| // Copyright (c) 2017, 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.errors.CompilationError; |
| import com.android.tools.r8.errors.Unimplemented; |
| import com.android.tools.r8.graph.ClassAccessFlags; |
| import com.android.tools.r8.graph.Code; |
| import com.android.tools.r8.graph.DexAnnotationSet; |
| import com.android.tools.r8.graph.DexClass; |
| import com.android.tools.r8.graph.DexCode; |
| import com.android.tools.r8.graph.DexEncodedField; |
| import com.android.tools.r8.graph.DexEncodedMethod; |
| import com.android.tools.r8.graph.DexMethod; |
| import com.android.tools.r8.graph.DexProgramClass; |
| import com.android.tools.r8.graph.DexType; |
| import com.android.tools.r8.graph.DexTypeList; |
| import com.android.tools.r8.graph.MethodAccessFlags; |
| import com.android.tools.r8.origin.SynthesizedOrigin; |
| import com.google.common.collect.BiMap; |
| import com.google.common.collect.HashBiMap; |
| import java.util.ArrayDeque; |
| import java.util.ArrayList; |
| import java.util.Collections; |
| import java.util.Deque; |
| import java.util.HashSet; |
| import java.util.IdentityHashMap; |
| import java.util.List; |
| import java.util.Map; |
| import java.util.Set; |
| |
| // Default and static method interface desugaring processor for interfaces. |
| // |
| // Makes default interface methods abstract, moves their implementation to |
| // a companion class. Removes bridge default methods. |
| // |
| // Also moves static interface methods into a companion class. |
| final class InterfaceProcessor { |
| private final InterfaceMethodRewriter rewriter; |
| // All created companion classes indexed by interface classes. |
| final Map<DexProgramClass, DexProgramClass> companionClasses = new IdentityHashMap<>(); |
| |
| final BiMap<DexMethod, DexMethod> movedMethods = HashBiMap.create(); |
| final Map<DexEncodedMethod, DexEncodedMethod> methodsWithMovedCode = new IdentityHashMap<>(); |
| |
| InterfaceProcessor(InterfaceMethodRewriter rewriter) { |
| this.rewriter = rewriter; |
| } |
| |
| void process(DexProgramClass iface) { |
| assert iface.isInterface(); |
| |
| // The list of methods to be created in companion class. |
| List<DexEncodedMethod> companionMethods = new ArrayList<>(); |
| |
| // Process virtual interface methods first. |
| List<DexEncodedMethod> remainingMethods = new ArrayList<>(); |
| for (DexEncodedMethod virtual : iface.virtualMethods()) { |
| if (rewriter.isDefaultMethod(virtual)) { |
| // Create a new method in a companion class to represent default method implementation. |
| DexMethod companionMethod = rewriter.defaultAsMethodOfCompanionClass(virtual.method); |
| |
| Code code = virtual.getCode(); |
| if (code == null) { |
| throw new CompilationError("Code is missing for default " |
| + "interface method: " + virtual.method.toSourceString(), iface.origin); |
| } |
| |
| MethodAccessFlags newFlags = virtual.accessFlags.copy(); |
| newFlags.unsetBridge(); |
| newFlags.setStatic(); |
| DexCode dexCode = code.asDexCode(); |
| // We cannot name the parameter "this" because the debugger may omit it due to the method |
| // actually being static. Instead we prepend it with a special character. |
| dexCode.setDebugInfo(dexCode.debugInfoWithAdditionalFirstParameter( |
| rewriter.factory.createString("-this"))); |
| assert (dexCode.getDebugInfo() == null) |
| || (companionMethod.getArity() == dexCode.getDebugInfo().parameters.length); |
| |
| // Make the method abstract. |
| virtual.accessFlags.setAbstract(); |
| virtual.removeCode(); // Remove code first to void ownership. |
| |
| DexEncodedMethod implMethod = new DexEncodedMethod( |
| companionMethod, newFlags, virtual.annotations, virtual.parameterAnnotationsList, code); |
| companionMethods.add(implMethod); |
| |
| methodsWithMovedCode.put(virtual, implMethod); |
| } |
| |
| // Remove bridge methods. |
| if (interfaceMethodRemovalChangesApi(virtual, iface)) { |
| remainingMethods.add(virtual); |
| } |
| } |
| |
| // If at least one bridge methods was removed update the table. |
| if (remainingMethods.size() < iface.virtualMethods().length) { |
| iface.setVirtualMethods(remainingMethods.toArray( |
| new DexEncodedMethod[remainingMethods.size()])); |
| } |
| remainingMethods.clear(); |
| |
| // Process static and private methods, move them into companion class as well, |
| // make private instance methods public static. |
| for (DexEncodedMethod direct : iface.directMethods()) { |
| MethodAccessFlags originalFlags = direct.accessFlags; |
| MethodAccessFlags newFlags = originalFlags.copy(); |
| if (originalFlags.isPrivate()) { |
| newFlags.unsetPrivate(); |
| newFlags.setPublic(); |
| } |
| |
| DexMethod oldMethod = direct.method; |
| if (isStaticMethod(direct)) { |
| assert originalFlags.isPrivate() || originalFlags.isPublic() |
| : "Static interface method " + direct.toSourceString() + " is expected to " |
| + "either be public or private in " + iface.origin; |
| DexMethod companionMethod = rewriter.staticAsMethodOfCompanionClass(oldMethod); |
| companionMethods.add(new DexEncodedMethod(companionMethod, newFlags, |
| direct.annotations, direct.parameterAnnotationsList, direct.getCode())); |
| movedMethods.put(oldMethod, companionMethod); |
| |
| } else { |
| if (originalFlags.isPrivate()) { |
| assert !rewriter.factory.isClassConstructor(oldMethod) |
| : "Unexpected private constructor " + direct.toSourceString() |
| + " in " + iface.origin; |
| newFlags.setStatic(); |
| |
| DexMethod companionMethod = rewriter.privateAsMethodOfCompanionClass(oldMethod); |
| |
| Code code = direct.getCode(); |
| if (code == null) { |
| throw new CompilationError("Code is missing for private instance " |
| + "interface method: " + oldMethod.toSourceString(), iface.origin); |
| } |
| DexCode dexCode = code.asDexCode(); |
| // TODO(ager): Should we give the new first parameter an actual name? Maybe 'this'? |
| dexCode.setDebugInfo(dexCode.debugInfoWithAdditionalFirstParameter(null)); |
| assert (dexCode.getDebugInfo() == null) |
| || (companionMethod.getArity() == dexCode.getDebugInfo().parameters.length); |
| |
| companionMethods.add(new DexEncodedMethod(companionMethod, |
| newFlags, direct.annotations, direct.parameterAnnotationsList, code)); |
| movedMethods.put(oldMethod, companionMethod); |
| |
| } else { |
| // Since there are no interface constructors at this point, |
| // this should only be class constructor. |
| assert rewriter.factory.isClassConstructor(oldMethod); |
| remainingMethods.add(direct); |
| } |
| } |
| } |
| if (remainingMethods.size() < iface.directMethods().length) { |
| iface.setDirectMethods(remainingMethods.toArray( |
| new DexEncodedMethod[remainingMethods.size()])); |
| } |
| |
| if (companionMethods.isEmpty()) { |
| return; // No methods to create, companion class not needed. |
| } |
| |
| ClassAccessFlags companionClassFlags = iface.accessFlags.copy(); |
| companionClassFlags.unsetAbstract(); |
| companionClassFlags.unsetInterface(); |
| companionClassFlags.unsetAnnotation(); |
| companionClassFlags.setFinal(); |
| companionClassFlags.setSynthetic(); |
| // Companion class must be public so moved methods can be called from anywhere. |
| companionClassFlags.setPublic(); |
| |
| // Create companion class. |
| DexType companionClassType = rewriter.getCompanionClassType(iface.type); |
| DexProgramClass companionClass = |
| new DexProgramClass( |
| companionClassType, |
| null, |
| new SynthesizedOrigin("interface desugaring", getClass()), |
| companionClassFlags, |
| rewriter.factory.objectType, |
| DexTypeList.empty(), |
| iface.sourceFile, |
| null, |
| Collections.emptyList(), |
| DexAnnotationSet.empty(), |
| DexEncodedField.EMPTY_ARRAY, |
| DexEncodedField.EMPTY_ARRAY, |
| companionMethods.toArray(new DexEncodedMethod[companionMethods.size()]), |
| DexEncodedMethod.EMPTY_ARRAY, |
| rewriter.factory.getSkipNameValidationForTesting(), |
| Collections.singletonList(iface)); |
| companionClasses.put(iface, companionClass); |
| } |
| |
| // Returns true if the given interface method must be kept on [iface] after moving its |
| // implementation to the companion class of [iface]. This is always the case for non-bridge |
| // methods. Bridge methods that does not override an implementation in a super-interface must |
| // also be kept (such a situation can happen if the vertical class merger merges two interfaces). |
| private boolean interfaceMethodRemovalChangesApi(DexEncodedMethod method, DexClass iface) { |
| if (method.accessFlags.isBridge()) { |
| Deque<DexType> worklist = new ArrayDeque<>(); |
| Set<DexType> seenBefore = new HashSet<>(); |
| if (iface.superType != null) { |
| worklist.add(iface.superType); |
| } |
| Collections.addAll(worklist, iface.interfaces.values); |
| while (!worklist.isEmpty()) { |
| DexType superType = worklist.pop(); |
| if (!seenBefore.add(superType)) { |
| continue; |
| } |
| DexClass clazz = rewriter.findDefinitionFor(superType); |
| if (clazz != null) { |
| if (clazz.lookupVirtualMethod(method.method) != null) { |
| return false; |
| } |
| if (clazz.superType != null) { |
| worklist.add(clazz.superType); |
| } |
| Collections.addAll(worklist, clazz.interfaces.values); |
| } |
| } |
| } |
| return true; |
| } |
| |
| private boolean isStaticMethod(DexEncodedMethod method) { |
| if (method.accessFlags.isNative()) { |
| throw new Unimplemented("Native interface methods are not yet supported."); |
| } |
| return method.accessFlags.isStatic() && !rewriter.factory.isClassConstructor(method.method); |
| } |
| } |