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nac3/nac3ast/asdl_rs.py

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22 KiB
Python
Executable File

#! /usr/bin/env python
"""Generate Rust code from an ASDL description."""
import os
import sys
import textwrap
import json
from argparse import ArgumentParser
from pathlib import Path
import asdl
TABSIZE = 4
AUTOGEN_MESSAGE = "// File automatically generated by {}.\n\n"
builtin_type_mapping = {
'identifier': 'Ident',
'string': 'String',
'int': 'usize',
'constant': 'Constant',
'bool': 'bool',
'conversion_flag': 'ConversionFlag',
}
assert builtin_type_mapping.keys() == asdl.builtin_types
def get_rust_type(name):
"""Return a string for the C name of the type.
This function special cases the default types provided by asdl.
"""
if name in asdl.builtin_types:
return builtin_type_mapping[name]
else:
return "".join(part.capitalize() for part in name.split("_"))
def is_simple(sum):
"""Return True if a sum is a simple.
A sum is simple if its types have no fields, e.g.
unaryop = Invert | Not | UAdd | USub
"""
for t in sum.types:
if t.fields:
return False
return True
def asdl_of(name, obj):
if isinstance(obj, asdl.Product) or isinstance(obj, asdl.Constructor):
fields = ", ".join(map(str, obj.fields))
if fields:
fields = "({})".format(fields)
return "{}{}".format(name, fields)
else:
if is_simple(obj):
types = " | ".join(type.name for type in obj.types)
else:
sep = "\n{}| ".format(" " * (len(name) + 1))
types = sep.join(
asdl_of(type.name, type) for type in obj.types
)
return "{} = {}".format(name, types)
class EmitVisitor(asdl.VisitorBase):
"""Visit that emits lines"""
def __init__(self, file):
self.file = file
self.identifiers = set()
super(EmitVisitor, self).__init__()
def emit_identifier(self, name):
name = str(name)
if name in self.identifiers:
return
self.emit("_Py_IDENTIFIER(%s);" % name, 0)
self.identifiers.add(name)
def emit(self, line, depth):
if line:
line = (" " * TABSIZE * depth) + line
self.file.write(line + "\n")
class TypeInfo:
def __init__(self, name):
self.name = name
self.has_userdata = None
self.children = set()
self.boxed = False
def __repr__(self):
return f"<TypeInfo: {self.name}>"
def determine_userdata(self, typeinfo, stack):
if self.name in stack:
return None
stack.add(self.name)
for child, child_seq in self.children:
if child in asdl.builtin_types:
continue
childinfo = typeinfo[child]
child_has_userdata = childinfo.determine_userdata(typeinfo, stack)
if self.has_userdata is None and child_has_userdata is True:
self.has_userdata = True
stack.remove(self.name)
return self.has_userdata
class FindUserdataTypesVisitor(asdl.VisitorBase):
def __init__(self, typeinfo):
self.typeinfo = typeinfo
super().__init__()
def visitModule(self, mod):
for dfn in mod.dfns:
self.visit(dfn)
stack = set()
for info in self.typeinfo.values():
info.determine_userdata(self.typeinfo, stack)
def visitType(self, type):
self.typeinfo[type.name] = TypeInfo(type.name)
self.visit(type.value, type.name)
def visitSum(self, sum, name):
info = self.typeinfo[name]
if is_simple(sum):
info.has_userdata = False
else:
if len(sum.types) > 1:
info.boxed = True
if sum.attributes:
# attributes means Located, which has the `custom: U` field
info.has_userdata = True
for variant in sum.types:
self.add_children(name, variant.fields)
def visitProduct(self, product, name):
info = self.typeinfo[name]
if product.attributes:
# attributes means Located, which has the `custom: U` field
info.has_userdata = True
if len(product.fields) > 2:
info.boxed = True
self.add_children(name, product.fields)
def add_children(self, name, fields):
self.typeinfo[name].children.update((field.type, field.seq) for field in fields)
def rust_field(field_name):
if field_name == 'type':
return 'type_'
else:
return field_name
class TypeInfoEmitVisitor(EmitVisitor):
def __init__(self, file, typeinfo):
self.typeinfo = typeinfo
super().__init__(file)
def has_userdata(self, typ):
return self.typeinfo[typ].has_userdata
def get_generics(self, typ, *generics):
if self.has_userdata(typ):
return [f"<{g}>" for g in generics]
else:
return ["" for g in generics]
class StructVisitor(TypeInfoEmitVisitor):
"""Visitor to generate typedefs for AST."""
def visitModule(self, mod):
for dfn in mod.dfns:
self.visit(dfn)
def visitType(self, type, depth=0):
self.visit(type.value, type.name, depth)
def visitSum(self, sum, name, depth):
if is_simple(sum):
self.simple_sum(sum, name, depth)
else:
self.sum_with_constructors(sum, name, depth)
def emit_attrs(self, depth):
self.emit("#[derive(Clone, Debug, PartialEq)]", depth)
def simple_sum(self, sum, name, depth):
rustname = get_rust_type(name)
self.emit_attrs(depth)
self.emit(f"pub enum {rustname} {{", depth)
for variant in sum.types:
self.emit(f"{variant.name},", depth + 1)
self.emit("}", depth)
self.emit("", depth)
def sum_with_constructors(self, sum, name, depth):
typeinfo = self.typeinfo[name]
generics, generics_applied = self.get_generics(name, "U = ()", "U")
enumname = rustname = get_rust_type(name)
# all the attributes right now are for location, so if it has attrs we
# can just wrap it in Located<>
if sum.attributes:
enumname = rustname + "Kind"
self.emit_attrs(depth)
self.emit(f"pub enum {enumname}{generics} {{", depth)
for t in sum.types:
self.visit(t, typeinfo, depth + 1)
self.emit("}", depth)
if sum.attributes:
self.emit(f"pub type {rustname}<U = ()> = Located<{enumname}{generics_applied}, U>;", depth)
self.emit("", depth)
def visitConstructor(self, cons, parent, depth):
if cons.fields:
self.emit(f"{cons.name} {{", depth)
for f in cons.fields:
self.visit(f, parent, "", depth + 1)
self.emit("},", depth)
else:
self.emit(f"{cons.name},", depth)
def visitField(self, field, parent, vis, depth):
typ = get_rust_type(field.type)
fieldtype = self.typeinfo.get(field.type)
if fieldtype and fieldtype.has_userdata:
typ = f"{typ}<U>"
# don't box if we're doing Vec<T>, but do box if we're doing Vec<Option<Box<T>>>
if fieldtype and fieldtype.boxed and (not field.seq or field.opt):
typ = f"Box<{typ}>"
if field.opt:
typ = f"Option<{typ}>"
if field.seq:
typ = f"Vec<{typ}>"
name = rust_field(field.name)
self.emit(f"{vis}{name}: {typ},", depth)
def visitProduct(self, product, name, depth):
typeinfo = self.typeinfo[name]
generics, generics_applied = self.get_generics(name, "U = ()", "U")
dataname = rustname = get_rust_type(name)
if product.attributes:
dataname = rustname + "Data"
self.emit_attrs(depth)
self.emit(f"pub struct {dataname}{generics} {{", depth)
for f in product.fields:
self.visit(f, typeinfo, "pub ", depth + 1)
self.emit("}", depth)
if product.attributes:
# attributes should just be location info
self.emit(f"pub type {rustname}<U = ()> = Located<{dataname}{generics_applied}, U>;", depth);
self.emit("", depth)
class FoldTraitDefVisitor(TypeInfoEmitVisitor):
def visitModule(self, mod, depth):
self.emit("pub trait Fold<U> {", depth)
self.emit("type TargetU;", depth + 1)
self.emit("type Error;", depth + 1)
self.emit("fn map_user(&mut self, user: U) -> Result<Self::TargetU, Self::Error>;", depth + 2)
for dfn in mod.dfns:
self.visit(dfn, depth + 2)
self.emit("}", depth)
def visitType(self, type, depth):
name = type.name
apply_u, apply_target_u = self.get_generics(name, "U", "Self::TargetU")
enumname = get_rust_type(name)
self.emit(f"fn fold_{name}(&mut self, node: {enumname}{apply_u}) -> Result<{enumname}{apply_target_u}, Self::Error> {{", depth)
self.emit(f"fold_{name}(self, node)", depth + 1)
self.emit("}", depth)
class FoldImplVisitor(TypeInfoEmitVisitor):
def visitModule(self, mod, depth):
self.emit("fn fold_located<U, F: Fold<U> + ?Sized, T, MT>(folder: &mut F, node: Located<T, U>, f: impl FnOnce(&mut F, T) -> Result<MT, F::Error>) -> Result<Located<MT, F::TargetU>, F::Error> {", depth)
self.emit("Ok(Located { custom: folder.map_user(node.custom)?, location: node.location, node: f(folder, node.node)? })", depth + 1)
self.emit("}", depth)
for dfn in mod.dfns:
self.visit(dfn, depth)
def visitType(self, type, depth=0):
self.visit(type.value, type.name, depth)
def visitSum(self, sum, name, depth):
apply_t, apply_u, apply_target_u = self.get_generics(name, "T", "U", "F::TargetU")
enumname = get_rust_type(name)
is_located = bool(sum.attributes)
self.emit(f"impl<T, U> Foldable<T, U> for {enumname}{apply_t} {{", depth)
self.emit(f"type Mapped = {enumname}{apply_u};", depth + 1)
self.emit("fn fold<F: Fold<T, TargetU = U> + ?Sized>(self, folder: &mut F) -> Result<Self::Mapped, F::Error> {", depth + 1)
self.emit(f"folder.fold_{name}(self)", depth + 2)
self.emit("}", depth + 1)
self.emit("}", depth)
self.emit(f"pub fn fold_{name}<U, F: Fold<U> + ?Sized>(#[allow(unused)] folder: &mut F, node: {enumname}{apply_u}) -> Result<{enumname}{apply_target_u}, F::Error> {{", depth)
if is_located:
self.emit("fold_located(folder, node, |folder, node| {", depth)
enumname += "Kind"
self.emit("match node {", depth + 1)
for cons in sum.types:
fields_pattern = self.make_pattern(cons.fields)
self.emit(f"{enumname}::{cons.name} {{ {fields_pattern} }} => {{", depth + 2)
self.gen_construction(f"{enumname}::{cons.name}", cons.fields, depth + 3)
self.emit("}", depth + 2)
self.emit("}", depth + 1)
if is_located:
self.emit("})", depth)
self.emit("}", depth)
def visitProduct(self, product, name, depth):
apply_t, apply_u, apply_target_u = self.get_generics(name, "T", "U", "F::TargetU")
structname = get_rust_type(name)
is_located = bool(product.attributes)
self.emit(f"impl<T, U> Foldable<T, U> for {structname}{apply_t} {{", depth)
self.emit(f"type Mapped = {structname}{apply_u};", depth + 1)
self.emit("fn fold<F: Fold<T, TargetU = U> + ?Sized>(self, folder: &mut F) -> Result<Self::Mapped, F::Error> {", depth + 1)
self.emit(f"folder.fold_{name}(self)", depth + 2)
self.emit("}", depth + 1)
self.emit("}", depth)
self.emit(f"pub fn fold_{name}<U, F: Fold<U> + ?Sized>(#[allow(unused)] folder: &mut F, node: {structname}{apply_u}) -> Result<{structname}{apply_target_u}, F::Error> {{", depth)
if is_located:
self.emit("fold_located(folder, node, |folder, node| {", depth)
structname += "Data"
fields_pattern = self.make_pattern(product.fields)
self.emit(f"let {structname} {{ {fields_pattern} }} = node;", depth + 1)
self.gen_construction(structname, product.fields, depth + 1)
if is_located:
self.emit("})", depth)
self.emit("}", depth)
def make_pattern(self, fields):
return ",".join(rust_field(f.name) for f in fields)
def gen_construction(self, cons_path, fields, depth):
self.emit(f"Ok({cons_path} {{", depth)
for field in fields:
name = rust_field(field.name)
self.emit(f"{name}: Foldable::fold({name}, folder)?,", depth + 1)
self.emit("})", depth)
class FoldModuleVisitor(TypeInfoEmitVisitor):
def visitModule(self, mod):
depth = 0
self.emit('#[cfg(feature = "fold")]', depth)
self.emit("pub mod fold {", depth)
self.emit("use super::*;", depth + 1)
self.emit("use crate::fold_helpers::Foldable;", depth + 1)
FoldTraitDefVisitor(self.file, self.typeinfo).visit(mod, depth + 1)
FoldImplVisitor(self.file, self.typeinfo).visit(mod, depth + 1)
self.emit("}", depth)
class ClassDefVisitor(EmitVisitor):
def visitModule(self, mod):
for dfn in mod.dfns:
self.visit(dfn)
def visitType(self, type, depth=0):
self.visit(type.value, type.name, depth)
def visitSum(self, sum, name, depth):
for cons in sum.types:
self.visit(cons, sum.attributes, depth)
def visitConstructor(self, cons, attrs, depth):
self.gen_classdef(cons.name, cons.fields, attrs, depth)
def visitProduct(self, product, name, depth):
self.gen_classdef(name, product.fields, product.attributes, depth)
def gen_classdef(self, name, fields, attrs, depth):
structname = "Node" + name
self.emit(f'#[pyclass(module = "_ast", name = {json.dumps(name)}, base = "AstNode")]', depth)
self.emit(f"struct {structname};", depth)
self.emit("#[pyimpl(flags(HAS_DICT, BASETYPE))]", depth)
self.emit(f"impl {structname} {{", depth)
self.emit(f"#[extend_class]", depth + 1)
self.emit("fn extend_class_with_fields(ctx: &PyContext, class: &PyTypeRef) {", depth + 1)
fields = ",".join(f"ctx.new_str({json.dumps(f.name)})" for f in fields)
self.emit(f'class.set_str_attr("_fields", ctx.new_list(vec![{fields}]));', depth + 2)
attrs = ",".join(f"ctx.new_str({json.dumps(attr.name)})" for attr in attrs)
self.emit(f'class.set_str_attr("_attributes", ctx.new_list(vec![{attrs}]));', depth + 2)
self.emit("}", depth + 1)
self.emit("}", depth)
class ExtendModuleVisitor(EmitVisitor):
def visitModule(self, mod):
depth = 0
self.emit("pub fn extend_module_nodes(vm: &VirtualMachine, module: &PyObjectRef) {", depth)
self.emit("extend_module!(vm, module, {", depth + 1)
for dfn in mod.dfns:
self.visit(dfn, depth + 2)
self.emit("})", depth + 1)
self.emit("}", depth)
def visitType(self, type, depth):
self.visit(type.value, type.name, depth)
def visitSum(self, sum, name, depth):
for cons in sum.types:
self.visit(cons, depth)
def visitConstructor(self, cons, depth):
self.gen_extension(cons.name, depth)
def visitProduct(self, product, name, depth):
self.gen_extension(name, depth)
def gen_extension(self, name, depth):
self.emit(f"{json.dumps(name)} => Node{name}::make_class(&vm.ctx),", depth)
class TraitImplVisitor(EmitVisitor):
def visitModule(self, mod):
for dfn in mod.dfns:
self.visit(dfn)
def visitType(self, type, depth=0):
self.visit(type.value, type.name, depth)
def visitSum(self, sum, name, depth):
enumname = get_rust_type(name)
if sum.attributes:
enumname += "Kind"
self.emit(f"impl NamedNode for ast::{enumname} {{", depth)
self.emit(f"const NAME: &'static str = {json.dumps(name)};", depth + 1)
self.emit("}", depth)
self.emit(f"impl Node for ast::{enumname} {{", depth)
self.emit("fn ast_to_object(self, _vm: &VirtualMachine) -> PyObjectRef {", depth + 1)
self.emit("match self {", depth + 2)
for variant in sum.types:
self.constructor_to_object(variant, enumname, depth + 3)
self.emit("}", depth + 2)
self.emit("}", depth + 1)
self.emit("fn ast_from_object(_vm: &VirtualMachine, _object: PyObjectRef) -> PyResult<Self> {", depth + 1)
self.gen_sum_fromobj(sum, name, enumname, depth + 2)
self.emit("}", depth + 1)
self.emit("}", depth)
def constructor_to_object(self, cons, enumname, depth):
fields_pattern = self.make_pattern(cons.fields)
self.emit(f"ast::{enumname}::{cons.name} {{ {fields_pattern} }} => {{", depth)
self.make_node(cons.name, cons.fields, depth + 1)
self.emit("}", depth)
def visitProduct(self, product, name, depth):
structname = get_rust_type(name)
if product.attributes:
structname += "Data"
self.emit(f"impl NamedNode for ast::{structname} {{", depth)
self.emit(f"const NAME: &'static str = {json.dumps(name)};", depth + 1)
self.emit("}", depth)
self.emit(f"impl Node for ast::{structname} {{", depth)
self.emit("fn ast_to_object(self, _vm: &VirtualMachine) -> PyObjectRef {", depth + 1)
fields_pattern = self.make_pattern(product.fields)
self.emit(f"let ast::{structname} {{ {fields_pattern} }} = self;", depth + 2)
self.make_node(name, product.fields, depth + 2)
self.emit("}", depth + 1)
self.emit("fn ast_from_object(_vm: &VirtualMachine, _object: PyObjectRef) -> PyResult<Self> {", depth + 1)
self.gen_product_fromobj(product, name, structname, depth + 2)
self.emit("}", depth + 1)
self.emit("}", depth)
def make_node(self, variant, fields, depth):
lines = []
self.emit(f"let _node = AstNode.into_ref_with_type(_vm, Node{variant}::static_type().clone()).unwrap();", depth)
if fields:
self.emit("let _dict = _node.as_object().dict().unwrap();", depth)
for f in fields:
self.emit(f"_dict.set_item({json.dumps(f.name)}, {rust_field(f.name)}.ast_to_object(_vm), _vm).unwrap();", depth)
self.emit("_node.into_object()", depth)
def make_pattern(self, fields):
return ",".join(rust_field(f.name) for f in fields)
def gen_sum_fromobj(self, sum, sumname, enumname, depth):
if sum.attributes:
self.extract_location(sumname, depth)
self.emit("let _cls = _object.class();", depth)
self.emit("Ok(", depth)
for cons in sum.types:
self.emit(f"if _cls.is(Node{cons.name}::static_type()) {{", depth)
self.gen_construction(f"{enumname}::{cons.name}", cons, sumname, depth + 1)
self.emit("} else", depth)
self.emit("{", depth)
msg = f'format!("expected some sort of {sumname}, but got {{}}",_vm.to_repr(&_object)?)'
self.emit(f"return Err(_vm.new_type_error({msg}));", depth + 1)
self.emit("})", depth)
def gen_product_fromobj(self, product, prodname, structname, depth):
if product.attributes:
self.extract_location(prodname, depth)
self.emit("Ok(", depth)
self.gen_construction(structname, product, prodname, depth + 1)
self.emit(")", depth)
def gen_construction(self, cons_path, cons, name, depth):
self.emit(f"ast::{cons_path} {{", depth)
for field in cons.fields:
self.emit(f"{rust_field(field.name)}: {self.decode_field(field, name)},", depth + 1)
self.emit("}", depth)
def extract_location(self, typename, depth):
row = self.decode_field(asdl.Field('int', 'lineno'), typename)
column = self.decode_field(asdl.Field('int', 'col_offset'), typename)
self.emit(f"let _location = ast::Location::new({row}, {column});", depth)
def wrap_located_node(self, depth):
self.emit(f"let node = ast::Located::new(_location, node);", depth)
def decode_field(self, field, typename):
name = json.dumps(field.name)
if field.opt and not field.seq:
return f"get_node_field_opt(_vm, &_object, {name})?.map(|obj| Node::ast_from_object(_vm, obj)).transpose()?"
else:
return f"Node::ast_from_object(_vm, get_node_field(_vm, &_object, {name}, {json.dumps(typename)})?)?"
class ChainOfVisitors:
def __init__(self, *visitors):
self.visitors = visitors
def visit(self, object):
for v in self.visitors:
v.visit(object)
v.emit("", 0)
def write_ast_def(mod, typeinfo, f):
f.write('pub use crate::location::Location;\n')
f.write('pub use crate::constant::*;\n')
f.write('\n')
f.write('type Ident = String;\n')
f.write('\n')
StructVisitor(f, typeinfo).emit_attrs(0)
f.write('pub struct Located<T, U = ()> {\n')
f.write(' pub location: Location,\n')
f.write(' pub custom: U,\n')
f.write(' pub node: T,\n')
f.write('}\n')
f.write('\n')
f.write('impl<T> Located<T> {\n')
f.write(' pub fn new(location: Location, node: T) -> Self {\n')
f.write(' Self { location, custom: (), node }\n')
f.write(' }\n')
f.write('}\n')
f.write('\n')
c = ChainOfVisitors(StructVisitor(f, typeinfo),
FoldModuleVisitor(f, typeinfo))
c.visit(mod)
def write_ast_mod(mod, f):
f.write('use super::*;\n')
f.write('\n')
c = ChainOfVisitors(ClassDefVisitor(f),
TraitImplVisitor(f),
ExtendModuleVisitor(f))
c.visit(mod)
def main(input_filename, ast_mod_filename, ast_def_filename, dump_module=False):
auto_gen_msg = AUTOGEN_MESSAGE.format("/".join(Path(__file__).parts[-2:]))
mod = asdl.parse(input_filename)
if dump_module:
print('Parsed Module:')
print(mod)
if not asdl.check(mod):
sys.exit(1)
typeinfo = {}
FindUserdataTypesVisitor(typeinfo).visit(mod)
with ast_def_filename.open("w") as def_file, \
ast_mod_filename.open("w") as mod_file:
def_file.write(auto_gen_msg)
write_ast_def(mod, typeinfo, def_file)
mod_file.write(auto_gen_msg)
write_ast_mod(mod, mod_file)
print(f"{ast_def_filename}, {ast_mod_filename} regenerated.")
if __name__ == "__main__":
parser = ArgumentParser()
parser.add_argument("input_file", type=Path)
parser.add_argument("-M", "--mod-file", type=Path, required=True)
parser.add_argument("-D", "--def-file", type=Path, required=True)
parser.add_argument("-d", "--dump-module", action="store_true")
args = parser.parse_args()
main(args.input_file, args.mod_file, args.def_file, args.dump_module)