[cfe-dev] [PATCH] Libc++ Windows fixes

[Howard Hinnant]

On Sep 22, 2011, at 11:33 AM, Ruben Van Boxem wrote:

> Thanks! I'd like to do more, but I think I've reached my knowledge and
> capability limits. Some Windows guru (or even better, a Windows C++
> guru) will have to step up and implement more of libc++ to be usable.
> Remember that the _strto*_l functions are very new, and most probably
> don't work on XP, and may not work on Vista. I look to the Linux patch
> on this and *hope* it is general/compatible enough to work without
> much modification on Windows as well.
> 
> I have finally gotten to more libc++ Windows work, and attached is a patch that addresses some of the issues that pop up. I know it's a lot to take in, but most changes are pretty logical (or I wouldn't have been able to find/code them). I'm currently facing implementing  wcsnrtombs and after that there's the more troubling issue of catgets and associates, which I'm quite worried about, as Win32 is almost orthogonal to this whole API. Ideas for that are very welcome.
> 
> The patch explained:
> - include/__config/type_traits: add a define _LIBCXX_HAS_FEATURE_IS_BASE_OF for MSVC and GCC, which both have this, but not __has_feature, which is Clang-only. Modify <type_traits> accordingly.
>  - include/locale: Win32 does not have nl_types, which really sucks... big time.
>  - include/cerrno: the missing error constants, very much acceptable as said by Howard in this thread some time ago.
>  - include/__locale: include the new support/win32/locale.h header, and leave out the missing xlocale.h. Maybe a stupid name, but I haven't found a better name for it. Maybe once the whole win32 stuff is complete, some refactoring is in order. The mask type is defined and all values are defined to the correct values (extracted from mingw-w64 headers).
>  - include/support/win32/support.h: a place for missing functions' declarations to live.
>  - include/support/win32/locale.h: locale-related stuff (duh!) missing or otherwise defined in Win32 headers.
>  - CMakeLists.txt: add the new files, only on Win32.
>  - src/support/win32/support.cpp: implementation of functions in include/support/win32/support.h.
> 
> All this should work for both MinGW(-w64)/GCC and Microsoft/MSVC headers/libraries. Note the *_l functions are only available on recent Windows versions, which should be good enough for now. Especially the locale stuff (up till now!) should work for more than only plain "C" locale.
> 
> One point of attention: the FIXME in the new locale.h header needs attention: Win32 needs to call a function to enable thread-local locales, and then setlocale operates on the thread's locale, which is great. But this function needs to be called somewhere before everything else (in some static initialization function or something). On top of that, I'm not quite sure that what I do in my short implementation of uselocale is correct. I think it is, and it definitely is inefficient.
> 
> I tested this on GCC and Clang built for mingw-w64.
> 
> Please review and commit if you're OK. Thanks!

I've slightly modified your patch (enclosed below) for your review.  My modification consisted of changes only to <__config> and <type_traits>.

I've confirmed that there is no impact to OS X.  I have no opinion on what this does for _WIN32 (if others do, please speak up).  If you (and everyone else) is ok with this patch, then add to this patch your entry in CREDITS.TXT and post back.  I'll commit it.

Thanks,
Howard
-------------- next part --------------
A non-text attachment was scrubbed...
Name: windows-locale.patch
Type: application/octet-stream
Size: 11240 bytes
Desc: not available
URL: <http://lists.llvm.org/pipermail/cfe-dev/attachments/20110922/8c38d746/attachment.obj>