SERVER-35154 Propagate JS exceptions through ScopedThread#join().

This makes it so that if the ScopedThread exited due to an uncaught
JavaScript exception, then calling .join() or .returnData() on it throws
a JavaScript exception with the error message and stacktrace intact.

1 files changed, 63 insertions, 0 deletions

diff --git a/src/mongo/scripting/jsexception.h b/src/mongo/scripting/jsexception.h
new file mode 100644
index 00000000000..3871486d046
--- /dev/null
+++ b/src/mongo/scripting/jsexception.h
@@ -0,0 +1,63 @@
+/**
+ * Copyright (C) 2018 MongoDB Inc.
+ *
+ * This program is free software: you can redistribute it and/or  modify
+ * it under the terms of the GNU Affero General Public License, version 3,
+ * as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ * As a special exception, the copyright holders give permission to link the
+ * code of portions of this program with the OpenSSL library under certain
+ * conditions as described in each individual source file and distribute
+ * linked combinations including the program with the OpenSSL library. You
+ * must comply with the GNU Affero General Public License in all respects
+ * for all of the code used other than as permitted herein. If you modify
+ * file(s) with this exception, you may extend this exception to your
+ * version of the file(s), but you are not obligated to do so. If you do not
+ * wish to do so, delete this exception statement from your version. If you
+ * delete this exception statement from all source files in the program,
+ * then also delete it in the license file.
+ */
+
+#pragma once
+
+#include <string>
+
+#include "mongo/base/error_codes.h"
+#include "mongo/base/error_extra_info.h"
+#include "mongo/base/status.h"
+
+namespace mongo {
+
+/**
+ * Represents information about a JavaScript exception. The "message" is stored as the Status's
+ * reason(), so only the "stack" is stored here.
+ *
+ * This class wraps an existing error and serializes it in a lossless way, so any other metadata
+ * about the JavaScript exception is also preserved.
+ */
+class JSExceptionInfo final : public ErrorExtraInfo {
+public:
+    static constexpr auto code = ErrorCodes::JSInterpreterFailureWithStack;
+
+    void serialize(BSONObjBuilder*) const override;
+    static std::shared_ptr<const ErrorExtraInfo> parse(const BSONObj&);
+
+    explicit JSExceptionInfo(std::string stack_, Status originalError_)
+        : stack(std::move(stack_)), originalError(std::move(originalError_)) {
+        invariant(!stack.empty());
+        invariant(!originalError.isOK());
+    }
+
+    const std::string stack;
+    const Status originalError;
+};
+
+}  // namespace mongo