zephyr/scripts/parse_syscalls.py

111 lines
3.4 KiB
Python

#!/usr/bin/env python3
#
# Copyright (c) 2017 Intel Corporation
#
# SPDX-License-Identifier: Apache-2.0
"""
Script to scan Zephyr include directories and emit system call metadata
System calls require a great deal of boilerplate code in order to implement
completely. This script is the first step in the build system's process of
auto-generating this code by doing a text scan of directories containing
header files, and building up a database of system calls and their
function call prototypes. This information is emitted to a generated
JSON file for further processing.
If the output JSON file already exists, its contents are checked against
what information this script would have outputted; if the result is that the
file would be unchanged, it is not modified to prevent unnecessary
incremental builds.
"""
import sys
import re
import argparse
import os
import json
api_regex = re.compile(r'''
__syscall\s+ # __syscall attribute, must be first
([^(]+) # type and name of system call (split later)
[(] # Function opening parenthesis
([^)]*) # Arg list (split later)
[)] # Closing parenthesis
''', re.MULTILINE | re.VERBOSE)
def analyze_headers(multiple_directories):
ret = []
for base_path in multiple_directories:
for root, dirs, files in os.walk(base_path, topdown=True):
dirs.sort()
files.sort()
for fn in files:
# toolchain/common.h has the definition of __syscall which we
# don't want to trip over
path = os.path.join(root, fn)
if not fn.endswith(".h") or path.endswith(os.path.join(os.sep, 'toolchain', 'common.h')):
continue
with open(path, "r", encoding="utf-8") as fp:
try:
result = [(mo.groups(), fn)
for mo in api_regex.finditer(fp.read())]
except Exception:
sys.stderr.write("While parsing %s\n" % fn)
raise
ret.extend(result)
return ret
def parse_args():
global args
parser = argparse.ArgumentParser(
description=__doc__,
formatter_class=argparse.RawDescriptionHelpFormatter)
parser.add_argument("-i", "--include", required=True, action='append',
help='''include directories recursively scanned
for .h files. Can be specified multiple times:
-i topdir1 -i topdir2 ...''')
parser.add_argument(
"-j", "--json-file", required=True,
help="Write system call prototype information as json to file")
args = parser.parse_args()
def main():
parse_args()
syscalls = analyze_headers(args.include)
syscalls_in_json = json.dumps(
syscalls,
indent=4,
sort_keys=True
)
# Check if the file already exists, and if there are no changes,
# don't touch it since that will force an incremental rebuild
path = args.json_file
new = syscalls_in_json
if os.path.exists(path):
with open(path, 'r') as fp:
old = fp.read()
if new != old:
with open(path, 'w') as fp:
fp.write(new)
else:
with open(path, 'w') as fp:
fp.write(new)
if __name__ == "__main__":
main()