1 files changed, 105 insertions, 0 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/EvalException.java b/src/main/java/com/google/devtools/build/lib/syntax/EvalException.java
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+++ b/src/main/java/com/google/devtools/build/lib/syntax/EvalException.java
@@ -0,0 +1,105 @@
+// 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;
+
+import com.google.common.base.Preconditions;
+import com.google.devtools.build.lib.events.Location;
+
+/**
+ * Exceptions thrown during evaluation of BUILD ASTs or Skylark extensions.
+ *
+ * <p>This exception must always correspond to a repeatable, permanent error, i.e. evaluating the
+ * same package again must yield the same exception. Notably, do not use this for reporting I/O
+ * errors.
+ *
+ * <p>This requirement is in place so that we can cache packages where an error is reported by way
+ * of {@link EvalException}.
+ */
+public class EvalException extends Exception {
+
+  private final Location location;
+  private final String message;
+  private final boolean dueToIncompleteAST;
+
+  /**
+   * @param location the location where evaluation/execution failed.
+   * @param message the error message.
+   */
+  public EvalException(Location location, String message) {
+    this.location = location;
+    this.message = Preconditions.checkNotNull(message);
+    this.dueToIncompleteAST = false;
+  }
+
+  /**
+   * @param location the location where evaluation/execution failed.
+   * @param message the error message.
+   * @param dueToIncompleteAST if the error is caused by a previous error, such as parsing.
+   */
+  public EvalException(Location location, String message, boolean dueToIncompleteAST) {
+    this.location = location;
+    this.message = Preconditions.checkNotNull(message);
+    this.dueToIncompleteAST = dueToIncompleteAST;
+  }
+
+  private EvalException(Location location, Throwable cause) {
+    super(cause);
+    this.location = location;
+    // This is only used from Skylark, it's useful for debugging. Note that this only happens
+    // when the Precondition below kills the execution anyway.
+    if (cause.getMessage() == null) {
+      cause.printStackTrace();
+    }
+    this.message = Preconditions.checkNotNull(cause.getMessage());
+    this.dueToIncompleteAST = false;
+  }
+
+  /**
+   * Returns the error message.
+   */
+  @Override
+  public String getMessage() {
+    return message;
+  }
+
+  /**
+   * Returns the location of the evaluation error.
+   */
+  public Location getLocation() {
+    return location;
+  }
+
+  public boolean isDueToIncompleteAST() {
+    return dueToIncompleteAST;
+  }
+
+  /**
+   * A class to support a special case of EvalException when the cause of the error is an
+   * Exception during a direct Java call.
+   */
+  public static final class EvalExceptionWithJavaCause extends EvalException {
+
+    public EvalExceptionWithJavaCause(Location location, Throwable cause) {
+      super(location, cause);
+    }
+  }
+
+  /**
+   * Returns the error message with location info if exists.
+   */
+  public String print() {
+    return getLocation() == null ? getMessage() : getLocation().print() + ": " + getMessage();
+  }
+}