sandboxed-api/oss-internship-2020/libuv/generator/wrapper_generator.py
Copybara-Service e6bb05a15d Merge pull request #55 from FedericoStazi:libuv
PiperOrigin-RevId: 343278766
Change-Id: I708fdc1cd98d5fbb2abcf3261d1cecd65cec46fe
2020-11-19 06:32:47 -08:00

297 lines
8.0 KiB
Python

# Copyright 2020 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""Script generating a wrapper API for LibUV.
Note: This scriptis highly specific to LibUV's source code and does not
generalize to any other library
"""
import os
import re
import sys
from typing import List
def get_var_type(string: str) -> str:
"""Gets the type from an argument variable.
Args:
string: Input variable declaration
Returns:
The type of the argument variable as a string, e.g. "int x" -> "int".
"""
var = string.strip()
# Unnamed variable
if var in ("void", "...") or var[-1] == "*":
return var
return " ".join(var.split(" ")[:-1]).strip()
def get_var_name(string: str) -> str:
"""Gets the name from an argument variable.
Args:
string: Input variable declaration
Returns:
The name of the arguments variable as a string, e.g. "int x" -> "x".
"""
var = string.strip()
# Not an actual variable
if var in ("void", "..."):
return ""
# Unnamed variable, use an arbitrary name
if var[-1] == "*":
return var.split("_")[1]
return var.split(" ")[-1].strip()
def fix_method_type(string: str) -> str:
"""Fixes the method type.
Args:
string: A parameter type declaration
Returns:
A fixed up string replacing pointers to concrete types with pointers to
void, e.g. "const int*" -> "const void*".
"""
method_type = string.strip()
# Const pointer
if "*" in method_type and "const" in method_type:
return "const void*"
# Regular pointer
if "*" in method_type:
return "void*"
# Not a pointer
return method_type
def fix_argument(string: str) -> str:
"""Fixes an argument.
Args:
string: An argument type to fix
Returns:
The fixed up argument as a string, e.g. "const int* x" -> "const void* x".
"""
arg_type = get_var_type(string)
arg_name = get_var_name(string)
# Array argument, becomes a pointer
if "[" in arg_name:
arg_type += "*"
arg_name = arg_name.split("[")[0] + arg_name.split("]")[-1]
# Pointer (in LibUV, types endind in "_cb" or "_func" are pointers)
if "*" in arg_type or "_cb" in arg_type or "_func" in arg_type:
if "const" in arg_type:
return "const void* " + arg_name
return "void* " + arg_name
# Not a pointer
return arg_type + " " + arg_name
def fix_call_argument(string: str) -> str:
"""Fixes an argument in a call the orignal method.
Args:
string: A method call argument
Returns:
The fixed call argument, e.g. "const int* x" ->
"reinterpret_cast<const int*>(x)".
"""
arg_type = get_var_type(string)
arg_name = get_var_name(string)
# Array argument, becomes a pointer
if "[" in arg_name:
arg_type += "*"
arg_name = arg_name.split("[")[0] + arg_name.split("]")[-1]
# Pointer (in LibUV, types endind in "_cb" or "_func" are pointers)
if "*" in arg_type or "_cb" in arg_type or "_func" in arg_type:
return "reinterpret_cast<" + arg_type + ">(" + arg_name + ")"
# Not a pointer
return arg_name
def read_file(filename: str) -> str:
"""Returns contents of filename as a string.
Args:
filename: The name of the file to read
Returns:
The contents of the file as a string.
"""
file = open(filename, "r")
return str(file.read())
def clean_file(text: str) -> str:
"""Prepares the file for parsing.
In particular, removes comments and macros from text
Additionally, moves pointer asterisks next to its type
Args:
text: The contents of the text file to prepare
Returns:
The cleaned up file contents.
"""
result = text
result = re.sub(r"//.*?\n", "", result, flags=re.S)
result = re.sub(r"/\*.*?\*/", "", result, flags=re.S)
result = re.sub(r"#.*?\n", "", result, flags=re.S)
result = result.replace(" *", "* ")
return result
def get_signatures(text: str) -> str:
"""Gets the signatures of all the methods in the header.
Note: This method only works on a certain version of LibUV's header.
Args:
text: The contents of the header file
Returns:
The extracted method signatures.
"""
signatures = [x.split(";")[0].strip() for x in text.split("UV_EXTERN")[1:]]
method_types = [
" ".join(s.split("(")[0].split(" ")[:-1]).strip() for s in signatures
]
names = [s.split("(")[0].split(" ")[-1].strip() for s in signatures]
arguments = [s.split("(")[1][:-1] for s in signatures]
arguments_lists = [[x.strip() for x in a.split(",")] for a in arguments]
return zip(method_types, names, arguments_lists)
def append_method(method_type: str, name: str, arguments_list: List[str],
header: List[str], source: List[str]) -> None:
"""Writes the method to the header and the source list of lines.
Args:
method_type: The return type of the method as a string
name: The name of the method
arguments_list: A list of method aruments
header: A list that receives method wrapper declarations
source: A list that receives the declarations of the method wrappers
"""
header.append(
fix_method_type(method_type) + " sapi_" + name + "(" +
", ".join(map(fix_argument, arguments_list)) + ");")
source.append(
fix_method_type(method_type) + " sapi_" + name + "(" +
", ".join(map(fix_argument, arguments_list)) + ") {\n" + " return " +
name + "(" + ", ".join(map(fix_call_argument, arguments_list)) + ");\n" +
"}")
def append_text(text: str, file: List[str]) -> None:
"""Writes text to file list of lines.
Useful for additional methods, includes, extern "C"...
Args:
text: The text to append to the file
file: A list receiving file lines
"""
file.append(text)
def generate_wrapper() -> None:
"""Generates the wrapper."""
header_file = open(sys.argv[2], "w")
source_file = open(sys.argv[3], "w")
text = read_file(sys.argv[1])
text = clean_file(text)
signatures = get_signatures(text)
header = []
source = []
append_text("#include <uv.h>", header)
append_text("#include <cstddef>", header)
append_text("extern \"C\" {", header)
append_text("#include \"" + os.path.abspath(header_file.name) + "\"", source)
for (method_type, name, arguments_list) in signatures:
# These wrapper methods are manually added at the end
if name in ("uv_once", "uv_loop_configure"):
continue
append_method(method_type, name, arguments_list, header, source)
# Add sapi_uv_once (uv_once uses a differnet kind of callback)
append_text("void sapi_uv_once(void* guard, void (*callback)(void));", header)
append_text(
"void sapi_uv_once(void* guard, void (*callback)(void)) {\n" +
" return uv_once(reinterpret_cast<uv_once_t*>(guard)," + "callback);\n" +
"}", source)
# Add sapi_uv_loop_configure (uv_loop_configure is variadic)
append_text(
"int sapi_uv_loop_configure(void* loop, uv_loop_option option)" + ";",
header)
append_text(
"int sapi_uv_loop_configure(void* loop, uv_loop_option option)" +
" {\n return uv_loop_configure(" +
"reinterpret_cast<uv_loop_t*>(loop), option);\n" + "}", source)
# Add sapi_uv_loop_configure_int (uv_loop_configure is variadic)
append_text(
"int sapi_uv_loop_configure_int(void* loop, " +
"uv_loop_option option, int ap);", header)
append_text(
"int sapi_uv_loop_configure_int(void* loop, " +
"uv_loop_option option, int ap) {\n" + " return uv_loop_configure(" +
"reinterpret_cast<uv_loop_t*>(loop), option, ap);\n}", source)
append_text("} // extern \"C\"\n", header)
header_file.write("\n\n".join(header))
source_file.write("\n\n".join(source))
generate_wrapper()