[PATCH 3/7] Step over syscalll insn with disp-step on and off

[Yao Qi <qiyaoltc@gmail.com>]

disp-step-syscall.exp was added to test displaced stepping over syscall
instructions, in which we set breakpoint on syscall instruction, and
step over it.  In fact, we can extend the test to non-displaced-stepping
case.  This patch wraps the test with displaced stepping on and off.
Note that the indentation and format isn't adjusted here to make this
patch easy to read.  The following patch will fix the format separately.

gdb/testsuite:

2016-02-26  Yao Qi  <yao.qi@linaro.org>

	* gdb.base/disp-step-syscall.exp: Don't invoke
	support_displaced_stepping.
	(disp_step_cross_syscall): Test with displaced stepping off and
	on if supported.
---
 gdb/testsuite/gdb.base/disp-step-syscall.exp | 13 +++++++------
 1 file changed, 7 insertions(+), 6 deletions(-)

diff --git a/gdb/testsuite/gdb.base/disp-step-syscall.exp b/gdb/testsuite/gdb.base/disp-step-syscall.exp
index a1af3b4..3cf436d 100644
--- a/gdb/testsuite/gdb.base/disp-step-syscall.exp
+++ b/gdb/testsuite/gdb.base/disp-step-syscall.exp
@@ -15,11 +15,6 @@
 # You should have received a copy of the GNU General Public License
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
-if { ![support_displaced_stepping] } {
-    unsupported "displaced stepping"
-    return -1
-}
-
 set syscall_insn ""
 
 # Define the syscall instruction for each target.
@@ -124,6 +119,11 @@ proc disp_step_cross_syscall { syscall } {
 	    return -1
 	}
 
+	foreach_with_prefix displaced {"off" "on"} {
+	    if {$displaced == "on" && ![support_displaced_stepping]} {
+		continue
+	    }
+
 	set ret [setup $syscall]
 
 	set syscall_insn_addr [lindex $ret 0]
@@ -149,7 +149,7 @@ proc disp_step_cross_syscall { syscall } {
 	gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, .*" \
 	    "continue to syscall insn $syscall"
 
-	gdb_test_no_output "set displaced-stepping on"
+	gdb_test_no_output "set displaced-stepping $displaced"
 
 	# Check the address of next instruction of syscall.
 	if {[gdb_test "stepi" "x/i .*=>.*" "single step over $syscall"] != 0} {
@@ -164,6 +164,7 @@ proc disp_step_cross_syscall { syscall } {
 	gdb_test "break marker" "Breakpoint.*at.* file .*${testfile}.c, line.*"
 	gdb_test "continue" "Continuing\\..*Breakpoint \[0-9\]+, marker \\(\\) at.*" \
 	    "continue to marker ($syscall)"
+	}
     }
 }
 
-- 
1.9.1