Forms of Semantic Specification

The way to specify a programming language has been a topic of heated debate for some decades and at present there is no consensus on how this is best done. Real languages are almost always specified informally; nevertheless, precision is often enough lacking that more formal approaches could benefit both programmers and language implementors. My purpose is to look at a few of these formal approaches in hope of establishing some distinctions or at least stirring some discussion

Provably Correct Compiler Generation

We have designed, implemented, and proved the correctness of a compiler generator that accepts action semantic descriptions of imperative programming languages. We have used it to generate compilers for both a toy language and a non-trivial subset of Ada. The generated compilers emit absolute code for an abstract RISC machine language that is assembled into code for the SPARC and the HP Precision Architecture. The generated code is an order of magnitude better than that produced by compilers generated by the classical systems of Mosses, Paulson, and Wand. Our machine language needs no run time type-checking and is thus more realistic than those considered in previous compiler proofs. We use solely algebraic specifications; proofs are given in the initiaI model. The use of action semantics makes the processable language specifications easy to read and pleasant to work with. We view our compiler generator as a promising first step towards user-friendly and automatic generation of realistic and provably correct compilers