Merge remote-tracking branch 'remotes/dagrh/tags/pull-virtiofs-20211026' into staging
[qemu.git] / scripts / clean-header-guards.pl
1 #!/usr/bin/env perl
2 #
3 # Clean up include guards in headers
4 #
5 # Copyright (C) 2016 Red Hat, Inc.
6 #
7 # Authors:
8 # Markus Armbruster <armbru@redhat.com>
9 #
10 # This work is licensed under the terms of the GNU GPL, version 2 or
11 # (at your option) any later version. See the COPYING file in the
12 # top-level directory.
13 #
14 # Usage: scripts/clean-header-guards.pl [OPTION]... [FILE]...
15 # -c CC Use a compiler other than cc
16 # -n Suppress actual cleanup
17 # -v Show which files are cleaned up, and which are skipped
18 #
19 # Does the following:
20 # - Header files without a recognizable header guard are skipped.
21 # - Clean up any untidy header guards in-place. Warn if the cleanup
22 # renames guard symbols, and explain how to find occurrences of these
23 # symbols that may have to be updated manually.
24 # - Warn about duplicate header guard symbols. To make full use of
25 # this warning, you should clean up *all* headers in one run.
26 # - Warn when preprocessing a header with its guard symbol defined
27 # produces anything but whitespace. The preprocessor is run like
28 # "cc -E -DGUARD_H -c -P -", and fed the test program on stdin.
29
30 use strict;
31 use warnings;
32 use Getopt::Std;
33
34 # Stuff we don't want to clean because we import it into our tree:
35 my $exclude = qr,^(disas/libvixl/|include/standard-headers/
36 |linux-headers/|pc-bios/|tests/tcg/|tests/multiboot/),x;
37 # Stuff that is expected to fail the preprocessing test:
38 my $exclude_cpp = qr,^include/libdecnumber/decNumberLocal.h,;
39
40 my %guarded = ();
41 my %old_guard = ();
42
43 our $opt_c = "cc";
44 our $opt_n = 0;
45 our $opt_v = 0;
46 getopts("c:nv");
47
48 sub skipping {
49 my ($fname, $msg, $line1, $line2) = @_;
50
51 return if !$opt_v or $fname =~ $exclude;
52 print "$fname skipped: $msg\n";
53 print " $line1" if defined $line1;
54 print " $line2" if defined $line2;
55 }
56
57 sub gripe {
58 my ($fname, $msg) = @_;
59 return if $fname =~ $exclude;
60 print STDERR "$fname: warning: $msg\n";
61 }
62
63 sub slurp {
64 my ($fname) = @_;
65 local $/; # slurp
66 open(my $in, "<", $fname)
67 or die "can't open $fname for reading: $!";
68 return <$in>;
69 }
70
71 sub unslurp {
72 my ($fname, $contents) = @_;
73 open (my $out, ">", $fname)
74 or die "can't open $fname for writing: $!";
75 print $out $contents
76 or die "error writing $fname: $!";
77 close $out
78 or die "error writing $fname: $!";
79 }
80
81 sub fname2guard {
82 my ($fname) = @_;
83 $fname =~ tr/a-z/A-Z/;
84 $fname =~ tr/A-Z0-9/_/cs;
85 return $fname;
86 }
87
88 sub preprocess {
89 my ($fname, $guard) = @_;
90
91 open(my $pipe, "-|", "$opt_c -E -D$guard -c -P - <$fname")
92 or die "can't run $opt_c: $!";
93 while (<$pipe>) {
94 if ($_ =~ /\S/) {
95 gripe($fname, "not blank after preprocessing");
96 last;
97 }
98 }
99 close $pipe
100 or gripe($fname, "preprocessing failed ($opt_c exit status $?)");
101 }
102
103 for my $fname (@ARGV) {
104 my $text = slurp($fname);
105
106 $text =~ m,\A(\s*\n|\s*//\N*\n|\s*/\*.*?\*/\s*\n)*|,sg;
107 my $pre = $&;
108 unless ($text =~ /\G(.*\n)/g) {
109 $text =~ /\G.*/;
110 skipping($fname, "no recognizable header guard", "$&\n");
111 next;
112 }
113 my $line1 = $1;
114 unless ($text =~ /\G(.*\n)/g) {
115 $text =~ /\G.*/;
116 skipping($fname, "no recognizable header guard", "$&\n");
117 next;
118 }
119 my $line2 = $1;
120 my $body = substr($text, pos($text));
121
122 unless ($line1 =~ /^\s*\#\s*(if\s*\!\s*defined(\s*\()?|ifndef)\s*
123 ([A-Za-z0-9_]+)/x) {
124 skipping($fname, "no recognizable header guard", $line1, $line2);
125 next;
126 }
127 my $guard = $3;
128 unless ($line2 =~ /^\s*\#\s*define\s+([A-Za-z0-9_]+)/) {
129 skipping($fname, "no recognizable header guard", $line1, $line2);
130 next;
131 }
132 my $guard2 = $1;
133 unless ($guard2 eq $guard) {
134 skipping($fname, "mismatched header guard ($guard vs. $guard2) ",
135 $line1, $line2);
136 next;
137 }
138
139 unless ($body =~ m,\A((.*\n)*)
140 ([ \t]*\#[ \t]*endif([ \t]*\N*)\n)
141 ((?s)(\s*\n|\s*//\N*\n|\s*/\*.*?\*/\s*\n)*)
142 \Z,x) {
143 skipping($fname, "can't find end of header guard");
144 next;
145 }
146 $body = $1;
147 my $line3 = $3;
148 my $endif_comment = $4;
149 my $post = $5;
150
151 my $oldg = $guard;
152
153 unless ($fname =~ $exclude) {
154 my @issues = ();
155 $guard =~ tr/a-z/A-Z/
156 and push @issues, "contains lowercase letters";
157 $guard =~ s/^_+//
158 and push @issues, "is a reserved identifier";
159 $guard =~ s/(_H)?_*$/_H/
160 and $& ne "_H" and push @issues, "doesn't end with _H";
161 unless ($guard =~ /^[A-Z][A-Z0-9_]*_H/) {
162 skipping($fname, "can't clean up odd guard symbol $oldg\n",
163 $line1, $line2);
164 next;
165 }
166
167 my $exp = fname2guard($fname =~ s,.*/,,r);
168 unless ($guard =~ /\Q$exp\E\Z/) {
169 $guard = fname2guard($fname =~ s,^include/,,r);
170 push @issues, "doesn't match the file name";
171 }
172 if (@issues and $opt_v) {
173 print "$fname guard $oldg needs cleanup:\n ",
174 join(", ", @issues), "\n";
175 }
176 }
177
178 $old_guard{$guard} = $oldg
179 if $guard ne $oldg;
180
181 if (exists $guarded{$guard}) {
182 gripe($fname, "guard $guard also used by $guarded{$guard}");
183 } else {
184 $guarded{$guard} = $fname;
185 }
186
187 unless ($fname =~ $exclude) {
188 my $newl1 = "#ifndef $guard\n";
189 my $newl2 = "#define $guard\n";
190 my $newl3 = "#endif\n";
191 $newl3 =~ s,\Z, /* $guard */, if $endif_comment;
192 if ($line1 ne $newl1 or $line2 ne $newl2 or $line3 ne $newl3) {
193 $pre =~ s/\n*\Z/\n\n/ if $pre =~ /\N/;
194 $body =~ s/\A\n*/\n/;
195 if ($opt_n) {
196 print "$fname would be cleaned up\n" if $opt_v;
197 } else {
198 unslurp($fname, "$pre$newl1$newl2$body$newl3$post");
199 print "$fname cleaned up\n" if $opt_v;
200 }
201 }
202 }
203
204 preprocess($fname, $opt_n ? $oldg : $guard)
205 unless $fname =~ $exclude or $fname =~ $exclude_cpp;
206 }
207
208 if (%old_guard) {
209 print STDERR "warning: guard symbol renaming may break things\n";
210 for my $guard (sort keys %old_guard) {
211 print STDERR " $old_guard{$guard} -> $guard\n";
212 }
213 print STDERR "To find uses that may have to be updated try:\n";
214 print STDERR " git grep -Ew '", join("|", sort values %old_guard),
215 "'\n";
216 }