linux/tools/net/sunrpc/xdrgen/generators/struct.py
Chuck Lever 4b132aacb0 tools: Add xdrgen
Add a Python-based tool for translating XDR specifications into XDR
encoder and decoder functions written in the Linux kernel's C coding
style. The generator attempts to match the usual C coding style of
the Linux kernel's SunRPC consumers.

This approach is similar to the netlink code generator in
tools/net/ynl .

The maintainability benefits of machine-generated XDR code include:

- Stronger type checking
- Reduces the number of bugs introduced by human error
- Makes the XDR code easier to audit and analyze
- Enables rapid prototyping of new RPC-based protocols
- Hardens the layering between protocol logic and marshaling
- Makes it easier to add observability on demand
- Unit tests might be built for both the tool and (automatically)
  for the generated code

In addition, converting the XDR layer to use memory-safe languages
such as Rust will be easier if much of the code can be converted
automatically.

Tested-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
2024-09-20 19:31:39 -04:00

273 lines
9.5 KiB
Python

#!/usr/bin/env python3
# ex: set filetype=python:
"""Generate code to handle XDR struct types"""
from jinja2 import Environment
from generators import SourceGenerator, kernel_c_type
from generators import create_jinja2_environment, get_jinja2_template
from xdr_ast import _XdrBasic, _XdrVariableLengthString
from xdr_ast import _XdrFixedLengthOpaque, _XdrVariableLengthOpaque
from xdr_ast import _XdrFixedLengthArray, _XdrVariableLengthArray
from xdr_ast import _XdrOptionalData, _XdrStruct, _XdrDeclaration
from xdr_ast import public_apis
def emit_struct_declaration(environment: Environment, node: _XdrStruct) -> None:
"""Emit one declaration pair for an XDR struct type"""
if node.name in public_apis:
template = get_jinja2_template(environment, "declaration", "close")
print(template.render(name=node.name))
def emit_struct_member_definition(
environment: Environment, field: _XdrDeclaration
) -> None:
"""Emit a definition for one field in an XDR struct"""
if isinstance(field, _XdrBasic):
template = get_jinja2_template(environment, "definition", field.template)
print(
template.render(
name=field.name,
type=kernel_c_type(field.spec),
classifier=field.spec.c_classifier,
)
)
elif isinstance(field, _XdrFixedLengthOpaque):
template = get_jinja2_template(environment, "definition", field.template)
print(
template.render(
name=field.name,
size=field.size,
)
)
elif isinstance(field, _XdrVariableLengthOpaque):
template = get_jinja2_template(environment, "definition", field.template)
print(template.render(name=field.name))
elif isinstance(field, _XdrVariableLengthString):
template = get_jinja2_template(environment, "definition", field.template)
print(template.render(name=field.name))
elif isinstance(field, _XdrFixedLengthArray):
template = get_jinja2_template(environment, "definition", field.template)
print(
template.render(
name=field.name,
type=kernel_c_type(field.spec),
size=field.size,
)
)
elif isinstance(field, _XdrVariableLengthArray):
template = get_jinja2_template(environment, "definition", field.template)
print(
template.render(
name=field.name,
type=kernel_c_type(field.spec),
classifier=field.spec.c_classifier,
)
)
elif isinstance(field, _XdrOptionalData):
template = get_jinja2_template(environment, "definition", field.template)
print(
template.render(
name=field.name,
type=kernel_c_type(field.spec),
classifier=field.spec.c_classifier,
)
)
def emit_struct_definition(environment: Environment, node: _XdrStruct) -> None:
"""Emit one definition for an XDR struct type"""
template = get_jinja2_template(environment, "definition", "open")
print(template.render(name=node.name))
for field in node.fields:
emit_struct_member_definition(environment, field)
template = get_jinja2_template(environment, "definition", "close")
print(template.render(name=node.name))
def emit_struct_member_decoder(
environment: Environment, field: _XdrDeclaration
) -> None:
"""Emit a decoder for one field in an XDR struct"""
if isinstance(field, _XdrBasic):
template = get_jinja2_template(environment, "decoder", field.template)
print(
template.render(
name=field.name,
type=field.spec.type_name,
classifier=field.spec.c_classifier,
)
)
elif isinstance(field, _XdrFixedLengthOpaque):
template = get_jinja2_template(environment, "decoder", field.template)
print(
template.render(
name=field.name,
size=field.size,
)
)
elif isinstance(field, _XdrVariableLengthOpaque):
template = get_jinja2_template(environment, "decoder", field.template)
print(
template.render(
name=field.name,
maxsize=field.maxsize,
)
)
elif isinstance(field, _XdrVariableLengthString):
template = get_jinja2_template(environment, "decoder", field.template)
print(
template.render(
name=field.name,
maxsize=field.maxsize,
)
)
elif isinstance(field, _XdrFixedLengthArray):
template = get_jinja2_template(environment, "decoder", field.template)
print(
template.render(
name=field.name,
type=field.spec.type_name,
size=field.size,
classifier=field.spec.c_classifier,
)
)
elif isinstance(field, _XdrVariableLengthArray):
template = get_jinja2_template(environment, "decoder", field.template)
print(
template.render(
name=field.name,
type=field.spec.type_name,
maxsize=field.maxsize,
classifier=field.spec.c_classifier,
)
)
elif isinstance(field, _XdrOptionalData):
template = get_jinja2_template(environment, "decoder", field.template)
print(
template.render(
name=field.name,
type=field.spec.type_name,
classifier=field.spec.c_classifier,
)
)
def emit_struct_decoder(environment: Environment, node: _XdrStruct) -> None:
"""Emit one decoder function for an XDR struct type"""
template = get_jinja2_template(environment, "decoder", "open")
print(template.render(name=node.name))
for field in node.fields:
emit_struct_member_decoder(environment, field)
template = get_jinja2_template(environment, "decoder", "close")
print(template.render())
def emit_struct_member_encoder(
environment: Environment, field: _XdrDeclaration
) -> None:
"""Emit an encoder for one field in an XDR struct"""
if isinstance(field, _XdrBasic):
template = get_jinja2_template(environment, "encoder", field.template)
print(
template.render(
name=field.name,
type=field.spec.type_name,
)
)
elif isinstance(field, _XdrFixedLengthOpaque):
template = get_jinja2_template(environment, "encoder", field.template)
print(
template.render(
name=field.name,
size=field.size,
)
)
elif isinstance(field, _XdrVariableLengthOpaque):
template = get_jinja2_template(environment, "encoder", field.template)
print(
template.render(
name=field.name,
maxsize=field.maxsize,
)
)
elif isinstance(field, _XdrVariableLengthString):
template = get_jinja2_template(environment, "encoder", field.template)
print(
template.render(
name=field.name,
maxsize=field.maxsize,
)
)
elif isinstance(field, _XdrFixedLengthArray):
template = get_jinja2_template(environment, "encoder", field.template)
print(
template.render(
name=field.name,
type=field.spec.type_name,
size=field.size,
)
)
elif isinstance(field, _XdrVariableLengthArray):
template = get_jinja2_template(environment, "encoder", field.template)
print(
template.render(
name=field.name,
type=field.spec.type_name,
maxsize=field.maxsize,
)
)
elif isinstance(field, _XdrOptionalData):
template = get_jinja2_template(environment, "encoder", field.template)
print(
template.render(
name=field.name,
type=field.spec.type_name,
classifier=field.spec.c_classifier,
)
)
def emit_struct_encoder(environment: Environment, node: _XdrStruct) -> None:
"""Emit one encoder function for an XDR struct type"""
template = get_jinja2_template(environment, "encoder", "open")
print(template.render(name=node.name))
for field in node.fields:
emit_struct_member_encoder(environment, field)
template = get_jinja2_template(environment, "encoder", "close")
print(template.render())
class XdrStructGenerator(SourceGenerator):
"""Generate source code for XDR structs"""
def __init__(self, language: str, peer: str):
"""Initialize an instance of this class"""
self.environment = create_jinja2_environment(language, "struct")
self.peer = peer
def emit_declaration(self, node: _XdrStruct) -> None:
"""Emit one declaration pair for an XDR struct type"""
emit_struct_declaration(self.environment, node)
def emit_definition(self, node: _XdrStruct) -> None:
"""Emit one definition for an XDR struct type"""
emit_struct_definition(self.environment, node)
def emit_decoder(self, node: _XdrStruct) -> None:
"""Emit one decoder function for an XDR struct type"""
emit_struct_decoder(self.environment, node)
def emit_encoder(self, node: _XdrStruct) -> None:
"""Emit one encoder function for an XDR struct type"""
emit_struct_encoder(self.environment, node)