use ccache in caffe2 build if installed

Author: prigoyal

build.sh

@@ -20,6 +20,7 @@ CMAKE_VERSION=${CMAKE_VERSION:="`which cmake3 || which cmake`"}
 CAFFE2_BUILD_CACHE=${CAFFE2_BUILD_CACHE:=${TC_DIR}/third-party/.caffe2_build_cache}
 HALIDE_BUILD_CACHE=${HALIDE_BUILD_CACHE:=${TC_DIR}/third-party/.halide_build_cache}
 INSTALL_PREFIX=${INSTALL_PREFIX:=${TC_DIR}/third-party-install/}
+CCACHE_WRAPPER_DIR=${CCACHE_WRAPPER_DIR:=/usr/local/bin/ccache}
 CC=${CC:="`which gcc`"}
 CXX=${CXX:="`which g++`"}
 
@@ -244,12 +245,23 @@ function install_caffe2() {
     echo "Reconfiguring Caffe2"
     rm -rf * || exit 1
 
+    CMAKE_ARGS=("-DBUILD_BINARY=OFF -DCMAKE_CXX_FLAGS='-fno-var-tracking-assignments' -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DUSE_GLOG=OFF -DUSE_GFLAGS=OFF -DUSE_GLOO=OFF -DUSE_NCCL=OFF -DUSE_LMDB=OFF -DUSE_LEVELDB=OFF -DBUILD_TEST=OFF -DUSE_OPENCV=OFF -DUSE_OPENMP=OFF -DCMAKE_INSTALL_MESSAGE=NEVER")
+    CMAKE_ARGS+=("-DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} -DCMAKE_INSTALL_PREFIX=${INSTALL_PREFIX} -DCMAKE_BUILD_TYPE=${BUILD_TYPE} -DBUILD_PYTHON=${WITH_PYTHON_C2} -DUSE_NNPACK=${WITH_NNPACK} -DPROTOBUF_PROTOC_EXECUTABLE=${PROTOC} -DCUB_INCLUDE_DIR=${CUB_INCLUDE_DIR} -DCMAKE_C_COMPILER=${CC} -DCMAKE_CXX_COMPILER=${CXX}")
+
     if ! test ${USE_CONTBUILD_CACHE}; then
-      ${CMAKE_VERSION} -DBUILD_BINARY=OFF -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} -DCMAKE_INSTALL_PREFIX=${INSTALL_PREFIX} -DCMAKE_BUILD_TYPE=${BUILD_TYPE} -DBUILD_PYTHON=${WITH_PYTHON_C2} -DUSE_GLOG=OFF -DUSE_GFLAGS=OFF -DUSE_NNPACK=${WITH_NNPACK} -DGLOG_ROOT_DIR=${INSTALL_PREFIX} -DUSE_GLOO=OFF -DUSE_NCCL=OFF -DUSE_LMDB=OFF -DUSE_LEVELDB=OFF -DBUILD_TEST=OFF -DUSE_OPENCV=OFF -DUSE_OPENMP=OFF -DCMAKE_INSTALL_MESSAGE=NEVER -DCMAKE_CXX_FLAGS="-fno-var-tracking-assignments" -DPROTOBUF_PROTOC_EXECUTABLE=${PROTOC} -DCUDNN_ROOT_DIR=${CUDNN_ROOT_DIR} -DCUB_INCLUDE_DIR=${CUB_INCLUDE_DIR} -DCMAKE_C_COMPILER=${CC} -DCMAKE_CXX_COMPILER=${CXX} .. || exit
+      CMAKE_ARGS+=("-DCUDNN_ROOT_DIR=${CUDNN_ROOT_DIR}")
     else
-      ${CMAKE_VERSION} -DBUILD_BINARY=OFF -DCMAKE_EXPORT_COMPILE_COMMANDS=ON -DCUDA_ARCH_NAME="Maxwell" -DCMAKE_PREFIX_PATH=${INSTALL_PREFIX} -DCMAKE_INSTALL_PREFIX=${INSTALL_PREFIX} -DCMAKE_BUILD_TYPE=${BUILD_TYPE} -DBUILD_PYTHON=${WITH_PYTHON_C2} -DUSE_GLOG=OFF -DUSE_GFLAGS=OFF -DGLOG_ROOT_DIR=${INSTALL_PREFIX} -DUSE_GLOO=OFF -DUSE_NNPACK=${WITH_NNPACK} -DUSE_NCCL=OFF -DUSE_LMDB=OFF -DUSE_LEVELDB=OFF -DBUILD_TEST=OFF -DUSE_OPENCV=OFF -DUSE_OPENMP=OFF -DCMAKE_INSTALL_MESSAGE=NEVER -DCMAKE_CXX_FLAGS="-fno-var-tracking-assignments" -DPROTOBUF_PROTOC_EXECUTABLE=${PROTOC} -DCUB_INCLUDE_DIR=${CUB_INCLUDE_DIR} -DCMAKE_C_COMPILER=${CC} -DCMAKE_CXX_COMPILER=${CXX} .. || exit
+      CMAKE_ARGS+=("-DCUDA_ARCH_NAME='Maxwell'")
+    fi
+
+    if [[ $(which ccache | wc -c) -ne 0 ]]; then
+      CMAKE_ARGS+=("-DCUDA_NVCC_EXECUTABLE=${CCACHE_WRAPPER_DIR}/nvcc")
     fi
+
+    ${CMAKE_VERSION} "${TC_DIR}/third-party/caffe2" ${CMAKE_ARGS[*]}
+
   fi
+
   VERBOSE=${VERBOSE} make -j $CORES install -s || exit 1
 
   set_cache .. .build_cache