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|
#!/usr/bin/perl -T
# Detect instances of "if (p) free (p);".
# Likewise for "if (p != NULL) free (p);". And with braces.
my $VERSION = '2008-02-10 16:09'; # UTC
# The definition above must lie within the first 8 lines in order
# for the Emacs time-stamp write hook (at end) to update it.
# If you change this file with Emacs, please let the write hook
# do its job. Otherwise, update this string manually.
# Copyright (C) 2008 Free Software Foundation, Inc.
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with this program. If not, see <http://www.gnu.org/licenses/>.
# Written by Jim Meyering
# Exit status is like grep: 0 for no match. 1 for any number.
# Note: giving line numbers isn't practical, since I've reset the
# input record separator.
use strict;
use warnings;
use Getopt::Long;
(my $ME = $0) =~ s|.*/||;
sub usage ($)
{
my ($exit_code) = @_;
my $STREAM = ($exit_code == 0 ? *STDOUT : *STDERR);
if ($exit_code != 0)
{
print $STREAM "Try `$ME --help' for more information.\n";
}
else
{
print $STREAM <<EOF;
Usage: $ME [OPTIONS] FILE...
Detect any instance in FILE of a useless "if" test before a free call, e.g.,
"if (p) free (p);". Any such test may be safely removed without affecting
the semantics of the C code in FILE. Use --name=FOO --name=BAR to also
detect free-like functions named FOO and BAR.
OPTIONS:
--name=N add name N to the list of `free'-like functions to detect;
may be repeated
--help display this help and exit
--version output version information and exit
EXAMPLE:
For example, this command prints all removable "if" tests before "free"
and "kfree" calls in the linux kernel sources:
git ls-files -z |xargs -0 $ME --name=kfree
EOF
}
exit $exit_code;
}
{
my @name = qw(free);
GetOptions
(
help => sub { usage 0 },
version => sub { print "$ME version $VERSION\n"; exit },
'name=s@' => \@name,
) or usage 1;
# Make sure we have the right number of non-option arguments.
# Always tell the user why we fail.
@ARGV < 1
and (warn "$ME: missing FILE argument\n"), usage 1;
my $or = join '|', @name;
my $regexp = qr/(?:$or)/;
# Set the input record separator.
$/ = '"';
my $found_match = 0;
foreach my $file (@ARGV)
{
open FH, '<', $file
or die "$ME: can't open `$file' for reading: $!\n";
while (defined (my $line = <FH>))
{
if ($line =~
/\b(if\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)
(?: \s*$regexp\s*\(\s*\2\s*\)|
\s*\{\s*$regexp\s*\(\s*\2\s*\)\s*;\s*\}))/sx)
{
print "$file: $1\n";
$found_match = 1;
}
}
close FH;
}
exit !$found_match;
}
my $foo = <<'EOF';
# The above is to *find* them.
# This adjusts them, removing the unnecessary "if (p)" part.
# FIXME: do something like this as an option (doesn't do braces):
git ls-files -z |xargs -0 \
perl -0x3b -pi -e 's/\bif\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)\s+(k?free\s*\(\s*\1\s*\))/$2/s'
Be careful that the result of the above transformation is valid.
If the matched string is followed by "else", then obviously, it won't be.
When modifying files, refuse to process anything other than a regular file.
EOF
## Local Variables:
## indent-tabs-mode: nil
## eval: (add-hook 'write-file-hooks 'time-stamp)
## time-stamp-start: "my $VERSION = '"
## time-stamp-format: "%:y-%02m-%02d %02H:%02M"
## time-stamp-time-zone: "UTC"
## time-stamp-end: "'; # UTC"
## End:
|
