The statement block surrounded by 'if' ... 'endif' is reduced into
if_stmt, which is accepted in the choice context. Therefore, you can
do anything within a choice block by wrapping 'if y' ... 'end'.
For example, you can create a menu inside a choice.
[Test Code]
---------------->8----------------
choice
prompt "choice"
config A
bool "A"
config B
bool "B"
if y
menu "strange menu"
config C
bool "C"
endmenu
endif
endchoice
---------------->8----------------
I want to make such a weird structure a syntax error.
In fact, the USB gadget Kconfig file used nested choice for no good
reason until commit df8df5e4bc37 ("usb: get rid of 'choice' for
legacy gadget drivers") killed it.
I think the 'source' statement inside choice is on the fence. It is
at least gramatically sensible as long as the included file contains
only bool/tristate config statements. However, it makes the code
unreadable, and in the end, people forget the fact that the file is
included from the choice block. Commit 10e5e6c24963 ("usb: gadget: move
choice ... endchoice to legacy/Kconfig") got rid of the only user.
Going forward, you can only use 'config', 'comment', and 'if' inside
choice blocks. This also recursively applies to 'if' blocks inside
choice blocks.
Signed-off-by: Masahiro Yamada <masahiroy@xxxxxxxxxx>
---
scripts/kconfig/parser.y | 30 ++++++++++++++++--------------
1 file changed, 16 insertions(+), 14 deletions(-)
diff --git a/scripts/kconfig/parser.y b/scripts/kconfig/parser.y
index 708b6c4b13ca..190f1117f35a 100644
--- a/scripts/kconfig/parser.y
+++ b/scripts/kconfig/parser.y
@@ -119,20 +119,24 @@ mainmenu_stmt: T_MAINMENU T_WORD_QUOTE T_EOL
stmt_list:
/* empty */
- | stmt_list common_stmt
+ | stmt_list assignment_stmt
| stmt_list choice_stmt
+ | stmt_list comment_stmt
+ | stmt_list config_stmt
+ | stmt_list if_stmt
| stmt_list menu_stmt
+ | stmt_list menuconfig_stmt
+ | stmt_list source_stmt
| stmt_list T_WORD error T_EOL { zconf_error("unknown statement \"%s\"", $2); }
| stmt_list error T_EOL { zconf_error("invalid statement"); }
;
-common_stmt:
- if_stmt
- | comment_stmt
- | config_stmt
- | menuconfig_stmt
- | source_stmt
- | assignment_stmt
+stmt_list_in_choice:
+ /* empty */
+ | stmt_list_in_choice comment_stmt
+ | stmt_list_in_choice config_stmt
+ | stmt_list_in_choice if_stmt_in_choice
+ | stmt_list_in_choice error T_EOL { zconf_error("invalid statement"); }
;
/* config/menuconfig entry */
@@ -254,7 +258,7 @@ choice_end: end
}
};
-choice_stmt: choice_entry choice_block choice_end
+choice_stmt: choice_entry stmt_list_in_choice choice_end
;
choice_option_list:
@@ -305,11 +309,6 @@ default:
| T_DEF_BOOL { $$ = S_BOOLEAN; }
| T_DEF_TRISTATE { $$ = S_TRISTATE; }
-choice_block:
- /* empty */
- | choice_block common_stmt
-;
-
/* if entry */
if_entry: T_IF expr T_EOL
@@ -331,6 +330,9 @@ if_end: end
if_stmt: if_entry stmt_list if_end
;
+if_stmt_in_choice: if_entry stmt_list_in_choice if_end
+;
+
/* menu entry */
menu: T_MENU T_WORD_QUOTE T_EOL
--
2.25.1
