Add a 'syntax-check' make target

The 'make syntax-check' target is used to perform various code
style sanity checks, as well as to detect certain trivial error
patterns. The target is placed in GNUmakefile, instead of Makefile.am
since it relies on GNU specific make extensions.

The actual GNUmakefile and maint.mk files are taken from the
GNULIB project, unchanged

The cfg.mk file is used to configure which of the syntax checks
are activated, to allow addition of new project specific syntax
checks, and to blacklist certain files which should not be checked

* .mailmap: Add mapping for various broken email addrs in
  commit log, to stop complaints about AUTHORS file missing
  entries
* GNUmakefile: define the 'syntax-check' rule
* maint.mk: definition of standard syntax checks
* cfg.mk: configuration for checks

2 files changed, 320 insertions, 0 deletions

diff --git a/build-aux/useless-if-before-free b/build-aux/useless-if-before-free
new file mode 100755
index 00000000..b8f5a263
--- /dev/null
+++ b/build-aux/useless-if-before-free
@@ -0,0 +1,207 @@
+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 "if (p != 0)", "if (0 != p)", or with NULL; and with braces.
+
+my $VERSION = '2011-04-20 13:43'; # 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) 2008-2011 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*\{\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*\)\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:
+## mode: perl
+## 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:
diff --git a/build-aux/vc-list-files b/build-aux/vc-list-files
new file mode 100755
index 00000000..405e458f
--- /dev/null
+++ b/build-aux/vc-list-files
@@ -0,0 +1,113 @@
+#!/bin/sh
+# List version-controlled file names.
+
+# Print a version string.
+scriptversion=2011-05-16.22; # UTC
+
+# Copyright (C) 2006-2011 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/>.
+
+
+# List the specified version-controlled files.
+# With no argument, list them all.  With a single DIRECTORY argument,
+# list the version-controlled files in that directory.
+
+# If there's an argument, it must be a single, "."-relative directory name.
+# cvsu is part of the cvsutils package: http://www.red-bean.com/cvsutils/
+
+postprocess=
+case $1 in
+  --help) cat <<EOF
+Usage: $0 [-C SRCDIR] [DIR...]
+
+Output a list of version-controlled files in DIR (default .), relative to
+SRCDIR (default .).  SRCDIR must be the top directory of a checkout.
+
+Options:
+  --help     print this help, then exit
+  --version  print version number, then exit
+  -C SRCDIR  change directory to SRCDIR before generating list
+
+Report bugs and patches to <bug-gnulib@gnu.org>.
+EOF
+    exit ;;
+
+  --version)
+    year=`echo "$scriptversion" | sed 's/[^0-9].*//'`
+    cat <<EOF
+vc-list-files $scriptversion
+Copyright (C) $year Free Software Foundation, Inc,
+License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
+This is free software: you are free to change and redistribute it.
+There is NO WARRANTY, to the extent permitted by law.
+EOF
+    exit ;;
+
+  -C)
+    test "$2" = . || postprocess="| sed 's|^|$2/|'"
+    cd "$2" || exit 1
+    shift; shift ;;
+esac
+
+test $# = 0 && set .
+
+for dir
+do
+  if test -d .git; then
+    test "x$dir" = x. \
+      && dir= sed_esc= \
+      || { dir="$dir/"; sed_esc=`echo "$dir"|env sed 's,\([\\/]\),\\\\\1,g'`; }
+    # Ignore git symlinks - either they point into the tree, in which case
+    # we don't need to visit the target twice, or they point somewhere
+    # else (often into a submodule), in which case the content does not
+    # belong to this package.
+    eval exec git ls-tree -r 'HEAD:"$dir"' \
+      \| sed -n '"s/^100[^	]*./$sed_esc/p"' $postprocess
+  elif test -d .hg; then
+    eval exec hg locate '"$dir/*"' $postprocess
+  elif test -d .bzr; then
+    test "$postprocess" = '' && postprocess="| sed 's|^\./||'"
+    eval exec bzr ls -R --versioned '"$dir"' $postprocess
+  elif test -d CVS; then
+    test "$postprocess" = '' && postprocess="| sed 's|^\./||'"
+    if test -x build-aux/cvsu; then
+      eval build-aux/cvsu --find --types=AFGM '"$dir"' $postprocess
+    elif (cvsu --help) >/dev/null 2>&1; then
+      eval cvsu --find --types=AFGM '"$dir"' $postprocess
+    else
+      eval awk -F/ \''{			\
+          if (!$1 && $3 !~ /^-/) {	\
+            f=FILENAME;			\
+            if (f ~ /CVS\/Entries$/)	\
+              f = substr(f, 1, length(f)-11); \
+            print f $2;			\
+          }}'\''				\
+        `find "$dir" -name Entries -print` /dev/null' $postprocess
+    fi
+  elif test -d .svn; then
+    eval exec svn list -R '"$dir"' $postprocess
+  else
+    echo "$0: Failed to determine type of version control used in `pwd`" 1>&2
+    exit 1
+  fi
+done
+
+# Local variables:
+# eval: (add-hook 'write-file-hooks 'time-stamp)
+# time-stamp-start: "scriptversion="
+# time-stamp-format: "%:y-%02m-%02d.%02H"
+# time-stamp-time-zone: "UTC"
+# time-stamp-end: "; # UTC"
+# End: