Question

In a bottom-up evaluation of a syntax directed definition its inherited attributes can do which of the following?

(a) Always evaluated

(b) Can be  evaluated  if the definition is L attributed

(c) Can be  evaluated  if the definition has synthesized attributes

(d) Never be evaluated

I got this question in semester exam.

My enquiry is from Top-Down Parsing topic in chapter Topdown Parsing of Compiler

Answer 1

Right answer is (b) Can be  evaluated  if the definition is L attributed

For explanation I would say: A Syntax Directed Definition (SDD) is called S Attributed if it has only synthesized attributes. Also the L-Attributed Definitions contain both synthesized and inherited attributes but do not need to build a dependency graph to evaluate them.