xref: /linux/usr/include/headers_check.pl (revision a016546ba60cbf3243f10670ae24fbd0bb343c08)
1#!/usr/bin/env perl
2# SPDX-License-Identifier: GPL-2.0
3#
4# headers_check.pl execute a number of trivial consistency checks
5#
6# Usage: headers_check.pl dir [files...]
7# dir:   dir to look for included files
8# files: list of files to check
9#
10# The script reads the supplied files line by line and:
11#
12# 1) for each include statement it checks if the
13#    included file actually exists.
14#    Only include files located in asm* and linux* are checked.
15#    The rest are assumed to be system include files.
16#
17# 2) It is checked that prototypes does not use "extern"
18#
19# 3) Check for leaked CONFIG_ symbols
20
21use warnings;
22use strict;
23use File::Basename;
24
25my ($dir, @files) = @ARGV;
26
27my $ret = 0;
28my $line;
29my $lineno = 0;
30my $filename;
31
32foreach my $file (@files) {
33	$filename = $file;
34
35	open(my $fh, '<', $filename)
36		or die "$filename: $!\n";
37	$lineno = 0;
38	while ($line = <$fh>) {
39		$lineno++;
40		&check_include();
41		&check_asm_types();
42		&check_sizetypes();
43		&check_declarations();
44		# Dropped for now. Too much noise &check_config();
45	}
46	close $fh;
47}
48exit $ret;
49
50sub check_include
51{
52	if ($line =~ m/^\s*#\s*include\s+<((asm|linux).*)>/) {
53		my $inc = $1;
54		my $found;
55		$found = stat($dir . "/" . $inc);
56		if (!$found) {
57			printf STDERR "$filename:$lineno: included file '$inc' is not exported\n";
58			$ret = 1;
59		}
60	}
61}
62
63sub check_declarations
64{
65	# soundcard.h is what it is
66	if ($line =~ m/^void seqbuf_dump\(void\);/) {
67		return;
68	}
69	# drm headers are being C++ friendly
70	if ($line =~ m/^extern "C"/) {
71		return;
72	}
73	if ($line =~ m/^(\s*extern|unsigned|char|short|int|long|void)\b/) {
74		printf STDERR "$filename:$lineno: " .
75			      "userspace cannot reference function or " .
76			      "variable defined in the kernel\n";
77	}
78}
79
80sub check_config
81{
82	if ($line =~ m/[^a-zA-Z0-9_]+CONFIG_([a-zA-Z0-9_]+)[^a-zA-Z0-9_]/) {
83		printf STDERR "$filename:$lineno: leaks CONFIG_$1 to userspace where it is not valid\n";
84	}
85}
86
87my $linux_asm_types;
88sub check_asm_types
89{
90	if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
91		return;
92	}
93	if ($lineno == 1) {
94		$linux_asm_types = 0;
95	} elsif ($linux_asm_types >= 1) {
96		return;
97	}
98	if ($line =~ m/^\s*#\s*include\s+<asm\/types.h>/) {
99		$linux_asm_types = 1;
100		printf STDERR "$filename:$lineno: " .
101		"include of <linux/types.h> is preferred over <asm/types.h>\n"
102		# Warn until headers are all fixed
103		#$ret = 1;
104	}
105}
106
107my $linux_types;
108my %import_stack = ();
109sub check_include_typesh
110{
111	my $path = $_[0];
112	my $import_path;
113
114	my $fh;
115	my @file_paths = ($path, $dir . "/" .  $path, dirname($filename) . "/" . $path);
116	for my $possible ( @file_paths ) {
117	    if (not $import_stack{$possible} and open($fh, '<', $possible)) {
118		$import_path = $possible;
119		$import_stack{$import_path} = 1;
120		last;
121	    }
122	}
123	if (eof $fh) {
124	    return;
125	}
126
127	my $line;
128	while ($line = <$fh>) {
129		if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
130			$linux_types = 1;
131			last;
132		}
133		if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
134			check_include_typesh($included);
135		}
136	}
137	close $fh;
138	delete $import_stack{$import_path};
139}
140
141sub check_sizetypes
142{
143	if ($filename =~ /types.h|int-l64.h|int-ll64.h/o) {
144		return;
145	}
146	if ($lineno == 1) {
147		$linux_types = 0;
148	} elsif ($linux_types >= 1) {
149		return;
150	}
151	if ($line =~ m/^\s*#\s*include\s+<linux\/types.h>/) {
152		$linux_types = 1;
153		return;
154	}
155	if (my $included = ($line =~ /^\s*#\s*include\s+[<"](\S+)[>"]/)[0]) {
156		check_include_typesh($included);
157	}
158	if ($line =~ m/__[us](8|16|32|64)\b/) {
159		printf STDERR "$filename:$lineno: " .
160		              "found __[us]{8,16,32,64} type " .
161		              "without #include <linux/types.h>\n";
162		$linux_types = 2;
163		# Warn until headers are all fixed
164		#$ret = 1;
165	}
166}
167