From 0ae8b548af38c8b8fccea7cdef11d54740d3bb6a Mon Sep 17 00:00:00 2001
From: Tobias Thierer <tobiast@google.com>
Date: Fri, 17 Nov 2017 14:14:29 +0000
Subject: [PATCH] Build with OpenJDK 9 -target 1.8 by default except for
 errorprone.

Before this CL topic, the build toolchain for .java source files
used OpenJDK 8, targeting 1.8 (v52 class files) by default.

This CL topic switches the default to OpenJDK 9, but still
targeting 1.8 (v52 class files) by default. If USE_ERROR_PRONE
is set to true, then the default remains OpenJDK 8.

Code in the Android platform should generally be unaffected,
but if host tools that are now compiled and run using
OpenJDK 9 are causing problems for your team, then let me
know.

To manually switch back to the old behavior for now (continue
using OpenJDK 8), run this command in your shell:
export EXPERIMENTAL_USE_OPENJDK9=false

Bug: 69449021
Test: Treehugger
Test: "make core-oj", checked that compilation now uses
      OpenJDK 9 javac -target 1.8
Test: Checked that this is still compiled using OpenJDK 8.
      export EXPERIMENTAL_USE_OPENJDK9=false
      make core-oj

Change-Id: Ic87e9bb2a2e5da0ff13a2e51845b5365901c1507
---
 android/config.go  |  7 +++++--
 ui/build/config.go | 11 ++++++++++-
 2 files changed, 15 insertions(+), 3 deletions(-)

diff --git a/android/config.go b/android/config.go
index 0eebb5fbd..f806b4987 100644
--- a/android/config.go
+++ b/android/config.go
@@ -295,7 +295,10 @@ func NewConfig(srcDir, buildDir string) (Config, error) {
 func (c *config) fromEnv() error {
 	switch c.Getenv("EXPERIMENTAL_USE_OPENJDK9") {
 	case "":
-		// Use OpenJDK8
+		if c.Getenv("RUN_ERROR_PRONE") != "true" {
+			// Use OpenJDK9, but target 1.8
+			c.useOpenJDK9 = true
+		}
 	case "false":
 		// Use OpenJDK8
 	case "1.8":
@@ -306,7 +309,7 @@ func (c *config) fromEnv() error {
 		c.useOpenJDK9 = true
 		c.targetOpenJDK9 = true
 	default:
-		return fmt.Errorf(`Invalid value for EXPERIMENTAL_USE_OPENJDK9, should be "", "1.8", or "true"`)
+		return fmt.Errorf(`Invalid value for EXPERIMENTAL_USE_OPENJDK9, should be "", "false", "1.8", or "true"`)
 	}
 
 	return nil
diff --git a/ui/build/config.go b/ui/build/config.go
index df97d803d..b608d3868 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -150,7 +150,16 @@ func NewConfig(ctx Context, args ...string) Config {
 		if override, ok := ret.environ.Get("OVERRIDE_ANDROID_JAVA_HOME"); ok {
 			return override
 		}
-		if v, ok := ret.environ.Get("EXPERIMENTAL_USE_OPENJDK9"); ok && v != "" && v != "false" {
+		v, ok := ret.environ.Get("EXPERIMENTAL_USE_OPENJDK9")
+		if !ok {
+			v2, ok2 := ret.environ.Get("RUN_ERROR_PRONE")
+			if ok2 && (v2 == "true") {
+				v = "false"
+			} else {
+				v = "1.8"
+			}
+		}
+		if v != "false" {
 			return filepath.Join("prebuilts/jdk/jdk9", ret.HostPrebuiltTag())
 		}
 		return filepath.Join("prebuilts/jdk/jdk8", ret.HostPrebuiltTag())