Parse layout/menu/drawable, etc XML files for R.id

To be used by a later CL where we use this more
complete picture of all the resource items to
generate our own R.java/class without invoking
AAPT (and split out AAPT to a separate action
that is off the java builder critical path).

Technically aapt creates R.id.foo for attr
<enum name="foo" ... /> and flag as well, but
I haven't seen code that actually relies on that.

Currently off-by-default (only exercised by tests).

--
MOS_MIGRATED_REVID=126407838

4 files changed, 143 insertions, 6 deletions

diff --git a/src/tools/android/java/com/google/devtools/build/android/AndroidDataMerger.java b/src/tools/android/java/com/google/devtools/build/android/AndroidDataMerger.java
index 32c9a23155..3f74e81d9a 100644
--- a/src/tools/android/java/com/google/devtools/build/android/AndroidDataMerger.java
+++ b/src/tools/android/java/com/google/devtools/build/android/AndroidDataMerger.java
@@ -48,7 +48,7 @@ public class AndroidDataMerger {
 
   private static final Logger logger = Logger.getLogger(AndroidDataMerger.class.getCanonicalName());
 
-  private final class ParseDependencyDataTask implements Callable<Boolean> {
+  private static final class ParseDependencyDataTask implements Callable<Boolean> {
 
     private final AndroidDataSerializer serializer;
 
@@ -157,6 +157,7 @@ public class AndroidDataMerger {
 
   private final SourceChecker deDuplicator;
   private final ListeningExecutorService executorService;
+  private boolean parseIds;
 
   /** Creates a merger with no path deduplication and a default {@link ExecutorService}. */
   public static AndroidDataMerger createWithDefaults() {
@@ -186,6 +187,10 @@ public class AndroidDataMerger {
     this.executorService = executorService;
   }
 
+  void enableIdParsing() {
+    this.parseIds = true;
+  }
+
   /**
    * Merges a list of {@link DependencyAndroidData} with a {@link UnvalidatedAndroidData}.
    *
@@ -299,7 +304,8 @@ public class AndroidDataMerger {
 
     try {
       // Extract the primary resources.
-      ParsedAndroidData parsedPrimary = ParsedAndroidData.from(primaryData);
+      ParsedAndroidData parsedPrimary = parseIds ? ParsedAndroidData.parseWithIds(primaryData)
+          : ParsedAndroidData.from(primaryData);
 
       // Create the builders for the final parsed data.
       final ParsedAndroidData.Builder primaryBuilder = ParsedAndroidData.Builder.newBuilder();
diff --git a/src/tools/android/java/com/google/devtools/build/android/DataValueFileWithIds.java b/src/tools/android/java/com/google/devtools/build/android/DataValueFileWithIds.java
new file mode 100644
index 0000000000..372e9dd989
--- /dev/null
+++ b/src/tools/android/java/com/google/devtools/build/android/DataValueFileWithIds.java
@@ -0,0 +1,85 @@
+// Copyright 2016 The Bazel Authors. All rights reserved.
+//
+// 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.build.android;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.devtools.build.android.ParsedAndroidData.KeyValueConsumer;
+import com.google.devtools.build.android.xml.IdXmlResourceValue;
+
+import com.android.SdkConstants;
+import com.android.resources.ResourceType;
+
+import java.io.BufferedInputStream;
+import java.io.IOException;
+import java.nio.charset.StandardCharsets;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.util.Iterator;
+
+import javax.xml.stream.XMLEventReader;
+import javax.xml.stream.XMLInputFactory;
+import javax.xml.stream.XMLStreamException;
+import javax.xml.stream.events.Attribute;
+import javax.xml.stream.events.StartElement;
+import javax.xml.stream.events.XMLEvent;
+
+/**
+ * Parses an XML file for "@+id/foo" and creates {@link IdXmlResourceValue} from parsed IDs.
+ * This can be a layout file, menu, drawable, etc.
+ */
+public class DataValueFileWithIds {
+
+  public static void parse(
+      XMLInputFactory xmlInputFactory,
+      Path source,
+      FullyQualifiedName fileKey,
+      FullyQualifiedName.Factory fqnFactory,
+      KeyValueConsumer<DataKey, DataResource> overwritingConsumer,
+      KeyValueConsumer<DataKey, DataResource> combiningConsumer)
+      throws IOException, XMLStreamException {
+    ImmutableSet.Builder<String> newIds = ImmutableSet.builder();
+    try (BufferedInputStream inStream = new BufferedInputStream(Files.newInputStream(source))) {
+      XMLEventReader eventReader =
+          xmlInputFactory.createXMLEventReader(inStream, StandardCharsets.UTF_8.toString());
+      // Go through every start tag and look at the values of all attributes (the attribute does
+      // not need to be android:id, e.g., android:layout_above="@+id/UpcomingView").
+      // If the any attribute's value begins with @+id/, then track it, since aapt seems to be
+      // forgiving and allow even non-android namespaced attributes to define a new ID.
+      while (eventReader.hasNext()) {
+        XMLEvent event = eventReader.nextEvent();
+        if (event.isStartElement()) {
+          StartElement start = event.asStartElement();
+          Iterator<Attribute> attributes = XmlResourceValues.iterateAttributesFrom(start);
+          while (attributes.hasNext()) {
+            Attribute attribute = attributes.next();
+            String value = attribute.getValue();
+            if (value.startsWith(SdkConstants.NEW_ID_PREFIX)) {
+              String idName = value.substring(SdkConstants.NEW_ID_PREFIX.length());
+              newIds.add(idName);
+            }
+          }
+        }
+      }
+      eventReader.close();
+    }
+    ImmutableSet<String> idResources = newIds.build();
+    overwritingConsumer.consume(fileKey, DataValueFile.of(source));
+    for (String id : idResources) {
+      combiningConsumer.consume(
+          fqnFactory.create(ResourceType.ID, id),
+          DataResourceXml.of(source, IdXmlResourceValue.of()));
+    }
+  }
+
+}
diff --git a/src/tools/android/java/com/google/devtools/build/android/ParsedAndroidData.java b/src/tools/android/java/com/google/devtools/build/android/ParsedAndroidData.java
index 15c551f6a5..abe1dfd395 100644
--- a/src/tools/android/java/com/google/devtools/build/android/ParsedAndroidData.java
+++ b/src/tools/android/java/com/google/devtools/build/android/ParsedAndroidData.java
@@ -20,7 +20,9 @@ import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Iterables;
 import com.google.devtools.build.android.xml.StyleableXmlResourceValue;
 
+import com.android.SdkConstants;
 import com.android.ide.common.res2.MergingException;
+import com.android.resources.FolderTypeRelationship;
 import com.android.resources.ResourceFolderType;
 
 import java.io.IOException;
@@ -31,6 +33,7 @@ import java.nio.file.Path;
 import java.nio.file.SimpleFileVisitor;
 import java.nio.file.attribute.BasicFileAttributes;
 import java.util.ArrayList;
+import java.util.EnumSet;
 import java.util.LinkedHashMap;
 import java.util.LinkedHashSet;
 import java.util.List;
@@ -63,6 +66,7 @@ public class ParsedAndroidData {
     private final Map<DataKey, DataAsset> assets;
     private final Set<MergeConflict> conflicts;
     private final List<Exception> errors = new ArrayList<>();
+    private boolean parseIds;
 
     public Builder(
         Map<DataKey, DataResource> overwritingResources,
@@ -83,6 +87,11 @@ public class ParsedAndroidData {
       return new Builder(overwritingResources, combiningResources, assets, conflicts);
     }
 
+    Builder enableIdParsing() {
+      this.parseIds = true;
+      return this;
+    }
+
     private void checkForErrors() throws MergingException {
       if (!errors.isEmpty()) {
         MergingException mergingException = new MergingException("Parse Error(s)");
@@ -121,7 +130,8 @@ public class ParsedAndroidData {
       return new ResourceFileVisitor(
           new OverwritableConsumer<>(overwritingResources, conflicts),
           new CombiningConsumer(combiningResources),
-          errors);
+          errors,
+          parseIds);
     }
 
     AssetFileVisitor assetVisitorFor(Path path) {
@@ -248,14 +258,28 @@ public class ParsedAndroidData {
     private ResourceFolderType folderType;
     private FullyQualifiedName.Factory fqnFactory;
     private final XMLInputFactory xmlInputFactory = XMLInputFactory.newFactory();
+    private final boolean parseIds;
+
+    /**
+     * Resource folders with XML files that may contain "@+id".
+     * See android_ide_common's {@link FolderTypeRelationship}.
+     */
+    private static final EnumSet<ResourceFolderType> ID_PROVIDING_RESOURCE_TYPES = EnumSet.of(
+        ResourceFolderType.DRAWABLE,
+        ResourceFolderType.LAYOUT,
+        ResourceFolderType.MENU,
+        ResourceFolderType.TRANSITION,
+        ResourceFolderType.XML);
 
     ResourceFileVisitor(
         KeyValueConsumer<DataKey, DataResource> overwritingConsumer,
         KeyValueConsumer<DataKey, DataResource> combiningResources,
-        List<Exception> errors) {
+        List<Exception> errors,
+        boolean parseIds) {
       this.overwritingConsumer = overwritingConsumer;
       this.combiningResources = combiningResources;
       this.errors = errors;
+      this.parseIds = parseIds;
     }
 
     private static String deriveRawFullyQualifiedName(Path path) {
@@ -303,7 +327,14 @@ public class ParsedAndroidData {
           } else if (folderType != null) {
             String rawFqn = deriveRawFullyQualifiedName(path);
             FullyQualifiedName key = fqnFactory.parse(rawFqn);
-            overwritingConsumer.consume(key, DataValueFile.of(path));
+            if (parseIds
+                && ID_PROVIDING_RESOURCE_TYPES.contains(folderType)
+                && path.getFileName().toString().endsWith(SdkConstants.DOT_XML)) {
+              DataValueFileWithIds.parse(
+                  xmlInputFactory, path, key, fqnFactory, overwritingConsumer, combiningResources);
+            } else {
+              overwritingConsumer.consume(key, DataValueFile.of(path));
+            }
           }
         }
       } catch (IllegalArgumentException | XMLStreamException e) {
@@ -361,6 +392,21 @@ public class ParsedAndroidData {
     return pathWalker.createParsedAndroidData();
   }
 
+  /**
+   * Parses resource symbols including "@+id/resourceName" (optional for now).
+   *
+   * @see ParsedAndroidData#from(UnvalidatedAndroidData)
+   */
+  @VisibleForTesting
+  static ParsedAndroidData parseWithIds(UnvalidatedAndroidData primary)
+      throws IOException, MergingException {
+    Builder builder = Builder.newBuilder().enableIdParsing();
+    final ParsedAndroidDataBuildingPathWalker pathWalker =
+        ParsedAndroidDataBuildingPathWalker.create(builder);
+    primary.walk(pathWalker);
+    return pathWalker.createParsedAndroidData();
+  }
+
   private final ImmutableSet<MergeConflict> conflicts;
   private final ImmutableMap<DataKey, DataResource> overwritingResources;
   private final ImmutableMap<DataKey, DataResource> combiningResources;
diff --git a/src/tools/android/java/com/google/devtools/build/android/XmlResourceValues.java b/src/tools/android/java/com/google/devtools/build/android/XmlResourceValues.java
index 4321b9ad96..5876966239 100644
--- a/src/tools/android/java/com/google/devtools/build/android/XmlResourceValues.java
+++ b/src/tools/android/java/com/google/devtools/build/android/XmlResourceValues.java
@@ -273,7 +273,7 @@ public class XmlResourceValues {
     "cast",
     "unchecked"
   }) // The interface returns Iterator, force casting based on documentation.
-  private static Iterator<Attribute> iterateAttributesFrom(StartElement start) {
+  static Iterator<Attribute> iterateAttributesFrom(StartElement start) {
     return (Iterator<Attribute>) start.getAttributes();
   }