Compiler Test: 50 Minutes, 50 MCQs to Answer, 60% to Pass

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

The answer is yes; a compiler does not impose the requirement that the languages used for input and output must be distinct from one another. It is necessary for us to declare a number of different types of data sets before the compiler may begin its work. The compiler takes data sets and libraries as input and generates multiple forms of output, such as object code, listings, and messages. During the compilation process, the compiler makes use of other data sets, such as utility data sets.

Concerning the SECOND STATEMENT:

An interpreter is a type of computer software that, according to the principles of computer science, directly executes, or carries out, instructions specified in a programming language, without first compiling those instructions into a program that is written in machine language. In most cases, the following methods are utilized by an interpreter in order to carry out the execution of a program:

(1) Perform direct actions based on the behavior of the source code once it has been parsed.

(2) Execute this immediately after translating the source code into an intermediate representation that is as efficient as possible.

(3) Perform an explicit execution of the code that has been stored and precompiled by a compiler that is a component of the interpreter system.

Basic differences between Compiler and Interpreter:

The most fundamental distinctions between a compiler and an interpreter are as follows: a compiler converts high-level instructions into machine language, whereas an interpreter converts high-level instructions into an intermediate code. The interpreter works through each line of code in the program one at a time, whereas the compiler works through the complete program at once. The compiler generates a list of errors that occur while the program is being run, whereas the interpreter stops translating the code shortly after discovering a mistake. This means that the progression of the remaining lines of the program will be completed once the error has been fixed. The compiler is responsible for producing the executable file on its own, however the interpreter is required for a program that operates as an interpreter.

Differences on the basis of various characteristics:

Comparatively, the amount of time spent evaluating and processing the program by a compiler is significantly more, whereas the amount of time spent doing so by an interpreter is far lower. The code that is produced as a result of a compiler is in the form of machine code or binary format. On the other hand, the code that is produced as a result of an interpreter is in the form of intermediate code. In the case of a compiler, the produced code is interpreted by another program, and the hardware of the computer is responsible for executing the code in an interpreter. In the case of the compiler, the pace at which the program is executed is rapid; on the other hand, the execution speed of the program in an interpreter is rather sluggish.

Differences on the basis of programming:

The compiler will check the syntax of a program, whereas the interpreter will check the keywords of a program. These are some of the differences that can be found in the programming world. The interpreter checks the program while it is being edited concurrently, in contrast to the compiler, which verifies the entirety of the program all at once. The execution of the program in the interpreter is carried out one line at a time, whereas the compilation process carries out the program in its whole.

Concerning the THIRD STATEMENT:

Compilers, interpreters, or possibly even a combination of the two may be utilized by the various programming languages.

Another essential idea to keep in mind:

A compiler is essentially a translator that works across different languages. There are a number of compilers that produce code in a high-level language rather than a low-level language like x86 machine code. The output of a compiler does not have to be a language on the same level as machine code. Additionally, there is no constraint stating that the languages used for input and output must be different from one another. An interpreter is a software that reads code that has been written in a certain programming language and then executes it directly, one statement (or expression, etc.) at a time. An interpreter may also translate between other programming languages. A translator does not actually translate anything at any stage during the interpreting process. A simple illustration of this would be the JAVA compiler (javac.exe), as well as the JAVA BYTEECODE interpreter (java.exe). It is unimportant that a compiler and interpreter could be written for any language; for instance, JAVASCRIPT, which is typically used as an interpreter language, could be compiled to another language (perhaps itself), and an interpreter could be written for C. Both of these things are possible, but it is unimportant that they could be written (typically a compiled language). For a particular language, such as HASKELL, there is the potential for the existence of interpreters in addition to compilers (the GHCi interpreter and the GHC compiler).

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

The statement is NOT TRUE. In reality, MICRO-SYNTAX is what deals with how case sensitivity affects syntax.

Concerning the SECOND STATEMENT:

No, the claim is NOT TRUE. In fact, Abstract Syntax Tree (AST) is what comes out of a syntax analyzer, while Semantic Graph is what comes out of a semantic analyzer (It is an AST with additional properties).

EXPLANATION

When it comes time to decide which production to employ, LL(1) parsers are only provided the currently active non-terminal and one token of LOOKAHEAD as information to work with. When determining whether to produce E -> E + E or E -> E * E, the parser only sees the next token of LOOKAHEAD, which means that it is unable to determine which operator is being applied even if it were aware of the order in which addition and multiplication take place. This is true even if the parser was aware of the precedence of addition and multiplication. As a consequence of this, knowing the relative precedence would not be of any assistance to the parser because the parser cannot see far enough ahead into the input to identify which operator is applied first.

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

Statement is FALSE. In point of fact, a compiler generates executable code by building BINARY OBJECT FILES that can be run several times, but an interpreter generates CODE directly in temporary memory that can only be run once.

Concerning the SECOND STATEMENT:  

Statement is FALSE. In point of fact, a compiler will read all of the input files before beginning the translation process, but an interpreter will only read a tiny portion of the input file (for example, a single line) and will then convert that line into code that can be executed.

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

Yes, what was said is TRUE. The LR(0) state machine is used by both SLR(1) and LALR(1). FOLLOW information is used by SLR. LALR combines all LR(1) states that are only different in their LOOKAHEAD.

Concerning the SECOND STATEMENT:

Yes, what was said is TRUE. LR(1) splits a single LR(0) state into two if it shows up in more than one context where the LOOKAHEADS are different.

EXPLANATION

(1) Every LL(k) grammar is also a LR(k) grammar.

(2) It is also decidable if a given LR(k) grammar is also a LL(m) grammar for some m. 

(3) A ε-free LL(1) grammar is also a SLR(1) grammar.

(4) A LL(1) grammar with symbols that have both empty and non-empty derivations is also a LALR(1) grammar.

(5) A LL(1) grammar with symbols that have only the empty derivation may or may not be LALR(1). 

(6) LL grammars cannot have rules left recursion. Removing left recursion from a context-free grammar is always possible. However, the resulting grammar may be bigger, require more LOOKAHEAD tokens than preferred to be an LL grammar, or not be an LL grammar at all.

(7) LL(k) grammars that are ε-free can be transformed into GNF (Greibach Normal Form) (which by definition do not have rules with left recursion) without increasing the LOOKEAHEAD tokens.

EXPLANATION

The right solutions can be verified by constructing SLR(1) item sets.

EXPLANATIONS

This answer of this MCQ is supported by the table of FIRST and FOLLOW sets that can be found following this paragraph.

EXPLANATION

The right solutions can be verified by constructing SLR(1) item sets.

EXPLANATIONS

This correct answer to this multiple choice question (MCQ) is supported by the table of FIRST and FOLLOW sets that can be found immediately following this paragraph.

EXPLANATIONS

The following are some possible explanations for this:

About the FIRST STATEMENT and SECOND STATEMENT:

Both of these statements are UNTRUE.

Both the C and C++ programming languages are, in point of fact, context-sensitive languages. There are many explanations for this, including the following:

In order to begin the process of parsing C and C++, we start by utilising a very sophisticated pre-processor. There is no way around the fact that these pre-processors are written by hand (they are not based on Regular Expressions or Context-Free Grammars).

LEXERS in C and C++ need lexical feedback in order to differentiate between TYPEDEF names and IDENTIFIERS. To put it another way, the CONTEXT-SENSITIVE LEXER needs assistance from the CONTEXT-FREE PARSER in order to differentiate between the IDENTIFIER "manishkumarjha" and the TYPEDEF name "manishkumarjha."

For example:

int manishkumarjha;

typedef int manishkumarjha;

manishkumarjha x;

In the piece of code that was just displayed, the first instance of the name "manishkumarjha" is an IDENTIFIER, while the second and third instances are TYPEDEF names. To figure this out, we will need to read through the TYPEDEF declarations (and since types have nested parentheses, this is definitely at least as hard as parsing a context-free language). Given that the PARSER and LEXER are mutually recursive, it does not make sense to state that the PARSER is context-free while the LEXER is context-sensitive. This is because the PARSER and LEXER are mutually recursive.

EXPLANATIONS

This solution to this multiple choice question (MCQ) is supported by the table of FIRST and FOLLOW sets, which can be found immediately following this paragraph.

EXPLANATION

Its resultant parse table contains no any conflict.

EXPLANATION

The grammar is ambiguous (unclear) because there are two different ways ‘c’ could be derived from the alphabetic string. There is no ambiguous grammar that can be parsed by LL(1), SLR(1), or LR(1) because all three are incompetent in this regard. Although it is conceivable to work through comprehensive LL(1), SLR(1), and LR(1) constructs in order to show exactly where they fail, doing so is not required. As soon as we demonstrate that a language is ambiguous, we immediately know that none of LL(1), SLR(1), or LR(1) can possibly function. This is because ambiguous grammars cannot be parsed using LL(1), SLR(1), or LR(1).

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

Yes, the assertion is TRUE. LR parsers are built by a parser generator; it is impossible for a human to manually construct one.

Concerning the SECOND STATEMENT:

Yes, the word is TURE. LR(1) parsing is more powerful than LL(1) parsing, but it is also harder to understand and less convenient.

EXPLANATION

The individual tokens are:

(1)        printf

(2)        (

(3)        "Hello, Manish! \n"

(4)        )

(5)        ;

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

The assertion is correct, in such case. The LR(1) approach can also be applied in reverse, in which case it is referred to as the RL(1) method.

Concerning the SECOND STATEMENT:

Yes, the assertion is TRUE. To verify the statement, we may easily construct LR(1) and LALR(1) parsing tables.

EXPLANATIONS

We can defend this in a variety of different ways; here are just a few of them.

Way1:

An SLR(1) parser traces out a rightmost derivation in reverse. If we try deriving aⁿ using both grammars, we get the following two rightmost derivations:

S                                              S

Aa                                           aA

Aaa                                         aaA

Aaaa                                       aaaA

Aaaaa                                     aaaaA

…..                                          …..

Because in a shift/reduce parse all reductions take place at the top of the parsing stack, this indicates that in the case of the first grammar, the parsing stack never has more than two symbols on it. This is due to the fact that the reduction that is performed, which is A -> Aa. We would not have been able to complete this reduction if there were more than two symbols already on the parsing stack. The second grammar, on the other hand, performs the reduction A -> aA. This indicates that the parsing stack will contain a string of O(n) a's, followed by the A for which the reduction is performed.

Way2:

In the first grammar, FOLLOW(A) equals {a, $}, while in the second grammar, it just equals {$}. We may make a note of this difference. Because SLR(1) parsers always reduce on the FOLLOW set, this indicates that (for the first grammar), we will always reduce A -> Aa as soon as it gets on the parsing stack. On the other hand, for the second grammar, we are unable to do any reductions until the LOOKAHEAD is $, which happens after the last terminal has been shifted.

EXPLANATIONS

Compiler handles it in Scanner stage.

A program known as a scanner is one that, given a string of characters (which represents the program's source file), generates a string of tokens that may then be used to feed the parser of the compiler.

Lexical phase errors:

These errors are discovered at the process of lexical analysis. Typical lexical errors are:

(1) Insufficient length of identifiers or constants

(2) Illegal characters

(3) String mismatch

EXPLANATIONS

The table of FIRST and FOLLOW sets that follows this paragraph provides more evidence in favour of the answer to this MCQ.

EXPLANATIONS

Please refer to the table of FIRST and FOLLOW sets that follows this paragraph to verify  response to this MCQ.

EXPLANATION

The right solutions can be verified by constructing SLR(1) item sets.

EXPLANATIONS

This solution to this multiple choice question (MCQ) is supported by the table of FIRST and FOLLOW sets, which can be found immediately after this paragraph.

EXPLANATION

Yes, the syntax-directed definition provided in this MCQ is L-attributed because D.s depends only on attributes of its siblings to its left (in F -> F D) or has no dependencies (in F -> D).

EXPLANATION

Synthesized forms appear at:

(1) F.w

(2) F.v

(3) D.v

EXPLANATION

EXPLANATION

Given grammar does not have left factors, and as a result, it cannot be parsed using LL(1). Left-factored grammar equivalents are as follows:

E -> int F | E G

F -> ε | + E | − E

G -> − (E) | ∗ E

EXPLANATIONS

The table of FIRST and FOLLOW sets that comes after this paragraph supports the answer to this MCQ.

EXPLANATIONS

Compiler manages it during the Scanner phase.

A scanner is a program that, given a string of characters (representing the program's source file), generates a string of tokens that may subsequently be fed to the compiler's parser.

Lexical phase errors:

These flaws are identified during the lexical analysis procedure. Common lexical problems include:

(1) Inadequate length of identifiers or constants

(2) Illegal characters

(3) Mismatching string

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

No, the assertion is untrue. In actuality, TARGET LANGUAGE and HOST LANGUAGE are different in Cross-compiler. In the SELF-RESIDENT compiler, both languages are identical.

Concerning the SECOND STATEMENT:

No, the claim is NOT TRUE. In fact, EBNF (Extended Backus Normal Form) is only more expressive in the sense that it is easier to use. All EBNF definitions can be changed into BNF definitions that are the same.

EXPLANATION

Given grammar belongs to LR(0), LR(1), and LALR(1).

EXPLANATIONS

Compiler handles it in Semantic stage.

Semantic analysis looks at how well the code makes sense. It uses the syntax tree from the last phase and the table of symbols to make sure that the given source code makes sense. It also checks to see if the code is sending the right message.

Semantic Analyzer will look for:

(1) Type Mismatches;

(2) Incompatible Operands;

(3) Function Called with the Wrong Arguments;

(4) Variables That Haven't Been Declared;

(5) and other problems.

The Semantic Analysis phase does the following:

(1) Helps you keep track of type information and store it in a symbol table or syntax tree.

(2) Allows you to check for typos.

(3) In the case of a type mismatch, a semantic error is shown if there are no exact type correction rules that meet the needs of the operation.

(4) Checks for type compatibility and gets information about types.

(5) Checks to see if the operands are allowed in the source language or not.

EXPLANATIONS

Compiler handles it in Parser stage.

In the Parser step of the Compilation process, the compiler learns the grammar of the language. Its job is to find syntax mistakes and turn a program without mistakes into internal data structures that can be read or written in another language.

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

Incorrect, the assertion is not true. When it comes to the Parsing phase of the compilation process, the Tree is unequivocally just a Tree. There is no cycle in existence.

Concerning the SECOND STATEMENT:

Incorrect, the assertion is not true. In point of fact, the expression 30 = x * 3 has a syntactic mistake, which manifests itself during the Parsing phase of the compilation process.

EXPLANATIONS

In the Parser stage, the compiler takes care of it.

The compiler acquires an understanding of the grammar of the target language at the Parser stage of the compilation process. It is responsible for finding errors in the program's syntax and transforming error-free code into internal data structures that can be read or created using a different programming language.

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

The grammar presented here is NOT SLR (1). This proves that STATEMENT-1 is false. The following link is an item set representation of the SLR(1) grammar. Please click on the link below.

SLR ITEM SET DIAGRAM

There is a conflict between the SHIFT and the REDUCE commands.

Concerning the SECOND STATEMENT:

Yes, FIRST(X) contains 2 elements.

FIRST(x) = {x};

FIRST(X) = {x, a}; and

FOLLOW(X) = {y, $}.

EXPLANATION

(1) Every LL(k) grammar is also a LR(k) grammar.

(2) It is also decidable if a given LR(k) grammar is also a LL(m) grammar for some m. 

(3) A ε-free LL(1) grammar is also a SLR(1) grammar.

(4) A LL(1) grammar with symbols that have both empty and non-empty derivations is also a LALR(1) grammar.

(5) A LL(1) grammar with symbols that have only the empty derivation may or may not be LALR(1). 

(6) LL grammars cannot have rules left recursion. Removing left recursion from a context-free grammar is always possible. However, the resulting grammar may be bigger, require more LOOKAHEAD tokens than preferred to be an LL grammar, or not be an LL grammar at all.

(7) LL(k) grammars that are ε-free can be transformed into GNF (Greibach Normal Form) (which by definition do not have rules with left recursion) without increasing the LOOKEAHEAD tokens.

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

Statement is FALSE. In fact, a compiler will construct a table of symbols and conduct both syntactic and semantic analysis, whereas an interpreter will often only study the syntax rules of the input language.

Concerning the SECOND STATEMENT:

Statement is FALSE. In point of fact, a compiler is able to conduct optimizations on the code that was input, whereas an interpreter would often not optimize the code that was supplied.

Concerning the THIRD STATEMENT:

Statement is FALSE. In point of fact, compilation is an offline activity, whereas interpretation is performed online.

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

The lexical analyzer does, in fact, check each character in the source code. The process of transforming a string of characters into a string of tokens is what is referred to as LEXICAL ANALYSIS in the field of computer science. A LEXICAL ANALYZER, often known as a LEXER or SCANNER, is a type of computer program or function that does lexical analysis. A LEXER is often implemented as a standalone function that may be accessed by a parser or any other function.

Concerning the SECOND STATEMENT:

The number of tokens in the FORTRAN statement DOES 5 I = 1.25 is not 5, as many people believe. In point of fact, there are three tokens in this particular sentence, which are as follows:

<variable, "DO5I"> <assign> <number,"1.25">.

Concerning the THIRD STATEMENT:

During the lexical analysis of the program, a language's KEYWORDS are identified, therefore yes, this is true. The process of deconstructing the source files into KEYWORDS, CONSTANTS, IDENTIFIERS, OPERATORS, and other straightforward tokens is referred to as lexical analysis. A language's definition of a language's smallest possible piece of text is called a token.

(A) The term "KEYWORDS" refers to terms that are defined by the language and that always have a particular meaning in the language. Some of the most important words in C and C++ are as follows: IF, ELSE, INT, CHAR, DO, WHILE, FOR, STRUCT, and RETURN.

(B) CONSTANTS are the literal valued entities that can be recognized by the language. In most cases, these components are comprised of NUMBERS, STRINGS, and CHARACTERS:

(B-1) The following examples of numbers that can be used in expressions are examples of NUMBERS: 3.14, 5.12, and 0. However, in most cases, negative numbers like -17 are formed by combining an operator (-) and a number (17).

(B-2) STRINGS are pieces of text that can be recognized by the language. In programming languages like C and C++, a string like "My name is Manish Kumar Jha" is surrounded by double quotations.

(B-3) CHARACTERS are single letters. A character is denoted by single quotes when written in C or C++, as in ‘m’.

(C) Identifiers are names that have been assigned to anything by the programmer. These can be anything from VARIABLES to FUNCTIONS to CLASSES to ENUMERATIONS and more. Each language has its own set of rules that govern the various ways in which these names might be written.

(D) The MATHEMATICAL, LOGICAL, and any other operators that can be recognized by the language are referred to as OPERATORS. In general, the conventional operators +, -, *, and / are present in every language, and numerous other operators are frequently defined as well. Examples of some of the additional variables that are defined in C and C++ include: % (modulo), --- (decrement), and ++ (increment).

(E) Other tokens include anything that is not included in any of the preceding categories. The majority of the time, they will result in errors; nevertheless, depending on the compiler, items like "{ ( }" might be valid in the language despite not being considered as a keyword or operator.

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT

Yes, parsing C++ is far more difficult than parsing C. Parsing is not difficult in Java. It is important to keep in mind that the grammars for both C and C++ are inherently ambiguous. This means that they will provide us with several possible parses, and we will need to make use of context in order to resolve the ambiguities. People then make the incorrect assumption that "we need to resolve ambiguities as we parse," which is a common misconception. If we insist on addressing ambiguities as we parse, it will make our parser more intricate and considerably more difficult to create. When we compare the parsing of the C language to that of C++, we will find that the parsing of C++ is far more difficult than that of the C language. Take note that Java makes use of the LALR(1) language, which does not allow for ambiguity and makes it simple to parse.

Concerning the SECOND STATEMENT:

It is not the back-end of the compiler that is responsible for parsing the program; rather, it is the front-end that is responsible for parsing the program.

EXPLANATION

Here are the FIRST and FOLLOW sets of non-terminals.

Here is the grammar's LL(1) parsing table.

EXPLANATION

The grammar that is presented is clear and unambiguous. This is due to the fact that the production that is used at each terminal in the string can only be uniquely determined by either the terminal itself or the terminal that is directly to its right.

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

For computer code written in one programming language (the SOURCE LANGUAGE), a compiler is a program (or combination of programs) that translates the code into a different programming language (the TARGET LANGUAGE, often having a BINARY FORM known as OBJECT CODE). EXECUTABLE PROGRAM CREATION IS THE MOST COMMON REASON FOR WANTING TO TRANSFORM SOURCE CODE.

Concerning the SECOND STATEMENT:

The output of a compiler does not necessarily have to be in a low-level language. Let's look at several definitions: The term "DE-COMPILER" refers to any program that performs this translation from a low-level language to a higher-level language. It is common to refer to software that translates between high-level languages as a LANGUAGE TRANSLATOR, SOURCE TO SOURCE TRANSLATOR, or LANGUAGE CONVERTER.

An additional essential idea:

A compiler is a translator that can move between different programming languages. There are various compilers that produce code in a high-level language rather than a low-level language like x86 machine code. The output of a compiler does not have to be a language on the same level as machine code. Additionally, there is no requirement that the languages used for input and output be different from one another. An interpreter is software that accepts code that has been written in a certain programming language and immediately executes it, one statement (or expression, etc.) at a time. An interpreter may also translate one programming language into another. An interpreter does not actually do any translation at any point in the process. A straightforward illustration of this would be the JAVA compiler (javac.exe) and the JAVA BYTEECODE interpreter (java.exe). It is unimportant that a compiler and interpreter could be written for any language; for instance, JAVASCRIPT, which is typically used as an interpreter language, could be compiled to another language (perhaps itself), and an interpreter could be written for C. Both of these things are possible, but it is unimportant that they could be (typically a compiled language). There is the possibility that a particular language, such as HASKELL, could have both interpreters and compilers (the GHCi interpreter and the GHC compiler).

EXPLANATION

Since the above language is left recursive, it cannot be parsed using the LL(1) algorithm. Grammar that is equivalent and free from left recursion is as follows:

A -> BA’

A’ -> +BA’ | ε

B -> int B’ | (A)B’

B’ -> ∗int B’ | ε 

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

Yes, the statement is TURE. The portion of the computer that does the actual work is called the Central Processing Unit (CPU for short). Its purpose is to carry out operations on computer programs that have been written in machine language and are kept in the computer's main memory (also known as RAM). It achieves this goal by repeatedly carrying out a process known as the fetch-and-execute cycle. More specifically, it retrieves an instruction written in machine language from memory and then carries out that instruction.

Concerning the SECOND STATEMENT:

Yes, the statement is TURE. CFGs are often used as models of syntax for natural languages as well as for programming languages.

EXPLANATION

D.s is the correct answer.

EXPLANATIONS

The table of FIRST and FOLLOW sets that follows this paragraph provides more evidence in support of the answer to this MCQ.

EXPLANATION

(1) Every LL(k) grammar is also a LR(k) grammar.

(2) It is also decidable if a given LR(k) grammar is also a LL(m) grammar for some m. 

(3) A ε-free LL(1) grammar is also a SLR(1) grammar.

(4) A LL(1) grammar with symbols that have both empty and non-empty derivations is also a LALR(1) grammar.

(5) A LL(1) grammar with symbols that have only the empty derivation may or may not be LALR(1). 

(6) LL grammars cannot have rules left recursion. Removing left recursion from a context-free grammar is always possible. However, the resulting grammar may be bigger, require more LOOKAHEAD tokens than preferred to be an LL grammar, or not be an LL grammar at all.

(7) LL(k) grammars that are ε-free can be transformed into GNF (Greibach Normal Form) (which by definition do not have rules with left recursion) without increasing the LOOKEAHEAD tokens.

EXPLANATIONS

Compiler handles it in Semantic stage.

Semantic analysis evaluates code clarity. It validates the source code using the syntax tree and symbol table from the previous phase. It also verifies the code's message.

Semantic Analyzer checks for type mismatches, incompatible operands, function calls with the wrong arguments, undeclared variables, and other issues.

Semantic Analysis:

(1) Keeps type information in a symbol table or syntax tree.

(2) Checks typos.

(3) If no exact type correction rules fit the operation's needs, a semantic error is shown for a type mismatch.

(4) Determines type compatibility and types.

(5) Determines if the source language allows operands.

EXPLANATIONS

The following are some possible explanations for this:

Concerning the FIRST STATEMENT:

The assertion is correct, in such case. Because it lacks left factorization, the grammar in question does not satisfy the criteria for LL(1) (non-terminals S and C).

Concerning the SECOND STATEMENT:

The assertion is correct, thanks for asking. Because it contains a left recursion (B -> BC), the presented grammar does not satisfy the requirements for LL(1).

Concerning the THIRD STATEMENT:

The assertion is correct, in such case. Due to the presence of ambiguity, the grammar in question does not satisfy the criteria for LL(1). There are two distinct leftmost derivations that can be made from the string bbcca:

S => bBa => bBCa => bbCa => bbcCa => bbcca

or

S => bBa => bBCa => bBCCa => bbCCa => bbcCa => bbcca

Making the give grammar LL(1)

S -> bT

T -> Ab | Ba

A -> aS | CB

B -> bD

C -> cD

D -> ε | cD

The left factoring of the S and C non-terminals can be completed with little effort. Left recursion and ambiguity were both caused by the B non-terminal, and both problems can be solved by first creating a single b, and then either zero or more c (via new non-terminal D).