scripts/config/symbol.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   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 enum symbol_type sym_get_type(struct symbol *sym)
  37 {
  38         enum symbol_type type = sym->type;
  39
  40         if (type == S_TRISTATE) {
  41                 if (sym_is_choice_value(sym) && sym->visible == yes)
  42                         type = S_BOOLEAN;
  43                 else if (modules_val == no)
  44                         type = S_BOOLEAN;
  45         }
  46         return type;
  47 }
  48
  49 const char *sym_type_name(enum symbol_type type)
  50 {
  51         switch (type) {
  52         case S_BOOLEAN:
  53                 return "bool";
  54         case S_TRISTATE:
  55                 return "tristate";
  56         case S_INT:
  57                 return "integer";
  58         case S_HEX:
  59                 return "hex";
  60         case S_STRING:
  61                 return "string";
  62         case S_UNKNOWN:
  63                 return "unknown";
  64         }
  65         return "???";
  66 }
  67
  68 struct property *sym_get_choice_prop(struct symbol *sym)
  69 {
  70         struct property *prop;
  71
  72         for_all_choices(sym, prop)
  73                 return prop;
  74         return NULL;
  75 }
  76
  77 static struct property *sym_get_default_prop(struct symbol *sym)
  78 {
  79         struct property *prop;
  80
  81         for_all_defaults(sym, prop) {
  82                 prop->visible.tri = expr_calc_value(prop->visible.expr);
  83                 if (prop->visible.tri != no)
  84                         return prop;
  85         }
  86         return NULL;
  87 }
  88
  89 struct property *sym_get_range_prop(struct symbol *sym)
  90 {
  91         struct property *prop;
  92
  93         for_all_properties(sym, prop, P_RANGE) {
  94                 prop->visible.tri = expr_calc_value(prop->visible.expr);
  95                 if (prop->visible.tri != no)
  96                         return prop;
  97         }
  98         return NULL;
  99 }
 100
 101 static long long sym_get_range_val(struct symbol *sym, int base)
 102 {
 103         sym_calc_value(sym);
 104         switch (sym->type) {
 105         case S_INT:
 106                 base = 10;
 107                 break;
 108         case S_HEX:
 109                 base = 16;
 110                 break;
 111         default:
 112                 break;
 113         }
 114         return strtoll(sym->curr.val, NULL, base);
 115 }
 116
 117 static void sym_validate_range(struct symbol *sym)
 118 {
 119         struct property *prop;
 120         int base;
 121         long long val, val2;
 122         char str[64];
 123
 124         switch (sym->type) {
 125         case S_INT:
 126                 base = 10;
 127                 break;
 128         case S_HEX:
 129                 base = 16;
 130                 break;
 131         default:
 132                 return;
 133         }
 134         prop = sym_get_range_prop(sym);
 135         if (!prop)
 136                 return;
 137         val = strtoll(sym->curr.val, NULL, base);
 138         val2 = sym_get_range_val(prop->expr->left.sym, base);
 139         if (val >= val2) {
 140                 val2 = sym_get_range_val(prop->expr->right.sym, base);
 141                 if (val <= val2)
 142                         return;
 143         }
 144         if (sym->type == S_INT)
 145                 sprintf(str, "%lld", val2);
 146         else
 147                 sprintf(str, "0x%llx", val2);
 148         sym->curr.val = xstrdup(str);
 149 }
 150
 151 static void sym_set_changed(struct symbol *sym)
 152 {
 153         struct property *prop;
 154
 155         sym->flags |= SYMBOL_CHANGED;
 156         for (prop = sym->prop; prop; prop = prop->next) {
 157                 if (prop->menu)
 158                         prop->menu->flags |= MENU_CHANGED;
 159         }
 160 }
 161
 162 static void sym_set_all_changed(void)
 163 {
 164         struct symbol *sym;
 165         int i;
 166
 167         for_all_symbols(i, sym)
 168                 sym_set_changed(sym);
 169 }
 170
 171 static void sym_calc_visibility(struct symbol *sym)
 172 {
 173         struct property *prop;
 174         struct symbol *choice_sym = NULL;
 175         tristate tri;
 176
 177         /* any prompt visible? */
 178         tri = no;
 179
 180         if (sym_is_choice_value(sym))
 181                 choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
 182
 183         for_all_prompts(sym, prop) {
 184                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 185                 /*
 186                  * Tristate choice_values with visibility 'mod' are
 187                  * not visible if the corresponding choice's value is
 188                  * 'yes'.
 189                  */
 190                 if (choice_sym && sym->type == S_TRISTATE &&
 191                     prop->visible.tri == mod && choice_sym->curr.tri == yes)
 192                         prop->visible.tri = no;
 193
 194                 tri = EXPR_OR(tri, prop->visible.tri);
 195         }
 196         if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 197                 tri = yes;
 198         if (sym->visible != tri) {
 199                 sym->visible = tri;
 200                 sym_set_changed(sym);
 201         }
 202         if (sym_is_choice_value(sym))
 203                 return;
 204         /* defaulting to "yes" if no explicit "depends on" are given */
 205         tri = yes;
 206         if (sym->dir_dep.expr)
 207                 tri = expr_calc_value(sym->dir_dep.expr);
 208         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 209                 tri = yes;
 210         if (sym->dir_dep.tri != tri) {
 211                 sym->dir_dep.tri = tri;
 212                 sym_set_changed(sym);
 213         }
 214         tri = no;
 215         if (sym->rev_dep.expr)
 216                 tri = expr_calc_value(sym->rev_dep.expr);
 217         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 218                 tri = yes;
 219         if (sym->rev_dep.tri != tri) {
 220                 sym->rev_dep.tri = tri;
 221                 sym_set_changed(sym);
 222         }
 223         tri = no;
 224         if (sym->implied.expr && sym->dir_dep.tri != no)
 225                 tri = expr_calc_value(sym->implied.expr);
 226         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 227                 tri = yes;
 228         if (sym->implied.tri != tri) {
 229                 sym->implied.tri = tri;
 230                 sym_set_changed(sym);
 231         }
 232 }
 233
 234 /*
 235  * Find the default symbol for a choice.
 236  * First try the default values for the choice symbol
 237  * Next locate the first visible choice value
 238  * Return NULL if none was found
 239  */
 240 struct symbol *sym_choice_default(struct symbol *sym)
 241 {
 242         struct symbol *def_sym;
 243         struct property *prop;
 244         struct expr *e;
 245
 246         /* any of the defaults visible? */
 247         for_all_defaults(sym, prop) {
 248                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 249                 if (prop->visible.tri == no)
 250                         continue;
 251                 def_sym = prop_get_symbol(prop);
 252                 if (def_sym->visible != no)
 253                         return def_sym;
 254         }
 255
 256         /* just get the first visible value */
 257         prop = sym_get_choice_prop(sym);
 258         expr_list_for_each_sym(prop->expr, e, def_sym)
 259                 if (def_sym->visible != no)
 260                         return def_sym;
 261
 262         /* failed to locate any defaults */
 263         return NULL;
 264 }
 265
 266 static struct symbol *sym_calc_choice(struct symbol *sym)
 267 {
 268         struct symbol *def_sym;
 269         struct property *prop;
 270         struct expr *e;
 271         int flags;
 272
 273         /* first calculate all choice values' visibilities */
 274         flags = sym->flags;
 275         prop = sym_get_choice_prop(sym);
 276         expr_list_for_each_sym(prop->expr, e, def_sym) {
 277                 sym_calc_visibility(def_sym);
 278                 if (def_sym->visible != no)
 279                         flags &= def_sym->flags;
 280         }
 281
 282         sym->flags &= flags | ~SYMBOL_DEF_USER;
 283
 284         /* is the user choice visible? */
 285         def_sym = sym->def[S_DEF_USER].val;
 286         if (def_sym && def_sym->visible != no)
 287                 return def_sym;
 288
 289         def_sym = sym_choice_default(sym);
 290
 291         if (def_sym == NULL)
 292                 /* no choice? reset tristate value */
 293                 sym->curr.tri = no;
 294
 295         return def_sym;
 296 }
 297
 298 void sym_calc_value(struct symbol *sym)
 299 {
 300         struct symbol_value newval, oldval;
 301         struct property *prop;
 302         struct expr *e;
 303
 304         if (!sym)
 305                 return;
 306
 307         if (sym->flags & SYMBOL_VALID)
 308                 return;
 309
 310         if (sym_is_choice_value(sym) &&
 311             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 312                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 313                 prop = sym_get_choice_prop(sym);
 314                 sym_calc_value(prop_get_symbol(prop));
 315         }
 316
 317         sym->flags |= SYMBOL_VALID;
 318
 319         oldval = sym->curr;
 320
 321         switch (sym->type) {
 322         case S_INT:
 323         case S_HEX:
 324         case S_STRING:
 325                 newval = symbol_empty.curr;
 326                 break;
 327         case S_BOOLEAN:
 328         case S_TRISTATE:
 329                 newval = symbol_no.curr;
 330                 break;
 331         default:
 332                 sym->curr.val = sym->name;
 333                 sym->curr.tri = no;
 334                 return;
 335         }
 336         sym->flags &= ~SYMBOL_WRITE;
 337
 338         sym_calc_visibility(sym);
 339
 340         if (sym->visible != no)
 341                 sym->flags |= SYMBOL_WRITE;
 342
 343         /* set default if recursively called */
 344         sym->curr = newval;
 345
 346         switch (sym_get_type(sym)) {
 347         case S_BOOLEAN:
 348         case S_TRISTATE:
 349                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 350                         prop = sym_get_choice_prop(sym);
 351                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 352                 } else {
 353                         if (sym->visible != no) {
 354                                 /* if the symbol is visible use the user value
 355                                  * if available, otherwise try the default value
 356                                  */
 357                                 if (sym_has_value(sym)) {
 358                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 359                                                               sym->visible);
 360                                         goto calc_newval;
 361                                 }
 362                         }
 363                         if (sym->rev_dep.tri != no)
 364                                 sym->flags |= SYMBOL_WRITE;
 365                         if (!sym_is_choice(sym)) {
 366                                 prop = sym_get_default_prop(sym);
 367                                 if (prop) {
 368                                         sym->flags |= SYMBOL_WRITE;
 369                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 370                                                               prop->visible.tri);
 371                                 }
 372                                 if (sym->implied.tri != no) {
 373                                         sym->flags |= SYMBOL_WRITE;
 374                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 375                                 }
 376                         }
 377                 calc_newval:
 378                         if (sym->dir_dep.tri < sym->rev_dep.tri) {
 379                                 newval.tri = no;
 380                         } else {
 381                                 newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 382                         }
 383                 }
 384                 if (newval.tri == mod &&
 385                     (sym_get_type(sym) == S_BOOLEAN || sym->implied.tri == yes))
 386                         newval.tri = yes;
 387                 break;
 388         case S_STRING:
 389         case S_HEX:
 390         case S_INT:
 391                 if (sym->visible != no && sym_has_value(sym)) {
 392                         newval.val = sym->def[S_DEF_USER].val;
 393                         break;
 394                 }
 395                 prop = sym_get_default_prop(sym);
 396                 if (prop) {
 397                         struct symbol *ds = prop_get_symbol(prop);
 398                         if (ds) {
 399                                 sym->flags |= SYMBOL_WRITE;
 400                                 sym_calc_value(ds);
 401                                 newval.val = ds->curr.val;
 402                         }
 403                 }
 404                 break;
 405         default:
 406                 ;
 407         }
 408
 409         sym->curr = newval;
 410         if (sym_is_choice(sym) && newval.tri == yes)
 411                 sym->curr.val = sym_calc_choice(sym);
 412         sym_validate_range(sym);
 413
 414         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 415                 sym_set_changed(sym);
 416                 if (modules_sym == sym) {
 417                         sym_set_all_changed();
 418                         modules_val = modules_sym->curr.tri;
 419                 }
 420         }
 421
 422         if (sym_is_choice(sym)) {
 423                 struct symbol *choice_sym;
 424
 425                 prop = sym_get_choice_prop(sym);
 426                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 427                         if ((sym->flags & SYMBOL_WRITE) &&
 428                             choice_sym->visible != no)
 429                                 choice_sym->flags |= SYMBOL_WRITE;
 430                         if (sym->flags & SYMBOL_CHANGED)
 431                                 sym_set_changed(choice_sym);
 432                 }
 433         }
 434
 435         if (sym->flags & SYMBOL_NO_WRITE)
 436                 sym->flags &= ~SYMBOL_WRITE;
 437
 438         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 439                 set_all_choice_values(sym);
 440 }
 441
 442 void sym_clear_all_valid(void)
 443 {
 444         struct symbol *sym;
 445         int i;
 446
 447         for_all_symbols(i, sym)
 448                 sym->flags &= ~SYMBOL_VALID;
 449         sym_add_change_count(1);
 450         sym_calc_value(modules_sym);
 451 }
 452
 453 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 454 {
 455         int type = sym_get_type(sym);
 456
 457         if (sym->visible == no)
 458                 return false;
 459
 460         if (type != S_BOOLEAN && type != S_TRISTATE)
 461                 return false;
 462
 463         if (type == S_BOOLEAN && val == mod)
 464                 return false;
 465         if (sym->visible <= sym->rev_dep.tri)
 466                 return false;
 467         if (sym->implied.tri == yes && val == mod)
 468                 return false;
 469         if (sym_is_choice_value(sym) && sym->visible == yes)
 470                 return val == yes;
 471         return val >= sym->rev_dep.tri && val <= sym->visible;
 472 }
 473
 474 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 475 {
 476         tristate oldval = sym_get_tristate_value(sym);
 477
 478         if (oldval != val && !sym_tristate_within_range(sym, val))
 479                 return false;
 480
 481         if (!(sym->flags & SYMBOL_DEF_USER)) {
 482                 sym->flags |= SYMBOL_DEF_USER;
 483                 sym_set_changed(sym);
 484         }
 485         /*
 486          * setting a choice value also resets the new flag of the choice
 487          * symbol and all other choice values.
 488          */
 489         if (sym_is_choice_value(sym) && val == yes) {
 490                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 491                 struct property *prop;
 492                 struct expr *e;
 493
 494                 cs->def[S_DEF_USER].val = sym;
 495                 cs->flags |= SYMBOL_DEF_USER;
 496                 prop = sym_get_choice_prop(cs);
 497                 for (e = prop->expr; e; e = e->left.expr) {
 498                         if (e->right.sym->visible != no)
 499                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 500                 }
 501         }
 502
 503         sym->def[S_DEF_USER].tri = val;
 504         if (oldval != val)
 505                 sym_clear_all_valid();
 506
 507         return true;
 508 }
 509
 510 tristate sym_toggle_tristate_value(struct symbol *sym)
 511 {
 512         tristate oldval, newval;
 513
 514         oldval = newval = sym_get_tristate_value(sym);
 515         do {
 516                 switch (newval) {
 517                 case no:
 518                         newval = mod;
 519                         break;
 520                 case mod:
 521                         newval = yes;
 522                         break;
 523                 case yes:
 524                         newval = no;
 525                         break;
 526                 }
 527                 if (sym_set_tristate_value(sym, newval))
 528                         break;
 529         } while (oldval != newval);
 530         return newval;
 531 }
 532
 533 bool sym_string_valid(struct symbol *sym, const char *str)
 534 {
 535         signed char ch;
 536
 537         switch (sym->type) {
 538         case S_STRING:
 539                 return true;
 540         case S_INT:
 541                 ch = *str++;
 542                 if (ch == '-')
 543                         ch = *str++;
 544                 if (!isdigit(ch))
 545                         return false;
 546                 if (ch == '0' && *str != 0)
 547                         return false;
 548                 while ((ch = *str++)) {
 549                         if (!isdigit(ch))
 550                                 return false;
 551                 }
 552                 return true;
 553         case S_HEX:
 554                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 555                         str += 2;
 556                 ch = *str++;
 557                 do {
 558                         if (!isxdigit(ch))
 559                                 return false;
 560                 } while ((ch = *str++));
 561                 return true;
 562         case S_BOOLEAN:
 563         case S_TRISTATE:
 564                 switch (str[0]) {
 565                 case 'y': case 'Y':
 566                 case 'm': case 'M':
 567                 case 'n': case 'N':
 568                         return true;
 569                 }
 570                 return false;
 571         default:
 572                 return false;
 573         }
 574 }
 575
 576 bool sym_string_within_range(struct symbol *sym, const char *str)
 577 {
 578         struct property *prop;
 579         long long val;
 580
 581         switch (sym->type) {
 582         case S_STRING:
 583                 return sym_string_valid(sym, str);
 584         case S_INT:
 585                 if (!sym_string_valid(sym, str))
 586                         return false;
 587                 prop = sym_get_range_prop(sym);
 588                 if (!prop)
 589                         return true;
 590                 val = strtoll(str, NULL, 10);
 591                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 592                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 593         case S_HEX:
 594                 if (!sym_string_valid(sym, str))
 595                         return false;
 596                 prop = sym_get_range_prop(sym);
 597                 if (!prop)
 598                         return true;
 599                 val = strtoll(str, NULL, 16);
 600                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 601                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 602         case S_BOOLEAN:
 603         case S_TRISTATE:
 604                 switch (str[0]) {
 605                 case 'y': case 'Y':
 606                         return sym_tristate_within_range(sym, yes);
 607                 case 'm': case 'M':
 608                         return sym_tristate_within_range(sym, mod);
 609                 case 'n': case 'N':
 610                         return sym_tristate_within_range(sym, no);
 611                 }
 612                 return false;
 613         default:
 614                 return false;
 615         }
 616 }
 617
 618 bool sym_set_string_value(struct symbol *sym, const char *newval)
 619 {
 620         const char *oldval;
 621         char *val;
 622         int size;
 623
 624         switch (sym->type) {
 625         case S_BOOLEAN:
 626         case S_TRISTATE:
 627                 switch (newval[0]) {
 628                 case 'y': case 'Y':
 629                         return sym_set_tristate_value(sym, yes);
 630                 case 'm': case 'M':
 631                         return sym_set_tristate_value(sym, mod);
 632                 case 'n': case 'N':
 633                         return sym_set_tristate_value(sym, no);
 634                 }
 635                 return false;
 636         default:
 637                 ;
 638         }
 639
 640         if (!sym_string_within_range(sym, newval))
 641                 return false;
 642
 643         if (!(sym->flags & SYMBOL_DEF_USER)) {
 644                 sym->flags |= SYMBOL_DEF_USER;
 645                 sym_set_changed(sym);
 646         }
 647
 648         oldval = sym->def[S_DEF_USER].val;
 649         size = strlen(newval) + 1;
 650         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 651                 size += 2;
 652                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 653                 *val++ = '0';
 654                 *val++ = 'x';
 655         } else if (!oldval || strcmp(oldval, newval))
 656                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 657         else
 658                 return true;
 659
 660         strcpy(val, newval);
 661         free((void *)oldval);
 662         sym_clear_all_valid();
 663
 664         return true;
 665 }
 666
 667 /*
 668  * Find the default value associated to a symbol.
 669  * For tristate symbol handle the modules=n case
 670  * in which case "m" becomes "y".
 671  * If the symbol does not have any default then fallback
 672  * to the fixed default values.
 673  */
 674 const char *sym_get_string_default(struct symbol *sym)
 675 {
 676         struct property *prop;
 677         struct symbol *ds;
 678         const char *str;
 679         tristate val;
 680
 681         sym_calc_visibility(sym);
 682         sym_calc_value(modules_sym);
 683         val = symbol_no.curr.tri;
 684         str = symbol_empty.curr.val;
 685
 686         /* If symbol has a default value look it up */
 687         prop = sym_get_default_prop(sym);
 688         if (prop != NULL) {
 689                 switch (sym->type) {
 690                 case S_BOOLEAN:
 691                 case S_TRISTATE:
 692                         /* The visibility may limit the value from yes => mod */
 693                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 694                         break;
 695                 default:
 696                         /*
 697                          * The following fails to handle the situation
 698                          * where a default value is further limited by
 699                          * the valid range.
 700                          */
 701                         ds = prop_get_symbol(prop);
 702                         if (ds != NULL) {
 703                                 sym_calc_value(ds);
 704                                 str = (const char *)ds->curr.val;
 705                         }
 706                 }
 707         }
 708
 709         /* Handle select statements */
 710         val = EXPR_OR(val, sym->rev_dep.tri);
 711
 712         /* transpose mod to yes if modules are not enabled */
 713         if (val == mod)
 714                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 715                         val = yes;
 716
 717         /* transpose mod to yes if type is bool */
 718         if (sym->type == S_BOOLEAN && val == mod)
 719                 val = yes;
 720
 721         /* adjust the default value if this symbol is implied by another */
 722         if (val < sym->implied.tri)
 723                 val = sym->implied.tri;
 724
 725         switch (sym->type) {
 726         case S_BOOLEAN:
 727         case S_TRISTATE:
 728                 switch (val) {
 729                 case no: return "n";
 730                 case mod: return "m";
 731                 case yes: return "y";
 732                 }
 733         case S_INT:
 734         case S_HEX:
 735                 return str;
 736         case S_STRING:
 737                 return str;
 738         case S_UNKNOWN:
 739                 break;
 740         }
 741         return "";
 742 }
 743
 744 const char *sym_get_string_value(struct symbol *sym)
 745 {
 746         tristate val;
 747
 748         switch (sym->type) {
 749         case S_BOOLEAN:
 750         case S_TRISTATE:
 751                 val = sym_get_tristate_value(sym);
 752                 switch (val) {
 753                 case no:
 754                         return "n";
 755                 case mod:
 756                         sym_calc_value(modules_sym);
 757                         return (modules_sym->curr.tri == no) ? "n" : "m";
 758                 case yes:
 759                         return "y";
 760                 }
 761                 break;
 762         default:
 763                 ;
 764         }
 765         return (const char *)sym->curr.val;
 766 }
 767
 768 bool sym_is_changeable(struct symbol *sym)
 769 {
 770         return sym->visible > sym->rev_dep.tri;
 771 }
 772
 773 static unsigned strhash(const char *s)
 774 {
 775         /* fnv32 hash */
 776         unsigned hash = 2166136261U;
 777         for (; *s; s++)
 778                 hash = (hash ^ *s) * 0x01000193;
 779         return hash;
 780 }
 781
 782 struct symbol *sym_lookup(const char *name, int flags)
 783 {
 784         struct symbol *symbol;
 785         char *new_name;
 786         int hash;
 787
 788         if (name) {
 789                 if (name[0] && !name[1]) {
 790                         switch (name[0]) {
 791                         case 'y': return &symbol_yes;
 792                         case 'm': return &symbol_mod;
 793                         case 'n': return &symbol_no;
 794                         }
 795                 }
 796                 hash = strhash(name) % SYMBOL_HASHSIZE;
 797
 798                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 799                         if (symbol->name &&
 800                             !strcmp(symbol->name, name) &&
 801                             (flags ? symbol->flags & flags
 802                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 803                                 return symbol;
 804                 }
 805                 new_name = xstrdup(name);
 806         } else {
 807                 new_name = NULL;
 808                 hash = 0;
 809         }
 810
 811         symbol = xmalloc(sizeof(*symbol));
 812         memset(symbol, 0, sizeof(*symbol));
 813         symbol->name = new_name;
 814         symbol->type = S_UNKNOWN;
 815         symbol->flags |= flags;
 816
 817         symbol->next = symbol_hash[hash];
 818         symbol_hash[hash] = symbol;
 819
 820         return symbol;
 821 }
 822
 823 struct symbol *sym_find(const char *name)
 824 {
 825         struct symbol *symbol = NULL;
 826         int hash = 0;
 827
 828         if (!name)
 829                 return NULL;
 830
 831         if (name[0] && !name[1]) {
 832                 switch (name[0]) {
 833                 case 'y': return &symbol_yes;
 834                 case 'm': return &symbol_mod;
 835                 case 'n': return &symbol_no;
 836                 }
 837         }
 838         hash = strhash(name) % SYMBOL_HASHSIZE;
 839
 840         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 841                 if (symbol->name &&
 842                     !strcmp(symbol->name, name) &&
 843                     !(symbol->flags & SYMBOL_CONST))
 844                                 break;
 845         }
 846
 847         return symbol;
 848 }
 849
 850 const char *sym_escape_string_value(const char *in)
 851 {
 852         const char *p;
 853         size_t reslen;
 854         char *res;
 855         size_t l;
 856
 857         reslen = strlen(in) + strlen("\"\"") + 1;
 858
 859         p = in;
 860         for (;;) {
 861                 l = strcspn(p, "\"\\");
 862                 p += l;
 863
 864                 if (p[0] == '\0')
 865                         break;
 866
 867                 reslen++;
 868                 p++;
 869         }
 870
 871         res = xmalloc(reslen);
 872         res[0] = '\0';
 873
 874         strcat(res, "\"");
 875
 876         p = in;
 877         for (;;) {
 878                 l = strcspn(p, "\"\\");
 879                 strncat(res, p, l);
 880                 p += l;
 881
 882                 if (p[0] == '\0')
 883                         break;
 884
 885                 strcat(res, "\\");
 886                 strncat(res, p++, 1);
 887         }
 888
 889         strcat(res, "\"");
 890         return res;
 891 }
 892
 893 struct sym_match {
 894         struct symbol   *sym;
 895         off_t           so, eo;
 896 };
 897
 898 /* Compare matched symbols as thus:
 899  * - first, symbols that match exactly
 900  * - then, alphabetical sort
 901  */
 902 static int sym_rel_comp(const void *sym1, const void *sym2)
 903 {
 904         const struct sym_match *s1 = sym1;
 905         const struct sym_match *s2 = sym2;
 906         int exact1, exact2;
 907
 908         /* Exact match:
 909          * - if matched length on symbol s1 is the length of that symbol,
 910          *   then this symbol should come first;
 911          * - if matched length on symbol s2 is the length of that symbol,
 912          *   then this symbol should come first.
 913          * Note: since the search can be a regexp, both symbols may match
 914          * exactly; if this is the case, we can't decide which comes first,
 915          * and we fallback to sorting alphabetically.
 916          */
 917         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 918         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 919         if (exact1 && !exact2)
 920                 return -1;
 921         if (!exact1 && exact2)
 922                 return 1;
 923
 924         /* As a fallback, sort symbols alphabetically */
 925         return strcmp(s1->sym->name, s2->sym->name);
 926 }
 927
 928 struct symbol **sym_re_search(const char *pattern)
 929 {
 930         struct symbol *sym, **sym_arr = NULL;
 931         struct sym_match *sym_match_arr = NULL;
 932         int i, cnt, size;
 933         regex_t re;
 934         regmatch_t match[1];
 935
 936         cnt = size = 0;
 937         /* Skip if empty */
 938         if (strlen(pattern) == 0)
 939                 return NULL;
 940         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 941                 return NULL;
 942
 943         for_all_symbols(i, sym) {
 944                 if (sym->flags & SYMBOL_CONST || !sym->name)
 945                         continue;
 946                 if (regexec(&re, sym->name, 1, match, 0))
 947                         continue;
 948                 if (cnt >= size) {
 949                         void *tmp;
 950                         size += 16;
 951                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 952                         if (!tmp)
 953                                 goto sym_re_search_free;
 954                         sym_match_arr = tmp;
 955                 }
 956                 sym_calc_value(sym);
 957                 /* As regexec returned 0, we know we have a match, so
 958                  * we can use match[0].rm_[se]o without further checks
 959                  */
 960                 sym_match_arr[cnt].so = match[0].rm_so;
 961                 sym_match_arr[cnt].eo = match[0].rm_eo;
 962                 sym_match_arr[cnt++].sym = sym;
 963         }
 964         if (sym_match_arr) {
 965                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 966                 sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 967                 if (!sym_arr)
 968                         goto sym_re_search_free;
 969                 for (i = 0; i < cnt; i++)
 970                         sym_arr[i] = sym_match_arr[i].sym;
 971                 sym_arr[cnt] = NULL;
 972         }
 973 sym_re_search_free:
 974         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
 975         free(sym_match_arr);
 976         regfree(&re);
 977
 978         return sym_arr;
 979 }
 980
 981 /*
 982  * When we check for recursive dependencies we use a stack to save
 983  * current state so we can print out relevant info to user.
 984  * The entries are located on the call stack so no need to free memory.
 985  * Note insert() remove() must always match to properly clear the stack.
 986  */
 987 static struct dep_stack {
 988         struct dep_stack *prev, *next;
 989         struct symbol *sym;
 990         struct property *prop;
 991         struct expr **expr;
 992 } *check_top;
 993
 994 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
 995 {
 996         memset(stack, 0, sizeof(*stack));
 997         if (check_top)
 998                 check_top->next = stack;
 999         stack->prev = check_top;
1000         stack->sym = sym;
1001         check_top = stack;
1002 }
1003
1004 static void dep_stack_remove(void)
1005 {
1006         check_top = check_top->prev;
1007         if (check_top)
1008                 check_top->next = NULL;
1009 }
1010
1011 /*
1012  * Called when we have detected a recursive dependency.
1013  * check_top point to the top of the stact so we use
1014  * the ->prev pointer to locate the bottom of the stack.
1015  */
1016 static void sym_check_print_recursive(struct symbol *last_sym)
1017 {
1018         struct dep_stack *stack;
1019         struct symbol *sym, *next_sym;
1020         struct menu *menu = NULL;
1021         struct property *prop;
1022         struct dep_stack cv_stack;
1023
1024         if (sym_is_choice_value(last_sym)) {
1025                 dep_stack_insert(&cv_stack, last_sym);
1026                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1027         }
1028
1029         for (stack = check_top; stack != NULL; stack = stack->prev)
1030                 if (stack->sym == last_sym)
1031                         break;
1032         if (!stack) {
1033                 fprintf(stderr, "unexpected recursive dependency error\n");
1034                 return;
1035         }
1036
1037         for (; stack; stack = stack->next) {
1038                 sym = stack->sym;
1039                 next_sym = stack->next ? stack->next->sym : last_sym;
1040                 prop = stack->prop;
1041                 if (prop == NULL)
1042                         prop = stack->sym->prop;
1043
1044                 /* for choice values find the menu entry (used below) */
1045                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1046                         for (prop = sym->prop; prop; prop = prop->next) {
1047                                 menu = prop->menu;
1048                                 if (prop->menu)
1049                                         break;
1050                         }
1051                 }
1052                 if (stack->sym == last_sym)
1053                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1054                                 prop->file->name, prop->lineno);
1055
1056                 if (sym_is_choice(sym)) {
1057                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1058                                 menu->file->name, menu->lineno,
1059                                 sym->name ? sym->name : "<choice>",
1060                                 next_sym->name ? next_sym->name : "<choice>");
1061                 } else if (sym_is_choice_value(sym)) {
1062                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1063                                 menu->file->name, menu->lineno,
1064                                 sym->name ? sym->name : "<choice>",
1065                                 next_sym->name ? next_sym->name : "<choice>");
1066                 } else if (stack->expr == &sym->dir_dep.expr) {
1067                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1068                                 prop->file->name, prop->lineno,
1069                                 sym->name ? sym->name : "<choice>",
1070                                 next_sym->name ? next_sym->name : "<choice>");
1071                 } else if (stack->expr == &sym->rev_dep.expr) {
1072                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1073                                 prop->file->name, prop->lineno,
1074                                 sym->name ? sym->name : "<choice>",
1075                                 next_sym->name ? next_sym->name : "<choice>");
1076                 } else if (stack->expr == &sym->implied.expr) {
1077                         fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1078                                 prop->file->name, prop->lineno,
1079                                 sym->name ? sym->name : "<choice>",
1080                                 next_sym->name ? next_sym->name : "<choice>");
1081                 } else if (stack->expr) {
1082                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1083                                 prop->file->name, prop->lineno,
1084                                 sym->name ? sym->name : "<choice>",
1085                                 prop_get_type_name(prop->type),
1086                                 next_sym->name ? next_sym->name : "<choice>");
1087                 } else {
1088                         fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1089                                 prop->file->name, prop->lineno,
1090                                 sym->name ? sym->name : "<choice>",
1091                                 prop_get_type_name(prop->type),
1092                                 next_sym->name ? next_sym->name : "<choice>");
1093                 }
1094         }
1095
1096         fprintf(stderr,
1097                 "For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1098                 "subsection \"Kconfig recursive dependency limitations\"\n"
1099                 "\n");
1100
1101         if (check_top == &cv_stack)
1102                 dep_stack_remove();
1103 }
1104
1105 static struct symbol *sym_check_expr_deps(struct expr *e)
1106 {
1107         struct symbol *sym;
1108
1109         if (!e)
1110                 return NULL;
1111         switch (e->type) {
1112         case E_OR:
1113         case E_AND:
1114                 sym = sym_check_expr_deps(e->left.expr);
1115                 if (sym)
1116                         return sym;
1117                 return sym_check_expr_deps(e->right.expr);
1118         case E_NOT:
1119                 return sym_check_expr_deps(e->left.expr);
1120         case E_EQUAL:
1121         case E_GEQ:
1122         case E_GTH:
1123         case E_LEQ:
1124         case E_LTH:
1125         case E_UNEQUAL:
1126                 sym = sym_check_deps(e->left.sym);
1127                 if (sym)
1128                         return sym;
1129                 return sym_check_deps(e->right.sym);
1130         case E_SYMBOL:
1131                 return sym_check_deps(e->left.sym);
1132         default:
1133                 break;
1134         }
1135         fprintf(stderr, "Oops! How to check %d?\n", e->type);
1136         return NULL;
1137 }
1138
1139 /* return NULL when dependencies are OK */
1140 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1141 {
1142         struct symbol *sym2;
1143         struct property *prop;
1144         struct dep_stack stack;
1145
1146         dep_stack_insert(&stack, sym);
1147
1148         stack.expr = &sym->dir_dep.expr;
1149         sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1150         if (sym2)
1151                 goto out;
1152
1153         stack.expr = &sym->rev_dep.expr;
1154         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1155         if (sym2)
1156                 goto out;
1157
1158         stack.expr = &sym->implied.expr;
1159         sym2 = sym_check_expr_deps(sym->implied.expr);
1160         if (sym2)
1161                 goto out;
1162
1163         stack.expr = NULL;
1164
1165         for (prop = sym->prop; prop; prop = prop->next) {
1166                 if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1167                     prop->type == P_IMPLY)
1168                         continue;
1169                 stack.prop = prop;
1170                 sym2 = sym_check_expr_deps(prop->visible.expr);
1171                 if (sym2)
1172                         break;
1173                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1174                         continue;
1175                 stack.expr = &prop->expr;
1176                 sym2 = sym_check_expr_deps(prop->expr);
1177                 if (sym2)
1178                         break;
1179                 stack.expr = NULL;
1180         }
1181
1182 out:
1183         dep_stack_remove();
1184
1185         return sym2;
1186 }
1187
1188 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1189 {
1190         struct symbol *sym, *sym2;
1191         struct property *prop;
1192         struct expr *e;
1193         struct dep_stack stack;
1194
1195         dep_stack_insert(&stack, choice);
1196
1197         prop = sym_get_choice_prop(choice);
1198         expr_list_for_each_sym(prop->expr, e, sym)
1199                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1200
1201         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1202         sym2 = sym_check_sym_deps(choice);
1203         choice->flags &= ~SYMBOL_CHECK;
1204         if (sym2)
1205                 goto out;
1206
1207         expr_list_for_each_sym(prop->expr, e, sym) {
1208                 sym2 = sym_check_sym_deps(sym);
1209                 if (sym2)
1210                         break;
1211         }
1212 out:
1213         expr_list_for_each_sym(prop->expr, e, sym)
1214                 sym->flags &= ~SYMBOL_CHECK;
1215
1216         if (sym2 && sym_is_choice_value(sym2) &&
1217             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1218                 sym2 = choice;
1219
1220         dep_stack_remove();
1221
1222         return sym2;
1223 }
1224
1225 struct symbol *sym_check_deps(struct symbol *sym)
1226 {
1227         struct symbol *sym2;
1228         struct property *prop;
1229
1230         if (sym->flags & SYMBOL_CHECK) {
1231                 sym_check_print_recursive(sym);
1232                 return sym;
1233         }
1234         if (sym->flags & SYMBOL_CHECKED)
1235                 return NULL;
1236
1237         if (sym_is_choice_value(sym)) {
1238                 struct dep_stack stack;
1239
1240                 /* for choice groups start the check with main choice symbol */
1241                 dep_stack_insert(&stack, sym);
1242                 prop = sym_get_choice_prop(sym);
1243                 sym2 = sym_check_deps(prop_get_symbol(prop));
1244                 dep_stack_remove();
1245         } else if (sym_is_choice(sym)) {
1246                 sym2 = sym_check_choice_deps(sym);
1247         } else {
1248                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1249                 sym2 = sym_check_sym_deps(sym);
1250                 sym->flags &= ~SYMBOL_CHECK;
1251         }
1252
1253         return sym2;
1254 }
1255
1256 struct symbol *prop_get_symbol(struct property *prop)
1257 {
1258         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1259                            prop->expr->type == E_LIST))
1260                 return prop->expr->left.sym;
1261         return NULL;
1262 }
1263
1264 const char *prop_get_type_name(enum prop_type type)
1265 {
1266         switch (type) {
1267         case P_PROMPT:
1268                 return "prompt";
1269         case P_COMMENT:
1270                 return "comment";
1271         case P_MENU:
1272                 return "menu";
1273         case P_DEFAULT:
1274                 return "default";
1275         case P_CHOICE:
1276                 return "choice";
1277         case P_SELECT:
1278                 return "select";
1279         case P_IMPLY:
1280                 return "imply";
1281         case P_RANGE:
1282                 return "range";
1283         case P_SYMBOL:
1284                 return "symbol";
1285         case P_RESET:
1286                 return "reset";
1287         case P_UNKNOWN:
1288                 break;
1289         }
1290         return "unknown";
1291 }