compiletime_assert(9)

💅 compiletime_assert(9) — the Kernel API Manual page, bestie

okay so real talk, we're in the Kernel API Manual today and the star of the show is compiletime_assert — yes that's the manual name in the header, and honestly? iconic. let's get into it 🎀

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✨ NAME ✨

compiletime_assert — it breaks your build and emits msg if condition is false. that's it. that's the whole gig. no cap 💀

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🌸 SYNOPSIS 🌸

compiletime_assert (condition , msg );

literally just those two things, in that order. copy it exactly, she's sensitive 🙈

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🦋 ARGUMENTS 🦋

• condition — a compile-time constant condition to check. like, it has to be knowable at compile time, not vibes-at-runtime, iykyk ✨
• msg — the message to emit if condition is false. your moment to say something meaningful 💌

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💖 DESCRIPTION 💖

so in the grand tradition of POSIX assert, this macro will break the build if the supplied condition is false — and when it does, it emits the supplied error message, but only if the compiler has support to do so 🫶

which is honestly giving main character energy: it doesn't wait till runtime to have a problem with you, it stops the whole build at the door. periodt 👑

ngl this is a feature, not a bug — it's the compiler refusing to let you ship nonsense. respect 💅

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🔥 SEE ALSO 🔥

• Kernel file ./tools/include/linux/compiler.h 👀

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that's the whole page, bestie, go forth and assert at compile time 🌈💜

sign-off time: this little gem comes from ./tools/include/linux, dated October 2026, and it's filed under compiletime_assert(9) — mwah, slay, bye 🎀🦋✨