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