qapi: Plumb in 'boxed' to qapi generator lower levels

The next patch will add support for passing a qapi union type
as the 'data' of a command.  But to do that, the user function
for implementing the command, as called by the generated
marshal command, must take the corresponding C struct as a
single boxed pointer, rather than a breakdown into one
parameter per member.  Even without a union, being able to use
a C struct rather than a list of parameters can make it much
easier to handle coding with QAPI.

This patch adds the internal plumbing of a 'boxed' flag
associated with each command and event.  In several cases,
this means adding indentation, with one new dead branch and
the remaining branch being the original code more deeply
nested; this was done so that the new implementation in the
next patch is easier to review without also being mixed with
indentation changes.

For this patch, no behavior or generated output changes, other
than the testsuite outputting the value of the new flag
(always False for now).

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1468468228-27827-9-git-send-email-eblake@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Identifier box renamed to boxed in two places]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

1 files changed, 27 insertions, 16 deletions

diff --git a/scripts/qapi.py b/scripts/qapi.py
index 9c48f6d80a..0c6159c400 100644
--- a/scripts/qapi.py
+++ b/scripts/qapi.py
@@ -826,10 +826,10 @@ class QAPISchemaVisitor(object):
         pass
 
     def visit_command(self, name, info, arg_type, ret_type,
-                      gen, success_response):
+                      gen, success_response, boxed):
         pass
 
-    def visit_event(self, name, info, arg_type):
+    def visit_event(self, name, info, arg_type, boxed):
         pass
 
 
@@ -1165,7 +1165,8 @@ class QAPISchemaAlternateType(QAPISchemaType):
 
 
 class QAPISchemaCommand(QAPISchemaEntity):
-    def __init__(self, name, info, arg_type, ret_type, gen, success_response):
+    def __init__(self, name, info, arg_type, ret_type, gen, success_response,
+                 boxed):
         QAPISchemaEntity.__init__(self, name, info)
         assert not arg_type or isinstance(arg_type, str)
         assert not ret_type or isinstance(ret_type, str)
@@ -1175,12 +1176,14 @@ class QAPISchemaCommand(QAPISchemaEntity):
         self.ret_type = None
         self.gen = gen
         self.success_response = success_response
+        self.boxed = boxed
 
     def check(self, schema):
         if self._arg_type_name:
             self.arg_type = schema.lookup_type(self._arg_type_name)
             assert isinstance(self.arg_type, QAPISchemaObjectType)
             assert not self.arg_type.variants   # not implemented
+            assert not self.boxed               # not implemented
         if self._ret_type_name:
             self.ret_type = schema.lookup_type(self._ret_type_name)
             assert isinstance(self.ret_type, QAPISchemaType)
@@ -1188,24 +1191,26 @@ class QAPISchemaCommand(QAPISchemaEntity):
     def visit(self, visitor):
         visitor.visit_command(self.name, self.info,
                               self.arg_type, self.ret_type,
-                              self.gen, self.success_response)
+                              self.gen, self.success_response, self.boxed)
 
 
 class QAPISchemaEvent(QAPISchemaEntity):
-    def __init__(self, name, info, arg_type):
+    def __init__(self, name, info, arg_type, boxed):
         QAPISchemaEntity.__init__(self, name, info)
         assert not arg_type or isinstance(arg_type, str)
         self._arg_type_name = arg_type
         self.arg_type = None
+        self.boxed = boxed
 
     def check(self, schema):
         if self._arg_type_name:
             self.arg_type = schema.lookup_type(self._arg_type_name)
             assert isinstance(self.arg_type, QAPISchemaObjectType)
             assert not self.arg_type.variants   # not implemented
+            assert not self.boxed               # not implemented
 
     def visit(self, visitor):
-        visitor.visit_event(self.name, self.info, self.arg_type)
+        visitor.visit_event(self.name, self.info, self.arg_type, self.boxed)
 
 
 class QAPISchema(object):
@@ -1381,6 +1386,7 @@ class QAPISchema(object):
         rets = expr.get('returns')
         gen = expr.get('gen', True)
         success_response = expr.get('success-response', True)
+        boxed = expr.get('boxed', False)
         if isinstance(data, OrderedDict):
             data = self._make_implicit_object_type(
                 name, info, 'arg', self._make_members(data, info))
@@ -1388,15 +1394,16 @@ class QAPISchema(object):
             assert len(rets) == 1
             rets = self._make_array_type(rets[0], info)
         self._def_entity(QAPISchemaCommand(name, info, data, rets, gen,
-                                           success_response))
+                                           success_response, boxed))
 
     def _def_event(self, expr, info):
         name = expr['event']
         data = expr.get('data')
+        boxed = expr.get('boxed', False)
         if isinstance(data, OrderedDict):
             data = self._make_implicit_object_type(
                 name, info, 'arg', self._make_members(data, info))
-        self._def_entity(QAPISchemaEvent(name, info, data))
+        self._def_entity(QAPISchemaEvent(name, info, data, boxed))
 
     def _def_exprs(self):
         for expr_elem in self.exprs:
@@ -1639,18 +1646,22 @@ extern const char *const %(c_name)s_lookup[];
     return ret
 
 
-def gen_params(arg_type, extra):
+def gen_params(arg_type, boxed, extra):
     if not arg_type:
         return extra
-    assert not arg_type.variants
     ret = ''
     sep = ''
-    for memb in arg_type.members:
-        ret += sep
-        sep = ', '
-        if memb.optional:
-            ret += 'bool has_%s, ' % c_name(memb.name)
-        ret += '%s %s' % (memb.type.c_param_type(), c_name(memb.name))
+    if boxed:
+        assert False     # not implemented
+    else:
+        assert not arg_type.variants
+        for memb in arg_type.members:
+            ret += sep
+            sep = ', '
+            if memb.optional:
+                ret += 'bool has_%s, ' % c_name(memb.name)
+            ret += '%s %s' % (memb.type.c_param_type(),
+                              c_name(memb.name))
     if extra:
         ret += sep + extra
     return ret