xref: /openbmc/linux/scripts/kconfig/confdata.c (revision 3bf90eca)
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 	if (conf_changed_callback && conf_changed != val)
1230 		conf_changed_callback();
1231 
1232 	conf_changed = val;
1233 }
1234 
1235 bool conf_get_changed(void)
1236 {
1237 	return conf_changed;
1238 }
1239 
1240 void conf_set_changed_callback(void (*fn)(void))
1241 {
1242 	conf_changed_callback = fn;
1243 }
1244 
1245 void set_all_choice_values(struct symbol *csym)
1246 {
1247 	struct property *prop;
1248 	struct symbol *sym;
1249 	struct expr *e;
1250 
1251 	prop = sym_get_choice_prop(csym);
1252 
1253 	/*
1254 	 * Set all non-assinged choice values to no
1255 	 */
1256 	expr_list_for_each_sym(prop->expr, e, sym) {
1257 		if (!sym_has_value(sym))
1258 			sym->def[S_DEF_USER].tri = no;
1259 	}
1260 	csym->flags |= SYMBOL_DEF_USER;
1261 	/* clear VALID to get value calculated */
1262 	csym->flags &= ~(SYMBOL_VALID | SYMBOL_NEED_SET_CHOICE_VALUES);
1263 }
1264