1 files changed, 78 insertions, 0 deletions
diff --git a/src/csharp/Grpc.Tools/ProtoReadDependencies.cs b/src/csharp/Grpc.Tools/ProtoReadDependencies.cs
new file mode 100644
index 0000000000..963837e8b7
--- /dev/null
+++ b/src/csharp/Grpc.Tools/ProtoReadDependencies.cs
@@ -0,0 +1,78 @@
+#region Copyright notice and license
+
+// Copyright 2018 gRPC authors.
+//
+// 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.
+
+#endregion
+
+using System.Collections.Generic;
+using Microsoft.Build.Framework;
+using Microsoft.Build.Utilities;
+
+namespace Grpc.Tools
+{
+    public class ProtoReadDependencies : Task
+    {
+        /// <summary>
+        /// The collection is used to collect possible additional dependencies
+        /// of proto files cached under ProtoDepDir.
+        /// </summary>
+        [Required]
+        public ITaskItem[] ProtoBuf { get; set; }
+
+        /// <summary>
+        /// Directory where protoc dependency files are cached.
+        /// </summary>
+        [Required]
+        public string ProtoDepDir { get; set; }
+
+        /// <summary>
+        /// Additional items that a proto file depends on. This list may include
+        /// extra dependencies; we do our best to include as few extra positives
+        /// as reasonable to avoid missing any. The collection item is the
+        /// dependency, and its Source metadatum is the dependent proto file, like
+        ///     <ItemName Include="/usr/include/proto/wrapper.proto"
+        ///               Source="my_proto.proto" />
+        /// </summary>
+        [Output]
+        public ITaskItem[] Dependencies { get; private set; }
+
+        public override bool Execute()
+        {
+            // Read dependency files, where available. There might be none,
+            // just use a best effort.
+            if (ProtoDepDir != null)
+            {
+                var dependencies = new List<ITaskItem>();
+                foreach (var proto in ProtoBuf)
+                {
+                    string[] deps = DepFileUtil.ReadDependencyInputs(ProtoDepDir, proto.ItemSpec, Log);
+                    foreach (string dep in deps)
+                    {
+                        var ti = new TaskItem(dep);
+                        ti.SetMetadata(Metadata.Source, proto.ItemSpec);
+                        dependencies.Add(ti);
+                    }
+                }
+                Dependencies = dependencies.ToArray();
+            }
+            else
+            {
+                Dependencies = new ITaskItem[0];
+            }
+
+            return !Log.HasLoggedErrors;
+        }
+    };
+}