Add cmake option USE_SYSTEM_NCCL (#5897)

* Add cmake option USE_SYSTEM_NCCL

nccl target

* rm mark_as_advanced

cmake/third_party/nccl.cmake

-include (ExternalProject)
 
 option(NCCL_STATIC "" ON)
 if(OF_CUDA_LINK_DYNAMIC_LIBRARY)
-   set(NCCL_STATIC OFF)
+    set(NCCL_STATIC OFF)
 endif()
-
-set(NCCL_INSTALL_DIR ${THIRD_PARTY_DIR}/nccl)
-set(NCCL_INCLUDE_DIR ${NCCL_INSTALL_DIR}/include)
-set(NCCL_LIBRARY_DIR ${NCCL_INSTALL_DIR}/lib)
-
-set(NCCL_URL https://github.com/NVIDIA/nccl/archive/refs/tags/v2.9.8-1.tar.gz)
-use_mirror(VARIABLE NCCL_URL URL ${NCCL_URL})
+option(USE_SYSTEM_NCCL "" OFF)
+set(NCCL_ROOT_DIR "" CACHE PATH "Folder contains NVIDIA NCCL")
 
 if(WIN32)
-    set(NCCL_LIBRARY_NAMES libnccl_static.lib)
+    set(NCCL_LIBRARY_NAME libnccl_static.lib)
 else()
     if(NCCL_STATIC)
-        set(NCCL_LIBRARY_NAMES libnccl_static.a)
+        set(NCCL_LIBRARY_NAME libnccl_static.a)
     else()
-        set(NCCL_LIBRARY_NAMES libnccl.so)
+        set(NCCL_LIBRARY_NAME libnccl.so)
     endif()
 endif()
 
-foreach(LIBRARY_NAME ${NCCL_LIBRARY_NAMES})
-    list(APPEND NCCL_LIBRARIES ${NCCL_LIBRARY_DIR}/${LIBRARY_NAME})
-endforeach()
-
-if(THIRD_PARTY)
-
-include(ProcessorCount)
-ProcessorCount(PROC_NUM)
-ExternalProject_Add(nccl
-    PREFIX nccl
-    URL ${NCCL_URL}
-    URL_MD5 9894dffc51d9d276f01286094ac220ac
-    UPDATE_COMMAND ""
-    CONFIGURE_COMMAND ""
-    BUILD_IN_SOURCE 1
-    BUILD_COMMAND make -j${PROC_NUM} src.build CUDA_HOME=${CUDA_TOOLKIT_ROOT_DIR}
-    INSTALL_COMMAND make src.install PREFIX=${NCCL_INSTALL_DIR}
-    BUILD_BYPRODUCTS ${NCCL_LIBRARIES}
-)
-
-endif(THIRD_PARTY)
+if(USE_SYSTEM_NCCL)
+    include(FindPackageHandleStandardArgs)
+    find_path(NCCL_INCLUDE_DIR nccl.h
+            HINTS ${NCCL_ROOT_DIR} ${CUDA_TOOLKIT_ROOT_DIR}
+            PATH_SUFFIXES cuda/include include)
+    unset(NCCL_LIBRARY CACHE)
+    find_library(NCCL_LIBRARY ${NCCL_LIBRARY_NAME}
+            HINTS ${NCCL_ROOT_DIR} ${CUDA_TOOLKIT_ROOT_DIR}
+            PATH_SUFFIXES lib lib64 cuda/lib cuda/lib64 lib/x64)
+    find_package_handle_standard_args(
+            NCCL DEFAULT_MSG NCCL_INCLUDE_DIR NCCL_LIBRARY)
+    set(NCCL_LIBRARIES ${NCCL_LIBRARY})
+    add_custom_target(nccl)
+else()
+    include (ExternalProject)
+    set(NCCL_INSTALL_DIR ${THIRD_PARTY_DIR}/nccl)
+    set(NCCL_INCLUDE_DIR ${NCCL_INSTALL_DIR}/include)
+    set(NCCL_LIBRARY_DIR ${NCCL_INSTALL_DIR}/lib)
+
+    set(NCCL_URL https://github.com/NVIDIA/nccl/archive/refs/tags/v2.9.8-1.tar.gz)
+    use_mirror(VARIABLE NCCL_URL URL ${NCCL_URL})
+
+    list(APPEND NCCL_LIBRARIES ${NCCL_LIBRARY_DIR}/${NCCL_LIBRARY_NAME})
+
+    if(THIRD_PARTY)
+
+        include(ProcessorCount)
+        ProcessorCount(PROC_NUM)
+        ExternalProject_Add(nccl
+            PREFIX nccl
+            URL ${NCCL_URL}
+            URL_MD5 9894dffc51d9d276f01286094ac220ac
+            UPDATE_COMMAND ""
+            CONFIGURE_COMMAND ""
+            BUILD_IN_SOURCE 1
+            BUILD_COMMAND make -j${PROC_NUM} src.build CUDA_HOME=${CUDA_TOOLKIT_ROOT_DIR}
+            INSTALL_COMMAND make src.install PREFIX=${NCCL_INSTALL_DIR}
+            BUILD_BYPRODUCTS ${NCCL_LIBRARIES}
+        )
+
+    endif(THIRD_PARTY)
+
+endif()
+