Compiler design – permanent vs. transient tables In the general model of a compiler, which of the following is a permanent database (i.e., not rebuilt for each compilation)?

Introduction / Context:Compilers maintain a variety of tables while translating source code. Some are permanent parts of the compiler's definition of a language, whereas others are created afresh for each compilation unit.

Given Data / Assumptions:

• Literal and identifier tables are populated from the current program.
• Source code is input, not a compiler database.
• The terminal table lists the language’s tokens (keywords, operators, punctuation).

Concept / Approach:

The terminal table is a permanent specification of the language's alphabet (token types) known to the compiler. In contrast, the identifier table (symbol table entries for user-defined names) and literal table (constants found in the program) are transient and rebuilt for each compilation.

Step-by-Step Solution:

Verification / Alternative check:

Compiler textbooks describe lexical analysis using a DFA over the terminal set; the definition of terminals is part of the language specification and persists across compilations.

Why Other Options Are Wrong:

Literal/identifier tables are populated per source file or per build; source code is not a compiler database. Therefore, only the terminal table fits the “permanent” description.

Common Pitfalls:

Confusing the symbol table (which can be persisted by IDEs) with the permanent language tables inside the compiler; overlooking reserved word tables as part of terminals.

Final Answer:

Terminal Table.