Sprimo/skills/unsafe-checker/rules/_sections.md

Unsafe Checker - Section Definitions

Section Overview

#	Section	Prefix	Level	Count	Impact
1	General Principles	general-	CRITICAL	3	Foundational unsafe usage guidance
2	Safety Abstraction	safety-	CRITICAL	11	Building sound safe APIs
3	Raw Pointers	ptr-	HIGH	6	Pointer manipulation safety
4	Union	union-	HIGH	2	Union type safety
5	Memory Layout	mem-	HIGH	6	Data representation correctness
6	FFI	ffi-	CRITICAL	18	C interoperability safety
7	I/O Safety	io-	MEDIUM	1	Handle/resource safety

Section Details

1. General Principles (general-)

Focus: When and why to use unsafe

• P.UNS.01: Don't abuse unsafe to escape borrow checker
• P.UNS.02: Don't use unsafe blindly for performance
• G.UNS.01: Don't create aliases for "unsafe" named items

2. Safety Abstraction (safety-)

Focus: Building sound safe abstractions over unsafe code

Key invariants:

• Panic safety
• Memory initialization
• Send/Sync correctness
• API soundness

3. Raw Pointers (ptr-)

Focus: Safe pointer manipulation patterns

• Aliasing rules
• Alignment requirements
• Null/dangling prevention
• Type casting

4. Union (union-)

Focus: Safe union usage (primarily for C interop)

• Initialization rules
• Lifetime considerations
• Type punning dangers

5. Memory Layout (mem-)

Focus: Correct data representation

• #[repr(C)] usage
• Alignment and padding
• Uninitialized memory
• Cross-process memory

6. FFI (ffi-)

Focus: Safe C interoperability

Subcategories:

• String handling (CString, CStr)
• Type compatibility
• Error handling across FFI
• Thread safety
• Resource management

7. I/O Safety (io-)

Focus: Handle and resource ownership

• Raw file descriptor safety
• Handle validity guarantees