xref: /linux/scripts/kconfig/confdata.c (revision 561add0da6d3d07c9bccb0832fb6ed5619167d26)
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 }
1283