unresolved symbol rdl_oom when compiling cdylib crate with no_global_oom_handling on pc-windows-msvc target #138758
Description
Full repro crate available here: https://github.com/wmmc88/minimal-repros/tree/no_global_oom_handling
I tried this code:
lib.rs
#![no_std] extern crate alloc; use core::alloc::{GlobalAlloc, Layout}; use alloc::{ alloc::{alloc, dealloc}, vec::Vec, }; #[panic_handler] fn panic(_info: &core::panic::PanicInfo) -> ! { loop {} } #[global_allocator] static ALLOCATOR: Allocator = Allocator; pub struct Allocator; unsafe impl GlobalAlloc for Allocator { unsafe fn alloc(&self, layout: Layout) -> *mut u8 { unsafe { alloc(layout) } } unsafe fn dealloc(&self, ptr: *mut u8, layout: Layout) { unsafe { dealloc(ptr, layout) }; } } pub fn foo() { let _v = Vec::<u32>::new(); }Cargo.toml
[package] name = "no_global_oom_handling-test" version = "0.1.0" edition = "2024" [lib] crate-type = ["cdylib"] [dependencies] [profile.dev] panic = "abort" # lto = "thin" # Requires at least thin lto or else error: error LNK2019: unresolved external symbol __rdl_oom referenced in function __rust_alloc_error_handler␍ [profile.release] panic = "abort" # lto = "thin" # Requires at least thin lto or else error: error LNK2019: unresolved external symbol __rdl_oom referenced in function __rust_alloc_error_handler␍.cargo/config.toml
[build] rustflags = [ "--cfg", "no_global_oom_handling", ] [unstable] build-std = ["core", "alloc"]I expected to see this happen: successful compilation
Instead, this happened:
On pc-windows-msvc target, this causes the following linker error:
error LNK2019: unresolved external symbol _RNvCs95KLPZDDxvS_7___rustc9___rdl_oom referenced in function _RNvCs95KLPZDDxvS_7___rustc26___rust_alloc_error_handler Some important observations:
- enabling
lto = "thin"causes the linker error to disappear - this linker error does not happen when the crate is not a
cdylib - both
x86_64-pc-windows-msvcandaarch64-pc-windows-msvccause this error - there is no error when compiling with
x86_64-unknown-linux-gnutarget
Meta
rustc --version --verbose:
rustc 1.87.0-nightly (1aeb99d24 2025-03-19) binary: rustc commit-hash: 1aeb99d248e1b0069110cb03c6f1dcc7b36fd7f3 commit-date: 2025-03-19 host: aarch64-pc-windows-msvc release: 1.87.0-nightly LLVM version: 20.1.0