config/symbol.c

   1 /*
   2  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   3  * Released under the terms of the GNU GPL v2.0.
   4  */
   5
   6 #include <ctype.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <regex.h>
  10 #include <sys/utsname.h>
  11
  12 #include "lkc.h"
  13
  14 struct symbol symbol_yes = {
  15         .name = "y",
  16         .curr = { "y", yes },
  17         .flags = SYMBOL_CONST|SYMBOL_VALID,
  18 }, symbol_mod = {
  19         .name = "m",
  20         .curr = { "m", mod },
  21         .flags = SYMBOL_CONST|SYMBOL_VALID,
  22 }, symbol_no = {
  23         .name = "n",
  24         .curr = { "n", no },
  25         .flags = SYMBOL_CONST|SYMBOL_VALID,
  26 }, symbol_empty = {
  27         .name = "",
  28         .curr = { "", no },
  29         .flags = SYMBOL_VALID,
  30 };
  31
  32 struct symbol *sym_defconfig_list;
  33 struct symbol *modules_sym;
  34 tristate modules_val;
  35
  36 struct expr *sym_env_list;
  37
  38 static void sym_add_default(struct symbol *sym, const char *def)
  39 {
  40         struct property *prop = prop_alloc(P_DEFAULT, sym);
  41
  42         prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));
  43 }
  44
  45 void sym_init(void)
  46 {
  47         struct symbol *sym;
  48         struct utsname uts;
  49         static bool inited = false;
  50
  51         if (inited)
  52                 return;
  53         inited = true;
  54
  55         uname(&uts);
  56
  57         sym = sym_lookup("UNAME_RELEASE", 0);
  58         sym->type = S_STRING;
  59         sym->flags |= SYMBOL_AUTO;
  60         sym_add_default(sym, uts.release);
  61 }
  62
  63 enum symbol_type sym_get_type(struct symbol *sym)
  64 {
  65         enum symbol_type type = sym->type;
  66
  67         if (type == S_TRISTATE) {
  68                 if (sym_is_choice_value(sym) && sym->visible == yes)
  69                         type = S_BOOLEAN;
  70                 else if (modules_val == no)
  71                         type = S_BOOLEAN;
  72         }
  73         return type;
  74 }
  75
  76 const char *sym_type_name(enum symbol_type type)
  77 {
  78         switch (type) {
  79         case S_BOOLEAN:
  80                 return "bool";
  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 = xstrdup(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 && sym_get_type(sym) == S_BOOLEAN)
 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 static void sym_warn_unmet_dep(struct symbol *sym)
 337 {
 338         struct gstr gs = str_new();
 339
 340         str_printf(&gs,
 341                    "\nWARNING: unmet direct dependencies detected for %s\n",
 342                    sym->name);
 343         str_printf(&gs,
 344                    "  Depends on [%c]: ",
 345                    sym->dir_dep.tri == mod ? 'm' : 'n');
 346         expr_gstr_print(sym->dir_dep.expr, &gs);
 347         str_printf(&gs, "\n");
 348
 349         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
 350                                "  Selected by [y]:\n");
 351         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
 352                                "  Selected by [m]:\n");
 353
 354         fputs(str_get(&gs), stderr);
 355 }
 356
 357 void sym_calc_value(struct symbol *sym)
 358 {
 359         struct symbol_value newval, oldval;
 360         struct property *prop;
 361         struct expr *e;
 362
 363         if (!sym)
 364                 return;
 365
 366         if (sym->flags & SYMBOL_VALID)
 367                 return;
 368
 369         if (sym_is_choice_value(sym) &&
 370             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 371                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 372                 prop = sym_get_choice_prop(sym);
 373                 sym_calc_value(prop_get_symbol(prop));
 374         }
 375
 376         sym->flags |= SYMBOL_VALID;
 377
 378         oldval = sym->curr;
 379
 380         switch (sym->type) {
 381         case S_INT:
 382         case S_HEX:
 383         case S_STRING:
 384                 newval = symbol_empty.curr;
 385                 break;
 386         case S_BOOLEAN:
 387         case S_TRISTATE:
 388                 newval = symbol_no.curr;
 389                 break;
 390         default:
 391                 sym->curr.val = sym->name;
 392                 sym->curr.tri = no;
 393                 return;
 394         }
 395         sym->flags &= ~SYMBOL_WRITE;
 396
 397         sym_calc_visibility(sym);
 398
 399         if (sym->visible != no)
 400                 sym->flags |= SYMBOL_WRITE;
 401
 402         /* set default if recursively called */
 403         sym->curr = newval;
 404
 405         switch (sym_get_type(sym)) {
 406         case S_BOOLEAN:
 407         case S_TRISTATE:
 408                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 409                         prop = sym_get_choice_prop(sym);
 410                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 411                 } else {
 412                         if (sym->visible != no) {
 413                                 /* if the symbol is visible use the user value
 414                                  * if available, otherwise try the default value
 415                                  */
 416                                 if (sym_has_value(sym)) {
 417                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 418                                                               sym->visible);
 419                                         goto calc_newval;
 420                                 }
 421                         }
 422                         if (sym->rev_dep.tri != no)
 423                                 sym->flags |= SYMBOL_WRITE;
 424                         if (!sym_is_choice(sym)) {
 425                                 prop = sym_get_default_prop(sym);
 426                                 if (prop) {
 427                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 428                                                               prop->visible.tri);
 429                                         if (newval.tri != no)
 430                                                 sym->flags |= SYMBOL_WRITE;
 431                                 }
 432                                 if (sym->implied.tri != no) {
 433                                         sym->flags |= SYMBOL_WRITE;
 434                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 435                                 }
 436                         }
 437                 calc_newval:
 438                         if (sym->dir_dep.tri < sym->rev_dep.tri)
 439                                 sym_warn_unmet_dep(sym);
 440                         newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 441                 }
 442                 if (newval.tri == mod &&
 443                     (sym_get_type(sym) == S_BOOLEAN || sym->implied.tri == yes))
 444                         newval.tri = yes;
 445                 break;
 446         case S_STRING:
 447         case S_HEX:
 448         case S_INT:
 449                 if (sym->visible != no && sym_has_value(sym)) {
 450                         newval.val = sym->def[S_DEF_USER].val;
 451                         break;
 452                 }
 453                 prop = sym_get_default_prop(sym);
 454                 if (prop) {
 455                         struct symbol *ds = prop_get_symbol(prop);
 456                         if (ds) {
 457                                 sym->flags |= SYMBOL_WRITE;
 458                                 sym_calc_value(ds);
 459                                 newval.val = ds->curr.val;
 460                         }
 461                 }
 462                 break;
 463         default:
 464                 ;
 465         }
 466
 467         sym->curr = newval;
 468         if (sym_is_choice(sym) && newval.tri == yes)
 469                 sym->curr.val = sym_calc_choice(sym);
 470         sym_validate_range(sym);
 471
 472         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 473                 sym_set_changed(sym);
 474                 if (modules_sym == sym) {
 475                         sym_set_all_changed();
 476                         modules_val = modules_sym->curr.tri;
 477                 }
 478         }
 479
 480         if (sym_is_choice(sym)) {
 481                 struct symbol *choice_sym;
 482
 483                 prop = sym_get_choice_prop(sym);
 484                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 485                         if ((sym->flags & SYMBOL_WRITE) &&
 486                             choice_sym->visible != no)
 487                                 choice_sym->flags |= SYMBOL_WRITE;
 488                         if (sym->flags & SYMBOL_CHANGED)
 489                                 sym_set_changed(choice_sym);
 490                 }
 491         }
 492
 493         if (sym->flags & SYMBOL_AUTO)
 494                 sym->flags &= ~SYMBOL_WRITE;
 495
 496         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 497                 set_all_choice_values(sym);
 498 }
 499
 500 void sym_clear_all_valid(void)
 501 {
 502         struct symbol *sym;
 503         int i;
 504
 505         for_all_symbols(i, sym)
 506                 sym->flags &= ~SYMBOL_VALID;
 507         sym_add_change_count(1);
 508         sym_calc_value(modules_sym);
 509 }
 510
 511 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 512 {
 513         int type = sym_get_type(sym);
 514
 515         if (sym->visible == no)
 516                 return false;
 517
 518         if (type != S_BOOLEAN && type != S_TRISTATE)
 519                 return false;
 520
 521         if (type == S_BOOLEAN && val == mod)
 522                 return false;
 523         if (sym->visible <= sym->rev_dep.tri)
 524                 return false;
 525         if (sym->implied.tri == yes && val == mod)
 526                 return false;
 527         if (sym_is_choice_value(sym) && sym->visible == yes)
 528                 return val == yes;
 529         return val >= sym->rev_dep.tri && val <= sym->visible;
 530 }
 531
 532 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 533 {
 534         tristate oldval = sym_get_tristate_value(sym);
 535
 536         if (oldval != val && !sym_tristate_within_range(sym, val))
 537                 return false;
 538
 539         if (!(sym->flags & SYMBOL_DEF_USER)) {
 540                 sym->flags |= SYMBOL_DEF_USER;
 541                 sym_set_changed(sym);
 542         }
 543         /*
 544          * setting a choice value also resets the new flag of the choice
 545          * symbol and all other choice values.
 546          */
 547         if (sym_is_choice_value(sym) && val == yes) {
 548                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 549                 struct property *prop;
 550                 struct expr *e;
 551
 552                 cs->def[S_DEF_USER].val = sym;
 553                 cs->flags |= SYMBOL_DEF_USER;
 554                 prop = sym_get_choice_prop(cs);
 555                 for (e = prop->expr; e; e = e->left.expr) {
 556                         if (e->right.sym->visible != no)
 557                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 558                 }
 559         }
 560
 561         sym->def[S_DEF_USER].tri = val;
 562         if (oldval != val)
 563                 sym_clear_all_valid();
 564
 565         return true;
 566 }
 567
 568 tristate sym_toggle_tristate_value(struct symbol *sym)
 569 {
 570         tristate oldval, newval;
 571
 572         oldval = newval = sym_get_tristate_value(sym);
 573         do {
 574                 switch (newval) {
 575                 case no:
 576                         newval = mod;
 577                         break;
 578                 case mod:
 579                         newval = yes;
 580                         break;
 581                 case yes:
 582                         newval = no;
 583                         break;
 584                 }
 585                 if (sym_set_tristate_value(sym, newval))
 586                         break;
 587         } while (oldval != newval);
 588         return newval;
 589 }
 590
 591 bool sym_string_valid(struct symbol *sym, const char *str)
 592 {
 593         signed char ch;
 594
 595         switch (sym->type) {
 596         case S_STRING:
 597                 return true;
 598         case S_INT:
 599                 ch = *str++;
 600                 if (ch == '-')
 601                         ch = *str++;
 602                 if (!isdigit(ch))
 603                         return false;
 604                 if (ch == '0' && *str != 0)
 605                         return false;
 606                 while ((ch = *str++)) {
 607                         if (!isdigit(ch))
 608                                 return false;
 609                 }
 610                 return true;
 611         case S_HEX:
 612                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 613                         str += 2;
 614                 ch = *str++;
 615                 do {
 616                         if (!isxdigit(ch))
 617                                 return false;
 618                 } while ((ch = *str++));
 619                 return true;
 620         case S_BOOLEAN:
 621         case S_TRISTATE:
 622                 switch (str[0]) {
 623                 case 'y': case 'Y':
 624                 case 'm': case 'M':
 625                 case 'n': case 'N':
 626                         return true;
 627                 }
 628                 return false;
 629         default:
 630                 return false;
 631         }
 632 }
 633
 634 bool sym_string_within_range(struct symbol *sym, const char *str)
 635 {
 636         struct property *prop;
 637         long long val;
 638
 639         switch (sym->type) {
 640         case S_STRING:
 641                 return sym_string_valid(sym, str);
 642         case S_INT:
 643                 if (!sym_string_valid(sym, str))
 644                         return false;
 645                 prop = sym_get_range_prop(sym);
 646                 if (!prop)
 647                         return true;
 648                 val = strtoll(str, NULL, 10);
 649                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 650                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 651         case S_HEX:
 652                 if (!sym_string_valid(sym, str))
 653                         return false;
 654                 prop = sym_get_range_prop(sym);
 655                 if (!prop)
 656                         return true;
 657                 val = strtoll(str, NULL, 16);
 658                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 659                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 660         case S_BOOLEAN:
 661         case S_TRISTATE:
 662                 switch (str[0]) {
 663                 case 'y': case 'Y':
 664                         return sym_tristate_within_range(sym, yes);
 665                 case 'm': case 'M':
 666                         return sym_tristate_within_range(sym, mod);
 667                 case 'n': case 'N':
 668                         return sym_tristate_within_range(sym, no);
 669                 }
 670                 return false;
 671         default:
 672                 return false;
 673         }
 674 }
 675
 676 bool sym_set_string_value(struct symbol *sym, const char *newval)
 677 {
 678         const char *oldval;
 679         char *val;
 680         int size;
 681
 682         switch (sym->type) {
 683         case S_BOOLEAN:
 684         case S_TRISTATE:
 685                 switch (newval[0]) {
 686                 case 'y': case 'Y':
 687                         return sym_set_tristate_value(sym, yes);
 688                 case 'm': case 'M':
 689                         return sym_set_tristate_value(sym, mod);
 690                 case 'n': case 'N':
 691                         return sym_set_tristate_value(sym, no);
 692                 }
 693                 return false;
 694         default:
 695                 ;
 696         }
 697
 698         if (!sym_string_within_range(sym, newval))
 699                 return false;
 700
 701         if (!(sym->flags & SYMBOL_DEF_USER)) {
 702                 sym->flags |= SYMBOL_DEF_USER;
 703                 sym_set_changed(sym);
 704         }
 705
 706         oldval = sym->def[S_DEF_USER].val;
 707         size = strlen(newval) + 1;
 708         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 709                 size += 2;
 710                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 711                 *val++ = '0';
 712                 *val++ = 'x';
 713         } else if (!oldval || strcmp(oldval, newval))
 714                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 715         else
 716                 return true;
 717
 718         strcpy(val, newval);
 719         free((void *)oldval);
 720         sym_clear_all_valid();
 721
 722         return true;
 723 }
 724
 725 /*
 726  * Find the default value associated to a symbol.
 727  * For tristate symbol handle the modules=n case
 728  * in which case "m" becomes "y".
 729  * If the symbol does not have any default then fallback
 730  * to the fixed default values.
 731  */
 732 const char *sym_get_string_default(struct symbol *sym)
 733 {
 734         struct property *prop;
 735         struct symbol *ds;
 736         const char *str;
 737         tristate val;
 738
 739         sym_calc_visibility(sym);
 740         sym_calc_value(modules_sym);
 741         val = symbol_no.curr.tri;
 742         str = symbol_empty.curr.val;
 743
 744         /* If symbol has a default value look it up */
 745         prop = sym_get_default_prop(sym);
 746         if (prop != NULL) {
 747                 switch (sym->type) {
 748                 case S_BOOLEAN:
 749                 case S_TRISTATE:
 750                         /* The visibility may limit the value from yes => mod */
 751                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 752                         break;
 753                 default:
 754                         /*
 755                          * The following fails to handle the situation
 756                          * where a default value is further limited by
 757                          * the valid range.
 758                          */
 759                         ds = prop_get_symbol(prop);
 760                         if (ds != NULL) {
 761                                 sym_calc_value(ds);
 762                                 str = (const char *)ds->curr.val;
 763                         }
 764                 }
 765         }
 766
 767         /* Handle select statements */
 768         val = EXPR_OR(val, sym->rev_dep.tri);
 769
 770         /* transpose mod to yes if modules are not enabled */
 771         if (val == mod)
 772                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 773                         val = yes;
 774
 775         /* transpose mod to yes if type is bool */
 776         if (sym->type == S_BOOLEAN && val == mod)
 777                 val = yes;
 778
 779         /* adjust the default value if this symbol is implied by another */
 780         if (val < sym->implied.tri)
 781                 val = sym->implied.tri;
 782
 783         switch (sym->type) {
 784         case S_BOOLEAN:
 785         case S_TRISTATE:
 786                 switch (val) {
 787                 case no: return "n";
 788                 case mod: return "m";
 789                 case yes: return "y";
 790                 }
 791         case S_INT:
 792         case S_HEX:
 793                 return str;
 794         case S_STRING:
 795                 return str;
 796         case S_OTHER:
 797         case S_UNKNOWN:
 798                 break;
 799         }
 800         return "";
 801 }
 802
 803 const char *sym_get_string_value(struct symbol *sym)
 804 {
 805         tristate val;
 806
 807         switch (sym->type) {
 808         case S_BOOLEAN:
 809         case S_TRISTATE:
 810                 val = sym_get_tristate_value(sym);
 811                 switch (val) {
 812                 case no:
 813                         return "n";
 814                 case mod:
 815                         sym_calc_value(modules_sym);
 816                         return (modules_sym->curr.tri == no) ? "n" : "m";
 817                 case yes:
 818                         return "y";
 819                 }
 820                 break;
 821         default:
 822                 ;
 823         }
 824         return (const char *)sym->curr.val;
 825 }
 826
 827 bool sym_is_changable(struct symbol *sym)
 828 {
 829         return sym->visible > sym->rev_dep.tri;
 830 }
 831
 832 static unsigned strhash(const char *s)
 833 {
 834         /* fnv32 hash */
 835         unsigned hash = 2166136261U;
 836         for (; *s; s++)
 837                 hash = (hash ^ *s) * 0x01000193;
 838         return hash;
 839 }
 840
 841 struct symbol *sym_lookup(const char *name, int flags)
 842 {
 843         struct symbol *symbol;
 844         char *new_name;
 845         int hash;
 846
 847         if (name) {
 848                 if (name[0] && !name[1]) {
 849                         switch (name[0]) {
 850                         case 'y': return &symbol_yes;
 851                         case 'm': return &symbol_mod;
 852                         case 'n': return &symbol_no;
 853                         }
 854                 }
 855                 hash = strhash(name) % SYMBOL_HASHSIZE;
 856
 857                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 858                         if (symbol->name &&
 859                             !strcmp(symbol->name, name) &&
 860                             (flags ? symbol->flags & flags
 861                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 862                                 return symbol;
 863                 }
 864                 new_name = xstrdup(name);
 865         } else {
 866                 new_name = NULL;
 867                 hash = 0;
 868         }
 869
 870         symbol = xmalloc(sizeof(*symbol));
 871         memset(symbol, 0, sizeof(*symbol));
 872         symbol->name = new_name;
 873         symbol->type = S_UNKNOWN;
 874         symbol->flags |= flags;
 875
 876         symbol->next = symbol_hash[hash];
 877         symbol_hash[hash] = symbol;
 878
 879         return symbol;
 880 }
 881
 882 struct symbol *sym_find(const char *name)
 883 {
 884         struct symbol *symbol = NULL;
 885         int hash = 0;
 886
 887         if (!name)
 888                 return NULL;
 889
 890         if (name[0] && !name[1]) {
 891                 switch (name[0]) {
 892                 case 'y': return &symbol_yes;
 893                 case 'm': return &symbol_mod;
 894                 case 'n': return &symbol_no;
 895                 }
 896         }
 897         hash = strhash(name) % SYMBOL_HASHSIZE;
 898
 899         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 900                 if (symbol->name &&
 901                     !strcmp(symbol->name, name) &&
 902                     !(symbol->flags & SYMBOL_CONST))
 903                                 break;
 904         }
 905
 906         return symbol;
 907 }
 908
 909 /*
 910  * Expand symbol's names embedded in the string given in argument. Symbols'
 911  * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
 912  * the empty string.
 913  */
 914 char *sym_expand_string_value(const char *in)
 915 {
 916         const char *src;
 917         char *res;
 918         size_t reslen;
 919
 920         /*
 921          * Note: 'in' might come from a token that's about to be
 922          * freed, so make sure to always allocate a new string
 923          */
 924         reslen = strlen(in) + 1;
 925         res = xmalloc(reslen);
 926         res[0] = '\0';
 927
 928         while ((src = strchr(in, '$'))) {
 929                 char *p, name[SYMBOL_MAXLENGTH];
 930                 const char *symval = "";
 931                 struct symbol *sym;
 932                 size_t newlen;
 933
 934                 strncat(res, in, src - in);
 935                 src++;
 936
 937                 p = name;
 938                 while (isalnum(*src) || *src == '_')
 939                         *p++ = *src++;
 940                 *p = '\0';
 941
 942                 sym = sym_find(name);
 943                 if (sym != NULL) {
 944                         sym_calc_value(sym);
 945                         symval = sym_get_string_value(sym);
 946                 }
 947
 948                 newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
 949                 if (newlen > reslen) {
 950                         reslen = newlen;
 951                         res = xrealloc(res, reslen);
 952                 }
 953
 954                 strcat(res, symval);
 955                 in = src;
 956         }
 957         strcat(res, in);
 958
 959         return res;
 960 }
 961
 962 const char *sym_escape_string_value(const char *in)
 963 {
 964         const char *p;
 965         size_t reslen;
 966         char *res;
 967         size_t l;
 968
 969         reslen = strlen(in) + strlen("\"\"") + 1;
 970
 971         p = in;
 972         for (;;) {
 973                 l = strcspn(p, "\"\\");
 974                 p += l;
 975
 976                 if (p[0] == '\0')
 977                         break;
 978
 979                 reslen++;
 980                 p++;
 981         }
 982
 983         res = xmalloc(reslen);
 984         res[0] = '\0';
 985
 986         strcat(res, "\"");
 987
 988         p = in;
 989         for (;;) {
 990                 l = strcspn(p, "\"\\");
 991                 strncat(res, p, l);
 992                 p += l;
 993
 994                 if (p[0] == '\0')
 995                         break;
 996
 997                 strcat(res, "\\");
 998                 strncat(res, p++, 1);
 999         }
1000
1001         strcat(res, "\"");
1002         return res;
1003 }
1004
1005 struct sym_match {
1006         struct symbol   *sym;
1007         off_t           so, eo;
1008 };
1009
1010 /* Compare matched symbols as thus:
1011  * - first, symbols that match exactly
1012  * - then, alphabetical sort
1013  */
1014 static int sym_rel_comp(const void *sym1, const void *sym2)
1015 {
1016         const struct sym_match *s1 = sym1;
1017         const struct sym_match *s2 = sym2;
1018         int exact1, exact2;
1019
1020         /* Exact match:
1021          * - if matched length on symbol s1 is the length of that symbol,
1022          *   then this symbol should come first;
1023          * - if matched length on symbol s2 is the length of that symbol,
1024          *   then this symbol should come first.
1025          * Note: since the search can be a regexp, both symbols may match
1026          * exactly; if this is the case, we can't decide which comes first,
1027          * and we fallback to sorting alphabetically.
1028          */
1029         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
1030         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
1031         if (exact1 && !exact2)
1032                 return -1;
1033         if (!exact1 && exact2)
1034                 return 1;
1035
1036         /* As a fallback, sort symbols alphabetically */
1037         return strcmp(s1->sym->name, s2->sym->name);
1038 }
1039
1040 struct symbol **sym_re_search(const char *pattern)
1041 {
1042         struct symbol *sym, **sym_arr = NULL;
1043         struct sym_match *sym_match_arr = NULL;
1044         int i, cnt, size;
1045         regex_t re;
1046         regmatch_t match[1];
1047
1048         cnt = size = 0;
1049         /* Skip if empty */
1050         if (strlen(pattern) == 0)
1051                 return NULL;
1052         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
1053                 return NULL;
1054
1055         for_all_symbols(i, sym) {
1056                 if (sym->flags & SYMBOL_CONST || !sym->name)
1057                         continue;
1058                 if (regexec(&re, sym->name, 1, match, 0))
1059                         continue;
1060                 if (cnt >= size) {
1061                         void *tmp;
1062                         size += 16;
1063                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
1064                         if (!tmp)
1065                                 goto sym_re_search_free;
1066                         sym_match_arr = tmp;
1067                 }
1068                 sym_calc_value(sym);
1069                 /* As regexec returned 0, we know we have a match, so
1070                  * we can use match[0].rm_[se]o without further checks
1071                  */
1072                 sym_match_arr[cnt].so = match[0].rm_so;
1073                 sym_match_arr[cnt].eo = match[0].rm_eo;
1074                 sym_match_arr[cnt++].sym = sym;
1075         }
1076         if (sym_match_arr) {
1077                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
1078                 sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
1079                 if (!sym_arr)
1080                         goto sym_re_search_free;
1081                 for (i = 0; i < cnt; i++)
1082                         sym_arr[i] = sym_match_arr[i].sym;
1083                 sym_arr[cnt] = NULL;
1084         }
1085 sym_re_search_free:
1086         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
1087         free(sym_match_arr);
1088         regfree(&re);
1089
1090         return sym_arr;
1091 }
1092
1093 /*
1094  * When we check for recursive dependencies we use a stack to save
1095  * current state so we can print out relevant info to user.
1096  * The entries are located on the call stack so no need to free memory.
1097  * Note insert() remove() must always match to properly clear the stack.
1098  */
1099 static struct dep_stack {
1100         struct dep_stack *prev, *next;
1101         struct symbol *sym;
1102         struct property *prop;
1103         struct expr *expr;
1104 } *check_top;
1105
1106 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1107 {
1108         memset(stack, 0, sizeof(*stack));
1109         if (check_top)
1110                 check_top->next = stack;
1111         stack->prev = check_top;
1112         stack->sym = sym;
1113         check_top = stack;
1114 }
1115
1116 static void dep_stack_remove(void)
1117 {
1118         check_top = check_top->prev;
1119         if (check_top)
1120                 check_top->next = NULL;
1121 }
1122
1123 /*
1124  * Called when we have detected a recursive dependency.
1125  * check_top point to the top of the stact so we use
1126  * the ->prev pointer to locate the bottom of the stack.
1127  */
1128 static void sym_check_print_recursive(struct symbol *last_sym)
1129 {
1130         struct dep_stack *stack;
1131         struct symbol *sym, *next_sym;
1132         struct menu *menu = NULL;
1133         struct property *prop;
1134         struct dep_stack cv_stack;
1135
1136         if (sym_is_choice_value(last_sym)) {
1137                 dep_stack_insert(&cv_stack, last_sym);
1138                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1139         }
1140
1141         for (stack = check_top; stack != NULL; stack = stack->prev)
1142                 if (stack->sym == last_sym)
1143                         break;
1144         if (!stack) {
1145                 fprintf(stderr, "unexpected recursive dependency error\n");
1146                 return;
1147         }
1148
1149         for (; stack; stack = stack->next) {
1150                 sym = stack->sym;
1151                 next_sym = stack->next ? stack->next->sym : last_sym;
1152                 prop = stack->prop;
1153                 if (prop == NULL)
1154                         prop = stack->sym->prop;
1155
1156                 /* for choice values find the menu entry (used below) */
1157                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1158                         for (prop = sym->prop; prop; prop = prop->next) {
1159                                 menu = prop->menu;
1160                                 if (prop->menu)
1161                                         break;
1162                         }
1163                 }
1164                 if (stack->sym == last_sym)
1165                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1166                                 prop->file->name, prop->lineno);
1167
1168                 if (stack->expr) {
1169                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1170                                 prop->file->name, prop->lineno,
1171                                 sym->name ? sym->name : "<choice>",
1172                                 prop_get_type_name(prop->type),
1173                                 next_sym->name ? next_sym->name : "<choice>");
1174                 } else if (stack->prop) {
1175                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1176                                 prop->file->name, prop->lineno,
1177                                 sym->name ? sym->name : "<choice>",
1178                                 next_sym->name ? next_sym->name : "<choice>");
1179                 } else if (sym_is_choice(sym)) {
1180                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1181                                 menu->file->name, menu->lineno,
1182                                 sym->name ? sym->name : "<choice>",
1183                                 next_sym->name ? next_sym->name : "<choice>");
1184                 } else if (sym_is_choice_value(sym)) {
1185                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1186                                 menu->file->name, menu->lineno,
1187                                 sym->name ? sym->name : "<choice>",
1188                                 next_sym->name ? next_sym->name : "<choice>");
1189                 } else {
1190                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1191                                 prop->file->name, prop->lineno,
1192                                 sym->name ? sym->name : "<choice>",
1193                                 next_sym->name ? next_sym->name : "<choice>");
1194                 }
1195         }
1196
1197         fprintf(stderr,
1198                 "For a resolution refer to Documentation/kbuild/kconfig-language.txt\n"
1199                 "subsection \"Kconfig recursive dependency limitations\"\n"
1200                 "\n");
1201
1202         if (check_top == &cv_stack)
1203                 dep_stack_remove();
1204 }
1205
1206 static struct symbol *sym_check_expr_deps(struct expr *e)
1207 {
1208         struct symbol *sym;
1209
1210         if (!e)
1211                 return NULL;
1212         switch (e->type) {
1213         case E_OR:
1214         case E_AND:
1215                 sym = sym_check_expr_deps(e->left.expr);
1216                 if (sym)
1217                         return sym;
1218                 return sym_check_expr_deps(e->right.expr);
1219         case E_NOT:
1220                 return sym_check_expr_deps(e->left.expr);
1221         case E_EQUAL:
1222         case E_GEQ:
1223         case E_GTH:
1224         case E_LEQ:
1225         case E_LTH:
1226         case E_UNEQUAL:
1227                 sym = sym_check_deps(e->left.sym);
1228                 if (sym)
1229                         return sym;
1230                 return sym_check_deps(e->right.sym);
1231         case E_SYMBOL:
1232                 return sym_check_deps(e->left.sym);
1233         default:
1234                 break;
1235         }
1236         fprintf(stderr, "Oops! How to check %d?\n", e->type);
1237         return NULL;
1238 }
1239
1240 /* return NULL when dependencies are OK */
1241 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1242 {
1243         struct symbol *sym2;
1244         struct property *prop;
1245         struct dep_stack stack;
1246
1247         dep_stack_insert(&stack, sym);
1248
1249         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1250         if (sym2)
1251                 goto out;
1252
1253         for (prop = sym->prop; prop; prop = prop->next) {
1254                 if (prop->type == P_CHOICE || prop->type == P_SELECT)
1255                         continue;
1256                 stack.prop = prop;
1257                 sym2 = sym_check_expr_deps(prop->visible.expr);
1258                 if (sym2)
1259                         break;
1260                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1261                         continue;
1262                 stack.expr = prop->expr;
1263                 sym2 = sym_check_expr_deps(prop->expr);
1264                 if (sym2)
1265                         break;
1266                 stack.expr = NULL;
1267         }
1268
1269 out:
1270         dep_stack_remove();
1271
1272         return sym2;
1273 }
1274
1275 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1276 {
1277         struct symbol *sym, *sym2;
1278         struct property *prop;
1279         struct expr *e;
1280         struct dep_stack stack;
1281
1282         dep_stack_insert(&stack, choice);
1283
1284         prop = sym_get_choice_prop(choice);
1285         expr_list_for_each_sym(prop->expr, e, sym)
1286                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1287
1288         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1289         sym2 = sym_check_sym_deps(choice);
1290         choice->flags &= ~SYMBOL_CHECK;
1291         if (sym2)
1292                 goto out;
1293
1294         expr_list_for_each_sym(prop->expr, e, sym) {
1295                 sym2 = sym_check_sym_deps(sym);
1296                 if (sym2)
1297                         break;
1298         }
1299 out:
1300         expr_list_for_each_sym(prop->expr, e, sym)
1301                 sym->flags &= ~SYMBOL_CHECK;
1302
1303         if (sym2 && sym_is_choice_value(sym2) &&
1304             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1305                 sym2 = choice;
1306
1307         dep_stack_remove();
1308
1309         return sym2;
1310 }
1311
1312 struct symbol *sym_check_deps(struct symbol *sym)
1313 {
1314         struct symbol *sym2;
1315         struct property *prop;
1316
1317         if (sym->flags & SYMBOL_CHECK) {
1318                 sym_check_print_recursive(sym);
1319                 return sym;
1320         }
1321         if (sym->flags & SYMBOL_CHECKED)
1322                 return NULL;
1323
1324         if (sym_is_choice_value(sym)) {
1325                 struct dep_stack stack;
1326
1327                 /* for choice groups start the check with main choice symbol */
1328                 dep_stack_insert(&stack, sym);
1329                 prop = sym_get_choice_prop(sym);
1330                 sym2 = sym_check_deps(prop_get_symbol(prop));
1331                 dep_stack_remove();
1332         } else if (sym_is_choice(sym)) {
1333                 sym2 = sym_check_choice_deps(sym);
1334         } else {
1335                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1336                 sym2 = sym_check_sym_deps(sym);
1337                 sym->flags &= ~SYMBOL_CHECK;
1338         }
1339
1340         if (sym2 && sym2 == sym)
1341                 sym2 = NULL;
1342
1343         return sym2;
1344 }
1345
1346 struct property *prop_alloc(enum prop_type type, struct symbol *sym)
1347 {
1348         struct property *prop;
1349         struct property **propp;
1350
1351         prop = xmalloc(sizeof(*prop));
1352         memset(prop, 0, sizeof(*prop));
1353         prop->type = type;
1354         prop->sym = sym;
1355         prop->file = current_file;
1356         prop->lineno = zconf_lineno();
1357
1358         /* append property to the prop list of symbol */
1359         if (sym) {
1360                 for (propp = &sym->prop; *propp; propp = &(*propp)->next)
1361                         ;
1362                 *propp = prop;
1363         }
1364
1365         return prop;
1366 }
1367
1368 struct symbol *prop_get_symbol(struct property *prop)
1369 {
1370         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1371                            prop->expr->type == E_LIST))
1372                 return prop->expr->left.sym;
1373         return NULL;
1374 }
1375
1376 const char *prop_get_type_name(enum prop_type type)
1377 {
1378         switch (type) {
1379         case P_PROMPT:
1380                 return "prompt";
1381         case P_ENV:
1382                 return "env";
1383         case P_COMMENT:
1384                 return "comment";
1385         case P_MENU:
1386                 return "menu";
1387         case P_DEFAULT:
1388                 return "default";
1389         case P_CHOICE:
1390                 return "choice";
1391         case P_SELECT:
1392                 return "select";
1393         case P_IMPLY:
1394                 return "imply";
1395         case P_RANGE:
1396                 return "range";
1397         case P_SYMBOL:
1398                 return "symbol";
1399         case P_UNKNOWN:
1400                 break;
1401         }
1402         return "unknown";
1403 }
1404
1405 static void prop_add_env(const char *env)
1406 {
1407         struct symbol *sym, *sym2;
1408         struct property *prop;
1409         char *p;
1410
1411         sym = current_entry->sym;
1412         sym->flags |= SYMBOL_AUTO;
1413         for_all_properties(sym, prop, P_ENV) {
1414                 sym2 = prop_get_symbol(prop);
1415                 if (strcmp(sym2->name, env))
1416                         menu_warn(current_entry, "redefining environment symbol from %s",
1417                                   sym2->name);
1418                 return;
1419         }
1420
1421         prop = prop_alloc(P_ENV, sym);
1422         prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
1423
1424         sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
1425         sym_env_list->right.sym = sym;
1426
1427         p = getenv(env);
1428         if (p)
1429                 sym_add_default(sym, p);
1430         else
1431                 menu_warn(current_entry, "environment variable %s undefined", env);
1432 }