From 2f60e46e605a9bcd8dc4fe7745b5576084900850 Mon Sep 17 00:00:00 2001
From: Masahiro Yamada <yamada.masahiro@socionext.com>
Date: Tue, 11 Dec 2018 20:00:53 +0900
Subject: [PATCH] kconfig: remove grammatically ambiguous option_error
This commit decreases 6 shift/reduce conflicts, and finally achieves
conflict-free parser.
Since Kconfig has no terminator for a config block, detecting the end
of config_stmt is not easy.
For example, there are two ways for handling the error in the following
code:
1 config FOO
2 =
[A] Print "unknown option" error, assuming the line 2 is a part of
config_option_list
[B] Print "invalid statement", assuming the line 1 is reduced into
a config_stmt by itself
Bison actually chooses [A] because it performs the shift rather than
the reduction where both are possible.
However, there is no reason to choose one over the other.
Let's remove the option_error, and let it fall back to [B].
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
scripts/kconfig/zconf.y | 10 ----------
1 file changed, 10 deletions(-)
diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y
index cef6123228c01..a92f167e8267b 100644
--- a/scripts/kconfig/zconf.y
+++ b/scripts/kconfig/zconf.y
@@ -31,7 +31,6 @@ struct symbol *symbol_hash[SYMBOL_HASHSIZE];
static struct menu *current_menu, *current_entry;
%}
-%expect 6
%union
{
@@ -138,12 +137,6 @@ 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
@@ -180,7 +173,6 @@ config_option_list:
| config_option_list symbol_option
| config_option_list depends
| config_option_list help
- | config_option_list option_error
;
config_option: T_TYPE prompt_stmt_opt T_EOL
@@ -280,7 +272,6 @@ choice_option_list:
| choice_option_list choice_option
| choice_option_list depends
| choice_option_list help
- | choice_option_list option_error
;
choice_option: T_PROMPT prompt if_expr T_EOL
@@ -429,7 +420,6 @@ help: help_start T_HELPTEXT
depends_list:
/* empty */
| depends_list depends
- | depends_list option_error
;
depends: T_DEPENDS T_ON expr T_EOL
--
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