qapi: generate a literal qobject for introspection

Replace the generated json string with a literal qobject. The later is
easier to deal with, at run time as well as compile time: adding #if
conditionals will be easier than in a json string.

The output of query-qmp-schema is not changed.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180305172951.2150-5-marcandre.lureau@redhat.com>
[eblake: fix python 3 failure]
Signed-off-by: Eric Blake <eblake@redhat.com>

docs/devel/qapi-code-gen.txt

@@ -1319,18 +1319,27 @@ Example:
     #ifndef EXAMPLE_QMP_INTROSPECT_H
     #define EXAMPLE_QMP_INTROSPECT_H
 
-    extern const char example_qmp_schema_json[];
+    extern const QLitObject qmp_schema_qlit;
 
     #endif
     $ cat qapi-generated/example-qapi-introspect.c
 [Uninteresting stuff omitted...]
 
-    const char example_qmp_schema_json[] = "["
+    const QLitObject example_qmp_schema_qlit = QLIT_QLIST(((QLitObject[]) {
-        "{\"arg-type\": \"0\", \"meta-type\": \"event\", \"name\": \"MY_EVENT\"}, "
+        QLIT_QDICT(((QLitDictEntry[]) {
-        "{\"arg-type\": \"1\", \"meta-type\": \"command\", \"name\": \"my-command\", \"ret-type\": \"2\"}, "
+            { "arg-type", QLIT_QSTR("0") },
-        "{\"members\": [], \"meta-type\": \"object\", \"name\": \"0\"}, "
+            { "meta-type", QLIT_QSTR("event") },
-        "{\"members\": [{\"name\": \"arg1\", \"type\": \"[2]\"}], \"meta-type\": \"object\", \"name\": \"1\"}, "
+            { "name", QLIT_QSTR("Event") },
-        "{\"members\": [{\"name\": \"integer\", \"type\": \"int\"}, {\"default\": null, \"name\": \"string\", \"type\": \"str\"}], \"meta-type\": \"object\", \"name\": \"2\"}, "
+            { }
-        "{\"element-type\": \"2\", \"meta-type\": \"array\", \"name\": \"[2]\"}, "
+        })),
-        "{\"json-type\": \"int\", \"meta-type\": \"builtin\", \"name\": \"int\"}, "
+        QLIT_QDICT(((QLitDictEntry[]) {
-        "{\"json-type\": \"string\", \"meta-type\": \"builtin\", \"name\": \"str\"}]";
+            { "members", QLIT_QLIST(((QLitObject[]) {
+                { }
+            })) },
+            { "meta-type", QLIT_QSTR("object") },
+            { "name", QLIT_QSTR("0") },
+            { }
+        })),
+        ...
+        { }
+    }));

monitor.c

@@ -956,7 +956,7 @@ EventInfoList *qmp_query_events(Error **errp)
 static void qmp_query_qmp_schema(QDict *qdict, QObject **ret_data,
                                  Error **errp)
 {
-    *ret_data = qobject_from_json(qmp_schema_json, &error_abort);
+    *ret_data = qobject_from_qlit(&qmp_schema_qlit);
 }
 
 /*

scripts/qapi/introspect.py

@@ -13,26 +13,36 @@
 from qapi.common import *
 
 
-# Caveman's json.dumps() replacement (we're stuck at Python 2.4)
+def to_qlit(obj, level=0, suppress_first_indent=False):
-# TODO try to use json.dumps() once we get unstuck
+
-def to_json(obj, level=0):
+    def indent(level):
+        return level * 4 * ' '
+
+    ret = ''
+    if not suppress_first_indent:
+        ret += indent(level)
     if obj is None:
-        ret = 'null'
+        ret += 'QLIT_QNULL'
     elif isinstance(obj, str):
-        ret = '"' + obj.replace('"', r'\"') + '"'
+        ret += 'QLIT_QSTR(' + to_c_string(obj) + ')'
     elif isinstance(obj, list):
-        elts = [to_json(elt, level + 1)
+        elts = [to_qlit(elt, level + 1)
                 for elt in obj]
-        ret = '[' + ', '.join(elts) + ']'
+        elts.append(indent(level + 1) + "{}")
+        ret += 'QLIT_QLIST(((QLitObject[]) {\n'
+        ret += ',\n'.join(elts) + '\n'
+        ret += indent(level) + '}))'
     elif isinstance(obj, dict):
-        elts = ['"%s": %s' % (key.replace('"', r'\"'),
+        elts = []
-                              to_json(obj[key], level + 1))
+        for key, value in sorted(obj.items()):
-                for key in sorted(obj.keys())]
+            elts.append(indent(level + 1) + '{ %s, %s }' %
-        ret = '{' + ', '.join(elts) + '}'
+                        (to_c_string(key), to_qlit(value, level + 1, True)))
+        elts.append(indent(level + 1) + '{}')
+        ret += 'QLIT_QDICT(((QLitDictEntry[]) {\n'
+        ret += ',\n'.join(elts) + '\n'
+        ret += indent(level) + '}))'
     else:
         assert False                # not implemented
-    if level == 1:
-        ret = '\n' + ret
     return ret
 
 
@@ -48,7 +58,7 @@ def __init__(self, prefix, unmask):
             ' * QAPI/QMP schema introspection', __doc__)
         self._unmask = unmask
         self._schema = None
-        self._jsons = []
+        self._qlits = []
         self._used_types = []
         self._name_map = {}
         self._genc.add(mcgen('''
@@ -63,27 +73,27 @@ def visit_begin(self, schema):
 
     def visit_end(self):
         # visit the types that are actually used
-        jsons = self._jsons
+        qlits = self._qlits
-        self._jsons = []
+        self._qlits = []
         for typ in self._used_types:
             typ.visit(self)
         # generate C
         # TODO can generate awfully long lines
-        jsons.extend(self._jsons)
+        qlits.extend(self._qlits)
-        name = c_name(self._prefix, protect=False) + 'qmp_schema_json'
+        name = c_name(self._prefix, protect=False) + 'qmp_schema_qlit'
         self._genh.add(mcgen('''
-extern const char %(c_name)s[];
+#include "qapi/qmp/qlit.h"
+
+extern const QLitObject %(c_name)s;
 ''',
                              c_name=c_name(name)))
-        lines = to_json(jsons).split('\n')
-        c_string = '\n    '.join([to_c_string(line) for line in lines])
         self._genc.add(mcgen('''
-const char %(c_name)s[] = %(c_string)s;
+const QLitObject %(c_name)s = %(c_string)s;
 ''',
                              c_name=c_name(name),
-                             c_string=c_string))
+                             c_string=to_qlit(qlits)))
         self._schema = None
-        self._jsons = []
+        self._qlits = []
         self._used_types = []
         self._name_map = {}
 
@@ -117,12 +127,12 @@ def _use_type(self, typ):
             return '[' + self._use_type(typ.element_type) + ']'
         return self._name(typ.name)
 
-    def _gen_json(self, name, mtype, obj):
+    def _gen_qlit(self, name, mtype, obj):
         if mtype not in ('command', 'event', 'builtin', 'array'):
             name = self._name(name)
         obj['name'] = name
         obj['meta-type'] = mtype
-        self._jsons.append(obj)
+        self._qlits.append(obj)
 
     def _gen_member(self, member):
         ret = {'name': member.name, 'type': self._use_type(member.type)}
@@ -138,24 +148,24 @@ def _gen_variant(self, variant):
         return {'case': variant.name, 'type': self._use_type(variant.type)}
 
     def visit_builtin_type(self, name, info, json_type):
-        self._gen_json(name, 'builtin', {'json-type': json_type})
+        self._gen_qlit(name, 'builtin', {'json-type': json_type})
 
     def visit_enum_type(self, name, info, values, prefix):
-        self._gen_json(name, 'enum', {'values': values})
+        self._gen_qlit(name, 'enum', {'values': values})
 
     def visit_array_type(self, name, info, element_type):
         element = self._use_type(element_type)
-        self._gen_json('[' + element + ']', 'array', {'element-type': element})
+        self._gen_qlit('[' + element + ']', 'array', {'element-type': element})
 
     def visit_object_type_flat(self, name, info, members, variants):
         obj = {'members': [self._gen_member(m) for m in members]}
         if variants:
             obj.update(self._gen_variants(variants.tag_member.name,
                                           variants.variants))
-        self._gen_json(name, 'object', obj)
+        self._gen_qlit(name, 'object', obj)
 
     def visit_alternate_type(self, name, info, variants):
-        self._gen_json(name, 'alternate',
+        self._gen_qlit(name, 'alternate',
                        {'members': [{'type': self._use_type(m.type)}
                                     for m in variants.variants]})
 
@@ -163,13 +173,13 @@ def visit_command(self, name, info, arg_type, ret_type,
                       gen, success_response, boxed):
         arg_type = arg_type or self._schema.the_empty_object_type
         ret_type = ret_type or self._schema.the_empty_object_type
-        self._gen_json(name, 'command',
+        self._gen_qlit(name, 'command',
                        {'arg-type': self._use_type(arg_type),
                         'ret-type': self._use_type(ret_type)})
 
     def visit_event(self, name, info, arg_type, boxed):
         arg_type = arg_type or self._schema.the_empty_object_type
-        self._gen_json(name, 'event', {'arg-type': self._use_type(arg_type)})
+        self._gen_qlit(name, 'event', {'arg-type': self._use_type(arg_type)})
 
 
 def gen_introspect(schema, output_dir, prefix, opt_unmask):

tests/test-qobject-input-visitor.c

@@ -1250,24 +1250,27 @@ static void test_visitor_in_fail_alternate(TestInputVisitorData *data,
 }
 
 static void do_test_visitor_in_qmp_introspect(TestInputVisitorData *data,
-                                              const char *schema_json)
+                                              const QLitObject *qlit)
 {
     SchemaInfoList *schema = NULL;
+    QObject *obj = qobject_from_qlit(qlit);
     Visitor *v;
 
-    v = visitor_input_test_init_raw(data, schema_json);
+    v = qobject_input_visitor_new(obj);
 
     visit_type_SchemaInfoList(v, NULL, &schema, &error_abort);
     g_assert(schema);
 
     qapi_free_SchemaInfoList(schema);
+    qobject_decref(obj);
+    visit_free(v);
 }
 
 static void test_visitor_in_qmp_introspect(TestInputVisitorData *data,
                                            const void *unused)
 {
-    do_test_visitor_in_qmp_introspect(data, test_qmp_schema_json);
+    do_test_visitor_in_qmp_introspect(data, &test_qmp_schema_qlit);
-    do_test_visitor_in_qmp_introspect(data, qmp_schema_json);
+    do_test_visitor_in_qmp_introspect(data, &qmp_schema_qlit);
 }
 
 int main(int argc, char **argv)