Simple classes are parsed into correct ASTs.

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=160198078

translator/Makefile

@@ -132,6 +132,7 @@ JAVA_SOURCES = \
 	ast/QualifiedName.java \
 	ast/QualifiedType.java \
 	ast/ReturnStatement.java \
+	ast/SignatureASTPrinter.java \
 	ast/SimpleName.java \
 	ast/SimpleType.java \
 	ast/SingleMemberAnnotation.java \

translator/src/main/java/com/google/devtools/j2objc/ast/DebugASTPrinter.java

@@ -20,6 +20,7 @@
 import com.google.devtools.j2objc.util.TypeUtil;
 import com.google.devtools.j2objc.util.UnicodeUtils;
 import java.lang.reflect.Modifier;
+import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import javax.lang.model.element.ExecutableElement;
@@ -34,7 +35,7 @@
  * @author Tom Ball
  */
 public class DebugASTPrinter extends TreeVisitor {
-  private SourceBuilder sb = new SourceBuilder(false);
+  protected SourceBuilder sb = new SourceBuilder(false);
   private boolean inIfStatement = false;
 
   public static String toString(TreeNode node) {
@@ -629,6 +630,14 @@ public boolean visit(MemberValuePair node) {
     return false;
   }
 
+  protected void printMethodBody(MethodDeclaration node) {
+    if (node.getBody() == null) {
+      sb.println(';');
+    } else {
+      node.getBody().accept(this);
+    }
+  }
+
   @Override
   public boolean visit(MethodDeclaration node) {
     sb.printIndent();
@@ -660,11 +669,7 @@ public boolean visit(MethodDeclaration node) {
       }
       sb.print(' ');
     }
-    if (node.getBody() == null) {
-      sb.println(';');
-    } else {
-      node.getBody().accept(this);
-    }
+    printMethodBody(node);
     return false;
   }
 
@@ -1031,6 +1036,8 @@ public boolean visit(TryStatement node) {
     return false;
   }
 
+  protected void sort(List<BodyDeclaration> lst) {}
+
   @Override
   public boolean visit(TypeDeclaration node) {
     if (node.getJavadoc() != null) {
@@ -1062,8 +1069,10 @@ public boolean visit(TypeDeclaration node) {
     }
     sb.println('{');
     sb.indent();
-    for (Iterator<BodyDeclaration> it = node.getBodyDeclarations().iterator(); it.hasNext(); ) {
-      it.next().accept(this);
+    List<BodyDeclaration> bodyDeclarations = new ArrayList<>(node.getBodyDeclarations());
+    sort(bodyDeclarations);
+    for (BodyDeclaration bodyDecl : bodyDeclarations) {
+      bodyDecl.accept(this);
     }
     printStaticBlock(node);
     sb.unindent();
@@ -1165,7 +1174,7 @@ public boolean visit(WhileStatement node) {
     return false;
   }
 
-  private void printAnnotations(List<Annotation> annotations) {
+  protected void printAnnotations(List<Annotation> annotations) {
     Iterator<Annotation> iterator = annotations.iterator();
     while (iterator.hasNext()) {
       iterator.next().accept(this);
@@ -1179,7 +1188,7 @@ public static void printModifiers(int modifiers, StringBuilder builder) {
     builder.append(temp.sb.toString());
   }
 
-  private void printModifiers(int modifiers) {
+  protected void printModifiers(int modifiers) {
     if (Modifier.isPublic(modifiers)) {
       sb.print("public ");
     }
@@ -1218,7 +1227,7 @@ private void printModifiers(int modifiers) {
     }
   }
 
-  private void printTypeParameters(List<? extends TypeParameterElement> typeParams) {
+  protected void printTypeParameters(List<? extends TypeParameterElement> typeParams) {
     if (!typeParams.isEmpty()) {
       sb.print('<');
       for (int i = 0; i < typeParams.size(); ) {
@@ -1231,7 +1240,7 @@ private void printTypeParameters(List<? extends TypeParameterElement> typeParams
     }
   }
 
-  private void printStaticBlock(AbstractTypeDeclaration node) {
+  protected void printStaticBlock(AbstractTypeDeclaration node) {
     if (!node.getClassInitStatements().isEmpty()) {
       sb.printIndent();
       sb.println("static {");

translator/src/main/java/com/google/devtools/j2objc/ast/SignatureASTPrinter.java

@@ -0,0 +1,43 @@
+/*
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.google.devtools.j2objc.ast;
+
+import java.util.Comparator;
+import java.util.List;
+
+/**
+ * An AST printer which is identical to DebugASTPrinter except MethodDeclaration bodies are not
+ * printed.
+ *
+ * @author Manvith Narahari
+ */
+public class SignatureASTPrinter extends DebugASTPrinter {
+
+  public static String toString(TreeNode node) {
+    SignatureASTPrinter printer = new SignatureASTPrinter();
+    node.accept(printer);
+    return printer.sb.toString();
+  }
+
+  @Override
+  protected void sort(List<BodyDeclaration> lst) {
+    lst.sort(Comparator.comparing(BodyDeclaration::toString));
+  }
+
+  @Override
+  protected void printMethodBody(MethodDeclaration node) {
+    sb.println(';');
+  }
+}

translator/src/main/java/com/google/devtools/j2objc/javac/ClassFileConverter.java

@@ -18,6 +18,8 @@
 import com.google.devtools.j2objc.ast.AbstractTypeDeclaration;
 import com.google.devtools.j2objc.ast.BodyDeclaration;
 import com.google.devtools.j2objc.ast.CompilationUnit;
+import com.google.devtools.j2objc.ast.Expression;
+import com.google.devtools.j2objc.ast.FieldDeclaration;
 import com.google.devtools.j2objc.ast.MethodDeclaration;
 import com.google.devtools.j2objc.ast.Name;
 import com.google.devtools.j2objc.ast.PackageDeclaration;
@@ -26,6 +28,7 @@
 import com.google.devtools.j2objc.ast.SingleVariableDeclaration;
 import com.google.devtools.j2objc.ast.SourcePosition;
 import com.google.devtools.j2objc.ast.TreeNode;
+import com.google.devtools.j2objc.ast.TreeUtil;
 import com.google.devtools.j2objc.ast.Type;
 import com.google.devtools.j2objc.ast.TypeDeclaration;
 import com.google.devtools.j2objc.file.InputFile;
@@ -134,8 +137,9 @@ private TreeNode convert(Element element) {
 //        break;
 //      case EXCEPTION_PARAMETER:
 //        break;
-//      case FIELD:
-//        break;
+      case FIELD:
+        node = convertFieldDeclaration((VariableElement) element);
+        break;
 //      case INSTANCE_INIT:
 //        break;
 //      case LOCAL_VARIABLE:
@@ -222,4 +226,16 @@ private TreeNode convertParameter(VariableElement element) {
         /* TODO(user): annotations; finish when supported
          * .setAnnotations(convertAnnotations(node.getModifiers())); */
   }
+
+  /* TODO(user): fields are linked to the static initializer and constructors;
+   * consider storing static final compile-time constants;
+   * static final primitive types or Strings */
+  private TreeNode convertFieldDeclaration(VariableElement element) {
+    Object constantValue = element.getConstantValue();
+    Expression initializer = constantValue != null
+        ? TreeUtil.newLiteral(constantValue, translationEnv.typeUtil()) : null;
+    FieldDeclaration fieldDecl = new FieldDeclaration(element, initializer);
+    convertBodyDeclaration(fieldDecl);
+    return fieldDecl;
+  }
 }

translator/src/test/java/com/google/devtools/j2objc/GenerationTest.java

@@ -22,6 +22,7 @@
 import com.google.common.io.Resources;
 import com.google.devtools.j2objc.ast.CompilationUnit;
 import com.google.devtools.j2objc.ast.MethodDeclaration;
+import com.google.devtools.j2objc.ast.SignatureASTPrinter;
 import com.google.devtools.j2objc.ast.Statement;
 import com.google.devtools.j2objc.ast.TreeNode;
 import com.google.devtools.j2objc.ast.TreeVisitor;
@@ -381,7 +382,19 @@ protected void assertOccurrences(String translation, String expected, int times)
    */
   protected void assertEqualASTs(TreeNode first, TreeNode second) {
     if (!first.toString().equals(second.toString())) {
-      fail("unmatched:\"" + first + "\" vs:\n" + second);
+      fail("unmatched:\n" + first + "vs:\n" + second);
+    }
+  }
+
+  /**
+   * Verify that two AST nodes are equal excepting MethodDeclaration bodies, by comparing their
+   * signatures.
+   */
+  protected void assertEqualASTSignatures(TreeNode first, TreeNode second) {
+    String firstStr = SignatureASTPrinter.toString(first);
+    String secondStr = SignatureASTPrinter.toString(second);
+    if (!firstStr.equals(secondStr)) {
+      fail("unmatched:\n" + firstStr + "vs:\n" + secondStr);
     }
   }
 
@@ -395,7 +408,7 @@ protected void assertEqualASTs(TreeNode first, TreeNode second) {
   protected void assertEqualSrcClassfile(String type, String source) throws IOException {
     CompilationUnit srcUnit = compileType(type, source);
     CompilationUnit classfileUnit = compileAsClassFile(type, source);
-    assertEqualASTs(srcUnit, classfileUnit);
+    assertEqualASTSignatures(srcUnit, classfileUnit);
   }
 
   /**