Introduce a new NestedGraphLens with newMethodSignatures
Bug: 182099754
Change-Id: Ic6990f9361b8218889f3a440fd7805921455dd23
diff --git a/src/main/java/com/android/tools/r8/graph/NestedGraphLens.java b/src/main/java/com/android/tools/r8/graph/NestedGraphLens.java
new file mode 100644
index 0000000..e367004
--- /dev/null
+++ b/src/main/java/com/android/tools/r8/graph/NestedGraphLens.java
@@ -0,0 +1,308 @@
+// 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.graph;
+
+import com.android.tools.r8.graph.GraphLens.NonIdentityGraphLens;
+import com.android.tools.r8.ir.code.Invoke.Type;
+import com.android.tools.r8.utils.IterableUtils;
+import com.android.tools.r8.utils.collections.BidirectionalManyToManyRepresentativeMap;
+import com.android.tools.r8.utils.collections.BidirectionalManyToOneRepresentativeMap;
+import java.util.Map;
+import java.util.stream.Collectors;
+
+/**
+ * GraphLens implementation with a parent lens using a simple mapping for type, method and field
+ * mapping.
+ *
+ * <p>Subclasses can override the lookup methods.
+ *
+ * <p>For method mapping where invocation type can change just override {@link
+ * #mapInvocationType(DexMethod, DexMethod, Type)} if the default name mapping applies, and only
+ * invocation type might need to change.
+ */
+public class NestedGraphLens extends NonIdentityGraphLens {
+
+ protected final DexItemFactory dexItemFactory;
+
+ protected final BidirectionalManyToOneRepresentativeMap<DexField, DexField> fieldMap;
+ protected final Map<DexMethod, DexMethod> methodMap;
+ protected final Map<DexType, DexType> typeMap;
+
+ // Map that stores the new signature of methods that have been affected by class merging, unused
+ // argument removal, repackaging, synthetic finalization, etc. This is needed to generate a
+ // correct mapping file in the end.
+ //
+ // The difference to `methodMap` is that `methodMap` specifies how invoke-method instructions
+ // should be rewritten, whereas this map specifies where methods have been moved. In most cases
+ // the two maps are the same, but in a few cases we move a method m1 to m2 and rewrite invokes to
+ // m1 to m3.
+ //
+ // The static type of this map is a many-to-many map to facilitate both one-to-many mappings and
+ // many-to-one mappings. Currently, the concrete map is always *either* a one-to-many or a
+ // many-to-one map, and not a many-to-many map.
+ //
+ // One-to-many mappings are generally found when methods are split into two. This could be due to
+ // the code object being moved elsewhere (e.g., interface desugaring).
+ //
+ // Many-to-one mappings are generally found when methods are shared, e.g., due to horizontal class
+ // merging of synthetic finalization.
+ protected BidirectionalManyToManyRepresentativeMap<DexMethod, DexMethod> newMethodSignatures;
+
+ // Overrides this if the sub type needs to be a nested lens while it doesn't have any mappings
+ // at all, e.g., publicizer lens that changes invocation type only.
+ protected boolean isLegitimateToHaveEmptyMappings() {
+ return false;
+ }
+
+ public NestedGraphLens(
+ Map<DexType, DexType> typeMap,
+ Map<DexMethod, DexMethod> methodMap,
+ BidirectionalManyToOneRepresentativeMap<DexField, DexField> fieldMap,
+ BidirectionalManyToManyRepresentativeMap<DexMethod, DexMethod> newMethodSignatures,
+ GraphLens previousLens,
+ DexItemFactory dexItemFactory) {
+ super(dexItemFactory, previousLens);
+ assert !typeMap.isEmpty()
+ || !methodMap.isEmpty()
+ || !fieldMap.isEmpty()
+ || isLegitimateToHaveEmptyMappings();
+ this.typeMap = typeMap.isEmpty() ? null : typeMap;
+ this.methodMap = methodMap;
+ this.fieldMap = fieldMap;
+ this.newMethodSignatures = newMethodSignatures;
+ this.dexItemFactory = dexItemFactory;
+ }
+
+ public static Builder builder() {
+ return new Builder();
+ }
+
+ protected DexType internalGetOriginalType(DexType previous) {
+ return previous;
+ }
+
+ protected Iterable<DexType> internalGetOriginalTypes(DexType previous) {
+ return IterableUtils.singleton(internalGetOriginalType(previous));
+ }
+
+ @Override
+ public DexType getOriginalType(DexType type) {
+ return getPrevious().getOriginalType(internalGetOriginalType(type));
+ }
+
+ @Override
+ public Iterable<DexType> getOriginalTypes(DexType type) {
+ return IterableUtils.flatMap(internalGetOriginalTypes(type), getPrevious()::getOriginalTypes);
+ }
+
+ @Override
+ public DexField getOriginalFieldSignature(DexField field) {
+ DexField originalField = fieldMap.getRepresentativeKeyOrDefault(field, field);
+ return getPrevious().getOriginalFieldSignature(originalField);
+ }
+
+ @Override
+ public DexMethod getOriginalMethodSignature(DexMethod method) {
+ DexMethod originalMethod = internalGetPreviousMethodSignature(method);
+ return getPrevious().getOriginalMethodSignature(originalMethod);
+ }
+
+ @Override
+ public DexField getRenamedFieldSignature(DexField originalField) {
+ DexField renamedField = getPrevious().getRenamedFieldSignature(originalField);
+ return internalGetNextFieldSignature(renamedField);
+ }
+
+ @Override
+ public DexMethod getRenamedMethodSignature(DexMethod originalMethod, GraphLens applied) {
+ if (this == applied) {
+ return originalMethod;
+ }
+ DexMethod renamedMethod = getPrevious().getRenamedMethodSignature(originalMethod, applied);
+ return internalGetNextMethodSignature(renamedMethod);
+ }
+
+ @Override
+ protected DexType internalDescribeLookupClassType(DexType previous) {
+ return typeMap != null ? typeMap.getOrDefault(previous, previous) : previous;
+ }
+
+ @Override
+ protected FieldLookupResult internalDescribeLookupField(FieldLookupResult previous) {
+ if (previous.hasReboundReference()) {
+ // Rewrite the rebound reference and then "fixup" the non-rebound reference.
+ DexField rewrittenReboundReference = previous.getRewrittenReboundReference(fieldMap);
+ DexField rewrittenNonReboundReference =
+ previous.getReference() == previous.getReboundReference()
+ ? rewrittenReboundReference
+ : rewrittenReboundReference.withHolder(
+ internalDescribeLookupClassType(previous.getReference().getHolderType()),
+ dexItemFactory);
+ return FieldLookupResult.builder(this)
+ .setReboundReference(rewrittenReboundReference)
+ .setReference(rewrittenNonReboundReference)
+ .setCastType(previous.getRewrittenCastType(this::internalDescribeLookupClassType))
+ .build();
+ } else {
+ // TODO(b/168282032): We should always have the rebound reference, so this should become
+ // unreachable.
+ DexField rewrittenReference = previous.getRewrittenReference(fieldMap);
+ return FieldLookupResult.builder(this)
+ .setReference(rewrittenReference)
+ .setCastType(previous.getRewrittenCastType(this::internalDescribeLookupClassType))
+ .build();
+ }
+ }
+
+ @Override
+ public MethodLookupResult internalDescribeLookupMethod(
+ MethodLookupResult previous, DexMethod context) {
+ if (previous.hasReboundReference()) {
+ // TODO(sgjesse): Should we always do interface to virtual mapping? Is it a performance win
+ // that only subclasses which are known to need it actually do it?
+ DexMethod rewrittenReboundReference = previous.getRewrittenReboundReference(methodMap);
+ DexMethod rewrittenReference =
+ previous.getReference() == previous.getReboundReference()
+ ? rewrittenReboundReference
+ : // This assumes that the holder will always be moved in lock-step with the method!
+ rewrittenReboundReference.withHolder(
+ internalDescribeLookupClassType(previous.getReference().getHolderType()),
+ dexItemFactory);
+ return MethodLookupResult.builder(this)
+ .setReference(rewrittenReference)
+ .setReboundReference(rewrittenReboundReference)
+ .setPrototypeChanges(
+ internalDescribePrototypeChanges(
+ previous.getPrototypeChanges(), rewrittenReboundReference))
+ .setType(
+ mapInvocationType(
+ rewrittenReboundReference, previous.getReference(), previous.getType()))
+ .build();
+ } else {
+ // TODO(b/168282032): We should always have the rebound reference, so this should become
+ // unreachable.
+ DexMethod newMethod = methodMap.get(previous.getReference());
+ if (newMethod == null) {
+ return previous;
+ }
+ // TODO(sgjesse): Should we always do interface to virtual mapping? Is it a performance win
+ // that only subclasses which are known to need it actually do it?
+ return MethodLookupResult.builder(this)
+ .setReference(newMethod)
+ .setPrototypeChanges(
+ internalDescribePrototypeChanges(previous.getPrototypeChanges(), newMethod))
+ .setType(mapInvocationType(newMethod, previous.getReference(), previous.getType()))
+ .build();
+ }
+ }
+
+ @Override
+ public RewrittenPrototypeDescription lookupPrototypeChangesForMethodDefinition(DexMethod method) {
+ DexMethod previous = internalGetPreviousMethodSignature(method);
+ RewrittenPrototypeDescription lookup =
+ getPrevious().lookupPrototypeChangesForMethodDefinition(previous);
+ return internalDescribePrototypeChanges(lookup, method);
+ }
+
+ protected RewrittenPrototypeDescription internalDescribePrototypeChanges(
+ RewrittenPrototypeDescription prototypeChanges, DexMethod method) {
+ return prototypeChanges;
+ }
+
+ protected DexField internalGetNextFieldSignature(DexField field) {
+ return fieldMap.getOrDefault(field, field);
+ }
+
+ @Override
+ protected DexMethod internalGetPreviousMethodSignature(DexMethod method) {
+ return newMethodSignatures.getRepresentativeKeyOrDefault(method, method);
+ }
+
+ protected DexMethod internalGetNextMethodSignature(DexMethod method) {
+ return newMethodSignatures.getRepresentativeValueOrDefault(method, method);
+ }
+
+ @Override
+ public DexMethod lookupGetFieldForMethod(DexField field, DexMethod context) {
+ return getPrevious().lookupGetFieldForMethod(field, context);
+ }
+
+ @Override
+ public DexMethod lookupPutFieldForMethod(DexField field, DexMethod context) {
+ return getPrevious().lookupPutFieldForMethod(field, context);
+ }
+
+ /**
+ * Default invocation type mapping.
+ *
+ * <p>This is an identity mapping. If a subclass need invocation type mapping either override this
+ * method or {@link #lookupMethod(DexMethod, DexMethod, Type)}
+ */
+ protected Type mapInvocationType(DexMethod newMethod, DexMethod originalMethod, Type type) {
+ return type;
+ }
+
+ /**
+ * Standard mapping between interface and virtual invoke type.
+ *
+ * <p>Handle methods moved from interface to class or class to interface.
+ */
+ public static Type mapVirtualInterfaceInvocationTypes(
+ DexDefinitionSupplier definitions, DexMethod newMethod, DexMethod originalMethod, Type type) {
+ if (type == Type.VIRTUAL || type == Type.INTERFACE) {
+ // Get the invoke type of the actual definition.
+ DexClass newTargetClass = definitions.definitionFor(newMethod.getHolderType());
+ if (newTargetClass == null) {
+ return type;
+ }
+ DexClass originalTargetClass = definitions.definitionFor(originalMethod.getHolderType());
+ if (originalTargetClass != null
+ && (originalTargetClass.isInterface() ^ (type == Type.INTERFACE))) {
+ // The invoke was wrong to start with, so we keep it wrong. This is to ensure we get
+ // the IncompatibleClassChangeError the original invoke would have triggered.
+ return newTargetClass.accessFlags.isInterface() ? Type.VIRTUAL : Type.INTERFACE;
+ }
+ return newTargetClass.accessFlags.isInterface() ? Type.INTERFACE : Type.VIRTUAL;
+ }
+ return type;
+ }
+
+ @Override
+ public boolean isContextFreeForMethods() {
+ return getPrevious().isContextFreeForMethods();
+ }
+
+ @Override
+ public boolean verifyIsContextFreeForMethod(DexMethod method) {
+ assert getPrevious().verifyIsContextFreeForMethod(method);
+ return true;
+ }
+
+ @Override
+ public String toString() {
+ StringBuilder builder = new StringBuilder();
+ if (typeMap != null) {
+ for (Map.Entry<DexType, DexType> entry : typeMap.entrySet()) {
+ builder.append(entry.getKey().toSourceString()).append(" -> ");
+ builder.append(entry.getValue().toSourceString()).append(System.lineSeparator());
+ }
+ }
+ for (Map.Entry<DexMethod, DexMethod> entry : methodMap.entrySet()) {
+ builder.append(entry.getKey().toSourceString()).append(" -> ");
+ builder.append(entry.getValue().toSourceString()).append(System.lineSeparator());
+ }
+ fieldMap.forEachManyToOneMapping(
+ (keys, value) -> {
+ builder.append(
+ keys.stream()
+ .map(DexField::toSourceString)
+ .collect(Collectors.joining("," + System.lineSeparator())));
+ builder.append(" -> ");
+ builder.append(value.toSourceString()).append(System.lineSeparator());
+ });
+ builder.append(getPrevious().toString());
+ return builder.toString();
+ }
+}
