[Pixman] Pixman not building on MacOS X 10.11

[Jeremy Huddleston Sequoia]

This is not a bug in clang.  It isn't a case of "the asm constraints we need are not implemented" it is a case of the code not being valid.  The error printed by clang is correct.  See this post for more details:
https://code.google.com/p/nativeclient/issues/detail?id=4201#c5

Or the description of the K constraint here:
https://gcc.gnu.org/onlinedocs/gcc/Simple-Constraints.html#Simple-Constraints

I think a simple  (albeit not quite elegant) fix would be to just use X instead of K.

--Jeremy

> On Oct 10, 2015, at 13:48, Andrea Canciani <ranma42 at gmail.com> wrote:
> 
> It looks like the latest XCode cannot build pixman:
> 
> $ clang --version
> Apple LLVM version 7.0.0 (clang-700.0.72)
> Target: x86_64-apple-darwin14.5.0
> Thread model: posix
> 
> pixman-mmx.c:100:20: error: constraint 'K' expects an integer constant expression
>         : "y" (__A), "K" (__N)
>                           ^~~
> Reported here:
> https://github.com/Homebrew/homebrew/issues/41056
> 
> It looks like the test performed in configure.ac does not match the code with sufficient accuracy.
> In particular, the constant is hardcoded in the configure.ac test, while in the code it is only available after inlining.
> 
> The attached hack gets the code to compile on modern clang, but I believe first of all we should improve the configure.ac detection code so that pixman can actually build both on old and on new clang versions (possibly with mmx disabled, if the asm constraints we need are not implemented).
> 
> Andrea
> <pixman-mmx.c.diff>_______________________________________________
> Pixman mailing list
> Pixman at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/pixman

-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 4127 bytes
Desc: not available
URL: <http://lists.freedesktop.org/archives/pixman/attachments/20151010/0437f865/attachment.bin>