Add gdb.free_objfile event registry

Currently, Python code can use event registries to detect when gdb
loads a new objfile, and when gdb clears the objfile list.  However,
there's no way to detect the removal of an objfile, say when the
inferior calls dlclose.

This patch adds a gdb.free_objfile event registry and arranges for an
event to be emitted in this case.

1 files changed, 30 insertions, 0 deletions

diff --git a/gdb/testsuite/gdb.python/py-event-load.py b/gdb/testsuite/gdb.python/py-event-load.py
new file mode 100644
index 0000000..9cf5611
--- /dev/null
+++ b/gdb/testsuite/gdb.python/py-event-load.py
@@ -0,0 +1,30 @@
+# Copyright (C) 2022 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/>.
+
+# Test Python free_objfile event.
+
+import gdb
+
+
+freed_objfile = None
+
+
+def free_objfile_handler(event):
+    assert isinstance(event, gdb.FreeObjFileEvent)
+    global freed_objfile
+    freed_objfile = event.objfile.username
+
+
+gdb.events.free_objfile.connect(free_objfile_handler)