Adds ToolchainConstructor interface and implementations.

ToolchainConstructor is used to create instances of ToolchainInfo, for
toolchain-aware rule sets.

Part of #2219.

Change-Id: Iae4e519b156910cc28704b3ca5b11e57dd561107
PiperOrigin-RevId: 156303854

1 files changed, 37 insertions, 0 deletions

diff --git a/src/main/java/com/google/devtools/build/lib/rules/platform/NativeToolchainConstructor.java b/src/main/java/com/google/devtools/build/lib/rules/platform/NativeToolchainConstructor.java
new file mode 100644
index 0000000000..6d62b25a48
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/rules/platform/NativeToolchainConstructor.java
@@ -0,0 +1,37 @@
+// Copyright 2017 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.platform;
+
+import com.google.devtools.build.lib.packages.NativeClassObjectConstructor;
+import com.google.devtools.build.lib.packages.ToolchainConstructor;
+import com.google.devtools.build.lib.syntax.Environment;
+import com.google.devtools.build.lib.syntax.EvalException;
+import com.google.devtools.build.lib.syntax.FuncallExpression;
+import javax.annotation.Nullable;
+
+/** Native value that can be used to create toolchains. */
+public class NativeToolchainConstructor extends NativeClassObjectConstructor
+    implements ToolchainConstructor {
+
+  protected NativeToolchainConstructor(String name) {
+    super(name);
+  }
+
+  // TODO(katre): Implement this.
+  @Override
+  protected Object call(Object[] args, @Nullable FuncallExpression ast, @Nullable Environment env)
+      throws EvalException, InterruptedException {
+    throw new IllegalStateException("Native toolchains not yet implemented.");
+  }
+}