SDL_stack_alloc(3)

💖 SDL_stack_alloc(3) 💖

okay bestie, welcome to the SDL3 FUNCTIONS corner of the manual, where today's main character is SDL_stack_alloc. yes it's a macro, yes it's lowkey chaotic, and yes we're gonna get into it. no cap.

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✨ NAME ✨

SDL_stack_alloc — Allocate memory on the stack (maybe).

like... maybe. she's mysterious. she's giving "we'll see".

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🎀 SYNOPSIS 🎀

#include <SDL3/SDL_stdinc.h>

#define SDL_stack_alloc(type, count)    (type*)alloca(sizeof(type)*(count))

that's it. that's the whole thing. one (1) macro. slay.

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🌸 DESCRIPTION 🌸

okay so here's the tea, and the tea is genuinely important, so put your phone down for a sec:

If SDL knows how to access alloca() on the current platform, it will use it to stack-allocate memory here. If it doesn't, it will use SDL_malloc() to heap-allocate memory.

THE WAY THAT THIS MIGHT NOT BE STACK MEMORY AT ALL?? it depends on the platform, and you do not get to pick. it's giving surprise me. so, because of that:

• Since this might not be stack memory at all, it's important that you check the returned pointer for NULL, and that you call SDL_stack_free on the memory when done with it. (yes, even if it came from SDL_malloc under the hood. especially then. bestie just call it.)
• Since this might be stack memory, it's important that you don't allocate large amounts of it, or allocate in a loop without returning from the function, so the stack doesn't overflow.

🚨 real talk: this is the "danger girlboss" part of the page. no NULL check = crash energy. no SDL_stack_free = leak energy. huge stack allocations or loop-allocating without ever returning = stack overflow energy. all three are, respectfully, not it. 💀

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🦋 MACRO PARAMETERS 🦋

• type — the datatype of the memory to allocate. 🧚
• count — the number of type objects to allocate. like, how many of the thing. the quantity. the amount.

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🌈 RETURN VALUE 🌈

Returns newly-allocated memory, or NULL on failure. so like. check it. pls. 🥺

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💜 THREAD SAFETY 💜

It is safe to call this macro from any thread. 🌟 go off, multitasker.

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👑 AVAILABILITY 👑

This macro is available since SDL 3.2.0. vintage-ish, but in a fresh way.

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🔥 SEE ALSO 🔥

• SDL_stack_free(3) — the other half of the situationship. you literally cannot skip this one. iykyk. 🫶

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and that's the whole page, periodt. every flag, every warning, every vibe, all accounted for. ✨

mwah 💅 this was brought to you by Simple Directmedia Layer, SDL 3.4.18 — the SDL3 FUNCTIONS collection, no date stamp on this one because the footer didn't give us one, but the version is right there and it's cute. stay safe, check your pointers, and free your memory bestie 🎀🦋