qapi: add qapi-commands.py code generator

This is the code generator for qapi command marshaling/dispatch.
Currently only generators for synchronous qapi/qmp functions are
supported. This script generates the following files:

  $(prefix)qmp-marshal.c: command marshal/dispatch functions for each
                          QMP command defined in the schema. Functions
                          generated by qapi-visit.py are used to
                          convert qobjects recieved from the wire into
                          function parameters, and uses the same
                          visiter functions to convert native C return
                          values to qobjects from transmission back
                          over the wire.

  $(prefix)qmp-commands.h: Function prototypes for the QMP commands
                           specified in the schema.

$(prefix) is used in the same manner as with qapi-types.py

Signed-off-by: Michael Roth <mdroth@linux.vnet.ibm.com>
Signed-off-by: Luiz Capitulino <lcapitulino@gmail.com>

scripts/qapi-commands.py

@@ -0,0 +1,385 @@
+#
+# QAPI command marshaller generator
+#
+# Copyright IBM, Corp. 2011
+#
+# Authors:
+#  Anthony Liguori <aliguori@us.ibm.com>
+#  Michael Roth    <mdroth@linux.vnet.ibm.com>
+#
+# This work is licensed under the terms of the GNU GPLv2.
+# See the COPYING.LIB file in the top-level directory.
+
+from ordereddict import OrderedDict
+from qapi import *
+import sys
+import os
+import getopt
+import errno
+
+def generate_decl_enum(name, members, genlist=True):
+    return mcgen('''
+
+void visit_type_%(name)s(Visitor *m, %(name)s * obj, const char *name, Error **errp);
+''',
+                name=name)
+
+def generate_command_decl(name, args, ret_type):
+    arglist=""
+    for argname, argtype, optional, structured in parse_args(args):
+        argtype = c_type(argtype)
+        if argtype == "char *":
+            argtype = "const char *"
+        if optional:
+            arglist += "bool has_%s, " % c_var(argname)
+        arglist += "%s %s, " % (argtype, c_var(argname))
+    return mcgen('''
+%(ret_type)s qmp_%(name)s(%(args)sError **errp);
+''',
+                 ret_type=c_type(ret_type), name=c_var(name), args=arglist).strip()
+
+def gen_sync_call(name, args, ret_type, indent=0):
+    ret = ""
+    arglist=""
+    retval=""
+    if ret_type:
+        retval = "retval = "
+    for argname, argtype, optional, structured in parse_args(args):
+        if optional:
+            arglist += "has_%s, " % c_var(argname)
+        arglist += "%s, " % (c_var(argname))
+    push_indent(indent)
+    ret = mcgen('''
+%(retval)sqmp_%(name)s(%(args)serrp);
+
+''',
+                name=c_var(name), args=arglist, retval=retval).rstrip()
+    if ret_type:
+        ret += "\n" + mcgen(''''
+%(marshal_output_call)s
+''',
+                            marshal_output_call=gen_marshal_output_call(name, ret_type)).rstrip()
+    pop_indent(indent)
+    return ret.rstrip()
+
+
+def gen_marshal_output_call(name, ret_type):
+    if not ret_type:
+        return ""
+    return "qmp_marshal_output_%s(retval, ret, errp);" % c_var(name)
+
+def gen_visitor_output_containers_decl(ret_type):
+    ret = ""
+    push_indent()
+    if ret_type:
+        ret += mcgen('''
+QmpOutputVisitor *mo;
+QapiDeallocVisitor *md;
+Visitor *v;
+''')
+    pop_indent()
+
+    return ret
+
+def gen_visitor_input_containers_decl(args):
+    ret = ""
+
+    push_indent()
+    if len(args) > 0:
+        ret += mcgen('''
+QmpInputVisitor *mi;
+QapiDeallocVisitor *md;
+Visitor *v;
+''')
+    pop_indent()
+
+    return ret.rstrip()
+
+def gen_visitor_input_vars_decl(args):
+    ret = ""
+    push_indent()
+    for argname, argtype, optional, structured in parse_args(args):
+        if optional:
+            ret += mcgen('''
+bool has_%(argname)s = false;
+''',
+                         argname=c_var(argname))
+        if c_type(argtype).endswith("*"):
+            ret += mcgen('''
+%(argtype)s %(argname)s = NULL;
+''',
+                         argname=c_var(argname), argtype=c_type(argtype))
+        else:
+            ret += mcgen('''
+%(argtype)s %(argname)s;
+''',
+                         argname=c_var(argname), argtype=c_type(argtype))
+
+    pop_indent()
+    return ret.rstrip()
+
+def gen_visitor_input_block(args, obj, dealloc=False):
+    ret = ""
+    if len(args) == 0:
+        return ret
+
+    push_indent()
+
+    if dealloc:
+        ret += mcgen('''
+md = qapi_dealloc_visitor_new();
+v = qapi_dealloc_get_visitor(md);
+''')
+    else:
+        ret += mcgen('''
+mi = qmp_input_visitor_new(%(obj)s);
+v = qmp_input_get_visitor(mi);
+''',
+                     obj=obj)
+
+    for argname, argtype, optional, structured in parse_args(args):
+        if optional:
+            ret += mcgen('''
+visit_start_optional(v, &has_%(c_name)s, "%(name)s", errp);
+if (has_%(c_name)s) {
+''',
+                         c_name=c_var(argname), name=argname)
+            push_indent()
+        ret += mcgen('''
+visit_type_%(argtype)s(v, &%(c_name)s, "%(name)s", errp);
+''',
+                      c_name=c_var(argname), name=argname, argtype=argtype)
+        if optional:
+            pop_indent()
+            ret += mcgen('''
+}
+visit_end_optional(v, errp);
+''')
+
+    if dealloc:
+        ret += mcgen('''
+qapi_dealloc_visitor_cleanup(md);
+''')
+    else:
+        ret += mcgen('''
+qmp_input_visitor_cleanup(mi);
+''')
+    pop_indent()
+    return ret.rstrip()
+
+def gen_marshal_output(name, args, ret_type):
+    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)
+{
+    QapiDeallocVisitor *md = qapi_dealloc_visitor_new();
+    QmpOutputVisitor *mo = qmp_output_visitor_new();
+    Visitor *v;
+
+    v = qmp_output_get_visitor(mo);
+    visit_type_%(ret_type)s(v, &ret_in, "unused", errp);
+    if (!error_is_set(errp)) {
+        *ret_out = qmp_output_get_qobject(mo);
+    }
+    qmp_output_visitor_cleanup(mo);
+    v = qapi_dealloc_get_visitor(md);
+    visit_type_%(ret_type)s(v, &ret_in, "unused", errp);
+    qapi_dealloc_visitor_cleanup(md);
+}
+''',
+            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):
+    ret = mcgen('''
+static void qmp_marshal_input_%(c_name)s(QDict *args, QObject **ret, Error **errp)
+{
+''',
+                c_name=c_var(name))
+
+    if ret_type:
+        if c_type(ret_type).endswith("*"):
+            retval = "    %s retval = NULL;" % c_type(ret_type)
+        else:
+            retval = "    %s retval;" % c_type(ret_type)
+        ret += mcgen('''
+%(retval)s
+''',
+                     retval=retval)
+
+    if len(args) > 0:
+        ret += mcgen('''
+%(visitor_input_containers_decl)s
+%(visitor_input_vars_decl)s
+
+%(visitor_input_block)s
+
+''',
+                     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)"))
+
+    ret += mcgen('''
+    if (error_is_set(errp)) {
+        goto out;
+    }
+%(sync_call)s
+''',
+                 sync_call=gen_sync_call(name, args, ret_type, indent=4))
+    ret += mcgen('''
+
+out:
+''')
+    ret += mcgen('''
+%(visitor_input_block_cleanup)s
+    return;
+}
+''',
+                 visitor_input_block_cleanup=gen_visitor_input_block(args, None, dealloc=True))
+    return ret
+
+def gen_registry(commands):
+    registry=""
+    push_indent()
+    for cmd in commands:
+        registry += mcgen('''
+qmp_register_command("%(name)s", qmp_marshal_input_%(c_name)s);
+''',
+                     name=cmd['command'], c_name=c_var(cmd['command']))
+    pop_indent()
+    ret = mcgen('''
+static void qmp_init_marshal(void)
+{
+%(registry)s
+}
+
+qapi_init(qmp_init_marshal);
+''',
+                registry=registry.rstrip())
+    return ret
+
+def gen_command_decl_prologue(header, guard, prefix=""):
+    ret = mcgen('''
+/* THIS FILE IS AUTOMATICALLY GENERATED, DO NOT MODIFY */
+
+/*
+ * schema-defined QAPI function prototypes
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#ifndef %(guard)s
+#define %(guard)s
+
+#include "%(prefix)sqapi-types.h"
+#include "error.h"
+
+''',
+                 header=basename(h_file), guard=guardname(h_file), prefix=prefix)
+    return ret
+
+def gen_command_def_prologue(prefix="", proxy=False):
+    ret = mcgen('''
+/* THIS FILE IS AUTOMATICALLY GENERATED, DO NOT MODIFY */
+
+/*
+ * schema-defined QMP->QAPI command dispatch
+ *
+ * Copyright IBM, Corp. 2011
+ *
+ * Authors:
+ *  Anthony Liguori   <aliguori@us.ibm.com>
+ *
+ * This work is licensed under the terms of the GNU LGPL, version 2.1 or later.
+ * See the COPYING.LIB file in the top-level directory.
+ *
+ */
+
+#include "qemu-objects.h"
+#include "qapi/qmp-core.h"
+#include "qapi/qapi-visit-core.h"
+#include "qapi/qmp-output-visitor.h"
+#include "qapi/qmp-input-visitor.h"
+#include "qapi/qapi-dealloc-visitor.h"
+#include "%(prefix)sqapi-types.h"
+#include "%(prefix)sqapi-visit.h"
+
+''',
+                prefix=prefix)
+    if not proxy:
+        ret += '#include "%sqmp-commands.h"' % prefix
+    return ret + "\n"
+
+
+try:
+    opts, args = getopt.gnu_getopt(sys.argv[1:], "p:o:", ["prefix=", "output-dir=", "type="])
+except getopt.GetoptError, err:
+    print str(err)
+    sys.exit(1)
+
+output_dir = ""
+prefix = ""
+dispatch_type = "sync"
+c_file = 'qmp-marshal.c'
+h_file = 'qmp-commands.h'
+
+for o, a in opts:
+    if o in ("-p", "--prefix"):
+        prefix = a
+    elif o in ("-o", "--output-dir"):
+        output_dir = a + "/"
+    elif o in ("-t", "--type"):
+        dispatch_type = a
+
+c_file = output_dir + prefix + c_file
+h_file = output_dir + prefix + h_file
+
+try:
+    os.makedirs(output_dir)
+except os.error, e:
+    if e.errno != errno.EEXIST:
+        raise
+
+exprs = parse_schema(sys.stdin)
+commands = filter(lambda expr: expr.has_key('command'), exprs)
+
+if dispatch_type == "sync":
+    fdecl = open(h_file, 'w')
+    fdef = open(c_file, 'w')
+    ret = gen_command_decl_prologue(header=basename(h_file), guard=guardname(h_file), prefix=prefix)
+    fdecl.write(ret)
+    ret = gen_command_def_prologue(prefix=prefix)
+    fdef.write(ret)
+
+    for cmd in commands:
+        arglist = []
+        ret_type = None
+        if cmd.has_key('data'):
+            arglist = cmd['data']
+        if cmd.has_key('returns'):
+            ret_type = cmd['returns']
+        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"
+            fdef.write(ret)
+        ret = gen_marshal_input(cmd['command'], arglist, ret_type) + "\n"
+        fdef.write(ret)
+
+    fdecl.write("\n#endif");
+    ret = gen_registry(commands)
+    fdef.write(ret)
+
+    fdef.flush()
+    fdef.close()
+    fdecl.flush()
+    fdecl.close()