Compilers: Principles and Practice by Pearson

Syntax-directed Translation 155

associates a set of attributes with each grammar symbol, and with each production, it associates a set

of semantic rules for computing the values of the attributes of the grammar symbols appearing in that

production. Therefore, the grammar and the set of semantic rules constitute syntax-directed definitions.

5.4.3 Dependency Graphs

Given an attribute grammar, each rule has an associated dependency graph. This graph has a node for

each attribute A

j

(X

i

) of each symbol X

i

in the rule. For each attribute rule of the form

A

j

(X

i

) = f(A

p

(X

0

), …, A

q

(X

k

), …))

there is one edge from each node A

q

(X

k

) on the RHS, to the node ...