A computer-implemented error detection mechanism for detecting programming errors in a computer program. The computer-implemented error detection method described herein can make use of a Function Behavior Knowledge Base (FBKB) to approximate how a virtual function changes state of the program execution for all methods that can be called at each specific invocation point. The FBKB is used to select what implementation of a virtual function should be called in order to give rise to a programming defect. By dropping implementations that do not lead to a programming defect, the set of possible object runtime types is reduced. If this set is empty by the end of the analysis, then a defect is not possible, otherwise the set of object runtime types will contain types that may cause a defect.