On Thu, Sep 28, 2023 at 04:20:55PM +0200, Markus Armbruster wrote: > Daniel P. Berrangé <berra...@redhat.com> writes: > > > On Wed, Sep 27, 2023 at 01:25:36PM +0200, Victor Toso wrote: > >> This patch handles QAPI enum types and generates its equivalent in Go. > >> > >> Basically, Enums are being handled as strings in Golang. > >> > >> 1. For each QAPI enum, we will define a string type in Go to be the > >> assigned type of this specific enum. > >> > >> 2. Naming: CamelCase will be used in any identifier that we want to > >> export [0], which is everything. > >> > >> [0] https://go.dev/ref/spec#Exported_identifiers > >> > >> Example: > >> > >> qapi: > >> | { 'enum': 'DisplayProtocol', > >> | 'data': [ 'vnc', 'spice' ] } > >> > >> go: > >> | type DisplayProtocol string > >> | > >> | const ( > >> | DisplayProtocolVnc DisplayProtocol = "vnc" > >> | DisplayProtocolSpice DisplayProtocol = "spice" > >> | ) > >> > >> Signed-off-by: Victor Toso <victort...@redhat.com> > >> --- > >> scripts/qapi/golang.py | 140 +++++++++++++++++++++++++++++++++++++++++ > >> scripts/qapi/main.py | 2 + > >> 2 files changed, 142 insertions(+) > >> create mode 100644 scripts/qapi/golang.py > >> > >> diff --git a/scripts/qapi/golang.py b/scripts/qapi/golang.py > >> new file mode 100644 > >> index 0000000000..87081cdd05 > >> --- /dev/null > >> +++ b/scripts/qapi/golang.py > >> @@ -0,0 +1,140 @@ > >> +""" > >> +Golang QAPI generator > >> +""" > >> +# Copyright (c) 2023 Red Hat Inc. > >> +# > >> +# Authors: > >> +# Victor Toso <victort...@redhat.com> > >> +# > >> +# This work is licensed under the terms of the GNU GPL, version 2. > >> +# See the COPYING file in the top-level directory. > >> + > >> +# due QAPISchemaVisitor interface > >> +# pylint: disable=too-many-arguments > >> + > >> +# Just for type hint on self > >> +from __future__ import annotations > >> + > >> +import os > >> +from typing import List, Optional > >> + > >> +from .schema import ( > >> + QAPISchema, > >> + QAPISchemaType, > >> + QAPISchemaVisitor, > >> + QAPISchemaEnumMember, > >> + QAPISchemaFeature, > >> + QAPISchemaIfCond, > >> + QAPISchemaObjectType, > >> + QAPISchemaObjectTypeMember, > >> + QAPISchemaVariants, > >> +) > >> +from .source import QAPISourceInfo > >> + > >> +TEMPLATE_ENUM = ''' > >> +type {name} string > >> +const ( > >> +{fields} > >> +) > >> +''' > >> + > >> + > >> +def gen_golang(schema: QAPISchema, > >> + output_dir: str, > >> + prefix: str) -> None: > >> + vis = QAPISchemaGenGolangVisitor(prefix) > >> + schema.visit(vis) > >> + vis.write(output_dir) > >> + > >> + > >> +def qapi_to_field_name_enum(name: str) -> str: > >> + return name.title().replace("-", "") > >> + > >> + > >> +class QAPISchemaGenGolangVisitor(QAPISchemaVisitor): > >> + > >> + def __init__(self, _: str): > >> + super().__init__() > >> + types = ["enum"] > >> + self.target = {name: "" for name in types} > >> + self.schema = None > >> + self.golang_package_name = "qapi" > >> + > >> + def visit_begin(self, schema): > >> + self.schema = schema > >> + > >> + # Every Go file needs to reference its package name > >> + for target in self.target: > >> + self.target[target] = f"package {self.golang_package_name}\n" > >> + > >> + def visit_end(self): > >> + self.schema = None > >> + > >> + def visit_object_type(self: QAPISchemaGenGolangVisitor, > >> + name: str, > >> + info: Optional[QAPISourceInfo], > >> + ifcond: QAPISchemaIfCond, > >> + features: List[QAPISchemaFeature], > >> + base: Optional[QAPISchemaObjectType], > >> + members: List[QAPISchemaObjectTypeMember], > >> + variants: Optional[QAPISchemaVariants] > >> + ) -> None: > >> + pass > >> + > >> + def visit_alternate_type(self: QAPISchemaGenGolangVisitor, > >> + name: str, > >> + info: Optional[QAPISourceInfo], > >> + ifcond: QAPISchemaIfCond, > >> + features: List[QAPISchemaFeature], > >> + variants: QAPISchemaVariants > >> + ) -> None: > >> + pass > >> + > >> + def visit_enum_type(self: QAPISchemaGenGolangVisitor, > >> + name: str, > >> + info: Optional[QAPISourceInfo], > >> + ifcond: QAPISchemaIfCond, > >> + features: List[QAPISchemaFeature], > >> + members: List[QAPISchemaEnumMember], > >> + prefix: Optional[str] > >> + ) -> None: > >> + > >> + value = qapi_to_field_name_enum(members[0].name) > >> + fields = "" > >> + for member in members: > >> + value = qapi_to_field_name_enum(member.name) > >> + fields += f'''\t{name}{value} {name} = "{member.name}"\n''' > >> + > >> + self.target["enum"] += TEMPLATE_ENUM.format(name=name, > >> fields=fields[:-1]) > > > > Here you are formatting the enums as you visit them, appending to > > the output buffer. The resulting enums appear in whatever order we > > visited them with, which is pretty arbitrary. > > We visit in source order, not in arbitrary order.
I meant arbitrary in the sense that us developers just add new QAPI types pretty much anywhere we feel like it in the .qapi files. > > > Browsing the generated Go code to understand it, I find myself > > wishing that it was emitted in alphabetical order. > > If that's easier to read in generated Go, then I suspect it would also > be easier to read in the QAPI schema and in generated C. Yes, although C has some ordering constraints on things being declared, so it would be a bit harder to do this in C. With regards, Daniel -- |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| |: https://libvirt.org -o- https://fstop138.berrange.com :| |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :|
