gdb/check-include-guards.py

   1 #!/usr/bin/env python3
   2
   3 # Copyright (C) 2024 Free Software Foundation, Inc.
   4 #
   5 # This file is part of GDB.
   6 #
   7 # This program is free software; you can redistribute it and/or modify
   8 # it under the terms of the GNU General Public License as published by
   9 # the Free Software Foundation; either version 3 of the License, or
  10 # (at your option) any later version.
  11 #
  12 # This program is distributed in the hope that it will be useful,
  13 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 # GNU General Public License for more details.
  16 #
  17 # You should have received a copy of the GNU General Public License
  18 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19
  20 # This is intended to be run from pre-commit.  You can also run it by
  21 # hand by passing repository-relative filenames to it, like:
  22 #   ./gdb/check-include-guards.py [--update] gdb/*.h
  23 # When --update is used, rewrite the files in place as needed.
  24
  25
  26 import re
  27 import sys
  28 from typing import List
  29
  30 DEF = re.compile("^#ifndef ([A-Za-z0-9_]+)\n")
  31 OLDDEF = re.compile("^#if !defined *\\(([A-Za-z0-9_]+)\\)\n")
  32
  33 # Some headers -- in particular, ones that aren't maintained by gdb --
  34 # should be excluded from the checks.
  35 EXCLUDED = frozenset(["gdbsupport/unordered_dense.h"])
  36
  37
  38 # See if
  39 write_files = False
  40 args = sys.argv[1:]
  41 if len(args) > 0 and args[0] == "--update":
  42     write_files = True
  43     args = args[1:]
  44
  45
  46 def failure(filename: str, ndx: int, text: str):
  47     print(filename + ":" + str(ndx + 1) + ": " + text, file=sys.stderr)
  48     sys.exit(1)
  49
  50
  51 def skip_comments_and_blanks(ndx: int, contents: List[str]):
  52     while ndx < len(contents) and contents[ndx].startswith("/*"):
  53         while ndx < len(contents):
  54             ndx += 1
  55             if contents[ndx - 1].endswith("*/\n"):
  56                 break
  57         # Skip blank lines.
  58         while ndx < len(contents):
  59             if contents[ndx].strip() != "":
  60                 break
  61             ndx += 1
  62     return ndx
  63
  64
  65 def write_header(filename: str, contents: List[str]):
  66     with open(filename, "w") as f:
  67         f.writelines(contents)
  68
  69
  70 def check_header(filename: str):
  71     if filename in EXCLUDED:
  72         return
  73
  74     # Turn x/y-z.h into X_Y_Z_H.
  75     assert filename.endswith(".h")
  76     expected = filename.replace("-", "_")
  77     expected = expected.replace(".", "_")
  78     expected = expected.replace("/", "_")
  79     expected = expected.upper()
  80     with open(filename) as f:
  81         contents = list(f)
  82     if len(contents) == 0:
  83         # Empty file -- pathological but we can just ignore rather
  84         # than crashing.
  85         return
  86     if "THIS FILE IS GENERATED" in contents[0]:
  87         # Ignore.
  88         return
  89     if not contents[0].startswith("/*"):
  90         failure(filename, 0, "header should start with comment")
  91     i = skip_comments_and_blanks(0, contents)
  92     if i == len(contents):
  93         failure(filename, i, "unterminated intro comment or missing body")
  94     m = DEF.match(contents[i])
  95     force_rewrite = False
  96     if not m:
  97         m = OLDDEF.match(contents[i])
  98         if not m:
  99             failure(filename, i, "no header guard")
 100         force_rewrite = True
 101     symbol = m.group(1)
 102     updated = False
 103     if symbol != expected:
 104         force_rewrite = True
 105     if force_rewrite:
 106         contents[i] = "#ifndef " + expected + "\n"
 107         updated = True
 108     i += 1
 109     if i == len(contents):
 110         failure(filename, i, "premature EOF")
 111     if not contents[i].startswith("#define "):
 112         failure(filename, i, "no define of header guard")
 113     if contents[i] != "#define " + expected + "\n":
 114         contents[i] = "#define " + expected + "\n"
 115         updated = True
 116     i = len(contents) - 1
 117     if not contents[i].startswith("#endif"):
 118         failure(filename, i, "no trailing endif")
 119     if contents[i] != "#endif /* " + expected + " */\n":
 120         contents[i] = "#endif /* " + expected + " */\n"
 121         updated = True
 122     if updated and write_files:
 123         write_header(filename, contents)
 124
 125
 126 for filename in args:
 127     check_header(filename)