scripts/macro_checker.py

   1 #!/usr/bin/python3
   2 # SPDX-License-Identifier: GPL-2.0
   3 # Author: Julian Sun <sunjunchao2870@gmail.com>
   4
   5 """ Find macro definitions with unused parameters. """
   6
   7 import argparse
   8 import os
   9 import re
  10
  11 parser = argparse.ArgumentParser()
  12
  13 parser.add_argument("path", type=str, help="The file or dir path that needs check")
  14 parser.add_argument("-v", "--verbose", action="store_true",
  15                     help="Check conditional macros, but may lead to more false positives")
  16 args = parser.parse_args()
  17
  18 macro_pattern = r"#define\s+(\w+)\(([^)]*)\)"
  19 # below vars were used to reduce false positives
  20 fp_patterns = [r"\s*do\s*\{\s*\}\s*while\s*\(\s*0\s*\)",
  21                r"\(?0\)?", r"\(?1\)?"]
  22 correct_macros = []
  23 cond_compile_mark = "#if"
  24 cond_compile_end = "#endif"
  25
  26 def check_macro(macro_line, report):
  27     match = re.match(macro_pattern, macro_line)
  28     if match:
  29         macro_def = re.sub(macro_pattern, '', macro_line)
  30         identifier = match.group(1)
  31         content = match.group(2)
  32         arguments = [item.strip() for item in content.split(',') if item.strip()]
  33
  34         macro_def = macro_def.strip()
  35         if not macro_def:
  36             return
  37         # used to reduce false positives, like #define endfor_nexthops(rt) }
  38         if len(macro_def) == 1:
  39             return
  40
  41         for fp_pattern in fp_patterns:
  42             if (re.match(fp_pattern, macro_def)):
  43                 return
  44
  45         for arg in arguments:
  46             # used to reduce false positives
  47             if "..." in arg:
  48                 return
  49         for arg in arguments:
  50             if not arg in macro_def and report == False:
  51                 return
  52             # if there is a correct macro with the same name, do not report it.
  53             if not arg in macro_def and identifier not in correct_macros:
  54                 print(f"Argument {arg} is not used in function-line macro {identifier}")
  55                 return
  56
  57         correct_macros.append(identifier)
  58
  59
  60 # remove comment and whitespace
  61 def macro_strip(macro):
  62     comment_pattern1 = r"\/\/*"
  63     comment_pattern2 = r"\/\**\*\/"
  64
  65     macro = macro.strip()
  66     macro = re.sub(comment_pattern1, '', macro)
  67     macro = re.sub(comment_pattern2, '', macro)
  68
  69     return macro
  70
  71 def file_check_macro(file_path, report):
  72     # number of conditional compiling
  73     cond_compile = 0
  74     # only check .c and .h file
  75     if not file_path.endswith(".c") and not file_path.endswith(".h"):
  76         return
  77
  78     with open(file_path, "r") as f:
  79         while True:
  80             line = f.readline()
  81             if not line:
  82                 break
  83             line = line.strip()
  84             if line.startswith(cond_compile_mark):
  85                 cond_compile += 1
  86                 continue
  87             if line.startswith(cond_compile_end):
  88                 cond_compile -= 1
  89                 continue
  90
  91             macro = re.match(macro_pattern, line)
  92             if macro:
  93                 macro = macro_strip(macro.string)
  94                 while macro[-1] == '\\':
  95                     macro = macro[0:-1]
  96                     macro = macro.strip()
  97                     macro += f.readline()
  98                     macro = macro_strip(macro)
  99                 if not args.verbose:
 100                     if file_path.endswith(".c")  and cond_compile != 0:
 101                         continue
 102                     # 1 is for #ifdef xxx at the beginning of the header file
 103                     if file_path.endswith(".h") and cond_compile != 1:
 104                         continue
 105                 check_macro(macro, report)
 106
 107 def get_correct_macros(path):
 108     file_check_macro(path, False)
 109
 110 def dir_check_macro(dir_path):
 111
 112     for dentry in os.listdir(dir_path):
 113         path = os.path.join(dir_path, dentry)
 114         if os.path.isdir(path):
 115             dir_check_macro(path)
 116         elif os.path.isfile(path):
 117             get_correct_macros(path)
 118             file_check_macro(path, True)
 119
 120
 121 def main():
 122     if os.path.isfile(args.path):
 123         get_correct_macros(args.path)
 124         file_check_macro(args.path, True)
 125     elif os.path.isdir(args.path):
 126         dir_check_macro(args.path)
 127     else:
 128         print(f"{args.path} doesn't exit or is neither a file nor a dir")
 129
 130 if __name__ == "__main__":
 131     main()