fix macos build for High Sierra (#5780)

* fix macos build by changing xcode version

* add comments

* fix benchmark build for mac

* fix for gem option and install npm

* add test for node and npm

* fix node

* fix for node

* another attempts to fix node

* another attempts

* clean up

benchmarks/Makefile.am

@@ -90,8 +90,8 @@ $(benchmarks_protoc_outputs_proto2_header): protoc_middleman2
 
 initialize_submodule:
 	oldpwd=`pwd`
-	cd $(top_srcdir) && git submodule update --init -r third_party/benchmark
-	cd $(top_srcdir)/third_party/benchmark && cmake -DCMAKE_BUILD_TYPE=Release && make
+	cd $(top_srcdir) && git submodule update --init -r third_party/benchmark && \
+		cd third_party/benchmark && cmake -DCMAKE_BUILD_TYPE=Release && make
 	cd $$oldpwd
 	touch initialize_submodule
 

kokoro/macos/prepare_build_macos_rc

@@ -5,7 +5,10 @@
 ##
 # Select Xcode version
 
-export DEVELOPER_DIR=/Applications/Xcode_9.1.app/Contents/Developer
+# Remember to udpate the Xcode version when xcode_9.4.1 is not available.
+# If xcode is not available, it will probaly encounter the failure for 
+# "autom4te: need GNU m4 1.4 or later: /usr/bin/m4""
+export DEVELOPER_DIR=/Applications/Xcode_9.4.1.app/Contents/Developer
 
 ##
 # Select C/C++ compilers
@@ -18,8 +21,11 @@ export CXX=g++
 
 ruby -e "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/master/install)"
 source $HOME/.rvm/scripts/rvm
-brew uninstall node icu4c
-brew install gflags gpg gpg2 node pcre ruby
+brew uninstall node icu4c cmake
+brew prune
+brew install gflags gpg gpg2 node pcre ruby cmake
+sudo chown -R $(whoami) /usr/local
+brew postinstall node
 
 ##
 # Install Tox

tests.sh

@@ -226,7 +226,7 @@ build_objectivec_tvos_release() {
 
 build_objectivec_cocoapods_integration() {
   # Update pod to the latest version.
-  gem install cocoapods --no-ri --no-rdoc
+  gem install cocoapods --no_document
   objectivec/Tests/CocoaPods/run_tests.sh
 }