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         char *nline;
 293         size_t new_size = slen + 1;
 294         if (new_size > *n) {
 295                 new_size += LINE_GROWTH - 1;
 296                 new_size *= 2;
 297                 nline = xrealloc(*lineptr, new_size);
 298                 if (!nline)
 299                         return -1;
 300
 301                 *lineptr = nline;
 302                 *n = new_size;
 303         }
 304
 305         (*lineptr)[slen] = c;
 306
 307         return 0;
 308 }
 309
 310 static ssize_t compat_getline(char **lineptr, size_t *n, FILE *stream)
 311 {
 312         char *line = *lineptr;
 313         size_t slen = 0;
 314
 315         for (;;) {
 316                 int c = getc(stream);
 317
 318                 switch (c) {
 319                 case '\n':
 320                         if (add_byte(c, &line, slen, n) < 0)
 321                                 goto e_out;
 322                         slen++;
 323                         /* fall through */
 324                 case EOF:
 325                         if (add_byte('\0', &line, slen, n) < 0)
 326                                 goto e_out;
 327                         *lineptr = line;
 328                         if (slen == 0)
 329                                 return -1;
 330                         return slen;
 331                 default:
 332                         if (add_byte(c, &line, slen, n) < 0)
 333                                 goto e_out;
 334                         slen++;
 335                 }
 336         }
 337
 338 e_out:
 339         line[slen-1] = '\0';
 340         *lineptr = line;
 341         return -1;
 342 }
 343
 344 int conf_read_simple(const char *name, int def)
 345 {
 346         FILE *in = NULL;
 347         char   *line = NULL;
 348         size_t  line_asize = 0;
 349         char *p, *p2;
 350         struct symbol *sym;
 351         int i, def_flags;
 352         const char *warn_unknown;
 353         const char *werror;
 354
 355         warn_unknown = getenv("KCONFIG_WARN_UNKNOWN_SYMBOLS");
 356         werror = getenv("KCONFIG_WERROR");
 357         if (name) {
 358                 in = zconf_fopen(name);
 359         } else {
 360                 char *env;
 361
 362                 name = conf_get_configname();
 363                 in = zconf_fopen(name);
 364                 if (in)
 365                         goto load;
 366                 conf_set_changed(true);
 367
 368                 env = getenv("KCONFIG_DEFCONFIG_LIST");
 369                 if (!env)
 370                         return 1;
 371
 372                 while (1) {
 373                         bool is_last;
 374
 375                         while (isspace(*env))
 376                                 env++;
 377
 378                         if (!*env)
 379                                 break;
 380
 381                         p = env;
 382                         while (*p && !isspace(*p))
 383                                 p++;
 384
 385                         is_last = (*p == '\0');
 386
 387                         *p = '\0';
 388
 389                         in = zconf_fopen(env);
 390                         if (in) {
 391                                 conf_message("using defaults found in %s",
 392                                              env);
 393                                 goto load;
 394                         }
 395
 396                         if (is_last)
 397                                 break;
 398
 399                         env = p + 1;
 400                 }
 401         }
 402         if (!in)
 403                 return 1;
 404
 405 load:
 406         conf_filename = name;
 407         conf_lineno = 0;
 408         conf_warnings = 0;
 409
 410         def_flags = SYMBOL_DEF << def;
 411         for_all_symbols(i, sym) {
 412                 sym->flags |= SYMBOL_CHANGED;
 413                 sym->flags &= ~(def_flags|SYMBOL_VALID);
 414                 if (sym_is_choice(sym))
 415                         sym->flags |= def_flags;
 416                 switch (sym->type) {
 417                 case S_INT:
 418                 case S_HEX:
 419                 case S_STRING:
 420                         if (sym->def[def].val)
 421                                 free(sym->def[def].val);
 422                         /* fall through */
 423                 default:
 424                         sym->def[def].val = NULL;
 425                         sym->def[def].tri = no;
 426                 }
 427         }
 428
 429         while (compat_getline(&line, &line_asize, in) != -1) {
 430                 conf_lineno++;
 431                 sym = NULL;
 432                 if (line[0] == '#') {
 433                         if (memcmp(line + 2, CONFIG_, strlen(CONFIG_)))
 434                                 continue;
 435                         p = strchr(line + 2 + strlen(CONFIG_), ' ');
 436                         if (!p)
 437                                 continue;
 438                         *p++ = 0;
 439                         if (strncmp(p, "is not set", 10))
 440                                 continue;
 441                         if (def == S_DEF_USER) {
 442                                 sym = sym_find(line + 2 + strlen(CONFIG_));
 443                                 if (!sym) {
 444                                         if (warn_unknown)
 445                                                 conf_warning("unknown symbol: %s",
 446                                                              line + 2 + strlen(CONFIG_));
 447
 448                                         conf_set_changed(true);
 449                                         continue;
 450                                 }
 451                         } else {
 452                                 sym = sym_lookup(line + 2 + strlen(CONFIG_), 0);
 453                                 if (sym->type == S_UNKNOWN)
 454                                         sym->type = S_BOOLEAN;
 455                         }
 456                         if (sym->flags & def_flags) {
 457                                 conf_warning("override: reassigning to symbol %s", sym->name);
 458                         }
 459                         switch (sym->type) {
 460                         case S_BOOLEAN:
 461                         case S_TRISTATE:
 462                                 sym->def[def].tri = no;
 463                                 sym->flags |= def_flags;
 464                                 break;
 465                         default:
 466                                 ;
 467                         }
 468                 } else if (memcmp(line, CONFIG_, strlen(CONFIG_)) == 0) {
 469                         p = strchr(line + strlen(CONFIG_), '=');
 470                         if (!p)
 471                                 continue;
 472                         *p++ = 0;
 473                         p2 = strchr(p, '\n');
 474                         if (p2) {
 475                                 *p2-- = 0;
 476                                 if (*p2 == '\r')
 477                                         *p2 = 0;
 478                         }
 479
 480                         sym = sym_find(line + strlen(CONFIG_));
 481                         if (!sym) {
 482                                 if (def == S_DEF_AUTO) {
 483                                         /*
 484                                          * Reading from include/config/auto.conf
 485                                          * If CONFIG_FOO previously existed in
 486                                          * auto.conf but it is missing now,
 487                                          * include/config/FOO must be touched.
 488                                          */
 489                                         conf_touch_dep(line + strlen(CONFIG_));
 490                                 } else {
 491                                         if (warn_unknown)
 492                                                 conf_warning("unknown symbol: %s",
 493                                                              line + strlen(CONFIG_));
 494
 495                                         conf_set_changed(true);
 496                                 }
 497                                 continue;
 498                         }
 499
 500                         if (sym->flags & def_flags) {
 501                                 conf_warning("override: reassigning to symbol %s", sym->name);
 502                         }
 503                         if (conf_set_sym_val(sym, def, def_flags, p))
 504                                 continue;
 505                 } else {
 506                         if (line[0] != '\r' && line[0] != '\n')
 507                                 conf_warning("unexpected data: %.*s",
 508                                              (int)strcspn(line, "\r\n"), line);
 509
 510                         continue;
 511                 }
 512
 513                 if (sym && sym_is_choice_value(sym)) {
 514                         struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 515                         switch (sym->def[def].tri) {
 516                         case no:
 517                                 break;
 518                         case mod:
 519                                 if (cs->def[def].tri == yes) {
 520                                         conf_warning("%s creates inconsistent choice state", sym->name);
 521                                         cs->flags &= ~def_flags;
 522                                 }
 523                                 break;
 524                         case yes:
 525                                 if (cs->def[def].tri != no)
 526                                         conf_warning("override: %s changes choice state", sym->name);
 527                                 cs->def[def].val = sym;
 528                                 break;
 529                         }
 530                         cs->def[def].tri = EXPR_OR(cs->def[def].tri, sym->def[def].tri);
 531                 }
 532         }
 533         free(line);
 534         fclose(in);
 535
 536         if (conf_warnings && werror)
 537                 exit(1);
 538
 539         return 0;
 540 }
 541
 542 int conf_read(const char *name)
 543 {
 544         struct symbol *sym;
 545         int conf_unsaved = 0;
 546         int i;
 547
 548         conf_set_changed(false);
 549
 550         if (conf_read_simple(name, S_DEF_USER)) {
 551                 sym_calc_value(modules_sym);
 552                 return 1;
 553         }
 554
 555         sym_calc_value(modules_sym);
 556
 557         for_all_symbols(i, sym) {
 558                 sym_calc_value(sym);
 559                 if (sym_is_choice(sym) || (sym->flags & SYMBOL_NO_WRITE))
 560                         continue;
 561                 if (sym_has_value(sym) && (sym->flags & SYMBOL_WRITE)) {
 562                         /* check that calculated value agrees with saved value */
 563                         switch (sym->type) {
 564                         case S_BOOLEAN:
 565                         case S_TRISTATE:
 566                                 if (sym->def[S_DEF_USER].tri == sym_get_tristate_value(sym))
 567                                         continue;
 568                                 break;
 569                         default:
 570                                 if (!strcmp(sym->curr.val, sym->def[S_DEF_USER].val))
 571                                         continue;
 572                                 break;
 573                         }
 574                 } else if (!sym_has_value(sym) && !(sym->flags & SYMBOL_WRITE))
 575                         /* no previous value and not saved */
 576                         continue;
 577                 conf_unsaved++;
 578                 /* maybe print value in verbose mode... */
 579         }
 580
 581         for_all_symbols(i, sym) {
 582                 if (sym_has_value(sym) && !sym_is_choice_value(sym)) {
 583                         /* Reset values of generates values, so they'll appear
 584                          * as new, if they should become visible, but that
 585                          * doesn't quite work if the Kconfig and the saved
 586                          * configuration disagree.
 587                          */
 588                         if (sym->visible == no && !conf_unsaved)
 589                                 sym->flags &= ~SYMBOL_DEF_USER;
 590                         switch (sym->type) {
 591                         case S_STRING:
 592                         case S_INT:
 593                         case S_HEX:
 594                                 /* Reset a string value if it's out of range */
 595                                 if (sym_string_within_range(sym, sym->def[S_DEF_USER].val))
 596                                         break;
 597                                 sym->flags &= ~(SYMBOL_VALID|SYMBOL_DEF_USER);
 598                                 conf_unsaved++;
 599                                 break;
 600                         default:
 601                                 break;
 602                         }
 603                 }
 604         }
 605
 606         if (conf_warnings || conf_unsaved)
 607                 conf_set_changed(true);
 608
 609         return 0;
 610 }
 611
 612 struct comment_style {
 613         const char *decoration;
 614         const char *prefix;
 615         const char *postfix;
 616 };
 617
 618 static const struct comment_style comment_style_pound = {
 619         .decoration = "#",
 620         .prefix = "#",
 621         .postfix = "#",
 622 };
 623
 624 static const struct comment_style comment_style_c = {
 625         .decoration = " *",
 626         .prefix = "/*",
 627         .postfix = " */",
 628 };
 629
 630 static void conf_write_heading(FILE *fp, const struct comment_style *cs)
 631 {
 632         if (!cs)
 633                 return;
 634
 635         fprintf(fp, "%s\n", cs->prefix);
 636
 637         fprintf(fp, "%s Automatically generated file; DO NOT EDIT.\n",
 638                 cs->decoration);
 639
 640         fprintf(fp, "%s %s\n", cs->decoration, rootmenu.prompt->text);
 641
 642         fprintf(fp, "%s\n", cs->postfix);
 643 }
 644
 645 /* The returned pointer must be freed on the caller side */
 646 static char *escape_string_value(const char *in)
 647 {
 648         const char *p;
 649         char *out;
 650         size_t len;
 651
 652         len = strlen(in) + strlen("\"\"") + 1;
 653
 654         p = in;
 655         while (1) {
 656                 p += strcspn(p, "\"\\");
 657
 658                 if (p[0] == '\0')
 659                         break;
 660
 661                 len++;
 662                 p++;
 663         }
 664
 665         out = xmalloc(len);
 666         out[0] = '\0';
 667
 668         strcat(out, "\"");
 669
 670         p = in;
 671         while (1) {
 672                 len = strcspn(p, "\"\\");
 673                 strncat(out, p, len);
 674                 p += len;
 675
 676                 if (p[0] == '\0')
 677                         break;
 678
 679                 strcat(out, "\\");
 680                 strncat(out, p++, 1);
 681         }
 682
 683         strcat(out, "\"");
 684
 685         return out;
 686 }
 687
 688 enum output_n { OUTPUT_N, OUTPUT_N_AS_UNSET, OUTPUT_N_NONE };
 689
 690 static void __print_symbol(FILE *fp, struct symbol *sym, enum output_n output_n,
 691                            bool escape_string)
 692 {
 693         const char *val;
 694         char *escaped = NULL;
 695
 696         if (sym->type == S_UNKNOWN)
 697                 return;
 698
 699         val = sym_get_string_value(sym);
 700
 701         if ((sym->type == S_BOOLEAN || sym->type == S_TRISTATE) &&
 702             output_n != OUTPUT_N && *val == 'n') {
 703                 if (output_n == OUTPUT_N_AS_UNSET)
 704                         fprintf(fp, "# %s%s is not set\n", CONFIG_, sym->name);
 705                 return;
 706         }
 707
 708         if (sym->type == S_STRING && escape_string) {
 709                 escaped = escape_string_value(val);
 710                 val = escaped;
 711         }
 712
 713         fprintf(fp, "%s%s=%s\n", CONFIG_, sym->name, val);
 714
 715         free(escaped);
 716 }
 717
 718 static void print_symbol_for_dotconfig(FILE *fp, struct symbol *sym)
 719 {
 720         __print_symbol(fp, sym, OUTPUT_N_AS_UNSET, true);
 721 }
 722
 723 static void print_symbol_for_autoconf(FILE *fp, struct symbol *sym)
 724 {
 725         __print_symbol(fp, sym, OUTPUT_N_NONE, false);
 726 }
 727
 728 void print_symbol_for_listconfig(struct symbol *sym)
 729 {
 730         __print_symbol(stdout, sym, OUTPUT_N, true);
 731 }
 732
 733 static void print_symbol_for_c(FILE *fp, struct symbol *sym)
 734 {
 735         const char *val;
 736         const char *sym_suffix = "";
 737         const char *val_prefix = "";
 738         char *escaped = NULL;
 739
 740         if (sym->type == S_UNKNOWN)
 741                 return;
 742
 743         val = sym_get_string_value(sym);
 744
 745         switch (sym->type) {
 746         case S_BOOLEAN:
 747         case S_TRISTATE:
 748                 switch (*val) {
 749                 case 'n':
 750                         return;
 751                 case 'm':
 752                         sym_suffix = "_MODULE";
 753                         /* fall through */
 754                 default:
 755                         val = "1";
 756                 }
 757                 break;
 758         case S_HEX:
 759                 if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
 760                         val_prefix = "0x";
 761                 break;
 762         case S_STRING:
 763                 escaped = escape_string_value(val);
 764                 val = escaped;
 765         default:
 766                 break;
 767         }
 768
 769         fprintf(fp, "#define %s%s%s %s%s\n", CONFIG_, sym->name, sym_suffix,
 770                 val_prefix, val);
 771
 772         free(escaped);
 773 }
 774
 775 static void print_symbol_for_rustccfg(FILE *fp, struct symbol *sym)
 776 {
 777         const char *val;
 778         const char *val_prefix = "";
 779         char *val_prefixed = NULL;
 780         size_t val_prefixed_len;
 781         char *escaped = NULL;
 782
 783         if (sym->type == S_UNKNOWN)
 784                 return;
 785
 786         val = sym_get_string_value(sym);
 787
 788         switch (sym->type) {
 789         case S_BOOLEAN:
 790         case S_TRISTATE:
 791                 /*
 792                  * We do not care about disabled ones, i.e. no need for
 793                  * what otherwise are "comments" in other printers.
 794                  */
 795                 if (*val == 'n')
 796                         return;
 797
 798                 /*
 799                  * To have similar functionality to the C macro `IS_ENABLED()`
 800                  * we provide an empty `--cfg CONFIG_X` here in both `y`
 801                  * and `m` cases.
 802                  *
 803                  * Then, the common `fprintf()` below will also give us
 804                  * a `--cfg CONFIG_X="y"` or `--cfg CONFIG_X="m"`, which can
 805                  * be used as the equivalent of `IS_BUILTIN()`/`IS_MODULE()`.
 806                  */
 807                 fprintf(fp, "--cfg=%s%s\n", CONFIG_, sym->name);
 808                 break;
 809         case S_HEX:
 810                 if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
 811                         val_prefix = "0x";
 812                 break;
 813         default:
 814                 break;
 815         }
 816
 817         if (strlen(val_prefix) > 0) {
 818                 val_prefixed_len = strlen(val) + strlen(val_prefix) + 1;
 819                 val_prefixed = xmalloc(val_prefixed_len);
 820                 snprintf(val_prefixed, val_prefixed_len, "%s%s", val_prefix, val);
 821                 val = val_prefixed;
 822         }
 823
 824         /* All values get escaped: the `--cfg` option only takes strings */
 825         escaped = escape_string_value(val);
 826         val = escaped;
 827
 828         fprintf(fp, "--cfg=%s%s=%s\n", CONFIG_, sym->name, val);
 829
 830         free(escaped);
 831         free(val_prefixed);
 832 }
 833
 834 /*
 835  * Write out a minimal config.
 836  * All values that has default values are skipped as this is redundant.
 837  */
 838 int conf_write_defconfig(const char *filename)
 839 {
 840         struct symbol *sym;
 841         struct menu *menu;
 842         FILE *out;
 843
 844         out = fopen(filename, "w");
 845         if (!out)
 846                 return 1;
 847
 848         sym_clear_all_valid();
 849
 850         /* Traverse all menus to find all relevant symbols */
 851         menu = rootmenu.list;
 852
 853         while (menu != NULL)
 854         {
 855                 sym = menu->sym;
 856                 if (sym == NULL) {
 857                         if (!menu_is_visible(menu))
 858                                 goto next_menu;
 859                 } else if (!sym_is_choice(sym)) {
 860                         sym_calc_value(sym);
 861                         if (!(sym->flags & SYMBOL_WRITE))
 862                                 goto next_menu;
 863                         sym->flags &= ~SYMBOL_WRITE;
 864                         /* If we cannot change the symbol - skip */
 865                         if (!sym_is_changeable(sym))
 866                                 goto next_menu;
 867                         /* If symbol equals to default value - skip */
 868                         if (strcmp(sym_get_string_value(sym), sym_get_string_default(sym)) == 0)
 869                                 goto next_menu;
 870
 871                         /*
 872                          * If symbol is a choice value and equals to the
 873                          * default for a choice - skip.
 874                          * But only if value is bool and equal to "y" and
 875                          * choice is not "optional".
 876                          * (If choice is "optional" then all values can be "n")
 877                          */
 878                         if (sym_is_choice_value(sym)) {
 879                                 struct symbol *cs;
 880                                 struct symbol *ds;
 881
 882                                 cs = prop_get_symbol(sym_get_choice_prop(sym));
 883                                 ds = sym_choice_default(cs);
 884                                 if (!sym_is_optional(cs) && sym == ds) {
 885                                         if ((sym->type == S_BOOLEAN) &&
 886                                             sym_get_tristate_value(sym) == yes)
 887                                                 goto next_menu;
 888                                 }
 889                         }
 890                         print_symbol_for_dotconfig(out, sym);
 891                 }
 892 next_menu:
 893                 if (menu->list != NULL) {
 894                         menu = menu->list;
 895                 }
 896                 else if (menu->next != NULL) {
 897                         menu = menu->next;
 898                 } else {
 899                         while ((menu = menu->parent)) {
 900                                 if (menu->next != NULL) {
 901                                         menu = menu->next;
 902                                         break;
 903                                 }
 904                         }
 905                 }
 906         }
 907         fclose(out);
 908         return 0;
 909 }
 910
 911 int conf_write(const char *name)
 912 {
 913         FILE *out;
 914         struct symbol *sym;
 915         struct menu *menu;
 916         const char *str;
 917         char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1];
 918         char *env;
 919         int i;
 920         bool need_newline = false;
 921
 922         if (!name)
 923                 name = conf_get_configname();
 924
 925         if (!*name) {
 926                 fprintf(stderr, "config name is empty\n");
 927                 return -1;
 928         }
 929
 930         if (is_dir(name)) {
 931                 fprintf(stderr, "%s: Is a directory\n", name);
 932                 return -1;
 933         }
 934
 935         if (make_parent_dir(name))
 936                 return -1;
 937
 938         env = getenv("KCONFIG_OVERWRITECONFIG");
 939         if (env && *env) {
 940                 *tmpname = 0;
 941                 out = fopen(name, "w");
 942         } else {
 943                 snprintf(tmpname, sizeof(tmpname), "%s.%d.tmp",
 944                          name, (int)getpid());
 945                 out = fopen(tmpname, "w");
 946         }
 947         if (!out)
 948                 return 1;
 949
 950         conf_write_heading(out, &comment_style_pound);
 951
 952         if (!conf_get_changed())
 953                 sym_clear_all_valid();
 954
 955         menu = rootmenu.list;
 956         while (menu) {
 957                 sym = menu->sym;
 958                 if (!sym) {
 959                         if (!menu_is_visible(menu))
 960                                 goto next;
 961                         str = menu_get_prompt(menu);
 962                         fprintf(out, "\n"
 963                                      "#\n"
 964                                      "# %s\n"
 965                                      "#\n", str);
 966                         need_newline = false;
 967                 } else if (!(sym->flags & SYMBOL_CHOICE) &&
 968                            !(sym->flags & SYMBOL_WRITTEN)) {
 969                         sym_calc_value(sym);
 970                         if (!(sym->flags & SYMBOL_WRITE))
 971                                 goto next;
 972                         if (need_newline) {
 973                                 fprintf(out, "\n");
 974                                 need_newline = false;
 975                         }
 976                         sym->flags |= SYMBOL_WRITTEN;
 977                         print_symbol_for_dotconfig(out, sym);
 978                 }
 979
 980 next:
 981                 if (menu->list) {
 982                         menu = menu->list;
 983                         continue;
 984                 }
 985
 986 end_check:
 987                 if (!menu->sym && menu_is_visible(menu) && menu != &rootmenu &&
 988                     menu->prompt->type == P_MENU) {
 989                         fprintf(out, "# end of %s\n", menu_get_prompt(menu));
 990                         need_newline = true;
 991                 }
 992
 993                 if (menu->next) {
 994                         menu = menu->next;
 995                 } else {
 996                         menu = menu->parent;
 997                         if (menu)
 998                                 goto end_check;
 999                 }
1000         }
1001         fclose(out);
1002
1003         for_all_symbols(i, sym)
1004                 sym->flags &= ~SYMBOL_WRITTEN;
1005
1006         if (*tmpname) {
1007                 if (is_same(name, tmpname)) {
1008                         conf_message("No change to %s", name);
1009                         unlink(tmpname);
1010                         conf_set_changed(false);
1011                         return 0;
1012                 }
1013
1014                 snprintf(oldname, sizeof(oldname), "%s.old", name);
1015                 rename(name, oldname);
1016                 if (rename(tmpname, name))
1017                         return 1;
1018         }
1019
1020         conf_message("configuration written to %s", name);
1021
1022         conf_set_changed(false);
1023
1024         return 0;
1025 }
1026
1027 /* write a dependency file as used by kbuild to track dependencies */
1028 static int conf_write_autoconf_cmd(const char *autoconf_name)
1029 {
1030         char name[PATH_MAX], tmp[PATH_MAX];
1031         struct file *file;
1032         FILE *out;
1033         int ret;
1034
1035         ret = snprintf(name, sizeof(name), "%s.cmd", autoconf_name);
1036         if (ret >= sizeof(name)) /* check truncation */
1037                 return -1;
1038
1039         if (make_parent_dir(name))
1040                 return -1;
1041
1042         ret = snprintf(tmp, sizeof(tmp), "%s.cmd.tmp", autoconf_name);
1043         if (ret >= sizeof(tmp)) /* check truncation */
1044                 return -1;
1045
1046         out = fopen(tmp, "w");
1047         if (!out) {
1048                 perror("fopen");
1049                 return -1;
1050         }
1051
1052         fprintf(out, "deps_config := \\\n");
1053         for (file = file_list; file; file = file->next)
1054                 fprintf(out, "\t%s \\\n", file->name);
1055
1056         fprintf(out, "\n%s: $(deps_config)\n\n", autoconf_name);
1057
1058         env_write_dep(out, autoconf_name);
1059
1060         fprintf(out, "\n$(deps_config): ;\n");
1061
1062         fflush(out);
1063         ret = ferror(out); /* error check for all fprintf() calls */
1064         fclose(out);
1065         if (ret)
1066                 return -1;
1067
1068         if (rename(tmp, name)) {
1069                 perror("rename");
1070                 return -1;
1071         }
1072
1073         return 0;
1074 }
1075
1076 static int conf_touch_deps(void)
1077 {
1078         const char *name, *tmp;
1079         struct symbol *sym;
1080         int res, i;
1081
1082         name = conf_get_autoconfig_name();
1083         tmp = strrchr(name, '/');
1084         depfile_prefix_len = tmp ? tmp - name + 1 : 0;
1085         if (depfile_prefix_len + 1 > sizeof(depfile_path))
1086                 return -1;
1087
1088         strncpy(depfile_path, name, depfile_prefix_len);
1089         depfile_path[depfile_prefix_len] = 0;
1090
1091         conf_read_simple(name, S_DEF_AUTO);
1092         sym_calc_value(modules_sym);
1093
1094         for_all_symbols(i, sym) {
1095                 sym_calc_value(sym);
1096                 if ((sym->flags & SYMBOL_NO_WRITE) || !sym->name)
1097                         continue;
1098                 if (sym->flags & SYMBOL_WRITE) {
1099                         if (sym->flags & SYMBOL_DEF_AUTO) {
1100                                 /*
1101                                  * symbol has old and new value,
1102                                  * so compare them...
1103                                  */
1104                                 switch (sym->type) {
1105                                 case S_BOOLEAN:
1106                                 case S_TRISTATE:
1107                                         if (sym_get_tristate_value(sym) ==
1108                                             sym->def[S_DEF_AUTO].tri)
1109                                                 continue;
1110                                         break;
1111                                 case S_STRING:
1112                                 case S_HEX:
1113                                 case S_INT:
1114                                         if (!strcmp(sym_get_string_value(sym),
1115                                                     sym->def[S_DEF_AUTO].val))
1116                                                 continue;
1117                                         break;
1118                                 default:
1119                                         break;
1120                                 }
1121                         } else {
1122                                 /*
1123                                  * If there is no old value, only 'no' (unset)
1124                                  * is allowed as new value.
1125                                  */
1126                                 switch (sym->type) {
1127                                 case S_BOOLEAN:
1128                                 case S_TRISTATE:
1129                                         if (sym_get_tristate_value(sym) == no)
1130                                                 continue;
1131                                         break;
1132                                 default:
1133                                         break;
1134                                 }
1135                         }
1136                 } else if (!(sym->flags & SYMBOL_DEF_AUTO))
1137                         /* There is neither an old nor a new value. */
1138                         continue;
1139                 /* else
1140                  *      There is an old value, but no new value ('no' (unset)
1141                  *      isn't saved in auto.conf, so the old value is always
1142                  *      different from 'no').
1143                  */
1144
1145                 res = conf_touch_dep(sym->name);
1146                 if (res)
1147                         return res;
1148         }
1149
1150         return 0;
1151 }
1152
1153 static int __conf_write_autoconf(const char *filename,
1154                                  void (*print_symbol)(FILE *, struct symbol *),
1155                                  const struct comment_style *comment_style)
1156 {
1157         char tmp[PATH_MAX];
1158         FILE *file;
1159         struct symbol *sym;
1160         int ret, i;
1161
1162         if (make_parent_dir(filename))
1163                 return -1;
1164
1165         ret = snprintf(tmp, sizeof(tmp), "%s.tmp", filename);
1166         if (ret >= sizeof(tmp)) /* check truncation */
1167                 return -1;
1168
1169         file = fopen(tmp, "w");
1170         if (!file) {
1171                 perror("fopen");
1172                 return -1;
1173         }
1174
1175         conf_write_heading(file, comment_style);
1176
1177         for_all_symbols(i, sym)
1178                 if ((sym->flags & SYMBOL_WRITE) && sym->name)
1179                         print_symbol(file, sym);
1180
1181         fflush(file);
1182         /* check possible errors in conf_write_heading() and print_symbol() */
1183         ret = ferror(file);
1184         fclose(file);
1185         if (ret)
1186                 return -1;
1187
1188         if (rename(tmp, filename)) {
1189                 perror("rename");
1190                 return -1;
1191         }
1192
1193         return 0;
1194 }
1195
1196 int conf_write_autoconf(int overwrite)
1197 {
1198         struct symbol *sym;
1199         const char *autoconf_name = conf_get_autoconfig_name();
1200         int ret, i;
1201
1202         if (!overwrite && is_present(autoconf_name))
1203                 return 0;
1204
1205         ret = conf_write_autoconf_cmd(autoconf_name);
1206         if (ret)
1207                 return -1;
1208
1209         if (conf_touch_deps())
1210                 return 1;
1211
1212         for_all_symbols(i, sym)
1213                 sym_calc_value(sym);
1214
1215         ret = __conf_write_autoconf(conf_get_autoheader_name(),
1216                                     print_symbol_for_c,
1217                                     &comment_style_c);
1218         if (ret)
1219                 return ret;
1220
1221         ret = __conf_write_autoconf(conf_get_rustccfg_name(),
1222                                     print_symbol_for_rustccfg,
1223                                     NULL);
1224         if (ret)
1225                 return ret;
1226
1227         /*
1228          * Create include/config/auto.conf. This must be the last step because
1229          * Kbuild has a dependency on auto.conf and this marks the successful
1230          * completion of the previous steps.
1231          */
1232         ret = __conf_write_autoconf(conf_get_autoconfig_name(),
1233                                     print_symbol_for_autoconf,
1234                                     &comment_style_pound);
1235         if (ret)
1236                 return ret;
1237
1238         return 0;
1239 }
1240
1241 static bool conf_changed;
1242 static void (*conf_changed_callback)(void);
1243
1244 void conf_set_changed(bool val)
1245 {
1246         bool changed = conf_changed != val;
1247
1248         conf_changed = val;
1249
1250         if (conf_changed_callback && changed)
1251                 conf_changed_callback();
1252 }
1253
1254 bool conf_get_changed(void)
1255 {
1256         return conf_changed;
1257 }
1258
1259 void conf_set_changed_callback(void (*fn)(void))
1260 {
1261         conf_changed_callback = fn;
1262 }
1263
1264 void set_all_choice_values(struct symbol *csym)
1265 {
1266         struct property *prop;
1267         struct symbol *sym;
1268         struct expr *e;
1269
1270         prop = sym_get_choice_prop(csym);
1271
1272         /*
1273          * Set all non-assinged choice values to no
1274          */
1275         expr_list_for_each_sym(prop->expr, e, sym) {
1276                 if (!sym_has_value(sym))
1277                         sym->def[S_DEF_USER].tri = no;
1278         }
1279         csym->flags |= SYMBOL_DEF_USER;
1280         /* clear VALID to get value calculated */
1281         csym->flags &= ~(SYMBOL_VALID | SYMBOL_NEED_SET_CHOICE_VALUES);
1282 }