binutils-gdb/gdb/python
Andrew Burgess 1ba1ac8801 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
2020-01-24 00:11:53 +00:00
..
lib/gdb
py-all-events.def
py-arch.c
py-auto-load.c
py-block.c
py-bpevent.c
py-breakpoint.c
py-cmd.c
py-continueevent.c
py-event-types.def
py-event.c
py-event.h
py-events.h
py-evtregistry.c
py-evts.c
py-exitedevent.c
py-finishbreakpoint.c
py-frame.c
py-framefilter.c
py-function.c
py-gdb-readline.c
py-inferior.c
py-infevents.c
py-infthread.c
py-instruction.c
py-instruction.h
py-lazy-string.c
py-linetable.c
py-newobjfileevent.c
py-objfile.c
py-param.c
py-prettyprint.c
py-progspace.c
py-record-btrace.c
py-record-btrace.h
py-record-full.c
py-record-full.h
py-record.c
py-record.h
py-ref.h
py-signalevent.c
py-stopevent.c
py-stopevent.h
py-symbol.c
py-symtab.c
py-threadevent.c
py-type.c
py-unwind.c
py-utils.c
py-value.c
py-varobj.c
py-xmethods.c
python-config.py
python-internal.h
python.c
python.h