qapi: Adjust names of implicit types

The original choice of ':obj-' as the prefix for implicit types
made it obvious that we weren't going to clash with any user-defined
names, which cannot contain ':'.  But now we want to create structs
for implicit types, to get rid of special cases in the generators,
and our use of ':' in implicit names needs a tweak to produce valid
C code.

We could transliterate ':' to '_', except that C99 mandates that
"identifiers that begin with an underscore are always reserved for
use as identifiers with file scope in both the ordinary and tag name
spaces".  So it's time to change our naming convention: we can
instead use the 'q_' prefix that we reserved for ourselves back in
commit 9fb081e0.  Technically, since we aren't planning on exposing
the empty type in generated code, we could keep the name ':empty',
but renaming it to 'q_empty' makes the check for startswith('q_')
cover all implicit types, whether or not code is generated for them.

As long as we don't declare 'empty' or 'obj' ticklish, it shouldn't
clash with c_name() prepending 'q_' to the user's ticklish names.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <1458254921-17042-5-git-send-email-eblake@redhat.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>

docs/qapi-code-gen.txt

@@ -575,9 +575,9 @@ names an object type without members.
 Example: the SchemaInfo for command query-qmp-schema
 
     { "name": "query-qmp-schema", "meta-type": "command",
-      "arg-type": ":empty", "ret-type": "SchemaInfoList" }
+      "arg-type": "q_empty", "ret-type": "SchemaInfoList" }
 
-    Type ":empty" is an object type without members, and type
+    Type "q_empty" is an automatic object type without members, and type
     "SchemaInfoList" is the array of SchemaInfo type.
 
 The SchemaInfo for an event has meta-type "event", and variant member
@@ -594,9 +594,9 @@ QAPI schema implicitly defines an object type.
 Example: the SchemaInfo for EVENT_C from section Events
 
     { "name": "EVENT_C", "meta-type": "event",
-      "arg-type": ":obj-EVENT_C-arg" }
+      "arg-type": "q_obj-EVENT_C-arg" }
 
-    Type ":obj-EVENT_C-arg" is an implicitly defined object type with
+    Type "q_obj-EVENT_C-arg" is an implicitly defined object type with
     the two members from the event's definition.
 
 The SchemaInfo for struct and union types has meta-type "object".
@@ -660,11 +660,11 @@ Union types
           { "name": "type", "type": "BlockdevOptionsKind" } ],
       "tag": "type",
       "variants": [
-          { "case": "file", "type": ":obj-FileOptions-wrapper" },
+          { "case": "file", "type": "q_obj-FileOptions-wrapper" },
-          { "case": "qcow2", "type": ":obj-Qcow2Options-wrapper" } ] }
+          { "case": "qcow2", "type": "q_obj-Qcow2Options-wrapper" } ] }
 
     Enumeration type "BlockdevOptionsKind" and the object types
-    ":obj-FileOptions-wrapper", ":obj-Qcow2Options-wrapper" are
+    "q_obj-FileOptions-wrapper", "q_obj-Qcow2Options-wrapper" are
     implicitly defined.
 
 The SchemaInfo for an alternate type has meta-type "alternate", and

scripts/qapi.py

@@ -391,7 +391,8 @@ def check_name(expr_info, source, name, allow_optional=False,
     # code always prefixes it with the enum name
     if enum_member and membername[0].isdigit():
         membername = 'D' + membername
-    # Reserve the entire 'q_' namespace for c_name()
+    # Reserve the entire 'q_' namespace for c_name(), and for 'q_empty'
+    # and 'q_obj_*' implicit type names.
     if not valid_name.match(membername) or \
        c_name(membername, False).startswith('q_'):
         raise QAPIExprError(expr_info,
@@ -994,8 +995,9 @@ class QAPISchemaObjectType(QAPISchemaType):
             m.check_clash(info, seen)
 
     def is_implicit(self):
-        # See QAPISchema._make_implicit_object_type()
+        # See QAPISchema._make_implicit_object_type(), as well as
-        return self.name[0] == ':'
+        # _def_predefineds()
+        return self.name.startswith('q_')
 
     def c_name(self):
         assert not self.is_implicit()
@@ -1044,10 +1046,10 @@ class QAPISchemaMember(object):
 
     def _pretty_owner(self):
         owner = self.owner
-        if owner.startswith(':obj-'):
+        if owner.startswith('q_obj_'):
             # See QAPISchema._make_implicit_object_type() - reverse the
             # mapping there to create a nice human-readable description
-            owner = owner[5:]
+            owner = owner[6:]
             if owner.endswith('-arg'):
                 return '(parameter of %s)' % owner[:-4]
             else:
@@ -1266,8 +1268,8 @@ class QAPISchema(object):
                   ('bool',   'boolean', 'bool',     'false'),
                   ('any',    'value',   'QObject' + pointer_suffix, 'NULL')]:
             self._def_builtin_type(*t)
-        self.the_empty_object_type = QAPISchemaObjectType(':empty', None, None,
+        self.the_empty_object_type = QAPISchemaObjectType('q_empty', None,
-                                                          [], None)
+                                                          None, [], None)
         self._def_entity(self.the_empty_object_type)
         qtype_values = self._make_enum_members(['none', 'qnull', 'qint',
                                                 'qstring', 'qdict', 'qlist',
@@ -1295,7 +1297,7 @@ class QAPISchema(object):
         if not members:
             return None
         # See also QAPISchemaObjectTypeMember._pretty_owner()
-        name = ':obj-%s-%s' % (name, role)
+        name = 'q_obj_%s-%s' % (name, role)
         if not self.lookup_entity(name, QAPISchemaObjectType):
             self._def_entity(QAPISchemaObjectType(name, info, None,
                                                   members, None))

tests/qapi-schema/comments.out

@@ -1,4 +1,4 @@
-object :empty
 enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool']
     prefix QTYPE
 enum Status ['good', 'bad', 'ugly']
+object q_empty

tests/qapi-schema/empty.out

@@ -1,3 +1,3 @@
-object :empty
 enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool']
     prefix QTYPE
+object q_empty

tests/qapi-schema/event-case.out

@@ -1,4 +1,4 @@
-object :empty
 enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool']
     prefix QTYPE
 event oops None
+object q_empty

tests/qapi-schema/ident-with-escape.out

@@ -1,7 +1,7 @@
-object :empty
-object :obj-fooA-arg
-    member bar1: str optional=False
 enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool']
     prefix QTYPE
-command fooA :obj-fooA-arg -> None
+command fooA q_obj_fooA-arg -> None
    gen=True success_response=True
+object q_empty
+object q_obj_fooA-arg
+    member bar1: str optional=False

tests/qapi-schema/include-relpath.out

@@ -1,4 +1,4 @@
-object :empty
 enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool']
     prefix QTYPE
 enum Status ['good', 'bad', 'ugly']
+object q_empty

tests/qapi-schema/include-repetition.out

@@ -1,4 +1,4 @@
-object :empty
 enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool']
     prefix QTYPE
 enum Status ['good', 'bad', 'ugly']
+object q_empty

tests/qapi-schema/include-simple.out

@@ -1,4 +1,4 @@
-object :empty
 enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool']
     prefix QTYPE
 enum Status ['good', 'bad', 'ugly']
+object q_empty

tests/qapi-schema/indented-expr.out

@@ -1,7 +1,7 @@
-object :empty
 enum QType ['none', 'qnull', 'qint', 'qstring', 'qdict', 'qlist', 'qfloat', 'qbool']
     prefix QTYPE
 command eins None -> None
    gen=True success_response=True
+object q_empty
 command zwei None -> None
    gen=True success_response=True

tests/qapi-schema/qapi-schema-test.out

@@ -1,58 +1,3 @@
-object :empty
-object :obj-EVENT_C-arg
-    member a: int optional=True
-    member b: UserDefOne optional=True
-    member c: str optional=False
-object :obj-EVENT_D-arg
-    member a: EventStructOne optional=False
-    member b: str optional=False
-    member c: str optional=True
-    member enum3: EnumOne optional=True
-object :obj-__org.qemu_x-command-arg
-    member a: __org.qemu_x-EnumList optional=False
-    member b: __org.qemu_x-StructList optional=False
-    member c: __org.qemu_x-Union2 optional=False
-    member d: __org.qemu_x-Alt optional=False
-object :obj-anyList-wrapper
-    member data: anyList optional=False
-object :obj-boolList-wrapper
-    member data: boolList optional=False
-object :obj-guest-get-time-arg
-    member a: int optional=False
-    member b: int optional=True
-object :obj-guest-sync-arg
-    member arg: any optional=False
-object :obj-int16List-wrapper
-    member data: int16List optional=False
-object :obj-int32List-wrapper
-    member data: int32List optional=False
-object :obj-int64List-wrapper
-    member data: int64List optional=False
-object :obj-int8List-wrapper
-    member data: int8List optional=False
-object :obj-intList-wrapper
-    member data: intList optional=False
-object :obj-numberList-wrapper
-    member data: numberList optional=False
-object :obj-sizeList-wrapper
-    member data: sizeList optional=False
-object :obj-str-wrapper
-    member data: str optional=False
-object :obj-strList-wrapper
-    member data: strList optional=False
-object :obj-uint16List-wrapper
-    member data: uint16List optional=False
-object :obj-uint32List-wrapper
-    member data: uint32List optional=False
-object :obj-uint64List-wrapper
-    member data: uint64List optional=False
-object :obj-uint8List-wrapper
-    member data: uint8List optional=False
-object :obj-user_def_cmd1-arg
-    member ud1a: UserDefOne optional=False
-object :obj-user_def_cmd2-arg
-    member ud1a: UserDefOne optional=False
-    member ud1b: UserDefOne optional=True
 alternate AltIntNum
     case i: int
     case n: number
@@ -73,8 +18,8 @@ alternate AltStrNum
     case n: number
 event EVENT_A None
 event EVENT_B None
-event EVENT_C :obj-EVENT_C-arg
+event EVENT_C q_obj_EVENT_C-arg
-event EVENT_D :obj-EVENT_D-arg
+event EVENT_D q_obj_EVENT_D-arg
 object Empty1
 object Empty2
     base Empty1
@@ -127,20 +72,20 @@ object UserDefFlatUnion2
     case value2: UserDefB
 object UserDefNativeListUnion
     member type: UserDefNativeListUnionKind optional=False
-    case integer: :obj-intList-wrapper
+    case integer: q_obj_intList-wrapper
-    case s8: :obj-int8List-wrapper
+    case s8: q_obj_int8List-wrapper
-    case s16: :obj-int16List-wrapper
+    case s16: q_obj_int16List-wrapper
-    case s32: :obj-int32List-wrapper
+    case s32: q_obj_int32List-wrapper
-    case s64: :obj-int64List-wrapper
+    case s64: q_obj_int64List-wrapper
-    case u8: :obj-uint8List-wrapper
+    case u8: q_obj_uint8List-wrapper
-    case u16: :obj-uint16List-wrapper
+    case u16: q_obj_uint16List-wrapper
-    case u32: :obj-uint32List-wrapper
+    case u32: q_obj_uint32List-wrapper
-    case u64: :obj-uint64List-wrapper
+    case u64: q_obj_uint64List-wrapper
-    case number: :obj-numberList-wrapper
+    case number: q_obj_numberList-wrapper
-    case boolean: :obj-boolList-wrapper
+    case boolean: q_obj_boolList-wrapper
-    case string: :obj-strList-wrapper
+    case string: q_obj_strList-wrapper
-    case sizes: :obj-sizeList-wrapper
+    case sizes: q_obj_sizeList-wrapper
-    case any: :obj-anyList-wrapper
+    case any: q_obj_anyList-wrapper
 enum UserDefNativeListUnionKind ['integer', 's8', 's16', 's32', 's64', 'u8', 'u16', 'u32', 'u64', 'number', 'boolean', 'string', 'sizes', 'any']
 object UserDefOne
     base UserDefZero
@@ -189,23 +134,78 @@ object __org.qemu_x-Struct2
     member array: __org.qemu_x-Union1List optional=False
 object __org.qemu_x-Union1
     member type: __org.qemu_x-Union1Kind optional=False
-    case __org.qemu_x-branch: :obj-str-wrapper
+    case __org.qemu_x-branch: q_obj_str-wrapper
 enum __org.qemu_x-Union1Kind ['__org.qemu_x-branch']
 object __org.qemu_x-Union2
     base __org.qemu_x-Base
     tag __org.qemu_x-member1
     case __org.qemu_x-value: __org.qemu_x-Struct2
-command __org.qemu_x-command :obj-__org.qemu_x-command-arg -> __org.qemu_x-Union1
+command __org.qemu_x-command q_obj___org.qemu_x-command-arg -> __org.qemu_x-Union1
    gen=True success_response=True
-command guest-get-time :obj-guest-get-time-arg -> int
+command guest-get-time q_obj_guest-get-time-arg -> int
    gen=True success_response=True
-command guest-sync :obj-guest-sync-arg -> any
+command guest-sync q_obj_guest-sync-arg -> any
    gen=True success_response=True
+object q_empty
+object q_obj_EVENT_C-arg
+    member a: int optional=True
+    member b: UserDefOne optional=True
+    member c: str optional=False
+object q_obj_EVENT_D-arg
+    member a: EventStructOne optional=False
+    member b: str optional=False
+    member c: str optional=True
+    member enum3: EnumOne optional=True
+object q_obj___org.qemu_x-command-arg
+    member a: __org.qemu_x-EnumList optional=False
+    member b: __org.qemu_x-StructList optional=False
+    member c: __org.qemu_x-Union2 optional=False
+    member d: __org.qemu_x-Alt optional=False
+object q_obj_anyList-wrapper
+    member data: anyList optional=False
+object q_obj_boolList-wrapper
+    member data: boolList optional=False
+object q_obj_guest-get-time-arg
+    member a: int optional=False
+    member b: int optional=True
+object q_obj_guest-sync-arg
+    member arg: any optional=False
+object q_obj_int16List-wrapper
+    member data: int16List optional=False
+object q_obj_int32List-wrapper
+    member data: int32List optional=False
+object q_obj_int64List-wrapper
+    member data: int64List optional=False
+object q_obj_int8List-wrapper
+    member data: int8List optional=False
+object q_obj_intList-wrapper
+    member data: intList optional=False
+object q_obj_numberList-wrapper
+    member data: numberList optional=False
+object q_obj_sizeList-wrapper
+    member data: sizeList optional=False
+object q_obj_str-wrapper
+    member data: str optional=False
+object q_obj_strList-wrapper
+    member data: strList optional=False
+object q_obj_uint16List-wrapper
+    member data: uint16List optional=False
+object q_obj_uint32List-wrapper
+    member data: uint32List optional=False
+object q_obj_uint64List-wrapper
+    member data: uint64List optional=False
+object q_obj_uint8List-wrapper
+    member data: uint8List optional=False
+object q_obj_user_def_cmd1-arg
+    member ud1a: UserDefOne optional=False
+object q_obj_user_def_cmd2-arg
+    member ud1a: UserDefOne optional=False
+    member ud1b: UserDefOne optional=True
 command user_def_cmd None -> None
    gen=True success_response=True
 command user_def_cmd0 Empty2 -> Empty2
    gen=True success_response=True
-command user_def_cmd1 :obj-user_def_cmd1-arg -> None
+command user_def_cmd1 q_obj_user_def_cmd1-arg -> None
    gen=True success_response=True
-command user_def_cmd2 :obj-user_def_cmd2-arg -> UserDefTwo
+command user_def_cmd2 q_obj_user_def_cmd2-arg -> UserDefTwo
    gen=True success_response=True