Processing of @CovariantReturnType annotations
This CL is responsible for processing the annotations dalvik.annotation.codegen.CovariantReturnType and dalvik.annotation.codegen.CovariantReturnType$CovariantReturnTypes. If such an annotation is attached to a method m, then the compiler should insert a new synthetic method that is equivalent to method m, but has the return type specified by the annotation.
Bug: 78618808
Change-Id: Id4ea6c1e3f5c97a57954b1ededca473a022736a3
diff --git a/src/main/java/com/android/tools/r8/graph/DexItemFactory.java b/src/main/java/com/android/tools/r8/graph/DexItemFactory.java
index 86ca12a..4e4a78f 100644
--- a/src/main/java/com/android/tools/r8/graph/DexItemFactory.java
+++ b/src/main/java/com/android/tools/r8/graph/DexItemFactory.java
@@ -230,6 +230,10 @@
public final DexType annotationThrows = createType("Ldalvik/annotation/Throws;");
public final DexType annotationSynthesizedClassMap =
createType("Lcom/android/tools/r8/annotations/SynthesizedClassMap;");
+ public final DexType annotationCovariantReturnType =
+ createType("Ldalvik/annotation/codegen/CovariantReturnType;");
+ public final DexType annotationCovariantReturnTypes =
+ createType("Ldalvik/annotation/codegen/CovariantReturnType$CovariantReturnTypes;");
private static final String METAFACTORY_METHOD_NAME = "metafactory";
private static final String METAFACTORY_ALT_METHOD_NAME = "altMetafactory";
diff --git a/src/main/java/com/android/tools/r8/ir/conversion/IRConverter.java b/src/main/java/com/android/tools/r8/ir/conversion/IRConverter.java
index fc5e95b..fa00cd1 100644
--- a/src/main/java/com/android/tools/r8/ir/conversion/IRConverter.java
+++ b/src/main/java/com/android/tools/r8/ir/conversion/IRConverter.java
@@ -6,6 +6,7 @@
import static com.android.tools.r8.ir.desugar.InterfaceMethodRewriter.Flavor.ExcludeDexResources;
import static com.android.tools.r8.ir.desugar.InterfaceMethodRewriter.Flavor.IncludeAllResources;
+import com.android.tools.r8.ApiLevelException;
import com.android.tools.r8.errors.Unreachable;
import com.android.tools.r8.graph.AppInfo;
import com.android.tools.r8.graph.AppInfoWithSubtyping;
@@ -32,6 +33,7 @@
import com.android.tools.r8.ir.code.InstructionListIterator;
import com.android.tools.r8.ir.code.Value;
import com.android.tools.r8.ir.code.ValueType;
+import com.android.tools.r8.ir.desugar.CovariantReturnTypeAnnotationTransformer;
import com.android.tools.r8.ir.desugar.InterfaceMethodRewriter;
import com.android.tools.r8.ir.desugar.LambdaRewriter;
import com.android.tools.r8.ir.desugar.StringConcatRewriter;
@@ -99,6 +101,7 @@
private final ProtoLitePruner protoLiteRewriter;
private final IdentifierNameStringMarker identifierNameStringMarker;
private final Devirtualizer devirtualizer;
+ private final CovariantReturnTypeAnnotationTransformer covariantReturnTypeAnnotationTransformer;
private final OptimizationFeedback ignoreOptimizationFeedback = new OptimizationFeedbackIgnore();
private DexString highestSortingString;
@@ -126,6 +129,10 @@
? new InterfaceMethodRewriter(this, options) : null;
this.lambdaMerger = options.enableLambdaMerging
? new LambdaMerger(appInfo.dexItemFactory, options.reporter) : null;
+ this.covariantReturnTypeAnnotationTransformer =
+ options.processCovariantReturnTypeAnnotations
+ ? new CovariantReturnTypeAnnotationTransformer(this, appInfo.dexItemFactory)
+ : null;
if (enableWholeProgramOptimizations) {
assert appInfo.hasLiveness();
this.nonNullTracker = new NonNullTracker();
@@ -246,6 +253,12 @@
}
}
+ private void processCovariantReturnTypeAnnotations(Builder<?> builder) throws ApiLevelException {
+ if (covariantReturnTypeAnnotationTransformer != null) {
+ covariantReturnTypeAnnotationTransformer.process(builder);
+ }
+ }
+
public DexApplication convertToDex(DexApplication application, ExecutorService executor)
throws ExecutionException {
removeLambdaDeserializationMethods();
@@ -259,6 +272,7 @@
synthesizeLambdaClasses(builder);
desugarInterfaceMethods(builder, ExcludeDexResources);
+ processCovariantReturnTypeAnnotations(builder);
handleSynthesizedClassMapping(builder);
timing.end();
diff --git a/src/main/java/com/android/tools/r8/ir/desugar/CovariantReturnTypeAnnotationTransformer.java b/src/main/java/com/android/tools/r8/ir/desugar/CovariantReturnTypeAnnotationTransformer.java
new file mode 100644
index 0000000..64fe450
--- /dev/null
+++ b/src/main/java/com/android/tools/r8/ir/desugar/CovariantReturnTypeAnnotationTransformer.java
@@ -0,0 +1,269 @@
+// Copyright (c) 2018, 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.ir.desugar;
+
+import com.android.tools.r8.ApiLevelException;
+import com.android.tools.r8.errors.CompilationError;
+import com.android.tools.r8.graph.DexAnnotation;
+import com.android.tools.r8.graph.DexAnnotationElement;
+import com.android.tools.r8.graph.DexApplication;
+import com.android.tools.r8.graph.DexClass;
+import com.android.tools.r8.graph.DexEncodedAnnotation;
+import com.android.tools.r8.graph.DexEncodedMethod;
+import com.android.tools.r8.graph.DexItemFactory;
+import com.android.tools.r8.graph.DexProto;
+import com.android.tools.r8.graph.DexType;
+import com.android.tools.r8.graph.DexValue;
+import com.android.tools.r8.graph.MethodAccessFlags;
+import com.android.tools.r8.ir.code.Invoke;
+import com.android.tools.r8.ir.conversion.IRConverter;
+import com.android.tools.r8.ir.synthetic.ForwardMethodSourceCode;
+import com.android.tools.r8.ir.synthetic.SynthesizedCode;
+import com.google.common.base.Predicates;
+import java.util.HashSet;
+import java.util.LinkedList;
+import java.util.List;
+import java.util.Set;
+
+// Responsible for processing the annotations dalvik.annotation.codegen.CovariantReturnType and
+// dalvik.annotation.codegen.CovariantReturnType$CovariantReturnTypes.
+//
+// Consider the following class:
+// public class B extends A {
+// @CovariantReturnType(returnType = B.class, presentAfter = 25)
+// @Override
+// public A m(...) { ... return new B(); }
+// }
+//
+// The annotation is used to indicate that the compiler should insert a synthetic method that is
+// equivalent to method m, but has return type B instead of A. Thus, for this example, this
+// component is responsible for inserting the following method in class B (in addition to the
+// existing method m):
+// public B m(...) { A result = "invoke B.m(...)A;"; return (B) result; }
+//
+// Note that a method may be annotated with more than one CovariantReturnType annotation. In this
+// case there will be a CovariantReturnType$CovariantReturnTypes annotation on the method that wraps
+// several CovariantReturnType annotations. In this case, a new method is synthesized for each of
+// the contained CovariantReturnType annotations.
+public final class CovariantReturnTypeAnnotationTransformer {
+ private final IRConverter converter;
+ private final DexItemFactory factory;
+
+ public CovariantReturnTypeAnnotationTransformer(IRConverter converter, DexItemFactory factory) {
+ this.converter = converter;
+ this.factory = factory;
+ }
+
+ public void process(DexApplication.Builder<?> builder) throws ApiLevelException {
+ // List of methods that should be added to the next class.
+ List<DexEncodedMethod> methodsWithCovariantReturnTypeAnnotation = new LinkedList<>();
+ List<DexEncodedMethod> covariantReturnTypeMethods = new LinkedList<>();
+ for (DexClass clazz : builder.getProgramClasses()) {
+ // Construct the methods that should be added to clazz.
+ buildCovariantReturnTypeMethodsForClass(
+ clazz, methodsWithCovariantReturnTypeAnnotation, covariantReturnTypeMethods);
+ if (covariantReturnTypeMethods.isEmpty()) {
+ continue;
+ }
+ updateClass(clazz, methodsWithCovariantReturnTypeAnnotation, covariantReturnTypeMethods);
+ // Reset lists for the next class that will have a CovariantReturnType or
+ // CovariantReturnType$CovariantReturnTypes annotation.
+ methodsWithCovariantReturnTypeAnnotation.clear();
+ covariantReturnTypeMethods.clear();
+ }
+ }
+
+ private void updateClass(
+ DexClass clazz,
+ List<DexEncodedMethod> methodsWithCovariantReturnTypeAnnotation,
+ List<DexEncodedMethod> covariantReturnTypeMethods) {
+ // It is a compilation error if the class already has a method with a signature similar to one
+ // of the methods in covariantReturnTypeMethods.
+ for (DexEncodedMethod syntheticMethod : covariantReturnTypeMethods) {
+ if (hasVirtualMethodWithSignature(clazz, syntheticMethod)) {
+ throw new CompilationError(
+ String.format(
+ "Cannot process CovariantReturnType annotation: Class %s already "
+ + "has a method \"%s\"",
+ clazz.getType(), syntheticMethod.toSourceString()));
+ }
+ }
+ // Remove the CovariantReturnType annotations.
+ for (DexEncodedMethod method : methodsWithCovariantReturnTypeAnnotation) {
+ method.annotations =
+ method.annotations.keepIf(x -> !isCovariantReturnTypeAnnotation(x.annotation));
+ }
+ // Add the newly constructed methods to the class.
+ DexEncodedMethod[] oldVirtualMethods = clazz.virtualMethods();
+ DexEncodedMethod[] newVirtualMethods =
+ new DexEncodedMethod[oldVirtualMethods.length + covariantReturnTypeMethods.size()];
+ System.arraycopy(oldVirtualMethods, 0, newVirtualMethods, 0, oldVirtualMethods.length);
+ int i = oldVirtualMethods.length;
+ for (DexEncodedMethod syntheticMethod : covariantReturnTypeMethods) {
+ newVirtualMethods[i] = syntheticMethod;
+ i++;
+ }
+ clazz.setVirtualMethods(newVirtualMethods);
+ }
+
+ // Processes all the dalvik.annotation.codegen.CovariantReturnType and dalvik.annotation.codegen.
+ // CovariantReturnTypes annotations in the given DexClass. Adds the newly constructed, synthetic
+ // methods to the list covariantReturnTypeMethods.
+ private void buildCovariantReturnTypeMethodsForClass(
+ DexClass clazz,
+ List<DexEncodedMethod> methodsWithCovariantReturnTypeAnnotation,
+ List<DexEncodedMethod> covariantReturnTypeMethods)
+ throws ApiLevelException {
+ for (DexEncodedMethod method : clazz.virtualMethods()) {
+ if (methodHasCovariantReturnTypeAnnotation(method)) {
+ methodsWithCovariantReturnTypeAnnotation.add(method);
+ buildCovariantReturnTypeMethodsForMethod(clazz, method, covariantReturnTypeMethods);
+ }
+ }
+ }
+
+ private boolean methodHasCovariantReturnTypeAnnotation(DexEncodedMethod method) {
+ for (DexAnnotation annotation : method.annotations.annotations) {
+ if (isCovariantReturnTypeAnnotation(annotation.annotation)) {
+ return true;
+ }
+ }
+ return false;
+ }
+
+ // Processes all the dalvik.annotation.codegen.CovariantReturnType and dalvik.annotation.Co-
+ // variantReturnTypes annotations on the given method. Adds the newly constructed, synthetic
+ // methods to the list covariantReturnTypeMethods.
+ private void buildCovariantReturnTypeMethodsForMethod(
+ DexClass clazz, DexEncodedMethod method, List<DexEncodedMethod> covariantReturnTypeMethods)
+ throws ApiLevelException {
+ assert methodHasCovariantReturnTypeAnnotation(method);
+ for (DexType covariantReturnType : getCovariantReturnTypes(clazz, method)) {
+ DexEncodedMethod covariantReturnTypeMethod =
+ buildCovariantReturnTypeMethod(clazz, method, covariantReturnType);
+ covariantReturnTypeMethods.add(covariantReturnTypeMethod);
+ }
+ }
+
+ // Builds a synthetic method that invokes the given method, casts the result to
+ // covariantReturnType, and then returns the result. The newly created method will have return
+ // type covariantReturnType.
+ //
+ // Note: any "synchronized" or "strictfp" modifier could be dropped safely.
+ private DexEncodedMethod buildCovariantReturnTypeMethod(
+ DexClass clazz, DexEncodedMethod method, DexType covariantReturnType)
+ throws ApiLevelException {
+ DexProto newProto =
+ factory.createProto(
+ covariantReturnType, method.method.proto.shorty, method.method.proto.parameters);
+ MethodAccessFlags newAccessFlags = method.accessFlags.copy();
+ newAccessFlags.setSynthetic();
+ DexEncodedMethod newVirtualMethod =
+ new DexEncodedMethod(
+ factory.createMethod(method.method.holder, newProto, method.method.name),
+ newAccessFlags,
+ method.annotations.keepIf(x -> !isCovariantReturnTypeAnnotation(x.annotation)),
+ method.parameterAnnotationsList.keepIf(Predicates.alwaysTrue()),
+ new SynthesizedCode(
+ new ForwardMethodSourceCode(
+ clazz.type,
+ newProto,
+ method.method.holder,
+ method.method,
+ Invoke.Type.VIRTUAL,
+ true)));
+ // Optimize to generate DexCode instead of SynthesizedCode.
+ converter.optimizeSynthesizedMethod(newVirtualMethod);
+ return newVirtualMethod;
+ }
+
+ // Returns the set of covariant return types for method.
+ //
+ // If the method is:
+ // @dalvik.annotation.codegen.CovariantReturnType(returnType=SubOfFoo, presentAfter=25)
+ // @dalvik.annotation.codegen.CovariantReturnType(returnType=SubOfSubOfFoo, presentAfter=28)
+ // @Override
+ // public Foo foo() { ... return new SubOfSubOfFoo(); }
+ // then this method returns the set { SubOfFoo, SubOfSubOfFoo }.
+ private Set<DexType> getCovariantReturnTypes(DexClass clazz, DexEncodedMethod method) {
+ Set<DexType> covariantReturnTypes = new HashSet<>();
+ for (DexAnnotation annotation : method.annotations.annotations) {
+ if (isCovariantReturnTypeAnnotation(annotation.annotation)) {
+ getCovariantReturnTypesFromAnnotation(
+ clazz, method, annotation.annotation, covariantReturnTypes);
+ }
+ }
+ return covariantReturnTypes;
+ }
+
+ private void getCovariantReturnTypesFromAnnotation(
+ DexClass clazz,
+ DexEncodedMethod method,
+ DexEncodedAnnotation annotation,
+ Set<DexType> covariantReturnTypes) {
+ assert isCovariantReturnTypeAnnotation(annotation);
+ boolean hasPresentAfterElement = false;
+ for (DexAnnotationElement element : annotation.elements) {
+ String name = element.name.toString();
+ if (annotation.type == factory.annotationCovariantReturnType) {
+ if (name.equals("returnType")) {
+ if (!(element.value instanceof DexValue.DexValueType)) {
+ throw new CompilationError(
+ String.format(
+ "Expected element \"returnType\" of CovariantReturnType annotation to "
+ + "reference a type (method: \"%s\", was: %s)",
+ method.toSourceString(), element.value.getClass().getCanonicalName()));
+ }
+
+ DexValue.DexValueType dexValueType = (DexValue.DexValueType) element.value;
+ covariantReturnTypes.add(dexValueType.value);
+ } else if (name.equals("presentAfter")) {
+ hasPresentAfterElement = true;
+ }
+ } else {
+ if (name.equals("value")) {
+ if (!(element.value instanceof DexValue.DexValueArray)) {
+ throw new CompilationError(
+ String.format(
+ "Expected element \"value\" of CovariantReturnTypes annotation to "
+ + "be an array (method: \"%s\", was: %s)",
+ method.toSourceString(), element.value.getClass().getCanonicalName()));
+ }
+
+ DexValue.DexValueArray array = (DexValue.DexValueArray) element.value;
+ // Handle the inner dalvik.annotation.codegen.CovariantReturnType annotations recursively.
+ for (DexValue value : array.getValues()) {
+ assert value instanceof DexValue.DexValueAnnotation;
+ DexValue.DexValueAnnotation innerAnnotation = (DexValue.DexValueAnnotation) value;
+ getCovariantReturnTypesFromAnnotation(
+ clazz, method, innerAnnotation.value, covariantReturnTypes);
+ }
+ }
+ }
+ }
+
+ if (annotation.type == factory.annotationCovariantReturnType && !hasPresentAfterElement) {
+ throw new CompilationError(
+ String.format(
+ "CovariantReturnType annotation for method \"%s\" is missing mandatory element "
+ + "\"presentAfter\" (class %s)",
+ clazz.getType(), method.toSourceString()));
+ }
+ }
+
+ private boolean isCovariantReturnTypeAnnotation(DexEncodedAnnotation annotation) {
+ return annotation.type == factory.annotationCovariantReturnType
+ || annotation.type == factory.annotationCovariantReturnTypes;
+ }
+
+ private static boolean hasVirtualMethodWithSignature(DexClass clazz, DexEncodedMethod method) {
+ for (DexEncodedMethod existingMethod : clazz.virtualMethods()) {
+ if (existingMethod.method.equals(method.method)) {
+ return true;
+ }
+ }
+ return false;
+ }
+}
diff --git a/src/main/java/com/android/tools/r8/ir/synthetic/ForwardMethodSourceCode.java b/src/main/java/com/android/tools/r8/ir/synthetic/ForwardMethodSourceCode.java
index 9259485..0ba49d3 100644
--- a/src/main/java/com/android/tools/r8/ir/synthetic/ForwardMethodSourceCode.java
+++ b/src/main/java/com/android/tools/r8/ir/synthetic/ForwardMethodSourceCode.java
@@ -21,15 +21,27 @@
private final DexType targetReceiver;
private final DexMethod target;
private final Invoke.Type invokeType;
+ private final boolean castResult;
public ForwardMethodSourceCode(DexType receiver, DexProto proto,
DexType targetReceiver, DexMethod target, Invoke.Type invokeType) {
+ this(receiver, proto, targetReceiver, target, invokeType, false);
+ }
+
+ public ForwardMethodSourceCode(
+ DexType receiver,
+ DexProto proto,
+ DexType targetReceiver,
+ DexMethod target,
+ Invoke.Type invokeType,
+ boolean castResult) {
super(receiver, proto);
assert (targetReceiver == null) == (invokeType == Invoke.Type.STATIC);
this.target = target;
this.targetReceiver = targetReceiver;
this.invokeType = invokeType;
+ this.castResult = castResult;
assert checkSignatures();
switch (invokeType) {
@@ -67,7 +79,7 @@
assert (source.isClassType() && target.isClassType()) || source == target;
}
- assert this.proto.returnType == target.proto.returnType;
+ assert this.proto.returnType == target.proto.returnType || castResult;
return true;
}
@@ -99,6 +111,9 @@
ValueType valueType = ValueType.fromDexType(proto.returnType);
int tempValue = nextRegister(valueType);
add(builder -> builder.addMoveResult(tempValue));
+ if (this.proto.returnType != target.proto.returnType) {
+ add(builder -> builder.addCheckCast(tempValue, this.proto.returnType));
+ }
add(builder -> builder.addReturn(valueType, tempValue));
}
}
diff --git a/src/test/java/com/android/tools/r8/ir/desugar/annotations/CovariantReturnTypeAnnotationTransformerTest.java b/src/test/java/com/android/tools/r8/ir/desugar/annotations/CovariantReturnTypeAnnotationTransformerTest.java
index 9c58d25..1f4d2ba 100644
--- a/src/test/java/com/android/tools/r8/ir/desugar/annotations/CovariantReturnTypeAnnotationTransformerTest.java
+++ b/src/test/java/com/android/tools/r8/ir/desugar/annotations/CovariantReturnTypeAnnotationTransformerTest.java
@@ -14,7 +14,6 @@
import com.android.tools.r8.utils.DexInspector;
import java.util.Collections;
import org.junit.Assert;
-import org.junit.Ignore;
import org.junit.Test;
public class CovariantReturnTypeAnnotationTransformerTest extends AsmTestBase {
@@ -49,7 +48,6 @@
failsIndependentOfFlag(input);
}
- @Ignore("b/78618808")
@Test
public void testVersion2WithClient1And2() throws Exception {
AndroidApp input =
@@ -63,7 +61,6 @@
succeedsIndependentOfFlag(input, true);
}
- @Ignore("b/78618808")
@Test
public void testVersion2WithClient3() throws Exception {
AndroidApp input =
@@ -108,6 +105,23 @@
succeedsIndependentOfFlag(input, false);
}
+ @Test
+ public void testRepeatedCompilation() throws Exception {
+ AndroidApp input =
+ buildAndroidApp(
+ ToolHelper.getClassAsBytes(Client.class),
+ ToolHelper.getClassAsBytes(A.class),
+ com.android.tools.r8.ir.desugar.annotations.version2.BDump.dump(),
+ com.android.tools.r8.ir.desugar.annotations.version2.CDump.dump());
+
+ AndroidApp output =
+ compileWithD8(input, options -> options.processCovariantReturnTypeAnnotations = true);
+
+ // Compilation will fail with a compilation error the second time if the implementation does
+ // not remove the CovariantReturnType annotations properly during the first compilation.
+ compileWithD8(output, options -> options.processCovariantReturnTypeAnnotations = true);
+ }
+
private void succeedsWithOption(
AndroidApp input, boolean option, boolean checkPresenceOfSyntheticMethods) throws Exception {
AndroidApp output =
