Steering Clear of Triples: Deriving the Control Flow Graph Directly from the Abstract Syntax Tree in C Programs

This article explores the extension of Morgenthaler's Virtual Control Flow techniqueeMor97], which derives control owwASU86] semantics directly from the Abstract Syntax Tree, from the relatively coarse granularity of syntactic C expressions to the ner granularity of basic block expressions, that is, expressions without embedded control ow. We explain why this is a better level of abstraction for program analysis, and discuss the elements of an eecient and elegant solution, motivating the presentation by appealing to a more explicit intermediate form. We present our algorithm, and conclude with remarks about the suitability of Morgenthaler's version of Virtual Control Flow for customary exhaustive data-ow analysis.