LC

Detect Use-Before-Declaration and Undefined Variables

easy2/8

Implement Function Signature Checking (Argument Count and Types)Implement Type Inference for a Simple Expression Language

Language

Compiler

2.0s Limit 256MB

Implementation

Implement detection of variables used before declaration.

Requirements:

Track variable declarations in symbol table
Check each variable use against declarations
Report use-before-declaration errors with line numbers
Detect undefined variables
Handle scope properly (local vs global)
Test with various valid and invalid code

Why This Matters

TypeScript's 'used before its declaration' error and C's implicit-declaration warnings both come from this analysis; it caught real bugs like OpenSSL misusing functions declared nowhere. The two-pass approach you build — declare first, then resolve — is exactly how the JVM verifier and TypeScript's binder handle forward references.

Hints

0 / 3 revealed

Validation Suite

main.c

Workspace 1.0