This is a software system, originally announced in 1982 without a name and subsequently dubbed PSP (Paulson's Semantics Processor) and occasionally CGSG (Compiler Generator for Semantic Grammars). It is a very early example of a compiler generator: something that can accept a formal definition of a programming language's syntax and semantics and deliver a compiler for that language. For PSP, the resulting compilers are slow and the generated code much slower (by three orders of magnitude compared with a normal compiler). Nevertheless they are interesting as subjects of research. The system consists of three separate programs (Grammar Analyser, Universal Translator, Stack Machine), all written in standard Pascal. The input language is a so-called Semantic Grammar, which is an attribute grammar incorporating denotational semantics.

This research data supports “A semantics-directed compiler generator” which has been published in “Ninth Symposium on Principles of Programming Languages”