[cfe-dev] Question about an interesting blog

[Kai Tietz]

Hello,

I was recently reading in the blog at
http://blog.llvm.org/2013/09/a-path-forward-for-llvm-toolchain-on.html
that clang/llvm made big progress in supporting native Windows as
target.  This actually sounds pretty promising, but this blog raised
some questions you might be able to answer.

First,  it seems to us that within that blog, the author often
mistakenly implying Windows is MSVC.  In general, I assume that he
meant "Visual Studio Compatible" instead of the term "Windows".  But I
am not sure if I got this right.

Next, the Visual Studio plugin is indeed a cool thing, but why should
I want to use a different compiler for native Windows-code in Visual
Studio Professional (required for plugin support), as the OP already
has a fully compatible, C++ bug-per-bug compatible non-free compiler
available (msvc)?

The news that now an application can be built with clang/llvm for
Windows native isn't actual something really new.  This works together
with mingw-w64's runtime/header now for more than a year.
Nevertheless our community at mingw-w64 stopped working on llvm/clang
support as there were some major bugs, which made it impossible to
build more complex applications by clang/llvm for Windows. Btw this
was true for C and C++ languages.

Does clang/llvm support now dllimport/dllexport semantics?  As far as
I can see this is still an open issue.  Therefore the compiler is
still not usable for more serious applications.

As claimed by this article, the PSDK can be used now directly as
provided by MS, I would be interested to learn if the disable/enable
warning functionality by numbers is supported?  Are the
sal-annotations supported?  Is the pragma comment(lib, ...) & co
supported?  Does clang/llvm supports the .metadata intializers for
DCOM?  Is native TLS supported by it?  Is the C++-name-mangling
compatible to VC implemented?  Is the C __try/__except/__finally
supported?

Especially the missing dllimport/dllexport (on class and
variable/function-base) was the reason for mingw-w64's community to
stop to improve further support of clang/llvm.  Furthermore there were
some issues about ABI.  For 64-bit floating-point, variadic, and some
SEH-exception-mechanism were road-blocks, and for 32-bit & 64-bit
Windows the debug-information quality, and the missing support for
dllimport/dllexport/selectany (and some other) attributes were real
blockers.

If things have changed here, it would be great to read about that in
more detail in feature lists too.  It would be great if you could
reply to us - mingw-w64 community and developers.

Thanks in advance,
Kai