tests: Clean up string interpolation around qtest_qmp_device_add()

Leaving interpolation into JSON to qmp() is more robust than building
QMP input manually, as explained in the commit before previous.

qtest_qmp_device_add() and its wrappers interpolate into JSON as
follows:

* qtest_qmp_device_add() interpolates members into a JSON object.

* So do its wrappers qpci_plug_device_test() and usb_test_hotplug().

* usb_test_hotplug() additionally interpolates strings and numbers
  into JSON strings.

Clean them up:

* Have qtest_qmp_device_add() take its extra device properties as
  arguments for qdict_from_jsonf_nofail() instead of a string
  containing JSON members.

* Drop qpci_plug_device_test(), use qtest_qmp_device_add()
  directly.

* Change usb_test_hotplug() parameter @port to string, to avoid
  interpolation.  Interpolate @hcd_id separately.

Bonus: gets rid of a non-literal format string.  A step towards
compile-time format string checking without triggering
-Wformat-nonliteral.

Cc: Thomas Huth <thuth@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20180806065344.7103-15-armbru@redhat.com>

1 files changed, 6 insertions, 4 deletions

diff --git a/tests/libqos/usb.c b/tests/libqos/usb.c
index 2a47604..49e2f4b 100644
--- a/tests/libqos/usb.c
+++ b/tests/libqos/usb.c
@@ -37,13 +37,14 @@ void uhci_port_test(struct qhc *hc, int port, uint16_t expect)
     g_assert((value & mask) == (expect & mask));
 }
 
-void usb_test_hotplug(const char *hcd_id, const int port,
+void usb_test_hotplug(const char *hcd_id, const char *port,
                       void (*port_check)(void))
 {
-    char  *id = g_strdup_printf("usbdev%d", port);
+    char *id = g_strdup_printf("usbdev%s", port);
+    char *bus = g_strdup_printf("%s.0", hcd_id);
 
-    qtest_qmp_device_add("usb-tablet", id, "'port': '%d', 'bus': '%s.0'",
-                         port, hcd_id);
+    qtest_qmp_device_add("usb-tablet", id, "{'port': %s, 'bus': %s}",
+                         port, bus);
 
     if (port_check) {
         port_check();
@@ -51,5 +52,6 @@ void usb_test_hotplug(const char *hcd_id, const int port,
 
     qtest_qmp_device_del(id);
 
+    g_free(bus);
     g_free(id);
 }