Deck 10: Compilers and Language Translation

Question 1

The code a compiler produces should be efficient and concise.

Answer 1

True

Question 2

If a parser cannot produce a parse tree for a high-level language statement, then that statement is not correctly formed.

Answer 2

True

Question 3

The goal symbol is the highest-level nonterminal.

Answer 3

True

Question 4

A lexical analyzer is more commonly known as a scanner.

Question 5

The output of a scanner is a list of all the tokens contained in a high-level language statement, as well as the classification number of each token found.

Question 6

Performing local optimization is much more difficult than performing global optimization.

Question 7

One of the possible local optimizations is eliminating unnecessary operations.

Question 8

A high-level language statement is translated into a single machine language instruction.

Question 9

Nonterminals must appear on the left-hand side of one or more BNF rules.

Question 10

The right-hand side of a BNF rule is the name of a single grammatical category.

Question 11

In addition to building tokens, a scanner must classify them by type.

Question 12

Parsing is the first phase of the compilation process.

Question 13

All high-level programming language statements are translated into machine language code, whether or not they are semantically correct.

Question 14

The single goal of compilers is correctness.

Question 15

A grammar that allows the construction of two or more distinct parse trees for the same statement is called a recursive grammar.

Question 16

The BNF language's syntax is specified as a series of grammars.

Question 17

High-level languages must be translated into machine language before they can be executed.

Question 18

The input to a scanner is the machine language statement from the source program.

Question 19

The output of a parser is either a parse tree or an error message.

Question 20

On-line debuggers help programmers locate and correct errors in programs.

Question 21

In BNF, the ____ is used to separate two alternative definitions of a nonterminal.

A) forward slash
B) vertical bar
C) backward slash
D) asterisk

Question 22

In the ____ phase, the compiler examines the individual characters in the source program and groups them into tokens.

A) semantic analysis and code generation
B) parsing
C) lexical analysis
D) code optimization

Question 23

Grammars for high-level languages like C++ or Java are very large.

Question 24

A(n) ____ definition defines a nonterminal symbol in terms of itself.

A) ambiguous
B) recursive
C) local
D) global

Question 25

If a parser can convert the sequence of tokens into the goal symbol, then the sequence is an invalid statement.

Question 26

The English-language sentence, "The orange artichoke flew through the elephant" is syntactically incorrect, but semantically meaningful.

Question 27

A ____ is a data structure that stores information about a nonterminal, such as the actual name of the object and its data type.

A) rule
B) production
C) parse tree
D) semantic record

Question 28

In ____ optimization, the compiler looks at large segments of the program to decide how to improve performance.

A) local
B) global
C) semantic
D) syntactical

Question 29

A high-level language program is called a(n) ____ program.

A) object
B) source
C) lexical
D) token

Question 30

A BNF rule is also known as a production.

Question 31

____ begins at the productions in the tree that are nearest to the original input tokens.

A) Code generation
B) Parsing
C) Lexical analysis
D) Semantic analysis

Question 32

____ is the ability to write highly optimized programs that contain no wasted time or unnecessary memory cells.

A) Conciseness
B) Ambiguity
C) Code-aware
D) Efficiency

Question 33

During the ____ phase, the sequence of tokens formed by the scanner is checked to see whether it is syntactically correct according to the rules of the programming language.

A) lexical analysis
B) parsing
C) code optimization
D) semantic analysis and code generation

Question 34

In the ____ phase, the compiler determines whether the machine language translation that it had produced can be made more efficient.

A) code optimization
B) parsing
C) lexical analysis
D) semantic analysis and code generation

Question 35

BNF metasymbols are symbols of BNF that are used to describe BNF symbols.

Question 36

The collection of all statements that can be successfully parsed is called the ____ defined by a grammar.

A) language
B) terminal
C) nonterminal
D) rule

Question 37

Following ____, the compiler makes a second pass over the parse tree to produce the code.

A) semantic analysis
B) lexical analysis
C) code optimization
D) code generation

Question 38

In BNF, a ____ is an intermediate grammatical category used to help explain and organize the language.

A) production
B) rule
C) terminal
D) nonterminal

Question 39

In the ____ phase, the compiler analyzes the meaning of the tokens making up a programming language statement and tries to understand the actions they perform.

A) semantic analysis and code generation
B) parsing
C) lexical analysis
D) code optimization

Question 40

During the compilation process, ____ is the next step after the code generation step.

A) semantic analysis
B) code optimization
C) lexical analysis
D) parsing

Question 41

A(n) ____ is a compiler embedded with a collection of supporting software.

A) debugger
B) reusable code library
C) visual development library
D) integrated development environment

Question 42

What is the format of a BNF rule?

A) left-hand side := right-hand side
B) left-hand side ::= "definition"
C) grammar = rule
D) grammar | rule

Question 43

____, the replacement of an arithmetic operation with a faster one is an example of a possible local optimization.

A) Strength reduction
B) Constant evaluation
C) Eliminating unnecessary operations
D) Parse tree construction

Question 44

____ parsing algorithms examine several tokens "down the road" to see what would happen if a certain choice was made.

A) Look-ahead
B) Token prediction
C) Down-the-road
D) Recursive

Question 45

Which factor plays the biggest role in code efficiency?

A) compilation process
B) code optimization
C) algorithm selected
D) code conciseness

Question 46

The ____ represents the empty nonterminal.

A) zero
B) null string
C) asterisk
D) vertical line

Question 47

In BNF, ____ are not defined any further by other rules of the grammar.

A) terminals
B) nonterminals
C) constants
D) variables

Question 48

The ____ of a statement is its grammatical structure.

A) syntax
B) semantics
C) correctness
D) grammar

Question 49

The collection of all statements that can be successfully parsed is called the ____ defined by a grammar.

A) language
B) syntax
C) grammar
D) rule

Question 50

A ____ shows how individual tokens can be grouped into predefined grammatical categories until the desired goal is reached.

A) parse tree
B) scanner
C) parser
D) compiler