gcc-poison

As a compile-time directive using #pragma GCC poison, it adds no performance penalty to the final binary, making it ideal for security-sensitive applications where efficiency is critical.

Just include the gcc-poison.h header in source files; no additional build steps or dependencies are required for GCC-based compilations, as shown in the example usage.

Allows defining macros before inclusion to permit specific unsafe functions, enabling controlled use while forcing acknowledgment, as demonstrated with strcat in the README.

Turns potential runtime vulnerabilities into compile-time errors, directly educating developers about dangerous functions like strcpy and encouraging safer alternatives.