Re: scripts/checkpatch: Concatenated strings should use spaces between elements

From: Heinrich Schuchardt
Date: Tue Oct 17 2017 - 18:59:06 EST


On 10/18/2017 12:43 AM, Joe Perches wrote:
> On Tue, 2017-10-17 at 23:17 +0200, Heinrich Schuchardt wrote:
>> This patch creates a warning (CHECK)
>> "Concatenated strings should use spaces between elements"
>>
>> There are no concatenated strings here.
>
> Yes, there are.
>
>> (checkpatch is also used in the U-Boot project where wide strings
>> occur in the EFI implementation.)
>>
>> Signed-off-by: Heinrich Schuchardt <xypron.glpk@xxxxxx>
>> ---
>> test.c | 7 +++++++
>> 1 file changed, 7 insertions(+)
>> create mode 100644 test.c
>>
>> diff --git a/test.c b/test.c
>> new file mode 100644
>> index 0000000000..dfd33cd765
>> --- /dev/null
>> +++ b/test.c
>> @@ -0,0 +1,6 @@
>> +#include <foo.h>
>> +
>> +void foo(void)
>> +{
>> + test(L"\"");
>
> In this case, L must be a constant string and you
> are concatenating L and "\""
>
>
See ISO/IEC 9899:1999

6.4.5 String literals

<cite>
A character string literal is a sequence of zero or more multibyte
characters enclosed in double-quotes, as in "xyz"
A wide string literal is the same, except prefixed by the
letter L.
</cite>

L"foo" is a literal of type wchar_t * and not two strings.
L is a qualifier and not a constant string.

Just like ULL in 10ULL.

Regards

Heinrich