Syntax Directed TranslationFinal_Presentation

8/7/2019 Syntax Directed TranslationFinal_Presentation

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Syntax Directed Translation


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Presented by

Md. Chhafrul Alam Khan (Rayhan)

Batch: 30th,

ID: 200910142And

Jinnat Sultana Jeny

Batch: 30th,

ID: 200911097


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Overviewy Syntax Directed Translation (SDT)

y Syntax Directed Definitions (SDD)

y

Attributesy Synthesized Attributes

y Inherited Attributes

y Annotated Parse Tree

y Dependency Graph


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Syntax Directed Translations

y The translation of infix expressions into postfixnotation


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Syntax Directed Definitions (SDD)

y

SDD associated set of attributes partitioned into twosubsets called the synthesized and inherited attributes

y An attribute can represent anything we choose: a

string, a number, a type, a memory location, orwhatever.


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Synthesized Attributes

y X at a parse tree node N is defined by a semantic rule

associated with the production at N

y Node N is defined only in terms of attribute values atthe children of N and at N itself.


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Synthesized Attributes

y Example:

y The given production rule is a synthesized attribute

Production Semantic Rules

L E L.val = E.val

L En L.val = E.val

T T1 * F T.val = T1.val * F.val

F (E) F.val = E.val


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Inherited Attributesy B at a parse-tree node N is defined by a semantic rule

associated with the production at the parent of N.

y The production must have B as a symbol in its body.

y At node N is defined only in terms of attribute valuesat N s parent, N itself, and N s siblings.


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Inherited Attributes

y Example:

y The given production is an inherited attribute.


T FT` T`.inh = F.val

T` *FT1` T1`.inh = T`.inh * F.val

F (E) E.val = F.val

E E1 + T T.inh = E1.val + E.val


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Annotated Parse-Tree

y Parse-tree that also shows the values of the attributesat each node.

y Values of Attributes in nodes of annotated parse-treeare either,

y

initialized to constant values or by the lexical analyzer.y determined by the semantic-rules.


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Dependency Graphy Depicts the flow of information among the attribute

instances in a particular parse tree

y An edge from one attribute instance to another meansthat the value of the first is needed to compute thesecond.


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L

E n


Lp En L.Val = E.val

Ep E1+T

Ep T

Tp T1*F

Tp F

Fp (E)

Fp digit

E.Val = E1.val + T.val

E.Val = T.val

T.Val = T.val * F.val

T.Val = F.val

F.Val = E.val

F.Val = digit.lexval

Input string : 3 * 5n


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L

E n


Lp En

Ep E1+T

L.Val = E.val


EpT E.Val = T.val

Tp T1*F

Tp F

Fp (E)

Fp

digit


T.Val = F.val

F.Val = E.val

F.Val = digit.lexval T



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Annotated Parse-TreeL

E n


Lp En

Ep E1+T

Ep T

L.Val = E.val


E.Val = T.val

TpT1*F T.Val = T.val * F.val

Tp F

Fp (E)

Fp

digit

T.Val = F.val

F.Val = E.val


T

*T1 F



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E n


Lp En

Ep E1+T

Ep T

Tp T1*F

L.Val = E.val


E.Val = T.val


Tp F T.Val = F.val

Fp (E)

Fp

digit

F.Val = E.val


T

*T1 F

F



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E n


Lp En

Ep E1+T

Ep T

Tp T1*F

Tp F

Fp (E)

L.Val = E.val


E.Val = T.val


T.Val = F.val

F.Val = E.val

Fpdigit F.Val = digit.lexval

T

*T1 F

F

digit

digit



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Annotated Parse-TreeL.val

E.val n


Lp En

Ep E1+T

Ep T

Tp T1*F

Tp F

Fp (E)

Fp digit

L.Val = E.val


E.Val = T.val


T.Val = F.val

F.Val = E.val


T.Val

*T1.val F.Val

F.val

digit.lexval

digit.lexval



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Annotated Parse-Tree & Dependency GraphL.val

E.val n


Lp En

Ep E1+T

Ep T

Tp T1*F

Tp F

Fp (E)

Fp digit

L.Val = E.val


E.Val = T.val


T.Val = F.val

F.Val = E.val


T.Val

*T1.val F.Val = 5

F.Val = 3

digit.lexval = 3

digit.lexval = 5



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Annotated Parse-Tree & Dependency Graph


Lp En

Ep E1+T

Ep T

Tp T1*F

Tp F

Fp (E)

Fp digit

L.Val = E.val


E.Val = T.val


T.Val = F.val

F.Val = E.val


L.val

E.val n

T.Val

*T1.val = 3 F.Val = 5

F.val=3

digit.lexval = 3

digit.lexval = 5



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Lp En

Ep E1+T

Ep T

Tp T1*F

Tp F

Fp (E)

Fp digit

L.Val = E.val


E.Val = T.val


T.Val = F.val

F.Val = E.val


L.val

E.val n

T.Val = 3*5

= 15

*T1.val = 3 F.Val = 5

F.val=3

digit.lexval = 3

digit.lexval = 5



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Lp En

Ep E1+T

Ep T

Tp T1*F

Tp F

Fp (E)

Fp digit

L.Val = E.val


E.Val = T.val


T.Val = F.val

F.Val = E.val


L.val

E.Val = 15 n

T.Val = 3*5

= 15

*T1.val = 3 F.Val = 5

F.val=3

digit.lexval = 3

digit.lexval = 5



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Lp En

Ep E1+T

Ep T

Tp T1*F

Tp F

Fp (E)

Fp digit

L.Val = E.val


E.Val = T.val


T.Val = F.val

F.Val = E.val


L.Val = 15

E.Val = 15 n

T.Val = 3*5

= 15

*T1.val = 3 F.Val = 5

F.val=3

digit.lexval = 3

digit.lexval = 5



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Conclusion

y Conclusion


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Thank you

Syntax Directed TranslationFinal_Presentation

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