1 //! Implementation of Rust panics via process aborts
3 //! When compared to the implementation via unwinding, this crate is *much*
4 //! simpler! That being said, it's not quite as versatile, but here goes!
7 #![unstable(feature = "panic_abort", issue = "32837")]
9 html_root_url = "https://doc.rust-lang.org/nightly/",
10 issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/"
13 #![allow(unused_features)]
14 #![feature(core_intrinsics)]
17 #![feature(panic_runtime)]
18 #![feature(staged_api)]
19 #![feature(rustc_attrs)]
22 #[rustc_std_internal_symbol]
23 pub unsafe extern "C" fn __rust_cleanup(_: *mut u8) -> core::raw::TraitObject {
27 // "Leak" the payload and shim to the relevant abort on the platform in
30 // For Unix we just use `abort` from libc as it'll trigger debuggers, core
31 // dumps, etc, as one might expect. On Windows, however, the best option we have
32 // is the `__fastfail` intrinsics, but that's unfortunately not defined in LLVM,
33 // and the `RaiseFailFastException` function isn't available until Windows 7
34 // which would break compat with XP. For now just use `intrinsics::abort` which
35 // will kill us with an illegal instruction, which will do a good enough job for
37 #[rustc_std_internal_symbol]
38 pub unsafe extern "C" fn __rust_start_panic(_payload: usize) -> u32 {
41 #[cfg(any(unix, target_os = "cloudabi"))]
42 unsafe fn abort() -> ! {
46 #[cfg(any(windows, all(target_arch = "wasm32", not(target_os = "emscripten"))))]
47 unsafe fn abort() -> ! {
48 core::intrinsics::abort();
51 #[cfg(any(target_os = "hermit", all(target_vendor = "fortanix", target_env = "sgx")))]
52 unsafe fn abort() -> ! {
53 // call std::sys::abort_internal
55 pub fn __rust_abort() -> !;
61 // This... is a bit of an oddity. The tl;dr; is that this is required to link
62 // correctly, the longer explanation is below.
64 // Right now the binaries of libcore/libstd that we ship are all compiled with
65 // `-C panic=unwind`. This is done to ensure that the binaries are maximally
66 // compatible with as many situations as possible. The compiler, however,
67 // requires a "personality function" for all functions compiled with `-C
68 // panic=unwind`. This personality function is hardcoded to the symbol
69 // `rust_eh_personality` and is defined by the `eh_personality` lang item.
71 // So... why not just define that lang item here? Good question! The way that
72 // panic runtimes are linked in is actually a little subtle in that they're
73 // "sort of" in the compiler's crate store, but only actually linked if another
74 // isn't actually linked. This ends up meaning that both this crate and the
75 // panic_unwind crate can appear in the compiler's crate store, and if both
76 // define the `eh_personality` lang item then that'll hit an error.
78 // To handle this the compiler only requires the `eh_personality` is defined if
79 // the panic runtime being linked in is the unwinding runtime, and otherwise
80 // it's not required to be defined (rightfully so). In this case, however, this
81 // library just defines this symbol so there's at least some personality
84 // Essentially this symbol is just defined to get wired up to libcore/libstd
85 // binaries, but it should never be called as we don't link in an unwinding
87 pub mod personalities {
90 all(target_arch = "wasm32", not(target_os = "emscripten"),),
91 all(target_os = "windows", target_env = "gnu", target_arch = "x86_64",),
93 pub extern "C" fn rust_eh_personality() {}
95 // On x86_64-pc-windows-gnu we use our own personality function that needs
96 // to return `ExceptionContinueSearch` as we're passing on all our frames.
98 #[cfg(all(target_os = "windows", target_env = "gnu", target_arch = "x86_64"))]
99 pub extern "C" fn rust_eh_personality(
105 1 // `ExceptionContinueSearch`
108 // Similar to above, this corresponds to the `eh_unwind_resume` lang item
109 // that's only used on Windows currently.
111 // Note that we don't execute landing pads, so this is never called, so it's
114 #[cfg(all(target_os = "windows", target_env = "gnu"))]
115 pub extern "C" fn rust_eh_unwind_resume() {}
117 // These two are called by our startup objects on i686-pc-windows-gnu, but
118 // they don't need to do anything so the bodies are nops.
120 #[cfg(all(target_os = "windows", target_env = "gnu", target_arch = "x86"))]
121 pub extern "C" fn rust_eh_register_frames() {}
123 #[cfg(all(target_os = "windows", target_env = "gnu", target_arch = "x86"))]
124 pub extern "C" fn rust_eh_unregister_frames() {}