qapi/common.py: move build_params into gen.py

Including it in common.py creates a circular import dependency; schema
relies on common, but common.build_params requires a type annotation
from schema. To type this properly, it needs to be moved outside the
cycle.

Signed-off-by: John Snow <jsnow@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>
Reviewed-by: Cleber Rosa <crosa@redhat.com>
Message-Id: <20201009161558.107041-18-jsnow@redhat.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

scripts/qapi/commands.py

@@ -13,8 +13,13 @@
 See the COPYING file in the top-level directory.
 """
 
-from .common import build_params, c_name, mcgen
-from .gen import QAPIGenCCode, QAPISchemaModularCVisitor, ifcontext
+from .common import c_name, mcgen
+from .gen import (
+    QAPIGenCCode,
+    QAPISchemaModularCVisitor,
+    build_params,
+    ifcontext,
+)
 
 
 def gen_command_decl(name, arg_type, boxed, ret_type):

scripts/qapi/common.py

@@ -210,26 +210,3 @@ def gen_endif(ifcond: Sequence[str]) -> str:
 #endif /* %(cond)s */
 ''', cond=ifc)
     return ret
-
-
-def build_params(arg_type,
-                 boxed: bool,
-                 extra: Optional[str] = None) -> str:
-    ret = ''
-    sep = ''
-    if boxed:
-        assert arg_type
-        ret += '%s arg' % arg_type.c_param_type()
-        sep = ', '
-    elif arg_type:
-        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 if ret else 'void'

scripts/qapi/events.py

@@ -12,13 +12,8 @@
 See the COPYING file in the top-level directory.
 """
 
-from .common import (
-    build_params,
-    c_enum_const,
-    c_name,
-    mcgen,
-)
-from .gen import QAPISchemaModularCVisitor, ifcontext
+from .common import c_enum_const, c_name, mcgen
+from .gen import QAPISchemaModularCVisitor, build_params, ifcontext
 from .schema import QAPISchemaEnumMember
 from .types import gen_enum, gen_enum_lookup
 

scripts/qapi/gen.py

@@ -2,7 +2,7 @@
 #
 # QAPI code generation
 #
-# Copyright (c) 2018-2019 Red Hat Inc.
+# Copyright (c) 2015-2019 Red Hat Inc.
 #
 # Authors:
 #  Markus Armbruster <armbru@redhat.com>
@@ -15,16 +15,18 @@
 import errno
 import os
 import re
+from typing import Optional
 
 from .common import (
     c_fname,
+    c_name,
     gen_endif,
     gen_if,
     guardend,
     guardstart,
     mcgen,
 )
-from .schema import QAPISchemaVisitor
+from .schema import QAPISchemaObjectType, QAPISchemaVisitor
 
 
 class QAPIGen:
@@ -90,6 +92,29 @@ def _wrap_ifcond(ifcond, before, after):
     return out
 
 
+def build_params(arg_type: Optional[QAPISchemaObjectType],
+                 boxed: bool,
+                 extra: Optional[str] = None) -> str:
+    ret = ''
+    sep = ''
+    if boxed:
+        assert arg_type
+        ret += '%s arg' % arg_type.c_param_type()
+        sep = ', '
+    elif arg_type:
+        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 if ret else 'void'
+
+
 class QAPIGenCCode(QAPIGen):
 
     def __init__(self, fname):