Improve doc in MODULES.html.

[gnulib.git] / build-aux / useless-if-before-free

diff --git a/build-aux/useless-if-before-free b/build-aux/useless-if-before-free
index a2fc773..6aa7d39 100755 (executable)
--- a/build-aux/useless-if-before-free
+++ b/build-aux/useless-if-before-free
@@ -1,16 +1,18 @@
-#!/usr/bin/perl -T
+eval '(exit $?0)' && eval 'exec perl -wST "$0" ${1+"$@"}'
+  & eval 'exec perl -wST "$0" $argv:q'
+    if 0;
 # 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 or "(void *)0" in place of NULL.
+# And with 0 in place of NULL.
 
-my $VERSION = '2009-01-28 08:16'; # UTC
+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.
+# Copyright (C) 2008-2010 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
@@ -89,9 +91,7 @@ EOF
 sub is_NULL ($)
 {
   my ($expr) = @_;
-  return ($expr eq 'NULL'
-          || $expr eq '0'
-          || $expr =~ /^\(\s*(char|void)\s*\*\s*\)\s*0$/);
+  return ($expr eq 'NULL' || $expr eq '0');
 }
 
 {
@@ -177,12 +177,20 @@ my $foo = <<'EOF';
 # This adjusts them, removing the unnecessary "if (p)" part.
 
 # FIXME: do something like this as an option (doesn't do braces):
-useless-if-before-free -l $(lid -knone free) | xargs -0 \
-  perl -0x3b -pi -e \
-   's/\bif\s*\(\s*(\S+?)(?:\s*!=\s*NULL)?\s*\)\s+(free\s*\((?:\s*\([^)]+\))?\s*\1\s*\))/$2/s'
-
-# Or, with git:
-git ls-files -z |xargs -0 perl -0x3b -pi -e '...'
+free=xfree
+git grep -l -z "$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.
@@ -191,6 +199,7 @@ When modifying files, refuse to process anything other than a regular file.
 EOF
 
 ## Local Variables:
+## mode: perl
 ## indent-tabs-mode: nil
 ## eval: (add-hook 'write-file-hooks 'time-stamp)
 ## time-stamp-start: "my $VERSION = '"