Add a regression test for the modules used from the JDK.

It's critical for Bazel's binary size that we don't increase the list of
modules.
We will also use the same list in a later commit build a reduced JDK.

src/test/shell/bazel/BUILD

@@ -737,3 +737,18 @@ sh_test(
     ],
     tags = ["no_windows"],
 )
+
+sh_test(
+    name = "jdeps_test",
+    size = "medium",
+    srcs = ["jdeps_test.sh"],
+    data = [
+        ":jdeps_modules.golden",
+        ":jdeps_class_blacklist.txt",
+        ":test-deps",
+        "//src:embedded_jdk",
+        "//src/main/java/com/google/devtools/build/lib:bazel/BazelServer_deploy.jar",
+        "@bazel_tools//tools/bash/runfiles",
+    ],
+    tags = ["no_windows"],
+)

src/test/shell/bazel/jdeps_class_blacklist.txt

@@ -0,0 +1,11 @@
+# This is a blacklist of class files that trigger a NPE in jdeps.
+./com/android/sdklib/internal/build/SignedJarBuilder.class
+./lombok/ast/app/Main$3.class
+./lombok/ast/javac/JcTreePrinter.class
+./lombok/javac/java6/CommentCollectingParser.class
+./lombok/javac/java6/CommentCollectingParserFactory.class
+./lombok/javac/java6/CommentCollectingScanner.class
+./lombok/javac/java6/CommentCollectingScannerFactory$1.class
+./lombok/javac/java6/CommentCollectingScannerFactory.class
+./lombok/javac/java7/CommentCollectingParser.class
+./lombok/javac/java7/CommentCollectingScanner.class

src/test/shell/bazel/jdeps_modules.golden

@@ -0,0 +1,15 @@
+java.base
+java.compiler
+java.desktop
+java.instrument
+java.logging
+java.management
+java.naming
+java.security.jgss
+java.sql
+java.xml
+java.xml.bind
+jdk.compiler
+jdk.management
+jdk.sctp
+jdk.unsupported

src/test/shell/bazel/jdeps_test.sh

@@ -0,0 +1,90 @@
+#!/bin/bash
+# Copyright 2018 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.
+
+# Tests that we don't accidentally add more dependencies.
+# The test uses jdeps from the embedded JDK to compute the module dependencies
+# of all class files in A-server.jar.
+#
+# If the test fails:
+# - with a removed dependency: just remove it from the jdeps_modules.golden file
+# - with an additional dependency: think twice whether to add it to
+#   jdeps_modules.golden since every additional dependency will contribute to
+#   Bazel's binary size
+# - with an NPE: jdeps crashes on a few class files, add new crashing class
+#   files to jdeps_class_blacklist.txt
+
+# --- begin runfiles.bash initialization ---
+# Copy-pasted from Bazel's Bash runfiles library (tools/bash/runfiles/runfiles.bash).
+set -euo pipefail
+if [[ ! -d "${RUNFILES_DIR:-/dev/null}" && ! -f "${RUNFILES_MANIFEST_FILE:-/dev/null}" ]]; then
+  if [[ -f "$0.runfiles_manifest" ]]; then
+    export RUNFILES_MANIFEST_FILE="$0.runfiles_manifest"
+  elif [[ -f "$0.runfiles/MANIFEST" ]]; then
+    export RUNFILES_MANIFEST_FILE="$0.runfiles/MANIFEST"
+  elif [[ -f "$0.runfiles/bazel_tools/tools/bash/runfiles/runfiles.bash" ]]; then
+    export RUNFILES_DIR="$0.runfiles"
+  fi
+fi
+if [[ -f "${RUNFILES_DIR:-/dev/null}/bazel_tools/tools/bash/runfiles/runfiles.bash" ]]; then
+  source "${RUNFILES_DIR}/bazel_tools/tools/bash/runfiles/runfiles.bash"
+elif [[ -f "${RUNFILES_MANIFEST_FILE:-/dev/null}" ]]; then
+  source "$(grep -m1 "^bazel_tools/tools/bash/runfiles/runfiles.bash " \
+            "$RUNFILES_MANIFEST_FILE" | cut -d ' ' -f 2-)"
+else
+  echo >&2 "ERROR: cannot find @bazel_tools//tools/bash/runfiles:runfiles.bash"
+  exit 1
+fi
+# --- end runfiles.bash initialization ---
+
+source "$(rlocation "io_bazel/src/test/shell/integration_test_setup.sh")" \
+  || { echo "integration_test_setup.sh not found!" >&2; exit 1; }
+
+function test_jdeps() {
+  mkdir jdk bazeljar
+  cd jdk
+  if is_darwin; then
+    platform="macos"
+  else
+    platform="linux"
+  fi
+  cp $(rlocation openjdk_${platform}/file/zulu-${platform}.tar.gz) .
+  tar xf zulu-${platform}.tar.gz || fail "Failed to extract JDK."
+  find . | grep jdeps
+  blacklist=$(rlocation io_bazel/src/test/shell/bazel/jdeps_class_blacklist.txt)
+  deploy_jar=$(rlocation io_bazel/src/main/java/com/google/devtools/build/lib/bazel/BazelServer_deploy.jar)
+  cd ../bazeljar
+  unzip "$deploy_jar" || fail "Failed to extract Bazel's server.jar"
+
+  # TODO(twerth): Replace --list-reduced-deps with --print-module-deps when
+  # switching to JDK10.
+  # If jdeps fails with a NPE, just add the class file to the list in
+  # src/test/shell/bazel/jdeps_class_blacklist.txt.
+  find . -type f -iname \*class | \
+    grep -vFf "$blacklist" | \
+    xargs ../jdk/zulu9.0.7.1-jdk9.0.7-*/bin/jdeps --list-reduced-deps | \
+    grep -v "unnamed module" > ../jdeps \
+    || fail "Failed to run jdeps on non blacklisted class files."
+  cd ..
+
+  # Make the list sorted and unique and compare it with expected results.
+  cat jdeps | \
+    sed -e 's|\s*||g' -e 's|/.*||' | \
+    grep -v "notfound" | \
+    sort -u > jdeps-sorted
+  expected=$(rlocation io_bazel/src/test/shell/bazel/jdeps_modules.golden)
+  diff -u jdeps-sorted "$expected" || fail "List of modules has changed."
+}
+
+run_suite "Tests included JDK modules."