Merge commit '36bca61764984ff5395653cf8377ec5daa71b709' as 'libs/protobuf'

libs/protobuf/kokoro/linux/aarch64/python_crosscompile_aarch64.sh

@@ -0,0 +1,44 @@
+#!/bin/bash
+#
+# Builds protobuf python including the C++ extension with aarch64 crosscompiler.
+# The outputs of this script are laid out so that we can later test them under an aarch64 emulator.
+# NOTE: This script is expected to run under the dockcross/manylinux2014-aarch64 docker image.
+
+set -ex
+
+PYTHON="/opt/python/cp38-cp38/bin/python"
+
+# Initialize any submodules.
+git submodule update --init --recursive
+
+# Build protoc and libprotobuf
+cmake -DCMAKE_POSITION_INDEPENDENT_CODE=ON -Dprotobuf_WITH_ZLIB=0 -Dprotobuf_BUILD_TESTS=OFF .
+make -j8
+
+# create a simple shell wrapper that runs crosscompiled protoc under qemu
+echo '#!/bin/bash' >protoc_qemu_wrapper.sh
+echo 'exec qemu-aarch64 "../protoc" "$@"' >>protoc_qemu_wrapper.sh
+chmod ugo+x protoc_qemu_wrapper.sh
+
+# PROTOC variable is by build_py step that runs under ./python directory
+export PROTOC=../protoc_qemu_wrapper.sh
+
+pushd python
+
+# NOTE: this step will use protoc_qemu_wrapper.sh to generate protobuf files.
+${PYTHON} setup.py build_py
+
+# when crosscompiling for aarch64, --plat-name needs to be set explicitly
+# to end up with correctly named wheel file
+# the value should be manylinuxABC_ARCH and dockcross docker image
+# conveniently provides the value in the AUDITWHEEL_PLAT env
+plat_name_flag="--plat-name=$AUDITWHEEL_PLAT"
+
+# override the value of EXT_SUFFIX to make sure the crosscompiled .so files in the wheel have the correct filename suffix
+export PROTOCOL_BUFFERS_OVERRIDE_EXT_SUFFIX="$(${PYTHON} -c 'import sysconfig; print(sysconfig.get_config_var("EXT_SUFFIX").replace("-x86_64-linux-gnu.so", "-aarch64-linux-gnu.so"))')"
+
+# Build the python extension inplace to be able to python unittests later
+${PYTHON} setup.py build_ext --cpp_implementation --compile_static_extension --inplace
+
+# Build the binary wheel (to check it with auditwheel)
+${PYTHON} setup.py bdist_wheel --cpp_implementation --compile_static_extension $plat_name_flag