Fix NGRAPH_DOC_BUILD_ENABLE flag (#3664)

CMakeLists.txt

@@ -169,6 +169,7 @@ set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -DEIGEN_MPL2_ONLY -DTBB_USE_THREADING_TO
 ngraph_var(NGRAPH_USE_PREBUILT_LLVM DEFAULT "FALSE")
 
 option(NGRAPH_UNIT_TEST_ENABLE "Control the building of unit tests" TRUE)
+option(NGRAPH_DOC_BUILD_ENABLE "Control the building of documentation" FALSE)
 option(NGRAPH_TOOLS_ENABLE "Control the building of tool" TRUE)
 option(NGRAPH_CPU_ENABLE "Control the building of the CPU backend" TRUE)
 option(NGRAPH_USE_LEGACY_MKLDNN "Use legacy MKLDNN" TRUE)
@@ -247,6 +248,7 @@ macro (NORMALIZE_BOOL VAL)
 endmacro()
 
 NORMALIZE_BOOL(NGRAPH_UNIT_TEST_ENABLE)
+NORMALIZE_BOOL(NGRAPH_DOC_BUILD_ENABLE)
 NORMALIZE_BOOL(NGRAPH_TOOLS_ENABLE)
 NORMALIZE_BOOL(NGRAPH_CPU_ENABLE)
 NORMALIZE_BOOL(NGRAPH_USE_LEGACY_MKLDNN)
@@ -277,6 +279,7 @@ endif()
 
 message(STATUS "NGRAPH_CXX_STANDARD:                  ${NGRAPH_CXX_STANDARD}")
 message(STATUS "NGRAPH_UNIT_TEST_ENABLE:              ${NGRAPH_UNIT_TEST_ENABLE}")
+message(STATUS "NGRAPH_DOC_BUILD_ENABLE:              ${NGRAPH_DOC_BUILD_ENABLE}")
 message(STATUS "NGRAPH_TOOLS_ENABLE:                  ${NGRAPH_TOOLS_ENABLE}")
 message(STATUS "NGRAPH_CPU_ENABLE:                    ${NGRAPH_CPU_ENABLE}")
 message(STATUS "NGRAPH_USE_LEGACY_MKLDNN:             ${NGRAPH_USE_LEGACY_MKLDNN}")

doc/CMakeLists.txt

@@ -16,7 +16,7 @@
 
 add_subdirectory(examples)
 
-if ("${NGRAPH_BUILD_DOCS}" MATCHES "^ON$")
+if ("${NGRAPH_DOC_BUILD_ENABLE}" MATCHES "^ON$")
     add_custom_target( docs
         COMMENT "Build all of the documentation types selected during CMake configuration."
         )
@@ -26,7 +26,7 @@ if ("${NGRAPH_BUILD_DOCS}" MATCHES "^ON$")
 else()
     add_custom_target( docs
         COMMAND echo
-        COMMAND echo "The 'docs' target is disabled. To enable the building of documentation, re-run cmake with the option -DNGRAPH_BUILD_DOCS=ON."
+        COMMAND echo "The 'docs' target is disabled. To enable the building of documentation, re-run cmake with the option -DNGRAPH_DOC_BUILD_ENABLE=ON."
         COMMAND echo
         COMMAND false
         VERBATIM