memory-safety-patterns

SKILL.md

Memory Safety Patterns

Cross-language patterns for memory-safe programming including RAII, ownership, smart pointers, and resource management.

When to Use This Skill

Writing memory-safe systems code

Managing resources (files, sockets, memory)

Preventing use-after-free and leaks

Implementing RAII patterns

Choosing between languages for safety

Debugging memory issues

Core Concepts

1. Memory Bug Categories

Bug Type
Description
Prevention

Use-after-free
Access freed memory
Ownership, RAII

Double-free
Free same memory twice
Smart pointers

Memory leak
Never free memory
RAII, GC

Buffer overflow
Write past buffer end
Bounds checking

Dangling pointer
Pointer to freed memory
Lifetime tracking

Data race
Concurrent unsynchronized access
Ownership, Sync

2. Safety Spectrum

Manual (C) → Smart Pointers (C++) → Ownership (Rust) → GC (Go, Java)
Less safe                                              More safe
More control                                           Less control

Detailed patterns and worked examples

Detailed pattern documentation lives in references/details.md. Read that file when the navigation tier above is insufficient.

Best Practices

Do's

Prefer RAII - Tie resource lifetime to scope

Use smart pointers - Avoid raw pointers in C++

Understand ownership - Know who owns what

Check bounds - Use safe access methods

Use tools - AddressSanitizer, Valgrind, Miri

Don'ts

Don't use raw pointers - Unless interfacing with C

Don't return local references - Dangling pointer

Don't ignore compiler warnings - They catch bugs

Don't use unsafe carelessly - In Rust, minimize it

Don't assume thread safety - Be explicit

Debugging Tools

# AddressSanitizer (Clang/GCC)
clang++ -fsanitize=address -g source.cpp

# Valgrind
valgrind --leak-check=full ./program

# Rust Miri (undefined behavior detector)
cargo +nightly miri run

# ThreadSanitizer
clang++ -fsanitize=thread -g source.cpp

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