linux/scripts/kconfig/symbol.c
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   1/*
   2 * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   3 * Released under the terms of the GNU GPL v2.0.
   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
  14struct 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
  32struct symbol *sym_defconfig_list;
  33struct symbol *modules_sym;
  34tristate modules_val;
  35
  36struct expr *sym_env_list;
  37
  38static void sym_add_default(struct symbol *sym, const char *def)
  39{
  40        struct property *prop = prop_alloc(P_DEFAULT, sym);
  41
  42        prop->expr = expr_alloc_symbol(sym_lookup(def, SYMBOL_CONST));
  43}
  44
  45void sym_init(void)
  46{
  47        struct symbol *sym;
  48        struct utsname uts;
  49        static bool inited = false;
  50
  51        if (inited)
  52                return;
  53        inited = true;
  54
  55        uname(&uts);
  56
  57        sym = sym_lookup("UNAME_RELEASE", 0);
  58        sym->type = S_STRING;
  59        sym->flags |= SYMBOL_AUTO;
  60        sym_add_default(sym, uts.release);
  61}
  62
  63enum symbol_type sym_get_type(struct symbol *sym)
  64{
  65        enum symbol_type type = sym->type;
  66
  67        if (type == S_TRISTATE) {
  68                if (sym_is_choice_value(sym) && sym->visible == yes)
  69                        type = S_BOOLEAN;
  70                else if (modules_val == no)
  71                        type = S_BOOLEAN;
  72        }
  73        return type;
  74}
  75
  76const char *sym_type_name(enum symbol_type type)
  77{
  78        switch (type) {
  79        case S_BOOLEAN:
  80                return "boolean";
  81        case S_TRISTATE:
  82                return "tristate";
  83        case S_INT:
  84                return "integer";
  85        case S_HEX:
  86                return "hex";
  87        case S_STRING:
  88                return "string";
  89        case S_UNKNOWN:
  90                return "unknown";
  91        case S_OTHER:
  92                break;
  93        }
  94        return "???";
  95}
  96
  97struct property *sym_get_choice_prop(struct symbol *sym)
  98{
  99        struct property *prop;
 100
 101        for_all_choices(sym, prop)
 102                return prop;
 103        return NULL;
 104}
 105
 106struct property *sym_get_env_prop(struct symbol *sym)
 107{
 108        struct property *prop;
 109
 110        for_all_properties(sym, prop, P_ENV)
 111                return prop;
 112        return NULL;
 113}
 114
 115static struct property *sym_get_default_prop(struct symbol *sym)
 116{
 117        struct property *prop;
 118
 119        for_all_defaults(sym, prop) {
 120                prop->visible.tri = expr_calc_value(prop->visible.expr);
 121                if (prop->visible.tri != no)
 122                        return prop;
 123        }
 124        return NULL;
 125}
 126
 127static struct property *sym_get_range_prop(struct symbol *sym)
 128{
 129        struct property *prop;
 130
 131        for_all_properties(sym, prop, P_RANGE) {
 132                prop->visible.tri = expr_calc_value(prop->visible.expr);
 133                if (prop->visible.tri != no)
 134                        return prop;
 135        }
 136        return NULL;
 137}
 138
 139static long long sym_get_range_val(struct symbol *sym, int base)
 140{
 141        sym_calc_value(sym);
 142        switch (sym->type) {
 143        case S_INT:
 144                base = 10;
 145                break;
 146        case S_HEX:
 147                base = 16;
 148                break;
 149        default:
 150                break;
 151        }
 152        return strtoll(sym->curr.val, NULL, base);
 153}
 154
 155static void sym_validate_range(struct symbol *sym)
 156{
 157        struct property *prop;
 158        int base;
 159        long long val, val2;
 160        char str[64];
 161
 162        switch (sym->type) {
 163        case S_INT:
 164                base = 10;
 165                break;
 166        case S_HEX:
 167                base = 16;
 168                break;
 169        default:
 170                return;
 171        }
 172        prop = sym_get_range_prop(sym);
 173        if (!prop)
 174                return;
 175        val = strtoll(sym->curr.val, NULL, base);
 176        val2 = sym_get_range_val(prop->expr->left.sym, base);
 177        if (val >= val2) {
 178                val2 = sym_get_range_val(prop->expr->right.sym, base);
 179                if (val <= val2)
 180                        return;
 181        }
 182        if (sym->type == S_INT)
 183                sprintf(str, "%lld", val2);
 184        else
 185                sprintf(str, "0x%llx", val2);
 186        sym->curr.val = strdup(str);
 187}
 188
 189static void sym_set_changed(struct symbol *sym)
 190{
 191        struct property *prop;
 192
 193        sym->flags |= SYMBOL_CHANGED;
 194        for (prop = sym->prop; prop; prop = prop->next) {
 195                if (prop->menu)
 196                        prop->menu->flags |= MENU_CHANGED;
 197        }
 198}
 199
 200static void sym_set_all_changed(void)
 201{
 202        struct symbol *sym;
 203        int i;
 204
 205        for_all_symbols(i, sym)
 206                sym_set_changed(sym);
 207}
 208
 209static void sym_calc_visibility(struct symbol *sym)
 210{
 211        struct property *prop;
 212        struct symbol *choice_sym = NULL;
 213        tristate tri;
 214
 215        /* any prompt visible? */
 216        tri = no;
 217
 218        if (sym_is_choice_value(sym))
 219                choice_sym = prop_get_symbol(sym_get_choice_prop(sym));
 220
 221        for_all_prompts(sym, prop) {
 222                prop->visible.tri = expr_calc_value(prop->visible.expr);
 223                /*
 224                 * Tristate choice_values with visibility 'mod' are
 225                 * not visible if the corresponding choice's value is
 226                 * 'yes'.
 227                 */
 228                if (choice_sym && sym->type == S_TRISTATE &&
 229                    prop->visible.tri == mod && choice_sym->curr.tri == yes)
 230                        prop->visible.tri = no;
 231
 232                tri = EXPR_OR(tri, prop->visible.tri);
 233        }
 234        if (tri == mod && (sym->type != S_TRISTATE || modules_val == no))
 235                tri = yes;
 236        if (sym->visible != tri) {
 237                sym->visible = tri;
 238                sym_set_changed(sym);
 239        }
 240        if (sym_is_choice_value(sym))
 241                return;
 242        /* defaulting to "yes" if no explicit "depends on" are given */
 243        tri = yes;
 244        if (sym->dir_dep.expr)
 245                tri = expr_calc_value(sym->dir_dep.expr);
 246        if (tri == mod)
 247                tri = yes;
 248        if (sym->dir_dep.tri != tri) {
 249                sym->dir_dep.tri = tri;
 250                sym_set_changed(sym);
 251        }
 252        tri = no;
 253        if (sym->rev_dep.expr)
 254                tri = expr_calc_value(sym->rev_dep.expr);
 255        if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 256                tri = yes;
 257        if (sym->rev_dep.tri != tri) {
 258                sym->rev_dep.tri = tri;
 259                sym_set_changed(sym);
 260        }
 261        tri = no;
 262        if (sym->implied.expr && sym->dir_dep.tri != no)
 263                tri = expr_calc_value(sym->implied.expr);
 264        if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
 265                tri = yes;
 266        if (sym->implied.tri != tri) {
 267                sym->implied.tri = tri;
 268                sym_set_changed(sym);
 269        }
 270}
 271
 272/*
 273 * Find the default symbol for a choice.
 274 * First try the default values for the choice symbol
 275 * Next locate the first visible choice value
 276 * Return NULL if none was found
 277 */
 278struct symbol *sym_choice_default(struct symbol *sym)
 279{
 280        struct symbol *def_sym;
 281        struct property *prop;
 282        struct expr *e;
 283
 284        /* any of the defaults visible? */
 285        for_all_defaults(sym, prop) {
 286                prop->visible.tri = expr_calc_value(prop->visible.expr);
 287                if (prop->visible.tri == no)
 288                        continue;
 289                def_sym = prop_get_symbol(prop);
 290                if (def_sym->visible != no)
 291                        return def_sym;
 292        }
 293
 294        /* just get the first visible value */
 295        prop = sym_get_choice_prop(sym);
 296        expr_list_for_each_sym(prop->expr, e, def_sym)
 297                if (def_sym->visible != no)
 298                        return def_sym;
 299
 300        /* failed to locate any defaults */
 301        return NULL;
 302}
 303
 304static struct symbol *sym_calc_choice(struct symbol *sym)
 305{
 306        struct symbol *def_sym;
 307        struct property *prop;
 308        struct expr *e;
 309        int flags;
 310
 311        /* first calculate all choice values' visibilities */
 312        flags = sym->flags;
 313        prop = sym_get_choice_prop(sym);
 314        expr_list_for_each_sym(prop->expr, e, def_sym) {
 315                sym_calc_visibility(def_sym);
 316                if (def_sym->visible != no)
 317                        flags &= def_sym->flags;
 318        }
 319
 320        sym->flags &= flags | ~SYMBOL_DEF_USER;
 321
 322        /* is the user choice visible? */
 323        def_sym = sym->def[S_DEF_USER].val;
 324        if (def_sym && def_sym->visible != no)
 325                return def_sym;
 326
 327        def_sym = sym_choice_default(sym);
 328
 329        if (def_sym == NULL)
 330                /* no choice? reset tristate value */
 331                sym->curr.tri = no;
 332
 333        return def_sym;
 334}
 335
 336void sym_calc_value(struct symbol *sym)
 337{
 338        struct symbol_value newval, oldval;
 339        struct property *prop;
 340        struct expr *e;
 341
 342        if (!sym)
 343                return;
 344
 345        if (sym->flags & SYMBOL_VALID)
 346                return;
 347
 348        if (sym_is_choice_value(sym) &&
 349            sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES) {
 350                sym->flags &= ~SYMBOL_NEED_SET_CHOICE_VALUES;
 351                prop = sym_get_choice_prop(sym);
 352                sym_calc_value(prop_get_symbol(prop));
 353        }
 354
 355        sym->flags |= SYMBOL_VALID;
 356
 357        oldval = sym->curr;
 358
 359        switch (sym->type) {
 360        case S_INT:
 361        case S_HEX:
 362        case S_STRING:
 363                newval = symbol_empty.curr;
 364                break;
 365        case S_BOOLEAN:
 366        case S_TRISTATE:
 367                newval = symbol_no.curr;
 368                break;
 369        default:
 370                sym->curr.val = sym->name;
 371                sym->curr.tri = no;
 372                return;
 373        }
 374        if (!sym_is_choice_value(sym))
 375                sym->flags &= ~SYMBOL_WRITE;
 376
 377        sym_calc_visibility(sym);
 378
 379        /* set default if recursively called */
 380        sym->curr = newval;
 381
 382        switch (sym_get_type(sym)) {
 383        case S_BOOLEAN:
 384        case S_TRISTATE:
 385                if (sym_is_choice_value(sym) && sym->visible == yes) {
 386                        prop = sym_get_choice_prop(sym);
 387                        newval.tri = (prop_get_symbol(prop)->curr.val == sym) ? yes : no;
 388                } else {
 389                        if (sym->visible != no) {
 390                                /* if the symbol is visible use the user value
 391                                 * if available, otherwise try the default value
 392                                 */
 393                                sym->flags |= SYMBOL_WRITE;
 394                                if (sym_has_value(sym)) {
 395                                        newval.tri = EXPR_AND(sym->def[S_DEF_USER].tri,
 396                                                              sym->visible);
 397                                        goto calc_newval;
 398                                }
 399                        }
 400                        if (sym->rev_dep.tri != no)
 401                                sym->flags |= SYMBOL_WRITE;
 402                        if (!sym_is_choice(sym)) {
 403                                prop = sym_get_default_prop(sym);
 404                                if (prop) {
 405                                        sym->flags |= SYMBOL_WRITE;
 406                                        newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 407                                                              prop->visible.tri);
 408                                }
 409                                if (sym->implied.tri != no) {
 410                                        sym->flags |= SYMBOL_WRITE;
 411                                        newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
 412                                }
 413                        }
 414                calc_newval:
 415                        if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
 416                                struct expr *e;
 417                                e = expr_simplify_unmet_dep(sym->rev_dep.expr,
 418                                    sym->dir_dep.expr);
 419                                fprintf(stderr, "warning: (");
 420                                expr_fprint(e, stderr);
 421                                fprintf(stderr, ") selects %s which has unmet direct dependencies (",
 422                                        sym->name);
 423                                expr_fprint(sym->dir_dep.expr, stderr);
 424                                fprintf(stderr, ")\n");
 425                                expr_free(e);
 426                        }
 427                        newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 428                }
 429                if (newval.tri == mod &&
 430                    (sym_get_type(sym) == S_BOOLEAN || sym->implied.tri == yes))
 431                        newval.tri = yes;
 432                break;
 433        case S_STRING:
 434        case S_HEX:
 435        case S_INT:
 436                if (sym->visible != no) {
 437                        sym->flags |= SYMBOL_WRITE;
 438                        if (sym_has_value(sym)) {
 439                                newval.val = sym->def[S_DEF_USER].val;
 440                                break;
 441                        }
 442                }
 443                prop = sym_get_default_prop(sym);
 444                if (prop) {
 445                        struct symbol *ds = prop_get_symbol(prop);
 446                        if (ds) {
 447                                sym->flags |= SYMBOL_WRITE;
 448                                sym_calc_value(ds);
 449                                newval.val = ds->curr.val;
 450                        }
 451                }
 452                break;
 453        default:
 454                ;
 455        }
 456
 457        sym->curr = newval;
 458        if (sym_is_choice(sym) && newval.tri == yes)
 459                sym->curr.val = sym_calc_choice(sym);
 460        sym_validate_range(sym);
 461
 462        if (memcmp(&oldval, &sym->curr, sizeof(oldval))) {
 463                sym_set_changed(sym);
 464                if (modules_sym == sym) {
 465                        sym_set_all_changed();
 466                        modules_val = modules_sym->curr.tri;
 467                }
 468        }
 469
 470        if (sym_is_choice(sym)) {
 471                struct symbol *choice_sym;
 472
 473                prop = sym_get_choice_prop(sym);
 474                expr_list_for_each_sym(prop->expr, e, choice_sym) {
 475                        if ((sym->flags & SYMBOL_WRITE) &&
 476                            choice_sym->visible != no)
 477                                choice_sym->flags |= SYMBOL_WRITE;
 478                        if (sym->flags & SYMBOL_CHANGED)
 479                                sym_set_changed(choice_sym);
 480                }
 481        }
 482
 483        if (sym->flags & SYMBOL_AUTO)
 484                sym->flags &= ~SYMBOL_WRITE;
 485
 486        if (sym->flags & SYMBOL_NEED_SET_CHOICE_VALUES)
 487                set_all_choice_values(sym);
 488}
 489
 490void sym_clear_all_valid(void)
 491{
 492        struct symbol *sym;
 493        int i;
 494
 495        for_all_symbols(i, sym)
 496                sym->flags &= ~SYMBOL_VALID;
 497        sym_add_change_count(1);
 498        sym_calc_value(modules_sym);
 499}
 500
 501bool sym_tristate_within_range(struct symbol *sym, tristate val)
 502{
 503        int type = sym_get_type(sym);
 504
 505        if (sym->visible == no)
 506                return false;
 507
 508        if (type != S_BOOLEAN && type != S_TRISTATE)
 509                return false;
 510
 511        if (type == S_BOOLEAN && val == mod)
 512                return false;
 513        if (sym->visible <= sym->rev_dep.tri)
 514                return false;
 515        if (sym->implied.tri == yes && val == mod)
 516                return false;
 517        if (sym_is_choice_value(sym) && sym->visible == yes)
 518                return val == yes;
 519        return val >= sym->rev_dep.tri && val <= sym->visible;
 520}
 521
 522bool sym_set_tristate_value(struct symbol *sym, tristate val)
 523{
 524        tristate oldval = sym_get_tristate_value(sym);
 525
 526        if (oldval != val && !sym_tristate_within_range(sym, val))
 527                return false;
 528
 529        if (!(sym->flags & SYMBOL_DEF_USER)) {
 530                sym->flags |= SYMBOL_DEF_USER;
 531                sym_set_changed(sym);
 532        }
 533        /*
 534         * setting a choice value also resets the new flag of the choice
 535         * symbol and all other choice values.
 536         */
 537        if (sym_is_choice_value(sym) && val == yes) {
 538                struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 539                struct property *prop;
 540                struct expr *e;
 541
 542                cs->def[S_DEF_USER].val = sym;
 543                cs->flags |= SYMBOL_DEF_USER;
 544                prop = sym_get_choice_prop(cs);
 545                for (e = prop->expr; e; e = e->left.expr) {
 546                        if (e->right.sym->visible != no)
 547                                e->right.sym->flags |= SYMBOL_DEF_USER;
 548                }
 549        }
 550
 551        sym->def[S_DEF_USER].tri = val;
 552        if (oldval != val)
 553                sym_clear_all_valid();
 554
 555        return true;
 556}
 557
 558tristate sym_toggle_tristate_value(struct symbol *sym)
 559{
 560        tristate oldval, newval;
 561
 562        oldval = newval = sym_get_tristate_value(sym);
 563        do {
 564                switch (newval) {
 565                case no:
 566                        newval = mod;
 567                        break;
 568                case mod:
 569                        newval = yes;
 570                        break;
 571                case yes:
 572                        newval = no;
 573                        break;
 574                }
 575                if (sym_set_tristate_value(sym, newval))
 576                        break;
 577        } while (oldval != newval);
 578        return newval;
 579}
 580
 581bool sym_string_valid(struct symbol *sym, const char *str)
 582{
 583        signed char ch;
 584
 585        switch (sym->type) {
 586        case S_STRING:
 587                return true;
 588        case S_INT:
 589                ch = *str++;
 590                if (ch == '-')
 591                        ch = *str++;
 592                if (!isdigit(ch))
 593                        return false;
 594                if (ch == '0' && *str != 0)
 595                        return false;
 596                while ((ch = *str++)) {
 597                        if (!isdigit(ch))
 598                                return false;
 599                }
 600                return true;
 601        case S_HEX:
 602                if (str[0] == '0' && (str[1] == 'x' || str[1] == 'X'))
 603                        str += 2;
 604                ch = *str++;
 605                do {
 606                        if (!isxdigit(ch))
 607                                return false;
 608                } while ((ch = *str++));
 609                return true;
 610        case S_BOOLEAN:
 611        case S_TRISTATE:
 612                switch (str[0]) {
 613                case 'y': case 'Y':
 614                case 'm': case 'M':
 615                case 'n': case 'N':
 616                        return true;
 617                }
 618                return false;
 619        default:
 620                return false;
 621        }
 622}
 623
 624bool sym_string_within_range(struct symbol *sym, const char *str)
 625{
 626        struct property *prop;
 627        long long val;
 628
 629        switch (sym->type) {
 630        case S_STRING:
 631                return sym_string_valid(sym, str);
 632        case S_INT:
 633                if (!sym_string_valid(sym, str))
 634                        return false;
 635                prop = sym_get_range_prop(sym);
 636                if (!prop)
 637                        return true;
 638                val = strtoll(str, NULL, 10);
 639                return val >= sym_get_range_val(prop->expr->left.sym, 10) &&
 640                       val <= sym_get_range_val(prop->expr->right.sym, 10);
 641        case S_HEX:
 642                if (!sym_string_valid(sym, str))
 643                        return false;
 644                prop = sym_get_range_prop(sym);
 645                if (!prop)
 646                        return true;
 647                val = strtoll(str, NULL, 16);
 648                return val >= sym_get_range_val(prop->expr->left.sym, 16) &&
 649                       val <= sym_get_range_val(prop->expr->right.sym, 16);
 650        case S_BOOLEAN:
 651        case S_TRISTATE:
 652                switch (str[0]) {
 653                case 'y': case 'Y':
 654                        return sym_tristate_within_range(sym, yes);
 655                case 'm': case 'M':
 656                        return sym_tristate_within_range(sym, mod);
 657                case 'n': case 'N':
 658                        return sym_tristate_within_range(sym, no);
 659                }
 660                return false;
 661        default:
 662                return false;
 663        }
 664}
 665
 666bool sym_set_string_value(struct symbol *sym, const char *newval)
 667{
 668        const char *oldval;
 669        char *val;
 670        int size;
 671
 672        switch (sym->type) {
 673        case S_BOOLEAN:
 674        case S_TRISTATE:
 675                switch (newval[0]) {
 676                case 'y': case 'Y':
 677                        return sym_set_tristate_value(sym, yes);
 678                case 'm': case 'M':
 679                        return sym_set_tristate_value(sym, mod);
 680                case 'n': case 'N':
 681                        return sym_set_tristate_value(sym, no);
 682                }
 683                return false;
 684        default:
 685                ;
 686        }
 687
 688        if (!sym_string_within_range(sym, newval))
 689                return false;
 690
 691        if (!(sym->flags & SYMBOL_DEF_USER)) {
 692                sym->flags |= SYMBOL_DEF_USER;
 693                sym_set_changed(sym);
 694        }
 695
 696        oldval = sym->def[S_DEF_USER].val;
 697        size = strlen(newval) + 1;
 698        if (sym->type == S_HEX && (newval[0] != '0' || (newval[1] != 'x' && newval[1] != 'X'))) {
 699                size += 2;
 700                sym->def[S_DEF_USER].val = val = xmalloc(size);
 701                *val++ = '0';
 702                *val++ = 'x';
 703        } else if (!oldval || strcmp(oldval, newval))
 704                sym->def[S_DEF_USER].val = val = xmalloc(size);
 705        else
 706                return true;
 707
 708        strcpy(val, newval);
 709        free((void *)oldval);
 710        sym_clear_all_valid();
 711
 712        return true;
 713}
 714
 715/*
 716 * Find the default value associated to a symbol.
 717 * For tristate symbol handle the modules=n case
 718 * in which case "m" becomes "y".
 719 * If the symbol does not have any default then fallback
 720 * to the fixed default values.
 721 */
 722const char *sym_get_string_default(struct symbol *sym)
 723{
 724        struct property *prop;
 725        struct symbol *ds;
 726        const char *str;
 727        tristate val;
 728
 729        sym_calc_visibility(sym);
 730        sym_calc_value(modules_sym);
 731        val = symbol_no.curr.tri;
 732        str = symbol_empty.curr.val;
 733
 734        /* If symbol has a default value look it up */
 735        prop = sym_get_default_prop(sym);
 736        if (prop != NULL) {
 737                switch (sym->type) {
 738                case S_BOOLEAN:
 739                case S_TRISTATE:
 740                        /* The visibility may limit the value from yes => mod */
 741                        val = EXPR_AND(expr_calc_value(prop->expr), prop->visible.tri);
 742                        break;
 743                default:
 744                        /*
 745                         * The following fails to handle the situation
 746                         * where a default value is further limited by
 747                         * the valid range.
 748                         */
 749                        ds = prop_get_symbol(prop);
 750                        if (ds != NULL) {
 751                                sym_calc_value(ds);
 752                                str = (const char *)ds->curr.val;
 753                        }
 754                }
 755        }
 756
 757        /* Handle select statements */
 758        val = EXPR_OR(val, sym->rev_dep.tri);
 759
 760        /* transpose mod to yes if modules are not enabled */
 761        if (val == mod)
 762                if (!sym_is_choice_value(sym) && modules_sym->curr.tri == no)
 763                        val = yes;
 764
 765        /* transpose mod to yes if type is bool */
 766        if (sym->type == S_BOOLEAN && val == mod)
 767                val = yes;
 768
 769        /* adjust the default value if this symbol is implied by another */
 770        if (val < sym->implied.tri)
 771                val = sym->implied.tri;
 772
 773        switch (sym->type) {
 774        case S_BOOLEAN:
 775        case S_TRISTATE:
 776                switch (val) {
 777                case no: return "n";
 778                case mod: return "m";
 779                case yes: return "y";
 780                }
 781        case S_INT:
 782        case S_HEX:
 783                return str;
 784        case S_STRING:
 785                return str;
 786        case S_OTHER:
 787        case S_UNKNOWN:
 788                break;
 789        }
 790        return "";
 791}
 792
 793const char *sym_get_string_value(struct symbol *sym)
 794{
 795        tristate val;
 796
 797        switch (sym->type) {
 798        case S_BOOLEAN:
 799        case S_TRISTATE:
 800                val = sym_get_tristate_value(sym);
 801                switch (val) {
 802                case no:
 803                        return "n";
 804                case mod:
 805                        sym_calc_value(modules_sym);
 806                        return (modules_sym->curr.tri == no) ? "n" : "m";
 807                case yes:
 808                        return "y";
 809                }
 810                break;
 811        default:
 812                ;
 813        }
 814        return (const char *)sym->curr.val;
 815}
 816
 817bool sym_is_changable(struct symbol *sym)
 818{
 819        return sym->visible > sym->rev_dep.tri;
 820}
 821
 822static unsigned strhash(const char *s)
 823{
 824        /* fnv32 hash */
 825        unsigned hash = 2166136261U;
 826        for (; *s; s++)
 827                hash = (hash ^ *s) * 0x01000193;
 828        return hash;
 829}
 830
 831struct symbol *sym_lookup(const char *name, int flags)
 832{
 833        struct symbol *symbol;
 834        char *new_name;
 835        int hash;
 836
 837        if (name) {
 838                if (name[0] && !name[1]) {
 839                        switch (name[0]) {
 840                        case 'y': return &symbol_yes;
 841                        case 'm': return &symbol_mod;
 842                        case 'n': return &symbol_no;
 843                        }
 844                }
 845                hash = strhash(name) % SYMBOL_HASHSIZE;
 846
 847                for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 848                        if (symbol->name &&
 849                            !strcmp(symbol->name, name) &&
 850                            (flags ? symbol->flags & flags
 851                                   : !(symbol->flags & (SYMBOL_CONST|SYMBOL_CHOICE))))
 852                                return symbol;
 853                }
 854                new_name = strdup(name);
 855        } else {
 856                new_name = NULL;
 857                hash = 0;
 858        }
 859
 860        symbol = xmalloc(sizeof(*symbol));
 861        memset(symbol, 0, sizeof(*symbol));
 862        symbol->name = new_name;
 863        symbol->type = S_UNKNOWN;
 864        symbol->flags |= flags;
 865
 866        symbol->next = symbol_hash[hash];
 867        symbol_hash[hash] = symbol;
 868
 869        return symbol;
 870}
 871
 872struct symbol *sym_find(const char *name)
 873{
 874        struct symbol *symbol = NULL;
 875        int hash = 0;
 876
 877        if (!name)
 878                return NULL;
 879
 880        if (name[0] && !name[1]) {
 881                switch (name[0]) {
 882                case 'y': return &symbol_yes;
 883                case 'm': return &symbol_mod;
 884                case 'n': return &symbol_no;
 885                }
 886        }
 887        hash = strhash(name) % SYMBOL_HASHSIZE;
 888
 889        for (symbol = symbol_hash[hash]; symbol; symbol = symbol->next) {
 890                if (symbol->name &&
 891                    !strcmp(symbol->name, name) &&
 892                    !(symbol->flags & SYMBOL_CONST))
 893                                break;
 894        }
 895
 896        return symbol;
 897}
 898
 899/*
 900 * Expand symbol's names embedded in the string given in argument. Symbols'
 901 * name to be expanded shall be prefixed by a '$'. Unknown symbol expands to
 902 * the empty string.
 903 */
 904const char *sym_expand_string_value(const char *in)
 905{
 906        const char *src;
 907        char *res;
 908        size_t reslen;
 909
 910        reslen = strlen(in) + 1;
 911        res = xmalloc(reslen);
 912        res[0] = '\0';
 913
 914        while ((src = strchr(in, '$'))) {
 915                char *p, name[SYMBOL_MAXLENGTH];
 916                const char *symval = "";
 917                struct symbol *sym;
 918                size_t newlen;
 919
 920                strncat(res, in, src - in);
 921                src++;
 922
 923                p = name;
 924                while (isalnum(*src) || *src == '_')
 925                        *p++ = *src++;
 926                *p = '\0';
 927
 928                sym = sym_find(name);
 929                if (sym != NULL) {
 930                        sym_calc_value(sym);
 931                        symval = sym_get_string_value(sym);
 932                }
 933
 934                newlen = strlen(res) + strlen(symval) + strlen(src) + 1;
 935                if (newlen > reslen) {
 936                        reslen = newlen;
 937                        res = realloc(res, reslen);
 938                }
 939
 940                strcat(res, symval);
 941                in = src;
 942        }
 943        strcat(res, in);
 944
 945        return res;
 946}
 947
 948const char *sym_escape_string_value(const char *in)
 949{
 950        const char *p;
 951        size_t reslen;
 952        char *res;
 953        size_t l;
 954
 955        reslen = strlen(in) + strlen("\"\"") + 1;
 956
 957        p = in;
 958        for (;;) {
 959                l = strcspn(p, "\"\\");
 960                p += l;
 961
 962                if (p[0] == '\0')
 963                        break;
 964
 965                reslen++;
 966                p++;
 967        }
 968
 969        res = xmalloc(reslen);
 970        res[0] = '\0';
 971
 972        strcat(res, "\"");
 973
 974        p = in;
 975        for (;;) {
 976                l = strcspn(p, "\"\\");
 977                strncat(res, p, l);
 978                p += l;
 979
 980                if (p[0] == '\0')
 981                        break;
 982
 983                strcat(res, "\\");
 984                strncat(res, p++, 1);
 985        }
 986
 987        strcat(res, "\"");
 988        return res;
 989}
 990
 991struct sym_match {
 992        struct symbol   *sym;
 993        off_t           so, eo;
 994};
 995
 996/* Compare matched symbols as thus:
 997 * - first, symbols that match exactly
 998 * - then, alphabetical sort
 999 */
1000static int sym_rel_comp(const void *sym1, const void *sym2)
1001{
1002        const struct sym_match *s1 = sym1;
1003        const struct sym_match *s2 = sym2;
1004        int exact1, exact2;
1005
1006        /* Exact match:
1007         * - if matched length on symbol s1 is the length of that symbol,
1008         *   then this symbol should come first;
1009         * - if matched length on symbol s2 is the length of that symbol,
1010         *   then this symbol should come first.
1011         * Note: since the search can be a regexp, both symbols may match
1012         * exactly; if this is the case, we can't decide which comes first,
1013         * and we fallback to sorting alphabetically.
1014         */
1015        exact1 = (s1->eo - s1->so) == strlen(s1->sym->name);
1016        exact2 = (s2->eo - s2->so) == strlen(s2->sym->name);
1017        if (exact1 && !exact2)
1018                return -1;
1019        if (!exact1 && exact2)
1020                return 1;
1021
1022        /* As a fallback, sort symbols alphabetically */
1023        return strcmp(s1->sym->name, s2->sym->name);
1024}
1025
1026struct symbol **sym_re_search(const char *pattern)
1027{
1028        struct symbol *sym, **sym_arr = NULL;
1029        struct sym_match *sym_match_arr = NULL;
1030        int i, cnt, size;
1031        regex_t re;
1032        regmatch_t match[1];
1033
1034        cnt = size = 0;
1035        /* Skip if empty */
1036        if (strlen(pattern) == 0)
1037                return NULL;
1038        if (regcomp(&re, pattern, REG_EXTENDED|REG_ICASE))
1039                return NULL;
1040
1041        for_all_symbols(i, sym) {
1042                if (sym->flags & SYMBOL_CONST || !sym->name)
1043                        continue;
1044                if (regexec(&re, sym->name, 1, match, 0))
1045                        continue;
1046                if (cnt >= size) {
1047                        void *tmp;
1048                        size += 16;
1049                        tmp = realloc(sym_match_arr, size * sizeof(struct sym_match));
1050                        if (!tmp)
1051                                goto sym_re_search_free;
1052                        sym_match_arr = tmp;
1053                }
1054                sym_calc_value(sym);
1055                /* As regexec returned 0, we know we have a match, so
1056                 * we can use match[0].rm_[se]o without further checks
1057                 */
1058                sym_match_arr[cnt].so = match[0].rm_so;
1059                sym_match_arr[cnt].eo = match[0].rm_eo;
1060                sym_match_arr[cnt++].sym = sym;
1061        }
1062        if (sym_match_arr) {
1063                qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
1064                sym_arr = malloc((cnt+1) * sizeof(struct symbol));
1065                if (!sym_arr)
1066                        goto sym_re_search_free;
1067                for (i = 0; i < cnt; i++)
1068                        sym_arr[i] = sym_match_arr[i].sym;
1069                sym_arr[cnt] = NULL;
1070        }
1071sym_re_search_free:
1072        /* sym_match_arr can be NULL if no match, but free(NULL) is OK */
1073        free(sym_match_arr);
1074        regfree(&re);
1075
1076        return sym_arr;
1077}
1078
1079/*
1080 * When we check for recursive dependencies we use a stack to save
1081 * current state so we can print out relevant info to user.
1082 * The entries are located on the call stack so no need to free memory.
1083 * Note insert() remove() must always match to properly clear the stack.
1084 */
1085static struct dep_stack {
1086        struct dep_stack *prev, *next;
1087        struct symbol *sym;
1088        struct property *prop;
1089        struct expr *expr;
1090} *check_top;
1091
1092static void dep_stack_insert(struct dep_stack *stack, struct symbol *sym)
1093{
1094        memset(stack, 0, sizeof(*stack));
1095        if (check_top)
1096                check_top->next = stack;
1097        stack->prev = check_top;
1098        stack->sym = sym;
1099        check_top = stack;
1100}
1101
1102static void dep_stack_remove(void)
1103{
1104        check_top = check_top->prev;
1105        if (check_top)
1106                check_top->next = NULL;
1107}
1108
1109/*
1110 * Called when we have detected a recursive dependency.
1111 * check_top point to the top of the stact so we use
1112 * the ->prev pointer to locate the bottom of the stack.
1113 */
1114static void sym_check_print_recursive(struct symbol *last_sym)
1115{
1116        struct dep_stack *stack;
1117        struct symbol *sym, *next_sym;
1118        struct menu *menu = NULL;
1119        struct property *prop;
1120        struct dep_stack cv_stack;
1121
1122        if (sym_is_choice_value(last_sym)) {
1123                dep_stack_insert(&cv_stack, last_sym);
1124                last_sym = prop_get_symbol(sym_get_choice_prop(last_sym));
1125        }
1126
1127        for (stack = check_top; stack != NULL; stack = stack->prev)
1128                if (stack->sym == last_sym)
1129                        break;
1130        if (!stack) {
1131                fprintf(stderr, "unexpected recursive dependency error\n");
1132                return;
1133        }
1134
1135        for (; stack; stack = stack->next) {
1136                sym = stack->sym;
1137                next_sym = stack->next ? stack->next->sym : last_sym;
1138                prop = stack->prop;
1139                if (prop == NULL)
1140                        prop = stack->sym->prop;
1141
1142                /* for choice values find the menu entry (used below) */
1143                if (sym_is_choice(sym) || sym_is_choice_value(sym)) {
1144                        for (prop = sym->prop; prop; prop = prop->next) {
1145                                menu = prop->menu;
1146                                if (prop->menu)
1147                                        break;
1148                        }
1149                }
1150                if (stack->sym == last_sym)
1151                        fprintf(stderr, "%s:%d:error: recursive dependency detected!\n",
1152                                prop->file->name, prop->lineno);
1153                        fprintf(stderr, "For a resolution refer to Documentation/kbuild/kconfig-language.txt\n");
1154                        fprintf(stderr, "subsection \"Kconfig recursive dependency limitations\"\n");
1155                if (stack->expr) {
1156                        fprintf(stderr, "%s:%d:\tsymbol %s %s value contains %s\n",
1157                                prop->file->name, prop->lineno,
1158                                sym->name ? sym->name : "<choice>",
1159                                prop_get_type_name(prop->type),
1160                                next_sym->name ? next_sym->name : "<choice>");
1161                } else if (stack->prop) {
1162                        fprintf(stderr, "%s:%d:\tsymbol %s depends on %s\n",
1163                                prop->file->name, prop->lineno,
1164                                sym->name ? sym->name : "<choice>",
1165                                next_sym->name ? next_sym->name : "<choice>");
1166                } else if (sym_is_choice(sym)) {
1167                        fprintf(stderr, "%s:%d:\tchoice %s contains symbol %s\n",
1168                                menu->file->name, menu->lineno,
1169                                sym->name ? sym->name : "<choice>",
1170                                next_sym->name ? next_sym->name : "<choice>");
1171                } else if (sym_is_choice_value(sym)) {
1172                        fprintf(stderr, "%s:%d:\tsymbol %s is part of choice %s\n",
1173                                menu->file->name, menu->lineno,
1174                                sym->name ? sym->name : "<choice>",
1175                                next_sym->name ? next_sym->name : "<choice>");
1176                } else {
1177                        fprintf(stderr, "%s:%d:\tsymbol %s is selected by %s\n",
1178                                prop->file->name, prop->lineno,
1179                                sym->name ? sym->name : "<choice>",
1180                                next_sym->name ? next_sym->name : "<choice>");
1181                }
1182        }
1183
1184        if (check_top == &cv_stack)
1185                dep_stack_remove();
1186}
1187
1188static struct symbol *sym_check_expr_deps(struct expr *e)
1189{
1190        struct symbol *sym;
1191
1192        if (!e)
1193                return NULL;
1194        switch (e->type) {
1195        case E_OR:
1196        case E_AND:
1197                sym = sym_check_expr_deps(e->left.expr);
1198                if (sym)
1199                        return sym;
1200                return sym_check_expr_deps(e->right.expr);
1201        case E_NOT:
1202                return sym_check_expr_deps(e->left.expr);
1203        case E_EQUAL:
1204        case E_GEQ:
1205        case E_GTH:
1206        case E_LEQ:
1207        case E_LTH:
1208        case E_UNEQUAL:
1209                sym = sym_check_deps(e->left.sym);
1210                if (sym)
1211                        return sym;
1212                return sym_check_deps(e->right.sym);
1213        case E_SYMBOL:
1214                return sym_check_deps(e->left.sym);
1215        default:
1216                break;
1217        }
1218        printf("Oops! How to check %d?\n", e->type);
1219        return NULL;
1220}
1221
1222/* return NULL when dependencies are OK */
1223static struct symbol *sym_check_sym_deps(struct symbol *sym)
1224{
1225        struct symbol *sym2;
1226        struct property *prop;
1227        struct dep_stack stack;
1228
1229        dep_stack_insert(&stack, sym);
1230
1231        sym2 = sym_check_expr_deps(sym->rev_dep.expr);
1232        if (sym2)
1233                goto out;
1234
1235        for (prop = sym->prop; prop; prop = prop->next) {
1236                if (prop->type == P_CHOICE || prop->type == P_SELECT)
1237                        continue;
1238                stack.prop = prop;
1239                sym2 = sym_check_expr_deps(prop->visible.expr);
1240                if (sym2)
1241                        break;
1242                if (prop->type != P_DEFAULT || sym_is_choice(sym))
1243                        continue;
1244                stack.expr = prop->expr;
1245                sym2 = sym_check_expr_deps(prop->expr);
1246                if (sym2)
1247                        break;
1248                stack.expr = NULL;
1249        }
1250
1251out:
1252        dep_stack_remove();
1253
1254        return sym2;
1255}
1256
1257static struct symbol *sym_check_choice_deps(struct symbol *choice)
1258{
1259        struct symbol *sym, *sym2;
1260        struct property *prop;
1261        struct expr *e;
1262        struct dep_stack stack;
1263
1264        dep_stack_insert(&stack, choice);
1265
1266        prop = sym_get_choice_prop(choice);
1267        expr_list_for_each_sym(prop->expr, e, sym)
1268                sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1269
1270        choice->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1271        sym2 = sym_check_sym_deps(choice);
1272        choice->flags &= ~SYMBOL_CHECK;
1273        if (sym2)
1274                goto out;
1275
1276        expr_list_for_each_sym(prop->expr, e, sym) {
1277                sym2 = sym_check_sym_deps(sym);
1278                if (sym2)
1279                        break;
1280        }
1281out:
1282        expr_list_for_each_sym(prop->expr, e, sym)
1283                sym->flags &= ~SYMBOL_CHECK;
1284
1285        if (sym2 && sym_is_choice_value(sym2) &&
1286            prop_get_symbol(sym_get_choice_prop(sym2)) == choice)
1287                sym2 = choice;
1288
1289        dep_stack_remove();
1290
1291        return sym2;
1292}
1293
1294struct symbol *sym_check_deps(struct symbol *sym)
1295{
1296        struct symbol *sym2;
1297        struct property *prop;
1298
1299        if (sym->flags & SYMBOL_CHECK) {
1300                sym_check_print_recursive(sym);
1301                return sym;
1302        }
1303        if (sym->flags & SYMBOL_CHECKED)
1304                return NULL;
1305
1306        if (sym_is_choice_value(sym)) {
1307                struct dep_stack stack;
1308
1309                /* for choice groups start the check with main choice symbol */
1310                dep_stack_insert(&stack, sym);
1311                prop = sym_get_choice_prop(sym);
1312                sym2 = sym_check_deps(prop_get_symbol(prop));
1313                dep_stack_remove();
1314        } else if (sym_is_choice(sym)) {
1315                sym2 = sym_check_choice_deps(sym);
1316        } else {
1317                sym->flags |= (SYMBOL_CHECK | SYMBOL_CHECKED);
1318                sym2 = sym_check_sym_deps(sym);
1319                sym->flags &= ~SYMBOL_CHECK;
1320        }
1321
1322        if (sym2 && sym2 == sym)
1323                sym2 = NULL;
1324
1325        return sym2;
1326}
1327
1328struct property *prop_alloc(enum prop_type type, struct symbol *sym)
1329{
1330        struct property *prop;
1331        struct property **propp;
1332
1333        prop = xmalloc(sizeof(*prop));
1334        memset(prop, 0, sizeof(*prop));
1335        prop->type = type;
1336        prop->sym = sym;
1337        prop->file = current_file;
1338        prop->lineno = zconf_lineno();
1339
1340        /* append property to the prop list of symbol */
1341        if (sym) {
1342                for (propp = &sym->prop; *propp; propp = &(*propp)->next)
1343                        ;
1344                *propp = prop;
1345        }
1346
1347        return prop;
1348}
1349
1350struct symbol *prop_get_symbol(struct property *prop)
1351{
1352        if (prop->expr && (prop->expr->type == E_SYMBOL ||
1353                           prop->expr->type == E_LIST))
1354                return prop->expr->left.sym;
1355        return NULL;
1356}
1357
1358const char *prop_get_type_name(enum prop_type type)
1359{
1360        switch (type) {
1361        case P_PROMPT:
1362                return "prompt";
1363        case P_ENV:
1364                return "env";
1365        case P_COMMENT:
1366                return "comment";
1367        case P_MENU:
1368                return "menu";
1369        case P_DEFAULT:
1370                return "default";
1371        case P_CHOICE:
1372                return "choice";
1373        case P_SELECT:
1374                return "select";
1375        case P_IMPLY:
1376                return "imply";
1377        case P_RANGE:
1378                return "range";
1379        case P_SYMBOL:
1380                return "symbol";
1381        case P_UNKNOWN:
1382                break;
1383        }
1384        return "unknown";
1385}
1386
1387static void prop_add_env(const char *env)
1388{
1389        struct symbol *sym, *sym2;
1390        struct property *prop;
1391        char *p;
1392
1393        sym = current_entry->sym;
1394        sym->flags |= SYMBOL_AUTO;
1395        for_all_properties(sym, prop, P_ENV) {
1396                sym2 = prop_get_symbol(prop);
1397                if (strcmp(sym2->name, env))
1398                        menu_warn(current_entry, "redefining environment symbol from %s",
1399                                  sym2->name);
1400                return;
1401        }
1402
1403        prop = prop_alloc(P_ENV, sym);
1404        prop->expr = expr_alloc_symbol(sym_lookup(env, SYMBOL_CONST));
1405
1406        sym_env_list = expr_alloc_one(E_LIST, sym_env_list);
1407        sym_env_list->right.sym = sym;
1408
1409        p = getenv(env);
1410        if (p)
1411                sym_add_default(sym, p);
1412        else
1413                menu_warn(current_entry, "environment variable %s undefined", env);
1414}
1415