alloca(3avr)

✨ NAME ✨

alloca — bestie, this one lives in <alloca.h> and it's literally the "grab me some space on the stack" function 💅

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🎀 SYNOPSIS 🎀

Functions

void * alloca (size_t __size)

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🌸 DESCRIPTION 🌸

Detailed Description

okay so this is the whole vibe, no cap.

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🦋 FUNCTION DOCUMENTATION 🦋

void * alloca (size_t __size) [extern]

Allocate __size bytes of space in the stack frame of the caller. That's it, that's the whole job. 🫶

And here's the iconic part: this temporary space gets automatically freed the moment the function that called alloca() returns to its caller. No free(), no cleanup era, no nothing. It's giving self-cleaning. ✨

AVR-LibC defines alloca() as a macro, which gets translated into the inlined __builtin_alloca() function. Not me explaining that twice, that's literally what it says. 🎀

⚠️ And because the code is inlined, two things are just, like, not possible: - you can't take the address of this function 😭 - you can't change its behaviour by linking against a different library 🙈

🌟 Returns

alloca() returns a pointer to the beginning of the allocated space. Slay. 💅

BUT. Bestie. Listen. If the allocation causes stack overflow, program behaviour is undefined. Not "kinda weird", not "a little broken" — undefined, periodt. 💀

🚨 Warning

Avoid use alloca() inside the list of arguments of a function call. Just... don't do it. Put it on its own line first. Trust. 🦋

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👑 Author

Generated automatically by Doxygen for AVR-LibC from the source code. (So not a human author with a fun bio, just Doxygen doing its thing, we love a bot that's consistent 😌)

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okay and that's the whole page!! this manual page is from AVR-LibC, Version 2.2.1, and yeah that's the version, that's the date-adjacent info we got, so jot it down bestie 💖 byeeee 👋✨