[cfe-dev] MinGW(-w64) fixes to InitHeaderSearch.cpp and float.h

[Douglas Gregor]

On Jun 25, 2011, at 7:51 AM, Ruben Van Boxem wrote:

> Hi,
> 
> I bring fixes for MinGW(-w64) Clang users:
> 
> 1. InitHeaderSearch.cpp: add a HeaderSearchOptions argument to
> AddDefaultCXXIncludePaths (AddDefaultCIncludePaths already had this,
> seems only logical to have it here) and use ResourceDir to find the
> sysroot of where Clang.exe is located. From there, add the
> x86_64-w64-mingw32 and i686-w64-mingw32 include paths for C and C++.
> All mingw-w64 toolchains are built --with-sysroot, and thus
> relocatable, so this change will always find the accompanying headers.

I've committed this part as r133911.

> 2. float.h: MinGW needs an #include_next, because as described on this
> page (http://msdn.microsoft.com/en-us/library/y0ybw9fy.aspx) there are
> non-standard extensions to float.h which are expected on Windows, and
> MinGW provides these declarations in their system header. GCC's
> float.h is "fixinclude"d to include_next the system header. Note that
> a trivial change is needed in mingw-w64's float.h, and that change
> will be committed as soon as Clang's header does what it's supposed to
> do.


If we're including MinGW's float.h first, then our own definitions of all of the standard float.h macros are going to stomp on the ones that come from MinGW's float.h. I think that's a reasonable thing to do, but if that's the intent, I'd prefer to have #undef's in our own float.h to make it explicit that this is what we're doing (and so that our own headers don't generate warnings, even if they're suppressed).

	- Doug