A generator for production quality compilers

Abstract

This paper presents a compiler description language and its implementation Coco/R (Compiler Compiler for Recursive Descent). Coco/R reads an attributed EBNF grammar of a language and translates it into a recursive descent parser and a scanner for that language. The programmer has to supply a main program that calls the parser and semantic modules that are called from within the parser. Coco/R evolved from two predecessors: the scanner generator Alex [Moss86] and the parser generator Coco [ReM689]. Their input languages were merged and simplified due to our experiences with these tools over several years (a similar tool with a slightly different motivation also emerged from Alex and Coco [DoPi90]). Using Coco/R, compilers can be generated that are as efficient as hand-coded and carefully optimized production quality compilers. Almost as important as efficiency is the simplicity and adequacy of the system. Programmers are not willing to use a tool if it does not come in handy to their work, if it uses an arcane notation or a bulk of options and special cases. Coco/R puts simplicity and efficiency over power.