Adds an ObjcProtoProvider which bundles the proto sources and filters, along with an ObjcProtoAspect which propagates the proto provider through the dependency chain.

--
MOS_MIGRATED_REVID=120747710

1 files changed, 100 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoProvider.java b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoProvider.java
new file mode 100644
index 0000000000..d1ed2b9aea
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/objc/ObjcProtoProvider.java
@@ -0,0 +1,100 @@
+// 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.objc;
+
+import com.google.common.base.Preconditions;
+import com.google.devtools.build.lib.actions.Artifact;
+import com.google.devtools.build.lib.analysis.TransitiveInfoProvider;
+import com.google.devtools.build.lib.collect.nestedset.NestedSet;
+import com.google.devtools.build.lib.collect.nestedset.NestedSetBuilder;
+
+/**
+ * A provider that provides all protos and portable proto filters information in the transitive
+ * closure of its dependencies that are needed for generating and compiling only one version of
+ * proto files.
+ */
+public class ObjcProtoProvider implements TransitiveInfoProvider {
+
+  private final NestedSet<Artifact> protoSources;
+  private final NestedSet<Artifact> portableProtoFilters;
+
+  private ObjcProtoProvider(
+      NestedSet<Artifact> protoSources, NestedSet<Artifact> portableProtoFilters) {
+    this.protoSources = Preconditions.checkNotNull(protoSources);
+    this.portableProtoFilters = Preconditions.checkNotNull(portableProtoFilters);
+  }
+
+  /**
+   * Returns the set of all the protos that the dependencies of this provider has seen.
+   */
+  public NestedSet<Artifact> getProtoSources() {
+    return protoSources;
+  }
+
+  /**
+   * Returns the set of all the associated filters to the collected protos.
+   */
+  public NestedSet<Artifact> getPortableProtoFilters() {
+    return portableProtoFilters;
+  }
+
+  /**
+   * A builder for this context with an API that is optimized for collecting information from
+   * several transitive dependencies.
+   */
+  public static final class Builder {
+    private final NestedSetBuilder<Artifact> protoSources = NestedSetBuilder.linkOrder();
+    private final NestedSetBuilder<Artifact> portableProtoFilters = NestedSetBuilder.linkOrder();
+
+    /**
+     * Adds all the protos to the set of dependencies.
+     */
+    public Builder addProtoSources(NestedSet<Artifact> protoSources) {
+      this.protoSources.addTransitive(protoSources);
+      return this;
+    }
+
+    /**
+     * Adds all the proto filters to the set of dependencies.
+     */
+    public Builder addPortableProtoFilters(Iterable<Artifact> protoFilters) {
+      this.portableProtoFilters.addAll(protoFilters);
+      return this;
+    }
+
+    /**
+     * Add all protos and filters from providers, and propagate them to any (transitive) dependers
+     * on this ObjcProtoProvider.
+     */
+    public Builder addTransitive(Iterable<ObjcProtoProvider> providers) {
+      for (ObjcProtoProvider provider : providers) {
+        this.protoSources.addTransitive(provider.getProtoSources());
+        this.portableProtoFilters.addTransitive(provider.getPortableProtoFilters());
+      }
+      return this;
+    }
+
+    /**
+     * Whether this provider has any protos or filters.
+     */
+    public boolean isEmpty() {
+      return protoSources.isEmpty() && portableProtoFilters.isEmpty();
+    }
+
+    public ObjcProtoProvider build() {
+      return new ObjcProtoProvider(protoSources.build(), portableProtoFilters.build());
+    }
+  }
+}