--- /dev/null
+#!/usr/bin/perl -T
+# Detect instances of "if (p) free (p);".
+# Likewise for "if (p != NULL) free (p);". And with braces.
+# Also detect "if (NULL != p) free (p);".
+# And with 0 in place of NULL.
+
+my $VERSION = '2009-04-16 15:57'; # 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, 2009 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
+
+use strict;
+use warnings;
+use Getopt::Long;
+
+(my $ME = $0) =~ s|.*/||;
+
+# use File::Coda; # http://meyering.net/code/Coda/
+END {
+ defined fileno STDOUT or return;
+ close STDOUT and return;
+ warn "$ME: failed to close standard output: $!\n";
+ $? ||= 1;
+}
+
+sub usage ($)
+{
+ 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:
+
+ --list print only the name of each matching FILE (\0-terminated)
+ --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
+
+Exit status:
+
+ 0 one or more matches
+ 1 no match
+ 2 an error
+
+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 $exit_code;
+}
+
+sub is_NULL ($)
+{
+ my ($expr) = @_;
+ return ($expr eq 'NULL' || $expr eq '0');
+}
+
+{
+ sub EXIT_MATCH {0}
+ sub EXIT_NO_MATCH {1}
+ sub EXIT_ERROR {2}
+ my $err = EXIT_NO_MATCH;
+
+ my $list;
+ my @name = qw(free);
+ GetOptions
+ (
+ help => sub { usage 0 },
+ version => sub { print "$ME version $VERSION\n"; exit },
+ list => \$list,
+ 'name=s@' => \@name,
+ ) or usage 1;
+
+ # Make sure we have the right number of non-option arguments.
+ # Always tell the user why we fail.
+ @ARGV < 1
+ and (warn "$ME: missing FILE argument\n"), usage EXIT_ERROR;
+
+ my $or = join '|', @name;
+ my $regexp = qr/(?:$or)/;
+
+ # Set the input record separator.
+ # Note: this makes it impractical to print line numbers.
+ $/ = '"';
+
+ my $found_match = 0;
+ FILE:
+ foreach my $file (@ARGV)
+ {
+ open FH, '<', $file
+ or (warn "$ME: can't open `$file' for reading: $!\n"),
+ $err = EXIT_ERROR, next;
+ while (defined (my $line = <FH>))
+ {
+ while ($line =~
+ /\b(if\s*\(\s*([^)]+?)(?:\s*!=\s*([^)]+?))?\s*\)
+ # 1 2 3
+ (?: \s*$regexp\s*\((?:\s*\([^)]+\))?\s*([^)]+)\)|
+ \s*\{\s*$regexp\s*\((?:\s*\([^)]+\))?\s*([^)]+)\)\s*;\s*\}))/sxg)
+ {
+ my $all = $1;
+ my ($lhs, $rhs) = ($2, $3);
+ my ($free_opnd, $braced_free_opnd) = ($4, $5);
+ my $non_NULL;
+ if (!defined $rhs) { $non_NULL = $lhs }
+ elsif (is_NULL $rhs) { $non_NULL = $lhs }
+ elsif (is_NULL $lhs) { $non_NULL = $rhs }
+ else { next }
+
+ # Compare the non-NULL part of the "if" expression and the
+ # free'd expression, without regard to white space.
+ $non_NULL =~ tr/ \t//d;
+ my $e2 = defined $free_opnd ? $free_opnd : $braced_free_opnd;
+ $e2 =~ tr/ \t//d;
+ if ($non_NULL eq $e2)
+ {
+ $found_match = 1;
+ $list
+ and (print "$file\0"), next FILE;
+ print "$file: $all\n";
+ }
+ }
+ }
+ }
+ continue
+ {
+ close FH;
+ }
+
+ $found_match && $err == EXIT_NO_MATCH
+ and $err = EXIT_MATCH;
+
+ exit $err;
+}
+
+my $foo = <<'EOF';
+# The above is to *find* them.
+# This adjusts them, removing the unnecessary "if (p)" part.
+
+# FIXME: do something like this as an option (doesn't do braces):
+free=xfree
+git grep -l -z "$free *(" \
+ | xargs -0 useless-if-before-free -l --name="$free" \
+ | xargs -0 perl -0x3b -pi -e \
+ 's/\bif\s*\(\s*(\S+?)(?:\s*!=\s*(?:0|NULL))?\s*\)\s+('"$free"'\s*\((?:\s*\([^)]+\))?\s*\1\s*\))/$2/s'
+
+# Use the following to remove redundant uses of kfree inside braces.
+# Note that -0777 puts perl in slurp-whole-file mode;
+# but we have plenty of memory, these days...
+free=kfree
+git grep -l -z "$free *(" \
+ | xargs -0 useless-if-before-free -l --name="$free" \
+ | xargs -0 perl -0777 -pi -e \
+ 's/\bif\s*\(\s*(\S+?)(?:\s*!=\s*(?:0|NULL))?\s*\)\s*\{\s*('"$free"'\s*\((?:\s*\([^)]+\))?\s*\1\s*\);)\s*\}[^\n]*$/$2/gms'
+
+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:
projects / wget / blobdiff