[LLVMdev] 3.4 branch gcc 4.9 build error

[Alp Toker]

On 04/05/2014 02:30, Tom Stellard wrote:
> On Sat, May 03, 2014 at 12:32:02AM +0100, Alp Toker wrote:
>> On 02/05/2014 20:45, Tuncer Ayaz wrote:
>>> Bump.
>>>
>>> Is it really unsupported to build llvm from scratch with gcc 4.9 and
>>> libstdc++ 4.9? Should I file a bugzilla ticket instead?
>> Obviously LLVM/clang should compile out of the box using the current
>> stable GCC version, and failure to do so would be a potential release
>> blocker. Please file a PR
>>
>> Tom, do you know about this issue?
>>
> Yes, but this would only be considered a release blocker if
> the 3.4 release builds successfully with gcc 4.9 and the current 3.4
> branch does not.

Ensuring the stable branch works with 4.9 is a good idea because it will 
be a standard configuration in coming months.

>
> Has anyone tried the 3.4 release with gcc 4.9?  I doubt this was tested
> much since LLVM 3.4 was released several months before gcc 4.9.

I suspect that pulling in clang header fixes r201729, r202911 and 
r207606 to 3.4.1 will resolve libstdc++ / glibc compatibility issues 
people have been having with 3.4:

   r201729: Teach Clang to provide ::max_align_t in C11 and C++11 modes)
   r202911: Headers: Provide an ABI compatible max_align_t when _MSC_VER 
is defined)
   r207606: Let stddef.h respect __need_{wchar_t, size_t, NULL, 
ptrdiff_t, wint_t}.

The changes look safe to merge but I'd like to hear a second opinion 
from Chandler or Nico.

Alp.

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