1 files changed, 52 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/NotExpression.java b/src/main/java/com/google/devtools/build/lib/syntax/NotExpression.java
new file mode 100644
index 0000000000..5a13e79b8f
--- /dev/null
+++ b/src/main/java/com/google/devtools/build/lib/syntax/NotExpression.java
@@ -0,0 +1,52 @@
+// Copyright 2014 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.syntax;
+
+/**
+ * As syntax node for the not boolean operation.
+ */
+public class NotExpression extends Expression {
+
+  private final Expression expression;
+
+  public NotExpression(Expression expression) {
+    this.expression = expression;
+  }
+
+  Expression getExpression() {
+    return expression;
+  }
+
+  @Override
+  Object eval(Environment env) throws EvalException, InterruptedException {
+    return !EvalUtils.toBoolean(expression.eval(env));
+  }
+
+  @Override
+  public String toString() {
+    return "not " + expression;
+  }
+
+  @Override
+  public void accept(SyntaxTreeVisitor visitor) {
+    visitor.visit(this);
+  }
+
+  @Override
+  SkylarkType validate(ValidationEnvironment env) throws EvalException {
+    // Don't need type check here since EvalUtils.toBoolean() converts everything.
+    expression.validate(env);
+    return SkylarkType.BOOL;
+  }
+}