Added --offline-build option to skip update of external Cmake projects

CMakeLists.txt

@@ -19,6 +19,7 @@ project( tnl )
 set( tnlVersion "0.1" )
 
 # declare all custom build options
+option(OFFLINE_BUILD "Offline build (i.e. without downloading libraries such as pybind11)" OFF)
 option(WITH_MIC "Build with MIC support" OFF)
 option(WITH_CUDA "Build with CUDA support" ON)
 set(WITH_CUDA_ARCH "auto" CACHE STRING "Build for these CUDA architectures")
@@ -377,6 +378,7 @@ INCLUDE( CPack )
 
 # Print custom build options
 message( "-- Build options:" )
+message( "   OFFLINE_BUILD=${OFFLINE_BUILD}" )
 message( "   WITH_MIC=${WITH_MIC}" )
 message( "   WITH_CUDA=${WITH_CUDA}" )
 message( "   WITH_CUDA_ARCH=${WITH_CUDA_ARCH}" )

build

@@ -11,6 +11,7 @@ CMAKE="cmake"
 CMAKE_ONLY="no"
 HELP="no"
 VERBOSE=""
+OFFLINE_BUILD="no"
 
 WITH_CLANG="no"
 WITH_CUDA="yes"
@@ -40,6 +41,7 @@ do
         --cmake=*                        ) CMAKE="${option#*=}" ;;
         --cmake-only=*                   ) CMAKE_ONLY="${option#*=}" ;;
         --verbose                        ) VERBOSE="VERBOSE=1" ;;
+        --offline-build                  ) OFFLINE_BUILD="yes" ;;
         --help                           ) HELP="yes" ;;
         --with-clang=*                   ) WITH_CLANG="${option#*=}" ;;
         --with-mic=*                     ) WITH_MIC="${option#*=}" ;;
@@ -104,6 +106,7 @@ echo "Configuring ${BUILD} $TARGET ..."
 ${CMAKE} ${ROOT_DIR} \
          -DCMAKE_BUILD_TYPE=${BUILD} \
          -DCMAKE_INSTALL_PREFIX=${PREFIX} \
+         -DOFFLINE_BUILD=${OFFLINE_BUILD} \
          -DWITH_MIC=${WITH_MIC} \
          -DWITH_CUDA=${WITH_CUDA} \
          -DWITH_CUDA_ARCH=${WITH_CUDA_ARCH} \

cmake/Gtest.cmake.in

@@ -19,4 +19,7 @@ ExternalProject_Add(googletest
   BUILD_COMMAND     ""
   INSTALL_COMMAND   ""
   TEST_COMMAND      ""
+  # Disable update of the external project in an offline build
+  # reference: https://stackoverflow.com/a/40423683
+  UPDATE_DISCONNECTED ${OFFLINE_BUILD}
 )

src/Python/pybind11.cmake.in

@@ -9,4 +9,7 @@ ExternalProject_Add(pybind11
   SOURCE_DIR        "${CMAKE_BINARY_DIR}/pybind11-src"
   BINARY_DIR        "${CMAKE_BINARY_DIR}/pybind11-build"
   CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX} -DPYBIND11_TEST=FALSE
+  # Disable update of the external project in an offline build
+  # reference: https://stackoverflow.com/a/40423683
+  UPDATE_DISCONNECTED ${OFFLINE_BUILD}
 )

[Tomáš Oberhuber]

I would keep the new flag. However, it would be better if the build would continue by default even if the online updates fail ... to be more user friendly.