From 1ba1ac88011703abcd0271e4f5d00927dc69a09a Mon Sep 17 00:00:00 2001 From: Andrew Burgess Date: Tue, 19 Nov 2019 11:17:20 +0000 Subject: gdb: Enable stdin on exception in execute_gdb_command This is an update of this patch: https://sourceware.org/ml/gdb-patches/2018-09/msg00884.html This patch attempts to address PR gdb/23718 by re-enabling stdin whenever an exception is caught during gdb.execute(). When Python gdb.execute() is called, an exception could occur (e.g. the target disappearing), which is then converted into a Python exception. If stdin was disabled before the exception is caught, it is not re-enabled, because the exception doesn't propagate to the top level of the event loop, whose catch block would otherwise enable it. The result is that when execution of a Python script completes, GDB does not prompt or accept input, and is effectively hung. This change rectifies the issue by re-enabling stdin in the catch block of execute_gdb_command, prior to converting the exception to a Python exception. Since this patch was originally posted I've added a test, and also I converted the code to re-enable stdin from this: SWITCH_THRU_ALL_UIS () { async_enable_stdin (); } to simply this: async_enable_stdin (); My reasoning is that we only need the SWITCH_THRU_ALL_UIS if, at the time the exception is caught, the current_ui might be different than at the time we called async_disable_stdin. Within python's execute_gdb_command I think it should be impossible to switch current_ui, so the SWITCH_THRU_ALL_UIS isn't needed. gdb/ChangeLog: PR gdb/23718 * gdb/python/python.c (execute_gdb_command): Call async_enable_stdin in catch block. gdb/testsuite/ChangeLog: PR gdb/23718 * gdb.server/server-kill-python.exp: New file. Change-Id: I1cfc36ee9f8484cc1ed82be9be338353db6bc080 --- gdb/python/python.c | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'gdb/python/python.c') diff --git a/gdb/python/python.c b/gdb/python/python.c index f75c7b1..27d6042 100644 --- a/gdb/python/python.c +++ b/gdb/python/python.c @@ -624,6 +624,12 @@ execute_gdb_command (PyObject *self, PyObject *args, PyObject *kw) } catch (const gdb_exception &except) { + /* If an exception occurred then we won't hit normal_stop (), or have + an exception reach the top level of the event loop, which are the + two usual places in which stdin would be re-enabled. So, before we + convert the exception and continue back in Python, we should + re-enable stdin here. */ + async_enable_stdin (); GDB_PY_HANDLE_EXCEPTION (except); } -- cgit v1.1