scripts/kconfig/symbol.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   4  */
   5
   6 #include <ctype.h>
   7 #include <stdlib.h>
   8 #include <string.h>
   9 #include <regex.h>
  10 #include <sys/utsname.h>
  11
  12 #include "lkc.h"
  13
  14 struct symbol symbol_yes = {
  15         .name = "y",
  16         .curr = { "y", yes },
  17         .flags = SYMBOL_CONST|SYMBOL_VALID,
  18 };
  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 *sym_defconfig_list;
  39 struct symbol *modules_sym;
  40 static tristate modules_val;
  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 }
 322
 323 void sym_calc_value(struct symbol *sym)
 324 {
 325         struct symbol_value newval, oldval;
 326         struct property *prop;
 327         struct expr *e;
 328
 329         if (!sym)
 330                 return;
 331
 332         if (sym->flags & SYMBOL_VALID)
 333                 return;
 334
 335         if (sym_is_choice_value(sym) &&
 336             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 337                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 338                 prop = sym_get_choice_prop(sym);
 339                 sym_calc_value(prop_get_symbol(prop));
 340         }
 341
 342         sym->flags |= SYMBOL_VALID;
 343
 344         oldval = sym->curr;
 345
 346         switch (sym->type) {
 347         case S_INT:
 348         case S_HEX:
 349         case S_STRING:
 350                 newval = symbol_empty.curr;
 351                 break;
 352         case S_BOOLEAN:
 353         case S_TRISTATE:
 354                 newval = symbol_no.curr;
 355                 break;
 356         default:
 357                 sym->curr.val = sym->name;
 358                 sym->curr.tri = no;
 359                 return;
 360         }
 361         sym->flags &= ~SYMBOL_WRITE;
 362
 363         sym_calc_visibility(sym);
 364
 365         if (sym->visible != no)
 366                 sym->flags |= SYMBOL_WRITE;
 367
 368         /* set default if recursively called */
 369         sym->curr = newval;
 370
 371         switch (sym_get_type(sym)) {
 372         case S_BOOLEAN:
 373         case S_TRISTATE:
 374                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 375                         prop = sym_get_choice_prop(sym);
 376                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 377                 } else {
 378                         if (sym->visible != no) {
 379                                 /* if the symbol is visible use the user value
 380                                  * if available, otherwise try the default value
 381                                  */
 382                                 if (sym_has_value(sym)) {
 383                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 384                                                               sym->visible);
 385                                         goto calc_newval;
 386                                 }
 387                         }
 388                         if (sym->rev_dep.tri != no)
 389                                 sym->flags |= SYMBOL_WRITE;
 390                         if (!sym_is_choice(sym)) {
 391                                 prop = sym_get_default_prop(sym);
 392                                 if (prop) {
 393                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 394                                                               prop->visible.tri);
 395                                         if (newval.tri != no)
 396                                                 sym->flags |= SYMBOL_WRITE;
 397                                 }
 398                                 if (sym->implied.tri != no) {
 399                                         sym->flags |= SYMBOL_WRITE;
 400                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 401                                         newval.tri = EXPR_AND(newval.tri,
 402                                                               sym->dir_dep.tri);
 403                                 }
 404                         }
 405                 calc_newval:
 406                         if (sym->dir_dep.tri < sym->rev_dep.tri)
 407                                 sym_warn_unmet_dep(sym);
 408                         newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 409                 }
 410                 if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 411                         newval.tri = yes;
 412                 break;
 413         case S_STRING:
 414         case S_HEX:
 415         case S_INT:
 416                 if (sym->visible != no && sym_has_value(sym)) {
 417                         newval.val = sym->def[S_DEF_USER].val;
 418                         break;
 419                 }
 420                 prop = sym_get_default_prop(sym);
 421                 if (prop) {
 422                         struct symbol *ds = prop_get_symbol(prop);
 423                         if (ds) {
 424                                 sym->flags |= SYMBOL_WRITE;
 425                                 sym_calc_value(ds);
 426                                 newval.val = ds->curr.val;
 427                         }
 428                 }
 429                 break;
 430         default:
 431                 ;
 432         }
 433
 434         sym->curr = newval;
 435         if (sym_is_choice(sym) && newval.tri == yes)
 436                 sym->curr.val = sym_calc_choice(sym);
 437         sym_validate_range(sym);
 438
 439         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 440                 sym_set_changed(sym);
 441                 if (modules_sym == sym) {
 442                         sym_set_all_changed();
 443                         modules_val = modules_sym->curr.tri;
 444                 }
 445         }
 446
 447         if (sym_is_choice(sym)) {
 448                 struct symbol *choice_sym;
 449
 450                 prop = sym_get_choice_prop(sym);
 451                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 452                         if ((sym->flags & SYMBOL_WRITE) &&
 453                             choice_sym->visible != no)
 454                                 choice_sym->flags |= SYMBOL_WRITE;
 455                         if (sym->flags & SYMBOL_CHANGED)
 456                                 sym_set_changed(choice_sym);
 457                 }
 458         }
 459
 460         if (sym->flags & SYMBOL_NO_WRITE)
 461                 sym->flags &= ~SYMBOL_WRITE;
 462
 463         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 464                 set_all_choice_values(sym);
 465 }
 466
 467 void sym_clear_all_valid(void)
 468 {
 469         struct symbol *sym;
 470         int i;
 471
 472         for_all_symbols(i, sym)
 473                 sym->flags &= ~SYMBOL_VALID;
 474         sym_add_change_count(1);
 475         sym_calc_value(modules_sym);
 476 }
 477
 478 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 479 {
 480         int type = sym_get_type(sym);
 481
 482         if (sym->visible == no)
 483                 return false;
 484
 485         if (type != S_BOOLEAN && type != S_TRISTATE)
 486                 return false;
 487
 488         if (type == S_BOOLEAN && val == mod)
 489                 return false;
 490         if (sym->visible <= sym->rev_dep.tri)
 491                 return false;
 492         if (sym_is_choice_value(sym) && sym->visible == yes)
 493                 return val == yes;
 494         return val >= sym->rev_dep.tri && val <= sym->visible;
 495 }
 496
 497 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 498 {
 499         tristate oldval = sym_get_tristate_value(sym);
 500
 501         if (oldval != val && !sym_tristate_within_range(sym, val))
 502                 return false;
 503
 504         if (!(sym->flags & SYMBOL_DEF_USER)) {
 505                 sym->flags |= SYMBOL_DEF_USER;
 506                 sym_set_changed(sym);
 507         }
 508         /*
 509          * setting a choice value also resets the new flag of the choice
 510          * symbol and all other choice values.
 511          */
 512         if (sym_is_choice_value(sym) && val == yes) {
 513                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 514                 struct property *prop;
 515                 struct expr *e;
 516
 517                 cs->def[S_DEF_USER].val = sym;
 518                 cs->flags |= SYMBOL_DEF_USER;
 519                 prop = sym_get_choice_prop(cs);
 520                 for (e = prop->expr; e; e = e->left.expr) {
 521                         if (e->right.sym->visible != no)
 522                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 523                 }
 524         }
 525
 526         sym->def[S_DEF_USER].tri = val;
 527         if (oldval != val)
 528                 sym_clear_all_valid();
 529
 530         return true;
 531 }
 532
 533 tristate sym_toggle_tristate_value(struct symbol *sym)
 534 {
 535         tristate oldval, newval;
 536
 537         oldval = newval = sym_get_tristate_value(sym);
 538         do {
 539                 switch (newval) {
 540                 case no:
 541                         newval = mod;
 542                         break;
 543                 case mod:
 544                         newval = yes;
 545                         break;
 546                 case yes:
 547                         newval = no;
 548                         break;
 549                 }
 550                 if (sym_set_tristate_value(sym, newval))
 551                         break;
 552         } while (oldval != newval);
 553         return newval;
 554 }
 555
 556 bool sym_string_valid(struct symbol *sym, const char *str)
 557 {
 558         signed char ch;
 559
 560         switch (sym->type) {
 561         case S_STRING:
 562                 return true;
 563         case S_INT:
 564                 ch = *str++;
 565                 if (ch == '-')
 566                         ch = *str++;
 567                 if (!isdigit(ch))
 568                         return false;
 569                 if (ch == '0' && *str != 0)
 570                         return false;
 571                 while ((ch = *str++)) {
 572                         if (!isdigit(ch))
 573                                 return false;
 574                 }
 575                 return true;
 576         case S_HEX:
 577                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 578                         str += 2;
 579                 ch = *str++;
 580                 do {
 581                         if (!isxdigit(ch))
 582                                 return false;
 583                 } while ((ch = *str++));
 584                 return true;
 585         case S_BOOLEAN:
 586         case S_TRISTATE:
 587                 switch (str[0]) {
 588                 case 'y': case 'Y':
 589                 case 'm': case 'M':
 590                 case 'n': case 'N':
 591                         return true;
 592                 }
 593                 return false;
 594         default:
 595                 return false;
 596         }
 597 }
 598
 599 bool sym_string_within_range(struct symbol *sym, const char *str)
 600 {
 601         struct property *prop;
 602         long long val;
 603
 604         switch (sym->type) {
 605         case S_STRING:
 606                 return sym_string_valid(sym, str);
 607         case S_INT:
 608                 if (!sym_string_valid(sym, str))
 609                         return false;
 610                 prop = sym_get_range_prop(sym);
 611                 if (!prop)
 612                         return true;
 613                 val = strtoll(str, NULL, 10);
 614                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 615                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 616         case S_HEX:
 617                 if (!sym_string_valid(sym, str))
 618                         return false;
 619                 prop = sym_get_range_prop(sym);
 620                 if (!prop)
 621                         return true;
 622                 val = strtoll(str, NULL, 16);
 623                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 624                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 625         case S_BOOLEAN:
 626         case S_TRISTATE:
 627                 switch (str[0]) {
 628                 case 'y': case 'Y':
 629                         return sym_tristate_within_range(sym, yes);
 630                 case 'm': case 'M':
 631                         return sym_tristate_within_range(sym, mod);
 632                 case 'n': case 'N':
 633                         return sym_tristate_within_range(sym, no);
 634                 }
 635                 return false;
 636         default:
 637                 return false;
 638         }
 639 }
 640
 641 bool sym_set_string_value(struct symbol *sym, const char *newval)
 642 {
 643         const char *oldval;
 644         char *val;
 645         int size;
 646
 647         switch (sym->type) {
 648         case S_BOOLEAN:
 649         case S_TRISTATE:
 650                 switch (newval[0]) {
 651                 case 'y': case 'Y':
 652                         return sym_set_tristate_value(sym, yes);
 653                 case 'm': case 'M':
 654                         return sym_set_tristate_value(sym, mod);
 655                 case 'n': case 'N':
 656                         return sym_set_tristate_value(sym, no);
 657                 }
 658                 return false;
 659         default:
 660                 ;
 661         }
 662
 663         if (!sym_string_within_range(sym, newval))
 664                 return false;
 665
 666         if (!(sym->flags & SYMBOL_DEF_USER)) {
 667                 sym->flags |= SYMBOL_DEF_USER;
 668                 sym_set_changed(sym);
 669         }
 670
 671         oldval = sym->def[S_DEF_USER].val;
 672         size = strlen(newval) + 1;
 673         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 674                 size += 2;
 675                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 676                 *val++ = '0';
 677                 *val++ = 'x';
 678         } else if (!oldval || strcmp(oldval, newval))
 679                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 680         else
 681                 return true;
 682
 683         strcpy(val, newval);
 684         free((void *)oldval);
 685         sym_clear_all_valid();
 686
 687         return true;
 688 }
 689
 690 /*
 691  * Find the default value associated to a symbol.
 692  * For tristate symbol handle the modules=n case
 693  * in which case "m" becomes "y".
 694  * If the symbol does not have any default then fallback
 695  * to the fixed default values.
 696  */
 697 const char *sym_get_string_default(struct symbol *sym)
 698 {
 699         struct property *prop;
 700         struct symbol *ds;
 701         const char *str;
 702         tristate val;
 703
 704         sym_calc_visibility(sym);
 705         sym_calc_value(modules_sym);
 706         val = symbol_no.curr.tri;
 707         str = symbol_empty.curr.val;
 708
 709         /* If symbol has a default value look it up */
 710         prop = sym_get_default_prop(sym);
 711         if (prop != NULL) {
 712                 switch (sym->type) {
 713                 case S_BOOLEAN:
 714                 case S_TRISTATE:
 715                         /* The visibility may limit the value from yes => mod */
 716                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 717                         break;
 718                 default:
 719                         /*
 720                          * The following fails to handle the situation
 721                          * where a default value is further limited by
 722                          * the valid range.
 723                          */
 724                         ds = prop_get_symbol(prop);
 725                         if (ds != NULL) {
 726                                 sym_calc_value(ds);
 727                                 str = (const char *)ds->curr.val;
 728                         }
 729                 }
 730         }
 731
 732         /* Handle select statements */
 733         val = EXPR_OR(val, sym->rev_dep.tri);
 734
 735         /* transpose mod to yes if modules are not enabled */
 736         if (val == mod)
 737                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 738                         val = yes;
 739
 740         /* transpose mod to yes if type is bool */
 741         if (sym->type == S_BOOLEAN && val == mod)
 742                 val = yes;
 743
 744         /* adjust the default value if this symbol is implied by another */
 745         if (val < sym->implied.tri)
 746                 val = sym->implied.tri;
 747
 748         switch (sym->type) {
 749         case S_BOOLEAN:
 750         case S_TRISTATE:
 751                 switch (val) {
 752                 case no: return "n";
 753                 case mod: return "m";
 754                 case yes: return "y";
 755                 }
 756         case S_INT:
 757         case S_HEX:
 758                 return str;
 759         case S_STRING:
 760                 return str;
 761         case S_UNKNOWN:
 762                 break;
 763         }
 764         return "";
 765 }
 766
 767 const char *sym_get_string_value(struct symbol *sym)
 768 {
 769         tristate val;
 770
 771         switch (sym->type) {
 772         case S_BOOLEAN:
 773         case S_TRISTATE:
 774                 val = sym_get_tristate_value(sym);
 775                 switch (val) {
 776                 case no:
 777                         return "n";
 778                 case mod:
 779                         sym_calc_value(modules_sym);
 780                         return (modules_sym->curr.tri == no) ? "n" : "m";
 781                 case yes:
 782                         return "y";
 783                 }
 784                 break;
 785         default:
 786                 ;
 787         }
 788         return (const char *)sym->curr.val;
 789 }
 790
 791 bool sym_is_changeable(struct symbol *sym)
 792 {
 793         return sym->visible > sym->rev_dep.tri;
 794 }
 795
 796 static unsigned strhash(const char *s)
 797 {
 798         /* fnv32 hash */
 799         unsigned hash = 2166136261U;
 800         for (; *s; s++)
 801                 hash = (hash ^ *s) * 0x01000193;
 802         return hash;
 803 }
 804
 805 struct symbol *sym_lookup(const char *name, int flags)
 806 {
 807         struct symbol *symbol;
 808         char *new_name;
 809         int hash;
 810
 811         if (name) {
 812                 if (name[0] && !name[1]) {
 813                         switch (name[0]) {
 814                         case 'y': return &symbol_yes;
 815                         case 'm': return &symbol_mod;
 816                         case 'n': return &symbol_no;
 817                         }
 818                 }
 819                 hash = strhash(name) % SYMBOL_HASHSIZE;
 820
 821                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 822                         if (symbol->name &&
 823                             !strcmp(symbol->name, name) &&
 824                             (flags ? symbol->flags & flags
 825                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 826                                 return symbol;
 827                 }
 828                 new_name = xstrdup(name);
 829         } else {
 830                 new_name = NULL;
 831                 hash = 0;
 832         }
 833
 834         symbol = xmalloc(sizeof(*symbol));
 835         memset(symbol, 0, sizeof(*symbol));
 836         symbol->name = new_name;
 837         symbol->type = S_UNKNOWN;
 838         symbol->flags = flags;
 839
 840         symbol->next = symbol_hash[hash];
 841         symbol_hash[hash] = symbol;
 842
 843         return symbol;
 844 }
 845
 846 struct symbol *sym_find(const char *name)
 847 {
 848         struct symbol *symbol = NULL;
 849         int hash = 0;
 850
 851         if (!name)
 852                 return NULL;
 853
 854         if (name[0] && !name[1]) {
 855                 switch (name[0]) {
 856                 case 'y': return &symbol_yes;
 857                 case 'm': return &symbol_mod;
 858                 case 'n': return &symbol_no;
 859                 }
 860         }
 861         hash = strhash(name) % SYMBOL_HASHSIZE;
 862
 863         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 864                 if (symbol->name &&
 865                     !strcmp(symbol->name, name) &&
 866                     !(symbol->flags & SYMBOL_CONST))
 867                                 break;
 868         }
 869
 870         return symbol;
 871 }
 872
 873 const char *sym_escape_string_value(const char *in)
 874 {
 875         const char *p;
 876         size_t reslen;
 877         char *res;
 878         size_t l;
 879
 880         reslen = strlen(in) + strlen("\"\"") + 1;
 881
 882         p = in;
 883         for (;;) {
 884                 l = strcspn(p, "\"\\");
 885                 p += l;
 886
 887                 if (p[0] == '\0')
 888                         break;
 889
 890                 reslen++;
 891                 p++;
 892         }
 893
 894         res = xmalloc(reslen);
 895         res[0] = '\0';
 896
 897         strcat(res, "\"");
 898
 899         p = in;
 900         for (;;) {
 901                 l = strcspn(p, "\"\\");
 902                 strncat(res, p, l);
 903                 p += l;
 904
 905                 if (p[0] == '\0')
 906                         break;
 907
 908                 strcat(res, "\\");
 909                 strncat(res, p++, 1);
 910         }
 911
 912         strcat(res, "\"");
 913         return res;
 914 }
 915
 916 struct sym_match {
 917         struct symbol   *sym;
 918         off_t           so, eo;
 919 };
 920
 921 /* Compare matched symbols as thus:
 922  * - first, symbols that match exactly
 923  * - then, alphabetical sort
 924  */
 925 static int sym_rel_comp(const void *sym1, const void *sym2)
 926 {
 927         const struct sym_match *s1 = sym1;
 928         const struct sym_match *s2 = sym2;
 929         int exact1, exact2;
 930
 931         /* Exact match:
 932          * - if matched length on symbol s1 is the length of that symbol,
 933          *   then this symbol should come first;
 934          * - if matched length on symbol s2 is the length of that symbol,
 935          *   then this symbol should come first.
 936          * Note: since the search can be a regexp, both symbols may match
 937          * exactly; if this is the case, we can't decide which comes first,
 938          * and we fallback to sorting alphabetically.
 939          */
 940         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 941         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 942         if (exact1 && !exact2)
 943                 return -1;
 944         if (!exact1 && exact2)
 945                 return 1;
 946
 947         /* As a fallback, sort symbols alphabetically */
 948         return strcmp(s1->sym->name, s2->sym->name);
 949 }
 950
 951 struct symbol **sym_re_search(const char *pattern)
 952 {
 953         struct symbol *sym, **sym_arr = NULL;
 954         struct sym_match *sym_match_arr = NULL;
 955         int i, cnt, size;
 956         regex_t re;
 957         regmatch_t match[1];
 958
 959         cnt = size = 0;
 960         /* Skip if empty */
 961         if (strlen(pattern) == 0)
 962                 return NULL;
 963         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 964                 return NULL;
 965
 966         for_all_symbols(i, sym) {
 967                 if (sym->flags & SYMBOL_CONST || !sym->name)
 968                         continue;
 969                 if (regexec(&re, sym->name, 1, match, 0))
 970                         continue;
 971                 if (cnt >= size) {
 972                         void *tmp;
 973                         size += 16;
 974                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 975                         if (!tmp)
 976                                 goto sym_re_search_free;
 977                         sym_match_arr = tmp;
 978                 }
 979                 sym_calc_value(sym);
 980                 /* As regexec returned 0, we know we have a match, so
 981                  * we can use match[0].rm_[se]o without further checks
 982                  */
 983                 sym_match_arr[cnt].so = match[0].rm_so;
 984                 sym_match_arr[cnt].eo = match[0].rm_eo;
 985                 sym_match_arr[cnt++].sym = sym;
 986         }
 987         if (sym_match_arr) {
 988                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 989                 sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 990                 if (!sym_arr)
 991                         goto sym_re_search_free;
 992                 for (i = 0; i < cnt; i++)
 993                         sym_arr[i] = sym_match_arr[i].sym;
 994                 sym_arr[cnt] = NULL;
 995         }
 996 sym_re_search_free:
 997         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
 998         free(sym_match_arr);
 999         regfree(&re);
1000
1001         return sym_arr;
1002 }
1003
1004 /*
1005  * When we check for recursive dependencies we use a stack to save
1006  * current state so we can print out relevant info to user.
1007  * The entries are located on the call stack so no need to free memory.
1008  * Note insert() remove() must always match to properly clear the stack.
1009  */
1010 static struct dep_stack {
1011         struct dep_stack *prev, *next;
1012         struct symbol *sym;
1013         struct property *prop;
1014         struct expr **expr;
1015 } *check_top;
1016
1017 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1018 {
1019         memset(stack, 0, sizeof(*stack));
1020         if (check_top)
1021                 check_top->next = stack;
1022         stack->prev = check_top;
1023         stack->sym = sym;
1024         check_top = stack;
1025 }
1026
1027 static void dep_stack_remove(void)
1028 {
1029         check_top = check_top->prev;
1030         if (check_top)
1031                 check_top->next = NULL;
1032 }
1033
1034 /*
1035  * Called when we have detected a recursive dependency.
1036  * check_top point to the top of the stact so we use
1037  * the ->prev pointer to locate the bottom of the stack.
1038  */
1039 static void sym_check_print_recursive(struct symbol *last_sym)
1040 {
1041         struct dep_stack *stack;
1042         struct symbol *sym, *next_sym;
1043         struct menu *menu = NULL;
1044         struct property *prop;
1045         struct dep_stack cv_stack;
1046
1047         if (sym_is_choice_value(last_sym)) {
1048                 dep_stack_insert(&cv_stack, last_sym);
1049                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1050         }
1051
1052         for (stack = check_top; stack != NULL; stack = stack->prev)
1053                 if (stack->sym == last_sym)
1054                         break;
1055         if (!stack) {
1056                 fprintf(stderr, "unexpected recursive dependency error\n");
1057                 return;
1058         }
1059
1060         for (; stack; stack = stack->next) {
1061                 sym = stack->sym;
1062                 next_sym = stack->next ? stack->next->sym : last_sym;
1063                 prop = stack->prop;
1064                 if (prop == NULL)
1065                         prop = stack->sym->prop;
1066
1067                 /* for choice values find the menu entry (used below) */
1068                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1069                         for (prop = sym->prop; prop; prop = prop->next) {
1070                                 menu = prop->menu;
1071                                 if (prop->menu)
1072                                         break;
1073                         }
1074                 }
1075                 if (stack->sym == last_sym)
1076                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1077                                 prop->file->name, prop->lineno);
1078
1079                 if (sym_is_choice(sym)) {
1080                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1081                                 menu->file->name, menu->lineno,
1082                                 sym->name ? sym->name : "<choice>",
1083                                 next_sym->name ? next_sym->name : "<choice>");
1084                 } else if (sym_is_choice_value(sym)) {
1085                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1086                                 menu->file->name, menu->lineno,
1087                                 sym->name ? sym->name : "<choice>",
1088                                 next_sym->name ? next_sym->name : "<choice>");
1089                 } else if (stack->expr == &sym->dir_dep.expr) {
1090                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1091                                 prop->file->name, prop->lineno,
1092                                 sym->name ? sym->name : "<choice>",
1093                                 next_sym->name ? next_sym->name : "<choice>");
1094                 } else if (stack->expr == &sym->rev_dep.expr) {
1095                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1096                                 prop->file->name, prop->lineno,
1097                                 sym->name ? sym->name : "<choice>",
1098                                 next_sym->name ? next_sym->name : "<choice>");
1099                 } else if (stack->expr == &sym->implied.expr) {
1100                         fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1101                                 prop->file->name, prop->lineno,
1102                                 sym->name ? sym->name : "<choice>",
1103                                 next_sym->name ? next_sym->name : "<choice>");
1104                 } else if (stack->expr) {
1105                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1106                                 prop->file->name, prop->lineno,
1107                                 sym->name ? sym->name : "<choice>",
1108                                 prop_get_type_name(prop->type),
1109                                 next_sym->name ? next_sym->name : "<choice>");
1110                 } else {
1111                         fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1112                                 prop->file->name, prop->lineno,
1113                                 sym->name ? sym->name : "<choice>",
1114                                 prop_get_type_name(prop->type),
1115                                 next_sym->name ? next_sym->name : "<choice>");
1116                 }
1117         }
1118
1119         fprintf(stderr,
1120                 "For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1121                 "subsection \"Kconfig recursive dependency limitations\"\n"
1122                 "\n");
1123
1124         if (check_top == &cv_stack)
1125                 dep_stack_remove();
1126 }
1127
1128 static struct symbol *sym_check_expr_deps(struct expr *e)
1129 {
1130         struct symbol *sym;
1131
1132         if (!e)
1133                 return NULL;
1134         switch (e->type) {
1135         case E_OR:
1136         case E_AND:
1137                 sym = sym_check_expr_deps(e->left.expr);
1138                 if (sym)
1139                         return sym;
1140                 return sym_check_expr_deps(e->right.expr);
1141         case E_NOT:
1142                 return sym_check_expr_deps(e->left.expr);
1143         case E_EQUAL:
1144         case E_GEQ:
1145         case E_GTH:
1146         case E_LEQ:
1147         case E_LTH:
1148         case E_UNEQUAL:
1149                 sym = sym_check_deps(e->left.sym);
1150                 if (sym)
1151                         return sym;
1152                 return sym_check_deps(e->right.sym);
1153         case E_SYMBOL:
1154                 return sym_check_deps(e->left.sym);
1155         default:
1156                 break;
1157         }
1158         fprintf(stderr, "Oops! How to check %d?\n", e->type);
1159         return NULL;
1160 }
1161
1162 /* return NULL when dependencies are OK */
1163 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1164 {
1165         struct symbol *sym2;
1166         struct property *prop;
1167         struct dep_stack stack;
1168
1169         dep_stack_insert(&stack, sym);
1170
1171         stack.expr = &sym->dir_dep.expr;
1172         sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1173         if (sym2)
1174                 goto out;
1175
1176         stack.expr = &sym->rev_dep.expr;
1177         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1178         if (sym2)
1179                 goto out;
1180
1181         stack.expr = &sym->implied.expr;
1182         sym2 = sym_check_expr_deps(sym->implied.expr);
1183         if (sym2)
1184                 goto out;
1185
1186         stack.expr = NULL;
1187
1188         for (prop = sym->prop; prop; prop = prop->next) {
1189                 if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1190                     prop->type == P_IMPLY)
1191                         continue;
1192                 stack.prop = prop;
1193                 sym2 = sym_check_expr_deps(prop->visible.expr);
1194                 if (sym2)
1195                         break;
1196                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1197                         continue;
1198                 stack.expr = &prop->expr;
1199                 sym2 = sym_check_expr_deps(prop->expr);
1200                 if (sym2)
1201                         break;
1202                 stack.expr = NULL;
1203         }
1204
1205 out:
1206         dep_stack_remove();
1207
1208         return sym2;
1209 }
1210
1211 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1212 {
1213         struct symbol *sym, *sym2;
1214         struct property *prop;
1215         struct expr *e;
1216         struct dep_stack stack;
1217
1218         dep_stack_insert(&stack, choice);
1219
1220         prop = sym_get_choice_prop(choice);
1221         expr_list_for_each_sym(prop->expr, e, sym)
1222                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1223
1224         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1225         sym2 = sym_check_sym_deps(choice);
1226         choice->flags &= ~SYMBOL_CHECK;
1227         if (sym2)
1228                 goto out;
1229
1230         expr_list_for_each_sym(prop->expr, e, sym) {
1231                 sym2 = sym_check_sym_deps(sym);
1232                 if (sym2)
1233                         break;
1234         }
1235 out:
1236         expr_list_for_each_sym(prop->expr, e, sym)
1237                 sym->flags &= ~SYMBOL_CHECK;
1238
1239         if (sym2 && sym_is_choice_value(sym2) &&
1240             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1241                 sym2 = choice;
1242
1243         dep_stack_remove();
1244
1245         return sym2;
1246 }
1247
1248 struct symbol *sym_check_deps(struct symbol *sym)
1249 {
1250         struct symbol *sym2;
1251         struct property *prop;
1252
1253         if (sym->flags & SYMBOL_CHECK) {
1254                 sym_check_print_recursive(sym);
1255                 return sym;
1256         }
1257         if (sym->flags & SYMBOL_CHECKED)
1258                 return NULL;
1259
1260         if (sym_is_choice_value(sym)) {
1261                 struct dep_stack stack;
1262
1263                 /* for choice groups start the check with main choice symbol */
1264                 dep_stack_insert(&stack, sym);
1265                 prop = sym_get_choice_prop(sym);
1266                 sym2 = sym_check_deps(prop_get_symbol(prop));
1267                 dep_stack_remove();
1268         } else if (sym_is_choice(sym)) {
1269                 sym2 = sym_check_choice_deps(sym);
1270         } else {
1271                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1272                 sym2 = sym_check_sym_deps(sym);
1273                 sym->flags &= ~SYMBOL_CHECK;
1274         }
1275
1276         return sym2;
1277 }
1278
1279 struct symbol *prop_get_symbol(struct property *prop)
1280 {
1281         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1282                            prop->expr->type == E_LIST))
1283                 return prop->expr->left.sym;
1284         return NULL;
1285 }
1286
1287 const char *prop_get_type_name(enum prop_type type)
1288 {
1289         switch (type) {
1290         case P_PROMPT:
1291                 return "prompt";
1292         case P_COMMENT:
1293                 return "comment";
1294         case P_MENU:
1295                 return "menu";
1296         case P_DEFAULT:
1297                 return "default";
1298         case P_CHOICE:
1299                 return "choice";
1300         case P_SELECT:
1301                 return "select";
1302         case P_IMPLY:
1303                 return "imply";
1304         case P_RANGE:
1305                 return "range";
1306         case P_SYMBOL:
1307                 return "symbol";
1308         case P_UNKNOWN:
1309                 break;
1310         }
1311         return "unknown";
1312 }