[U-Boot] [PATCH v1 1/4] Kconfig: Enable usage of escape char '\' in string values

Stefan Roese sr at denx.de
Thu May 7 14:46:28 CEST 2015


Hi Masahiro,

On 07.05.2015 14:41, Masahiro Yamada wrote:
> 2015-05-07 21:13 GMT+09:00 Stefan Roese <sr at denx.de>:
>> I might have missed something, but I failed to use the escape char '\'
>> in strings. To pass a printf format string like "foo %d bar\n" via
>> Kconfig to the code.
>>
>> Right now its not possible to use the escape character '\' in Kconfig
>> string values correctly to e.g. set this string value "test output\n".
>> The '\n' will be converted to 'n'.
>>
>> The current implementation removes some of the '\' chars from the input
>> string in conf_set_sym_val(). Examples:
>>
>> '\'     -> ''
>> '\\'    -> '\'
>> '\\\'   -> '\'
>> '\\\\'  -> '\\'
>> ...
>>
>> And then doubles the backslash chars in the output string in
>> sym_escape_string_value(). Example:
>>
>> '\'     -> ''   -> ''
>> '\\'    -> '\'  -> '\\'
>> '\\\'   -> '\'  -> '\\'
>> '\\\\'  -> '\\' -> '\\\\'
>> ...
>>
>> As you see in these examples, its impossible to generate a single '\'
>> charater in the output string as its needed for something like '\n'.
>>
>> This patch now changes this behavior to not drop some backslashes in
>> conf_set_sym_val() and to not add new backslashes in the resulting
>> output string. Removing the function sym_escape_string_value()
>> completely as its not needed anymore.
>
>
> Interesting.
> I did not know this behavior of strings in Kconfig.

Then I'm not the only one. ;)

> I want to see the reaction from linux-kconfig ML.

Okay. It makes sense then to send this patch to this list right away. A 
quick search didn't reveal any results though. Where is this list hosted?

Thanks,
Stefan



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