Merge pull request #269 from FloopCZ/cxx_17

Add C++17 support

Author: FloopCZ

tensorflow_cc/CMakeLists.txt

@@ -6,13 +6,12 @@ project(
   VERSION ${version}
 )
 
-# If enabled, bazel has to be installed.
 option(ALLOW_CUDA "Try to find and use CUDA." ON)
 option(REQUIRE_CUDA "Make sure to find and use CUDA (implies ALLOW_CUDA)." OFF)
 set(LOCAL_RAM_RESOURCES 4096 CACHE STRING "The amount of local RAM resources passed to bazel scheduler (e.g., 4096).")
 set(LOCAL_CPU_RESOURCES HOST_CPUS CACHE STRING "The amount of local CPU cores passed to bazel scheduler (e.g., 2).")
 set(TENSORFLOW_TAG "v${version}" CACHE STRING "The tensorflow release tag to be checked out (default v${version}).")
-set(TARGET_CXX_STANDARD "cxx_std_11" CACHE STRING "C++ standard to be enforced when linking to TensorflowCC targets (e.g., cxx_std_11).")
+set(CMAKE_CXX_STANDARD 14 CACHE STRING "The C++ standard for building and linking the library (e.g., 14).")
 
 # -------------
 # CMake Options
@@ -24,9 +23,6 @@ set(CMAKE_LIBRARY_OUTPUT_DIRECTORY "${CMAKE_CURRENT_BINARY_DIR}/lib")
 include(CMakePackageConfigHelpers)
 set(CMAKECFG_INSTALL_DIR lib/cmake/TensorflowCC)
 
-set_property(CACHE TARGET_CXX_STANDARD PROPERTY STRINGS
-    "cxx_std_11" "cxx_std_14" "cxx_std_17" "cxx_std_20")
-
 # Configure the build_tensorflow script.
 configure_file("cmake/build_tensorflow.sh.in" "build_tensorflow.sh" @ONLY)
 
@@ -41,7 +37,7 @@ include(TensorflowBase)
 # ------------------------------
 
 add_library(tensorflow_cc INTERFACE)
-target_compile_features(tensorflow_cc INTERFACE ${TARGET_CXX_STANDARD})
+target_compile_features(tensorflow_cc INTERFACE "cxx_std_${CMAKE_CXX_STANDARD}")
 
 # The include folders are sometimes contained under bazel-bin/bin/ and sometimes just bazel-bin.
 target_include_directories(

tensorflow_cc/cmake/build_tensorflow.sh.in

@@ -93,6 +93,13 @@ else
     export TF_NEED_CUDA=0
 fi
 
+# set bazel options for c++17 standard if necessary
+cxx_std_opts=""
+if [ "@CMAKE_CXX_STANDARD@" == 17 ]; then
+    echo "Using C++17 standard"
+    cxx_std_opts="--config=c++17_gcc"
+fi
+
 # configure and build
 ./configure
 JVM_RAM_RESOURCES=$((@LOCAL_RAM_RESOURCES@ / 4))
@@ -103,6 +110,7 @@ bazel --host_jvm_args="-Xmx${JVM_RAM_RESOURCES}m" \
             --local_ram_resources=@LOCAL_RAM_RESOURCES@ \
             --local_cpu_resources=@LOCAL_CPU_RESOURCES@ \
             --discard_analysis_cache \
+            $cxx_std_opts \
             $cuda_config_opts \
             tensorflow:libtensorflow_cc.so \
             tensorflow:install_headers