scripts/kconfig/symbol.c

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