[PATCH] Fix -exec-run not running asynchronously with mi-async on

[Simon Marchi <simon dot marchi at polymtl dot ca>]

From: Simon Marchi <simon.marchi@ericsson.com>

This patch is a long overdue v2 of:

  https://sourceware.org/ml/gdb-patches/2015-03/msg00110.html

The problem is that when doing -exec-run on a freshly started GDB, the
only target pushed is the dummy one.  When mi_async_p is called to know
whether the run should be async, it queries whether the current target
(dummy) supports async, and the answer is no.  The fix is to make the
code query the target that will be used for the run, which is not
necessarily the current target.

I cleaned up the test a little bit.

No regressions in the gdb.mi directory using the unix, native-gdbserver
and native-extended-gdbserver boards.  The test doesn't pass when
forcing maint set target-async off, obviously, since it makes mi-async
have no effect.  It doesn't seem like other tests are checking for that
eventuality, so I didn't in the new test.

gdb/ChangeLog:

	* mi/mi-main.c (run_one_inferior): Use run target to determine
	whether to run async or not.
	(mi_cmd_exec_run): Likewise.

gdb/testsuite/ChangeLog:

	* gdb.mi/mi-async-run.exp: New file.
	* gdb.mi/mi-async-run.c: New file.
---
 gdb/mi/mi-main.c                      | 12 ++++++---
 gdb/testsuite/gdb.mi/mi-async-run.c   | 30 +++++++++++++++++++++
 gdb/testsuite/gdb.mi/mi-async-run.exp | 50 +++++++++++++++++++++++++++++++++++
 3 files changed, 88 insertions(+), 4 deletions(-)
 create mode 100644 gdb/testsuite/gdb.mi/mi-async-run.c
 create mode 100644 gdb/testsuite/gdb.mi/mi-async-run.exp

diff --git a/gdb/mi/mi-main.c b/gdb/mi/mi-main.c
index 7cb7bf5..904cee0 100644
--- a/gdb/mi/mi-main.c
+++ b/gdb/mi/mi-main.c
@@ -415,6 +415,8 @@ run_one_inferior (struct inferior *inf, void *arg)
 {
   int start_p = *(int *) arg;
   const char *run_cmd = start_p ? "start" : "run";
+  struct target_ops *run_target = find_run_target ();
+  int async_p = run_target->to_can_async_p (run_target) && mi_async;
 
   if (inf->pid != 0)
     {
@@ -435,8 +437,8 @@ run_one_inferior (struct inferior *inf, void *arg)
       switch_to_thread (null_ptid);
       set_current_program_space (inf->pspace);
     }
-  mi_execute_cli_command (run_cmd, mi_async_p (),
-			  mi_async_p () ? "&" : NULL);
+  mi_execute_cli_command (run_cmd, async_p,
+			  async_p ? "&" : NULL);
   return 0;
 }
 
@@ -489,9 +491,11 @@ mi_cmd_exec_run (char *command, char **argv, int argc)
   else
     {
       const char *run_cmd = start_p ? "start" : "run";
+      struct target_ops *run_target = find_run_target ();
+      int async_p = run_target->to_can_async_p (run_target) && mi_async;
 
-      mi_execute_cli_command (run_cmd, mi_async_p (),
-			      mi_async_p () ? "&" : NULL);
+      mi_execute_cli_command (run_cmd, async_p,
+			      async_p ? "&" : NULL);
     }
 }
 
diff --git a/gdb/testsuite/gdb.mi/mi-async-run.c b/gdb/testsuite/gdb.mi/mi-async-run.c
new file mode 100644
index 0000000..2910cbf
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi-async-run.c
@@ -0,0 +1,30 @@
+/* Copyright 2016 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   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/>.  */
+
+#include <unistd.h>
+
+int main ()
+{
+  int i;
+
+  for (i = 0; i < 30; i++)
+    {
+      sleep (1);
+    }
+
+  return 0;
+}
diff --git a/gdb/testsuite/gdb.mi/mi-async-run.exp b/gdb/testsuite/gdb.mi/mi-async-run.exp
new file mode 100644
index 0000000..c08a4a6
--- /dev/null
+++ b/gdb/testsuite/gdb.mi/mi-async-run.exp
@@ -0,0 +1,50 @@
+# Copyright 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/>.
+
+load_lib mi-support.exp
+
+standard_testfile
+
+if  { [gdb_compile "${srcdir}/${subdir}/${srcfile}" "${binfile}" executable {debug}] != "" } {
+     untested "mi-async-run.exp"
+     return -1
+}
+
+# Test the resolution of PR 18077
+#
+# When doing an -exec-run with a fresh copy of GDB, it would result in
+# synchronous execution, even though mi-async was on.
+
+proc test_async_run {} {
+    global GDBFLAGS
+
+    save_vars { GDBFLAGS } {
+	global binfile
+
+	set GDBFLAGS [concat $GDBFLAGS " -ex \"set mi-async on\""]
+
+	gdb_exit
+	if [mi_gdb_start] {
+	    continue
+	}
+
+	mi_gdb_load ${binfile}
+	mi_run_cmd
+	mi_gdb_test "123-exec-interrupt --all" "123\\^done" "send interrupt command"
+	mi_expect_interrupt "expect interrupt"
+    }
+}
+
+test_async_run
-- 
2.8.2