[binutils-gdb] Have SIGTERM promptly quit GDB even when the dummy target is active

[Patrick Palka <ppalka at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=077836f7cf6725386c01ae3bb7111663b8f2b85e

commit 077836f7cf6725386c01ae3bb7111663b8f2b85e
Author: Patrick Palka <patrick@parcs.ath.cx>
Date:   Fri Jul 24 13:58:47 2015 -0400

    Have SIGTERM promptly quit GDB even when the dummy target is active
    
    GDB currently does not promptly quit after receiving a SIGTERM while no
    proper target is active.  This is because in handle_sigterm we currently
    look at target_can_async_p to determine whether to asynchronously quit
    GDB using an async signal handler or to asynchronously quit using the
    quit flag.  However, target_can_async_p is always false under the dummy
    target, so under this target we always use the quit flag and not the
    async signal handler to signal that GDB should quit.  So GDB won't quit
    until a code path that checks the quit flag is executed.
    
    To fix this issue, this patch makes the SIGTERM handler no longer
    inspect target_can_async_p, and instead makes the handler
    unconditionally set the quit flag _and_ mark the corresponding async
    signal handler, so that if the target is async (or if it's the dummy
    target) then we will likely quit through the async signal handler, and
    if it's not async then we will likely quit through the quit flag.  This
    redundant approach is similar to how we handle SIGINT.
    
    gdb/ChangeLog:
    
    	* event-top.c (handle_sigterm): Don't inspect
    	target_can_async_p.  Always set the quit flag and always mark
    	the async signal handler.
    
    gdb/testsuite/ChangeLog:
    
    	* gdb.base/gdb-sigterm-2.exp: New test.

Diff:
---
 gdb/ChangeLog                            |  6 ++++++
 gdb/event-top.c                          | 13 ++++---------
 gdb/testsuite/ChangeLog                  |  4 ++++
 gdb/testsuite/gdb.base/gdb-sigterm-2.exp | 32 ++++++++++++++++++++++++++++++++
 4 files changed, 46 insertions(+), 9 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index a6e993e..a03ca35 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,9 @@
+2015-07-27  Patrick Palka  <patrick@parcs.ath.cx>
+
+	* event-top.c (handle_sigterm): Don't inspect
+	target_can_async_p.  Always set the quit flag and always mark
+	the async signal handler.
+
 2015-07-27  Yao Qi  <yao.qi@linaro.org>
 
 	* Makefile.in (REMOTE_EXAMPLES): Remove it.
diff --git a/gdb/event-top.c b/gdb/event-top.c
index e9cc2d7..1762e3b 100644
--- a/gdb/event-top.c
+++ b/gdb/event-top.c
@@ -876,15 +876,10 @@ handle_sigterm (int sig)
 {
   signal (sig, handle_sigterm);
 
-  /* Call quit_force in a signal safe way.
-     quit_force itself is not signal safe.  */
-  if (target_can_async_p ())
-    mark_async_signal_handler (async_sigterm_token);
-  else
-    {
-      sync_quit_force_run = 1;
-      set_quit_flag ();
-    }
+  sync_quit_force_run = 1;
+  set_quit_flag ();
+
+  mark_async_signal_handler (async_sigterm_token);
 }
 
 /* Do the quit.  All the checks have been done by the caller.  */
diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index 1faf1ab..818ea30 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2015-07-27  Patrick Palka  <patrick@parcs.ath.cx>
+
+	* gdb.base/gdb-sigterm-2.exp: New test.
+
 2015-07-25  Doug Evans  <xdje42@gmail.com>
 
 	Revert:
diff --git a/gdb/testsuite/gdb.base/gdb-sigterm-2.exp b/gdb/testsuite/gdb.base/gdb-sigterm-2.exp
new file mode 100644
index 0000000..e2121a4
--- /dev/null
+++ b/gdb/testsuite/gdb.base/gdb-sigterm-2.exp
@@ -0,0 +1,32 @@
+# This testcase is part of GDB, the GNU debugger.
+#
+# Copyright 2015 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/>.
+
+# Check that GDB promptly quits after receiving a SIGTERM while no proper
+# target is active.
+
+gdb_start
+
+set gdb_pid [exp_pid -i [board_info host fileid]]
+remote_exec host "kill -TERM $gdb_pid"
+
+set test "expect eof"
+gdb_test_multiple "" $test {
+    -timeout 5
+    eof {
+	pass $test
+    }
+}