From 86acaa1b31a072573b4108d0bef4d74cad51427a Mon Sep 17 00:00:00 2001
From: Weimin Yu <weiminyu@google.com>
Date: Mon, 11 Apr 2022 11:00:00 -0400
Subject: [PATCH] Build Java8-compatible release (#1586)

* Build Java8-compatible release

Use the new options.release Gradle property to make sure builds are
compatible with Java 8, which is the runtime on Appengine.

This new property replaces sourceCompatibility, targetCompatibility, and
bootclasspath (wasn't previously set, which is the reason why we
couldn't detect Java9 api usage when building).
---
 build.gradle       | 7 +++++++
 docs/build.gradle  | 3 ---
 java_common.gradle | 7 -------
 3 files changed, 7 insertions(+), 10 deletions(-)

diff --git a/build.gradle b/build.gradle
index 207a3f0b1..e3f4ee02d 100644
--- a/build.gradle
+++ b/build.gradle
@@ -331,6 +331,13 @@ subprojects {
 
   apply from: "${rootDir.path}/java_common.gradle"
 
+  if (project.name != 'docs') {
+    compileJava {
+      // TODO: Remove this once we migrate off AppEngine.
+      options.release = 8
+    }
+  }
+
   if (project.name == 'third_party') return
 
   project.tasks.test.dependsOn runPresubmits
diff --git a/docs/build.gradle b/docs/build.gradle
index ac564c7c0..7e34a7d57 100644
--- a/docs/build.gradle
+++ b/docs/build.gradle
@@ -37,9 +37,6 @@ test {
   useJUnitPlatform()
 }
 
-sourceCompatibility = '11'
-targetCompatibility = '11'
-
 task flowDocsTool(type: JavaExec) {
   systemProperty 'test.projectRoot', rootProject.projectRootDir
   jvmArgs = ['--add-exports', 'jdk.javadoc/jdk.javadoc.internal.tool=ALL-UNNAMED']
diff --git a/java_common.gradle b/java_common.gradle
index dd1a82b95..0b38eef3f 100644
--- a/java_common.gradle
+++ b/java_common.gradle
@@ -128,13 +128,6 @@ tasks.withType(JavaCompile).configureEach {
     }
 }
 
-// TODO: Change source version to 11 after target version is changed to 11 and
-// once we figure out what's wrong with Dagger compilation with source version
-// >8.
-sourceCompatibility = '8'
-// TODO: Change target version to 11. Source version can stay at 8.
-targetCompatibility = '8'
-
 compileJava { options.encoding = "UTF-8" }
 compileTestJava { options.encoding = "UTF-8" }