Handling Context-Sensitive Syntactic Issues in the Design of a Front-end for a MATLAB

In recent times, the MATLAB language has emerged as a popular alternative for program-ming in diverse application domains such as sig-nal processing and meteorology. The language has a powerful array syntax with a large set of pre-defined operators and functions that operate on arrays or array sections, making it an ideal candidate for applications involving substantial array-based processing. Yet, for all the programming convenience that the language offers, designing a parser and scan-ner capable of mimicking the language’s syn-tax has proven to be an acutely difficult task. The language has many context-sensitive con-structions, and though numerous front-end im-plementations of MATLAB and MATLAB-like languages exist, not much has been discussed re-garding the efficient compile-time parsing of such languages or how its syntax impacts the parsing process. In this paper, we present the design and implementation of a compiler front-end for the MATLAB language. We discuss in detail both the indigenously designed grammar responsible for syntax analysis as well as the lexical speci-fication that complements the grammar. In the course of our attempts to emulate MATLAB’s syntax, we were able to unravel certain key is-sues relating to its syntax, such as the complica-tions arising in parsing command-form function invocations within a compile-time environment, the context-sensitive interpretation of the sin-gle quote character, and the translation of white space within matrices into element separators. The front-end effects a conversion of the original source to an intermediate form in which state-∗This research was supported by DARPA under Contract F30602–98–2–0144. ments are represented as abstract syntax trees and the flow of control between statements by a control-flow graph. All subsequent compiler passes work on this intermediate representation. The front-end was designed and implemente