1 //! Implementation of panics via stack unwinding
3 //! This crate is an implementation of panics in Rust using "most native" stack
4 //! unwinding mechanism of the platform this is being compiled for. This
5 //! essentially gets categorized into three buckets currently:
7 //! 1. MSVC targets use SEH in the `seh.rs` file.
8 //! 2. The 64-bit MinGW target half-uses SEH and half-use gcc-like information
9 //! in the `seh64_gnu.rs` module.
10 //! 3. All other targets use libunwind/libgcc in the `gcc/mod.rs` module.
12 //! More documentation about each implementation can be found in the respective
16 #![unstable(feature = "panic_unwind", issue = "32837")]
17 #![doc(html_root_url = "https://doc.rust-lang.org/nightly/",
18 issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/")]
20 #![feature(core_intrinsics)]
21 #![feature(lang_items)]
24 #![feature(panic_unwind)]
26 #![feature(staged_api)]
27 #![feature(std_internals)]
28 #![feature(unwind_attributes)]
31 #![feature(panic_runtime)]
33 use alloc::boxed::Box;
37 use core::panic::BoxMeUp;
40 if #[cfg(target_os = "emscripten")] {
43 } else if #[cfg(target_arch = "wasm32")] {
46 } else if #[cfg(all(target_env = "msvc", target_arch = "aarch64"))] {
49 } else if #[cfg(target_env = "msvc")] {
52 } else if #[cfg(all(windows, target_arch = "x86_64", target_env = "gnu"))] {
53 #[path = "seh64_gnu.rs"]
56 // Rust runtime's startup objects depend on these symbols, so make them public.
57 #[cfg(all(target_os="windows", target_arch = "x86", target_env="gnu"))]
58 pub use imp::eh_frame_registry::*;
67 // Entry point for catching an exception, implemented using the `try` intrinsic
70 // The interaction between the `payload` function and the compiler is pretty
71 // hairy and tightly coupled, for more information see the compiler's
72 // implementation of this.
74 pub unsafe extern "C" fn __rust_maybe_catch_panic(f: fn(*mut u8),
77 vtable_ptr: *mut usize)
79 let mut payload = imp::payload();
80 if intrinsics::r#try(f, data, &mut payload as *mut _ as *mut _) == 0 {
83 let obj = mem::transmute::<_, raw::TraitObject>(imp::cleanup(payload));
84 *data_ptr = obj.data as usize;
85 *vtable_ptr = obj.vtable as usize;
90 // Entry point for raising an exception, just delegates to the platform-specific
94 pub unsafe extern "C" fn __rust_start_panic(payload: usize) -> u32 {
95 let payload = payload as *mut &mut dyn BoxMeUp;
96 imp::panic(Box::from_raw((*payload).box_me_up()))