fixes error introduced in #842

[andrewcorrigan]

I think that this should fix #845. I'm sorry for introducing this regression.

[jaredhoberock]

Thanks, Andrew. It looks like this change rolls back that line to what it was before Artem-B's recent change to compiler.h, is that right?

[3gx]

We should revert this file to the state it had before PR #842? It appears we do not fully understand interaction of different macros, and until we do it we should revert to what used to work.

[andrewcorrigan]

I didn't roll it back completely, but I think this fixes the error reported in #845 and is more correct than the check was before. Basically, the cumulative changed from before my previous PR is that this:

#if defined(__CUDA__)
#define THRUST_DEVICE_COMPILER THRUST_DEVICE_COMPILER_NVCC
#else
#define THRUST_DEVICE_COMPILER THRUST_DEVICE_COMPILER_CLANG
#endif

which doesn't make sense but is innocuous, changes now to:

#if defined(__CUDA__) && defined(__clang__)
#define THRUST_DEVICE_COMPILER THRUST_DEVICE_COMPILER_CLANG
#elif defined(__CUDA__)
#define THRUST_DEVICE_COMPILER THRUST_DEVICE_COMPILER_NVCC
#endif

Which is correct, but ineffective, as pointed out by Artem.

The error message reported in #845, I believe is due to my change which incorrectly made the above:

#if defined(__CUDA__) && defined(__clang__)
#define THRUST_DEVICE_COMPILER THRUST_DEVICE_COMPILER_CLANG
#else
#define THRUST_DEVICE_COMPILER THRUST_DEVICE_COMPILER_NVCC
#endif

which failed to actually check for __CUDA__ before setting THRUST_DEVICE_COMPILER_NVCC.

[andrewcorrigan]

@egaburov Whatever you guys prefer. I can submit a different PR with the change just rolled back.

Another option: I'd be happy to get THRUST_DEVICE_COMPILER_CLANG actually working too, and deal with all the rest of the code that only allows for THRUST_DEVICE_COMPILER_NVCC.

[jaredhoberock]

Agreed with @egaburov - let's roll it back to the state it was before and then try to fix the issue separately.

[andrewcorrigan]

Please see #853.