Make to use different javac for target and host builds

When benchmark Java sources are compiled for a target, they are compiled
with '-source 1.8 -target 1.8'. However bootclasspath is not set to
libraries of the target. This causes that the built classes depend on
libraries of the host and can work incorrectly.

This CL makes to use different javac for target and host builds:
* For target: the script art/tools/javac-helper.sh is used to
correctly invoke javac. The script sets a correct bootclasspath.
* For host: javac from PATH is used.

In addition, bench.apk is built only for target builds.

Test: scripts/benchmarks/benchmarks_run_target.sh --mode 64 --cpu big benchmarks/specjvm2008/compress/CompressBench
Test: scripts/benchmarks/benchmarks_run_target.sh --mode 64 --cpu little --iterations 1 benchmarks/algorithm/Linpack
Test: ./benchmarks/build.sh ./benchmarks/benchmarks/algorithm/DeltaBlue.java
Test: env PATH=./prebuilts/jdk/jdk9/linux-x86/bin:$PATH ./benchmarks/build.sh ./benchmarks/benchmarks/algorithm/DeltaBlue.java
Change-Id: I6dc848fdf78918473605d2b6fc5655c592d63585

1 files changed, 20 insertions, 17 deletions

diff --git a/build.sh b/build.sh
index 2d06636..66cbe26 100755
--- a/build.sh
+++ b/build.sh
@@ -22,7 +22,7 @@ DIR_BUILD=$DIR_ROOT/out/build
 DIR_BENCHMARKS=$DIR_ROOT/benchmarks
 DIR_FRAMEWORK=$DIR_ROOT/framework
 JAVA_VERSION=1.8
-
+CROSS_COMPILE_FLAGS="-target $JAVA_VERSION -source $JAVA_VERSION"
 
 # Set to true to build for the target.
 TARGET_BUILD=false
@@ -32,8 +32,6 @@ VERBOSE=false
 WERROR=true
 JAVA_BENCHMARK_FILES=
 
-
-
 # Helpers.
 
 CRED="\033[0;31m"
@@ -161,20 +159,11 @@ echo "$BENCHMARK_LIST_TEMPLATE" > $DIR_FRAMEWORK/org/linaro/bench/BenchmarkList.
 # Framework java files are compiled unconditionally.
 JAVA_FRAMEWORK_FILES="$(find $DIR_FRAMEWORK -type f -name '*'.java)"
 
-
-
 # Build everything.
 
 verbose_safe rm -rf $DIR_BUILD
 verbose_safe mkdir -p $DIR_BUILD/classes/
 
-JAVAC_RUNTIME_VERSION=$(javac -version 2>&1)
-if [[ $JAVAC_RUNTIME_VERSION =~ "javac 9" ]]; then
-  CROSS_COMPILE_FLAGS="--release 8"
-else
-  CROSS_COMPILE_FLAGS="-target $JAVA_VERSION -source $JAVA_VERSION"
-fi
-
 for jar_file in "${DIR_BENCHMARKS}"/lib/*.jar
 do
   jar_file="$(realpath "${jar_file}")"
@@ -183,21 +172,35 @@ do
   (cd $DIR_BUILD/classes && jar xfv "${jar_file}" && rm -rf META-INF)
 done
 
-if [[ -d "${DIR_BENCHMARKS}"/resources ]]; then
-  tar cfv $DIR_BUILD/resources.tar -C "${DIR_BENCHMARKS}" ./resources
-fi
-verbose_safe javac -encoding UTF-8 $CROSS_COMPILE_FLAGS -cp $DIR_BENCHMARKS:$DIR_BUILD/classes -d $DIR_BUILD/classes/ $JAVA_FRAMEWORK_FILES $JAVA_BENCHMARK_FILES
-verbose_safe jar cf $DIR_BUILD/bench.jar $DIR_BUILD/classes/
+javac_cmd_options=("-encoding" "UTF-8" \
+  "-cp" "${DIR_BENCHMARKS}:${DIR_BUILD}/classes" \
+  "-d" "$DIR_BUILD/classes/" \
+  $JAVA_FRAMEWORK_FILES \
+  $JAVA_BENCHMARK_FILES)
+
 DX=$(which dx)
+# Use different javac for target and host builds:
+#  For target: the art/tools/javac-helper.sh is used to invoke javac with the correct bootclasspath.
+#  For host: javac from PATH is used.
 if [ $TARGET_BUILD = "true" ] || [ -n "$DX" ]; then
   if [ $TARGET_BUILD = "false" ]; then
     info "This is not a target build (\`-t\` was not specified), but" \
       "the \`dx\` command was found, so the APK will be built. (\`dx\`: $DX)"
   fi
+  if [[ -d "${DIR_BENCHMARKS}"/resources ]]; then
+    tar cfv $DIR_BUILD/resources.tar -C "${DIR_BENCHMARKS}" ./resources
+  fi
+  verbose_safe ${ANDROID_BUILD_TOP}/art/tools/javac-helper.sh --show-commands --core-only \
+    $CROSS_COMPILE_FLAGS \
+    "${javac_cmd_options[@]}"
   if hash dx 2> /dev/null; then
     verbose_safe dx --dex --output $DIR_BUILD/bench.apk $DIR_BUILD/classes/
   else
     warning "\`dx\` command not found. bench.apk won't be generated." \
       "Are you running from an Android environment?"
   fi
+else
+  verbose_safe javac \
+    "${javac_cmd_options[@]}"
+  (cd $DIR_BUILD/classes && jar cf ../bench.jar .)
 fi