diff --git a/library/stdarch/crates/core_arch/src/wasm32/mod.rs b/library/stdarch/crates/core_arch/src/wasm32/mod.rs index 2c4361f1639f..60049c73295c 100644 --- a/library/stdarch/crates/core_arch/src/wasm32/mod.rs +++ b/library/stdarch/crates/core_arch/src/wasm32/mod.rs @@ -191,6 +191,16 @@ unsafe extern "C-unwind" { // #[cfg_attr(test, assert_instr(throw, TAG = 0, ptr = core::ptr::null_mut()))] #[inline] #[unstable(feature = "wasm_exception_handling_intrinsics", issue = "122465")] +// FIXME: Since this instruction unwinds, `core` built with `-C panic=unwind` +// cannot be linked with `-C panic=abort` programs. But that's not +// entirely supported anyway, because runtimes without EH support won't +// be able to handle `try` blocks in `-C panic=unwind` crates either. +// We ship `-C panic=abort` `core`, so this doesn't affect users +// directly. Resolving this will likely require patching out both `try` +// and `throw` instructions, at which point we can look into whitelisting +// this function in the compiler to allow linking. +// See https://github.com/rust-lang/rust/issues/118168. +#[allow(ffi_unwind_calls)] pub unsafe fn throw(ptr: *mut u8) -> ! { static_assert!(TAG == 0); // LLVM only supports tag 0 == C++ right now. wasm_throw(TAG, ptr)