Down-integrate from internal code base.

[ci skip]

Change-Id: I9391c09640e0b0b2b21c45a97a1fc91814d95c5d

1 files changed, 89 insertions, 0 deletions

diff --git a/src/google/protobuf/stubs/status_macros.h b/src/google/protobuf/stubs/status_macros.h
new file mode 100644
index 00000000..743e79a7
--- /dev/null
+++ b/src/google/protobuf/stubs/status_macros.h
@@ -0,0 +1,89 @@
+// Protocol Buffers - Google's data interchange format
+// Copyright 2008 Google Inc.  All rights reserved.
+// https://developers.google.com/protocol-buffers/
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// From: util/task/contrib/status_macros/status_macros.h
+
+#ifndef GOOGLE_PROTOBUF_STUBS_STATUS_MACROS_H_
+#define GOOGLE_PROTOBUF_STUBS_STATUS_MACROS_H_
+
+#include <google/protobuf/stubs/common.h>
+#include <google/protobuf/stubs/status.h>
+#include <google/protobuf/stubs/statusor.h>
+
+namespace google {
+namespace protobuf {
+namespace util {
+
+// Run a command that returns a util::Status.  If the called code returns an
+// error status, return that status up out of this method too.
+//
+// Example:
+//   RETURN_IF_ERROR(DoThings(4));
+#define RETURN_IF_ERROR(expr) \
+  do { \
+    /* Using _status below to avoid capture problems if expr is "status". */ \
+    const ::google::protobuf::util::Status _status = (expr); \
+    if (GOOGLE_PREDICT_FALSE(!_status.ok())) return _status; \
+  } while (0)
+
+// Internal helper for concatenating macro values.
+#define STATUS_MACROS_CONCAT_NAME_INNER(x, y) x##y
+#define STATUS_MACROS_CONCAT_NAME(x, y) STATUS_MACROS_CONCAT_NAME_INNER(x, y)
+
+template<typename T>
+Status DoAssignOrReturn(T& lhs, StatusOr<T> result) {
+  if (result.ok()) {
+    lhs = result.ValueOrDie();
+  }
+  return result.status();
+}
+
+#define ASSIGN_OR_RETURN_IMPL(status, lhs, rexpr) \
+  Status status = DoAssignOrReturn(lhs, (rexpr)); \
+  if (GOOGLE_PREDICT_FALSE(!status.ok())) return status;
+
+// Executes an expression that returns a util::StatusOr, extracting its value
+// into the variable defined by lhs (or returning on error).
+//
+// Example: Assigning to an existing value
+//   ValueType value;
+//   ASSIGN_OR_RETURN(value, MaybeGetValue(arg));
+//
+// WARNING: ASSIGN_OR_RETURN expands into multiple statements; it cannot be used
+//  in a single statement (e.g. as the body of an if statement without {})!
+#define ASSIGN_OR_RETURN(lhs, rexpr) \
+  ASSIGN_OR_RETURN_IMPL( \
+      STATUS_MACROS_CONCAT_NAME(_status_or_value, __COUNTER__), lhs, rexpr);
+
+}  // namespace util
+}  // namespace protobuf
+}  // namespace google
+
+#endif  // GOOGLE_PROTOBUF_STUBS_STATUS_H_