Performance Rules

These rules focus specifically on C# patterns inside Unity that destroy CPU frametimes.

Code Hygienist detects these runtime allocations and intercepts them.

Included Rules

Core Logic

• GetComponentInUpdateRule: Detects and caches GetComponent<T>() out of Update.
• CameraMainInUpdateRule: Scans for .main string evaluation properties in loops.
• HeavyFindsRule: Strips FindObjectOfType, GameObject.Find, and tag searches out of looping behaviors.

Memory & Allocations

• BoxingDetectionRule: Detects boxing allocations (e.g., passing value types to object parameters).
• StringAllocationInUpdateRule: Flags string concatenations and allocations inside per-frame loops.
• LinqInUpdateRule: Detects LINQ usage (.Where, .First, etc.) inside Update, which causes hidden per-frame allocations.

Unity Specifics

• CompareTagRule: Replaces .tag == "string" with the allocation-free .CompareTag("string").
• EmptyUnityEventsRule: Detects empty Unity Events (like Update, Start) that still incur a native-to-managed call overhead.
• PhysicsNonAllocRule: Encourages the use of NonAlloc physics variants (e.g., OverlapSphereNonAlloc) to avoid array allocations.

Look at the child pages for deep dives into how the Auto-Fix engine translates these rules safely.

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Table of contents

• Use CompareTag
• Boxing Detection
• Empty Unity Events
• LINQ in Update
• Physics NonAlloc
• String Allocation in Update