Syntax Directed Definition

What data structure in a compiler is used for managing information about variables and their attributes?

• Abstract syntax tree

• Symbol table

• Semantic stack

• Parse table

What value does the variable a have after ALL of the code above executes?

int a;

int b;

a=1;

b=a++;

• 1

• 2

• 3

• None

In a syntax directed translation scheme, if value of an attribute of a node is a function of the values of the attributes of its children, then it is called

• synthesized attribute

• inherited attribute

• canonical attribute

• None of the above

Inherited attribute is a natural choice in

• keeping track of variable declaration

• checking for the correct use of L-values and R-values

• both (a) and (b)

• None of these

Syntax directed translation scheme is desirable because

• it is based on the syntax

• its description is independent of any implementation

• it is easy to modify

• all of these

Which is not true about syntax and semantic parts of a computer language?

• Syntax is generally checked by the programmer.

• Semantics is the responsibility of the programmer

• Semantics is checked mechanically by a computer.

• Both (b) and (c)

Type checking is normally done during

• lexical analysis

• syntax analysis

• syntax directed translation

• code optimization

A parse tree showing the value of attributes at each node

• annotated parse tree

• syntax tree

• semantic tree

• all of the above

Synthesized attributes can be easily simulated by

• LL grammar

• LR grammar

• Ambiguous Grammar

• None of the above

A parse tree for __________ can be always annotated by evaluating semantic rules for attributes at each node bottom up

• S-attributed

• Inherited attributes

• Both a and b

• Syntax directed definition