src/main/java/com/android/tools/r8/kotlin/KotlinMetadataSynthesizer.java - r8 - Git at Google

 // Copyright (c) 2019, 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.kotlin;

 import static com.android.tools.r8.kotlin.KotlinMetadataJvmExtensionUtils.toJvmFieldSignature;
 import static com.android.tools.r8.kotlin.KotlinMetadataJvmExtensionUtils.toJvmMethodSignature;
 import static com.android.tools.r8.utils.DescriptorUtils.getDescriptorFromKmType;
 import static com.android.tools.r8.kotlin.Kotlin.NAME;
 import static com.android.tools.r8.utils.DescriptorUtils.descriptorToKotlinClassifier;
 import static kotlinx.metadata.FlagsKt.flagsOf;

 import com.android.tools.r8.graph.AppView;
 import com.android.tools.r8.graph.DebugLocalInfo;
 import com.android.tools.r8.graph.DexClass;
 import com.android.tools.r8.graph.DexEncodedField;
 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.DexType;
 import com.android.tools.r8.naming.NamingLens;
 import com.android.tools.r8.shaking.AppInfoWithLiveness;
 import java.util.List;
 import kotlinx.metadata.KmConstructor;
 import kotlinx.metadata.KmFunction;
 import kotlinx.metadata.KmProperty;
 import kotlinx.metadata.KmType;
 import kotlinx.metadata.KmValueParameter;
 import kotlinx.metadata.jvm.JvmExtensionsKt;

 class KotlinMetadataSynthesizer {

   static boolean isExtension(KmFunction kmFunction) {
     return kmFunction.getReceiverParameterType() != null;
   }

   static boolean isExtension(KmProperty kmProperty) {
     return kmProperty.getReceiverParameterType() != null;
   }

   static KmType toKmType(String descriptor) {
     KmType kmType = new KmType(flagsOf());
     kmType.visitClass(descriptorToKotlinClassifier(descriptor));
     return kmType;
   }

   static String toRenamedClassifier(
       DexType type, AppView<AppInfoWithLiveness> appView, NamingLens lens) {
     // E.g., V -> kotlin/Unit, J -> kotlin/Long, [J -> kotlin/LongArray
     if (appView.dexItemFactory().kotlin.knownTypeConversion.containsKey(type)) {
       DexType convertedType = appView.dexItemFactory().kotlin.knownTypeConversion.get(type);
       assert convertedType != null;
       return descriptorToKotlinClassifier(convertedType.toDescriptorString());
     }
     // E.g., [Ljava/lang/String; -> kotlin/Array
     if (type.isArrayType()) {
       return NAME + "/Array";
     }
     // For library or classpath class, synthesize @Metadata always.
     // For a program class, make sure it is live.
     if (!appView.appInfo().isNonProgramTypeOrLiveProgramType(type)) {
       return null;
     }
     DexType renamedType = lens.lookupType(type, appView.dexItemFactory());
     // For library or classpath class, we should not have renamed it.
     DexClass clazz = appView.definitionFor(type);
     assert clazz == null || clazz.isProgramClass() || renamedType == type
         : type.toSourceString() + " -> " + renamedType.toSourceString();
     return descriptorToKotlinClassifier(renamedType.toDescriptorString());
   }

   static KmType toRenamedKmType(
       DexType type, AppView<AppInfoWithLiveness> appView, NamingLens lens) {
     String classifier = toRenamedClassifier(type, appView, lens);
     if (classifier == null) {
       return null;
     }
     // TODO(b/70169921): Mysterious, why attempts to properly set flags bothers kotlinc?
     //   and/or why wiping out flags works for KmType but not KmFunction?!
     KmType kmType = new KmType(flagsOf());
     kmType.visitClass(classifier);
     // TODO(b/70169921): Need to set arguments as type parameter.
     //  E.g., for kotlin/Function1<P1, R>, P1 and R are recorded inside KmType.arguments, which
     //  enables kotlinc to resolve `this` type and return type of the lambda.
     return kmType;
   }

   static KmConstructor toRenamedKmConstructor(
       DexEncodedMethod method,
       AppView<AppInfoWithLiveness> appView,
       NamingLens lens) {
     // Make sure it is an instance initializer and live.
     if (!method.isInstanceInitializer()
         || !appView.appInfo().liveMethods.contains(method.method)) {
       return null;
     }
     KmConstructor kmConstructor = new KmConstructor(method.accessFlags.getAsKotlinFlags());
     JvmExtensionsKt.setSignature(kmConstructor, toJvmMethodSignature(method.method));
     List<KmValueParameter> parameters = kmConstructor.getValueParameters();
     if (!populateKmValueParameters(parameters, method, appView, lens)) {
       return null;
     }
     return kmConstructor;
   }

   static KmFunction toRenamedKmFunction(
       DexEncodedMethod method,
       AppView<AppInfoWithLiveness> appView,
       NamingLens lens) {
     // For library overrides, synthesize @Metadata always.
     // For regular methods, make sure it is live or pinned.
     if (!method.isLibraryMethodOverride().isTrue()
         && !appView.appInfo().isPinned(method.method)
         && !appView.appInfo().liveMethods.contains(method.method)) {
       return null;
     }
     DexMethod renamedMethod = lens.lookupMethod(method.method, appView.dexItemFactory());
     // For a library method override, we should not have renamed it.
     assert !method.isLibraryMethodOverride().isTrue() || renamedMethod.name == method.method.name
         : method.toSourceString() + " -> " + renamedMethod.toSourceString();
     // TODO(b/70169921): Should we keep kotlin-specific flags only while synthesizing the base
     //  value from general JVM flags?
     int flag =
         appView.appInfo().isPinned(method.method) && method.getKotlinMemberInfo() != null
             ? method.getKotlinMemberInfo().flag
             : method.accessFlags.getAsKotlinFlags();
     KmFunction kmFunction = new KmFunction(flag, renamedMethod.name.toString());
     JvmExtensionsKt.setSignature(kmFunction, toJvmMethodSignature(method.method));
     KmType kmReturnType = toRenamedKmType(method.method.proto.returnType, appView, lens);
     if (kmReturnType == null) {
       return null;
     }
     kmFunction.setReturnType(kmReturnType);
     if (method.isKotlinExtensionFunction()) {
       assert method.method.proto.parameters.values.length > 0
           : method.method.toSourceString();
       KmType kmReceiverType =
           toRenamedKmType(method.method.proto.parameters.values[0], appView, lens);
       if (kmReceiverType == null) {
         return null;
       }
       kmFunction.setReceiverParameterType(kmReceiverType);
     }
     List<KmValueParameter> parameters = kmFunction.getValueParameters();
     if (!populateKmValueParameters(parameters, method, appView, lens)) {
       return null;
     }
     return kmFunction;
   }

   private static boolean populateKmValueParameters(
       List<KmValueParameter> parameters,
       DexEncodedMethod method,
       AppView<AppInfoWithLiveness> appView,
       NamingLens lens) {
     boolean isExtension = method.isKotlinExtensionFunction();
     for (int i = isExtension ? 1 : 0; i < method.method.proto.parameters.values.length; i++) {
       DexType parameterType = method.method.proto.parameters.values[i];
       DebugLocalInfo debugLocalInfo = method.getParameterInfo().get(i);
       String parameterName = debugLocalInfo != null ? debugLocalInfo.name.toString() : ("p" + i);
       KotlinValueParameterInfo valueParameterInfo =
           method.getKotlinMemberInfo().getValueParameterInfo(isExtension ? i - 1 : i);
       KmValueParameter kmValueParameter =
           toRewrittenKmValueParameter(
               valueParameterInfo, parameterType, parameterName, appView, lens);
       if (kmValueParameter == null) {
         return false;
       }
       parameters.add(kmValueParameter);
     }
     return true;
   }

   private static KmValueParameter toRewrittenKmValueParameter(
       KotlinValueParameterInfo valueParameterInfo,
       DexType parameterType,
       String candidateParameterName,
       AppView<AppInfoWithLiveness> appView,
       NamingLens lens) {
     KmType kmParamType = toRenamedKmType(parameterType, appView, lens);
     if (kmParamType == null) {
       return null;
     }
     int flag = valueParameterInfo != null ? valueParameterInfo.flag : flagsOf();
     String name = valueParameterInfo != null ? valueParameterInfo.name : candidateParameterName;
     KmValueParameter kmValueParameter = new KmValueParameter(flag, name);
     kmValueParameter.setType(kmParamType);
     if (valueParameterInfo != null && valueParameterInfo.isVararg) {
       if (!parameterType.isArrayType()) {
         return null;
       }
       DexType elementType = parameterType.toBaseType(appView.dexItemFactory());
       KmType kmElementType = toRenamedKmType(elementType, appView, lens);
       if (kmElementType == null) {
         return null;
       }
       kmValueParameter.setVarargElementType(kmElementType);
     }
     return kmValueParameter;
   }

   /**
    * A group of a field, and methods that correspond to a Kotlin property.
    *
    * <p>
    * va(l|r) prop: T
    *
    * is converted to a backing field with signature `T prop` if necessary. If the property is a pure
    * computation, e.g., return `this` or access to the status of other properties, a field is not
    * needed for the property.
    * <p>
    * Depending on property visibility, getter is defined with signature `T getProp()` (or `isProp`
    * for boolean property).
    * <p>
    * If it's editable, i.e., declared as `var`, setter is defined with signature `void setProp(T)`.
    * <p>
    * Yet another addition, `void prop$annotations()`, seems(?) to be used to store associated
    * annotations.
    *
    * <p>
    * Currently, it's unclear how users can selectively keep each. Assuming every piece is kept by
    * more general rules, such as keeping non-private members, we expect to find those as a whole.
    * When rewriting a corresponding property, each information is used to update corresponding part,
    * e.g., field to update the return type of the property, getter to update jvmMethodSignature of
    * getter, and so on.
    */
   static class KmPropertyGroup {
     final int flag;
     final String name;
     final DexEncodedField field;
     final DexEncodedMethod getter;
     final DexEncodedMethod setter;
     final DexEncodedMethod annotations;
     final boolean isExtension;

     private KmPropertyGroup(
         int flag,
         String name,
         DexEncodedField field,
         DexEncodedMethod getter,
         DexEncodedMethod setter,
         DexEncodedMethod annotations,
         boolean isExtension) {
       this.flag = flag;
       this.name = name;
       this.field = field;
       this.getter = getter;
       this.setter = setter;
       this.annotations = annotations;
       this.isExtension = isExtension;
     }

     static Builder builder(int flag, String name) {
       return new Builder(flag, name);
     }

     static class Builder {
       private final int flag;
       private final String name;
       private DexEncodedField field;
       private DexEncodedMethod getter;
       private DexEncodedMethod setter;
       private DexEncodedMethod annotations;

       private boolean isExtensionGetter;
       private boolean isExtensionSetter;
       private boolean isExtensionAnnotations;

       private Builder(int flag, String name) {
         this.flag = flag;
         this.name = name;
       }

       Builder foundBackingField(DexEncodedField field) {
         this.field = field;
         return this;
       }

       Builder foundGetter(DexEncodedMethod getter) {
         this.getter = getter;
         return this;
       }

       Builder foundSetter(DexEncodedMethod setter) {
         this.setter = setter;
         return this;
       }

       Builder foundAnnotations(DexEncodedMethod annotations) {
         this.annotations = annotations;
         return this;
       }

       Builder isExtensionGetter() {
         this.isExtensionGetter = true;
         return this;
       }

       Builder isExtensionSetter() {
         this.isExtensionSetter = true;
         return this;
       }

       Builder isExtensionAnnotations() {
         this.isExtensionAnnotations = true;
         return this;
       }

       KmPropertyGroup build() {
         boolean isExtension = isExtensionGetter || isExtensionSetter || isExtensionAnnotations;
         // If this is an extension property, everything should be an extension.
         if (isExtension) {
           if (getter != null && !isExtensionGetter) {
             return null;
           }
           if (setter != null && !isExtensionSetter) {
             return null;
           }
           if (annotations != null && !isExtensionAnnotations) {
             return null;
           }
         }
         return new KmPropertyGroup(flag, name, field, getter, setter, annotations, isExtension);
       }
     }

     KmProperty toRenamedKmProperty(AppView<AppInfoWithLiveness> appView, NamingLens lens) {
       KmProperty kmProperty = new KmProperty(flag, name, flagsOf(), flagsOf());
       KmType kmPropertyType = null;
       KmType kmReceiverType = null;

       // A flag to indicate we can rename the property name. This will become false if any member
       // is pinned. Then, we conservatively assume that users want the property to be pinned too.
       // That is, we won't rename the property even though some other members could be renamed.
       boolean canChangePropertyName = true;
       // A candidate property name. Not overwritten by the following members, hence the order of
       // preference: a backing field, getter, and setter.
       String renamedPropertyName = name;
       if (field != null) {
         if (appView.appInfo().isPinned(field.field)) {
           canChangePropertyName = false;
         }
         DexField renamedField = lens.lookupField(field.field, appView.dexItemFactory());
         if (canChangePropertyName && renamedField.name != field.field.name) {
           renamedPropertyName = renamedField.name.toString();
         }
         kmPropertyType = toRenamedKmType(field.field.type, appView, lens);
         if (kmPropertyType != null) {
           kmProperty.setReturnType(kmPropertyType);
         }
         JvmExtensionsKt.setFieldSignature(kmProperty, toJvmFieldSignature(renamedField));
       }

       GetterSetterCriteria criteria = checkGetterCriteria();
       if (criteria == GetterSetterCriteria.VIOLATE) {
         return null;
       }

       if (criteria == GetterSetterCriteria.MET) {
         assert getter != null
             : "checkGetterCriteria: " + this.toString();
         if (isExtension) {
           assert getter.method.proto.parameters.size() == 1
               : "checkGetterCriteria: " + this.toString();
           kmReceiverType = toRenamedKmType(getter.method.proto.parameters.values[0], appView, lens);
           if (kmReceiverType != null) {
             kmProperty.setReceiverParameterType(kmReceiverType);
           }
         }
         if (kmPropertyType == null) {
           // The property type is not set yet.
           kmPropertyType = toRenamedKmType(getter.method.proto.returnType, appView, lens);
           if (kmPropertyType != null) {
             kmProperty.setReturnType(kmPropertyType);
           }
         } else {
           // If property type is set already (via backing field), make sure it's consistent.
           KmType kmPropertyTypeFromGetter =
               toRenamedKmType(getter.method.proto.returnType, appView, lens);
           if (!getDescriptorFromKmType(kmPropertyType)
               .equals(getDescriptorFromKmType(kmPropertyTypeFromGetter))) {
             return null;
           }
         }
         if (appView.appInfo().isPinned(getter.method)) {
           canChangePropertyName = false;
         }
         DexMethod renamedGetter = lens.lookupMethod(getter.method, appView.dexItemFactory());
         if (canChangePropertyName
             && renamedGetter.name != getter.method.name
             && renamedPropertyName.equals(name)) {
           renamedPropertyName = renamedGetter.name.toString();
         }
         kmProperty.setGetterFlags(getter.accessFlags.getAsKotlinFlags());
         JvmExtensionsKt.setGetterSignature(kmProperty, toJvmMethodSignature(renamedGetter));
       }

       criteria = checkSetterCriteria();
       if (criteria == GetterSetterCriteria.VIOLATE) {
         return null;
       }

       if (criteria == GetterSetterCriteria.MET) {
         assert setter != null && setter.method.proto.parameters.size() >= 1
             : "checkSetterCriteria: " + this.toString();
         if (isExtension) {
           assert setter.method.proto.parameters.size() == 2
               : "checkSetterCriteria: " + this.toString();
           if (kmReceiverType == null) {
             kmReceiverType =
                 toRenamedKmType(setter.method.proto.parameters.values[0], appView, lens);
             if (kmReceiverType != null) {
               kmProperty.setReceiverParameterType(kmReceiverType);
             }
           } else {
             // If the receiver type for the extension property is set already (via getter),
             // make sure it's consistent.
             KmType kmReceiverTypeFromSetter =
                 toRenamedKmType(setter.method.proto.parameters.values[0], appView, lens);
             if (!getDescriptorFromKmType(kmReceiverType)
                 .equals(getDescriptorFromKmType(kmReceiverTypeFromSetter))) {
               return null;
             }
           }
         }
         int valueIndex = isExtension ? 1 : 0;
         DexType valueType = setter.method.proto.parameters.values[valueIndex];
         if (kmPropertyType == null) {
           // The property type is not set yet.
           kmPropertyType = toRenamedKmType(valueType, appView, lens);
           if (kmPropertyType != null) {
             kmProperty.setReturnType(kmPropertyType);
           }
         } else {
           // If property type is set already (via either backing field or getter),
           // make sure it's consistent.
           KmType kmPropertyTypeFromSetter = toRenamedKmType(valueType, appView, lens);
           if (!getDescriptorFromKmType(kmPropertyType)
               .equals(getDescriptorFromKmType(kmPropertyTypeFromSetter))) {
             return null;
           }
         }
         KotlinValueParameterInfo valueParameterInfo =
             setter.getKotlinMemberInfo().getValueParameterInfo(valueIndex);
         KmValueParameter kmValueParameter =
             toRewrittenKmValueParameter(valueParameterInfo, valueType, "value", appView, lens);
         if (kmValueParameter != null) {
           kmProperty.setSetterParameter(kmValueParameter);
         }
         if (appView.appInfo().isPinned(setter.method)) {
           canChangePropertyName = false;
         }
         DexMethod renamedSetter = lens.lookupMethod(setter.method, appView.dexItemFactory());
         if (canChangePropertyName
             && renamedSetter.name != setter.method.name
             && renamedPropertyName.equals(name)) {
           renamedPropertyName = renamedSetter.name.toString();
         }
         kmProperty.setSetterFlags(setter.accessFlags.getAsKotlinFlags());
         JvmExtensionsKt.setSetterSignature(kmProperty, toJvmMethodSignature(renamedSetter));
       }

       // If the property type remains null at the end, bail out to synthesize this property.
       if (kmPropertyType == null) {
         return null;
       }
       // For extension property, if the receiver type remains null at the end, bail out too.
       if (isExtension && kmReceiverType == null) {
         return null;
       }
       // Rename the property name if and only if none of participating members is pinned, and
       // any of them is indeed renamed (to a new name).
       if (canChangePropertyName && !renamedPropertyName.equals(name)) {
         kmProperty.setName(renamedPropertyName);
       }
       return kmProperty;
     }

     enum GetterSetterCriteria {
       NOT_AVAILABLE,
       MET,
       VIOLATE
     }

     // Getter should look like:
     //   1) T getProp(); for regular property, or
     //   2) T getProp(R); for extension property, where
     // T is a property type, and R is a receiver type.
     private GetterSetterCriteria checkGetterCriteria() {
       if (getter == null) {
         return GetterSetterCriteria.NOT_AVAILABLE;
       }
       // Property type will be checked against a backing field type if any.
       // And if they're different, we won't synthesize KmProperty for that.
       // Checking parameter size.
       if (isExtension) {
         return getter.method.proto.parameters.size() == 1
             ? GetterSetterCriteria.MET : GetterSetterCriteria.VIOLATE;
       } else {
         return getter.method.proto.parameters.size() == 0
             ? GetterSetterCriteria.MET : GetterSetterCriteria.VIOLATE;
       }
     }

     // Setter should look like:
     //   1) void setProp(T); for regular property, or
     //   2) void setProp(R, T); for extension property, where
     // T is a property type, and R is a receiver type.
     private GetterSetterCriteria checkSetterCriteria() {
       if (setter == null) {
         return GetterSetterCriteria.NOT_AVAILABLE;
       }
       if (!setter.method.proto.returnType.isVoidType()) {
         return GetterSetterCriteria.VIOLATE;
       }
       // Property type will be checked against a backing field type if any.
       // And if they're different, we won't synthesize KmProperty for that.
       // Plus, receiver type will be checked, too, against a getter.
       if (isExtension) {
         return setter.method.proto.parameters.size() == 2
             ? GetterSetterCriteria.MET : GetterSetterCriteria.VIOLATE;
       } else {
         return setter.method.proto.parameters.size() == 1
             ? GetterSetterCriteria.MET : GetterSetterCriteria.VIOLATE;
       }
     }

     @Override
     public String toString() {
       StringBuilder builder = new StringBuilder();
       builder.append("KmPropertyGroup {").append(System.lineSeparator());
       builder.append("  name: ").append(name).append(System.lineSeparator());
       builder.append("  isExtension: ").append(isExtension).append(System.lineSeparator());
       if (field != null) {
         builder.append("  field: ")
             .append(field.toSourceString())
             .append(System.lineSeparator());
       }
       if (getter != null) {
         builder
             .append("  getter: ")
             .append(getter.toSourceString())
             .append(System.lineSeparator());
       }
       if (setter != null) {
         builder
             .append("  setter: ")
             .append(setter.toSourceString())
             .append(System.lineSeparator());
       }
       if (annotations != null) {
         builder
             .append("  annotations: ")
             .append(annotations.toSourceString())
             .append(System.lineSeparator());
       }
       builder.append("}");
       return builder.toString();
     }
   }
 }
	// Copyright (c) 2019, 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.kotlin;

	import static com.android.tools.r8.kotlin.KotlinMetadataJvmExtensionUtils.toJvmFieldSignature;
	import static com.android.tools.r8.kotlin.KotlinMetadataJvmExtensionUtils.toJvmMethodSignature;
	import static com.android.tools.r8.utils.DescriptorUtils.getDescriptorFromKmType;
	import static com.android.tools.r8.kotlin.Kotlin.NAME;
	import static com.android.tools.r8.utils.DescriptorUtils.descriptorToKotlinClassifier;
	import static kotlinx.metadata.FlagsKt.flagsOf;

	import com.android.tools.r8.graph.AppView;
	import com.android.tools.r8.graph.DebugLocalInfo;
	import com.android.tools.r8.graph.DexClass;
	import com.android.tools.r8.graph.DexEncodedField;
	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.DexType;
	import com.android.tools.r8.naming.NamingLens;
	import com.android.tools.r8.shaking.AppInfoWithLiveness;
	import java.util.List;
	import kotlinx.metadata.KmConstructor;
	import kotlinx.metadata.KmFunction;
	import kotlinx.metadata.KmProperty;
	import kotlinx.metadata.KmType;
	import kotlinx.metadata.KmValueParameter;
	import kotlinx.metadata.jvm.JvmExtensionsKt;

	class KotlinMetadataSynthesizer {

	static boolean isExtension(KmFunction kmFunction) {
	return kmFunction.getReceiverParameterType() != null;
	}

	static boolean isExtension(KmProperty kmProperty) {
	return kmProperty.getReceiverParameterType() != null;
	}

	static KmType toKmType(String descriptor) {
	KmType kmType = new KmType(flagsOf());
	kmType.visitClass(descriptorToKotlinClassifier(descriptor));
	return kmType;
	}

	static String toRenamedClassifier(
	DexType type, AppView<AppInfoWithLiveness> appView, NamingLens lens) {
	// E.g., V -> kotlin/Unit, J -> kotlin/Long, [J -> kotlin/LongArray
	if (appView.dexItemFactory().kotlin.knownTypeConversion.containsKey(type)) {
	DexType convertedType = appView.dexItemFactory().kotlin.knownTypeConversion.get(type);
	assert convertedType != null;
	return descriptorToKotlinClassifier(convertedType.toDescriptorString());
	}
	// E.g., [Ljava/lang/String; -> kotlin/Array
	if (type.isArrayType()) {
	return NAME + "/Array";
	}
	// For library or classpath class, synthesize @Metadata always.
	// For a program class, make sure it is live.
	if (!appView.appInfo().isNonProgramTypeOrLiveProgramType(type)) {
	return null;
	}
	DexType renamedType = lens.lookupType(type, appView.dexItemFactory());
	// For library or classpath class, we should not have renamed it.
	DexClass clazz = appView.definitionFor(type);
	assert clazz == null \|\| clazz.isProgramClass() \|\| renamedType == type
	: type.toSourceString() + " -> " + renamedType.toSourceString();
	return descriptorToKotlinClassifier(renamedType.toDescriptorString());
	}

	static KmType toRenamedKmType(
	DexType type, AppView<AppInfoWithLiveness> appView, NamingLens lens) {
	String classifier = toRenamedClassifier(type, appView, lens);
	if (classifier == null) {
	return null;
	}
	// TODO(b/70169921): Mysterious, why attempts to properly set flags bothers kotlinc?
	// and/or why wiping out flags works for KmType but not KmFunction?!
	KmType kmType = new KmType(flagsOf());
	kmType.visitClass(classifier);
	// TODO(b/70169921): Need to set arguments as type parameter.
	// E.g., for kotlin/Function1<P1, R>, P1 and R are recorded inside KmType.arguments, which
	// enables kotlinc to resolve `this` type and return type of the lambda.
	return kmType;
	}

	static KmConstructor toRenamedKmConstructor(
	DexEncodedMethod method,
	AppView<AppInfoWithLiveness> appView,
	NamingLens lens) {
	// Make sure it is an instance initializer and live.
	if (!method.isInstanceInitializer()
	\|\| !appView.appInfo().liveMethods.contains(method.method)) {
	return null;
	}
	KmConstructor kmConstructor = new KmConstructor(method.accessFlags.getAsKotlinFlags());
	JvmExtensionsKt.setSignature(kmConstructor, toJvmMethodSignature(method.method));
	List<KmValueParameter> parameters = kmConstructor.getValueParameters();
	if (!populateKmValueParameters(parameters, method, appView, lens)) {
	return null;
	}
	return kmConstructor;
	}

	static KmFunction toRenamedKmFunction(
	DexEncodedMethod method,
	AppView<AppInfoWithLiveness> appView,
	NamingLens lens) {
	// For library overrides, synthesize @Metadata always.
	// For regular methods, make sure it is live or pinned.
	if (!method.isLibraryMethodOverride().isTrue()
	&& !appView.appInfo().isPinned(method.method)
	&& !appView.appInfo().liveMethods.contains(method.method)) {
	return null;
	}
	DexMethod renamedMethod = lens.lookupMethod(method.method, appView.dexItemFactory());
	// For a library method override, we should not have renamed it.
	assert !method.isLibraryMethodOverride().isTrue() \|\| renamedMethod.name == method.method.name
	: method.toSourceString() + " -> " + renamedMethod.toSourceString();
	// TODO(b/70169921): Should we keep kotlin-specific flags only while synthesizing the base
	// value from general JVM flags?
	int flag =
	appView.appInfo().isPinned(method.method) && method.getKotlinMemberInfo() != null
	? method.getKotlinMemberInfo().flag
	: method.accessFlags.getAsKotlinFlags();
	KmFunction kmFunction = new KmFunction(flag, renamedMethod.name.toString());
	JvmExtensionsKt.setSignature(kmFunction, toJvmMethodSignature(method.method));
	KmType kmReturnType = toRenamedKmType(method.method.proto.returnType, appView, lens);
	if (kmReturnType == null) {
	return null;
	}
	kmFunction.setReturnType(kmReturnType);
	if (method.isKotlinExtensionFunction()) {
	assert method.method.proto.parameters.values.length > 0
	: method.method.toSourceString();
	KmType kmReceiverType =
	toRenamedKmType(method.method.proto.parameters.values[0], appView, lens);
	if (kmReceiverType == null) {
	return null;
	}
	kmFunction.setReceiverParameterType(kmReceiverType);
	}
	List<KmValueParameter> parameters = kmFunction.getValueParameters();
	if (!populateKmValueParameters(parameters, method, appView, lens)) {
	return null;
	}
	return kmFunction;
	}

	private static boolean populateKmValueParameters(
	List<KmValueParameter> parameters,
	DexEncodedMethod method,
	AppView<AppInfoWithLiveness> appView,
	NamingLens lens) {
	boolean isExtension = method.isKotlinExtensionFunction();
	for (int i = isExtension ? 1 : 0; i < method.method.proto.parameters.values.length; i++) {
	DexType parameterType = method.method.proto.parameters.values[i];
	DebugLocalInfo debugLocalInfo = method.getParameterInfo().get(i);
	String parameterName = debugLocalInfo != null ? debugLocalInfo.name.toString() : ("p" + i);
	KotlinValueParameterInfo valueParameterInfo =
	method.getKotlinMemberInfo().getValueParameterInfo(isExtension ? i - 1 : i);
	KmValueParameter kmValueParameter =
	toRewrittenKmValueParameter(
	valueParameterInfo, parameterType, parameterName, appView, lens);
	if (kmValueParameter == null) {
	return false;
	}
	parameters.add(kmValueParameter);
	}
	return true;
	}

	private static KmValueParameter toRewrittenKmValueParameter(
	KotlinValueParameterInfo valueParameterInfo,
	DexType parameterType,
	String candidateParameterName,
	AppView<AppInfoWithLiveness> appView,
	NamingLens lens) {
	KmType kmParamType = toRenamedKmType(parameterType, appView, lens);
	if (kmParamType == null) {
	return null;
	}
	int flag = valueParameterInfo != null ? valueParameterInfo.flag : flagsOf();
	String name = valueParameterInfo != null ? valueParameterInfo.name : candidateParameterName;
	KmValueParameter kmValueParameter = new KmValueParameter(flag, name);
	kmValueParameter.setType(kmParamType);
	if (valueParameterInfo != null && valueParameterInfo.isVararg) {
	if (!parameterType.isArrayType()) {
	return null;
	}
	DexType elementType = parameterType.toBaseType(appView.dexItemFactory());
	KmType kmElementType = toRenamedKmType(elementType, appView, lens);
	if (kmElementType == null) {
	return null;
	}
	kmValueParameter.setVarargElementType(kmElementType);
	}
	return kmValueParameter;
	}

	/**
	* A group of a field, and methods that correspond to a Kotlin property.
	*
	* <p>
	* va(l\|r) prop: T
	*
	* is converted to a backing field with signature `T prop` if necessary. If the property is a pure
	* computation, e.g., return `this` or access to the status of other properties, a field is not
	* needed for the property.
	* <p>
	* Depending on property visibility, getter is defined with signature `T getProp()` (or `isProp`
	* for boolean property).
	* <p>
	* If it's editable, i.e., declared as `var`, setter is defined with signature `void setProp(T)`.
	* <p>
	* Yet another addition, `void prop$annotations()`, seems(?) to be used to store associated
	* annotations.
	*
	* <p>
	* Currently, it's unclear how users can selectively keep each. Assuming every piece is kept by
	* more general rules, such as keeping non-private members, we expect to find those as a whole.
	* When rewriting a corresponding property, each information is used to update corresponding part,
	* e.g., field to update the return type of the property, getter to update jvmMethodSignature of
	* getter, and so on.
	*/
	static class KmPropertyGroup {
	final int flag;
	final String name;
	final DexEncodedField field;
	final DexEncodedMethod getter;
	final DexEncodedMethod setter;
	final DexEncodedMethod annotations;
	final boolean isExtension;

	private KmPropertyGroup(
	int flag,
	String name,
	DexEncodedField field,
	DexEncodedMethod getter,
	DexEncodedMethod setter,
	DexEncodedMethod annotations,
	boolean isExtension) {
	this.flag = flag;
	this.name = name;
	this.field = field;
	this.getter = getter;
	this.setter = setter;
	this.annotations = annotations;
	this.isExtension = isExtension;
	}

	static Builder builder(int flag, String name) {
	return new Builder(flag, name);
	}

	static class Builder {
	private final int flag;
	private final String name;
	private DexEncodedField field;
	private DexEncodedMethod getter;
	private DexEncodedMethod setter;
	private DexEncodedMethod annotations;

	private boolean isExtensionGetter;
	private boolean isExtensionSetter;
	private boolean isExtensionAnnotations;

	private Builder(int flag, String name) {
	this.flag = flag;
	this.name = name;
	}

	Builder foundBackingField(DexEncodedField field) {
	this.field = field;
	return this;
	}

	Builder foundGetter(DexEncodedMethod getter) {
	this.getter = getter;
	return this;
	}

	Builder foundSetter(DexEncodedMethod setter) {
	this.setter = setter;
	return this;
	}

	Builder foundAnnotations(DexEncodedMethod annotations) {
	this.annotations = annotations;
	return this;
	}

	Builder isExtensionGetter() {
	this.isExtensionGetter = true;
	return this;
	}

	Builder isExtensionSetter() {
	this.isExtensionSetter = true;
	return this;
	}

	Builder isExtensionAnnotations() {
	this.isExtensionAnnotations = true;
	return this;
	}

	KmPropertyGroup build() {
	boolean isExtension = isExtensionGetter \|\| isExtensionSetter \|\| isExtensionAnnotations;
	// If this is an extension property, everything should be an extension.
	if (isExtension) {
	if (getter != null && !isExtensionGetter) {
	return null;
	}
	if (setter != null && !isExtensionSetter) {
	return null;
	}
	if (annotations != null && !isExtensionAnnotations) {
	return null;
	}
	}
	return new KmPropertyGroup(flag, name, field, getter, setter, annotations, isExtension);
	}
	}

	KmProperty toRenamedKmProperty(AppView<AppInfoWithLiveness> appView, NamingLens lens) {
	KmProperty kmProperty = new KmProperty(flag, name, flagsOf(), flagsOf());
	KmType kmPropertyType = null;
	KmType kmReceiverType = null;

	// A flag to indicate we can rename the property name. This will become false if any member
	// is pinned. Then, we conservatively assume that users want the property to be pinned too.
	// That is, we won't rename the property even though some other members could be renamed.
	boolean canChangePropertyName = true;
	// A candidate property name. Not overwritten by the following members, hence the order of
	// preference: a backing field, getter, and setter.
	String renamedPropertyName = name;
	if (field != null) {
	if (appView.appInfo().isPinned(field.field)) {
	canChangePropertyName = false;
	}
	DexField renamedField = lens.lookupField(field.field, appView.dexItemFactory());
	if (canChangePropertyName && renamedField.name != field.field.name) {
	renamedPropertyName = renamedField.name.toString();
	}
	kmPropertyType = toRenamedKmType(field.field.type, appView, lens);
	if (kmPropertyType != null) {
	kmProperty.setReturnType(kmPropertyType);
	}
	JvmExtensionsKt.setFieldSignature(kmProperty, toJvmFieldSignature(renamedField));
	}

	GetterSetterCriteria criteria = checkGetterCriteria();
	if (criteria == GetterSetterCriteria.VIOLATE) {
	return null;
	}

	if (criteria == GetterSetterCriteria.MET) {
	assert getter != null
	: "checkGetterCriteria: " + this.toString();
	if (isExtension) {
	assert getter.method.proto.parameters.size() == 1
	: "checkGetterCriteria: " + this.toString();
	kmReceiverType = toRenamedKmType(getter.method.proto.parameters.values[0], appView, lens);
	if (kmReceiverType != null) {
	kmProperty.setReceiverParameterType(kmReceiverType);
	}
	}
	if (kmPropertyType == null) {
	// The property type is not set yet.
	kmPropertyType = toRenamedKmType(getter.method.proto.returnType, appView, lens);
	if (kmPropertyType != null) {
	kmProperty.setReturnType(kmPropertyType);
	}
	} else {
	// If property type is set already (via backing field), make sure it's consistent.
	KmType kmPropertyTypeFromGetter =
	toRenamedKmType(getter.method.proto.returnType, appView, lens);
	if (!getDescriptorFromKmType(kmPropertyType)
	.equals(getDescriptorFromKmType(kmPropertyTypeFromGetter))) {
	return null;
	}
	}
	if (appView.appInfo().isPinned(getter.method)) {
	canChangePropertyName = false;
	}
	DexMethod renamedGetter = lens.lookupMethod(getter.method, appView.dexItemFactory());
	if (canChangePropertyName
	&& renamedGetter.name != getter.method.name
	&& renamedPropertyName.equals(name)) {
	renamedPropertyName = renamedGetter.name.toString();
	}
	kmProperty.setGetterFlags(getter.accessFlags.getAsKotlinFlags());
	JvmExtensionsKt.setGetterSignature(kmProperty, toJvmMethodSignature(renamedGetter));
	}

	criteria = checkSetterCriteria();
	if (criteria == GetterSetterCriteria.VIOLATE) {
	return null;
	}

	if (criteria == GetterSetterCriteria.MET) {
	assert setter != null && setter.method.proto.parameters.size() >= 1
	: "checkSetterCriteria: " + this.toString();
	if (isExtension) {
	assert setter.method.proto.parameters.size() == 2
	: "checkSetterCriteria: " + this.toString();
	if (kmReceiverType == null) {
	kmReceiverType =
	toRenamedKmType(setter.method.proto.parameters.values[0], appView, lens);
	if (kmReceiverType != null) {
	kmProperty.setReceiverParameterType(kmReceiverType);
	}
	} else {
	// If the receiver type for the extension property is set already (via getter),
	// make sure it's consistent.
	KmType kmReceiverTypeFromSetter =
	toRenamedKmType(setter.method.proto.parameters.values[0], appView, lens);
	if (!getDescriptorFromKmType(kmReceiverType)
	.equals(getDescriptorFromKmType(kmReceiverTypeFromSetter))) {
	return null;
	}
	}
	}
	int valueIndex = isExtension ? 1 : 0;
	DexType valueType = setter.method.proto.parameters.values[valueIndex];
	if (kmPropertyType == null) {
	// The property type is not set yet.
	kmPropertyType = toRenamedKmType(valueType, appView, lens);
	if (kmPropertyType != null) {
	kmProperty.setReturnType(kmPropertyType);
	}
	} else {
	// If property type is set already (via either backing field or getter),
	// make sure it's consistent.
	KmType kmPropertyTypeFromSetter = toRenamedKmType(valueType, appView, lens);
	if (!getDescriptorFromKmType(kmPropertyType)
	.equals(getDescriptorFromKmType(kmPropertyTypeFromSetter))) {
	return null;
	}
	}
	KotlinValueParameterInfo valueParameterInfo =
	setter.getKotlinMemberInfo().getValueParameterInfo(valueIndex);
	KmValueParameter kmValueParameter =
	toRewrittenKmValueParameter(valueParameterInfo, valueType, "value", appView, lens);
	if (kmValueParameter != null) {
	kmProperty.setSetterParameter(kmValueParameter);
	}
	if (appView.appInfo().isPinned(setter.method)) {
	canChangePropertyName = false;
	}
	DexMethod renamedSetter = lens.lookupMethod(setter.method, appView.dexItemFactory());
	if (canChangePropertyName
	&& renamedSetter.name != setter.method.name
	&& renamedPropertyName.equals(name)) {
	renamedPropertyName = renamedSetter.name.toString();
	}
	kmProperty.setSetterFlags(setter.accessFlags.getAsKotlinFlags());
	JvmExtensionsKt.setSetterSignature(kmProperty, toJvmMethodSignature(renamedSetter));
	}

	// If the property type remains null at the end, bail out to synthesize this property.
	if (kmPropertyType == null) {
	return null;
	}
	// For extension property, if the receiver type remains null at the end, bail out too.
	if (isExtension && kmReceiverType == null) {
	return null;
	}
	// Rename the property name if and only if none of participating members is pinned, and
	// any of them is indeed renamed (to a new name).
	if (canChangePropertyName && !renamedPropertyName.equals(name)) {
	kmProperty.setName(renamedPropertyName);
	}
	return kmProperty;
	}

	enum GetterSetterCriteria {
	NOT_AVAILABLE,
	MET,
	VIOLATE
	}

	// Getter should look like:
	// 1) T getProp(); for regular property, or
	// 2) T getProp(R); for extension property, where
	// T is a property type, and R is a receiver type.
	private GetterSetterCriteria checkGetterCriteria() {
	if (getter == null) {
	return GetterSetterCriteria.NOT_AVAILABLE;
	}
	// Property type will be checked against a backing field type if any.
	// And if they're different, we won't synthesize KmProperty for that.
	// Checking parameter size.
	if (isExtension) {
	return getter.method.proto.parameters.size() == 1
	? GetterSetterCriteria.MET : GetterSetterCriteria.VIOLATE;
	} else {
	return getter.method.proto.parameters.size() == 0
	? GetterSetterCriteria.MET : GetterSetterCriteria.VIOLATE;
	}
	}

	// Setter should look like:
	// 1) void setProp(T); for regular property, or
	// 2) void setProp(R, T); for extension property, where
	// T is a property type, and R is a receiver type.
	private GetterSetterCriteria checkSetterCriteria() {
	if (setter == null) {
	return GetterSetterCriteria.NOT_AVAILABLE;
	}
	if (!setter.method.proto.returnType.isVoidType()) {
	return GetterSetterCriteria.VIOLATE;
	}
	// Property type will be checked against a backing field type if any.
	// And if they're different, we won't synthesize KmProperty for that.
	// Plus, receiver type will be checked, too, against a getter.
	if (isExtension) {
	return setter.method.proto.parameters.size() == 2
	? GetterSetterCriteria.MET : GetterSetterCriteria.VIOLATE;
	} else {
	return setter.method.proto.parameters.size() == 1
	? GetterSetterCriteria.MET : GetterSetterCriteria.VIOLATE;
	}
	}

	@Override
	public String toString() {
	StringBuilder builder = new StringBuilder();
	builder.append("KmPropertyGroup {").append(System.lineSeparator());
	builder.append(" name: ").append(name).append(System.lineSeparator());
	builder.append(" isExtension: ").append(isExtension).append(System.lineSeparator());
	if (field != null) {
	builder.append(" field: ")
	.append(field.toSourceString())
	.append(System.lineSeparator());
	}
	if (getter != null) {
	builder
	.append(" getter: ")
	.append(getter.toSourceString())
	.append(System.lineSeparator());
	}
	if (setter != null) {
	builder
	.append(" setter: ")
	.append(setter.toSourceString())
	.append(System.lineSeparator());
	}
	if (annotations != null) {
	builder
	.append(" annotations: ")
	.append(annotations.toSourceString())
	.append(System.lineSeparator());
	}
	builder.append("}");
	return builder.toString();
	}
	}
	}