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diff --git a/share/gdb/python/gdb/unwinder.py b/share/gdb/python/gdb/unwinder.py
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+++ b/share/gdb/python/gdb/unwinder.py
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+# Copyright (C) 2015-2023 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# 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 General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+"""Unwinder class and register_unwinder function."""
+
+import gdb
+
+
+class Unwinder(object):
+    """Base class (or a template) for frame unwinders written in Python.
+
+    An unwinder has a single method __call__ and the attributes
+    described below.
+
+    Attributes:
+        name: The name of the unwinder.
+        enabled: A boolean indicating whether the unwinder is enabled.
+    """
+
+    def __init__(self, name):
+        """Constructor.
+
+        Args:
+            name: An identifying name for the unwinder.
+        """
+        self.name = name
+        self.enabled = True
+
+    def __call__(self, pending_frame):
+        """GDB calls this method to unwind a frame.
+
+        Arguments:
+            pending_frame: gdb.PendingFrame instance.
+
+        Returns:
+            gdb.UnwindInfo instance.
+        """
+        raise NotImplementedError("Unwinder __call__.")
+
+
+def register_unwinder(locus, unwinder, replace=False):
+    """Register unwinder in given locus.
+
+    The unwinder is prepended to the locus's unwinders list. Unwinder
+    name should be unique.
+
+    Arguments:
+        locus: Either an objfile, progspace, or None (in which case
+               the unwinder is registered globally).
+        unwinder: An object of a gdb.Unwinder subclass
+        replace: If True, replaces existing unwinder with the same name.
+                 Otherwise, raises exception if unwinder with the same
+                 name already exists.
+
+    Returns:
+        Nothing.
+
+    Raises:
+        RuntimeError: Unwinder name is not unique
+        TypeError: Bad locus type
+    """
+    if locus is None:
+        if gdb.parameter("verbose"):
+            gdb.write("Registering global %s unwinder ...\n" % unwinder.name)
+        locus = gdb
+    elif isinstance(locus, gdb.Objfile) or isinstance(locus, gdb.Progspace):
+        if gdb.parameter("verbose"):
+            gdb.write(
+                "Registering %s unwinder for %s ...\n" % (unwinder.name, locus.filename)
+            )
+    else:
+        raise TypeError("locus should be gdb.Objfile or gdb.Progspace or None")
+
+    i = 0
+    for needle in locus.frame_unwinders:
+        if needle.name == unwinder.name:
+            if replace:
+                del locus.frame_unwinders[i]
+            else:
+                raise RuntimeError("Unwinder %s already exists." % unwinder.name)
+        i += 1
+    locus.frame_unwinders.insert(0, unwinder)
+    gdb.invalidate_cached_frames()