Semantic attributes processing in the system DELTA

Abstract

In the translator writing system DELTA*, the language to be translated and the translation process (including optimization) are described by means of semantic attributes. While this method provides a rigorous formal description, its practical applications suffer from the large number of attributes involved and from the problems encountered when evaluating them by synthesis and inheritance.

DELTA accepts the most general descriptions for the translation of programs of any length. It checks the consistency of the description, i.e. circularities, double definitions and non existing definitions in the semantic description of the language and of its translator. For each translated program, DELTA eliminates useless and identical attributes and produces a sequential evaluation of "productive" attributes.

A simplified version of DELTA accepts one pass left to right descriptions for semantic attributes evaluation during syntactic analysis.