Fix -exec-run not running asynchronously with mi-async on (PR gdb/18077)

When doing -exec-run on a freshly started GDB, the only target on the
target stack at the time 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.

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/ChangeLog

@@ -1,3 +1,10 @@
+2016-05-17  Simon Marchi  <simon.marchi@ericsson.com>
+
+	PR gdb/18077
+	* mi/mi-main.c (run_one_inferior): Use run target to determine
+	whether to run async or not.
+	(mi_cmd_exec_run): Likewise.
+
 2016-05-17  Tom Tromey  <tom@tromey.com>
 
 	* std-operator.def (OP_RANGE): Rename from OP_F90_RANGE.

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 = mi_async && run_target->to_can_async_p (run_target);
 
   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;
 }
 
@@ -488,9 +490,11 @@ 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 = mi_async && run_target->to_can_async_p (run_target);
 
-      mi_execute_cli_command (run_cmd, mi_async_p (),
-			      mi_async_p () ? "&" : NULL);
+      mi_execute_cli_command (run_cmd, async_p,
+			      async_p ? "&" : NULL);
     }
 }
 

gdb/testsuite/ChangeLog

@@ -1,3 +1,9 @@
+2016-05-17  Simon Marchi  <simon.marchi@ericsson.com>
+
+	PR gdb/18077
+	* gdb.mi/mi-async-run.exp: New file.
+	* gdb.mi/mi-async-run.c: New file.
+
 2016-05-17  Tom Tromey  <tom@tromey.com>
 	    Manish Goregaokar <manishsmail@gmail.com>
 

gdb/testsuite/gdb.mi/mi-async-run.c

@@ -0,0 +1,31 @@
+/* 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;
+}

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