Add Rust Code Analysis: Infinite Loop Detection

[Allen-Cherian]

This PR introduces Rust code analysis during contract generation and fetching. If the Rust code contains an infinite loop, contract generation will be blocked. The same analysis is also performed when fetching the contract.

Core Logic

• Analyzes specific loop types (while, for, loop) and recursive function calls for conditions that may lead to infinite loops.

Recursive Traversal

• Processes nodes recursively to check the entire syntax tree.

Loop Identification and Checks

While Loops

• Flags loops with conditions always true or unmodified variables.

Rust's loop {} Syntax

• Flags unless a break statement is present to exit the loop.

For Loops

• Detects non-terminating iterators (e.g., std::iter::repeat) and checks for break statements.

Recursive Function Calls

• Flags direct recursion as potential infinite recursion.

Known Limitations

Complex While Conditions

• Dynamic conditions (dependent on external states or computations) may not be fully analyzed.

External Break Conditions

• Break conditions dependent on external threads or asynchronous contexts may be missed.

Custom Iterators

• Does not analyze termination for user-defined iterators.

Indirect Recursion

• Only detects direct recursion, not circular dependencies between functions.

Unreachable Code

• Flags loops in unreachable code (e.g., within if false) unnecessarily.

[arnabghose997]

LGTM