[libcxx] Convert Solaris support library to C++ to fix -std=c++11 build

[mgorny]

Summary

Convert the Solaris xlocale.c compatibility library from plain C to C++,
and fix the prototype for declared functions in order to fix the build
failures caused by the addition of -std=c++11 to LIBCXX_COMPILE_FLAGS.
The additional flag got propagated to the C file, resulting in error
with strict compilers.

[theraven]

It sounds as if the bug here is either that the .c files are being treated as c++, or that we're sticking -std=c++{whatever} in CFLAGS as well as CXXFLAGS. This is probably the bug that should be fixed.

[mgorny]

In D25431#566096, @theraven wrote:

It sounds as if the bug here is either that the .c files are being treated as c++, or that we're sticking -std=c++{whatever} in CFLAGS as well as CXXFLAGS. This is probably the bug that should be fixed.

We're sticking them into LIBCXX_COMPILE_FLAGS, to be more precise. And this is the only C file in the whole libcxx, so I'm not sure if anyone even remember about that ;-).

[EricWF]

Why not just compile the sources files as C++ by changing their extensions? This change seems all kinds of wrong because we're throwing away *all* of our flags, including things like -m32 or -target <cross-compile-target>.

[mgorny]

In D25431#570227, @EricWF wrote:

Why not just compile the sources files as C++ by changing their extensions? This change seems all kinds of wrong because we're throwing away *all* of our flags, including things like -m32 or -target <cross-compile-target>.

That's another option. Having a lot of other problems on Solaris at the time, using a separate library was simpler to test. I will try this alternative today.

[mgorny]

Ok, here's an updated patch that changes the code to C++. Since C++ is more strict than C, I also had to remove some conflicting declarations -- and while at it, I updated the header to avoid any collisions and redundancy on SunOS 5.11 (OpenIndiana). I don't have access to any older system, and considering that the support for SunOS in clang is still incomplete, I don't think it important to support older systems.

[mgorny]

Damn it, it seems that SunOS isn't actually exposing some functions. I need to work on this further, and figure out WTF.

[mgorny]

Ok, here's a minimal change necessary to fix the build. I'm not touching anything else not to break it ;-).

[theraven]

Looks like a much better change to me.

[joerg]

Commit the prototype fix separately, please.

[mgorny]

Thanks for the review. Committed the prototype fix first, and followed it by the C++ conversion.

libcxx/trunk/src/support/solaris/xlocale.c

 #include <stdio.h>
 #include <sys/localedef.h>
 
 
 int isxdigit_l(int __c, locale_t __l) {
     return isxdigit(__c);
 }
 
-int iswxdigit_l(wchar_t __c, locale_t __l) {
+int iswxdigit_l(wint_t __c, locale_t __l) {
     return isxdigit(__c);
 }
 
 // FIXME: This disregards the locale, which is Very Wrong
 #define vsnprintf_l(__s, __n, __l, __format, __va)  \
     vsnprintf(__s, __n, __format, __va) 
 
 int snprintf_l(char *__s, size_t __n, locale_t __l, const char *__format, ...)