[cfe-commits] r154640 - in /cfe/trunk: include/clang/Basic/Builtins.def lib/AST/ExprConstant.cpp lib/CodeGen/CGBuiltin.cpp lib/CodeGen/CGExpr.cpp lib/Frontend/InitPreprocessor.cpp test/CodeGen/atomic-ops.c test/Sema/atomic-ops.c

[Sebastian Redl]

On 13.04.2012 02:45, Richard Smith wrote:
> Author: rsmith
> Date: Thu Apr 12 19:45:38 2012
> New Revision: 154640
>
> URL: http://llvm.org/viewvc/llvm-project?rev=154640&view=rev
> Log:
> Implement the missing pieces needed to support libstdc++4.7's<atomic>:
> __atomic_test_and_set, __atomic_clear, plus a pile of undocumented __GCC_*
> predefined macros.
>
> Implement library fallback for __atomic_is_lock_free and
> __c11_atomic_is_lock_free, and implement __atomic_always_lock_free.
>
> Contrary to their documentation, GCC's __atomic_fetch_add family don't
> multiply the operand by sizeof(T) when operating on a pointer type.
> libstdc++ relies on this quirk. Remove this handling for all but the
> __c11_atomic_fetch_add and __c11_atomic_fetch_sub builtins.
>
This is scary. Do we have any idea how to handle it if GCC 4.8 fixes 
this? They can, since they just fix libstdc++ at the same time, but it 
will be a problem for us.

Sebastian