# -*-perl-*- hey - emacs - this is a perl file

# src/tools/msvc/pgflex.pl

# silence flex bleatings about file path style
$ENV{CYGWIN} = 'nodosfilewarning';

use strict;

# assume we are in the postgres source root

require 'src/tools/msvc/buildenv.pl' if -e 'src/tools/msvc/buildenv.pl';

system ('flex -V > NUL');
if ($? != 0)
{
	print "WARNING! flex install not found, attempting to build without\n";
	exit 0;
}

my $input = shift;
if ($input !~ /\.l$/)
{
	print "Input must be a .l file\n";
	exit 1;
}
elsif (! -e $input)
{
	print "Input file $input not found\n";
	exit 1;
}

(my $output = $input) =~ s/\.l$/.c/;

# get flex flags from make file
my $makefile = dirname($input) . "/Makefile";
my ($mf, $make);
open($mf,$makefile);
local $/ = undef;
$make=<$mf>;
close($mf);
my $flexflags = ($make =~ /\FLEXFLAGS\s*=\s*(\S+)/ ? $1 : '');


system("flex $flexflags -o$output $input");
if ($? == 0)
{
	# For non-reentrant scanners we need to fix up the yywrap macro definition
	# to keep the MS compiler happy.
	# For reentrant scanners (like the core scanner) we do not
	# need to (and must not) change the yywrap definition.
	my $cfile;
	open($cfile,$output) || die "opening $output for reading: $!";
	my $ccode = <$cfile>;
	close($cfile);
	if ($ccode !~ /\%option\sreentrant/)
	{
		$ccode =~ s/yywrap\(n\)/yywrap()/;
		open($cfile,">$output") || die "opening $output for reading: $!";
		print $cfile $ccode;
		close($cfile);
	}	

	exit 0;

}
else
{
	exit $? >> 8;
}