The platin Tool Kit - The T-CREST Approach for Compiler and WCET Integration

The construction of safety-critical real-time applications requires predictable computer platforms that enable a safe and tight static analysis of those systems. The worst-case performance and the availability of tight bounds on the worst-case execution time (WCET) of the tasks of the applications are of central importance in such systems. The compiler tool-chain plays an integral part in a real-time platform infrastructure. Not only is the compiler responsible for relating source code level annotations such as flow facts to the generated machine code – a task necessary to achieve high-quality bounds on optimised code. Also, the analysis tools profit from program information that is readily available in the compiler but difficult to retrieve from the generated binary alone. Therefore, the compiler should export internal knowledge about the program to the analysis. Furthermore, compilation for hard real-time systems requires optimisations that specifically aim at reducing the worst-case execution path instead of reducing the average case performance. This requires feedback from the worst-case analysis back to the compiler. In this paper we describe the our approach to the compiler tool integration that has been realised in the platin tool kit, developed in the EU FP7 T-CREST project. The platin tool kit is a portable glue tool that interfaces our LLVM-based T-CREST compiler with several research and industrial strength analysis tools. Our approach is transferable to other compiler tool-chains and minimises the effort for adapting them for the requirements of real-time platforms.