xref: /linux/scripts/kconfig/confdata.c (revision eb01fe7abbe2d0b38824d2a93fdb4cc3eaf2ccc1)
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 bool conf_errors(void)
159 {
160 	if (conf_warnings)
161 		return getenv("KCONFIG_WERROR");
162 	return false;
163 }
164 
165 static void conf_warning(const char *fmt, ...)
166 {
167 	va_list ap;
168 	va_start(ap, fmt);
169 	fprintf(stderr, "%s:%d:warning: ", conf_filename, conf_lineno);
170 	vfprintf(stderr, fmt, ap);
171 	fprintf(stderr, "\n");
172 	va_end(ap);
173 	conf_warnings++;
174 }
175 
176 static void conf_default_message_callback(const char *s)
177 {
178 	printf("#\n# ");
179 	printf("%s", s);
180 	printf("\n#\n");
181 }
182 
183 static void (*conf_message_callback)(const char *s) =
184 	conf_default_message_callback;
185 void conf_set_message_callback(void (*fn)(const char *s))
186 {
187 	conf_message_callback = fn;
188 }
189 
190 static void conf_message(const char *fmt, ...)
191 {
192 	va_list ap;
193 	char buf[4096];
194 
195 	if (!conf_message_callback)
196 		return;
197 
198 	va_start(ap, fmt);
199 
200 	vsnprintf(buf, sizeof(buf), fmt, ap);
201 	conf_message_callback(buf);
202 	va_end(ap);
203 }
204 
205 const char *conf_get_configname(void)
206 {
207 	char *name = getenv("KCONFIG_CONFIG");
208 
209 	return name ? name : ".config";
210 }
211 
212 static const char *conf_get_autoconfig_name(void)
213 {
214 	char *name = getenv("KCONFIG_AUTOCONFIG");
215 
216 	return name ? name : "include/config/auto.conf";
217 }
218 
219 static const char *conf_get_autoheader_name(void)
220 {
221 	char *name = getenv("KCONFIG_AUTOHEADER");
222 
223 	return name ? name : "include/generated/autoconf.h";
224 }
225 
226 static const char *conf_get_rustccfg_name(void)
227 {
228 	char *name = getenv("KCONFIG_RUSTCCFG");
229 
230 	return name ? name : "include/generated/rustc_cfg";
231 }
232 
233 static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
234 {
235 	char *p2;
236 
237 	switch (sym->type) {
238 	case S_TRISTATE:
239 		if (p[0] == 'm') {
240 			sym->def[def].tri = mod;
241 			sym->flags |= def_flags;
242 			break;
243 		}
244 		/* fall through */
245 	case S_BOOLEAN:
246 		if (p[0] == 'y') {
247 			sym->def[def].tri = yes;
248 			sym->flags |= def_flags;
249 			break;
250 		}
251 		if (p[0] == 'n') {
252 			sym->def[def].tri = no;
253 			sym->flags |= def_flags;
254 			break;
255 		}
256 		if (def != S_DEF_AUTO)
257 			conf_warning("symbol value '%s' invalid for %s",
258 				     p, sym->name);
259 		return 1;
260 	case S_STRING:
261 		/* No escaping for S_DEF_AUTO (include/config/auto.conf) */
262 		if (def != S_DEF_AUTO) {
263 			if (*p++ != '"')
264 				break;
265 			for (p2 = p; (p2 = strpbrk(p2, "\"\\")); p2++) {
266 				if (*p2 == '"') {
267 					*p2 = 0;
268 					break;
269 				}
270 				memmove(p2, p2 + 1, strlen(p2));
271 			}
272 			if (!p2) {
273 				conf_warning("invalid string found");
274 				return 1;
275 			}
276 		}
277 		/* fall through */
278 	case S_INT:
279 	case S_HEX:
280 		if (sym_string_valid(sym, p)) {
281 			sym->def[def].val = xstrdup(p);
282 			sym->flags |= def_flags;
283 		} else {
284 			if (def != S_DEF_AUTO)
285 				conf_warning("symbol value '%s' invalid for %s",
286 					     p, sym->name);
287 			return 1;
288 		}
289 		break;
290 	default:
291 		;
292 	}
293 	return 0;
294 }
295 
296 #define LINE_GROWTH 16
297 static int add_byte(int c, char **lineptr, size_t slen, size_t *n)
298 {
299 	size_t new_size = slen + 1;
300 
301 	if (new_size > *n) {
302 		new_size += LINE_GROWTH - 1;
303 		new_size *= 2;
304 		*lineptr = xrealloc(*lineptr, new_size);
305 		*n = new_size;
306 	}
307 
308 	(*lineptr)[slen] = c;
309 
310 	return 0;
311 }
312 
313 static ssize_t compat_getline(char **lineptr, size_t *n, FILE *stream)
314 {
315 	char *line = *lineptr;
316 	size_t slen = 0;
317 
318 	for (;;) {
319 		int c = getc(stream);
320 
321 		switch (c) {
322 		case '\n':
323 			if (add_byte(c, &line, slen, n) < 0)
324 				goto e_out;
325 			slen++;
326 			/* fall through */
327 		case EOF:
328 			if (add_byte('\0', &line, slen, n) < 0)
329 				goto e_out;
330 			*lineptr = line;
331 			if (slen == 0)
332 				return -1;
333 			return slen;
334 		default:
335 			if (add_byte(c, &line, slen, n) < 0)
336 				goto e_out;
337 			slen++;
338 		}
339 	}
340 
341 e_out:
342 	line[slen-1] = '\0';
343 	*lineptr = line;
344 	return -1;
345 }
346 
347 /* like getline(), but the newline character is stripped away */
348 static ssize_t getline_stripped(char **lineptr, size_t *n, FILE *stream)
349 {
350 	ssize_t len;
351 
352 	len = compat_getline(lineptr, n, stream);
353 
354 	if (len > 0 && (*lineptr)[len - 1] == '\n') {
355 		len--;
356 		(*lineptr)[len] = '\0';
357 
358 		if (len > 0 && (*lineptr)[len - 1] == '\r') {
359 			len--;
360 			(*lineptr)[len] = '\0';
361 		}
362 	}
363 
364 	return len;
365 }
366 
367 int conf_read_simple(const char *name, int def)
368 {
369 	FILE *in = NULL;
370 	char   *line = NULL;
371 	size_t  line_asize = 0;
372 	char *p, *val;
373 	struct symbol *sym;
374 	int i, def_flags;
375 	const char *warn_unknown, *sym_name;
376 
377 	warn_unknown = getenv("KCONFIG_WARN_UNKNOWN_SYMBOLS");
378 	if (name) {
379 		in = zconf_fopen(name);
380 	} else {
381 		char *env;
382 
383 		name = conf_get_configname();
384 		in = zconf_fopen(name);
385 		if (in)
386 			goto load;
387 		conf_set_changed(true);
388 
389 		env = getenv("KCONFIG_DEFCONFIG_LIST");
390 		if (!env)
391 			return 1;
392 
393 		while (1) {
394 			bool is_last;
395 
396 			while (isspace(*env))
397 				env++;
398 
399 			if (!*env)
400 				break;
401 
402 			p = env;
403 			while (*p && !isspace(*p))
404 				p++;
405 
406 			is_last = (*p == '\0');
407 
408 			*p = '\0';
409 
410 			in = zconf_fopen(env);
411 			if (in) {
412 				conf_message("using defaults found in %s",
413 					     env);
414 				goto load;
415 			}
416 
417 			if (is_last)
418 				break;
419 
420 			env = p + 1;
421 		}
422 	}
423 	if (!in)
424 		return 1;
425 
426 load:
427 	conf_filename = name;
428 	conf_lineno = 0;
429 	conf_warnings = 0;
430 
431 	def_flags = SYMBOL_DEF << def;
432 	for_all_symbols(i, sym) {
433 		sym->flags |= SYMBOL_CHANGED;
434 		sym->flags &= ~(def_flags|SYMBOL_VALID);
435 		if (sym_is_choice(sym))
436 			sym->flags |= def_flags;
437 		switch (sym->type) {
438 		case S_INT:
439 		case S_HEX:
440 		case S_STRING:
441 			free(sym->def[def].val);
442 			/* fall through */
443 		default:
444 			sym->def[def].val = NULL;
445 			sym->def[def].tri = no;
446 		}
447 	}
448 
449 	while (getline_stripped(&line, &line_asize, in) != -1) {
450 		conf_lineno++;
451 
452 		if (!line[0]) /* blank line */
453 			continue;
454 
455 		if (line[0] == '#') {
456 			if (line[1] != ' ')
457 				continue;
458 			p = line + 2;
459 			if (memcmp(p, CONFIG_, strlen(CONFIG_)))
460 				continue;
461 			sym_name = p + strlen(CONFIG_);
462 			p = strchr(sym_name, ' ');
463 			if (!p)
464 				continue;
465 			*p++ = 0;
466 			if (strcmp(p, "is not set"))
467 				continue;
468 
469 			val = "n";
470 		} else {
471 			if (memcmp(line, CONFIG_, strlen(CONFIG_))) {
472 				conf_warning("unexpected data: %s", line);
473 				continue;
474 			}
475 
476 			sym_name = line + strlen(CONFIG_);
477 			p = strchr(sym_name, '=');
478 			if (!p) {
479 				conf_warning("unexpected data: %s", line);
480 				continue;
481 			}
482 			*p = 0;
483 			val = p + 1;
484 		}
485 
486 		sym = sym_find(sym_name);
487 		if (!sym) {
488 			if (def == S_DEF_AUTO) {
489 				/*
490 				 * Reading from include/config/auto.conf.
491 				 * If CONFIG_FOO previously existed in auto.conf
492 				 * but it is missing now, include/config/FOO
493 				 * must be touched.
494 				 */
495 				conf_touch_dep(sym_name);
496 			} else {
497 				if (warn_unknown)
498 					conf_warning("unknown symbol: %s", sym_name);
499 
500 				conf_set_changed(true);
501 			}
502 			continue;
503 		}
504 
505 		if (sym->flags & def_flags)
506 			conf_warning("override: reassigning to symbol %s", sym->name);
507 
508 		if (conf_set_sym_val(sym, def, def_flags, val))
509 			continue;
510 
511 		if (sym && sym_is_choice_value(sym)) {
512 			struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
513 			switch (sym->def[def].tri) {
514 			case no:
515 				break;
516 			case mod:
517 				if (cs->def[def].tri == yes) {
518 					conf_warning("%s creates inconsistent choice state", sym->name);
519 					cs->flags &= ~def_flags;
520 				}
521 				break;
522 			case yes:
523 				if (cs->def[def].tri != no)
524 					conf_warning("override: %s changes choice state", sym->name);
525 				cs->def[def].val = sym;
526 				break;
527 			}
528 			cs->def[def].tri = EXPR_OR(cs->def[def].tri, sym->def[def].tri);
529 		}
530 	}
531 	free(line);
532 	fclose(in);
533 
534 	return 0;
535 }
536 
537 int conf_read(const char *name)
538 {
539 	struct symbol *sym;
540 	int conf_unsaved = 0;
541 	int i;
542 
543 	conf_set_changed(false);
544 
545 	if (conf_read_simple(name, S_DEF_USER)) {
546 		sym_calc_value(modules_sym);
547 		return 1;
548 	}
549 
550 	sym_calc_value(modules_sym);
551 
552 	for_all_symbols(i, sym) {
553 		sym_calc_value(sym);
554 		if (sym_is_choice(sym) || (sym->flags & SYMBOL_NO_WRITE))
555 			continue;
556 		if (sym_has_value(sym) && (sym->flags & SYMBOL_WRITE)) {
557 			/* check that calculated value agrees with saved value */
558 			switch (sym->type) {
559 			case S_BOOLEAN:
560 			case S_TRISTATE:
561 				if (sym->def[S_DEF_USER].tri == sym_get_tristate_value(sym))
562 					continue;
563 				break;
564 			default:
565 				if (!strcmp(sym->curr.val, sym->def[S_DEF_USER].val))
566 					continue;
567 				break;
568 			}
569 		} else if (!sym_has_value(sym) && !(sym->flags & SYMBOL_WRITE))
570 			/* no previous value and not saved */
571 			continue;
572 		conf_unsaved++;
573 		/* maybe print value in verbose mode... */
574 	}
575 
576 	for_all_symbols(i, sym) {
577 		if (sym_has_value(sym) && !sym_is_choice_value(sym)) {
578 			/* Reset values of generates values, so they'll appear
579 			 * as new, if they should become visible, but that
580 			 * doesn't quite work if the Kconfig and the saved
581 			 * configuration disagree.
582 			 */
583 			if (sym->visible == no && !conf_unsaved)
584 				sym->flags &= ~SYMBOL_DEF_USER;
585 			switch (sym->type) {
586 			case S_STRING:
587 			case S_INT:
588 			case S_HEX:
589 				/* Reset a string value if it's out of range */
590 				if (sym_string_within_range(sym, sym->def[S_DEF_USER].val))
591 					break;
592 				sym->flags &= ~SYMBOL_VALID;
593 				conf_unsaved++;
594 				break;
595 			default:
596 				break;
597 			}
598 		}
599 	}
600 
601 	if (conf_warnings || conf_unsaved)
602 		conf_set_changed(true);
603 
604 	return 0;
605 }
606 
607 struct comment_style {
608 	const char *decoration;
609 	const char *prefix;
610 	const char *postfix;
611 };
612 
613 static const struct comment_style comment_style_pound = {
614 	.decoration = "#",
615 	.prefix = "#",
616 	.postfix = "#",
617 };
618 
619 static const struct comment_style comment_style_c = {
620 	.decoration = " *",
621 	.prefix = "/*",
622 	.postfix = " */",
623 };
624 
625 static void conf_write_heading(FILE *fp, const struct comment_style *cs)
626 {
627 	if (!cs)
628 		return;
629 
630 	fprintf(fp, "%s\n", cs->prefix);
631 
632 	fprintf(fp, "%s Automatically generated file; DO NOT EDIT.\n",
633 		cs->decoration);
634 
635 	fprintf(fp, "%s %s\n", cs->decoration, rootmenu.prompt->text);
636 
637 	fprintf(fp, "%s\n", cs->postfix);
638 }
639 
640 /* The returned pointer must be freed on the caller side */
641 static char *escape_string_value(const char *in)
642 {
643 	const char *p;
644 	char *out;
645 	size_t len;
646 
647 	len = strlen(in) + strlen("\"\"") + 1;
648 
649 	p = in;
650 	while (1) {
651 		p += strcspn(p, "\"\\");
652 
653 		if (p[0] == '\0')
654 			break;
655 
656 		len++;
657 		p++;
658 	}
659 
660 	out = xmalloc(len);
661 	out[0] = '\0';
662 
663 	strcat(out, "\"");
664 
665 	p = in;
666 	while (1) {
667 		len = strcspn(p, "\"\\");
668 		strncat(out, p, len);
669 		p += len;
670 
671 		if (p[0] == '\0')
672 			break;
673 
674 		strcat(out, "\\");
675 		strncat(out, p++, 1);
676 	}
677 
678 	strcat(out, "\"");
679 
680 	return out;
681 }
682 
683 enum output_n { OUTPUT_N, OUTPUT_N_AS_UNSET, OUTPUT_N_NONE };
684 
685 static void __print_symbol(FILE *fp, struct symbol *sym, enum output_n output_n,
686 			   bool escape_string)
687 {
688 	const char *val;
689 	char *escaped = NULL;
690 
691 	if (sym->type == S_UNKNOWN)
692 		return;
693 
694 	val = sym_get_string_value(sym);
695 
696 	if ((sym->type == S_BOOLEAN || sym->type == S_TRISTATE) &&
697 	    output_n != OUTPUT_N && *val == 'n') {
698 		if (output_n == OUTPUT_N_AS_UNSET)
699 			fprintf(fp, "# %s%s is not set\n", CONFIG_, sym->name);
700 		return;
701 	}
702 
703 	if (sym->type == S_STRING && escape_string) {
704 		escaped = escape_string_value(val);
705 		val = escaped;
706 	}
707 
708 	fprintf(fp, "%s%s=%s\n", CONFIG_, sym->name, val);
709 
710 	free(escaped);
711 }
712 
713 static void print_symbol_for_dotconfig(FILE *fp, struct symbol *sym)
714 {
715 	__print_symbol(fp, sym, OUTPUT_N_AS_UNSET, true);
716 }
717 
718 static void print_symbol_for_autoconf(FILE *fp, struct symbol *sym)
719 {
720 	__print_symbol(fp, sym, OUTPUT_N_NONE, false);
721 }
722 
723 void print_symbol_for_listconfig(struct symbol *sym)
724 {
725 	__print_symbol(stdout, sym, OUTPUT_N, true);
726 }
727 
728 static void print_symbol_for_c(FILE *fp, struct symbol *sym)
729 {
730 	const char *val;
731 	const char *sym_suffix = "";
732 	const char *val_prefix = "";
733 	char *escaped = NULL;
734 
735 	if (sym->type == S_UNKNOWN)
736 		return;
737 
738 	val = sym_get_string_value(sym);
739 
740 	switch (sym->type) {
741 	case S_BOOLEAN:
742 	case S_TRISTATE:
743 		switch (*val) {
744 		case 'n':
745 			return;
746 		case 'm':
747 			sym_suffix = "_MODULE";
748 			/* fall through */
749 		default:
750 			val = "1";
751 		}
752 		break;
753 	case S_HEX:
754 		if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
755 			val_prefix = "0x";
756 		break;
757 	case S_STRING:
758 		escaped = escape_string_value(val);
759 		val = escaped;
760 	default:
761 		break;
762 	}
763 
764 	fprintf(fp, "#define %s%s%s %s%s\n", CONFIG_, sym->name, sym_suffix,
765 		val_prefix, val);
766 
767 	free(escaped);
768 }
769 
770 static void print_symbol_for_rustccfg(FILE *fp, struct symbol *sym)
771 {
772 	const char *val;
773 	const char *val_prefix = "";
774 	char *val_prefixed = NULL;
775 	size_t val_prefixed_len;
776 	char *escaped = NULL;
777 
778 	if (sym->type == S_UNKNOWN)
779 		return;
780 
781 	val = sym_get_string_value(sym);
782 
783 	switch (sym->type) {
784 	case S_BOOLEAN:
785 	case S_TRISTATE:
786 		/*
787 		 * We do not care about disabled ones, i.e. no need for
788 		 * what otherwise are "comments" in other printers.
789 		 */
790 		if (*val == 'n')
791 			return;
792 
793 		/*
794 		 * To have similar functionality to the C macro `IS_ENABLED()`
795 		 * we provide an empty `--cfg CONFIG_X` here in both `y`
796 		 * and `m` cases.
797 		 *
798 		 * Then, the common `fprintf()` below will also give us
799 		 * a `--cfg CONFIG_X="y"` or `--cfg CONFIG_X="m"`, which can
800 		 * be used as the equivalent of `IS_BUILTIN()`/`IS_MODULE()`.
801 		 */
802 		fprintf(fp, "--cfg=%s%s\n", CONFIG_, sym->name);
803 		break;
804 	case S_HEX:
805 		if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
806 			val_prefix = "0x";
807 		break;
808 	default:
809 		break;
810 	}
811 
812 	if (strlen(val_prefix) > 0) {
813 		val_prefixed_len = strlen(val) + strlen(val_prefix) + 1;
814 		val_prefixed = xmalloc(val_prefixed_len);
815 		snprintf(val_prefixed, val_prefixed_len, "%s%s", val_prefix, val);
816 		val = val_prefixed;
817 	}
818 
819 	/* All values get escaped: the `--cfg` option only takes strings */
820 	escaped = escape_string_value(val);
821 	val = escaped;
822 
823 	fprintf(fp, "--cfg=%s%s=%s\n", CONFIG_, sym->name, val);
824 
825 	free(escaped);
826 	free(val_prefixed);
827 }
828 
829 /*
830  * Write out a minimal config.
831  * All values that has default values are skipped as this is redundant.
832  */
833 int conf_write_defconfig(const char *filename)
834 {
835 	struct symbol *sym;
836 	struct menu *menu;
837 	FILE *out;
838 
839 	out = fopen(filename, "w");
840 	if (!out)
841 		return 1;
842 
843 	sym_clear_all_valid();
844 
845 	/* Traverse all menus to find all relevant symbols */
846 	menu = rootmenu.list;
847 
848 	while (menu != NULL)
849 	{
850 		sym = menu->sym;
851 		if (sym == NULL) {
852 			if (!menu_is_visible(menu))
853 				goto next_menu;
854 		} else if (!sym_is_choice(sym)) {
855 			sym_calc_value(sym);
856 			if (!(sym->flags & SYMBOL_WRITE))
857 				goto next_menu;
858 			sym->flags &= ~SYMBOL_WRITE;
859 			/* If we cannot change the symbol - skip */
860 			if (!sym_is_changeable(sym))
861 				goto next_menu;
862 			/* If symbol equals to default value - skip */
863 			if (strcmp(sym_get_string_value(sym), sym_get_string_default(sym)) == 0)
864 				goto next_menu;
865 
866 			/*
867 			 * If symbol is a choice value and equals to the
868 			 * default for a choice - skip.
869 			 * But only if value is bool and equal to "y" and
870 			 * choice is not "optional".
871 			 * (If choice is "optional" then all values can be "n")
872 			 */
873 			if (sym_is_choice_value(sym)) {
874 				struct symbol *cs;
875 				struct symbol *ds;
876 
877 				cs = prop_get_symbol(sym_get_choice_prop(sym));
878 				ds = sym_choice_default(cs);
879 				if (!sym_is_optional(cs) && sym == ds) {
880 					if ((sym->type == S_BOOLEAN) &&
881 					    sym_get_tristate_value(sym) == yes)
882 						goto next_menu;
883 				}
884 			}
885 			print_symbol_for_dotconfig(out, sym);
886 		}
887 next_menu:
888 		if (menu->list != NULL) {
889 			menu = menu->list;
890 		}
891 		else if (menu->next != NULL) {
892 			menu = menu->next;
893 		} else {
894 			while ((menu = menu->parent)) {
895 				if (menu->next != NULL) {
896 					menu = menu->next;
897 					break;
898 				}
899 			}
900 		}
901 	}
902 	fclose(out);
903 	return 0;
904 }
905 
906 int conf_write(const char *name)
907 {
908 	FILE *out;
909 	struct symbol *sym;
910 	struct menu *menu;
911 	const char *str;
912 	char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1];
913 	char *env;
914 	int i;
915 	bool need_newline = false;
916 
917 	if (!name)
918 		name = conf_get_configname();
919 
920 	if (!*name) {
921 		fprintf(stderr, "config name is empty\n");
922 		return -1;
923 	}
924 
925 	if (is_dir(name)) {
926 		fprintf(stderr, "%s: Is a directory\n", name);
927 		return -1;
928 	}
929 
930 	if (make_parent_dir(name))
931 		return -1;
932 
933 	env = getenv("KCONFIG_OVERWRITECONFIG");
934 	if (env && *env) {
935 		*tmpname = 0;
936 		out = fopen(name, "w");
937 	} else {
938 		snprintf(tmpname, sizeof(tmpname), "%s.%d.tmp",
939 			 name, (int)getpid());
940 		out = fopen(tmpname, "w");
941 	}
942 	if (!out)
943 		return 1;
944 
945 	conf_write_heading(out, &comment_style_pound);
946 
947 	if (!conf_get_changed())
948 		sym_clear_all_valid();
949 
950 	menu = rootmenu.list;
951 	while (menu) {
952 		sym = menu->sym;
953 		if (!sym) {
954 			if (!menu_is_visible(menu))
955 				goto next;
956 			str = menu_get_prompt(menu);
957 			fprintf(out, "\n"
958 				     "#\n"
959 				     "# %s\n"
960 				     "#\n", str);
961 			need_newline = false;
962 		} else if (!(sym->flags & SYMBOL_CHOICE) &&
963 			   !(sym->flags & SYMBOL_WRITTEN)) {
964 			sym_calc_value(sym);
965 			if (!(sym->flags & SYMBOL_WRITE))
966 				goto next;
967 			if (need_newline) {
968 				fprintf(out, "\n");
969 				need_newline = false;
970 			}
971 			sym->flags |= SYMBOL_WRITTEN;
972 			print_symbol_for_dotconfig(out, sym);
973 		}
974 
975 next:
976 		if (menu->list) {
977 			menu = menu->list;
978 			continue;
979 		}
980 
981 end_check:
982 		if (!menu->sym && menu_is_visible(menu) && menu != &rootmenu &&
983 		    menu->prompt->type == P_MENU) {
984 			fprintf(out, "# end of %s\n", menu_get_prompt(menu));
985 			need_newline = true;
986 		}
987 
988 		if (menu->next) {
989 			menu = menu->next;
990 		} else {
991 			menu = menu->parent;
992 			if (menu)
993 				goto end_check;
994 		}
995 	}
996 	fclose(out);
997 
998 	for_all_symbols(i, sym)
999 		sym->flags &= ~SYMBOL_WRITTEN;
1000 
1001 	if (*tmpname) {
1002 		if (is_same(name, tmpname)) {
1003 			conf_message("No change to %s", name);
1004 			unlink(tmpname);
1005 			conf_set_changed(false);
1006 			return 0;
1007 		}
1008 
1009 		snprintf(oldname, sizeof(oldname), "%s.old", name);
1010 		rename(name, oldname);
1011 		if (rename(tmpname, name))
1012 			return 1;
1013 	}
1014 
1015 	conf_message("configuration written to %s", name);
1016 
1017 	conf_set_changed(false);
1018 
1019 	return 0;
1020 }
1021 
1022 /* write a dependency file as used by kbuild to track dependencies */
1023 static int conf_write_autoconf_cmd(const char *autoconf_name)
1024 {
1025 	char name[PATH_MAX], tmp[PATH_MAX];
1026 	struct file *file;
1027 	FILE *out;
1028 	int ret;
1029 
1030 	ret = snprintf(name, sizeof(name), "%s.cmd", autoconf_name);
1031 	if (ret >= sizeof(name)) /* check truncation */
1032 		return -1;
1033 
1034 	if (make_parent_dir(name))
1035 		return -1;
1036 
1037 	ret = snprintf(tmp, sizeof(tmp), "%s.cmd.tmp", autoconf_name);
1038 	if (ret >= sizeof(tmp)) /* check truncation */
1039 		return -1;
1040 
1041 	out = fopen(tmp, "w");
1042 	if (!out) {
1043 		perror("fopen");
1044 		return -1;
1045 	}
1046 
1047 	fprintf(out, "deps_config := \\\n");
1048 	for (file = file_list; file; file = file->next)
1049 		fprintf(out, "\t%s \\\n", file->name);
1050 
1051 	fprintf(out, "\n%s: $(deps_config)\n\n", autoconf_name);
1052 
1053 	env_write_dep(out, autoconf_name);
1054 
1055 	fprintf(out, "\n$(deps_config): ;\n");
1056 
1057 	fflush(out);
1058 	ret = ferror(out); /* error check for all fprintf() calls */
1059 	fclose(out);
1060 	if (ret)
1061 		return -1;
1062 
1063 	if (rename(tmp, name)) {
1064 		perror("rename");
1065 		return -1;
1066 	}
1067 
1068 	return 0;
1069 }
1070 
1071 static int conf_touch_deps(void)
1072 {
1073 	const char *name, *tmp;
1074 	struct symbol *sym;
1075 	int res, i;
1076 
1077 	name = conf_get_autoconfig_name();
1078 	tmp = strrchr(name, '/');
1079 	depfile_prefix_len = tmp ? tmp - name + 1 : 0;
1080 	if (depfile_prefix_len + 1 > sizeof(depfile_path))
1081 		return -1;
1082 
1083 	strncpy(depfile_path, name, depfile_prefix_len);
1084 	depfile_path[depfile_prefix_len] = 0;
1085 
1086 	conf_read_simple(name, S_DEF_AUTO);
1087 	sym_calc_value(modules_sym);
1088 
1089 	for_all_symbols(i, sym) {
1090 		sym_calc_value(sym);
1091 		if ((sym->flags & SYMBOL_NO_WRITE) || !sym->name)
1092 			continue;
1093 		if (sym->flags & SYMBOL_WRITE) {
1094 			if (sym->flags & SYMBOL_DEF_AUTO) {
1095 				/*
1096 				 * symbol has old and new value,
1097 				 * so compare them...
1098 				 */
1099 				switch (sym->type) {
1100 				case S_BOOLEAN:
1101 				case S_TRISTATE:
1102 					if (sym_get_tristate_value(sym) ==
1103 					    sym->def[S_DEF_AUTO].tri)
1104 						continue;
1105 					break;
1106 				case S_STRING:
1107 				case S_HEX:
1108 				case S_INT:
1109 					if (!strcmp(sym_get_string_value(sym),
1110 						    sym->def[S_DEF_AUTO].val))
1111 						continue;
1112 					break;
1113 				default:
1114 					break;
1115 				}
1116 			} else {
1117 				/*
1118 				 * If there is no old value, only 'no' (unset)
1119 				 * is allowed as new value.
1120 				 */
1121 				switch (sym->type) {
1122 				case S_BOOLEAN:
1123 				case S_TRISTATE:
1124 					if (sym_get_tristate_value(sym) == no)
1125 						continue;
1126 					break;
1127 				default:
1128 					break;
1129 				}
1130 			}
1131 		} else if (!(sym->flags & SYMBOL_DEF_AUTO))
1132 			/* There is neither an old nor a new value. */
1133 			continue;
1134 		/* else
1135 		 *	There is an old value, but no new value ('no' (unset)
1136 		 *	isn't saved in auto.conf, so the old value is always
1137 		 *	different from 'no').
1138 		 */
1139 
1140 		res = conf_touch_dep(sym->name);
1141 		if (res)
1142 			return res;
1143 	}
1144 
1145 	return 0;
1146 }
1147 
1148 static int __conf_write_autoconf(const char *filename,
1149 				 void (*print_symbol)(FILE *, struct symbol *),
1150 				 const struct comment_style *comment_style)
1151 {
1152 	char tmp[PATH_MAX];
1153 	FILE *file;
1154 	struct symbol *sym;
1155 	int ret, i;
1156 
1157 	if (make_parent_dir(filename))
1158 		return -1;
1159 
1160 	ret = snprintf(tmp, sizeof(tmp), "%s.tmp", filename);
1161 	if (ret >= sizeof(tmp)) /* check truncation */
1162 		return -1;
1163 
1164 	file = fopen(tmp, "w");
1165 	if (!file) {
1166 		perror("fopen");
1167 		return -1;
1168 	}
1169 
1170 	conf_write_heading(file, comment_style);
1171 
1172 	for_all_symbols(i, sym)
1173 		if ((sym->flags & SYMBOL_WRITE) && sym->name)
1174 			print_symbol(file, sym);
1175 
1176 	fflush(file);
1177 	/* check possible errors in conf_write_heading() and print_symbol() */
1178 	ret = ferror(file);
1179 	fclose(file);
1180 	if (ret)
1181 		return -1;
1182 
1183 	if (rename(tmp, filename)) {
1184 		perror("rename");
1185 		return -1;
1186 	}
1187 
1188 	return 0;
1189 }
1190 
1191 int conf_write_autoconf(int overwrite)
1192 {
1193 	struct symbol *sym;
1194 	const char *autoconf_name = conf_get_autoconfig_name();
1195 	int ret, i;
1196 
1197 	if (!overwrite && is_present(autoconf_name))
1198 		return 0;
1199 
1200 	ret = conf_write_autoconf_cmd(autoconf_name);
1201 	if (ret)
1202 		return -1;
1203 
1204 	if (conf_touch_deps())
1205 		return 1;
1206 
1207 	for_all_symbols(i, sym)
1208 		sym_calc_value(sym);
1209 
1210 	ret = __conf_write_autoconf(conf_get_autoheader_name(),
1211 				    print_symbol_for_c,
1212 				    &comment_style_c);
1213 	if (ret)
1214 		return ret;
1215 
1216 	ret = __conf_write_autoconf(conf_get_rustccfg_name(),
1217 				    print_symbol_for_rustccfg,
1218 				    NULL);
1219 	if (ret)
1220 		return ret;
1221 
1222 	/*
1223 	 * Create include/config/auto.conf. This must be the last step because
1224 	 * Kbuild has a dependency on auto.conf and this marks the successful
1225 	 * completion of the previous steps.
1226 	 */
1227 	ret = __conf_write_autoconf(conf_get_autoconfig_name(),
1228 				    print_symbol_for_autoconf,
1229 				    &comment_style_pound);
1230 	if (ret)
1231 		return ret;
1232 
1233 	return 0;
1234 }
1235 
1236 static bool conf_changed;
1237 static void (*conf_changed_callback)(void);
1238 
1239 void conf_set_changed(bool val)
1240 {
1241 	bool changed = conf_changed != val;
1242 
1243 	conf_changed = val;
1244 
1245 	if (conf_changed_callback && changed)
1246 		conf_changed_callback();
1247 }
1248 
1249 bool conf_get_changed(void)
1250 {
1251 	return conf_changed;
1252 }
1253 
1254 void conf_set_changed_callback(void (*fn)(void))
1255 {
1256 	conf_changed_callback = fn;
1257 }
1258 
1259 void set_all_choice_values(struct symbol *csym)
1260 {
1261 	struct property *prop;
1262 	struct symbol *sym;
1263 	struct expr *e;
1264 
1265 	prop = sym_get_choice_prop(csym);
1266 
1267 	/*
1268 	 * Set all non-assinged choice values to no
1269 	 */
1270 	expr_list_for_each_sym(prop->expr, e, sym) {
1271 		if (!sym_has_value(sym))
1272 			sym->def[S_DEF_USER].tri = no;
1273 	}
1274 	csym->flags |= SYMBOL_DEF_USER;
1275 	/* clear VALID to get value calculated */
1276 	csym->flags &= ~(SYMBOL_VALID | SYMBOL_NEED_SET_CHOICE_VALUES);
1277 }
1278