Add --{no,}autodetect_server_javabase.

We want bazel to fail to start instead of falling back to a host
JRE/JDK.  We are using a hermetic JDK and the embedded JRE, so there
should be no need to use anything from the host.  We've debugged enough
cases so far where the host installed JDK was buggy and causing random
crashes on specific machines.

Fixes: bazelbuild#12451

Closes bazelbuild#12542.

PiperOrigin-RevId: 347411720

site/docs/user-manual.html

@@ -2836,6 +2836,14 @@ <h4 id='flag--host_jvm_debug'><code class='flag'>--host_jvm_debug</code></h4>
   subprocesses of Bazel: applications, tests, tools, etc.)
 </p>
 
+<h4 id='flag--autodetect_server_javabase'><code class='flag'>--autodetect_server_javabase</code></h4>
+<p>
+  This option causes Bazel to automatically search for an installed JDK on startup,
+  and to fall back to the installed JRE if the embedded JRE isn't available.
+  <code>--explicit_server_javabase</code> can be used to pick an explicit JRE to
+  run bazel with.
+</p>
+
 <h4 id='flag--batch'><code class='flag'>--batch</code></h4>
 
 <p>

src/main/cpp/blaze.cc

@@ -458,7 +458,9 @@ static vector<string> GetServerExeArgs(const blaze_util::Path &jvm_path,
                    startup_options.output_base.AsCommandLineArgument());
   result.push_back("--workspace_directory=" +
                    blaze_util::ConvertPath(workspace));
-  result.push_back("--default_system_javabase=" + GetSystemJavabase());
+  if (startup_options.autodetect_server_javabase) {
+    result.push_back("--default_system_javabase=" + GetSystemJavabase());
+  }
 
   if (!startup_options.server_jvm_out.IsEmpty()) {
     result.push_back("--server_jvm_out=" +

src/main/cpp/startup_options.cc

@@ -71,6 +71,7 @@ StartupOptions::StartupOptions(const string &product_name,
       ignore_all_rc_files(false),
       block_for_lock(true),
       host_jvm_debug(false),
+      autodetect_server_javabase(true),
       batch(false),
       batch_cpu_scheduling(false),
       io_nice_level(-1),
@@ -137,6 +138,8 @@ StartupOptions::StartupOptions(const string &product_name,
   RegisterNullaryStartupFlag("fatal_event_bus_exceptions",
                              &fatal_event_bus_exceptions);
   RegisterNullaryStartupFlag("host_jvm_debug", &host_jvm_debug);
+  RegisterNullaryStartupFlag("autodetect_server_javabase",
+                             &autodetect_server_javabase);
   RegisterNullaryStartupFlag("idle_server_tasks", &idle_server_tasks);
   RegisterNullaryStartupFlag("incompatible_enable_execution_transition",
                              &incompatible_enable_execution_transition);
@@ -483,6 +486,10 @@ StartupOptions::GetServerJavabaseAndType() const {
       // 2) Use a bundled JVM if we have one.
       default_server_javabase_ = std::pair<blaze_util::Path, JavabaseType>(
           bundled_jre_path, JavabaseType::EMBEDDED);
+    } else if (!autodetect_server_javabase) {
+      BAZEL_DIE(blaze_exit_code::LOCAL_ENVIRONMENTAL_ERROR)
+          << "Could not find embedded or explicit server javabase, and "
+             "--noautodetect_server_javabase is set.";
     } else {
       // 3) Otherwise fall back to using the default system JVM.
       blaze_util::Path system_javabase = GetSystemJavabase();

src/main/cpp/startup_options.h

@@ -165,6 +165,8 @@ class StartupOptions {
 
   bool host_jvm_debug;
 
+  bool autodetect_server_javabase;
+
   std::string host_jvm_profile;
 
   std::vector<std::string> host_jvm_args;

src/main/java/com/google/devtools/build/lib/runtime/BlazeServerStartupOptions.java

@@ -501,4 +501,14 @@ public String getTypeDescription() {
               + "extended attribute is checked on all source files and output files, meaning "
               + "that it causes a significant number of invocations of the getxattr() system call.")
   public String unixDigestHashAttributeName;
+
+  @Option(
+      name = "autodetect_server_javabase",
+      defaultValue = "true", // NOTE: only for documentation, value never passed to the server.
+      documentationCategory = OptionDocumentationCategory.BAZEL_CLIENT_OPTIONS,
+      effectTags = {OptionEffectTag.AFFECTS_OUTPUTS, OptionEffectTag.LOSES_INCREMENTAL_STATE},
+      help =
+          "When --noautodetect_server_javabase is passed, Bazel does not fall back to the local "
+              + "JDK for running the bazel server and instead exits.")
+  public boolean autodetectServerJavabase;
 }

src/test/cpp/bazel_startup_options_test.cc

@@ -100,6 +100,7 @@ TEST_F(BazelStartupOptionsTest, ValidStartupFlags) {
   ExpectValidNullaryOption(options, "fatal_event_bus_exceptions");
   ExpectValidNullaryOption(options, "home_rc");
   ExpectValidNullaryOption(options, "host_jvm_debug");
+  ExpectValidNullaryOption(options, "autodetect_server_javabase");
   ExpectValidNullaryOption(options, "ignore_all_rc_files");
   ExpectValidNullaryOption(options, "incompatible_enable_execution_transition");
   ExpectValidNullaryOption(options, "master_bazelrc");

src/test/shell/BUILD

@@ -5,6 +5,7 @@ package(default_visibility = ["//visibility:private"])
 exports_files([
     "bin/bazel",
     "bin/bazel_jdk_minimal",
+    "bin/bazel_nojdk",
     "testenv.sh",
     "integration_test_setup.sh",
     "sandboxing_test_utils.sh",

src/test/shell/bin/bazel_nojdk

@@ -0,0 +1,21 @@
+#!/bin/bash
+#
+# Copyright 2020 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 to run bazel in the tests. Any change to this file will
+# affect all our integration tests.
+#
+exec $(rlocation io_bazel/src/bazel_nojdk) \
+  --bazelrc=$TEST_TMPDIR/bazelrc "$@"

src/test/shell/integration/BUILD

@@ -26,6 +26,16 @@ filegroup(
     ],
 )
 
+filegroup(
+    name = "test-deps-nojdk",
+    testonly = 1,
+    srcs = [
+        "//src:bazel-bin_nojdk",
+        "//src/test/shell:bin/bazel_nojdk",
+        "//src/test/shell/bazel:test-deps-wo-bazel",
+    ],
+)
+
 sh_test(
     name = "progress_reporting_test",
     size = "large",
@@ -185,6 +195,18 @@ sh_test(
     ],
 )
 
+sh_test(
+    name = "nojdk_startup_options_test",
+    size = "medium",
+    srcs = ["nojdk_startup_options_test.sh"],
+    data = [
+        ":test-deps-nojdk",
+        "@bazel_tools//tools/bash/runfiles",
+    ],
+    # Windows doesn't support sandboxing, which BAZEL_SUFFIX needs.
+    tags = ["no_windows"],
+)
+
 sh_test(
     name = "run_test",
     size = "medium",

src/test/shell/integration/nojdk_startup_options_test.sh

@@ -0,0 +1,74 @@
+#!/bin/bash
+#
+# Copyright 2020 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.
+#
+# Test of Bazel's startup option handling cof the nojdk version.
+
+# --- begin runfiles.bash initialization ---
+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 ---
+
+# We don't want to use the cached, extracted bazel.  It will have a different
+# sha1 and fail the test.  The 2 version commands below are cheap.
+unset TEST_INSTALL_BASE
+
+export BAZEL_SUFFIX="_nojdk"
+source "$(rlocation "io_bazel/src/test/shell/integration_test_setup.sh")" \
+  || { echo "integration_test_setup.sh not found!" >&2; exit 1; }
+
+case "$(uname -s | tr [:upper:] [:lower:])" in
+msys*|mingw*|cygwin*)
+  declare -r is_windows=true
+  ;;
+*)
+  declare -r is_windows=false
+  ;;
+esac
+
+if "$is_windows"; then
+  export MSYS_NO_PATHCONV=1
+  export MSYS2_ARG_CONV_EXCL="*"
+fi
+
+# Test that nojdk bazel works with --autodetect_server_javabase
+function test_autodetect_server_javabase() {
+  bazel --autodetect_server_javabase version &> $TEST_log || fail "Should pass"
+}
+
+# Test that nojdk bazel fails with --noautodetect_server_javabase
+function test_noautodetect_server_javabase() {
+  bazel --noautodetect_server_javabase version &> $TEST_log && fail "Should fail"
+  expect_log "FATAL: Could not find embedded or explicit server javabase, and --noautodetect_server_javabase is set."
+}
+
+run_suite "${PRODUCT_NAME} startup options test"

src/test/shell/integration/startup_options_test.sh

@@ -75,4 +75,11 @@ function test_command_args_are_not_parsed_as_startup_args() {
   expect_not_log "Error: Unable to read .bazelrc file"
 }
 
+# Test that normal bazel works with and without --autodetect_server_javabase
+# because it has an embedded JRE.
+function test_autodetect_server_javabase() {
+  bazel --autodetect_server_javabase version &> $TEST_log || fail "Should pass"
+  bazel --noautodetect_server_javabase version &> $TEST_log || fail "Should pass"
+}
+
 run_suite "${PRODUCT_NAME} startup options test"