[Qemu-devel] [PATCH RFC v3 04/32] qapi: New QAPISchemaVisitor

[Markus Armbruster]

The visitor will help keeping the code generation code simple and
reasonably separated from QAPISchema details.

Signed-off-by: Markus Armbruster <address@hidden>
Reviewed-by: Eric Blake <address@hidden>
---
 scripts/qapi.py | 46 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 46 insertions(+)

diff --git a/scripts/qapi.py b/scripts/qapi.py
index 3c596c3..019d22c 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -771,6 +771,29 @@ class QAPISchemaEntity(object):
         return c_name(self.name)
     def check(self, schema):
         pass
+    def visit(self, visitor):
+        pass
+
+class QAPISchemaVisitor(object):
+    def visit_begin(self):
+        pass
+    def visit_end(self):
+        pass
+    def visit_builtin_type(self, name, info, json_type):
+        pass
+    def visit_enum_type(self, name, info, values):
+        pass
+    def visit_array_type(self, name, info, element_type):
+        pass
+    def visit_object_type(self, name, info, base, members, variants):
+        pass
+    def visit_alternate_type(self, name, info, variants):
+        pass
+    def visit_command(self, name, info, arg_type, ret_type,
+                      gen, success_response):
+        pass
+    def visit_event(self, name, info, arg_type):
+        pass
 
 class QAPISchemaType(QAPISchemaEntity):
     def c_type(self, is_param=False):
@@ -808,6 +831,8 @@ class QAPISchemaBuiltinType(QAPISchemaType):
         return self.c_null_val
     def json_type(self):
         return self.json_type_name
+    def visit(self, visitor):
+        visitor.visit_builtin_type(self.name, self.info, self.json_type())
 
 class QAPISchemaEnumType(QAPISchemaType):
     def __init__(self, name, info, values):
@@ -823,6 +848,8 @@ class QAPISchemaEnumType(QAPISchemaType):
         return c_enum_const(self.name, (self.values + ['MAX'])[0])
     def json_type(self):
         return 'string'
+    def visit(self, visitor):
+        visitor.visit_enum_type(self.name, self.info, self.values)
 
 class QAPISchemaArrayType(QAPISchemaType):
     def __init__(self, name, info, element_type):
@@ -833,6 +860,8 @@ class QAPISchemaArrayType(QAPISchemaType):
     def check(self, schema):
         self.element_type = schema.lookup_type(self.element_type_name)
         assert self.element_type
+    def visit(self, visitor):
+        visitor.visit_array_type(self.name, self.info, self.element_type)
 
 class QAPISchemaObjectType(QAPISchemaType):
     def __init__(self, name, info, base, local_members, variants):
@@ -876,6 +905,9 @@ class QAPISchemaObjectType(QAPISchemaType):
         return QAPISchemaType.c_type(self)
     def json_type(self):
         return 'object'
+    def visit(self, visitor):
+        visitor.visit_object_type(self.name, self.info,
+                                  self.base, self.local_members, self.variants)
 
 class QAPISchemaObjectTypeMember(object):
     def __init__(self, name, typ, optional):
@@ -939,6 +971,8 @@ class QAPISchemaAlternateType(QAPISchemaType):
         self.variants = variants
     def check(self, schema):
         self.variants.check(schema, [], {})
+    def visit(self, visitor):
+        visitor.visit_alternate_type(self.name, self.info, self.variants)
 
 class QAPISchemaCommand(QAPISchemaEntity):
     def __init__(self, name, info, arg_type, ret_type, gen, success_response):
@@ -959,6 +993,10 @@ class QAPISchemaCommand(QAPISchemaEntity):
         if self.ret_type_name:
             self.ret_type = schema.lookup_type(self.ret_type_name)
             assert isinstance(self.ret_type, QAPISchemaType)
+    def visit(self, visitor):
+        visitor.visit_command(self.name, self.info,
+                              self.arg_type, self.ret_type,
+                              self.gen, self.success_response)
 
 class QAPISchemaEvent(QAPISchemaEntity):
     def __init__(self, name, info, arg_type):
@@ -971,6 +1009,8 @@ class QAPISchemaEvent(QAPISchemaEntity):
             self.arg_type = schema.lookup_type(self.arg_type_name)
             assert isinstance(self.arg_type, QAPISchemaObjectType)
             assert not self.arg_type.variants # not implemented
+    def visit(self, visitor):
+        visitor.visit_event(self.name, self.info, self.arg_type)
 
 class QAPISchema(object):
     def __init__(self, fname):
@@ -1166,6 +1206,12 @@ class QAPISchema(object):
         for ent in self.entity_dict.values():
             ent.check(self)
 
+    def visit(self, visitor):
+        visitor.visit_begin()
+        for name in sorted(self.entity_dict.keys()):
+            self.entity_dict[name].visit(visitor)
+        visitor.visit_end()
+
 #
 # Code generation helpers
 #
-- 
2.4.3