Compilation with CLFFT_APPLE (in ocl mode) fails

[myurkin]

Describe the bug

The problem is due to the fact that cpp/fft_execute.cpp includes function.h (for ATT_UNUSED), which in turn includes const.h (for some simple macro). And the latter header tests for C99 compliance, which naturally fails in C++ compilation mode.

To reproduce

make ocl OPTIONS=CLFFT_APPLE

Expected behavior

Normal compilation

Output

...
g++ -c -O3 -ffast-math -funroll-loops -w  -MD ../cpp/fft_execute.cpp
In file included from ../cpp/../function.h:20:0,
                 from ../cpp/fft_execute.cpp:50:
../cpp/../const.h:29:5: error: #error "Support for C99 standard (at least many of its parts) is strongly recommended for compilation. Otherwise         the compilation will may failor produce wrong results. If you still want to try, you may enable an override in       the Makefile."
...

Technical information

• ADDA version: latest - 8e8d03b

[myurkin]

Fixed by be0830d