scripts/config/symbol.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   4  */
   5
   6 #include <sys/types.h>
   7 #include <ctype.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <regex.h>
  11
  12 #include "lkc.h"
  13
  14 struct symbol symbol_yes = {
  15         .name = "y",
  16         .curr = { "y", yes },
  17         .flags = SYMBOL_CONST|SYMBOL_VALID,
  18 };
  19
  20 struct symbol symbol_mod = {
  21         .name = "m",
  22         .curr = { "m", mod },
  23         .flags = SYMBOL_CONST|SYMBOL_VALID,
  24 };
  25
  26 struct symbol symbol_no = {
  27         .name = "n",
  28         .curr = { "n", no },
  29         .flags = SYMBOL_CONST|SYMBOL_VALID,
  30 };
  31
  32 static struct symbol symbol_empty = {
  33         .name = "",
  34         .curr = { "", no },
  35         .flags = SYMBOL_VALID,
  36 };
  37
  38 struct symbol *modules_sym;
  39 static tristate modules_val;
  40 int recursive_is_error;
  41
  42 enum symbol_type sym_get_type(struct symbol *sym)
  43 {
  44         enum symbol_type type = sym->type;
  45
  46         if (type == S_TRISTATE) {
  47                 if (sym_is_choice_value(sym) && sym->visible == yes)
  48                         type = S_BOOLEAN;
  49                 else if (modules_val == no)
  50                         type = S_BOOLEAN;
  51         }
  52         return type;
  53 }
  54
  55 const char *sym_type_name(enum symbol_type type)
  56 {
  57         switch (type) {
  58         case S_BOOLEAN:
  59                 return "bool";
  60         case S_TRISTATE:
  61                 return "tristate";
  62         case S_INT:
  63                 return "integer";
  64         case S_HEX:
  65                 return "hex";
  66         case S_STRING:
  67                 return "string";
  68         case S_UNKNOWN:
  69                 return "unknown";
  70         }
  71         return "???";
  72 }
  73
  74 struct property *sym_get_choice_prop(struct symbol *sym)
  75 {
  76         struct property *prop;
  77
  78         for_all_choices(sym, prop)
  79                 return prop;
  80         return NULL;
  81 }
  82
  83 static struct property *sym_get_default_prop(struct symbol *sym)
  84 {
  85         struct property *prop;
  86
  87         for_all_defaults(sym, prop) {
  88                 prop->visible.tri = expr_calc_value(prop->visible.expr);
  89                 if (prop->visible.tri != no)
  90                         return prop;
  91         }
  92         return NULL;
  93 }
  94
  95 struct property *sym_get_range_prop(struct symbol *sym)
  96 {
  97         struct property *prop;
  98
  99         for_all_properties(sym, prop, P_RANGE) {
 100                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 101                 if (prop->visible.tri != no)
 102                         return prop;
 103         }
 104         return NULL;
 105 }
 106
 107 static long long sym_get_range_val(struct symbol *sym, int base)
 108 {
 109         sym_calc_value(sym);
 110         switch (sym->type) {
 111         case S_INT:
 112                 base = 10;
 113                 break;
 114         case S_HEX:
 115                 base = 16;
 116                 break;
 117         default:
 118                 break;
 119         }
 120         return strtoll(sym->curr.val, NULL, base);
 121 }
 122
 123 static void sym_validate_range(struct symbol *sym)
 124 {
 125         struct property *prop;
 126         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 void sym_calc_value(struct symbol *sym)
 303 {
 304         struct symbol_value newval, oldval;
 305         struct property *prop;
 306         struct expr *e;
 307
 308         if (!sym)
 309                 return;
 310
 311         if (sym->flags & SYMBOL_VALID)
 312                 return;
 313
 314         if (sym_is_choice_value(sym) &&
 315             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 316                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 317                 prop = sym_get_choice_prop(sym);
 318                 sym_calc_value(prop_get_symbol(prop));
 319         }
 320
 321         sym->flags |= SYMBOL_VALID;
 322
 323         oldval = sym->curr;
 324
 325         switch (sym->type) {
 326         case S_INT:
 327         case S_HEX:
 328         case S_STRING:
 329                 newval = symbol_empty.curr;
 330                 break;
 331         case S_BOOLEAN:
 332         case S_TRISTATE:
 333                 newval = symbol_no.curr;
 334                 break;
 335         default:
 336                 sym->curr.val = sym->name;
 337                 sym->curr.tri = no;
 338                 return;
 339         }
 340         sym->flags &= ~SYMBOL_WRITE;
 341
 342         sym_calc_visibility(sym);
 343
 344         if (sym->visible != no)
 345                 sym->flags |= SYMBOL_WRITE;
 346
 347         /* set default if recursively called */
 348         sym->curr = newval;
 349
 350         switch (sym_get_type(sym)) {
 351         case S_BOOLEAN:
 352         case S_TRISTATE:
 353                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 354                         prop = sym_get_choice_prop(sym);
 355                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 356                 } else {
 357                         if (sym->visible != no) {
 358                                 /* if the symbol is visible use the user value
 359                                  * if available, otherwise try the default value
 360                                  */
 361                                 if (sym_has_value(sym)) {
 362                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 363                                                               sym->visible);
 364                                         goto calc_newval;
 365                                 }
 366                         }
 367                         if (sym->rev_dep.tri != no)
 368                                 sym->flags |= SYMBOL_WRITE;
 369                         if (!sym_is_choice(sym)) {
 370                                 prop = sym_get_default_prop(sym);
 371                                 if (prop) {
 372                                         sym->flags |= SYMBOL_WRITE;
 373                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 374                                                               prop->visible.tri);
 375                                 }
 376                                 if (sym->implied.tri != no) {
 377                                         sym->flags |= SYMBOL_WRITE;
 378                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 379                                         newval.tri = EXPR_AND(newval.tri,
 380                                                               sym->dir_dep.tri);
 381                                 }
 382                         }
 383                 calc_newval:
 384                         if (sym->dir_dep.tri == no && sym->rev_dep.tri != no)
 385                                 newval.tri = no;
 386                         else
 387                                 newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 388                 }
 389                 if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 390                         newval.tri = yes;
 391                 break;
 392         case S_STRING:
 393         case S_HEX:
 394         case S_INT:
 395                 if (sym->visible != no && sym_has_value(sym)) {
 396                         newval.val = sym->def[S_DEF_USER].val;
 397                         break;
 398                 }
 399                 prop = sym_get_default_prop(sym);
 400                 if (prop) {
 401                         struct symbol *ds = prop_get_symbol(prop);
 402                         if (ds) {
 403                                 sym->flags |= SYMBOL_WRITE;
 404                                 sym_calc_value(ds);
 405                                 newval.val = ds->curr.val;
 406                         }
 407                 }
 408                 break;
 409         default:
 410                 ;
 411         }
 412
 413         sym->curr = newval;
 414         if (sym_is_choice(sym) && newval.tri == yes)
 415                 sym->curr.val = sym_calc_choice(sym);
 416         sym_validate_range(sym);
 417
 418         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 419                 sym_set_changed(sym);
 420                 if (modules_sym == sym) {
 421                         sym_set_all_changed();
 422                         modules_val = modules_sym->curr.tri;
 423                 }
 424         }
 425
 426         if (sym_is_choice(sym)) {
 427                 struct symbol *choice_sym;
 428
 429                 prop = sym_get_choice_prop(sym);
 430                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 431                         if ((sym->flags & SYMBOL_WRITE) &&
 432                             choice_sym->visible != no)
 433                                 choice_sym->flags |= SYMBOL_WRITE;
 434                         if (sym->flags & SYMBOL_CHANGED)
 435                                 sym_set_changed(choice_sym);
 436                 }
 437         }
 438
 439         if (sym->flags & SYMBOL_NO_WRITE)
 440                 sym->flags &= ~SYMBOL_WRITE;
 441
 442         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 443                 set_all_choice_values(sym);
 444 }
 445
 446 void sym_clear_all_valid(void)
 447 {
 448         struct symbol *sym;
 449         int i;
 450
 451         for_all_symbols(i, sym)
 452                 sym->flags &= ~SYMBOL_VALID;
 453         conf_set_changed(true);
 454         sym_calc_value(modules_sym);
 455 }
 456
 457 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 458 {
 459         int type = sym_get_type(sym);
 460
 461         if (sym->visible == no)
 462                 return false;
 463
 464         if (type != S_BOOLEAN && type != S_TRISTATE)
 465                 return false;
 466
 467         if (type == S_BOOLEAN && val == mod)
 468                 return false;
 469         if (sym->visible <= sym->rev_dep.tri)
 470                 return false;
 471         if (sym_is_choice_value(sym) && sym->visible == yes)
 472                 return val == yes;
 473         return val >= sym->rev_dep.tri && val <= sym->visible;
 474 }
 475
 476 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 477 {
 478         tristate oldval = sym_get_tristate_value(sym);
 479
 480         if (oldval != val && !sym_tristate_within_range(sym, val))
 481                 return false;
 482
 483         if (!(sym->flags & SYMBOL_DEF_USER)) {
 484                 sym->flags |= SYMBOL_DEF_USER;
 485                 sym_set_changed(sym);
 486         }
 487         /*
 488          * setting a choice value also resets the new flag of the choice
 489          * symbol and all other choice values.
 490          */
 491         if (sym_is_choice_value(sym) && val == yes) {
 492                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 493                 struct property *prop;
 494                 struct expr *e;
 495
 496                 cs->def[S_DEF_USER].val = sym;
 497                 cs->flags |= SYMBOL_DEF_USER;
 498                 prop = sym_get_choice_prop(cs);
 499                 for (e = prop->expr; e; e = e->left.expr) {
 500                         if (e->right.sym->visible != no)
 501                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 502                 }
 503         }
 504
 505         sym->def[S_DEF_USER].tri = val;
 506         if (oldval != val)
 507                 sym_clear_all_valid();
 508
 509         return true;
 510 }
 511
 512 tristate sym_toggle_tristate_value(struct symbol *sym)
 513 {
 514         tristate oldval, newval;
 515
 516         oldval = newval = sym_get_tristate_value(sym);
 517         do {
 518                 switch (newval) {
 519                 case no:
 520                         newval = mod;
 521                         break;
 522                 case mod:
 523                         newval = yes;
 524                         break;
 525                 case yes:
 526                         newval = no;
 527                         break;
 528                 }
 529                 if (sym_set_tristate_value(sym, newval))
 530                         break;
 531         } while (oldval != newval);
 532         return newval;
 533 }
 534
 535 bool sym_string_valid(struct symbol *sym, const char *str)
 536 {
 537         signed char ch;
 538
 539         switch (sym->type) {
 540         case S_STRING:
 541                 return true;
 542         case S_INT:
 543                 ch = *str++;
 544                 if (ch == '-')
 545                         ch = *str++;
 546                 if (!isdigit(ch))
 547                         return false;
 548                 if (ch == '0' && *str != 0)
 549                         return false;
 550                 while ((ch = *str++)) {
 551                         if (!isdigit(ch))
 552                                 return false;
 553                 }
 554                 return true;
 555         case S_HEX:
 556                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 557                         str += 2;
 558                 ch = *str++;
 559                 do {
 560                         if (!isxdigit(ch))
 561                                 return false;
 562                 } while ((ch = *str++));
 563                 return true;
 564         case S_BOOLEAN:
 565         case S_TRISTATE:
 566                 switch (str[0]) {
 567                 case 'y': case 'Y':
 568                 case 'm': case 'M':
 569                 case 'n': case 'N':
 570                         return true;
 571                 }
 572                 return false;
 573         default:
 574                 return false;
 575         }
 576 }
 577
 578 bool sym_string_within_range(struct symbol *sym, const char *str)
 579 {
 580         struct property *prop;
 581         long long val;
 582
 583         switch (sym->type) {
 584         case S_STRING:
 585                 return sym_string_valid(sym, str);
 586         case S_INT:
 587                 if (!sym_string_valid(sym, str))
 588                         return false;
 589                 prop = sym_get_range_prop(sym);
 590                 if (!prop)
 591                         return true;
 592                 val = strtoll(str, NULL, 10);
 593                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 594                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 595         case S_HEX:
 596                 if (!sym_string_valid(sym, str))
 597                         return false;
 598                 prop = sym_get_range_prop(sym);
 599                 if (!prop)
 600                         return true;
 601                 val = strtoll(str, NULL, 16);
 602                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 603                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 604         case S_BOOLEAN:
 605         case S_TRISTATE:
 606                 switch (str[0]) {
 607                 case 'y': case 'Y':
 608                         return sym_tristate_within_range(sym, yes);
 609                 case 'm': case 'M':
 610                         return sym_tristate_within_range(sym, mod);
 611                 case 'n': case 'N':
 612                         return sym_tristate_within_range(sym, no);
 613                 }
 614                 return false;
 615         default:
 616                 return false;
 617         }
 618 }
 619
 620 bool sym_set_string_value(struct symbol *sym, const char *newval)
 621 {
 622         const char *oldval;
 623         char *val;
 624         int size;
 625
 626         switch (sym->type) {
 627         case S_BOOLEAN:
 628         case S_TRISTATE:
 629                 switch (newval[0]) {
 630                 case 'y': case 'Y':
 631                         return sym_set_tristate_value(sym, yes);
 632                 case 'm': case 'M':
 633                         return sym_set_tristate_value(sym, mod);
 634                 case 'n': case 'N':
 635                         return sym_set_tristate_value(sym, no);
 636                 }
 637                 return false;
 638         default:
 639                 ;
 640         }
 641
 642         if (!sym_string_within_range(sym, newval))
 643                 return false;
 644
 645         if (!(sym->flags & SYMBOL_DEF_USER)) {
 646                 sym->flags |= SYMBOL_DEF_USER;
 647                 sym_set_changed(sym);
 648         }
 649
 650         oldval = sym->def[S_DEF_USER].val;
 651         size = strlen(newval) + 1;
 652         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 653                 size += 2;
 654                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 655                 *val++ = '0';
 656                 *val++ = 'x';
 657         } else if (!oldval || strcmp(oldval, newval))
 658                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 659         else
 660                 return true;
 661
 662         strcpy(val, newval);
 663         free((void *)oldval);
 664         sym_clear_all_valid();
 665
 666         return true;
 667 }
 668
 669 /*
 670  * Find the default value associated to a symbol.
 671  * For tristate symbol handle the modules=n case
 672  * in which case "m" becomes "y".
 673  * If the symbol does not have any default then fallback
 674  * to the fixed default values.
 675  */
 676 const char *sym_get_string_default(struct symbol *sym)
 677 {
 678         struct property *prop;
 679         struct symbol *ds;
 680         const char *str;
 681         tristate val;
 682
 683         sym_calc_visibility(sym);
 684         sym_calc_value(modules_sym);
 685         val = symbol_no.curr.tri;
 686         str = symbol_empty.curr.val;
 687
 688         /* If symbol has a default value look it up */
 689         prop = sym_get_default_prop(sym);
 690         if (prop != NULL) {
 691                 switch (sym->type) {
 692                 case S_BOOLEAN:
 693                 case S_TRISTATE:
 694                         /* The visibility may limit the value from yes => mod */
 695                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 696                         break;
 697                 default:
 698                         /*
 699                          * The following fails to handle the situation
 700                          * where a default value is further limited by
 701                          * the valid range.
 702                          */
 703                         ds = prop_get_symbol(prop);
 704                         if (ds != NULL) {
 705                                 sym_calc_value(ds);
 706                                 str = (const char *)ds->curr.val;
 707                         }
 708                 }
 709         }
 710
 711         /* Handle select statements */
 712         val = EXPR_OR(val, sym->rev_dep.tri);
 713
 714         /* transpose mod to yes if modules are not enabled */
 715         if (val == mod)
 716                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 717                         val = yes;
 718
 719         /* transpose mod to yes if type is bool */
 720         if (sym->type == S_BOOLEAN && val == mod)
 721                 val = yes;
 722
 723         /* adjust the default value if this symbol is implied by another */
 724         if (val < sym->implied.tri)
 725                 val = sym->implied.tri;
 726
 727         switch (sym->type) {
 728         case S_BOOLEAN:
 729         case S_TRISTATE:
 730                 switch (val) {
 731                 case no: return "n";
 732                 case mod: return "m";
 733                 case yes: return "y";
 734                 }
 735         case S_INT:
 736         case S_HEX:
 737                 return str;
 738         case S_STRING:
 739                 return str;
 740         case S_UNKNOWN:
 741                 break;
 742         }
 743         return "";
 744 }
 745
 746 const char *sym_get_string_value(struct symbol *sym)
 747 {
 748         tristate val;
 749
 750         switch (sym->type) {
 751         case S_BOOLEAN:
 752         case S_TRISTATE:
 753                 val = sym_get_tristate_value(sym);
 754                 switch (val) {
 755                 case no:
 756                         return "n";
 757                 case mod:
 758                         sym_calc_value(modules_sym);
 759                         return (modules_sym->curr.tri == no) ? "n" : "m";
 760                 case yes:
 761                         return "y";
 762                 }
 763                 break;
 764         default:
 765                 ;
 766         }
 767         return (const char *)sym->curr.val;
 768 }
 769
 770 bool sym_is_changeable(struct symbol *sym)
 771 {
 772         return sym->visible > sym->rev_dep.tri;
 773 }
 774
 775 static unsigned strhash(const char *s)
 776 {
 777         /* fnv32 hash */
 778         unsigned hash = 2166136261U;
 779         for (; *s; s++)
 780                 hash = (hash ^ *s) * 0x01000193;
 781         return hash;
 782 }
 783
 784 struct symbol *sym_lookup(const char *name, int flags)
 785 {
 786         struct symbol *symbol;
 787         char *new_name;
 788         int hash;
 789
 790         if (name) {
 791                 if (name[0] && !name[1]) {
 792                         switch (name[0]) {
 793                         case 'y': return &symbol_yes;
 794                         case 'm': return &symbol_mod;
 795                         case 'n': return &symbol_no;
 796                         }
 797                 }
 798                 hash = strhash(name) % SYMBOL_HASHSIZE;
 799
 800                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 801                         if (symbol->name &&
 802                             !strcmp(symbol->name, name) &&
 803                             (flags ? symbol->flags & flags
 804                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 805                                 return symbol;
 806                 }
 807                 new_name = xstrdup(name);
 808         } else {
 809                 new_name = NULL;
 810                 hash = 0;
 811         }
 812
 813         symbol = xmalloc(sizeof(*symbol));
 814         memset(symbol, 0, sizeof(*symbol));
 815         symbol->name = new_name;
 816         symbol->type = S_UNKNOWN;
 817         symbol->flags = flags;
 818
 819         symbol->next = symbol_hash[hash];
 820         symbol_hash[hash] = symbol;
 821
 822         return symbol;
 823 }
 824
 825 struct symbol *sym_find(const char *name)
 826 {
 827         struct symbol *symbol = NULL;
 828         int hash = 0;
 829
 830         if (!name)
 831                 return NULL;
 832
 833         if (name[0] && !name[1]) {
 834                 switch (name[0]) {
 835                 case 'y': return &symbol_yes;
 836                 case 'm': return &symbol_mod;
 837                 case 'n': return &symbol_no;
 838                 }
 839         }
 840         hash = strhash(name) % SYMBOL_HASHSIZE;
 841
 842         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 843                 if (symbol->name &&
 844                     !strcmp(symbol->name, name) &&
 845                     !(symbol->flags & SYMBOL_CONST))
 846                                 break;
 847         }
 848
 849         return symbol;
 850 }
 851
 852 struct sym_match {
 853         struct symbol   *sym;
 854         off_t           so, eo;
 855 };
 856
 857 /* Compare matched symbols as thus:
 858  * - first, symbols that match exactly
 859  * - then, alphabetical sort
 860  */
 861 static int sym_rel_comp(const void *sym1, const void *sym2)
 862 {
 863         const struct sym_match *s1 = sym1;
 864         const struct sym_match *s2 = sym2;
 865         int exact1, exact2;
 866
 867         /* Exact match:
 868          * - if matched length on symbol s1 is the length of that symbol,
 869          *   then this symbol should come first;
 870          * - if matched length on symbol s2 is the length of that symbol,
 871          *   then this symbol should come first.
 872          * Note: since the search can be a regexp, both symbols may match
 873          * exactly; if this is the case, we can't decide which comes first,
 874          * and we fallback to sorting alphabetically.
 875          */
 876         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 877         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 878         if (exact1 && !exact2)
 879                 return -1;
 880         if (!exact1 && exact2)
 881                 return 1;
 882
 883         /* As a fallback, sort symbols alphabetically */
 884         return strcmp(s1->sym->name, s2->sym->name);
 885 }
 886
 887 struct symbol **sym_re_search(const char *pattern)
 888 {
 889         struct symbol *sym, **sym_arr = NULL;
 890         struct sym_match *sym_match_arr = NULL;
 891         int i, cnt, size;
 892         regex_t re;
 893         regmatch_t match[1];
 894
 895         cnt = size = 0;
 896         /* Skip if empty */
 897         if (strlen(pattern) == 0)
 898                 return NULL;
 899         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 900                 return NULL;
 901
 902         for_all_symbols(i, sym) {
 903                 if (sym->flags & SYMBOL_CONST || !sym->name)
 904                         continue;
 905                 if (regexec(&re, sym->name, 1, match, 0))
 906                         continue;
 907                 if (cnt >= size) {
 908                         void *tmp;
 909                         size += 16;
 910                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 911                         if (!tmp)
 912                                 goto sym_re_search_free;
 913                         sym_match_arr = tmp;
 914                 }
 915                 sym_calc_value(sym);
 916                 /* As regexec returned 0, we know we have a match, so
 917                  * we can use match[0].rm_[se]o without further checks
 918                  */
 919                 sym_match_arr[cnt].so = match[0].rm_so;
 920                 sym_match_arr[cnt].eo = match[0].rm_eo;
 921                 sym_match_arr[cnt++].sym = sym;
 922         }
 923         if (sym_match_arr) {
 924                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 925                 sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 926                 if (!sym_arr)
 927                         goto sym_re_search_free;
 928                 for (i = 0; i < cnt; i++)
 929                         sym_arr[i] = sym_match_arr[i].sym;
 930                 sym_arr[cnt] = NULL;
 931         }
 932 sym_re_search_free:
 933         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
 934         free(sym_match_arr);
 935         regfree(&re);
 936
 937         return sym_arr;
 938 }
 939
 940 /*
 941  * When we check for recursive dependencies we use a stack to save
 942  * current state so we can print out relevant info to user.
 943  * The entries are located on the call stack so no need to free memory.
 944  * Note insert() remove() must always match to properly clear the stack.
 945  */
 946 static struct dep_stack {
 947         struct dep_stack *prev, *next;
 948         struct symbol *sym;
 949         struct property *prop;
 950         struct expr **expr;
 951 } *check_top;
 952
 953 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
 954 {
 955         memset(stack, 0, sizeof(*stack));
 956         if (check_top)
 957                 check_top->next = stack;
 958         stack->prev = check_top;
 959         stack->sym = sym;
 960         check_top = stack;
 961 }
 962
 963 static void dep_stack_remove(void)
 964 {
 965         check_top = check_top->prev;
 966         if (check_top)
 967                 check_top->next = NULL;
 968 }
 969
 970 /*
 971  * Called when we have detected a recursive dependency.
 972  * check_top point to the top of the stact so we use
 973  * the ->prev pointer to locate the bottom of the stack.
 974  */
 975 static void sym_check_print_recursive(struct symbol *last_sym)
 976 {
 977         struct dep_stack *stack;
 978         struct symbol *sym, *next_sym;
 979         struct menu *menu = NULL;
 980         struct property *prop;
 981         struct dep_stack cv_stack;
 982
 983         if (sym_is_choice_value(last_sym)) {
 984                 dep_stack_insert(&cv_stack, last_sym);
 985                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
 986         }
 987
 988         for (stack = check_top; stack != NULL; stack = stack->prev)
 989                 if (stack->sym == last_sym)
 990                         break;
 991         if (!stack) {
 992                 fprintf(stderr, "unexpected recursive dependency error\n");
 993                 return;
 994         }
 995
 996         for (; stack; stack = stack->next) {
 997                 sym = stack->sym;
 998                 next_sym = stack->next ? stack->next->sym : last_sym;
 999                 prop = stack->prop;
1000                 if (prop == NULL)
1001                         prop = stack->sym->prop;
1002
1003                 /* for choice values find the menu entry (used below) */
1004                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1005                         for (prop = sym->prop; prop; prop = prop->next) {
1006                                 menu = prop->menu;
1007                                 if (prop->menu)
1008                                         break;
1009                         }
1010                 }
1011                 if (stack->sym == last_sym)
1012                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1013                                 prop->file->name, prop->lineno);
1014
1015                 if (sym_is_choice(sym)) {
1016                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1017                                 menu->file->name, menu->lineno,
1018                                 sym->name ? sym->name : "<choice>",
1019                                 next_sym->name ? next_sym->name : "<choice>");
1020                 } else if (sym_is_choice_value(sym)) {
1021                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1022                                 menu->file->name, menu->lineno,
1023                                 sym->name ? sym->name : "<choice>",
1024                                 next_sym->name ? next_sym->name : "<choice>");
1025                 } else if (stack->expr == &sym->dir_dep.expr) {
1026                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1027                                 prop->file->name, prop->lineno,
1028                                 sym->name ? sym->name : "<choice>",
1029                                 next_sym->name ? next_sym->name : "<choice>");
1030                 } else if (stack->expr == &sym->rev_dep.expr) {
1031                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1032                                 prop->file->name, prop->lineno,
1033                                 sym->name ? sym->name : "<choice>",
1034                                 next_sym->name ? next_sym->name : "<choice>");
1035                 } else if (stack->expr == &sym->implied.expr) {
1036                         fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1037                                 prop->file->name, prop->lineno,
1038                                 sym->name ? sym->name : "<choice>",
1039                                 next_sym->name ? next_sym->name : "<choice>");
1040                 } else if (stack->expr) {
1041                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1042                                 prop->file->name, prop->lineno,
1043                                 sym->name ? sym->name : "<choice>",
1044                                 prop_get_type_name(prop->type),
1045                                 next_sym->name ? next_sym->name : "<choice>");
1046                 } else {
1047                         fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1048                                 prop->file->name, prop->lineno,
1049                                 sym->name ? sym->name : "<choice>",
1050                                 prop_get_type_name(prop->type),
1051                                 next_sym->name ? next_sym->name : "<choice>");
1052                 }
1053         }
1054
1055         fprintf(stderr,
1056                 "For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1057                 "subsection \"Kconfig recursive dependency limitations\"\n"
1058                 "\n");
1059
1060         if (check_top == &cv_stack)
1061                 dep_stack_remove();
1062 }
1063
1064 static struct symbol *sym_check_expr_deps(struct expr *e)
1065 {
1066         struct symbol *sym;
1067
1068         if (!e)
1069                 return NULL;
1070         switch (e->type) {
1071         case E_OR:
1072         case E_AND:
1073                 sym = sym_check_expr_deps(e->left.expr);
1074                 if (sym)
1075                         return sym;
1076                 return sym_check_expr_deps(e->right.expr);
1077         case E_NOT:
1078                 return sym_check_expr_deps(e->left.expr);
1079         case E_EQUAL:
1080         case E_GEQ:
1081         case E_GTH:
1082         case E_LEQ:
1083         case E_LTH:
1084         case E_UNEQUAL:
1085                 sym = sym_check_deps(e->left.sym);
1086                 if (sym)
1087                         return sym;
1088                 return sym_check_deps(e->right.sym);
1089         case E_SYMBOL:
1090                 return sym_check_deps(e->left.sym);
1091         default:
1092                 break;
1093         }
1094         fprintf(stderr, "Oops! How to check %d?\n", e->type);
1095         return NULL;
1096 }
1097
1098 /* return NULL when dependencies are OK */
1099 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1100 {
1101         struct symbol *sym2;
1102         struct property *prop;
1103         struct dep_stack stack;
1104
1105         dep_stack_insert(&stack, sym);
1106
1107         stack.expr = &sym->dir_dep.expr;
1108         sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1109         if (sym2)
1110                 goto out;
1111
1112         stack.expr = &sym->rev_dep.expr;
1113         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1114         if (sym2)
1115                 goto out;
1116
1117         stack.expr = &sym->implied.expr;
1118         sym2 = sym_check_expr_deps(sym->implied.expr);
1119         if (sym2)
1120                 goto out;
1121
1122         stack.expr = NULL;
1123
1124         for (prop = sym->prop; prop; prop = prop->next) {
1125                 if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1126                     prop->type == P_IMPLY)
1127                         continue;
1128                 stack.prop = prop;
1129                 sym2 = sym_check_expr_deps(prop->visible.expr);
1130                 if (sym2)
1131                         break;
1132                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1133                         continue;
1134                 stack.expr = &prop->expr;
1135                 sym2 = sym_check_expr_deps(prop->expr);
1136                 if (sym2)
1137                         break;
1138                 stack.expr = NULL;
1139         }
1140
1141 out:
1142         dep_stack_remove();
1143
1144         return sym2;
1145 }
1146
1147 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1148 {
1149         struct symbol *sym, *sym2;
1150         struct property *prop;
1151         struct expr *e;
1152         struct dep_stack stack;
1153
1154         dep_stack_insert(&stack, choice);
1155
1156         prop = sym_get_choice_prop(choice);
1157         expr_list_for_each_sym(prop->expr, e, sym)
1158                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1159
1160         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1161         sym2 = sym_check_sym_deps(choice);
1162         choice->flags &= ~SYMBOL_CHECK;
1163         if (sym2)
1164                 goto out;
1165
1166         expr_list_for_each_sym(prop->expr, e, sym) {
1167                 sym2 = sym_check_sym_deps(sym);
1168                 if (sym2)
1169                         break;
1170         }
1171 out:
1172         expr_list_for_each_sym(prop->expr, e, sym)
1173                 sym->flags &= ~SYMBOL_CHECK;
1174
1175         if (sym2 && sym_is_choice_value(sym2) &&
1176             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1177                 sym2 = choice;
1178
1179         dep_stack_remove();
1180
1181         return sym2;
1182 }
1183
1184 struct symbol *sym_check_deps(struct symbol *sym)
1185 {
1186         struct symbol *sym2;
1187         struct property *prop;
1188
1189         if (sym->flags & SYMBOL_CHECK) {
1190                 sym_check_print_recursive(sym);
1191                 return sym;
1192         }
1193         if (sym->flags & SYMBOL_CHECKED)
1194                 return NULL;
1195
1196         if (sym_is_choice_value(sym)) {
1197                 struct dep_stack stack;
1198
1199                 /* for choice groups start the check with main choice symbol */
1200                 dep_stack_insert(&stack, sym);
1201                 prop = sym_get_choice_prop(sym);
1202                 sym2 = sym_check_deps(prop_get_symbol(prop));
1203                 dep_stack_remove();
1204         } else if (sym_is_choice(sym)) {
1205                 sym2 = sym_check_choice_deps(sym);
1206         } else {
1207                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1208                 sym2 = sym_check_sym_deps(sym);
1209                 sym->flags &= ~SYMBOL_CHECK;
1210         }
1211
1212         if (!recursive_is_error && sym2 && sym2 == sym)
1213                 sym2 = NULL;
1214
1215         return sym2;
1216 }
1217
1218 struct symbol *prop_get_symbol(struct property *prop)
1219 {
1220         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1221                            prop->expr->type == E_LIST))
1222                 return prop->expr->left.sym;
1223         return NULL;
1224 }
1225
1226 const char *prop_get_type_name(enum prop_type type)
1227 {
1228         switch (type) {
1229         case P_PROMPT:
1230                 return "prompt";
1231         case P_COMMENT:
1232                 return "comment";
1233         case P_MENU:
1234                 return "menu";
1235         case P_DEFAULT:
1236                 return "default";
1237         case P_CHOICE:
1238                 return "choice";
1239         case P_SELECT:
1240                 return "select";
1241         case P_IMPLY:
1242                 return "imply";
1243         case P_RANGE:
1244                 return "range";
1245         case P_SYMBOL:
1246                 return "symbol";
1247         case P_RESET:
1248                 return "reset";
1249         case P_UNKNOWN:
1250                 break;
1251         }
1252         return "unknown";
1253 }