libqtest: New hmp() & friends

New convenience function hmp() to facilitate use of
human-monitor-command in tests.  Use it to simplify its existing uses.

To blend into existing libqtest code, also add qtest_hmpv() and
qtest_hmp().  That, and the egregiously verbose GTK-Doc comment format
make this patch look bigger than it is.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-Id: <1443689999-12182-7-git-send-email-armbru@redhat.com>

tests/drive_del-test.c

@@ -16,28 +16,18 @@
 
 static void drive_add(void)
 {
-    QDict *response;
+    char *resp = hmp("drive_add 0 if=none,id=drive0");
 
-    response = qmp("{'execute': 'human-monitor-command',"
-                   " 'arguments': {"
-                   "   'command-line': 'drive_add 0 if=none,id=drive0'"
-                   "}}");
-    g_assert(response);
-    g_assert_cmpstr(qdict_get_try_str(response, "return"), ==, "OK\r\n");
-    QDECREF(response);
+    g_assert_cmpstr(resp, ==, "OK\r\n");
+    g_free(resp);
 }
 
 static void drive_del(void)
 {
-    QDict *response;
+    char *resp = hmp("drive_del drive0");
 
-    response = qmp("{'execute': 'human-monitor-command',"
-                   " 'arguments': {"
-                   "   'command-line': 'drive_del drive0'"
-                   "}}");
-    g_assert(response);
-    g_assert_cmpstr(qdict_get_try_str(response, "return"), ==, "");
-    QDECREF(response);
+    g_assert_cmpstr(resp, ==, "");
+    g_free(resp);
 }
 
 static void device_del(void)

tests/ide-test.c

@@ -510,9 +510,7 @@ static void test_flush(void)
         tmp_path);
 
     /* Delay the completion of the flush request until we explicitly do it */
-    qmp_discard_response("{'execute':'human-monitor-command', 'arguments': {"
-                         " 'command-line':"
-                         " 'qemu-io ide0-hd0 \"break flush_to_os A\"'} }");
+    g_free(hmp("qemu-io ide0-hd0 \"break flush_to_os A\""));
 
     /* FLUSH CACHE command on device 0*/
     outb(IDE_BASE + reg_device, 0);
@@ -524,9 +522,7 @@ static void test_flush(void)
     assert_bit_clear(data, DF | ERR | DRQ);
 
     /* Complete the command */
-    qmp_discard_response("{'execute':'human-monitor-command', 'arguments': {"
-                         " 'command-line':"
-                         " 'qemu-io ide0-hd0 \"resume A\"'} }");
+    g_free(hmp("qemu-io ide0-hd0 \"resume A\""));
 
     /* Check registers */
     data = inb(IDE_BASE + reg_device);

tests/libqtest.c

@@ -483,6 +483,33 @@ void qtest_qmp_eventwait(QTestState *s, const char *event)
     }
 }
 
+char *qtest_hmpv(QTestState *s, const char *fmt, va_list ap)
+{
+    char *cmd;
+    QDict *resp;
+    char *ret;
+
+    cmd = g_strdup_vprintf(fmt, ap);
+    resp = qtest_qmp(s, "{'execute': 'human-monitor-command',"
+                     " 'arguments': {'command-line': %s}}",
+                     cmd);
+    ret = g_strdup(qdict_get_try_str(resp, "return"));
+    g_assert(ret);
+    QDECREF(resp);
+    g_free(cmd);
+    return ret;
+}
+
+char *qtest_hmp(QTestState *s, const char *fmt, ...)
+{
+    va_list ap;
+    char *ret;
+
+    va_start(ap, fmt);
+    ret = qtest_hmpv(s, fmt, ap);
+    va_end(ap);
+    return ret;
+}
 
 const char *qtest_get_arch(void)
 {
@@ -774,6 +801,16 @@ void qmp_discard_response(const char *fmt, ...)
     qtest_qmpv_discard_response(global_qtest, fmt, ap);
     va_end(ap);
 }
+char *hmp(const char *fmt, ...)
+{
+    va_list ap;
+    char *ret;
+
+    va_start(ap, fmt);
+    ret = qtest_hmpv(global_qtest, fmt, ap);
+    va_end(ap);
+    return ret;
+}
 
 bool qtest_big_endian(void)
 {

tests/libqtest.h

@@ -119,6 +119,29 @@ QDict *qtest_qmp_receive(QTestState *s);
  */
 void qtest_qmp_eventwait(QTestState *s, const char *event);
 
+/**
+ * qtest_hmpv:
+ * @s: #QTestState instance to operate on.
+ * @fmt...: HMP command to send to QEMU
+ *
+ * Send HMP command to QEMU via QMP's human-monitor-command.
+ *
+ * Returns: the command's output.  The caller should g_free() it.
+ */
+char *qtest_hmp(QTestState *s, const char *fmt, ...);
+
+/**
+ * qtest_hmpv:
+ * @s: #QTestState instance to operate on.
+ * @fmt: HMP command to send to QEMU
+ * @ap: HMP command arguments
+ *
+ * Send HMP command to QEMU via QMP's human-monitor-command.
+ *
+ * Returns: the command's output.  The caller should g_free() it.
+ */
+char *qtest_hmpv(QTestState *s, const char *fmt, va_list ap);
+
 /**
  * qtest_get_irq:
  * @s: #QTestState instance to operate on.
@@ -498,6 +521,16 @@ static inline void qmp_eventwait(const char *event)
     return qtest_qmp_eventwait(global_qtest, event);
 }
 
+/**
+ * hmp:
+ * @fmt...: HMP command to send to QEMU
+ *
+ * Send HMP command to QEMU via QMP's human-monitor-command.
+ *
+ * Returns: the command's output.  The caller should g_free() it.
+ */
+char *hmp(const char *fmt, ...);
+
 /**
  * get_irq:
  * @num: Interrupt to observe.