util/kconfig/symbol.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   4  */
   5
   6 #include <sys/types.h>
   7 #include <ctype.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <regex.h>
  11
  12 #include "lkc.h"
  13
  14 struct symbol symbol_yes = {
  15         .name = "y",
  16         .curr = { "y", yes },
  17         .flags = SYMBOL_CONST|SYMBOL_VALID,
  18 };
  19
  20 struct symbol symbol_mod = {
  21         .name = "m",
  22         .curr = { "m", mod },
  23         .flags = SYMBOL_CONST|SYMBOL_VALID,
  24 };
  25
  26 struct symbol symbol_no = {
  27         .name = "n",
  28         .curr = { "n", no },
  29         .flags = SYMBOL_CONST|SYMBOL_VALID,
  30 };
  31
  32 static struct symbol symbol_empty = {
  33         .name = "",
  34         .curr = { "", no },
  35         .flags = SYMBOL_VALID,
  36 };
  37
  38 struct symbol *modules_sym;
  39 static tristate modules_val;
  40 static int sym_warnings;
  41
  42 enum symbol_type sym_get_type(struct symbol *sym)
  43 {
  44         enum symbol_type type = sym->type;
  45
  46         if (type == S_TRISTATE) {
  47                 if (sym_is_choice_value(sym) && sym->visible == yes)
  48                         type = S_BOOLEAN;
  49                 else if (modules_val == no)
  50                         type = S_BOOLEAN;
  51         }
  52         return type;
  53 }
  54
  55 const char *sym_type_name(enum symbol_type type)
  56 {
  57         switch (type) {
  58         case S_BOOLEAN:
  59                 return "bool";
  60         case S_TRISTATE:
  61                 return "tristate";
  62         case S_INT:
  63                 return "integer";
  64         case S_HEX:
  65                 return "hex";
  66         case S_STRING:
  67                 return "string";
  68         case S_UNKNOWN:
  69                 return "unknown";
  70         }
  71         return "???";
  72 }
  73
  74 struct property *sym_get_choice_prop(struct symbol *sym)
  75 {
  76         struct property *prop;
  77
  78         for_all_choices(sym, prop)
  79                 return prop;
  80         return NULL;
  81 }
  82
  83 static struct property *sym_get_default_prop(struct symbol *sym)
  84 {
  85         struct property *prop;
  86
  87         for_all_defaults(sym, prop) {
  88                 prop->visible.tri = expr_calc_value(prop->visible.expr);
  89                 if (prop->visible.tri != no)
  90                         return prop;
  91         }
  92         return NULL;
  93 }
  94
  95 struct property *sym_get_range_prop(struct symbol *sym)
  96 {
  97         struct property *prop;
  98
  99         for_all_properties(sym, prop, P_RANGE) {
 100                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 101                 if (prop->visible.tri != no)
 102                         return prop;
 103         }
 104         return NULL;
 105 }
 106
 107 static long long sym_get_range_val(struct symbol *sym, int base)
 108 {
 109         sym_calc_value(sym);
 110         switch (sym->type) {
 111         case S_INT:
 112                 base = 10;
 113                 break;
 114         case S_HEX:
 115                 base = 16;
 116                 break;
 117         default:
 118                 break;
 119         }
 120         return strtoll(sym->curr.val, NULL, base);
 121 }
 122
 123 static void sym_validate_range(struct symbol *sym)
 124 {
 125         struct property *prop;
 126         struct symbol *range_sym;
 127         int base;
 128         long long val, val2;
 129
 130         switch (sym->type) {
 131         case S_INT:
 132                 base = 10;
 133                 break;
 134         case S_HEX:
 135                 base = 16;
 136                 break;
 137         default:
 138                 return;
 139         }
 140         prop = sym_get_range_prop(sym);
 141         if (!prop)
 142                 return;
 143         val = strtoll(sym->curr.val, NULL, base);
 144         range_sym = prop->expr->left.sym;
 145         val2 = sym_get_range_val(range_sym, base);
 146         if (val >= val2) {
 147                 range_sym = prop->expr->right.sym;
 148                 val2 = sym_get_range_val(range_sym, base);
 149                 if (val <= val2)
 150                         return;
 151         }
 152         sym->curr.val = range_sym->curr.val;
 153 }
 154
 155 static void sym_set_changed(struct symbol *sym)
 156 {
 157         struct property *prop;
 158
 159         sym->flags |= SYMBOL_CHANGED;
 160         for (prop = sym->prop; prop; prop = prop->next) {
 161                 if (prop->menu)
 162                         prop->menu->flags |= MENU_CHANGED;
 163         }
 164 }
 165
 166 static void sym_set_all_changed(void)
 167 {
 168         struct symbol *sym;
 169         int i;
 170
 171         for_all_symbols(i, sym)
 172                 sym_set_changed(sym);
 173 }
 174
 175 static void sym_calc_visibility(struct symbol *sym)
 176 {
 177         struct property *prop;
 178         struct symbol *choice_sym = NULL;
 179         tristate tri;
 180
 181         /* any prompt visible? */
 182         tri = no;
 183
 184         if (sym_is_choice_value(sym))
 185                 choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
 186
 187         for_all_prompts(sym, prop) {
 188                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 189                 /*
 190                  * Tristate choice_values with visibility 'mod' are
 191                  * not visible if the corresponding choice's value is
 192                  * 'yes'.
 193                  */
 194                 if (choice_sym && sym->type == S_TRISTATE &&
 195                     prop->visible.tri == mod && choice_sym->curr.tri == yes)
 196                         prop->visible.tri = no;
 197
 198                 tri = EXPR_OR(tri, prop->visible.tri);
 199         }
 200         if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 201                 tri = yes;
 202         if (sym->visible != tri) {
 203                 sym->visible = tri;
 204                 sym_set_changed(sym);
 205         }
 206         if (sym_is_choice_value(sym))
 207                 return;
 208         /* defaulting to "yes" if no explicit "depends on" are given */
 209         tri = yes;
 210         if (sym->dir_dep.expr)
 211                 tri = expr_calc_value(sym->dir_dep.expr);
 212         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 213                 tri = yes;
 214         if (sym->dir_dep.tri != tri) {
 215                 sym->dir_dep.tri = tri;
 216                 sym_set_changed(sym);
 217         }
 218         tri = no;
 219         if (sym->rev_dep.expr)
 220                 tri = expr_calc_value(sym->rev_dep.expr);
 221         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 222                 tri = yes;
 223         if (sym->rev_dep.tri != tri) {
 224                 sym->rev_dep.tri = tri;
 225                 sym_set_changed(sym);
 226         }
 227         tri = no;
 228         if (sym->implied.expr)
 229                 tri = expr_calc_value(sym->implied.expr);
 230         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 231                 tri = yes;
 232         if (sym->implied.tri != tri) {
 233                 sym->implied.tri = tri;
 234                 sym_set_changed(sym);
 235         }
 236 }
 237
 238 /*
 239  * Find the default symbol for a choice.
 240  * First try the default values for the choice symbol
 241  * Next locate the first visible choice value
 242  * Return NULL if none was found
 243  */
 244 struct symbol *sym_choice_default(struct symbol *sym)
 245 {
 246         struct symbol *def_sym;
 247         struct property *prop;
 248         struct expr *e;
 249
 250         /* any of the defaults visible? */
 251         for_all_defaults(sym, prop) {
 252                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 253                 if (prop->visible.tri == no)
 254                         continue;
 255                 def_sym = prop_get_symbol(prop);
 256                 if (def_sym->visible != no)
 257                         return def_sym;
 258         }
 259
 260         /* just get the first visible value */
 261         prop = sym_get_choice_prop(sym);
 262         expr_list_for_each_sym(prop->expr, e, def_sym)
 263                 if (def_sym->visible != no)
 264                         return def_sym;
 265
 266         /* failed to locate any defaults */
 267         return NULL;
 268 }
 269
 270 static struct symbol *sym_calc_choice(struct symbol *sym)
 271 {
 272         struct symbol *def_sym;
 273         struct property *prop;
 274         struct expr *e;
 275         int flags;
 276
 277         /* first calculate all choice values' visibilities */
 278         flags = sym->flags;
 279         prop = sym_get_choice_prop(sym);
 280         expr_list_for_each_sym(prop->expr, e, def_sym) {
 281                 sym_calc_visibility(def_sym);
 282                 if (def_sym->visible != no)
 283                         flags &= def_sym->flags;
 284         }
 285
 286         sym->flags &= flags | ~SYMBOL_DEF_USER;
 287
 288         /* is the user choice visible? */
 289         def_sym = sym->def[S_DEF_USER].val;
 290         if (def_sym && def_sym->visible != no)
 291                 return def_sym;
 292
 293         def_sym = sym_choice_default(sym);
 294
 295         if (def_sym == NULL)
 296                 /* no choice? reset tristate value */
 297                 sym->curr.tri = no;
 298
 299         return def_sym;
 300 }
 301
 302 static void sym_warn_unmet_dep(struct symbol *sym)
 303 {
 304         struct gstr gs = str_new();
 305
 306         str_printf(&gs,
 307                    "\nWARNING: unmet direct dependencies detected for %s\n",
 308                    sym->name);
 309         str_printf(&gs,
 310                    "  Depends on [%c]: ",
 311                    sym->dir_dep.tri == mod ? 'm' : 'n');
 312         expr_gstr_print(sym->dir_dep.expr, &gs);
 313         str_printf(&gs, "\n");
 314
 315         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
 316                                "  Selected by [y]:\n");
 317         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
 318                                "  Selected by [m]:\n");
 319
 320         fputs(str_get(&gs), stderr);
 321         sym_warnings++;
 322 }
 323
 324 void sym_calc_value(struct symbol *sym)
 325 {
 326         struct symbol_value newval, oldval;
 327         struct property *prop;
 328         const char *werror;
 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         werror = getenv("KCONFIG_WERROR");
 345         sym_warnings = 0;
 346         sym->flags |= SYMBOL_VALID;
 347         oldval = sym->curr;
 348
 349         switch (sym->type) {
 350         case S_INT:
 351         case S_HEX:
 352         case S_STRING:
 353                 newval = symbol_empty.curr;
 354                 break;
 355         case S_BOOLEAN:
 356         case S_TRISTATE:
 357                 newval = symbol_no.curr;
 358                 break;
 359         default:
 360                 sym->curr.val = sym->name;
 361                 sym->curr.tri = no;
 362                 return;
 363         }
 364         sym->flags &= ~SYMBOL_WRITE;
 365
 366         sym_calc_visibility(sym);
 367
 368         if (sym->visible != no)
 369                 sym->flags |= SYMBOL_WRITE;
 370
 371         /* set default if recursively called */
 372         sym->curr = newval;
 373
 374         switch (sym_get_type(sym)) {
 375         case S_BOOLEAN:
 376         case S_TRISTATE:
 377                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 378                         prop = sym_get_choice_prop(sym);
 379                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 380                 } else {
 381                         if (sym->visible != no) {
 382                                 /* if the symbol is visible use the user value
 383                                  * if available, otherwise try the default value
 384                                  */
 385                                 if (sym_has_value(sym)) {
 386                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 387                                                               sym->visible);
 388                                         goto calc_newval;
 389                                 }
 390                         }
 391                         if (sym->rev_dep.tri != no)
 392                                 sym->flags |= SYMBOL_WRITE;
 393                         if (!sym_is_choice(sym)) {
 394                                 prop = sym_get_default_prop(sym);
 395                                 if (prop) {
 396                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 397                                                               prop->visible.tri);
 398                                         if (newval.tri != no)
 399                                                 sym->flags |= SYMBOL_WRITE;
 400                                 }
 401                                 if (sym->implied.tri != no) {
 402                                         sym->flags |= SYMBOL_WRITE;
 403                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 404                                         newval.tri = EXPR_AND(newval.tri,
 405                                                               sym->dir_dep.tri);
 406                                 }
 407                         }
 408                 calc_newval:
 409                         if (sym->dir_dep.tri < sym->rev_dep.tri)
 410                                 sym_warn_unmet_dep(sym);
 411                         newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 412                 }
 413                 if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 414                         newval.tri = yes;
 415                 break;
 416         case S_STRING:
 417         case S_HEX:
 418         case S_INT:
 419                 if (sym->visible != no && sym_has_value(sym)) {
 420                         newval.val = sym->def[S_DEF_USER].val;
 421                         break;
 422                 }
 423                 prop = sym_get_default_prop(sym);
 424                 if (prop) {
 425                         struct symbol *ds = prop_get_symbol(prop);
 426                         if (ds) {
 427                                 sym->flags |= SYMBOL_WRITE;
 428                                 sym_calc_value(ds);
 429                                 newval.val = ds->curr.val;
 430                         }
 431                 }
 432                 break;
 433         default:
 434                 ;
 435         }
 436
 437         if (sym_warnings && werror)
 438                 exit(1);
 439
 440         sym->curr = newval;
 441         if (sym_is_choice(sym) && newval.tri == yes)
 442                 sym->curr.val = sym_calc_choice(sym);
 443         sym_validate_range(sym);
 444
 445         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 446                 sym_set_changed(sym);
 447                 if (modules_sym == sym) {
 448                         sym_set_all_changed();
 449                         modules_val = modules_sym->curr.tri;
 450                 }
 451         }
 452
 453         if (sym_is_choice(sym)) {
 454                 struct symbol *choice_sym;
 455
 456                 prop = sym_get_choice_prop(sym);
 457                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 458                         if ((sym->flags & SYMBOL_WRITE) &&
 459                             choice_sym->visible != no)
 460                                 choice_sym->flags |= SYMBOL_WRITE;
 461                         if (sym->flags & SYMBOL_CHANGED)
 462                                 sym_set_changed(choice_sym);
 463                 }
 464         }
 465
 466         if (sym->flags & SYMBOL_NO_WRITE)
 467                 sym->flags &= ~SYMBOL_WRITE;
 468
 469         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 470                 set_all_choice_values(sym);
 471 }
 472
 473 void sym_clear_all_valid(void)
 474 {
 475         struct symbol *sym;
 476         int i;
 477
 478         for_all_symbols(i, sym)
 479                 sym->flags &= ~SYMBOL_VALID;
 480         conf_set_changed(true);
 481         sym_calc_value(modules_sym);
 482 }
 483
 484 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 485 {
 486         int type = sym_get_type(sym);
 487
 488         if (sym->visible == no)
 489                 return false;
 490
 491         if (type != S_BOOLEAN && type != S_TRISTATE)
 492                 return false;
 493
 494         if (type == S_BOOLEAN && val == mod)
 495                 return false;
 496         if (sym->visible <= sym->rev_dep.tri)
 497                 return false;
 498         if (sym_is_choice_value(sym) && sym->visible == yes)
 499                 return val == yes;
 500         return val >= sym->rev_dep.tri && val <= sym->visible;
 501 }
 502
 503 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 504 {
 505         tristate oldval = sym_get_tristate_value(sym);
 506
 507         if (oldval != val && !sym_tristate_within_range(sym, val))
 508                 return false;
 509
 510         if (!(sym->flags & SYMBOL_DEF_USER)) {
 511                 sym->flags |= SYMBOL_DEF_USER;
 512                 sym_set_changed(sym);
 513         }
 514         /*
 515          * setting a choice value also resets the new flag of the choice
 516          * symbol and all other choice values.
 517          */
 518         if (sym_is_choice_value(sym) && val == yes) {
 519                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 520                 struct property *prop;
 521                 struct expr *e;
 522
 523                 cs->def[S_DEF_USER].val = sym;
 524                 cs->flags |= SYMBOL_DEF_USER;
 525                 prop = sym_get_choice_prop(cs);
 526                 for (e = prop->expr; e; e = e->left.expr) {
 527                         if (e->right.sym->visible != no)
 528                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 529                 }
 530         }
 531
 532         sym->def[S_DEF_USER].tri = val;
 533         if (oldval != val)
 534                 sym_clear_all_valid();
 535
 536         return true;
 537 }
 538
 539 tristate sym_toggle_tristate_value(struct symbol *sym)
 540 {
 541         tristate oldval, newval;
 542
 543         oldval = newval = sym_get_tristate_value(sym);
 544         do {
 545                 switch (newval) {
 546                 case no:
 547                         newval = mod;
 548                         break;
 549                 case mod:
 550                         newval = yes;
 551                         break;
 552                 case yes:
 553                         newval = no;
 554                         break;
 555                 }
 556                 if (sym_set_tristate_value(sym, newval))
 557                         break;
 558         } while (oldval != newval);
 559         return newval;
 560 }
 561
 562 bool sym_string_valid(struct symbol *sym, const char *str)
 563 {
 564         signed char ch;
 565
 566         switch (sym->type) {
 567         case S_STRING:
 568                 return true;
 569         case S_INT:
 570                 ch = *str++;
 571                 if (ch == '-')
 572                         ch = *str++;
 573                 if (!isdigit(ch))
 574                         return false;
 575                 if (ch == '0' && *str != 0)
 576                         return false;
 577                 while ((ch = *str++)) {
 578                         if (!isdigit(ch))
 579                                 return false;
 580                 }
 581                 return true;
 582         case S_HEX:
 583                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 584                         str += 2;
 585                 ch = *str++;
 586                 do {
 587                         if (!isxdigit(ch))
 588                                 return false;
 589                 } while ((ch = *str++));
 590                 return true;
 591         case S_BOOLEAN:
 592         case S_TRISTATE:
 593                 switch (str[0]) {
 594                 case 'y': case 'Y':
 595                 case 'm': case 'M':
 596                 case 'n': case 'N':
 597                         return true;
 598                 }
 599                 return false;
 600         default:
 601                 return false;
 602         }
 603 }
 604
 605 bool sym_string_within_range(struct symbol *sym, const char *str)
 606 {
 607         struct property *prop;
 608         long long val;
 609
 610         switch (sym->type) {
 611         case S_STRING:
 612                 return sym_string_valid(sym, str);
 613         case S_INT:
 614                 if (!sym_string_valid(sym, str))
 615                         return false;
 616                 prop = sym_get_range_prop(sym);
 617                 if (!prop)
 618                         return true;
 619                 val = strtoll(str, NULL, 10);
 620                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 621                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 622         case S_HEX:
 623                 if (!sym_string_valid(sym, str))
 624                         return false;
 625                 prop = sym_get_range_prop(sym);
 626                 if (!prop)
 627                         return true;
 628                 val = strtoll(str, NULL, 16);
 629                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 630                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 631         case S_BOOLEAN:
 632         case S_TRISTATE:
 633                 switch (str[0]) {
 634                 case 'y': case 'Y':
 635                         return sym_tristate_within_range(sym, yes);
 636                 case 'm': case 'M':
 637                         return sym_tristate_within_range(sym, mod);
 638                 case 'n': case 'N':
 639                         return sym_tristate_within_range(sym, no);
 640                 }
 641                 return false;
 642         default:
 643                 return false;
 644         }
 645 }
 646
 647 bool sym_set_string_value(struct symbol *sym, const char *newval)
 648 {
 649         const char *oldval;
 650         char *val;
 651         int size;
 652
 653         switch (sym->type) {
 654         case S_BOOLEAN:
 655         case S_TRISTATE:
 656                 switch (newval[0]) {
 657                 case 'y': case 'Y':
 658                         return sym_set_tristate_value(sym, yes);
 659                 case 'm': case 'M':
 660                         return sym_set_tristate_value(sym, mod);
 661                 case 'n': case 'N':
 662                         return sym_set_tristate_value(sym, no);
 663                 }
 664                 return false;
 665         default:
 666                 ;
 667         }
 668
 669         if (!sym_string_within_range(sym, newval))
 670                 return false;
 671
 672         if (!(sym->flags & SYMBOL_DEF_USER)) {
 673                 sym->flags |= SYMBOL_DEF_USER;
 674                 sym_set_changed(sym);
 675         }
 676
 677         oldval = sym->def[S_DEF_USER].val;
 678         size = strlen(newval) + 1;
 679         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 680                 size += 2;
 681                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 682                 *val++ = '0';
 683                 *val++ = 'x';
 684         } else if (!oldval || strcmp(oldval, newval))
 685                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 686         else
 687                 return true;
 688
 689         strcpy(val, newval);
 690         free((void *)oldval);
 691         sym_clear_all_valid();
 692
 693         return true;
 694 }
 695
 696 /*
 697  * Find the default value associated to a symbol.
 698  * For tristate symbol handle the modules=n case
 699  * in which case "m" becomes "y".
 700  * If the symbol does not have any default then fallback
 701  * to the fixed default values.
 702  */
 703 const char *sym_get_string_default(struct symbol *sym)
 704 {
 705         struct property *prop;
 706         struct symbol *ds;
 707         const char *str;
 708         tristate val;
 709
 710         sym_calc_visibility(sym);
 711         sym_calc_value(modules_sym);
 712         val = symbol_no.curr.tri;
 713         str = symbol_empty.curr.val;
 714
 715         /* If symbol has a default value look it up */
 716         prop = sym_get_default_prop(sym);
 717         if (prop != NULL) {
 718                 switch (sym->type) {
 719                 case S_BOOLEAN:
 720                 case S_TRISTATE:
 721                         /* The visibility may limit the value from yes => mod */
 722                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 723                         break;
 724                 default:
 725                         /*
 726                          * The following fails to handle the situation
 727                          * where a default value is further limited by
 728                          * the valid range.
 729                          */
 730                         ds = prop_get_symbol(prop);
 731                         if (ds != NULL) {
 732                                 sym_calc_value(ds);
 733                                 str = (const char *)ds->curr.val;
 734                         }
 735                 }
 736         }
 737
 738         /* Handle select statements */
 739         val = EXPR_OR(val, sym->rev_dep.tri);
 740
 741         /* transpose mod to yes if modules are not enabled */
 742         if (val == mod)
 743                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 744                         val = yes;
 745
 746         /* transpose mod to yes if type is bool */
 747         if (sym->type == S_BOOLEAN && val == mod)
 748                 val = yes;
 749
 750         /* adjust the default value if this symbol is implied by another */
 751         if (val < sym->implied.tri)
 752                 val = sym->implied.tri;
 753
 754         switch (sym->type) {
 755         case S_BOOLEAN:
 756         case S_TRISTATE:
 757                 switch (val) {
 758                 case no: return "n";
 759                 case mod: return "m";
 760                 case yes: return "y";
 761                 }
 762         case S_INT:
 763         case S_HEX:
 764                 return str;
 765         case S_STRING:
 766                 return str;
 767         case S_UNKNOWN:
 768                 break;
 769         }
 770         return "";
 771 }
 772
 773 const char *sym_get_string_value(struct symbol *sym)
 774 {
 775         tristate val;
 776
 777         switch (sym->type) {
 778         case S_BOOLEAN:
 779         case S_TRISTATE:
 780                 val = sym_get_tristate_value(sym);
 781                 switch (val) {
 782                 case no:
 783                         return "n";
 784                 case mod:
 785                         sym_calc_value(modules_sym);
 786                         return (modules_sym->curr.tri == no) ? "n" : "m";
 787                 case yes:
 788                         return "y";
 789                 }
 790                 break;
 791         default:
 792                 ;
 793         }
 794         return (const char *)sym->curr.val;
 795 }
 796
 797 bool sym_is_changeable(struct symbol *sym)
 798 {
 799         return sym->visible > sym->rev_dep.tri;
 800 }
 801
 802 static unsigned strhash(const char *s)
 803 {
 804         /* fnv32 hash */
 805         unsigned hash = 2166136261U;
 806         for (; *s; s++)
 807                 hash = (hash ^ *s) * 0x01000193;
 808         return hash;
 809 }
 810
 811 struct symbol *sym_lookup(const char *name, int flags)
 812 {
 813         struct symbol *symbol;
 814         char *new_name;
 815         int hash;
 816
 817         if (name) {
 818                 if (name[0] && !name[1]) {
 819                         switch (name[0]) {
 820                         case 'y': return &symbol_yes;
 821                         case 'm': return &symbol_mod;
 822                         case 'n': return &symbol_no;
 823                         }
 824                 }
 825                 hash = strhash(name) % SYMBOL_HASHSIZE;
 826
 827                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 828                         if (symbol->name &&
 829                             !strcmp(symbol->name, name) &&
 830                             (flags ? symbol->flags & flags
 831                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 832                                 return symbol;
 833                 }
 834                 new_name = xstrdup(name);
 835         } else {
 836                 new_name = NULL;
 837                 hash = 0;
 838         }
 839
 840         symbol = xmalloc(sizeof(*symbol));
 841         memset(symbol, 0, sizeof(*symbol));
 842         symbol->name = new_name;
 843         symbol->type = S_UNKNOWN;
 844         symbol->flags = flags;
 845
 846         symbol->next = symbol_hash[hash];
 847         symbol_hash[hash] = symbol;
 848
 849         return symbol;
 850 }
 851
 852 struct symbol *sym_find(const char *name)
 853 {
 854         struct symbol *symbol = NULL;
 855         int hash = 0;
 856
 857         if (!name)
 858                 return NULL;
 859
 860         if (name[0] && !name[1]) {
 861                 switch (name[0]) {
 862                 case 'y': return &symbol_yes;
 863                 case 'm': return &symbol_mod;
 864                 case 'n': return &symbol_no;
 865                 }
 866         }
 867         hash = strhash(name) % SYMBOL_HASHSIZE;
 868
 869         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 870                 if (symbol->name &&
 871                     !strcmp(symbol->name, name) &&
 872                     !(symbol->flags & SYMBOL_CONST))
 873                                 break;
 874         }
 875
 876         return symbol;
 877 }
 878
 879 struct sym_match {
 880         struct symbol   *sym;
 881         off_t           so, eo;
 882 };
 883
 884 /* Compare matched symbols as thus:
 885  * - first, symbols that match exactly
 886  * - then, alphabetical sort
 887  */
 888 static int sym_rel_comp(const void *sym1, const void *sym2)
 889 {
 890         const struct sym_match *s1 = sym1;
 891         const struct sym_match *s2 = sym2;
 892         int exact1, exact2;
 893
 894         /* Exact match:
 895          * - if matched length on symbol s1 is the length of that symbol,
 896          *   then this symbol should come first;
 897          * - if matched length on symbol s2 is the length of that symbol,
 898          *   then this symbol should come first.
 899          * Note: since the search can be a regexp, both symbols may match
 900          * exactly; if this is the case, we can't decide which comes first,
 901          * and we fallback to sorting alphabetically.
 902          */
 903         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 904         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 905         if (exact1 && !exact2)
 906                 return -1;
 907         if (!exact1 && exact2)
 908                 return 1;
 909
 910         /* As a fallback, sort symbols alphabetically */
 911         return strcmp(s1->sym->name, s2->sym->name);
 912 }
 913
 914 struct symbol **sym_re_search(const char *pattern)
 915 {
 916         struct symbol *sym, **sym_arr = NULL;
 917         struct sym_match *sym_match_arr = NULL;
 918         int i, cnt, size;
 919         regex_t re;
 920         regmatch_t match[1];
 921
 922         cnt = size = 0;
 923         /* Skip if empty */
 924         if (strlen(pattern) == 0)
 925                 return NULL;
 926         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 927                 return NULL;
 928
 929         for_all_symbols(i, sym) {
 930                 if (sym->flags & SYMBOL_CONST || !sym->name)
 931                         continue;
 932                 if (regexec(&re, sym->name, 1, match, 0))
 933                         continue;
 934                 if (cnt >= size) {
 935                         void *tmp;
 936                         size += 16;
 937                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 938                         if (!tmp)
 939                                 goto sym_re_search_free;
 940                         sym_match_arr = tmp;
 941                 }
 942                 sym_calc_value(sym);
 943                 /* As regexec returned 0, we know we have a match, so
 944                  * we can use match[0].rm_[se]o without further checks
 945                  */
 946                 sym_match_arr[cnt].so = match[0].rm_so;
 947                 sym_match_arr[cnt].eo = match[0].rm_eo;
 948                 sym_match_arr[cnt++].sym = sym;
 949         }
 950         if (sym_match_arr) {
 951                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 952                 sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 953                 if (!sym_arr)
 954                         goto sym_re_search_free;
 955                 for (i = 0; i < cnt; i++)
 956                         sym_arr[i] = sym_match_arr[i].sym;
 957                 sym_arr[cnt] = NULL;
 958         }
 959 sym_re_search_free:
 960         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
 961         free(sym_match_arr);
 962         regfree(&re);
 963
 964         return sym_arr;
 965 }
 966
 967 /*
 968  * When we check for recursive dependencies we use a stack to save
 969  * current state so we can print out relevant info to user.
 970  * The entries are located on the call stack so no need to free memory.
 971  * Note insert() remove() must always match to properly clear the stack.
 972  */
 973 static struct dep_stack {
 974         struct dep_stack *prev, *next;
 975         struct symbol *sym;
 976         struct property *prop;
 977         struct expr **expr;
 978 } *check_top;
 979
 980 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
 981 {
 982         memset(stack, 0, sizeof(*stack));
 983         if (check_top)
 984                 check_top->next = stack;
 985         stack->prev = check_top;
 986         stack->sym = sym;
 987         check_top = stack;
 988 }
 989
 990 static void dep_stack_remove(void)
 991 {
 992         check_top = check_top->prev;
 993         if (check_top)
 994                 check_top->next = NULL;
 995 }
 996
 997 /*
 998  * Called when we have detected a recursive dependency.
 999  * check_top point to the top of the stact so we use
1000  * the ->prev pointer to locate the bottom of the stack.
1001  */
1002 static void sym_check_print_recursive(struct symbol *last_sym)
1003 {
1004         struct dep_stack *stack;
1005         struct symbol *sym, *next_sym;
1006         struct menu *menu = NULL;
1007         struct property *prop;
1008         struct dep_stack cv_stack;
1009
1010         if (sym_is_choice_value(last_sym)) {
1011                 dep_stack_insert(&cv_stack, last_sym);
1012                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1013         }
1014
1015         for (stack = check_top; stack != NULL; stack = stack->prev)
1016                 if (stack->sym == last_sym)
1017                         break;
1018         if (!stack) {
1019                 fprintf(stderr, "unexpected recursive dependency error\n");
1020                 return;
1021         }
1022
1023         for (; stack; stack = stack->next) {
1024                 sym = stack->sym;
1025                 next_sym = stack->next ? stack->next->sym : last_sym;
1026                 prop = stack->prop;
1027                 if (prop == NULL)
1028                         prop = stack->sym->prop;
1029
1030                 /* for choice values find the menu entry (used below) */
1031                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1032                         for (prop = sym->prop; prop; prop = prop->next) {
1033                                 menu = prop->menu;
1034                                 if (prop->menu)
1035                                         break;
1036                         }
1037                 }
1038                 if (stack->sym == last_sym)
1039                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1040                                 prop->file->name, prop->lineno);
1041
1042                 if (sym_is_choice(sym)) {
1043                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1044                                 menu->file->name, menu->lineno,
1045                                 sym->name ? sym->name : "<choice>",
1046                                 next_sym->name ? next_sym->name : "<choice>");
1047                 } else if (sym_is_choice_value(sym)) {
1048                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1049                                 menu->file->name, menu->lineno,
1050                                 sym->name ? sym->name : "<choice>",
1051                                 next_sym->name ? next_sym->name : "<choice>");
1052                 } else if (stack->expr == &sym->dir_dep.expr) {
1053                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1054                                 prop->file->name, prop->lineno,
1055                                 sym->name ? sym->name : "<choice>",
1056                                 next_sym->name ? next_sym->name : "<choice>");
1057                 } else if (stack->expr == &sym->rev_dep.expr) {
1058                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1059                                 prop->file->name, prop->lineno,
1060                                 sym->name ? sym->name : "<choice>",
1061                                 next_sym->name ? next_sym->name : "<choice>");
1062                 } else if (stack->expr == &sym->implied.expr) {
1063                         fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1064                                 prop->file->name, prop->lineno,
1065                                 sym->name ? sym->name : "<choice>",
1066                                 next_sym->name ? next_sym->name : "<choice>");
1067                 } else if (stack->expr) {
1068                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1069                                 prop->file->name, prop->lineno,
1070                                 sym->name ? sym->name : "<choice>",
1071                                 prop_get_type_name(prop->type),
1072                                 next_sym->name ? next_sym->name : "<choice>");
1073                 } else {
1074                         fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1075                                 prop->file->name, prop->lineno,
1076                                 sym->name ? sym->name : "<choice>",
1077                                 prop_get_type_name(prop->type),
1078                                 next_sym->name ? next_sym->name : "<choice>");
1079                 }
1080         }
1081
1082         fprintf(stderr,
1083                 "For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1084                 "subsection \"Kconfig recursive dependency limitations\"\n"
1085                 "\n");
1086
1087         if (check_top == &cv_stack)
1088                 dep_stack_remove();
1089 }
1090
1091 static struct symbol *sym_check_expr_deps(struct expr *e)
1092 {
1093         struct symbol *sym;
1094
1095         if (!e)
1096                 return NULL;
1097         switch (e->type) {
1098         case E_OR:
1099         case E_AND:
1100                 sym = sym_check_expr_deps(e->left.expr);
1101                 if (sym)
1102                         return sym;
1103                 return sym_check_expr_deps(e->right.expr);
1104         case E_NOT:
1105                 return sym_check_expr_deps(e->left.expr);
1106         case E_EQUAL:
1107         case E_GEQ:
1108         case E_GTH:
1109         case E_LEQ:
1110         case E_LTH:
1111         case E_UNEQUAL:
1112                 sym = sym_check_deps(e->left.sym);
1113                 if (sym)
1114                         return sym;
1115                 return sym_check_deps(e->right.sym);
1116         case E_SYMBOL:
1117                 return sym_check_deps(e->left.sym);
1118         default:
1119                 break;
1120         }
1121         fprintf(stderr, "Oops! How to check %d?\n", e->type);
1122         return NULL;
1123 }
1124
1125 /* return NULL when dependencies are OK */
1126 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1127 {
1128         struct symbol *sym2;
1129         struct property *prop;
1130         struct dep_stack stack;
1131
1132         dep_stack_insert(&stack, sym);
1133
1134         stack.expr = &sym->dir_dep.expr;
1135         sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1136         if (sym2)
1137                 goto out;
1138
1139         stack.expr = &sym->rev_dep.expr;
1140         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1141         if (sym2)
1142                 goto out;
1143
1144         stack.expr = &sym->implied.expr;
1145         sym2 = sym_check_expr_deps(sym->implied.expr);
1146         if (sym2)
1147                 goto out;
1148
1149         stack.expr = NULL;
1150
1151         for (prop = sym->prop; prop; prop = prop->next) {
1152                 if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1153                     prop->type == P_IMPLY)
1154                         continue;
1155                 stack.prop = prop;
1156                 sym2 = sym_check_expr_deps(prop->visible.expr);
1157                 if (sym2)
1158                         break;
1159                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1160                         continue;
1161                 stack.expr = &prop->expr;
1162                 sym2 = sym_check_expr_deps(prop->expr);
1163                 if (sym2)
1164                         break;
1165                 stack.expr = NULL;
1166         }
1167
1168 out:
1169         dep_stack_remove();
1170
1171         return sym2;
1172 }
1173
1174 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1175 {
1176         struct symbol *sym, *sym2;
1177         struct property *prop;
1178         struct expr *e;
1179         struct dep_stack stack;
1180
1181         dep_stack_insert(&stack, choice);
1182
1183         prop = sym_get_choice_prop(choice);
1184         expr_list_for_each_sym(prop->expr, e, sym)
1185                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1186
1187         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1188         sym2 = sym_check_sym_deps(choice);
1189         choice->flags &= ~SYMBOL_CHECK;
1190         if (sym2)
1191                 goto out;
1192
1193         expr_list_for_each_sym(prop->expr, e, sym) {
1194                 sym2 = sym_check_sym_deps(sym);
1195                 if (sym2)
1196                         break;
1197         }
1198 out:
1199         expr_list_for_each_sym(prop->expr, e, sym)
1200                 sym->flags &= ~SYMBOL_CHECK;
1201
1202         if (sym2 && sym_is_choice_value(sym2) &&
1203             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1204                 sym2 = choice;
1205
1206         dep_stack_remove();
1207
1208         return sym2;
1209 }
1210
1211 struct symbol *sym_check_deps(struct symbol *sym)
1212 {
1213         struct symbol *sym2;
1214         struct property *prop;
1215
1216         if (sym->flags & SYMBOL_CHECK) {
1217                 sym_check_print_recursive(sym);
1218                 return sym;
1219         }
1220         if (sym->flags & SYMBOL_CHECKED)
1221                 return NULL;
1222
1223         if (sym_is_choice_value(sym)) {
1224                 struct dep_stack stack;
1225
1226                 /* for choice groups start the check with main choice symbol */
1227                 dep_stack_insert(&stack, sym);
1228                 prop = sym_get_choice_prop(sym);
1229                 sym2 = sym_check_deps(prop_get_symbol(prop));
1230                 dep_stack_remove();
1231         } else if (sym_is_choice(sym)) {
1232                 sym2 = sym_check_choice_deps(sym);
1233         } else {
1234                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1235                 sym2 = sym_check_sym_deps(sym);
1236                 sym->flags &= ~SYMBOL_CHECK;
1237         }
1238
1239         return sym2;
1240 }
1241
1242 struct symbol *prop_get_symbol(struct property *prop)
1243 {
1244         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1245                            prop->expr->type == E_LIST))
1246                 return prop->expr->left.sym;
1247         return NULL;
1248 }
1249
1250 const char *prop_get_type_name(enum prop_type type)
1251 {
1252         switch (type) {
1253         case P_PROMPT:
1254                 return "prompt";
1255         case P_COMMENT:
1256                 return "comment";
1257         case P_MENU:
1258                 return "menu";
1259         case P_DEFAULT:
1260                 return "default";
1261         case P_CHOICE:
1262                 return "choice";
1263         case P_SELECT:
1264                 return "select";
1265         case P_IMPLY:
1266                 return "imply";
1267         case P_RANGE:
1268                 return "range";
1269         case P_SYMBOL:
1270                 return "symbol";
1271         case P_UNKNOWN:
1272                 break;
1273         }
1274         return "unknown";
1275 }