util/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         int base;
 126         long long val, val2;
 127         char str[64];
 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         val2 = sym_get_range_val(prop->expr->left.sym, base);
 144         if (val >= val2) {
 145                 val2 = sym_get_range_val(prop->expr->right.sym, base);
 146                 if (val <= val2)
 147                         return;
 148         }
 149         if (sym->type == S_INT)
 150                 sprintf(str, "%lld", val2);
 151         else
 152                 sprintf(str, "0x%llx", val2);
 153         sym->curr.val = xstrdup(str);
 154 }
 155
 156 static void sym_set_changed(struct symbol *sym)
 157 {
 158         struct property *prop;
 159
 160         sym->flags |= SYMBOL_CHANGED;
 161         for (prop = sym->prop; prop; prop = prop->next) {
 162                 if (prop->menu)
 163                         prop->menu->flags |= MENU_CHANGED;
 164         }
 165 }
 166
 167 static void sym_set_all_changed(void)
 168 {
 169         struct symbol *sym;
 170         int i;
 171
 172         for_all_symbols(i, sym)
 173                 sym_set_changed(sym);
 174 }
 175
 176 static void sym_calc_visibility(struct symbol *sym)
 177 {
 178         struct property *prop;
 179         struct symbol *choice_sym = NULL;
 180         tristate tri;
 181
 182         /* any prompt visible? */
 183         tri = no;
 184
 185         if (sym_is_choice_value(sym))
 186                 choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
 187
 188         for_all_prompts(sym, prop) {
 189                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 190                 /*
 191                  * Tristate choice_values with visibility 'mod' are
 192                  * not visible if the corresponding choice's value is
 193                  * 'yes'.
 194                  */
 195                 if (choice_sym && sym->type == S_TRISTATE &&
 196                     prop->visible.tri == mod && choice_sym->curr.tri == yes)
 197                         prop->visible.tri = no;
 198
 199                 tri = EXPR_OR(tri, prop->visible.tri);
 200         }
 201         if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 202                 tri = yes;
 203         if (sym->visible != tri) {
 204                 sym->visible = tri;
 205                 sym_set_changed(sym);
 206         }
 207         if (sym_is_choice_value(sym))
 208                 return;
 209         /* defaulting to "yes" if no explicit "depends on" are given */
 210         tri = yes;
 211         if (sym->dir_dep.expr)
 212                 tri = expr_calc_value(sym->dir_dep.expr);
 213         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 214                 tri = yes;
 215         if (sym->dir_dep.tri != tri) {
 216                 sym->dir_dep.tri = tri;
 217                 sym_set_changed(sym);
 218         }
 219         tri = no;
 220         if (sym->rev_dep.expr)
 221                 tri = expr_calc_value(sym->rev_dep.expr);
 222         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 223                 tri = yes;
 224         if (sym->rev_dep.tri != tri) {
 225                 sym->rev_dep.tri = tri;
 226                 sym_set_changed(sym);
 227         }
 228         tri = no;
 229         if (sym->implied.expr)
 230                 tri = expr_calc_value(sym->implied.expr);
 231         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 232                 tri = yes;
 233         if (sym->implied.tri != tri) {
 234                 sym->implied.tri = tri;
 235                 sym_set_changed(sym);
 236         }
 237 }
 238
 239 /*
 240  * Find the default symbol for a choice.
 241  * First try the default values for the choice symbol
 242  * Next locate the first visible choice value
 243  * Return NULL if none was found
 244  */
 245 struct symbol *sym_choice_default(struct symbol *sym)
 246 {
 247         struct symbol *def_sym;
 248         struct property *prop;
 249         struct expr *e;
 250
 251         /* any of the defaults visible? */
 252         for_all_defaults(sym, prop) {
 253                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 254                 if (prop->visible.tri == no)
 255                         continue;
 256                 def_sym = prop_get_symbol(prop);
 257                 if (def_sym->visible != no)
 258                         return def_sym;
 259         }
 260
 261         /* just get the first visible value */
 262         prop = sym_get_choice_prop(sym);
 263         expr_list_for_each_sym(prop->expr, e, def_sym)
 264                 if (def_sym->visible != no)
 265                         return def_sym;
 266
 267         /* failed to locate any defaults */
 268         return NULL;
 269 }
 270
 271 static struct symbol *sym_calc_choice(struct symbol *sym)
 272 {
 273         struct symbol *def_sym;
 274         struct property *prop;
 275         struct expr *e;
 276         int flags;
 277
 278         /* first calculate all choice values' visibilities */
 279         flags = sym->flags;
 280         prop = sym_get_choice_prop(sym);
 281         expr_list_for_each_sym(prop->expr, e, def_sym) {
 282                 sym_calc_visibility(def_sym);
 283                 if (def_sym->visible != no)
 284                         flags &= def_sym->flags;
 285         }
 286
 287         sym->flags &= flags | ~SYMBOL_DEF_USER;
 288
 289         /* is the user choice visible? */
 290         def_sym = sym->def[S_DEF_USER].val;
 291         if (def_sym && def_sym->visible != no)
 292                 return def_sym;
 293
 294         def_sym = sym_choice_default(sym);
 295
 296         if (def_sym == NULL)
 297                 /* no choice? reset tristate value */
 298                 sym->curr.tri = no;
 299
 300         return def_sym;
 301 }
 302
 303 static void sym_warn_unmet_dep(struct symbol *sym)
 304 {
 305         struct gstr gs = str_new();
 306
 307         str_printf(&gs,
 308                    "\nWARNING: unmet direct dependencies detected for %s\n",
 309                    sym->name);
 310         str_printf(&gs,
 311                    "  Depends on [%c]: ",
 312                    sym->dir_dep.tri == mod ? 'm' : 'n');
 313         expr_gstr_print(sym->dir_dep.expr, &gs);
 314         str_printf(&gs, "\n");
 315
 316         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
 317                                "  Selected by [y]:\n");
 318         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
 319                                "  Selected by [m]:\n");
 320
 321         fputs(str_get(&gs), stderr);
 322         kconfig_warnings++;
 323 }
 324
 325 void sym_calc_value(struct symbol *sym)
 326 {
 327         struct symbol_value newval, oldval;
 328         struct property *prop;
 329         struct expr *e;
 330
 331         if (!sym)
 332                 return;
 333
 334         if (sym->flags & SYMBOL_VALID)
 335                 return;
 336
 337         if (sym_is_choice_value(sym) &&
 338             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 339                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 340                 prop = sym_get_choice_prop(sym);
 341                 sym_calc_value(prop_get_symbol(prop));
 342         }
 343
 344         sym->flags |= SYMBOL_VALID;
 345
 346         oldval = sym->curr;
 347
 348         switch (sym->type) {
 349         case S_INT:
 350         case S_HEX:
 351         case S_STRING:
 352                 newval = symbol_empty.curr;
 353                 break;
 354         case S_BOOLEAN:
 355         case S_TRISTATE:
 356                 newval = symbol_no.curr;
 357                 break;
 358         default:
 359                 sym->curr.val = sym->name;
 360                 sym->curr.tri = no;
 361                 return;
 362         }
 363         sym->flags &= ~SYMBOL_WRITE;
 364
 365         sym_calc_visibility(sym);
 366
 367         if (sym->visible != no)
 368                 sym->flags |= SYMBOL_WRITE;
 369
 370         /* set default if recursively called */
 371         sym->curr = newval;
 372
 373         switch (sym_get_type(sym)) {
 374         case S_BOOLEAN:
 375         case S_TRISTATE:
 376                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 377                         prop = sym_get_choice_prop(sym);
 378                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 379                 } else {
 380                         if (sym->visible != no) {
 381                                 /* if the symbol is visible use the user value
 382                                  * if available, otherwise try the default value
 383                                  */
 384                                 if (sym_has_value(sym)) {
 385                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 386                                                               sym->visible);
 387                                         goto calc_newval;
 388                                 }
 389                         }
 390                         if (sym->rev_dep.tri != no)
 391                                 sym->flags |= SYMBOL_WRITE;
 392                         if (!sym_is_choice(sym)) {
 393                                 prop = sym_get_default_prop(sym);
 394                                 if (prop) {
 395                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 396                                                               prop->visible.tri);
 397                                         if (newval.tri != no)
 398                                                 sym->flags |= SYMBOL_WRITE;
 399                                 }
 400                                 if (sym->implied.tri != no) {
 401                                         sym->flags |= SYMBOL_WRITE;
 402                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 403                                         newval.tri = EXPR_AND(newval.tri,
 404                                                               sym->dir_dep.tri);
 405                                 }
 406                         }
 407                 calc_newval:
 408                         if (sym->dir_dep.tri < sym->rev_dep.tri)
 409                                 sym_warn_unmet_dep(sym);
 410                         newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 411                 }
 412                 if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 413                         newval.tri = yes;
 414                 break;
 415         case S_STRING:
 416         case S_HEX:
 417         case S_INT:
 418                 if (sym->visible != no && sym_has_value(sym)) {
 419                         newval.val = sym->def[S_DEF_USER].val;
 420                         break;
 421                 }
 422                 prop = sym_get_default_prop(sym);
 423                 if (prop) {
 424                         struct symbol *ds = prop_get_symbol(prop);
 425                         if (ds) {
 426                                 sym->flags |= SYMBOL_WRITE;
 427                                 sym_calc_value(ds);
 428                                 newval.val = ds->curr.val;
 429                         }
 430                 }
 431                 break;
 432         default:
 433                 ;
 434         }
 435
 436         sym->curr = newval;
 437         if (sym_is_choice(sym) && newval.tri == yes)
 438                 sym->curr.val = sym_calc_choice(sym);
 439         sym_validate_range(sym);
 440
 441         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 442                 sym_set_changed(sym);
 443                 if (modules_sym == sym) {
 444                         sym_set_all_changed();
 445                         modules_val = modules_sym->curr.tri;
 446                 }
 447         }
 448
 449         if (sym_is_choice(sym)) {
 450                 struct symbol *choice_sym;
 451
 452                 prop = sym_get_choice_prop(sym);
 453                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 454                         if ((sym->flags & SYMBOL_WRITE) &&
 455                             choice_sym->visible != no)
 456                                 choice_sym->flags |= SYMBOL_WRITE;
 457                         if (sym->flags & SYMBOL_CHANGED)
 458                                 sym_set_changed(choice_sym);
 459                 }
 460         }
 461
 462         if (sym->flags & SYMBOL_NO_WRITE)
 463                 sym->flags &= ~SYMBOL_WRITE;
 464
 465         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 466                 set_all_choice_values(sym);
 467 }
 468
 469 void sym_clear_all_valid(void)
 470 {
 471         struct symbol *sym;
 472         int i;
 473
 474         for_all_symbols(i, sym)
 475                 sym->flags &= ~SYMBOL_VALID;
 476         conf_set_changed(true);
 477         sym_calc_value(modules_sym);
 478 }
 479
 480 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 481 {
 482         int type = sym_get_type(sym);
 483
 484         if (sym->visible == no)
 485                 return false;
 486
 487         if (type != S_BOOLEAN && type != S_TRISTATE)
 488                 return false;
 489
 490         if (type == S_BOOLEAN && val == mod)
 491                 return false;
 492         if (sym->visible <= sym->rev_dep.tri)
 493                 return false;
 494         if (sym_is_choice_value(sym) && sym->visible == yes)
 495                 return val == yes;
 496         return val >= sym->rev_dep.tri && val <= sym->visible;
 497 }
 498
 499 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 500 {
 501         tristate oldval = sym_get_tristate_value(sym);
 502
 503         if (oldval != val && !sym_tristate_within_range(sym, val))
 504                 return false;
 505
 506         if (!(sym->flags & SYMBOL_DEF_USER)) {
 507                 sym->flags |= SYMBOL_DEF_USER;
 508                 sym_set_changed(sym);
 509         }
 510         /*
 511          * setting a choice value also resets the new flag of the choice
 512          * symbol and all other choice values.
 513          */
 514         if (sym_is_choice_value(sym) && val == yes) {
 515                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 516                 struct property *prop;
 517                 struct expr *e;
 518
 519                 cs->def[S_DEF_USER].val = sym;
 520                 cs->flags |= SYMBOL_DEF_USER;
 521                 prop = sym_get_choice_prop(cs);
 522                 for (e = prop->expr; e; e = e->left.expr) {
 523                         if (e->right.sym->visible != no)
 524                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 525                 }
 526         }
 527
 528         sym->def[S_DEF_USER].tri = val;
 529         if (oldval != val)
 530                 sym_clear_all_valid();
 531
 532         return true;
 533 }
 534
 535 tristate sym_toggle_tristate_value(struct symbol *sym)
 536 {
 537         tristate oldval, newval;
 538
 539         oldval = newval = sym_get_tristate_value(sym);
 540         do {
 541                 switch (newval) {
 542                 case no:
 543                         newval = mod;
 544                         break;
 545                 case mod:
 546                         newval = yes;
 547                         break;
 548                 case yes:
 549                         newval = no;
 550                         break;
 551                 }
 552                 if (sym_set_tristate_value(sym, newval))
 553                         break;
 554         } while (oldval != newval);
 555         return newval;
 556 }
 557
 558 bool sym_string_valid(struct symbol *sym, const char *str)
 559 {
 560         signed char ch;
 561
 562         switch (sym->type) {
 563         case S_STRING:
 564                 return true;
 565         case S_INT:
 566                 ch = *str++;
 567                 if (ch == '-')
 568                         ch = *str++;
 569                 if (!isdigit(ch))
 570                         return false;
 571                 if (ch == '0' && *str != 0)
 572                         return false;
 573                 while ((ch = *str++)) {
 574                         if (!isdigit(ch))
 575                                 return false;
 576                 }
 577                 return true;
 578         case S_HEX:
 579                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 580                         str += 2;
 581                 ch = *str++;
 582                 do {
 583                         if (!isxdigit(ch))
 584                                 return false;
 585                 } while ((ch = *str++));
 586                 return true;
 587         case S_BOOLEAN:
 588         case S_TRISTATE:
 589                 switch (str[0]) {
 590                 case 'y': case 'Y':
 591                 case 'm': case 'M':
 592                 case 'n': case 'N':
 593                         return true;
 594                 }
 595                 return false;
 596         default:
 597                 return false;
 598         }
 599 }
 600
 601 bool sym_string_within_range(struct symbol *sym, const char *str)
 602 {
 603         struct property *prop;
 604         long long val;
 605
 606         switch (sym->type) {
 607         case S_STRING:
 608                 return sym_string_valid(sym, str);
 609         case S_INT:
 610                 if (!sym_string_valid(sym, str))
 611                         return false;
 612                 prop = sym_get_range_prop(sym);
 613                 if (!prop)
 614                         return true;
 615                 val = strtoll(str, NULL, 10);
 616                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 617                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 618         case S_HEX:
 619                 if (!sym_string_valid(sym, str))
 620                         return false;
 621                 prop = sym_get_range_prop(sym);
 622                 if (!prop)
 623                         return true;
 624                 val = strtoll(str, NULL, 16);
 625                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 626                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 627         case S_BOOLEAN:
 628         case S_TRISTATE:
 629                 switch (str[0]) {
 630                 case 'y': case 'Y':
 631                         return sym_tristate_within_range(sym, yes);
 632                 case 'm': case 'M':
 633                         return sym_tristate_within_range(sym, mod);
 634                 case 'n': case 'N':
 635                         return sym_tristate_within_range(sym, no);
 636                 }
 637                 return false;
 638         default:
 639                 return false;
 640         }
 641 }
 642
 643 bool sym_set_string_value(struct symbol *sym, const char *newval)
 644 {
 645         const char *oldval;
 646         char *val;
 647         int size;
 648
 649         switch (sym->type) {
 650         case S_BOOLEAN:
 651         case S_TRISTATE:
 652                 switch (newval[0]) {
 653                 case 'y': case 'Y':
 654                         return sym_set_tristate_value(sym, yes);
 655                 case 'm': case 'M':
 656                         return sym_set_tristate_value(sym, mod);
 657                 case 'n': case 'N':
 658                         return sym_set_tristate_value(sym, no);
 659                 }
 660                 return false;
 661         default:
 662                 ;
 663         }
 664
 665         if (!sym_string_within_range(sym, newval))
 666                 return false;
 667
 668         if (!(sym->flags & SYMBOL_DEF_USER)) {
 669                 sym->flags |= SYMBOL_DEF_USER;
 670                 sym_set_changed(sym);
 671         }
 672
 673         oldval = sym->def[S_DEF_USER].val;
 674         size = strlen(newval) + 1;
 675         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 676                 size += 2;
 677                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 678                 *val++ = '0';
 679                 *val++ = 'x';
 680         } else if (!oldval || strcmp(oldval, newval))
 681                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 682         else
 683                 return true;
 684
 685         strcpy(val, newval);
 686         free((void *)oldval);
 687         sym_clear_all_valid();
 688
 689         return true;
 690 }
 691
 692 /*
 693  * Find the default value associated to a symbol.
 694  * For tristate symbol handle the modules=n case
 695  * in which case "m" becomes "y".
 696  * If the symbol does not have any default then fallback
 697  * to the fixed default values.
 698  */
 699 const char *sym_get_string_default(struct symbol *sym)
 700 {
 701         struct property *prop;
 702         struct symbol *ds;
 703         const char *str;
 704         tristate val;
 705
 706         sym_calc_visibility(sym);
 707         sym_calc_value(modules_sym);
 708         val = symbol_no.curr.tri;
 709         str = symbol_empty.curr.val;
 710
 711         /* If symbol has a default value look it up */
 712         prop = sym_get_default_prop(sym);
 713         if (prop != NULL) {
 714                 switch (sym->type) {
 715                 case S_BOOLEAN:
 716                 case S_TRISTATE:
 717                         /* The visibility may limit the value from yes => mod */
 718                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 719                         break;
 720                 default:
 721                         /*
 722                          * The following fails to handle the situation
 723                          * where a default value is further limited by
 724                          * the valid range.
 725                          */
 726                         ds = prop_get_symbol(prop);
 727                         if (ds != NULL) {
 728                                 sym_calc_value(ds);
 729                                 str = (const char *)ds->curr.val;
 730                         }
 731                 }
 732         }
 733
 734         /* Handle select statements */
 735         val = EXPR_OR(val, sym->rev_dep.tri);
 736
 737         /* transpose mod to yes if modules are not enabled */
 738         if (val == mod)
 739                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 740                         val = yes;
 741
 742         /* transpose mod to yes if type is bool */
 743         if (sym->type == S_BOOLEAN && val == mod)
 744                 val = yes;
 745
 746         /* adjust the default value if this symbol is implied by another */
 747         if (val < sym->implied.tri)
 748                 val = sym->implied.tri;
 749
 750         switch (sym->type) {
 751         case S_BOOLEAN:
 752         case S_TRISTATE:
 753                 switch (val) {
 754                 case no: return "n";
 755                 case mod: return "m";
 756                 case yes: return "y";
 757                 }
 758         case S_INT:
 759         case S_HEX:
 760                 return "0";
 761         case S_STRING:
 762                 return str;
 763         case S_UNKNOWN:
 764                 break;
 765         }
 766         return "";
 767 }
 768
 769 const char *sym_get_string_value(struct symbol *sym)
 770 {
 771         tristate val;
 772
 773         switch (sym->type) {
 774         case S_BOOLEAN:
 775         case S_TRISTATE:
 776                 val = sym_get_tristate_value(sym);
 777                 switch (val) {
 778                 case no:
 779                         return "n";
 780                 case mod:
 781                         sym_calc_value(modules_sym);
 782                         return (modules_sym->curr.tri == no) ? "n" : "m";
 783                 case yes:
 784                         return "y";
 785                 }
 786                 break;
 787         default:
 788                 ;
 789         }
 790         return (const char *)sym->curr.val;
 791 }
 792
 793 bool sym_is_changeable(struct symbol *sym)
 794 {
 795         return sym->visible > sym->rev_dep.tri;
 796 }
 797
 798 static unsigned strhash(const char *s)
 799 {
 800         /* fnv32 hash */
 801         unsigned hash = 2166136261U;
 802         for (; *s; s++)
 803                 hash = (hash ^ *s) * 0x01000193;
 804         return hash;
 805 }
 806
 807 struct symbol *sym_lookup(const char *name, int flags)
 808 {
 809         struct symbol *symbol;
 810         char *new_name;
 811         int hash;
 812
 813         if (name) {
 814                 if (name[0] && !name[1]) {
 815                         switch (name[0]) {
 816                         case 'y': return &symbol_yes;
 817                         case 'm': return &symbol_mod;
 818                         case 'n': return &symbol_no;
 819                         }
 820                 }
 821                 hash = strhash(name) % SYMBOL_HASHSIZE;
 822
 823                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 824                         if (symbol->name &&
 825                             !strcmp(symbol->name, name) &&
 826                             (flags ? symbol->flags & flags
 827                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 828                                 return symbol;
 829                 }
 830                 new_name = xstrdup(name);
 831         } else {
 832                 new_name = NULL;
 833                 hash = 0;
 834         }
 835
 836         symbol = xmalloc(sizeof(*symbol));
 837         memset(symbol, 0, sizeof(*symbol));
 838         symbol->name = new_name;
 839         symbol->type = S_UNKNOWN;
 840         symbol->flags = flags;
 841
 842         symbol->next = symbol_hash[hash];
 843         symbol_hash[hash] = symbol;
 844
 845         return symbol;
 846 }
 847
 848 struct symbol *sym_find(const char *name)
 849 {
 850         struct symbol *symbol = NULL;
 851         int hash = 0;
 852
 853         if (!name)
 854                 return NULL;
 855
 856         if (name[0] && !name[1]) {
 857                 switch (name[0]) {
 858                 case 'y': return &symbol_yes;
 859                 case 'm': return &symbol_mod;
 860                 case 'n': return &symbol_no;
 861                 }
 862         }
 863         hash = strhash(name) % SYMBOL_HASHSIZE;
 864
 865         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 866                 if (symbol->name &&
 867                     !strcmp(symbol->name, name) &&
 868                     !(symbol->flags & SYMBOL_CONST))
 869                                 break;
 870         }
 871
 872         return symbol;
 873 }
 874
 875 const char *sym_escape_string_value(const char *in)
 876 {
 877         const char *p;
 878         size_t reslen;
 879         char *res;
 880         size_t l;
 881
 882         reslen = strlen(in) + strlen("\"\"") + 1;
 883
 884         p = in;
 885         for (;;) {
 886                 l = strcspn(p, "\"\\");
 887                 p += l;
 888
 889                 if (p[0] == '\0')
 890                         break;
 891
 892                 reslen++;
 893                 p++;
 894         }
 895
 896         res = xmalloc(reslen);
 897         res[0] = '\0';
 898
 899         strcat(res, "\"");
 900
 901         p = in;
 902         for (;;) {
 903                 l = strcspn(p, "\"\\");
 904                 strncat(res, p, l);
 905                 p += l;
 906
 907                 if (p[0] == '\0')
 908                         break;
 909
 910                 strcat(res, "\\");
 911                 strncat(res, p++, 1);
 912         }
 913
 914         strcat(res, "\"");
 915         return res;
 916 }
 917
 918 struct sym_match {
 919         struct symbol   *sym;
 920         off_t           so, eo;
 921 };
 922
 923 /* Compare matched symbols as thus:
 924  * - first, symbols that match exactly
 925  * - then, alphabetical sort
 926  */
 927 static int sym_rel_comp(const void *sym1, const void *sym2)
 928 {
 929         const struct sym_match *s1 = sym1;
 930         const struct sym_match *s2 = sym2;
 931         int exact1, exact2;
 932
 933         /* Exact match:
 934          * - if matched length on symbol s1 is the length of that symbol,
 935          *   then this symbol should come first;
 936          * - if matched length on symbol s2 is the length of that symbol,
 937          *   then this symbol should come first.
 938          * Note: since the search can be a regexp, both symbols may match
 939          * exactly; if this is the case, we can't decide which comes first,
 940          * and we fallback to sorting alphabetically.
 941          */
 942         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 943         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 944         if (exact1 && !exact2)
 945                 return -1;
 946         if (!exact1 && exact2)
 947                 return 1;
 948
 949         /* As a fallback, sort symbols alphabetically */
 950         return strcmp(s1->sym->name, s2->sym->name);
 951 }
 952
 953 struct symbol **sym_re_search(const char *pattern)
 954 {
 955         struct symbol *sym, **sym_arr = NULL;
 956         struct sym_match *sym_match_arr = NULL;
 957         int i, cnt, size;
 958         regex_t re;
 959         regmatch_t match[1];
 960
 961         cnt = size = 0;
 962         /* Skip if empty */
 963         if (strlen(pattern) == 0)
 964                 return NULL;
 965         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 966                 return NULL;
 967
 968         for_all_symbols(i, sym) {
 969                 if (sym->flags & SYMBOL_CONST || !sym->name)
 970                         continue;
 971                 if (regexec(&re, sym->name, 1, match, 0))
 972                         continue;
 973                 if (cnt >= size) {
 974                         void *tmp;
 975                         size += 16;
 976                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 977                         if (!tmp)
 978                                 goto sym_re_search_free;
 979                         sym_match_arr = tmp;
 980                 }
 981                 sym_calc_value(sym);
 982                 /* As regexec returned 0, we know we have a match, so
 983                  * we can use match[0].rm_[se]o without further checks
 984                  */
 985                 sym_match_arr[cnt].so = match[0].rm_so;
 986                 sym_match_arr[cnt].eo = match[0].rm_eo;
 987                 sym_match_arr[cnt++].sym = sym;
 988         }
 989         if (sym_match_arr) {
 990                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 991                 sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 992                 if (!sym_arr)
 993                         goto sym_re_search_free;
 994                 for (i = 0; i < cnt; i++)
 995                         sym_arr[i] = sym_match_arr[i].sym;
 996                 sym_arr[cnt] = NULL;
 997         }
 998 sym_re_search_free:
 999         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
1000         free(sym_match_arr);
1001         regfree(&re);
1002
1003         return sym_arr;
1004 }
1005
1006 /*
1007  * When we check for recursive dependencies we use a stack to save
1008  * current state so we can print out relevant info to user.
1009  * The entries are located on the call stack so no need to free memory.
1010  * Note insert() remove() must always match to properly clear the stack.
1011  */
1012 static struct dep_stack {
1013         struct dep_stack *prev, *next;
1014         struct symbol *sym;
1015         struct property *prop;
1016         struct expr **expr;
1017 } *check_top;
1018
1019 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1020 {
1021         memset(stack, 0, sizeof(*stack));
1022         if (check_top)
1023                 check_top->next = stack;
1024         stack->prev = check_top;
1025         stack->sym = sym;
1026         check_top = stack;
1027 }
1028
1029 static void dep_stack_remove(void)
1030 {
1031         check_top = check_top->prev;
1032         if (check_top)
1033                 check_top->next = NULL;
1034 }
1035
1036 /*
1037  * Called when we have detected a recursive dependency.
1038  * check_top point to the top of the stact so we use
1039  * the ->prev pointer to locate the bottom of the stack.
1040  */
1041 static void sym_check_print_recursive(struct symbol *last_sym)
1042 {
1043         struct dep_stack *stack;
1044         struct symbol *sym, *next_sym;
1045         struct menu *menu = NULL;
1046         struct property *prop;
1047         struct dep_stack cv_stack;
1048
1049         if (sym_is_choice_value(last_sym)) {
1050                 dep_stack_insert(&cv_stack, last_sym);
1051                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1052         }
1053
1054         for (stack = check_top; stack != NULL; stack = stack->prev)
1055                 if (stack->sym == last_sym)
1056                         break;
1057         if (!stack) {
1058                 fprintf(stderr, "unexpected recursive dependency error\n");
1059                 return;
1060         }
1061
1062         for (; stack; stack = stack->next) {
1063                 sym = stack->sym;
1064                 next_sym = stack->next ? stack->next->sym : last_sym;
1065                 prop = stack->prop;
1066                 if (prop == NULL)
1067                         prop = stack->sym->prop;
1068
1069                 /* for choice values find the menu entry (used below) */
1070                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1071                         for (prop = sym->prop; prop; prop = prop->next) {
1072                                 menu = prop->menu;
1073                                 if (prop->menu)
1074                                         break;
1075                         }
1076                 }
1077                 if (stack->sym == last_sym)
1078                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1079                                 prop->file->name, prop->lineno);
1080
1081                 if (sym_is_choice(sym)) {
1082                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1083                                 menu->file->name, menu->lineno,
1084                                 sym->name ? sym->name : "<choice>",
1085                                 next_sym->name ? next_sym->name : "<choice>");
1086                 } else if (sym_is_choice_value(sym)) {
1087                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1088                                 menu->file->name, menu->lineno,
1089                                 sym->name ? sym->name : "<choice>",
1090                                 next_sym->name ? next_sym->name : "<choice>");
1091                 } else if (stack->expr == &sym->dir_dep.expr) {
1092                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1093                                 prop->file->name, prop->lineno,
1094                                 sym->name ? sym->name : "<choice>",
1095                                 next_sym->name ? next_sym->name : "<choice>");
1096                 } else if (stack->expr == &sym->rev_dep.expr) {
1097                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1098                                 prop->file->name, prop->lineno,
1099                                 sym->name ? sym->name : "<choice>",
1100                                 next_sym->name ? next_sym->name : "<choice>");
1101                 } else if (stack->expr == &sym->implied.expr) {
1102                         fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1103                                 prop->file->name, prop->lineno,
1104                                 sym->name ? sym->name : "<choice>",
1105                                 next_sym->name ? next_sym->name : "<choice>");
1106                 } else if (stack->expr) {
1107                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1108                                 prop->file->name, prop->lineno,
1109                                 sym->name ? sym->name : "<choice>",
1110                                 prop_get_type_name(prop->type),
1111                                 next_sym->name ? next_sym->name : "<choice>");
1112                 } else {
1113                         fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1114                                 prop->file->name, prop->lineno,
1115                                 sym->name ? sym->name : "<choice>",
1116                                 prop_get_type_name(prop->type),
1117                                 next_sym->name ? next_sym->name : "<choice>");
1118                 }
1119         }
1120
1121         fprintf(stderr,
1122                 "For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1123                 "subsection \"Kconfig recursive dependency limitations\"\n"
1124                 "\n");
1125
1126         if (check_top == &cv_stack)
1127                 dep_stack_remove();
1128 }
1129
1130 static struct symbol *sym_check_expr_deps(struct expr *e)
1131 {
1132         struct symbol *sym;
1133
1134         if (!e)
1135                 return NULL;
1136         switch (e->type) {
1137         case E_OR:
1138         case E_AND:
1139                 sym = sym_check_expr_deps(e->left.expr);
1140                 if (sym)
1141                         return sym;
1142                 return sym_check_expr_deps(e->right.expr);
1143         case E_NOT:
1144                 return sym_check_expr_deps(e->left.expr);
1145         case E_EQUAL:
1146         case E_GEQ:
1147         case E_GTH:
1148         case E_LEQ:
1149         case E_LTH:
1150         case E_UNEQUAL:
1151                 sym = sym_check_deps(e->left.sym);
1152                 if (sym)
1153                         return sym;
1154                 return sym_check_deps(e->right.sym);
1155         case E_SYMBOL:
1156                 return sym_check_deps(e->left.sym);
1157         default:
1158                 break;
1159         }
1160         fprintf(stderr, "Oops! How to check %d?\n", e->type);
1161         return NULL;
1162 }
1163
1164 /* return NULL when dependencies are OK */
1165 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1166 {
1167         struct symbol *sym2;
1168         struct property *prop;
1169         struct dep_stack stack;
1170
1171         dep_stack_insert(&stack, sym);
1172
1173         stack.expr = &sym->dir_dep.expr;
1174         sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1175         if (sym2)
1176                 goto out;
1177
1178         stack.expr = &sym->rev_dep.expr;
1179         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1180         if (sym2)
1181                 goto out;
1182
1183         stack.expr = &sym->implied.expr;
1184         sym2 = sym_check_expr_deps(sym->implied.expr);
1185         if (sym2)
1186                 goto out;
1187
1188         stack.expr = NULL;
1189
1190         for (prop = sym->prop; prop; prop = prop->next) {
1191                 if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1192                     prop->type == P_IMPLY)
1193                         continue;
1194                 stack.prop = prop;
1195                 sym2 = sym_check_expr_deps(prop->visible.expr);
1196                 if (sym2)
1197                         break;
1198                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1199                         continue;
1200                 stack.expr = &prop->expr;
1201                 sym2 = sym_check_expr_deps(prop->expr);
1202                 if (sym2)
1203                         break;
1204                 stack.expr = NULL;
1205         }
1206
1207 out:
1208         dep_stack_remove();
1209
1210         return sym2;
1211 }
1212
1213 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1214 {
1215         struct symbol *sym, *sym2;
1216         struct property *prop;
1217         struct expr *e;
1218         struct dep_stack stack;
1219
1220         dep_stack_insert(&stack, choice);
1221
1222         prop = sym_get_choice_prop(choice);
1223         expr_list_for_each_sym(prop->expr, e, sym)
1224                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1225
1226         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1227         sym2 = sym_check_sym_deps(choice);
1228         choice->flags &= ~SYMBOL_CHECK;
1229         if (sym2)
1230                 goto out;
1231
1232         expr_list_for_each_sym(prop->expr, e, sym) {
1233                 sym2 = sym_check_sym_deps(sym);
1234                 if (sym2)
1235                         break;
1236         }
1237 out:
1238         expr_list_for_each_sym(prop->expr, e, sym)
1239                 sym->flags &= ~SYMBOL_CHECK;
1240
1241         if (sym2 && sym_is_choice_value(sym2) &&
1242             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1243                 sym2 = choice;
1244
1245         dep_stack_remove();
1246
1247         return sym2;
1248 }
1249
1250 struct symbol *sym_check_deps(struct symbol *sym)
1251 {
1252         struct symbol *sym2;
1253         struct property *prop;
1254
1255         if (sym->flags & SYMBOL_CHECK) {
1256                 sym_check_print_recursive(sym);
1257                 return sym;
1258         }
1259         if (sym->flags & SYMBOL_CHECKED)
1260                 return NULL;
1261
1262         if (sym_is_choice_value(sym)) {
1263                 struct dep_stack stack;
1264
1265                 /* for choice groups start the check with main choice symbol */
1266                 dep_stack_insert(&stack, sym);
1267                 prop = sym_get_choice_prop(sym);
1268                 sym2 = sym_check_deps(prop_get_symbol(prop));
1269                 dep_stack_remove();
1270         } else if (sym_is_choice(sym)) {
1271                 sym2 = sym_check_choice_deps(sym);
1272         } else {
1273                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1274                 sym2 = sym_check_sym_deps(sym);
1275                 sym->flags &= ~SYMBOL_CHECK;
1276         }
1277
1278         return sym2;
1279 }
1280
1281 struct symbol *prop_get_symbol(struct property *prop)
1282 {
1283         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1284                            prop->expr->type == E_LIST))
1285                 return prop->expr->left.sym;
1286         return NULL;
1287 }
1288
1289 const char *prop_get_type_name(enum prop_type type)
1290 {
1291         switch (type) {
1292         case P_PROMPT:
1293                 return "prompt";
1294         case P_COMMENT:
1295                 return "comment";
1296         case P_MENU:
1297                 return "menu";
1298         case P_DEFAULT:
1299                 return "default";
1300         case P_CHOICE:
1301                 return "choice";
1302         case P_SELECT:
1303                 return "select";
1304         case P_IMPLY:
1305                 return "imply";
1306         case P_RANGE:
1307                 return "range";
1308         case P_SYMBOL:
1309                 return "symbol";
1310         case P_UNKNOWN:
1311                 break;
1312         }
1313         return "unknown";
1314 }