CS606 MCQs by Junaid

1. convert the relocatable machine code into absolute machine code by linking library and relocatable objectfiles.

•  Assembler
•  Loader/link-editor
•  Compiler
•  Preprocessor

2. Parsers take as input from lexical analyzer.

•  Linker
•  Token
•  Instruction

3. The regular expression denotes, the set of all strings of a’s and b’s of length two  a*  (a*|b*)*  (a*b*)*  (a|b)(a|b)

4. is a regular expression for the set of all strings over the alphabet {a} that has an even number of a’s.  aa*  (aa)*  aa*a  a(aa)* 5. Phase supports macro substitution and conditional compilation.  Semantic  Syntax  Preprocessing  None of given

6. In LL(1) parsing algorithm, contains a sequence of grammar symbols.  Stack PG # 62  Link List  Array
7. Consider the grammar A  B C D B  h B | € C  C g | g | C h | i D AB | £ First of A is  h, g, i  g  h

8. parsers never shifts into an error state.  LS  LT  LR  LP

9. In parser, the two LL stand for  Left-to-right scan of input  left-most derivation  Left-to-right scan of input and left-most derivation PG # 54

10. is elaborated to produce bindings.  Declaration  Expression  Command

11. A lexical analyzer generated by is essentially a FSA.

 Dex  Mex  Fex  Lex 12. A lexical analyzer generated by lex is essentially a PDA (Push Down Automaton).  True  False 13. T he actions (shift, reduce) in a SLR(1) parser depend on a look ahead symbol (  Current input token  Next Input Token  Previous output Token  Previous Input Token. 14. The following grammar contains a conflict. S → A | xb

 First-Reduce  Shift-First

15. S  A | xb A  aAb | x This grammar contains a conflict.

 First-Reduce  Shift-First

16. Consider the Following S → AB  1  2  3  4

17. is a register allocation technique that always finds the minimal number of registers needed for aprocedure.

 Dangling reference  Graph coloring  Left Factoring  Right Recursion 18. Graph coloring is a register allocation technique that operates at individual basic blocks.

•  True
•  False