Introduce Virtio-loopback epsilon release:

Epsilon release introduces a new compatibility layer which make virtio-loopback
design to work with QEMU and rust-vmm vhost-user backend without require any
changes.

Signed-off-by: Timos Ampelikiotis <t.ampelikiotis@virtualopensystems.com>
Change-Id: I52e57563e08a7d0bdc002f8e928ee61ba0c53dd9

1 files changed, 50 insertions, 0 deletions

diff --git a/scripts/qapi/error.py b/scripts/qapi/error.py
new file mode 100644
index 000000000..e35e4ddb2
--- /dev/null
+++ b/scripts/qapi/error.py
@@ -0,0 +1,50 @@
+# -*- coding: utf-8 -*-
+#
+# Copyright (c) 2017-2019 Red Hat Inc.
+#
+# Authors:
+#  Markus Armbruster <armbru@redhat.com>
+#  Marc-André Lureau <marcandre.lureau@redhat.com>
+#
+# This work is licensed under the terms of the GNU GPL, version 2.
+# See the COPYING file in the top-level directory.
+
+"""
+QAPI error classes
+
+Common error classes used throughout the package.  Additional errors may
+be defined in other modules.  At present, `QAPIParseError` is defined in
+parser.py.
+"""
+
+from typing import Optional
+
+from .source import QAPISourceInfo
+
+
+class QAPIError(Exception):
+    """Base class for all exceptions from the QAPI package."""
+
+
+class QAPISourceError(QAPIError):
+    """Error class for all exceptions identifying a source location."""
+    def __init__(self,
+                 info: Optional[QAPISourceInfo],
+                 msg: str,
+                 col: Optional[int] = None):
+        super().__init__()
+        self.info = info
+        self.msg = msg
+        self.col = col
+
+    def __str__(self) -> str:
+        assert self.info is not None
+        loc = str(self.info)
+        if self.col is not None:
+            assert self.info.line is not None
+            loc += ':%s' % self.col
+        return loc + ': ' + self.msg
+
+
+class QAPISemError(QAPISourceError):
+    """Error class for semantic QAPI errors."""