JacocoRunner script: update for Bazel 5.0+

Upgraded jacoco package name for Bazel 5.0+.

Upgraded jacoco from 0.8.3 to 0.8.6.

Jacoco upgrade to 0.8.6 was made in Bazel in:
bazelbuild/bazel#11674
bazelbuild/bazel@cb7c1a2

Removed options for workarounds where those have been fixed in the meantime:

Bazel's handling for branch coverage was fixed in:
bazelbuild/bazel#12696

Instead of changing the existing script for building Jacoco, added a new
one that can be used for Bazel 5.0.

scripts/build_jacocorunner/0001-Build-Jacoco-for-Bazel-5.0+.patch

@@ -0,0 +1,25 @@
+From 712d62a8238f3a7fe51e1cf4cc2520b5f249e1d3 Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Gergely=20F=C3=A1bi=C3=A1n?= <gergo.fb@gmail.com>
+Date: Fri, 18 Dec 2020 11:43:59 +0100
+Subject: [PATCH] Build Jacoco for Bazel
+
+---
+ org.jacoco.build/pom.xml | 2 +-
+ 1 file changed, 1 insertion(+), 1 deletion(-)
+
+diff --git a/org.jacoco.build/pom.xml b/org.jacoco.build/pom.xml
+index 8aae1543..067cc6a7 100644
+--- a/org.jacoco.build/pom.xml
++++ b/org.jacoco.build/pom.xml
+@@ -706,7 +706,7 @@
+                 project.getProperties().setProperty("build.date", buildDate);
+
+                 buildNumber = project.getProperties().get("buildNumber");
+-                pkgName = buildNumber.substring(buildNumber.length() - 7, buildNumber.length());
++                pkgName = "b864216";
+                 project.getProperties().setProperty("jacoco.runtime.package.name", "org.jacoco.agent.rt.internal_" + pkgName);
+
+                 void loadLicense(String libraryId) {
+-- 
+2.25.1
+

scripts/build_jacocorunner/build_jacocorunner_bazel_5.0+.sh

@@ -0,0 +1,131 @@
+#!/usr/bin/env bash
+#
+# Script to build custom version of `JacocoCoverage_jarjar_deploy.jar` from Jacoco and Bazel repositories.
+#
+# The default `JacocoCoverage_jarjar_deploy.jar` has some issues:
+#
+# 1. Scala support on newer Jacoco versions (including 0.8.6) is still lacking some functionality
+#
+#    E.g. a lot of generated methods for case classes, lazy vals or other Scala features are causing falsely missed branches in branch coverage.
+#
+#    Proposed changes in:
+#    https://github.com/gergelyfabian/jacoco/tree/scala
+#
+#    Backported to 0.8.6 (to be usable with current Bazel):
+#    https://github.com/gergelyfabian/jacoco/tree/0.8.6-scala
+#
+# You can use this script to build a custom version of `JacocoCoverage_jarjar_deploy.jar`, including any fixes from the above list you wish
+# and then provide the built jar as a parameter of `java_toolchain` and/or `scala_toolchain` to use the changed behavior for coverage.
+#
+# Choose the fixes from the above list by configuring the used branch for Jacoco repo below.
+#
+# Patches:
+#
+# There are also some patches that may need to be applied for Jacoco, according to your preferences:
+#
+# 1. Bazel is compatible only with Jacoco in a specific package name. This is not Jacoco-specific, so not committed to the Jacoco fork.
+#    See 0001-Build-Jacoco-for-Bazel.patch.
+# 2. Building Jacoco behind a proxy needs a workaround.
+#    See 0002-Build-Jacoco-behind-proxy.patch.
+#
+# Set up the patch file names in `jacoco_patches`.
+#
+# Dependencies:
+#
+# On OS X greadlink is needed (by running `brew install coreutils`).
+
+set -e
+
+
+
+if [[ "$OSTYPE" == "linux-gnu"* ]]; then
+  readlink_cmd="readlink"
+elif [[ "$OSTYPE" == "darwin"* ]]; then
+  readlink_cmd="greadlink"
+else
+  echo "OS not supported: $OSTYPE"
+  exit 1
+fi
+
+source_path=$($readlink_cmd -f $(dirname ${BASH_SOURCE[0]}))
+
+build_dir=/tmp/bazel_jacocorunner_build
+
+mkdir -p $build_dir
+
+jacoco_repo=$build_dir/jacoco
+# Take a fork for Jacoco that contains Scala fixes.
+jacoco_remote=https://github.com/gergelyfabian/jacoco
+# Take further fixes for Scala (2.11, 2.12 and 2.13) - branch in development:
+jacoco_branch=0.8.6-scala
+
+# Choose the patches that you'd like to use:
+jacoco_patches=""
+# Bazel needs to have a certain Jacoco package version:
+jacoco_patches="$jacoco_patches 0001-Build-Jacoco-for-Bazel-5.0+.patch"
+# Uncomment this if you are behind a proxy:
+#jacoco_patches="$jacoco_patches 0002-Build-Jacoco-behind-proxy.patch"
+
+
+# Jacoco version should be 0.8.6 in any case as Bazel is only compatible with that at this moment.
+jacoco_version=0.8.6
+
+bazel_repo=$build_dir/bazel
+bazel_remote=https://github.com/bazelbuild/bazel
+bazel_tag=5.1.1
+
+bazel_build_target=JacocoCoverage_jarjar_deploy.jar
+
+destination_dir=$build_dir
+
+# Generate the jar.
+
+if [ ! -d $jacoco_repo ]; then
+  (
+  cd $(dirname $jacoco_repo)
+  git clone $jacoco_remote
+  )
+fi
+
+if [ ! -d $bazel_repo ]; then
+  (
+  cd $(dirname $bazel_repo)
+  git clone $bazel_remote
+  )
+fi
+
+(
+cd $jacoco_repo
+git remote update
+git checkout origin/$jacoco_branch
+# Need to patch Jacoco:
+for patch in $jacoco_patches; do
+  git am $source_path/$patch
+done
+mvn clean install
+)
+
+(
+cd $bazel_repo
+git remote update
+git checkout tags/$bazel_tag
+
+# Prepare Jacoco version.
+cd third_party/java/jacoco
+# Remove any previously unpacked Jacoco files.
+rm -rf coverage/ doc/ index.html lib/ test/
+unzip $HOME/.m2/repository/org/jacoco/jacoco/${jacoco_version}/jacoco-${jacoco_version}.zip
+cp lib/jacocoagent.jar jacocoagent-${jacoco_version}.jar
+cp lib/org.jacoco.agent-* org.jacoco.agent-${jacoco_version}.jar
+cp lib/org.jacoco.core-* org.jacoco.core-${jacoco_version}.jar
+cp lib/org.jacoco.report-* org.jacoco.report-${jacoco_version}.jar
+cd ../../..
+
+# Build JacocoRunner.
+bazel build src/java_tools/junitrunner/java/com/google/testing/coverage:$bazel_build_target
+cp bazel-bin/src/java_tools/junitrunner/java/com/google/testing/coverage/$bazel_build_target $destination_dir/
+# Make the jar writable to enable re-running the script.
+chmod +w $destination_dir/$bazel_build_target
+
+echo "JacocoRunner is available at: $destination_dir/$bazel_build_target"
+)