Create asset merging action

This action is a trimmed-down version of the resource merging action (no
resources or manifests).

Also, create a base class to collect boilerplate action code, and a new
Exception to indicate that we should exit an action immediately (rather than
throw and print the stack trace).

RELNOTES: none
PiperOrigin-RevId: 193054422

1 files changed, 31 insertions, 0 deletions

diff --git a/src/tools/android/java/com/google/devtools/build/android/UserException.java b/src/tools/android/java/com/google/devtools/build/android/UserException.java
new file mode 100644
index 0000000000..6efbe8c360
--- /dev/null
+++ b/src/tools/android/java/com/google/devtools/build/android/UserException.java
@@ -0,0 +1,31 @@
+// Copyright 2018 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.android;
+
+/**
+ * An exception triggered by a user error (including problems with input).
+ *
+ * <p>In Bazel, users tend to assume that a stack trace indicates a bug in underlying Bazel code and
+ * ignore the content of the exception. If we know that the exception was actually their fault, we
+ * should just exit immediately rather than print a stack trace.
+ */
+public class UserException extends RuntimeException {
+  UserException(String message, Throwable e) {
+    super(message, e);
+  }
+
+  UserException(String message) {
+    super(message);
+  }
+}