Compiler Design

A shift reduce parser carries out the actions specified within braces immediately after reducing with the corresponding rule of grammar:
$S \to xxW$ {print "1"}, $S \to y$ {print "2"}, $S \to Sz$ {print "3"}
What is the translation of $xxxxyzz$ using the syntax directed translation scheme described by the above rules?
(i) 23131
(ii) 11233
(iii) 11231
(iv) 33211

Synthesized attributed are calculated
(i) From the values of attributes of the children of the node
(ii) From the values of attributes of the parent of the node
(iii) From the values of attributes of the siblings of the node
(iv) None of these

What is an activation record? Explain how they are used to access various local and global variables.

Given the Syntax-Directed Definition below with the synthesized attribute val. Draw the annotated parse tree for the expression $(3+4) * (5+6)$

$L \to E$, $L.val = E.val$
$E \to T$, $E.val = T.val$
$E \to E_1 + T$, $E.val = E_1.val + T.val$
$T \to F$, $T.val = F.val$
$T \to T_1 * F$, $T.val = T_1.val * F.val$
$F \to (E)$, $F.val = E.val$
$F \to digit$, $F.val = digit.lexval$

Explain how type checking and error reporting are performed in compiler. Draw syntax tree and DAG for the statement:
$a = (a * b + c) \uparrow (b + c) * b + c$

Differentiate between S-attribute SDT and L-attribute SDT with suitable examples.