build rccl module only when USE_RCCL is ON (#325)

Summary:
Pull Request resolved: #325

Current code always builds nccl module as long as USE_ROCM is ON.
However, we should build it only when USE_RCCL is ON. This patch fixes
it by adding the hipified nccl files in nccl/CMakeLists.txt which will be included
only when USE_RCCL is ON.

Reviewed By: jiayisuse

Differential Revision: D35636872

fbshipit-source-id: b3a5a36912b674bc43a474adafddb40d5af0ab6c

Author: minsii

gloo/CMakeLists.txt

@@ -66,12 +66,10 @@ if(USE_ROCM)
   file(GLOB GLOO_HIP_SRCS
     "${HIPIFY_OUTPUT_DIR}/hip*.cc"
     "${HIPIFY_OUTPUT_DIR}/hip*.hip"
-    "${HIPIFY_OUTPUT_DIR}/nccl/nccl.hip"
     )
 
   file(GLOB GLOO_HIP_HDRS
     "${HIPIFY_OUTPUT_DIR}/hip*.h"
-    "${HIPIFY_OUTPUT_DIR}/nccl/nccl.h"
     )
 endif()
 

gloo/nccl/CMakeLists.txt

@@ -1,12 +1,29 @@
-set(GLOO_NCCL_SRCS
-  "${CMAKE_CURRENT_SOURCE_DIR}/nccl.cu"
-  )
-
-set(GLOO_NCCL_HDRS
-  "${CMAKE_CURRENT_SOURCE_DIR}/nccl.h"
-  )
-
-list(APPEND GLOO_CUDA_SRCS ${GLOO_NCCL_SRCS})
-list(APPEND GLOO_CUDA_HDRS ${GLOO_NCCL_HDRS})
-set(GLOO_CUDA_SRCS ${GLOO_CUDA_SRCS} PARENT_SCOPE)
-set(GLOO_CUDA_HDRS ${GLOO_CUDA_HDRS} PARENT_SCOPE)
+if(USE_CUDA)
+    set(GLOO_NCCL_SRCS
+      "${CMAKE_CURRENT_SOURCE_DIR}/nccl.cu"
+      )
+
+    set(GLOO_NCCL_HDRS
+      "${CMAKE_CURRENT_SOURCE_DIR}/nccl.h"
+      )
+
+    list(APPEND GLOO_CUDA_SRCS ${GLOO_NCCL_SRCS})
+    list(APPEND GLOO_CUDA_HDRS ${GLOO_NCCL_HDRS})
+    set(GLOO_CUDA_SRCS ${GLOO_CUDA_SRCS} PARENT_SCOPE)
+    set(GLOO_CUDA_HDRS ${GLOO_CUDA_HDRS} PARENT_SCOPE)
+endif()
+
+if(USE_ROCM)
+    set(GLOO_NCCL_SRCS
+      "${CMAKE_CURRENT_SOURCE_DIR}/nccl.hip"
+      )
+
+    set(GLOO_NCCL_HDRS
+      "${CMAKE_CURRENT_SOURCE_DIR}/nccl.h"
+      )
+
+    list(APPEND GLOO_HIP_SRCS ${GLOO_NCCL_SRCS})
+    list(APPEND GLOO_HIP_HDRS ${GLOO_NCCL_HDRS})
+    set(GLOO_HIP_SRCS ${GLOO_HIP_SRCS} PARENT_SCOPE)
+    set(GLOO_HIP_HDRS ${GLOO_HIP_HDRS} PARENT_SCOPE)
+endif()