Test step-over-{lands-on-breakpoint|trips-on-watchpoint}.exp with displaced stepping

These tests exercise the infrun.c:proceed code that needs to know to
start new step overs (along with switch_back_to_stepped_thread, etc.).
That code is tricky to get right in the multitude of possible
combinations (at least):

 (native | remote)
  X (all-stop | all-stop-but-target-always-in-non-stop)
  X (displaced-stepping | in-line step-over).

The first two above are properties of the target, but the different
step-over-breakpoint methods should work with any target that supports
them.  This patch makes sure we always test both methods on all
targets.

Tested on x86-64 Fedora 20.

gdb/testsuite/ChangeLog:
2015-04-10  Pedro Alves  <palves@redhat.com>

	* gdb.threads/step-over-lands-on-breakpoint.exp (do_test): New
	procedure, factored out from ...
	(top level): ... here.  Add "set displaced-stepping" testing axis.
	* gdb.threads/step-over-trips-on-watchpoint.exp (do_test): New
	parameter "displaced".  Use it.
	(top level): Use foreach and add "set displaced-stepping" testing
	axis.

3 files changed, 46 insertions, 10 deletions

diff --git a/gdb/testsuite/ChangeLog b/gdb/testsuite/ChangeLog
index ec319ab..0d5d07f 100644
--- a/gdb/testsuite/ChangeLog
+++ b/gdb/testsuite/ChangeLog
@@ -1,5 +1,15 @@
 2015-04-10  Pedro Alves  <palves@redhat.com>
 
+	* gdb.threads/step-over-lands-on-breakpoint.exp (do_test): New
+	procedure, factored out from ...
+	(top level): ... here.  Add "set displaced-stepping" testing axis.
+	* gdb.threads/step-over-trips-on-watchpoint.exp (do_test): New
+	parameter "displaced".  Use it.
+	(top level): Use foreach and add "set displaced-stepping" testing
+	axis.
+
+2015-04-10  Pedro Alves  <palves@redhat.com>
+
 	* gdb.threads/step-over-trips-on-watchpoint.c (child_function):
 	Remove comment.
 	* gdb.threads/step-over-trips-on-watchpoint.exp (do_test): Find
diff --git a/gdb/testsuite/gdb.threads/step-over-lands-on-breakpoint.exp b/gdb/testsuite/gdb.threads/step-over-lands-on-breakpoint.exp
index 1e12314..52b59ec 100644
--- a/gdb/testsuite/gdb.threads/step-over-lands-on-breakpoint.exp
+++ b/gdb/testsuite/gdb.threads/step-over-lands-on-breakpoint.exp
@@ -24,15 +24,20 @@ if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
     return -1
 }
 
-# Cover both stepping and non-stepping execution commands.
-foreach command {"step" "next" "continue" } {
-    with_test_prefix $command {
+# The test proper.  DISPLACED is true if we should try with displaced
+# stepping.  COMMAND is the execution command to test.
+proc do_test {displaced command} {
+    global executable
+
+    with_test_prefix "displaced=$displaced: $command" {
 	clean_restart $executable
 
 	if ![runto_main] {
 	    continue
 	}
 
+	gdb_test_no_output "set displaced-stepping $displaced"
+
 	gdb_breakpoint [gdb_get_line_number "set wait-thread breakpoint here"]
 	gdb_continue_to_breakpoint "run to wait-thread breakpoint"
 	gdb_test "info threads" "2 .*\\\* 1.*" "info threads shows all threads"
@@ -60,3 +65,14 @@ foreach command {"step" "next" "continue" } {
 	gdb_test "$command" "step-over here.*"
     }
 }
+
+foreach displaced { "off" "on" } {
+    if { $displaced != "off" && ![support_displaced_stepping] } {
+	continue
+    }
+
+    # Cover both stepping and non-stepping execution commands.
+    foreach command { "step" "next" "continue" } {
+	do_test $displaced $command
+    }
+}
diff --git a/gdb/testsuite/gdb.threads/step-over-trips-on-watchpoint.exp b/gdb/testsuite/gdb.threads/step-over-trips-on-watchpoint.exp
index 17cd758..aa983f7 100644
--- a/gdb/testsuite/gdb.threads/step-over-trips-on-watchpoint.exp
+++ b/gdb/testsuite/gdb.threads/step-over-trips-on-watchpoint.exp
@@ -31,7 +31,11 @@ if {[gdb_compile_pthreads "${srcdir}/${subdir}/${srcfile}" "${binfile}" \
     return -1
 }
 
-proc do_test { with_bp } {
+# The test proper.  DISPLACED is true if we should try with displaced
+# stepping.  WITH_BP is true if we should try with a thread-specific
+# breakpoint (for the wrong thread) right after the instruction that
+# triggers the watchpoint.
+proc do_test { displaced with_bp } {
     global executable
     global gdb_prompt
     global hex
@@ -41,7 +45,7 @@ proc do_test { with_bp } {
     } else {
 	set prefix "no thread-specific bp"
     }
-    with_test_prefix $prefix {
+    with_test_prefix "displaced=$displaced: $prefix" {
 	# Cover both stepping and non-stepping execution commands.
 	foreach command {"step" "next" "continue" } {
 	    with_test_prefix $command {
@@ -51,6 +55,8 @@ proc do_test { with_bp } {
 		    continue
 		}
 
+		gdb_test_no_output "set displaced-stepping $displaced"
+
 		gdb_breakpoint [gdb_get_line_number "set wait-thread breakpoint here"]
 		gdb_continue_to_breakpoint "run to wait-thread breakpoint"
 		gdb_test "info threads" "2 .*\\\* 1.*" "info threads shows all threads"
@@ -99,9 +105,6 @@ proc do_test { with_bp } {
 		gdb_test "watch watch_me" "Hardware watchpoint .*"
 
 		if ${with_bp} {
-		    # Set a thread-specific breakpoint (for the wrong
-		    # thread) right after instruction that triggers
-		    # the watchpoint.
 		    gdb_test "b *$after_address_triggers_watch thread 1"
 		}
 
@@ -120,5 +123,12 @@ proc do_test { with_bp } {
     }
 }
 
-do_test 0
-do_test 1
+foreach displaced { "off" "on" } {
+    if { $displaced != "off" && ![support_displaced_stepping] } {
+	continue
+    }
+
+    foreach with_bp { 0 1 } {
+	do_test $displaced $with_bp
+    }
+}