Files
linux/tools/net/sunrpc/xdrgen/subcmds/source.py
Chuck Lever 6bc85baba4 xdrgen: Implement pass-through lines in specifications
XDR specification files can contain lines prefixed with '%' that
pass through unchanged to generated output. Traditional rpcgen
removes the '%' and emits the remainder verbatim, allowing direct
insertion of C includes, pragma directives, or other language-
specific content into the generated code.

Until now, xdrgen silently discarded these lines during parsing.
This prevented specifications from including necessary headers or
preprocessor directives that might be required for the generated
code to compile correctly.

The grammar now captures pass-through lines instead of ignoring
them. A new AST node type represents pass-through content, and
the AST transformer strips the leading '%' character. Definition
and source generators emit pass-through content in document order,
preserving the original placement within the specification.

This brings xdrgen closer to feature parity with traditional
rpcgen while maintaining the existing document-order processing
model.

Existing generated xdrgen source code has been regenerated.

Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2026-01-29 09:48:33 -05:00

135 lines
4.8 KiB
Python

#!/usr/bin/env python3
# ex: set filetype=python:
"""Translate an XDR specification into executable code that
can be compiled for the Linux kernel."""
import logging
from argparse import Namespace
from lark import logger
from lark.exceptions import VisitError
from generators.source_top import XdrSourceTopGenerator
from generators.enum import XdrEnumGenerator
from generators.passthru import XdrPassthruGenerator
from generators.pointer import XdrPointerGenerator
from generators.program import XdrProgramGenerator
from generators.typedef import XdrTypedefGenerator
from generators.struct import XdrStructGenerator
from generators.union import XdrUnionGenerator
from xdr_ast import transform_parse_tree, _RpcProgram, Specification
from xdr_ast import _XdrAst, _XdrEnum, _XdrPassthru, _XdrPointer
from xdr_ast import _XdrStruct, _XdrTypedef, _XdrUnion
from xdr_parse import xdr_parser, set_xdr_annotate, set_xdr_enum_validation
from xdr_parse import make_error_handler, XdrParseError
from xdr_parse import handle_transform_error
logger.setLevel(logging.INFO)
def emit_source_decoder(node: _XdrAst, language: str, peer: str) -> None:
"""Emit one XDR decoder function for a source file"""
if isinstance(node, _XdrEnum):
gen = XdrEnumGenerator(language, peer)
elif isinstance(node, _XdrPointer):
gen = XdrPointerGenerator(language, peer)
elif isinstance(node, _XdrTypedef):
gen = XdrTypedefGenerator(language, peer)
elif isinstance(node, _XdrStruct):
gen = XdrStructGenerator(language, peer)
elif isinstance(node, _XdrUnion):
gen = XdrUnionGenerator(language, peer)
elif isinstance(node, _RpcProgram):
gen = XdrProgramGenerator(language, peer)
else:
return
gen.emit_decoder(node)
def emit_source_encoder(node: _XdrAst, language: str, peer: str) -> None:
"""Emit one XDR encoder function for a source file"""
if isinstance(node, _XdrEnum):
gen = XdrEnumGenerator(language, peer)
elif isinstance(node, _XdrPointer):
gen = XdrPointerGenerator(language, peer)
elif isinstance(node, _XdrTypedef):
gen = XdrTypedefGenerator(language, peer)
elif isinstance(node, _XdrStruct):
gen = XdrStructGenerator(language, peer)
elif isinstance(node, _XdrUnion):
gen = XdrUnionGenerator(language, peer)
elif isinstance(node, _RpcProgram):
gen = XdrProgramGenerator(language, peer)
else:
return
gen.emit_encoder(node)
def generate_server_source(filename: str, root: Specification, language: str) -> None:
"""Generate server-side source code"""
gen = XdrSourceTopGenerator(language, "server")
gen.emit_source(filename, root)
for definition in root.definitions:
if isinstance(definition.value, _XdrPassthru):
passthru_gen = XdrPassthruGenerator(language, "server")
passthru_gen.emit_decoder(definition.value)
else:
emit_source_decoder(definition.value, language, "server")
for definition in root.definitions:
if not isinstance(definition.value, _XdrPassthru):
emit_source_encoder(definition.value, language, "server")
def generate_client_source(filename: str, root: Specification, language: str) -> None:
"""Generate client-side source code"""
gen = XdrSourceTopGenerator(language, "client")
gen.emit_source(filename, root)
for definition in root.definitions:
if isinstance(definition.value, _XdrPassthru):
passthru_gen = XdrPassthruGenerator(language, "client")
passthru_gen.emit_decoder(definition.value)
else:
emit_source_encoder(definition.value, language, "client")
for definition in root.definitions:
if not isinstance(definition.value, _XdrPassthru):
emit_source_decoder(definition.value, language, "client")
# cel: todo: client needs PROC macros
def subcmd(args: Namespace) -> int:
"""Generate encoder and decoder functions"""
set_xdr_annotate(args.annotate)
set_xdr_enum_validation(not args.no_enum_validation)
parser = xdr_parser()
with open(args.filename, encoding="utf-8") as f:
source = f.read()
try:
parse_tree = parser.parse(
source, on_error=make_error_handler(source, args.filename)
)
except XdrParseError:
return 1
try:
ast = transform_parse_tree(parse_tree)
except VisitError as e:
handle_transform_error(e, source, args.filename)
return 1
match args.peer:
case "server":
generate_server_source(args.filename, ast, args.language)
case "client":
generate_client_source(args.filename, ast, args.language)
case _:
print("Code generation for", args.peer, "is not yet supported")
return 0