@ Override public void visitClassContext ( ClassContext classContext ) { currentClass = classContext . getJavaClass ( ) ; if ( currentClass . getMajor ( ) >= Const . MAJOR_1_8 ) { try { stack = new OpcodeStack ( ) ; activeStackOps = new ArrayDeque <> ( ) ; super . visitClassContext ( classContext ) ; } finally { activeStackOps = null ; stack = null ; } } currentClass = null ; }
implements the visitor to filter out pre - 1 . 8 classes for 1 . 8 + classes it creates the opcode stack and active stack ops