Always use OpenJDK9 for building

Remove support for compiling with javac from OpenJDK8.
We still target 1.8 by default, and OpenJDK8 prebuilts are still
required for the bootclasspath and running robolectric.

Bug: 38418220
Test: m java
Change-Id: I5686deb0ae4f9927192a039d08adc0117b2605dd

4 files changed, 13 insertions, 39 deletions

diff --git a/android/config.go b/android/config.go
index b415443b..8330b3df 100644
--- a/android/config.go
+++ b/android/config.go
@@ -108,8 +108,7 @@ type config struct {
 	captureBuild      bool // true for tests, saves build parameters for each module
 	ignoreEnvironment bool // true for tests, returns empty from all Getenv calls
 
-	useOpenJDK9    bool // Use OpenJDK9, but possibly target 1.8
-	targetOpenJDK9 bool // Use OpenJDK9 and target 1.9
+	targetOpenJDK9 bool // Target 1.9
 
 	stopBefore bootstrap.StopBefore
 
@@ -321,20 +320,13 @@ func NewConfig(srcDir, buildDir string) (Config, error) {
 
 func (c *config) fromEnv() error {
 	switch c.Getenv("EXPERIMENTAL_USE_OPENJDK9") {
-	case "":
-		// Use OpenJDK9, but target 1.8
-		c.useOpenJDK9 = true
-	case "false":
-		// Use OpenJDK8
-	case "1.8":
-		// Use OpenJDK9, but target 1.8
-		c.useOpenJDK9 = true
+	case "", "1.8":
+		// Nothing, we always use OpenJDK9
 	case "true":
 		// Use OpenJDK9 and target 1.9
-		c.useOpenJDK9 = true
 		c.targetOpenJDK9 = true
 	default:
-		return fmt.Errorf(`Invalid value for EXPERIMENTAL_USE_OPENJDK9, should be "", "false", "1.8", or "true"`)
+		return fmt.Errorf(`Invalid value for EXPERIMENTAL_USE_OPENJDK9, should be "", "1.8", or "true"`)
 	}
 
 	return nil
@@ -633,11 +625,6 @@ func (c *config) RunErrorProne() bool {
 	return c.IsEnvTrue("RUN_ERROR_PRONE")
 }
 
-// Returns true if OpenJDK9 prebuilts are being used
-func (c *config) UseOpenJDK9() bool {
-	return c.useOpenJDK9
-}
-
 // Returns true if -source 1.9 -target 1.9 is being passed to javac
 func (c *config) TargetOpenJDK9() bool {
 	return c.targetOpenJDK9
diff --git a/java/config/makevars.go b/java/config/makevars.go
index 8dfd3986..d3788774 100644
--- a/java/config/makevars.go
+++ b/java/config/makevars.go
@@ -61,10 +61,8 @@ func makeVarsProvider(ctx android.MakeVarsContext) {
 	ctx.Strict("TARGET_JAVAC", "${JavacCmd} ${CommonJdkFlags}")
 	ctx.Strict("HOST_JAVAC", "${JavacCmd} ${CommonJdkFlags}")
 
-	if ctx.Config().UseOpenJDK9() {
-		ctx.Strict("JLINK", "${JlinkCmd}")
-		ctx.Strict("JMOD", "${JmodCmd}")
-	}
+	ctx.Strict("JLINK", "${JlinkCmd}")
+	ctx.Strict("JMOD", "${JmodCmd}")
 
 	ctx.Strict("SOONG_JAVAC_WRAPPER", "${SoongJavacWrapper}")
 	ctx.Strict("ZIPSYNC", "${ZipSyncCmd}")
diff --git a/java/droiddoc.go b/java/droiddoc.go
index 3b7ead50..9821bcf2 100644
--- a/java/droiddoc.go
+++ b/java/droiddoc.go
@@ -540,20 +540,13 @@ func (j *Javadoc) GenerateAndroidBuildActions(ctx android.ModuleContext) {
 	var bootClasspathArgs, classpathArgs string
 
 	javaVersion := getJavaVersion(ctx, String(j.properties.Java_version), String(j.properties.Sdk_version))
-	if javaVersion == "1.9" || ctx.Config().UseOpenJDK9() {
-		if len(deps.bootClasspath) > 0 {
-			var systemModules classpath
-			if deps.systemModules != nil {
-				systemModules = append(systemModules, deps.systemModules)
-			}
-			bootClasspathArgs = systemModules.FormJavaSystemModulesPath("--system ", ctx.Device())
-			bootClasspathArgs = bootClasspathArgs + " --patch-module java.base=."
-		}
-	} else {
-		if len(deps.bootClasspath.Strings()) > 0 {
-			// For OpenJDK 8 we can use -bootclasspath to define the core libraries code.
-			bootClasspathArgs = deps.bootClasspath.FormJavaClassPath("-bootclasspath")
+	if len(deps.bootClasspath) > 0 {
+		var systemModules classpath
+		if deps.systemModules != nil {
+			systemModules = append(systemModules, deps.systemModules)
 		}
+		bootClasspathArgs = systemModules.FormJavaSystemModulesPath("--system ", ctx.Device())
+		bootClasspathArgs = bootClasspathArgs + " --patch-module java.base=."
 	}
 	if len(deps.classpath.Strings()) > 0 {
 		classpathArgs = "-classpath " + strings.Join(deps.classpath.Strings(), ":")
diff --git a/ui/build/config.go b/ui/build/config.go
index 5dcdf874..d0378ec0 100644
--- a/ui/build/config.go
+++ b/ui/build/config.go
@@ -164,11 +164,7 @@ func NewConfig(ctx Context, args ...string) Config {
 		if override, ok := ret.environ.Get("OVERRIDE_ANDROID_JAVA_HOME"); ok {
 			return override
 		}
-		v, ok := ret.environ.Get("EXPERIMENTAL_USE_OPENJDK9")
-		if !ok || v != "false" {
-			return java9Home
-		}
-		return java8Home
+		return java9Home
 	}()
 	absJavaHome := absPath(ctx, javaHome)