1. A method for compiling source code comprising operating a computer to perform steps of: receiving source code written in a computer programming language; and generating executable program code in only one pass of a compilation process of the source code without modifying the source code by, detecting, during the one pass of the compilation process, invalid programming constructs in the source code and generating, during the one pass of the compilation process, valid compiler constructs that represent detected invalid programming constructs, wherein invalid programming constructs are programming constructs in the source code that violate one or more grammar rules of the computer programming language; wherein the executable program code is generated without modifying errors in the source code.