4. An interpreter is a program that

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1 1. In an aboslute loading scheme, which loader function is accomplished by programmer? A. Allocation B. LInking C. Reallocation D. both (A) and (B) 2. A compiler program written in a high level language is called A. source program B. object program C. machine language program D. none of these Advantage of using assembly language rather than machine language is that A. it is mneomonic and easy to read B. addresses any symbolic not absolute C. introduction of data to program is easier D. All of these 4. An interpreter is a program that A. places programs into memory and prepares them for execution B. automates the translation of assembly language into machine language. C. accesses a program written in a high level language and produces an object program. D. appears to execute a source program as if it were machine language. 5. Language which have many types, but the type of every name and expression must be calculated at compile time are A. strongly-type languages B. weakly typed languages C. loosely typed languages D. none of these 6. Terminal table A. contains all constants in the program. B. is a permanent table of decision rules in the form of patterns for matching with the uniform symbol table to discover syntactic structure.

2 C. consist of a full or partial list of the token is as they appear in the program created by lexical analysis and used for syntax analysis and interpretation. D. is a permanent table which lists all keywords and special symbols of the language in symbolic form 7. Advantage of incorporating the macro-processor into pass 1 is that A. many functions have to be implemented twice B. functions are combined and it is not necessary to create intermediate files as output from the macro-processor and input to the assembler. C. more flexibility is available to the programmer in that he may use all the features of the assembler in conjunction with macros. D. all of these 8. Which of the following is a phase of a compilation process? A. Lexical analysis B. Code generation C. Both (a) and (b) D. None of these 9. System program such a s compiler are designed so that they are A. re-enterable B. non-reusable C. serially usable D. None of these 10. A series of statements explaining how the data is to be processed is called A. assembly B. machine C. COBOL D. program 11. A loader is a program that A. program that places programs into memory and prepares them for execution. B. program that automates the translation of assembly language into machine language.

3 C. program that accepts a program written in a high level language and produces as object program D. None of these 12. A system program that setup an executable program in main memory ready for execution is A. assembler B. linker C. loader D. load and go 13. Which of the following system program forgoes the production of object code to generate absolute machine code and load it into the physical main storage location from which it will be executed immediately upon completion of the assembly? A. Two pass assembler B. Load-and-go-assembler C. Macroprocessor D. Linker 14. Uniform symbol table A. contains all constants in the program B. is a permanent table of decision rules in the form of patterns for matching with the uniform symbol table to discover syntactic structure. C. consists of full or partial list of the token's as they appear in the program created by Lexical analysis and used for syntax analysis and interpretation. D. a permanent table which lists all key words and special symbols of the language in symbolic form. 15. Assembler is a program that A. places programs into memory and prepares them for execution B. automates the translation of assembly language into machine language C. accepts a program written in a high level language and produces an object program. D. None of these

4 16. For the C program given below the statement that does not hold true is for (i = 0; i for(j = 0; j if (i%c) { x += (4*j+5*i); y+=(7+4*j); A) There is a scope strength reduction B) There is a scope of dead code elimination C) There is a scope of common sub-expression elimination D) None of the above 17. In compilers generation of intermediate code based on an abstract machine model is useful because (A) Syntax-directed translations can be written for intermediate code generation (B) To generate code for real machines directly from high-level language programs is not possible (C) Portability of the front end of the compiler is enhanced (D) Implementation of lexical and syntax analysis is easier 18. Consider the grammar where P, Q, R are not terminals and r, s, t are terminals a. P->Q R b. P->Q s R c. P->ε d. P->Q t R r The grammar rules that violate the requirements of an operator grammar is (A) a and c only (B) b and c only (C) a and d only (D) a only

5 and C 19. Which one of the following statement is false for the SLR (1) and LALR (1) parsing tables for a context free grammar? (A) The reduce entries in both the tables may be different (B) The error entries in both the tables may be different (C) The go to part of both tables may be different (D) The shift entries in both the tables may be identical 20. We have a grammar with not epsilon and unit production (i.e. of type A->ε and A ->a) to parse a string, with n tokens. What is the maximum number of reduces moves that can be taken by a bottom-up parser for this grammar? (A) 2n - 1 (B) 2n (C) n-1 (D) n/2 For questions 21 and 22 refer to the data given below: The processor allows only register operands in its instructions and the given code segment is executed in that processor. For each instruction almost two source operands and one destination operand is available. Assume that all the variables are dead after this code segment. z = x + y; p = z * x; q = c + x; j = z * z; If (j > x) { M = x*x; else {

6 p = p*p; q = q*q; 21. Only two registers are available in the instruction set architecture of the processor. The code motion moves the statements from one place to another while preserving correctness. The only allowed complier optimization is code motion. In the compiled code, the minimum number of spills to memory is (A) 0 (B) 1 (C) 2 (D) Assume that no other optimization other than optimizing register allocation is applied. To compile this code segment without any spill to memory the minimum number of registers needed in the instruction set architecture of the processor is (A) 3 (B) 6 (C) 4 (D) We have the grammar E->E + n I E x n I n. The handles in the right-sentential form of the reduction for a sentence n + n x n are (A) n, n + n and n + n x n (B) n, E + n and E x n (C) n, E + n and E + E x n (D) n, E + n and E + n x n 24. The languages that need heap allocation in the runtime environment are (A) Those that use global variables (B) Those that use dynamic scoping (C) Those that support recursion (D) Those that allow dynamic data structure

7 25. When is the type checking usually done? (A) During syntax directed translation (B) During lexical analysis (C) During code optimization (D) During syntax analysis 26. What information need to be included in an object module, if a linker is given object modules for a set of programs that were compiled separately? (A) Names and locations of all external symbols defined in the object module (B) Object code (C) Absolute addresses of internal symbols (D) Relocation bits 27. We have two sets of LR (1) items of LR (1) grammar described below. X->c.X, c/d X->c.X, $ X->.cX, c/d X->.cX, $ X->.d, c/d X->.d, $ Related to the merging of two sets in the corresponding parser, the statement that does not hold true is (A) Cannot be merged since look aheads are different. (B) Cannot be merged but will result in R-R conflict (C) Cannot be merged but will result in S-R conflict (D) All of the above 28. S->xx W {print 1 S->y {print 2 W->Sz {print 3 A shift reduce parser carries out the actions specified within braces immediately after reducing with the corresponding rule of grammar. Using the syntax directed translation scheme described

8 by the above rule, the translation of xxxxyzz is (A) (B) (C) (D) In some programming language, L denotes the set of letters and D denotes the set of digits. An identifier is permitted to be a letter followed by any number of letters or digits. The expression that defines an identifier is (A) (L.D)* (B) (L + D)* (C) L (L.D) (D) L (L + D)* 30. Which one of the following statement is true? (A) Canonical LR parser is more powerful than LALR parser (B) SLR parser is more powerful than LALR (C) LALR parser is more powerful than canonical LR parser (D) SLR parser, canonical LR parser and LALR parser all have the same power 31. The activities are listed below. What is the pass numbers of each of the activities respectively? a. Object code generation b. Literals added to the literal table c. Listing printed d. Address resolution of local symbols that occur in a two pass assembler (A) 1, 2, 2, 2 (B) 2, 1, 1, 1 (C) 1, 2, 1, 2 (D) 2, 1, 2, 1

9 32. In a compiler checks every character of the source text. (A) The lexical analyzer (B) The syntax analyzer (C) The code generator (D) The code optimizer For questions 33 and 34 refer to the data given below: The programming language given below is written in the programming language that does not allow nested declarations of functions and allows global variables. global int j = 100, k = 5; void M(n) { int j = 10; print (n + 10); j = 200; k = 20; print (n); main() { M(j + k); 33. What is the output of the above program if the programming language uses static scoping and call by need parameter passing mechanism? (A) 25, 220 (B) 115, 105 (C) 220, 115 (D) 105, What is the output of the above program if the programming language uses dynamic scoping and call by name parameter passing mechanism? (A) 105, 25 (B) 105, 115 (C) 220, 25 (D) 115, 220

10 35. is not an advantage of using shared, dynamically linked libraries as opposed to using statically linked libraries. (A) Lesser overall page fault rate in the system (B) Faster program startup (C) Existing programs need not be relinked to take advantage of newer versions (D) Smaller sizes of executable files

COMPILER DESIGN LEXICAL ANALYSIS, PARSING

COMPILER DESIGN LEXICAL ANALYSIS, PARSING 1. Which of the following system program forgoes the production of object code to generate absolute machine code and load it into the Physical main storage location