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

Masahiro Yamada yamada.masahiro at socionext.com
Thu May 7 14:41:15 CEST 2015


Hi Stefan,

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.

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



-- 
Best Regards
Masahiro Yamada


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