Abstract: A method for determining a set of f low paths in a code listing that are most likely to fail comprises the steps of: converting the code listing to a directed acyclic graph representation, the representation including nodes and directed edges, each node representing a basic block of unconditional code statements. The method loads, as facts into a knowledge base, representations of the nodes and edges, and unconditional statements from the basic blocks. The method also loads, as rules into the knowledge base, conditional statements and complexity indicator values for conditional and unconditional statements. Weights are assigned to each node based upon complexity indicator values for statements associated with the node. A determination is then made of a set of flow paths through the code listing, each path ranked in order of assigned weights, those flow paths with larger assigned weights being assumed as those paths most likely to fail.

Abstract: A method for displaying statements of a computer program during an animation of the program's execution, the display using multiple colors to identify statements based on their respective frequency of execution, is disclosed. As a program statement becomes the current executed statement during the animation, the statement's frequency of execution is calculated as the number of times the statement has been executed so far during the animation, divided by the total number of statement executions throughout the animation. A display color is assigned based on whether the statement's execution frequency has reached one of two or more thresholds. The multi-hued display of program statements based on thresholds of execution frequency assists the programmer in understanding the operation of the program.