#!/usr/bin/perl
#
# Usage:  make_qfeatures_dot_h
#
# Generates core/base/qfeatures.h from core/base/qfeatures.txt.
#
# The tools/qfeatures.txt file can contain redundancies, and this program
# will show them.
#

open FL, "$ENV{QTDIR}/src/corelib/global/qfeatures.txt"
    or die "Cannot open $ENV{QTDIR}/src/corelib/global/qfeatures.txt";

while (<FL>) {
    if ( /^Feature: (\S*)/ ) {
	print STDERR "Duplicate: $1\n" if $macro{$1};
	$macro{$macro=$1}=1;
    } elsif ( /^Requires: (.*?)\s*$/ ) {
	$deps{$macro}=$1;
	map { $dep{"$macro $_"}=1 } split /\s+/, $1;
    } elsif ( /^Name: (.*?)\s*$/ ) {
	$label{$macro}=$1;
    }
}

close FL;

sub depends {
    my($x,$y) = @_;
    return 1 if $dep{"$x $y"};
    return 0 if $dep{"$y $x"};
    return 0 if $x eq $y;
    my $d;
    for $d (split /\s+/, $deps{$x}) {
	return 1 if depends($d,$y);
    }
    return 0;
}
sub dependants_rec {
    my($x) = @_;
    my $n = 0;
    my $d = 0;
    $dependants_rec_count++;
    if ( $dependants_rec_count > $dependants_rec_limit ) {
	if ( $circularity_start eq $x ) {
	    print STDERR "Circular dependency: $circularity\n";
	    exit;
	}
	$circularity_start=$x if !$circularity_start;
	$circularity="$x $circularity";
    }
    for $d (split /\s+/, $deps{$x}) {
	$n += 1 + dependants_rec($d);
    }
    $dependants_rec_count--;
    return $n;
}
sub dependants {
    $dependants_rec_limit=keys %macro if !$dependants_rec_limit;
    $dependants_rec_count=0;
    return dependants_rec @_;
}
sub dependencysort {
    my($x, $y) = @_;
    my $xd = dependants($x);
    my $yd = dependants($y);
    return $xd-$yd if $xd != $yd;
    return $x cmp $y;
}

@macros = sort { dependencysort($a,$b) } keys %macro;

for $macro ( @macros ) {
    for $d1 (split /\s+/, $deps{$macro} ) {
	for $d2 (split /\s+/, $deps{$macro} ) {
	    print STDERR "Redundancy in $macro - $d1 depends on $d2\n" if depends($d1,$d2);
	}
	print STDERR "Unknown in $macro - $d1\n" if !$macro{$d1};
    }
}

open OUT, ">$ENV{QTDIR}/src/corelib/global/qfeatures.h"
    or die "Cannot open $ENV{QTDIR}/src/corelib/global/qfeatures.h for writing";

print OUT
"/****************************************************************************
**
** Copyright (C) 1992-\$THISYEAR\$ \$TROLLTECH\$. All rights reserved.
**
** This file is part of the \$MODULE\$ of the Qt Toolkit.
**
** \$TROLLTECH_DUAL_LICENSE\$
**
****************************************************************************/

/*
 * All features and their dependencies.
 *
 * This list is generated from \$QTDIR/src/corelib/global/qfeatures.txt
 */

";

for $macro ( @macros ) {
    print OUT "// $label{$macro}\n";
    if ( $deps{$macro} ) {
	print OUT "#if !defined(QT_NO_$macro)";
	print OUT " && (", (join " || ", map { "defined(QT_NO_$_)" } split /\s+/, $deps{$macro}), ")";
	print OUT "\n";
	print OUT "#define QT_NO_$macro\n";
	print OUT "#endif\n";
    } else {
	print OUT "//#define QT_NO_$macro\n";
    }
    print OUT "\n";
}

close OUT;