1 files changed, 313 insertions, 220 deletions

diff --git a/scripts/config/confdata.c b/scripts/config/confdata.c
index 3a3a4bff43..b696dda5e0 100644
--- a/scripts/config/confdata.c
+++ b/scripts/config/confdata.c
@@ -1,12 +1,14 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2002 Roman Zippel <zippel@linux-m68k.org>
- * Released under the terms of the GNU GPL v2.0.
  */
 
+#include <sys/mman.h>
 #include <sys/stat.h>
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <limits.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -16,6 +18,151 @@
 
 #include "lkc.h"
 
+/* return true if 'path' exists, false otherwise */
+static bool is_present(const char *path)
+{
+	struct stat st;
+
+	return !stat(path, &st);
+}
+
+/* return true if 'path' exists and it is a directory, false otherwise */
+static bool is_dir(const char *path)
+{
+	struct stat st;
+
+	if (stat(path, &st))
+		return 0;
+
+	return S_ISDIR(st.st_mode);
+}
+
+/* return true if the given two files are the same, false otherwise */
+static bool is_same(const char *file1, const char *file2)
+{
+	int fd1, fd2;
+	struct stat st1, st2;
+	void *map1, *map2;
+	bool ret = false;
+
+	fd1 = open(file1, O_RDONLY);
+	if (fd1 < 0)
+		return ret;
+
+	fd2 = open(file2, O_RDONLY);
+	if (fd2 < 0)
+		goto close1;
+
+	ret = fstat(fd1, &st1);
+	if (ret)
+		goto close2;
+	ret = fstat(fd2, &st2);
+	if (ret)
+		goto close2;
+
+	if (st1.st_size != st2.st_size)
+		goto close2;
+
+	map1 = mmap(NULL, st1.st_size, PROT_READ, MAP_PRIVATE, fd1, 0);
+	if (map1 == MAP_FAILED)
+		goto close2;
+
+	map2 = mmap(NULL, st2.st_size, PROT_READ, MAP_PRIVATE, fd2, 0);
+	if (map2 == MAP_FAILED)
+		goto close2;
+
+	if (bcmp(map1, map2, st1.st_size))
+		goto close2;
+
+	ret = true;
+close2:
+	close(fd2);
+close1:
+	close(fd1);
+
+	return ret;
+}
+
+/*
+ * Create the parent directory of the given path.
+ *
+ * For example, if 'include/config/auto.conf' is given, create 'include/config'.
+ */
+static int make_parent_dir(const char *path)
+{
+	char tmp[PATH_MAX + 1];
+	char *p;
+
+	strncpy(tmp, path, sizeof(tmp));
+	tmp[sizeof(tmp) - 1] = 0;
+
+	/* Remove the base name. Just return if nothing is left */
+	p = strrchr(tmp, '/');
+	if (!p)
+		return 0;
+	*(p + 1) = 0;
+
+	/* Just in case it is an absolute path */
+	p = tmp;
+	while (*p == '/')
+		p++;
+
+	while ((p = strchr(p, '/'))) {
+		*p = 0;
+
+		/* skip if the directory exists */
+		if (!is_dir(tmp) && mkdir(tmp, 0755))
+			return -1;
+
+		*p = '/';
+		while (*p == '/')
+			p++;
+	}
+
+	return 0;
+}
+
+static char depfile_path[PATH_MAX];
+static size_t depfile_prefix_len;
+
+/* touch depfile for symbol 'name' */
+static int conf_touch_dep(const char *name)
+{
+	int fd, ret;
+	const char *s;
+	char *d, c;
+
+	/* check overflow: prefix + name + ".h" + '\0' must fit in buffer. */
+	if (depfile_prefix_len + strlen(name) + 3 > sizeof(depfile_path))
+		return -1;
+
+	d = depfile_path + depfile_prefix_len;
+	s = name;
+
+	while ((c = *s++))
+		*d++ = (c == '_') ? '/' : tolower(c);
+	strcpy(d, ".h");
+
+	/* Assume directory path already exists. */
+	fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+	if (fd == -1) {
+		if (errno != ENOENT)
+			return -1;
+
+		ret = make_parent_dir(depfile_path);
+		if (ret)
+			return ret;
+
+		/* Try it again. */
+		fd = open(depfile_path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+		if (fd == -1)
+			return -1;
+	}
+	close(fd);
+
+	return 0;
+}
+
 struct conf_printer {
 	void (*print_symbol)(FILE *, struct symbol *, const char *, void *);
 	void (*print_comment)(FILE *, const char *, void *);
@@ -28,9 +175,7 @@ static void conf_message(const char *fmt, ...)
 	__attribute__ ((format (printf, 1, 2)));
 
 static const char *conf_filename;
-static int conf_lineno, conf_warnings, conf_unsaved;
-
-const char conf_defname[] = "arch/$ARCH/defconfig";
+static int conf_lineno, conf_warnings;
 
 static void conf_warning(const char *fmt, ...)
 {
@@ -43,16 +188,16 @@ static void conf_warning(const char *fmt, ...)
 	conf_warnings++;
 }
 
-static void conf_default_message_callback(const char *fmt, va_list ap)
+static void conf_default_message_callback(const char *s)
 {
 	printf("#\n# ");
-	vprintf(fmt, ap);
+	printf("%s", s);
 	printf("\n#\n");
 }
 
-static void (*conf_message_callback) (const char *fmt, va_list ap) =
+static void (*conf_message_callback)(const char *s) =
 	conf_default_message_callback;
-void conf_set_message_callback(void (*fn) (const char *fmt, va_list ap))
+void conf_set_message_callback(void (*fn)(const char *s))
 {
 	conf_message_callback = fn;
 }
@@ -60,10 +205,15 @@ void conf_set_message_callback(void (*fn) (const char *fmt, va_list ap))
 static void conf_message(const char *fmt, ...)
 {
 	va_list ap;
+	char buf[4096];
+
+	if (!conf_message_callback)
+		return;
 
 	va_start(ap, fmt);
-	if (conf_message_callback)
-		conf_message_callback(fmt, ap);
+
+	vsnprintf(buf, sizeof(buf), fmt, ap);
+	conf_message_callback(buf);
 	va_end(ap);
 }
 
@@ -74,55 +224,13 @@ const char *conf_get_configname(void)
 	return name ? name : ".config";
 }
 
-const char *conf_get_autoconfig_name(void)
+static const char *conf_get_autoconfig_name(void)
 {
 	char *name = getenv("KCONFIG_AUTOCONFIG");
 
 	return name ? name : "include/config/auto.conf";
 }
 
-static char *conf_expand_value(const char *in)
-{
-	struct symbol *sym;
-	const char *src;
-	static char res_value[SYMBOL_MAXLENGTH];
-	char *dst, name[SYMBOL_MAXLENGTH];
-
-	res_value[0] = 0;
-	dst = name;
-	while ((src = strchr(in, '$'))) {
-		strncat(res_value, in, src - in);
-		src++;
-		dst = name;
-		while (isalnum(*src) || *src == '_')
-			*dst++ = *src++;
-		*dst = 0;
-		sym = sym_lookup(name, 0);
-		sym_calc_value(sym);
-		strcat(res_value, sym_get_string_value(sym));
-		in = src;
-	}
-	strcat(res_value, in);
-
-	return res_value;
-}
-
-char *conf_get_default_confname(void)
-{
-	struct stat buf;
-	static char fullname[PATH_MAX+1];
-	char *env, *name;
-
-	name = conf_expand_value(conf_defname);
-	env = getenv(SRCTREE);
-	if (env) {
-		sprintf(fullname, "%s/%s", env, name);
-		if (!stat(fullname, &buf))
-			return fullname;
-	}
-	return name;
-}
-
 static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 {
 	char *p2;
@@ -150,14 +258,6 @@ static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 			conf_warning("symbol value '%s' invalid for %s",
 				     p, sym->name);
 		return 1;
-	case S_OTHER:
-		if (*p != '"') {
-			for (p2 = p; *p2 && !isspace(*p2); p2++)
-				;
-			sym->type = S_STRING;
-			goto done;
-		}
-		/* fall through */
 	case S_STRING:
 		if (*p++ != '"')
 			break;
@@ -176,9 +276,8 @@ static int conf_set_sym_val(struct symbol *sym, int def, int def_flags, char *p)
 		/* fall through */
 	case S_INT:
 	case S_HEX:
-	done:
 		if (sym_string_valid(sym, p)) {
-			sym->def[def].val = strdup(p);
+			sym->def[def].val = xstrdup(p);
 			sym->flags |= def_flags;
 		} else {
 			if (def != S_DEF_AUTO)
@@ -201,7 +300,7 @@ static int add_byte(int c, char **lineptr, size_t slen, size_t *n)
 	if (new_size > *n) {
 		new_size += LINE_GROWTH - 1;
 		new_size *= 2;
-		nline = realloc(*lineptr, new_size);
+		nline = xrealloc(*lineptr, new_size);
 		if (!nline)
 			return -1;
 
@@ -299,10 +398,11 @@ int conf_read_simple(const char *name, int def)
 			if (expr_calc_value(prop->visible.expr) == no ||
 			    prop->expr->type != E_SYMBOL)
 				continue;
-			name = conf_expand_value(prop->expr->left.sym->name);
+			sym_calc_value(prop->expr->left.sym);
+			name = sym_get_string_value(prop->expr->left.sym);
 			in = zconf_fopen(name);
 			if (in) {
-				conf_message(_("using defaults found in %s"),
+				conf_message("using defaults found in %s",
 					 name);
 				goto load;
 			}
@@ -315,7 +415,6 @@ load:
 	conf_filename = name;
 	conf_lineno = 0;
 	conf_warnings = 0;
-	conf_unsaved = 0;
 
 	def_flags = SYMBOL_DEF << def;
 	conf_reset(def);
@@ -336,7 +435,7 @@ load:
 				sym = sym_find(line + 2 + strlen(CONFIG_));
 				if (!sym) {
 					sym_add_change_count(1);
-					goto setsym;
+					continue;
 				}
 			} else {
 				sym = sym_lookup(line + 2 + strlen(CONFIG_), 0);
@@ -363,17 +462,22 @@ load:
 				if (*p2 == '\r')
 					*p2 = 0;
 			}
-			if (def == S_DEF_USER) {
-				sym = sym_find(line + strlen(CONFIG_));
-				if (!sym) {
+
+			sym = sym_find(line + strlen(CONFIG_));
+			if (!sym) {
+				if (def == S_DEF_AUTO)
+					/*
+					 * Reading from include/config/auto.conf
+					 * If CONFIG_FOO previously existed in
+					 * auto.conf but it is missing now,
+					 * include/config/foo.h must be touched.
+					 */
+					conf_touch_dep(line + strlen(CONFIG_));
+				else
 					sym_add_change_count(1);
-					goto setsym;
-				}
-			} else {
-				sym = sym_lookup(line + strlen(CONFIG_), 0);
-				if (sym->type == S_UNKNOWN)
-					sym->type = S_OTHER;
+				continue;
 			}
+
 			if (conf_set_sym_val(sym, def, def_flags, p))
 				continue;
 		} else {
@@ -383,7 +487,7 @@ load:
 
 			continue;
 		}
-setsym:
+
 		if (sym && sym_is_choice_value(sym)) {
 			struct symbol *cs = prop_get_symbol(sym_get_choice_prop(sym));
 			switch (sym->def[def].tri) {
@@ -412,6 +516,7 @@ setsym:
 int conf_read(const char *name)
 {
 	struct symbol *sym;
+	int conf_unsaved = 0;
 	int i;
 
 	sym_set_change_count(0);
@@ -425,18 +530,16 @@ int conf_read(const char *name)
 
 	for_all_symbols(i, sym) {
 		sym_calc_value(sym);
-		if (sym_is_choice(sym) || (sym->flags & SYMBOL_AUTO))
+		if (sym_is_choice(sym) || (sym->flags & SYMBOL_NO_WRITE))
 			continue;
 		if (sym_has_value(sym) && (sym->flags & SYMBOL_WRITE)) {
 			/* check that calculated value agrees with saved value */
 			switch (sym->type) {
 			case S_BOOLEAN:
 			case S_TRISTATE:
-				if (sym->def[S_DEF_USER].tri != sym_get_tristate_value(sym))
-					break;
-				if (!sym_is_choice(sym))
+				if (sym->def[S_DEF_USER].tri == sym_get_tristate_value(sym))
 					continue;
-				/* fall through */
+				break;
 			default:
 				if (!strcmp(sym->curr.val, sym->def[S_DEF_USER].val))
 					continue;
@@ -610,32 +713,12 @@ static struct conf_printer header_printer_cb =
 	.print_comment = header_print_comment,
 };
 
-/*
- * Tristate printer
- *
- * This printer is used when generating the `include/config/tristate.conf' file.
- */
-static void
-tristate_print_symbol(FILE *fp, struct symbol *sym, const char *value, void *arg)
-{
-
-	if (sym->type == S_TRISTATE && *value != 'n')
-		fprintf(fp, "%s%s=%c\n", CONFIG_, sym->name, (char)toupper(*value));
-}
-
-static struct conf_printer tristate_printer_cb =
-{
-	.print_symbol = tristate_print_symbol,
-	.print_comment = kconfig_print_comment,
-};
-
 static void conf_write_symbol(FILE *fp, struct symbol *sym,
 			      struct conf_printer *printer, void *printer_arg)
 {
 	const char *str;
 
 	switch (sym->type) {
-	case S_OTHER:
 	case S_UNKNOWN:
 		break;
 	case S_STRING:
@@ -695,7 +778,7 @@ int conf_write_defconfig(const char *filename)
 				goto next_menu;
 			sym->flags &= ~SYMBOL_WRITE;
 			/* If we cannot change the symbol - skip */
-			if (!sym_is_changable(sym))
+			if (!sym_is_changeable(sym))
 				goto next_menu;
 			/* If symbol equals to default value - skip */
 			if (strcmp(sym_get_string_value(sym), sym_get_string_default(sym)) == 0)
@@ -746,41 +829,36 @@ int conf_write(const char *name)
 	FILE *out;
 	struct symbol *sym;
 	struct menu *menu;
-	const char *basename;
 	const char *str;
-	char dirname[PATH_MAX+1], tmpname[PATH_MAX+1], newname[PATH_MAX+1];
+	char tmpname[PATH_MAX + 1], oldname[PATH_MAX + 1];
 	char *env;
+	int i;
+	bool need_newline = false;
+
+	if (!name)
+		name = conf_get_configname();
+
+	if (!*name) {
+		fprintf(stderr, "config name is empty\n");
+		return -1;
+	}
+
+	if (is_dir(name)) {
+		fprintf(stderr, "%s: Is a directory\n", name);
+		return -1;
+	}
+
+	if (make_parent_dir(name))
+		return -1;
 
-	dirname[0] = 0;
-	if (name && name[0]) {
-		struct stat st;
-		char *slash;
-
-		if (!stat(name, &st) && S_ISDIR(st.st_mode)) {
-			strcpy(dirname, name);
-			strcat(dirname, "/");
-			basename = conf_get_configname();
-		} else if ((slash = strrchr(name, '/'))) {
-			int size = slash - name + 1;
-			memcpy(dirname, name, size);
-			dirname[size] = 0;
-			if (slash[1])
-				basename = slash + 1;
-			else
-				basename = conf_get_configname();
-		} else
-			basename = name;
-	} else
-		basename = conf_get_configname();
-
-	sprintf(newname, "%s%s", dirname, basename);
 	env = getenv("KCONFIG_OVERWRITECONFIG");
-	if (!env || !*env) {
-		sprintf(tmpname, "%s.tmpconfig.%d", dirname, (int)getpid());
-		out = fopen(tmpname, "w");
-	} else {
+	if (env && *env) {
 		*tmpname = 0;
-		out = fopen(newname, "w");
+		out = fopen(name, "w");
+	} else {
+		snprintf(tmpname, sizeof(tmpname), "%s.%d.tmp",
+			 name, (int)getpid());
+		out = fopen(tmpname, "w");
 	}
 	if (!out)
 		return 1;
@@ -801,12 +879,17 @@ int conf_write(const char *name)
 				     "#\n"
 				     "# %s\n"
 				     "#\n", str);
-		} else if (!(sym->flags & SYMBOL_CHOICE)) {
+			need_newline = false;
+		} else if (!(sym->flags & SYMBOL_CHOICE) &&
+			   !(sym->flags & SYMBOL_WRITTEN)) {
 			sym_calc_value(sym);
 			if (!(sym->flags & SYMBOL_WRITE))
 				goto next;
-			sym->flags &= ~SYMBOL_WRITE;
-
+			if (need_newline) {
+				fprintf(out, "\n");
+				need_newline = false;
+			}
+			sym->flags |= SYMBOL_WRITTEN;
 			conf_write_symbol(out, sym, &kconfig_printer_cb, NULL);
 		}
 
@@ -818,6 +901,12 @@ next:
 		if (menu->next)
 			menu = menu->next;
 		else while ((menu = menu->parent)) {
+			if (!menu->sym && menu_is_visible(menu) &&
+			    menu != &rootmenu) {
+				str = menu_get_prompt(menu);
+				fprintf(out, "# end of %s\n", str);
+				need_newline = true;
+			}
 			if (menu->next) {
 				menu = menu->next;
 				break;
@@ -826,41 +915,76 @@ next:
 	}
 	fclose(out);
 
+	for_all_symbols(i, sym)
+		sym->flags &= ~SYMBOL_WRITTEN;
+
 	if (*tmpname) {
-		strcat(dirname, basename);
-		strcat(dirname, ".old");
-		rename(newname, dirname);
-		if (rename(tmpname, newname))
+		if (is_same(name, tmpname)) {
+			conf_message("No change to %s", name);
+			unlink(tmpname);
+			sym_set_change_count(0);
+			return 0;
+		}
+
+		snprintf(oldname, sizeof(oldname), "%s.old", name);
+		rename(name, oldname);
+		if (rename(tmpname, name))
 			return 1;
 	}
 
-	conf_message(_("configuration written to %s"), newname);
+	conf_message("configuration written to %s", name);
 
 	sym_set_change_count(0);
 
 	return 0;
 }
 
-static int conf_split_config(void)
+/* write a dependency file as used by kbuild to track dependencies */
+static int conf_write_dep(const char *name)
+{
+	struct file *file;
+	FILE *out;
+
+	out = fopen("..config.tmp", "w");
+	if (!out)
+		return 1;
+	fprintf(out, "deps_config := \\\n");
+	for (file = file_list; file; file = file->next) {
+		if (file->next)
+			fprintf(out, "\t%s \\\n", file->name);
+		else
+			fprintf(out, "\t%s\n", file->name);
+	}
+	fprintf(out, "\n%s: \\\n"
+		     "\t$(deps_config)\n\n", conf_get_autoconfig_name());
+
+	env_write_dep(out, conf_get_autoconfig_name());
+
+	fprintf(out, "\n$(deps_config): ;\n");
+	fclose(out);
+
+	if (make_parent_dir(name))
+		return 1;
+	rename("..config.tmp", name);
+	return 0;
+}
+
+static int conf_touch_deps(void)
 {
 	const char *name;
-	char path[PATH_MAX+1];
-	char *s, *d, c;
 	struct symbol *sym;
-	struct stat sb;
-	int res, i, fd;
+	int res, i;
+
+	strcpy(depfile_path, "include/config/");
+	depfile_prefix_len = strlen(depfile_path);
 
 	name = conf_get_autoconfig_name();
 	conf_read_simple(name, S_DEF_AUTO);
 	sym_calc_value(modules_sym);
 
-	if (chdir("include/config"))
-		return 1;
-
-	res = 0;
 	for_all_symbols(i, sym) {
 		sym_calc_value(sym);
-		if ((sym->flags & SYMBOL_AUTO) || !sym->name)
+		if ((sym->flags & SYMBOL_NO_WRITE) || !sym->name)
 			continue;
 		if (sym->flags & SYMBOL_WRITE) {
 			if (sym->flags & SYMBOL_DEF_AUTO) {
@@ -909,86 +1033,44 @@ static int conf_split_config(void)
 		 *	different from 'no').
 		 */
 
-		/* Replace all '_' and append ".h" */
-		s = sym->name;
-		d = path;
-		while ((c = *s++)) {
-			c = tolower(c);
-			*d++ = (c == '_') ? '/' : c;
-		}
-		strcpy(d, ".h");
-
-		/* Assume directory path already exists. */
-		fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-		if (fd == -1) {
-			if (errno != ENOENT) {
-				res = 1;
-				break;
-			}
-			/*
-			 * Create directory components,
-			 * unless they exist already.
-			 */
-			d = path;
-			while ((d = strchr(d, '/'))) {
-				*d = 0;
-				if (stat(path, &sb) && mkdir(path, 0755)) {
-					res = 1;
-					goto out;
-				}
-				*d++ = '/';
-			}
-			/* Try it again. */
-			fd = open(path, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-			if (fd == -1) {
-				res = 1;
-				break;
-			}
-		}
-		close(fd);
+		res = conf_touch_dep(sym->name);
+		if (res)
+			return res;
 	}
-out:
-	if (chdir("../.."))
-		return 1;
 
-	return res;
+	return 0;
 }
 
-int conf_write_autoconf(void)
+int conf_write_autoconf(int overwrite)
 {
 	struct symbol *sym;
 	const char *name;
-	FILE *out, *tristate, *out_h;
+	const char *autoconf_name = conf_get_autoconfig_name();
+	FILE *out, *out_h;
 	int i;
 
-	sym_clear_all_valid();
+#ifndef OPENWRT_DOES_NOT_WANT_THIS
+	return 0;
+#endif
+	if (!overwrite && is_present(autoconf_name))
+		return 0;
 
-	file_write_dep("include/config/auto.conf.cmd");
+	conf_write_dep("include/config/auto.conf.cmd");
 
-	if (conf_split_config())
+	if (conf_touch_deps())
 		return 1;
 
 	out = fopen(".tmpconfig", "w");
 	if (!out)
 		return 1;
 
-	tristate = fopen(".tmpconfig_tristate", "w");
-	if (!tristate) {
-		fclose(out);
-		return 1;
-	}
-
 	out_h = fopen(".tmpconfig.h", "w");
 	if (!out_h) {
 		fclose(out);
-		fclose(tristate);
 		return 1;
 	}
 
 	conf_write_heading(out, &kconfig_printer_cb, NULL);
-
-	conf_write_heading(tristate, &tristate_printer_cb, NULL);
-
 	conf_write_heading(out_h, &header_printer_cb, NULL);
 
 	for_all_symbols(i, sym) {
@@ -996,33 +1078,28 @@ int conf_write_autoconf(void)
 		if (!(sym->flags & SYMBOL_WRITE) || !sym->name)
 			continue;
 
-		/* write symbol to auto.conf, tristate and header files */
+		/* write symbols to auto.conf and autoconf.h */
 		conf_write_symbol(out, sym, &kconfig_printer_cb, (void *)1);
-
-		conf_write_symbol(tristate, sym, &tristate_printer_cb, (void *)1);
-
 		conf_write_symbol(out_h, sym, &header_printer_cb, NULL);
 	}
 	fclose(out);
-	fclose(tristate);
 	fclose(out_h);
 
 	name = getenv("KCONFIG_AUTOHEADER");
 	if (!name)
 		name = "include/generated/autoconf.h";
+	if (make_parent_dir(name))
+		return 1;
 	if (rename(".tmpconfig.h", name))
 		return 1;
-	name = getenv("KCONFIG_TRISTATE");
-	if (!name)
-		name = "include/config/tristate.conf";
-	if (rename(".tmpconfig_tristate", name))
+
+	if (make_parent_dir(autoconf_name))
 		return 1;
-	name = conf_get_autoconfig_name();
 	/*
 	 * This must be the last step, kbuild has a dependency on auto.conf
 	 * and this marks the successful completion of the previous steps.
 	 */
-	if (rename(".tmpconfig", name))
+	if (rename(".tmpconfig", autoconf_name))
 		return 1;
 
 	return 0;
@@ -1126,7 +1203,7 @@ void set_all_choice_values(struct symbol *csym)
 bool conf_set_all_new_symbols(enum conf_def_mode mode)
 {
 	struct symbol *sym, *csym;
-	int i, cnt, pby, pty, ptm;	/* pby: probability of boolean  = y
+	int i, cnt, pby, pty, ptm;	/* pby: probability of bool     = y
 					 * pty: probability of tristate = y
 					 * ptm: probability of tristate = m
 					 */
@@ -1250,3 +1327,19 @@ bool conf_set_all_new_symbols(enum conf_def_mode mode)
 
 	return has_changed;
 }
+
+void conf_rewrite_mod_or_yes(enum conf_def_mode mode)
+{
+	struct symbol *sym;
+	int i;
+	tristate old_val = (mode == def_y2m) ? yes : mod;
+	tristate new_val = (mode == def_y2m) ? mod : yes;
+
+	for_all_symbols(i, sym) {
+		if (sym_get_type(sym) == S_TRISTATE &&
+		    sym->def[S_DEF_USER].tri == old_val) {
+			sym->def[S_DEF_USER].tri = new_val;
+			sym_add_change_count(1);
+		}
+	}
+}