scripts/kconfig/confdata.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
   4  */
   5
   6 #include <sys/mman.h>
   7 #include <sys/stat.h>
   8 #include <sys/types.h>
   9 #include <ctype.h>
  10 #include <errno.h>
  11 #include <fcntl.h>
  12 #include <limits.h>
  13 #include <stdarg.h>
  14 #include <stdbool.h>
  15 #include <stdio.h>
  16 #include <stdlib.h>
  17 #include <string.h>
  18 #include <time.h>
  19 #include <unistd.h>
  20
  21 #include "lkc.h"
  22
  23 /* return true if 'path' exists, false otherwise */
  24 static bool is_present(const char *path)
  25 {
  26         struct stat st;
  27
  28         return !stat(path, &st);
  29 }
  30
  31 /* return true if 'path' exists and it is a directory, false otherwise */
  32 static bool is_dir(const char *path)
  33 {
  34         struct stat st;
  35
  36         if (stat(path, &st))
  37                 return false;
  38
  39         return S_ISDIR(st.st_mode);
  40 }
  41
  42 /* return true if the given two files are the same, false otherwise */
  43 static bool is_same(const char *file1, const char *file2)
  44 {
  45         int fd1, fd2;
  46         struct stat st1, st2;
  47         void *map1, *map2;
  48         bool ret = false;
  49
  50         fd1 = open(file1, O_RDONLY);
  51         if (fd1 < 0)
  52                 return ret;
  53
  54         fd2 = open(file2, O_RDONLY);
  55         if (fd2 < 0)
  56                 goto close1;
  57
  58         ret = fstat(fd1, &st1);
  59         if (ret)
  60                 goto close2;
  61         ret = fstat(fd2, &st2);
  62         if (ret)
  63                 goto close2;
  64
  65         if (st1.st_size != st2.st_size)
  66                 goto close2;
  67
  68         map1 = mmap(NULL, st1.st_size, PROT_READ, MAP_PRIVATE, fd1, 0);
  69         if (map1 == MAP_FAILED)
  70                 goto close2;
  71
  72         map2 = mmap(NULL, st2.st_size, PROT_READ, MAP_PRIVATE, fd2, 0);
  73         if (map2 == MAP_FAILED)
  74                 goto close2;
  75
  76         if (bcmp(map1, map2, st1.st_size))
  77                 goto close2;
  78
  79         ret = true;
  80 close2:
  81         close(fd2);
  82 close1:
  83         close(fd1);
  84
  85         return ret;
  86 }
  87
  88 /*
  89  * Create the parent directory of the given path.
  90  *
  91  * For example, if 'include/config/auto.conf' is given, create 'include/config'.
  92  */
  93 static int make_parent_dir(const char *path)
  94 {
  95         char tmp[PATH_MAX + 1];
  96         char *p;
  97
  98         strncpy(tmp, path, sizeof(tmp));
  99         tmp[sizeof(tmp) - 1] = 0;
 100
 101         /* Remove the base name. Just return if nothing is left */
 102         p = strrchr(tmp, '/');
 103         if (!p)
 104                 return 0;
 105         *(p + 1) = 0;
 106
 107         /* Just in case it is an absolute path */
 108         p = tmp;
 109         while (*p == '/')
 110                 p++;
 111
 112         while ((p = strchr(p, '/'))) {
 113                 *p = 0;
 114
 115                 /* skip if the directory exists */
 116                 if (!is_dir(tmp) && mkdir(tmp, 0755))
 117                         return -1;
 118
 119                 *p = '/';
 120                 while (*p == '/')
 121                         p++;
 122         }
 123
 124         return 0;
 125 }
 126
 127 static char depfile_path[PATH_MAX];
 128 static size_t depfile_prefix_len;
 129
 130 /* touch depfile for symbol 'name' */
 131 static int conf_touch_dep(const char *name)
 132 {
 133         int fd;
 134
 135         /* check overflow: prefix + name + '\0' must fit in buffer. */
 136         if (depfile_prefix_len + strlen(name) + 1 > sizeof(depfile_path))
 137                 return -1;
 138
 139         strcpy(depfile_path + depfile_prefix_len, name);
 140
 141         fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
 142         if (fd == -1)
 143                 return -1;
 144         close(fd);
 145
 146         return 0;
 147 }
 148
 149 static void conf_warning(const char *fmt, ...)
 150         __attribute__ ((format (printf, 1, 2)));
 151
 152 static void conf_message(const char *fmt, ...)
 153         __attribute__ ((format (printf, 1, 2)));
 154
 155 static const char *conf_filename;
 156 static int conf_lineno, conf_warnings;
 157
 158 static void conf_warning(const char *fmt, ...)
 159 {
 160         va_list ap;
 161         va_start(ap, fmt);
 162         fprintf(stderr, "%s:%d:warning: ", conf_filename, conf_lineno);
 163         vfprintf(stderr, fmt, ap);
 164         fprintf(stderr, "\n");
 165         va_end(ap);
 166         conf_warnings++;
 167 }
 168
 169 static void conf_default_message_callback(const char *s)
 170 {
 171         printf("#\n# ");
 172         printf("%s", s);
 173         printf("\n#\n");
 174 }
 175
 176 static void (*conf_message_callback)(const char *s) =
 177         conf_default_message_callback;
 178 void conf_set_message_callback(void (*fn)(const char *s))
 179 {
 180         conf_message_callback = fn;
 181 }
 182
 183 static void conf_message(const char *fmt, ...)
 184 {
 185         va_list ap;
 186         char buf[4096];
 187
 188         if (!conf_message_callback)
 189                 return;
 190
 191         va_start(ap, fmt);
 192
 193         vsnprintf(buf, sizeof(buf), fmt, ap);
 194         conf_message_callback(buf);
 195         va_end(ap);
 196 }
 197
 198 const char *conf_get_configname(void)
 199 {
 200         char *name = getenv("KCONFIG_CONFIG");
 201
 202         return name ? name : ".config";
 203 }
 204
 205 static const char *conf_get_autoconfig_name(void)
 206 {
 207         char *name = getenv("KCONFIG_AUTOCONFIG");
 208
 209         return name ? name : "include/config/auto.conf";
 210 }
 211
 212 static const char *conf_get_autoheader_name(void)
 213 {
 214         char *name = getenv("KCONFIG_AUTOHEADER");
 215
 216         return name ? name : "include/generated/autoconf.h";
 217 }
 218
 219 static const char *conf_get_rustccfg_name(void)
 220 {
 221         char *name = getenv("KCONFIG_RUSTCCFG");
 222
 223         return name ? name : "include/generated/rustc_cfg";
 224 }
 225
 226 static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 227 {
 228         char *p2;
 229
 230         switch (sym->type) {
 231         case S_TRISTATE:
 232                 if (p[0] == 'm') {
 233                         sym->def[def].tri = mod;
 234                         sym->flags |= def_flags;
 235                         break;
 236                 }
 237                 /* fall through */
 238         case S_BOOLEAN:
 239                 if (p[0] == 'y') {
 240                         sym->def[def].tri = yes;
 241                         sym->flags |= def_flags;
 242                         break;
 243                 }
 244                 if (p[0] == 'n') {
 245                         sym->def[def].tri = no;
 246                         sym->flags |= def_flags;
 247                         break;
 248                 }
 249                 if (def != S_DEF_AUTO)
 250                         conf_warning("symbol value '%s' invalid for %s",
 251                                      p, sym->name);
 252                 return 1;
 253         case S_STRING:
 254                 /* No escaping for S_DEF_AUTO (include/config/auto.conf) */
 255                 if (def != S_DEF_AUTO) {
 256                         if (*p++ != '"')
 257                                 break;
 258                         for (p2 = p; (p2 = strpbrk(p2, "\"\\")); p2++) {
 259                                 if (*p2 == '"') {
 260                                         *p2 = 0;
 261                                         break;
 262                                 }
 263                                 memmove(p2, p2 + 1, strlen(p2));
 264                         }
 265                         if (!p2) {
 266                                 conf_warning("invalid string found");
 267                                 return 1;
 268                         }
 269                 }
 270                 /* fall through */
 271         case S_INT:
 272         case S_HEX:
 273                 if (sym_string_valid(sym, p)) {
 274                         sym->def[def].val = xstrdup(p);
 275                         sym->flags |= def_flags;
 276                 } else {
 277                         if (def != S_DEF_AUTO)
 278                                 conf_warning("symbol value '%s' invalid for %s",
 279                                              p, sym->name);
 280                         return 1;
 281                 }
 282                 break;
 283         default:
 284                 ;
 285         }
 286         return 0;
 287 }
 288
 289 #define LINE_GROWTH 16
 290 static int add_byte(int c, char **lineptr, size_t slen, size_t *n)
 291 {
 292         size_t new_size = slen + 1;
 293
 294         if (new_size > *n) {
 295                 new_size += LINE_GROWTH - 1;
 296                 new_size *= 2;
 297                 *lineptr = xrealloc(*lineptr, new_size);
 298                 *n = new_size;
 299         }
 300
 301         (*lineptr)[slen] = c;
 302
 303         return 0;
 304 }
 305
 306 static ssize_t compat_getline(char **lineptr, size_t *n, FILE *stream)
 307 {
 308         char *line = *lineptr;
 309         size_t slen = 0;
 310
 311         for (;;) {
 312                 int c = getc(stream);
 313
 314                 switch (c) {
 315                 case '\n':
 316                         if (add_byte(c, &line, slen, n) < 0)
 317                                 goto e_out;
 318                         slen++;
 319                         /* fall through */
 320                 case EOF:
 321                         if (add_byte('\0', &line, slen, n) < 0)
 322                                 goto e_out;
 323                         *lineptr = line;
 324                         if (slen == 0)
 325                                 return -1;
 326                         return slen;
 327                 default:
 328                         if (add_byte(c, &line, slen, n) < 0)
 329                                 goto e_out;
 330                         slen++;
 331                 }
 332         }
 333
 334 e_out:
 335         line[slen-1] = '\0';
 336         *lineptr = line;
 337         return -1;
 338 }
 339
 340 int conf_read_simple(const char *name, int def)
 341 {
 342         FILE *in = NULL;
 343         char   *line = NULL;
 344         size_t  line_asize = 0;
 345         char *p, *p2, *val;
 346         struct symbol *sym;
 347         int i, def_flags;
 348         const char *warn_unknown, *werror, *sym_name;
 349
 350         warn_unknown = getenv("KCONFIG_WARN_UNKNOWN_SYMBOLS");
 351         werror = getenv("KCONFIG_WERROR");
 352         if (name) {
 353                 in = zconf_fopen(name);
 354         } else {
 355                 char *env;
 356
 357                 name = conf_get_configname();
 358                 in = zconf_fopen(name);
 359                 if (in)
 360                         goto load;
 361                 conf_set_changed(true);
 362
 363                 env = getenv("KCONFIG_DEFCONFIG_LIST");
 364                 if (!env)
 365                         return 1;
 366
 367                 while (1) {
 368                         bool is_last;
 369
 370                         while (isspace(*env))
 371                                 env++;
 372
 373                         if (!*env)
 374                                 break;
 375
 376                         p = env;
 377                         while (*p && !isspace(*p))
 378                                 p++;
 379
 380                         is_last = (*p == '\0');
 381
 382                         *p = '\0';
 383
 384                         in = zconf_fopen(env);
 385                         if (in) {
 386                                 conf_message("using defaults found in %s",
 387                                              env);
 388                                 goto load;
 389                         }
 390
 391                         if (is_last)
 392                                 break;
 393
 394                         env = p + 1;
 395                 }
 396         }
 397         if (!in)
 398                 return 1;
 399
 400 load:
 401         conf_filename = name;
 402         conf_lineno = 0;
 403         conf_warnings = 0;
 404
 405         def_flags = SYMBOL_DEF << def;
 406         for_all_symbols(i, sym) {
 407                 sym->flags |= SYMBOL_CHANGED;
 408                 sym->flags &= ~(def_flags|SYMBOL_VALID);
 409                 if (sym_is_choice(sym))
 410                         sym->flags |= def_flags;
 411                 switch (sym->type) {
 412                 case S_INT:
 413                 case S_HEX:
 414                 case S_STRING:
 415                         if (sym->def[def].val)
 416                                 free(sym->def[def].val);
 417                         /* fall through */
 418                 default:
 419                         sym->def[def].val = NULL;
 420                         sym->def[def].tri = no;
 421                 }
 422         }
 423
 424         while (compat_getline(&line, &line_asize, in) != -1) {
 425                 conf_lineno++;
 426                 if (line[0] == '#') {
 427                         if (line[1] != ' ')
 428                                 continue;
 429                         p = line + 2;
 430                         if (memcmp(p, CONFIG_, strlen(CONFIG_)))
 431                                 continue;
 432                         sym_name = p + strlen(CONFIG_);
 433                         p = strchr(sym_name, ' ');
 434                         if (!p)
 435                                 continue;
 436                         *p++ = 0;
 437                         if (strncmp(p, "is not set", 10))
 438                                 continue;
 439
 440                         val = "n";
 441                 } else if (memcmp(line, CONFIG_, strlen(CONFIG_)) == 0) {
 442                         sym_name = line + strlen(CONFIG_);
 443                         p = strchr(sym_name, '=');
 444                         if (!p)
 445                                 continue;
 446                         *p++ = 0;
 447                         val = p;
 448                         p2 = strchr(p, '\n');
 449                         if (p2) {
 450                                 *p2-- = 0;
 451                                 if (*p2 == '\r')
 452                                         *p2 = 0;
 453                         }
 454                 } else {
 455                         if (line[0] != '\r' && line[0] != '\n')
 456                                 conf_warning("unexpected data: %.*s",
 457                                              (int)strcspn(line, "\r\n"), line);
 458
 459                         continue;
 460                 }
 461
 462                 sym = sym_find(sym_name);
 463                 if (!sym) {
 464                         if (def == S_DEF_AUTO) {
 465                                 /*
 466                                  * Reading from include/config/auto.conf.
 467                                  * If CONFIG_FOO previously existed in auto.conf
 468                                  * but it is missing now, include/config/FOO
 469                                  * must be touched.
 470                                  */
 471                                 conf_touch_dep(sym_name);
 472                         } else {
 473                                 if (warn_unknown)
 474                                         conf_warning("unknown symbol: %s", sym_name);
 475
 476                                 conf_set_changed(true);
 477                         }
 478                         continue;
 479                 }
 480
 481                 if (sym->flags & def_flags)
 482                         conf_warning("override: reassigning to symbol %s", sym->name);
 483
 484                 if (conf_set_sym_val(sym, def, def_flags, val))
 485                         continue;
 486
 487                 if (sym && sym_is_choice_value(sym)) {
 488                         struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 489                         switch (sym->def[def].tri) {
 490                         case no:
 491                                 break;
 492                         case mod:
 493                                 if (cs->def[def].tri == yes) {
 494                                         conf_warning("%s creates inconsistent choice state", sym->name);
 495                                         cs->flags &= ~def_flags;
 496                                 }
 497                                 break;
 498                         case yes:
 499                                 if (cs->def[def].tri != no)
 500                                         conf_warning("override: %s changes choice state", sym->name);
 501                                 cs->def[def].val = sym;
 502                                 break;
 503                         }
 504                         cs->def[def].tri = EXPR_OR(cs->def[def].tri, sym->def[def].tri);
 505                 }
 506         }
 507         free(line);
 508         fclose(in);
 509
 510         if (conf_warnings && werror)
 511                 exit(1);
 512
 513         return 0;
 514 }
 515
 516 int conf_read(const char *name)
 517 {
 518         struct symbol *sym;
 519         int conf_unsaved = 0;
 520         int i;
 521
 522         conf_set_changed(false);
 523
 524         if (conf_read_simple(name, S_DEF_USER)) {
 525                 sym_calc_value(modules_sym);
 526                 return 1;
 527         }
 528
 529         sym_calc_value(modules_sym);
 530
 531         for_all_symbols(i, sym) {
 532                 sym_calc_value(sym);
 533                 if (sym_is_choice(sym) || (sym->flags & SYMBOL_NO_WRITE))
 534                         continue;
 535                 if (sym_has_value(sym) && (sym->flags & SYMBOL_WRITE)) {
 536                         /* check that calculated value agrees with saved value */
 537                         switch (sym->type) {
 538                         case S_BOOLEAN:
 539                         case S_TRISTATE:
 540                                 if (sym->def[S_DEF_USER].tri == sym_get_tristate_value(sym))
 541                                         continue;
 542                                 break;
 543                         default:
 544                                 if (!strcmp(sym->curr.val, sym->def[S_DEF_USER].val))
 545                                         continue;
 546                                 break;
 547                         }
 548                 } else if (!sym_has_value(sym) && !(sym->flags & SYMBOL_WRITE))
 549                         /* no previous value and not saved */
 550                         continue;
 551                 conf_unsaved++;
 552                 /* maybe print value in verbose mode... */
 553         }
 554
 555         for_all_symbols(i, sym) {
 556                 if (sym_has_value(sym) && !sym_is_choice_value(sym)) {
 557                         /* Reset values of generates values, so they'll appear
 558                          * as new, if they should become visible, but that
 559                          * doesn't quite work if the Kconfig and the saved
 560                          * configuration disagree.
 561                          */
 562                         if (sym->visible == no && !conf_unsaved)
 563                                 sym->flags &= ~SYMBOL_DEF_USER;
 564                         switch (sym->type) {
 565                         case S_STRING:
 566                         case S_INT:
 567                         case S_HEX:
 568                                 /* Reset a string value if it's out of range */
 569                                 if (sym_string_within_range(sym, sym->def[S_DEF_USER].val))
 570                                         break;
 571                                 sym->flags &= ~SYMBOL_VALID;
 572                                 conf_unsaved++;
 573                                 break;
 574                         default:
 575                                 break;
 576                         }
 577                 }
 578         }
 579
 580         if (conf_warnings || conf_unsaved)
 581                 conf_set_changed(true);
 582
 583         return 0;
 584 }
 585
 586 struct comment_style {
 587         const char *decoration;
 588         const char *prefix;
 589         const char *postfix;
 590 };
 591
 592 static const struct comment_style comment_style_pound = {
 593         .decoration = "#",
 594         .prefix = "#",
 595         .postfix = "#",
 596 };
 597
 598 static const struct comment_style comment_style_c = {
 599         .decoration = " *",
 600         .prefix = "/*",
 601         .postfix = " */",
 602 };
 603
 604 static void conf_write_heading(FILE *fp, const struct comment_style *cs)
 605 {
 606         if (!cs)
 607                 return;
 608
 609         fprintf(fp, "%s\n", cs->prefix);
 610
 611         fprintf(fp, "%s Automatically generated file; DO NOT EDIT.\n",
 612                 cs->decoration);
 613
 614         fprintf(fp, "%s %s\n", cs->decoration, rootmenu.prompt->text);
 615
 616         fprintf(fp, "%s\n", cs->postfix);
 617 }
 618
 619 /* The returned pointer must be freed on the caller side */
 620 static char *escape_string_value(const char *in)
 621 {
 622         const char *p;
 623         char *out;
 624         size_t len;
 625
 626         len = strlen(in) + strlen("\"\"") + 1;
 627
 628         p = in;
 629         while (1) {
 630                 p += strcspn(p, "\"\\");
 631
 632                 if (p[0] == '\0')
 633                         break;
 634
 635                 len++;
 636                 p++;
 637         }
 638
 639         out = xmalloc(len);
 640         out[0] = '\0';
 641
 642         strcat(out, "\"");
 643
 644         p = in;
 645         while (1) {
 646                 len = strcspn(p, "\"\\");
 647                 strncat(out, p, len);
 648                 p += len;
 649
 650                 if (p[0] == '\0')
 651                         break;
 652
 653                 strcat(out, "\\");
 654                 strncat(out, p++, 1);
 655         }
 656
 657         strcat(out, "\"");
 658
 659         return out;
 660 }
 661
 662 enum output_n { OUTPUT_N, OUTPUT_N_AS_UNSET, OUTPUT_N_NONE };
 663
 664 static void __print_symbol(FILE *fp, struct symbol *sym, enum output_n output_n,
 665                            bool escape_string)
 666 {
 667         const char *val;
 668         char *escaped = NULL;
 669
 670         if (sym->type == S_UNKNOWN)
 671                 return;
 672
 673         val = sym_get_string_value(sym);
 674
 675         if ((sym->type == S_BOOLEAN || sym->type == S_TRISTATE) &&
 676             output_n != OUTPUT_N && *val == 'n') {
 677                 if (output_n == OUTPUT_N_AS_UNSET)
 678                         fprintf(fp, "# %s%s is not set\n", CONFIG_, sym->name);
 679                 return;
 680         }
 681
 682         if (sym->type == S_STRING && escape_string) {
 683                 escaped = escape_string_value(val);
 684                 val = escaped;
 685         }
 686
 687         fprintf(fp, "%s%s=%s\n", CONFIG_, sym->name, val);
 688
 689         free(escaped);
 690 }
 691
 692 static void print_symbol_for_dotconfig(FILE *fp, struct symbol *sym)
 693 {
 694         __print_symbol(fp, sym, OUTPUT_N_AS_UNSET, true);
 695 }
 696
 697 static void print_symbol_for_autoconf(FILE *fp, struct symbol *sym)
 698 {
 699         __print_symbol(fp, sym, OUTPUT_N_NONE, false);
 700 }
 701
 702 void print_symbol_for_listconfig(struct symbol *sym)
 703 {
 704         __print_symbol(stdout, sym, OUTPUT_N, true);
 705 }
 706
 707 static void print_symbol_for_c(FILE *fp, struct symbol *sym)
 708 {
 709         const char *val;
 710         const char *sym_suffix = "";
 711         const char *val_prefix = "";
 712         char *escaped = NULL;
 713
 714         if (sym->type == S_UNKNOWN)
 715                 return;
 716
 717         val = sym_get_string_value(sym);
 718
 719         switch (sym->type) {
 720         case S_BOOLEAN:
 721         case S_TRISTATE:
 722                 switch (*val) {
 723                 case 'n':
 724                         return;
 725                 case 'm':
 726                         sym_suffix = "_MODULE";
 727                         /* fall through */
 728                 default:
 729                         val = "1";
 730                 }
 731                 break;
 732         case S_HEX:
 733                 if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
 734                         val_prefix = "0x";
 735                 break;
 736         case S_STRING:
 737                 escaped = escape_string_value(val);
 738                 val = escaped;
 739         default:
 740                 break;
 741         }
 742
 743         fprintf(fp, "#define %s%s%s %s%s\n", CONFIG_, sym->name, sym_suffix,
 744                 val_prefix, val);
 745
 746         free(escaped);
 747 }
 748
 749 static void print_symbol_for_rustccfg(FILE *fp, struct symbol *sym)
 750 {
 751         const char *val;
 752         const char *val_prefix = "";
 753         char *val_prefixed = NULL;
 754         size_t val_prefixed_len;
 755         char *escaped = NULL;
 756
 757         if (sym->type == S_UNKNOWN)
 758                 return;
 759
 760         val = sym_get_string_value(sym);
 761
 762         switch (sym->type) {
 763         case S_BOOLEAN:
 764         case S_TRISTATE:
 765                 /*
 766                  * We do not care about disabled ones, i.e. no need for
 767                  * what otherwise are "comments" in other printers.
 768                  */
 769                 if (*val == 'n')
 770                         return;
 771
 772                 /*
 773                  * To have similar functionality to the C macro `IS_ENABLED()`
 774                  * we provide an empty `--cfg CONFIG_X` here in both `y`
 775                  * and `m` cases.
 776                  *
 777                  * Then, the common `fprintf()` below will also give us
 778                  * a `--cfg CONFIG_X="y"` or `--cfg CONFIG_X="m"`, which can
 779                  * be used as the equivalent of `IS_BUILTIN()`/`IS_MODULE()`.
 780                  */
 781                 fprintf(fp, "--cfg=%s%s\n", CONFIG_, sym->name);
 782                 break;
 783         case S_HEX:
 784                 if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
 785                         val_prefix = "0x";
 786                 break;
 787         default:
 788                 break;
 789         }
 790
 791         if (strlen(val_prefix) > 0) {
 792                 val_prefixed_len = strlen(val) + strlen(val_prefix) + 1;
 793                 val_prefixed = xmalloc(val_prefixed_len);
 794                 snprintf(val_prefixed, val_prefixed_len, "%s%s", val_prefix, val);
 795                 val = val_prefixed;
 796         }
 797
 798         /* All values get escaped: the `--cfg` option only takes strings */
 799         escaped = escape_string_value(val);
 800         val = escaped;
 801
 802         fprintf(fp, "--cfg=%s%s=%s\n", CONFIG_, sym->name, val);
 803
 804         free(escaped);
 805         free(val_prefixed);
 806 }
 807
 808 /*
 809  * Write out a minimal config.
 810  * All values that has default values are skipped as this is redundant.
 811  */
 812 int conf_write_defconfig(const char *filename)
 813 {
 814         struct symbol *sym;
 815         struct menu *menu;
 816         FILE *out;
 817
 818         out = fopen(filename, "w");
 819         if (!out)
 820                 return 1;
 821
 822         sym_clear_all_valid();
 823
 824         /* Traverse all menus to find all relevant symbols */
 825         menu = rootmenu.list;
 826
 827         while (menu != NULL)
 828         {
 829                 sym = menu->sym;
 830                 if (sym == NULL) {
 831                         if (!menu_is_visible(menu))
 832                                 goto next_menu;
 833                 } else if (!sym_is_choice(sym)) {
 834                         sym_calc_value(sym);
 835                         if (!(sym->flags & SYMBOL_WRITE))
 836                                 goto next_menu;
 837                         sym->flags &= ~SYMBOL_WRITE;
 838                         /* If we cannot change the symbol - skip */
 839                         if (!sym_is_changeable(sym))
 840                                 goto next_menu;
 841                         /* If symbol equals to default value - skip */
 842                         if (strcmp(sym_get_string_value(sym), sym_get_string_default(sym)) == 0)
 843                                 goto next_menu;
 844
 845                         /*
 846                          * If symbol is a choice value and equals to the
 847                          * default for a choice - skip.
 848                          * But only if value is bool and equal to "y" and
 849                          * choice is not "optional".
 850                          * (If choice is "optional" then all values can be "n")
 851                          */
 852                         if (sym_is_choice_value(sym)) {
 853                                 struct symbol *cs;
 854                                 struct symbol *ds;
 855
 856                                 cs = prop_get_symbol(sym_get_choice_prop(sym));
 857                                 ds = sym_choice_default(cs);
 858                                 if (!sym_is_optional(cs) && sym == ds) {
 859                                         if ((sym->type == S_BOOLEAN) &&
 860                                             sym_get_tristate_value(sym) == yes)
 861                                                 goto next_menu;
 862                                 }
 863                         }
 864                         print_symbol_for_dotconfig(out, sym);
 865                 }
 866 next_menu:
 867                 if (menu->list != NULL) {
 868                         menu = menu->list;
 869                 }
 870                 else if (menu->next != NULL) {
 871                         menu = menu->next;
 872                 } else {
 873                         while ((menu = menu->parent)) {
 874                                 if (menu->next != NULL) {
 875                                         menu = menu->next;
 876                                         break;
 877                                 }
 878                         }
 879                 }
 880         }
 881         fclose(out);
 882         return 0;
 883 }
 884
 885 int conf_write(const char *name)
 886 {
 887         FILE *out;
 888         struct symbol *sym;
 889         struct menu *menu;
 890         const char *str;
 891         char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1];
 892         char *env;
 893         int i;
 894         bool need_newline = false;
 895
 896         if (!name)
 897                 name = conf_get_configname();
 898
 899         if (!*name) {
 900                 fprintf(stderr, "config name is empty\n");
 901                 return -1;
 902         }
 903
 904         if (is_dir(name)) {
 905                 fprintf(stderr, "%s: Is a directory\n", name);
 906                 return -1;
 907         }
 908
 909         if (make_parent_dir(name))
 910                 return -1;
 911
 912         env = getenv("KCONFIG_OVERWRITECONFIG");
 913         if (env && *env) {
 914                 *tmpname = 0;
 915                 out = fopen(name, "w");
 916         } else {
 917                 snprintf(tmpname, sizeof(tmpname), "%s.%d.tmp",
 918                          name, (int)getpid());
 919                 out = fopen(tmpname, "w");
 920         }
 921         if (!out)
 922                 return 1;
 923
 924         conf_write_heading(out, &comment_style_pound);
 925
 926         if (!conf_get_changed())
 927                 sym_clear_all_valid();
 928
 929         menu = rootmenu.list;
 930         while (menu) {
 931                 sym = menu->sym;
 932                 if (!sym) {
 933                         if (!menu_is_visible(menu))
 934                                 goto next;
 935                         str = menu_get_prompt(menu);
 936                         fprintf(out, "\n"
 937                                      "#\n"
 938                                      "# %s\n"
 939                                      "#\n", str);
 940                         need_newline = false;
 941                 } else if (!(sym->flags & SYMBOL_CHOICE) &&
 942                            !(sym->flags & SYMBOL_WRITTEN)) {
 943                         sym_calc_value(sym);
 944                         if (!(sym->flags & SYMBOL_WRITE))
 945                                 goto next;
 946                         if (need_newline) {
 947                                 fprintf(out, "\n");
 948                                 need_newline = false;
 949                         }
 950                         sym->flags |= SYMBOL_WRITTEN;
 951                         print_symbol_for_dotconfig(out, sym);
 952                 }
 953
 954 next:
 955                 if (menu->list) {
 956                         menu = menu->list;
 957                         continue;
 958                 }
 959
 960 end_check:
 961                 if (!menu->sym && menu_is_visible(menu) && menu != &rootmenu &&
 962                     menu->prompt->type == P_MENU) {
 963                         fprintf(out, "# end of %s\n", menu_get_prompt(menu));
 964                         need_newline = true;
 965                 }
 966
 967                 if (menu->next) {
 968                         menu = menu->next;
 969                 } else {
 970                         menu = menu->parent;
 971                         if (menu)
 972                                 goto end_check;
 973                 }
 974         }
 975         fclose(out);
 976
 977         for_all_symbols(i, sym)
 978                 sym->flags &= ~SYMBOL_WRITTEN;
 979
 980         if (*tmpname) {
 981                 if (is_same(name, tmpname)) {
 982                         conf_message("No change to %s", name);
 983                         unlink(tmpname);
 984                         conf_set_changed(false);
 985                         return 0;
 986                 }
 987
 988                 snprintf(oldname, sizeof(oldname), "%s.old", name);
 989                 rename(name, oldname);
 990                 if (rename(tmpname, name))
 991                         return 1;
 992         }
 993
 994         conf_message("configuration written to %s", name);
 995
 996         conf_set_changed(false);
 997
 998         return 0;
 999 }
1000
1001 /* write a dependency file as used by kbuild to track dependencies */
1002 static int conf_write_autoconf_cmd(const char *autoconf_name)
1003 {
1004         char name[PATH_MAX], tmp[PATH_MAX];
1005         struct file *file;
1006         FILE *out;
1007         int ret;
1008
1009         ret = snprintf(name, sizeof(name), "%s.cmd", autoconf_name);
1010         if (ret >= sizeof(name)) /* check truncation */
1011                 return -1;
1012
1013         if (make_parent_dir(name))
1014                 return -1;
1015
1016         ret = snprintf(tmp, sizeof(tmp), "%s.cmd.tmp", autoconf_name);
1017         if (ret >= sizeof(tmp)) /* check truncation */
1018                 return -1;
1019
1020         out = fopen(tmp, "w");
1021         if (!out) {
1022                 perror("fopen");
1023                 return -1;
1024         }
1025
1026         fprintf(out, "deps_config := \\\n");
1027         for (file = file_list; file; file = file->next)
1028                 fprintf(out, "\t%s \\\n", file->name);
1029
1030         fprintf(out, "\n%s: $(deps_config)\n\n", autoconf_name);
1031
1032         env_write_dep(out, autoconf_name);
1033
1034         fprintf(out, "\n$(deps_config): ;\n");
1035
1036         fflush(out);
1037         ret = ferror(out); /* error check for all fprintf() calls */
1038         fclose(out);
1039         if (ret)
1040                 return -1;
1041
1042         if (rename(tmp, name)) {
1043                 perror("rename");
1044                 return -1;
1045         }
1046
1047         return 0;
1048 }
1049
1050 static int conf_touch_deps(void)
1051 {
1052         const char *name, *tmp;
1053         struct symbol *sym;
1054         int res, i;
1055
1056         name = conf_get_autoconfig_name();
1057         tmp = strrchr(name, '/');
1058         depfile_prefix_len = tmp ? tmp - name + 1 : 0;
1059         if (depfile_prefix_len + 1 > sizeof(depfile_path))
1060                 return -1;
1061
1062         strncpy(depfile_path, name, depfile_prefix_len);
1063         depfile_path[depfile_prefix_len] = 0;
1064
1065         conf_read_simple(name, S_DEF_AUTO);
1066         sym_calc_value(modules_sym);
1067
1068         for_all_symbols(i, sym) {
1069                 sym_calc_value(sym);
1070                 if ((sym->flags & SYMBOL_NO_WRITE) || !sym->name)
1071                         continue;
1072                 if (sym->flags & SYMBOL_WRITE) {
1073                         if (sym->flags & SYMBOL_DEF_AUTO) {
1074                                 /*
1075                                  * symbol has old and new value,
1076                                  * so compare them...
1077                                  */
1078                                 switch (sym->type) {
1079                                 case S_BOOLEAN:
1080                                 case S_TRISTATE:
1081                                         if (sym_get_tristate_value(sym) ==
1082                                             sym->def[S_DEF_AUTO].tri)
1083                                                 continue;
1084                                         break;
1085                                 case S_STRING:
1086                                 case S_HEX:
1087                                 case S_INT:
1088                                         if (!strcmp(sym_get_string_value(sym),
1089                                                     sym->def[S_DEF_AUTO].val))
1090                                                 continue;
1091                                         break;
1092                                 default:
1093                                         break;
1094                                 }
1095                         } else {
1096                                 /*
1097                                  * If there is no old value, only 'no' (unset)
1098                                  * is allowed as new value.
1099                                  */
1100                                 switch (sym->type) {
1101                                 case S_BOOLEAN:
1102                                 case S_TRISTATE:
1103                                         if (sym_get_tristate_value(sym) == no)
1104                                                 continue;
1105                                         break;
1106                                 default:
1107                                         break;
1108                                 }
1109                         }
1110                 } else if (!(sym->flags & SYMBOL_DEF_AUTO))
1111                         /* There is neither an old nor a new value. */
1112                         continue;
1113                 /* else
1114                  *      There is an old value, but no new value ('no' (unset)
1115                  *      isn't saved in auto.conf, so the old value is always
1116                  *      different from 'no').
1117                  */
1118
1119                 res = conf_touch_dep(sym->name);
1120                 if (res)
1121                         return res;
1122         }
1123
1124         return 0;
1125 }
1126
1127 static int __conf_write_autoconf(const char *filename,
1128                                  void (*print_symbol)(FILE *, struct symbol *),
1129                                  const struct comment_style *comment_style)
1130 {
1131         char tmp[PATH_MAX];
1132         FILE *file;
1133         struct symbol *sym;
1134         int ret, i;
1135
1136         if (make_parent_dir(filename))
1137                 return -1;
1138
1139         ret = snprintf(tmp, sizeof(tmp), "%s.tmp", filename);
1140         if (ret >= sizeof(tmp)) /* check truncation */
1141                 return -1;
1142
1143         file = fopen(tmp, "w");
1144         if (!file) {
1145                 perror("fopen");
1146                 return -1;
1147         }
1148
1149         conf_write_heading(file, comment_style);
1150
1151         for_all_symbols(i, sym)
1152                 if ((sym->flags & SYMBOL_WRITE) && sym->name)
1153                         print_symbol(file, sym);
1154
1155         fflush(file);
1156         /* check possible errors in conf_write_heading() and print_symbol() */
1157         ret = ferror(file);
1158         fclose(file);
1159         if (ret)
1160                 return -1;
1161
1162         if (rename(tmp, filename)) {
1163                 perror("rename");
1164                 return -1;
1165         }
1166
1167         return 0;
1168 }
1169
1170 int conf_write_autoconf(int overwrite)
1171 {
1172         struct symbol *sym;
1173         const char *autoconf_name = conf_get_autoconfig_name();
1174         int ret, i;
1175
1176         if (!overwrite && is_present(autoconf_name))
1177                 return 0;
1178
1179         ret = conf_write_autoconf_cmd(autoconf_name);
1180         if (ret)
1181                 return -1;
1182
1183         if (conf_touch_deps())
1184                 return 1;
1185
1186         for_all_symbols(i, sym)
1187                 sym_calc_value(sym);
1188
1189         ret = __conf_write_autoconf(conf_get_autoheader_name(),
1190                                     print_symbol_for_c,
1191                                     &comment_style_c);
1192         if (ret)
1193                 return ret;
1194
1195         ret = __conf_write_autoconf(conf_get_rustccfg_name(),
1196                                     print_symbol_for_rustccfg,
1197                                     NULL);
1198         if (ret)
1199                 return ret;
1200
1201         /*
1202          * Create include/config/auto.conf. This must be the last step because
1203          * Kbuild has a dependency on auto.conf and this marks the successful
1204          * completion of the previous steps.
1205          */
1206         ret = __conf_write_autoconf(conf_get_autoconfig_name(),
1207                                     print_symbol_for_autoconf,
1208                                     &comment_style_pound);
1209         if (ret)
1210                 return ret;
1211
1212         return 0;
1213 }
1214
1215 static bool conf_changed;
1216 static void (*conf_changed_callback)(void);
1217
1218 void conf_set_changed(bool val)
1219 {
1220         bool changed = conf_changed != val;
1221
1222         conf_changed = val;
1223
1224         if (conf_changed_callback && changed)
1225                 conf_changed_callback();
1226 }
1227
1228 bool conf_get_changed(void)
1229 {
1230         return conf_changed;
1231 }
1232
1233 void conf_set_changed_callback(void (*fn)(void))
1234 {
1235         conf_changed_callback = fn;
1236 }
1237
1238 void set_all_choice_values(struct symbol *csym)
1239 {
1240         struct property *prop;
1241         struct symbol *sym;
1242         struct expr *e;
1243
1244         prop = sym_get_choice_prop(csym);
1245
1246         /*
1247          * Set all non-assinged choice values to no
1248          */
1249         expr_list_for_each_sym(prop->expr, e, sym) {
1250                 if (!sym_has_value(sym))
1251                         sym->def[S_DEF_USER].tri = no;
1252         }
1253         csym->flags |= SYMBOL_DEF_USER;
1254         /* clear VALID to get value calculated */
1255         csym->flags &= ~(SYMBOL_VALID | SYMBOL_NEED_SET_CHOICE_VALUES);
1256 }