Sync kconfig files with upstream 4.15

Last updated with 4.9-rc7.
This commit introduces the following upstream changes:

9059a3493efe kconfig: fix relational operators for bool and tristate symbols
88127dae6ed9 kconfig/symbol.c: use correct pointer type argument for sizeof
b24413180f56 License cleanup: add SPDX GPL-2.0 license identifier to files with no license
bb3290d91695 Remove gperf usage from toolchain
ad8181060788 kconfig: fix sparse warnings in nconfig
ff85a1a80e00 kconfig: Check for libncurses before menuconfig
9be3213b14d4 gconfig: remove misleading parentheses around a condition
83c3a1bad224 xconfig: fix missing suboption and help panels on first run
e039303ff71a xconfig: fix 'Show Debug' functionality
79e51b5c2dee kconfig/nconf: Fix hang when editing symbol with a long prompt
0eb47346968f Scripts: kconfig: nconf: fix _GNU_SOURCE redefined warning
237e3ad0f195 Kconfig: Introduce the "imply" keyword

Signed-off-by: Bryan Hundven <bryanhundven@gmail.com>

kconfig/.gitignore

@@ -3,7 +3,6 @@ conf
 *.o
 *.dep
 zconf.lex.c
-zconf.hash.c
 zconf.tab.c
 *.exe
 Makefile

kconfig/Makefile.in

@@ -11,8 +11,7 @@ all: $(PROGS)
 	@true   # Just be silent, you fscking son of a fscking beach...
 
 # Build flags
-CFLAGS = -DCONFIG_=\"CT_\" -DPACKAGE="\"crosstool-NG $(VERSION)\"" \
-	 -DGPERF_LEN_TYPE="$(gperf_len_type)"
+CFLAGS = -DCONFIG_=\"CT_\" -DPACKAGE="\"crosstool-NG $(VERSION)\""
 LDFLAGS = $(INTL_LIBS)
 
 ifneq (@DPKG_BUILDFLAGS@,)
@@ -78,16 +77,13 @@ DEPS += $(nconf_DEP)
 	$(call __silent,DEP,$@)$(CC) $(CFLAGS) $(EXTRA_CFLAGS) -MM $< |$(sed) -r -e 's|([^:]+.o)( *:+)|$(<:.c=.o) $@\2|;' >$@
 
 # Generate the grammar parser
-zconf.tab.o: zconf.tab.c zconf.hash.c zconf.lex.c
-zconf.tab.dep: zconf.tab.c zconf.hash.c zconf.lex.c
+zconf.tab.o: zconf.tab.c zconf.lex.c
+zconf.tab.dep: zconf.tab.c zconf.lex.c
 
 .PRECIOUS: zconf.tab.c
 zconf.tab.c: zconf.y
 	$(call __silent,BISON)bison -l -b zconf -p zconf $<
 
-zconf.hash.c: zconf.gperf
-	$(call __silent,GPERF)$(gperf) -C < $< > $@
-
 zconf.lex.c: zconf.l
 	$(call __silent,LEX)flex -L -Pzconf -o$@ $<
 
@@ -121,4 +117,4 @@ install-kconfig.mk: kconfig.mk
 clean:
 	$(call __silent,RM,objs)rm -f $(ALL_OBJS) $(ALL_DEPS)
 	$(call __silent_rm,$(PROGS))
-	$(call __silent_rm,zconf.tab.c zconf.hash.c zconf.lex.c lex.backup)
+	$(call __silent_rm,zconf.tab.c zconf.lex.c lex.backup)

kconfig/check.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
 # Needed for systems without gettext
 $* -x c -o /dev/null - > /dev/null 2>&1 << EOF
 #include <libintl.h>

kconfig/conf.c

@@ -538,6 +538,7 @@ int main(int ac, char **av)
 	}
 	if (ac == optind) {
 		printf(_("%s: Kconfig file missing\n"), av[0]);
+		fprintf(stderr, _("See README for usage info\n"));
 		exit(1);
 	}
 	name = av[optind];

kconfig/expr.c

@@ -893,7 +893,10 @@ static enum string_value_kind expr_parse_string(const char *str,
 	switch (type) {
 	case S_BOOLEAN:
 	case S_TRISTATE:
-		return k_string;
+		val->s = !strcmp(str, "n") ? 0 :
+			 !strcmp(str, "m") ? 1 :
+			 !strcmp(str, "y") ? 2 : -1;
+		return k_signed;
 	case S_INT:
 		val->s = strtoll(str, &tail, 10);
 		kind = k_signed;

kconfig/expr.h

@@ -85,6 +85,7 @@ struct symbol {
 	struct property *prop;
 	struct expr_value dir_dep;
 	struct expr_value rev_dep;
+	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)
@@ -136,6 +137,7 @@ enum prop_type {
 	P_DEFAULT,  /* default y */
 	P_CHOICE,   /* choice value */
 	P_SELECT,   /* select BAR */
+	P_IMPLY,    /* imply BAR */
 	P_RANGE,    /* range 7..100 (for a symbol) */
 	P_ENV,      /* value from environment variable */
 	P_SYMBOL,   /* where a symbol is defined */

kconfig/kconf_id.c

@@ -0,0 +1,54 @@
+
+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 },
+	{ "boolean",		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 },
+	{ "env",		T_OPT_ENV,		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;
+}

kconfig/list.h

@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #ifndef LIST_H
 #define LIST_H
 

kconfig/lkc.h

@@ -62,7 +62,7 @@ enum conf_def_mode {
 #define T_OPT_ALLNOCONFIG_Y	4
 
 struct kconf_id {
-	int name;
+	const char *name;
 	int token;
 	unsigned int flags;
 	enum symbol_type stype;

kconfig/lkc_proto.h

@@ -1,3 +1,4 @@
+/* SPDX-License-Identifier: GPL-2.0 */
 #include <stdarg.h>
 
 /* confdata.c */

kconfig/lxdialog/check-lxdialog.sh

@@ -1,4 +1,5 @@
 #!/bin/sh
+# SPDX-License-Identifier: GPL-2.0
 # Check ncurses compatibility
 
 # What library to link

kconfig/menu.c

@@ -239,6 +239,8 @@ static void sym_check_prop(struct symbol *sym)
 {
 	struct property *prop;
 	struct symbol *sym2;
+	char *use;
+
 	for (prop = sym->prop; prop; prop = prop->next) {
 		switch (prop->type) {
 		case P_DEFAULT:
@@ -258,18 +260,20 @@ static void sym_check_prop(struct symbol *sym)
 			}
 			break;
 		case P_SELECT:
+		case P_IMPLY:
+			use = prop->type == P_SELECT ? "select" : "imply";
 			sym2 = prop_get_symbol(prop);
 			if (sym->type != S_BOOLEAN && sym->type != S_TRISTATE)
 				prop_warn(prop,
-				    "config symbol '%s' uses select, but is "
-				    "not boolean or tristate", sym->name);
+				    "config symbol '%s' uses %s, but is "
+				    "not boolean or tristate", sym->name, use);
 			else if (sym2->type != S_UNKNOWN &&
 				 sym2->type != S_BOOLEAN &&
 				 sym2->type != S_TRISTATE)
 				prop_warn(prop,
-				    "'%s' has wrong type. 'select' only "
+				    "'%s' has wrong type. '%s' only "
 				    "accept arguments of boolean and "
-				    "tristate type", sym2->name);
+				    "tristate type", sym2->name, use);
 			break;
 		case P_RANGE:
 			if (sym->type != S_INT && sym->type != S_HEX)
@@ -339,6 +343,10 @@ void menu_finalize(struct menu *parent)
 					struct symbol *es = prop_get_symbol(prop);
 					es->rev_dep.expr = expr_alloc_or(es->rev_dep.expr,
 							expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep)));
+				} else if (prop->type == P_IMPLY) {
+					struct symbol *es = prop_get_symbol(prop);
+					es->implied.expr = expr_alloc_or(es->implied.expr,
+							expr_alloc_and(expr_alloc_symbol(menu->sym), expr_copy(dep)));
 				}
 			}
 		}
@@ -483,7 +491,7 @@ bool menu_is_visible(struct menu *menu)
 
 	if (menu->visibility) {
 		if (expr_calc_value(menu->visibility) == no)
-			return no;
+			return false;
 	}
 
 	sym = menu->sym;
@@ -618,13 +626,30 @@ static struct property *get_symbol_prop(struct symbol *sym)
 	return prop;
 }
 
+static void get_symbol_props_str(struct gstr *r, struct symbol *sym,
+				 enum prop_type tok, const char *prefix)
+{
+	bool hit = false;
+	struct property *prop;
+
+	for_all_properties(sym, prop, tok) {
+		if (!hit) {
+			str_append(r, prefix);
+			hit = true;
+		} else
+			str_printf(r, " && ");
+		expr_gstr_print(prop->expr, r);
+	}
+	if (hit)
+		str_append(r, "\n");
+}
+
 /*
  * head is optional and may be NULL
  */
 static void get_symbol_str(struct gstr *r, struct symbol *sym,
 		    struct list_head *head)
 {
-	bool hit;
 	struct property *prop;
 
 	if (sym && sym->name) {
@@ -654,22 +679,20 @@ static void get_symbol_str(struct gstr *r, struct symbol *sym,
 		}
 	}
 
-	hit = false;
-	for_all_properties(sym, prop, P_SELECT) {
-		if (!hit) {
-			str_append(r, "  Selects: ");
-			hit = true;
-		} else
-			str_printf(r, " && ");
-		expr_gstr_print(prop->expr, r);
-	}
-	if (hit)
-		str_append(r, "\n");
+	get_symbol_props_str(r, sym, P_SELECT, _("  Selects: "));
 	if (sym->rev_dep.expr) {
 		str_append(r, _("  Selected by: "));
 		expr_gstr_print(sym->rev_dep.expr, r);
 		str_append(r, "\n");
 	}
+
+	get_symbol_props_str(r, sym, P_IMPLY, _("  Implies: "));
+	if (sym->implied.expr) {
+		str_append(r, _("  Implied by: "));
+		expr_gstr_print(sym->implied.expr, r);
+		str_append(r, "\n");
+	}
+
 	str_append(r, "\n\n");
 }
 

kconfig/nconf.c

@@ -5,7 +5,9 @@
  * Derived from menuconfig.
  *
  */
+#ifndef _GNU_SOURCE
 #define _GNU_SOURCE
+#endif
 #include <string.h>
 #include <stdlib.h>
 
@@ -272,7 +274,7 @@ static struct mitem k_menu_items[MAX_MENU_ITEMS];
 static int items_num;
 static int global_exit;
 /* the currently selected button */
-const char *current_instructions = menu_instructions;
+static const char *current_instructions = menu_instructions;
 
 static char *dialog_input_result;
 static int dialog_input_result_len;
@@ -306,7 +308,7 @@ struct function_keys {
 };
 
 static const int function_keys_num = 9;
-struct function_keys function_keys[] = {
+static struct function_keys function_keys[] = {
 	{
 		.key_str = "F1",
 		.func = "Help",
@@ -509,7 +511,7 @@ static int get_mext_match(const char *match_str, match_f flag)
 	index = (index + items_num) % items_num;
 	while (true) {
 		char *str = k_menu_items[index].str;
-		if (strcasestr(str, match_str) != 0)
+		if (strcasestr(str, match_str) != NULL)
 			return index;
 		if (flag == FIND_NEXT_MATCH_UP ||
 		    flag == MATCH_TINKER_PATTERN_UP)
@@ -1068,7 +1070,7 @@ static int do_match(int key, struct match_state *state, int *ans)
 
 static void conf(struct menu *menu)
 {
-	struct menu *submenu = 0;
+	struct menu *submenu = NULL;
 	const char *prompt = menu_get_prompt(menu);
 	struct symbol *sym;
 	int res;
@@ -1235,7 +1237,7 @@ static void show_help(struct menu *menu)
 static void conf_choice(struct menu *menu)
 {
 	const char *prompt = _(menu_get_prompt(menu));
-	struct menu *child = 0;
+	struct menu *child = NULL;
 	struct symbol *active;
 	int selected_index = 0;
 	int last_top_row = 0;
@@ -1457,7 +1459,7 @@ static void conf_save(void)
 	}
 }
 
-void setup_windows(void)
+static void setup_windows(void)
 {
 	int lines, columns;
 

kconfig/nconf.gui.c

@@ -129,7 +129,7 @@ static void no_colors_theme(void)
 	mkattrn(FUNCTION_TEXT, A_REVERSE);
 }
 
-void set_colors()
+void set_colors(void)
 {
 	start_color();
 	use_default_colors();
@@ -192,7 +192,7 @@ const char *get_line(const char *text, int line_no)
 	int lines = 0;
 
 	if (!text)
-		return 0;
+		return NULL;
 
 	for (i = 0; text[i] != '\0' && lines < line_no; i++)
 		if (text[i] == '\n')
@@ -364,12 +364,14 @@ int dialog_inputbox(WINDOW *main_window,
 	WINDOW *prompt_win;
 	WINDOW *form_win;
 	PANEL *panel;
-	int i, x, y;
+	int i, x, y, lines, columns, win_lines, win_cols;
 	int res = -1;
 	int cursor_position = strlen(init);
 	int cursor_form_win;
 	char *result = *resultp;
 
+	getmaxyx(stdscr, lines, columns);
+
 	if (strlen(init)+1 > *result_len) {
 		*result_len = strlen(init)+1;
 		*resultp = result = realloc(result, *result_len);
@@ -386,14 +388,19 @@ int dialog_inputbox(WINDOW *main_window,
 	if (title)
 		prompt_width = max(prompt_width, strlen(title));
 
+	win_lines = min(prompt_lines+6, lines-2);
+	win_cols = min(prompt_width+7, columns-2);
+	prompt_lines = max(win_lines-6, 0);
+	prompt_width = max(win_cols-7, 0);
+
 	/* place dialog in middle of screen */
-	y = (getmaxy(stdscr)-(prompt_lines+4))/2;
-	x = (getmaxx(stdscr)-(prompt_width+4))/2;
+	y = (lines-win_lines)/2;
+	x = (columns-win_cols)/2;
 
 	strncpy(result, init, *result_len);
 
 	/* create the windows */
-	win = newwin(prompt_lines+6, prompt_width+7, y, x);
+	win = newwin(win_lines, win_cols, y, x);
 	prompt_win = derwin(win, prompt_lines+1, prompt_width, 2, 2);
 	form_win = derwin(win, 1, prompt_width, prompt_lines+3, 2);
 	keypad(form_win, TRUE);

kconfig/symbol.c

@@ -258,6 +258,15 @@ static void sym_calc_visibility(struct symbol *sym)
 		sym->rev_dep.tri = tri;
 		sym_set_changed(sym);
 	}
+	tri = no;
+	if (sym->implied.expr && sym->dir_dep.tri != no)
+		tri = expr_calc_value(sym->implied.expr);
+	if (tri == mod && sym_get_type(sym) == S_BOOLEAN)
+		tri = yes;
+	if (sym->implied.tri != tri) {
+		sym->implied.tri = tri;
+		sym_set_changed(sym);
+	}
 }
 
 /*
@@ -397,6 +406,10 @@ void sym_calc_value(struct symbol *sym)
 					newval.tri = EXPR_AND(expr_calc_value(prop->expr),
 							      prop->visible.tri);
 				}
+				if (sym->implied.tri != no) {
+					sym->flags |= SYMBOL_WRITE;
+					newval.tri = EXPR_OR(newval.tri, sym->implied.tri);
+				}
 			}
 		calc_newval:
 			if (sym->dir_dep.tri == no && sym->rev_dep.tri != no) {
@@ -413,7 +426,8 @@ void sym_calc_value(struct symbol *sym)
 			}
 			newval.tri = EXPR_OR(newval.tri, sym->rev_dep.tri);
 		}
-		if (newval.tri == mod && sym_get_type(sym) == S_BOOLEAN)
+		if (newval.tri == mod &&
+		    (sym_get_type(sym) == S_BOOLEAN || sym->implied.tri == yes))
 			newval.tri = yes;
 		break;
 	case S_STRING:
@@ -498,6 +512,8 @@ bool sym_tristate_within_range(struct symbol *sym, tristate val)
 		return false;
 	if (sym->visible <= sym->rev_dep.tri)
 		return false;
+	if (sym->implied.tri == yes && val == mod)
+		return false;
 	if (sym_is_choice_value(sym) && sym->visible == yes)
 		return val == yes;
 	return val >= sym->rev_dep.tri && val <= sym->visible;
@@ -750,6 +766,10 @@ const char *sym_get_string_default(struct symbol *sym)
 	if (sym->type == S_BOOLEAN && val == mod)
 		val = yes;
 
+	/* adjust the default value if this symbol is implied by another */
+	if (val < sym->implied.tri)
+		val = sym->implied.tri;
+
 	switch (sym->type) {
 	case S_BOOLEAN:
 	case S_TRISTATE:
@@ -1041,7 +1061,7 @@ struct symbol **sym_re_search(const char *pattern)
 	}
 	if (sym_match_arr) {
 		qsort(sym_match_arr, cnt, sizeof(struct sym_match), sym_rel_comp);
-		sym_arr = malloc((cnt+1) * sizeof(struct symbol));
+		sym_arr = malloc((cnt+1) * sizeof(struct symbol *));
 		if (!sym_arr)
 			goto sym_re_search_free;
 		for (i = 0; i < cnt; i++)
@@ -1352,6 +1372,8 @@ const char *prop_get_type_name(enum prop_type type)
 		return "choice";
 	case P_SELECT:
 		return "select";
+	case P_IMPLY:
+		return "imply";
 	case P_RANGE:
 		return "range";
 	case P_SYMBOL:

kconfig/zconf.gperf

@@ -1,49 +0,0 @@
-%language=ANSI-C
-%define hash-function-name kconf_id_hash
-%define lookup-function-name kconf_id_lookup
-%define string-pool-name kconf_id_strings
-%compare-strncmp
-%enum
-%pic
-%struct-type
-
-struct kconf_id;
-
-static const struct kconf_id *kconf_id_lookup(register const char *str, register GPERF_LEN_TYPE len);
-
-%%
-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
-boolean,	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
-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
-env,		T_OPT_ENV,	TF_OPTION
-allnoconfig_y,	T_OPT_ALLNOCONFIG_Y,TF_OPTION
-%%

kconfig/zconf.y

@@ -31,7 +31,7 @@ struct symbol *symbol_hash[SYMBOL_HASHSIZE];
 static struct menu *current_menu, *current_entry;
 
 %}
-%expect 30
+%expect 32
 
 %union
 {
@@ -62,6 +62,7 @@ static struct menu *current_menu, *current_entry;
 %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
@@ -100,8 +101,8 @@ static struct menu *current_menu, *current_entry;
 } if_entry menu_entry choice_entry
 
 %{
-/* Include zconf.hash.c here so it can see the token constants. */
-#include "zconf.hash.c"
+/* Include zconf_id.c here so it can see the token constants. */
+#include "kconf_id.c"
 %}
 
 %%
@@ -118,13 +119,13 @@ stmt_list:
 	| 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\"", kconf_id_strings + $2->name);
+	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_OPTIONAL | T_RANGE | T_DEFAULT | T_VISIBLE
+	T_DEPENDS | T_PROMPT | T_TYPE | T_SELECT | T_IMPLY | T_OPTIONAL | T_RANGE | T_DEFAULT | T_VISIBLE
 ;
 
 common_stmt:
@@ -216,6 +217,12 @@ config_option: T_SELECT T_WORD if_expr T_EOL
 	printd(DEBUG_PARSE, "%s:%d:select\n", zconf_curname(), zconf_lineno());
 };
 
+config_option: T_IMPLY T_WORD if_expr T_EOL
+{
+	menu_add_symbol(P_IMPLY, sym_lookup($2, 0), $3);
+	printd(DEBUG_PARSE, "%s:%d:imply\n", zconf_curname(), zconf_lineno());
+};
+
 config_option: T_RANGE symbol symbol if_expr T_EOL
 {
 	menu_add_expr(P_RANGE, expr_alloc_comp(E_RANGE,$2, $3), $4);
@@ -546,13 +553,13 @@ static bool zconf_endtoken(const struct kconf_id *id, int starttoken, int endtok
 {
 	if (id->token != endtoken) {
 		zconf_error("unexpected '%s' within %s block",
-			kconf_id_strings + id->name, zconf_tokenname(starttoken));
+			id->name, zconf_tokenname(starttoken));
 		zconfnerrs++;
 		return false;
 	}
 	if (current_menu->file != current_file) {
 		zconf_error("'%s' in different file than '%s'",
-			kconf_id_strings + id->name, zconf_tokenname(starttoken));
+			id->name, zconf_tokenname(starttoken));
 		fprintf(stderr, "%s:%d: location of the '%s'\n",
 			current_menu->file->name, current_menu->lineno,
 			zconf_tokenname(starttoken));
@@ -666,6 +673,11 @@ static void print_symbol(FILE *out, struct menu *menu)
 			expr_fprint(prop->expr, out);
 			fputc('\n', out);
 			break;
+		case P_IMPLY:
+			fputs( "  imply ", out);
+			expr_fprint(prop->expr, out);
+			fputc('\n', out);
+			break;
 		case P_RANGE:
 			fputs( "  range ", out);
 			expr_fprint(prop->expr, out);