linux-kernel - [PATCH v2 1/2] kconfig: warn of unhandled characters in Kconfig commands

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Date:	Tue,  7 Jul 2015 12:31:16 +0200
From:	Andreas Ruprecht <andreas.ruprecht@....de>
To:	Ulf Magnusson <ulfalizer.lkml@...il.com>
Cc:	Paul Bolle <pebolle@...cali.nl>,
	Valentin Rothberg <valentinrothberg@...il.com>,
	rafael.j.wysocki@...el.com, <linux-kbuild@...r.kernel.org>,
	<linux-kernel@...r.kernel.org>,
	hengelein Stefan <stefan.hengelein@....de>,
	linux@...inikbrodowski.net, Michal Marek <mmarek@...e.cz>,
	Andreas Ruprecht <andreas.ruprecht@....de>
Subject: [PATCH v2 1/2] kconfig: warn of unhandled characters in Kconfig commands

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 around it.

This change makes Kconfig emit a warning if superfluous characters
are found around 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@...il.com>
Signed-off-by: Andreas Ruprecht <andreas.ruprecht@....de>
---
 scripts/kconfig/zconf.gperf |  1 +
 scripts/kconfig/zconf.l     | 18 ++++++++++++------
 2 files changed, 13 insertions(+), 6 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..3078244 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(const 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 +113,9 @@ n	[A-Za-z0-9_]
 		zconflval.string = text;
 		return T_WORD;
 	}
-	.
+	.	{
+		warn_ignored_character(*yytext);
+	}
 	\n	{
 		BEGIN(INITIAL);
 		current_file->lineno++;
@@ -132,7 +141,6 @@ n	[A-Za-z0-9_]
 		BEGIN(STRING);
 	}
 	\n	BEGIN(INITIAL); current_file->lineno++; return T_EOL;
-	---	/* ignore */
 	({n}|[-/.])+	{
 		const struct kconf_id *id = kconf_id_lookup(yytext, yyleng);
 		if (id && id->flags & TF_PARAM) {
@@ -147,9 +155,7 @@ n	[A-Za-z0-9_]
 	\\\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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