[cfe-commits] [patch] Expect 16bit type for %S in NSStrings (was Re: r148324)

[Nico Weber]

Better?

On Mon, Jan 30, 2012 at 4:24 PM, Jean-Daniel Dupas
<devlists at shadowlab.org> wrote:
>
> Le 31 janv. 2012 à 01:10, Nico Weber a écrit :
>
>> On Mon, Jan 30, 2012 at 9:46 AM, Sebastian Redl
>> <sebastian.redl at getdesigned.at> wrote:
>>>
>>> On 30.01.2012, at 18:37, Nico Weber wrote:
>>>
>>>>
>>>> The current %S warning implementation is wrong for just printf() as
>>>> well: It compares the argument to wchar_t, but if you build your
>>>> program with -fshort-wchar, clang won't warn (since your program uses
>>>> wchar_t) yet printf won't work (because libc was built without
>>>> -fshort-wchar). If you store your characters in an uint32* and pass
>>>> that to printf() and build your program with -fshort-wchar, clang will
>>>> warn (because uint32* doesn't match wchar_t* with -fshort-whar) yet
>>>> the program will work correctly.
>>>
>>> And just to make things more fun, Microsoft's printf takes "%S" to mean "UCS-2 string" and wprintf interprets L"%S" as "narrow string".
>>
>> wchar_t is always 2 byte in Microsoft land, so -fms-extensions should
>> implicitly enable -fshort-wchar, which would take care of the
>> Microsoft part.
>>
>> The attached patch lets %S, %C, and %ls look for a 16bit type in
>> NSStrings as discussed. OK?
>>
>> Nico
>> <clang-percent-S.patch>
>
>
>
>> + // AppKit was built with -fshort-wchar, so passing in 4-byte wchars is a bug.
>
> I don't think it is right to say that AppKit was built with "-fshort-wchar".
> This is just that the %S modifier is implemented to take a UTF-16 string and not a wchar_t as the lib C does.
>
> -- Jean-Daniel
>
>
>
>
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