xref: /linux/scripts/kconfig/confdata.c (revision ba6ec09911b805778a2fed6d626bfe77b011a717)
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 <xalloc.h>
22 #include "internal.h"
23 #include "lkc.h"
24 
25 struct gstr autoconf_cmd;
26 
27 /* return true if 'path' exists, false otherwise */
is_present(const char * path)28 static bool is_present(const char *path)
29 {
30 	struct stat st;
31 
32 	return !stat(path, &st);
33 }
34 
35 /* return true if 'path' exists and it is a directory, false otherwise */
is_dir(const char * path)36 static bool is_dir(const char *path)
37 {
38 	struct stat st;
39 
40 	if (stat(path, &st))
41 		return false;
42 
43 	return S_ISDIR(st.st_mode);
44 }
45 
46 /* return true if the given two files are the same, false otherwise */
is_same(const char * file1,const char * file2)47 static bool is_same(const char *file1, const char *file2)
48 {
49 	int fd1, fd2;
50 	struct stat st1, st2;
51 	void *map1, *map2;
52 	bool ret = false;
53 
54 	fd1 = open(file1, O_RDONLY);
55 	if (fd1 < 0)
56 		return ret;
57 
58 	fd2 = open(file2, O_RDONLY);
59 	if (fd2 < 0)
60 		goto close1;
61 
62 	ret = fstat(fd1, &st1);
63 	if (ret)
64 		goto close2;
65 	ret = fstat(fd2, &st2);
66 	if (ret)
67 		goto close2;
68 
69 	if (st1.st_size != st2.st_size)
70 		goto close2;
71 
72 	map1 = mmap(NULL, st1.st_size, PROT_READ, MAP_PRIVATE, fd1, 0);
73 	if (map1 == MAP_FAILED)
74 		goto close2;
75 
76 	map2 = mmap(NULL, st2.st_size, PROT_READ, MAP_PRIVATE, fd2, 0);
77 	if (map2 == MAP_FAILED)
78 		goto close2;
79 
80 	if (bcmp(map1, map2, st1.st_size))
81 		goto close2;
82 
83 	ret = true;
84 close2:
85 	close(fd2);
86 close1:
87 	close(fd1);
88 
89 	return ret;
90 }
91 
92 /*
93  * Create the parent directory of the given path.
94  *
95  * For example, if 'include/config/auto.conf' is given, create 'include/config'.
96  */
make_parent_dir(const char * path)97 static int make_parent_dir(const char *path)
98 {
99 	char tmp[PATH_MAX + 1];
100 	char *p;
101 
102 	strncpy(tmp, path, sizeof(tmp));
103 	tmp[sizeof(tmp) - 1] = 0;
104 
105 	/* Remove the base name. Just return if nothing is left */
106 	p = strrchr(tmp, '/');
107 	if (!p)
108 		return 0;
109 	*(p + 1) = 0;
110 
111 	/* Just in case it is an absolute path */
112 	p = tmp;
113 	while (*p == '/')
114 		p++;
115 
116 	while ((p = strchr(p, '/'))) {
117 		*p = 0;
118 
119 		/* skip if the directory exists */
120 		if (!is_dir(tmp) && mkdir(tmp, 0755))
121 			return -1;
122 
123 		*p = '/';
124 		while (*p == '/')
125 			p++;
126 	}
127 
128 	return 0;
129 }
130 
131 static char depfile_path[PATH_MAX];
132 static size_t depfile_prefix_len;
133 
134 /* touch depfile for symbol 'name' */
conf_touch_dep(const char * name)135 static int conf_touch_dep(const char *name)
136 {
137 	int fd;
138 
139 	/* check overflow: prefix + name + '\0' must fit in buffer. */
140 	if (depfile_prefix_len + strlen(name) + 1 > sizeof(depfile_path))
141 		return -1;
142 
143 	strcpy(depfile_path + depfile_prefix_len, name);
144 
145 	fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
146 	if (fd == -1)
147 		return -1;
148 	close(fd);
149 
150 	return 0;
151 }
152 
153 static void conf_warning(const char *fmt, ...)
154 	__attribute__ ((format (printf, 1, 2)));
155 
156 static void conf_message(const char *fmt, ...)
157 	__attribute__ ((format (printf, 1, 2)));
158 
159 static const char *conf_filename;
160 static int conf_lineno, conf_warnings;
161 
conf_errors(void)162 bool conf_errors(void)
163 {
164 	if (conf_warnings)
165 		return getenv("KCONFIG_WERROR");
166 	return false;
167 }
168 
conf_warning(const char * fmt,...)169 static void conf_warning(const char *fmt, ...)
170 {
171 	va_list ap;
172 	va_start(ap, fmt);
173 	fprintf(stderr, "%s:%d:warning: ", conf_filename, conf_lineno);
174 	vfprintf(stderr, fmt, ap);
175 	fprintf(stderr, "\n");
176 	va_end(ap);
177 	conf_warnings++;
178 }
179 
conf_default_message_callback(const char * s)180 static void conf_default_message_callback(const char *s)
181 {
182 	printf("#\n# ");
183 	printf("%s", s);
184 	printf("\n#\n");
185 }
186 
187 static void (*conf_message_callback)(const char *s) =
188 	conf_default_message_callback;
conf_set_message_callback(void (* fn)(const char * s))189 void conf_set_message_callback(void (*fn)(const char *s))
190 {
191 	conf_message_callback = fn;
192 }
193 
conf_message(const char * fmt,...)194 static void conf_message(const char *fmt, ...)
195 {
196 	va_list ap;
197 	char buf[4096];
198 
199 	if (!conf_message_callback)
200 		return;
201 
202 	va_start(ap, fmt);
203 
204 	vsnprintf(buf, sizeof(buf), fmt, ap);
205 	conf_message_callback(buf);
206 	va_end(ap);
207 }
208 
conf_get_configname(void)209 const char *conf_get_configname(void)
210 {
211 	char *name = getenv("KCONFIG_CONFIG");
212 
213 	return name ? name : ".config";
214 }
215 
conf_get_autoconfig_name(void)216 static const char *conf_get_autoconfig_name(void)
217 {
218 	char *name = getenv("KCONFIG_AUTOCONFIG");
219 
220 	return name ? name : "include/config/auto.conf";
221 }
222 
conf_get_autoheader_name(void)223 static const char *conf_get_autoheader_name(void)
224 {
225 	char *name = getenv("KCONFIG_AUTOHEADER");
226 
227 	return name ? name : "include/generated/autoconf.h";
228 }
229 
conf_get_rustccfg_name(void)230 static const char *conf_get_rustccfg_name(void)
231 {
232 	char *name = getenv("KCONFIG_RUSTCCFG");
233 
234 	return name ? name : "include/generated/rustc_cfg";
235 }
236 
conf_set_sym_val(struct symbol * sym,int def,int def_flags,char * p)237 static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
238 {
239 	char *p2;
240 
241 	switch (sym->type) {
242 	case S_TRISTATE:
243 		if (p[0] == 'm') {
244 			sym->def[def].tri = mod;
245 			sym->flags |= def_flags;
246 			break;
247 		}
248 		/* fall through */
249 	case S_BOOLEAN:
250 		if (p[0] == 'y') {
251 			sym->def[def].tri = yes;
252 			sym->flags |= def_flags;
253 			break;
254 		}
255 		if (p[0] == 'n') {
256 			sym->def[def].tri = no;
257 			sym->flags |= def_flags;
258 			break;
259 		}
260 		if (def != S_DEF_AUTO)
261 			conf_warning("symbol value '%s' invalid for %s",
262 				     p, sym->name);
263 		return 1;
264 	case S_STRING:
265 		/* No escaping for S_DEF_AUTO (include/config/auto.conf) */
266 		if (def != S_DEF_AUTO) {
267 			if (*p++ != '"')
268 				break;
269 			for (p2 = p; (p2 = strpbrk(p2, "\"\\")); p2++) {
270 				if (*p2 == '"') {
271 					*p2 = 0;
272 					break;
273 				}
274 				memmove(p2, p2 + 1, strlen(p2));
275 			}
276 			if (!p2) {
277 				conf_warning("invalid string found");
278 				return 1;
279 			}
280 		}
281 		/* fall through */
282 	case S_INT:
283 	case S_HEX:
284 		if (sym_string_valid(sym, p)) {
285 			sym->def[def].val = xstrdup(p);
286 			sym->flags |= def_flags;
287 		} else {
288 			if (def != S_DEF_AUTO)
289 				conf_warning("symbol value '%s' invalid for %s",
290 					     p, sym->name);
291 			return 1;
292 		}
293 		break;
294 	default:
295 		;
296 	}
297 	return 0;
298 }
299 
300 /* like getline(), but the newline character is stripped away */
getline_stripped(char ** lineptr,size_t * n,FILE * stream)301 static ssize_t getline_stripped(char **lineptr, size_t *n, FILE *stream)
302 {
303 	ssize_t len;
304 
305 	len = getline(lineptr, n, stream);
306 
307 	if (len > 0 && (*lineptr)[len - 1] == '\n') {
308 		len--;
309 		(*lineptr)[len] = '\0';
310 
311 		if (len > 0 && (*lineptr)[len - 1] == '\r') {
312 			len--;
313 			(*lineptr)[len] = '\0';
314 		}
315 	}
316 
317 	return len;
318 }
319 
conf_read_simple(const char * name,int def)320 int conf_read_simple(const char *name, int def)
321 {
322 	FILE *in = NULL;
323 	char   *line = NULL;
324 	size_t  line_asize = 0;
325 	char *p, *val;
326 	struct symbol *sym;
327 	int def_flags;
328 	const char *warn_unknown, *sym_name;
329 
330 	warn_unknown = getenv("KCONFIG_WARN_UNKNOWN_SYMBOLS");
331 	if (name) {
332 		in = zconf_fopen(name);
333 	} else {
334 		char *env;
335 
336 		name = conf_get_configname();
337 		in = zconf_fopen(name);
338 		if (in)
339 			goto load;
340 		conf_set_changed(true);
341 
342 		env = getenv("KCONFIG_DEFCONFIG_LIST");
343 		if (!env)
344 			return 1;
345 
346 		while (1) {
347 			bool is_last;
348 
349 			while (isspace(*env))
350 				env++;
351 
352 			if (!*env)
353 				break;
354 
355 			p = env;
356 			while (*p && !isspace(*p))
357 				p++;
358 
359 			is_last = (*p == '\0');
360 
361 			*p = '\0';
362 
363 			name = env;
364 
365 			in = zconf_fopen(name);
366 			if (in) {
367 				conf_message("using defaults found in %s",
368 					     name);
369 				goto load;
370 			}
371 
372 			if (is_last)
373 				break;
374 
375 			env = p + 1;
376 		}
377 	}
378 	if (!in)
379 		return 1;
380 
381 load:
382 	conf_filename = name;
383 	conf_lineno = 0;
384 	conf_warnings = 0;
385 
386 	def_flags = SYMBOL_DEF << def;
387 	for_all_symbols(sym) {
388 		sym->flags &= ~(def_flags|SYMBOL_VALID);
389 		switch (sym->type) {
390 		case S_INT:
391 		case S_HEX:
392 		case S_STRING:
393 			free(sym->def[def].val);
394 			/* fall through */
395 		default:
396 			sym->def[def].val = NULL;
397 			sym->def[def].tri = no;
398 		}
399 	}
400 
401 	expr_invalidate_all();
402 
403 	while (getline_stripped(&line, &line_asize, in) != -1) {
404 		struct menu *choice;
405 
406 		conf_lineno++;
407 
408 		if (!line[0]) /* blank line */
409 			continue;
410 
411 		if (line[0] == '#') {
412 			if (line[1] != ' ')
413 				continue;
414 			p = line + 2;
415 			if (memcmp(p, CONFIG_, strlen(CONFIG_)))
416 				continue;
417 			sym_name = p + strlen(CONFIG_);
418 			p = strchr(sym_name, ' ');
419 			if (!p)
420 				continue;
421 			*p++ = 0;
422 			if (strcmp(p, "is not set"))
423 				continue;
424 
425 			val = "n";
426 		} else {
427 			if (memcmp(line, CONFIG_, strlen(CONFIG_))) {
428 				conf_warning("unexpected data: %s", line);
429 				continue;
430 			}
431 
432 			sym_name = line + strlen(CONFIG_);
433 			p = strchr(sym_name, '=');
434 			if (!p) {
435 				conf_warning("unexpected data: %s", line);
436 				continue;
437 			}
438 			*p = 0;
439 			val = p + 1;
440 		}
441 
442 		sym = sym_find(sym_name);
443 		if (!sym) {
444 			if (def == S_DEF_AUTO) {
445 				/*
446 				 * Reading from include/config/auto.conf.
447 				 * If CONFIG_FOO previously existed in auto.conf
448 				 * but it is missing now, include/config/FOO
449 				 * must be touched.
450 				 */
451 				conf_touch_dep(sym_name);
452 			} else {
453 				if (warn_unknown)
454 					conf_warning("unknown symbol: %s", sym_name);
455 
456 				conf_set_changed(true);
457 			}
458 			continue;
459 		}
460 
461 		if (sym->flags & def_flags)
462 			conf_warning("override: reassigning to symbol %s", sym->name);
463 
464 		if (conf_set_sym_val(sym, def, def_flags, val))
465 			continue;
466 
467 		/*
468 		 * If this is a choice member, give it the highest priority.
469 		 * If conflicting CONFIG options are given from an input file,
470 		 * the last one wins.
471 		 */
472 		choice = sym_get_choice_menu(sym);
473 		if (choice)
474 			list_move(&sym->choice_link, &choice->choice_members);
475 	}
476 	free(line);
477 	fclose(in);
478 
479 	return 0;
480 }
481 
conf_read(const char * name)482 int conf_read(const char *name)
483 {
484 	struct symbol *sym;
485 
486 	conf_set_changed(false);
487 
488 	if (conf_read_simple(name, S_DEF_USER)) {
489 		sym_calc_value(modules_sym);
490 		return 1;
491 	}
492 
493 	sym_calc_value(modules_sym);
494 
495 	for_all_symbols(sym) {
496 		sym_calc_value(sym);
497 		if (sym_is_choice(sym))
498 			continue;
499 		if (sym_has_value(sym) && (sym->flags & SYMBOL_WRITE)) {
500 			/* check that calculated value agrees with saved value */
501 			switch (sym->type) {
502 			case S_BOOLEAN:
503 			case S_TRISTATE:
504 				if (sym->def[S_DEF_USER].tri == sym_get_tristate_value(sym))
505 					continue;
506 				break;
507 			default:
508 				if (!strcmp(sym->curr.val, sym->def[S_DEF_USER].val))
509 					continue;
510 				break;
511 			}
512 		} else if (!sym_has_value(sym) && !(sym->flags & SYMBOL_WRITE))
513 			/* no previous value and not saved */
514 			continue;
515 		conf_set_changed(true);
516 		/* maybe print value in verbose mode... */
517 	}
518 
519 	if (conf_warnings)
520 		conf_set_changed(true);
521 
522 	return 0;
523 }
524 
525 struct comment_style {
526 	const char *decoration;
527 	const char *prefix;
528 	const char *postfix;
529 };
530 
531 static const struct comment_style comment_style_pound = {
532 	.decoration = "#",
533 	.prefix = "#",
534 	.postfix = "#",
535 };
536 
537 static const struct comment_style comment_style_c = {
538 	.decoration = " *",
539 	.prefix = "/*",
540 	.postfix = " */",
541 };
542 
conf_write_heading(FILE * fp,const struct comment_style * cs)543 static void conf_write_heading(FILE *fp, const struct comment_style *cs)
544 {
545 	if (!cs)
546 		return;
547 
548 	fprintf(fp, "%s\n", cs->prefix);
549 
550 	fprintf(fp, "%s Automatically generated file; DO NOT EDIT.\n",
551 		cs->decoration);
552 
553 	fprintf(fp, "%s %s\n", cs->decoration, rootmenu.prompt->text);
554 
555 	fprintf(fp, "%s\n", cs->postfix);
556 }
557 
558 /* The returned pointer must be freed on the caller side */
escape_string_value(const char * in)559 static char *escape_string_value(const char *in)
560 {
561 	const char *p;
562 	char *out;
563 	size_t len;
564 
565 	len = strlen(in) + strlen("\"\"") + 1;
566 
567 	p = in;
568 	while (1) {
569 		p += strcspn(p, "\"\\");
570 
571 		if (p[0] == '\0')
572 			break;
573 
574 		len++;
575 		p++;
576 	}
577 
578 	out = xmalloc(len);
579 	out[0] = '\0';
580 
581 	strcat(out, "\"");
582 
583 	p = in;
584 	while (1) {
585 		len = strcspn(p, "\"\\");
586 		strncat(out, p, len);
587 		p += len;
588 
589 		if (p[0] == '\0')
590 			break;
591 
592 		strcat(out, "\\");
593 		strncat(out, p++, 1);
594 	}
595 
596 	strcat(out, "\"");
597 
598 	return out;
599 }
600 
601 enum output_n { OUTPUT_N, OUTPUT_N_AS_UNSET, OUTPUT_N_NONE };
602 
__print_symbol(FILE * fp,struct symbol * sym,enum output_n output_n,bool escape_string)603 static void __print_symbol(FILE *fp, struct symbol *sym, enum output_n output_n,
604 			   bool escape_string)
605 {
606 	const char *val;
607 	char *escaped = NULL;
608 
609 	if (sym->type == S_UNKNOWN)
610 		return;
611 
612 	val = sym_get_string_value(sym);
613 
614 	if ((sym->type == S_BOOLEAN || sym->type == S_TRISTATE) &&
615 	    output_n != OUTPUT_N && *val == 'n') {
616 		if (output_n == OUTPUT_N_AS_UNSET)
617 			fprintf(fp, "# %s%s is not set\n", CONFIG_, sym->name);
618 		return;
619 	}
620 
621 	if (sym->type == S_STRING && escape_string) {
622 		escaped = escape_string_value(val);
623 		val = escaped;
624 	}
625 
626 	fprintf(fp, "%s%s=%s\n", CONFIG_, sym->name, val);
627 
628 	free(escaped);
629 }
630 
print_symbol_for_dotconfig(FILE * fp,struct symbol * sym)631 static void print_symbol_for_dotconfig(FILE *fp, struct symbol *sym)
632 {
633 	__print_symbol(fp, sym, OUTPUT_N_AS_UNSET, true);
634 }
635 
print_symbol_for_autoconf(FILE * fp,struct symbol * sym)636 static void print_symbol_for_autoconf(FILE *fp, struct symbol *sym)
637 {
638 	__print_symbol(fp, sym, OUTPUT_N_NONE, false);
639 }
640 
print_symbol_for_listconfig(struct symbol * sym)641 void print_symbol_for_listconfig(struct symbol *sym)
642 {
643 	__print_symbol(stdout, sym, OUTPUT_N, true);
644 }
645 
print_symbol_for_c(FILE * fp,struct symbol * sym)646 static void print_symbol_for_c(FILE *fp, struct symbol *sym)
647 {
648 	const char *val;
649 	const char *sym_suffix = "";
650 	const char *val_prefix = "";
651 	char *escaped = NULL;
652 
653 	if (sym->type == S_UNKNOWN)
654 		return;
655 
656 	val = sym_get_string_value(sym);
657 
658 	switch (sym->type) {
659 	case S_BOOLEAN:
660 	case S_TRISTATE:
661 		switch (*val) {
662 		case 'n':
663 			return;
664 		case 'm':
665 			sym_suffix = "_MODULE";
666 			/* fall through */
667 		default:
668 			val = "1";
669 		}
670 		break;
671 	case S_HEX:
672 		if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
673 			val_prefix = "0x";
674 		break;
675 	case S_STRING:
676 		escaped = escape_string_value(val);
677 		val = escaped;
678 	default:
679 		break;
680 	}
681 
682 	fprintf(fp, "#define %s%s%s %s%s\n", CONFIG_, sym->name, sym_suffix,
683 		val_prefix, val);
684 
685 	free(escaped);
686 }
687 
print_symbol_for_rustccfg(FILE * fp,struct symbol * sym)688 static void print_symbol_for_rustccfg(FILE *fp, struct symbol *sym)
689 {
690 	const char *val;
691 	const char *val_prefix = "";
692 	char *val_prefixed = NULL;
693 	size_t val_prefixed_len;
694 	char *escaped = NULL;
695 
696 	if (sym->type == S_UNKNOWN)
697 		return;
698 
699 	val = sym_get_string_value(sym);
700 
701 	switch (sym->type) {
702 	case S_BOOLEAN:
703 	case S_TRISTATE:
704 		/*
705 		 * We do not care about disabled ones, i.e. no need for
706 		 * what otherwise are "comments" in other printers.
707 		 */
708 		if (*val == 'n')
709 			return;
710 
711 		/*
712 		 * To have similar functionality to the C macro `IS_ENABLED()`
713 		 * we provide an empty `--cfg CONFIG_X` here in both `y`
714 		 * and `m` cases.
715 		 *
716 		 * Then, the common `fprintf()` below will also give us
717 		 * a `--cfg CONFIG_X="y"` or `--cfg CONFIG_X="m"`, which can
718 		 * be used as the equivalent of `IS_BUILTIN()`/`IS_MODULE()`.
719 		 */
720 		fprintf(fp, "--cfg=%s%s\n", CONFIG_, sym->name);
721 		break;
722 	case S_HEX:
723 		if (val[0] != '0' || (val[1] != 'x' && val[1] != 'X'))
724 			val_prefix = "0x";
725 		break;
726 	default:
727 		break;
728 	}
729 
730 	if (strlen(val_prefix) > 0) {
731 		val_prefixed_len = strlen(val) + strlen(val_prefix) + 1;
732 		val_prefixed = xmalloc(val_prefixed_len);
733 		snprintf(val_prefixed, val_prefixed_len, "%s%s", val_prefix, val);
734 		val = val_prefixed;
735 	}
736 
737 	/* All values get escaped: the `--cfg` option only takes strings */
738 	escaped = escape_string_value(val);
739 	val = escaped;
740 
741 	fprintf(fp, "--cfg=%s%s=%s\n", CONFIG_, sym->name, val);
742 
743 	free(escaped);
744 	free(val_prefixed);
745 }
746 
747 /*
748  * Write out a minimal config.
749  * All values that has default values are skipped as this is redundant.
750  */
conf_write_defconfig(const char * filename)751 int conf_write_defconfig(const char *filename)
752 {
753 	struct symbol *sym;
754 	struct menu *menu;
755 	FILE *out;
756 
757 	out = fopen(filename, "w");
758 	if (!out)
759 		return 1;
760 
761 	sym_clear_all_valid();
762 
763 	menu_for_each_entry(menu) {
764 		struct menu *choice;
765 
766 		sym = menu->sym;
767 
768 		if (!sym || sym_is_choice(sym))
769 			continue;
770 
771 		sym_calc_value(sym);
772 		if (!(sym->flags & SYMBOL_WRITE))
773 			continue;
774 		sym->flags &= ~SYMBOL_WRITE;
775 		/* Skip unchangeable symbols */
776 		if (!sym_is_changeable(sym))
777 			continue;
778 		/* Skip symbols that are equal to the default */
779 		if (!strcmp(sym_get_string_value(sym), sym_get_string_default(sym)))
780 			continue;
781 
782 		/* Skip choice values that are equal to the default */
783 		choice = sym_get_choice_menu(sym);
784 		if (choice) {
785 			struct symbol *ds;
786 
787 			ds = sym_choice_default(choice);
788 			if (sym == ds && sym_get_tristate_value(sym) == yes)
789 				continue;
790 		}
791 		print_symbol_for_dotconfig(out, sym);
792 	}
793 	fclose(out);
794 	return 0;
795 }
796 
conf_write(const char * name)797 int conf_write(const char *name)
798 {
799 	FILE *out;
800 	struct symbol *sym;
801 	struct menu *menu;
802 	const char *str;
803 	char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1];
804 	char *env;
805 	bool need_newline = false;
806 
807 	if (!name)
808 		name = conf_get_configname();
809 
810 	if (!*name) {
811 		fprintf(stderr, "config name is empty\n");
812 		return -1;
813 	}
814 
815 	if (is_dir(name)) {
816 		fprintf(stderr, "%s: Is a directory\n", name);
817 		return -1;
818 	}
819 
820 	if (make_parent_dir(name))
821 		return -1;
822 
823 	env = getenv("KCONFIG_OVERWRITECONFIG");
824 	if (env && *env) {
825 		*tmpname = 0;
826 		out = fopen(name, "w");
827 	} else {
828 		snprintf(tmpname, sizeof(tmpname), "%s.%d.tmp",
829 			 name, (int)getpid());
830 		out = fopen(tmpname, "w");
831 	}
832 	if (!out)
833 		return 1;
834 
835 	conf_write_heading(out, &comment_style_pound);
836 
837 	if (!conf_get_changed())
838 		sym_clear_all_valid();
839 
840 	menu = rootmenu.list;
841 	while (menu) {
842 		sym = menu->sym;
843 		if (!sym) {
844 			if (!menu_is_visible(menu))
845 				goto next;
846 			str = menu_get_prompt(menu);
847 			fprintf(out, "\n"
848 				     "#\n"
849 				     "# %s\n"
850 				     "#\n", str);
851 			need_newline = false;
852 		} else if (!sym_is_choice(sym) &&
853 			   !(sym->flags & SYMBOL_WRITTEN)) {
854 			sym_calc_value(sym);
855 			if (!(sym->flags & SYMBOL_WRITE))
856 				goto next;
857 			if (need_newline) {
858 				fprintf(out, "\n");
859 				need_newline = false;
860 			}
861 			sym->flags |= SYMBOL_WRITTEN;
862 			print_symbol_for_dotconfig(out, sym);
863 		}
864 
865 next:
866 		if (menu->list) {
867 			menu = menu->list;
868 			continue;
869 		}
870 
871 end_check:
872 		if (!menu->sym && menu_is_visible(menu) && menu != &rootmenu &&
873 		    menu->prompt->type == P_MENU) {
874 			fprintf(out, "# end of %s\n", menu_get_prompt(menu));
875 			need_newline = true;
876 		}
877 
878 		if (menu->next) {
879 			menu = menu->next;
880 		} else {
881 			menu = menu->parent;
882 			if (menu)
883 				goto end_check;
884 		}
885 	}
886 	fclose(out);
887 
888 	for_all_symbols(sym)
889 		sym->flags &= ~SYMBOL_WRITTEN;
890 
891 	if (*tmpname) {
892 		if (is_same(name, tmpname)) {
893 			conf_message("No change to %s", name);
894 			unlink(tmpname);
895 			conf_set_changed(false);
896 			return 0;
897 		}
898 
899 		snprintf(oldname, sizeof(oldname), "%s.old", name);
900 		rename(name, oldname);
901 		if (rename(tmpname, name))
902 			return 1;
903 	}
904 
905 	conf_message("configuration written to %s", name);
906 
907 	conf_set_changed(false);
908 
909 	return 0;
910 }
911 
912 /* write a dependency file as used by kbuild to track dependencies */
conf_write_autoconf_cmd(const char * autoconf_name)913 static int conf_write_autoconf_cmd(const char *autoconf_name)
914 {
915 	char name[PATH_MAX], tmp[PATH_MAX];
916 	FILE *out;
917 	int ret;
918 
919 	ret = snprintf(name, sizeof(name), "%s.cmd", autoconf_name);
920 	if (ret >= sizeof(name)) /* check truncation */
921 		return -1;
922 
923 	if (make_parent_dir(name))
924 		return -1;
925 
926 	ret = snprintf(tmp, sizeof(tmp), "%s.cmd.tmp", autoconf_name);
927 	if (ret >= sizeof(tmp)) /* check truncation */
928 		return -1;
929 
930 	out = fopen(tmp, "w");
931 	if (!out) {
932 		perror("fopen");
933 		return -1;
934 	}
935 
936 	fprintf(out, "autoconfig := %s\n", autoconf_name);
937 
938 	fputs(str_get(&autoconf_cmd), out);
939 
940 	fflush(out);
941 	ret = ferror(out); /* error check for all fprintf() calls */
942 	fclose(out);
943 	if (ret)
944 		return -1;
945 
946 	if (rename(tmp, name)) {
947 		perror("rename");
948 		return -1;
949 	}
950 
951 	return 0;
952 }
953 
conf_touch_deps(void)954 static int conf_touch_deps(void)
955 {
956 	const char *name, *tmp;
957 	struct symbol *sym;
958 	int res;
959 
960 	name = conf_get_autoconfig_name();
961 	tmp = strrchr(name, '/');
962 	depfile_prefix_len = tmp ? tmp - name + 1 : 0;
963 	if (depfile_prefix_len + 1 > sizeof(depfile_path))
964 		return -1;
965 
966 	strncpy(depfile_path, name, depfile_prefix_len);
967 	depfile_path[depfile_prefix_len] = 0;
968 
969 	conf_read_simple(name, S_DEF_AUTO);
970 	sym_calc_value(modules_sym);
971 
972 	for_all_symbols(sym) {
973 		sym_calc_value(sym);
974 		if (sym_is_choice(sym))
975 			continue;
976 		if (sym->flags & SYMBOL_WRITE) {
977 			if (sym->flags & SYMBOL_DEF_AUTO) {
978 				/*
979 				 * symbol has old and new value,
980 				 * so compare them...
981 				 */
982 				switch (sym->type) {
983 				case S_BOOLEAN:
984 				case S_TRISTATE:
985 					if (sym_get_tristate_value(sym) ==
986 					    sym->def[S_DEF_AUTO].tri)
987 						continue;
988 					break;
989 				case S_STRING:
990 				case S_HEX:
991 				case S_INT:
992 					if (!strcmp(sym_get_string_value(sym),
993 						    sym->def[S_DEF_AUTO].val))
994 						continue;
995 					break;
996 				default:
997 					break;
998 				}
999 			} else {
1000 				/*
1001 				 * If there is no old value, only 'no' (unset)
1002 				 * is allowed as new value.
1003 				 */
1004 				switch (sym->type) {
1005 				case S_BOOLEAN:
1006 				case S_TRISTATE:
1007 					if (sym_get_tristate_value(sym) == no)
1008 						continue;
1009 					break;
1010 				default:
1011 					break;
1012 				}
1013 			}
1014 		} else if (!(sym->flags & SYMBOL_DEF_AUTO))
1015 			/* There is neither an old nor a new value. */
1016 			continue;
1017 		/* else
1018 		 *	There is an old value, but no new value ('no' (unset)
1019 		 *	isn't saved in auto.conf, so the old value is always
1020 		 *	different from 'no').
1021 		 */
1022 
1023 		res = conf_touch_dep(sym->name);
1024 		if (res)
1025 			return res;
1026 	}
1027 
1028 	return 0;
1029 }
1030 
__conf_write_autoconf(const char * filename,void (* print_symbol)(FILE *,struct symbol *),const struct comment_style * comment_style)1031 static int __conf_write_autoconf(const char *filename,
1032 				 void (*print_symbol)(FILE *, struct symbol *),
1033 				 const struct comment_style *comment_style)
1034 {
1035 	char tmp[PATH_MAX];
1036 	FILE *file;
1037 	struct symbol *sym;
1038 	int ret;
1039 
1040 	if (make_parent_dir(filename))
1041 		return -1;
1042 
1043 	ret = snprintf(tmp, sizeof(tmp), "%s.tmp", filename);
1044 	if (ret >= sizeof(tmp)) /* check truncation */
1045 		return -1;
1046 
1047 	file = fopen(tmp, "w");
1048 	if (!file) {
1049 		perror("fopen");
1050 		return -1;
1051 	}
1052 
1053 	conf_write_heading(file, comment_style);
1054 
1055 	for_all_symbols(sym)
1056 		if ((sym->flags & SYMBOL_WRITE) && sym->name)
1057 			print_symbol(file, sym);
1058 
1059 	fflush(file);
1060 	/* check possible errors in conf_write_heading() and print_symbol() */
1061 	ret = ferror(file);
1062 	fclose(file);
1063 	if (ret)
1064 		return -1;
1065 
1066 	if (rename(tmp, filename)) {
1067 		perror("rename");
1068 		return -1;
1069 	}
1070 
1071 	return 0;
1072 }
1073 
conf_write_autoconf(int overwrite)1074 int conf_write_autoconf(int overwrite)
1075 {
1076 	struct symbol *sym;
1077 	const char *autoconf_name = conf_get_autoconfig_name();
1078 	int ret;
1079 
1080 	if (!overwrite && is_present(autoconf_name))
1081 		return 0;
1082 
1083 	ret = conf_write_autoconf_cmd(autoconf_name);
1084 	if (ret)
1085 		return -1;
1086 
1087 	if (conf_touch_deps())
1088 		return 1;
1089 
1090 	for_all_symbols(sym)
1091 		sym_calc_value(sym);
1092 
1093 	ret = __conf_write_autoconf(conf_get_autoheader_name(),
1094 				    print_symbol_for_c,
1095 				    &comment_style_c);
1096 	if (ret)
1097 		return ret;
1098 
1099 	ret = __conf_write_autoconf(conf_get_rustccfg_name(),
1100 				    print_symbol_for_rustccfg,
1101 				    NULL);
1102 	if (ret)
1103 		return ret;
1104 
1105 	/*
1106 	 * Create include/config/auto.conf. This must be the last step because
1107 	 * Kbuild has a dependency on auto.conf and this marks the successful
1108 	 * completion of the previous steps.
1109 	 */
1110 	ret = __conf_write_autoconf(conf_get_autoconfig_name(),
1111 				    print_symbol_for_autoconf,
1112 				    &comment_style_pound);
1113 	if (ret)
1114 		return ret;
1115 
1116 	return 0;
1117 }
1118 
1119 static bool conf_changed;
1120 static void (*conf_changed_callback)(bool);
1121 
conf_set_changed(bool val)1122 void conf_set_changed(bool val)
1123 {
1124 	if (conf_changed_callback && conf_changed != val)
1125 		conf_changed_callback(val);
1126 
1127 	conf_changed = val;
1128 }
1129 
conf_get_changed(void)1130 bool conf_get_changed(void)
1131 {
1132 	return conf_changed;
1133 }
1134 
conf_set_changed_callback(void (* fn)(bool))1135 void conf_set_changed_callback(void (*fn)(bool))
1136 {
1137 	conf_changed_callback = fn;
1138 }
1139