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29 | 29 | use crate::fmt; |
30 | 30 | use crate::panic::{Location, PanicInfo}; |
31 | 31 |
|
| 32 | +// First we define the two main entry points that all panics go through. |
| 33 | +// In the end both are just convenience wrappers around `panic_impl`. |
| 34 | + |
| 35 | +/// The entry point for panicking with a formatted message. |
| 36 | +/// |
| 37 | +/// This is designed to reduce the amount of code required at the call |
| 38 | +/// site as much as possible (so that `panic!()` has as low an impact |
| 39 | +/// on (e.g.) the inlining of other functions as possible), by moving |
| 40 | +/// the actual formatting into this shared place. |
| 41 | +#[cold] |
| 42 | +// If panic_immediate_abort, inline the abort call, |
| 43 | +// otherwise avoid inlining because of it is cold path. |
| 44 | +#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))] |
| 45 | +#[cfg_attr(feature = "panic_immediate_abort", inline)] |
| 46 | +#[track_caller] |
| 47 | +#[lang = "panic_fmt"] // needed for const-evaluated panics |
| 48 | +#[rustc_do_not_const_check] // hooked by const-eval |
| 49 | +#[rustc_const_unstable(feature = "core_panic", issue = "none")] |
| 50 | +pub const fn panic_fmt(fmt: fmt::Arguments<'_>) -> ! { |
| 51 | + if cfg!(feature = "panic_immediate_abort") { |
| 52 | + super::intrinsics::abort() |
| 53 | + } |
| 54 | + |
| 55 | + // NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call |
| 56 | + // that gets resolved to the `#[panic_handler]` function. |
| 57 | + extern "Rust" { |
| 58 | + #[lang = "panic_impl"] |
| 59 | + fn panic_impl(pi: &PanicInfo<'_>) -> !; |
| 60 | + } |
| 61 | + |
| 62 | + let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller(), true); |
| 63 | + |
| 64 | + // SAFETY: `panic_impl` is defined in safe Rust code and thus is safe to call. |
| 65 | + unsafe { panic_impl(&pi) } |
| 66 | +} |
| 67 | + |
| 68 | +/// Like panic_fmt, but without unwinding and track_caller to reduce the impact on codesize. |
| 69 | +/// Also just works on `str`, as a `fmt::Arguments` needs more space to be passed. |
| 70 | +#[cold] |
| 71 | +#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))] |
| 72 | +#[cfg_attr(feature = "panic_immediate_abort", inline)] |
| 73 | +#[cfg_attr(not(bootstrap), rustc_nounwind)] |
| 74 | +#[cfg_attr(bootstrap, rustc_allocator_nounwind)] |
| 75 | +pub fn panic_str_nounwind(msg: &'static str) -> ! { |
| 76 | + if cfg!(feature = "panic_immediate_abort") { |
| 77 | + super::intrinsics::abort() |
| 78 | + } |
| 79 | + |
| 80 | + // NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call |
| 81 | + // that gets resolved to the `#[panic_handler]` function. |
| 82 | + extern "Rust" { |
| 83 | + #[lang = "panic_impl"] |
| 84 | + fn panic_impl(pi: &PanicInfo<'_>) -> !; |
| 85 | + } |
| 86 | + |
| 87 | + // PanicInfo with the `can_unwind` flag set to false forces an abort. |
| 88 | + let pieces = [msg]; |
| 89 | + let fmt = fmt::Arguments::new_v1(&pieces, &[]); |
| 90 | + let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller(), false); |
| 91 | + |
| 92 | + // SAFETY: `panic_impl` is defined in safe Rust code and thus is safe to call. |
| 93 | + unsafe { panic_impl(&pi) } |
| 94 | +} |
| 95 | + |
| 96 | +// Next we define a bunch of higher-level wrappers that all bottom out in the two core functions |
| 97 | +// above. |
| 98 | + |
32 | 99 | /// The underlying implementation of libcore's `panic!` macro when no formatting is used. |
33 | 100 | #[cold] |
34 | 101 | // never inline unless panic_immediate_abort to avoid code |
@@ -84,62 +151,17 @@ fn panic_bounds_check(index: usize, len: usize) -> ! { |
84 | 151 | panic!("index out of bounds: the len is {len} but the index is {index}") |
85 | 152 | } |
86 | 153 |
|
87 | | -// This function is called directly by the codegen backend, and must not have |
88 | | -// any extra arguments (including those synthesized by track_caller). |
| 154 | +/// Panic because we cannot unwind out of a function. |
| 155 | +/// |
| 156 | +/// This function is called directly by the codegen backend, and must not have |
| 157 | +/// any extra arguments (including those synthesized by track_caller). |
89 | 158 | #[cold] |
90 | 159 | #[inline(never)] |
91 | 160 | #[lang = "panic_no_unwind"] // needed by codegen for panic in nounwind function |
| 161 | +#[cfg_attr(not(bootstrap), rustc_nounwind)] |
| 162 | +#[cfg_attr(bootstrap, rustc_allocator_nounwind)] |
92 | 163 | fn panic_no_unwind() -> ! { |
93 | | - if cfg!(feature = "panic_immediate_abort") { |
94 | | - super::intrinsics::abort() |
95 | | - } |
96 | | - |
97 | | - // NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call |
98 | | - // that gets resolved to the `#[panic_handler]` function. |
99 | | - extern "Rust" { |
100 | | - #[lang = "panic_impl"] |
101 | | - fn panic_impl(pi: &PanicInfo<'_>) -> !; |
102 | | - } |
103 | | - |
104 | | - // PanicInfo with the `can_unwind` flag set to false forces an abort. |
105 | | - let fmt = format_args!("panic in a function that cannot unwind"); |
106 | | - let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller(), false); |
107 | | - |
108 | | - // SAFETY: `panic_impl` is defined in safe Rust code and thus is safe to call. |
109 | | - unsafe { panic_impl(&pi) } |
110 | | -} |
111 | | - |
112 | | -/// The entry point for panicking with a formatted message. |
113 | | -/// |
114 | | -/// This is designed to reduce the amount of code required at the call |
115 | | -/// site as much as possible (so that `panic!()` has as low an impact |
116 | | -/// on (e.g.) the inlining of other functions as possible), by moving |
117 | | -/// the actual formatting into this shared place. |
118 | | -#[cold] |
119 | | -// If panic_immediate_abort, inline the abort call, |
120 | | -// otherwise avoid inlining because of it is cold path. |
121 | | -#[cfg_attr(not(feature = "panic_immediate_abort"), inline(never))] |
122 | | -#[cfg_attr(feature = "panic_immediate_abort", inline)] |
123 | | -#[track_caller] |
124 | | -#[lang = "panic_fmt"] // needed for const-evaluated panics |
125 | | -#[rustc_do_not_const_check] // hooked by const-eval |
126 | | -#[rustc_const_unstable(feature = "core_panic", issue = "none")] |
127 | | -pub const fn panic_fmt(fmt: fmt::Arguments<'_>) -> ! { |
128 | | - if cfg!(feature = "panic_immediate_abort") { |
129 | | - super::intrinsics::abort() |
130 | | - } |
131 | | - |
132 | | - // NOTE This function never crosses the FFI boundary; it's a Rust-to-Rust call |
133 | | - // that gets resolved to the `#[panic_handler]` function. |
134 | | - extern "Rust" { |
135 | | - #[lang = "panic_impl"] |
136 | | - fn panic_impl(pi: &PanicInfo<'_>) -> !; |
137 | | - } |
138 | | - |
139 | | - let pi = PanicInfo::internal_constructor(Some(&fmt), Location::caller(), true); |
140 | | - |
141 | | - // SAFETY: `panic_impl` is defined in safe Rust code and thus is safe to call. |
142 | | - unsafe { panic_impl(&pi) } |
| 164 | + panic_str_nounwind("panic in a function that cannot unwind") |
143 | 165 | } |
144 | 166 |
|
145 | 167 | /// This function is used instead of panic_fmt in const eval. |
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