#!/usr/bin/perl -w
# -----------------------------------------------------------------------------

my $srcfile = $ARGV[0];
my @callstack = ();

open (IN, "<$srcfile") || die "Cannot open $srcfile for reading: $!\n";
LINE:
while (<IN>) {
    if (/^Call ([A-Za-z0-9]+\.[0-9]+): .*\)/) {
	my $func = $1;
	if (/ ret=(........)$/ ||
	    / ret=(....:....) ds=....$/) {
	    my $retaddr = $1;
	    push @callstack, [$func,$retaddr];
	    next;
	} else {
	    # Assume a line got cut by a line feed in a string.
	    $_ .= scalar (<IN>);
	    print "[$_]";
	    redo;
	}
    }


    if (/^Ret  ([A-Za-z0-9]+\.[0-9]+): .* ret=(........)$/ ||
	/^Ret  ([A-Za-z0-9]+\.[0-9]+): .* ret=(....:....) ds=....$/) {
	my $func = $1;
	my $retaddr = $2;
	my ($topfunc,$topaddr);

      POP:
	while (1) {
	    if ($#callstack == -1) {
		print "Error: Return from $func to $retaddr with empty stack.\n";
		next LINE;
	    }

	    ($topfunc,$topaddr) = @{pop @callstack};

	    if ($topfunc ne $func) {
		print "Error: Return from $topfunc, but call from $func.\n";
		next POP 
	    }
	    last POP;
	}

	if ($topaddr eq $retaddr) {
	    print "OK: $func from $retaddr.\n";
	} else {
	    print "Error: Return from $func is to $retaddr, not $topaddr.\n";
	}    
    }
}

while ($#callstack != -1) {
    my ($topfunc,$topaddr) = @{pop @callstack};
    print "Error: leftover call to $topfunc from $topaddr.\n";
}

close (IN);