Expose Android resources in Skylark API.

Also expose functionality to calculate resource source directory from
Android resource artifact.

--
MOS_MIGRATED_REVID=115492705

6 files changed, 156 insertions, 61 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java b/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java
index d5e19f766d..9df8a6fa54 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/rules/BazelRuleClassProvider.java
@@ -17,6 +17,7 @@ package com.google.devtools.build.lib.bazel.rules;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.base.Functions;
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableMap;
 import com.google.devtools.build.lib.analysis.BaseRuleClasses;
 import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider;
 import com.google.devtools.build.lib.analysis.ConfiguredRuleClassProvider.PrerequisiteValidator;
@@ -76,6 +77,7 @@ import com.google.devtools.build.lib.rules.android.AndroidBinaryOnlyRule;
 import com.google.devtools.build.lib.rules.android.AndroidConfiguration;
 import com.google.devtools.build.lib.rules.android.AndroidLibraryBaseRule;
 import com.google.devtools.build.lib.rules.android.AndroidRuleClasses;
+import com.google.devtools.build.lib.rules.android.AndroidSkylarkCommon;
 import com.google.devtools.build.lib.rules.apple.AppleCommandLineOptions;
 import com.google.devtools.build.lib.rules.apple.AppleConfiguration;
 import com.google.devtools.build.lib.rules.apple.AppleToolchain;
@@ -124,6 +126,7 @@ import com.google.devtools.build.lib.rules.repository.BindRule;
 import com.google.devtools.build.lib.rules.repository.LocalRepositoryRule;
 import com.google.devtools.build.lib.rules.repository.NewLocalRepositoryRule;
 import com.google.devtools.build.lib.rules.repository.WorkspaceBaseRule;
+import com.google.devtools.build.lib.syntax.SkylarkType;
 import com.google.devtools.build.lib.util.ResourceFileLoader;
 
 import java.io.IOException;
@@ -222,6 +225,13 @@ public class BazelRuleClassProvider {
           AndroidConfiguration.Options.class
       );
 
+  /**
+   * Java objects accessible from Skylark rule implementations using this module.
+   */
+  public static final ImmutableMap<String, SkylarkType> skylarkBuiltinJavaObects =
+      ImmutableMap.of("android_common", SkylarkType.of(AndroidSkylarkCommon.class));
+
+
   public static void setup(ConfiguredRuleClassProvider.Builder builder) {
     builder
         .addBuildInfoFactory(new BazelJavaBuildInfoFactory())
@@ -231,7 +241,9 @@ public class BazelRuleClassProvider {
         .setPrelude("//tools/build_rules:prelude_bazel")
         .setRunfilesPrefix("")
         .setToolsRepository("@bazel_tools")
-        .setPrerequisiteValidator(new BazelPrerequisiteValidator());
+        .setPrerequisiteValidator(new BazelPrerequisiteValidator())
+        .setSkylarkAccessibleJavaClasses(ImmutableMap.<String, SkylarkType>of())
+        .setSkylarkAccessibleJavaClasses(skylarkBuiltinJavaObects);
 
     builder.addBuildOptions(BUILD_OPTIONS);
 
diff --git a/src/main/java/com/google/devtools/build/lib/ideinfo/AndroidStudioInfoAspect.java b/src/main/java/com/google/devtools/build/lib/ideinfo/AndroidStudioInfoAspect.java
index 1e1f2535e5..4749ab69bf 100644
--- a/src/main/java/com/google/devtools/build/lib/ideinfo/AndroidStudioInfoAspect.java
+++ b/src/main/java/com/google/devtools/build/lib/ideinfo/AndroidStudioInfoAspect.java
@@ -315,8 +315,7 @@ public class AndroidStudioInfoAspect implements ConfiguredNativeAspectFactory {
     if (ruleKind == Kind.ANDROID_LIBRARY
         || ruleKind == Kind.ANDROID_BINARY
         || ruleKind == Kind.ANDROID_TEST) {
-      outputBuilder.setAndroidRuleIdeInfo(
-          makeAndroidRuleIdeInfo(base, ideResolveArtifacts));
+      outputBuilder.setAndroidRuleIdeInfo(makeAndroidRuleIdeInfo(base, ideResolveArtifacts));
     }
 
     AndroidStudioInfoFilesProvider provider = providerBuilder.build();
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidCommon.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidCommon.java
index 306418e08a..061018ce90 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidCommon.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidCommon.java
@@ -292,6 +292,69 @@ public class AndroidCommon {
     }
   }
 
+  static PathFragment getSourceDirectoryRelativePathFromResource(Artifact resource) {
+    PathFragment resourceDir = LocalResourceContainer.Builder.findResourceDir(resource);
+    if (resourceDir == null) {
+      return null;
+    }
+    return trimTo(resource.getRootRelativePath(), resourceDir);
+  }
+
+  /**
+   * Finds the rightmost occurrence of the needle and returns subfragment of the haystack from
+   * left to the end of the occurrence inclusive of the needle.
+   *
+   * <pre>
+   * `Example:
+   *   Given the haystack:
+   *     res/research/handwriting/res/values/strings.xml
+   *   And the needle:
+   *     res
+   *   Returns:
+   *     res/research/handwriting/res
+   * </pre>
+   */
+  static PathFragment trimTo(PathFragment haystack, PathFragment needle) {
+    if (needle.equals(PathFragment.EMPTY_FRAGMENT)) {
+      return haystack;
+    }
+    // Compute the overlap offset for duplicated parts of the needle.
+    int[] overlap = new int[needle.segmentCount() + 1];
+    // Start overlap at -1, as it will cancel out the increment in the search.
+    // See http://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm for the
+    // details.
+    overlap[0] = -1;
+    for (int i = 0, j = -1; i < needle.segmentCount(); j++, i++, overlap[i] = j) {
+      while (j >= 0 && !needle.getSegment(i).equals(needle.getSegment(j))) {
+        // Walk the overlap until the bound is found.
+        j = overlap[j];
+      }
+    }
+    // TODO(corysmith): reverse the search algorithm.
+    // Keep the index of the found so that the rightmost index is taken.
+    int found = -1;
+    for (int i = 0, j = 0; i < haystack.segmentCount(); i++) {
+
+      while (j >= 0 && !haystack.getSegment(i).equals(needle.getSegment(j))) {
+        // Not matching, walk the needle index to attempt another match.
+        j = overlap[j];
+      }
+      j++;
+      // Needle index is exhausted, so the needle must match.
+      if (j == needle.segmentCount()) {
+        // Record the found index + 1 to be inclusive of the end index.
+        found = i + 1;
+        // Subtract one from the needle index to restart the search process
+        j = j - 1;
+      }
+    }
+    if (found != -1) {
+      // Return the subsection of the haystack.
+      return haystack.subFragment(0, found);
+    }
+    throw new IllegalArgumentException(String.format("%s was not found in %s", needle, haystack));
+  }
+
   Artifact compileDexWithJack(
       MultidexMode mode, Optional<Artifact> mainDexList, Collection<Artifact> proguardSpecs) {
     return jackCompilationHelper.compileAsDex(mode, mainDexList, proguardSpecs);
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidIdeInfoProvider.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidIdeInfoProvider.java
index 8a5184ad29..d39365a17a 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidIdeInfoProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidIdeInfoProvider.java
@@ -239,11 +239,10 @@ public final class AndroidIdeInfoProvider implements TransitiveInfoProvider {
     }
 
     public Builder addResourceSource(Artifact resource) {
-      PathFragment resourceDir = LocalResourceContainer.Builder.findResourceDir(resource);
       resourceDirs.add(
           SourceDirectory.fromRoot(
               resource.getRoot(),
-              trimTo(resource.getRootRelativePath(), resourceDir)));
+              AndroidCommon.getSourceDirectoryRelativePathFromResource(resource)));
       return this;
     }
 
@@ -264,8 +263,7 @@ public final class AndroidIdeInfoProvider implements TransitiveInfoProvider {
     public Builder addAssetSource(Artifact asset, PathFragment assetDir) {
       assetDirs.add(
           SourceDirectory.fromRoot(
-              asset.getRoot(),
-              trimTo(asset.getRootRelativePath(), assetDir)));
+              asset.getRoot(), AndroidCommon.trimTo(asset.getRootRelativePath(), assetDir)));
       return this;
     }
 
@@ -274,60 +272,6 @@ public final class AndroidIdeInfoProvider implements TransitiveInfoProvider {
       return this;
     }
 
-    /**
-     * Finds the rightmost occurrence of the needle and returns subfragment of the haystack from
-     * left to the end of the occurrence inclusive of the needle.
-     *
-     * <pre>
-     * `Example:
-     *   Given the haystack:
-     *     res/research/handwriting/res/values/strings.xml
-     *   And the needle:
-     *     res
-     *   Returns:
-     *     res/research/handwriting/res
-     * </pre>
-     */
-    private static PathFragment trimTo(PathFragment haystack, PathFragment needle) {
-      if (needle.equals(PathFragment.EMPTY_FRAGMENT)) {
-        return haystack;
-      }
-      // Compute the overlap offset for duplicated parts of the needle.
-      int[] overlap = new int[needle.segmentCount() + 1];
-      // Start overlap at -1, as it will cancel out the increment in the search.
-      // See http://en.wikipedia.org/wiki/Knuth%E2%80%93Morris%E2%80%93Pratt_algorithm for the
-      // details.
-      overlap[0] = -1;
-      for (int i = 0, j = -1; i < needle.segmentCount(); j++, i++, overlap[i] = j) {
-        while (j >= 0 && !needle.getSegment(i).equals(needle.getSegment(j))) {
-          // Walk the overlap until the bound is found.
-          j = overlap[j];
-        }
-      }
-      // TODO(corysmith): reverse the search algorithm.
-      // Keep the index of the found so that the rightmost index is taken.
-      int found = -1;
-      for (int i = 0, j = 0; i < haystack.segmentCount(); i++) {
-
-        while (j >= 0 && !haystack.getSegment(i).equals(needle.getSegment(j))) {
-          // Not matching, walk the needle index to attempt another match.
-          j = overlap[j];
-        }
-        j++;
-        // Needle index is exhausted, so the needle must match.
-        if (j == needle.segmentCount()) {
-          // Record the found index + 1 to be inclusive of the end index.
-          found = i + 1;
-          // Subtract one from the needle index to restart the search process
-          j = j - 1;
-        }
-      }
-      if (found != -1) {
-        // Return the subsection of the haystack.
-        return haystack.subFragment(0, found);
-      }
-      throw new IllegalArgumentException(String.format("%s was not found in %s", needle, haystack));
-    }
   }
 
   private final String javaPackage;
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkApiProvider.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkApiProvider.java
index 2580a05b85..707e8ed794 100644
--- a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkApiProvider.java
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkApiProvider.java
@@ -13,9 +13,16 @@
 // limitations under the License.
 package com.google.devtools.build.lib.rules.android;
 
+import com.google.common.base.Function;
 import com.google.common.collect.ImmutableCollection;
+import com.google.common.collect.Iterables;
 import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.collect.nestedset.NestedSet;
+import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
+import com.google.devtools.build.lib.collect.nestedset.Order;
 import com.google.devtools.build.lib.rules.SkylarkApiProvider;
+import com.google.devtools.build.lib.rules.android.AndroidResourcesProvider.ResourceContainer;
+import com.google.devtools.build.lib.rules.android.AndroidResourcesProvider.ResourceType;
 import com.google.devtools.build.lib.rules.java.JavaRuleOutputJarsProvider;
 import com.google.devtools.build.lib.rules.java.JavaRuleOutputJarsProvider.OutputJar;
 import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
@@ -100,6 +107,35 @@ public class AndroidSkylarkApiProvider extends SkylarkApiProvider {
     return idlInfo;
   }
 
+  @SkylarkCallable(
+    name = "resources",
+    structField = true,
+    doc = "Returns resources defined by this target."
+  )
+  public NestedSet<Artifact> getResources() {
+    return collectDirectArtifacts(ResourceType.RESOURCES);
+  }
+
+  private NestedSet<Artifact> collectDirectArtifacts(final ResourceType resources) {
+    AndroidResourcesProvider provider = getInfo().getProvider(AndroidResourcesProvider.class);
+    if (provider == null) {
+      return NestedSetBuilder.emptySet(Order.STABLE_ORDER);
+    }
+    // This will iterate over all (direct) resources. If this turns out to be a performance
+    // problem, {@link ResourceContainer#getArtifacts} can be changed to return NestedSets.
+    return NestedSetBuilder.wrap(
+        Order.STABLE_ORDER,
+        Iterables.concat(
+            Iterables.transform(
+                provider.getDirectAndroidResources(),
+                new Function<ResourceContainer, Iterable<Artifact>>() {
+                  @Override
+                  public Iterable<Artifact> apply(ResourceContainer resourceContainer) {
+                    return resourceContainer.getArtifacts(resources);
+                  }
+                })));
+  }
+
   /**
    * Helper class to provide information about IDLs related to this rule.
    */
diff --git a/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkCommon.java b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkCommon.java
new file mode 100644
index 0000000000..1724cfa4f8
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/android/AndroidSkylarkCommon.java
@@ -0,0 +1,41 @@
+// 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.lib.rules.android;
+
+import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkCallable;
+import com.google.devtools.build.lib.skylarkinterface.SkylarkModule;
+import com.google.devtools.build.lib.vfs.PathFragment;
+
+/**
+ * Common utilities for Skylark rules related to Android.
+ */
+@SkylarkModule(
+  name = "android_common",
+  doc = "Common utilities and fucntionality related to Android rules."
+)
+public class AndroidSkylarkCommon {
+  @SkylarkCallable(
+    name = "resource_source_directory",
+    allowReturnNones = true,
+    doc =
+        "Returns a source directory for Android resource file. "
+            + "The source directory is a prefix of resource's relative path up to "
+            + "a directory that designates resource kind (cf. "
+            + "http://developer.android.com/guide/topics/resources/providing-resources.html)."
+  )
+  public static PathFragment getSourceDirectoryRelativePathFromResource(Artifact resource) {
+    return AndroidCommon.getSourceDirectoryRelativePathFromResource(resource);
+  }
+}