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 {
19 (__status_to_bool active) => {
22 (__status_to_bool incomplete) => {
26 $(#[doc = $doc:tt])* ($status:ident, $feature:ident, $ver:expr, $issue:expr, $edition:expr),
28 /// Represents active features that are currently being implemented or
29 /// currently being considered for addition/removal.
30 pub const ACTIVE_FEATURES:
33 // (sym::$feature, $ver, $issue, $edition, set!($feature))
35 state: State::Active { set: set!($feature) },
38 issue: to_nonzero($issue),
43 /// A set of features to be used by later passes.
44 #[derive(Clone, Default, Debug)]
46 /// `#![feature]` attrs for language features, for error reporting.
47 pub declared_lang_features: Vec<(Symbol, Span, Option<Symbol>)>,
48 /// `#![feature]` attrs for non-language (library) features.
49 pub declared_lib_features: Vec<(Symbol, Span)>,
57 pub fn walk_feature_fields(&self, mut f: impl FnMut(&str, bool)) {
58 $(f(stringify!($feature), self.$feature);)+
61 /// Is the given feature enabled?
63 /// Panics if the symbol doesn't correspond to a declared feature.
64 pub fn enabled(&self, feature: Symbol) -> bool {
66 $( sym::$feature => self.$feature, )*
68 _ => panic!("`{}` was not listed in `declare_features`", feature),
72 /// Some features are known to be incomplete and using them is likely to have
73 /// unanticipated results, such as compiler crashes. We warn the user about these
75 pub fn incomplete(&self, feature: Symbol) -> bool {
78 sym::$feature => declare_features!(__status_to_bool $status),
80 // accepted and removed features aren't in this file but are never incomplete
81 _ if self.declared_lang_features.iter().any(|f| f.0 == feature) => false,
82 _ if self.declared_lib_features.iter().any(|f| f.0 == feature) => false,
83 _ => panic!("`{}` was not listed in `declare_features`", feature),
91 /// Sets this feature in `Features`. Panics if called on a non-active feature.
92 pub fn set(&self, features: &mut Features, span: Span) {
94 State::Active { set } => set(features, span),
95 _ => panic!("called `set` on feature `{}` which is not `active`", self.name),
100 // See https://rustc-dev-guide.rust-lang.org/feature-gates.html#feature-gates for more
101 // documentation about handling feature gates.
103 // If you change this, please modify `src/doc/unstable-book` as well.
105 // Don't ever remove anything from this list; move them to `accepted.rs` if
106 // accepted or `removed.rs` if removed.
108 // The version numbers here correspond to the version in which the current status
109 // was set. This is most important for knowing when a particular feature became
112 // Note that the features are grouped into internal/user-facing and then
113 // sorted by version inside those groups. This is enforced with tidy.
115 // N.B., `tools/tidy/src/features.rs` parses this information directly out of the
116 // source, so take care when modifying it.
120 // -------------------------------------------------------------------------
121 // feature-group-start: internal feature gates (no tracking issue)
122 // -------------------------------------------------------------------------
123 // no-tracking-issue-start
125 /// Allows using the `thiscall` ABI.
126 (active, abi_thiscall, "1.19.0", None, None),
127 /// Allows using the `unadjusted` ABI; perma-unstable.
128 (active, abi_unadjusted, "1.16.0", None, None),
129 /// Allows using the `vectorcall` ABI.
130 (active, abi_vectorcall, "1.7.0", None, None),
131 /// Allows using `#![needs_allocator]`, an implementation detail of `#[global_allocator]`.
132 (active, allocator_internals, "1.20.0", None, None),
133 /// Allows using `#[allow_internal_unsafe]`. This is an
134 /// attribute on `macro_rules!` and can't use the attribute handling
135 /// below (it has to be checked before expansion possibly makes
136 /// macros disappear).
137 (active, allow_internal_unsafe, "1.0.0", None, None),
138 /// Allows using `#[allow_internal_unstable]`. This is an
139 /// attribute on `macro_rules!` and can't use the attribute handling
140 /// below (it has to be checked before expansion possibly makes
141 /// macros disappear).
142 (active, allow_internal_unstable, "1.0.0", None, None),
143 /// Allows identifying the `compiler_builtins` crate.
144 (active, compiler_builtins, "1.13.0", None, None),
145 /// Allows using the `rust-intrinsic`'s "ABI".
146 (active, intrinsics, "1.0.0", None, None),
147 /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic.
148 (active, lang_items, "1.0.0", None, None),
149 /// Allows `#[repr(no_niche)]` (an implementation detail of `rustc`,
150 /// it is not on path for eventual stabilization).
151 (active, no_niche, "1.42.0", None, None),
152 /// Allows using `#[omit_gdb_pretty_printer_section]`.
153 (active, omit_gdb_pretty_printer_section, "1.5.0", None, None),
154 /// Allows using `#[prelude_import]` on glob `use` items.
155 (active, prelude_import, "1.2.0", None, None),
156 /// Used to identify crates that contain the profiler runtime.
157 (active, profiler_runtime, "1.18.0", None, None),
158 /// Allows using `rustc_*` attributes (RFC 572).
159 (active, rustc_attrs, "1.0.0", None, None),
160 /// Allows using the `#[stable]` and `#[unstable]` attributes.
161 (active, staged_api, "1.0.0", None, None),
162 /// Added for testing E0705; perma-unstable.
163 (active, test_2018_feature, "1.31.0", None, Some(Edition::Edition2018)),
164 /// Use for stable + negative coherence and strict coherence depending on trait's
165 /// rustc_strict_coherence value.
166 (active, with_negative_coherence, "1.60.0", None, None),
167 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
168 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
169 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
171 // no-tracking-issue-end
172 // -------------------------------------------------------------------------
173 // feature-group-end: internal feature gates (no tracking issue)
174 // -------------------------------------------------------------------------
176 // -------------------------------------------------------------------------
177 // feature-group-start: internal feature gates
178 // -------------------------------------------------------------------------
180 /// Allows features specific to auto traits.
181 /// Renamed from `optin_builtin_traits`.
182 (active, auto_traits, "1.50.0", Some(13231), None),
183 /// Allows using `box` in patterns (RFC 469).
184 (active, box_patterns, "1.0.0", Some(29641), None),
185 /// Allows using the `box $expr` syntax.
186 (active, box_syntax, "1.0.0", Some(49733), None),
187 /// Allows `#[doc(notable_trait)]`.
188 /// Renamed from `doc_spotlight`.
189 (active, doc_notable_trait, "1.52.0", Some(45040), None),
190 /// Allows using the `may_dangle` attribute (RFC 1327).
191 (active, dropck_eyepatch, "1.10.0", Some(34761), None),
192 /// Allows using the `#[fundamental]` attribute.
193 (active, fundamental, "1.0.0", Some(29635), None),
194 /// Allows using `#[link_name="llvm.*"]`.
195 (active, link_llvm_intrinsics, "1.0.0", Some(29602), None),
196 /// Allows using the `#[linkage = ".."]` attribute.
197 (active, linkage, "1.0.0", Some(29603), None),
198 /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed.
199 (active, needs_panic_runtime, "1.10.0", Some(32837), None),
200 /// Allows using the `#![panic_runtime]` attribute.
201 (active, panic_runtime, "1.10.0", Some(32837), None),
202 /// Allows using `#[rustc_allow_const_fn_unstable]`.
203 /// This is an attribute on `const fn` for the same
204 /// purpose as `#[allow_internal_unstable]`.
205 (active, rustc_allow_const_fn_unstable, "1.49.0", Some(69399), None),
206 /// Allows using compiler's own crates.
207 (active, rustc_private, "1.0.0", Some(27812), None),
208 /// Allows using internal rustdoc features like `doc(primitive)` or `doc(keyword)`.
209 (active, rustdoc_internals, "1.58.0", Some(90418), None),
210 /// Allows using `#[start]` on a function indicating that it is the program entrypoint.
211 (active, start, "1.0.0", Some(29633), None),
212 /// Allows using `#[structural_match]` which indicates that a type is structurally matchable.
213 /// FIXME: Subsumed by trait `StructuralPartialEq`, cannot move to removed until a library
214 /// feature with the same name exists.
215 (active, structural_match, "1.8.0", Some(31434), None),
216 /// Allows using the `rust-call` ABI.
217 (active, unboxed_closures, "1.0.0", Some(29625), None),
218 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
219 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
220 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
222 // -------------------------------------------------------------------------
223 // feature-group-end: internal feature gates
224 // -------------------------------------------------------------------------
226 // -------------------------------------------------------------------------
227 // feature-group-start: actual feature gates (target features)
228 // -------------------------------------------------------------------------
230 // FIXME: Document these and merge with the list below.
232 // Unstable `#[target_feature]` directives.
233 (active, aarch64_target_feature, "1.27.0", Some(44839), None),
234 (active, adx_target_feature, "1.32.0", Some(44839), None),
235 (active, arm_target_feature, "1.27.0", Some(44839), None),
236 (active, avx512_target_feature, "1.27.0", Some(44839), None),
237 (active, bpf_target_feature, "1.54.0", Some(44839), None),
238 (active, cmpxchg16b_target_feature, "1.32.0", Some(44839), None),
239 (active, ermsb_target_feature, "1.49.0", Some(44839), None),
240 (active, f16c_target_feature, "1.36.0", Some(44839), None),
241 (active, hexagon_target_feature, "1.27.0", Some(44839), None),
242 (active, mips_target_feature, "1.27.0", Some(44839), None),
243 (active, movbe_target_feature, "1.34.0", Some(44839), None),
244 (active, powerpc_target_feature, "1.27.0", Some(44839), None),
245 (active, riscv_target_feature, "1.45.0", Some(44839), None),
246 (active, rtm_target_feature, "1.35.0", Some(44839), None),
247 (active, sse4a_target_feature, "1.27.0", Some(44839), None),
248 (active, tbm_target_feature, "1.27.0", Some(44839), None),
249 (active, wasm_target_feature, "1.30.0", Some(44839), None),
250 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
251 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
252 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
254 // -------------------------------------------------------------------------
255 // feature-group-end: actual feature gates (target features)
256 // -------------------------------------------------------------------------
258 // -------------------------------------------------------------------------
259 // feature-group-start: actual feature gates
260 // -------------------------------------------------------------------------
262 /// Allows using the `amdgpu-kernel` ABI.
263 (active, abi_amdgpu_kernel, "1.29.0", Some(51575), None),
264 /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`.
265 (active, abi_avr_interrupt, "1.45.0", Some(69664), None),
266 /// Allows `extern "C-cmse-nonsecure-call" fn()`.
267 (active, abi_c_cmse_nonsecure_call, "1.51.0", Some(81391), None),
268 /// Allows using the `efiapi` ABI.
269 (active, abi_efiapi, "1.40.0", Some(65815), None),
270 /// Allows `extern "msp430-interrupt" fn()`.
271 (active, abi_msp430_interrupt, "1.16.0", Some(38487), None),
272 /// Allows `extern "ptx-*" fn()`.
273 (active, abi_ptx, "1.15.0", Some(38788), None),
274 /// Allows `extern "x86-interrupt" fn()`.
275 (active, abi_x86_interrupt, "1.17.0", Some(40180), None),
276 /// Allows additional const parameter types, such as `&'static str` or user defined types
277 (incomplete, adt_const_params, "1.56.0", Some(44580), None),
278 /// Allows defining an `#[alloc_error_handler]`.
279 (active, alloc_error_handler, "1.29.0", Some(51540), None),
280 /// Allows a test to fail without failing the whole suite.
281 (active, allow_fail, "1.19.0", Some(46488), None),
282 /// Allows explicit discriminants on non-unit enum variants.
283 (active, arbitrary_enum_discriminant, "1.37.0", Some(60553), None),
284 /// Allows trait methods with arbitrary self types.
285 (active, arbitrary_self_types, "1.23.0", Some(44874), None),
286 /// Allows using `const` operands in inline assembly.
287 (active, asm_const, "1.58.0", Some(72016), None),
288 /// Enables experimental inline assembly support for additional architectures.
289 (active, asm_experimental_arch, "1.58.0", Some(72016), None),
290 /// Allows using `sym` operands in inline assembly.
291 (active, asm_sym, "1.58.0", Some(72016), None),
292 /// Allows the `may_unwind` option in inline assembly.
293 (active, asm_unwind, "1.58.0", Some(72016), None),
294 /// Allows users to enforce equality of associated constants `TraitImpl<AssocConst=3>`.
295 (active, associated_const_equality, "1.58.0", Some(92827), None),
296 /// Allows the user of associated type bounds.
297 (active, associated_type_bounds, "1.34.0", Some(52662), None),
298 /// Allows associated type defaults.
299 (active, associated_type_defaults, "1.2.0", Some(29661), None),
300 /// Allows `async || body` closures.
301 (active, async_closure, "1.37.0", Some(62290), None),
302 /// Allows `extern "C-unwind" fn` to enable unwinding across ABI boundaries.
303 (active, c_unwind, "1.52.0", Some(74990), None),
304 /// Allows using C-variadics.
305 (active, c_variadic, "1.34.0", Some(44930), None),
306 /// Allows capturing disjoint fields in a closure/generator (RFC 2229).
307 (incomplete, capture_disjoint_fields, "1.49.0", Some(53488), None),
308 /// Enables `#[cfg(panic = "...")]` config key.
309 (active, cfg_panic, "1.49.0", Some(77443), None),
310 /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used.
311 (active, cfg_sanitize, "1.41.0", Some(39699), None),
312 /// Allows `cfg(target_abi = "...")`.
313 (active, cfg_target_abi, "1.55.0", Some(80970), None),
314 /// Allows `cfg(target_has_atomic = "...")`.
315 (active, cfg_target_has_atomic, "1.9.0", Some(32976), None),
316 /// Allows `cfg(target_thread_local)`.
317 (active, cfg_target_thread_local, "1.7.0", Some(29594), None),
318 /// Allow conditional compilation depending on rust version
319 (active, cfg_version, "1.45.0", Some(64796), None),
320 /// Allows `#[track_caller]` on closures and generators.
321 (active, closure_track_caller, "1.57.0", Some(87417), None),
322 /// Allows to use the `#[cmse_nonsecure_entry]` attribute.
323 (active, cmse_nonsecure_entry, "1.48.0", Some(75835), None),
324 /// Allows `async {}` expressions in const contexts.
325 (active, const_async_blocks, "1.53.0", Some(85368), None),
326 // Allows limiting the evaluation steps of const expressions
327 (active, const_eval_limit, "1.43.0", Some(67217), None),
328 /// Allows the definition of `const extern fn` and `const unsafe extern fn`.
329 (active, const_extern_fn, "1.40.0", Some(64926), None),
330 /// Allows basic arithmetic on floating point types in a `const fn`.
331 (active, const_fn_floating_point_arithmetic, "1.48.0", Some(57241), None),
332 /// Allows using and casting function pointers in a `const fn`.
333 (active, const_fn_fn_ptr_basics, "1.48.0", Some(57563), None),
334 /// Allows trait bounds in `const fn`.
335 (active, const_fn_trait_bound, "1.53.0", Some(57563), None),
336 /// Allows `for _ in _` loops in const contexts.
337 (active, const_for, "1.56.0", Some(87575), None),
338 /// Allows argument and return position `impl Trait` in a `const fn`.
339 (active, const_impl_trait, "1.48.0", Some(77463), None),
340 /// Allows using `&mut` in constant functions.
341 (active, const_mut_refs, "1.41.0", Some(57349), None),
342 /// Be more precise when looking for live drops in a const context.
343 (active, const_precise_live_drops, "1.46.0", Some(73255), None),
344 /// Allows references to types with interior mutability within constants
345 (active, const_refs_to_cell, "1.51.0", Some(80384), None),
346 /// Allows `impl const Trait for T` syntax.
347 (active, const_trait_impl, "1.42.0", Some(67792), None),
348 /// Allows the `?` operator in const contexts.
349 (active, const_try, "1.56.0", Some(74935), None),
350 /// Allows using `crate` as visibility modifier, synonymous with `pub(crate)`.
351 (active, crate_visibility_modifier, "1.23.0", Some(53120), None),
352 /// Allows non-builtin attributes in inner attribute position.
353 (active, custom_inner_attributes, "1.30.0", Some(54726), None),
354 /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`.
355 (active, custom_test_frameworks, "1.30.0", Some(50297), None),
356 /// Allows declarative macros 2.0 (`macro`).
357 (active, decl_macro, "1.17.0", Some(39412), None),
358 /// Allows rustc to inject a default alloc_error_handler
359 (active, default_alloc_error_handler, "1.48.0", Some(66741), None),
360 /// Allows default type parameters to influence type inference.
361 (active, default_type_parameter_fallback, "1.3.0", Some(27336), None),
362 /// Allows `#[derive(Default)]` and `#[default]` on enums.
363 (active, derive_default_enum, "1.56.0", Some(86985), None),
364 /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`.
365 (active, doc_auto_cfg, "1.58.0", Some(43781), None),
366 /// Allows `#[doc(cfg(...))]`.
367 (active, doc_cfg, "1.21.0", Some(43781), None),
368 /// Allows `#[doc(cfg_hide(...))]`.
369 (active, doc_cfg_hide, "1.57.0", Some(43781), None),
370 /// Allows `#[doc(masked)]`.
371 (active, doc_masked, "1.21.0", Some(44027), None),
372 /// Allows `X..Y` patterns.
373 (active, exclusive_range_pattern, "1.11.0", Some(37854), None),
374 /// Allows exhaustive pattern matching on types that contain uninhabited types.
375 (active, exhaustive_patterns, "1.13.0", Some(51085), None),
376 /// Allows explicit generic arguments specification with `impl Trait` present.
377 (active, explicit_generic_args_with_impl_trait, "1.56.0", Some(83701), None),
378 /// Allows defining `extern type`s.
379 (active, extern_types, "1.23.0", Some(43467), None),
380 /// Allows the use of `#[ffi_const]` on foreign functions.
381 (active, ffi_const, "1.45.0", Some(58328), None),
382 /// Allows the use of `#[ffi_pure]` on foreign functions.
383 (active, ffi_pure, "1.45.0", Some(58329), None),
384 /// Allows using `#[ffi_returns_twice]` on foreign functions.
385 (active, ffi_returns_twice, "1.34.0", Some(58314), None),
386 /// Allows using `#[repr(align(...))]` on function items
387 (active, fn_align, "1.53.0", Some(82232), None),
388 /// Allows defining generators.
389 (active, generators, "1.21.0", Some(43122), None),
390 /// Infer generic args for both consts and types.
391 (active, generic_arg_infer, "1.55.0", Some(85077), None),
392 /// Allows associated types to be generic, e.g., `type Foo<T>;` (RFC 1598).
393 (active, generic_associated_types, "1.23.0", Some(44265), None),
394 /// Allows non-trivial generic constants which have to have wfness manually propagated to callers
395 (incomplete, generic_const_exprs, "1.56.0", Some(76560), None),
396 /// Allows using `..X`, `..=X`, `...X`, and `X..` as a pattern.
397 (active, half_open_range_patterns, "1.41.0", Some(67264), None),
398 /// Allows `if let` guard in match arms.
399 (active, if_let_guard, "1.47.0", Some(51114), None),
400 /// Allows using imported `main` function
401 (active, imported_main, "1.53.0", Some(28937), None),
402 /// Allows in-band quantification of lifetime bindings (e.g., `fn foo(x: &'a u8) -> &'a u8`).
403 (active, in_band_lifetimes, "1.23.0", Some(44524), None),
404 /// Allows inferring `'static` outlives requirements (RFC 2093).
405 (active, infer_static_outlives_requirements, "1.26.0", Some(54185), None),
406 /// Allows associated types in inherent impls.
407 (incomplete, inherent_associated_types, "1.52.0", Some(8995), None),
408 /// Allow anonymous constants from an inline `const` block
409 (active, inline_const, "1.49.0", Some(76001), None),
410 /// Allow anonymous constants from an inline `const` block in pattern position
411 (incomplete, inline_const_pat, "1.58.0", Some(76001), None),
412 /// Allows using `pointer` and `reference` in intra-doc links
413 (active, intra_doc_pointers, "1.51.0", Some(80896), None),
414 /// Allows `#[instruction_set(_)]` attribute
415 (active, isa_attribute, "1.48.0", Some(74727), None),
416 /// Allows `'a: { break 'a; }`.
417 (active, label_break_value, "1.28.0", Some(48594), None),
418 // Allows setting the threshold for the `large_assignments` lint.
419 (active, large_assignments, "1.52.0", Some(83518), None),
420 /// Allows `if/while p && let q = r && ...` chains.
421 (active, let_chains, "1.37.0", Some(53667), None),
422 /// Allows `let...else` statements.
423 (active, let_else, "1.56.0", Some(87335), None),
424 /// Allows `#[link(..., cfg(..))]`.
425 (active, link_cfg, "1.14.0", Some(37406), None),
426 /// Allows using `reason` in lint attributes and the `#[expect(lint)]` lint check.
427 (active, lint_reasons, "1.31.0", Some(54503), None),
428 /// Allows `#[marker]` on certain traits allowing overlapping implementations.
429 (active, marker_trait_attr, "1.30.0", Some(29864), None),
430 /// A minimal, sound subset of specialization intended to be used by the
431 /// standard library until the soundness issues with specialization
433 (active, min_specialization, "1.7.0", Some(31844), None),
434 /// Allows qualified paths in struct expressions, struct patterns and tuple struct patterns.
435 (active, more_qualified_paths, "1.54.0", Some(86935), None),
436 /// Allows the `#[must_not_suspend]` attribute.
437 (active, must_not_suspend, "1.57.0", Some(83310), None),
438 /// Allows using `#[naked]` on functions.
439 (active, naked_functions, "1.9.0", Some(32408), None),
440 /// Allows specifying modifiers in the link attribute: `#[link(modifiers = "...")]`
441 (active, native_link_modifiers, "1.53.0", Some(81490), None),
442 /// Allows specifying the as-needed link modifier
443 (active, native_link_modifiers_as_needed, "1.53.0", Some(81490), None),
444 /// Allows specifying the bundle link modifier
445 (active, native_link_modifiers_bundle, "1.53.0", Some(81490), None),
446 /// Allows specifying the verbatim link modifier
447 (active, native_link_modifiers_verbatim, "1.53.0", Some(81490), None),
448 /// Allows specifying the whole-archive link modifier
449 (active, native_link_modifiers_whole_archive, "1.53.0", Some(81490), None),
450 /// Allow negative trait implementations.
451 (active, negative_impls, "1.44.0", Some(68318), None),
452 /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more.
453 (active, never_type, "1.13.0", Some(35121), None),
454 /// Allows diverging expressions to fall back to `!` rather than `()`.
455 (active, never_type_fallback, "1.41.0", Some(65992), None),
456 /// Allows using non lexical lifetimes (RFC 2094).
457 (active, nll, "1.0.0", Some(43234), None),
458 /// Allows `#![no_core]`.
459 (active, no_core, "1.3.0", Some(29639), None),
460 /// Allows function attribute `#[no_coverage]`, to bypass coverage
461 /// instrumentation of that function.
462 (active, no_coverage, "1.53.0", Some(84605), None),
463 /// Allows the use of `no_sanitize` attribute.
464 (active, no_sanitize, "1.42.0", Some(39699), None),
465 /// Allows using the `non_exhaustive_omitted_patterns` lint.
466 (active, non_exhaustive_omitted_patterns_lint, "1.57.0", Some(89554), None),
467 /// Allows making `dyn Trait` well-formed even if `Trait` is not object safe.
468 /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and
469 /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.
470 (active, object_safe_for_dispatch, "1.40.0", Some(43561), None),
471 /// Allows using `#[optimize(X)]`.
472 (active, optimize_attribute, "1.34.0", Some(54882), None),
473 /// Allows `extern "platform-intrinsic" { ... }`.
474 (active, platform_intrinsics, "1.4.0", Some(27731), None),
475 /// Allows using `#![plugin(myplugin)]`.
476 (active, plugin, "1.0.0", Some(29597), None),
477 /// Allows exhaustive integer pattern matching on `usize` and `isize`.
478 (active, precise_pointer_size_matching, "1.32.0", Some(56354), None),
479 /// Allows macro attributes on expressions, statements and non-inline modules.
480 (active, proc_macro_hygiene, "1.30.0", Some(54727), None),
481 /// Allows the use of raw-dylibs (RFC 2627).
482 (incomplete, raw_dylib, "1.40.0", Some(58713), None),
483 /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions.
484 (active, raw_ref_op, "1.41.0", Some(64490), None),
485 /// Allows using the `#[register_attr]` attribute.
486 (active, register_attr, "1.41.0", Some(66080), None),
487 /// Allows using the `#[register_tool]` attribute.
488 (active, register_tool, "1.41.0", Some(66079), None),
489 /// Allows the `#[repr(i128)]` attribute for enums.
490 (incomplete, repr128, "1.16.0", Some(56071), None),
491 /// Allows `repr(simd)` and importing the various simd intrinsics.
492 (active, repr_simd, "1.4.0", Some(27731), None),
493 /// Allows the use of SIMD types in functions declared in `extern` blocks.
494 (active, simd_ffi, "1.0.0", Some(27731), None),
495 /// Allows specialization of implementations (RFC 1210).
496 (incomplete, specialization, "1.7.0", Some(31844), None),
497 /// Allows `#[link(kind="static-nobundle"...)]`.
498 (active, static_nobundle, "1.16.0", Some(37403), None),
499 /// Allows attributes on expressions and non-item statements.
500 (active, stmt_expr_attributes, "1.6.0", Some(15701), None),
501 /// Allows the use of `#[target_feature]` on safe functions.
502 (active, target_feature_11, "1.45.0", Some(69098), None),
503 /// Allows using `#[thread_local]` on `static` items.
504 (active, thread_local, "1.0.0", Some(29594), None),
505 /// Allows defining `trait X = A + B;` alias items.
506 (active, trait_alias, "1.24.0", Some(41517), None),
507 /// Allows upcasting trait objects via supertraits.
508 /// Trait upcasting is casting, e.g., `dyn Foo -> dyn Bar` where `Foo: Bar`.
509 (incomplete, trait_upcasting, "1.56.0", Some(65991), None),
510 /// Allows #[repr(transparent)] on unions (RFC 2645).
511 (active, transparent_unions, "1.37.0", Some(60405), None),
512 /// Allows inconsistent bounds in where clauses.
513 (active, trivial_bounds, "1.28.0", Some(48214), None),
514 /// Allows using `try {...}` expressions.
515 (active, try_blocks, "1.29.0", Some(31436), None),
516 /// Allows `impl Trait` to be used inside type aliases (RFC 2515).
517 (active, type_alias_impl_trait, "1.38.0", Some(63063), None),
518 /// Allows the use of type ascription in expressions.
519 (active, type_ascription, "1.6.0", Some(23416), None),
520 /// Allows creation of instances of a struct by moving fields that have
521 /// not changed from prior instances of the same struct (RFC #2528)
522 (incomplete, type_changing_struct_update, "1.58.0", Some(86555), None),
523 /// Allows unsized fn parameters.
524 (active, unsized_fn_params, "1.49.0", Some(48055), None),
525 /// Allows unsized rvalues at arguments and parameters.
526 (incomplete, unsized_locals, "1.30.0", Some(48055), None),
527 /// Allows unsized tuple coercion.
528 (active, unsized_tuple_coercion, "1.20.0", Some(42877), None),
529 /// Allows `union`s to implement `Drop`. Moreover, `union`s may now include fields
530 /// that don't implement `Copy` as long as they don't have any drop glue.
531 /// This is checked recursively. On encountering type variable where no progress can be made,
532 /// `T: Copy` is used as a substitute for "no drop glue".
534 /// NOTE: A limited form of `union U { ... }` was accepted in 1.19.0.
535 (active, untagged_unions, "1.13.0", Some(55149), None),
536 /// Allows `extern "wasm" fn`
537 (active, wasm_abi, "1.53.0", Some(83788), None),
538 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
539 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
540 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
542 // -------------------------------------------------------------------------
543 // feature-group-end: actual feature gates
544 // -------------------------------------------------------------------------
547 /// Some features are not allowed to be used together at the same time, if
548 /// the two are present, produce an error.
550 /// Currently empty, but we will probably need this again in the future,
551 /// so let's keep it in for now.
552 pub const INCOMPATIBLE_FEATURES: &[(Symbol, Symbol)] = &[];