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Write syntax directed definitions (semantic rules) for the following grammar to add the type of each identifier to its entry in the symbol table during semantic analysis. Rewriting the grammar is not permitted and semantic rules are to be added to the ends of productions only.

$D \rightarrow TL;$

$T \rightarrow \text{int}$

$T \rightarrow \text{real}$

$L \rightarrow L,id$

$L \rightarrow id$
asked in Compiler Design by Veteran (68.8k points)
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+6 votes
Best answer
PRODUCTION RULE                                                        SEMANTIC ACTIONS

$D \rightarrow TL$                                                                          $L.in:=T.type$

$T  \rightarrow int$                                                                           $T.type:=integer$

$T \rightarrow  real$                                                                        $T.type:=real$

$L \rightarrow L,id$                                                                      $L1.in=L.in$

                                                                                       Enter_type$(id.entry, L.in)$

$L  \rightarrow  id$                                                                        Enter_type$(id.entry, L.in)$
answered by (421 points)
selected by
What is L.in?

Why two times Enter_Type(id.entry, L.in)?
+3 votes
quadruples consists of the 4-section they are operator, operand1, operand2, result

operator                 operand1           operand2                    result

+                               a                     b                              t1

+                               c                      d                             t2

>                               t1                     t2                            t3

>                                a                     c                             t4

<                               b                      d                             t5

and                            t4                    t5                             t6

or                              t3                     t6                            t7
answered by (421 points)


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