| // 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.conversion; |
| |
| import static com.android.tools.r8.graph.UseRegistry.MethodHandleUse.ARGUMENT_TO_LAMBDA_METAFACTORY; |
| import static com.android.tools.r8.graph.UseRegistry.MethodHandleUse.NOT_ARGUMENT_TO_LAMBDA_METAFACTORY; |
| import static com.android.tools.r8.ir.code.Invoke.Type.STATIC; |
| import static com.android.tools.r8.ir.code.Invoke.Type.VIRTUAL; |
| |
| import com.android.tools.r8.errors.Unreachable; |
| import com.android.tools.r8.graph.AppInfoWithSubtyping; |
| import com.android.tools.r8.graph.AppView; |
| import com.android.tools.r8.graph.DexCallSite; |
| import com.android.tools.r8.graph.DexClass; |
| import com.android.tools.r8.graph.DexEncodedMethod; |
| import com.android.tools.r8.graph.DexField; |
| import com.android.tools.r8.graph.DexMethod; |
| import com.android.tools.r8.graph.DexMethodHandle; |
| import com.android.tools.r8.graph.DexMethodHandle.MethodHandleType; |
| 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.DexValue.DexValueMethodHandle; |
| import com.android.tools.r8.graph.DexValue.DexValueMethodType; |
| import com.android.tools.r8.graph.DexValue.DexValueType; |
| import com.android.tools.r8.graph.GraphLense; |
| import com.android.tools.r8.graph.GraphLense.GraphLenseLookupResult; |
| import com.android.tools.r8.graph.GraphLense.RewrittenPrototypeDescription; |
| import com.android.tools.r8.graph.GraphLense.RewrittenPrototypeDescription.RemovedArgumentsInfo; |
| import com.android.tools.r8.graph.UseRegistry.MethodHandleUse; |
| import com.android.tools.r8.ir.analysis.type.TypeAnalysis; |
| import com.android.tools.r8.ir.code.BasicBlock; |
| import com.android.tools.r8.ir.code.CatchHandlers; |
| import com.android.tools.r8.ir.code.CheckCast; |
| import com.android.tools.r8.ir.code.ConstClass; |
| import com.android.tools.r8.ir.code.ConstInstruction; |
| import com.android.tools.r8.ir.code.ConstMethodHandle; |
| import com.android.tools.r8.ir.code.IRCode; |
| import com.android.tools.r8.ir.code.InstanceGet; |
| import com.android.tools.r8.ir.code.InstanceOf; |
| import com.android.tools.r8.ir.code.InstancePut; |
| import com.android.tools.r8.ir.code.Instruction; |
| import com.android.tools.r8.ir.code.InstructionListIterator; |
| import com.android.tools.r8.ir.code.Invoke; |
| import com.android.tools.r8.ir.code.Invoke.Type; |
| import com.android.tools.r8.ir.code.InvokeCustom; |
| import com.android.tools.r8.ir.code.InvokeDirect; |
| import com.android.tools.r8.ir.code.InvokeMethod; |
| import com.android.tools.r8.ir.code.InvokeMultiNewArray; |
| import com.android.tools.r8.ir.code.InvokeNewArray; |
| import com.android.tools.r8.ir.code.MoveException; |
| import com.android.tools.r8.ir.code.NewArrayEmpty; |
| import com.android.tools.r8.ir.code.NewInstance; |
| import com.android.tools.r8.ir.code.StaticGet; |
| import com.android.tools.r8.ir.code.StaticPut; |
| import com.android.tools.r8.ir.code.Value; |
| import com.android.tools.r8.logging.Log; |
| import com.android.tools.r8.shaking.VerticalClassMerger.VerticallyMergedClasses; |
| import com.android.tools.r8.utils.InternalOptions; |
| import com.google.common.collect.Sets; |
| import java.util.ArrayList; |
| import java.util.HashSet; |
| import java.util.List; |
| import java.util.ListIterator; |
| import java.util.Map; |
| import java.util.Set; |
| import java.util.concurrent.ConcurrentHashMap; |
| |
| public class LensCodeRewriter { |
| |
| private final AppInfoWithSubtyping appInfo; |
| private final GraphLense graphLense; |
| private final VerticallyMergedClasses verticallyMergedClasses; |
| private final InternalOptions options; |
| |
| private final Map<DexProto, DexProto> protoFixupCache = new ConcurrentHashMap<>(); |
| |
| public LensCodeRewriter( |
| AppView<? extends AppInfoWithSubtyping> appView, InternalOptions options) { |
| this.appInfo = appView.appInfo(); |
| this.graphLense = appView.graphLense(); |
| this.verticallyMergedClasses = appView.verticallyMergedClasses(); |
| this.options = options; |
| } |
| |
| private Value makeOutValue(Instruction insn, IRCode code, Set<Value> collector) { |
| if (insn.outValue() == null) { |
| return null; |
| } else { |
| Value newValue = code.createValue(insn.outValue().getTypeLattice(), insn.getLocalInfo()); |
| collector.add(newValue); |
| return newValue; |
| } |
| } |
| |
| /** |
| * Replace type appearances, invoke targets and field accesses with actual definitions. |
| */ |
| public void rewrite(IRCode code, DexEncodedMethod method) { |
| Set<Value> newSSAValues = Sets.newIdentityHashSet(); |
| ListIterator<BasicBlock> blocks = code.blocks.listIterator(); |
| boolean mayHaveUnreachableBlocks = false; |
| while (blocks.hasNext()) { |
| BasicBlock block = blocks.next(); |
| if (block.hasCatchHandlers() && options.enableVerticalClassMerging) { |
| boolean anyGuardsRenamed = block.renameGuardsInCatchHandlers(graphLense); |
| if (anyGuardsRenamed) { |
| mayHaveUnreachableBlocks |= unlinkDeadCatchHandlers(block); |
| } |
| } |
| InstructionListIterator iterator = block.listIterator(); |
| while (iterator.hasNext()) { |
| Instruction current = iterator.next(); |
| if (current.isInvokeCustom()) { |
| InvokeCustom invokeCustom = current.asInvokeCustom(); |
| DexCallSite callSite = invokeCustom.getCallSite(); |
| DexProto newMethodProto = |
| appInfo.dexItemFactory.applyClassMappingToProto( |
| callSite.methodProto, graphLense::lookupType, protoFixupCache); |
| DexMethodHandle newBootstrapMethod = rewriteDexMethodHandle( |
| callSite.bootstrapMethod, method, NOT_ARGUMENT_TO_LAMBDA_METAFACTORY); |
| boolean isLambdaMetaFactory = |
| appInfo.dexItemFactory.isLambdaMetafactoryMethod(callSite.bootstrapMethod.asMethod()); |
| MethodHandleUse methodHandleUse = isLambdaMetaFactory |
| ? ARGUMENT_TO_LAMBDA_METAFACTORY |
| : NOT_ARGUMENT_TO_LAMBDA_METAFACTORY; |
| List<DexValue> newArgs = |
| rewriteBootstrapArgs(callSite.bootstrapArgs, method, methodHandleUse); |
| if (!newMethodProto.equals(callSite.methodProto) |
| || newBootstrapMethod != callSite.bootstrapMethod |
| || !newArgs.equals(callSite.bootstrapArgs)) { |
| DexCallSite newCallSite = |
| appInfo.dexItemFactory.createCallSite( |
| callSite.methodName, newMethodProto, newBootstrapMethod, newArgs); |
| InvokeCustom newInvokeCustom = new InvokeCustom(newCallSite, invokeCustom.outValue(), |
| invokeCustom.inValues()); |
| iterator.replaceCurrentInstruction(newInvokeCustom); |
| } |
| } else if (current.isConstMethodHandle()) { |
| DexMethodHandle handle = current.asConstMethodHandle().getValue(); |
| DexMethodHandle newHandle = rewriteDexMethodHandle( |
| handle, method, NOT_ARGUMENT_TO_LAMBDA_METAFACTORY); |
| if (newHandle != handle) { |
| ConstMethodHandle newInstruction = |
| new ConstMethodHandle(makeOutValue(current, code, newSSAValues), newHandle); |
| iterator.replaceCurrentInstruction(newInstruction); |
| } |
| } else if (current.isInvokeMethod()) { |
| InvokeMethod invoke = current.asInvokeMethod(); |
| DexMethod invokedMethod = invoke.getInvokedMethod(); |
| DexType invokedHolder = invokedMethod.getHolder(); |
| if (invokedHolder.isArrayType()) { |
| if (invokedMethod.name == appInfo.dexItemFactory.cloneMethodName) { |
| DexType baseType = invokedHolder.toBaseType(appInfo.dexItemFactory); |
| DexType mappedBaseType = graphLense.lookupType(baseType); |
| if (baseType != mappedBaseType) { |
| DexType mappedHolder = |
| invokedHolder.replaceBaseType(mappedBaseType, appInfo.dexItemFactory); |
| // The clone proto is ()Ljava/lang/Object;, so just reuse it. |
| DexMethod actualTarget = |
| appInfo.dexItemFactory.createMethod( |
| mappedHolder, invokedMethod.proto, appInfo.dexItemFactory.cloneMethodName); |
| Invoke newInvoke = |
| Invoke.create( |
| VIRTUAL, |
| actualTarget, |
| null, |
| makeOutValue(invoke, code, newSSAValues), |
| invoke.inValues()); |
| iterator.replaceCurrentInstruction(newInvoke); |
| } |
| } |
| continue; |
| } |
| if (!invokedHolder.isClassType()) { |
| assert false; |
| continue; |
| } |
| if (invoke.isInvokeDirect()) { |
| checkInvokeDirect(method.method, invoke.asInvokeDirect()); |
| } |
| GraphLenseLookupResult lenseLookup = |
| graphLense.lookupMethod(invokedMethod, method.method, invoke.getType()); |
| DexMethod actualTarget = lenseLookup.getMethod(); |
| Invoke.Type actualInvokeType = lenseLookup.getType(); |
| if (actualInvokeType == Type.VIRTUAL) { |
| actualTarget = |
| rebindVirtualInvokeToMostSpecific( |
| actualTarget, invoke.inValues().get(0), method.method.holder); |
| } |
| if (actualTarget != invokedMethod || invoke.getType() != actualInvokeType) { |
| RewrittenPrototypeDescription prototypeChanges = |
| graphLense.lookupPrototypeChanges(actualTarget); |
| RemovedArgumentsInfo removedArgumentsInfo = prototypeChanges.getRemovedArgumentsInfo(); |
| |
| ConstInstruction constantReturnMaterializingInstruction = null; |
| if (prototypeChanges.hasBeenChangedToReturnVoid() && invoke.outValue() != null) { |
| constantReturnMaterializingInstruction = |
| prototypeChanges.getConstantReturn(code, invoke.getPosition()); |
| invoke.outValue().replaceUsers(constantReturnMaterializingInstruction.outValue()); |
| } |
| |
| Value newOutValue = |
| prototypeChanges.hasBeenChangedToReturnVoid() |
| ? null |
| : makeOutValue(invoke, code, newSSAValues); |
| |
| List<Value> newInValues; |
| if (removedArgumentsInfo.hasRemovedArguments()) { |
| if (Log.ENABLED) { |
| Log.info( |
| getClass(), |
| "Invoked method " |
| + invokedMethod.toSourceString() |
| + " with " |
| + removedArgumentsInfo.numberOfRemovedArguments() |
| + " arguments removed"); |
| } |
| // Remove removed arguments from the invoke. |
| newInValues = new ArrayList<>(actualTarget.proto.parameters.size()); |
| for (int i = 0; i < invoke.inValues().size(); i++) { |
| if (!removedArgumentsInfo.isArgumentRemoved(i)) { |
| newInValues.add(invoke.inValues().get(i)); |
| } |
| } |
| assert newInValues.size() |
| == actualTarget.proto.parameters.size() + (actualInvokeType == STATIC ? 0 : 1); |
| } else { |
| newInValues = invoke.inValues(); |
| } |
| |
| Invoke newInvoke = |
| Invoke.create(actualInvokeType, actualTarget, null, newOutValue, newInValues); |
| iterator.replaceCurrentInstruction(newInvoke); |
| |
| if (constantReturnMaterializingInstruction != null) { |
| if (block.hasCatchHandlers()) { |
| // Split the block to ensure no instructions after throwing instructions. |
| iterator |
| .split(code, blocks) |
| .listIterator() |
| .add(constantReturnMaterializingInstruction); |
| } else { |
| iterator.add(constantReturnMaterializingInstruction); |
| } |
| } |
| |
| DexType actualReturnType = actualTarget.proto.returnType; |
| DexType expectedReturnType = graphLense.lookupType(invokedMethod.proto.returnType); |
| if (newInvoke.outValue() != null && actualReturnType != expectedReturnType) { |
| throw new Unreachable( |
| "Unexpected need to insert a cast. Possibly related to resolving b/79143143.\n" |
| + invokedMethod |
| + " type changed from " + expectedReturnType |
| + " to " + actualReturnType); |
| } |
| } |
| } else if (current.isInstanceGet()) { |
| InstanceGet instanceGet = current.asInstanceGet(); |
| DexField field = instanceGet.getField(); |
| DexField actualField = graphLense.lookupField(field); |
| if (actualField != field) { |
| InstanceGet newInstanceGet = |
| new InstanceGet( |
| makeOutValue(instanceGet, code, newSSAValues), |
| instanceGet.object(), |
| actualField); |
| iterator.replaceCurrentInstruction(newInstanceGet); |
| } |
| } else if (current.isInstancePut()) { |
| InstancePut instancePut = current.asInstancePut(); |
| DexField field = instancePut.getField(); |
| DexField actualField = graphLense.lookupField(field); |
| if (actualField != field) { |
| InstancePut newInstancePut = |
| new InstancePut(actualField, instancePut.object(), instancePut.value()); |
| iterator.replaceCurrentInstruction(newInstancePut); |
| } |
| } else if (current.isStaticGet()) { |
| StaticGet staticGet = current.asStaticGet(); |
| DexField field = staticGet.getField(); |
| DexField actualField = graphLense.lookupField(field); |
| if (actualField != field) { |
| StaticGet newStaticGet = |
| new StaticGet(makeOutValue(staticGet, code, newSSAValues), actualField); |
| iterator.replaceCurrentInstruction(newStaticGet); |
| } |
| } else if (current.isStaticPut()) { |
| StaticPut staticPut = current.asStaticPut(); |
| DexField field = staticPut.getField(); |
| DexField actualField = graphLense.lookupField(field); |
| if (actualField != field) { |
| StaticPut newStaticPut = new StaticPut(staticPut.inValue(), actualField); |
| iterator.replaceCurrentInstruction(newStaticPut); |
| } |
| } else if (current.isCheckCast()) { |
| CheckCast checkCast = current.asCheckCast(); |
| DexType newType = graphLense.lookupType(checkCast.getType()); |
| if (newType != checkCast.getType()) { |
| CheckCast newCheckCast = new CheckCast( |
| makeOutValue(checkCast, code, newSSAValues), checkCast.object(), newType); |
| iterator.replaceCurrentInstruction(newCheckCast); |
| } |
| } else if (current.isConstClass()) { |
| ConstClass constClass = current.asConstClass(); |
| DexType newType = graphLense.lookupType(constClass.getValue()); |
| if (newType != constClass.getValue()) { |
| ConstClass newConstClass = new ConstClass( |
| makeOutValue(constClass, code, newSSAValues), newType); |
| iterator.replaceCurrentInstruction(newConstClass); |
| } |
| } else if (current.isInstanceOf()) { |
| InstanceOf instanceOf = current.asInstanceOf(); |
| DexType newType = graphLense.lookupType(instanceOf.type()); |
| if (newType != instanceOf.type()) { |
| InstanceOf newInstanceOf = new InstanceOf( |
| makeOutValue(instanceOf, code, newSSAValues), instanceOf.value(), newType); |
| iterator.replaceCurrentInstruction(newInstanceOf); |
| } |
| } else if (current.isInvokeMultiNewArray()) { |
| InvokeMultiNewArray multiNewArray = current.asInvokeMultiNewArray(); |
| DexType newType = graphLense.lookupType(multiNewArray.getArrayType()); |
| if (newType != multiNewArray.getArrayType()) { |
| InvokeMultiNewArray newMultiNewArray = |
| new InvokeMultiNewArray( |
| newType, |
| makeOutValue(multiNewArray, code, newSSAValues), |
| multiNewArray.inValues()); |
| iterator.replaceCurrentInstruction(newMultiNewArray); |
| } |
| } else if (current.isInvokeNewArray()) { |
| InvokeNewArray newArray = current.asInvokeNewArray(); |
| DexType newType = graphLense.lookupType(newArray.getArrayType()); |
| if (newType != newArray.getArrayType()) { |
| InvokeNewArray newNewArray = new InvokeNewArray( |
| newType, makeOutValue(newArray, code, newSSAValues), newArray.inValues()); |
| iterator.replaceCurrentInstruction(newNewArray); |
| } |
| } else if (current.isMoveException()) { |
| MoveException moveException = current.asMoveException(); |
| DexType newExceptionType = graphLense.lookupType(moveException.getExceptionType()); |
| if (newExceptionType != moveException.getExceptionType()) { |
| iterator.replaceCurrentInstruction( |
| new MoveException( |
| makeOutValue(moveException, code, newSSAValues), newExceptionType, options)); |
| } |
| } else if (current.isNewArrayEmpty()) { |
| NewArrayEmpty newArrayEmpty = current.asNewArrayEmpty(); |
| DexType newType = graphLense.lookupType(newArrayEmpty.type); |
| if (newType != newArrayEmpty.type) { |
| NewArrayEmpty newNewArray = new NewArrayEmpty( |
| makeOutValue(newArrayEmpty, code, newSSAValues), newArrayEmpty.size(), newType); |
| iterator.replaceCurrentInstruction(newNewArray); |
| } |
| } else if (current.isNewInstance()) { |
| NewInstance newInstance = current.asNewInstance(); |
| DexType newClazz = graphLense.lookupType(newInstance.clazz); |
| if (newClazz != newInstance.clazz) { |
| NewInstance newNewInstance = new NewInstance( |
| newClazz, makeOutValue(newInstance, code, newSSAValues)); |
| iterator.replaceCurrentInstruction(newNewInstance); |
| } |
| } |
| } |
| } |
| if (mayHaveUnreachableBlocks) { |
| code.removeUnreachableBlocks(); |
| } |
| if (!newSSAValues.isEmpty()) { |
| new TypeAnalysis(appInfo, method).widening(newSSAValues); |
| } |
| assert code.isConsistentSSA(); |
| } |
| |
| // If the given invoke is on the form "invoke-direct A.<init>, v0, ..." and the definition of |
| // value v0 is "new-instance v0, B", where B is a subtype of A (see the Art800 and B116282409 |
| // tests), then fail with a compilation error if A has previously been merged into B. |
| // |
| // The motivation for this is that the vertical class merger cannot easily recognize the above |
| // code pattern, since it runs prior to IR construction. Therefore, we currently allow merging |
| // A and B although this will lead to invalid code, because this code pattern does generally |
| // not occur in practice (it leads to a verification error on the JVM, but not on Art). |
| private void checkInvokeDirect(DexMethod method, InvokeDirect invoke) { |
| if (verticallyMergedClasses == null) { |
| // No need to check the invocation. |
| return; |
| } |
| DexMethod invokedMethod = invoke.getInvokedMethod(); |
| if (invokedMethod.name != appInfo.dexItemFactory.constructorMethodName) { |
| // Not a constructor call. |
| return; |
| } |
| if (invoke.arguments().isEmpty()) { |
| // The new instance should always be passed to the constructor call, but continue gracefully. |
| return; |
| } |
| Value receiver = invoke.arguments().get(0); |
| if (!receiver.isPhi() && receiver.definition.isNewInstance()) { |
| NewInstance newInstance = receiver.definition.asNewInstance(); |
| if (newInstance.clazz != invokedMethod.holder |
| && verticallyMergedClasses.hasBeenMergedIntoSubtype(invokedMethod.holder)) { |
| // Generated code will not work. Fail with a compilation error. |
| throw options.reporter.fatalError( |
| String.format( |
| "Unable to rewrite `invoke-direct %s.<init>(new %s, ...)` in method `%s` after " |
| + "type `%s` was merged into `%s`. Please add the following rule to your " |
| + "Proguard configuration file: `-keep,allowobfuscation class %s`.", |
| invokedMethod.holder.toSourceString(), |
| newInstance.clazz, |
| method.toSourceString(), |
| invokedMethod.holder, |
| verticallyMergedClasses.getTargetFor(invokedMethod.holder), |
| invokedMethod.holder.toSourceString())); |
| } |
| } |
| } |
| |
| /** |
| * Due to class merging, it is possible that two exception classes have been merged into one. This |
| * function removes catch handlers where the guards ended up being the same as a previous one. |
| * |
| * @return true if any dead catch handlers were removed. |
| */ |
| private boolean unlinkDeadCatchHandlers(BasicBlock block) { |
| assert block.hasCatchHandlers(); |
| CatchHandlers<BasicBlock> catchHandlers = block.getCatchHandlers(); |
| List<DexType> guards = catchHandlers.getGuards(); |
| List<BasicBlock> targets = catchHandlers.getAllTargets(); |
| |
| Set<DexType> previouslySeenGuards = new HashSet<>(); |
| List<BasicBlock> deadCatchHandlers = new ArrayList<>(); |
| for (int i = 0; i < guards.size(); i++) { |
| // The type may have changed due to class merging. |
| DexType guard = graphLense.lookupType(guards.get(i)); |
| boolean guardSeenBefore = !previouslySeenGuards.add(guard); |
| if (guardSeenBefore) { |
| deadCatchHandlers.add(targets.get(i)); |
| } |
| } |
| // Remove the guards that are guaranteed to be dead. |
| for (BasicBlock deadCatchHandler : deadCatchHandlers) { |
| deadCatchHandler.unlinkCatchHandler(); |
| } |
| assert block.consistentCatchHandlers(); |
| return !deadCatchHandlers.isEmpty(); |
| } |
| |
| private List<DexValue> rewriteBootstrapArgs( |
| List<DexValue> bootstrapArgs, DexEncodedMethod method, MethodHandleUse use) { |
| List<DexValue> newBootstrapArgs = null; |
| boolean changed = false; |
| for (int i = 0; i < bootstrapArgs.size(); i++) { |
| DexValue argument = bootstrapArgs.get(i); |
| DexValue newArgument = null; |
| if (argument instanceof DexValueMethodHandle) { |
| newArgument = rewriteDexValueMethodHandle(argument.asDexValueMethodHandle(), method, use); |
| } else if (argument instanceof DexValueMethodType) { |
| newArgument = rewriteDexMethodType(argument.asDexValueMethodType()); |
| } else if (argument instanceof DexValueType) { |
| DexType oldType = ((DexValueType) argument).value; |
| DexType newType = graphLense.lookupType(oldType); |
| if (newType != oldType) { |
| newArgument = new DexValueType(newType); |
| } |
| } |
| if (newArgument != null) { |
| if (newBootstrapArgs == null) { |
| newBootstrapArgs = new ArrayList<>(bootstrapArgs.subList(0, i)); |
| } |
| newBootstrapArgs.add(newArgument); |
| changed = true; |
| } else if (newBootstrapArgs != null) { |
| newBootstrapArgs.add(argument); |
| } |
| } |
| return changed ? newBootstrapArgs : bootstrapArgs; |
| } |
| |
| private DexValueMethodHandle rewriteDexValueMethodHandle( |
| DexValueMethodHandle methodHandle, DexEncodedMethod context, MethodHandleUse use) { |
| DexMethodHandle oldHandle = methodHandle.value; |
| DexMethodHandle newHandle = rewriteDexMethodHandle(oldHandle, context, use); |
| return newHandle != oldHandle ? new DexValueMethodHandle(newHandle) : methodHandle; |
| } |
| |
| private DexMethodHandle rewriteDexMethodHandle( |
| DexMethodHandle methodHandle, DexEncodedMethod context, MethodHandleUse use) { |
| if (methodHandle.isMethodHandle()) { |
| DexMethod invokedMethod = methodHandle.asMethod(); |
| MethodHandleType oldType = methodHandle.type; |
| GraphLenseLookupResult lenseLookup = |
| graphLense.lookupMethod(invokedMethod, context.method, oldType.toInvokeType()); |
| DexMethod rewrittenTarget = lenseLookup.getMethod(); |
| DexMethod actualTarget; |
| MethodHandleType newType; |
| if (use == ARGUMENT_TO_LAMBDA_METAFACTORY) { |
| // Lambda metafactory arguments will be lambda desugared away and therefore cannot flow |
| // to a MethodHandle.invokeExact call. We can therefore member-rebind with no issues. |
| actualTarget = rewrittenTarget; |
| newType = lenseLookup.getType().toMethodHandle(actualTarget); |
| } else { |
| assert use == NOT_ARGUMENT_TO_LAMBDA_METAFACTORY; |
| // MethodHandles that are not arguments to a lambda metafactory will not be desugared |
| // away. Therefore they could flow to a MethodHandle.invokeExact call which means that |
| // we cannot member rebind. We therefore keep the receiver and also pin the receiver |
| // with a keep rule (see Enqueuer.registerMethodHandle). |
| actualTarget = |
| appInfo.dexItemFactory.createMethod( |
| invokedMethod.holder, rewrittenTarget.proto, rewrittenTarget.name); |
| newType = oldType; |
| if (oldType.isInvokeDirect()) { |
| // For an invoke direct, the rewritten target must have the same holder as the original. |
| // If the method has changed from private to public we need to use virtual instead of |
| // direct. |
| assert rewrittenTarget.holder == actualTarget.holder; |
| newType = lenseLookup.getType().toMethodHandle(actualTarget); |
| assert newType == MethodHandleType.INVOKE_DIRECT |
| || newType == MethodHandleType.INVOKE_INSTANCE; |
| } |
| } |
| if (newType != oldType || actualTarget != invokedMethod || rewrittenTarget != actualTarget) { |
| return new DexMethodHandle( |
| newType, |
| actualTarget, |
| rewrittenTarget != actualTarget ? rewrittenTarget : null); |
| } |
| } else { |
| DexField field = methodHandle.asField(); |
| DexField actualField = graphLense.lookupField(field); |
| if (actualField != field) { |
| return new DexMethodHandle(methodHandle.type, actualField); |
| } |
| } |
| return methodHandle; |
| } |
| |
| private DexValueMethodType rewriteDexMethodType(DexValueMethodType type) { |
| DexProto oldProto = type.value; |
| DexProto newProto = |
| appInfo.dexItemFactory.applyClassMappingToProto( |
| oldProto, graphLense::lookupType, protoFixupCache); |
| return newProto != oldProto ? new DexValueMethodType(newProto) : type; |
| } |
| |
| /** |
| * This rebinds invoke-virtual instructions to their most specific target. |
| * |
| * <p>As a simple example, consider the instruction "invoke-virtual A.foo(v0)", and assume that v0 |
| * is defined by an instruction "new-instance v0, B". If B is a subtype of A, and B overrides the |
| * method foo(), then we rewrite the invocation into "invoke-virtual B.foo(v0)". |
| * |
| * <p>If A.foo() ends up being unused, this helps to ensure that we can get rid of A.foo() |
| * entirely. Without this rewriting, we would have to keep A.foo() because the method is targeted. |
| */ |
| private DexMethod rebindVirtualInvokeToMostSpecific( |
| DexMethod target, Value receiver, DexType context) { |
| if (!receiver.getTypeLattice().isClassType()) { |
| return target; |
| } |
| DexEncodedMethod encodedTarget = appInfo.definitionFor(target); |
| if (encodedTarget == null |
| || !canInvokeTargetWithInvokeVirtual(encodedTarget) |
| || !hasAccessToInvokeTargetFromContext(encodedTarget, context)) { |
| // Don't rewrite this instruction as it could remove an error from the program. |
| return target; |
| } |
| DexType receiverType = |
| graphLense.lookupType(receiver.getTypeLattice().asClassTypeLatticeElement().getClassType()); |
| if (receiverType == target.holder) { |
| // Virtual invoke is already as specific as it can get. |
| return target; |
| } |
| DexEncodedMethod newTarget = appInfo.lookupVirtualTarget(receiverType, target); |
| if (newTarget == null || newTarget.method == target) { |
| // Most likely due to a missing class, or invoke is already as specific as it gets. |
| return target; |
| } |
| if (!canInvokeTargetWithInvokeVirtual(newTarget) |
| || !hasAccessToInvokeTargetFromContext(newTarget, context)) { |
| // Not safe to invoke `newTarget` with virtual invoke from the current context. |
| return target; |
| } |
| return newTarget.method; |
| } |
| |
| private boolean canInvokeTargetWithInvokeVirtual(DexEncodedMethod target) { |
| return target.isVirtualMethod() && !target.method.holder.isInterface(); |
| } |
| |
| private boolean hasAccessToInvokeTargetFromContext(DexEncodedMethod target, DexType context) { |
| assert !target.accessFlags.isPrivate(); |
| DexType holder = target.method.holder; |
| if (holder == context) { |
| // It is always safe to invoke a method from the same enclosing class. |
| return true; |
| } |
| DexClass clazz = appInfo.definitionFor(holder); |
| if (clazz == null) { |
| // Conservatively report an illegal access. |
| return false; |
| } |
| if (holder.isSamePackage(context)) { |
| // The class must be accessible (note that we have already established that the method is not |
| // private). |
| return !clazz.accessFlags.isPrivate(); |
| } |
| // If the method is in another package, then the method and its holder must be public. |
| return clazz.accessFlags.isPublic() && target.accessFlags.isPublic(); |
| } |
| } |
