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 <sys/types.h>
   7 #include <ctype.h>
   8 #include <stdlib.h>
   9 #include <string.h>
  10 #include <regex.h>
  11
  12 #include "lkc.h"
  13
  14 struct symbol symbol_yes = {
  15         .name = "y",
  16         .curr = { "y", yes },
  17         .flags = SYMBOL_CONST|SYMBOL_VALID,
  18 };
  19
  20 struct symbol symbol_mod = {
  21         .name = "m",
  22         .curr = { "m", mod },
  23         .flags = SYMBOL_CONST|SYMBOL_VALID,
  24 };
  25
  26 struct symbol symbol_no = {
  27         .name = "n",
  28         .curr = { "n", no },
  29         .flags = SYMBOL_CONST|SYMBOL_VALID,
  30 };
  31
  32 static struct symbol symbol_empty = {
  33         .name = "",
  34         .curr = { "", no },
  35         .flags = SYMBOL_VALID,
  36 };
  37
  38 struct symbol *modules_sym;
  39 static tristate modules_val;
  40
  41 enum symbol_type sym_get_type(struct symbol *sym)
  42 {
  43         enum symbol_type type = sym->type;
  44
  45         if (type == S_TRISTATE) {
  46                 if (sym_is_choice_value(sym) && sym->visible == yes)
  47                         type = S_BOOLEAN;
  48                 else if (modules_val == no)
  49                         type = S_BOOLEAN;
  50         }
  51         return type;
  52 }
  53
  54 const char *sym_type_name(enum symbol_type type)
  55 {
  56         switch (type) {
  57         case S_BOOLEAN:
  58                 return "bool";
  59         case S_TRISTATE:
  60                 return "tristate";
  61         case S_INT:
  62                 return "integer";
  63         case S_HEX:
  64                 return "hex";
  65         case S_STRING:
  66                 return "string";
  67         case S_UNKNOWN:
  68                 return "unknown";
  69         }
  70         return "???";
  71 }
  72
  73 struct property *sym_get_choice_prop(struct symbol *sym)
  74 {
  75         struct property *prop;
  76
  77         for_all_choices(sym, prop)
  78                 return prop;
  79         return NULL;
  80 }
  81
  82 static struct property *sym_get_default_prop(struct symbol *sym)
  83 {
  84         struct property *prop;
  85
  86         for_all_defaults(sym, prop) {
  87                 prop->visible.tri = expr_calc_value(prop->visible.expr);
  88                 if (prop->visible.tri != no)
  89                         return prop;
  90         }
  91         return NULL;
  92 }
  93
  94 struct property *sym_get_range_prop(struct symbol *sym)
  95 {
  96         struct property *prop;
  97
  98         for_all_properties(sym, prop, P_RANGE) {
  99                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 100                 if (prop->visible.tri != no)
 101                         return prop;
 102         }
 103         return NULL;
 104 }
 105
 106 static long long sym_get_range_val(struct symbol *sym, int base)
 107 {
 108         sym_calc_value(sym);
 109         switch (sym->type) {
 110         case S_INT:
 111                 base = 10;
 112                 break;
 113         case S_HEX:
 114                 base = 16;
 115                 break;
 116         default:
 117                 break;
 118         }
 119         return strtoll(sym->curr.val, NULL, base);
 120 }
 121
 122 static void sym_validate_range(struct symbol *sym)
 123 {
 124         struct property *prop;
 125         int base;
 126         long long val, val2;
 127         char str[64];
 128
 129         switch (sym->type) {
 130         case S_INT:
 131                 base = 10;
 132                 break;
 133         case S_HEX:
 134                 base = 16;
 135                 break;
 136         default:
 137                 return;
 138         }
 139         prop = sym_get_range_prop(sym);
 140         if (!prop)
 141                 return;
 142         val = strtoll(sym->curr.val, NULL, base);
 143         val2 = sym_get_range_val(prop->expr->left.sym, base);
 144         if (val >= val2) {
 145                 val2 = sym_get_range_val(prop->expr->right.sym, base);
 146                 if (val <= val2)
 147                         return;
 148         }
 149         if (sym->type == S_INT)
 150                 sprintf(str, "%lld", val2);
 151         else
 152                 sprintf(str, "0x%llx", val2);
 153         sym->curr.val = xstrdup(str);
 154 }
 155
 156 static void sym_set_changed(struct symbol *sym)
 157 {
 158         struct property *prop;
 159
 160         sym->flags |= SYMBOL_CHANGED;
 161         for (prop = sym->prop; prop; prop = prop->next) {
 162                 if (prop->menu)
 163                         prop->menu->flags |= MENU_CHANGED;
 164         }
 165 }
 166
 167 static void sym_set_all_changed(void)
 168 {
 169         struct symbol *sym;
 170         int i;
 171
 172         for_all_symbols(i, sym)
 173                 sym_set_changed(sym);
 174 }
 175
 176 static void sym_calc_visibility(struct symbol *sym)
 177 {
 178         struct property *prop;
 179         struct symbol *choice_sym = NULL;
 180         tristate tri;
 181
 182         /* any prompt visible? */
 183         tri = no;
 184
 185         if (sym_is_choice_value(sym))
 186                 choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
 187
 188         for_all_prompts(sym, prop) {
 189                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 190                 /*
 191                  * Tristate choice_values with visibility 'mod' are
 192                  * not visible if the corresponding choice's value is
 193                  * 'yes'.
 194                  */
 195                 if (choice_sym && sym->type == S_TRISTATE &&
 196                     prop->visible.tri == mod && choice_sym->curr.tri == yes)
 197                         prop->visible.tri = no;
 198
 199                 tri = EXPR_OR(tri, prop->visible.tri);
 200         }
 201         if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 202                 tri = yes;
 203         if (sym->visible != tri) {
 204                 sym->visible = tri;
 205                 sym_set_changed(sym);
 206         }
 207         if (sym_is_choice_value(sym))
 208                 return;
 209         /* defaulting to "yes" if no explicit "depends on" are given */
 210         tri = yes;
 211         if (sym->dir_dep.expr)
 212                 tri = expr_calc_value(sym->dir_dep.expr);
 213         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 214                 tri = yes;
 215         if (sym->dir_dep.tri != tri) {
 216                 sym->dir_dep.tri = tri;
 217                 sym_set_changed(sym);
 218         }
 219         tri = no;
 220         if (sym->rev_dep.expr)
 221                 tri = expr_calc_value(sym->rev_dep.expr);
 222         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 223                 tri = yes;
 224         if (sym->rev_dep.tri != tri) {
 225                 sym->rev_dep.tri = tri;
 226                 sym_set_changed(sym);
 227         }
 228         tri = no;
 229         if (sym->implied.expr)
 230                 tri = expr_calc_value(sym->implied.expr);
 231         if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 232                 tri = yes;
 233         if (sym->implied.tri != tri) {
 234                 sym->implied.tri = tri;
 235                 sym_set_changed(sym);
 236         }
 237 }
 238
 239 /*
 240  * Find the default symbol for a choice.
 241  * First try the default values for the choice symbol
 242  * Next locate the first visible choice value
 243  * Return NULL if none was found
 244  */
 245 struct symbol *sym_choice_default(struct symbol *sym)
 246 {
 247         struct symbol *def_sym;
 248         struct property *prop;
 249         struct expr *e;
 250
 251         /* any of the defaults visible? */
 252         for_all_defaults(sym, prop) {
 253                 prop->visible.tri = expr_calc_value(prop->visible.expr);
 254                 if (prop->visible.tri == no)
 255                         continue;
 256                 def_sym = prop_get_symbol(prop);
 257                 if (def_sym->visible != no)
 258                         return def_sym;
 259         }
 260
 261         /* just get the first visible value */
 262         prop = sym_get_choice_prop(sym);
 263         expr_list_for_each_sym(prop->expr, e, def_sym)
 264                 if (def_sym->visible != no)
 265                         return def_sym;
 266
 267         /* failed to locate any defaults */
 268         return NULL;
 269 }
 270
 271 static struct symbol *sym_calc_choice(struct symbol *sym)
 272 {
 273         struct symbol *def_sym;
 274         struct property *prop;
 275         struct expr *e;
 276         int flags;
 277
 278         /* first calculate all choice values' visibilities */
 279         flags = sym->flags;
 280         prop = sym_get_choice_prop(sym);
 281         expr_list_for_each_sym(prop->expr, e, def_sym) {
 282                 sym_calc_visibility(def_sym);
 283                 if (def_sym->visible != no)
 284                         flags &= def_sym->flags;
 285         }
 286
 287         sym->flags &= flags | ~SYMBOL_DEF_USER;
 288
 289         /* is the user choice visible? */
 290         def_sym = sym->def[S_DEF_USER].val;
 291         if (def_sym && def_sym->visible != no)
 292                 return def_sym;
 293
 294         def_sym = sym_choice_default(sym);
 295
 296         if (def_sym == NULL)
 297                 /* no choice? reset tristate value */
 298                 sym->curr.tri = no;
 299
 300         return def_sym;
 301 }
 302
 303 static void sym_warn_unmet_dep(struct symbol *sym)
 304 {
 305         struct gstr gs = str_new();
 306
 307         str_printf(&gs,
 308                    "\nWARNING: unmet direct dependencies detected for %s\n",
 309                    sym->name);
 310         str_printf(&gs,
 311                    "  Depends on [%c]: ",
 312                    sym->dir_dep.tri == mod ? 'm' : 'n');
 313         expr_gstr_print(sym->dir_dep.expr, &gs);
 314         str_printf(&gs, "\n");
 315
 316         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, yes,
 317                                "  Selected by [y]:\n");
 318         expr_gstr_print_revdep(sym->rev_dep.expr, &gs, mod,
 319                                "  Selected by [m]:\n");
 320
 321         fputs(str_get(&gs), stderr);
 322 }
 323
 324 void sym_calc_value(struct symbol *sym)
 325 {
 326         struct symbol_value newval, oldval;
 327         struct property *prop;
 328         struct expr *e;
 329
 330         if (!sym)
 331                 return;
 332
 333         if (sym->flags & SYMBOL_VALID)
 334                 return;
 335
 336         if (sym_is_choice_value(sym) &&
 337             sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 338                 sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 339                 prop = sym_get_choice_prop(sym);
 340                 sym_calc_value(prop_get_symbol(prop));
 341         }
 342
 343         sym->flags |= SYMBOL_VALID;
 344
 345         oldval = sym->curr;
 346
 347         switch (sym->type) {
 348         case S_INT:
 349         case S_HEX:
 350         case S_STRING:
 351                 newval = symbol_empty.curr;
 352                 break;
 353         case S_BOOLEAN:
 354         case S_TRISTATE:
 355                 newval = symbol_no.curr;
 356                 break;
 357         default:
 358                 sym->curr.val = sym->name;
 359                 sym->curr.tri = no;
 360                 return;
 361         }
 362         sym->flags &= ~SYMBOL_WRITE;
 363
 364         sym_calc_visibility(sym);
 365
 366         if (sym->visible != no)
 367                 sym->flags |= SYMBOL_WRITE;
 368
 369         /* set default if recursively called */
 370         sym->curr = newval;
 371
 372         switch (sym_get_type(sym)) {
 373         case S_BOOLEAN:
 374         case S_TRISTATE:
 375                 if (sym_is_choice_value(sym) && sym->visible == yes) {
 376                         prop = sym_get_choice_prop(sym);
 377                         newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 378                 } else {
 379                         if (sym->visible != no) {
 380                                 /* if the symbol is visible use the user value
 381                                  * if available, otherwise try the default value
 382                                  */
 383                                 if (sym_has_value(sym)) {
 384                                         newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 385                                                               sym->visible);
 386                                         goto calc_newval;
 387                                 }
 388                         }
 389                         if (sym->rev_dep.tri != no)
 390                                 sym->flags |= SYMBOL_WRITE;
 391                         if (!sym_is_choice(sym)) {
 392                                 prop = sym_get_default_prop(sym);
 393                                 if (prop) {
 394                                         newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 395                                                               prop->visible.tri);
 396                                         if (newval.tri != no)
 397                                                 sym->flags |= SYMBOL_WRITE;
 398                                 }
 399                                 if (sym->implied.tri != no) {
 400                                         sym->flags |= SYMBOL_WRITE;
 401                                         newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 402                                         newval.tri = EXPR_AND(newval.tri,
 403                                                               sym->dir_dep.tri);
 404                                 }
 405                         }
 406                 calc_newval:
 407                         if (sym->dir_dep.tri < sym->rev_dep.tri)
 408                                 sym_warn_unmet_dep(sym);
 409                         newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 410                 }
 411                 if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
 412                         newval.tri = yes;
 413                 break;
 414         case S_STRING:
 415         case S_HEX:
 416         case S_INT:
 417                 if (sym->visible != no && sym_has_value(sym)) {
 418                         newval.val = sym->def[S_DEF_USER].val;
 419                         break;
 420                 }
 421                 prop = sym_get_default_prop(sym);
 422                 if (prop) {
 423                         struct symbol *ds = prop_get_symbol(prop);
 424                         if (ds) {
 425                                 sym->flags |= SYMBOL_WRITE;
 426                                 sym_calc_value(ds);
 427                                 newval.val = ds->curr.val;
 428                         }
 429                 }
 430                 break;
 431         default:
 432                 ;
 433         }
 434
 435         sym->curr = newval;
 436         if (sym_is_choice(sym) && newval.tri == yes)
 437                 sym->curr.val = sym_calc_choice(sym);
 438         sym_validate_range(sym);
 439
 440         if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 441                 sym_set_changed(sym);
 442                 if (modules_sym == sym) {
 443                         sym_set_all_changed();
 444                         modules_val = modules_sym->curr.tri;
 445                 }
 446         }
 447
 448         if (sym_is_choice(sym)) {
 449                 struct symbol *choice_sym;
 450
 451                 prop = sym_get_choice_prop(sym);
 452                 expr_list_for_each_sym(prop->expr, e, choice_sym) {
 453                         if ((sym->flags & SYMBOL_WRITE) &&
 454                             choice_sym->visible != no)
 455                                 choice_sym->flags |= SYMBOL_WRITE;
 456                         if (sym->flags & SYMBOL_CHANGED)
 457                                 sym_set_changed(choice_sym);
 458                 }
 459         }
 460
 461         if (sym->flags & SYMBOL_NO_WRITE)
 462                 sym->flags &= ~SYMBOL_WRITE;
 463
 464         if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 465                 set_all_choice_values(sym);
 466 }
 467
 468 void sym_clear_all_valid(void)
 469 {
 470         struct symbol *sym;
 471         int i;
 472
 473         for_all_symbols(i, sym)
 474                 sym->flags &= ~SYMBOL_VALID;
 475         conf_set_changed(true);
 476         sym_calc_value(modules_sym);
 477 }
 478
 479 bool sym_tristate_within_range(struct symbol *sym, tristate val)
 480 {
 481         int type = sym_get_type(sym);
 482
 483         if (sym->visible == no)
 484                 return false;
 485
 486         if (type != S_BOOLEAN && type != S_TRISTATE)
 487                 return false;
 488
 489         if (type == S_BOOLEAN && val == mod)
 490                 return false;
 491         if (sym->visible <= sym->rev_dep.tri)
 492                 return false;
 493         if (sym_is_choice_value(sym) && sym->visible == yes)
 494                 return val == yes;
 495         return val >= sym->rev_dep.tri && val <= sym->visible;
 496 }
 497
 498 bool sym_set_tristate_value(struct symbol *sym, tristate val)
 499 {
 500         tristate oldval = sym_get_tristate_value(sym);
 501
 502         if (oldval != val && !sym_tristate_within_range(sym, val))
 503                 return false;
 504
 505         if (!(sym->flags & SYMBOL_DEF_USER)) {
 506                 sym->flags |= SYMBOL_DEF_USER;
 507                 sym_set_changed(sym);
 508         }
 509         /*
 510          * setting a choice value also resets the new flag of the choice
 511          * symbol and all other choice values.
 512          */
 513         if (sym_is_choice_value(sym) && val == yes) {
 514                 struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 515                 struct property *prop;
 516                 struct expr *e;
 517
 518                 cs->def[S_DEF_USER].val = sym;
 519                 cs->flags |= SYMBOL_DEF_USER;
 520                 prop = sym_get_choice_prop(cs);
 521                 for (e = prop->expr; e; e = e->left.expr) {
 522                         if (e->right.sym->visible != no)
 523                                 e->right.sym->flags |= SYMBOL_DEF_USER;
 524                 }
 525         }
 526
 527         sym->def[S_DEF_USER].tri = val;
 528         if (oldval != val)
 529                 sym_clear_all_valid();
 530
 531         return true;
 532 }
 533
 534 tristate sym_toggle_tristate_value(struct symbol *sym)
 535 {
 536         tristate oldval, newval;
 537
 538         oldval = newval = sym_get_tristate_value(sym);
 539         do {
 540                 switch (newval) {
 541                 case no:
 542                         newval = mod;
 543                         break;
 544                 case mod:
 545                         newval = yes;
 546                         break;
 547                 case yes:
 548                         newval = no;
 549                         break;
 550                 }
 551                 if (sym_set_tristate_value(sym, newval))
 552                         break;
 553         } while (oldval != newval);
 554         return newval;
 555 }
 556
 557 bool sym_string_valid(struct symbol *sym, const char *str)
 558 {
 559         signed char ch;
 560
 561         switch (sym->type) {
 562         case S_STRING:
 563                 return true;
 564         case S_INT:
 565                 ch = *str++;
 566                 if (ch == '-')
 567                         ch = *str++;
 568                 if (!isdigit(ch))
 569                         return false;
 570                 if (ch == '0' && *str != 0)
 571                         return false;
 572                 while ((ch = *str++)) {
 573                         if (!isdigit(ch))
 574                                 return false;
 575                 }
 576                 return true;
 577         case S_HEX:
 578                 if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 579                         str += 2;
 580                 ch = *str++;
 581                 do {
 582                         if (!isxdigit(ch))
 583                                 return false;
 584                 } while ((ch = *str++));
 585                 return true;
 586         case S_BOOLEAN:
 587         case S_TRISTATE:
 588                 switch (str[0]) {
 589                 case 'y': case 'Y':
 590                 case 'm': case 'M':
 591                 case 'n': case 'N':
 592                         return true;
 593                 }
 594                 return false;
 595         default:
 596                 return false;
 597         }
 598 }
 599
 600 bool sym_string_within_range(struct symbol *sym, const char *str)
 601 {
 602         struct property *prop;
 603         long long val;
 604
 605         switch (sym->type) {
 606         case S_STRING:
 607                 return sym_string_valid(sym, str);
 608         case S_INT:
 609                 if (!sym_string_valid(sym, str))
 610                         return false;
 611                 prop = sym_get_range_prop(sym);
 612                 if (!prop)
 613                         return true;
 614                 val = strtoll(str, NULL, 10);
 615                 return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 616                        val <= sym_get_range_val(prop->expr->right.sym, 10);
 617         case S_HEX:
 618                 if (!sym_string_valid(sym, str))
 619                         return false;
 620                 prop = sym_get_range_prop(sym);
 621                 if (!prop)
 622                         return true;
 623                 val = strtoll(str, NULL, 16);
 624                 return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 625                        val <= sym_get_range_val(prop->expr->right.sym, 16);
 626         case S_BOOLEAN:
 627         case S_TRISTATE:
 628                 switch (str[0]) {
 629                 case 'y': case 'Y':
 630                         return sym_tristate_within_range(sym, yes);
 631                 case 'm': case 'M':
 632                         return sym_tristate_within_range(sym, mod);
 633                 case 'n': case 'N':
 634                         return sym_tristate_within_range(sym, no);
 635                 }
 636                 return false;
 637         default:
 638                 return false;
 639         }
 640 }
 641
 642 bool sym_set_string_value(struct symbol *sym, const char *newval)
 643 {
 644         const char *oldval;
 645         char *val;
 646         int size;
 647
 648         switch (sym->type) {
 649         case S_BOOLEAN:
 650         case S_TRISTATE:
 651                 switch (newval[0]) {
 652                 case 'y': case 'Y':
 653                         return sym_set_tristate_value(sym, yes);
 654                 case 'm': case 'M':
 655                         return sym_set_tristate_value(sym, mod);
 656                 case 'n': case 'N':
 657                         return sym_set_tristate_value(sym, no);
 658                 }
 659                 return false;
 660         default:
 661                 ;
 662         }
 663
 664         if (!sym_string_within_range(sym, newval))
 665                 return false;
 666
 667         if (!(sym->flags & SYMBOL_DEF_USER)) {
 668                 sym->flags |= SYMBOL_DEF_USER;
 669                 sym_set_changed(sym);
 670         }
 671
 672         oldval = sym->def[S_DEF_USER].val;
 673         size = strlen(newval) + 1;
 674         if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 675                 size += 2;
 676                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 677                 *val++ = '0';
 678                 *val++ = 'x';
 679         } else if (!oldval || strcmp(oldval, newval))
 680                 sym->def[S_DEF_USER].val = val = xmalloc(size);
 681         else
 682                 return true;
 683
 684         strcpy(val, newval);
 685         free((void *)oldval);
 686         sym_clear_all_valid();
 687
 688         return true;
 689 }
 690
 691 /*
 692  * Find the default value associated to a symbol.
 693  * For tristate symbol handle the modules=n case
 694  * in which case "m" becomes "y".
 695  * If the symbol does not have any default then fallback
 696  * to the fixed default values.
 697  */
 698 const char *sym_get_string_default(struct symbol *sym)
 699 {
 700         struct property *prop;
 701         struct symbol *ds;
 702         const char *str;
 703         tristate val;
 704
 705         sym_calc_visibility(sym);
 706         sym_calc_value(modules_sym);
 707         val = symbol_no.curr.tri;
 708         str = symbol_empty.curr.val;
 709
 710         /* If symbol has a default value look it up */
 711         prop = sym_get_default_prop(sym);
 712         if (prop != NULL) {
 713                 switch (sym->type) {
 714                 case S_BOOLEAN:
 715                 case S_TRISTATE:
 716                         /* The visibility may limit the value from yes => mod */
 717                         val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 718                         break;
 719                 default:
 720                         /*
 721                          * The following fails to handle the situation
 722                          * where a default value is further limited by
 723                          * the valid range.
 724                          */
 725                         ds = prop_get_symbol(prop);
 726                         if (ds != NULL) {
 727                                 sym_calc_value(ds);
 728                                 str = (const char *)ds->curr.val;
 729                         }
 730                 }
 731         }
 732
 733         /* Handle select statements */
 734         val = EXPR_OR(val, sym->rev_dep.tri);
 735
 736         /* transpose mod to yes if modules are not enabled */
 737         if (val == mod)
 738                 if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 739                         val = yes;
 740
 741         /* transpose mod to yes if type is bool */
 742         if (sym->type == S_BOOLEAN && val == mod)
 743                 val = yes;
 744
 745         /* adjust the default value if this symbol is implied by another */
 746         if (val < sym->implied.tri)
 747                 val = sym->implied.tri;
 748
 749         switch (sym->type) {
 750         case S_BOOLEAN:
 751         case S_TRISTATE:
 752                 switch (val) {
 753                 case no: return "n";
 754                 case mod: return "m";
 755                 case yes: return "y";
 756                 }
 757         case S_INT:
 758         case S_HEX:
 759                 return str;
 760         case S_STRING:
 761                 return str;
 762         case S_UNKNOWN:
 763                 break;
 764         }
 765         return "";
 766 }
 767
 768 const char *sym_get_string_value(struct symbol *sym)
 769 {
 770         tristate val;
 771
 772         switch (sym->type) {
 773         case S_BOOLEAN:
 774         case S_TRISTATE:
 775                 val = sym_get_tristate_value(sym);
 776                 switch (val) {
 777                 case no:
 778                         return "n";
 779                 case mod:
 780                         sym_calc_value(modules_sym);
 781                         return (modules_sym->curr.tri == no) ? "n" : "m";
 782                 case yes:
 783                         return "y";
 784                 }
 785                 break;
 786         default:
 787                 ;
 788         }
 789         return (const char *)sym->curr.val;
 790 }
 791
 792 bool sym_is_changeable(struct symbol *sym)
 793 {
 794         return sym->visible > sym->rev_dep.tri;
 795 }
 796
 797 static unsigned strhash(const char *s)
 798 {
 799         /* fnv32 hash */
 800         unsigned hash = 2166136261U;
 801         for (; *s; s++)
 802                 hash = (hash ^ *s) * 0x01000193;
 803         return hash;
 804 }
 805
 806 struct symbol *sym_lookup(const char *name, int flags)
 807 {
 808         struct symbol *symbol;
 809         char *new_name;
 810         int hash;
 811
 812         if (name) {
 813                 if (name[0] && !name[1]) {
 814                         switch (name[0]) {
 815                         case 'y': return &symbol_yes;
 816                         case 'm': return &symbol_mod;
 817                         case 'n': return &symbol_no;
 818                         }
 819                 }
 820                 hash = strhash(name) % SYMBOL_HASHSIZE;
 821
 822                 for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 823                         if (symbol->name &&
 824                             !strcmp(symbol->name, name) &&
 825                             (flags ? symbol->flags & flags
 826                                    : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 827                                 return symbol;
 828                 }
 829                 new_name = xstrdup(name);
 830         } else {
 831                 new_name = NULL;
 832                 hash = 0;
 833         }
 834
 835         symbol = xmalloc(sizeof(*symbol));
 836         memset(symbol, 0, sizeof(*symbol));
 837         symbol->name = new_name;
 838         symbol->type = S_UNKNOWN;
 839         symbol->flags = flags;
 840
 841         symbol->next = symbol_hash[hash];
 842         symbol_hash[hash] = symbol;
 843
 844         return symbol;
 845 }
 846
 847 struct symbol *sym_find(const char *name)
 848 {
 849         struct symbol *symbol = NULL;
 850         int hash = 0;
 851
 852         if (!name)
 853                 return NULL;
 854
 855         if (name[0] && !name[1]) {
 856                 switch (name[0]) {
 857                 case 'y': return &symbol_yes;
 858                 case 'm': return &symbol_mod;
 859                 case 'n': return &symbol_no;
 860                 }
 861         }
 862         hash = strhash(name) % SYMBOL_HASHSIZE;
 863
 864         for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 865                 if (symbol->name &&
 866                     !strcmp(symbol->name, name) &&
 867                     !(symbol->flags & SYMBOL_CONST))
 868                                 break;
 869         }
 870
 871         return symbol;
 872 }
 873
 874 const char *sym_escape_string_value(const char *in)
 875 {
 876         const char *p;
 877         size_t reslen;
 878         char *res;
 879         size_t l;
 880
 881         reslen = strlen(in) + strlen("\"\"") + 1;
 882
 883         p = in;
 884         for (;;) {
 885                 l = strcspn(p, "\"\\");
 886                 p += l;
 887
 888                 if (p[0] == '\0')
 889                         break;
 890
 891                 reslen++;
 892                 p++;
 893         }
 894
 895         res = xmalloc(reslen);
 896         res[0] = '\0';
 897
 898         strcat(res, "\"");
 899
 900         p = in;
 901         for (;;) {
 902                 l = strcspn(p, "\"\\");
 903                 strncat(res, p, l);
 904                 p += l;
 905
 906                 if (p[0] == '\0')
 907                         break;
 908
 909                 strcat(res, "\\");
 910                 strncat(res, p++, 1);
 911         }
 912
 913         strcat(res, "\"");
 914         return res;
 915 }
 916
 917 struct sym_match {
 918         struct symbol   *sym;
 919         off_t           so, eo;
 920 };
 921
 922 /* Compare matched symbols as thus:
 923  * - first, symbols that match exactly
 924  * - then, alphabetical sort
 925  */
 926 static int sym_rel_comp(const void *sym1, const void *sym2)
 927 {
 928         const struct sym_match *s1 = sym1;
 929         const struct sym_match *s2 = sym2;
 930         int exact1, exact2;
 931
 932         /* Exact match:
 933          * - if matched length on symbol s1 is the length of that symbol,
 934          *   then this symbol should come first;
 935          * - if matched length on symbol s2 is the length of that symbol,
 936          *   then this symbol should come first.
 937          * Note: since the search can be a regexp, both symbols may match
 938          * exactly; if this is the case, we can't decide which comes first,
 939          * and we fallback to sorting alphabetically.
 940          */
 941         exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
 942         exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
 943         if (exact1 && !exact2)
 944                 return -1;
 945         if (!exact1 && exact2)
 946                 return 1;
 947
 948         /* As a fallback, sort symbols alphabetically */
 949         return strcmp(s1->sym->name, s2->sym->name);
 950 }
 951
 952 struct symbol **sym_re_search(const char *pattern)
 953 {
 954         struct symbol *sym, **sym_arr = NULL;
 955         struct sym_match *sym_match_arr = NULL;
 956         int i, cnt, size;
 957         regex_t re;
 958         regmatch_t match[1];
 959
 960         cnt = size = 0;
 961         /* Skip if empty */
 962         if (strlen(pattern) == 0)
 963                 return NULL;
 964         if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
 965                 return NULL;
 966
 967         for_all_symbols(i, sym) {
 968                 if (sym->flags & SYMBOL_CONST || !sym->name)
 969                         continue;
 970                 if (regexec(&re, sym->name, 1, match, 0))
 971                         continue;
 972                 if (cnt >= size) {
 973                         void *tmp;
 974                         size += 16;
 975                         tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
 976                         if (!tmp)
 977                                 goto sym_re_search_free;
 978                         sym_match_arr = tmp;
 979                 }
 980                 sym_calc_value(sym);
 981                 /* As regexec returned 0, we know we have a match, so
 982                  * we can use match[0].rm_[se]o without further checks
 983                  */
 984                 sym_match_arr[cnt].so = match[0].rm_so;
 985                 sym_match_arr[cnt].eo = match[0].rm_eo;
 986                 sym_match_arr[cnt++].sym = sym;
 987         }
 988         if (sym_match_arr) {
 989                 qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
 990                 sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 991                 if (!sym_arr)
 992                         goto sym_re_search_free;
 993                 for (i = 0; i < cnt; i++)
 994                         sym_arr[i] = sym_match_arr[i].sym;
 995                 sym_arr[cnt] = NULL;
 996         }
 997 sym_re_search_free:
 998         /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
 999         free(sym_match_arr);
1000         regfree(&re);
1001
1002         return sym_arr;
1003 }
1004
1005 /*
1006  * When we check for recursive dependencies we use a stack to save
1007  * current state so we can print out relevant info to user.
1008  * The entries are located on the call stack so no need to free memory.
1009  * Note insert() remove() must always match to properly clear the stack.
1010  */
1011 static struct dep_stack {
1012         struct dep_stack *prev, *next;
1013         struct symbol *sym;
1014         struct property *prop;
1015         struct expr **expr;
1016 } *check_top;
1017
1018 static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1019 {
1020         memset(stack, 0, sizeof(*stack));
1021         if (check_top)
1022                 check_top->next = stack;
1023         stack->prev = check_top;
1024         stack->sym = sym;
1025         check_top = stack;
1026 }
1027
1028 static void dep_stack_remove(void)
1029 {
1030         check_top = check_top->prev;
1031         if (check_top)
1032                 check_top->next = NULL;
1033 }
1034
1035 /*
1036  * Called when we have detected a recursive dependency.
1037  * check_top point to the top of the stact so we use
1038  * the ->prev pointer to locate the bottom of the stack.
1039  */
1040 static void sym_check_print_recursive(struct symbol *last_sym)
1041 {
1042         struct dep_stack *stack;
1043         struct symbol *sym, *next_sym;
1044         struct menu *menu = NULL;
1045         struct property *prop;
1046         struct dep_stack cv_stack;
1047
1048         if (sym_is_choice_value(last_sym)) {
1049                 dep_stack_insert(&cv_stack, last_sym);
1050                 last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1051         }
1052
1053         for (stack = check_top; stack != NULL; stack = stack->prev)
1054                 if (stack->sym == last_sym)
1055                         break;
1056         if (!stack) {
1057                 fprintf(stderr, "unexpected recursive dependency error\n");
1058                 return;
1059         }
1060
1061         for (; stack; stack = stack->next) {
1062                 sym = stack->sym;
1063                 next_sym = stack->next ? stack->next->sym : last_sym;
1064                 prop = stack->prop;
1065                 if (prop == NULL)
1066                         prop = stack->sym->prop;
1067
1068                 /* for choice values find the menu entry (used below) */
1069                 if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1070                         for (prop = sym->prop; prop; prop = prop->next) {
1071                                 menu = prop->menu;
1072                                 if (prop->menu)
1073                                         break;
1074                         }
1075                 }
1076                 if (stack->sym == last_sym)
1077                         fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1078                                 prop->file->name, prop->lineno);
1079
1080                 if (sym_is_choice(sym)) {
1081                         fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1082                                 menu->file->name, menu->lineno,
1083                                 sym->name ? sym->name : "<choice>",
1084                                 next_sym->name ? next_sym->name : "<choice>");
1085                 } else if (sym_is_choice_value(sym)) {
1086                         fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1087                                 menu->file->name, menu->lineno,
1088                                 sym->name ? sym->name : "<choice>",
1089                                 next_sym->name ? next_sym->name : "<choice>");
1090                 } else if (stack->expr == &sym->dir_dep.expr) {
1091                         fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1092                                 prop->file->name, prop->lineno,
1093                                 sym->name ? sym->name : "<choice>",
1094                                 next_sym->name ? next_sym->name : "<choice>");
1095                 } else if (stack->expr == &sym->rev_dep.expr) {
1096                         fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1097                                 prop->file->name, prop->lineno,
1098                                 sym->name ? sym->name : "<choice>",
1099                                 next_sym->name ? next_sym->name : "<choice>");
1100                 } else if (stack->expr == &sym->implied.expr) {
1101                         fprintf(stderr, "%s:%d:\tsymbol %s is implied by %s\n",
1102                                 prop->file->name, prop->lineno,
1103                                 sym->name ? sym->name : "<choice>",
1104                                 next_sym->name ? next_sym->name : "<choice>");
1105                 } else if (stack->expr) {
1106                         fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1107                                 prop->file->name, prop->lineno,
1108                                 sym->name ? sym->name : "<choice>",
1109                                 prop_get_type_name(prop->type),
1110                                 next_sym->name ? next_sym->name : "<choice>");
1111                 } else {
1112                         fprintf(stderr, "%s:%d:\tsymbol %s %s is visible depending on %s\n",
1113                                 prop->file->name, prop->lineno,
1114                                 sym->name ? sym->name : "<choice>",
1115                                 prop_get_type_name(prop->type),
1116                                 next_sym->name ? next_sym->name : "<choice>");
1117                 }
1118         }
1119
1120         fprintf(stderr,
1121                 "For a resolution refer to Documentation/kbuild/kconfig-language.rst\n"
1122                 "subsection \"Kconfig recursive dependency limitations\"\n"
1123                 "\n");
1124
1125         if (check_top == &cv_stack)
1126                 dep_stack_remove();
1127 }
1128
1129 static struct symbol *sym_check_expr_deps(struct expr *e)
1130 {
1131         struct symbol *sym;
1132
1133         if (!e)
1134                 return NULL;
1135         switch (e->type) {
1136         case E_OR:
1137         case E_AND:
1138                 sym = sym_check_expr_deps(e->left.expr);
1139                 if (sym)
1140                         return sym;
1141                 return sym_check_expr_deps(e->right.expr);
1142         case E_NOT:
1143                 return sym_check_expr_deps(e->left.expr);
1144         case E_EQUAL:
1145         case E_GEQ:
1146         case E_GTH:
1147         case E_LEQ:
1148         case E_LTH:
1149         case E_UNEQUAL:
1150                 sym = sym_check_deps(e->left.sym);
1151                 if (sym)
1152                         return sym;
1153                 return sym_check_deps(e->right.sym);
1154         case E_SYMBOL:
1155                 return sym_check_deps(e->left.sym);
1156         default:
1157                 break;
1158         }
1159         fprintf(stderr, "Oops! How to check %d?\n", e->type);
1160         return NULL;
1161 }
1162
1163 /* return NULL when dependencies are OK */
1164 static struct symbol *sym_check_sym_deps(struct symbol *sym)
1165 {
1166         struct symbol *sym2;
1167         struct property *prop;
1168         struct dep_stack stack;
1169
1170         dep_stack_insert(&stack, sym);
1171
1172         stack.expr = &sym->dir_dep.expr;
1173         sym2 = sym_check_expr_deps(sym->dir_dep.expr);
1174         if (sym2)
1175                 goto out;
1176
1177         stack.expr = &sym->rev_dep.expr;
1178         sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1179         if (sym2)
1180                 goto out;
1181
1182         stack.expr = &sym->implied.expr;
1183         sym2 = sym_check_expr_deps(sym->implied.expr);
1184         if (sym2)
1185                 goto out;
1186
1187         stack.expr = NULL;
1188
1189         for (prop = sym->prop; prop; prop = prop->next) {
1190                 if (prop->type == P_CHOICE || prop->type == P_SELECT ||
1191                     prop->type == P_IMPLY)
1192                         continue;
1193                 stack.prop = prop;
1194                 sym2 = sym_check_expr_deps(prop->visible.expr);
1195                 if (sym2)
1196                         break;
1197                 if (prop->type != P_DEFAULT || sym_is_choice(sym))
1198                         continue;
1199                 stack.expr = &prop->expr;
1200                 sym2 = sym_check_expr_deps(prop->expr);
1201                 if (sym2)
1202                         break;
1203                 stack.expr = NULL;
1204         }
1205
1206 out:
1207         dep_stack_remove();
1208
1209         return sym2;
1210 }
1211
1212 static struct symbol *sym_check_choice_deps(struct symbol *choice)
1213 {
1214         struct symbol *sym, *sym2;
1215         struct property *prop;
1216         struct expr *e;
1217         struct dep_stack stack;
1218
1219         dep_stack_insert(&stack, choice);
1220
1221         prop = sym_get_choice_prop(choice);
1222         expr_list_for_each_sym(prop->expr, e, sym)
1223                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1224
1225         choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1226         sym2 = sym_check_sym_deps(choice);
1227         choice->flags &= ~SYMBOL_CHECK;
1228         if (sym2)
1229                 goto out;
1230
1231         expr_list_for_each_sym(prop->expr, e, sym) {
1232                 sym2 = sym_check_sym_deps(sym);
1233                 if (sym2)
1234                         break;
1235         }
1236 out:
1237         expr_list_for_each_sym(prop->expr, e, sym)
1238                 sym->flags &= ~SYMBOL_CHECK;
1239
1240         if (sym2 && sym_is_choice_value(sym2) &&
1241             prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1242                 sym2 = choice;
1243
1244         dep_stack_remove();
1245
1246         return sym2;
1247 }
1248
1249 struct symbol *sym_check_deps(struct symbol *sym)
1250 {
1251         struct symbol *sym2;
1252         struct property *prop;
1253
1254         if (sym->flags & SYMBOL_CHECK) {
1255                 sym_check_print_recursive(sym);
1256                 return sym;
1257         }
1258         if (sym->flags & SYMBOL_CHECKED)
1259                 return NULL;
1260
1261         if (sym_is_choice_value(sym)) {
1262                 struct dep_stack stack;
1263
1264                 /* for choice groups start the check with main choice symbol */
1265                 dep_stack_insert(&stack, sym);
1266                 prop = sym_get_choice_prop(sym);
1267                 sym2 = sym_check_deps(prop_get_symbol(prop));
1268                 dep_stack_remove();
1269         } else if (sym_is_choice(sym)) {
1270                 sym2 = sym_check_choice_deps(sym);
1271         } else {
1272                 sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1273                 sym2 = sym_check_sym_deps(sym);
1274                 sym->flags &= ~SYMBOL_CHECK;
1275         }
1276
1277         return sym2;
1278 }
1279
1280 struct symbol *prop_get_symbol(struct property *prop)
1281 {
1282         if (prop->expr && (prop->expr->type == E_SYMBOL ||
1283                            prop->expr->type == E_LIST))
1284                 return prop->expr->left.sym;
1285         return NULL;
1286 }
1287
1288 const char *prop_get_type_name(enum prop_type type)
1289 {
1290         switch (type) {
1291         case P_PROMPT:
1292                 return "prompt";
1293         case P_COMMENT:
1294                 return "comment";
1295         case P_MENU:
1296                 return "menu";
1297         case P_DEFAULT:
1298                 return "default";
1299         case P_CHOICE:
1300                 return "choice";
1301         case P_SELECT:
1302                 return "select";
1303         case P_IMPLY:
1304                 return "imply";
1305         case P_RANGE:
1306                 return "range";
1307         case P_SYMBOL:
1308                 return "symbol";
1309         case P_UNKNOWN:
1310                 break;
1311         }
1312         return "unknown";
1313 }