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 @@ def gen_visitor_input_block(args, obj, dealloc=False):
     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 @@ def gen_marshal_output(name, args, ret_type):
     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 @@ def gen_marshal_input(name, args, ret_type):
                      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 @@ def gen_marshal_input(name, args, ret_type):
 ''')
     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 @@ def gen_command_def_prologue(prefix="", proxy=False):
 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 @@ def gen_command_def_prologue(prefix="", proxy=False):
         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
@@ -370,12 +415,18 @@ def gen_command_def_prologue(prefix="", proxy=False):
         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");
+
+    if not middle_mode:
         ret = gen_registry(commands)
         fdef.write(ret)
 

scripts/qapi-types.py

@@ -268,3 +268,6 @@ def generate_type_cleanup(name):
 
 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'