1 files changed, 58 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java b/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java
new file mode 100644
index 0000000000..655aff90fa
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/analysis/config/FragmentCollection.java
@@ -0,0 +1,58 @@
+// Copyright 2015 Google Inc. 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.analysis.config;
+
+import com.google.common.base.Joiner;
+import com.google.common.collect.ImmutableCollection;
+import com.google.devtools.build.lib.analysis.RuleContext;
+import com.google.devtools.build.lib.concurrent.ThreadSafety.Immutable;
+import com.google.devtools.build.lib.syntax.ClassObject;
+import com.google.devtools.build.lib.syntax.SkylarkModule;
+
+import javax.annotation.Nullable;
+
+/**
+ * Represents a collection of configuration fragments in Skylark.
+ */
+@Immutable
+@SkylarkModule(name = "fragments", doc = "Allows access to configuration fragments.")
+public class FragmentCollection implements ClassObject {
+  private final RuleContext ruleContext;
+
+  public FragmentCollection(RuleContext ruleContext) {
+    this.ruleContext = ruleContext;
+  }
+
+  @Override
+  @Nullable
+  public Object getValue(String name) {
+    return ruleContext.getSkylarkFragment(name);
+  }
+
+  @Override
+  public ImmutableCollection<String> getKeys() {
+    return ruleContext.getSkylarkFragmentNames();
+  }
+
+  @Override
+  @Nullable
+  public String errorMessage(String name) {
+    return String.format("There is no configuration fragment named '%s'. Available fragments: %s",
+        name, printKeys());
+  }
+
+  private String printKeys() {
+    return String.format("'%s'", Joiner.on("', '").join(getKeys()));
+  }
+}
+\ No newline at end of file