xref: /openbmc/linux/scripts/kconfig/confdata.c (revision 229d0cfae5b21bfc42525cf43b0b4279243acc4e)
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 <stdio.h>
15 #include <stdlib.h>
16 #include <string.h>
17 #include <time.h>
18 #include <unistd.h>
19 
20 #include "lkc.h"
21 
22 /* return true if 'path' exists, false otherwise */
23 static bool is_present(const char *path)
24 {
25 	struct stat st;
26 
27 	return !stat(path, &st);
28 }
29 
30 /* return true if 'path' exists and it is a directory, false otherwise */
31 static bool is_dir(const char *path)
32 {
33 	struct stat st;
34 
35 	if (stat(path, &st))
36 		return false;
37 
38 	return S_ISDIR(st.st_mode);
39 }
40 
41 /* return true if the given two files are the same, false otherwise */
42 static bool is_same(const char *file1, const char *file2)
43 {
44 	int fd1, fd2;
45 	struct stat st1, st2;
46 	void *map1, *map2;
47 	bool ret = false;
48 
49 	fd1 = open(file1, O_RDONLY);
50 	if (fd1 < 0)
51 		return ret;
52 
53 	fd2 = open(file2, O_RDONLY);
54 	if (fd2 < 0)
55 		goto close1;
56 
57 	ret = fstat(fd1, &st1);
58 	if (ret)
59 		goto close2;
60 	ret = fstat(fd2, &st2);
61 	if (ret)
62 		goto close2;
63 
64 	if (st1.st_size != st2.st_size)
65 		goto close2;
66 
67 	map1 = mmap(NULL, st1.st_size, PROT_READ, MAP_PRIVATE, fd1, 0);
68 	if (map1 == MAP_FAILED)
69 		goto close2;
70 
71 	map2 = mmap(NULL, st2.st_size, PROT_READ, MAP_PRIVATE, fd2, 0);
72 	if (map2 == MAP_FAILED)
73 		goto close2;
74 
75 	if (bcmp(map1, map2, st1.st_size))
76 		goto close2;
77 
78 	ret = true;
79 close2:
80 	close(fd2);
81 close1:
82 	close(fd1);
83 
84 	return ret;
85 }
86 
87 /*
88  * Create the parent directory of the given path.
89  *
90  * For example, if 'include/config/auto.conf' is given, create 'include/config'.
91  */
92 static int make_parent_dir(const char *path)
93 {
94 	char tmp[PATH_MAX + 1];
95 	char *p;
96 
97 	strncpy(tmp, path, sizeof(tmp));
98 	tmp[sizeof(tmp) - 1] = 0;
99 
100 	/* Remove the base name. Just return if nothing is left */
101 	p = strrchr(tmp, '/');
102 	if (!p)
103 		return 0;
104 	*(p + 1) = 0;
105 
106 	/* Just in case it is an absolute path */
107 	p = tmp;
108 	while (*p == '/')
109 		p++;
110 
111 	while ((p = strchr(p, '/'))) {
112 		*p = 0;
113 
114 		/* skip if the directory exists */
115 		if (!is_dir(tmp) && mkdir(tmp, 0755))
116 			return -1;
117 
118 		*p = '/';
119 		while (*p == '/')
120 			p++;
121 	}
122 
123 	return 0;
124 }
125 
126 static char depfile_path[PATH_MAX];
127 static size_t depfile_prefix_len;
128 
129 /* touch depfile for symbol 'name' */
130 static int conf_touch_dep(const char *name)
131 {
132 	int fd, ret;
133 	char *d;
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 	d = depfile_path + depfile_prefix_len;
140 	strcpy(d, name);
141 
142 	/* Assume directory path already exists. */
143 	fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
144 	if (fd == -1) {
145 		if (errno != ENOENT)
146 			return -1;
147 
148 		ret = make_parent_dir(depfile_path);
149 		if (ret)
150 			return ret;
151 
152 		/* Try it again. */
153 		fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
154 		if (fd == -1)
155 			return -1;
156 	}
157 	close(fd);
158 
159 	return 0;
160 }
161 
162 struct conf_printer {
163 	void (*print_symbol)(FILE *, struct symbol *, const char *, void *);
164 	void (*print_comment)(FILE *, const char *, void *);
165 };
166 
167 static void conf_warning(const char *fmt, ...)
168 	__attribute__ ((format (printf, 1, 2)));
169 
170 static void conf_message(const char *fmt, ...)
171 	__attribute__ ((format (printf, 1, 2)));
172 
173 static const char *conf_filename;
174 static int conf_lineno, conf_warnings;
175 
176 static void conf_warning(const char *fmt, ...)
177 {
178 	va_list ap;
179 	va_start(ap, fmt);
180 	fprintf(stderr, "%s:%d:warning: ", conf_filename, conf_lineno);
181 	vfprintf(stderr, fmt, ap);
182 	fprintf(stderr, "\n");
183 	va_end(ap);
184 	conf_warnings++;
185 }
186 
187 static void conf_default_message_callback(const char *s)
188 {
189 	printf("#\n# ");
190 	printf("%s", s);
191 	printf("\n#\n");
192 }
193 
194 static void (*conf_message_callback)(const char *s) =
195 	conf_default_message_callback;
196 void conf_set_message_callback(void (*fn)(const char *s))
197 {
198 	conf_message_callback = fn;
199 }
200 
201 static void conf_message(const char *fmt, ...)
202 {
203 	va_list ap;
204 	char buf[4096];
205 
206 	if (!conf_message_callback)
207 		return;
208 
209 	va_start(ap, fmt);
210 
211 	vsnprintf(buf, sizeof(buf), fmt, ap);
212 	conf_message_callback(buf);
213 	va_end(ap);
214 }
215 
216 const char *conf_get_configname(void)
217 {
218 	char *name = getenv("KCONFIG_CONFIG");
219 
220 	return name ? name : ".config";
221 }
222 
223 static const char *conf_get_autoconfig_name(void)
224 {
225 	char *name = getenv("KCONFIG_AUTOCONFIG");
226 
227 	return name ? name : "include/config/auto.conf";
228 }
229 
230 static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
231 {
232 	char *p2;
233 
234 	switch (sym->type) {
235 	case S_TRISTATE:
236 		if (p[0] == 'm') {
237 			sym->def[def].tri = mod;
238 			sym->flags |= def_flags;
239 			break;
240 		}
241 		/* fall through */
242 	case S_BOOLEAN:
243 		if (p[0] == 'y') {
244 			sym->def[def].tri = yes;
245 			sym->flags |= def_flags;
246 			break;
247 		}
248 		if (p[0] == 'n') {
249 			sym->def[def].tri = no;
250 			sym->flags |= def_flags;
251 			break;
252 		}
253 		if (def != S_DEF_AUTO)
254 			conf_warning("symbol value '%s' invalid for %s",
255 				     p, sym->name);
256 		return 1;
257 	case S_STRING:
258 		if (*p++ != '"')
259 			break;
260 		for (p2 = p; (p2 = strpbrk(p2, "\"\\")); p2++) {
261 			if (*p2 == '"') {
262 				*p2 = 0;
263 				break;
264 			}
265 			memmove(p2, p2 + 1, strlen(p2));
266 		}
267 		if (!p2) {
268 			if (def != S_DEF_AUTO)
269 				conf_warning("invalid string found");
270 			return 1;
271 		}
272 		/* fall through */
273 	case S_INT:
274 	case S_HEX:
275 		if (sym_string_valid(sym, p)) {
276 			sym->def[def].val = xstrdup(p);
277 			sym->flags |= def_flags;
278 		} else {
279 			if (def != S_DEF_AUTO)
280 				conf_warning("symbol value '%s' invalid for %s",
281 					     p, sym->name);
282 			return 1;
283 		}
284 		break;
285 	default:
286 		;
287 	}
288 	return 0;
289 }
290 
291 #define LINE_GROWTH 16
292 static int add_byte(int c, char **lineptr, size_t slen, size_t *n)
293 {
294 	char *nline;
295 	size_t new_size = slen + 1;
296 	if (new_size > *n) {
297 		new_size += LINE_GROWTH - 1;
298 		new_size *= 2;
299 		nline = xrealloc(*lineptr, new_size);
300 		if (!nline)
301 			return -1;
302 
303 		*lineptr = nline;
304 		*n = new_size;
305 	}
306 
307 	(*lineptr)[slen] = c;
308 
309 	return 0;
310 }
311 
312 static ssize_t compat_getline(char **lineptr, size_t *n, FILE *stream)
313 {
314 	char *line = *lineptr;
315 	size_t slen = 0;
316 
317 	for (;;) {
318 		int c = getc(stream);
319 
320 		switch (c) {
321 		case '\n':
322 			if (add_byte(c, &line, slen, n) < 0)
323 				goto e_out;
324 			slen++;
325 			/* fall through */
326 		case EOF:
327 			if (add_byte('\0', &line, slen, n) < 0)
328 				goto e_out;
329 			*lineptr = line;
330 			if (slen == 0)
331 				return -1;
332 			return slen;
333 		default:
334 			if (add_byte(c, &line, slen, n) < 0)
335 				goto e_out;
336 			slen++;
337 		}
338 	}
339 
340 e_out:
341 	line[slen-1] = '\0';
342 	*lineptr = line;
343 	return -1;
344 }
345 
346 int conf_read_simple(const char *name, int def)
347 {
348 	FILE *in = NULL;
349 	char   *line = NULL;
350 	size_t  line_asize = 0;
351 	char *p, *p2;
352 	struct symbol *sym;
353 	int i, def_flags;
354 
355 	if (name) {
356 		in = zconf_fopen(name);
357 	} else {
358 		char *env;
359 
360 		name = conf_get_configname();
361 		in = zconf_fopen(name);
362 		if (in)
363 			goto load;
364 		conf_set_changed(true);
365 
366 		env = getenv("KCONFIG_DEFCONFIG_LIST");
367 		if (!env)
368 			return 1;
369 
370 		while (1) {
371 			bool is_last;
372 
373 			while (isspace(*env))
374 				env++;
375 
376 			if (!*env)
377 				break;
378 
379 			p = env;
380 			while (*p && !isspace(*p))
381 				p++;
382 
383 			is_last = (*p == '\0');
384 
385 			*p = '\0';
386 
387 			in = zconf_fopen(env);
388 			if (in) {
389 				conf_message("using defaults found in %s",
390 					     env);
391 				goto load;
392 			}
393 
394 			if (is_last)
395 				break;
396 
397 			env = p + 1;
398 		}
399 	}
400 	if (!in)
401 		return 1;
402 
403 load:
404 	conf_filename = name;
405 	conf_lineno = 0;
406 	conf_warnings = 0;
407 
408 	def_flags = SYMBOL_DEF << def;
409 	for_all_symbols(i, sym) {
410 		sym->flags |= SYMBOL_CHANGED;
411 		sym->flags &= ~(def_flags|SYMBOL_VALID);
412 		if (sym_is_choice(sym))
413 			sym->flags |= def_flags;
414 		switch (sym->type) {
415 		case S_INT:
416 		case S_HEX:
417 		case S_STRING:
418 			if (sym->def[def].val)
419 				free(sym->def[def].val);
420 			/* fall through */
421 		default:
422 			sym->def[def].val = NULL;
423 			sym->def[def].tri = no;
424 		}
425 	}
426 
427 	while (compat_getline(&line, &line_asize, in) != -1) {
428 		conf_lineno++;
429 		sym = NULL;
430 		if (line[0] == '#') {
431 			if (memcmp(line + 2, CONFIG_, strlen(CONFIG_)))
432 				continue;
433 			p = strchr(line + 2 + strlen(CONFIG_), ' ');
434 			if (!p)
435 				continue;
436 			*p++ = 0;
437 			if (strncmp(p, "is not set", 10))
438 				continue;
439 			if (def == S_DEF_USER) {
440 				sym = sym_find(line + 2 + strlen(CONFIG_));
441 				if (!sym) {
442 					conf_set_changed(true);
443 					continue;
444 				}
445 			} else {
446 				sym = sym_lookup(line + 2 + strlen(CONFIG_), 0);
447 				if (sym->type == S_UNKNOWN)
448 					sym->type = S_BOOLEAN;
449 			}
450 			if (sym->flags & def_flags) {
451 				conf_warning("override: reassigning to symbol %s", sym->name);
452 			}
453 			switch (sym->type) {
454 			case S_BOOLEAN:
455 			case S_TRISTATE:
456 				sym->def[def].tri = no;
457 				sym->flags |= def_flags;
458 				break;
459 			default:
460 				;
461 			}
462 		} else if (memcmp(line, CONFIG_, strlen(CONFIG_)) == 0) {
463 			p = strchr(line + strlen(CONFIG_), '=');
464 			if (!p)
465 				continue;
466 			*p++ = 0;
467 			p2 = strchr(p, '\n');
468 			if (p2) {
469 				*p2-- = 0;
470 				if (*p2 == '\r')
471 					*p2 = 0;
472 			}
473 
474 			sym = sym_find(line + strlen(CONFIG_));
475 			if (!sym) {
476 				if (def == S_DEF_AUTO)
477 					/*
478 					 * Reading from include/config/auto.conf
479 					 * If CONFIG_FOO previously existed in
480 					 * auto.conf but it is missing now,
481 					 * include/config/FOO must be touched.
482 					 */
483 					conf_touch_dep(line + strlen(CONFIG_));
484 				else
485 					conf_set_changed(true);
486 				continue;
487 			}
488 
489 			if (sym->flags & def_flags) {
490 				conf_warning("override: reassigning to symbol %s", sym->name);
491 			}
492 			if (conf_set_sym_val(sym, def, def_flags, p))
493 				continue;
494 		} else {
495 			if (line[0] != '\r' && line[0] != '\n')
496 				conf_warning("unexpected data: %.*s",
497 					     (int)strcspn(line, "\r\n"), line);
498 
499 			continue;
500 		}
501 
502 		if (sym && sym_is_choice_value(sym)) {
503 			struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
504 			switch (sym->def[def].tri) {
505 			case no:
506 				break;
507 			case mod:
508 				if (cs->def[def].tri == yes) {
509 					conf_warning("%s creates inconsistent choice state", sym->name);
510 					cs->flags &= ~def_flags;
511 				}
512 				break;
513 			case yes:
514 				if (cs->def[def].tri != no)
515 					conf_warning("override: %s changes choice state", sym->name);
516 				cs->def[def].val = sym;
517 				break;
518 			}
519 			cs->def[def].tri = EXPR_OR(cs->def[def].tri, sym->def[def].tri);
520 		}
521 	}
522 	free(line);
523 	fclose(in);
524 	return 0;
525 }
526 
527 int conf_read(const char *name)
528 {
529 	struct symbol *sym;
530 	int conf_unsaved = 0;
531 	int i;
532 
533 	conf_set_changed(false);
534 
535 	if (conf_read_simple(name, S_DEF_USER)) {
536 		sym_calc_value(modules_sym);
537 		return 1;
538 	}
539 
540 	sym_calc_value(modules_sym);
541 
542 	for_all_symbols(i, sym) {
543 		sym_calc_value(sym);
544 		if (sym_is_choice(sym) || (sym->flags & SYMBOL_NO_WRITE))
545 			continue;
546 		if (sym_has_value(sym) && (sym->flags & SYMBOL_WRITE)) {
547 			/* check that calculated value agrees with saved value */
548 			switch (sym->type) {
549 			case S_BOOLEAN:
550 			case S_TRISTATE:
551 				if (sym->def[S_DEF_USER].tri == sym_get_tristate_value(sym))
552 					continue;
553 				break;
554 			default:
555 				if (!strcmp(sym->curr.val, sym->def[S_DEF_USER].val))
556 					continue;
557 				break;
558 			}
559 		} else if (!sym_has_value(sym) && !(sym->flags & SYMBOL_WRITE))
560 			/* no previous value and not saved */
561 			continue;
562 		conf_unsaved++;
563 		/* maybe print value in verbose mode... */
564 	}
565 
566 	for_all_symbols(i, sym) {
567 		if (sym_has_value(sym) && !sym_is_choice_value(sym)) {
568 			/* Reset values of generates values, so they'll appear
569 			 * as new, if they should become visible, but that
570 			 * doesn't quite work if the Kconfig and the saved
571 			 * configuration disagree.
572 			 */
573 			if (sym->visible == no && !conf_unsaved)
574 				sym->flags &= ~SYMBOL_DEF_USER;
575 			switch (sym->type) {
576 			case S_STRING:
577 			case S_INT:
578 			case S_HEX:
579 				/* Reset a string value if it's out of range */
580 				if (sym_string_within_range(sym, sym->def[S_DEF_USER].val))
581 					break;
582 				sym->flags &= ~(SYMBOL_VALID|SYMBOL_DEF_USER);
583 				conf_unsaved++;
584 				break;
585 			default:
586 				break;
587 			}
588 		}
589 	}
590 
591 	if (conf_warnings || conf_unsaved)
592 		conf_set_changed(true);
593 
594 	return 0;
595 }
596 
597 /*
598  * Kconfig configuration printer
599  *
600  * This printer is used when generating the resulting configuration after
601  * kconfig invocation and `defconfig' files. Unset symbol might be omitted by
602  * passing a non-NULL argument to the printer.
603  *
604  */
605 static void
606 kconfig_print_symbol(FILE *fp, struct symbol *sym, const char *value, void *arg)
607 {
608 
609 	switch (sym->type) {
610 	case S_BOOLEAN:
611 	case S_TRISTATE:
612 		if (*value == 'n') {
613 			bool skip_unset = (arg != NULL);
614 
615 			if (!skip_unset)
616 				fprintf(fp, "# %s%s is not set\n",
617 				    CONFIG_, sym->name);
618 			return;
619 		}
620 		break;
621 	default:
622 		break;
623 	}
624 
625 	fprintf(fp, "%s%s=%s\n", CONFIG_, sym->name, value);
626 }
627 
628 static void
629 kconfig_print_comment(FILE *fp, const char *value, void *arg)
630 {
631 	const char *p = value;
632 	size_t l;
633 
634 	for (;;) {
635 		l = strcspn(p, "\n");
636 		fprintf(fp, "#");
637 		if (l) {
638 			fprintf(fp, " ");
639 			xfwrite(p, l, 1, fp);
640 			p += l;
641 		}
642 		fprintf(fp, "\n");
643 		if (*p++ == '\0')
644 			break;
645 	}
646 }
647 
648 static struct conf_printer kconfig_printer_cb =
649 {
650 	.print_symbol = kconfig_print_symbol,
651 	.print_comment = kconfig_print_comment,
652 };
653 
654 /*
655  * Header printer
656  *
657  * This printer is used when generating the `include/generated/autoconf.h' file.
658  */
659 static void
660 header_print_symbol(FILE *fp, struct symbol *sym, const char *value, void *arg)
661 {
662 
663 	switch (sym->type) {
664 	case S_BOOLEAN:
665 	case S_TRISTATE: {
666 		const char *suffix = "";
667 
668 		switch (*value) {
669 		case 'n':
670 			break;
671 		case 'm':
672 			suffix = "_MODULE";
673 			/* fall through */
674 		default:
675 			fprintf(fp, "#define %s%s%s 1\n",
676 			    CONFIG_, sym->name, suffix);
677 		}
678 		break;
679 	}
680 	case S_HEX: {
681 		const char *prefix = "";
682 
683 		if (value[0] != '0' || (value[1] != 'x' && value[1] != 'X'))
684 			prefix = "0x";
685 		fprintf(fp, "#define %s%s %s%s\n",
686 		    CONFIG_, sym->name, prefix, value);
687 		break;
688 	}
689 	case S_STRING:
690 	case S_INT:
691 		fprintf(fp, "#define %s%s %s\n",
692 		    CONFIG_, sym->name, value);
693 		break;
694 	default:
695 		break;
696 	}
697 
698 }
699 
700 static void
701 header_print_comment(FILE *fp, const char *value, void *arg)
702 {
703 	const char *p = value;
704 	size_t l;
705 
706 	fprintf(fp, "/*\n");
707 	for (;;) {
708 		l = strcspn(p, "\n");
709 		fprintf(fp, " *");
710 		if (l) {
711 			fprintf(fp, " ");
712 			xfwrite(p, l, 1, fp);
713 			p += l;
714 		}
715 		fprintf(fp, "\n");
716 		if (*p++ == '\0')
717 			break;
718 	}
719 	fprintf(fp, " */\n");
720 }
721 
722 static struct conf_printer header_printer_cb =
723 {
724 	.print_symbol = header_print_symbol,
725 	.print_comment = header_print_comment,
726 };
727 
728 static void conf_write_symbol(FILE *fp, struct symbol *sym,
729 			      struct conf_printer *printer, void *printer_arg)
730 {
731 	const char *val;
732 	char *escaped = NULL;
733 
734 	if (sym->type == S_UNKNOWN)
735 		return;
736 
737 	val = sym_get_string_value(sym);
738 
739 	if (sym->type == S_STRING) {
740 		escaped = sym_escape_string_value(val);
741 		val = escaped;
742 	}
743 
744 	printer->print_symbol(fp, sym, val, printer_arg);
745 
746 	free(escaped);
747 }
748 
749 static void
750 conf_write_heading(FILE *fp, struct conf_printer *printer, void *printer_arg)
751 {
752 	char buf[256];
753 
754 	snprintf(buf, sizeof(buf),
755 	    "\n"
756 	    "Automatically generated file; DO NOT EDIT.\n"
757 	    "%s\n",
758 	    rootmenu.prompt->text);
759 
760 	printer->print_comment(fp, buf, printer_arg);
761 }
762 
763 /*
764  * Write out a minimal config.
765  * All values that has default values are skipped as this is redundant.
766  */
767 int conf_write_defconfig(const char *filename)
768 {
769 	struct symbol *sym;
770 	struct menu *menu;
771 	FILE *out;
772 
773 	out = fopen(filename, "w");
774 	if (!out)
775 		return 1;
776 
777 	sym_clear_all_valid();
778 
779 	/* Traverse all menus to find all relevant symbols */
780 	menu = rootmenu.list;
781 
782 	while (menu != NULL)
783 	{
784 		sym = menu->sym;
785 		if (sym == NULL) {
786 			if (!menu_is_visible(menu))
787 				goto next_menu;
788 		} else if (!sym_is_choice(sym)) {
789 			sym_calc_value(sym);
790 			if (!(sym->flags & SYMBOL_WRITE))
791 				goto next_menu;
792 			sym->flags &= ~SYMBOL_WRITE;
793 			/* If we cannot change the symbol - skip */
794 			if (!sym_is_changeable(sym))
795 				goto next_menu;
796 			/* If symbol equals to default value - skip */
797 			if (strcmp(sym_get_string_value(sym), sym_get_string_default(sym)) == 0)
798 				goto next_menu;
799 
800 			/*
801 			 * If symbol is a choice value and equals to the
802 			 * default for a choice - skip.
803 			 * But only if value is bool and equal to "y" and
804 			 * choice is not "optional".
805 			 * (If choice is "optional" then all values can be "n")
806 			 */
807 			if (sym_is_choice_value(sym)) {
808 				struct symbol *cs;
809 				struct symbol *ds;
810 
811 				cs = prop_get_symbol(sym_get_choice_prop(sym));
812 				ds = sym_choice_default(cs);
813 				if (!sym_is_optional(cs) && sym == ds) {
814 					if ((sym->type == S_BOOLEAN) &&
815 					    sym_get_tristate_value(sym) == yes)
816 						goto next_menu;
817 				}
818 			}
819 			conf_write_symbol(out, sym, &kconfig_printer_cb, NULL);
820 		}
821 next_menu:
822 		if (menu->list != NULL) {
823 			menu = menu->list;
824 		}
825 		else if (menu->next != NULL) {
826 			menu = menu->next;
827 		} else {
828 			while ((menu = menu->parent)) {
829 				if (menu->next != NULL) {
830 					menu = menu->next;
831 					break;
832 				}
833 			}
834 		}
835 	}
836 	fclose(out);
837 	return 0;
838 }
839 
840 int conf_write(const char *name)
841 {
842 	FILE *out;
843 	struct symbol *sym;
844 	struct menu *menu;
845 	const char *str;
846 	char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1];
847 	char *env;
848 	int i;
849 	bool need_newline = false;
850 
851 	if (!name)
852 		name = conf_get_configname();
853 
854 	if (!*name) {
855 		fprintf(stderr, "config name is empty\n");
856 		return -1;
857 	}
858 
859 	if (is_dir(name)) {
860 		fprintf(stderr, "%s: Is a directory\n", name);
861 		return -1;
862 	}
863 
864 	if (make_parent_dir(name))
865 		return -1;
866 
867 	env = getenv("KCONFIG_OVERWRITECONFIG");
868 	if (env && *env) {
869 		*tmpname = 0;
870 		out = fopen(name, "w");
871 	} else {
872 		snprintf(tmpname, sizeof(tmpname), "%s.%d.tmp",
873 			 name, (int)getpid());
874 		out = fopen(tmpname, "w");
875 	}
876 	if (!out)
877 		return 1;
878 
879 	conf_write_heading(out, &kconfig_printer_cb, NULL);
880 
881 	if (!conf_get_changed())
882 		sym_clear_all_valid();
883 
884 	menu = rootmenu.list;
885 	while (menu) {
886 		sym = menu->sym;
887 		if (!sym) {
888 			if (!menu_is_visible(menu))
889 				goto next;
890 			str = menu_get_prompt(menu);
891 			fprintf(out, "\n"
892 				     "#\n"
893 				     "# %s\n"
894 				     "#\n", str);
895 			need_newline = false;
896 		} else if (!(sym->flags & SYMBOL_CHOICE) &&
897 			   !(sym->flags & SYMBOL_WRITTEN)) {
898 			sym_calc_value(sym);
899 			if (!(sym->flags & SYMBOL_WRITE))
900 				goto next;
901 			if (need_newline) {
902 				fprintf(out, "\n");
903 				need_newline = false;
904 			}
905 			sym->flags |= SYMBOL_WRITTEN;
906 			conf_write_symbol(out, sym, &kconfig_printer_cb, NULL);
907 		}
908 
909 next:
910 		if (menu->list) {
911 			menu = menu->list;
912 			continue;
913 		}
914 		if (menu->next)
915 			menu = menu->next;
916 		else while ((menu = menu->parent)) {
917 			if (!menu->sym && menu_is_visible(menu) &&
918 			    menu != &rootmenu) {
919 				str = menu_get_prompt(menu);
920 				fprintf(out, "# end of %s\n", str);
921 				need_newline = true;
922 			}
923 			if (menu->next) {
924 				menu = menu->next;
925 				break;
926 			}
927 		}
928 	}
929 	fclose(out);
930 
931 	for_all_symbols(i, sym)
932 		sym->flags &= ~SYMBOL_WRITTEN;
933 
934 	if (*tmpname) {
935 		if (is_same(name, tmpname)) {
936 			conf_message("No change to %s", name);
937 			unlink(tmpname);
938 			conf_set_changed(false);
939 			return 0;
940 		}
941 
942 		snprintf(oldname, sizeof(oldname), "%s.old", name);
943 		rename(name, oldname);
944 		if (rename(tmpname, name))
945 			return 1;
946 	}
947 
948 	conf_message("configuration written to %s", name);
949 
950 	conf_set_changed(false);
951 
952 	return 0;
953 }
954 
955 /* write a dependency file as used by kbuild to track dependencies */
956 static int conf_write_dep(const char *name)
957 {
958 	struct file *file;
959 	FILE *out;
960 
961 	out = fopen("..config.tmp", "w");
962 	if (!out)
963 		return 1;
964 	fprintf(out, "deps_config := \\\n");
965 	for (file = file_list; file; file = file->next) {
966 		if (file->next)
967 			fprintf(out, "\t%s \\\n", file->name);
968 		else
969 			fprintf(out, "\t%s\n", file->name);
970 	}
971 	fprintf(out, "\n%s: \\\n"
972 		     "\t$(deps_config)\n\n", conf_get_autoconfig_name());
973 
974 	env_write_dep(out, conf_get_autoconfig_name());
975 
976 	fprintf(out, "\n$(deps_config): ;\n");
977 	fclose(out);
978 
979 	if (make_parent_dir(name))
980 		return 1;
981 	rename("..config.tmp", name);
982 	return 0;
983 }
984 
985 static int conf_touch_deps(void)
986 {
987 	const char *name;
988 	struct symbol *sym;
989 	int res, i;
990 
991 	strcpy(depfile_path, "include/config/");
992 	depfile_prefix_len = strlen(depfile_path);
993 
994 	name = conf_get_autoconfig_name();
995 	conf_read_simple(name, S_DEF_AUTO);
996 	sym_calc_value(modules_sym);
997 
998 	for_all_symbols(i, sym) {
999 		sym_calc_value(sym);
1000 		if ((sym->flags & SYMBOL_NO_WRITE) || !sym->name)
1001 			continue;
1002 		if (sym->flags & SYMBOL_WRITE) {
1003 			if (sym->flags & SYMBOL_DEF_AUTO) {
1004 				/*
1005 				 * symbol has old and new value,
1006 				 * so compare them...
1007 				 */
1008 				switch (sym->type) {
1009 				case S_BOOLEAN:
1010 				case S_TRISTATE:
1011 					if (sym_get_tristate_value(sym) ==
1012 					    sym->def[S_DEF_AUTO].tri)
1013 						continue;
1014 					break;
1015 				case S_STRING:
1016 				case S_HEX:
1017 				case S_INT:
1018 					if (!strcmp(sym_get_string_value(sym),
1019 						    sym->def[S_DEF_AUTO].val))
1020 						continue;
1021 					break;
1022 				default:
1023 					break;
1024 				}
1025 			} else {
1026 				/*
1027 				 * If there is no old value, only 'no' (unset)
1028 				 * is allowed as new value.
1029 				 */
1030 				switch (sym->type) {
1031 				case S_BOOLEAN:
1032 				case S_TRISTATE:
1033 					if (sym_get_tristate_value(sym) == no)
1034 						continue;
1035 					break;
1036 				default:
1037 					break;
1038 				}
1039 			}
1040 		} else if (!(sym->flags & SYMBOL_DEF_AUTO))
1041 			/* There is neither an old nor a new value. */
1042 			continue;
1043 		/* else
1044 		 *	There is an old value, but no new value ('no' (unset)
1045 		 *	isn't saved in auto.conf, so the old value is always
1046 		 *	different from 'no').
1047 		 */
1048 
1049 		res = conf_touch_dep(sym->name);
1050 		if (res)
1051 			return res;
1052 	}
1053 
1054 	return 0;
1055 }
1056 
1057 int conf_write_autoconf(int overwrite)
1058 {
1059 	struct symbol *sym;
1060 	const char *name;
1061 	const char *autoconf_name = conf_get_autoconfig_name();
1062 	FILE *out, *out_h;
1063 	int i;
1064 
1065 	if (!overwrite && is_present(autoconf_name))
1066 		return 0;
1067 
1068 	conf_write_dep("include/config/auto.conf.cmd");
1069 
1070 	if (conf_touch_deps())
1071 		return 1;
1072 
1073 	out = fopen(".tmpconfig", "w");
1074 	if (!out)
1075 		return 1;
1076 
1077 	out_h = fopen(".tmpconfig.h", "w");
1078 	if (!out_h) {
1079 		fclose(out);
1080 		return 1;
1081 	}
1082 
1083 	conf_write_heading(out, &kconfig_printer_cb, NULL);
1084 	conf_write_heading(out_h, &header_printer_cb, NULL);
1085 
1086 	for_all_symbols(i, sym) {
1087 		sym_calc_value(sym);
1088 		if (!(sym->flags & SYMBOL_WRITE) || !sym->name)
1089 			continue;
1090 
1091 		/* write symbols to auto.conf and autoconf.h */
1092 		conf_write_symbol(out, sym, &kconfig_printer_cb, (void *)1);
1093 		conf_write_symbol(out_h, sym, &header_printer_cb, NULL);
1094 	}
1095 	fclose(out);
1096 	fclose(out_h);
1097 
1098 	name = getenv("KCONFIG_AUTOHEADER");
1099 	if (!name)
1100 		name = "include/generated/autoconf.h";
1101 	if (make_parent_dir(name))
1102 		return 1;
1103 	if (rename(".tmpconfig.h", name))
1104 		return 1;
1105 
1106 	if (make_parent_dir(autoconf_name))
1107 		return 1;
1108 	/*
1109 	 * This must be the last step, kbuild has a dependency on auto.conf
1110 	 * and this marks the successful completion of the previous steps.
1111 	 */
1112 	if (rename(".tmpconfig", autoconf_name))
1113 		return 1;
1114 
1115 	return 0;
1116 }
1117 
1118 static bool conf_changed;
1119 static void (*conf_changed_callback)(void);
1120 
1121 void conf_set_changed(bool val)
1122 {
1123 	if (conf_changed_callback && conf_changed != val)
1124 		conf_changed_callback();
1125 
1126 	conf_changed = val;
1127 }
1128 
1129 bool conf_get_changed(void)
1130 {
1131 	return conf_changed;
1132 }
1133 
1134 void conf_set_changed_callback(void (*fn)(void))
1135 {
1136 	conf_changed_callback = fn;
1137 }
1138 
1139 void set_all_choice_values(struct symbol *csym)
1140 {
1141 	struct property *prop;
1142 	struct symbol *sym;
1143 	struct expr *e;
1144 
1145 	prop = sym_get_choice_prop(csym);
1146 
1147 	/*
1148 	 * Set all non-assinged choice values to no
1149 	 */
1150 	expr_list_for_each_sym(prop->expr, e, sym) {
1151 		if (!sym_has_value(sym))
1152 			sym->def[S_DEF_USER].tri = no;
1153 	}
1154 	csym->flags |= SYMBOL_DEF_USER;
1155 	/* clear VALID to get value calculated */
1156 	csym->flags &= ~(SYMBOL_VALID | SYMBOL_NEED_SET_CHOICE_VALUES);
1157 }
1158