Program modules, separate compilation, and intermodule optimisation

iii Abstract This thesis is about a framework for elaborating and interpreting module language constructs at compile time in such a way that (1) arbitrary compile time information about declared identiiers of a module may be propagated to other modules and (2) no code is generated for module language constructs. The framework for interpreting module language constructs is called static interpretation. More information about referenced identiiers than can be obtained from programmer provided interfaces is necessary for analyses such as region inference. Further, many other analyses improve sig-niicantly from availability of analysis speciic information about referenced identiiers. Static interpretation facilitates intermodule optimisation, yet, it still supports a variant of separate compilation called cut-oo incremental recompilation. The thesis is divided into three parts. The rst part is about the static properties of a small language called ModML, which features a small Core language and the essential constructs of the Standard ML Modules language. The second part develops the framework for static interpretation by showing how ModML can be compiled into an explicitly typed intermediate language. The third part describes the ML Kit with Regions compiler, which is based on the techniques developed in part one and part two.