GATE CS 2022 Q3 — Parsing (LL, LR)

Let us analyze each statement to determine its correctness:

• Option A is FALSE: When merging states with the same core to construct an $\textit{LALR}(1)$ parser from an $\textit{LR}(1)$ parser, the combination of lookaheads can introduce new reduce-reduce conflicts, even if the original $\textit{LR}(1)$ parser had none.
• Option B is FALSE: The symbol table is a central data structure accessed and updated across almost all phases of a compiler, including semantic analysis, intermediate code generation, and code optimization.
• Option C is FALSE: Data flow analysis is used for compile-time code optimizations (such as liveness analysis and constant propagation), not for run-time memory management.
• Option D is TRUE: The class of languages that can be parsed by an $\textit{LR}(1)$ parser is precisely the class of Deterministic Context-Free Languages (DCFLs). Therefore, $\textit{LR}(1)$ parsing is sufficient for any DCFL.