GATE CS Compiler Design questions

Consider the CFG with $\left\{S, A, B\right\}$ as the non-terminal alphabet, $\{a, b\}$ as the terminal alphabet, $S$ as the start symbol and the following set of production rules: $S \rightarrow aB$ $S \rightarrow bA$ $B \rightarrow b$ $A \rightarrow a$ $B \rightarrow bS$ $A \rightarrow aS$ $B \rightarrow aBB$ $A \rightarrow bAA$ For …

Consider the CFG with $\left\{S, A, B\right\}$ as the non-terminal alphabet, $\{a, b\}$ as the terminal alphabet, $S$ as the start symbol and the following set of production rules: $S \rightarrow aB$ $S \rightarrow bA$ $B \rightarrow b$ $A \rightarrow a$ $B \rightarrow bS$ $A \rightarrow aS$ $B \rightarrow aBB$ $A \rightarrow bAA$ Which …

Consider the following two statements: P: Every regular grammar is LL(1) Q: Every regular set has a LR(1) grammar Which of the following is TRUE?

Consider the grammar with non-terminals $N=\left\{S,C,S_1\right\}$, terminals $T=\left\{a, b, i, t, e\right\}$, with $S$ as the start symbol, and the following set of rules: $S \rightarrow iCtSS_1 \mid a$ $S_1 \rightarrow eS \mid \epsilon$ $C \rightarrow b$ The grammar is NOT LL(1) because:

Which one of the following is a top-down parser?

The grammar $S\rightarrow AC\mid CB$ $C\rightarrow aCb\mid \epsilon$ $A\rightarrow aA\mid a$ $B\rightarrow Bb\mid b$ generates the language $L=\left \{ a^{i}b^{j}\mid i\neq j \right \}$. In this grammar what is the length of the derivation (number of steps starting from $S$) to generate the string $a^{l}b^{m}$ with $l\neq m$

Which one of the following grammars generates the language $L=\left \{ a^{i}b^{j}\mid i\neq j \right \}$?

Consider the following C code segment. for (i = 0, i < n; i++) { for (j = 0; j < n; j++) { if (i%2) { x += (4*j + 5*i); y += (7 + 4*j); } } } Which one of the following is false?

Consider the following translation scheme. $S\rightarrow ER$ $R\rightarrow *E\left \{ \text{print}(\text{‘}*\text{’}); \right \} R\mid \varepsilon$ $E\rightarrow F+E\left \{ \text{print}(\text{‘}+\text{’}); \right \}\mid F$ $F\rightarrow (S)\mid id \left \{ \text{print}(id.value); \right \}$ Here $id$ is a token that represents an integer and …

Consider these two functions and two statements S1 and S2 about them. int work1(int *a, int i, int j) { int x = a[i+2]; a[j] = x+1; return a[i+2] - 3; } int work2(int *a, int i, int j) { int t1 = i+2; int t2 = a[t1]; a[j] = t2+1; return t2 - 3; } S1: The transformation form work1 to work2 is valid, i.e., for any program state and input arguments, work2 will …

Consider the following statements about the context free grammar $$G = \left \{ S \rightarrow SS, S \rightarrow ab, S \rightarrow ba, S \rightarrow \epsilon \right \}$$ $G$ is ambiguous $G$ produces all strings with equal number of $a$’s and $b$’s $G$ can be accepted by a deterministic PDA. Which combination below expresses all the true statements …

Consider the following grammar $S \rightarrow S * E$ $S \rightarrow E$ $E \rightarrow F + E$ $E \rightarrow F$ $F \rightarrow id$ Consider the following LR(0) items corresponding to the grammar above $S \rightarrow S *.E$ $E \rightarrow F. + E$ $E \rightarrow F + .E$ Given the items above, which two of them will appear in the same set in the …

Consider the following expression grammar. The semantic rules for expression evaluation are stated next to each grammar production. …

Consider line number $3$ of the following C-program. int main() { /*Line 1 */ int I, N; /*Line 2 */ fro (I=0, I<N, I++); /*Line 3 */ } Identify the compiler’s response about this line while creating the object-module:

Statement for Linked Answer Questions 83a & 83b: Consider the following expression grammar. The semantic rules for expression evaluation are stated next to each grammar production. …

Consider the grammar: $$S \rightarrow (S) \mid a$$ Let the number of states in SLR (1), LR(1) and LALR(1) parsers for the grammar be $n_1, n_2$ and $n_3$ respectively. The following relationship holds good:

Consider the grammar: $$E \rightarrow E + n \mid E \times n \mid n$$ For a sentence $n + n \times n$, the handles in the right-sentential form of the reduction are:

The grammar $A \rightarrow AA \mid (A) \mid \epsilon$ is not suitable for predictive-parsing because the grammar is:

Consider the grammar rule $E \rightarrow E1 – E2$ for arith­metic expressions. The code generated is targeted to a CPU having a single user register. The sub­traction operation requires the first operand to be in the register. If $E1$ and $E2$ do not have any com­mon sub expression, in order to get the shortest possible code

Consider the following grammar G: $S \rightarrow bS \mid aA \mid b$ $A \rightarrow bA \mid aB$ $B \rightarrow bB \mid aS \mid a$ Let $N_a(w)$ and $N_b(w)$ denote the number of a’s and b’s in a string $\omega$ respectively. The language $L(G)$ over $\left\{a, b\right\}^+$ generated by $G$ is