#!/sw/bin/perl -w
# alter the path above to the result of `which perl` on your system

# usage: cgal_conditional_include file1 ...

# Author: Geert-Jan Giezeman.

# Protects CGAL and other include directives in the following way:

#   #include <CGAL/Handle>
#
# is converted to
#
#   #ifndef CGAL_HANDLE_H
#   #include <CGAL/Handle>
#   #endif

#   #include <stdlib.h>
#
# is converted to
#
#   #ifndef CGAL_PROTECT_STDLIB_H
#   #include <stdlib.h>
#   #define CGAL_PROTECT_STDLIB_H
#   #endif

# The only filenames that are not protected are the ones that figure in
# the following list (with .h suffix added).

@non_protected_files = (
'LEDA/REDEFINE_NAMES',
'LEDA/UNDEFINE_NAMES',
'assert');

$tmpfilename = "CondIncl$$";
FILE:
foreach $filename (@ARGV) {
    if (!open("infile", $filename)) {
	print STDERR "Could not open ${filename} for reading\n$!\n";
	next FILE;
    }
    open("tmpfile", ">$tmpfilename")
	    || die "Could not open temp file for writing\n$!\n";
    $last = '';
    Line:
    while (<infile>) {
	if (($leading_space, $basename) = m|^([\s]*)#[\s]*include[\s]*<CGAL/(.*)\.h>[\s]*|)  
	{
	    # protect CGAL header files
	    $protect_name = $basename;
	    $protect_name =~ s'/'_'g;
	    $protect_name =~ tr/a-z/A-Z/;
	    $protect_name = "CGAL_" . $protect_name . '_H';
	    $protect_line = '#ifndef ' . $protect_name . "\n";
	    if ( $last !~ m|^[\s]*$protect_line|) {
		print tmpfile $leading_space;
		print tmpfile $protect_line;
#		print tmpfile "#include <CGAL/$basename.h>\n";
		print tmpfile $_;
		print tmpfile $leading_space;
		print tmpfile "#endif // $protect_name\n";
	    } else {
		print tmpfile $_;
	    }
	    $last = '';
	} elsif (($leading_space, $basename) = m|^([\s]*)#[\s]*include[\s]*<(.*)\.h>[\s]*|) {
		# protect other header files
		foreach $special_name (@non_protected_files) {
		    if ($basename =~ m#^$special_name$#) {
			print tmpfile $_;
			$last = '';
			next Line;
		    }
		}
		$protect_name = $basename;
		$protect_name =~ s'/'_'g;
		$protect_name =~ tr/a-z/A-Z/;
		$protect_name = 'CGAL_PROTECT_' . $protect_name . '_H';
		$protect_line = '#ifndef ' . $protect_name . "\n";
		if ( $last !~ m|^[\s]*$protect_line|) {
		    print tmpfile $leading_space;
		    print tmpfile $protect_line;
		    print tmpfile $_;
		    print tmpfile $leading_space;
		    print tmpfile "#define $protect_name\n";
		    print tmpfile $leading_space;
		    print tmpfile "#endif // $protect_name\n";
		} else {
		    print tmpfile $_;
		}
		$last = '';
	} else {
	    # copy other lines
	    print tmpfile $_;
	    $last = $_;
	}
    }
    close infile;
    close tmpfile;
    if ($?) {
	print STDERR "Conversion of ${filename} failed\n$!\n";
	next FILE;
    }
    if (!rename($tmpfilename,${filename})) {
	print STDERR "Cannot rename $tmpfilename to ${filename}.\n$!\n";
	print STDERR "Conversion of ${filename} failed\n";
    }
}