1 files changed, 68 insertions, 0 deletions
diff --git a/gdb/testsuite/gdb.python/py-recurse-unwind.py b/gdb/testsuite/gdb.python/py-recurse-unwind.py
new file mode 100644
index 00000000000..1da7aca9339
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-recurse-unwind.py
@@ -0,0 +1,68 @@
+# Copyright (C) 2016 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/>.
+
+# This unwinder never does any unwinding.  It'll (pretend to) "sniff"
+# the frame and ultimately return None, indicating that actual unwinding
+# should be performed by some other unwinder.
+# 
+# But, prior to returning None, it will attempt to obtain the value
+# associated with a symbol via a call to gdb.parse_and_eval().  In
+# the course of doing this evaluation, GDB will potentially access
+# some frames, leading to the possibility of a recursive invocation of
+# this unwinder.  If that should happen, code contained herein detects
+# that and prints a message which will cause some of the associated
+# tests to FAIL.
+
+import gdb
+from gdb.unwinder import Unwinder
+
+class TestUnwinder(Unwinder):
+
+    count = 0
+
+    @classmethod
+    def reset_count (cls):
+        cls.count = 0
+
+    @classmethod
+    def inc_count (cls):
+        cls.count += 1
+
+    def __init__(self):
+        Unwinder.__init__(self, "test unwinder")
+        self.recurse_level = 0
+
+    def __call__(self, pending_frame):
+
+
+        if self.recurse_level > 0:
+            gdb.write("TestUnwinder: Recursion detected - returning early.\n")
+            return None
+
+        self.recurse_level += 1
+        TestUnwinder.inc_count()
+
+        try:
+            val = gdb.parse_and_eval("undefined_symbol")
+
+        except Exception as arg:
+            pass
+
+        self.recurse_level -= 1
+
+        return None
+
+gdb.unwinder.register_unwinder(None, TestUnwinder(), True)
+gdb.write("Python script imported\n")