Remove support for EXPERIMENTAL_JAVA_LANGUAGE_LEVEL_9.

Prior to this change, setting that to "false" turned the default Java
language level back to 8. This change removes that option.

Bug: 115604102
Test: m java droid docs tests cts
Change-Id: I97bfd0dc8d941008b4071c6efe1c0c24950c4f1f

android/config.go

@@ -113,8 +113,6 @@ 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
 
-	targetOpenJDK9 bool // Target 1.9
-
 	stopBefore bootstrap.StopBefore
 
 	OncePer
@@ -392,13 +390,9 @@ func NewConfig(srcDir, buildDir string) (Config, error) {
 func (c *config) fromEnv() error {
 	switch c.Getenv("EXPERIMENTAL_JAVA_LANGUAGE_LEVEL_9") {
 	case "", "true":
-		// Use -source 9 -target 9. This is the default.
+		// Do nothing
-		c.targetOpenJDK9 = true
-	case "false":
-		// Use -source 8 -target 8. This is the legacy behaviour.
-		c.targetOpenJDK9 = false
 	default:
-		return fmt.Errorf(`Invalid value for EXPERIMENTAL_JAVA_LANGUAGE_LEVEL_9, should be "", "true", or "false"`)
+		return fmt.Errorf("The environment variable EXPERIMENTAL_JAVA_LANGUAGE_LEVEL_9 is no longer supported. Java language level 9 is now the global default.")
 	}
 
 	return nil
@@ -779,11 +773,6 @@ func (c *config) EmitXrefRules() bool {
 	return c.XrefCorpusName() != ""
 }
 
-// Returns true if -source 1.9 -target 1.9 is being passed to javac
-func (c *config) TargetOpenJDK9() bool {
-	return c.targetOpenJDK9
-}
-
 func (c *config) ClangTidy() bool {
 	return Bool(c.productVariables.ClangTidy)
 }

java/config/makevars.go

@@ -29,12 +29,6 @@ func makeVarsProvider(ctx android.MakeVarsContext) {
 	ctx.Strict("TARGET_DEFAULT_BOOTCLASSPATH_LIBRARIES", strings.Join(DefaultBootclasspathLibraries, " "))
 	ctx.Strict("DEFAULT_SYSTEM_MODULES", DefaultSystemModules)
 
-	if ctx.Config().TargetOpenJDK9() {
-		ctx.Strict("DEFAULT_JAVA_LANGUAGE_VERSION", "1.9")
-	} else {
-		ctx.Strict("DEFAULT_JAVA_LANGUAGE_VERSION", "1.8")
-	}
-
 	ctx.Strict("ANDROID_JAVA_HOME", "${JavaHome}")
 	ctx.Strict("ANDROID_JAVA8_HOME", "prebuilts/jdk/jdk8/${hostPrebuiltTag}")
 	ctx.Strict("ANDROID_JAVA9_HOME", "prebuilts/jdk/jdk9/${hostPrebuiltTag}")

java/droiddoc.go

@@ -425,16 +425,12 @@ func (j *Javadoc) addDeps(ctx android.BottomUpMutatorContext) {
 		if sdkDep.hasStandardLibs() {
 			if sdkDep.useDefaultLibs {
 				ctx.AddVariationDependencies(nil, bootClasspathTag, config.DefaultBootclasspathLibraries...)
-				if ctx.Config().TargetOpenJDK9() {
+				ctx.AddVariationDependencies(nil, systemModulesTag, config.DefaultSystemModules)
-					ctx.AddVariationDependencies(nil, systemModulesTag, config.DefaultSystemModules)
-				}
 				if sdkDep.hasFrameworkLibs() {
 					ctx.AddVariationDependencies(nil, libTag, config.DefaultLibraries...)
 				}
 			} else if sdkDep.useModule {
-				if ctx.Config().TargetOpenJDK9() {
+				ctx.AddVariationDependencies(nil, systemModulesTag, sdkDep.systemModules)
-					ctx.AddVariationDependencies(nil, systemModulesTag, sdkDep.systemModules)
-				}
 				ctx.AddVariationDependencies(nil, bootClasspathTag, sdkDep.modules...)
 			}
 		} else if sdkDep.systemModules != "" {

java/java.go

@@ -884,7 +884,7 @@ func getJavaVersion(ctx android.ModuleContext, javaVersion string, sdkContext sd
 		ret = normalizeJavaVersion(ctx, javaVersion)
 	} else if ctx.Device() && sdk <= 23 {
 		ret = "1.7"
-	} else if ctx.Device() && sdk <= 29 || !ctx.Config().TargetOpenJDK9() {
+	} else if ctx.Device() && sdk <= 29 {
 		ret = "1.8"
 	} else if ctx.Device() &&
 		sdkContext.sdkVersion() != "" &&