From: Masahiro Yamada <yamada.masahiro@socionext.com>
To: linux-kbuild@vger.kernel.org
Cc: Ulf Magnusson <ulfalizer@gmail.com>,
linux-kernel@vger.kernel.org,
Masahiro Yamada <yamada.masahiro@socionext.com>
Subject: [PATCH 09/27] kconfig: remove grammatically ambiguous "unexpected option" diagnostic
Date: Tue, 11 Dec 2018 20:00:52 +0900 [thread overview]
Message-ID: <1544526070-16690-10-git-send-email-yamada.masahiro@socionext.com> (raw)
In-Reply-To: <1544526070-16690-1-git-send-email-yamada.masahiro@socionext.com>
This commit decreases 15 shift/reduce conflicts.
The location of this error recovery is ambiguous.
For example, there are two ways to interpret the following code:
1 config FOO
2 bool "foo"
[A] Both lines are reduced together into a config_stmt.
[B] The only line 1 is reduced into a config_stmt, and the line 2
matches to "option_name error T_EOL"
Of course, we expect [A], but [B] could be grammatically possible.
Kconfig has no terminator for a config block. So, we cannot detect its
end until we see non-property keywords. People often insert a blank
line between two config blocks, but it is just a coding convention.
Blank lines are actually allowed anywhere in Kconfig files.
The real error is when a property keyword appears right after "endif",
"endchoice", "endmenu", "source", "comment", or variable assignments.
Instead of fixing the grammatical ambiguity, I chose to simply remove
this error recovery.
The difference is
unexpected option "bool"
... is turned into a more generic message:
invalid statement
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
---
scripts/kconfig/zconf.y | 11 +----------
1 file changed, 1 insertion(+), 10 deletions(-)
diff --git a/scripts/kconfig/zconf.y b/scripts/kconfig/zconf.y
index 02bfc62..cef6123 100644
--- a/scripts/kconfig/zconf.y
+++ b/scripts/kconfig/zconf.y
@@ -31,7 +31,7 @@ struct symbol *symbol_hash[SYMBOL_HASHSIZE];
static struct menu *current_menu, *current_entry;
%}
-%expect 21
+%expect 6
%union
{
@@ -94,7 +94,6 @@ static struct menu *current_menu, *current_entry;
%type <expr> expr
%type <expr> if_expr
%type <id> end
-%type <id> option_name
%type <menu> if_entry menu_entry choice_entry
%type <string> symbol_option_arg word_opt assign_val
@@ -127,17 +126,9 @@ stmt_list:
| 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:
if_stmt
| comment_stmt
--
2.7.4
next prev parent reply other threads:[~2018-12-11 11:01 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-11 11:00 [PATCH 00/27] kconfig: remove all reduce/shift conflicts, refactor lexer, fix various issues Masahiro Yamada
2018-12-11 11:00 ` [PATCH 01/27] kconfig: fix file name and line number of warn_ignored_character() Masahiro Yamada
2018-12-11 11:00 ` [PATCH 02/27] kconfig: fix memory leak when EOF is encountered in quotation Masahiro Yamada
2018-12-11 11:00 ` [PATCH 03/27] kconfig: require T_EOL to reduce visible statement Masahiro Yamada
2018-12-11 11:00 ` [PATCH 04/27] kconfig: remove unneeded pattern matching to whitespaces Masahiro Yamada
2018-12-11 11:00 ` [PATCH 05/27] kconfig: refactor pattern matching in STRING state Masahiro Yamada
2018-12-11 11:00 ` [PATCH 06/27] kconfig: fix ambiguous grammar in terms of new lines Masahiro Yamada
2018-12-11 11:00 ` [PATCH 07/27] kconfig: clean up EOF handling in the lexer Masahiro Yamada
2018-12-11 11:00 ` [PATCH 08/27] kconfig: warn no new line at end of file Masahiro Yamada
2018-12-11 11:00 ` Masahiro Yamada [this message]
2018-12-11 11:00 ` [PATCH 10/27] kconfig: remove grammatically ambiguous option_error Masahiro Yamada
2018-12-11 11:00 ` [PATCH 11/27] kconfig: remove redundant if_block rule Masahiro Yamada
2018-12-11 11:00 ` [PATCH 12/27] kconfig: remove redundant menu_block rule Masahiro Yamada
2018-12-11 11:00 ` [PATCH 13/27] kconfig: loosen the order of "visible" and "depends on" in menu entry Masahiro Yamada
2018-12-11 11:00 ` [PATCH 14/27] kconfig: rename depends_list to comment_option_list Masahiro Yamada
2018-12-11 11:00 ` [PATCH 15/27] kconfig: remove redundant token defines Masahiro Yamada
2018-12-11 11:00 ` [PATCH 16/27] kconfig: use distinct tokens for type and default properties Masahiro Yamada
2018-12-11 11:01 ` [PATCH 17/27] kconfig: refactor scanning and parsing "option" properties Masahiro Yamada
2018-12-11 11:01 ` [PATCH 18/27] kconfig: use specific tokens instead of T_ASSIGN for assignments Masahiro Yamada
2018-12-11 11:01 ` [PATCH 19/27] kconfig: use T_WORD instead of T_VARIABLE for variables Masahiro Yamada
2018-12-11 11:01 ` [PATCH 20/27] microblaze: surround string default in Kconfig with double quotes Masahiro Yamada
2018-12-12 8:28 ` Michal Simek
2018-12-11 11:01 ` [PATCH 21/27] treewide: surround file paths in Kconfig files " Masahiro Yamada
2018-12-11 11:19 ` Wolfram Sang
2018-12-11 11:25 ` Geert Uytterhoeven
2018-12-11 14:43 ` Ingo Molnar
2018-12-11 11:01 ` [PATCH 22/27] kconfig: ban the use of '.' and '/' in unquoted words Masahiro Yamada
2018-12-11 11:01 ` [PATCH 23/27] kconfig: refactor end token rules Masahiro Yamada
2018-12-11 11:01 ` [PATCH 24/27] kconfig: stop associating kconf_id with yylval Masahiro Yamada
2018-12-11 11:01 ` [PATCH 25/27] kconfig: switch to ASSIGN_VAL state in the second lexer Masahiro Yamada
2018-12-11 11:01 ` [PATCH 26/27] kconfig: update current_pos " Masahiro Yamada
2018-12-11 11:01 ` [PATCH 27/27] kconfig: remove keyword lookup table entirely Masahiro Yamada
2018-12-19 14:59 ` [PATCH 00/27] kconfig: remove all reduce/shift conflicts, refactor lexer, fix various issues Masahiro Yamada
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