Introduction to Compilers

What is a compiler? a) A software that interprets code line-by-line b) A tool that translates high-level language code into machine code c) A hardware component for processing instructions d) A program that executes code directly Answer: b) A tool that translates high-level language code into machine code Which phase of a compiler checks for syntax errors? a) Lexical Analysis b) Syntax Analysis c) Semantic Analysis d) Optimization Answer: b) Syntax Analysis What does the lexical analysis phase of a compiler do? a) Translates code into machine code b) Checks for syntactic correctness c) Breaks down code into tokens d) Optimizes code for performance Answer: c) Breaks down code into tokens In which phase of compilation is intermediate code generated? a) Lexical Analysis b) Syntax Analysis c) Semantic Analysis d) Code Generation Answer: d) Code Generation Which data structure is typically used to represent syntax trees? a) Stack b) Queue c) Tree d) Graph Answer: c) Tree What is the purpose of semantic analysis in a compiler? a) To check if the syntax of the code is correct b) To convert high-level code into machine code c) To ensure the code adheres to the language’s semantics d) To optimize the code for performance Answer: c) To ensure the code adheres to the language’s semantics Which of the following is NOT a phase of compilation? a) Preprocessing b) Parsing c) Debugging d) Code Optimization Answer: c) Debugging What is a parse tree? a) A tree that represents the token stream of the code b) A tree that represents the syntactic structure of the source code c) A tree used for code optimization d) A tree that represents the execution flow of the program Answer: b) A tree that represents the syntactic structure of the source code What is the role of the symbol table in a compiler? a) To store intermediate code b) To keep track of variable names and their attributes c) To optimize the compiled code d) To generate machine code Answer: b) To keep track of variable names and their attributes Which type of grammar is commonly used to define the syntax of programming languages? a) Regular Grammar b) Context-Free Grammar c) Context-Sensitive Grammar d) Unrestricted Grammar Answer: b) Context-Free Grammar What is a lexical analyzer (scanner)? a) A program that generates machine code b) A program that checks for syntax errors c) A program that converts a sequence of characters into tokens d) A program that optimizes code Answer: c) A program that converts a sequence of characters into tokens What is the purpose of the Code Optimization phase in a compiler? a) To generate intermediate code b) To improve the performance of the generated code c) To check for syntax errors d) To convert source code into assembly code Answer: b) To improve the performance of the generated code Which of the following is a type of intermediate code representation? a) Abstract Syntax Tree (AST) b) Bytecode c) Assembly Language d) Source Code Answer: b) Bytecode What is the purpose of the semantic analysis phase? a) To generate the final executable code b) To ensure that the code complies with the language’s rules and semantics c) To parse the source code into tokens d) To optimize the code for performance Answer: b) To ensure that the code complies with the language’s rules and semantics Which compiler phase involves translating code into assembly language? a) Lexical Analysis b) Syntax Analysis c) Code Generation d) Code Optimization Answer: c) Code Generation What is a token in the context of lexical analysis? a) A unit of syntax b) A unit of meaning in the code c) A sequence of characters that represent a keyword or identifier d) A structure in the parse tree Answer: c) A sequence of characters that represent a keyword or identifier Which data structure is commonly used to implement a parser? a) Stack b) Queue c) Tree d) List Answer: a) Stack What does “code generation” refer to in the compilation process? a) Converting source code into an intermediate representation b) Generating assembly or machine code from intermediate code c) Checking the syntax of the source code d) Optimizing the intermediate code Answer: b) Generating assembly or machine code from intermediate code Which phase of a compiler is responsible for translating a program’s control flow into a form that can be executed by a CPU? a) Lexical Analysis b) Syntax Analysis c) Code Optimization d) Code Generation Answer: d) Code Generation What is the primary goal of code optimization? a) To correct syntax errors b) To make the code more readable c) To improve the performance of the code d) To convert code to a different programming language Answer: c) To improve the performance of the code What is a grammar in the context of programming languages? a) A set of rules for syntax and semantics b) A type of compiler optimization c) A representation of the code in machine language d) A tool for debugging code Answer: a) A set of rules for syntax and semantics What is the main function of syntax-directed translation? a) To translate code into machine language b) To translate tokens into a syntax tree c) To use syntax rules to guide the translation of source code d) To generate intermediate code Answer: c) To use syntax rules to guide the translation of source code What does “tokenization” refer to in the context of lexical analysis? a) The process of generating tokens from intermediate code b) The process of converting a sequence of characters into meaningful tokens c) The process of translating tokens into machine code d) The process of analyzing the syntax of tokens Answer: b) The process of converting a sequence of characters into meaningful tokens What is a “parse tree” used for in a compiler? a) To represent the execution flow of a program b) To represent the lexical structure of the source code c) To represent the syntactic structure of the source code d) To represent the memory layout of variables Answer: c) To represent the syntactic structure of the source code Which phase of a compiler is typically the first to process the source code? a) Lexical Analysis b) Syntax Analysis c) Semantic Analysis d) Code Optimization Answer: a) Lexical Analysis What is an “abstract syntax tree” (AST)? a) A representation of the code’s execution flow b) A hierarchical representation of the syntactic structure of the code c) A representation of the code in assembly language d) A linear representation of the source code Answer: b) A hierarchical representation of the syntactic structure of the code Which of the following is an example of a high-level programming language? a) Assembly Language b) Machine Code c) C++ d) Bytecode Answer: c) C++ What is “semantic checking” in the context of compilation? a) Ensuring that the syntax of the code is correct b) Verifying that the code adheres to the language’s semantic rules c) Optimizing the generated machine code d) Generating intermediate code Answer: b) Verifying that the code adheres to the language’s semantic rules Which of the following phases is responsible for optimizing the performance of the compiled code? a) Lexical Analysis b) Syntax Analysis c) Semantic Analysis d) Code Optimization Answer: d) Code Optimization What is a “token” in the context of lexical analysis? a) A symbolic representation of a data type b) A unit of syntax that is recognized by the lexer c) A part of the machine code d) A semantic error in the code Answer: b) A unit of syntax that is recognized by the lexer Which phase of compilation involves creating a symbol table? a) Lexical Analysis b) Syntax Analysis c) Semantic Analysis d) Code Generation Answer: c) Semantic Analysis What is the purpose of a “control flow graph” in a compiler? a) To represent the logical flow of control in the source code b) To represent the syntactic structure of the code c) To track variable usage in the code d) To optimize the performance of the generated machine code Answer: a) To represent the logical flow of control in the source code What is a “machine language” in the context of compilation? a) A low-level programming language that is directly executed by the CPU b) A high-level programming language that needs to be compiled c) An intermediate code used for optimization d) A language used for debugging Answer: a) A low-level programming language that is directly executed by the CPU What is a “lexer” in the context of lexical analysis? a) A tool that generates machine code b) A tool that parses the syntax of the code c) A tool that performs lexical analysis and generates tokens d) A tool that optimizes the code Answer: c) A tool that performs lexical analysis and generates tokens Which compiler phase involves checking the correctness of variable types and operations? a) Lexical Analysis b) Syntax Analysis c) Semantic Analysis d) Code Generation Answer: c) Semantic Analysis What is a “register allocation” in the context of code generation? a) A process of allocating memory for variables b) A process of assigning variables to processor registers c) A process of optimizing loop structures d) A process of converting source code into intermediate code Answer: b) A process of assigning variables to processor registers What is an “optimization pass” in the context of code optimization? a) A phase that generates intermediate code b) A phase that refines and improves code performance c) A phase that converts source code into assembly language d) A phase that checks for syntax errors Answer: b) A phase that refines and improves code performance What is “inline expansion” in compiler optimization? a) Replacing a function call with the function’s body b) Generating additional intermediate code for optimization c) Replacing a variable with its computed value d) Removing unused functions from the code Answer: a) Replacing a function call with the function’s body What is “dead code elimination” in the context of optimization? a) Removing code that will never be executed b) Replacing old code with new code c) Generating additional code for optimization d) Removing redundant variables Answer: a) Removing code that will never be executed Which of the following is an example of a high-level language construct? a) Assembly Instructions b) Machine Code Instructions c) Loops and Conditional Statements d) Register Allocation Answer: c) Loops and Conditional Statements What does the term “syntax-directed translation” refer to? a) Using syntax rules to guide the generation of code b) Translating machine code into source code c) Directly translating tokens into machine code d) Analyzing the semantics of the code Answer: a) Using syntax rules to guide the generation of code What is the purpose of a “back end” in a compiler? a) To analyze the syntax and semantics of the source code b) To generate and optimize the machine code c) To convert tokens into a syntax tree d) To perform lexical analysis Answer: b) To generate and optimize the machine code What is “syntax error reporting” in the context of compilation? a) Generating warnings about potential issues in the code b) Displaying errors related to incorrect syntax in the code c) Generating machine code from intermediate code d) Checking for semantic errors Answer: b) Displaying errors related to incorrect syntax in the code What is a “preprocessor” in the context of compilation? a) A tool that generates machine code b) A tool that performs lexical analysis c) A tool that processes source code before actual compilation d) A tool that optimizes code Answer: c) A tool that processes source code before actual compilation What is the purpose of “error recovery” in a compiler? a) To handle and recover from errors encountered during compilation b) To remove redundant code c) To optimize the performance of the code d) To generate the final machine code Answer: a) To handle and recover from errors encountered during compilation What is “code generation” in a compiler’s context? a) The process of translating high-level code into an intermediate representation b) The process of generating executable machine code from intermediate code c) The process of parsing the source code d) The process of analyzing code for semantic errors Answer: b) The process of generating executable machine code from intermediate code What does “type checking” refer to in semantic analysis? a) Ensuring that variables are correctly assigned to memory locations b) Ensuring that operations are performed on compatible data types c) Verifying the correctness of the syntax of the code d) Optimizing the performance of the generated machine code Answer: b) Ensuring that operations are performed on compatible data types What is a “symbol table” used for in a compiler? a) Storing intermediate code b) Storing information about variables, functions, and objects c) Generating machine code d) Optimizing the code Answer: b) Storing information about variables, functions, and objects Which of the following best describes “source code”? a) The machine code generated by the compiler b) The high-level code written by the programmer c) The intermediate code used for optimization d) The code generated during lexical analysis Answer: b) The high-level code written by the programmer Which of the following is a key goal of compiler design? a) To ensure the source code is error-free b) To convert high-level code into efficient machine code c) To debug the source code d) To maintain the source code in a readable format Answer: b) To convert high-level code into efficient machine code