#
# reads CPP output and turns #line things into appropriate Haskell
# pragmas
#
# considered to be GHC-project specific
#
#
# NOTE: this script needs RAWCPP set in order to do something
# useful:
#

$Verbose = 0;

while ( $#ARGV >= 0 &&  $ARGV[0] eq '-v' ) {
    if ($ARGV[0] eq '-v') {
	$Verbose = 1;
    } else {
	die "hscpp: unrecognised argument: $$ARGV[0]\n";
    }
    shift(@ARGV);
}
#ToDo: print a version number ?

$OrigCpp = ${RAWCPP};

if ( $OrigCpp =~ /(\S+)\s+(.*)/ ) {
    $cmd  = $1;
    $rest = $2;
    if ( -x $cmd ) { # cool
	$Cpp = $OrigCpp;
    } else { # oops; try to guess
	$GccV = `gcc -v 2>&1`;
	if ( $GccV =~ /Reading specs from (.*)\/specs/ ) {
	    $Cpp = "$1/cpp $rest";
	} else {
	    die "hscpp: don't know how to run cpp: $OrigCpp\n";
	}
    }
} else {
    $Cpp = $OrigCpp;
}

print STDERR "hscpp:CPP invoked: $Cpp @ARGV\n" if $Verbose;

open(INPIPE, "$Cpp @ARGV |") || die "Can't open C pre-processor pipe\n";

while (<INPIPE>) {

# line directives come in flavo[u]rs:
#   s/^#\s*line\s+\d+$/\{\-# LINE \-\}/;   IGNORE THIS ONE FOR NOW
    s/^#\s*line\s+(\d+)\s+(\".+\")$/\{\-# LINE \1 \2 \-\}/;
    s/^#\s*(\d+)\s+(\".*\").*/\{\-# LINE \1 \2 \-\}/;

    print $_;
}

close(INPIPE) || exit(1); # exit is so we reflect any errors.

exit(0);