gtsam/wrap/gtwrap/pybind_wrapper.py

723 lines
30 KiB
Python
Executable File

#!/usr/bin/env python3
"""
GTSAM Copyright 2010-2020, Georgia Tech Research Corporation,
Atlanta, Georgia 30332-0415
All Rights Reserved
See LICENSE for the license information
Code generator for wrapping a C++ module with Pybind11
Author: Duy Nguyen Ta, Fan Jiang, Matthew Sklar, Varun Agrawal, and Frank Dellaert
"""
# pylint: disable=too-many-arguments, too-many-instance-attributes, no-self-use, no-else-return, too-many-arguments, unused-format-string-argument, line-too-long, consider-using-f-string
import re
from pathlib import Path
from typing import List
import gtwrap.interface_parser as parser
import gtwrap.template_instantiator as instantiator
class PybindWrapper:
"""
Class to generate binding code for Pybind11 specifically.
"""
def __init__(self,
module_name,
top_module_namespaces='',
use_boost_serialization=False,
ignore_classes=(),
module_template=""):
self.module_name = module_name
self.top_module_namespaces = top_module_namespaces
self.use_boost_serialization = use_boost_serialization
self.ignore_classes = ignore_classes
self._serializing_classes = []
self.module_template = module_template
self.python_keywords = [
'lambda', 'False', 'def', 'if', 'raise', 'None', 'del', 'import',
'return', 'True', 'elif', 'in', 'try', 'and', 'else', 'is',
'while', 'as', 'except', 'lambda', 'with', 'assert', 'finally',
'nonlocal', 'yield', 'break', 'for', 'not', 'class', 'from', 'or',
'continue', 'global', 'pass'
]
# amount of indentation to add before each function/method declaration.
self.method_indent = '\n' + (' ' * 8)
# Special methods which are leveraged by ipython/jupyter notebooks
self._ipython_special_methods = [
"svg", "png", "jpeg", "html", "javascript", "markdown", "latex"
]
def _py_args_names(self, args):
"""Set the argument names in Pybind11 format."""
names = args.names()
if names:
py_args = []
for arg in args.list():
if arg.default is not None:
default = ' = {arg.default}'.format(arg=arg)
else:
default = ''
argument = 'py::arg("{name}"){default}'.format(
name=arg.name, default='{0}'.format(default))
py_args.append(argument)
return ", " + ", ".join(py_args)
else:
return ''
def _method_args_signature(self, args):
"""Generate the argument types and names as per the method signature."""
cpp_types = args.to_cpp()
names = args.names()
types_names = [
"{} {}".format(ctype, name)
for ctype, name in zip(cpp_types, names)
]
return ', '.join(types_names)
def wrap_ctors(self, my_class):
"""Wrap the constructors."""
res = ""
for ctor in my_class.ctors:
res += (self.method_indent + '.def(py::init<{args_cpp_types}>()'
'{py_args_names})'.format(
args_cpp_types=", ".join(ctor.args.to_cpp()),
py_args_names=self._py_args_names(ctor.args),
))
return res
def _wrap_serialization(self, cpp_class):
"""Helper method to add serialize, deserialize and pickle methods to the wrapped class."""
if not cpp_class in self._serializing_classes:
self._serializing_classes.append(cpp_class)
serialize_method = self.method_indent + \
".def(\"serialize\", []({class_inst} self){{ return gtsam::serialize(*self); }})".format(class_inst=cpp_class + '*')
deserialize_method = self.method_indent + \
'.def("deserialize", []({class_inst} self, string serialized)' \
'{{ gtsam::deserialize(serialized, *self); }}, py::arg("serialized"))' \
.format(class_inst=cpp_class + '*')
# Since this class supports serialization, we also add the pickle method.
pickle_method = self.method_indent + \
".def(py::pickle({indent} [](const {cpp_class} &a){{ /* __getstate__: Returns a string that encodes the state of the object */ return py::make_tuple(gtsam::serialize(a)); }},{indent} [](py::tuple t){{ /* __setstate__ */ {cpp_class} obj; gtsam::deserialize(t[0].cast<std::string>(), obj); return obj; }}))"
return serialize_method + deserialize_method + \
pickle_method.format(cpp_class=cpp_class, indent=self.method_indent)
def _wrap_print(self, ret: str, method: parser.Method, cpp_class: str,
args_names: List[str], args_signature_with_names: str,
py_args_names: str, prefix: str, suffix: str):
"""
Update the print method to print to the output stream and append a __repr__ method.
Args:
ret (str): The result of the parser.
method (parser.Method): The method to be wrapped.
cpp_class (str): The C++ name of the class to which the method belongs.
args_names (List[str]): List of argument variable names passed to the method.
args_signature_with_names (str): C++ arguments containing their names and type signatures.
py_args_names (str): The pybind11 formatted version of the argument list.
prefix (str): Prefix to add to the wrapped method when writing to the cpp file.
suffix (str): Suffix to add to the wrapped method when writing to the cpp file.
Returns:
str: The wrapped print method.
"""
# Redirect stdout - see pybind docs for why this is a good idea:
# https://pybind11.readthedocs.io/en/stable/advanced/pycpp/utilities.html#capturing-standard-output-from-ostream
ret = ret.replace('self->print',
'py::scoped_ostream_redirect output; self->print')
# Make __repr__() call .print() internally
ret += '''{prefix}.def("__repr__",
[](const {cpp_class}& self{opt_comma}{args_signature_with_names}){{
gtsam::RedirectCout redirect;
self.{method_name}({method_args});
return redirect.str();
}}{py_args_names}){suffix}'''.format(
prefix=prefix,
cpp_class=cpp_class,
opt_comma=', ' if args_names else '',
args_signature_with_names=args_signature_with_names,
method_name=method.name,
method_args=", ".join(args_names) if args_names else '',
py_args_names=py_args_names,
suffix=suffix)
return ret
def _wrap_method(self,
method,
cpp_class,
prefix,
suffix,
method_suffix=""):
"""
Wrap the `method` for the class specified by `cpp_class`.
Args:
method: The method to wrap.
cpp_class: The C++ name of the class to which the method belongs.
prefix: Prefix to add to the wrapped method when writing to the cpp file.
suffix: Suffix to add to the wrapped method when writing to the cpp file.
method_suffix: A string to append to the wrapped method name.
"""
py_method = method.name + method_suffix
cpp_method = method.to_cpp()
args_names = method.args.names()
py_args_names = self._py_args_names(method.args)
args_signature_with_names = self._method_args_signature(method.args)
# Special handling for the serialize/serializable method
if cpp_method in ["serialize", "serializable"]:
if self.use_boost_serialization:
return self._wrap_serialization(cpp_class)
else:
return ""
# Special handling of ipython specific methods
# https://ipython.readthedocs.io/en/stable/config/integrating.html
if cpp_method in self._ipython_special_methods:
idx = self._ipython_special_methods.index(cpp_method)
py_method = f"_repr_{self._ipython_special_methods[idx]}_"
# Add underscore to disambiguate if the method name matches a python keyword
if py_method in self.python_keywords:
py_method = py_method + "_"
is_method = isinstance(
method, (parser.Method, instantiator.InstantiatedMethod))
is_static = isinstance(
method,
(parser.StaticMethod, instantiator.InstantiatedStaticMethod))
return_void = method.return_type.is_void()
caller = cpp_class + "::" if not is_method else "self->"
function_call = ('{opt_return} {caller}{method_name}'
'({args_names});'.format(
opt_return='return' if not return_void else '',
caller=caller,
method_name=cpp_method,
args_names=', '.join(args_names),
))
ret = ('{prefix}.{cdef}("{py_method}",'
'[]({opt_self}{opt_comma}{args_signature_with_names}){{'
'{function_call}'
'}}'
'{py_args_names}){suffix}'.format(
prefix=prefix,
cdef="def_static" if is_static else "def",
py_method=py_method,
opt_self="{cpp_class}* self".format(
cpp_class=cpp_class) if is_method else "",
opt_comma=', ' if is_method and args_names else '',
args_signature_with_names=args_signature_with_names,
function_call=function_call,
py_args_names=py_args_names,
suffix=suffix,
))
# Create __repr__ override
# We allow all arguments to .print() and let the compiler handle type mismatches.
if method.name == 'print':
ret = self._wrap_print(ret, method, cpp_class, args_names,
args_signature_with_names, py_args_names,
prefix, suffix)
return ret
def wrap_methods(self,
methods,
cpp_class,
prefix='\n' + ' ' * 8,
suffix=''):
"""
Wrap all the methods in the `cpp_class`.
"""
res = ""
for method in methods:
# To avoid type confusion for insert
if method.name == 'insert' and cpp_class == 'gtsam::Values':
name_list = method.args.names()
type_list = method.args.to_cpp()
# inserting non-wrapped value types
if type_list[0].strip() == 'size_t':
method_suffix = '_' + name_list[1].strip()
res += self._wrap_method(method=method,
cpp_class=cpp_class,
prefix=prefix,
suffix=suffix,
method_suffix=method_suffix)
res += self._wrap_method(
method=method,
cpp_class=cpp_class,
prefix=prefix,
suffix=suffix,
)
return res
def wrap_variable(self,
namespace,
module_var,
variable,
prefix='\n' + ' ' * 8):
"""
Wrap a variable that's not part of a class (i.e. global)
"""
variable_value = ""
if variable.default is None:
variable_value = variable.name
else:
variable_value = variable.default
return '{prefix}{module_var}.attr("{variable_name}") = {namespace}{variable_value};'.format(
prefix=prefix,
module_var=module_var,
variable_name=variable.name,
namespace=namespace,
variable_value=variable_value)
def wrap_properties(self, properties, cpp_class, prefix='\n' + ' ' * 8):
"""Wrap all the properties in the `cpp_class`."""
res = ""
for prop in properties:
res += ('{prefix}.def_{property}("{property_name}", '
'&{cpp_class}::{property_name})'.format(
prefix=prefix,
property="readonly"
if prop.ctype.is_const else "readwrite",
cpp_class=cpp_class,
property_name=prop.name,
))
return res
def wrap_operators(self, operators, cpp_class, prefix='\n' + ' ' * 8):
"""Wrap all the overloaded operators in the `cpp_class`."""
res = ""
template = "{prefix}.def({{0}})".format(prefix=prefix)
for op in operators:
if op.operator == "[]": # __getitem__
res += "{prefix}.def(\"__getitem__\", &{cpp_class}::operator[])".format(
prefix=prefix, cpp_class=cpp_class)
elif op.operator == "()": # __call__
res += "{prefix}.def(\"__call__\", &{cpp_class}::operator())".format(
prefix=prefix, cpp_class=cpp_class)
elif op.is_unary:
res += template.format("{0}py::self".format(op.operator))
else:
res += template.format("py::self {0} py::self".format(
op.operator))
return res
def wrap_enum(self, enum, class_name='', module=None, prefix=' ' * 4):
"""
Wrap an enum.
Args:
enum: The parsed enum to wrap.
class_name: The class under which the enum is defined.
prefix: The amount of indentation.
"""
if module is None:
module = self._gen_module_var(enum.namespaces())
cpp_class = enum.cpp_typename().to_cpp()
if class_name:
# If class_name is provided, add that as the namespace
cpp_class = class_name + "::" + cpp_class
res = '{prefix}py::enum_<{cpp_class}>({module}, "{enum.name}", py::arithmetic())'.format(
prefix=prefix, module=module, enum=enum, cpp_class=cpp_class)
for enumerator in enum.enumerators:
res += '\n{prefix} .value("{enumerator.name}", {cpp_class}::{enumerator.name})'.format(
prefix=prefix, enumerator=enumerator, cpp_class=cpp_class)
res += ";\n\n"
return res
def wrap_enums(self, enums, instantiated_class, prefix=' ' * 4):
"""Wrap multiple enums defined in a class."""
cpp_class = instantiated_class.to_cpp()
module_var = instantiated_class.name.lower()
res = ''
for enum in enums:
res += "\n" + self.wrap_enum(
enum, class_name=cpp_class, module=module_var, prefix=prefix)
return res
def wrap_instantiated_class(
self, instantiated_class: instantiator.InstantiatedClass):
"""Wrap the class."""
module_var = self._gen_module_var(instantiated_class.namespaces())
cpp_class = instantiated_class.to_cpp()
if cpp_class in self.ignore_classes:
return ""
if instantiated_class.parent_class:
class_parent = "{instantiated_class.parent_class}, ".format(
instantiated_class=instantiated_class)
else:
class_parent = ''
if instantiated_class.enums:
# If class has enums, define an instance and set module_var to the instance
instance_name = instantiated_class.name.lower()
class_declaration = (
'\n py::class_<{cpp_class}, {class_parent}'
'std::shared_ptr<{cpp_class}>> '
'{instance_name}({module_var}, "{class_name}");'
'\n {instance_name}').format(
cpp_class=cpp_class,
class_name=instantiated_class.name,
class_parent=class_parent,
instance_name=instance_name,
module_var=module_var)
module_var = instance_name
else:
class_declaration = (
'\n py::class_<{cpp_class}, {class_parent}'
'std::shared_ptr<{cpp_class}>>({module_var}, "{class_name}")'
).format(cpp_class=cpp_class,
class_name=instantiated_class.name,
class_parent=class_parent,
module_var=module_var)
return ('{class_declaration}'
'{wrapped_ctors}'
'{wrapped_methods}'
'{wrapped_static_methods}'
'{wrapped_properties}'
'{wrapped_operators};\n'.format(
class_declaration=class_declaration,
wrapped_ctors=self.wrap_ctors(instantiated_class),
wrapped_methods=self.wrap_methods(
instantiated_class.methods, cpp_class),
wrapped_static_methods=self.wrap_methods(
instantiated_class.static_methods, cpp_class),
wrapped_properties=self.wrap_properties(
instantiated_class.properties, cpp_class),
wrapped_operators=self.wrap_operators(
instantiated_class.operators, cpp_class)))
def wrap_instantiated_declaration(
self, instantiated_decl: instantiator.InstantiatedDeclaration):
"""Wrap the forward declaration."""
module_var = self._gen_module_var(instantiated_decl.namespaces())
cpp_class = instantiated_decl.to_cpp()
if cpp_class in self.ignore_classes:
return ""
res = ('\n py::class_<{cpp_class}, '
'std::shared_ptr<{cpp_class}>>({module_var}, "{class_name}");'
).format(cpp_class=cpp_class,
class_name=instantiated_decl.name,
module_var=module_var)
return res
def wrap_stl_class(self, stl_class):
"""Wrap STL containers."""
module_var = self._gen_module_var(stl_class.namespaces())
cpp_class = stl_class.to_cpp()
if cpp_class in self.ignore_classes:
return ""
return ('\n py::class_<{cpp_class}, {class_parent}'
'std::shared_ptr<{cpp_class}>>({module_var}, "{class_name}")'
'{wrapped_ctors}'
'{wrapped_methods}'
'{wrapped_static_methods}'
'{wrapped_properties};\n'.format(
cpp_class=cpp_class,
class_name=stl_class.name,
class_parent=str(stl_class.parent_class) +
(', ' if stl_class.parent_class else ''),
module_var=module_var,
wrapped_ctors=self.wrap_ctors(stl_class),
wrapped_methods=self.wrap_methods(stl_class.methods,
cpp_class),
wrapped_static_methods=self.wrap_methods(
stl_class.static_methods, cpp_class),
wrapped_properties=self.wrap_properties(
stl_class.properties, cpp_class),
))
def wrap_functions(self,
functions,
namespace,
prefix='\n' + ' ' * 8,
suffix=''):
"""
Wrap all the global functions.
"""
res = ""
for function in functions:
function_name = function.name
# Add underscore to disambiguate if the function name matches a python keyword
python_keywords = self.python_keywords + ['print']
if function_name in python_keywords:
function_name = function_name + "_"
cpp_method = function.to_cpp()
is_static = isinstance(function, parser.StaticMethod)
return_void = function.return_type.is_void()
args_names = function.args.names()
py_args_names = self._py_args_names(function.args)
args_signature = self._method_args_signature(function.args)
caller = namespace + "::"
function_call = ('{opt_return} {caller}{function_name}'
'({args_names});'.format(
opt_return='return'
if not return_void else '',
caller=caller,
function_name=cpp_method,
args_names=', '.join(args_names),
))
ret = ('{prefix}.{cdef}("{function_name}",'
'[]({args_signature}){{'
'{function_call}'
'}}'
'{py_args_names}){suffix}'.format(
prefix=prefix,
cdef="def_static" if is_static else "def",
function_name=function_name,
args_signature=args_signature,
function_call=function_call,
py_args_names=py_args_names,
suffix=suffix))
res += ret
return res
def _partial_match(self, namespaces1, namespaces2):
for i in range(min(len(namespaces1), len(namespaces2))):
if namespaces1[i] != namespaces2[i]:
return False
return True
def _gen_module_var(self, namespaces):
"""Get the Pybind11 module name from the namespaces."""
# We skip the first value in namespaces since it is empty
sub_module_namespaces = namespaces[len(self.top_module_namespaces):]
return "m_{}".format('_'.join(sub_module_namespaces))
def _add_namespaces(self, name, namespaces):
if namespaces:
# Ignore the first empty global namespace.
idx = 1 if not namespaces[0] else 0
return '::'.join(namespaces[idx:] + [name])
else:
return name
def wrap_namespace(self, namespace):
"""Wrap the complete `namespace`."""
wrapped = ""
includes = ""
namespaces = namespace.full_namespaces()
if not self._partial_match(namespaces, self.top_module_namespaces):
return "", ""
if len(namespaces) < len(self.top_module_namespaces):
for element in namespace.content:
if isinstance(element, parser.Include):
include = "{}\n".format(element)
# replace the angle brackets with quotes
include = include.replace('<', '"').replace('>', '"')
includes += include
if isinstance(element, parser.Namespace):
(
wrapped_namespace,
includes_namespace,
) = self.wrap_namespace( # noqa
element)
wrapped += wrapped_namespace
includes += includes_namespace
else:
module_var = self._gen_module_var(namespaces)
if len(namespaces) > len(self.top_module_namespaces):
wrapped += (
' ' * 4 + 'pybind11::module {module_var} = '
'{parent_module_var}.def_submodule("{namespace}", "'
'{namespace} submodule");\n'.format(
module_var=module_var,
namespace=namespace.name,
parent_module_var=self._gen_module_var(
namespaces[:-1]),
))
# Wrap an include statement, namespace, class or enum
for element in namespace.content:
if isinstance(element, parser.Include):
include = "{}\n".format(element)
# replace the angle brackets with quotes
include = include.replace('<', '"').replace('>', '"')
includes += include
elif isinstance(element, parser.Namespace):
wrapped_namespace, includes_namespace = self.wrap_namespace(
element)
wrapped += wrapped_namespace
includes += includes_namespace
elif isinstance(element, instantiator.InstantiatedClass):
wrapped += self.wrap_instantiated_class(element)
wrapped += self.wrap_enums(element.enums, element)
elif isinstance(element, instantiator.InstantiatedDeclaration):
wrapped += self.wrap_instantiated_declaration(element)
elif isinstance(element, parser.Variable):
variable_namespace = self._add_namespaces('', namespaces)
wrapped += self.wrap_variable(namespace=variable_namespace,
module_var=module_var,
variable=element,
prefix='\n' + ' ' * 4)
elif isinstance(element, parser.Enum):
wrapped += self.wrap_enum(element)
# Global functions.
all_funcs = [
func for func in namespace.content
if isinstance(func, (parser.GlobalFunction,
instantiator.InstantiatedGlobalFunction))
]
wrapped += self.wrap_functions(
all_funcs,
self._add_namespaces('', namespaces)[:-2],
prefix='\n' + ' ' * 4 + module_var,
suffix=';',
)
return wrapped, includes
def wrap_file(self, content, module_name=None, submodules=None):
"""
Wrap the code in the interface file.
Args:
content: The contents of the interface file.
module_name: The name of the module.
submodules: List of other interface file names that should be linked to.
"""
# Parse the contents of the interface file
module = parser.Module.parseString(content)
# Instantiate all templates
module = instantiator.instantiate_namespace(module)
wrapped_namespace, includes = self.wrap_namespace(module)
if self.use_boost_serialization:
includes += "#include <boost/serialization/export.hpp>"
# Export classes for serialization.
boost_class_export = ""
for cpp_class in self._serializing_classes:
new_name = cpp_class
# The boost's macro doesn't like commas, so we have to typedef.
if ',' in cpp_class:
new_name = re.sub("[,:<> ]", "", cpp_class)
boost_class_export += "typedef {cpp_class} {new_name};\n".format( # noqa
cpp_class=cpp_class, new_name=new_name)
boost_class_export += "BOOST_CLASS_EXPORT({new_name})\n".format(
new_name=new_name, )
else:
boost_class_export = ""
# Reset the serializing classes list
self._serializing_classes = []
submodules_init = []
if submodules is not None:
module_def = "PYBIND11_MODULE({0}, m_)".format(module_name)
for idx, submodule in enumerate(submodules):
submodules[idx] = "void {0}(py::module_ &);".format(submodule)
submodules_init.append("{0}(m_);".format(submodule))
else:
module_def = "void {0}(py::module_ &m_)".format(module_name)
submodules = []
return self.module_template.format(
module_def=module_def,
module_name=module_name,
includes=includes,
wrapped_namespace=wrapped_namespace,
boost_class_export=boost_class_export,
submodules="\n".join(submodules),
submodules_init="\n".join(submodules_init),
)
def wrap_submodule(self, source):
"""
Wrap a list of submodule files, i.e. a set of interface files which are
in support of a larger wrapping project.
E.g. This is used in GTSAM where we have a main gtsam.i, but various smaller .i files
which are the submodules.
The benefit of this scheme is that it reduces compute and memory usage during compilation.
Args:
source: Interface file which forms the submodule.
"""
filename = Path(source).name
module_name = Path(source).stem
# Read in the complete interface (.i) file
with open(source, "r", encoding="UTF-8") as f:
content = f.read()
# Wrap the read-in content
cc_content = self.wrap_file(content, module_name=module_name)
# Generate the C++ code which Pybind11 will use.
with open(filename.replace(".i", ".cpp"), "w", encoding="UTF-8") as f:
f.write(cc_content)
def wrap(self, sources, main_module_name):
"""
Wrap all the main interface file.
Args:
sources: List of all interface files.
The first file should be the main module.
main_module_name: The name for the main module.
"""
main_module = sources[0]
# Get all the submodule names.
submodules = []
for source in sources[1:]:
module_name = Path(source).stem
submodules.append(module_name)
with open(main_module, "r", encoding="UTF-8") as f:
content = f.read()
cc_content = self.wrap_file(content,
module_name=self.module_name,
submodules=submodules)
# Generate the C++ code which Pybind11 will use.
with open(main_module_name, "w", encoding="UTF-8") as f:
f.write(cc_content)