Mark effectively final classes as final
Fixes: 202745475
Change-Id: I44e8da0e6544a57de8f23ea8474eada3eb545619
diff --git a/src/main/java/com/android/tools/r8/graph/AppView.java b/src/main/java/com/android/tools/r8/graph/AppView.java
index 492a4ec..0e165f7 100644
--- a/src/main/java/com/android/tools/r8/graph/AppView.java
+++ b/src/main/java/com/android/tools/r8/graph/AppView.java
@@ -31,6 +31,7 @@
import com.android.tools.r8.naming.SeedMapper;
import com.android.tools.r8.optimize.argumentpropagation.ArgumentPropagator;
import com.android.tools.r8.shaking.AppInfoWithLiveness;
+import com.android.tools.r8.shaking.KeepClassInfo;
import com.android.tools.r8.shaking.KeepInfoCollection;
import com.android.tools.r8.shaking.KeepMethodInfo;
import com.android.tools.r8.shaking.LibraryModeledPredicate;
@@ -537,6 +538,10 @@
return keepInfo;
}
+ public KeepClassInfo getKeepInfo(DexProgramClass clazz) {
+ return getKeepInfo().getClassInfo(clazz);
+ }
+
public KeepMethodInfo getKeepInfo(ProgramMethod method) {
return getKeepInfo().getMethodInfo(method);
}
diff --git a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/VirtualRootMethodsAnalysis.java b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/VirtualRootMethodsAnalysis.java
index 6e90810..cd1e030 100644
--- a/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/VirtualRootMethodsAnalysis.java
+++ b/src/main/java/com/android/tools/r8/optimize/argumentpropagation/codescanner/VirtualRootMethodsAnalysis.java
@@ -20,10 +20,18 @@
import java.util.Collection;
import java.util.HashMap;
import java.util.IdentityHashMap;
+import java.util.List;
import java.util.Map;
import java.util.Set;
import java.util.function.Consumer;
+/**
+ * Computes the set of virtual methods for which we can use a monomorphic method state as well as
+ * the mapping from virtual methods to their representative root methods.
+ *
+ * <p>The analysis can be used to easily mark effectively final classes and methods as final, and
+ * therefore does this as a side effect.
+ */
public class VirtualRootMethodsAnalysis extends DepthFirstTopDownClassHierarchyTraversal {
static class VirtualRootMethod {
@@ -118,6 +126,16 @@
}
@Override
+ public void forEachSubClass(DexProgramClass clazz, Consumer<DexProgramClass> consumer) {
+ List<DexProgramClass> subclasses = immediateSubtypingInfo.getSubclasses(clazz);
+ if (subclasses.isEmpty()) {
+ promoteToFinalIfPossible(clazz);
+ } else {
+ subclasses.forEach(consumer);
+ }
+ }
+
+ @Override
public void visit(DexProgramClass clazz) {
Map<DexMethodSignature, VirtualRootMethod> state = computeVirtualRootMethodsState(clazz);
virtualRootMethodsPerClass.put(clazz, state);
@@ -157,12 +175,7 @@
rootCandidate -> {
VirtualRootMethod virtualRootMethod =
virtualRootMethodsForClass.remove(rootCandidate.getMethodSignature());
- if (!clazz.isInterface()
- && !rootCandidate.getAccessFlags().isAbstract()
- && !virtualRootMethod.hasOverrides()
- && appView.getKeepInfo(rootCandidate).isOptimizationAllowed(appView.options())) {
- rootCandidate.getAccessFlags().promoteToFinal();
- }
+ promoteToFinalIfPossible(rootCandidate, virtualRootMethod);
if (!rootCandidate.isStructurallyEqualTo(virtualRootMethod.getRoot())) {
return;
}
@@ -193,4 +206,21 @@
}
});
}
+
+ private void promoteToFinalIfPossible(DexProgramClass clazz) {
+ if (!clazz.isAbstract()
+ && !clazz.isInterface()
+ && appView.getKeepInfo(clazz).isOptimizationAllowed(appView.options())) {
+ clazz.getAccessFlags().promoteToFinal();
+ }
+ }
+
+ private void promoteToFinalIfPossible(ProgramMethod method, VirtualRootMethod virtualRootMethod) {
+ if (!method.getHolder().isInterface()
+ && !method.getAccessFlags().isAbstract()
+ && !virtualRootMethod.hasOverrides()
+ && appView.getKeepInfo(method).isOptimizationAllowed(appView.options())) {
+ method.getAccessFlags().promoteToFinal();
+ }
+ }
}
diff --git a/src/test/java/com/android/tools/r8/optimize/finalize/FinalizeKeptClassTest.java b/src/test/java/com/android/tools/r8/optimize/finalize/FinalizeKeptClassTest.java
new file mode 100644
index 0000000..b20a64b
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/optimize/finalize/FinalizeKeptClassTest.java
@@ -0,0 +1,55 @@
+// Copyright (c) 2021, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+package com.android.tools.r8.optimize.finalize;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isFinal;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.AllOf.allOf;
+
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.ClassSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class FinalizeKeptClassTest extends TestBase {
+
+ @Parameter(0)
+ public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection parameters() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void test() throws Exception {
+ testForR8(parameters.getBackend())
+ .addInnerClasses(getClass())
+ .addKeepMainRule(Main.class)
+ .setMinApi(parameters.getApiLevel())
+ .compile()
+ .inspect(
+ inspector -> {
+ ClassSubject mainClassSubject = inspector.clazz(Main.class);
+ assertThat(mainClassSubject, allOf(isPresent(), not(isFinal())));
+ })
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithEmptyOutput();
+ }
+
+ // Should not become final.
+ static class Main {
+
+ public static void main(String[] args) {}
+ }
+}
diff --git a/src/test/java/com/android/tools/r8/optimize/finalize/FinalizeSubclassTest.java b/src/test/java/com/android/tools/r8/optimize/finalize/FinalizeSubclassTest.java
new file mode 100644
index 0000000..f71d961
--- /dev/null
+++ b/src/test/java/com/android/tools/r8/optimize/finalize/FinalizeSubclassTest.java
@@ -0,0 +1,100 @@
+// Copyright (c) 2021, the R8 project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+package com.android.tools.r8.optimize.finalize;
+
+import static com.android.tools.r8.utils.codeinspector.Matchers.isFinal;
+import static com.android.tools.r8.utils.codeinspector.Matchers.isPresent;
+import static org.hamcrest.CoreMatchers.not;
+import static org.hamcrest.MatcherAssert.assertThat;
+import static org.hamcrest.core.AllOf.allOf;
+
+import com.android.tools.r8.NeverClassInline;
+import com.android.tools.r8.NeverInline;
+import com.android.tools.r8.NoVerticalClassMerging;
+import com.android.tools.r8.TestBase;
+import com.android.tools.r8.TestParameters;
+import com.android.tools.r8.TestParametersCollection;
+import com.android.tools.r8.utils.codeinspector.ClassSubject;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.junit.runners.Parameterized;
+import org.junit.runners.Parameterized.Parameter;
+import org.junit.runners.Parameterized.Parameters;
+
+@RunWith(Parameterized.class)
+public class FinalizeSubclassTest extends TestBase {
+
+ @Parameter(0)
+ public TestParameters parameters;
+
+ @Parameters(name = "{0}")
+ public static TestParametersCollection parameters() {
+ return getTestParameters().withAllRuntimesAndApiLevels().build();
+ }
+
+ @Test
+ public void test() throws Exception {
+ testForR8(parameters.getBackend())
+ .addInnerClasses(getClass())
+ .addKeepMainRule(Main.class)
+ .enableInliningAnnotations()
+ .enableNeverClassInliningAnnotations()
+ .enableNoVerticalClassMergingAnnotations()
+ .setMinApi(parameters.getApiLevel())
+ .compile()
+ .inspect(
+ inspector -> {
+ ClassSubject aClassSubject = inspector.clazz(A.class);
+ assertThat(aClassSubject, allOf(isPresent(), not(isFinal())));
+
+ ClassSubject bClassSubject = inspector.clazz(B.class);
+ assertThat(bClassSubject, allOf(isPresent(), not(isFinal())));
+
+ ClassSubject cClassSubject = inspector.clazz(C.class);
+ assertThat(cClassSubject, allOf(isPresent(), isFinal()));
+ })
+ .run(parameters.getRuntime(), Main.class)
+ .assertSuccessWithOutputLines("A.m()", "B.m()", "C.m()");
+ }
+
+ static class Main {
+
+ public static void main(String[] args) {
+ new A().m();
+ new B().m();
+ new C().m();
+ }
+ }
+
+ @NeverClassInline
+ @NoVerticalClassMerging
+ static class A {
+
+ @NeverInline
+ void m() {
+ System.out.println("A.m()");
+ }
+ }
+
+ @NeverClassInline
+ @NoVerticalClassMerging
+ static class B extends A {
+
+ @NeverInline
+ void m() {
+ System.out.println("B.m()");
+ }
+ }
+
+ // Should become final.
+ @NeverClassInline
+ static class C extends B {
+
+ @NeverInline
+ void m() {
+ System.out.println("C.m()");
+ }
+ }
+}
