1//! # The Rust Core Library
2//!
3//! The Rust Core Library is the dependency-free[^free] foundation of [The
4//! Rust Standard Library](../std/index.html). It is the portable glue
5//! between the language and its libraries, defining the intrinsic and
6//! primitive building blocks of all Rust code. It links to no
7//! upstream libraries, no system libraries, and no libc.
8//!
9//! [^free]: Strictly speaking, there are some symbols which are needed but
10//! they aren't always necessary.
11//!
12//! The core library is *minimal*: it isn't even aware of heap allocation,
13//! nor does it provide concurrency or I/O. These things require
14//! platform integration, and this library is platform-agnostic.
15//!
16//! # How to use the core library
17//!
18//! Please note that all of these details are currently not considered stable.
19//!
20// FIXME: Fill me in with more detail when the interface settles
21//! This library is built on the assumption of a few existing symbols:
22//!
23//! * `memcpy`, `memmove`, `memset`, `memcmp`, `bcmp`, `strlen` - These are core memory routines
24//! which are generated by Rust codegen backends. Additionally, this library can make explicit
25//! calls to `strlen`. Their signatures are the same as found in C, but there are extra
26//! assumptions about their semantics: For `memcpy`, `memmove`, `memset`, `memcmp`, and `bcmp`, if
27//! the `n` parameter is 0, the function is assumed to not be UB, even if the pointers are NULL or
28//! dangling. (Note that making extra assumptions about these functions is common among compilers:
29//! [clang](https://reviews.llvm.org/D86993) and [GCC](https://gcc.gnu.org/onlinedocs/gcc/Standards.html#C-Language) do the same.)
30//! These functions are often provided by the system libc, but can also be provided by the
31//! [compiler-builtins crate](https://crates.io/crates/compiler_builtins).
32//! Note that the library does not guarantee that it will always make these assumptions, so Rust
33//! user code directly calling the C functions should follow the C specification! The advice for
34//! Rust user code is to call the functions provided by this library instead (such as
35//! `ptr::copy`).
36//!
37//! * `rust_begin_panic` - This function takes four arguments, a
38//! `fmt::Arguments`, a `&'static str`, and two `u32`'s. These four arguments
39//! dictate the panic message, the file at which panic was invoked, and the
40//! line and column inside the file. It is up to consumers of this core
41//! library to define this panic function; it is only required to never
42//! return. This requires a `lang` attribute named `panic_impl`.
43//!
44//! * `rust_eh_personality` - is used by the failure mechanisms of the
45//! compiler. This is often mapped to GCC's personality function, but crates
46//! which do not trigger a panic can be assured that this function is never
47//! called. The `lang` attribute is called `eh_personality`.
48
49// Since core defines many fundamental lang items, all tests live in a
50// separate crate, libcoretest (library/core/tests), to avoid bizarre issues.
51//
52// Here we explicitly #[cfg]-out this whole crate when testing. If we don't do
53// this, both the generated test artifact and the linked libtest (which
54// transitively includes core) will both define the same set of lang items,
55// and this will cause the E0152 "found duplicate lang item" error. See
56// discussion in #50466 for details.
57//
58// This cfg won't affect doc tests.
59#![cfg(not(test))]
60// To run core tests without x.py without ending up with two copies of core, Miri needs to be
61// able to "empty" this crate. See <https://github.com/rust-lang/miri-test-libstd/issues/4>.
62// rustc itself never sets the feature, so this line has no effect there.
63#![cfg(any(not(feature = "miri-test-libstd"), test, doctest))]
64#![stable(feature = "core", since = "1.6.0")]
65#![doc(
66 html_playground_url = "https://play.rust-lang.org/",
67 issue_tracker_base_url = "https://github.com/rust-lang/rust/issues/",
68 test(no_crate_inject, attr(deny(warnings))),
69 test(attr(allow(dead_code, deprecated, unused_variables, unused_mut)))
70)]
71#![doc(rust_logo)]
72#![doc(cfg_hide(
73 not(test),
74 any(not(feature = "miri-test-libstd"), test, doctest),
75 no_fp_fmt_parse,
76 target_pointer_width = "16",
77 target_pointer_width = "32",
78 target_pointer_width = "64",
79 target_has_atomic = "8",
80 target_has_atomic = "16",
81 target_has_atomic = "32",
82 target_has_atomic = "64",
83 target_has_atomic = "ptr",
84 target_has_atomic_equal_alignment = "8",
85 target_has_atomic_equal_alignment = "16",
86 target_has_atomic_equal_alignment = "32",
87 target_has_atomic_equal_alignment = "64",
88 target_has_atomic_equal_alignment = "ptr",
89 target_has_atomic_load_store = "8",
90 target_has_atomic_load_store = "16",
91 target_has_atomic_load_store = "32",
92 target_has_atomic_load_store = "64",
93 target_has_atomic_load_store = "ptr",
94))]
95#![no_core]
96#![rustc_coherence_is_core]
97//
98// Lints:
99#![deny(rust_2021_incompatible_or_patterns)]
100#![deny(unsafe_op_in_unsafe_fn)]
101#![deny(fuzzy_provenance_casts)]
102#![warn(deprecated_in_future)]
103#![warn(missing_debug_implementations)]
104#![warn(missing_docs)]
105#![allow(explicit_outlives_requirements)]
106#![allow(incomplete_features)]
107#![warn(multiple_supertrait_upcastable)]
108#![allow(internal_features)]
109// Do not check link redundancy on bootstraping phase
110#![allow(rustdoc::redundant_explicit_links)]
111//
112// Library features:
113// tidy-alphabetical-start
114#![cfg_attr(not(bootstrap), feature(offset_of_nested))]
115#![feature(char_indices_offset)]
116#![feature(const_align_of_val)]
117#![feature(const_align_of_val_raw)]
118#![feature(const_align_offset)]
119#![feature(const_alloc_layout)]
120#![feature(const_arguments_as_str)]
121#![feature(const_array_from_ref)]
122#![feature(const_array_into_iter_constructors)]
123#![feature(const_bigint_helper_methods)]
124#![feature(const_black_box)]
125#![feature(const_caller_location)]
126#![feature(const_cell_into_inner)]
127#![feature(const_char_from_u32_unchecked)]
128#![feature(const_eval_select)]
129#![feature(const_exact_div)]
130#![feature(const_float_bits_conv)]
131#![feature(const_float_classify)]
132#![feature(const_fmt_arguments_new)]
133#![feature(const_hash)]
134#![feature(const_heap)]
135#![feature(const_hint_assert_unchecked)]
136#![feature(const_index_range_slice_index)]
137#![feature(const_int_unchecked_arith)]
138#![feature(const_intrinsic_forget)]
139#![feature(const_ipv4)]
140#![feature(const_ipv6)]
141#![feature(const_likely)]
142#![feature(const_maybe_uninit_as_mut_ptr)]
143#![feature(const_maybe_uninit_assume_init)]
144#![feature(const_maybe_uninit_uninit_array)]
145#![feature(const_nonnull_new)]
146#![feature(const_num_midpoint)]
147#![feature(const_option)]
148#![feature(const_option_ext)]
149#![feature(const_pin)]
150#![feature(const_pointer_is_aligned)]
151#![feature(const_ptr_as_ref)]
152#![feature(const_ptr_is_null)]
153#![feature(const_ptr_sub_ptr)]
154#![feature(const_ptr_write)]
155#![feature(const_raw_ptr_comparison)]
156#![feature(const_replace)]
157#![feature(const_size_of_val)]
158#![feature(const_size_of_val_raw)]
159#![feature(const_slice_from_raw_parts_mut)]
160#![feature(const_slice_from_ref)]
161#![feature(const_slice_index)]
162#![feature(const_slice_ptr_len)]
163#![feature(const_slice_split_at_mut)]
164#![feature(const_str_from_utf8_unchecked_mut)]
165#![feature(const_strict_overflow_ops)]
166#![feature(const_swap)]
167#![feature(const_try)]
168#![feature(const_type_id)]
169#![feature(const_type_name)]
170#![feature(const_unicode_case_lookup)]
171#![feature(const_unsafecell_get_mut)]
172#![feature(const_waker)]
173#![feature(coverage_attribute)]
174#![feature(duration_consts_float)]
175#![feature(internal_impls_macro)]
176#![feature(ip)]
177#![feature(ip_bits)]
178#![feature(is_ascii_octdigit)]
179#![feature(isqrt)]
180#![feature(maybe_uninit_uninit_array)]
181#![feature(non_null_convenience)]
182#![feature(offset_of_enum)]
183#![feature(panic_internals)]
184#![feature(ptr_alignment_type)]
185#![feature(ptr_metadata)]
186#![feature(set_ptr_value)]
187#![feature(slice_ptr_get)]
188#![feature(slice_split_at_unchecked)]
189#![feature(split_at_checked)]
190#![feature(str_internals)]
191#![feature(str_split_inclusive_remainder)]
192#![feature(str_split_remainder)]
193#![feature(strict_provenance)]
194#![feature(unchecked_math)]
195#![feature(unchecked_shifts)]
196#![feature(utf16_extra)]
197#![feature(utf16_extra_const)]
198#![feature(variant_count)]
199// tidy-alphabetical-end
200//
201// Language features:
202// tidy-alphabetical-start
203#![feature(abi_unadjusted)]
204#![feature(adt_const_params)]
205#![feature(allow_internal_unsafe)]
206#![feature(allow_internal_unstable)]
207#![feature(asm_const)]
208#![feature(associated_type_bounds)]
209#![feature(auto_traits)]
210#![feature(c_unwind)]
211#![feature(cfg_sanitize)]
212#![feature(cfg_target_has_atomic)]
213#![feature(cfg_target_has_atomic_equal_alignment)]
214#![feature(const_closures)]
215#![feature(const_fn_floating_point_arithmetic)]
216#![feature(const_for)]
217#![feature(const_mut_refs)]
218#![feature(const_precise_live_drops)]
219#![feature(const_refs_to_cell)]
220#![feature(const_trait_impl)]
221#![feature(decl_macro)]
222#![feature(deprecated_suggestion)]
223#![feature(diagnostic_namespace)]
224#![feature(doc_cfg)]
225#![feature(doc_cfg_hide)]
226#![feature(doc_notable_trait)]
227#![feature(effects)]
228#![feature(exhaustive_patterns)]
229#![feature(extern_types)]
230#![feature(fundamental)]
231#![feature(generic_arg_infer)]
232#![feature(if_let_guard)]
233#![feature(inline_const)]
234#![feature(intra_doc_pointers)]
235#![feature(intrinsics)]
236#![feature(lang_items)]
237#![feature(let_chains)]
238#![feature(link_llvm_intrinsics)]
239#![feature(macro_metavar_expr)]
240#![feature(min_specialization)]
241#![feature(multiple_supertrait_upcastable)]
242#![feature(must_not_suspend)]
243#![feature(negative_impls)]
244#![feature(never_type)]
245#![feature(no_core)]
246#![feature(no_sanitize)]
247#![feature(platform_intrinsics)]
248#![feature(prelude_import)]
249#![feature(repr_simd)]
250#![feature(rustc_allow_const_fn_unstable)]
251#![feature(rustc_attrs)]
252#![feature(rustdoc_internals)]
253#![feature(simd_ffi)]
254#![feature(staged_api)]
255#![feature(stmt_expr_attributes)]
256#![feature(target_feature_11)]
257#![feature(trait_alias)]
258#![feature(transparent_unions)]
259#![feature(try_blocks)]
260#![feature(unboxed_closures)]
261#![feature(unsized_fn_params)]
262#![feature(with_negative_coherence)]
263// tidy-alphabetical-end
264//
265// Target features:
266// tidy-alphabetical-start
267#![feature(arm_target_feature)]
268#![feature(avx512_target_feature)]
269#![feature(hexagon_target_feature)]
270#![feature(mips_target_feature)]
271#![feature(powerpc_target_feature)]
272#![feature(riscv_target_feature)]
273#![feature(rtm_target_feature)]
274#![feature(sse4a_target_feature)]
275#![feature(tbm_target_feature)]
276#![feature(wasm_target_feature)]
277// tidy-alphabetical-end
278
279// allow using `core::` in intra-doc links
280#[allow(unused_extern_crates)]
281extern crate self as core;
282
283#[prelude_import]
284#[allow(unused)]
285use prelude::v1::*;
286
287#[cfg(not(test))] // See #65860
288#[macro_use]
289mod macros;
290
291// We don't export this through #[macro_export] for now, to avoid breakage.
292// See https://github.com/rust-lang/rust/issues/82913
293#[cfg(not(test))]
294#[unstable(feature = "assert_matches", issue = "82775")]
295/// Unstable module containing the unstable `assert_matches` macro.
296pub mod assert_matches {
297 #[unstable(feature = "assert_matches", issue = "82775")]
298 pub use crate::macros::{assert_matches, debug_assert_matches};
299}
300
301#[unstable(feature = "cfg_match", issue = "115585")]
302pub use crate::macros::cfg_match;
303
304#[macro_use]
305mod internal_macros;
306
307#[path = "num/shells/int_macros.rs"]
308#[macro_use]
309mod int_macros;
310
311#[path = "num/shells/i128.rs"]
312pub mod i128;
313#[path = "num/shells/i16.rs"]
314pub mod i16;
315#[path = "num/shells/i32.rs"]
316pub mod i32;
317#[path = "num/shells/i64.rs"]
318pub mod i64;
319#[path = "num/shells/i8.rs"]
320pub mod i8;
321#[path = "num/shells/isize.rs"]
322pub mod isize;
323
324#[path = "num/shells/u128.rs"]
325pub mod u128;
326#[path = "num/shells/u16.rs"]
327pub mod u16;
328#[path = "num/shells/u32.rs"]
329pub mod u32;
330#[path = "num/shells/u64.rs"]
331pub mod u64;
332#[path = "num/shells/u8.rs"]
333pub mod u8;
334#[path = "num/shells/usize.rs"]
335pub mod usize;
336
337#[path = "num/f32.rs"]
338pub mod f32;
339#[path = "num/f64.rs"]
340pub mod f64;
341
342#[macro_use]
343pub mod num;
344
345/* The core prelude, not as all-encompassing as the std prelude */
346
347pub mod prelude;
348
349/* Core modules for ownership management */
350
351pub mod hint;
352pub mod intrinsics;
353pub mod mem;
354pub mod ptr;
355
356/* Core language traits */
357
358pub mod borrow;
359pub mod clone;
360pub mod cmp;
361pub mod convert;
362pub mod default;
363pub mod error;
364pub mod marker;
365pub mod ops;
366
367/* Core types and methods on primitives */
368
369pub mod any;
370pub mod array;
371pub mod ascii;
372pub mod asserting;
373#[unstable(feature = "async_iterator", issue = "79024")]
374pub mod async_iter;
375pub mod cell;
376pub mod char;
377pub mod ffi;
378#[unstable(feature = "core_io_borrowed_buf", issue = "117693")]
379pub mod io;
380pub mod iter;
381pub mod net;
382pub mod option;
383pub mod panic;
384pub mod panicking;
385pub mod pin;
386pub mod result;
387pub mod sync;
388
389pub mod fmt;
390pub mod hash;
391pub mod slice;
392pub mod str;
393pub mod time;
394
395pub mod unicode;
396
397/* Async */
398pub mod future;
399pub mod task;
400
401/* Heap memory allocator trait */
402#[allow(missing_docs)]
403pub mod alloc;
404
405// note: does not need to be public
406mod bool;
407mod escape;
408mod tuple;
409mod unit;
410
411#[stable(feature = "core_primitive", since = "1.43.0")]
412pub mod primitive;
413
414// Pull in the `core_arch` crate directly into core. The contents of
415// `core_arch` are in a different repository: rust-lang/stdarch.
416//
417// `core_arch` depends on core, but the contents of this module are
418// set up in such a way that directly pulling it here works such that the
419// crate uses the this crate as its core.
420#[path = "../../stdarch/crates/core_arch/src/mod.rs"]
421#[allow(
422 missing_docs,
423 missing_debug_implementations,
424 dead_code,
425 unused_imports,
426 unsafe_op_in_unsafe_fn,
427 ambiguous_glob_reexports,
428 deprecated_in_future
429)]
430#[allow(rustdoc::bare_urls)]
431// FIXME: This annotation should be moved into rust-lang/stdarch after clashing_extern_declarations is
432// merged. It currently cannot because bootstrap fails as the lint hasn't been defined yet.
433#[allow(clashing_extern_declarations)]
434#[unstable(feature = "stdsimd", issue = "48556")]
435mod core_arch;
436
437#[stable(feature = "simd_arch", since = "1.27.0")]
438pub mod arch;
439
440// Pull in the `core_simd` crate directly into core. The contents of
441// `core_simd` are in a different repository: rust-lang/portable-simd.
442//
443// `core_simd` depends on core, but the contents of this module are
444// set up in such a way that directly pulling it here works such that the
445// crate uses this crate as its core.
446#[path = "../../portable-simd/crates/core_simd/src/mod.rs"]
447#[allow(missing_debug_implementations, dead_code, unsafe_op_in_unsafe_fn)]
448#[allow(rustdoc::bare_urls)]
449#[unstable(feature = "portable_simd", issue = "86656")]
450mod core_simd;
451
452#[unstable(feature = "portable_simd", issue = "86656")]
453pub mod simd {
454 #![doc = include_str!("../../portable-simd/crates/core_simd/src/core_simd_docs.md")]
455
456 #[unstable(feature = "portable_simd", issue = "86656")]
457 pub use crate::core_simd::simd::*;
458}
459
460include!("primitive_docs.rs");
461