scripts: qmp-shell: Add verbose flag

Add a verbose flag that shows the QMP command that was
constructed, to allow for later copy/pasting, reference,
debugging, etc.

The QMP is converted from a Python literal to JSON first,
to ensure that it is viable input to the actual QMP parser.

As a side-effect, this JSON output will helpfully show all
the necessary conversions that were performed on the input,
illustrating that "True" was transformed back into "true",
literal values are now escaped with "" instead of '', and so on.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Tested-by: Kashyap Chamarthy <kchamart@redhat.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

scripts/qmp/qmp-shell

@@ -195,6 +195,13 @@ class QMPShell(qmp.QEMUMonitorProtocol):
         self.__cli_expr(cmdargs[1:], qmpcmd['arguments'])
         return qmpcmd
 
+    def _print(self, qmp):
+        jsobj = json.dumps(qmp)
+        if self._pp is not None:
+            self._pp.pprint(jsobj)
+        else:
+            print str(jsobj)
+
     def _execute_cmd(self, cmdline):
         try:
             qmpcmd = self.__build_cmd(cmdline)
@@ -206,15 +213,13 @@ class QMPShell(qmp.QEMUMonitorProtocol):
         # For transaction mode, we may have just cached the action:
         if qmpcmd is None:
             return True
+        if self._verbose:
+            self._print(qmpcmd)
         resp = self.cmd_obj(qmpcmd)
         if resp is None:
             print 'Disconnected'
             return False
-
-        if self._pp is not None:
-            self._pp.pprint(resp)
-        else:
-            print resp
+        self._print(resp)
         return True
 
     def connect(self):
@@ -250,6 +255,9 @@ class QMPShell(qmp.QEMUMonitorProtocol):
         else:
             return self._execute_cmd(cmdline)
 
+    def set_verbosity(self, verbose):
+        self._verbose = verbose
+
 class HMPShell(QMPShell):
     def __init__(self, address):
         QMPShell.__init__(self, address)
@@ -327,7 +335,7 @@ def die(msg):
 def fail_cmdline(option=None):
     if option:
         sys.stderr.write('ERROR: bad command-line option \'%s\'\n' % option)
-    sys.stderr.write('qemu-shell [ -p ] [ -H ] < UNIX socket path> | < TCP address:port >\n')
+    sys.stderr.write('qemu-shell [ -v ] [ -p ] [ -H ] < UNIX socket path> | < TCP address:port >\n')
     sys.exit(1)
 
 def main():
@@ -335,6 +343,7 @@ def main():
     qemu = None
     hmp = False
     pp = None
+    verbose = False
 
     try:
         for arg in sys.argv[1:]:
@@ -346,6 +355,8 @@ def main():
                 if pp is not None:
                     fail_cmdline(arg)
                 pp = pprint.PrettyPrinter(indent=4)
+            elif arg == "-v":
+                verbose = True
             else:
                 if qemu is not None:
                     fail_cmdline(arg)
@@ -370,6 +381,7 @@ def main():
         die('Could not connect to %s' % addr)
 
     qemu.show_banner()
+    qemu.set_verbosity(verbose)
     while qemu.read_exec_command(qemu.get_prompt()):
         pass
     qemu.close()