[PATCH] add menuconfig support

This adds the support for the menuconfig keyword, which allows to define
a config symbol and a submenu with a single step, e.g. instead of

	menu "SCSI device support"

	config SCSI
		tristate "SCSI device support"

this is now enough:

	menuconfig SCSI
		tristate "SCSI device support"

scripts/kconfig/expr.h

@@ -155,9 +155,11 @@ struct property {
 #define for_all_properties(sym, st, tok) \
 	for (st = sym->prop; st; st = st->next) \
 		if (st->type == (tok))
-#define for_all_prompts(sym, st) for_all_properties(sym, st, P_PROMPT)
 #define for_all_defaults(sym, st) for_all_properties(sym, st, P_DEFAULT)
 #define for_all_choices(sym, st) for_all_properties(sym, st, P_CHOICE)
+#define for_all_prompts(sym, st) \
+	for (st = sym->prop; st; st = st->next) \
+		if (st->text)
 
 struct menu {
 	struct menu *next;

scripts/kconfig/symbol.c

@@ -160,6 +160,9 @@ void sym_calc_value(struct symbol *sym)
 	struct symbol *def_sym;
 	struct expr *e;
 
+	if (!sym)
+		return;
+
 	if (sym->flags & SYMBOL_VALID)
 		return;
 

scripts/kconfig/zconf.l

@@ -96,6 +96,7 @@ n	[A-Za-z0-9_]
 	"endchoice"		BEGIN(PARAM); return T_ENDCHOICE;
 	"comment"		BEGIN(PARAM); return T_COMMENT;
 	"config"		BEGIN(PARAM); return T_CONFIG;
+	"menuconfig"		BEGIN(PARAM); return T_MENUCONFIG;
 	"help"			BEGIN(PARAM); return T_HELP;
 	"if"			BEGIN(PARAM); return T_IF;
 	"endif"			BEGIN(PARAM); return T_ENDIF;
@@ -141,6 +142,7 @@ n	[A-Za-z0-9_]
 		zconflval.string = text;
 		return T_WORD;
 	}
+	#.*	/* comment */
 	\\\n	current_file->lineno++;
 	.
 	<<EOF>> {
@@ -208,7 +210,7 @@ n	[A-Za-z0-9_]
 		}
 		
 	}
-	\n/[^ \t\n] {
+	[ \t]*\n/[^ \t\n] {
 		current_file->lineno++;
 		zconf_endhelp();
 		return T_HELPTEXT;

scripts/kconfig/zconf.y

@@ -27,7 +27,7 @@ struct symbol *symbol_hash[257];
 
 #define YYERROR_VERBOSE
 %}
-%expect 36
+%expect 40
 
 %union
 {
@@ -46,6 +46,7 @@ struct symbol *symbol_hash[257];
 %token T_ENDCHOICE
 %token T_COMMENT
 %token T_CONFIG
+%token T_MENUCONFIG
 %token T_HELP
 %token <string> T_HELPTEXT
 %token T_IF
@@ -104,12 +105,13 @@ common_block:
 	  if_stmt
 	| comment_stmt
 	| config_stmt
+	| menuconfig_stmt
 	| source_stmt
 	| nl_or_eof
 ;
 
 
-/* config entry */
+/* config/menuconfig entry */
 
 config_entry_start: T_CONFIG T_WORD
 {
@@ -125,6 +127,24 @@ config_stmt: config_entry_start T_EOL config_option_list
 	printd(DEBUG_PARSE, "%s:%d:endconfig\n", zconf_curname(), zconf_lineno());
 };
 
+menuconfig_entry_start: T_MENUCONFIG T_WORD
+{
+	struct symbol *sym = sym_lookup($2, 0);
+	sym->flags |= SYMBOL_OPTIONAL;
+	menu_add_entry(sym);
+	printd(DEBUG_PARSE, "%s:%d:menuconfig %s\n", zconf_curname(), zconf_lineno(), $2);
+};
+
+menuconfig_stmt: menuconfig_entry_start T_EOL config_option_list
+{
+	if (current_entry->prompt)
+		current_entry->prompt->type = P_MENU;
+	else
+		zconfprint("warning: menuconfig statement without prompt");
+	menu_end_entry();
+	printd(DEBUG_PARSE, "%s:%d:endconfig\n", zconf_curname(), zconf_lineno());
+};
+
 config_option_list:
 	  /* empty */
 	| config_option_list config_option T_EOL