Test --wrapper in extended-remote

We didn't test --wrapper option in extended-remote before, this patch
is to add a test case for it.  In order to pass option --wrapper to
gdbserver in extended-remote, I add arg in gdbserver_start_extended,
and its default value is "", so that other places use
gdbserver_start_extended don't have to be updated.

gdb/testsuite:

2015-07-24  Yao Qi  <yao.qi@linaro.org>

	* lib/gdbserver-support.exp (gdbserver_start_extended): Add
	argument options.
	* gdb.server/ext-wrapper.exp: New file.

gdb/testsuite/ChangeLog

@@ -1,3 +1,9 @@
+2015-07-24  Yao Qi  <yao.qi@linaro.org>
+
+	* lib/gdbserver-support.exp (gdbserver_start_extended): Add
+	argument options.
+	* gdb.server/ext-wrapper.exp: New file.
+
 2015-07-23  Doug Evans  <dje@google.com>
 
 	* gdb.dwarf2/dw2-dummy-cu.S: New file.

gdb/testsuite/gdb.server/ext-wrapper.exp

@@ -0,0 +1,50 @@
+# 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/>.
+
+load_lib gdbserver-support.exp
+
+standard_testfile wrapper.c
+
+if { [skip_gdbserver_tests] } {
+    return 0
+}
+
+if {[build_executable $testfile.exp $testfile $srcfile debug] == -1} {
+    return -1
+}
+
+if {[prepare_for_testing $testfile.exp $testfile $srcfile debug]} {
+    return -1
+}
+
+# Make sure we're disconnected, in case we're testing with an
+# extended-remote board, therefore already connected.
+gdb_test "disconnect" ".*"
+
+set target_exec [gdbserver_download_current_prog]
+gdbserver_start_extended "--wrapper env TEST=1 --"
+
+gdb_test_no_output "set remote exec-file $target_exec" "set remote exec-file"
+
+gdb_breakpoint marker
+gdb_test "run" "Breakpoint.* marker .*" "run to marker"
+
+gdb_test "print d" "\\$${decimal} = ${hex} \"1\".*"
+
+gdb_test "kill" "" "kill" "Kill the program being debugged.*" "y"
+
+gdb_test_no_output "monitor exit"

gdb/testsuite/lib/gdbserver-support.exp

@@ -434,15 +434,21 @@ proc gdbserver_reconnect { } {
     return [gdb_target_cmd $gdbserver_protocol $gdbserver_gdbport]
 }
 
-# Start and connect to a gdbserver in extended mode.  Note this frobs
-# $gdbserver_protocol, so should be used only from a board that
-# usually connects in target remote mode.
-proc gdbserver_start_extended { } {
+# Start gdbserver in extended mode with OPTIONS and connect to it.  Note
+# this frobs $gdbserver_protocol, so should be used only from a board
+# that usually connects in target remote mode.
+proc gdbserver_start_extended { {options ""} } {
     global gdbserver_protocol
     global gdbserver_gdbport
     global use_gdb_stub
 
-    if { [catch { gdbserver_start "--multi" "" } res] == 1 } {
+    set gdbserver_options "--multi"
+
+    if { $options != "" } {
+	append gdbserver_options " $options"
+    }
+
+    if { [catch { gdbserver_start $gdbserver_options "" } res] == 1 } {
 	perror $res
 	return 2
     }