From the series: Using Qualified Tools in a DO-178C Development Process
Bill Potter, MathWorks
Showing accuracy and consistency of source code is an objective in DO-178C. When using formal methods, DO-333 allows these objectives to be satisfied by formal analysis. Polyspace Code Prover™ is a tool that can perform formal analysis on C source code, using abstract interpretation. Polyspace Code Prover™ detects certain potential run-time errors in the source code. The types of errors that can be detected in the source code are: unreachable code or functions not called, numeric overflows, division by zero, invalid operation on floats, invalid shift operations, illegally dereferenced pointers, non-terminating calls or loops, and out-of-bound array index. These checks can all be analyzed in a single analysis run, with a combined report being generated for these potential errors. This report also clearly shows the line of code where the specific errors can occur. The reporting uses a color coded scheme for indicating the status of each line of code: Green indicates no bug in that line of code, gray indicates an unreachable line of code, red indicates a line of code proven to have a bug, and orange indicates a possible bug that may need further manual analysis. The DO Qualification Kit provides the necessary artifacts to qualify run-time error detection and reporting by Polyspace Code Prover. The kit also provides the evidence necessary to show soundness of the formal method, as required by DO-333.