Syntax Directed Translation Questions | Compiler Design

Question 1
Syntax directed translation scheme is desirable because:
It is based on the syntax
It is easy to modify
Its description is independent of any implementation
All of these
Question 1 Explanation: 
Syntax Directed Definition
  • An SDD is a CFG with attributes and rules.
    Attributes are associated with grammar symbols.
    Rules are associated with productions.
  • An SDD specifies the semantics of productions.
    It does not enforce a specific way of achieving the semantics
Syntax Directed Translation
  • An SDT is done by attaching rules or program fragments to productions.
  • The order induced by the syntax analysis produces a translation of the input program
Role of SDT
  •  To associate actions with productions
  •  To associate attributes with non-terminals
  •  To create implicit or explicit syntax tree
  •  To perform semantic analysis
Question 2
Synthesized attribute can easily be simulated by an
LL grammar
Ambiguous grammar
LR grammar
None of the above
Question 2 Explanation: 
Synthesized attributes follows bottom up parsing evaluation.

Example :
X -> Y | Z  i attribute is there in X,Y and Z
X.i = f( Y.i , Z.i ) means parent is taking attribute from there children

Bottom Up Parsers
LR( 0 ) , SLR( 1 ) , LR( 1 ) , LALR( 1 ) and Operator Precedence

Top Down Parsers
Non Recursive descent ( LL( 1 ) ) and Recursive descent

LR Parsers which are generated from LR grammar are also coming under bottom up parsing fashion Therefore option(C) is correct.
There are 2 questions to complete.

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  1. Anonymous

    bala chua

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