#alloc #vita #black-box #newlib #system #dealloc #play-station

yanked vita-system-alloc-wrapper

A proxy for std::alloc::System which wraps dealloc in std::hint::black_box

0.1.0 May 21, 2023

#34 in #black-box

MIT license

4KB

vita-system-alloc-wrapper

The standard library in Rust has a std::alloc::System allocator, which internally calls libc::malloc and libc::free for allocations. For PlayStation Vita, these functions are provided by newlib, which uses a preallocated pool for heap memory.

This should work and works for the majority of cases. Unfortunately though, with the -O3 optimization level compiled specifically for the PlayStation Vita target, it is possible for LLVM to incorrectly optimize libc::free calls, leading to crashes when heap-allocated structs are dropped in Rust.

This crate does a hack to fix that by providing a custom allocator, which proxies, all calls to std::alloc::System allocator, and wrapping dealloc call in std::hint::black_box, which prevents LLVM from doing any optimizations on libc::free call.

If you are experiencing crashes in Drop calls in seemingly correct code on PlayStation Vita, try adding this crate as a dependency, and registering provided allocator as a GlobalAllocator:

#[cfg(target_os = "vita")]
#[global_allocator]
static GLOBAL: vita_system_alloc_wrapper::SystemAllocWrapper = vita_system_alloc_wrapper::SystemAllocWrapper;

Dependencies

~43KB