Huge memory usage with `serde` proc macros

[vdrn]

Problem description

Rust analyzer keeps using more and more memory. It seems to be connected with serdes proc_macros and many fields in the struct.

After the file is opened, during the first minute, memory keeps slowly rising to about 3gb.
At around 2 min mark, it suddenly spikes to 4.3gb.
Around 3-4 mins, it spikes to 7gb.
Around 6-7 mins, it spikes to 12gb.

During all this time, CPU usage is 100% (not all cores, just one).

Started happening a month or 2 ago (I do weekly rust-analyzer updates).

Steps to reproduce

• Fresh install of VSCode on Ubuntu 20.04,
• clone this repo
• open main.rs and do nothing, just watch CPU/RAM

rust-analyzer version: 0.3.1774-standalone

rustc version: rustc 1.74.1 (a28077b28 2023-12-04)

relevant settings: fresh vs-code install, no custom settings, no ENV variables set

[lnicola]

Not related to proc macros per se, it's the uninitialized assignment analysis that never seems to finish.