Support ClassFile loading from jar files.

	Change on 2017/07/24 by tball <tball@google.com>

-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=162999485

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

@@ -109,7 +109,7 @@ private ClassFileConverter(JavacEnvironment parserEnv, TranslationEnvironment tr
     this.parserEnv = parserEnv;
     this.translationEnv = translationEnv;
     this.file = file;
-    this.classFile = ClassFile.create(file.getAbsolutePath(), translationEnv.typeUtil());
+    this.classFile = ClassFile.create(file, translationEnv.typeUtil());
     this.typeName = classFile.getFullName();
   }
 

translator/src/main/java/com/google/devtools/j2objc/util/ClassFile.java

@@ -14,13 +14,17 @@
 
 package com.google.devtools.j2objc.util;
 
+import com.google.devtools.j2objc.file.InputFile;
 import com.strobel.assembler.InputTypeLoader;
 import com.strobel.assembler.metadata.FieldDefinition;
+import com.strobel.assembler.metadata.ITypeLoader;
+import com.strobel.assembler.metadata.JarTypeLoader;
 import com.strobel.assembler.metadata.MetadataSystem;
 import com.strobel.assembler.metadata.MethodDefinition;
 import com.strobel.assembler.metadata.TypeDefinition;
 import com.strobel.assembler.metadata.TypeReference;
 import java.io.IOException;
+import java.util.jar.JarFile;
 import javax.lang.model.element.ExecutableElement;
 import javax.lang.model.element.VariableElement;
 import javax.lang.model.type.ExecutableType;
@@ -32,8 +36,21 @@ public class ClassFile {
   private final TypeDefinition typeDef;
   private final TypeUtil typeUtil;
 
-  public static ClassFile create(String path, TypeUtil typeUtil) throws IOException {
-    final MetadataSystem metadataSystem = new MetadataSystem(new InputTypeLoader());
+  public static ClassFile create(InputFile file, TypeUtil typeUtil) throws IOException {
+    ITypeLoader loader;
+    String path = file.getAbsolutePath();
+    if (path.endsWith(".jar")) {
+      loader = new JarTypeLoader(new JarFile(path));
+      path = file.getUnitName();
+      if (!path.endsWith(".class")) {
+        return null;
+      }
+      // Remove .class suffix, as JarTypeLoader adds it.
+      path = path.substring(0, path.length() - 6);
+    } else {
+      loader = new InputTypeLoader();
+    }
+    MetadataSystem metadataSystem = new MetadataSystem(loader);
     TypeReference typeRef = metadataSystem.lookupType(path);
     TypeDefinition typeDef = metadataSystem.resolve(typeRef);
     return new ClassFile(typeDef, typeUtil);

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

@@ -77,6 +77,7 @@
 import com.google.devtools.j2objc.types.CompoundTypeTest;
 import com.google.devtools.j2objc.types.HeaderImportCollectorTest;
 import com.google.devtools.j2objc.types.ImplementationImportCollectorTest;
+import com.google.devtools.j2objc.util.ClassFileTest;
 import com.google.devtools.j2objc.util.CodeReferenceMapTest;
 import com.google.devtools.j2objc.util.ElementUtilTest;
 import com.google.devtools.j2objc.util.ErrorUtilTest;
@@ -105,6 +106,7 @@ public class SmallTests {
     AutoboxerTest.class,
     CastResolverTest.class,
     ClassFileConverterTest.class,
+    ClassFileTest.class,
     CodeReferenceMapTest.class,
     ComplexExpressionExtractorTest.class,
     CompoundTypeTest.class,

translator/src/test/java/com/google/devtools/j2objc/util/ClassFileTest.java

@@ -0,0 +1,37 @@
+/*
+ * 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.util;
+
+import com.google.devtools.j2objc.GenerationTest;
+import com.google.devtools.j2objc.file.InputFile;
+import com.google.devtools.j2objc.file.JarredInputFile;
+import java.io.IOException;
+
+/**
+ * Tests for {@link ClassFile}.
+ *
+ * Note: classfile conversion is experimental and not supported.
+ */
+public class ClassFileTest extends GenerationTest {
+
+  public void testJarFileLoading() throws IOException {
+    String jarFilePath = getResourceAsFile("packageInfoLookupTest.jar");
+    InputFile input = new JarredInputFile(jarFilePath,
+        "com/google/test/packageInfoLookupTest/package-info.class");
+    ClassFile cf = ClassFile.create(input, null);
+    assertNotNull(cf);
+    assertEquals("com.google.test.packageInfoLookupTest.package-info", cf.getFullName());
+  }
+}