AutoCodec features.

* Support for Optional, Iterable, Collection and proto types.
* Support for getters that omit 'get' prefix.
* Support for constructors that throw exceptions.

PiperOrigin-RevId: 180235121

2 files changed, 96 insertions, 22 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodecProcessor.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodecProcessor.java
index 95b9706187..6638116617 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodecProcessor.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/AutoCodecProcessor.java
@@ -126,6 +126,37 @@ public class AutoCodecProcessor extends AbstractProcessor {
     return true;
   }
 
+  /**
+   * Heuristic for synthesizing a method getter.
+   *
+   * <p>Tries prepending {@code get} first, for example, a parameter called {@code target} results
+   * in {@code getTarget()}.
+   *
+   * <p>Falls back to {@code target()} if {@code getTarget()} doesn't exist.
+   */
+  private class GetGetter implements UnaryOperator<String> {
+    private final TypeElement encodedType;
+
+    GetGetter(TypeElement encodedType) {
+      this.encodedType = encodedType;
+    }
+
+    @Override
+    public String apply(String name) {
+      String getMethodName = "get" + name.substring(0, 1).toUpperCase() + name.substring(1);
+      List<ExecutableElement> methods =
+          ElementFilter.methodsIn(env.getElementUtils().getAllMembers(encodedType));
+      if (methods.stream().anyMatch(p -> p.getSimpleName().contentEquals(getMethodName))) {
+        return getMethodName + "()";
+      }
+      if (methods.stream().anyMatch(p -> p.getSimpleName().contentEquals(name))) {
+        return name + "()";
+      }
+      throw new IllegalArgumentException(
+          encodedType.getQualifiedName() + " has no getter for " + name);
+    }
+  }
+
   private void buildClassWithConstructorStrategy(
       TypeSpec.Builder codecClassBuilder, TypeElement encodedType) {
     // In Java, every class has a constructor, so this always succeeds.
@@ -133,8 +164,7 @@ public class AutoCodecProcessor extends AbstractProcessor {
         ElementFilter.constructorsIn(encodedType.getEnclosedElements()).get(0);
     List<? extends VariableElement> constructorParameters = constructor.getParameters();
     codecClassBuilder.addMethod(
-        buildSerializeMethod(
-            encodedType, constructorParameters, AutoCodecProcessor::paramNameAsGetter));
+        buildSerializeMethod(encodedType, constructorParameters, new GetGetter(encodedType)));
     MethodSpec.Builder deserializeBuilder =
         AutoCodecUtil.initializeDeserializeMethodBuilder(encodedType);
     buildDeserializeBody(deserializeBuilder, constructorParameters);
@@ -158,15 +188,6 @@ public class AutoCodecProcessor extends AbstractProcessor {
     codecClassBuilder.addMethod(deserializeBuilder.build());
   }
 
-  /**
-   * Heuristic that converts a constructor parameter to a getter.
-   *
-   * <p>For example, a parameter called {@code target} results in {@code getTarget()}.
-   */
-  private static String paramNameAsGetter(String name) {
-    return "get" + name.substring(0, 1).toUpperCase() + name.substring(1) + "()";
-  }
-
   private boolean isPublicField(VariableElement element) {
     if (matchesType(element.asType(), Void.class)) {
       return false; // Void types can't be instantiated, so the processor ignores them completely.
diff --git a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/Marshallers.java b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/Marshallers.java
index 4a34cd6e81..e87395d520 100644
--- a/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/Marshallers.java
+++ b/src/main/java/com/google/devtools/build/lib/skyframe/serialization/autocodec/Marshallers.java
@@ -14,13 +14,16 @@
 
 package com.google.devtools.build.lib.skyframe.serialization.autocodec;
 
+import com.google.common.base.Optional;
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSortedMap;
 import com.google.common.collect.ImmutableSortedSet;
 import com.google.common.collect.Maps;
 import com.google.devtools.build.lib.skyframe.serialization.autocodec.Marshaller.Context;
 import com.google.devtools.build.lib.skyframe.serialization.strings.StringCodecs;
+import com.google.protobuf.GeneratedMessage;
 import com.google.protobuf.ProtocolMessageEnum;
+import java.util.Collection;
 import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
@@ -136,6 +139,29 @@ class Marshallers {
         }
       };
 
+  private final Marshaller optionalMarshaller =
+      new Marshaller() {
+        @Override
+        public boolean matches(DeclaredType type) {
+          return matchesErased(type, Optional.class);
+        }
+
+        @Override
+        public void addSerializationCode(Context context) {
+          DeclaredType optionalType = (DeclaredType) context.type.getTypeArguments().get(0);
+          writeSerializationCode(context.with(optionalType, context.name + ".orNull()"));
+        }
+
+        @Override
+        public void addDeserializationCode(Context context) {
+          DeclaredType optionalType = (DeclaredType) context.type.getTypeArguments().get(0);
+          String optionalName = context.makeName("optional");
+          writeDeserializationCode(context.with(optionalType, optionalName));
+          context.builder.addStatement(
+              "$L = $T.fromNullable($L)", context.name, Optional.class, optionalName);
+        }
+      };
+
   private final Marshaller mapEntryMarshaller =
       new Marshaller() {
         @Override
@@ -168,9 +194,11 @@ class Marshallers {
       new Marshaller() {
         @Override
         public boolean matches(DeclaredType type) {
-          // TODO(shahan): List is more general than ImmutableList. Consider whether these
-          // two should have distinct marshallers.
-          return matchesErased(type, List.class) || matchesErased(type, ImmutableList.class);
+          // TODO(shahan): refine this as needed by splitting this into separate marshallers.
+          return matchesErased(type, Iterable.class)
+              || matchesErased(type, Collection.class)
+              || matchesErased(type, List.class)
+              || matchesErased(type, ImmutableList.class);
         }
 
         @Override
@@ -311,30 +339,55 @@ class Marshallers {
         }
       };
 
+  private final Marshaller protoMarshaller =
+      new Marshaller() {
+        @Override
+        public boolean matches(DeclaredType type) {
+          return isSubtype(type, GeneratedMessage.class);
+        }
+
+        @Override
+        public void addSerializationCode(Context context) {
+          context.builder.addStatement("$L.writeTo(codedOut)", context.name);
+        }
+
+        @Override
+        public void addDeserializationCode(Context context) {
+          context.builder.addStatement(
+              "$L = $T.parseFrom(codedIn)", context.name, context.getTypeName());
+        }
+      };
+
   private final ImmutableList<Marshaller> marshallers =
       ImmutableList.of(
           enumMarshaller,
           stringMarshaller,
+          optionalMarshaller,
           mapEntryMarshaller,
           listMarshaller,
           immutableSortedSetMarshaller,
           mapMarshaller,
+          protoMarshaller,
           CODEC_MARSHALLER);
 
   /** True when {@code type} has the same type as {@code clazz}. */
   private boolean matchesType(TypeMirror type, Class<?> clazz) {
-    return env.getTypeUtils()
-        .isSameType(
-            type, env.getElementUtils().getTypeElement((clazz.getCanonicalName())).asType());
+    return env.getTypeUtils().isSameType(type, getType(clazz));
+  }
+
+  /** True when {@code type} is a subtype of {@code clazz}. */
+  private boolean isSubtype(TypeMirror type, Class<?> clazz) {
+    return env.getTypeUtils().isSubtype(type, getType(clazz));
   }
 
   /** True when erasure of {@code type} matches erasure of {@code clazz}. */
   private boolean matchesErased(TypeMirror type, Class<?> clazz) {
     return env.getTypeUtils()
-        .isSameType(
-            env.getTypeUtils().erasure(type),
-            env.getTypeUtils()
-                .erasure(
-                    env.getElementUtils().getTypeElement((clazz.getCanonicalName())).asType()));
+        .isSameType(env.getTypeUtils().erasure(type), env.getTypeUtils().erasure(getType(clazz)));
+  }
+
+  /** Returns the TypeMirror corresponding to {@code clazz}. */
+  private TypeMirror getType(Class<?> clazz) {
+    return env.getElementUtils().getTypeElement((clazz.getCanonicalName())).asType();
   }
 }