1 //! List of the active feature gates.
3 use super::{to_nonzero, Feature, State}
;
5 use rustc_data_structures
::fx
::FxHashSet
;
6 use rustc_span
::edition
::Edition
;
7 use rustc_span
::symbol
::{sym, Symbol}
;
12 fn f(features
: &mut Features
, _
: Span
) {
13 features
.$field
= true;
15 f
as fn(&mut Features
, Span
)
19 macro_rules
! declare_features
{
20 (__status_to_bool active
) => {
23 (__status_to_bool incomplete
) => {
27 $
(#[doc = $doc:tt])* ($status:ident, $feature:ident, $ver:expr, $issue:expr, $edition:expr),
29 /// Represents active features that are currently being implemented or
30 /// currently being considered for addition/removal.
31 pub const ACTIVE_FEATURES
:
34 // (sym::$feature, $ver, $issue, $edition, set!($feature))
36 state
: State
::Active { set: set!($feature) }
,
39 issue
: to_nonzero($issue
),
44 /// A set of features to be used by later passes.
45 #[derive(Clone, Default, Debug)]
47 /// `#![feature]` attrs for language features, for error reporting.
48 pub declared_lang_features
: Vec
<(Symbol
, Span
, Option
<Symbol
>)>,
49 /// `#![feature]` attrs for non-language (library) features.
50 pub declared_lib_features
: Vec
<(Symbol
, Span
)>,
51 /// Features enabled for this crate.
52 pub active_features
: FxHashSet
<Symbol
>,
60 pub fn walk_feature_fields(&self, mut f
: impl FnMut(&str, bool
)) {
61 $
(f(stringify
!($feature
), self.$feature
);)+
64 /// Is the given feature active?
65 pub fn active(&self, feature
: Symbol
) -> bool
{
66 self.active_features
.contains(&feature
)
69 /// Is the given feature enabled?
71 /// Panics if the symbol doesn't correspond to a declared feature.
72 pub fn enabled(&self, feature
: Symbol
) -> bool
{
74 $
( sym
::$feature
=> self.$feature
, )*
76 _
=> panic
!("`{}` was not listed in `declare_features`", feature
),
80 /// Some features are known to be incomplete and using them is likely to have
81 /// unanticipated results, such as compiler crashes. We warn the user about these
83 pub fn incomplete(&self, feature
: Symbol
) -> bool
{
86 sym
::$feature
=> declare_features
!(__status_to_bool $status
),
88 // accepted and removed features aren't in this file but are never incomplete
89 _
if self.declared_lang_features
.iter().any(|f
| f
.0 == feature
) => false,
90 _
if self.declared_lib_features
.iter().any(|f
| f
.0 == feature
) => false,
91 _
=> panic
!("`{}` was not listed in `declare_features`", feature
),
99 /// Sets this feature in `Features`. Panics if called on a non-active feature.
100 pub fn set(&self, features
: &mut Features
, span
: Span
) {
102 State
::Active { set }
=> set(features
, span
),
103 _
=> panic
!("called `set` on feature `{}` which is not `active`", self.name
),
108 // See https://rustc-dev-guide.rust-lang.org/feature-gates.html#feature-gates for more
109 // documentation about handling feature gates.
111 // If you change this, please modify `src/doc/unstable-book` as well.
113 // Don't ever remove anything from this list; move them to `accepted.rs` if
114 // accepted or `removed.rs` if removed.
116 // The version numbers here correspond to the version in which the current status
117 // was set. This is most important for knowing when a particular feature became
120 // Note that the features are grouped into internal/user-facing and then
121 // sorted by version inside those groups. This is enforced with tidy.
123 // N.B., `tools/tidy/src/features.rs` parses this information directly out of the
124 // source, so take care when modifying it.
128 // -------------------------------------------------------------------------
129 // feature-group-start: internal feature gates (no tracking issue)
130 // -------------------------------------------------------------------------
131 // no-tracking-issue-start
133 /// Allows using the `thiscall` ABI.
134 (active
, abi_thiscall
, "1.19.0", None
, None
),
135 /// Allows using the `unadjusted` ABI; perma-unstable.
136 (active
, abi_unadjusted
, "1.16.0", None
, None
),
137 /// Allows using the `vectorcall` ABI.
138 (active
, abi_vectorcall
, "1.7.0", None
, None
),
139 /// Allows using `#![needs_allocator]`, an implementation detail of `#[global_allocator]`.
140 (active
, allocator_internals
, "1.20.0", None
, None
),
141 /// Allows using `#[allow_internal_unsafe]`. This is an
142 /// attribute on `macro_rules!` and can't use the attribute handling
143 /// below (it has to be checked before expansion possibly makes
144 /// macros disappear).
145 (active
, allow_internal_unsafe
, "1.0.0", None
, None
),
146 /// Allows using `#[allow_internal_unstable]`. This is an
147 /// attribute on `macro_rules!` and can't use the attribute handling
148 /// below (it has to be checked before expansion possibly makes
149 /// macros disappear).
150 (active
, allow_internal_unstable
, "1.0.0", None
, None
),
151 /// Allows identifying the `compiler_builtins` crate.
152 (active
, compiler_builtins
, "1.13.0", None
, None
),
153 /// Allows using the `rust-intrinsic`'s "ABI".
154 (active
, intrinsics
, "1.0.0", None
, None
),
155 /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic.
156 (active
, lang_items
, "1.0.0", None
, None
),
157 /// Allows `#[repr(no_niche)]` (an implementation detail of `rustc`,
158 /// it is not on path for eventual stabilization).
159 (active
, no_niche
, "1.42.0", None
, None
),
160 /// Allows using `#[omit_gdb_pretty_printer_section]`.
161 (active
, omit_gdb_pretty_printer_section
, "1.5.0", None
, None
),
162 /// Allows using `#[prelude_import]` on glob `use` items.
163 (active
, prelude_import
, "1.2.0", None
, None
),
164 /// Used to identify crates that contain the profiler runtime.
165 (active
, profiler_runtime
, "1.18.0", None
, None
),
166 /// Allows using `rustc_*` attributes (RFC 572).
167 (active
, rustc_attrs
, "1.0.0", None
, None
),
168 /// Allows using the `#[stable]` and `#[unstable]` attributes.
169 (active
, staged_api
, "1.0.0", None
, None
),
170 /// Added for testing E0705; perma-unstable.
171 (active
, test_2018_feature
, "1.31.0", None
, Some(Edition
::Edition2018
)),
172 /// Added for testing unstable lints; perma-unstable.
173 (active
, test_unstable_lint
, "1.60.0", None
, None
),
174 /// Allows non-`unsafe` —and thus, unsound— access to `Pin` constructions.
175 /// Marked `incomplete` since perma-unstable and unsound.
176 (incomplete
, unsafe_pin_internals
, "1.60.0", None
, None
),
177 /// Use for stable + negative coherence and strict coherence depending on trait's
178 /// rustc_strict_coherence value.
179 (active
, with_negative_coherence
, "1.60.0", None
, None
),
180 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
181 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
182 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
184 // no-tracking-issue-end
185 // -------------------------------------------------------------------------
186 // feature-group-end: internal feature gates (no tracking issue)
187 // -------------------------------------------------------------------------
189 // -------------------------------------------------------------------------
190 // feature-group-start: internal feature gates
191 // -------------------------------------------------------------------------
193 /// Allows features specific to auto traits.
194 /// Renamed from `optin_builtin_traits`.
195 (active
, auto_traits
, "1.50.0", Some(13231), None
),
196 /// Allows using `box` in patterns (RFC 469).
197 (active
, box_patterns
, "1.0.0", Some(29641), None
),
198 /// Allows using the `box $expr` syntax.
199 (active
, box_syntax
, "1.0.0", Some(49733), None
),
200 /// Allows `#[doc(notable_trait)]`.
201 /// Renamed from `doc_spotlight`.
202 (active
, doc_notable_trait
, "1.52.0", Some(45040), None
),
203 /// Allows using the `may_dangle` attribute (RFC 1327).
204 (active
, dropck_eyepatch
, "1.10.0", Some(34761), None
),
205 /// Allows using the `#[fundamental]` attribute.
206 (active
, fundamental
, "1.0.0", Some(29635), None
),
207 /// Allows using `#[link_name="llvm.*"]`.
208 (active
, link_llvm_intrinsics
, "1.0.0", Some(29602), None
),
209 /// Allows using the `#[linkage = ".."]` attribute.
210 (active
, linkage
, "1.0.0", Some(29603), None
),
211 /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed.
212 (active
, needs_panic_runtime
, "1.10.0", Some(32837), None
),
213 /// Allows using the `#![panic_runtime]` attribute.
214 (active
, panic_runtime
, "1.10.0", Some(32837), None
),
215 /// Allows using `#[rustc_allow_const_fn_unstable]`.
216 /// This is an attribute on `const fn` for the same
217 /// purpose as `#[allow_internal_unstable]`.
218 (active
, rustc_allow_const_fn_unstable
, "1.49.0", Some(69399), None
),
219 /// Allows using compiler's own crates.
220 (active
, rustc_private
, "1.0.0", Some(27812), None
),
221 /// Allows using internal rustdoc features like `doc(primitive)` or `doc(keyword)`.
222 (active
, rustdoc_internals
, "1.58.0", Some(90418), None
),
223 /// Allows using `#[start]` on a function indicating that it is the program entrypoint.
224 (active
, start
, "1.0.0", Some(29633), None
),
225 /// Allows using `#[structural_match]` which indicates that a type is structurally matchable.
226 /// FIXME: Subsumed by trait `StructuralPartialEq`, cannot move to removed until a library
227 /// feature with the same name exists.
228 (active
, structural_match
, "1.8.0", Some(31434), None
),
229 /// Allows using the `rust-call` ABI.
230 (active
, unboxed_closures
, "1.0.0", Some(29625), None
),
231 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
232 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
233 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
235 // -------------------------------------------------------------------------
236 // feature-group-end: internal feature gates
237 // -------------------------------------------------------------------------
239 // -------------------------------------------------------------------------
240 // feature-group-start: actual feature gates (target features)
241 // -------------------------------------------------------------------------
243 // FIXME: Document these and merge with the list below.
245 // Unstable `#[target_feature]` directives.
246 (active
, aarch64_ver_target_feature
, "1.27.0", Some(44839), None
),
247 (active
, adx_target_feature
, "1.32.0", Some(44839), None
),
248 (active
, arm_target_feature
, "1.27.0", Some(44839), None
),
249 (active
, avx512_target_feature
, "1.27.0", Some(44839), None
),
250 (active
, bpf_target_feature
, "1.54.0", Some(44839), None
),
251 (active
, cmpxchg16b_target_feature
, "1.32.0", Some(44839), None
),
252 (active
, ermsb_target_feature
, "1.49.0", Some(44839), None
),
253 (active
, f16c_target_feature
, "1.36.0", Some(44839), None
),
254 (active
, hexagon_target_feature
, "1.27.0", Some(44839), None
),
255 (active
, mips_target_feature
, "1.27.0", Some(44839), None
),
256 (active
, movbe_target_feature
, "1.34.0", Some(44839), None
),
257 (active
, powerpc_target_feature
, "1.27.0", Some(44839), None
),
258 (active
, riscv_target_feature
, "1.45.0", Some(44839), None
),
259 (active
, rtm_target_feature
, "1.35.0", Some(44839), None
),
260 (active
, sse4a_target_feature
, "1.27.0", Some(44839), None
),
261 (active
, tbm_target_feature
, "1.27.0", Some(44839), None
),
262 (active
, wasm_target_feature
, "1.30.0", Some(44839), None
),
263 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
264 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
265 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
267 // -------------------------------------------------------------------------
268 // feature-group-end: actual feature gates (target features)
269 // -------------------------------------------------------------------------
271 // -------------------------------------------------------------------------
272 // feature-group-start: actual feature gates
273 // -------------------------------------------------------------------------
275 /// Allows using the `amdgpu-kernel` ABI.
276 (active
, abi_amdgpu_kernel
, "1.29.0", Some(51575), None
),
277 /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`.
278 (active
, abi_avr_interrupt
, "1.45.0", Some(69664), None
),
279 /// Allows `extern "C-cmse-nonsecure-call" fn()`.
280 (active
, abi_c_cmse_nonsecure_call
, "1.51.0", Some(81391), None
),
281 /// Allows using the `efiapi` ABI.
282 (active
, abi_efiapi
, "1.40.0", Some(65815), None
),
283 /// Allows `extern "msp430-interrupt" fn()`.
284 (active
, abi_msp430_interrupt
, "1.16.0", Some(38487), None
),
285 /// Allows `extern "ptx-*" fn()`.
286 (active
, abi_ptx
, "1.15.0", Some(38788), None
),
287 /// Allows `extern "x86-interrupt" fn()`.
288 (active
, abi_x86_interrupt
, "1.17.0", Some(40180), None
),
289 /// Allows additional const parameter types, such as `&'static str` or user defined types
290 (incomplete
, adt_const_params
, "1.56.0", Some(95174), None
),
291 /// Allows defining an `#[alloc_error_handler]`.
292 (active
, alloc_error_handler
, "1.29.0", Some(51540), None
),
293 /// Allows explicit discriminants on non-unit enum variants.
294 (active
, arbitrary_enum_discriminant
, "1.37.0", Some(60553), None
),
295 /// Allows trait methods with arbitrary self types.
296 (active
, arbitrary_self_types
, "1.23.0", Some(44874), None
),
297 /// Allows using `const` operands in inline assembly.
298 (active
, asm_const
, "1.58.0", Some(93332), None
),
299 /// Enables experimental inline assembly support for additional architectures.
300 (active
, asm_experimental_arch
, "1.58.0", Some(93335), None
),
301 /// Allows using `sym` operands in inline assembly.
302 (active
, asm_sym
, "1.58.0", Some(93333), None
),
303 /// Allows the `may_unwind` option in inline assembly.
304 (active
, asm_unwind
, "1.58.0", Some(93334), None
),
305 /// Allows users to enforce equality of associated constants `TraitImpl<AssocConst=3>`.
306 (active
, associated_const_equality
, "1.58.0", Some(92827), None
),
307 /// Allows the user of associated type bounds.
308 (active
, associated_type_bounds
, "1.34.0", Some(52662), None
),
309 /// Allows associated type defaults.
310 (active
, associated_type_defaults
, "1.2.0", Some(29661), None
),
311 /// Allows `async || body` closures.
312 (active
, async_closure
, "1.37.0", Some(62290), None
),
313 /// Allows `extern "C-unwind" fn` to enable unwinding across ABI boundaries.
314 (active
, c_unwind
, "1.52.0", Some(74990), None
),
315 /// Allows using C-variadics.
316 (active
, c_variadic
, "1.34.0", Some(44930), None
),
317 /// Allows capturing disjoint fields in a closure/generator (RFC 2229).
318 (incomplete
, capture_disjoint_fields
, "1.49.0", Some(53488), None
),
319 /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used.
320 (active
, cfg_sanitize
, "1.41.0", Some(39699), None
),
321 /// Allows `cfg(target_abi = "...")`.
322 (active
, cfg_target_abi
, "1.55.0", Some(80970), None
),
323 /// Allows `cfg(target_has_atomic_load_store = "...")`.
324 (active
, cfg_target_has_atomic
, "1.60.0", Some(94039), None
),
325 /// Allows `cfg(target_has_atomic_equal_alignment = "...")`.
326 (active
, cfg_target_has_atomic_equal_alignment
, "1.60.0", Some(93822), None
),
327 /// Allows `cfg(target_thread_local)`.
328 (active
, cfg_target_thread_local
, "1.7.0", Some(29594), None
),
329 /// Allow conditional compilation depending on rust version
330 (active
, cfg_version
, "1.45.0", Some(64796), None
),
331 /// Allows `#[track_caller]` on closures and generators.
332 (active
, closure_track_caller
, "1.57.0", Some(87417), None
),
333 /// Allows to use the `#[cmse_nonsecure_entry]` attribute.
334 (active
, cmse_nonsecure_entry
, "1.48.0", Some(75835), None
),
335 /// Allows `async {}` expressions in const contexts.
336 (active
, const_async_blocks
, "1.53.0", Some(85368), None
),
337 // Allows limiting the evaluation steps of const expressions
338 (active
, const_eval_limit
, "1.43.0", Some(67217), None
),
339 /// Allows the definition of `const extern fn` and `const unsafe extern fn`.
340 (active
, const_extern_fn
, "1.40.0", Some(64926), None
),
341 /// Allows basic arithmetic on floating point types in a `const fn`.
342 (active
, const_fn_floating_point_arithmetic
, "1.48.0", Some(57241), None
),
343 /// Allows `for _ in _` loops in const contexts.
344 (active
, const_for
, "1.56.0", Some(87575), None
),
345 /// Allows using `&mut` in constant functions.
346 (active
, const_mut_refs
, "1.41.0", Some(57349), None
),
347 /// Be more precise when looking for live drops in a const context.
348 (active
, const_precise_live_drops
, "1.46.0", Some(73255), None
),
349 /// Allows references to types with interior mutability within constants
350 (active
, const_refs_to_cell
, "1.51.0", Some(80384), None
),
351 /// Allows `impl const Trait for T` syntax.
352 (active
, const_trait_impl
, "1.42.0", Some(67792), None
),
353 /// Allows the `?` operator in const contexts.
354 (active
, const_try
, "1.56.0", Some(74935), None
),
355 /// Allows using `crate` as visibility modifier, synonymous with `pub(crate)`.
356 (active
, crate_visibility_modifier
, "1.23.0", Some(53120), None
),
357 /// Allows non-builtin attributes in inner attribute position.
358 (active
, custom_inner_attributes
, "1.30.0", Some(54726), None
),
359 /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`.
360 (active
, custom_test_frameworks
, "1.30.0", Some(50297), None
),
361 /// Allows declarative macros 2.0 (`macro`).
362 (active
, decl_macro
, "1.17.0", Some(39412), None
),
363 /// Allows rustc to inject a default alloc_error_handler
364 (active
, default_alloc_error_handler
, "1.48.0", Some(66741), None
),
365 /// Allows default type parameters to influence type inference.
366 (active
, default_type_parameter_fallback
, "1.3.0", Some(27336), None
),
367 /// Allows using `#[deprecated_safe]` to deprecate the safeness of a function or trait
368 (active
, deprecated_safe
, "1.61.0", Some(94978), None
),
369 /// Allows having using `suggestion` in the `#[deprecated]` attribute.
370 (active
, deprecated_suggestion
, "1.61.0", Some(94785), None
),
371 /// Allows `#[derive(Default)]` and `#[default]` on enums.
372 (active
, derive_default_enum
, "1.56.0", Some(86985), None
),
373 /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`.
374 (active
, doc_auto_cfg
, "1.58.0", Some(43781), None
),
375 /// Allows `#[doc(cfg(...))]`.
376 (active
, doc_cfg
, "1.21.0", Some(43781), None
),
377 /// Allows `#[doc(cfg_hide(...))]`.
378 (active
, doc_cfg_hide
, "1.57.0", Some(43781), None
),
379 /// Allows `#[doc(masked)]`.
380 (active
, doc_masked
, "1.21.0", Some(44027), None
),
381 /// Allows `X..Y` patterns.
382 (active
, exclusive_range_pattern
, "1.11.0", Some(37854), None
),
383 /// Allows exhaustive pattern matching on types that contain uninhabited types.
384 (active
, exhaustive_patterns
, "1.13.0", Some(51085), None
),
385 /// Allows explicit generic arguments specification with `impl Trait` present.
386 (active
, explicit_generic_args_with_impl_trait
, "1.56.0", Some(83701), None
),
387 /// Allows defining `extern type`s.
388 (active
, extern_types
, "1.23.0", Some(43467), None
),
389 /// Allows the use of `#[ffi_const]` on foreign functions.
390 (active
, ffi_const
, "1.45.0", Some(58328), None
),
391 /// Allows the use of `#[ffi_pure]` on foreign functions.
392 (active
, ffi_pure
, "1.45.0", Some(58329), None
),
393 /// Allows using `#[ffi_returns_twice]` on foreign functions.
394 (active
, ffi_returns_twice
, "1.34.0", Some(58314), None
),
395 /// Allows using `#[repr(align(...))]` on function items
396 (active
, fn_align
, "1.53.0", Some(82232), None
),
397 /// Allows defining generators.
398 (active
, generators
, "1.21.0", Some(43122), None
),
399 /// Infer generic args for both consts and types.
400 (active
, generic_arg_infer
, "1.55.0", Some(85077), None
),
401 /// Allows associated types to be generic, e.g., `type Foo<T>;` (RFC 1598).
402 (active
, generic_associated_types
, "1.23.0", Some(44265), None
),
403 /// An extension to the `generic_associated_types` feature, allowing incomplete features.
404 (incomplete
, generic_associated_types_extended
, "1.61.0", Some(95451), None
),
405 /// Allows non-trivial generic constants which have to have wfness manually propagated to callers
406 (incomplete
, generic_const_exprs
, "1.56.0", Some(76560), None
),
407 /// Allows using `..X`, `..=X`, `...X`, and `X..` as a pattern.
408 (active
, half_open_range_patterns
, "1.41.0", Some(67264), None
),
409 /// Allows `if let` guard in match arms.
410 (active
, if_let_guard
, "1.47.0", Some(51114), None
),
411 /// Allows using imported `main` function
412 (active
, imported_main
, "1.53.0", Some(28937), None
),
413 /// Allows inferring `'static` outlives requirements (RFC 2093).
414 (active
, infer_static_outlives_requirements
, "1.26.0", Some(54185), None
),
415 /// Allows associated types in inherent impls.
416 (incomplete
, inherent_associated_types
, "1.52.0", Some(8995), None
),
417 /// Allow anonymous constants from an inline `const` block
418 (active
, inline_const
, "1.49.0", Some(76001), None
),
419 /// Allow anonymous constants from an inline `const` block in pattern position
420 (incomplete
, inline_const_pat
, "1.58.0", Some(76001), None
),
421 /// Allows using `pointer` and `reference` in intra-doc links
422 (active
, intra_doc_pointers
, "1.51.0", Some(80896), None
),
423 /// Allows `#[instruction_set(_)]` attribute
424 (active
, isa_attribute
, "1.48.0", Some(74727), None
),
425 /// Allows `'a: { break 'a; }`.
426 (active
, label_break_value
, "1.28.0", Some(48594), None
),
427 // Allows setting the threshold for the `large_assignments` lint.
428 (active
, large_assignments
, "1.52.0", Some(83518), None
),
429 /// Allows `if/while p && let q = r && ...` chains.
430 (active
, let_chains
, "1.37.0", Some(53667), None
),
431 /// Allows `let...else` statements.
432 (active
, let_else
, "1.56.0", Some(87335), None
),
433 /// Allows `#[link(..., cfg(..))]`.
434 (active
, link_cfg
, "1.14.0", Some(37406), None
),
435 /// Allows using `reason` in lint attributes and the `#[expect(lint)]` lint check.
436 (active
, lint_reasons
, "1.31.0", Some(54503), None
),
437 /// Give access to additional metadata about declarative macro meta-variables.
438 (active
, macro_metavar_expr
, "1.61.0", Some(83527), None
),
439 /// Allows `#[marker]` on certain traits allowing overlapping implementations.
440 (active
, marker_trait_attr
, "1.30.0", Some(29864), None
),
441 /// A minimal, sound subset of specialization intended to be used by the
442 /// standard library until the soundness issues with specialization
444 (active
, min_specialization
, "1.7.0", Some(31844), None
),
445 /// Allows qualified paths in struct expressions, struct patterns and tuple struct patterns.
446 (active
, more_qualified_paths
, "1.54.0", Some(86935), None
),
447 /// Allows the `#[must_not_suspend]` attribute.
448 (active
, must_not_suspend
, "1.57.0", Some(83310), None
),
449 /// Allows using `#[naked]` on functions.
450 (active
, naked_functions
, "1.9.0", Some(32408), None
),
451 /// Allows specifying the as-needed link modifier
452 (active
, native_link_modifiers_as_needed
, "1.53.0", Some(81490), None
),
453 /// Allows specifying the bundle link modifier
454 (active
, native_link_modifiers_bundle
, "1.53.0", Some(81490), None
),
455 /// Allows specifying the verbatim link modifier
456 (active
, native_link_modifiers_verbatim
, "1.53.0", Some(81490), None
),
457 /// Allow negative trait implementations.
458 (active
, negative_impls
, "1.44.0", Some(68318), None
),
459 /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more.
460 (active
, never_type
, "1.13.0", Some(35121), None
),
461 /// Allows diverging expressions to fall back to `!` rather than `()`.
462 (active
, never_type_fallback
, "1.41.0", Some(65992), None
),
463 /// Allows using non lexical lifetimes (RFC 2094).
464 (active
, nll
, "1.0.0", Some(43234), None
),
465 /// Allows `#![no_core]`.
466 (active
, no_core
, "1.3.0", Some(29639), None
),
467 /// Allows function attribute `#[no_coverage]`, to bypass coverage
468 /// instrumentation of that function.
469 (active
, no_coverage
, "1.53.0", Some(84605), None
),
470 /// Allows the use of `no_sanitize` attribute.
471 (active
, no_sanitize
, "1.42.0", Some(39699), None
),
472 /// Allows using the `non_exhaustive_omitted_patterns` lint.
473 (active
, non_exhaustive_omitted_patterns_lint
, "1.57.0", Some(89554), None
),
474 /// Allows making `dyn Trait` well-formed even if `Trait` is not object safe.
475 /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and
476 /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.
477 (active
, object_safe_for_dispatch
, "1.40.0", Some(43561), None
),
478 /// Allows using `#[optimize(X)]`.
479 (active
, optimize_attribute
, "1.34.0", Some(54882), None
),
480 /// Allows `extern "platform-intrinsic" { ... }`.
481 (active
, platform_intrinsics
, "1.4.0", Some(27731), None
),
482 /// Allows using `#![plugin(myplugin)]`.
483 (active
, plugin
, "1.0.0", Some(29597), None
),
484 /// Allows exhaustive integer pattern matching on `usize` and `isize`.
485 (active
, precise_pointer_size_matching
, "1.32.0", Some(56354), None
),
486 /// Allows macro attributes on expressions, statements and non-inline modules.
487 (active
, proc_macro_hygiene
, "1.30.0", Some(54727), None
),
488 /// Allows the use of raw-dylibs (RFC 2627).
489 (incomplete
, raw_dylib
, "1.40.0", Some(58713), None
),
490 /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions.
491 (active
, raw_ref_op
, "1.41.0", Some(64490), None
),
492 /// Allows using the `#[register_attr]` attribute.
493 (active
, register_attr
, "1.41.0", Some(66080), None
),
494 /// Allows using the `#[register_tool]` attribute.
495 (active
, register_tool
, "1.41.0", Some(66079), None
),
496 /// Allows the `#[repr(i128)]` attribute for enums.
497 (incomplete
, repr128
, "1.16.0", Some(56071), None
),
498 /// Allows `repr(simd)` and importing the various simd intrinsics.
499 (active
, repr_simd
, "1.4.0", Some(27731), None
),
500 /// Allows the use of SIMD types in functions declared in `extern` blocks.
501 (active
, simd_ffi
, "1.0.0", Some(27731), None
),
502 /// Allows specialization of implementations (RFC 1210).
503 (incomplete
, specialization
, "1.7.0", Some(31844), None
),
504 /// Allows `#[link(kind="static-nobundle"...)]`.
505 (active
, static_nobundle
, "1.16.0", Some(37403), None
),
506 /// Allows attributes on expressions and non-item statements.
507 (active
, stmt_expr_attributes
, "1.6.0", Some(15701), None
),
508 /// Allows the use of `#[target_feature]` on safe functions.
509 (active
, target_feature_11
, "1.45.0", Some(69098), None
),
510 /// Allows using `#[thread_local]` on `static` items.
511 (active
, thread_local
, "1.0.0", Some(29594), None
),
512 /// Allows defining `trait X = A + B;` alias items.
513 (active
, trait_alias
, "1.24.0", Some(41517), None
),
514 /// Allows upcasting trait objects via supertraits.
515 /// Trait upcasting is casting, e.g., `dyn Foo -> dyn Bar` where `Foo: Bar`.
516 (incomplete
, trait_upcasting
, "1.56.0", Some(65991), None
),
517 /// Allows #[repr(transparent)] on unions (RFC 2645).
518 (active
, transparent_unions
, "1.37.0", Some(60405), None
),
519 /// Allows inconsistent bounds in where clauses.
520 (active
, trivial_bounds
, "1.28.0", Some(48214), None
),
521 /// Allows using `try {...}` expressions.
522 (active
, try_blocks
, "1.29.0", Some(31436), None
),
523 /// Allows `impl Trait` to be used inside type aliases (RFC 2515).
524 (active
, type_alias_impl_trait
, "1.38.0", Some(63063), None
),
525 /// Allows the use of type ascription in expressions.
526 (active
, type_ascription
, "1.6.0", Some(23416), None
),
527 /// Allows creation of instances of a struct by moving fields that have
528 /// not changed from prior instances of the same struct (RFC #2528)
529 (incomplete
, type_changing_struct_update
, "1.58.0", Some(86555), None
),
530 /// Allows unsized fn parameters.
531 (active
, unsized_fn_params
, "1.49.0", Some(48055), None
),
532 /// Allows unsized rvalues at arguments and parameters.
533 (incomplete
, unsized_locals
, "1.30.0", Some(48055), None
),
534 /// Allows unsized tuple coercion.
535 (active
, unsized_tuple_coercion
, "1.20.0", Some(42877), None
),
536 /// Allows `union`s to implement `Drop`. Moreover, `union`s may now include fields
537 /// that don't implement `Copy` as long as they don't have any drop glue.
538 /// This is checked recursively. On encountering type variable where no progress can be made,
539 /// `T: Copy` is used as a substitute for "no drop glue".
541 /// NOTE: A limited form of `union U { ... }` was accepted in 1.19.0.
542 (active
, untagged_unions
, "1.13.0", Some(55149), None
),
543 /// Allows using the `#[used(linker)]` (or `#[used(compiler)]`) attribute.
544 (active
, used_with_arg
, "1.60.0", Some(93798), None
),
545 /// Allows `extern "wasm" fn`
546 (active
, wasm_abi
, "1.53.0", Some(83788), None
),
547 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
548 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
549 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
551 // -------------------------------------------------------------------------
552 // feature-group-end: actual feature gates
553 // -------------------------------------------------------------------------
556 /// Some features are not allowed to be used together at the same time, if
557 /// the two are present, produce an error.
559 /// Currently empty, but we will probably need this again in the future,
560 /// so let's keep it in for now.
561 pub const INCOMPATIBLE_FEATURES
: &[(Symbol
, Symbol
)] = &[];