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. > 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. > This could be done if we worked in two phase. In the visit phase, > we collect the bits of data we need, and then add a format phase > then generates the formatted output, having first sorted by enum > name. > > Same thought for the other types/commands. > >> + >> + def visit_array_type(self, name, info, ifcond, element_type): >> + pass >> + >> + def visit_command(self, >> + name: str, >> + info: Optional[QAPISourceInfo], >> + ifcond: QAPISchemaIfCond, >> + features: List[QAPISchemaFeature], >> + arg_type: Optional[QAPISchemaObjectType], >> + ret_type: Optional[QAPISchemaType], >> + gen: bool, >> + success_response: bool, >> + boxed: bool, >> + allow_oob: bool, >> + allow_preconfig: bool, >> + coroutine: bool) -> None: >> + pass >> + >> + def visit_event(self, name, info, ifcond, features, arg_type, boxed): >> + pass >> + >> + def write(self, output_dir: str) -> None: >> + for module_name, content in self.target.items(): >> + go_module = module_name + "s.go" >> + go_dir = "go" >> + pathname = os.path.join(output_dir, go_dir, go_module) >> + odir = os.path.dirname(pathname) >> + os.makedirs(odir, exist_ok=True) >> + >> + with open(pathname, "w", encoding="ascii") as outfile: > > IIUC, we defacto consider the .qapi json files to be UTF-8, and thus > in theory we could have non-ascii characters in there somewhere. I'd > suggest we using utf8 encoding when outputting to avoid surprises. Seconded. QAPIGen.write() already uses encoding='utf-8' for writing generated files. >> + outfile.write(content) > > > With regards, > Daniel
