Re: Kconfig: '+config' valid syntax?

[Andreas Ruprecht]

On 07/03/2015 10:59, Paul Bolle wrote:
> On vr, 2015-07-03 at 09:33 +0200, Andreas Ruprecht wrote:
>> I tested the behaviour on yesterday's linux-next, but the commit
>> mentioned above will only complain for invalid characters inside the
>> PARAM case and not for COMMANDs. So, as an example, if you write
>> something like
>>
>> config ACPI_REV_OVERRIDE_POSSIBLE
>> 	depends on X86 +
>> [...]
>>
>> Kconfig will complain about the '+'. This, however, does not apply for
>> top-level statements like 'config', 'menuconfig', and so on.
> 
> Which might explain why this silly mistake went unnoticed. (And, as I
> think you implied, it doesn't help that the empty rule we're hitting
> here is not commented.)
> 
> So the naive solution seems to be to also add the warning to COMMAND's
> rule for '.'. A quick test suggest that would work. Am I missing some
> obvious downside with that solution?

Well, as I mentioned earlier, with a patch similar to the one below this
warning is also generated three times for every '---' before 'help'.
This results in a giant pile of warnings:

ruprecht@box:linux-next$ rm -f scripts/kconfig/*_shipped &&
REGENERATE_PARSERS=1 make allyesconfig 2>&1 | wc -l
7419

The output looks like this:
scripts/kconfig/conf  --allyesconfig Kconfig
arch/x86/Kconfig:4:warning: ignoring unsupported character '-'
arch/x86/Kconfig:4:warning: ignoring unsupported character '-'
arch/x86/Kconfig:4:warning: ignoring unsupported character '-'
init/Kconfig:222:warning: ignoring unsupported character '-'
init/Kconfig:222:warning: ignoring unsupported character '-'
init/Kconfig:222:warning: ignoring unsupported character '-'
init/Kconfig:244:warning: ignoring unsupported character '-'
init/Kconfig:244:warning: ignoring unsupported character '-'
init/Kconfig:244:warning: ignoring unsupported character '-'
[...]

So we would need to add special treatment for '-' also in the command
case, right? But that doesn't look appealing to me, more like a dirty,
dirty hack around the actual problem...

Regards,

Andreas

diff --git a/scripts/kconfig/zconf.l b/scripts/kconfig/zconf.l
index 200a3fe..642f5b2 100644
--- a/scripts/kconfig/zconf.l
+++ b/scripts/kconfig/zconf.l
@@ -106,7 +106,11 @@ n	[A-Za-z0-9_]
 		zconflval.string = text;
 		return T_WORD;
 	}
-	.
+	.	{
+		fprintf(stderr,
+		        "%s:%d:warning: ignoring unsupported character '%c'\n",
+		        zconf_curname(), zconf_lineno(), *yytext);
+	}
 	\n	{
 		BEGIN(INITIAL);
 		current_file->lineno++;