add EXCLUDE_FROM_ALL to codegen directory (#1441)

* add EXCLUDE_FROM_ALL to codegen library so we don't need to using conditionals in build. If codegen is needed it will be built.

* update llvm dependencies

cmake/external_llvm.cmake

@@ -175,5 +175,6 @@ else()
 endif()
 
 add_library(libllvm INTERFACE)
+add_dependencies(libllvm ext_llvm)
 target_include_directories(libllvm SYSTEM INTERFACE ${EXTERNAL_PROJECTS_ROOT}/llvm/include)
 target_link_libraries(libllvm INTERFACE ${LLVM_LINK_LIBS})

cmake/external_llvm_prebuilt.cmake

@@ -139,5 +139,6 @@ set(LLVM_LINK_LIBS
 )
 
 add_library(libllvm INTERFACE)
+add_dependencies(libllvm ext_llvm)
 target_include_directories(libllvm SYSTEM INTERFACE ${SOURCE_DIR}/include)
 target_link_libraries(libllvm INTERFACE ${LLVM_LINK_LIBS})

cmake/external_mkldnn.cmake

@@ -166,6 +166,7 @@ add_custom_command(TARGET ext_mkldnn POST_BUILD
 )
 
 add_library(libmkldnn INTERFACE)
+add_dependencies(libmkldnn ext_mkldnn)
 target_include_directories(libmkldnn SYSTEM INTERFACE ${EXTERNAL_PROJECTS_ROOT}/mkldnn/include)
 target_link_libraries(libmkldnn INTERFACE
     ${EXTERNAL_PROJECTS_ROOT}/mkldnn/lib/libmkldnn${CMAKE_SHARED_LIBRARY_SUFFIX}

src/ngraph/CMakeLists.txt

@@ -185,7 +185,7 @@ endif()
 
 include_directories("${NGRAPH_INCLUDE_PATH}")
 
-add_subdirectory(codegen)
+add_subdirectory(codegen EXCLUDE_FROM_ALL)
 add_subdirectory(runtime)
 
 add_library(ngraph SHARED ${SRC})

src/ngraph/codegen/CMakeLists.txt

@@ -69,13 +69,9 @@ add_custom_target(header_resource
     BYPRODUCTS
 )
 
-# The conditional is a hack. I want to use EXCLUDE_FROM_ALL and OPTIONAL but that does not
-# seem to be working for me.
-if ((NGRAPH_CPU_ENABLE AND NOT NGRAPH_DEX_ONLY) OR NGRAPH_GPU_ENABLE)
-    add_library(codegen SHARED ${SRC})
-    set_target_properties(codegen PROPERTIES VERSION ${NGRAPH_VERSION} SOVERSION ${NGRAPH_API_VERSION})
-    add_dependencies(codegen header_resource libmkldnn libeigen)
-    target_include_directories(codegen SYSTEM PUBLIC ${CMAKE_BINARY_DIR})
-    target_link_libraries(codegen PRIVATE libllvm ngraph)
-    install(TARGETS codegen DESTINATION ${NGRAPH_INSTALL_LIB})
-endif()
+add_library(codegen SHARED ${SRC})
+set_target_properties(codegen PROPERTIES VERSION ${NGRAPH_VERSION} SOVERSION ${NGRAPH_API_VERSION})
+add_dependencies(codegen header_resource libmkldnn libeigen)
+target_include_directories(codegen SYSTEM PUBLIC ${CMAKE_BINARY_DIR})
+target_link_libraries(codegen PRIVATE libllvm ngraph)
+install(TARGETS codegen DESTINATION ${NGRAPH_INSTALL_LIB})