->name : "<choice>");
1177                 } else {
1178                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1179                                 prop->file->name, prop->lineno,
1180                                 sym->name ? sym->name : "<choice>",
1181                                 next_sym->name ? next_sym->name : "<choice>");
1182                 }
1183         }
1184
1185         if (check_top == &cv_stack)
1186                 dep_stack_remove();
1187 }
1188
1189 static struct symbol *sym_check_expr_deps(struct expr *e)
1190 {
1191         struct symbol *sym;
1192
1193         if (!e)
1194                 return NULL;
1195         switch (e->type) {
1196         case E_OR:
1197         case E_AND:
1198                 sym = sym_check_expr_deps(e->left.expr);
1199                 if (sym)
1200                         return sym;
1201                 return sym_check_expr_deps(e->right.expr);
1202         case E_NOT:
1203                 return sym_check_expr_deps(e->left.expr);
1204         case E_EQUAL:
1205         case E_GEQ:
1206         case E_GTH:
1207         case E_LEQ:
1208         case E_LTH:
1209         case E_UNEQUAL:
1210                 sym = sym_check_deps(e->left.sym);
1211                 if (sym)
1212                         return sym;
1213                 return sym_check_deps(e->right.sym);
1214         case E_SYMBOL:
1215                 return sym_check_deps(e->left.sym);
1216         default:
1217                 break;
1218         }
1219         printf("Oops! How to check %d?\n", e->type);
1220         return NULL;
1221 }
1222
1223 /* return NULL when dependencies are OK */
1224 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1225 {
1226         struct symbol *sym2;
1227         struct property *prop;
1228         struct dep_stack stack;
1229
1230         dep_stack_insert(&stack, sym);
1231
1232         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1233         if (sym2)
1234                 goto out;
1235
1236         for (prop = sym->prop; prop; prop = prop->next) {
1237                 if (prop->type == P_CHOICE || prop->type == P_SELECT)
1238                         continue;
1239                 stack.prop = prop;
1240                 sym2 = sym_check_expr_deps(prop->visible.expr);
1241                 if (sym2)
1242                         break;
1243                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1244                         continue;
1245                 stack.expr = prop->expr;
1246                 sym2 = sym_check_expr_deps(prop->expr);
1247                 if (sym2)
1248                         break;
1249                 stack.expr = NULL;
1250         }
1251
1252 out:
1253         dep_stack_remove();
1254
1255         return sym2;
1256 }
1257
1258 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1259 {
1260         struct symbol *sym, *sym2;
1261         struct property *prop;
1262         struct expr *e;
1263         struct dep_stack stack;
1264
1265         dep_stack_insert(&stack, choice);
1266
1267         prop = sym_get_choice_prop(choice);
1268         expr_list_for_each_sym(prop->expr, e, sym)
1269                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1270
1271         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1272         sym2 = sym_check_sym_deps(choice);
1273         choice->flags &= ~SYMBOL_CHECK;
1274         if (sym2)
1275                 goto out;
1276
1277         expr_list_for_each_sym(prop->expr, e, sym) {
1278                 sym2 = sym_check_sym_deps(sym);
1279                 if (sym2)
1280                         break;
1281         }
1282 out:
1283         expr_list_for_each_sym(prop->expr, e, sym)
1284                 sym->flags &= ~SYMBOL_CHECK;
1285
1286         if (sym2 && sym_is_choice_value(sym2) &&
1287             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1288                 sym2 = choice;
1289
1290         dep_stack_remove();
1291
1292         return sym2;
1293 }
1294
1295 struct symbol *sym_check_deps(struct symbol *sym)
1296 {
1297         struct symbol *sym2;
1298         struct property *prop;
1299
1300         if (sym->flags & SYMBOL_CHECK) {
1301                 sym_check_print_recursive(sym);
1302                 return sym;
1303         }
1304         if (sym->flags & SYMBOL_CHECKED)
1305                 return NULL;
1306
1307         if (sym_is_choice_value(sym)) {
1308                 struct dep_stack stack;
1309
1310                 /* for choice groups start the check with main choice symbol */
1311                 dep_stack_insert(&stack, sym);
1312                 prop = sym_get_choice_prop(sym);
1313                 sym2 = sym_check_deps(prop_get_symbol(prop));
1314                 dep_stack_remove();
1315         } else if (sym_is_choice(sym)) {
1316                 sym2 = sym_check_choice_deps(sym);
1317         } else {
1318                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1319                 sym2 = sym_check_sym_deps(sym);
1320                 sym->flags &= ~SYMBOL_CHECK;
1321         }
1322
1323         if (sym2 && sym2 == sym)
1324                 sym2 = NULL;
1325
1326         return sym2;
1327 }
1328
1329 struct property *prop_alloc(enum prop_type type, struct symbol *sym)
1330 {
1331         struct property *prop;
1332         struct property **propp;
1333
1334         prop = xmalloc(sizeof(*prop));
1335         memset(prop, 0, sizeof(*prop));
1336         prop->type = type;
1337         prop->sym = sym;
1338         prop->file = current_file;
1339         prop->lineno = zconf_lineno();
1340
1341         /* append property to the prop list of symbol */
1342         if (sym) {
1343                 for (propp = &sym->prop; *propp; propp = &(*propp)->next)
1344                         ;
1345                 *propp = prop;
1346         }
1347
1348         return prop;
1349 }
1350
1351 struct symbol *prop_get_symbol(struct property *prop)
1352 {
1353         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1354                            prop->expr->type == E_LIST))
1355                 return prop->expr->left.sym;
1356         return NULL;
1357 }
1358
1359 const char *prop_get_type_name(enum prop_type type)
1360 {
1361         switch (type) {
1362         case P_PROMPT:
1363                 return "prompt";
1364         case P_ENV:
1365                 return "env";
1366         case P_COMMENT:
1367                 return "comment";
1368         case P_MENU:
1369                 return "menu";
1370         case P_DEFAULT:
1371                 return "default";
1372         case P_CHOICE:
1373                 return "choice";
1374         case P_SELECT:
1375                 return "select";
1376         case P_IMPLY:
1377                 return "imply";
1378         case P_RANGE:
1379                 return "range";
1380         case P_SYMBOL:
1381                 return "symbol";
1382         case P_UNKNOWN:
1383                 break;
1384         }
1385         return "unknown";
1386 }
1387
1388 static void prop_add_env(const char *env)
1389 {
1390         struct symbol *sym, *sym2;
1391         struct property *prop;
1392         char *p;
1393
1394         sym = current_entry->sym;
1395         sym->flags |= SYMBOL_AUTO;
1396         for_all_properties(sym, prop, P_ENV) {
1397                 sym2 = prop_get_symbol(prop);
1398                 if (strcmp(sym2->name, env))
1399                         menu_warn(current_entry, "redefining environment symbol from %s",
1400                                   sym2->name);
1401                 return;
1402         }
1403
1404         prop = prop_alloc(P_ENV, sym);
1405         prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
1406
1407         sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
1408         sym_env_list->right.sym = sym;
1409
1410         p = getenv(env);
1411         if (p)
1412                 sym_add_default(sym, p);
1413         else
1414                 menu_warn(current_entry, "environment variable %s undefined", env);
1415 }