[test-release] Added -silent-log flag to test-release.sh

[thieta]

Summary

This flag silents the build output of test-release.sh so that
it can be used in CI systems a bit better. It will still log
the build output to the log files but not echo it to stdout.

[tstellar]

LGTM.

llvm/utils/release/test-release.sh

 do_libunwind="yes"
 do_test_suite="yes"
 do_openmp="yes"
 do_lld="yes"
 do_lldb="yes"
 do_polly="yes"
 do_mlir="yes"
 do_flang="yes"
+do_silent_log="no"
 BuildDir="`pwd`"
 ExtraConfigureFlags=""
 ExportBranch=""
 git_ref=""
 
 function usage() {
     echo "usage: `basename $0` -release X.Y.Z -rc NUM [OPTIONS]"
     echo ""
function usage() {
     echo " -no-test-suite       Disable check-out & build test-suite"
     echo " -no-openmp           Disable check-out & build libomp"
     echo " -no-lld              Disable check-out & build lld"
     echo " -lldb                Enable check-out & build lldb"
     echo " -no-lldb             Disable check-out & build lldb (default)"
     echo " -no-polly            Disable check-out & build Polly"
     echo " -no-mlir             Disable check-out & build MLIR"
     echo " -no-flang            Disable check-out & build Flang"
+    echo " -silent-log          Don't output build logs to stdout"
 }
 
 while [ $# -gt 0 ]; do
     case $1 in
         -release | --release )
             shift
             Release="$1"
             Release_no_dot="`echo $1 | sed -e 's,\.,,g'`"
case $1 in
             do_polly="no"
             ;;
         -no-mlir )
             do_mlir="no"
             ;;
         -no-flang )
             do_flang="no"
             ;;
+        -silent-log )
+            do_silent_log="yes"
+            ;;
         -help | --help | -h | --h | -\? )
             usage
             exit 0
             ;;
         * )
             echo "unknown option: $1"
             usage
             exit 1
function build_llvmCore() {
     ObjDir="$3"
     DestDir="$4"
 
     Verbose="VERBOSE=1"
     if [ ${MAKE} = 'ninja' ]; then
       Verbose="-v"
     fi
 
+    redir="/dev/stdout"
+    if [ $do_silent_log == "yes" ]; then
+      echo "# Silencing build logs because of -silent-log flag..."
+      redir="/dev/null"
+    fi
+
     cd $ObjDir
     echo "# Compiling llvm $Release-$RC $Flavor"
     echo "# ${MAKE} -j $NumJobs $Verbose"
     ${MAKE} -j $NumJobs $Verbose \
-        2>&1 | tee $LogDir/llvm.make-Phase$Phase-$Flavor.log
+        2>&1 | tee $LogDir/llvm.make-Phase$Phase-$Flavor.log > $redir
 
     echo "# Installing llvm $Release-$RC $Flavor"
     echo "# ${MAKE} install"
     DESTDIR="${DestDir}" ${MAKE} install \
-        2>&1 | tee $LogDir/llvm.install-Phase$Phase-$Flavor.log
+        2>&1 | tee $LogDir/llvm.install-Phase$Phase-$Flavor.log > $redir
     cd $BuildDir
 }
 
 function test_llvmCore() {
     Phase="$1"
     Flavor="$2"
     ObjDir="$3"