scripts/config/symbol.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   4  */
   5
   6 #include <sys/types.h>
   7 #include <ctype.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <regex.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 };
  19
  20 struct symbol symbol_mod = {
  21         .name = "m",
  22         .curr = { "m", mod },
  23         .flags = SYMBOL_CONST|SYMBOL_VALID,
  24 };
  25
  26 struct symbol symbol_no = {
  27         .name = "n",
  28         .curr = { "n", no },
  29         .flags = SYMBOL_CONST|SYMBOL_VALID,
  30 };
  31
  32 static struct symbol symbol_empty = {
  33         .name = "",
  34         .curr = { "", no },
  35         .flags = SYMBOL_VALID,
  36 };
  37
  38 struct symbol *modules_sym;
  39 static tristate modules_val;
  40 int recursive_is_error;
  41
  42 enum symbol_type sym_get_type(struct symbol *sym)
  43 {
  44         enum symbol_type type = sym->type;
  45
  46         if (type == S_TRISTATE) {
  47                 if (sym_is_choice_value(sym) && sym->visible == yes)
  48                         type = S_BOOLEAN;
  49                 else if (modules_val == no)
  50                         type = S_BOOLEAN;
  51         }
  52         return type;
  53 }
  54
  55 const char *sym_type_name(enum symbol_type type)
  56 {
  57         switch (type) {
  58         case S_BOOLEAN:
  59                 return "bool";
  60         case S_TRISTATE:
  61                 return "tristate";
  62         case S_INT:
  63                 return "integer";
  64         case S_HEX:
  65                 return "hex";
  66         case S_STRING:
  67                 return "string";
  68         case S_UNKNOWN:
  69                 return "unknown";
  70         }
  71         return "???";
  72 }
  73
  74 struct property *sym_get_choice_prop(struct symbol *sym)
  75 {
  76         struct property *prop;
  77
  78         for_all_choices(sym, prop)
  79                 return prop;
  80         return NULL;
  81 }
  82
  83 static struct property *sym_get_default_prop(struct symbol *sym)
  84 {
  85         struct property *prop;
  86
  87         for_all_defaults(sym, prop) {
  88                 prop->visible.tri = expr_calc_value(prop->visible.expr);
  89                 if (prop->visible.tri != no)
  90                         return prop;
  91         }
  92         return NULL;
  93 }
  94
  95 struct property *sym_get_range_prop(struct symbol *sym)
  96 {
  97         struct property *prop;
  98
  99         for_all_properties(sym, prop, P_RANGE) {
 100                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 101                 if (prop->visible.tri != no)
 102                         return prop;
 103         }
 104         return NULL;
 105 }
 106
 107 static long long sym_get_range_val(struct symbol *sym, int base)
 108 {
 109         sym_calc_value(sym);
 110         switch (sym->type) {
 111         case S_INT:
 112                 base = 10;
 113                 break;
 114         case S_HEX:
 115                 base = 16;
 116                 break;
 117         default:
 118                 break;
 119         }
 120         return strtoll(sym->curr.val, NULL, base);
 121 }
 122
 123 static void sym_validate_range(struct symbol *sym)
 124 {
 125         struct property *prop;
 126         int base;
 127         long long val, val2;
 128         char str[64];
 129
 130         switch (sym->type) {
 131         case S_INT:
 132                 base = 10;
 133                 break;
 134         case S_HEX:
 135                 base = 16;
 136                 break;
 137         default:
 138                 return;
 139         }
 140         prop = sym_get_range_prop(sym);
 141         if (!prop)
 142                 return;
 143         val = strtoll(sym->curr.val, NULL, base);
 144         val2 = sym_get_range_val(prop->expr->left.sym, base);
 145         if (val >= val2) {
 146                 val2 = sym_get_range_val(prop->expr->right.sym, base);
 147                 if (val <= val2)
 148                         return;
 149         }
 150         if (sym->type == S_INT)
 151                 sprintf(str, "%lld", val2);
 152         else
 153                 sprintf(str, "0x%llx", val2);
 154         sym->curr.val = xstrdup(str);
 155 }
 156
 157 static void sym_set_changed(struct symbol *sym)
 158 {
 159         struct property *prop;
 160
 161         sym->flags |= SYMBOL_CHANGED;
 162         for (prop = sym->prop; prop; prop = prop->next) {
 163                 if (prop->menu)
 164                         prop->menu->flags |= MENU_CHANGED;
 165         }
 166 }
 167
 168 static void sym_set_all_changed(void)
 169 {
 170         struct symbol *sym;
 171         int i;
 172
 173         for_all_symbols(i, sym)
 174                 sym_set_changed(sym);
 175 }
 176
 177 static void sym_calc_visibility(struct symbol *sym)
 178 {
 179         struct property *prop;
 180         struct symbol *choice_sym = NULL;
 181         tristate tri;
 182
 183         /* any prompt visible? */
 184         tri = no;
 185
 186         if (sym_is_choice_value(sym))
 187                 choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
 188
 189         for_all_prompts(sym, prop) {
 190                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 191                 /*
 192                  * Tristate choice_values with visibility 'mod' are
 193                  * not visible if the corresponding choice's value is
 194                  * 'yes'.
 195                  */
 196                 if (choice_sym && sym->type == S_TRISTATE &&
 197                     prop->visible.tri == mod && choice_sym->curr.tri == yes)
 198                         prop->visible.tri = no;
 199
 200                 tri = EXPR_OR(tri, prop->visible.tri);
 201         }
 202         if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 203                 tri = yes;
 204         if (sym->visible != tri) {
 205                 sym->visible = tri;
 206                 sym_set_changed(sym);
 207         }
 208         if (sym_is_choice_value(sym))
 209                 return;
 210         /* defaulting to "yes" if no explicit "depends on" are given */
 211         tri = yes;
 212         if (sym->dir_dep.expr)
 213                 tri = expr_calc_value(sym->dir_dep.expr);
 214         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 215                 tri = yes;
 216         if (sym->dir_dep.tri != tri) {
 217                 sym->dir_dep.tri = tri;
 218                 sym_set_changed(sym);
 219         }
 220         tri = no;
 221         if (sym->rev_dep.expr)
 222                 tri = expr_calc_value(sym->rev_dep.expr);
 223         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 224                 tri = yes;
 225         if (sym->rev_dep.tri != tri) {
 226                 sym->rev_dep.tri = tri;
 227                 sym_set_changed(sym);
 228         }
 229         tri = no;
 230         if (sym->implied.expr)
 231                 tri = expr_calc_value(sym->implied.expr);
 232         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 233                 tri = yes;
 234         if (sym->implied.tri != tri) {
 235                 sym->implied.tri = tri;
 236                 sym_set_changed(sym);
 237         }
 238 }
 239
 240 /*
 241  * Find the default symbol for a choice.
 242  * First try the default values for the choice symbol
 243  * Next locate the first visible choice value
 244  * Return NULL if none was found
 245  */
 246 struct symbol *sym_choice_default(struct symbol *sym)
 247 {
 248         struct symbol *def_sym;
 249         struct property *prop;
 250         struct expr *e;
 251
 252         /* any of the defaults visible? */
 253         for_all_defaults(sym, prop) {
 254                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 255                 if (prop->visible.tri == no)
 256                         continue;
 257                 def_sym = prop_get_symbol(prop);
 258                 if (def_sym->visible != no)
 259                         return def_sym;
 260         }
 261
 262         /* just get the first visible value */
 263         prop = sym_get_choice_prop(sym);
 264         expr_list_for_each_sym(prop->expr, e, def_sym)
 265                 if (def_sym->visible != no)
 266                         return def_sym;
 267
 268         /* failed to locate any defaults */
 269         return NULL;
 270 }
 271
 272 static struct symbol *sym_calc_choice(struct symbol *sym)
 273 {
 274         struct symbol *def_sym;
 275         struct property *prop;
 276         struct expr *e;
 277         int flags;
 278
 279         /* first calculate all choice values' visibilities */
 280         flags = sym->flags;
 281         prop = sym_get_choice_prop(sym);
 282         expr_list_for_each_sym(prop->expr, e, def_sym) {
 283                 sym_calc_visibility(def_sym);
 284                 if (def_sym->visible != no)
 285                         flags &= def_sym->flags;
 286         }
 287
 288         sym->flags &= flags | ~SYMBOL_DEF_USER;
 289
 290         /* is the user choice visible? */
 291         def_sym = sym->def[S_DEF_USER].val;
 292         if (def_sym && def_sym->visible != no)
 293                 return def_sym;
 294
 295         def_sym = sym_choice_default(sym);
 296
 297         if (def_sym == NULL)
 298                 /* no choice? reset tristate value */
 299                 sym->curr.tri = no;
 300
 301         return def_sym;
 302 }
 303
 304 void sym_calc_value(struct symbol *sym)
 305 {
 306         struct symbol_value newval, oldval;
 307         struct property *prop;
 308         struct expr *e;
 309
 310         if (!sym)
 311                 return;
 312
 313         if (sym->flags & SYMBOL_VALID)
 314                 return;
 315
 316         if (sym_is_choice_value(sym) &&
 317             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 318                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 319                 prop = sym_get_choice_prop(sym);
 320                 sym_calc_value(prop_get_symbol(prop));
 321         }
 322
 323         sym->flags |= SYMBOL_VALID;
 324
 325         oldval = sym->curr;
 326
 327         switch (sym->type) {
 328         case S_INT:
 329         case S_HEX:
 330         case S_STRING:
 331                 newval = symbol_empty.curr;
 332                 break;
 333         case S_BOOLEAN:
 334         case S_TRISTATE:
 335                 newval = symbol_no.curr;
 336                 break;
 337         default:
 338                 sym->curr.val = sym->name;
 339                 sym->curr.tri = no;
 340                 return;
 341         }
 342         sym->flags &= ~SYMBOL_WRITE;
 343
 344         sym_calc_visibility(sym);
 345
 346         if (sym->visible != no)
 347                 sym->flags |= SYMBOL_WRITE;
 348
 349         /* set default if recursively called */
 350         sym->curr = newval;
 351
 352         switch (sym_get_type(sym)) {
 353         case S_BOOLEAN:
 354         case S_TRISTATE:
 355                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 356                         prop = sym_get_choice_prop(sym);
 357                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 358                 } else {
 359                         if (sym->visible != no) {
 360                                 /* if the symbol is visible use the user value
 361                                  * if available, otherwise try the default value
 362                                  */
 363                                 if (sym_has_value(sym)) {
 364                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 365                                                               sym->visible);
 366                                         goto calc_newval;
 367                                 }
 368                         }
 369                         if (sym->rev_dep.tri != no)
 370                                 sym->flags |= SYMBOL_WRITE;
 371                         if (!sym_is_choice(sym)) {
 372                                 prop = sym_get_default_prop(sym);
 373                                 if (prop) {
 374                                         sym->flags |= SYMBOL_WRITE;
 375                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 376                                                               prop->visible.tri);
 377                                 }
 378                                 if (sym->implied.tri != no) {
 379                                         sym->flags |= SYMBOL_WRITE;
 380                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 381                                         newval.tri = EXPR_AND(newval.tri,
 382                                                               sym->dir_dep.tri);
 383                                 }
 384                         }
 385                 calc_newval:
 386                         if (sym->dir_dep.tri == no && sym->rev_dep.tri != no)
 387                                 newval.tri = no;
 388                         else
 389                                 newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 390                 }
 391                 if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 392                         newval.tri = yes;
 393                 break;
 394         case S_STRING:
 395         case S_HEX:
 396         case S_INT:
 397                 if (sym->visible != no && sym_has_value(sym)) {
 398                         newval.val = sym->def[S_DEF_USER].val;
 399                         break;
 400                 }
 401                 prop = sym_get_default_prop(sym);
 402                 if (prop) {
 403                         struct symbol *ds = prop_get_symbol(prop);
 404                         if (ds) {
 405                                 sym->flags |= SYMBOL_WRITE;
 406                                 sym_calc_value(ds);
 407                                 newval.val = ds->curr.val;
 408                         }
 409                 }
 410                 break;
 411         default:
 412                 ;
 413         }
 414
 415         sym->curr = newval;
 416         if (sym_is_choice(sym) && newval.tri == yes)
 417                 sym->curr.val = sym_calc_choice(sym);
 418         sym_validate_range(sym);
 419
 420         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 421                 sym_set_changed(sym);
 422                 if (modules_sym == sym) {
 423                         sym_set_all_changed();
 424                         modules_val = modules_sym->curr.tri;
 425                 }
 426         }
 427
 428         if (sym_is_choice(sym)) {
 429                 struct symbol *choice_sym;
 430
 431                 prop = sym_get_choice_prop(sym);
 432                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 433                         if ((sym->flags & SYMBOL_WRITE) &&
 434                             choice_sym->visible != no)
 435                                 choice_sym->flags |= SYMBOL_WRITE;
 436                         if (sym->flags & SYMBOL_CHANGED)
 437                                 sym_set_changed(choice_sym);
 438                 }
 439         }
 440
 441         if (sym->flags & SYMBOL_NO_WRITE)
 442                 sym->flags &= ~SYMBOL_WRITE;
 443
 444         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 445                 set_all_choice_values(sym);
 446 }
 447
 448 void sym_clear_all_valid(void)
 449 {
 450         struct symbol *sym;
 451         int i;
 452
 453         for_all_symbols(i, sym)
 454                 sym->flags &= ~SYMBOL_VALID;
 455         conf_set_changed(true);
 456         sym_calc_value(modules_sym);
 457 }
 458
 459 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 460 {
 461         int type = sym_get_type(sym);
 462
 463         if (sym->visible == no)
 464                 return false;
 465
 466         if (type != S_BOOLEAN && type != S_TRISTATE)
 467                 return false;
 468
 469         if (type == S_BOOLEAN && val == mod)
 470                 return false;
 471         if (sym->visible <= sym->rev_dep.tri)
 472                 return false;
 473         if (sym_is_choice_value(sym) && sym->visible == yes)
 474                 return val == yes;
 475         return val >= sym->rev_dep.tri && val <= sym->visible;
 476 }
 477
 478 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 479 {
 480         tristate oldval = sym_get_tristate_value(sym);
 481
 482         if (oldval != val && !sym_tristate_within_range(sym, val))
 483                 return false;
 484
 485         if (!(sym->flags & SYMBOL_DEF_USER)) {
 486                 sym->flags |= SYMBOL_DEF_USER;
 487                 sym_set_changed(sym);
 488         }
 489         /*
 490          * setting a choice value also resets the new flag of the choice
 491          * symbol and all other choice values.
 492          */
 493         if (sym_is_choice_value(sym) && val == yes) {
 494                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 495                 struct property *prop;
 496                 struct expr *e;
 497
 498                 cs->def[S_DEF_USER].val = sym;
 499                 cs->flags |= SYMBOL_DEF_USER;
 500                 prop = sym_get_choice_prop(cs);
 501                 for (e = prop->expr; e; e = e->left.expr) {
 502                         if (e->right.sym->visible != no)
 503                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 504                 }
 505         }
 506
 507         sym->def[S_DEF_USER].tri = val;
 508         if (oldval != val)
 509                 sym_clear_all_valid();
 510
 511         return true;
 512 }
 513
 514 tristate sym_toggle_tristate_value(struct symbol *sym)
 515 {
 516         tristate oldval, newval;
 517
 518         oldval = newval = sym_get_tristate_value(sym);
 519         do {
 520                 switch (newval) {
 521                 case no:
 522                         newval = mod;
 523                         break;
 524                 case mod:
 525                         newval = yes;
 526                         break;
 527                 case yes:
 528                         newval = no;
 529                         break;
 530                 }
 531                 if (sym_set_tristate_value(sym, newval))
 532                         break;
 533         } while (oldval != newval);
 534         return newval;
 535 }
 536
 537 bool sym_string_valid(struct symbol *sym, const char *str)
 538 {
 539         signed char ch;
 540
 541         switch (sym->type) {
 542         case S_STRING:
 543                 return true;
 544         case S_INT:
 545                 ch = *str++;
 546                 if (ch == '-')
 547                         ch = *str++;
 548                 if (!isdigit(ch))
 549                         return false;
 550                 if (ch == '0' && *str != 0)
 551                         return false;
 552                 while ((ch = *str++)) {
 553                         if (!isdigit(ch))
 554                                 return false;
 555                 }
 556                 return true;
 557         case S_HEX:
 558                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 559                         str += 2;
 560                 ch = *str++;
 561                 do {
 562                         if (!isxdigit(ch))
 563                                 return false;
 564                 } while ((ch = *str++));
 565                 return true;
 566         case S_BOOLEAN:
 567         case S_TRISTATE:
 568                 switch (str[0]) {
 569                 case 'y': case 'Y':
 570                 case 'm': case 'M':
 571                 case 'n': case 'N':
 572                         return true;
 573                 }
 574                 return false;
 575         default:
 576                 return false;
 577         }
 578 }
 579
 580 bool sym_string_within_range(struct symbol *sym, const char *str)
 581 {
 582         struct property *prop;
 583         long long val;
 584
 585         switch (sym->type) {
 586         case S_STRING:
 587                 return sym_string_valid(sym, str);
 588         case S_INT:
 589                 if (!sym_string_valid(sym, str))
 590                         return false;
 591                 prop = sym_get_range_prop(sym);
 592                 if (!prop)
 593                         return true;
 594                 val = strtoll(str, NULL, 10);
 595                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 596                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 597         case S_HEX:
 598                 if (!sym_string_valid(sym, str))
 599                         return false;
 600                 prop = sym_get_range_prop(sym);
 601                 if (!prop)
 602                         return true;
 603                 val = strtoll(str, NULL, 16);
 604                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 605                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 606         case S_BOOLEAN:
 607         case S_TRISTATE:
 608                 switch (str[0]) {
 609                 case 'y': case 'Y':
 610                         return sym_tristate_within_range(sym, yes);
 611                 case 'm': case 'M':
 612                         return sym_tristate_within_range(sym, mod);
 613                 case 'n': case 'N':
 614                         return sym_tristate_within_range(sym, no);
 615                 }
 616                 return false;
 617         default:
 618                 return false;
 619         }
 620 }
 621
 622 bool sym_set_string_value(struct symbol *sym, const char *newval)
 623 {
 624         const char *oldval;
 625         char *val;
 626         int size;
 627
 628         switch (sym->type) {
 629         case S_BOOLEAN:
 630         case S_TRISTATE:
 631                 switch (newval[0]) {
 632                 case 'y': case 'Y':
 633                         return sym_set_tristate_value(sym, yes);
 634                 case 'm': case 'M':
 635                         return sym_set_tristate_value(sym, mod);
 636                 case 'n': case 'N':
 637                         return sym_set_tristate_value(sym, no);
 638                 }
 639                 return false;
 640         default:
 641                 ;
 642         }
 643
 644         if (!sym_string_within_range(sym, newval))
 645                 return false;
 646
 647         if (!(sym->flags & SYMBOL_DEF_USER)) {
 648                 sym->flags |= SYMBOL_DEF_USER;
 649                 sym_set_changed(sym);
 650         }
 651
 652         oldval = sym->def[S_DEF_USER].val;
 653         size = strlen(newval) + 1;
 654         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 655                 size += 2;
 656                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 657                 *val++ = '0';
 658                 *val++ = 'x';
 659         } else if (!oldval || strcmp(oldval, newval))
 660                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 661         else
 662                 return true;
 663
 664         strcpy(val, newval);
 665         free((void *)oldval);
 666         sym_clear_all_valid();
 667
 668         return true;
 669 }
 670
 671 /*
 672  * Find the default value associated to a symbol.
 673  * For tristate symbol handle the modules=n case
 674  * in which case "m" becomes "y".
 675  * If the symbol does not have any default then fallback
 676  * to the fixed default values.
 677  */
 678 const char *sym_get_string_default(struct symbol *sym)
 679 {
 680         struct property *prop;
 681         struct symbol *ds;
 682         const char *str;
 683         tristate val;
 684
 685         sym_calc_visibility(sym);
 686         sym_calc_value(modules_sym);
 687         val = symbol_no.curr.tri;
 688         str = symbol_empty.curr.val;
 689
 690         /* If symbol has a default value look it up */
 691         prop = sym_get_default_prop(sym);
 692         if (prop != NULL) {
 693                 switch (sym->type) {
 694                 case S_BOOLEAN:
 695                 case S_TRISTATE:
 696                         /* The visibility may limit the value from yes => mod */
 697                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 698                         break;
 699                 default:
 700                         /*
 701                          * The following fails to handle the situation
 702                          * where a default value is further limited by
 703                          * the valid range.
 704                          */
 705                         ds = prop_get_symbol(prop);
 706                         if (ds != NULL) {
 707                                 sym_calc_value(ds);
 708                                 str = (const char *)ds->curr.val;
 709                         }
 710                 }
 711         }
 712
 713         /* Handle select statements */
 714         val = EXPR_OR(val, sym->rev_dep.tri);
 715
 716         /* transpose mod to yes if modules are not enabled */
 717         if (val == mod)
 718                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 719                         val = yes;
 720
 721         /* transpose mod to yes if type is bool */
 722         if (sym->type == S_BOOLEAN && val == mod)
 723                 val = yes;
 724
 725         /* adjust the default value if this symbol is implied by another */
 726         if (val < sym->implied.tri)
 727                 val = sym->implied.tri;
 728
 729         switch (sym->type) {
 730         case S_BOOLEAN:
 731         case S_TRISTATE:
 732                 switch (val) {
 733                 case no: return "n";
 734                 case mod: return "m";
 735                 case yes: return "y";
 736                 }
 737         case S_INT:
 738         case S_HEX:
 739                 return str;
 740         case S_STRING:
 741                 return str;
 742         case S_UNKNOWN:
 743                 break;
 744         }
 745         return "";
 746 }
 747
 748 const char *sym_get_string_value(struct symbol *sym)
 749 {
 750         tristate val;
 751
 752         switch (sym->type) {
 753         case S_BOOLEAN:
 754         case S_TRISTATE:
 755                 val = sym_get_tristate_value(sym);
 756                 switch (val) {
 757                 case no:
 758                         return "n";
 759                 case mod:
 760                         sym_calc_value(modules_sym);
 761                         return (modules_sym->curr.tri == no) ? "n" : "m";
 762                 case yes:
 763                         return "y";
 764                 }
 765                 break;
 766         default:
 767                 ;
 768         }
 769         return (const char *)sym->curr.val;
 770 }
 771
 772 bool sym_is_changeable(struct symbol *sym)
 773 {
 774         return sym->visible > sym->rev_dep.tri;
 775 }
 776
 777 static unsigned strhash(const char *s)
 778 {
 779         /* fnv32 hash */
 780         unsigned hash = 2166136261U;
 781         for (; *s; s++)
 782                 hash = (hash ^ *s) * 0x01000193;
 783         return hash;
 784 }
 785
 786 struct symbol *sym_lookup(const char *name, int flags)
 787 {
 788         struct symbol *symbol;
 789         char *new_name;
 790         int hash;
 791
 792         if (name) {
 793                 if (name[0] && !name[1]) {
 794                         switch (name[0]) {
 795                         case 'y': return &symbol_yes;
 796                         case 'm': return &symbol_mod;
 797                         case 'n': return &symbol_no;
 798                         }
 799                 }
 800                 hash = strhash(name) % SYMBOL_HASHSIZE;
 801
 802                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 803                         if (symbol->name &&
 804                             !strcmp(symbol->name, name) &&
 805                             (flags ? symbol->flags & flags
 806                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 807                                 return symbol;
 808                 }
 809                 new_name = xstrdup(name);
 810         } else {
 811                 new_name = NULL;
 812                 hash = 0;
 813         }
 814
 815         symbol = xmalloc(sizeof(*symbol));
 816         memset(symbol, 0, sizeof(*symbol));
 817         symbol->name = new_name;
 818         symbol->type = S_UNKNOWN;
 819         symbol->flags = flags;
 820
 821         symbol->next = symbol_hash[hash];
 822         symbol_hash[hash] = symbol;
 823
 824         return symbol;
 825 }
 826
 827 struct symbol *sym_find(const char *name)
 828 {
 829         struct symbol *symbol = NULL;
 830         int hash = 0;
 831
 832         if (!name)
 833                 return NULL;
 834
 835         if (name[0] && !name[1]) {
 836                 switch (name[0]) {
 837                 case 'y': return &symbol_yes;
 838                 case 'm': return &symbol_mod;
 839                 case 'n': return &symbol_no;
 840                 }
 841         }
 842         hash = strhash(name) % SYMBOL_HASHSIZE;
 843
 844         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 845                 if (symbol->name &&
 846                     !strcmp(symbol->name, name) &&
 847                     !(symbol->flags & SYMBOL_CONST))
 848                                 break;
 849         }
 850
 851         return symbol;
 852 }
 853
 854 const char *sym_escape_string_value(const char *in)
 855 {
 856         const char *p;
 857         size_t reslen;
 858         char *res;
 859         size_t l;
 860
 861         reslen = strlen(in) + strlen("\"\"") + 1;
 862
 863         p = in;
 864         for (;;) {
 865                 l = strcspn(p, "\"\\");
 866                 p += l;
 867
 868                 if (p[0] == '\0')
 869                         break;
 870
 871                 reslen++;
 872                 p++;
 873         }
 874
 875         res = xmalloc(reslen);
 876         res[0] = '\0';
 877
 878         strcat(res, "\"");
 879
 880         p = in;
 881         for (;;) {
 882                 l = strcspn(p, "\"\\");
 883                 strncat(res, p, l);
 884                 p += l;
 885
 886                 if (p[0] == '\0')
 887                         break;
 888
 889                 strcat(res, "\\");
 890                 strncat(res, p++, 1);
 891         }
 892
 893         strcat(res, "\"");
 894         return res;
 895 }
 896
 897 struct sym_match {
 898         struct symbol   *sym;
 899         off_t           so, eo;
 900 };
 901
 902 /* Compare matched symbols as thus:
 903  * - first, symbols that match exactly
 904  * - then, alphabetical sort
 905  */
 906 static int sym_rel_comp(const void *sym1, const void *sym2)
 907 {
 908         const struct sym_match *s1 = sym1;
 909         const struct sym_match *s2 = sym2;
 910         int exact1, exact2;
 911
 912         /* Exact match:
 913          * - if matched length on symbol s1 is the length of that symbol,
 914          *   then this symbol should come first;
 915          * - if matched length on symbol s2 is the length of that symbol,
 916          *   then this symbol should come first.
 917          * Note: since the search can be a regexp, both symbols may match
 918          * exactly; if this is the case, we can't decide which comes first,
 919          * and we fallback to sorting alphabetically.
 920          */
 921         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 922         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 923         if (exact1 && !exact2)
 924                 return -1;
 925         if (!exact1 && exact2)
 926                 return 1;
 927
 928         /* As a fallback, sort symbols alphabetically */
 929         return strcmp(s1->sym->name, s2->sym->name);
 930 }
 931
 932 struct symbol **sym_re_search(const char *pattern)
 933 {
 934         struct symbol *sym, **sym_arr = NULL;
 935         struct sym_match *sym_match_arr = NULL;
 936         int i, cnt, size;
 937         regex_t re;
 938         regmatch_t match[1];
 939
 940         cnt = size = 0;
 941         /* Skip if empty */
 942         if (strlen(pattern) == 0)
 943                 return NULL;
 944         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 945                 return NULL;
 946
 947         for_all_symbols(i, sym) {
 948                 if (sym->flags & SYMBOL_CONST || !sym->name)
 949                         continue;
 950                 if (regexec(&re, sym->name, 1, match, 0))
 951                         continue;
 952                 if (cnt >= size) {
 953                         void *tmp;
 954                         size += 16;
 955                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 956                         if (!tmp)
 957                                 goto sym_re_search_free;
 958                         sym_match_arr = tmp;
 959                 }
 960                 sym_calc_value(sym);
 961                 /* As regexec returned 0, we know we have a match, so
 962                  * we can use match[0].rm_[se]o without further checks
 963                  */
 964                 sym_match_arr[cnt].so = match[0].rm_so;
 965                 sym_match_arr[cnt].eo = match[0].rm_eo;
 966                 sym_match_arr[cnt++].sym = sym;
 967         }
 968         if (sym_match_arr) {
 969                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 970                 sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 971                 if (!sym_arr)
 972                         goto sym_re_search_free;
 973                 for (i = 0; i < cnt; i++)
 974                         sym_arr[i] = sym_match_arr[i].sym;
 975                 sym_arr[cnt] = NULL;
 976         }
 977 sym_re_search_free:
 978         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
 979         free(sym_match_arr);
 980         regfree(&re);
 981
 982         return sym_arr;
 983 }
 984
 985 /*
 986  * When we check for recursive dependencies we use a stack to save
 987  * current state so we can print out relevant info to user.
 988  * The entries are located on the call stack so no need to free memory.
 989  * Note insert() remove() must always match to properly clear the stack.
 990  */
 991 static struct dep_stack {
 992         struct dep_stack *prev, *next;
 993         struct symbol *sym;
 994         struct property *prop;
 995         struct expr **expr;
 996 } *check_top;
 997
 998 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
 999 {
1000         memset(stack, 0, sizeof(*stack));
1001         if (check_top)
1002                 check_top->next = stack;
1003         stack->prev = check_top;
1004         stack->sym = sym;
1005         check_top = stack;
1006 }
1007
1008 static void dep_stack_remove(void)
1009 {
1010         check_top = check_top->prev;
1011         if (check_top)
1012                 check_top->next = NULL;
1013 }
1014
1015 /*
1016  * Called when we have detected a recursive dependency.
1017  * check_top point to the top of the stact so we use
1018  * the ->prev pointer to locate the bottom of the stack.
1019  */
1020 static void sym_check_print_recursive(struct symbol *last_sym)
1021 {
1022         struct dep_stack *stack;
1023         struct symbol *sym, *next_sym;
1024         struct menu *menu = NULL;
1025         struct property *prop;
1026         struct dep_stack cv_stack;
1027
1028         if (sym_is_choice_value(last_sym)) {
1029                 dep_stack_insert(&cv_stack, last_sym);
1030                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1031         }
1032
1033         for (stack = check_top; stack != NULL; stack = stack->prev)
1034                 if (stack->sym == last_sym)
1035                         break;
1036         if (!stack) {
1037                 fprintf(stderr, "unexpected recursive dependency error\n");
1038                 return;
1039         }
1040
1041         for (; stack; stack = stack->next) {
1042                 sym = stack->sym;
1043                 next_sym = stack->next ? stack->next->sym : last_sym;
1044                 prop = stack->prop;
1045                 if (prop == NULL)
1046                         prop = stack->sym->prop;
1047
1048                 /* for choice values find the menu entry (used below) */
1049                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1050                         for (prop = sym->prop; prop; prop = prop->next) {
1051                                 menu = prop->menu;
1052                                 if (prop->menu)
1053                                         break;
1054                         }
1055                 }
1056                 if (stack->sym == last_sym)
1057                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1058                                 prop->file->name, prop->lineno);
1059
1060                 if (sym_is_choice(sym)) {
1061                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1062                                 menu->file->name, menu->lineno,
1063                                 sym->name ? sym->name : "<choice>",
1064                                 next_sym->name ? next_sym->name : "<choice>");
1065                 } else if (sym_is_choice_value(sym)) {
1066                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1067                                 menu->file->name, menu->lineno,
1068                                 sym->name ? sym->name : "<choice>",
1069                                 next_sym->name ? next_sym->name : "<choice>");
1070                 } else if (stack->expr == &sym->dir_dep.expr) {
1071                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1072                                 prop->file->name, prop->lineno,
1073                                 sym->name ? sym->name : "<choice>",
1074                                 next_sym->name ? next_sym->name : "<choice>");
1075                 } else if (stack->expr == &sym->rev_dep.expr) {
1076                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1077                                 prop->file->name, prop->lineno,
1078                                 sym->name ? sym->name : "<choice>",
1079                                 next_sym->name ? next_sym->name : "<choice>");
1080                 } else if (stack->expr == &sym->implied.expr) {
1081                         fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1082                                 prop->file->name, prop->lineno,
1083                                 sym->name ? sym->name : "<choice>",
1084                                 next_sym->name ? next_sym->name : "<choice>");
1085                 } else if (stack->expr) {
1086                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1087                                 prop->file->name, prop->lineno,
1088                                 sym->name ? sym->name : "<choice>",
1089                                 prop_get_type_name(prop->type),
1090                                 next_sym->name ? next_sym->name : "<choice>");
1091                 } else {
1092                         fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1093                                 prop->file->name, prop->lineno,
1094                                 sym->name ? sym->name : "<choice>",
1095                                 prop_get_type_name(prop->type),
1096                                 next_sym->name ? next_sym->name : "<choice>");
1097                 }
1098         }
1099
1100         fprintf(stderr,
1101                 "For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1102                 "subsection \"Kconfig recursive dependency limitations\"\n"
1103                 "\n");
1104
1105         if (check_top == &cv_stack)
1106                 dep_stack_remove();
1107 }
1108
1109 static struct symbol *sym_check_expr_deps(struct expr *e)
1110 {
1111         struct symbol *sym;
1112
1113         if (!e)
1114                 return NULL;
1115         switch (e->type) {
1116         case E_OR:
1117         case E_AND:
1118                 sym = sym_check_expr_deps(e->left.expr);
1119                 if (sym)
1120                         return sym;
1121                 return sym_check_expr_deps(e->right.expr);
1122         case E_NOT:
1123                 return sym_check_expr_deps(e->left.expr);
1124         case E_EQUAL:
1125         case E_GEQ:
1126         case E_GTH:
1127         case E_LEQ:
1128         case E_LTH:
1129         case E_UNEQUAL:
1130                 sym = sym_check_deps(e->left.sym);
1131                 if (sym)
1132                         return sym;
1133                 return sym_check_deps(e->right.sym);
1134         case E_SYMBOL:
1135                 return sym_check_deps(e->left.sym);
1136         default:
1137                 break;
1138         }
1139         fprintf(stderr, "Oops! How to check %d?\n", e->type);
1140         return NULL;
1141 }
1142
1143 /* return NULL when dependencies are OK */
1144 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1145 {
1146         struct symbol *sym2;
1147         struct property *prop;
1148         struct dep_stack stack;
1149
1150         dep_stack_insert(&stack, sym);
1151
1152         stack.expr = &sym->dir_dep.expr;
1153         sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1154         if (sym2)
1155                 goto out;
1156
1157         stack.expr = &sym->rev_dep.expr;
1158         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1159         if (sym2)
1160                 goto out;
1161
1162         stack.expr = &sym->implied.expr;
1163         sym2 = sym_check_expr_deps(sym->implied.expr);
1164         if (sym2)
1165                 goto out;
1166
1167         stack.expr = NULL;
1168
1169         for (prop = sym->prop; prop; prop = prop->next) {
1170                 if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1171                     prop->type == P_IMPLY)
1172                         continue;
1173                 stack.prop = prop;
1174                 sym2 = sym_check_expr_deps(prop->visible.expr);
1175                 if (sym2)
1176                         break;
1177                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1178                         continue;
1179                 stack.expr = &prop->expr;
1180                 sym2 = sym_check_expr_deps(prop->expr);
1181                 if (sym2)
1182                         break;
1183                 stack.expr = NULL;
1184         }
1185
1186 out:
1187         dep_stack_remove();
1188
1189         return sym2;
1190 }
1191
1192 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1193 {
1194         struct symbol *sym, *sym2;
1195         struct property *prop;
1196         struct expr *e;
1197         struct dep_stack stack;
1198
1199         dep_stack_insert(&stack, choice);
1200
1201         prop = sym_get_choice_prop(choice);
1202         expr_list_for_each_sym(prop->expr, e, sym)
1203                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1204
1205         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1206         sym2 = sym_check_sym_deps(choice);
1207         choice->flags &= ~SYMBOL_CHECK;
1208         if (sym2)
1209                 goto out;
1210
1211         expr_list_for_each_sym(prop->expr, e, sym) {
1212                 sym2 = sym_check_sym_deps(sym);
1213                 if (sym2)
1214                         break;
1215         }
1216 out:
1217         expr_list_for_each_sym(prop->expr, e, sym)
1218                 sym->flags &= ~SYMBOL_CHECK;
1219
1220         if (sym2 && sym_is_choice_value(sym2) &&
1221             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1222                 sym2 = choice;
1223
1224         dep_stack_remove();
1225
1226         return sym2;
1227 }
1228
1229 struct symbol *sym_check_deps(struct symbol *sym)
1230 {
1231         struct symbol *sym2;
1232         struct property *prop;
1233
1234         if (sym->flags & SYMBOL_CHECK) {
1235                 sym_check_print_recursive(sym);
1236                 return sym;
1237         }
1238         if (sym->flags & SYMBOL_CHECKED)
1239                 return NULL;
1240
1241         if (sym_is_choice_value(sym)) {
1242                 struct dep_stack stack;
1243
1244                 /* for choice groups start the check with main choice symbol */
1245                 dep_stack_insert(&stack, sym);
1246                 prop = sym_get_choice_prop(sym);
1247                 sym2 = sym_check_deps(prop_get_symbol(prop));
1248                 dep_stack_remove();
1249         } else if (sym_is_choice(sym)) {
1250                 sym2 = sym_check_choice_deps(sym);
1251         } else {
1252                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1253                 sym2 = sym_check_sym_deps(sym);
1254                 sym->flags &= ~SYMBOL_CHECK;
1255         }
1256
1257         if (!recursive_is_error && sym2 && sym2 == sym)
1258                 sym2 = NULL;
1259
1260         return sym2;
1261 }
1262
1263 struct symbol *prop_get_symbol(struct property *prop)
1264 {
1265         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1266                            prop->expr->type == E_LIST))
1267                 return prop->expr->left.sym;
1268         return NULL;
1269 }
1270
1271 const char *prop_get_type_name(enum prop_type type)
1272 {
1273         switch (type) {
1274         case P_PROMPT:
1275                 return "prompt";
1276         case P_COMMENT:
1277                 return "comment";
1278         case P_MENU:
1279                 return "menu";
1280         case P_DEFAULT:
1281                 return "default";
1282         case P_CHOICE:
1283                 return "choice";
1284         case P_SELECT:
1285                 return "select";
1286         case P_IMPLY:
1287                 return "imply";
1288         case P_RANGE:
1289                 return "range";
1290         case P_SYMBOL:
1291                 return "symbol";
1292         case P_RESET:
1293                 return "reset";
1294         case P_UNKNOWN:
1295                 break;
1296         }
1297         return "unknown";
1298 }