#!/usr/bin/perl

##############################################################################
#
#	generate_config_sh
#		Process that takes an automatically generated config.sh
#		file and allows the environment to overload the values
#		automatically discovered by Configure on our target platform.
#
#	Author	Redvers Davies <red@criticalintegration.com>
#
##############################################################################

my $config = shift;

my $sys = $ENV{SYS};

my $callbacks = {};
$callbacks->{'ar'} = [\&simple_process, ["AR", "arm-linux-ar"]];
$callbacks->{'archname'} = [\&simple_process, ["SYS", "armv4l-linux"]];
$callbacks->{'cc'} = [\&simple_process, ["CC", "arm-linux-gcc"]];
$callbacks->{'cccdlflags'} = [\&simple_process, ["CFLAGS", ""]];
$callbacks->{'ccdlflags'} = [\&simple_process, ["CFLAGS", ""]];
$callbacks->{'ccflags'} = [\&simple_process, ["CFLAGS", "-fno-strict-aliasing -D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"]];
$callbacks->{'ccflags_uselargefiles'} = [\&simple_process, ["CFLAGS", "-D_LARGEFILE_SOURCE -D_FILE_OFFSET_BITS=64"]];
$callbacks->{'ccname'} = [\&simple_process, ["CC", "arm-linux-gcc"]];
$callbacks->{'cpp'} = [\&simple_process, ["CCP", "arm-linux-cpp"]];
$callbacks->{'cppflags'} = [\&simple_process, ["CCPFLAGS", "-fno-strict-aliasing"]];
$callbacks->{'cpprun'} = [\&simple_process_append, ["CC", "arm-linux-gcc -E", "-E"]];
$callbacks->{'cppstdin'} = [\&simple_process_append, ["CC", "arm-linux-gcc -E", "-E"]];
$callbacks->{'full_ar'} = [\&backtick, ["AR", "which $ENV{AR}", "/usr/local/arm/2.95.3/bin/arm-linux-ar"]];
$callbacks->{'ld'} = [\&simple_process, ["LD", "arm-linux-ld"]];
$callbacks->{'ldflags'} = [\&simple_process, ["LDFLAGS", ""]];
$callbacks->{'ldflags_uselargefiles'} = [\&simple_process, ["LDFLAGS", ""]];
$callbacks->{'myarchname'} = [\&simple_process, ["SYS", "armv4l-linux"]];
$callbacks->{'archlib'} = [\&library_munge, ["SYS", "armv4l-linux"]];
$callbacks->{'archlibexp'} = [\&library_munge, ["SYS", "armv4l-linux"]];
$callbacks->{'installarchlib'} = [\&library_munge, ["SYS", "armv4l-linux"]];
$callbacks->{'installsitearch'} = [\&library_munge, ["SYS", "armv4l-linux"]];
$callbacks->{'sitearch'} = [\&library_munge, ["SYS", "armv4l-linux"]];
$callbacks->{'sitearchexp'} = [\&library_munge, ["SYS", "armv4l-linux"]];

if ($config eq "") {
	die("Please run me as generate_config_sh path/to/original/config.sh");
}

open(FILE, "$config") || die("Unable to open $config");

my $line_in;
while ($line_in = <FILE>) {
	if ($line_in =~ /^#/) {
		next;
	}

	if ($line_in !~ /./) {
		next;
	}

	$line_in =~ /^([^=]+)=(.*)/;
	my $key = $1;
	my $value = $2;
	if (ref($callbacks->{$key}) eq "ARRAY") {
		($callbacks->{$key}[0])->($key,$value);
	} else {
		print($line_in);
	}
}

sub backtick {
	my $key = shift;
	my $value = shift;
	my $envvar = $callbacks->{$key}->[1][0];

	if ($ENV{$envvar}) {
		my $rawtext = `$callbacks->{$key}->[1][1]`;
		chomp($rawtext);
		print("$key=\'$rawtext\'\n");
	} else {
		print("$key=\'$callbacks->{$key}->[1][2]\'\n");
	}
}
	

sub simple_process {
	my $key = shift;
	my $envvar = $callbacks->{$key}->[1][0];

	if ($ENV{$envvar}) {
		print("$key=\"$ENV{$envvar}\"\n");
	} else {
		print("$key=\'$callbacks->{$key}->[1][1]\'\n");
	}

}

sub simple_process_append {
	my $key = shift;
	my $envvar = $callbacks->{$key}->[1][0];

	if ($ENV{$envvar}) {
		print("$key=\"$ENV{$envvar} $callbacks->{$key}->[1][2]\"\n");
	} else {
		print("$key=\'$callbacks->{$key}->[1][1]\'\n");
	}

}

sub library_munge {
	my $key = shift;
	my $value = shift;
	my $envvar = $callbacks->{$key}->[1][0];

	if ($ENV{$envvar}) {
		$value =~ s/$callbacks->{$key}->[1][1]/$ENV{$envvar}/g;
		print("$key=$value\n");
	} else {
		print("$key=$value\n");
	}
		
}