7/31/2019 CD Question Bank PART A

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kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkk06kCSk63k:kCOMPILERkDESIGNkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkQUESTIONkBANKkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkPARTkAkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkUNITkIkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkIntroduction,kLexicalkAnalysis:k

k

OBJECTIVE:kThiskunitkdiscusseskaboutkdifferentksystemksoftwares,kthekstructurekofkcompilers,klexicalkanalysis,kaklexer,k&kto ens.k

1kWhatkareklanguagekprocessors?k

2kBrieflykexplainkakstrategyktokreducektheknumberkofkpasses.kk

3kBrieflykexplainkthekfollowingk:k

i)kLEXk

ii)kYACCkk

4kWhatkiskthekneedkforkakmultipasskcomplier?kExplain.k

5kDistinguishkbetweenkakphasekandkakpass.k

6kWhatkdokyoukmeankbyksyntactickanalysis?kDiscuss.k

7kDiscusskinkdetail,kthekevolutionkofkprogrammingklanguages.k

8kDefinekinkdetailkthekvariouskcompilerkkconstructionktools.k

9kConsiderkthekstatementkgivenkbelow.k

WhilekXk>kYkandkXk=kY3-6kdok

X:k=kXkYk

Forkthiskstatement.kGivekthekoutputskafterkeachkofkthekfollowingkphases.k

ki)kLexicalkanalysisk

kii)kSyntaxkAnalysisk

kiii)kIntermediatekcodekgenerationk

kiv)kCodekoptimizationk

10kExplainkwithkthekbloc kdiagram,kdifferentkphaseskofkakcomplier.k

11kBrieflykexplainkthekneedkofkmultipasskinkakcompiler.k

12kExplainkinkdetailkaklanguagekkprocessingksystem.k

13kWhatkdokyoukmeankbyksemantickanalysis?kExplainkinkdetail.k

7/31/2019 CD Question Bank PART A

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14kExplainkinkdetailkthekanalysiskksynthesiskmodelkofkcompilation.k

15kExplainkinkdetailkthekintermediatekcodekgenerationkphase.k

16kDiscusskaboutkvariouskissueskofklexicalkanalysis.k

17kWhatkiskmeantkbykinputkbuffering?kExplainkthekbufferkpairskschemekforkrecognizingklexemes.k

18kWritekthektransitionkdiagramktokrecognizek

i.kRelationalkoperatorskk=,k=k

ii.kIdentifierskandkKeywords.k

19kWhatkiskakloo kaheadkoperator?kWithkexamplekshowkhowkthiskoperatorkmaykbekusedktoksolveklexicalkanalysiskproblems.k

20kBrieflykexplainkthekusekofktransitionkdiagramkinkconstructingkaklexicalkanalyzerkwithkank

example.k

21kConstructkaktransitionkdiagramktokrecognizekthekto enskgivenkbelow:k

i)kKeywords:kBEGINkENDkii)kIntegerkconstantk

iii)kIdentifierk

kkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkUNITkkIIk,IIIkandkIVkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkkSyntaxkAna

lysis:k

k

OBJECTIVE:kThiskunitkdiscussesksyntaxkanalysis,kcontextkkfreekgrammars,kwritingkakgrammar,ktopkkdownkparsing,kbottomkkupkparsing,kLRkparsing,kusingkambiguouskgrammars,k&kparsekgenerators.k

22kDefinek:k

i.kleftkmostkderivationk

ii.krightkmostkderivationk

iii.kParsektreek

23kYourkarekgivenkthekgrammar:k

Sk.kak/kbk/k(L)k

7/31/2019 CD Question Bank PART A

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Lk.kL,kSk/kSk

Givekleftkmostkderivationkforktheksentencek((a,kb),ka)k

24kDefinekambiguitykandkshowkthatkthekgrammarkbelowkiskambiguousk

Ek.kEk+kEk/kEk*kEk/k(E)k/kid.k

25kGivekankunambiguouskgrammarkforkthekaboveklanguageksuchkthatk

i)k+khaskhigherkpriorityk

ii)k*khasklesskpriorityk

kiii)kBothkarekrightkassociative.k

26kBrieflykexplainkthekproblemskassociatedkwithktop-downkparsing.k

27kConstructkLL(I)kparsingktablekforkthekgrammar.k

Sk.kictkSS1k/ak

S1k.keSk/kk

IskthekgrammarkLL(I)?k

28kWritekaknotekonkerrorkrecoverykinkLRkparsers.k

29DefinekLL(I)kgrammar.kGivekconditionskforkakgrammarktokbekLL(I)kbasedkonkFIRSTkandkFOLLOWSksets.k

30kBrieflykexplainkthekruleskforkbuildingkoperatorkprecedencekrelationskfromkprioritykandkassociativity.k

31kGivenkthekgrammark

Ek.kTk+kEk/kTk

Tk.kTk*kFk/kFk

Fk.k(E)k/kidk

i)kMa ektheknecessarykchangesktokma ekitksuitablekforku(1)kparsing.k

ii)kForkthekresultingkgrammar,kconstructkFIRSTkandkFOLLOWksetskandkLL(1)k

kparsingktable.k

32kGivenkthekgrammark

Ek.kEk+kTk/kTk

T.Tk*kidk/kidk

i.kConstructksetskofkLR(1)kitemsk

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ii.kConstructkcanonicalkLR(1)kparsingktablek

kiii.kIskthekgrammarkLALR(1)?kJustifykyourkanswer.k

33kShowkthatkthekgrammarkbelowkiskambiguous.k

Ek.kEk*kEk/kEk+kEk/k(E)k/kidk

Givekankunambiguouskgrammarkforkthekaboveklanguageksuchkthatk

i.k+khaskhigherkpriority.k

kii.k*kandk+karekrightkassociative.k

34kConstructkSLR(I)kparsingktablekforkthekgrammar.k

Ek.kEkTk/kTk

kTk.kidk+kTk/kidk

35kGivektheklimitationskofkSLR(I)kparsers.k

36kBrieflykexplainkthekerrorkdetectionkandkrecoverykinkLRkparsers.k

37kWithkakschematickexplainkthekrolekofkakparser.kListkandkexplainkvariouskerrorkrecoverykstrategieskofkakparser.k

38kWhatkiskthekneedkofkleftkfactoringkandkleftkrecursionkelimination?kExplainkwithkexamples.k

39kClearykdefinekruleskforkfindingkFIRSTkandkFOLLOWksets.kDeterminekthekFIRSTkandk

FOLLOWSksetskforkthekgrammar.k

Ek.kTE1,kE1k+kTE1k/k,kTk.kFT1,kT1k.k*FT1k/k,kFk.k(E)k/kid.k

40kfindkLR(0)kitemskofkthekgrammark

Sk.kLk=kR,kSk.kR,kLk.k*R,kLk.kidkRk.kL.k

VerifykwhetherkthiskgrammarkiskSLRk(1)korknot.k

41kWhatkdokyoukmeankbykleftkrecursion?kGivekankalgorithmkforkeliminatingkleftkrecursionk

fromkakgrammar.kUsingkthekalgorithm,keliminatekleftkrecursionkfromkthekgrammarkgivenkbelow.k

Sk.kCkfk/kgk

kCk.kChk/kSlk/k.k

42kExplainkhandlekandkhandlekpruning.kHowktheykarekusedkinkthekstac kimplementationkofk

7/31/2019 CD Question Bank PART A

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shiftk-kreducekparsing?kExplainkwithkthekgrammarkEk.kEk+kEk/kEk*kEk/k(E)k/kidkandkthekinputkstringkid1k+kid2k*kid3$.k

43kWhatkarekFIRSTkandkFOLLOWkfunctions?kExplainkhowktheykarekcomputed.k

44ShowkthatkthekgrammarkgivenkbelowkisknotkankSLRkgrammarkbykshowingkthatkthekparsingktablekhaskakshift/reducekconflict.kCompletekthekparsingktable.k

Sk.kLk=kRk

Sk.kRk

Lk.k*Rk

Lk.kidk

kRk.kLk

47kConstructkakcanonicalkLRkparsingktablekforkthekgrammarkgivenkbelowk

Sk.kCCk

kCk.kcCk/kd.k

48kForkthekfollowingkgrammar,kconstructkthekcanonicalkparsingktable:k

S1k.kS,kSk.kCC,kCk.kcCk/kdk

49kDesignkankalgorithmkforkconstructingkLALRkparsingktable.k