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 }, symbol_mod = {
  19         .name = "m",
  20         .curr = { "m", mod },
  21         .flags = SYMBOL_CONST|SYMBOL_VALID,
  22 }, symbol_no = {
  23         .name = "n",
  24         .curr = { "n", no },
  25         .flags = SYMBOL_CONST|SYMBOL_VALID,
  26 }, symbol_empty = {
  27         .name = "",
  28         .curr = { "", no },
  29         .flags = SYMBOL_VALID,
  30 };
  31
  32 struct symbol *sym_defconfig_list;
  33 struct symbol *modules_sym;
  34 tristate modules_val;
  35
  36 enum symbol_type sym_get_type(struct symbol *sym)
  37 {
  38         enum symbol_type type = sym->type;
  39
  40         if (type == S_TRISTATE) {
  41                 if (sym_is_choice_value(sym) && sym->visible == yes)
  42                         type = S_BOOLEAN;
  43                 else if (modules_val == no)
  44                         type = S_BOOLEAN;
  45         }
  46         return type;
  47 }
  48
  49 const char *sym_type_name(enum symbol_type type)
  50 {
  51         switch (type) {
  52         case S_BOOLEAN:
  53                 return "bool";
  54         case S_TRISTATE:
  55                 return "tristate";
  56         case S_INT:
  57                 return "integer";
  58         case S_HEX:
  59                 return "hex";
  60         case S_STRING:
  61                 return "string";
  62         case S_UNKNOWN:
  63                 return "unknown";
  64         }
  65         return "???";
  66 }
  67
  68 struct property *sym_get_choice_prop(struct symbol *sym)
  69 {
  70         struct property *prop;
  71
  72         for_all_choices(sym, prop)
  73                 return prop;
  74         return NULL;
  75 }
  76
  77 static struct property *sym_get_default_prop(struct symbol *sym)
  78 {
  79         struct property *prop;
  80
  81         for_all_defaults(sym, prop) {
  82                 prop->visible.tri = expr_calc_value(prop->visible.expr);
  83                 if (prop->visible.tri != no)
  84                         return prop;
  85         }
  86         return NULL;
  87 }
  88
  89 struct property *sym_get_range_prop(struct symbol *sym)
  90 {
  91         struct property *prop;
  92
  93         for_all_properties(sym, prop, P_RANGE) {
  94                 prop->visible.tri = expr_calc_value(prop->visible.expr);
  95                 if (prop->visible.tri != no)
  96                         return prop;
  97         }
  98         return NULL;
  99 }
 100
 101 static long long sym_get_range_val(struct symbol *sym, int base)
 102 {
 103         sym_calc_value(sym);
 104         switch (sym->type) {
 105         case S_INT:
 106                 base = 10;
 107                 break;
 108         case S_HEX:
 109                 base = 16;
 110                 break;
 111         default:
 112                 break;
 113         }
 114         return strtoll(sym->curr.val, NULL, base);
 115 }
 116
 117 static void sym_validate_range(struct symbol *sym)
 118 {
 119         struct property *prop;
 120         int base;
 121         long long val, val2;
 122         char str[64];
 123
 124         switch (sym->type) {
 125         case S_INT:
 126                 base = 10;
 127                 break;
 128         case S_HEX:
 129                 base = 16;
 130                 break;
 131         default:
 132                 return;
 133         }
 134         prop = sym_get_range_prop(sym);
 135         if (!prop)
 136                 return;
 137         val = strtoll(sym->curr.val, NULL, base);
 138         val2 = sym_get_range_val(prop->expr->left.sym, base);
 139         if (val >= val2) {
 140                 val2 = sym_get_range_val(prop->expr->right.sym, base);
 141                 if (val <= val2)
 142                         return;
 143         }
 144         if (sym->type == S_INT)
 145                 sprintf(str, "%lld", val2);
 146         else
 147                 sprintf(str, "0x%llx", val2);
 148         sym->curr.val = xstrdup(str);
 149 }
 150
 151 static void sym_set_changed(struct symbol *sym)
 152 {
 153         struct property *prop;
 154
 155         sym->flags |= SYMBOL_CHANGED;
 156         for (prop = sym->prop; prop; prop = prop->next) {
 157                 if (prop->menu)
 158                         prop->menu->flags |= MENU_CHANGED;
 159         }
 160 }
 161
 162 static void sym_set_all_changed(void)
 163 {
 164         struct symbol *sym;
 165         int i;
 166
 167         for_all_symbols(i, sym)
 168                 sym_set_changed(sym);
 169 }
 170
 171 static void sym_calc_visibility(struct symbol *sym)
 172 {
 173         struct property *prop;
 174         struct symbol *choice_sym = NULL;
 175         tristate tri;
 176
 177         /* any prompt visible? */
 178         tri = no;
 179
 180         if (sym_is_choice_value(sym))
 181                 choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
 182
 183         for_all_prompts(sym, prop) {
 184                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 185                 /*
 186                  * Tristate choice_values with visibility 'mod' are
 187                  * not visible if the corresponding choice's value is
 188                  * 'yes'.
 189                  */
 190                 if (choice_sym && sym->type == S_TRISTATE &&
 191                     prop->visible.tri == mod && choice_sym->curr.tri == yes)
 192                         prop->visible.tri = no;
 193
 194                 tri = EXPR_OR(tri, prop->visible.tri);
 195         }
 196         if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 197                 tri = yes;
 198         if (sym->visible != tri) {
 199                 sym->visible = tri;
 200                 sym_set_changed(sym);
 201         }
 202         if (sym_is_choice_value(sym))
 203                 return;
 204         /* defaulting to "yes" if no explicit "depends on" are given */
 205         tri = yes;
 206         if (sym->dir_dep.expr)
 207                 tri = expr_calc_value(sym->dir_dep.expr);
 208         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 209                 tri = yes;
 210         if (sym->dir_dep.tri != tri) {
 211                 sym->dir_dep.tri = tri;
 212                 sym_set_changed(sym);
 213         }
 214         tri = no;
 215         if (sym->rev_dep.expr)
 216                 tri = expr_calc_value(sym->rev_dep.expr);
 217         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 218                 tri = yes;
 219         if (sym->rev_dep.tri != tri) {
 220                 sym->rev_dep.tri = tri;
 221                 sym_set_changed(sym);
 222         }
 223         tri = no;
 224         if (sym->implied.expr && sym->dir_dep.tri != no)
 225                 tri = expr_calc_value(sym->implied.expr);
 226         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 227                 tri = yes;
 228         if (sym->implied.tri != tri) {
 229                 sym->implied.tri = tri;
 230                 sym_set_changed(sym);
 231         }
 232 }
 233
 234 /*
 235  * Find the default symbol for a choice.
 236  * First try the default values for the choice symbol
 237  * Next locate the first visible choice value
 238  * Return NULL if none was found
 239  */
 240 struct symbol *sym_choice_default(struct symbol *sym)
 241 {
 242         struct symbol *def_sym;
 243         struct property *prop;
 244         struct expr *e;
 245
 246         /* any of the defaults visible? */
 247         for_all_defaults(sym, prop) {
 248                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 249                 if (prop->visible.tri == no)
 250                         continue;
 251                 def_sym = prop_get_symbol(prop);
 252                 if (def_sym->visible != no)
 253                         return def_sym;
 254         }
 255
 256         /* just get the first visible value */
 257         prop = sym_get_choice_prop(sym);
 258         expr_list_for_each_sym(prop->expr, e, def_sym)
 259                 if (def_sym->visible != no)
 260                         return def_sym;
 261
 262         /* failed to locate any defaults */
 263         return NULL;
 264 }
 265
 266 static struct symbol *sym_calc_choice(struct symbol *sym)
 267 {
 268         struct symbol *def_sym;
 269         struct property *prop;
 270         struct expr *e;
 271         int flags;
 272
 273         /* first calculate all choice values' visibilities */
 274         flags = sym->flags;
 275         prop = sym_get_choice_prop(sym);
 276         expr_list_for_each_sym(prop->expr, e, def_sym) {
 277                 sym_calc_visibility(def_sym);
 278                 if (def_sym->visible != no)
 279                         flags &= def_sym->flags;
 280         }
 281
 282         sym->flags &= flags | ~SYMBOL_DEF_USER;
 283
 284         /* is the user choice visible? */
 285         def_sym = sym->def[S_DEF_USER].val;
 286         if (def_sym && def_sym->visible != no)
 287                 return def_sym;
 288
 289         def_sym = sym_choice_default(sym);
 290
 291         if (def_sym == NULL)
 292                 /* no choice? reset tristate value */
 293                 sym->curr.tri = no;
 294
 295         return def_sym;
 296 }
 297
 298 static void sym_warn_unmet_dep(struct symbol *sym)
 299 {
 300         struct gstr gs = str_new();
 301
 302         str_printf(&gs,
 303                    "\nWARNING: unmet direct dependencies detected for %s\n",
 304                    sym->name);
 305         str_printf(&gs,
 306                    "  Depends on [%c]: ",
 307                    sym->dir_dep.tri == mod ? 'm' : 'n');
 308         expr_gstr_print(sym->dir_dep.expr, &gs);
 309         str_printf(&gs, "\n");
 310
 311         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
 312                                "  Selected by [y]:\n");
 313         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
 314                                "  Selected by [m]:\n");
 315
 316         fputs(str_get(&gs), stderr);
 317 }
 318
 319 void sym_calc_value(struct symbol *sym)
 320 {
 321         struct symbol_value newval, oldval;
 322         struct property *prop;
 323         struct expr *e;
 324
 325         if (!sym)
 326                 return;
 327
 328         if (sym->flags & SYMBOL_VALID)
 329                 return;
 330
 331         if (sym_is_choice_value(sym) &&
 332             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 333                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 334                 prop = sym_get_choice_prop(sym);
 335                 sym_calc_value(prop_get_symbol(prop));
 336         }
 337
 338         sym->flags |= SYMBOL_VALID;
 339
 340         oldval = sym->curr;
 341
 342         switch (sym->type) {
 343         case S_INT:
 344         case S_HEX:
 345         case S_STRING:
 346                 newval = symbol_empty.curr;
 347                 break;
 348         case S_BOOLEAN:
 349         case S_TRISTATE:
 350                 newval = symbol_no.curr;
 351                 break;
 352         default:
 353                 sym->curr.val = sym->name;
 354                 sym->curr.tri = no;
 355                 return;
 356         }
 357         sym->flags &= ~SYMBOL_WRITE;
 358
 359         sym_calc_visibility(sym);
 360
 361         if (sym->visible != no)
 362                 sym->flags |= SYMBOL_WRITE;
 363
 364         /* set default if recursively called */
 365         sym->curr = newval;
 366
 367         switch (sym_get_type(sym)) {
 368         case S_BOOLEAN:
 369         case S_TRISTATE:
 370                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 371                         prop = sym_get_choice_prop(sym);
 372                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 373                 } else {
 374                         if (sym->visible != no) {
 375                                 /* if the symbol is visible use the user value
 376                                  * if available, otherwise try the default value
 377                                  */
 378                                 if (sym_has_value(sym)) {
 379                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 380                                                               sym->visible);
 381                                         goto calc_newval;
 382                                 }
 383                         }
 384                         if (sym->rev_dep.tri != no)
 385                                 sym->flags |= SYMBOL_WRITE;
 386                         if (!sym_is_choice(sym)) {
 387                                 prop = sym_get_default_prop(sym);
 388                                 if (prop) {
 389                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 390                                                               prop->visible.tri);
 391                                         if (newval.tri != no)
 392                                                 sym->flags |= SYMBOL_WRITE;
 393                                 }
 394                                 if (sym->implied.tri != no) {
 395                                         sym->flags |= SYMBOL_WRITE;
 396                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 397                                 }
 398                         }
 399                 calc_newval:
 400                         if (sym->dir_dep.tri < sym->rev_dep.tri)
 401                                 sym_warn_unmet_dep(sym);
 402                         newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 403                 }
 404                 if (newval.tri == mod &&
 405                     (sym_get_type(sym) == S_BOOLEAN || sym->implied.tri == yes))
 406                         newval.tri = yes;
 407                 break;
 408         case S_STRING:
 409         case S_HEX:
 410         case S_INT:
 411                 if (sym->visible != no && sym_has_value(sym)) {
 412                         newval.val = sym->def[S_DEF_USER].val;
 413                         break;
 414                 }
 415                 prop = sym_get_default_prop(sym);
 416                 if (prop) {
 417                         struct symbol *ds = prop_get_symbol(prop);
 418                         if (ds) {
 419                                 sym->flags |= SYMBOL_WRITE;
 420                                 sym_calc_value(ds);
 421                                 newval.val = ds->curr.val;
 422                         }
 423                 }
 424                 break;
 425         default:
 426                 ;
 427         }
 428
 429         sym->curr = newval;
 430         if (sym_is_choice(sym) && newval.tri == yes)
 431                 sym->curr.val = sym_calc_choice(sym);
 432         sym_validate_range(sym);
 433
 434         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 435                 sym_set_changed(sym);
 436                 if (modules_sym == sym) {
 437                         sym_set_all_changed();
 438                         modules_val = modules_sym->curr.tri;
 439                 }
 440         }
 441
 442         if (sym_is_choice(sym)) {
 443                 struct symbol *choice_sym;
 444
 445                 prop = sym_get_choice_prop(sym);
 446                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 447                         if ((sym->flags & SYMBOL_WRITE) &&
 448                             choice_sym->visible != no)
 449                                 choice_sym->flags |= SYMBOL_WRITE;
 450                         if (sym->flags & SYMBOL_CHANGED)
 451                                 sym_set_changed(choice_sym);
 452                 }
 453         }
 454
 455         if (sym->flags & SYMBOL_NO_WRITE)
 456                 sym->flags &= ~SYMBOL_WRITE;
 457
 458         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 459                 set_all_choice_values(sym);
 460 }
 461
 462 void sym_clear_all_valid(void)
 463 {
 464         struct symbol *sym;
 465         int i;
 466
 467         for_all_symbols(i, sym)
 468                 sym->flags &= ~SYMBOL_VALID;
 469         sym_add_change_count(1);
 470         sym_calc_value(modules_sym);
 471 }
 472
 473 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 474 {
 475         int type = sym_get_type(sym);
 476
 477         if (sym->visible == no)
 478                 return false;
 479
 480         if (type != S_BOOLEAN && type != S_TRISTATE)
 481                 return false;
 482
 483         if (type == S_BOOLEAN && val == mod)
 484                 return false;
 485         if (sym->visible <= sym->rev_dep.tri)
 486                 return false;
 487         if (sym->implied.tri == yes && val == mod)
 488                 return false;
 489         if (sym_is_choice_value(sym) && sym->visible == yes)
 490                 return val == yes;
 491         return val >= sym->rev_dep.tri && val <= sym->visible;
 492 }
 493
 494 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 495 {
 496         tristate oldval = sym_get_tristate_value(sym);
 497
 498         if (oldval != val && !sym_tristate_within_range(sym, val))
 499                 return false;
 500
 501         if (!(sym->flags & SYMBOL_DEF_USER)) {
 502                 sym->flags |= SYMBOL_DEF_USER;
 503                 sym_set_changed(sym);
 504         }
 505         /*
 506          * setting a choice value also resets the new flag of the choice
 507          * symbol and all other choice values.
 508          */
 509         if (sym_is_choice_value(sym) && val == yes) {
 510                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 511                 struct property *prop;
 512                 struct expr *e;
 513
 514                 cs->def[S_DEF_USER].val = sym;
 515                 cs->flags |= SYMBOL_DEF_USER;
 516                 prop = sym_get_choice_prop(cs);
 517                 for (e = prop->expr; e; e = e->left.expr) {
 518                         if (e->right.sym->visible != no)
 519                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 520                 }
 521         }
 522
 523         sym->def[S_DEF_USER].tri = val;
 524         if (oldval != val)
 525                 sym_clear_all_valid();
 526
 527         return true;
 528 }
 529
 530 tristate sym_toggle_tristate_value(struct symbol *sym)
 531 {
 532         tristate oldval, newval;
 533
 534         oldval = newval = sym_get_tristate_value(sym);
 535         do {
 536                 switch (newval) {
 537                 case no:
 538                         newval = mod;
 539                         break;
 540                 case mod:
 541                         newval = yes;
 542                         break;
 543                 case yes:
 544                         newval = no;
 545                         break;
 546                 }
 547                 if (sym_set_tristate_value(sym, newval))
 548                         break;
 549         } while (oldval != newval);
 550         return newval;
 551 }
 552
 553 bool sym_string_valid(struct symbol *sym, const char *str)
 554 {
 555         signed char ch;
 556
 557         switch (sym->type) {
 558         case S_STRING:
 559                 return true;
 560         case S_INT:
 561                 ch = *str++;
 562                 if (ch == '-')
 563                         ch = *str++;
 564                 if (!isdigit(ch))
 565                         return false;
 566                 if (ch == '0' && *str != 0)
 567                         return false;
 568                 while ((ch = *str++)) {
 569                         if (!isdigit(ch))
 570                                 return false;
 571                 }
 572                 return true;
 573         case S_HEX:
 574                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 575                         str += 2;
 576                 ch = *str++;
 577                 do {
 578                         if (!isxdigit(ch))
 579                                 return false;
 580                 } while ((ch = *str++));
 581                 return true;
 582         case S_BOOLEAN:
 583         case S_TRISTATE:
 584                 switch (str[0]) {
 585                 case 'y': case 'Y':
 586                 case 'm': case 'M':
 587                 case 'n': case 'N':
 588                         return true;
 589                 }
 590                 return false;
 591         default:
 592                 return false;
 593         }
 594 }
 595
 596 bool sym_string_within_range(struct symbol *sym, const char *str)
 597 {
 598         struct property *prop;
 599         long long val;
 600
 601         switch (sym->type) {
 602         case S_STRING:
 603                 return sym_string_valid(sym, str);
 604         case S_INT:
 605                 if (!sym_string_valid(sym, str))
 606                         return false;
 607                 prop = sym_get_range_prop(sym);
 608                 if (!prop)
 609                         return true;
 610                 val = strtoll(str, NULL, 10);
 611                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 612                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 613         case S_HEX:
 614                 if (!sym_string_valid(sym, str))
 615                         return false;
 616                 prop = sym_get_range_prop(sym);
 617                 if (!prop)
 618                         return true;
 619                 val = strtoll(str, NULL, 16);
 620                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 621                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 622         case S_BOOLEAN:
 623         case S_TRISTATE:
 624                 switch (str[0]) {
 625                 case 'y': case 'Y':
 626                         return sym_tristate_within_range(sym, yes);
 627                 case 'm': case 'M':
 628                         return sym_tristate_within_range(sym, mod);
 629                 case 'n': case 'N':
 630                         return sym_tristate_within_range(sym, no);
 631                 }
 632                 return false;
 633         default:
 634                 return false;
 635         }
 636 }
 637
 638 bool sym_set_string_value(struct symbol *sym, const char *newval)
 639 {
 640         const char *oldval;
 641         char *val;
 642         int size;
 643
 644         switch (sym->type) {
 645         case S_BOOLEAN:
 646         case S_TRISTATE:
 647                 switch (newval[0]) {
 648                 case 'y': case 'Y':
 649                         return sym_set_tristate_value(sym, yes);
 650                 case 'm': case 'M':
 651                         return sym_set_tristate_value(sym, mod);
 652                 case 'n': case 'N':
 653                         return sym_set_tristate_value(sym, no);
 654                 }
 655                 return false;
 656         default:
 657                 ;
 658         }
 659
 660         if (!sym_string_within_range(sym, newval))
 661                 return false;
 662
 663         if (!(sym->flags & SYMBOL_DEF_USER)) {
 664                 sym->flags |= SYMBOL_DEF_USER;
 665                 sym_set_changed(sym);
 666         }
 667
 668         oldval = sym->def[S_DEF_USER].val;
 669         size = strlen(newval) + 1;
 670         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 671                 size += 2;
 672                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 673                 *val++ = '0';
 674                 *val++ = 'x';
 675         } else if (!oldval || strcmp(oldval, newval))
 676                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 677         else
 678                 return true;
 679
 680         strcpy(val, newval);
 681         free((void *)oldval);
 682         sym_clear_all_valid();
 683
 684         return true;
 685 }
 686
 687 /*
 688  * Find the default value associated to a symbol.
 689  * For tristate symbol handle the modules=n case
 690  * in which case "m" becomes "y".
 691  * If the symbol does not have any default then fallback
 692  * to the fixed default values.
 693  */
 694 const char *sym_get_string_default(struct symbol *sym)
 695 {
 696         struct property *prop;
 697         struct symbol *ds;
 698         const char *str;
 699         tristate val;
 700
 701         sym_calc_visibility(sym);
 702         sym_calc_value(modules_sym);
 703         val = symbol_no.curr.tri;
 704         str = symbol_empty.curr.val;
 705
 706         /* If symbol has a default value look it up */
 707         prop = sym_get_default_prop(sym);
 708         if (prop != NULL) {
 709                 switch (sym->type) {
 710                 case S_BOOLEAN:
 711                 case S_TRISTATE:
 712                         /* The visibility may limit the value from yes => mod */
 713                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 714                         break;
 715                 default:
 716                         /*
 717                          * The following fails to handle the situation
 718                          * where a default value is further limited by
 719                          * the valid range.
 720                          */
 721                         ds = prop_get_symbol(prop);
 722                         if (ds != NULL) {
 723                                 sym_calc_value(ds);
 724                                 str = (const char *)ds->curr.val;
 725                         }
 726                 }
 727         }
 728
 729         /* Handle select statements */
 730         val = EXPR_OR(val, sym->rev_dep.tri);
 731
 732         /* transpose mod to yes if modules are not enabled */
 733         if (val == mod)
 734                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 735                         val = yes;
 736
 737         /* transpose mod to yes if type is bool */
 738         if (sym->type == S_BOOLEAN && val == mod)
 739                 val = yes;
 740
 741         /* adjust the default value if this symbol is implied by another */
 742         if (val < sym->implied.tri)
 743                 val = sym->implied.tri;
 744
 745         switch (sym->type) {
 746         case S_BOOLEAN:
 747         case S_TRISTATE:
 748                 switch (val) {
 749                 case no: return "n";
 750                 case mod: return "m";
 751                 case yes: return "y";
 752                 }
 753         case S_INT:
 754         case S_HEX:
 755                 return str;
 756         case S_STRING:
 757                 return str;
 758         case S_UNKNOWN:
 759                 break;
 760         }
 761         return "";
 762 }
 763
 764 const char *sym_get_string_value(struct symbol *sym)
 765 {
 766         tristate val;
 767
 768         switch (sym->type) {
 769         case S_BOOLEAN:
 770         case S_TRISTATE:
 771                 val = sym_get_tristate_value(sym);
 772                 switch (val) {
 773                 case no:
 774                         return "n";
 775                 case mod:
 776                         sym_calc_value(modules_sym);
 777                         return (modules_sym->curr.tri == no) ? "n" : "m";
 778                 case yes:
 779                         return "y";
 780                 }
 781                 break;
 782         default:
 783                 ;
 784         }
 785         return (const char *)sym->curr.val;
 786 }
 787
 788 bool sym_is_changeable(struct symbol *sym)
 789 {
 790         return sym->visible > sym->rev_dep.tri;
 791 }
 792
 793 static unsigned strhash(const char *s)
 794 {
 795         /* fnv32 hash */
 796         unsigned hash = 2166136261U;
 797         for (; *s; s++)
 798                 hash = (hash ^ *s) * 0x01000193;
 799         return hash;
 800 }
 801
 802 struct symbol *sym_lookup(const char *name, int flags)
 803 {
 804         struct symbol *symbol;
 805         char *new_name;
 806         int hash;
 807
 808         if (name) {
 809                 if (name[0] && !name[1]) {
 810                         switch (name[0]) {
 811                         case 'y': return &symbol_yes;
 812                         case 'm': return &symbol_mod;
 813                         case 'n': return &symbol_no;
 814                         }
 815                 }
 816                 hash = strhash(name) % SYMBOL_HASHSIZE;
 817
 818                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 819                         if (symbol->name &&
 820                             !strcmp(symbol->name, name) &&
 821                             (flags ? symbol->flags & flags
 822                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 823                                 return symbol;
 824                 }
 825                 new_name = xstrdup(name);
 826         } else {
 827                 new_name = NULL;
 828                 hash = 0;
 829         }
 830
 831         symbol = xmalloc(sizeof(*symbol));
 832         memset(symbol, 0, sizeof(*symbol));
 833         symbol->name = new_name;
 834         symbol->type = S_UNKNOWN;
 835         symbol->flags |= flags;
 836
 837         symbol->next = symbol_hash[hash];
 838         symbol_hash[hash] = symbol;
 839
 840         return symbol;
 841 }
 842
 843 struct symbol *sym_find(const char *name)
 844 {
 845         struct symbol *symbol = NULL;
 846         int hash = 0;
 847
 848         if (!name)
 849                 return NULL;
 850
 851         if (name[0] && !name[1]) {
 852                 switch (name[0]) {
 853                 case 'y': return &symbol_yes;
 854                 case 'm': return &symbol_mod;
 855                 case 'n': return &symbol_no;
 856                 }
 857         }
 858         hash = strhash(name) % SYMBOL_HASHSIZE;
 859
 860         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 861                 if (symbol->name &&
 862                     !strcmp(symbol->name, name) &&
 863                     !(symbol->flags & SYMBOL_CONST))
 864                                 break;
 865         }
 866
 867         return symbol;
 868 }
 869
 870 const char *sym_escape_string_value(const char *in)
 871 {
 872         const char *p;
 873         size_t reslen;
 874         char *res;
 875         size_t l;
 876
 877         reslen = strlen(in) + strlen("\"\"") + 1;
 878
 879         p = in;
 880         for (;;) {
 881                 l = strcspn(p, "\"\\");
 882                 p += l;
 883
 884                 if (p[0] == '\0')
 885                         break;
 886
 887                 reslen++;
 888                 p++;
 889         }
 890
 891         res = xmalloc(reslen);
 892         res[0] = '\0';
 893
 894         strcat(res, "\"");
 895
 896         p = in;
 897         for (;;) {
 898                 l = strcspn(p, "\"\\");
 899                 strncat(res, p, l);
 900                 p += l;
 901
 902                 if (p[0] == '\0')
 903                         break;
 904
 905                 strcat(res, "\\");
 906                 strncat(res, p++, 1);
 907         }
 908
 909         strcat(res, "\"");
 910         return res;
 911 }
 912
 913 struct sym_match {
 914         struct symbol   *sym;
 915         off_t           so, eo;
 916 };
 917
 918 /* Compare matched symbols as thus:
 919  * - first, symbols that match exactly
 920  * - then, alphabetical sort
 921  */
 922 static int sym_rel_comp(const void *sym1, const void *sym2)
 923 {
 924         const struct sym_match *s1 = sym1;
 925         const struct sym_match *s2 = sym2;
 926         int exact1, exact2;
 927
 928         /* Exact match:
 929          * - if matched length on symbol s1 is the length of that symbol,
 930          *   then this symbol should come first;
 931          * - if matched length on symbol s2 is the length of that symbol,
 932          *   then this symbol should come first.
 933          * Note: since the search can be a regexp, both symbols may match
 934          * exactly; if this is the case, we can't decide which comes first,
 935          * and we fallback to sorting alphabetically.
 936          */
 937         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 938         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 939         if (exact1 && !exact2)
 940                 return -1;
 941         if (!exact1 && exact2)
 942                 return 1;
 943
 944         /* As a fallback, sort symbols alphabetically */
 945         return strcmp(s1->sym->name, s2->sym->name);
 946 }
 947
 948 struct symbol **sym_re_search(const char *pattern)
 949 {
 950         struct symbol *sym, **sym_arr = NULL;
 951         struct sym_match *sym_match_arr = NULL;
 952         int i, cnt, size;
 953         regex_t re;
 954         regmatch_t match[1];
 955
 956         cnt = size = 0;
 957         /* Skip if empty */
 958         if (strlen(pattern) == 0)
 959                 return NULL;
 960         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 961                 return NULL;
 962
 963         for_all_symbols(i, sym) {
 964                 if (sym->flags & SYMBOL_CONST || !sym->name)
 965                         continue;
 966                 if (regexec(&re, sym->name, 1, match, 0))
 967                         continue;
 968                 if (cnt >= size) {
 969                         void *tmp;
 970                         size += 16;
 971                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 972                         if (!tmp)
 973                                 goto sym_re_search_free;
 974                         sym_match_arr = tmp;
 975                 }
 976                 sym_calc_value(sym);
 977                 /* As regexec returned 0, we know we have a match, so
 978                  * we can use match[0].rm_[se]o without further checks
 979                  */
 980                 sym_match_arr[cnt].so = match[0].rm_so;
 981                 sym_match_arr[cnt].eo = match[0].rm_eo;
 982                 sym_match_arr[cnt++].sym = sym;
 983         }
 984         if (sym_match_arr) {
 985                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 986                 sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 987                 if (!sym_arr)
 988                         goto sym_re_search_free;
 989                 for (i = 0; i < cnt; i++)
 990                         sym_arr[i] = sym_match_arr[i].sym;
 991                 sym_arr[cnt] = NULL;
 992         }
 993 sym_re_search_free:
 994         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
 995         free(sym_match_arr);
 996         regfree(&re);
 997
 998         return sym_arr;
 999 }
1000
1001 /*
1002  * When we check for recursive dependencies we use a stack to save
1003  * current state so we can print out relevant info to user.
1004  * The entries are located on the call stack so no need to free memory.
1005  * Note insert() remove() must always match to properly clear the stack.
1006  */
1007 static struct dep_stack {
1008         struct dep_stack *prev, *next;
1009         struct symbol *sym;
1010         struct property *prop;
1011         struct expr **expr;
1012 } *check_top;
1013
1014 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1015 {
1016         memset(stack, 0, sizeof(*stack));
1017         if (check_top)
1018                 check_top->next = stack;
1019         stack->prev = check_top;
1020         stack->sym = sym;
1021         check_top = stack;
1022 }
1023
1024 static void dep_stack_remove(void)
1025 {
1026         check_top = check_top->prev;
1027         if (check_top)
1028                 check_top->next = NULL;
1029 }
1030
1031 /*
1032  * Called when we have detected a recursive dependency.
1033  * check_top point to the top of the stact so we use
1034  * the ->prev pointer to locate the bottom of the stack.
1035  */
1036 static void sym_check_print_recursive(struct symbol *last_sym)
1037 {
1038         struct dep_stack *stack;
1039         struct symbol *sym, *next_sym;
1040         struct menu *menu = NULL;
1041         struct property *prop;
1042         struct dep_stack cv_stack;
1043
1044         if (sym_is_choice_value(last_sym)) {
1045                 dep_stack_insert(&cv_stack, last_sym);
1046                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1047         }
1048
1049         for (stack = check_top; stack != NULL; stack = stack->prev)
1050                 if (stack->sym == last_sym)
1051                         break;
1052         if (!stack) {
1053                 fprintf(stderr, "unexpected recursive dependency error\n");
1054                 return;
1055         }
1056
1057         for (; stack; stack = stack->next) {
1058                 sym = stack->sym;
1059                 next_sym = stack->next ? stack->next->sym : last_sym;
1060                 prop = stack->prop;
1061                 if (prop == NULL)
1062                         prop = stack->sym->prop;
1063
1064                 /* for choice values find the menu entry (used below) */
1065                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1066                         for (prop = sym->prop; prop; prop = prop->next) {
1067                                 menu = prop->menu;
1068                                 if (prop->menu)
1069                                         break;
1070                         }
1071                 }
1072                 if (stack->sym == last_sym)
1073                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1074                                 prop->file->name, prop->lineno);
1075
1076                 if (sym_is_choice(sym)) {
1077                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1078                                 menu->file->name, menu->lineno,
1079                                 sym->name ? sym->name : "<choice>",
1080                                 next_sym->name ? next_sym->name : "<choice>");
1081                 } else if (sym_is_choice_value(sym)) {
1082                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1083                                 menu->file->name, menu->lineno,
1084                                 sym->name ? sym->name : "<choice>",
1085                                 next_sym->name ? next_sym->name : "<choice>");
1086                 } else if (stack->expr == &sym->dir_dep.expr) {
1087                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1088                                 prop->file->name, prop->lineno,
1089                                 sym->name ? sym->name : "<choice>",
1090                                 next_sym->name ? next_sym->name : "<choice>");
1091                 } else if (stack->expr == &sym->rev_dep.expr) {
1092                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1093                                 prop->file->name, prop->lineno,
1094                                 sym->name ? sym->name : "<choice>",
1095                                 next_sym->name ? next_sym->name : "<choice>");
1096                 } else if (stack->expr == &sym->implied.expr) {
1097                         fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1098                                 prop->file->name, prop->lineno,
1099                                 sym->name ? sym->name : "<choice>",
1100                                 next_sym->name ? next_sym->name : "<choice>");
1101                 } else if (stack->expr) {
1102                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1103                                 prop->file->name, prop->lineno,
1104                                 sym->name ? sym->name : "<choice>",
1105                                 prop_get_type_name(prop->type),
1106                                 next_sym->name ? next_sym->name : "<choice>");
1107                 } else {
1108                         fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1109                                 prop->file->name, prop->lineno,
1110                                 sym->name ? sym->name : "<choice>",
1111                                 prop_get_type_name(prop->type),
1112                                 next_sym->name ? next_sym->name : "<choice>");
1113                 }
1114         }
1115
1116         fprintf(stderr,
1117                 "For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1118                 "subsection \"Kconfig recursive dependency limitations\"\n"
1119                 "\n");
1120
1121         if (check_top == &cv_stack)
1122                 dep_stack_remove();
1123 }
1124
1125 static struct symbol *sym_check_expr_deps(struct expr *e)
1126 {
1127         struct symbol *sym;
1128
1129         if (!e)
1130                 return NULL;
1131         switch (e->type) {
1132         case E_OR:
1133         case E_AND:
1134                 sym = sym_check_expr_deps(e->left.expr);
1135                 if (sym)
1136                         return sym;
1137                 return sym_check_expr_deps(e->right.expr);
1138         case E_NOT:
1139                 return sym_check_expr_deps(e->left.expr);
1140         case E_EQUAL:
1141         case E_GEQ:
1142         case E_GTH:
1143         case E_LEQ:
1144         case E_LTH:
1145         case E_UNEQUAL:
1146                 sym = sym_check_deps(e->left.sym);
1147                 if (sym)
1148                         return sym;
1149                 return sym_check_deps(e->right.sym);
1150         case E_SYMBOL:
1151                 return sym_check_deps(e->left.sym);
1152         default:
1153                 break;
1154         }
1155         fprintf(stderr, "Oops! How to check %d?\n", e->type);
1156         return NULL;
1157 }
1158
1159 /* return NULL when dependencies are OK */
1160 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1161 {
1162         struct symbol *sym2;
1163         struct property *prop;
1164         struct dep_stack stack;
1165
1166         dep_stack_insert(&stack, sym);
1167
1168         stack.expr = &sym->dir_dep.expr;
1169         sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1170         if (sym2)
1171                 goto out;
1172
1173         stack.expr = &sym->rev_dep.expr;
1174         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1175         if (sym2)
1176                 goto out;
1177
1178         stack.expr = &sym->implied.expr;
1179         sym2 = sym_check_expr_deps(sym->implied.expr);
1180         if (sym2)
1181                 goto out;
1182
1183         stack.expr = NULL;
1184
1185         for (prop = sym->prop; prop; prop = prop->next) {
1186                 if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1187                     prop->type == P_IMPLY)
1188                         continue;
1189                 stack.prop = prop;
1190                 sym2 = sym_check_expr_deps(prop->visible.expr);
1191                 if (sym2)
1192                         break;
1193                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1194                         continue;
1195                 stack.expr = &prop->expr;
1196                 sym2 = sym_check_expr_deps(prop->expr);
1197                 if (sym2)
1198                         break;
1199                 stack.expr = NULL;
1200         }
1201
1202 out:
1203         dep_stack_remove();
1204
1205         return sym2;
1206 }
1207
1208 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1209 {
1210         struct symbol *sym, *sym2;
1211         struct property *prop;
1212         struct expr *e;
1213         struct dep_stack stack;
1214
1215         dep_stack_insert(&stack, choice);
1216
1217         prop = sym_get_choice_prop(choice);
1218         expr_list_for_each_sym(prop->expr, e, sym)
1219                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1220
1221         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1222         sym2 = sym_check_sym_deps(choice);
1223         choice->flags &= ~SYMBOL_CHECK;
1224         if (sym2)
1225                 goto out;
1226
1227         expr_list_for_each_sym(prop->expr, e, sym) {
1228                 sym2 = sym_check_sym_deps(sym);
1229                 if (sym2)
1230                         break;
1231         }
1232 out:
1233         expr_list_for_each_sym(prop->expr, e, sym)
1234                 sym->flags &= ~SYMBOL_CHECK;
1235
1236         if (sym2 && sym_is_choice_value(sym2) &&
1237             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1238                 sym2 = choice;
1239
1240         dep_stack_remove();
1241
1242         return sym2;
1243 }
1244
1245 struct symbol *sym_check_deps(struct symbol *sym)
1246 {
1247         struct symbol *sym2;
1248         struct property *prop;
1249
1250         if (sym->flags & SYMBOL_CHECK) {
1251                 sym_check_print_recursive(sym);
1252                 return sym;
1253         }
1254         if (sym->flags & SYMBOL_CHECKED)
1255                 return NULL;
1256
1257         if (sym_is_choice_value(sym)) {
1258                 struct dep_stack stack;
1259
1260                 /* for choice groups start the check with main choice symbol */
1261                 dep_stack_insert(&stack, sym);
1262                 prop = sym_get_choice_prop(sym);
1263                 sym2 = sym_check_deps(prop_get_symbol(prop));
1264                 dep_stack_remove();
1265         } else if (sym_is_choice(sym)) {
1266                 sym2 = sym_check_choice_deps(sym);
1267         } else {
1268                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1269                 sym2 = sym_check_sym_deps(sym);
1270                 sym->flags &= ~SYMBOL_CHECK;
1271         }
1272
1273         return sym2;
1274 }
1275
1276 struct symbol *prop_get_symbol(struct property *prop)
1277 {
1278         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1279                            prop->expr->type == E_LIST))
1280                 return prop->expr->left.sym;
1281         return NULL;
1282 }
1283
1284 const char *prop_get_type_name(enum prop_type type)
1285 {
1286         switch (type) {
1287         case P_PROMPT:
1288                 return "prompt";
1289         case P_COMMENT:
1290                 return "comment";
1291         case P_MENU:
1292                 return "menu";
1293         case P_DEFAULT:
1294                 return "default";
1295         case P_CHOICE:
1296                 return "choice";
1297         case P_SELECT:
1298                 return "select";
1299         case P_IMPLY:
1300                 return "imply";
1301         case P_RANGE:
1302                 return "range";
1303         case P_SYMBOL:
1304                 return "symbol";
1305         case P_UNKNOWN:
1306                 break;
1307         }
1308         return "unknown";
1309 }