Code Execution Reasoning

Overview & Purpose

Code Execution Reasoning performs a rigorous mental dry-run of code line by line. It tracks environment variables, heap/stack states, pointer mutations, and loop counters to detect off-by-one errors and race conditions.

When to Use

• Code Review: Auditing algorithmic code without running it directly.
• Static Bug Hunting: Locating off-by-one errors, null pointers, or memory leaks.

Execution Workflow

1. Initialize State: List input variables and their initial memory state.
2. Line-by-Line Execution Trace:
   • For each executed statement, record modified variables and current control flow line.
3. Loop & Condition Verification: Verify loop invariants, boundary indices ($i=0, i=N-1$), and terminating conditions.
4. Return State Verification: Confirm final returned payload matches requirements.

Expected Output Contract

### Code Dry-Run Trace
| Line | Code Statement | Variable States | Control Flow |
| :--- | :--- | :--- | :--- |
| L1 | `x = 5` | `{x: 5}` | Next L2 |
| L2 | `x += 1` | `{x: 6}` | Next L3 |

- **Final Returned Value**: [Result]
- **Detected Issues**: [Boundary/State errors]

Scripts

• scripts/code_execution_reasoning.py - Deterministic evaluation, state validation, and CLI tool for code-execution-reasoning.