Add LcovMerger.
(series 2/4 of open-sourcing coverage command for java test)

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PiperOrigin-RevId: 141044216
MOS_MIGRATED_REVID=141044216

tools/test/collect_coverage.sh

diff --git a/tools/test/collect_coverage.sh b/tools/test/collect_coverage.sh
new file mode 100755
index 0000000..33aa2e3
--- /dev/null
+++ b/tools/test/collect_coverage.sh
@@ -0,0 +1,113 @@
+#!/bin/bash
+
+# Copyright 2016 The Bazel Authors. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#    http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+# Wrapper script for collecting code coverage during test execution.
+#
+# Expected environment:
+#   COVERAGE_MANIFEST - mandatory, location of the instrumented file manifest
+#   LCOV_MERGER - mandatory, location of the LcovMerger
+#   COVERAGE_DIR - optional, location of the coverage temp directory
+#   COVERAGE_OUTPUT_FILE - optional, location of the final lcov file
+#
+# Script expects that it will be started in the execution root directory and
+# not in the test's runfiles directory.
+
+if [[ -z "$COVERAGE_MANIFEST" ]]; then
+  echo --
+  echo Coverage runner: \$COVERAGE_MANIFEST is not set
+  echo Current environment:
+  env | sort
+  exit 1
+fi
+
+# When collect_coverage.sh is used, test runner must be instructed not to cd
+# to the test's runfiles directory.
+ROOT="$PWD"
+
+if [[ "$COVERAGE_MANIFEST" != /* ]]; then
+  # Canonicalize the path to coverage manifest so that tests can find it.
+  export COVERAGE_MANIFEST="$ROOT/$COVERAGE_MANIFEST"
+fi
+
+# write coverage data outside of the runfiles tree
+export COVERAGE_DIR=${COVERAGE_DIR:-"$ROOT/coverage"}
+# make COVERAGE_DIR an absolute path
+if ! [[ $COVERAGE_DIR == $ROOT* ]]; then
+  COVERAGE_DIR=$ROOT/$COVERAGE_DIR
+fi
+
+mkdir -p "$COVERAGE_DIR"
+COVERAGE_OUTPUT_FILE=${COVERAGE_OUTPUT_FILE:-"$COVERAGE_DIR/_coverage.dat"}
+# make COVERAGE_OUTPUT_FILE an absolute path
+if ! [[ $COVERAGE_OUTPUT_FILE == $ROOT* ]]; then
+  COVERAGE_OUTPUT_FILE=$ROOT/$COVERAGE_OUTPUT_FILE
+fi
+
+
+# Java
+# --------------------------------------
+export JAVA_COVERAGE_FILE=$COVERAGE_DIR/jvcov.dat
+# Let tests know that it is a coverage run
+export COVERAGE=1
+export BULK_COVERAGE_RUN=1
+
+
+# Only check if file exists when LCOV_MERGER is set
+if [[ ! -z "$LCOV_MERGER" ]]; then
+  for name in "$LCOV_MERGER"; do
+    if [[ ! -e $name ]]; then
+      echo --
+      echo Coverage runner: cannot locate file $name
+      exit 1
+    fi
+  done
+fi
+
+
+cd "$TEST_SRCDIR"
+"$@"
+TEST_STATUS=$?
+
+# If LCOV_MERGER is not set, coverage is not supported.
+if [[ -z "$LCOV_MERGER" ]]; then
+  exit $TEST_STATUS
+fi
+
+
+# always create output files
+touch $COVERAGE_OUTPUT_FILE
+
+if [[ $TEST_STATUS -ne 0 ]]; then
+  echo --
+  echo Coverage runner: Not collecting coverage for failed test.
+  echo The following commands failed with status $TEST_STATUS
+  echo "$@"
+  exit $TEST_STATUS
+fi
+
+cd $ROOT
+
+export LCOV_MERGER_CMD="java -jar ${LCOV_MERGER} --coverage_dir=${COVERAGE_DIR} \
+--output_file=${COVERAGE_OUTPUT_FILE}"
+
+
+if [[ $DISPLAY_LCOV_CMD ]] ; then
+  echo "Running lcov_merger"
+  echo $LCOV_MERGER_CMD
+  echo "-----------------"
+fi
+
+exec $LCOV_MERGER_CMD