aclocal.in - automake - Git at Google

 #!@PERL@
 # -*- perl -*-
 # @configure_input@

 eval 'exec @PERL@ -S $0 ${1+"$@"}'
     if 0;

 # aclocal - create aclocal.m4 by scanning configure.ac

 # Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002
 #           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 2, 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, write to the Free Software
 # Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
 # 02111-1307, USA.

 # Written by Tom Tromey <tromey@redhat.com>.

 BEGIN
 {
   my $prefix = "@prefix@";
   my $perllibdir = $ENV{'perllibdir'} || "@datadir@/@PACKAGE@-@APIVERSION@";
   unshift @INC, "$perllibdir";
 }

 use Automake::General;
 use Automake::XFile;

 # Some constants.
 $VERSION = "@VERSION@";
 $APIVERSION = "@APIVERSION@";
 $PACKAGE = "@PACKAGE@";
 $prefix = "@prefix@";
 # Note that this isn't pkgdatadir, but a separate directory.
 # Note also that the versioned directory is handled later.
 $acdir = "@datadir@/aclocal";
 $default_acdir = $acdir;

 # Some globals.

 # Exit status.
 $exit_status = 0;

 # Name of the top autoconf input: `configure.ac' or `configure.in'.
 $configure_ac = find_configure_ac;

 # Text to output.
 $output = '';

 # Output file name.
 $output_file = 'aclocal.m4';

 # Which macros have been seen.
 %macro_seen = ();

 # Which files have been seen.
 %file_seen = ();

 # Map macro names to file names.
 %map = ();

 # Map file names to file contents.
 %file_contents = ();

 # How much to say.
 $verbose = 0;

 # Map from obsolete macros to hints for new macros.
 # If you change this, change the corresponding list in automake.in.
 # FIXME: should just put this into a single file.
 my %obsolete_macros =
     (
      'AC_FEATURE_CTYPE'		=> "use `AC_HEADER_STDC'",
      'AC_FEATURE_ERRNO'		=> "add `strerror' to `AC_REPLACE_FUNCS(...)'",
      'AC_FEATURE_EXIT'		=> '',
      'AC_SYSTEM_HEADER'		=> '',

      # Note that we do not handle this one, because it is still run
      # from AM_CONFIG_HEADER.  So we deal with it specially in
      # &scan_autoconf_files.
      # 'AC_CONFIG_HEADER'	=> "use `AM_CONFIG_HEADER'",

      'fp_C_PROTOTYPES'		=> "use `AM_C_PROTOTYPES'",
      'fp_PROG_CC_STDC'		=> "use `AM_PROG_CC_STDC'",
      'fp_PROG_INSTALL'		=> "use `AC_PROG_INSTALL'",
      'fp_WITH_DMALLOC'		=> "use `AM_WITH_DMALLOC'",
      'fp_WITH_REGEX'		=> "use `AM_WITH_REGEX'",
      'gm_PROG_LIBTOOL'		=> "use `AM_PROG_LIBTOOL'",
      'jm_MAINTAINER_MODE'	=> "use `AM_MAINTAINER_MODE'",
      'md_TYPE_PTRDIFF_T'	=> "add `ptrdiff_t' to `AC_CHECK_TYPES(...)'",
      'ud_PATH_LISPDIR'		=> "use `AM_PATH_LISPDIR'",
      'ud_GNU_GETTEXT'		=> "use `AM_GNU_GETTEXT'",

      # Now part of autoconf proper, under a different name.
      'fp_FUNC_FNMATCH'		=> "use `AC_FUNC_FNMATCH'",
      'AM_SANITY_CHECK_CC'	=> "automatically done by `AC_PROG_CC'",
      'AM_PROG_INSTALL'		=> "use `AC_PROG_INSTALL'",
      'AM_EXEEXT'		=> "automatically done by `AC_PROG_(CC|CXX|F77)'",
      'AM_CYGWIN32'		=> "use `AC_CYGWIN'",
      'AM_MINGW32'		=> "use `AC_MINGW32'",
      'AM_FUNC_MKTIME'		=> "use `AC_FUNC_MKTIME'",
      );

 # Regexp to match the above macros.
 $obsolete_rx = '\b(' . join ('|', keys %obsolete_macros) . ')\b';

 # Matches a macro definition.
 $ac_defun_rx = "AC_DEFUN\\(\\[?([^],)\n]+)\\]?";

 # Matches an AC_REQUIRE line.
 $ac_require_rx = "AC_REQUIRE\\(\\[?([^])]*)\\]?\\)";


 local (@dirlist) = &parse_arguments (@ARGV);
 &scan_m4_files (@dirlist);
 &scan_configure;
 if (! $exit_status)
 {
     &write_aclocal;
 }
 &check_acinclude;

 exit $exit_status;

 ################################################################

 # Print usage and exit.
 sub usage
 {
     local ($status) = @_;

     print "Usage: aclocal [OPTIONS] ...\n\n";
     print "\
 Generate `aclocal.m4' by scanning `configure.ac' or `configure.in'

   --acdir=DIR           directory holding config files
   --help                print this help, then exit
   -I DIR                add directory to search list for .m4 files
   --output=FILE         put output in FILE (default aclocal.m4)
   --print-ac-dir        print name of directory holding m4 files
   --verbose             don't be silent
   --version             print version number, then exit

 Report bugs to <bug-automake\@gnu.org>.\n";

     exit $status;
 }

 # Parse command line.
 sub parse_arguments
 {
     local (@arglist) = @_;
     local (@dirlist);
     local ($print_and_exit) = 0;

     while (@arglist)
     {
 	if ($arglist[0] =~ /^--acdir=(.+)$/)
 	{
 	    $acdir = $1;
 	}
 	elsif ($arglist[0] =~/^--output=(.+)$/)
 	{
 	    $output_file = $1;
 	}
 	elsif ($arglist[0] eq '-I')
 	{
 	    shift (@arglist);
 	    push (@dirlist, $arglist[0]);
 	}
 	elsif ($arglist[0] eq '--print-ac-dir')
 	{
 	    $print_and_exit = 1;
 	}
 	elsif ($arglist[0] eq '--verbose')
 	{
 	    ++$verbose;
 	}
 	elsif ($arglist[0] eq '--version')
 	{
 	    print "aclocal (GNU $PACKAGE) $VERSION\n\n";
 	    print "Copyright 2002 Free Software Foundation, Inc.\n";
 	    print "This is free software; see the source for copying conditions.  There is NO\n";
 	    print "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\n";
 	    print "Written by Tom Tromey <tromey\@redhat.com>\n";
 	    exit 0;
 	}
 	elsif ($arglist[0] eq '--help')
 	{
 	    &usage (0);
 	}
 	else
 	{
 	    die "aclocal: unrecognized option -- `$arglist[0]'\nTry `aclocal --help' for more information.\n";
 	}

 	shift (@arglist);
     }

     if ($print_and_exit)
     {
 	print $acdir, "\n";
 	exit 0;
     }

     # Search the versioned directory near the end, and then the
     # unversioned directory last.  Only do this if the user didn't
     # override acdir.
     push (@dirlist, "$acdir-$APIVERSION")
 	if $acdir eq $default_acdir;

     # By default $(datadir)/aclocal doesn't exist.  We don't want to
     # get an error in the case where we are searching the default
     # directory and it hasn't been created.
     push (@dirlist, $acdir)
 	unless $acdir eq $default_acdir && ! -d $acdir;

     return @dirlist;
 }

 ################################################################

 sub scan_configure
 {
     die "aclocal: `configure.ac' or `configure.in' is required\n"
         if !$configure_ac;

     open (CONFIGURE, $configure_ac)
 	|| die "aclocal: couldn't open `$configure_ac': $!\n";

     # Make sure we include acinclude.m4 if it exists.
     if (-f 'acinclude.m4')
     {
 	&add_file ('acinclude.m4');
     }

     while (<CONFIGURE>)
     {
 	# Remove comments from current line.
 	s/\bdnl\b.*$//;
 	s/\#.*$//;

 	if (/$obsolete_rx/o)
 	{
 	    local ($hint) = '';
 	    if ($obsolete_macros{$1} ne '')
 	    {
 		$hint = '; ' . $obsolete_macros{$1};
 	    }
 	    warn "aclocal: $configure_ac: $.: `$1' is obsolete$hint\n";
 	    $exit_status = 1;
 	    next;
 	}

 	# Search for things we know about.  The "search" sub is
 	# constructed dynamically by scan_m4_files.  The last
 	# parenthethical match makes sure we don't match things that
 	# look like macro assignments or AC_SUBSTs.
 	if (! &search && /(^|\s+)(AM_[A-Z0-9_]+)($|[^\]\)=A-Z0-9_])/)
 	{
 	    # Macro not found, but AM_ prefix found.
 	    warn "aclocal: $configure_ac: $.: macro `$2' not found in library\n";
 	    $exit_status = 1;
 	}
     }

     close (CONFIGURE);
 }

 ################################################################

 # Check macros in acinclude.m4.  If one is not used, warn.
 sub check_acinclude
 {
     local ($key);

     foreach $key (keys %map)
     {
 	next unless $map{$key} eq 'acinclude.m4';
 	if (! $macro_seen{$key})
 	{
 	    # FIXME: should print line number of acinclude.m4.
 	    warn "aclocal: macro `$key' defined in acinclude.m4 but never used\n";
 	}
     }
 }

 ################################################################

 # Scan all the installed m4 files and construct a map.
 sub scan_m4_files
 {
     local (@dirlist) = @_;

     # First, scan acinclude.m4 if it exists.
     if (-f 'acinclude.m4')
     {
 	$file_contents{'acinclude.m4'} = &scan_file ('acinclude.m4');
     }

     local ($m4dir);
     foreach $m4dir (@dirlist)
     {
 	opendir (DIR, $m4dir)
 	    || die "aclocal: couldn't open directory `$m4dir': $!\n";
 	local ($file, $fullfile);
 	foreach $file (sort grep (! /^\./, readdir (DIR)))
 	{
 	    # Only examine .m4 files.
 	    next unless $file =~ /\.m4$/;

 	    # Skip some files when running out of srcdir.
 	    next if $file eq 'aclocal.m4';

 	    $fullfile = $m4dir . '/' . $file;
 	    $file_contents{$fullfile} = &scan_file ($fullfile);
 	}
 	closedir (DIR);
     }

     # Construct a new function that does the searching.  We use a
     # function (instead of just evalling $search in the loop) so that
     # "die" is correctly and easily propagated if run.
     my $search = "sub search {\nmy \$found = 0;\n";
     foreach my $key (reverse sort keys %map)
     {
 	# EXPR is a regexp matching the name of the macro.
 	(my $expr = $key) =~ s/(\W)/\\$1/g;
 	$search .= ('if (/\b' . $key . '\b/) { & add_macro (' . $key
 		    . '); $found = 1; }' . "\n");
     }
     $search .= "return \$found;\n};\n";
     eval $search;
     die "internal error: $@\n search is $search" if $@;
 }

 ################################################################

 # Add a macro to the output.
 sub add_macro
 {
     local ($macro) = @_;

     # We want to ignore AC_ macros.  However, if an AC_ macro is
     # defined in (eg) acinclude.m4, then we want to make sure we mark
     # it as seen.
     return if $macro =~ /^AC_/ && ! defined $map{$macro};

     if (! defined $map{$macro})
     {
 	warn "aclocal: macro `$macro' required but not defined\n";
 	$exit_status = 1;
 	return;
     }

     print STDERR "aclocal: saw macro $macro\n" if $verbose;
     $macro_seen{$macro} = 1;
     &add_file ($map{$macro});
 }

 # Add a file to output.
 sub add_file
 {
     local ($file) = @_;

     # Only add a file once.
     return if ($file_seen{$file});
     $file_seen{$file} = 1;

     $output .= $file_contents{$file} . "\n";
     local ($a, @rlist);
     foreach (split ("\n", $file_contents{$file}))
     {
 	# This is a hack for Perl 4.
 	$a = $_;
 	if ($a =~ /$ac_require_rx/g)
 	{
 	    push (@rlist, $1);
 	}

 	# Remove comments from current line.
 	s/\bdnl\b.*$//;
 	s/\#.*$//;

 	# The search function is constructed dynamically by
 	# scan_m4_files.  The last parenthethical match makes sure we
 	# don't match things that look like macro assignments or
 	# AC_SUBSTs.
 	if (! &search && /(^|\s+)(AM_[A-Z0-9_]+)($|[^\]\)=A-Z0-9_])/)
 	{
 	    # Macro not found, but AM_ prefix found.
 	    warn "aclocal: $configure_ac: $.: macro `$2' not found in library\n";
 	    $exit_status = 1;
 	}
     }

     local ($macro);
     foreach $macro (@rlist)
     {
 	&add_macro ($macro);
     }
 }

 # Scan a single M4 file.  Return contents.
 sub scan_file
 {
     local ($file) = @_;

     my $fh = new Automake::XFile $file;
     my $contents = '';
     while ($_ = $fh->getline)
     {
 	# Ignore `##' lines.
 	next if /^##/;

 	$contents .= $_;

 	if (/$ac_defun_rx/)
 	{
 	    if (! defined $map{$1})
 	    {
 		$map{$1} = $file;
 	    }

 	    # Note: we used to give an error here if we saw a
 	    # duplicated macro.  However, this turns out to be
 	    # extremely unpopular.  It causes actual problems which
 	    # are hard to work around, especially when you must
 	    # mix-and-match tool versions.

 	    print STDERR "aclocal: found macro $1 in $file: $.\n" if $verbose;
 	}
     }

     return $contents;
 }

 ################################################################

 # Write output.
 sub write_aclocal
 {
     return if ! length ($output);

     print STDERR "aclocal: writing $output_file\n" if $verbose;

     my $out = new Automake::XFile "> $output_file";
     print $out
 "# $output_file generated automatically by aclocal $VERSION -*- Autoconf -*-

 # Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002
 # Free Software Foundation, Inc.
 # This file is free software; the Free Software Foundation
 # gives unlimited permission to copy and/or distribute it,
 # with or without modifications, as long as this notice is preserved.

 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY, to the extent permitted by law; without
 # even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 # PARTICULAR PURPOSE.

 $output";
 }
	#!@PERL@
	# -- perl --
	# @configure_input@

	eval 'exec @PERL@ -S $0 ${1+"$@"}'
	if 0;

	# aclocal - create aclocal.m4 by scanning configure.ac

	# Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002
	# 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 2, 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, write to the Free Software
	# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
	# 02111-1307, USA.

	# Written by Tom Tromey <tromey@redhat.com>.

	BEGIN
	{
	my $prefix = "@prefix@";
	my $perllibdir = $ENV{'perllibdir'} \|\| "@datadir@/@PACKAGE@-@APIVERSION@";
	unshift @INC, "$perllibdir";
	}

	use Automake::General;
	use Automake::XFile;

	# Some constants.
	$VERSION = "@VERSION@";
	$APIVERSION = "@APIVERSION@";
	$PACKAGE = "@PACKAGE@";
	$prefix = "@prefix@";
	# Note that this isn't pkgdatadir, but a separate directory.
	# Note also that the versioned directory is handled later.
	$acdir = "@datadir@/aclocal";
	$default_acdir = $acdir;

	# Some globals.

	# Exit status.
	$exit_status = 0;

	# Name of the top autoconf input: `configure.ac' or `configure.in'.
	$configure_ac = find_configure_ac;

	# Text to output.
	$output = '';

	# Output file name.
	$output_file = 'aclocal.m4';

	# Which macros have been seen.
	%macro_seen = ();

	# Which files have been seen.
	%file_seen = ();

	# Map macro names to file names.
	%map = ();

	# Map file names to file contents.
	%file_contents = ();

	# How much to say.
	$verbose = 0;

	# Map from obsolete macros to hints for new macros.
	# If you change this, change the corresponding list in automake.in.
	# FIXME: should just put this into a single file.
	my %obsolete_macros =
	(
	'AC_FEATURE_CTYPE' => "use `AC_HEADER_STDC'",
	'AC_FEATURE_ERRNO' => "add `strerror' to `AC_REPLACE_FUNCS(...)'",
	'AC_FEATURE_EXIT' => '',
	'AC_SYSTEM_HEADER' => '',

	# Note that we do not handle this one, because it is still run
	# from AM_CONFIG_HEADER. So we deal with it specially in
	# &scan_autoconf_files.
	# 'AC_CONFIG_HEADER' => "use `AM_CONFIG_HEADER'",

	'fp_C_PROTOTYPES' => "use `AM_C_PROTOTYPES'",
	'fp_PROG_CC_STDC' => "use `AM_PROG_CC_STDC'",
	'fp_PROG_INSTALL' => "use `AC_PROG_INSTALL'",
	'fp_WITH_DMALLOC' => "use `AM_WITH_DMALLOC'",
	'fp_WITH_REGEX' => "use `AM_WITH_REGEX'",
	'gm_PROG_LIBTOOL' => "use `AM_PROG_LIBTOOL'",
	'jm_MAINTAINER_MODE' => "use `AM_MAINTAINER_MODE'",
	'md_TYPE_PTRDIFF_T' => "add `ptrdiff_t' to `AC_CHECK_TYPES(...)'",
	'ud_PATH_LISPDIR' => "use `AM_PATH_LISPDIR'",
	'ud_GNU_GETTEXT' => "use `AM_GNU_GETTEXT'",

	# Now part of autoconf proper, under a different name.
	'fp_FUNC_FNMATCH' => "use `AC_FUNC_FNMATCH'",
	'AM_SANITY_CHECK_CC' => "automatically done by `AC_PROG_CC'",
	'AM_PROG_INSTALL' => "use `AC_PROG_INSTALL'",
	'AM_EXEEXT' => "automatically done by `AC_PROG_(CC\|CXX\|F77)'",
	'AM_CYGWIN32' => "use `AC_CYGWIN'",
	'AM_MINGW32' => "use `AC_MINGW32'",
	'AM_FUNC_MKTIME' => "use `AC_FUNC_MKTIME'",
	);

	# Regexp to match the above macros.
	$obsolete_rx = '\b(' . join ('\|', keys %obsolete_macros) . ')\b';

	# Matches a macro definition.
	$ac_defun_rx = "AC_DEFUN\\(\\[?([^],)\n]+)\\]?";

	# Matches an AC_REQUIRE line.
	$ac_require_rx = "AC_REQUIRE\\(\\[?([^])]*)\\]?\\)";



	local (@dirlist) = &parse_arguments (@ARGV);
	&scan_m4_files (@dirlist);
	&scan_configure;
	if (! $exit_status)
	{
	&write_aclocal;
	}
	&check_acinclude;

	exit $exit_status;

	################################################################

	# Print usage and exit.
	sub usage
	{
	local ($status) = @_;

	print "Usage: aclocal [OPTIONS] ...\n\n";
	print "\
	Generate `aclocal.m4' by scanning `configure.ac' or `configure.in'

	--acdir=DIR directory holding config files
	--help print this help, then exit
	-I DIR add directory to search list for .m4 files
	--output=FILE put output in FILE (default aclocal.m4)
	--print-ac-dir print name of directory holding m4 files
	--verbose don't be silent
	--version print version number, then exit

	Report bugs to <bug-automake\@gnu.org>.\n";

	exit $status;
	}

	# Parse command line.
	sub parse_arguments
	{
	local (@arglist) = @_;
	local (@dirlist);
	local ($print_and_exit) = 0;

	while (@arglist)
	{
	if ($arglist[0] =~ /^--acdir=(.+)$/)
	{
	$acdir = $1;
	}
	elsif ($arglist[0] =~/^--output=(.+)$/)
	{
	$output_file = $1;
	}
	elsif ($arglist[0] eq '-I')
	{
	shift (@arglist);
	push (@dirlist, $arglist[0]);
	}
	elsif ($arglist[0] eq '--print-ac-dir')
	{
	$print_and_exit = 1;
	}
	elsif ($arglist[0] eq '--verbose')
	{
	++$verbose;
	}
	elsif ($arglist[0] eq '--version')
	{
	print "aclocal (GNU $PACKAGE) $VERSION\n\n";
	print "Copyright 2002 Free Software Foundation, Inc.\n";
	print "This is free software; see the source for copying conditions. There is NO\n";
	print "warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.\n\n";
	print "Written by Tom Tromey <tromey\@redhat.com>\n";
	exit 0;
	}
	elsif ($arglist[0] eq '--help')
	{
	&usage (0);
	}
	else
	{
	die "aclocal: unrecognized option -- `$arglist[0]'\nTry `aclocal --help' for more information.\n";
	}

	shift (@arglist);
	}

	if ($print_and_exit)
	{
	print $acdir, "\n";
	exit 0;
	}

	# Search the versioned directory near the end, and then the
	# unversioned directory last. Only do this if the user didn't
	# override acdir.
	push (@dirlist, "$acdir-$APIVERSION")
	if $acdir eq $default_acdir;

	# By default $(datadir)/aclocal doesn't exist. We don't want to
	# get an error in the case where we are searching the default
	# directory and it hasn't been created.
	push (@dirlist, $acdir)
	unless $acdir eq $default_acdir && ! -d $acdir;

	return @dirlist;
	}

	################################################################

	sub scan_configure
	{
	die "aclocal: `configure.ac' or `configure.in' is required\n"
	if !$configure_ac;

	open (CONFIGURE, $configure_ac)
	\|\| die "aclocal: couldn't open `$configure_ac': $!\n";

	# Make sure we include acinclude.m4 if it exists.
	if (-f 'acinclude.m4')
	{
	&add_file ('acinclude.m4');
	}

	while (<CONFIGURE>)
	{
	# Remove comments from current line.
	s/\bdnl\b.*$//;
	s/\#.*$//;

	if (/$obsolete_rx/o)
	{
	local ($hint) = '';
	if ($obsolete_macros{$1} ne '')
	{
	$hint = '; ' . $obsolete_macros{$1};
	}
	warn "aclocal: $configure_ac: $.: `$1' is obsolete$hint\n";
	$exit_status = 1;
	next;
	}

	# Search for things we know about. The "search" sub is
	# constructed dynamically by scan_m4_files. The last
	# parenthethical match makes sure we don't match things that
	# look like macro assignments or AC_SUBSTs.
	if (! &search && /(^\|\s+)(AM_[A-Z0-9_]+)($\|[^\]\)=A-Z0-9_])/)
	{
	# Macro not found, but AM_ prefix found.
	warn "aclocal: $configure_ac: $.: macro `$2' not found in library\n";
	$exit_status = 1;
	}
	}

	close (CONFIGURE);
	}

	################################################################

	# Check macros in acinclude.m4. If one is not used, warn.
	sub check_acinclude
	{
	local ($key);

	foreach $key (keys %map)
	{
	next unless $map{$key} eq 'acinclude.m4';
	if (! $macro_seen{$key})
	{
	# FIXME: should print line number of acinclude.m4.
	warn "aclocal: macro `$key' defined in acinclude.m4 but never used\n";
	}
	}
	}

	################################################################

	# Scan all the installed m4 files and construct a map.
	sub scan_m4_files
	{
	local (@dirlist) = @_;

	# First, scan acinclude.m4 if it exists.
	if (-f 'acinclude.m4')
	{
	$file_contents{'acinclude.m4'} = &scan_file ('acinclude.m4');
	}

	local ($m4dir);
	foreach $m4dir (@dirlist)
	{
	opendir (DIR, $m4dir)
	\|\| die "aclocal: couldn't open directory `$m4dir': $!\n";
	local ($file, $fullfile);
	foreach $file (sort grep (! /^\./, readdir (DIR)))
	{
	# Only examine .m4 files.
	next unless $file =~ /\.m4$/;

	# Skip some files when running out of srcdir.
	next if $file eq 'aclocal.m4';

	$fullfile = $m4dir . '/' . $file;
	$file_contents{$fullfile} = &scan_file ($fullfile);
	}
	closedir (DIR);
	}

	# Construct a new function that does the searching. We use a
	# function (instead of just evalling $search in the loop) so that
	# "die" is correctly and easily propagated if run.
	my $search = "sub search {\nmy \$found = 0;\n";
	foreach my $key (reverse sort keys %map)
	{
	# EXPR is a regexp matching the name of the macro.
	(my $expr = $key) =~ s/(\W)/\\$1/g;
	$search .= ('if (/\b' . $key . '\b/) { & add_macro (' . $key
	. '); $found = 1; }' . "\n");
	}
	$search .= "return \$found;\n};\n";
	eval $search;
	die "internal error: $@\n search is $search" if $@;
	}

	################################################################

	# Add a macro to the output.
	sub add_macro
	{
	local ($macro) = @_;

	# We want to ignore AC_ macros. However, if an AC_ macro is
	# defined in (eg) acinclude.m4, then we want to make sure we mark
	# it as seen.
	return if $macro =~ /^AC_/ && ! defined $map{$macro};

	if (! defined $map{$macro})
	{
	warn "aclocal: macro `$macro' required but not defined\n";
	$exit_status = 1;
	return;
	}

	print STDERR "aclocal: saw macro $macro\n" if $verbose;
	$macro_seen{$macro} = 1;
	&add_file ($map{$macro});
	}

	# Add a file to output.
	sub add_file
	{
	local ($file) = @_;

	# Only add a file once.
	return if ($file_seen{$file});
	$file_seen{$file} = 1;

	$output .= $file_contents{$file} . "\n";
	local ($a, @rlist);
	foreach (split ("\n", $file_contents{$file}))
	{
	# This is a hack for Perl 4.
	$a = $_;
	if ($a =~ /$ac_require_rx/g)
	{
	push (@rlist, $1);
	}

	# Remove comments from current line.
	s/\bdnl\b.*$//;
	s/\#.*$//;

	# The search function is constructed dynamically by
	# scan_m4_files. The last parenthethical match makes sure we
	# don't match things that look like macro assignments or
	# AC_SUBSTs.
	if (! &search && /(^\|\s+)(AM_[A-Z0-9_]+)($\|[^\]\)=A-Z0-9_])/)
	{
	# Macro not found, but AM_ prefix found.
	warn "aclocal: $configure_ac: $.: macro `$2' not found in library\n";
	$exit_status = 1;
	}
	}

	local ($macro);
	foreach $macro (@rlist)
	{
	&add_macro ($macro);
	}
	}

	# Scan a single M4 file. Return contents.
	sub scan_file
	{
	local ($file) = @_;

	my $fh = new Automake::XFile $file;
	my $contents = '';
	while ($_ = $fh->getline)
	{
	# Ignore `##' lines.
	next if /^##/;

	$contents .= $_;

	if (/$ac_defun_rx/)
	{
	if (! defined $map{$1})
	{
	$map{$1} = $file;
	}

	# Note: we used to give an error here if we saw a
	# duplicated macro. However, this turns out to be
	# extremely unpopular. It causes actual problems which
	# are hard to work around, especially when you must
	# mix-and-match tool versions.

	print STDERR "aclocal: found macro $1 in $file: $.\n" if $verbose;
	}
	}

	return $contents;
	}

	################################################################

	# Write output.
	sub write_aclocal
	{
	return if ! length ($output);

	print STDERR "aclocal: writing $output_file\n" if $verbose;

	my $out = new Automake::XFile "> $output_file";
	print $out
	"# $output_file generated automatically by aclocal $VERSION -- Autoconf --

	# Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002
	# Free Software Foundation, Inc.
	# This file is free software; the Free Software Foundation
	# gives unlimited permission to copy and/or distribute it,
	# with or without modifications, as long as this notice is preserved.

	# This program is distributed in the hope that it will be useful,
	# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
	# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
	# PARTICULAR PURPOSE.

	$output";
	}