CoGenTe: a tool for code generator testing

We present the CoGenTe tool for automated black-box testing of code generators. A code generator is a program that takes a model in a high-level modeling language as input, and outputs a program that captures the behaviour of the model. Thus, a code generator's input and output are complex objects having not just syntactic structure but execution semantics, too. Hence, traditional test generation methods that take only syntax into account are not effective in testing code generators. CoGenTe amends this by incorporating various coverage criteria over semantics. This enables it to generate test-cases with a higher potential of revealing subtle semantic errors in code generators. CoGenTe has uncovered such issues in widely used real-life code generators: (i) lexical analyzer generators Flex and JFlex, and (ii) The MathWorks' simulator/code generator for Stateflow.