diff --git a/kconfig/Makefile.am b/kconfig/Makefile.am
index 0523ea95..82456060 100644
--- a/kconfig/Makefile.am
+++ b/kconfig/Makefile.am
@@ -9,22 +9,23 @@ EXTRA_DIST		= zconf.y zconf.l \
 				  expr.h list.h lkc.h lkc_proto.h nconf.h lxdialog/dialog.h \
 				  confdata.c expr.c kconf_id.c menu.c symbol.c util.c
 
-CLEANFILES		= zconf.lex.c zconf.c
-BUILT_SOURCES	= zconf.c zconf.lex.c
+CLEANFILES		= zconf.lex.c zconf.tab.c
+BUILT_SOURCES		= zconf.lex.c zconf.tab.c
 
-AM_LFLAGS		= -L -Pzconf
-AM_YFLAGS		= -l -b zconf -p zconf
+AM_LFLAGS		= -L
+AM_YFLAGS		= -t -l
 AM_CPPFLAGS		= -include config.h -DCONFIG_=\"CT_\"
 AM_LIBTOOLFLAGS	= --tag CC
 
-conf_SOURCES    = conf.c zconf.c
+conf_SOURCES    = conf.c confdata.c expr.c symbol.c preprocess.c zconf.lex.c zconf.tab.c
 conf_LDADD      = $(LIBINTL)
 
-nconf_SOURCES	= nconf.c nconf.gui.c zconf.c
+nconf_SOURCES	= nconf.c nconf.gui.c confdata.c expr.c symbol.c preprocess.c zconf.lex.c zconf.tab.c
 nconf_CFLAGS	= $(CURSES_CFLAGS)
 nconf_LDADD     = $(MENU_LIBS) $(PANEL_LIBS) $(CURSES_LIBS) $(LIBINTL)
 
-mconf_SOURCES	= mconf.c zconf.c lxdialog/checklist.c lxdialog/inputbox.c \
+mconf_SOURCES	= mconf.c confdata.c expr.c symbol.c preprocess.c zconf.lex.c zconf.tab.c \
+				  lxdialog/checklist.c lxdialog/inputbox.c \
 				  lxdialog/menubox.c lxdialog/textbox.c lxdialog/util.c \
 				  lxdialog/yesno.c
 mconf_LDADD     = $(CURSES_LIBS) $(LIBINTL)
@@ -42,8 +43,8 @@ AM_V_LEX		= $(am__v_LEX_@AM_V@)
 am__v_LEX_		= $(am__v_LEX_@AM_DEFAULT_V@)
 am__v_LEX_0		= @echo "  LEX     " $@;
 
-zconf.c: zconf.y
-	$(AM_V_YACC)$(YACCCOMPILE) -o$@ $<
+zconf.tab.c: zconf.y
+	$(AM_V_YACC)$(YACCCOMPILE) -o$@ --defines=zconf.tab.h $<
 
 zconf.lex.c: zconf.l
 	$(AM_V_LEX)$(LEXCOMPILE) -o$@ $<
diff --git a/kconfig/conf.c b/kconfig/conf.c
index 5a795c50..b86c7de8 100644
--- a/kconfig/conf.c
+++ b/kconfig/conf.c
@@ -1,6 +1,6 @@
+// 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 <ctype.h>
diff --git a/kconfig/confdata.c b/kconfig/confdata.c
index 91d0a5c0..08ba146a 100644
--- a/kconfig/confdata.c
+++ b/kconfig/confdata.c
@@ -1,12 +1,13 @@
+// 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/stat.h>
 #include <ctype.h>
 #include <errno.h>
 #include <fcntl.h>
+#include <limits.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -74,6 +75,47 @@ static int make_parent_dir(const char *path)
 	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 *);
@@ -186,14 +228,6 @@ 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;
@@ -212,7 +246,6 @@ 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 = xstrdup(p);
 			sym->flags |= def_flags;
@@ -363,7 +396,7 @@ 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);
@@ -393,17 +426,22 @@ 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 (sym->flags & def_flags) {
 				conf_warning("override: reassigning to symbol %s", sym->name);
 			}
@@ -416,7 +454,7 @@ 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) {
@@ -669,7 +707,6 @@ static void conf_write_symbol(FILE *fp, struct symbol *sym,
 	const char *str;
 
 	switch (sym->type) {
-	case S_OTHER:
 	case S_UNKNOWN:
 		break;
 	case S_STRING:
@@ -906,24 +943,19 @@ static int conf_write_dep(const char *name)
 	return 0;
 }
 
-static int conf_split_config(void)
+static int conf_touch_deps(void)
 {
 	const char *name;
-	char path[PATH_MAX+1];
-	char *s, *d, c;
 	struct symbol *sym;
-	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 (make_parent_dir("include/config/foo.h"))
-		return 1;
-	if (chdir("include/config"))
-		return 1;
-
-	res = 0;
 	for_all_symbols(i, sym) {
 		sym_calc_value(sym);
 		if ((sym->flags & SYMBOL_NO_WRITE) || !sym->name)
@@ -975,42 +1007,12 @@ 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;
-			}
-
-			if (make_parent_dir(path)) {
-				res = 1;
-				goto out;
-			}
-
-			/* 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(int overwrite)
@@ -1028,7 +1030,7 @@ int conf_write_autoconf(int overwrite)
 
 	conf_write_dep("include/config/auto.conf.cmd");
 
-	if (conf_split_config())
+	if (conf_touch_deps())
 		return 1;
 
 	out = fopen(".tmpconfig", "w");
diff --git a/kconfig/expr.c b/kconfig/expr.c
index e1a39e90..77ffff3a 100644
--- a/kconfig/expr.c
+++ b/kconfig/expr.c
@@ -1,8 +1,10 @@
+// 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 <ctype.h>
+#include <errno.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
@@ -980,7 +982,6 @@ enum string_value_kind {
 	k_string,
 	k_signed,
 	k_unsigned,
-	k_invalid
 };
 
 union string_value {
@@ -1011,13 +1012,10 @@ static enum string_value_kind expr_parse_string(const char *str,
 		val->u = strtoull(str, &tail, 16);
 		kind = k_unsigned;
 		break;
-	case S_STRING:
-	case S_UNKNOWN:
+	default:
 		val->s = strtoll(str, &tail, 0);
 		kind = k_signed;
 		break;
-	default:
-		return k_invalid;
 	}
 	return !errno && !*tail && tail > str && isxdigit(tail[-1])
 	       ? kind : k_string;
@@ -1073,13 +1071,7 @@ tristate expr_calc_value(struct expr *e)
 
 	if (k1 == k_string || k2 == k_string)
 		res = strcmp(str1, str2);
-	else if (k1 == k_invalid || k2 == k_invalid) {
-		if (e->type != E_EQUAL && e->type != E_UNEQUAL) {
-			printf("Cannot compare \"%s\" and \"%s\"\n", str1, str2);
-			return no;
-		}
-		res = strcmp(str1, str2);
-	} else if (k1 == k_unsigned || k2 == k_unsigned)
+	else if (k1 == k_unsigned || k2 == k_unsigned)
 		res = (lval.u > rval.u) - (lval.u < rval.u);
 	else /* if (k1 == k_signed && k2 == k_signed) */
 		res = (lval.s > rval.s) - (lval.s < rval.s);
diff --git a/kconfig/expr.h b/kconfig/expr.h
index 7c329e17..999edb60 100644
--- a/kconfig/expr.h
+++ b/kconfig/expr.h
@@ -1,6 +1,6 @@
+/* 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.
  */
 
 #ifndef EXPR_H
@@ -62,7 +62,7 @@ struct symbol_value {
 };
 
 enum symbol_type {
-	S_UNKNOWN, S_BOOLEAN, S_TRISTATE, S_INT, S_HEX, S_STRING, S_OTHER
+	S_UNKNOWN, S_BOOLEAN, S_TRISTATE, S_INT, S_HEX, S_STRING
 };
 
 /* enum values are used as index to symbol.def[] */
@@ -131,7 +131,7 @@ struct symbol {
 	struct expr_value implied;
 };
 
-#define for_all_symbols(i, sym) for (i = 0; i < SYMBOL_HASHSIZE; i++) for (sym = symbol_hash[i]; sym; sym = sym->next) if (sym->type != S_OTHER)
+#define for_all_symbols(i, sym) for (i = 0; i < SYMBOL_HASHSIZE; i++) for (sym = symbol_hash[i]; sym; sym = sym->next)
 
 #define SYMBOL_CONST      0x0001  /* symbol is const */
 #define SYMBOL_CHECK      0x0008  /* used during dependency checking */
diff --git a/kconfig/kconf_id.c b/kconfig/kconf_id.c
deleted file mode 100644
index b3e0ea0a..00000000
--- a/kconfig/kconf_id.c
+++ /dev/null
@@ -1,52 +0,0 @@
-
-static struct kconf_id kconf_id_array[] = {
-	{ "mainmenu",		T_MAINMENU,		TF_COMMAND },
-	{ "menu",		T_MENU,			TF_COMMAND },
-	{ "endmenu",		T_ENDMENU,		TF_COMMAND },
-	{ "source",		T_SOURCE,		TF_COMMAND },
-	{ "choice",		T_CHOICE,		TF_COMMAND },
-	{ "endchoice",		T_ENDCHOICE,		TF_COMMAND },
-	{ "comment",		T_COMMENT,		TF_COMMAND },
-	{ "config",		T_CONFIG,		TF_COMMAND },
-	{ "menuconfig",		T_MENUCONFIG,		TF_COMMAND },
-	{ "help",		T_HELP,			TF_COMMAND },
-	{ "---help---",		T_HELP,			TF_COMMAND },
-	{ "if",			T_IF,			TF_COMMAND|TF_PARAM },
-	{ "endif",		T_ENDIF,		TF_COMMAND },
-	{ "depends",		T_DEPENDS,		TF_COMMAND },
-	{ "optional",		T_OPTIONAL,		TF_COMMAND },
-	{ "default",		T_DEFAULT,		TF_COMMAND, S_UNKNOWN },
-	{ "prompt",		T_PROMPT,		TF_COMMAND },
-	{ "tristate",		T_TYPE,			TF_COMMAND, S_TRISTATE },
-	{ "def_tristate",	T_DEFAULT,		TF_COMMAND, S_TRISTATE },
-	{ "bool",		T_TYPE,			TF_COMMAND, S_BOOLEAN },
-	{ "def_bool",		T_DEFAULT,		TF_COMMAND, S_BOOLEAN },
-	{ "int",		T_TYPE,			TF_COMMAND, S_INT },
-	{ "hex",		T_TYPE,			TF_COMMAND, S_HEX },
-	{ "string",		T_TYPE,			TF_COMMAND, S_STRING },
-	{ "select",		T_SELECT,		TF_COMMAND },
-	{ "imply",		T_IMPLY,		TF_COMMAND },
-	{ "range",		T_RANGE,		TF_COMMAND },
-	{ "visible",		T_VISIBLE,		TF_COMMAND },
-	{ "option",		T_OPTION,		TF_COMMAND },
-	{ "on",			T_ON,			TF_PARAM },
-	{ "modules",		T_OPT_MODULES,		TF_OPTION },
-	{ "defconfig_list",	T_OPT_DEFCONFIG_LIST,	TF_OPTION },
-	{ "allnoconfig_y",	T_OPT_ALLNOCONFIG_Y,	TF_OPTION },
-};
-
-#define KCONF_ID_ARRAY_SIZE (sizeof(kconf_id_array)/sizeof(struct kconf_id))
-
-static const struct kconf_id *kconf_id_lookup(register const char *str, register unsigned int len)
-{
-	int i;
-
-	for (i = 0; i < KCONF_ID_ARRAY_SIZE; i++) {
-		struct kconf_id *id = kconf_id_array+i;
-		int l = strlen(id->name);
-
-		if (len == l && !memcmp(str, id->name, len))
-			return id;
-	}
-	return NULL;
-}
diff --git a/kconfig/lkc.h b/kconfig/lkc.h
index 9eb7c837..531ff7c5 100644
--- a/kconfig/lkc.h
+++ b/kconfig/lkc.h
@@ -1,6 +1,6 @@
+/* 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.
  */
 
 #ifndef LKC_H
@@ -30,10 +30,6 @@ static inline const char *CONFIG_prefix(void)
 #undef CONFIG_
 #define CONFIG_ CONFIG_prefix()
 
-#define TF_COMMAND	0x0001
-#define TF_PARAM	0x0002
-#define TF_OPTION	0x0004
-
 enum conf_def_mode {
 	def_default,
 	def_yes,
@@ -42,17 +38,6 @@ enum conf_def_mode {
 	def_random
 };
 
-#define T_OPT_MODULES		1
-#define T_OPT_DEFCONFIG_LIST	2
-#define T_OPT_ALLNOCONFIG_Y	4
-
-struct kconf_id {
-	const char *name;
-	int token;
-	unsigned int flags;
-	enum symbol_type stype;
-};
-
 extern int yylineno;
 void zconfdump(FILE *out);
 void zconf_starthelp(void);
@@ -91,7 +76,9 @@ void menu_add_visibility(struct expr *dep);
 struct property *menu_add_prompt(enum prop_type type, char *prompt, struct expr *dep);
 void menu_add_expr(enum prop_type type, struct expr *expr, struct expr *dep);
 void menu_add_symbol(enum prop_type type, struct symbol *sym, struct expr *dep);
-void menu_add_option(int token, char *arg);
+void menu_add_option_modules(void);
+void menu_add_option_defconfig_list(void);
+void menu_add_option_allnoconfig_y(void);
 void menu_finalize(struct menu *parent);
 void menu_set_type(int type);
 
@@ -103,6 +90,9 @@ void *xrealloc(void *p, size_t size);
 char *xstrdup(const char *s);
 char *xstrndup(const char *s, size_t n);
 
+/* zconf.l */
+int yylex(void);
+
 struct gstr {
 	size_t len;
 	char  *s;
@@ -121,6 +111,7 @@ const char *str_get(struct gstr *gs);
 /* symbol.c */
 void sym_clear_all_valid(void);
 struct symbol *sym_choice_default(struct symbol *sym);
+struct property *sym_get_range_prop(struct symbol *sym);
 const char *sym_get_string_default(struct symbol *sym);
 struct symbol *sym_check_deps(struct symbol *sym);
 struct property *prop_alloc(enum prop_type type, struct symbol *sym);
diff --git a/kconfig/lxdialog/checklist.c b/kconfig/lxdialog/checklist.c
index 2e96323a..fd161cff 100644
--- a/kconfig/lxdialog/checklist.c
+++ b/kconfig/lxdialog/checklist.c
@@ -1,3 +1,4 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  *  checklist.c -- implements the checklist box
  *
@@ -5,20 +6,6 @@
  *     Stuart Herbert - S.Herbert@sheffield.ac.uk: radiolist extension
  *     Alessandro Rubini - rubini@ipvvis.unipv.it: merged the two
  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version 2
- *  of the License, or (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include "dialog.h"
diff --git a/kconfig/lxdialog/dialog.h b/kconfig/lxdialog/dialog.h
index 0b00be5a..68b565e3 100644
--- a/kconfig/lxdialog/dialog.h
+++ b/kconfig/lxdialog/dialog.h
@@ -1,21 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
 /*
  *  dialog.h -- common declarations for all dialog modules
  *
  *  AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version 2
- *  of the License, or (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include <sys/types.h>
diff --git a/kconfig/lxdialog/inputbox.c b/kconfig/lxdialog/inputbox.c
index fe82ff6d..61194561 100644
--- a/kconfig/lxdialog/inputbox.c
+++ b/kconfig/lxdialog/inputbox.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  *  inputbox.c -- implements the input box
  *
  *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version 2
- *  of the License, or (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include "dialog.h"
diff --git a/kconfig/lxdialog/menubox.c b/kconfig/lxdialog/menubox.c
index d70cab36..58c2f8af 100644
--- a/kconfig/lxdialog/menubox.c
+++ b/kconfig/lxdialog/menubox.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  *  menubox.c -- implements the menu box
  *
  *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcapw@cfw.com)
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version 2
- *  of the License, or (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 /*
diff --git a/kconfig/lxdialog/textbox.c b/kconfig/lxdialog/textbox.c
index 88d2818e..4e339b12 100644
--- a/kconfig/lxdialog/textbox.c
+++ b/kconfig/lxdialog/textbox.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  *  textbox.c -- implements the text box
  *
  *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version 2
- *  of the License, or (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include "dialog.h"
diff --git a/kconfig/lxdialog/util.c b/kconfig/lxdialog/util.c
index f7abdeb9..1b490d4a 100644
--- a/kconfig/lxdialog/util.c
+++ b/kconfig/lxdialog/util.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  *  util.c
  *
  *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version 2
- *  of the License, or (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include <stdarg.h>
diff --git a/kconfig/lxdialog/yesno.c b/kconfig/lxdialog/yesno.c
index cd1223c9..bcaac9b7 100644
--- a/kconfig/lxdialog/yesno.c
+++ b/kconfig/lxdialog/yesno.c
@@ -1,22 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0+
 /*
  *  yesno.c -- implements the yes/no box
  *
  *  ORIGINAL AUTHOR: Savio Lam (lam836@cs.cuhk.hk)
  *  MODIFIED FOR LINUX KERNEL CONFIG BY: William Roadcap (roadcap@cfw.com)
- *
- *  This program is free software; you can redistribute it and/or
- *  modify it under the terms of the GNU General Public License
- *  as published by the Free Software Foundation; either version 2
- *  of the License, or (at your option) any later version.
- *
- *  This program is distributed in the hope that it will be useful,
- *  but WITHOUT ANY WARRANTY; without even the implied warranty of
- *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
- *  GNU General Public License for more details.
- *
- *  You should have received a copy of the GNU General Public License
- *  along with this program; if not, write to the Free Software
- *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
 
 #include "dialog.h"
diff --git a/kconfig/mconf.c b/kconfig/mconf.c
index c719f604..3d4bd5ef 100644
--- a/kconfig/mconf.c
+++ b/kconfig/mconf.c
@@ -1,6 +1,6 @@
+// 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.
  *
  * Introduced single menu mode (show all sub-menus in one large tree).
  * 2002-11-06 Petr Baudis <pasky@ucw.cz>
diff --git a/kconfig/menu.c b/kconfig/menu.c
index 539ff57f..264ba298 100644
--- a/kconfig/menu.c
+++ b/kconfig/menu.c
@@ -1,6 +1,6 @@
+// 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 <ctype.h>
@@ -201,29 +201,26 @@ void menu_add_symbol(enum prop_type type, struct symbol *sym, struct expr *dep)
 	menu_add_prop(type, NULL, expr_alloc_symbol(sym), dep);
 }
 
-void menu_add_option(int token, char *arg)
+void menu_add_option_modules(void)
 {
-	switch (token) {
-	case T_OPT_MODULES:
-		if (modules_sym)
-			zconf_error("symbol '%s' redefines option 'modules'"
-				    " already defined by symbol '%s'",
-				    current_entry->sym->name,
-				    modules_sym->name
-				    );
-		modules_sym = current_entry->sym;
-		break;
-	case T_OPT_DEFCONFIG_LIST:
-		if (!sym_defconfig_list)
-			sym_defconfig_list = current_entry->sym;
-		else if (sym_defconfig_list != current_entry->sym)
-			zconf_error("trying to redefine defconfig symbol");
-		sym_defconfig_list->flags |= SYMBOL_NO_WRITE;
-		break;
-	case T_OPT_ALLNOCONFIG_Y:
-		current_entry->sym->flags |= SYMBOL_ALLNOCONFIG_Y;
-		break;
-	}
+	if (modules_sym)
+		zconf_error("symbol '%s' redefines option 'modules' already defined by symbol '%s'",
+			    current_entry->sym->name, modules_sym->name);
+	modules_sym = current_entry->sym;
+}
+
+void menu_add_option_defconfig_list(void)
+{
+	if (!sym_defconfig_list)
+		sym_defconfig_list = current_entry->sym;
+	else if (sym_defconfig_list != current_entry->sym)
+		zconf_error("trying to redefine defconfig symbol");
+	sym_defconfig_list->flags |= SYMBOL_NO_WRITE;
+}
+
+void menu_add_option_allnoconfig_y(void)
+{
+	current_entry->sym->flags |= SYMBOL_ALLNOCONFIG_Y;
 }
 
 static int menu_validate_number(struct symbol *sym, struct symbol *sym2)
diff --git a/kconfig/nconf.c b/kconfig/nconf.c
index 93d186ed..fb6027af 100644
--- a/kconfig/nconf.c
+++ b/kconfig/nconf.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright (C) 2008 Nir Tzachar <nir.tzachar@gmail.com?
- * Released under the terms of the GNU GPL v2.0.
+ * Copyright (C) 2008 Nir Tzachar <nir.tzachar@gmail.com>
  *
  * Derived from menuconfig.
- *
  */
 #ifndef _GNU_SOURCE
 #define _GNU_SOURCE
diff --git a/kconfig/nconf.gui.c b/kconfig/nconf.gui.c
index 88874acf..7be620a1 100644
--- a/kconfig/nconf.gui.c
+++ b/kconfig/nconf.gui.c
@@ -1,9 +1,8 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
- * Copyright (C) 2008 Nir Tzachar <nir.tzachar@gmail.com?
- * Released under the terms of the GNU GPL v2.0.
+ * Copyright (C) 2008 Nir Tzachar <nir.tzachar@gmail.com>
  *
  * Derived from menuconfig.
- *
  */
 #include "nconf.h"
 #include "lkc.h"
diff --git a/kconfig/nconf.h b/kconfig/nconf.h
index 2b9e19f6..fa5245eb 100644
--- a/kconfig/nconf.h
+++ b/kconfig/nconf.h
@@ -1,9 +1,8 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 /*
- * Copyright (C) 2008 Nir Tzachar <nir.tzachar@gmail.com?
- * Released under the terms of the GNU GPL v2.0.
+ * Copyright (C) 2008 Nir Tzachar <nir.tzachar@gmail.com>
  *
  * Derived from menuconfig.
- *
  */
 
 #include <ctype.h>
diff --git a/kconfig/preprocess.c b/kconfig/preprocess.c
index 5ca2df79..592dfbfa 100644
--- a/kconfig/preprocess.c
+++ b/kconfig/preprocess.c
@@ -2,6 +2,7 @@
 //
 // Copyright (C) 2018 Masahiro Yamada <yamada.masahiro@socionext.com>
 
+#include <ctype.h>
 #include <stdarg.h>
 #include <stdbool.h>
 #include <stdio.h>
@@ -9,6 +10,7 @@
 #include <string.h>
 
 #include "list.h"
+#include "lkc.h"
 
 #define ARRAY_SIZE(arr)		(sizeof(arr) / sizeof((arr)[0]))
 
@@ -555,8 +557,7 @@ char *expand_string(const char *in)
 
 static bool is_end_of_token(char c)
 {
-	/* Why are '.' and '/' valid characters for symbols? */
-	return !(isalnum(c) || c == '_' || c == '-' || c == '.' || c == '/');
+	return !(isalnum(c) || c == '_' || c == '-');
 }
 
 /*
diff --git a/kconfig/symbol.c b/kconfig/symbol.c
index 703b9b89..1f9266da 100644
--- a/kconfig/symbol.c
+++ b/kconfig/symbol.c
@@ -1,6 +1,6 @@
+// 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 <ctype.h>
@@ -61,8 +61,6 @@ const char *sym_type_name(enum symbol_type type)
 		return "string";
 	case S_UNKNOWN:
 		return "unknown";
-	case S_OTHER:
-		break;
 	}
 	return "???";
 }
@@ -88,7 +86,7 @@ static struct property *sym_get_default_prop(struct symbol *sym)
 	return NULL;
 }
 
-static struct property *sym_get_range_prop(struct symbol *sym)
+struct property *sym_get_range_prop(struct symbol *sym)
 {
 	struct property *prop;
 
@@ -757,7 +755,6 @@ const char *sym_get_string_default(struct symbol *sym)
 		return str;
 	case S_STRING:
 		return str;
-	case S_OTHER:
 	case S_UNKNOWN:
 		break;
 	}
diff --git a/kconfig/util.c b/kconfig/util.c
index d999683b..29585394 100644
--- a/kconfig/util.c
+++ b/kconfig/util.c
@@ -1,8 +1,7 @@
+// SPDX-License-Identifier: GPL-2.0
 /*
  * Copyright (C) 2002-2005 Roman Zippel <zippel@linux-m68k.org>
  * Copyright (C) 2002-2005 Sam Ravnborg <sam@ravnborg.org>
- *
- * Released under the terms of the GNU GPL v2.0.
  */
 
 #include <stdarg.h>
diff --git a/kconfig/zconf.l b/kconfig/zconf.l
index 25bd2b89..b2d0a3b0 100644
--- a/kconfig/zconf.l
+++ b/kconfig/zconf.l
@@ -1,11 +1,11 @@
-%option nostdinit noyywrap never-interactive full ecs
-%option 8bit nodefault yylineno
-%x COMMAND HELP STRING PARAM ASSIGN_VAL
-%{
+/* 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.
  */
+%option nostdinit noyywrap never-interactive full ecs
+%option 8bit nodefault yylineno
+%x ASSIGN_VAL HELP STRING
+%{
 
 #include <assert.h>
 #include <limits.h>
@@ -15,6 +15,9 @@
 #include <unistd.h>
 
 #include "lkc.h"
+#include "zconf.tab.h"
+
+#define YY_DECL		static int yylex1(void)
 
 #define START_STRSIZE	16
 
@@ -23,6 +26,8 @@ static struct {
 	int lineno;
 } current_pos;
 
+static int prev_prev_token = T_EOL;
+static int prev_token = T_EOL;
 static char *text;
 static int text_size, text_asize;
 
@@ -73,7 +78,7 @@ static void warn_ignored_character(char chr)
 {
 	fprintf(stderr,
 	        "%s:%d:warning: ignoring unsupported character '%c'\n",
-	        zconf_curname(), zconf_lineno(), chr);
+	        current_file->name, yylineno, chr);
 }
 %}
 
@@ -83,54 +88,73 @@ n	[A-Za-z0-9_-]
 	int str = 0;
 	int ts, i;
 
-[ \t]*#.*\n	|
-[ \t]*\n	{
-	return T_EOL;
-}
-[ \t]*#.*
-
-
-[ \t]+	{
-	BEGIN(COMMAND);
-}
-
-.	{
-	unput(yytext[0]);
-	BEGIN(COMMAND);
-}
-
-
-<COMMAND>{
-	{n}+	{
-		const struct kconf_id *id = kconf_id_lookup(yytext, yyleng);
-		current_pos.file = current_file;
-		current_pos.lineno = yylineno;
-		if (id && id->flags & TF_COMMAND) {
-			BEGIN(PARAM);
-			yylval.id = id;
-			return id->token;
-		}
-		alloc_string(yytext, yyleng);
-		yylval.string = text;
-		return T_VARIABLE;
-	}
-	({n}|$)+	{
-		/* this token includes at least one '$' */
-		yylval.string = expand_token(yytext, yyleng);
-		if (strlen(yylval.string))
-			return T_VARIABLE;
-		free(yylval.string);
-	}
-	"="	{ BEGIN(ASSIGN_VAL); yylval.flavor = VAR_RECURSIVE; return T_ASSIGN; }
-	":="	{ BEGIN(ASSIGN_VAL); yylval.flavor = VAR_SIMPLE; return T_ASSIGN; }
-	"+="	{ BEGIN(ASSIGN_VAL); yylval.flavor = VAR_APPEND; return T_ASSIGN; }
-	[[:blank:]]+
-	.	warn_ignored_character(*yytext);
-	\n	{
-		BEGIN(INITIAL);
-		return T_EOL;
-	}
-}
+#.*			/* ignore comment */
+[ \t]*			/* whitespaces */
+\\\n			/* escaped new line */
+\n			return T_EOL;
+"allnoconfig_y"		return T_ALLNOCONFIG_Y;
+"bool"			return T_BOOL;
+"choice"		return T_CHOICE;
+"comment"		return T_COMMENT;
+"config"		return T_CONFIG;
+"def_bool"		return T_DEF_BOOL;
+"def_tristate"		return T_DEF_TRISTATE;
+"default"		return T_DEFAULT;
+"defconfig_list"	return T_DEFCONFIG_LIST;
+"depends"		return T_DEPENDS;
+"endchoice"		return T_ENDCHOICE;
+"endif"			return T_ENDIF;
+"endmenu"		return T_ENDMENU;
+"help"|"---help---"	return T_HELP;
+"hex"			return T_HEX;
+"if"			return T_IF;
+"imply"			return T_IMPLY;
+"int"			return T_INT;
+"mainmenu"		return T_MAINMENU;
+"menu"			return T_MENU;
+"menuconfig"		return T_MENUCONFIG;
+"modules"		return T_MODULES;
+"on"			return T_ON;
+"option"		return T_OPTION;
+"optional"		return T_OPTIONAL;
+"prompt"		return T_PROMPT;
+"range"			return T_RANGE;
+"select"		return T_SELECT;
+"source"		return T_SOURCE;
+"string"		return T_STRING;
+"tristate"		return T_TRISTATE;
+"visible"		return T_VISIBLE;
+"||"			return T_OR;
+"&&"			return T_AND;
+"="			return T_EQUAL;
+"!="			return T_UNEQUAL;
+"<"			return T_LESS;
+"<="			return T_LESS_EQUAL;
+">"			return T_GREATER;
+">="			return T_GREATER_EQUAL;
+"!"			return T_NOT;
+"("			return T_OPEN_PAREN;
+")"			return T_CLOSE_PAREN;
+":="			return T_COLON_EQUAL;
+"+="			return T_PLUS_EQUAL;
+\"|\'			{
+				str = yytext[0];
+				new_string();
+				BEGIN(STRING);
+			}
+{n}+			{
+				alloc_string(yytext, yyleng);
+				yylval.string = text;
+				return T_WORD;
+			}
+({n}|$)+		{
+				/* this token includes at least one '$' */
+				yylval.string = expand_token(yytext, yyleng);
+				if (strlen(yylval.string))
+					return T_WORD;
+				free(yylval.string);
+			}
+.			warn_ignored_character(*yytext);
 
 <ASSIGN_VAL>{
 	[^[:blank:]\n]+.*	{
@@ -142,71 +166,17 @@ n	[A-Za-z0-9_-]
 	.
 }
 
-<PARAM>{
-	"&&"	return T_AND;
-	"||"	return T_OR;
-	"("	return T_OPEN_PAREN;
-	")"	return T_CLOSE_PAREN;
-	"!"	return T_NOT;
-	"="	return T_EQUAL;
-	"!="	return T_UNEQUAL;
-	"<="	return T_LESS_EQUAL;
-	">="	return T_GREATER_EQUAL;
-	"<"	return T_LESS;
-	">"	return T_GREATER;
-	\"|\'	{
-		str = yytext[0];
-		new_string();
-		BEGIN(STRING);
-	}
-	\n	BEGIN(INITIAL); return T_EOL;
-	({n}|[/.])+	{
-		const struct kconf_id *id = kconf_id_lookup(yytext, yyleng);
-		if (id && id->flags & TF_PARAM) {
-			yylval.id = id;
-			return id->token;
-		}
-		alloc_string(yytext, yyleng);
-		yylval.string = text;
-		return T_WORD;
-	}
-	({n}|[/.$])+	{
-		/* this token includes at least one '$' */
-		yylval.string = expand_token(yytext, yyleng);
-		if (strlen(yylval.string))
-			return T_WORD;
-		free(yylval.string);
-	}
-	#.*	/* comment */
-	\\\n	;
-	[[:blank:]]+
-	.	warn_ignored_character(*yytext);
-	<<EOF>> {
-		BEGIN(INITIAL);
-	}
-}
-
 <STRING>{
 	"$".*	append_expanded_string(yytext);
-	[^$'"\\\n]+/\n	{
-		append_string(yytext, yyleng);
-		yylval.string = text;
-		return T_WORD_QUOTE;
-	}
 	[^$'"\\\n]+	{
 		append_string(yytext, yyleng);
 	}
-	\\.?/\n	{
-		append_string(yytext + 1, yyleng - 1);
-		yylval.string = text;
-		return T_WORD_QUOTE;
-	}
 	\\.?	{
 		append_string(yytext + 1, yyleng - 1);
 	}
 	\'|\"	{
 		if (str == yytext[0]) {
-			BEGIN(PARAM);
+			BEGIN(INITIAL);
 			yylval.string = text;
 			return T_WORD_QUOTE;
 		} else
@@ -216,11 +186,15 @@ n	[A-Za-z0-9_-]
 		fprintf(stderr,
 			"%s:%d:warning: multi-line strings not supported\n",
 			zconf_curname(), zconf_lineno());
+		unput('\n');
 		BEGIN(INITIAL);
-		return T_EOL;
+		yylval.string = text;
+		return T_WORD_QUOTE;
 	}
 	<<EOF>>	{
 		BEGIN(INITIAL);
+		yylval.string = text;
+		return T_WORD_QUOTE;
 	}
 }
 
@@ -271,6 +245,12 @@ n	[A-Za-z0-9_-]
 }
 
 <<EOF>>	{
+	BEGIN(INITIAL);
+
+	if (prev_token != T_EOL && prev_token != T_HELPTEXT)
+		fprintf(stderr, "%s:%d:warning: no new line at end of file\n",
+			current_file->name, yylineno);
+
 	if (current_file) {
 		zconf_endfile();
 		return T_EOL;
@@ -280,6 +260,41 @@ n	[A-Za-z0-9_-]
 }
 
 %%
+
+/* second stage lexer */
+int yylex(void)
+{
+	int token;
+
+repeat:
+	token = yylex1();
+
+	if (prev_token == T_EOL || prev_token == T_HELPTEXT) {
+		if (token == T_EOL) {
+			/* Do not pass unneeded T_EOL to the parser. */
+			goto repeat;
+		} else {
+			/*
+			 * For the parser, update file/lineno at the first token
+			 * of each statement. Generally, \n is a statement
+			 * terminator in Kconfig, but it is not always true
+			 * because \n could be escaped by a backslash.
+			 */
+			current_pos.file = current_file;
+			current_pos.lineno = yylineno;
+		}
+	}
+
+	if (prev_prev_token == T_EOL && prev_token == T_WORD &&
+	    (token == T_EQUAL || token == T_COLON_EQUAL || token == T_PLUS_EQUAL))
+		BEGIN(ASSIGN_VAL);
+
+	prev_prev_token = prev_token;
+	prev_token = token;
+
+	return token;
+}
+
 static char *expand_token(const char *in, size_t n)
 {
 	char *out;
diff --git a/kconfig/zconf.y b/kconfig/zconf.y
index 9d331da6..60936c76 100644
--- a/kconfig/zconf.y
+++ b/kconfig/zconf.y
@@ -1,8 +1,8 @@
-%{
+/* 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 <ctype.h>
 #include <stdarg.h>
@@ -20,66 +20,68 @@
 
 int cdebug = PRINTD;
 
-int yylex(void);
 static void yyerror(const char *err);
 static void zconfprint(const char *err, ...);
 static void zconf_error(const char *err, ...);
-static bool zconf_endtoken(const struct kconf_id *id, int starttoken, int endtoken);
+static bool zconf_endtoken(const char *tokenname,
+			   const char *expected_tokenname);
 
 struct symbol *symbol_hash[SYMBOL_HASHSIZE];
 
 static struct menu *current_menu, *current_entry;
 
 %}
-%expect 30
 
 %union
 {
 	char *string;
-	struct file *file;
 	struct symbol *symbol;
 	struct expr *expr;
 	struct menu *menu;
-	const struct kconf_id *id;
+	enum symbol_type type;
 	enum variable_flavor flavor;
 }
 
-%token <id>T_MAINMENU
-%token <id>T_MENU
-%token <id>T_ENDMENU
-%token <id>T_SOURCE
-%token <id>T_CHOICE
-%token <id>T_ENDCHOICE
-%token <id>T_COMMENT
-%token <id>T_CONFIG
-%token <id>T_MENUCONFIG
-%token <id>T_HELP
 %token <string> T_HELPTEXT
-%token <id>T_IF
-%token <id>T_ENDIF
-%token <id>T_DEPENDS
-%token <id>T_OPTIONAL
-%token <id>T_PROMPT
-%token <id>T_TYPE
-%token <id>T_DEFAULT
-%token <id>T_SELECT
-%token <id>T_IMPLY
-%token <id>T_RANGE
-%token <id>T_VISIBLE
-%token <id>T_OPTION
-%token <id>T_ON
 %token <string> T_WORD
 %token <string> T_WORD_QUOTE
-%token T_UNEQUAL
-%token T_LESS
-%token T_LESS_EQUAL
-%token T_GREATER
-%token T_GREATER_EQUAL
+%token T_ALLNOCONFIG_Y
+%token T_BOOL
+%token T_CHOICE
 %token T_CLOSE_PAREN
+%token T_COLON_EQUAL
+%token T_COMMENT
+%token T_CONFIG
+%token T_DEFAULT
+%token T_DEFCONFIG_LIST
+%token T_DEF_BOOL
+%token T_DEF_TRISTATE
+%token T_DEPENDS
+%token T_ENDCHOICE
+%token T_ENDIF
+%token T_ENDMENU
+%token T_HELP
+%token T_HEX
+%token T_IF
+%token T_IMPLY
+%token T_INT
+%token T_MAINMENU
+%token T_MENU
+%token T_MENUCONFIG
+%token T_MODULES
+%token T_ON
 %token T_OPEN_PAREN
+%token T_OPTION
+%token T_OPTIONAL
+%token T_PLUS_EQUAL
+%token T_PROMPT
+%token T_RANGE
+%token T_SELECT
+%token T_SOURCE
+%token T_STRING
+%token T_TRISTATE
+%token T_VISIBLE
 %token T_EOL
-%token <string> T_VARIABLE
-%token <flavor> T_ASSIGN
 %token <string> T_ASSIGN_VAL
 
 %left T_OR
@@ -91,12 +93,13 @@ static struct menu *current_menu, *current_entry;
 %type <string> prompt
 %type <symbol> nonconst_symbol
 %type <symbol> symbol
+%type <type> type logic_type default
 %type <expr> expr
 %type <expr> if_expr
-%type <id> end
-%type <id> option_name
+%type <string> end
 %type <menu> if_entry menu_entry choice_entry
-%type <string> symbol_option_arg word_opt assign_val
+%type <string> word_opt assign_val
+%type <flavor> assign_op
 
 %destructor {
 	fprintf(stderr, "%s:%d: missing end statement for this entry\n",
@@ -105,15 +108,8 @@ static struct menu *current_menu, *current_entry;
 		menu_end_menu();
 } if_entry menu_entry choice_entry
 
-%{
-/* Include kconf_id.c here so it can see the token constants. */
-#include "kconf_id.c"
-%}
-
 %%
-input: nl start | start;
-
-start: mainmenu_stmt stmt_list | stmt_list;
+input: mainmenu_stmt stmt_list | stmt_list;
 
 /* mainmenu entry */
 
@@ -127,22 +123,12 @@ stmt_list:
 	| stmt_list common_stmt
 	| stmt_list choice_stmt
 	| stmt_list menu_stmt
-	| stmt_list end			{ zconf_error("unexpected end statement"); }
 	| stmt_list T_WORD error T_EOL	{ zconf_error("unknown statement \"%s\"", $2); }
-	| stmt_list option_name error T_EOL
-{
-	zconf_error("unexpected option \"%s\"", $2->name);
-}
 	| stmt_list error T_EOL		{ zconf_error("invalid statement"); }
 ;
 
-option_name:
-	T_DEPENDS | T_PROMPT | T_TYPE | T_SELECT | T_IMPLY | T_OPTIONAL | T_RANGE | T_DEFAULT | T_VISIBLE
-;
-
 common_stmt:
-	  T_EOL
-	| if_stmt
+	  if_stmt
 	| comment_stmt
 	| config_stmt
 	| menuconfig_stmt
@@ -150,12 +136,6 @@ common_stmt:
 	| assignment_stmt
 ;
 
-option_error:
-	  T_WORD error T_EOL		{ zconf_error("unknown option \"%s\"", $1); }
-	| error T_EOL			{ zconf_error("invalid option"); }
-;
-
-
 /* config/menuconfig entry */
 
 config_entry_start: T_CONFIG nonconst_symbol T_EOL
@@ -189,19 +169,16 @@ menuconfig_stmt: menuconfig_entry_start config_option_list
 config_option_list:
 	  /* empty */
 	| config_option_list config_option
-	| config_option_list symbol_option
 	| config_option_list depends
 	| config_option_list help
-	| config_option_list option_error
-	| config_option_list T_EOL
 ;
 
-config_option: T_TYPE prompt_stmt_opt T_EOL
+config_option: type prompt_stmt_opt T_EOL
 {
-	menu_set_type($1->stype);
+	menu_set_type($1);
 	printd(DEBUG_PARSE, "%s:%d:type(%u)\n",
 		zconf_curname(), zconf_lineno(),
-		$1->stype);
+		$1);
 };
 
 config_option: T_PROMPT prompt if_expr T_EOL
@@ -210,14 +187,14 @@ config_option: T_PROMPT prompt if_expr T_EOL
 	printd(DEBUG_PARSE, "%s:%d:prompt\n", zconf_curname(), zconf_lineno());
 };
 
-config_option: T_DEFAULT expr if_expr T_EOL
+config_option: default expr if_expr T_EOL
 {
 	menu_add_expr(P_DEFAULT, $2, $3);
-	if ($1->stype != S_UNKNOWN)
-		menu_set_type($1->stype);
+	if ($1 != S_UNKNOWN)
+		menu_set_type($1);
 	printd(DEBUG_PARSE, "%s:%d:default(%u)\n",
 		zconf_curname(), zconf_lineno(),
-		$1->stype);
+		$1);
 };
 
 config_option: T_SELECT nonconst_symbol if_expr T_EOL
@@ -238,27 +215,20 @@ config_option: T_RANGE symbol symbol if_expr T_EOL
 	printd(DEBUG_PARSE, "%s:%d:range\n", zconf_curname(), zconf_lineno());
 };
 
-symbol_option: T_OPTION symbol_option_list T_EOL
-;
-
-symbol_option_list:
-	  /* empty */
-	| symbol_option_list T_WORD symbol_option_arg
+config_option: T_OPTION T_MODULES T_EOL
 {
-	const struct kconf_id *id = kconf_id_lookup($2, strlen($2));
-	if (id && id->flags & TF_OPTION) {
-		menu_add_option(id->token, $3);
-		free($3);
-	}
-	else
-		zconfprint("warning: ignoring unknown option %s", $2);
-	free($2);
+	menu_add_option_modules();
 };
 
-symbol_option_arg:
-	  /* empty */		{ $$ = NULL; }
-	| T_EQUAL prompt	{ $$ = $2; }
-;
+config_option: T_OPTION T_DEFCONFIG_LIST T_EOL
+{
+	menu_add_option_defconfig_list();
+};
+
+config_option: T_OPTION T_ALLNOCONFIG_Y T_EOL
+{
+	menu_add_option_allnoconfig_y();
+};
 
 /* choice entry */
 
@@ -279,7 +249,7 @@ choice_entry: choice choice_option_list
 
 choice_end: end
 {
-	if (zconf_endtoken($1, T_CHOICE, T_ENDCHOICE)) {
+	if (zconf_endtoken($1, "choice")) {
 		menu_end_menu();
 		printd(DEBUG_PARSE, "%s:%d:endchoice\n", zconf_curname(), zconf_lineno());
 	}
@@ -293,8 +263,6 @@ choice_option_list:
 	| choice_option_list choice_option
 	| choice_option_list depends
 	| choice_option_list help
-	| choice_option_list T_EOL
-	| choice_option_list option_error
 ;
 
 choice_option: T_PROMPT prompt if_expr T_EOL
@@ -303,15 +271,11 @@ choice_option: T_PROMPT prompt if_expr T_EOL
 	printd(DEBUG_PARSE, "%s:%d:prompt\n", zconf_curname(), zconf_lineno());
 };
 
-choice_option: T_TYPE prompt_stmt_opt T_EOL
+choice_option: logic_type prompt_stmt_opt T_EOL
 {
-	if ($1->stype == S_BOOLEAN || $1->stype == S_TRISTATE) {
-		menu_set_type($1->stype);
-		printd(DEBUG_PARSE, "%s:%d:type(%u)\n",
-			zconf_curname(), zconf_lineno(),
-			$1->stype);
-	} else
-		YYERROR;
+	menu_set_type($1);
+	printd(DEBUG_PARSE, "%s:%d:type(%u)\n",
+	       zconf_curname(), zconf_lineno(), $1);
 };
 
 choice_option: T_OPTIONAL T_EOL
@@ -322,14 +286,26 @@ choice_option: T_OPTIONAL T_EOL
 
 choice_option: T_DEFAULT nonconst_symbol if_expr T_EOL
 {
-	if ($1->stype == S_UNKNOWN) {
-		menu_add_symbol(P_DEFAULT, $2, $3);
-		printd(DEBUG_PARSE, "%s:%d:default\n",
-			zconf_curname(), zconf_lineno());
-	} else
-		YYERROR;
+	menu_add_symbol(P_DEFAULT, $2, $3);
+	printd(DEBUG_PARSE, "%s:%d:default\n",
+	       zconf_curname(), zconf_lineno());
 };
 
+type:
+	  logic_type
+	| T_INT			{ $$ = S_INT; }
+	| T_HEX			{ $$ = S_HEX; }
+	| T_STRING		{ $$ = S_STRING; }
+
+logic_type:
+	  T_BOOL		{ $$ = S_BOOLEAN; }
+	| T_TRISTATE		{ $$ = S_TRISTATE; }
+
+default:
+	  T_DEFAULT		{ $$ = S_UNKNOWN; }
+	| T_DEF_BOOL		{ $$ = S_BOOLEAN; }
+	| T_DEF_TRISTATE	{ $$ = S_TRISTATE; }
+
 choice_block:
 	  /* empty */
 	| choice_block common_stmt
@@ -347,20 +323,13 @@ if_entry: T_IF expr T_EOL
 
 if_end: end
 {
-	if (zconf_endtoken($1, T_IF, T_ENDIF)) {
+	if (zconf_endtoken($1, "if")) {
 		menu_end_menu();
 		printd(DEBUG_PARSE, "%s:%d:endif\n", zconf_curname(), zconf_lineno());
 	}
 };
 
-if_stmt: if_entry if_block if_end
-;
-
-if_block:
-	  /* empty */
-	| if_block common_stmt
-	| if_block menu_stmt
-	| if_block choice_stmt
+if_stmt: if_entry stmt_list if_end
 ;
 
 /* menu entry */
@@ -372,27 +341,26 @@ menu: T_MENU prompt T_EOL
 	printd(DEBUG_PARSE, "%s:%d:menu\n", zconf_curname(), zconf_lineno());
 };
 
-menu_entry: menu visibility_list depends_list
+menu_entry: menu menu_option_list
 {
 	$$ = menu_add_menu();
 };
 
 menu_end: end
 {
-	if (zconf_endtoken($1, T_MENU, T_ENDMENU)) {
+	if (zconf_endtoken($1, "menu")) {
 		menu_end_menu();
 		printd(DEBUG_PARSE, "%s:%d:endmenu\n", zconf_curname(), zconf_lineno());
 	}
 };
 
-menu_stmt: menu_entry menu_block menu_end
+menu_stmt: menu_entry stmt_list menu_end
 ;
 
-menu_block:
+menu_option_list:
 	  /* empty */
-	| menu_block common_stmt
-	| menu_block menu_stmt
-	| menu_block choice_stmt
+	| menu_option_list visible
+	| menu_option_list depends
 ;
 
 source_stmt: T_SOURCE prompt T_EOL
@@ -411,7 +379,12 @@ comment: T_COMMENT prompt T_EOL
 	printd(DEBUG_PARSE, "%s:%d:comment\n", zconf_curname(), zconf_lineno());
 };
 
-comment_stmt: comment depends_list
+comment_stmt: comment comment_option_list
+;
+
+comment_option_list:
+	  /* empty */
+	| comment_option_list depends
 ;
 
 /* help option */
@@ -440,13 +413,6 @@ help: help_start T_HELPTEXT
 
 /* depends option */
 
-depends_list:
-	  /* empty */
-	| depends_list depends
-	| depends_list T_EOL
-	| depends_list option_error
-;
-
 depends: T_DEPENDS T_ON expr T_EOL
 {
 	menu_add_dep($3);
@@ -454,14 +420,7 @@ depends: T_DEPENDS T_ON expr T_EOL
 };
 
 /* visibility option */
-
-visibility_list:
-	  /* empty */
-	| visibility_list visible
-	| visibility_list T_EOL
-;
-
-visible: T_VISIBLE if_expr
+visible: T_VISIBLE if_expr T_EOL
 {
 	menu_add_visibility($2);
 };
@@ -479,14 +438,9 @@ prompt:	  T_WORD
 	| T_WORD_QUOTE
 ;
 
-end:	  T_ENDMENU T_EOL	{ $$ = $1; }
-	| T_ENDCHOICE T_EOL	{ $$ = $1; }
-	| T_ENDIF T_EOL		{ $$ = $1; }
-;
-
-nl:
-	  T_EOL
-	| nl T_EOL
+end:	  T_ENDMENU T_EOL	{ $$ = "menu"; }
+	| T_ENDCHOICE T_EOL	{ $$ = "choice"; }
+	| T_ENDIF T_EOL		{ $$ = "if"; }
 ;
 
 if_expr:  /* empty */			{ $$ = NULL; }
@@ -518,7 +472,13 @@ word_opt: /* empty */			{ $$ = NULL; }
 
 /* assignment statement */
 
-assignment_stmt:  T_VARIABLE T_ASSIGN assign_val T_EOL	{ variable_add($1, $3, $2); free($1); free($3); }
+assignment_stmt:  T_WORD assign_op assign_val T_EOL	{ variable_add($1, $3, $2); free($1); free($3); }
+
+assign_op:
+	  T_EQUAL	{ $$ = VAR_RECURSIVE; }
+	| T_COLON_EQUAL	{ $$ = VAR_SIMPLE; }
+	| T_PLUS_EQUAL	{ $$ = VAR_APPEND; }
+;
 
 assign_val:
 	/* empty */		{ $$ = xstrdup(""); };
@@ -535,10 +495,9 @@ void conf_parse(const char *name)
 	zconf_initscan(name);
 
 	_menu_init();
-#if YYDEBUG
+
 	if (getenv("ZCONF_DEBUG"))
 		yydebug = 1;
-#endif
 	yyparse();
 
 	/* Variables are expanded in the parse phase. We can free them here. */
@@ -564,35 +523,21 @@ void conf_parse(const char *name)
 	sym_set_change_count(1);
 }
 
-static const char *zconf_tokenname(int token)
+static bool zconf_endtoken(const char *tokenname,
+			   const char *expected_tokenname)
 {
-	switch (token) {
-	case T_MENU:		return "menu";
-	case T_ENDMENU:		return "endmenu";
-	case T_CHOICE:		return "choice";
-	case T_ENDCHOICE:	return "endchoice";
-	case T_IF:		return "if";
-	case T_ENDIF:		return "endif";
-	case T_DEPENDS:		return "depends";
-	case T_VISIBLE:		return "visible";
-	}
-	return "<token>";
-}
-
-static bool zconf_endtoken(const struct kconf_id *id, int starttoken, int endtoken)
-{
-	if (id->token != endtoken) {
+	if (strcmp(tokenname, expected_tokenname)) {
 		zconf_error("unexpected '%s' within %s block",
-			id->name, zconf_tokenname(starttoken));
+			    tokenname, expected_tokenname);
 		yynerrs++;
 		return false;
 	}
 	if (current_menu->file != current_file) {
 		zconf_error("'%s' in different file than '%s'",
-			id->name, zconf_tokenname(starttoken));
+			    tokenname, expected_tokenname);
 		fprintf(stderr, "%s:%d: location of the '%s'\n",
 			current_menu->file->name, current_menu->lineno,
-			zconf_tokenname(starttoken));
+			expected_tokenname);
 		yynerrs++;
 		return false;
 	}
@@ -782,10 +727,5 @@ void zconfdump(FILE *out)
 	}
 }
 
-#include "zconf.lex.c"
 #include "util.c"
-#include "confdata.c"
-#include "expr.c"
-#include "symbol.c"
 #include "menu.c"
-#include "preprocess.c"