Fix for building under clang: specify C++ build and use C++ linkage (#42)

fairseq/clib/temporal_convolution_tbc/temporal_convolution_tbc.cpp

@@ -29,7 +29,7 @@ inline at::Tensor t(at::Type& type, void* i) {
   return type.unsafeTensorFromTH(i, true);
 }
 
-extern "C" void TemporalConvolutionTBC_forward(
+void TemporalConvolutionTBC_forward(
   const char* dtype,
   void* _input,
   void* _output,
@@ -72,7 +72,7 @@ extern "C" void TemporalConvolutionTBC_forward(
   }
 }
 
-extern "C" void TemporalConvolutionTBC_backward(
+void TemporalConvolutionTBC_backward(
   const char* dtype,
   void* _dOutput,
   void* _dInput,

setup.py

@@ -42,6 +42,7 @@ conv_tbc = create_extension(
     define_macros=[('WITH_CUDA', None)],
     with_cuda=True,
     extra_compile_args=['-std=c++11'],
+    source_extension='.cpp',
 )