Fix mi-nonstop.exp with extended-remote

Testing with "maint set target-non-stop on" makes mi-nonstop.exp run
with the extended-remote board.  That reveals that mi-nonstop.exp is
using the wrong predicate to check for "using remote protocol".

This is not visible today because non-stop tests all fail to run with
extended-remote board, because they spawn gdb and then do "set
non-stop on".  However, with that board, gdb connects to the gdbserver
from within mi_gdb_start, and changing non-stop when already connected
doesn't work.  Fix that by instead enabling non-stop mode on gdb's
command line.

gdb/testsuite/ChangeLog:
2015-11-30  Pedro Alves  <palves@redhat.com>

	* gdb.mi/mi-nonstop.exp: Append "set non-stop on" to GDBFLAGS
	instead of issuing "-gdb-set non-stop 1" after starting gdb.
	Use mi_is_target_remote instead of checking "is_remote target".
	* lib/gdb.exp (gdb_is_target_remote): Rename to ...
	(gdb_is_target_remote_prompt): ... this, and add 'prompt_regexp'
	parameter.
	(gdb_is_target_remote): Reimplement.
	* lib/mi-support.exp (mi_is_target_remote): New procedure.

2 files changed, 23 insertions, 6 deletions

diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index 90e8644..beb97ea 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -3023,25 +3023,33 @@ proc skip_compile_feature_tests {} {
     return $result
 }
 
-# Check whether we're testing with the remote or extended-remote
-# targets.
+# Helper for gdb_is_target_remote.  PROMPT_REGEXP is the expected
+# prompt.
 
-proc gdb_is_target_remote {} {
-    global gdb_prompt
+proc gdb_is_target_remote_prompt { prompt_regexp } {
 
     set test "probe for target remote"
     gdb_test_multiple "maint print target-stack" $test {
-	-re ".*emote serial target in gdb-specific protocol.*$gdb_prompt $" {
+	-re ".*emote serial target in gdb-specific protocol.*$prompt_regexp" {
 	    pass $test
 	    return 1
 	}
-	-re "$gdb_prompt $" {
+	-re "$prompt_regexp" {
 	    pass $test
 	}
     }
     return 0
 }
 
+# Check whether we're testing with the remote or extended-remote
+# targets.
+
+proc gdb_is_target_remote {} {
+    global gdb_prompt
+
+    return [gdb_is_target_remote_prompt "$gdb_prompt $"]
+}
+
 # Return 1 if the current remote target is an instance of our GDBserver, 0
 # otherwise.  Return -1 if there was an error and we can't tell.
 
diff --git a/gdb/testsuite/lib/mi-support.exp b/gdb/testsuite/lib/mi-support.exp
index 07a84ea..9619fb3 100644
--- a/gdb/testsuite/lib/mi-support.exp
+++ b/gdb/testsuite/lib/mi-support.exp
@@ -2499,3 +2499,12 @@ proc mi_skip_python_tests {} {
     global mi_gdb_prompt
     return [skip_python_tests_prompt "$mi_gdb_prompt$"]
 }
+
+# Check whether we're testing with the remote or extended-remote
+# targets.
+
+proc mi_is_target_remote {} {
+    global mi_gdb_prompt
+
+    return [gdb_is_target_remote_prompt "$mi_gdb_prompt"]
+}