qapi: add code generation support for middle mode

To get the ball rolling merging QAPI, this patch introduces a "middle mode" to
the code generator.  In middle mode, the code generator generates marshalling
functions that are compatible with the current QMP server.  We absolutely need
to replace the current QMP server in order to support proper asynchronous
commands but using a middle mode provides a middle-ground that lets us start
converting commands in tree.

Note that all of the commands have been converted already in my glib branch.
Middle mode only exists until we finish merging them from my branch into the
main tree.

Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@redhat.com>

qapi/qapi-types-core.h

@@ -17,4 +17,7 @@
 #include "qemu-common.h"
 #include "error.h"
 
+/* FIXME this is temporary until we remove middle mode */
+#include "monitor.h"
+
 #endif

scripts/qapi-commands.py

@@ -167,9 +167,10 @@ qmp_input_visitor_cleanup(mi);
     pop_indent()
     return ret.rstrip()
 
-def gen_marshal_output(name, args, ret_type):
+def gen_marshal_output(name, args, ret_type, middle_mode):
     if not ret_type:
         return ""
+
     ret = mcgen('''
 static void qmp_marshal_output_%(c_name)s(%(c_ret_type)s ret_in, QObject **ret_out, Error **errp)
 {
@@ -188,16 +189,34 @@ static void qmp_marshal_output_%(c_name)s(%(c_ret_type)s ret_in, QObject **ret_o
     qapi_dealloc_visitor_cleanup(md);
 }
 ''',
-            c_ret_type=c_type(ret_type), c_name=c_var(name), ret_type=ret_type)
+                 c_ret_type=c_type(ret_type), c_name=c_var(name),
+                 ret_type=ret_type)
 
     return ret
 
-def gen_marshal_input(name, args, ret_type):
+def gen_marshal_input_decl(name, args, ret_type, middle_mode):
+    if middle_mode:
+        return 'int qmp_marshal_input_%s(Monitor *mon, const QDict *qdict, QObject **ret)' % c_var(name)
+    else:
+        return 'static void qmp_marshal_input_%s(QDict *args, QObject **ret, Error **errp)' % c_var(name)
+
+
+
+def gen_marshal_input(name, args, ret_type, middle_mode):
+    hdr = gen_marshal_input_decl(name, args, ret_type, middle_mode)
+
     ret = mcgen('''
-static void qmp_marshal_input_%(c_name)s(QDict *args, QObject **ret, Error **errp)
+%(header)s
 {
 ''',
-                c_name=c_var(name))
+                header=hdr)
+
+    if middle_mode:
+        ret += mcgen('''
+    Error *local_err = NULL;
+    Error **errp = &local_err;
+    QDict *args = (QDict *)qdict;
+''')
 
     if ret_type:
         if c_type(ret_type).endswith("*"):
@@ -220,6 +239,10 @@ static void qmp_marshal_input_%(c_name)s(QDict *args, QObject **ret, Error **err
                      visitor_input_containers_decl=gen_visitor_input_containers_decl(args),
                      visitor_input_vars_decl=gen_visitor_input_vars_decl(args),
                      visitor_input_block=gen_visitor_input_block(args, "QOBJECT(args)"))
+    else:
+        ret += mcgen('''
+    (void)args;
+''')
 
     ret += mcgen('''
     if (error_is_set(errp)) {
@@ -234,10 +257,29 @@ out:
 ''')
     ret += mcgen('''
 %(visitor_input_block_cleanup)s
-    return;
-}
 ''',
-                 visitor_input_block_cleanup=gen_visitor_input_block(args, None, dealloc=True))
+                 visitor_input_block_cleanup=gen_visitor_input_block(args, None,
+                                                                     dealloc=True))
+
+    if middle_mode:
+        ret += mcgen('''
+
+    if (local_err) {
+        qerror_report_err(local_err);
+        error_free(local_err);
+        return -1;
+    }
+    return 0;
+''')
+    else:
+        ret += mcgen('''
+    return;
+''')
+
+    ret += mcgen('''
+}
+''')
+
     return ret
 
 def gen_registry(commands):
@@ -284,7 +326,7 @@ def gen_command_decl_prologue(header, guard, prefix=""):
 #include "error.h"
 
 ''',
-                 header=basename(h_file), guard=guardname(h_file), prefix=prefix)
+                 header=basename(header), guard=guardname(header), prefix=prefix)
     return ret
 
 def gen_command_def_prologue(prefix="", proxy=False):
@@ -317,11 +359,11 @@ def gen_command_def_prologue(prefix="", proxy=False):
                 prefix=prefix)
     if not proxy:
         ret += '#include "%sqmp-commands.h"' % prefix
-    return ret + "\n"
+    return ret + "\n\n"
 
 
 try:
-    opts, args = getopt.gnu_getopt(sys.argv[1:], "p:o:", ["prefix=", "output-dir=", "type="])
+    opts, args = getopt.gnu_getopt(sys.argv[1:], "p:o:m", ["prefix=", "output-dir=", "type=", "middle"])
 except getopt.GetoptError, err:
     print str(err)
     sys.exit(1)
@@ -331,6 +373,7 @@ prefix = ""
 dispatch_type = "sync"
 c_file = 'qmp-marshal.c'
 h_file = 'qmp-commands.h'
+middle_mode = False
 
 for o, a in opts:
     if o in ("-p", "--prefix"):
@@ -339,6 +382,8 @@ for o, a in opts:
         output_dir = a + "/"
     elif o in ("-t", "--type"):
         dispatch_type = a
+    elif o in ("-m", "--middle"):
+        middle_mode = True
 
 c_file = output_dir + prefix + c_file
 h_file = output_dir + prefix + h_file
@@ -370,14 +415,20 @@ if dispatch_type == "sync":
         ret = generate_command_decl(cmd['command'], arglist, ret_type) + "\n"
         fdecl.write(ret)
         if ret_type:
-            ret = gen_marshal_output(cmd['command'], arglist, ret_type) + "\n"
+            ret = gen_marshal_output(cmd['command'], arglist, ret_type, middle_mode) + "\n"
             fdef.write(ret)
-        ret = gen_marshal_input(cmd['command'], arglist, ret_type) + "\n"
+
+        if middle_mode:
+            fdecl.write('%s;\n' % gen_marshal_input_decl(cmd['command'], arglist, ret_type, middle_mode))
+
+        ret = gen_marshal_input(cmd['command'], arglist, ret_type, middle_mode) + "\n"
         fdef.write(ret)
 
     fdecl.write("\n#endif\n");
-    ret = gen_registry(commands)
+
-    fdef.write(ret)
+    if not middle_mode:
+        ret = gen_registry(commands)
+        fdef.write(ret)
 
     fdef.flush()
     fdef.close()

scripts/qapi-types.py

@@ -268,3 +268,6 @@ fdecl.write('''
 
 fdecl.flush()
 fdecl.close()
+
+fdef.flush()
+fdef.close()

scripts/qapi.py

@@ -200,4 +200,6 @@ def basename(filename):
     return filename.split("/")[-1]
 
 def guardname(filename):
-    return filename.replace("/", "_").replace("-", "_").split(".")[0].upper()
+    if filename.startswith('./'):
+        filename = filename[2:]
+    return filename.replace("/", "_").replace("-", "_").split(".")[0].upper() + '_H'