__DEFINE_FLEX(9)

📦 version 7.3.1, in nixpkgs unstable

🌸 __DEFINE_FLEX (9) 🌸

okay so bestie, we're in the Kernel API Manual today and this page is a short one but it's so good — it's the little helper macro that does the behind-the-scenes work for the DEFINE_FLEX() family 🫶

✨ NAME ✨

__DEFINE_FLEX — it's the helper macro for the DEFINE_FLEX() family. Its whole job? Letting the caller macro pass arbitrary trailing expressions. that's it. that's the gig 💅

🎀 SYNOPSIS 🎀

__DEFINE_FLEX (type , name , member , count , trailer... );

💖 ARGUMENTS 💖

so here's what you're feeding it, and yes every single one matters:

  • type — the structure type name, and ngl you gotta include the "struct" keyword. like, actually include it. don't skip it. 👑
  • name — the name for the variable you're defining. this is your new baby.
  • member — the name of the array member. yes, that one.
  • count — the number of elements in the array. important: it must be compile-time const. no runtime shenanigans, the compiler needs to know it up front, fr fr 💀
  • trailer — trailing expressions for attributes and/or initializers. this is the whole reason this macro exists, the main character energy of the parameter list ⭐
lowkey if count isn't a compile-time constant, put the keyboard down. that's a hard requirement, not a vibe suggestion 🙈

🦋 SEE ALSO 🦋

okay this is the long part, stay with me — these all live in the Kernel file ./include/linux/overflow.h and honestly it's giving overflow-hive, it's iconic:

like. that's a lot of besties. go read them, iykyk 🌈

and that's the whole page, bestie — short, sweet, and absolutely carried by that trailer parameter 💜

mwah 💋 this page came out of ./include/linux and it's dated October 2026 — go forth and define your flex arrays, you absolute legend 🧚✨

📦 where this page comes from