@@ -516,13 +516,16 @@ additional variant members depending on the value of meta-type.
Each SchemaInfo object describes a wire ABI entity of a certain
meta-type: a command, event or one of several kinds of type.
-SchemaInfo for entities defined in the QAPI schema have the same name
-as in the schema. This is the case for all commands and events, and
-most types.
+SchemaInfo for commands and events have the same name as in the QAPI
+schema
Command and event names are part of the wire ABI, but type names are
-not. Therefore, looking up a type by its name in the QAPI schema is
-wrong. Look up the command or event, then follow references by name.
+not. Therefore, the SchemaInfo for types have auto-generated
+meaningless names. For readability, the examples in this document use
+meaningful type names instead.
+
+To examine a type, start with a the command or event using it, then
+follow references by name.
QAPI schema definitions not reachable that way are omitted.
@@ -554,8 +557,7 @@ object type without members. The event may not have a data member on
the wire then.
Each command or event defined with dictionary-valued 'data' in the
-QAPI schema implicitly defines an object type called ":obj-NAME-arg",
-where NAME is the command or event's name.
+QAPI schema implicitly defines an object type.
Example: the SchemaInfo for EVENT_C from section Events
@@ -609,12 +611,9 @@ Note that base types are "flattened": its members are included in the
A simple union implicitly defines an enumeration type for its implicit
discriminator (called "type" on the wire, see section Union types).
-Such a type's name is made by appending "Kind" to the simple union's
-name.
A simple union implicitly defines an object type for each of its
-variants. The type's name is ":obj-NAME-wrapper", where NAME is the
-name of the name of the variant's type.
+variants.
Example: the SchemaInfo for simple union BlockdevOptions from section
Union types
@@ -645,8 +644,7 @@ Example: the SchemaInfo for BlockRef from section Alternate types
The SchemaInfo for an array type has meta-type "array", and variant
member "element-type", which names the array's element type. Array
-types are implicitly defined. An array type's name is made by
-appending "List" to its element type's name.
+types are implicitly defined.
Example: the SchemaInfo for ['str']
@@ -1053,13 +1051,13 @@ Example:
[Uninteresting stuff omitted...]
const char example_qmp_schema_json[] = "["
- "{\"arg-type\": \":empty\", \"meta-type\": \"event\", \"name\": \"MY_EVENT\"}, "
+ "{\"arg-type\": \"0\", \"meta-type\": \"event\", \"name\": \"MY_EVENT\"}, "
+ "{\"arg-type\": \"1\", \"meta-type\": \"command\", \"name\": \"my-command\", \"ret-type\": \"2\"}, "
+ "{\"members\": [], \"meta-type\": \"object\", \"name\": \"0\"}, "
+ "{\"members\": [{\"name\": \"arg1\", \"type\": \"2\"}], \"meta-type\": \"object\", \"name\": \"1\"}, "
+ "{\"members\": [{\"name\": \"integer\", \"type\": \"int\"}, {\"name\": \"string\", \"type\": \"str\"}], \"meta-type\": \"object\", \"name\": \"2\"}, "
"{\"json-type\": \"int\", \"meta-type\": \"builtin\", \"name\": \"int\"}, "
- "{\"json-type\": \"string\", \"meta-type\": \"builtin\", \"name\": \"str\"}, "
- "{\"members\": [], \"meta-type\": \"object\", \"name\": \":empty\"}, "
- "{\"members\": [{\"name\": \"arg1\", \"type\": \"UserDefOne\"}], \"meta-type\": \"object\", \"name\": \":obj-my-command-arg\"}, "
- "{\"members\": [{\"name\": \"integer\", \"type\": \"int\"}, {\"name\": \"string\", \"type\": \"str\"}], \"meta-type\": \"object\", \"name\": \"UserDefOne\"}, "
- "{\"arg-type\": \":obj-my-command-arg\", \"meta-type\": \"command\", \"name\": \"my-command\", \"ret-type\": \"UserDefOne\"}]";
+ "{\"json-type\": \"string\", \"meta-type\": \"builtin\", \"name\": \"str\"}]";
$ cat qapi-generated/example-qmp-introspect.h
[Uninteresting stuff omitted...]
@@ -70,17 +70,12 @@
# @SchemaInfo
#
# @name: the entity's name, inherited from @base.
-# Entities defined in the QAPI schema have the name defined in the schema.
-# Implicitly defined entities have generated names. See
-# docs/qapi-code-gen.txt section "Client JSON Protocol introspection"
-# for details.
+# Commands and events have the name defined in the QAPI schema.
+# Unlike command and event names, type names are not part of the wire
+# ABI. Consequently, type names are meaningless strings here.
#
# All references to other SchemaInfo are by name.
#
-# Command and event names are part of the wire ABI, but type names are
-# not. Therefore, looking up a type by "well-known" name is wrong.
-# Look up the command or event, then follow the references.
-#
# @meta-type: the entity's meta type, inherited from @base.
#
# Additional members depend on the value of @meta-type.
@@ -37,32 +37,37 @@ def to_c_string(string):
return '"' + string.replace('\\', r'\\').replace('"', r'\"') + '"'
class QAPISchemaGenIntrospectVisitor(QAPISchemaVisitor):
- def __init__(self):
+ def __init__(self, unmask):
+ self.unmask = unmask
self.defn = None
self.decl = None
self.schema = None
self.jsons = None
self.used_types = None
+ self.name_map = None
def visit_begin(self, schema):
self.schema = schema
self.jsons = []
self.used_types = []
+ self.name_map = {}
return QAPISchemaType # don't visit types for now
def visit_end(self):
# visit the types that are actually used
+ jsons = self.jsons
+ self.jsons = []
for typ in self.used_types:
typ.visit(self)
- self.jsons.sort()
# generate C
# TODO can generate awfully long lines
+ jsons.extend(self.jsons)
name = prefix + 'qmp_schema_json'
self.decl = mcgen('''
extern const char %(c_name)s[];
''',
c_name=c_name(name))
- lines = to_json(self.jsons).split('\n')
+ lines = to_json(jsons).split('\n')
c_string = '\n '.join([to_c_string(line) for line in lines])
self.defn = mcgen('''
const char %(c_name)s[] = %(c_string)s;
@@ -72,6 +77,14 @@ const char %(c_name)s[] = %(c_string)s;
self.schema = None
self.jsons = None
self.used_types = None
+ self.name_map = None
+
+ def _name(self, name):
+ if self.unmask:
+ return name
+ if name not in self.name_map:
+ self.name_map[name] = '%d' % len(self.name_map)
+ return self.name_map[name]
def _use_type(self, typ):
# Map the various integer types to plain int
@@ -83,9 +96,16 @@ const char %(c_name)s[] = %(c_string)s;
# Add type to work queue if new
if typ not in self.used_types:
self.used_types.append(typ)
- return typ.name
+ # Clients should examine commands and events, not types. Hide
+ # type names to reduce the temptation. Also saves a few
+ # characters.
+ if isinstance(typ, QAPISchemaBuiltinType):
+ return typ.name
+ return self._name(typ.name)
def _gen_json(self, name, mtype, obj):
+ if mtype != 'command' and mtype != 'event' and mtype != 'builtin':
+ name = self._name(name)
obj['name'] = name
obj['meta-type'] = mtype
self.jsons.append(obj)
@@ -137,7 +157,16 @@ const char %(c_name)s[] = %(c_string)s;
arg_type = arg_type or self.schema.the_empty_object_type
self._gen_json(name, 'event', {'arg-type': self._use_type(arg_type)})
-(input_file, output_dir, do_c, do_h, prefix, dummy) = parse_command_line()
+# Debugging aid: unmask QAPI schema's type names
+# We normally mask them, because they're not QMP wire ABI
+opt_unmask = False
+
+(input_file, output_dir, do_c, do_h, prefix, opts) = \
+ parse_command_line("u", ["unmask-non-abi-names"])
+
+for o, a in opts:
+ if o in ("-u", "--unmask-non-abi-names"):
+ opt_unmask = True
c_comment = '''
/*
@@ -173,7 +202,7 @@ fdef.write(mcgen('''
prefix=prefix))
schema = QAPISchema(input_file)
-gen = QAPISchemaGenIntrospectVisitor()
+gen = QAPISchemaGenIntrospectVisitor(opt_unmask)
schema.visit(gen)
fdef.write(gen.defn)
fdecl.write(gen.decl)
To eliminate the temptation for clients to look up types by name (which are not ABI), replace all type names by meaningless strings. Reduces output of query-schema by 13 out of 85KiB. As a debugging aid, provide option -u to suppress the hiding. Signed-off-by: Markus Armbruster <armbru@redhat.com> --- docs/qapi-code-gen.txt | 36 +++++++++++++++++------------------- qapi/introspect.json | 11 +++-------- scripts/qapi-introspect.py | 41 +++++++++++++++++++++++++++++++++++------ 3 files changed, 55 insertions(+), 33 deletions(-)