AAPT2: Fix inclusion of comments in R.java javadoc

Comments weren't being copied when merged from the various
resource tables.

Also refactored the JavaClassGenerator to omit a class
if no entries exist for it.

Change-Id: I6eaa89b7b3715bc05403635a2baf0d1db3efd142

tools/aapt2/java/AnnotationProcessor_test.cpp

@@ -0,0 +1,80 @@
+/*
+ * Copyright (C) 2015 The Android Open Source Project
+ *
+ * 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.
+ */
+
+#include "ResourceParser.h"
+#include "ResourceTable.h"
+#include "ResourceValues.h"
+#include "XmlPullParser.h"
+
+#include "java/AnnotationProcessor.h"
+
+#include "test/Builders.h"
+#include "test/Context.h"
+
+#include <gtest/gtest.h>
+
+namespace aapt {
+
+struct AnnotationProcessorTest : public ::testing::Test {
+    std::unique_ptr<IAaptContext> mContext;
+    ResourceTable mTable;
+
+    void SetUp() override {
+        mContext = test::ContextBuilder().build();
+    }
+
+    ::testing::AssertionResult parse(const StringPiece& str) {
+        ResourceParserOptions options;
+        ResourceParser parser(mContext->getDiagnostics(), &mTable, Source{}, ConfigDescription{},
+                              options);
+        std::stringstream in;
+        in << "<?xml version=\"1.0\" encoding=\"utf-8\"?>\n" << str;
+        XmlPullParser xmlParser(in);
+        if (parser.parse(&xmlParser)) {
+            return ::testing::AssertionSuccess();
+        }
+        return ::testing::AssertionFailure();
+    }
+};
+
+TEST_F(AnnotationProcessorTest, EmitsDeprecated) {
+    ASSERT_TRUE(parse(R"EOF(
+    <resources>
+      <declare-styleable name="foo">      
+        <!-- Some comment, and it should contain
+             a marker word, something that marks
+             this resource as nor needed.
+             {@deprecated That's the marker! } -->
+        <attr name="autoText" format="boolean" />
+      </declare-styleable>
+    </resources>)EOF"));
+
+    Attribute* attr = test::getValue<Attribute>(&mTable, u"@attr/autoText");
+    ASSERT_NE(nullptr, attr);
+
+    AnnotationProcessor processor;
+    processor.appendComment(attr->getComment());
+
+    std::stringstream result;
+    processor.writeToStream(&result, "");
+    std::string annotations = result.str();
+
+    EXPECT_NE(std::string::npos, annotations.find("@Deprecated"));
+}
+
+} // namespace aapt
+
+