1 //! List of the active feature gates.
3 use super::{to_nonzero, Feature, State};
5 use rustc_span::edition::Edition;
6 use rustc_span::symbol::{sym, Symbol};
11 fn f(features: &mut Features, _: Span) {
12 features.$field = true;
14 f as fn(&mut Features, Span)
18 macro_rules! declare_features {
20 $(#[doc = $doc:tt])* (active, $feature:ident, $ver:expr, $issue:expr, $edition:expr),
22 /// Represents active features that are currently being implemented or
23 /// currently being considered for addition/removal.
24 pub const ACTIVE_FEATURES:
27 // (sym::$feature, $ver, $issue, $edition, set!($feature))
29 state: State::Active { set: set!($feature) },
32 issue: to_nonzero($issue),
34 description: concat!($($doc,)*),
38 /// A set of features to be used by later passes.
39 #[derive(Clone, Default, Debug)]
41 /// `#![feature]` attrs for language features, for error reporting.
42 pub declared_lang_features: Vec<(Symbol, Span, Option<Symbol>)>,
43 /// `#![feature]` attrs for non-language (library) features.
44 pub declared_lib_features: Vec<(Symbol, Span)>,
52 pub fn walk_feature_fields(&self, mut f: impl FnMut(&str, bool)) {
53 $(f(stringify!($feature), self.$feature);)+
56 /// Is the given feature enabled?
58 /// Panics if the symbol doesn't correspond to a declared feature.
59 pub fn enabled(&self, feature: Symbol) -> bool {
61 $( sym::$feature => self.$feature, )*
63 _ => panic!("`{}` was not listed in `declare_features`", feature),
67 pub fn unordered_const_ty_params(&self) -> bool {
68 self.const_generics || self.const_generics_defaults
75 /// Sets this feature in `Features`. Panics if called on a non-active feature.
76 pub fn set(&self, features: &mut Features, span: Span) {
78 State::Active { set } => set(features, span),
79 _ => panic!("called `set` on feature `{}` which is not `active`", self.name),
84 // If you change this, please modify `src/doc/unstable-book` as well.
86 // Don't ever remove anything from this list; move them to `removed.rs`.
88 // The version numbers here correspond to the version in which the current status
89 // was set. This is most important for knowing when a particular feature became
92 // Note that the features are grouped into internal/user-facing and then
93 // sorted by version inside those groups. This is enforced with tidy.
95 // N.B., `tools/tidy/src/features.rs` parses this information directly out of the
96 // source, so take care when modifying it.
100 // -------------------------------------------------------------------------
101 // feature-group-start: internal feature gates
102 // -------------------------------------------------------------------------
104 // no-tracking-issue-start
106 /// Allows using `rustc_*` attributes (RFC 572).
107 (active, rustc_attrs, "1.0.0", None, None),
109 /// Allows using compiler's own crates.
110 (active, rustc_private, "1.0.0", Some(27812), None),
112 /// Allows using the `rust-intrinsic`'s "ABI".
113 (active, intrinsics, "1.0.0", None, None),
115 /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic.
116 (active, lang_items, "1.0.0", None, None),
118 /// Allows using the `#[stable]` and `#[unstable]` attributes.
119 (active, staged_api, "1.0.0", None, None),
121 /// Allows using `#[allow_internal_unstable]`. This is an
122 /// attribute on `macro_rules!` and can't use the attribute handling
123 /// below (it has to be checked before expansion possibly makes
124 /// macros disappear).
125 (active, allow_internal_unstable, "1.0.0", None, None),
127 /// Allows using `#[allow_internal_unsafe]`. This is an
128 /// attribute on `macro_rules!` and can't use the attribute handling
129 /// below (it has to be checked before expansion possibly makes
130 /// macros disappear).
131 (active, allow_internal_unsafe, "1.0.0", None, None),
133 /// no-tracking-issue-end
135 /// Allows using `#[link_name="llvm.*"]`.
136 (active, link_llvm_intrinsics, "1.0.0", Some(29602), None),
138 /// Allows using the `box $expr` syntax.
139 (active, box_syntax, "1.0.0", Some(49733), None),
141 /// Allows using `#[start]` on a function indicating that it is the program entrypoint.
142 (active, start, "1.0.0", Some(29633), None),
144 /// Allows using the `#[fundamental]` attribute.
145 (active, fundamental, "1.0.0", Some(29635), None),
147 /// Allows using the `rust-call` ABI.
148 (active, unboxed_closures, "1.0.0", Some(29625), None),
150 /// Allows using the `#[linkage = ".."]` attribute.
151 (active, linkage, "1.0.0", Some(29603), None),
153 /// Allows using `box` in patterns (RFC 469).
154 (active, box_patterns, "1.0.0", Some(29641), None),
156 // no-tracking-issue-start
158 /// Allows using `#[prelude_import]` on glob `use` items.
159 (active, prelude_import, "1.2.0", None, None),
161 // no-tracking-issue-end
163 // no-tracking-issue-start
165 /// Allows using `#[omit_gdb_pretty_printer_section]`.
166 (active, omit_gdb_pretty_printer_section, "1.5.0", None, None),
168 /// Allows using the `vectorcall` ABI.
169 (active, abi_vectorcall, "1.7.0", None, None),
171 // no-tracking-issue-end
173 /// Allows using `#[structural_match]` which indicates that a type is structurally matchable.
174 /// FIXME: Subsumed by trait `StructuralPartialEq`, cannot move to removed until a library
175 /// feature with the same name exists.
176 (active, structural_match, "1.8.0", Some(31434), None),
178 /// Allows using the `may_dangle` attribute (RFC 1327).
179 (active, dropck_eyepatch, "1.10.0", Some(34761), None),
181 /// Allows using the `#![panic_runtime]` attribute.
182 (active, panic_runtime, "1.10.0", Some(32837), None),
184 /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed.
185 (active, needs_panic_runtime, "1.10.0", Some(32837), None),
187 // no-tracking-issue-start
189 /// Allows identifying the `compiler_builtins` crate.
190 (active, compiler_builtins, "1.13.0", None, None),
192 /// Allows using the `unadjusted` ABI; perma-unstable.
193 (active, abi_unadjusted, "1.16.0", None, None),
195 /// Used to identify crates that contain the profiler runtime.
196 (active, profiler_runtime, "1.18.0", None, None),
198 /// Allows using the `thiscall` ABI.
199 (active, abi_thiscall, "1.19.0", None, None),
201 /// Allows using `#![needs_allocator]`, an implementation detail of `#[global_allocator]`.
202 (active, allocator_internals, "1.20.0", None, None),
204 /// Added for testing E0705; perma-unstable.
205 (active, test_2018_feature, "1.31.0", None, Some(Edition::Edition2018)),
207 /// Allows `#[repr(no_niche)]` (an implementation detail of `rustc`,
208 /// it is not on path for eventual stabilization).
209 (active, no_niche, "1.42.0", None, None),
211 /// Allows using `#[rustc_allow_const_fn_unstable]`.
212 /// This is an attribute on `const fn` for the same
213 /// purpose as `#[allow_internal_unstable]`.
214 (active, rustc_allow_const_fn_unstable, "1.49.0", Some(69399), None),
216 /// Allows features specific to auto traits.
217 /// Renamed from `optin_builtin_traits`.
218 (active, auto_traits, "1.50.0", Some(13231), None),
220 /// Allows `#[doc(notable_trait)]`.
221 /// Renamed from `doc_spotlight`.
222 (active, doc_notable_trait, "1.52.0", Some(45040), None),
224 // no-tracking-issue-end
226 // -------------------------------------------------------------------------
227 // feature-group-end: internal feature gates
228 // -------------------------------------------------------------------------
230 // -------------------------------------------------------------------------
231 // feature-group-start: actual feature gates (target features)
232 // -------------------------------------------------------------------------
234 // FIXME: Document these and merge with the list below.
236 // Unstable `#[target_feature]` directives.
237 (active, arm_target_feature, "1.27.0", Some(44839), None),
238 (active, aarch64_target_feature, "1.27.0", Some(44839), None),
239 (active, hexagon_target_feature, "1.27.0", Some(44839), None),
240 (active, powerpc_target_feature, "1.27.0", Some(44839), None),
241 (active, mips_target_feature, "1.27.0", Some(44839), None),
242 (active, avx512_target_feature, "1.27.0", Some(44839), None),
243 (active, sse4a_target_feature, "1.27.0", Some(44839), None),
244 (active, tbm_target_feature, "1.27.0", Some(44839), None),
245 (active, wasm_target_feature, "1.30.0", Some(44839), None),
246 (active, adx_target_feature, "1.32.0", Some(44839), None),
247 (active, cmpxchg16b_target_feature, "1.32.0", Some(44839), None),
248 (active, movbe_target_feature, "1.34.0", Some(44839), None),
249 (active, rtm_target_feature, "1.35.0", Some(44839), None),
250 (active, f16c_target_feature, "1.36.0", Some(44839), None),
251 (active, riscv_target_feature, "1.45.0", Some(44839), None),
252 (active, ermsb_target_feature, "1.49.0", Some(44839), None),
254 // -------------------------------------------------------------------------
255 // feature-group-end: actual feature gates (target features)
256 // -------------------------------------------------------------------------
258 // -------------------------------------------------------------------------
259 // feature-group-start: actual feature gates
260 // -------------------------------------------------------------------------
262 /// Allows using `#[plugin_registrar]` on functions.
263 (active, plugin_registrar, "1.0.0", Some(29597), None),
265 /// Allows using `#![plugin(myplugin)]`.
266 (active, plugin, "1.0.0", Some(29597), None),
268 /// Allows using `#[thread_local]` on `static` items.
269 (active, thread_local, "1.0.0", Some(29594), None),
271 /// Allows the use of SIMD types in functions declared in `extern` blocks.
272 (active, simd_ffi, "1.0.0", Some(27731), None),
274 /// Allows using non lexical lifetimes (RFC 2094).
275 (active, nll, "1.0.0", Some(43234), None),
277 /// Allows associated type defaults.
278 (active, associated_type_defaults, "1.2.0", Some(29661), None),
280 /// Allows `#![no_core]`.
281 (active, no_core, "1.3.0", Some(29639), None),
283 /// Allows default type parameters to influence type inference.
284 (active, default_type_parameter_fallback, "1.3.0", Some(27336), None),
286 /// Allows `repr(simd)` and importing the various simd intrinsics.
287 (active, repr_simd, "1.4.0", Some(27731), None),
289 /// Allows `extern "platform-intrinsic" { ... }`.
290 (active, platform_intrinsics, "1.4.0", Some(27731), None),
292 /// Allows `#[unwind(..)]`.
294 /// Permits specifying whether a function should permit unwinding or abort on unwind.
295 (active, unwind_attributes, "1.4.0", Some(58760), None),
297 /// Allows attributes on expressions and non-item statements.
298 (active, stmt_expr_attributes, "1.6.0", Some(15701), None),
300 /// Allows the use of type ascription in expressions.
301 (active, type_ascription, "1.6.0", Some(23416), None),
303 /// Allows `cfg(target_thread_local)`.
304 (active, cfg_target_thread_local, "1.7.0", Some(29594), None),
306 /// Allows specialization of implementations (RFC 1210).
307 (active, specialization, "1.7.0", Some(31844), None),
309 /// A minimal, sound subset of specialization intended to be used by the
310 /// standard library until the soundness issues with specialization
312 (active, min_specialization, "1.7.0", Some(31844), None),
314 /// Allows using `#[naked]` on functions.
315 (active, naked_functions, "1.9.0", Some(32408), None),
317 /// Allows `cfg(target_has_atomic = "...")`.
318 (active, cfg_target_has_atomic, "1.9.0", Some(32976), None),
320 /// Allows `X..Y` patterns.
321 (active, exclusive_range_pattern, "1.11.0", Some(37854), None),
323 /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more.
324 (active, never_type, "1.13.0", Some(35121), None),
326 /// Allows exhaustive pattern matching on types that contain uninhabited types.
327 (active, exhaustive_patterns, "1.13.0", Some(51085), None),
329 /// Allows `union`s to implement `Drop`. Moreover, `union`s may now include fields
330 /// that don't implement `Copy` as long as they don't have any drop glue.
331 /// This is checked recursively. On encountering type variable where no progress can be made,
332 /// `T: Copy` is used as a substitute for "no drop glue".
334 /// NOTE: A limited form of `union U { ... }` was accepted in 1.19.0.
335 (active, untagged_unions, "1.13.0", Some(55149), None),
337 /// Allows `#[link(..., cfg(..))]`.
338 (active, link_cfg, "1.14.0", Some(37406), None),
340 /// Allows `extern "ptx-*" fn()`.
341 (active, abi_ptx, "1.15.0", Some(38788), None),
343 /// Allows the `#[repr(i128)]` attribute for enums.
344 (active, repr128, "1.16.0", Some(56071), None),
346 /// Allows `#[link(kind="static-nobundle"...)]`.
347 (active, static_nobundle, "1.16.0", Some(37403), None),
349 /// Allows `extern "msp430-interrupt" fn()`.
350 (active, abi_msp430_interrupt, "1.16.0", Some(38487), None),
352 /// Allows declarative macros 2.0 (`macro`).
353 (active, decl_macro, "1.17.0", Some(39412), None),
355 /// Allows `extern "x86-interrupt" fn()`.
356 (active, abi_x86_interrupt, "1.17.0", Some(40180), None),
358 /// Allows a test to fail without failing the whole suite.
359 (active, allow_fail, "1.19.0", Some(46488), None),
361 /// Allows unsized tuple coercion.
362 (active, unsized_tuple_coercion, "1.20.0", Some(42877), None),
364 /// Allows defining generators.
365 (active, generators, "1.21.0", Some(43122), None),
367 /// Allows `#[doc(cfg(...))]`.
368 (active, doc_cfg, "1.21.0", Some(43781), None),
370 /// Allows `#[doc(masked)]`.
371 (active, doc_masked, "1.21.0", Some(44027), None),
373 /// Allows using `crate` as visibility modifier, synonymous with `pub(crate)`.
374 (active, crate_visibility_modifier, "1.23.0", Some(53120), None),
376 /// Allows defining `extern type`s.
377 (active, extern_types, "1.23.0", Some(43467), None),
379 /// Allows trait methods with arbitrary self types.
380 (active, arbitrary_self_types, "1.23.0", Some(44874), None),
382 /// Allows in-band quantification of lifetime bindings (e.g., `fn foo(x: &'a u8) -> &'a u8`).
383 (active, in_band_lifetimes, "1.23.0", Some(44524), None),
385 /// Allows associated types to be generic, e.g., `type Foo<T>;` (RFC 1598).
386 (active, generic_associated_types, "1.23.0", Some(44265), None),
388 /// Allows defining `trait X = A + B;` alias items.
389 (active, trait_alias, "1.24.0", Some(41517), None),
391 /// Allows inferring `'static` outlives requirements (RFC 2093).
392 (active, infer_static_outlives_requirements, "1.26.0", Some(54185), None),
394 /// Allows accessing fields of unions inside `const` functions.
395 (active, const_fn_union, "1.27.0", Some(51909), None),
397 /// Allows casting raw pointers to `usize` during const eval.
398 (active, const_raw_ptr_to_usize_cast, "1.27.0", Some(51910), None),
400 /// Allows dereferencing raw pointers during const eval.
401 (active, const_raw_ptr_deref, "1.27.0", Some(51911), None),
403 /// Allows inconsistent bounds in where clauses.
404 (active, trivial_bounds, "1.28.0", Some(48214), None),
406 /// Allows `'a: { break 'a; }`.
407 (active, label_break_value, "1.28.0", Some(48594), None),
409 /// Allows using `#[doc(keyword = "...")]`.
410 (active, doc_keyword, "1.28.0", Some(51315), None),
412 /// Allows using `try {...}` expressions.
413 (active, try_blocks, "1.29.0", Some(31436), None),
415 /// Allows defining an `#[alloc_error_handler]`.
416 (active, alloc_error_handler, "1.29.0", Some(51540), None),
418 /// Allows using the `amdgpu-kernel` ABI.
419 (active, abi_amdgpu_kernel, "1.29.0", Some(51575), None),
421 /// Allows panicking during const eval (producing compile-time errors).
422 (active, const_panic, "1.30.0", Some(51999), None),
424 /// Allows `#[marker]` on certain traits allowing overlapping implementations.
425 (active, marker_trait_attr, "1.30.0", Some(29864), None),
427 /// Allows macro attributes on expressions, statements and non-inline modules.
428 (active, proc_macro_hygiene, "1.30.0", Some(54727), None),
430 /// Allows unsized rvalues at arguments and parameters.
431 (active, unsized_locals, "1.30.0", Some(48055), None),
433 /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`.
434 (active, custom_test_frameworks, "1.30.0", Some(50297), None),
436 /// Allows non-builtin attributes in inner attribute position.
437 (active, custom_inner_attributes, "1.30.0", Some(54726), None),
439 /// Allows `impl Trait` in bindings (`let`, `const`, `static`).
440 (active, impl_trait_in_bindings, "1.30.0", Some(63065), None),
442 /// Allows using `reason` in lint attributes and the `#[expect(lint)]` lint check.
443 (active, lint_reasons, "1.31.0", Some(54503), None),
445 /// Allows exhaustive integer pattern matching on `usize` and `isize`.
446 (active, precise_pointer_size_matching, "1.32.0", Some(56354), None),
448 /// Allows using `#[ffi_returns_twice]` on foreign functions.
449 (active, ffi_returns_twice, "1.34.0", Some(58314), None),
451 /// Allows const generic types (e.g. `struct Foo<const N: usize>(...);`).
452 (active, const_generics, "1.34.0", Some(44580), None),
454 /// Allows using `#[optimize(X)]`.
455 (active, optimize_attribute, "1.34.0", Some(54882), None),
457 /// Allows using C-variadics.
458 (active, c_variadic, "1.34.0", Some(44930), None),
460 /// Allows the user of associated type bounds.
461 (active, associated_type_bounds, "1.34.0", Some(52662), None),
463 /// Allows `if/while p && let q = r && ...` chains.
464 (active, let_chains, "1.37.0", Some(53667), None),
466 /// Allows #[repr(transparent)] on unions (RFC 2645).
467 (active, transparent_unions, "1.37.0", Some(60405), None),
469 /// Allows explicit discriminants on non-unit enum variants.
470 (active, arbitrary_enum_discriminant, "1.37.0", Some(60553), None),
472 /// Allows `async || body` closures.
473 (active, async_closure, "1.37.0", Some(62290), None),
475 /// Allows `impl Trait` to be used inside type aliases (RFC 2515).
476 (active, type_alias_impl_trait, "1.38.0", Some(63063), None),
478 /// Allows the definition of `const extern fn` and `const unsafe extern fn`.
479 (active, const_extern_fn, "1.40.0", Some(64926), None),
481 /// Allows the use of raw-dylibs (RFC 2627).
482 (active, raw_dylib, "1.40.0", Some(58713), None),
484 /// Allows making `dyn Trait` well-formed even if `Trait` is not object safe.
485 /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and
486 /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.
487 (active, object_safe_for_dispatch, "1.40.0", Some(43561), None),
489 /// Allows using the `efiapi` ABI.
490 (active, abi_efiapi, "1.40.0", Some(65815), None),
492 /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions.
493 (active, raw_ref_op, "1.41.0", Some(64490), None),
495 /// Allows diverging expressions to fall back to `!` rather than `()`.
496 (active, never_type_fallback, "1.41.0", Some(65992), None),
498 /// Allows using the `#[register_attr]` attribute.
499 (active, register_attr, "1.41.0", Some(66080), None),
501 /// Allows using the `#[register_tool]` attribute.
502 (active, register_tool, "1.41.0", Some(66079), None),
504 /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used.
505 (active, cfg_sanitize, "1.41.0", Some(39699), None),
507 /// Allows using `..X`, `..=X`, `...X`, and `X..` as a pattern.
508 (active, half_open_range_patterns, "1.41.0", Some(67264), None),
510 /// Allows using `&mut` in constant functions.
511 (active, const_mut_refs, "1.41.0", Some(57349), None),
513 /// Allows bindings in the subpattern of a binding pattern.
514 /// For example, you can write `x @ Some(y)`.
515 (active, bindings_after_at, "1.41.0", Some(65490), None),
517 /// Allows `impl const Trait for T` syntax.
518 (active, const_trait_impl, "1.42.0", Some(67792), None),
520 /// Allows `T: ?const Trait` syntax in bounds.
521 (active, const_trait_bound_opt_out, "1.42.0", Some(67794), None),
523 /// Allows the use of `no_sanitize` attribute.
524 (active, no_sanitize, "1.42.0", Some(39699), None),
526 // Allows limiting the evaluation steps of const expressions
527 (active, const_eval_limit, "1.43.0", Some(67217), None),
529 /// Allow negative trait implementations.
530 (active, negative_impls, "1.44.0", Some(68318), None),
532 /// Allows the use of `#[target_feature]` on safe functions.
533 (active, target_feature_11, "1.45.0", Some(69098), None),
535 /// Allow conditional compilation depending on rust version
536 (active, cfg_version, "1.45.0", Some(64796), None),
538 /// Allows the use of `#[ffi_pure]` on foreign functions.
539 (active, ffi_pure, "1.45.0", Some(58329), None),
541 /// Allows the use of `#[ffi_const]` on foreign functions.
542 (active, ffi_const, "1.45.0", Some(58328), None),
544 /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`.
545 (active, abi_avr_interrupt, "1.45.0", Some(69664), None),
547 /// Be more precise when looking for live drops in a const context.
548 (active, const_precise_live_drops, "1.46.0", Some(73255), None),
550 /// Allows capturing variables in scope using format_args!
551 (active, format_args_capture, "1.46.0", Some(67984), None),
553 /// Lazily evaluate constants. This allows constants to depend on type parameters.
554 (active, lazy_normalization_consts, "1.46.0", Some(72219), None),
556 /// Allows calling `transmute` in const fn
557 (active, const_fn_transmute, "1.46.0", Some(53605), None),
559 /// Allows `if let` guard in match arms.
560 (active, if_let_guard, "1.47.0", Some(51114), None),
562 /// Allows non-trivial generic constants which have to be manually propagated upwards.
563 (active, const_evaluatable_checked, "1.48.0", Some(76560), None),
565 /// Allows basic arithmetic on floating point types in a `const fn`.
566 (active, const_fn_floating_point_arithmetic, "1.48.0", Some(57241), None),
568 /// Allows using and casting function pointers in a `const fn`.
569 (active, const_fn_fn_ptr_basics, "1.48.0", Some(57563), None),
571 /// Allows to use the `#[cmse_nonsecure_entry]` attribute.
572 (active, cmse_nonsecure_entry, "1.48.0", Some(75835), None),
574 /// Allows rustc to inject a default alloc_error_handler
575 (active, default_alloc_error_handler, "1.48.0", Some(66741), None),
577 /// Allows argument and return position `impl Trait` in a `const fn`.
578 (active, const_impl_trait, "1.48.0", Some(77463), None),
580 /// Allows `#[instruction_set(_)]` attribute
581 (active, isa_attribute, "1.48.0", Some(74727), None),
583 /// Allow anonymous constants from an inline `const` block
584 (active, inline_const, "1.49.0", Some(76001), None),
586 /// Allows unsized fn parameters.
587 (active, unsized_fn_params, "1.49.0", Some(48055), None),
589 /// Allows the use of destructuring assignments.
590 (active, destructuring_assignment, "1.49.0", Some(71126), None),
592 /// Enables `#[cfg(panic = "...")]` config key.
593 (active, cfg_panic, "1.49.0", Some(77443), None),
595 /// Allows capturing disjoint fields in a closure/generator (RFC 2229).
596 (active, capture_disjoint_fields, "1.49.0", Some(53488), None),
598 /// Allows const generics to have default values (e.g. `struct Foo<const N: usize = 3>(...);`).
599 (active, const_generics_defaults, "1.51.0", Some(44580), None),
601 /// Allows references to types with interior mutability within constants
602 (active, const_refs_to_cell, "1.51.0", Some(80384), None),
604 /// Allows using `pointer` and `reference` in intra-doc links
605 (active, intra_doc_pointers, "1.51.0", Some(80896), None),
607 /// Allows `extern "C-cmse-nonsecure-call" fn()`.
608 (active, abi_c_cmse_nonsecure_call, "1.51.0", Some(81391), None),
610 /// Lessens the requirements for structs to implement `Unsize`.
611 (active, relaxed_struct_unsize, "1.51.0", Some(81793), None),
613 /// Allows macro attributes to observe output of `#[derive]`.
614 (active, macro_attributes_in_derive_output, "1.51.0", Some(81119), None),
616 /// Allows the use of type alias impl trait in function return positions
617 (active, min_type_alias_impl_trait, "1.52.0", Some(63063), None),
619 /// Allows associated types in inherent impls.
620 (active, inherent_associated_types, "1.52.0", Some(8995), None),
622 // Allows setting the threshold for the `large_assignments` lint.
623 (active, large_assignments, "1.52.0", Some(83518), None),
625 /// Allows `extern "C-unwind" fn` to enable unwinding across ABI boundaries.
626 (active, c_unwind, "1.52.0", Some(74990), None),
628 /// Allows using `#[repr(align(...))]` on function items
629 (active, fn_align, "1.53.0", Some(82232), None),
631 /// Allows `extern "wasm" fn`
632 (active, wasm_abi, "1.53.0", Some(83788), None),
634 /// Allows function attribute `#[no_coverage]`, to bypass coverage
635 /// instrumentation of that function.
636 (active, no_coverage, "1.53.0", Some(84605), None),
638 /// Allows trait bounds in `const fn`.
639 (active, const_fn_trait_bound, "1.53.0", Some(57563), None),
641 /// Allows `async {}` expressions in const contexts.
642 (active, const_async_blocks, "1.53.0", Some(85368), None),
644 /// Allows using imported `main` function
645 (active, imported_main, "1.53.0", Some(28937), None),
647 /// Allows specifying modifiers in the link attribute: `#[link(modifiers = "...")]`
648 (active, native_link_modifiers, "1.53.0", Some(81490), None),
650 /// Allows specifying the bundle link modifier
651 (active, native_link_modifiers_bundle, "1.53.0", Some(81490), None),
653 /// Allows specifying the verbatim link modifier
654 (active, native_link_modifiers_verbatim, "1.53.0", Some(81490), None),
656 /// Allows specifying the whole-archive link modifier
657 (active, native_link_modifiers_whole_archive, "1.53.0", Some(81490), None),
659 /// Allows specifying the as-needed link modifier
660 (active, native_link_modifiers_as_needed, "1.53.0", Some(81490), None),
662 /// Allows unnamed fields of struct and union type
663 (active, unnamed_fields, "1.53.0", Some(49804), None),
665 // -------------------------------------------------------------------------
666 // feature-group-end: actual feature gates
667 // -------------------------------------------------------------------------
670 /// Some features are known to be incomplete and using them is likely to have
671 /// unanticipated results, such as compiler crashes. We warn the user about these
673 pub const INCOMPLETE_FEATURES: &[Symbol] = &[
675 sym::impl_trait_in_bindings,
676 sym::generic_associated_types,
680 sym::const_evaluatable_checked,
681 sym::const_trait_impl,
682 sym::const_trait_bound_opt_out,
683 sym::lazy_normalization_consts,
688 sym::capture_disjoint_fields,
689 sym::inherent_associated_types,
690 sym::type_alias_impl_trait,
691 sym::rustc_insignificant_dtor,
695 /// Some features are not allowed to be used together at the same time, if
696 /// the two are present, produce an error.
698 /// Currently empty, but we will probably need this again in the future,
699 /// so let's keep it in for now.
700 pub const INCOMPATIBLE_FEATURES: &[(Symbol, Symbol)] = &[];