#!/usr/bin/python3
# SPDX-License-Identifier: GPL-2.0
# Author: Julian Sun <[email protected]>
""" Find macro definitions with unused parameters. """
import argparse
import os
import re
parser = argparse.ArgumentParser()
parser.add_argument("path", type=str, help="The file or dir path that needs check")
parser.add_argument("-v", "--verbose", action="store_true",
help="Check conditional macros, but may lead to more false positives")
args = parser.parse_args()
macro_pattern = r"#define\s+(\w+)\(([^)]*)\)"
# below vars were used to reduce false positives
fp_patterns = [r"\s*do\s*\{\s*\}\s*while\s*\(\s*0\s*\)",
r"\(?0\)?", r"\(?1\)?"]
correct_macros = []
cond_compile_mark = "#if"
cond_compile_end = "#endif"
def check_macro(macro_line, report):
match = re.match(macro_pattern, macro_line)
if match:
macro_def = re.sub(macro_pattern, '', macro_line)
identifier = match.group(1)
content = match.group(2)
arguments = [item.strip() for item in content.split(',') if item.strip()]
macro_def = macro_def.strip()
if not macro_def:
return
# used to reduce false positives, like #define endfor_nexthops(rt) }
if len(macro_def) == 1:
return
for fp_pattern in fp_patterns:
if (re.match(fp_pattern, macro_def)):
return
for arg in arguments:
# used to reduce false positives
if "..." in arg:
return
for arg in arguments:
if not arg in macro_def and report == False:
return
# if there is a correct macro with the same name, do not report it.
if not arg in macro_def and identifier not in correct_macros:
print(f"Argument {arg} is not used in function-line macro {identifier}")
return
correct_macros.append(identifier)
# remove comment and whitespace
def macro_strip(macro):
comment_pattern1 = r"\/\/*"
comment_pattern2 = r"\/\**\*\/"
macro = macro.strip()
macro = re.sub(comment_pattern1, '', macro)
macro = re.sub(comment_pattern2, '', macro)
return macro
def file_check_macro(file_path, report):
# number of conditional compiling
cond_compile = 0
# only check .c and .h file
if not file_path.endswith(".c") and not file_path.endswith(".h"):
return
with open(file_path, "r") as f:
while True:
line = f.readline()
if not line:
break
line = line.strip()
if line.startswith(cond_compile_mark):
cond_compile += 1
continue
if line.startswith(cond_compile_end):
cond_compile -= 1
continue
macro = re.match(macro_pattern, line)
if macro:
macro = macro_strip(macro.string)
while macro[-1] == '\\':
macro = macro[0:-1]
macro = macro.strip()
macro += f.readline()
macro = macro_strip(macro)
if not args.verbose:
if file_path.endswith(".c") and cond_compile != 0:
continue
# 1 is for #ifdef xxx at the beginning of the header file
if file_path.endswith(".h") and cond_compile != 1:
continue
check_macro(macro, report)
def get_correct_macros(path):
file_check_macro(path, False)
def dir_check_macro(dir_path):
for dentry in os.listdir(dir_path):
path = os.path.join(dir_path, dentry)
if os.path.isdir(path):
dir_check_macro(path)
elif os.path.isfile(path):
get_correct_macros(path)
file_check_macro(path, True)
def main():
if os.path.isfile(args.path):
get_correct_macros(args.path)
file_check_macro(args.path, True)
elif os.path.isdir(args.path):
dir_check_macro(args.path)
else:
print(f"{args.path} doesn't exit or is neither a file nor a dir")
if __name__ == "__main__":
main()
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