| 1 | //! Implementation of panics via stack unwinding |
| 2 | //! |
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| 3 | //! This crate is an implementation of panics in Rust using "most native" stack |
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| 4 | //! unwinding mechanism of the platform this is being compiled for. This |
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| 5 | //! essentially gets categorized into three buckets currently: |
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| 6 | //! |
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| 7 | //! 1. MSVC targets use SEH in the `seh.rs` file. |
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| 8 | //! 2. Emscripten uses C++ exceptions in the `emcc.rs` file. |
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| 9 | //! 3. All other targets use libunwind/libgcc in the `gcc.rs` file. |
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| 10 | //! |
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| 11 | //! More documentation about each implementation can be found in the respective |
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| 12 | //! module. |
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| 13 | |
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| 14 | #![no_std ] |
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| 15 | #![unstable (feature = "panic_unwind" , issue = "32837" )] |
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| 16 | #![doc (issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/" )] |
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| 17 | #![feature (cfg_emscripten_wasm_eh)] |
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| 18 | #![feature (core_intrinsics)] |
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| 19 | #![feature (lang_items)] |
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| 20 | #![feature (panic_unwind)] |
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| 21 | #![feature (staged_api)] |
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| 22 | #![feature (std_internals)] |
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| 23 | #![feature (rustc_attrs)] |
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| 24 | #![panic_runtime ] |
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| 25 | #![feature (panic_runtime)] |
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| 26 | // `real_imp` is unused with Miri, so silence warnings. |
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| 27 | #![cfg_attr (miri, allow(dead_code))] |
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| 28 | #![allow (internal_features)] |
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| 29 | #![warn (unreachable_pub)] |
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| 30 | #![deny (unsafe_op_in_unsafe_fn)] |
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| 31 | |
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| 32 | use alloc::boxed::Box; |
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| 33 | use core::any::Any; |
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| 34 | use core::panic::PanicPayload; |
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| 35 | |
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| 36 | cfg_if::cfg_if! { |
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| 37 | if #[cfg(all(target_os = "emscripten" , not(emscripten_wasm_eh)))] { |
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| 38 | #[path = "emcc.rs" ] |
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| 39 | mod imp; |
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| 40 | } else if #[cfg(target_os = "hermit" )] { |
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| 41 | #[path = "hermit.rs" ] |
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| 42 | mod imp; |
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| 43 | } else if #[cfg(target_os = "l4re" )] { |
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| 44 | // L4Re is unix family but does not yet support unwinding. |
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| 45 | #[path = "dummy.rs" ] |
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| 46 | mod imp; |
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| 47 | } else if #[cfg(any( |
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| 48 | all(target_family = "windows" , target_env = "gnu" ), |
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| 49 | target_os = "psp" , |
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| 50 | target_os = "xous" , |
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| 51 | target_os = "solid_asp3" , |
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| 52 | all(target_family = "unix" , not(any(target_os = "espidf" , target_os = "nuttx" ))), |
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| 53 | all(target_vendor = "fortanix" , target_env = "sgx" ), |
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| 54 | target_family = "wasm" , |
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| 55 | ))] { |
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| 56 | #[path = "gcc.rs" ] |
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| 57 | mod imp; |
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| 58 | } else if #[cfg(miri)] { |
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| 59 | // Use the Miri runtime on Windows as miri doesn't support funclet based unwinding, |
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| 60 | // only landingpad based unwinding. Also use the Miri runtime on unsupported platforms. |
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| 61 | #[path = "miri.rs" ] |
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| 62 | mod imp; |
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| 63 | } else if #[cfg(all(target_env = "msvc" , not(target_arch = "arm" )))] { |
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| 64 | // LLVM does not support unwinding on 32 bit ARM msvc (thumbv7a-pc-windows-msvc) |
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| 65 | #[path = "seh.rs" ] |
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| 66 | mod imp; |
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| 67 | } else { |
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| 68 | // Targets that don't support unwinding. |
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| 69 | // - os=none ("bare metal" targets) |
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| 70 | // - os=uefi |
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| 71 | // - os=espidf |
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| 72 | // - nvptx64-nvidia-cuda |
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| 73 | // - arch=avr |
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| 74 | #[path = "dummy.rs" ] |
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| 75 | mod imp; |
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| 76 | } |
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| 77 | } |
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| 78 | |
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| 79 | unsafe extern "C" { |
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| 80 | /// Handler in std called when a panic object is dropped outside of |
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| 81 | /// `catch_unwind`. |
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| 82 | #[rustc_std_internal_symbol ] |
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| 83 | unsafefn __rust_drop_panic() -> !; |
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| 84 | |
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| 85 | /// Handler in std called when a foreign exception is caught. |
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| 86 | #[rustc_std_internal_symbol ] |
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| 87 | unsafefn __rust_foreign_exception() -> !; |
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| 88 | } |
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| 89 | |
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| 90 | #[rustc_std_internal_symbol ] |
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| 91 | #[allow (improper_ctypes_definitions)] |
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| 92 | pub unsafe extern "C" fn __rust_panic_cleanup(payload: *mut u8) -> *mut (dyn Any + Send + 'static) { |
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| 93 | unsafe { Box::into_raw(imp::cleanup(ptr:payload)) } |
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| 94 | } |
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| 95 | |
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| 96 | // Entry point for raising an exception, just delegates to the platform-specific |
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| 97 | // implementation. |
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| 98 | #[rustc_std_internal_symbol ] |
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| 99 | pub unsafe fn __rust_start_panic(payload: &mut dyn PanicPayload) -> u32 { |
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| 100 | unsafe { |
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| 101 | let payload: Box = Box::from_raw(payload.take_box()); |
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| 102 | |
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| 103 | imp::panic(data:payload) |
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| 104 | } |
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| 105 | } |
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| 106 | |
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