Compilers

LR Parser

Question 1
Marks : +2 | -2
Pass Ratio : 100%
A system program that setup an executable program in main memory ready for execution is?
Assembler
Linker
Loader
Load and go
Explanation:
A loader is the part of an operating system that is responsible for loading programs and libraries. It is one of the essential stages in the process of starting a program, as it places programs into memory and prepares them for execution.
Question 2
Marks : +2 | -2
Pass Ratio : 100%
Which of these is true about LR parsing?
Is most general non-backtracking shift-reduce parsing
It is still efficient
Is most general non-backtracking shift-reduce parsing & It is still efficient
None of the mentioned
Explanation:
LR parsers are a type of bottom-up parsers that efficiently handle deterministic context-free languages in guaranteed linear time.
Question 3
Marks : +2 | -2
Pass Ratio : 100%
When ß (in the LR(1) item A -> ß.a,a) is not empty, the look-head _________
Will be affecting
Does not have any affect
Shift will take place
Reduction will take place
Explanation:
There is no terminal before the non terminal beta.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
What is the similarity between LR, LALR and SLR?
Use same algorithm, but different parsing table
Same parsing table, but different algorithm
Their Parsing tables and algorithm are similar but uses top down approach
Both Parsing tables and algorithm are different
Explanation:
The common grounds of these 3 parser is the algorithm but parsing table is different.
Question 5
Marks : +2 | -2
Pass Ratio : 100%
System program such as compiler are designed so that they are _________
Re-enterable
Non reusable
Serially usable
None of the mentioned
Explanation:
Re-enterable is the keyword for compiler being designed.
Question 6
Marks : +2 | -2
Pass Ratio : 100%
If a state does not know whether it will make a shift operation or reduction for a terminal is called _________
Shift/reduce conflict
Reduce /shift conflict
Shift conflict
Reduce conflict
Explanation:
As the name suggests that the conflict is between shift and reduce hence it is called shift reduce conflict.
Question 7
Marks : +2 | -2
Pass Ratio : 100%
When there is a reduce/reduce conflict?
If a state does not know whether it will make a shift operation using the production rule i or j for a terminal
If a state does not know whether it will make a shift or reduction operation using the production rule i or j for a terminal
If a state does not know whether it will make a reduction operation using the production rule i or j for a terminal
None of the mentioned
Explanation:
It occurs when If a state does not know whether it will make a reduction operation using the production rule i or j for a terminal.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
A series of statements explaining how the data is to be processed is called _________
Assembly
Machine
COBOL
Program
Explanation:
A program is a sequence of instructions, written to perform a task by computer. It requires programs to function, typically executing the program’s instructions in a central processor.
Question 9
Marks : +2 | -2
Pass Ratio : 100%
Uniform symbol table _________
Has all constants in the program
Permanent table of rules in the form of patterns for matching with the uniform symbol table to discover syntactic structure
Consists of full or partial list of the tokens as they appear in the program created by Lexical analysis and used for syntax analysis and interpretation
A permanent table which has all key words and special symbols of the language in symbolic form
Explanation:
Each pass scans the program, the first pass generates the symbol table and the second pass generates the machine code.
Question 10
Marks : +2 | -2
Pass Ratio : 100%
Advantage of incorporating the macro-processor into pass 1 is that _________
Many functions have to be implemented twice
Functions are combined not necessarily creating intermediate files as output from the macro-processor and input to the assembler
More flexibility is provided to the programmer in that he may use all the features of the assembler in conjunction with macros
All of the mentioned
Explanation:
A general-purpose macro processor or general purpose pre-processor is a macro designed primarily for string manipulation, macro definition.