1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 //! Implementation of panics via stack unwinding
13 //! This crate is an implementation of panics in Rust using "most native" stack
14 //! unwinding mechanism of the platform this is being compiled for. This
15 //! essentially gets categorized into three buckets currently:
17 //! 1. MSVC targets use SEH in the `seh.rs` file.
18 //! 2. The 64-bit MinGW target half-uses SEH and half-use gcc-like information
19 //! in the `seh64_gnu.rs` module.
20 //! 3. All other targets use libunwind/libgcc in the `gcc/mod.rs` module.
22 //! More documentation about each implementation can be found in the respective
26 #![unstable(feature = "panic_unwind", issue = "32837")]
27 #![doc(html_logo_url = "https://www.rust-lang.org/logos/rust-logo-128x128-blk-v2.png",
28 html_favicon_url = "https://doc.rust-lang.org/favicon.ico",
29 html_root_url = "https://doc.rust-lang.org/nightly/",
30 issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/")]
32 #![feature(allocator_api)]
34 #![feature(core_intrinsics)]
35 #![feature(lang_items)]
37 #![cfg_attr(not(stage0), feature(nll))]
38 #![feature(panic_unwind)]
40 #![feature(staged_api)]
41 #![feature(std_internals)]
42 #![feature(unwind_attributes)]
45 #![feature(panic_runtime)]
49 #[cfg(not(any(target_env = "msvc", all(windows, target_arch = "x86_64", target_env = "gnu"))))]
52 use alloc::boxed::Box;
56 use core::panic::BoxMeUp;
62 if #[cfg(target_os = "emscripten")] {
65 } else if #[cfg(target_arch = "wasm32")] {
68 } else if #[cfg(all(target_env = "msvc", target_arch = "aarch64"))] {
71 } else if #[cfg(target_env = "msvc")] {
74 } else if #[cfg(all(windows, target_arch = "x86_64", target_env = "gnu"))] {
75 #[path = "seh64_gnu.rs"]
78 // Rust runtime's startup objects depend on these symbols, so make them public.
79 #[cfg(all(target_os="windows", target_arch = "x86", target_env="gnu"))]
80 pub use imp::eh_frame_registry::*;
89 // Entry point for catching an exception, implemented using the `try` intrinsic
92 // The interaction between the `payload` function and the compiler is pretty
93 // hairy and tightly coupled, for more information see the compiler's
94 // implementation of this.
96 pub unsafe extern "C" fn __rust_maybe_catch_panic(f: fn(*mut u8),
99 vtable_ptr: *mut usize)
101 let mut payload = imp::payload();
102 if intrinsics::try(f, data, &mut payload as *mut _ as *mut _) == 0 {
105 let obj = mem::transmute::<_, raw::TraitObject>(imp::cleanup(payload));
106 *data_ptr = obj.data as usize;
107 *vtable_ptr = obj.vtable as usize;
112 // Entry point for raising an exception, just delegates to the platform-specific
116 pub unsafe extern "C" fn __rust_start_panic(payload: usize) -> u32 {
117 let payload = payload as *mut &mut dyn BoxMeUp;
118 imp::panic(Box::from_raw((*payload).box_me_up()))