Online Test 1 - Compiler | Computer Science(CS)

To remove left recursion from E → Ea|Eb|a|b: The left-recursive productions are E → Ea and E → Eb. The new non-terminal E' handles the recursion. Original productions become E → aE'|bE'. The E' productions are E' → aE'|bE'|ε. This eliminates immediate left recursion.

Bottom-up parsers construct derivations by reducing strings to the start symbol. They generate rightmost derivations in reverse order because they work from the leaves (terminals) upward toward the root (start symbol), effectively undoing a rightmost derivation step by step.

When a computer is first turned on or restarted, a special absolute loader called a bootstrap loader is executed. This loader loads the operating system into memory. The term 'bootstrap' comes from 'pulling oneself up by bootstraps' - the loader gets the system running from nothing.

The grammar is not LL(1) because the grammar is ambiguous and left recursive. The regular expression for the language accepted by grammar is 0⁺.

Start A to accept $\epsilon$
$r_1 = (aan + ba)$
$\epsilon$ to C & D
$r_2 = (bab)^$
$r = r_1r_2 = (aab + ba)(bab)^$

The first pass of a two-pass assembler performs three key tasks: allocating space for literals/pool table, computing the total program length (for address calculation), and building the symbol table with symbol addresses. All options are correct.

The front end performs lexical and syntax analysis (validating statements), semantic analysis (determining content/meaning), and constructs intermediate representation for subsequent phases. All three functions are part of front-end processing.

Static Linking and Static Libraries is the result of the linker making copy of all used library functions to the executable file.
Static Linking creates larger binary files, and need more space on disk and main memory.
Examples of static libraries (libraries which are statically linked) are, .a files in Linux and .lib files in Windows.
Dynamic linking and Dynamic Libraries Dynamic Linking doesn’t require the code to be copied,
it is done by just placing name of the library in the binary file.
The actual linking happens when the program is run, when both the binary file and the library are in memory.
Examples of Dynamic libraries (libraries which are linked at run-time) are, .so in Linux and .dll in Windows.
In Dynamic Linking,the path for searching dynamic libraries is not known till runtime

Top-down parsing is also called recursive descent parsing because it recursively expands non-terminals starting from the root. Shift-reduce and operator precedence are bottom-up techniques.

Top-down parsers (including predictive parsers) use leftmost derivation - they expand the leftmost non-terminal at each step. Rightmost derivation is used by bottom-up parsers.

 The output of lexical analyzer is a stream of tokens.

Handle pruning is used in LR parsing to efficiently find the canonical reduction sequence - the unique reverse of rightmost derivation. It helps identify handles without exploring all possibilities.

Canonical LR (CLR) is the most powerful parsing method - it handles all grammars that LR parsing can handle, while SLR, LALR, and LL are progressively more restrictive subsets.

Type 0 grammars are phrase structure grammars with no restrictions - they generate all recursively enumerable languages. Both statements (1) and (2) correctly describe Type 0.