BUILD_BUG_ON(9)

💅 BUILD_BUG_ON(9) 💅

okay so bestie, welcome to the Kernel API Manual — this page is literally about making the compiler catch your vibes at build time, not runtime. no cap. ✨

🎀 NAME 🎀

BUILD_BUG_ON — break compile if a condition is true. periodt. 💥

🌸 SYNOPSIS 🌸

BUILD_BUG_ON (condition );

🦋 ARGUMENTS 🦋

• condition — the condition which the compiler should know is false. like, it has to be something the compiler can actually clock at compile time, bestie. 👀

💖 DESCRIPTION 💖

so here's the tea: if you have some code which relies on certain constants being equal, or some other compile-time-evaluated condition, you should use BUILD_BUG_ON to detect if someone changes it. it's giving “guardrail for your constants,” and honestly? iconic. 🛡️✨

like, not me trusting everyone to leave your compile-time assumptions alone — BUILD_BUG_ON is right there to catch it when somebody messes with them. 💅

🔥 SEE ALSO 🔥

also check out the kernel file ./tools/include/linux/build_bug.h, plus BUILD_BUG_ON_MSG(9), BUILD_BUG(9), and static_assert(9). iykyk 🫶

this page is from ./tools/include/linux, dated October 2026, and it's the BUILD_BUG_ON(9) manual page — mwah 💋🌸