Designing security softwares that evolve as quickly as threats is a truthful challenge. In addition, current software becomes increasingly more complex and difficult to handle even for security experts. Intrusion Detection Softwares (IDS) represent a solution that can alleviate these concerns. This paper proposes a framework to automatically build an effective online IDS which can check if the program's expected behavior is respected during the execution. The proposed framework extracts relevant information from the program's source code to build a dedicated IDS. We use the GCC compiler to produce the structure of our behavior's model and ensure the IDS is correct. Thanks to Petri nets, our framework allows program offline monitoring and simplifies the online monitoring development.