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

[Ruben Van Boxem]

2011/9/22 Ruben Van Boxem <vanboxem.ruben at gmail.com>

> 2011/9/22 Eli Friedman <eli.friedman at gmail.com>
>
>> On Thu, Sep 22, 2011 at 12:35 PM, Ruben Van Boxem
>> <vanboxem.ruben at gmail.com> wrote:
>> > 2011/9/22 Howard Hinnant <hhinnant at apple.com>
>> >>
>> >> Patch committed revision 140328.
>> >
>> > Thanks!
>> >
>> > Now that I've got your attention, on to more... involved... matters :-)
>> >
>> > In order to support libc++'s current implementation using
>> > cat[gets|open|close] and nl_types.h (which I ignored for now), I would
>> need
>> > to pull in some external code, namely mingw's libcatgets and a
>> supporting
>> > iconv library. These can all go under support/win32 and leave all other
>> > platforms unchanged of course, and leave the rest of libc++ as coherent
>> as
>> > possible on all platforms. I understand Howard has an acceptable
>> aversion to
>> > including too much foreign code in libc++, and hope you can see the need
>> for
>> > this here.
>> >
>> > There are some issues though:
>> >  - libcatgets is licensed under GPLv2. If I can go through with this, I
>> can
>> > ask/plead/beg the original author to allow a license change or ask him
>> to
>> > make an exception for libc++. I know of no existing alternative.
>> >  - for the iconv part, GNU libiconv is of course out of the question.
>> There
>> > are two projects of interest: APR-iconv (Apache License 2.0) and
>> win-iconv
>> > (BSD 2-clause license), the latter being tiny but primitive. The first
>> is a
>> > truly first class implementation as far as I can see, and with minor
>> > refactoring could be included in the libc++ Windows build.
>> >  - I am not an Open Source license lawyer, and do not know what would be
>> > acceptable for libc++ in this regard.
>> >
>> > I want to ask what's "best", before starting with the implementation.
>> The
>> > only real alternative is writing all this (ie catgets with supporting
>> iconv
>> > code) from scratch, which I don't see myself doing in the near to
>> distant
>> > future. Another way is to completely replace libc++ parts that use/rely
>> on
>> > these API's, but this would make libc++ a lot more assymetric across
>> > platforms. In theory, these support files could help other platforms
>> where
>> > these API's are missing.
>> >
>> > Please let me know what you think. Thanks!
>>
>> MSVC doesn't provide a non-trivial implementation of
>> std::messages::do_open etc., so I don't see why it matters if libc++
>> does not provide one on Windows.
>>
>
> Hmm, glancing through libstdc++'s headers, it doesn't seem to do much more
> :(. Then the question becomes (if the authors/copyright holders of the
> support code in question do not want to have it used in win32 libc++),
> should I just mimic current behavior of the other "Big 2" (MSVC/GCC) in this
> regard? What would I be missing out on then? Is it really only n3290's
> 22.4.7?
>

Implementing stubs was easy, so I just went ahead with it. I can always
improve on it later if I want. Attached is another incremental patch.

Notes:
 - inclue/__bit_reference: Win32 <yvals.h> has a line: "#define _C2 1" which
obviously messes up the templates in this file. I added n extra underscore
to work around this, and did the same to _C1 for consistency.
 - include/locale: include my support header for vasprintf, make the
std::message functions stubs for Windows, mirroring other C++ Standard
Library implementations on Windows.
 - include/support/win32/support.h: add two missing functions and implement
them naively in function of not-missing functions.
 - src/locale.cpp: exclude langinfo.h inclusion for Windows. More work is
needed here later to provide an alternative.
 - src/support/win32/suppport.cpp: implementation.

Please comment on this if something looks weird or wrong.

Clang failed me (http://llvm.org/bugs/show_bug.cgi?id=10989) so, I'll need
to resort to GCC and its unhelpful error messages in the meantime.

Ruben
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