| //! Implementation of Rust panics via process aborts |
| //! |
| //! When compared to the implementation via unwinding, this crate is *much* |
| //! simpler! That being said, it's not quite as versatile, but here goes! |
| |
| #![no_std] |
| #![unstable(feature = "panic_abort", issue = "32837")] |
| #![panic_runtime] |
| #![allow(unused_features)] |
| |
| #![feature(core_intrinsics)] |
| #![feature(nll)] |
| #![feature(panic_runtime)] |
| #![feature(staged_api)] |
| #![feature(rustc_attrs)] |
| |
| use core::any::Any; |
| |
| #[rustc_std_internal_symbol] |
| #[allow(improper_ctypes_definitions)] |
| pub unsafe extern "C" fn __rust_panic_cleanup(_: *mut u8) -> *mut (dyn Any + Send + 'static) { |
| unreachable!() |
| } |
| |
| // "Leak" the payload and shim to the relevant abort on the platform in |
| // question. |
| // |
| // For Unix we just use `abort` from libc as it'll trigger debuggers, core |
| // dumps, etc, as one might expect. On Windows, however, the best option we have |
| // is the `__fastfail` intrinsics, but that's unfortunately not defined in LLVM, |
| // and the `RaiseFailFastException` function isn't available until Windows 7 |
| // which would break compat with XP. For now just use `intrinsics::abort` which |
| // will kill us with an illegal instruction, which will do a good enough job for |
| // now hopefully. |
| #[rustc_std_internal_symbol] |
| pub unsafe extern "C" fn __rust_start_panic(_payload: usize) -> u32 { |
| sgx_abort(); |
| |
| #[link(name = "sgx_trts")] |
| extern "C" { |
| pub fn abort() -> !; |
| } |
| |
| fn sgx_abort() -> ! { |
| unsafe { abort() } |
| } |
| } |
| |
| // This... is a bit of an oddity. The tl;dr; is that this is required to link |
| // correctly, the longer explanation is below. |
| // |
| // Right now the binaries of libcore/libstd that we ship are all compiled with |
| // `-C panic=unwind`. This is done to ensure that the binaries are maximally |
| // compatible with as many situations as possible. The compiler, however, |
| // requires a "personality function" for all functions compiled with `-C |
| // panic=unwind`. This personality function is hardcoded to the symbol |
| // `rust_eh_personality` and is defined by the `eh_personality` lang item. |
| // |
| // So... why not just define that lang item here? Good question! The way that |
| // panic runtimes are linked in is actually a little subtle in that they're |
| // "sort of" in the compiler's crate store, but only actually linked if another |
| // isn't actually linked. This ends up meaning that both this crate and the |
| // panic_unwind crate can appear in the compiler's crate store, and if both |
| // define the `eh_personality` lang item then that'll hit an error. |
| // |
| // To handle this the compiler only requires the `eh_personality` is defined if |
| // the panic runtime being linked in is the unwinding runtime, and otherwise |
| // it's not required to be defined (rightfully so). In this case, however, this |
| // library just defines this symbol so there's at least some personality |
| // somewhere. |
| // |
| // Essentially this symbol is just defined to get wired up to libcore/libstd |
| // binaries, but it should never be called as we don't link in an unwinding |
| // runtime at all. |
| pub mod personalities { |
| #[rustc_std_internal_symbol] |
| pub extern "C" fn rust_eh_personality() {} |
| } |