[cfe-dev] Clang++/MSVC10 chokes on "__unaligned" in VS header files

[Charles Davis]

On 3/2/11 2:25 PM, Ruben Van Boxem wrote:
> Hi,
> 
> I built LLVM/Clang with MSVC 10.0 and tried to compile a little
> program using std::vector.
> 
>> In file included from main.cpp:2:
>> In file included from C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include/vector:6:
>> In file included from C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include/memory:6:
>> In file included from C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include/xmemory:6:
>> In file included from C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include/cstdlib:13:
>> C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include/stdlib.h(343) :  error: unknown type name '__unaligned'
>> char (*__countof_helper(UNALIGNED _CountofType (&_Array)[_SizeOfArray]))[_SizeOfArray];
>>                         ^
> 
> A google search shows clang/lib/CodeGen/MicrosoftCXXABI.cpp
> knows/should know about __unaligned, or at least this part of Clang
> knows about it.
I can explain that. I wrote that code.

Clang doesn't even know anything about the MSVC __unaligned keyword. The
__unaligned you saw in there was part of a comment documenting the MSVC
name-mangling scheme (which most of that file is dedicated to
implementing at the moment). MSVC will mangle __unaligned into the name;
but since Clang doesn't support __unaligned yet, Clang doesn't do that
just yet. I documented it so I'd remember how to mangle it if and when
Clang does support __unaligned.
> 
> Anything I can do? Thanks!
File a bug and write patches. Feel free to implement mangling
__unaligned in the Microsoft mangler (everything you need should be in
that file).

Chip