[PATCH v3 1/2] kconfig: warn of unhandled characters in Kconfig commands

From: Andreas Ruprecht
Date: Fri Jul 10 2015 - 04:26:03 EST


In Kconfig, definitions of options take the following form:
"<COMMAND> <PARAM> <PARAM> ...". COMMANDs and PARAMs are treated
slightly different by the underlying parser.

While commit 2e0d737fc76f ("kconfig: don't silently ignore unhandled
characters") introduced a warning for unsupported characters around
PARAMs, it does not cover situations where a COMMAND has additional
characters before it.

This change makes Kconfig emit a warning if superfluous characters
are found before COMMANDs. As the 'help' statement sometimes is
written as '---help---', the '-' character would now also be regarded
as unhandled and generate a warning. To avoid that, '-' is added to
the list of allowed characters, and the token '---help---' is included
in the zconf.gperf file.

Reported-by: Valentin Rothberg <valentinrothberg@xxxxxxxxx>
Signed-off-by: Andreas Ruprecht <andreas.ruprecht@xxxxxx>
---
Changes to v1:
- add '---help---' in zconf.gperf instead of special casing
it in zconf.l

Changes to v2:
- Do no constify char parameter to warn_ignored_character
- Shorten rule definitions for '.'

scripts/kconfig/zconf.gperf | 1 +
scripts/kconfig/zconf.l | 20 +++++++++++---------
2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/scripts/kconfig/zconf.gperf b/scripts/kconfig/zconf.gperf
index b6ac02d..7aceb7b 100644
--- a/scripts/kconfig/zconf.gperf
+++ b/scripts/kconfig/zconf.gperf
@@ -22,6 +22,7 @@ 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
diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index 200a3fe..c410d25 100644
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -66,9 +66,16 @@ static void alloc_string(const char *str, int size)
memcpy(text, str, size);
text[size] = 0;
}
+
+static void warn_ignored_character(char chr)
+{
+ fprintf(stderr,
+ "%s:%d:warning: ignoring unsupported character '%c'\n",
+ zconf_curname(), zconf_lineno(), chr);
+}
%}

-n [A-Za-z0-9_]
+n [A-Za-z0-9_-]

%%
int str = 0;
@@ -106,7 +113,7 @@ n [A-Za-z0-9_]
zconflval.string = text;
return T_WORD;
}
- .
+ . warn_ignored_character(*yytext);
\n {
BEGIN(INITIAL);
current_file->lineno++;
@@ -132,8 +139,7 @@ n [A-Za-z0-9_]
BEGIN(STRING);
}
\n BEGIN(INITIAL); current_file->lineno++; return T_EOL;
- --- /* ignore */
- ({n}|[-/.])+ {
+ ({n}|[/.])+ {
const struct kconf_id *id = kconf_id_lookup(yytext, yyleng);
if (id && id->flags & TF_PARAM) {
zconflval.id = id;
@@ -146,11 +152,7 @@ n [A-Za-z0-9_]
#.* /* comment */
\\\n current_file->lineno++;
[[:blank:]]+
- . {
- fprintf(stderr,
- "%s:%d:warning: ignoring unsupported character '%c'\n",
- zconf_curname(), zconf_lineno(), *yytext);
- }
+ . warn_ignored_character(*yytext);
<<EOF>> {
BEGIN(INITIAL);
}
--
1.9.1

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