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 using anonymous lifetimes in argument-position impl-trait.
152 (active
, anonymous_lifetime_in_impl_trait
, "1.63.0", None
, None
),
153 /// Allows identifying the `compiler_builtins` crate.
154 (active
, compiler_builtins
, "1.13.0", None
, None
),
155 /// Allows writing custom MIR
156 (active
, custom_mir
, "1.65.0", None
, None
),
157 /// Outputs useful `assert!` messages
158 (active
, generic_assert
, "1.63.0", None
, None
),
159 /// Allows using the `rust-intrinsic`'s "ABI".
160 (active
, intrinsics
, "1.0.0", None
, None
),
161 /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic.
162 (active
, lang_items
, "1.0.0", None
, None
),
163 /// Allows using `#[omit_gdb_pretty_printer_section]`.
164 (active
, omit_gdb_pretty_printer_section
, "1.5.0", None
, None
),
165 /// Allows using `#[prelude_import]` on glob `use` items.
166 (active
, prelude_import
, "1.2.0", None
, None
),
167 /// Used to identify crates that contain the profiler runtime.
168 (active
, profiler_runtime
, "1.18.0", None
, None
),
169 /// Allows using `rustc_*` attributes (RFC 572).
170 (active
, rustc_attrs
, "1.0.0", None
, None
),
171 /// Allows using the `#[stable]` and `#[unstable]` attributes.
172 (active
, staged_api
, "1.0.0", None
, None
),
173 /// Added for testing E0705; perma-unstable.
174 (active
, test_2018_feature
, "1.31.0", None
, Some(Edition
::Edition2018
)),
175 /// Added for testing unstable lints; perma-unstable.
176 (active
, test_unstable_lint
, "1.60.0", None
, None
),
177 /// Allows non-`unsafe` —and thus, unsound— access to `Pin` constructions.
178 /// Marked `incomplete` since perma-unstable and unsound.
179 (incomplete
, unsafe_pin_internals
, "1.60.0", None
, None
),
180 /// Use for stable + negative coherence and strict coherence depending on trait's
181 /// rustc_strict_coherence value.
182 (active
, with_negative_coherence
, "1.60.0", None
, None
),
183 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
184 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
185 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
187 // no-tracking-issue-end
188 // -------------------------------------------------------------------------
189 // feature-group-end: internal feature gates (no tracking issue)
190 // -------------------------------------------------------------------------
192 // -------------------------------------------------------------------------
193 // feature-group-start: internal feature gates
194 // -------------------------------------------------------------------------
196 /// Allows features specific to auto traits.
197 /// Renamed from `optin_builtin_traits`.
198 (active
, auto_traits
, "1.50.0", Some(13231), None
),
199 /// Allows using `box` in patterns (RFC 469).
200 (active
, box_patterns
, "1.0.0", Some(29641), None
),
201 /// Allows using the `box $expr` syntax.
202 (active
, box_syntax
, "1.0.0", Some(49733), None
),
203 /// Allows `#[doc(notable_trait)]`.
204 /// Renamed from `doc_spotlight`.
205 (active
, doc_notable_trait
, "1.52.0", Some(45040), None
),
206 /// Allows using the `may_dangle` attribute (RFC 1327).
207 (active
, dropck_eyepatch
, "1.10.0", Some(34761), None
),
208 /// Allows using the `#[fundamental]` attribute.
209 (active
, fundamental
, "1.0.0", Some(29635), None
),
210 /// Allows using `#[link_name="llvm.*"]`.
211 (active
, link_llvm_intrinsics
, "1.0.0", Some(29602), None
),
212 /// Allows using the `#[linkage = ".."]` attribute.
213 (active
, linkage
, "1.0.0", Some(29603), None
),
214 /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed.
215 (active
, needs_panic_runtime
, "1.10.0", Some(32837), None
),
216 /// Allows using the `#![panic_runtime]` attribute.
217 (active
, panic_runtime
, "1.10.0", Some(32837), None
),
218 /// Allows using `#[rustc_allow_const_fn_unstable]`.
219 /// This is an attribute on `const fn` for the same
220 /// purpose as `#[allow_internal_unstable]`.
221 (active
, rustc_allow_const_fn_unstable
, "1.49.0", Some(69399), None
),
222 /// Allows using compiler's own crates.
223 (active
, rustc_private
, "1.0.0", Some(27812), None
),
224 /// Allows using internal rustdoc features like `doc(primitive)` or `doc(keyword)`.
225 (active
, rustdoc_internals
, "1.58.0", Some(90418), None
),
226 /// Allows using the `rustdoc::missing_doc_code_examples` lint
227 (active
, rustdoc_missing_doc_code_examples
, "1.31.0", Some(101730), None
),
228 /// Allows using `#[start]` on a function indicating that it is the program entrypoint.
229 (active
, start
, "1.0.0", Some(29633), None
),
230 /// Allows using `#[structural_match]` which indicates that a type is structurally matchable.
231 /// FIXME: Subsumed by trait `StructuralPartialEq`, cannot move to removed until a library
232 /// feature with the same name exists.
233 (active
, structural_match
, "1.8.0", Some(31434), None
),
234 /// Allows using the `rust-call` ABI.
235 (active
, unboxed_closures
, "1.0.0", Some(29625), None
),
236 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
237 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
238 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
240 // -------------------------------------------------------------------------
241 // feature-group-end: internal feature gates
242 // -------------------------------------------------------------------------
244 // -------------------------------------------------------------------------
245 // feature-group-start: actual feature gates (target features)
246 // -------------------------------------------------------------------------
248 // FIXME: Document these and merge with the list below.
250 // Unstable `#[target_feature]` directives.
251 (active
, aarch64_ver_target_feature
, "1.27.0", Some(44839), None
),
252 (active
, arm_target_feature
, "1.27.0", Some(44839), None
),
253 (active
, avx512_target_feature
, "1.27.0", Some(44839), None
),
254 (active
, bpf_target_feature
, "1.54.0", Some(44839), None
),
255 (active
, cmpxchg16b_target_feature
, "1.32.0", Some(44839), None
),
256 (active
, ermsb_target_feature
, "1.49.0", Some(44839), None
),
257 (active
, f16c_target_feature
, "1.36.0", Some(44839), None
),
258 (active
, hexagon_target_feature
, "1.27.0", Some(44839), None
),
259 (active
, mips_target_feature
, "1.27.0", Some(44839), None
),
260 (active
, movbe_target_feature
, "1.34.0", Some(44839), None
),
261 (active
, powerpc_target_feature
, "1.27.0", Some(44839), None
),
262 (active
, riscv_target_feature
, "1.45.0", Some(44839), None
),
263 (active
, rtm_target_feature
, "1.35.0", Some(44839), None
),
264 (active
, sse4a_target_feature
, "1.27.0", Some(44839), None
),
265 (active
, tbm_target_feature
, "1.27.0", Some(44839), None
),
266 (active
, wasm_target_feature
, "1.30.0", Some(44839), None
),
267 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
268 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way.
269 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!!
271 // -------------------------------------------------------------------------
272 // feature-group-end: actual feature gates (target features)
273 // -------------------------------------------------------------------------
275 // -------------------------------------------------------------------------
276 // feature-group-start: actual feature gates
277 // -------------------------------------------------------------------------
279 /// Allows using the `amdgpu-kernel` ABI.
280 (active
, abi_amdgpu_kernel
, "1.29.0", Some(51575), None
),
281 /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`.
282 (active
, abi_avr_interrupt
, "1.45.0", Some(69664), None
),
283 /// Allows `extern "C-cmse-nonsecure-call" fn()`.
284 (active
, abi_c_cmse_nonsecure_call
, "1.51.0", Some(81391), None
),
285 /// Allows using the `efiapi` ABI.
286 (active
, abi_efiapi
, "1.40.0", Some(65815), None
),
287 /// Allows `extern "msp430-interrupt" fn()`.
288 (active
, abi_msp430_interrupt
, "1.16.0", Some(38487), None
),
289 /// Allows `extern "ptx-*" fn()`.
290 (active
, abi_ptx
, "1.15.0", Some(38788), None
),
291 /// Allows `extern "x86-interrupt" fn()`.
292 (active
, abi_x86_interrupt
, "1.17.0", Some(40180), None
),
293 /// Allows additional const parameter types, such as `&'static str` or user defined types
294 (incomplete
, adt_const_params
, "1.56.0", Some(95174), None
),
295 /// Allows defining an `#[alloc_error_handler]`.
296 (active
, alloc_error_handler
, "1.29.0", Some(51540), None
),
297 /// Allows trait methods with arbitrary self types.
298 (active
, arbitrary_self_types
, "1.23.0", Some(44874), None
),
299 /// Allows using `const` operands in inline assembly.
300 (active
, asm_const
, "1.58.0", Some(93332), None
),
301 /// Enables experimental inline assembly support for additional architectures.
302 (active
, asm_experimental_arch
, "1.58.0", Some(93335), 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 /// Alows async functions to be declared, implemented, and used in traits.
314 (incomplete
, async_fn_in_trait
, "1.66.0", Some(91611), None
),
315 /// Allows `extern "C-unwind" fn` to enable unwinding across ABI boundaries.
316 (active
, c_unwind
, "1.52.0", Some(74990), None
),
317 /// Allows using C-variadics.
318 (active
, c_variadic
, "1.34.0", Some(44930), None
),
319 /// Allows capturing disjoint fields in a closure/generator (RFC 2229).
320 (incomplete
, capture_disjoint_fields
, "1.49.0", Some(53488), None
),
321 /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used.
322 (active
, cfg_sanitize
, "1.41.0", Some(39699), None
),
323 /// Allows `cfg(target_abi = "...")`.
324 (active
, cfg_target_abi
, "1.55.0", Some(80970), None
),
325 /// Allows `cfg(target(abi = "..."))`.
326 (active
, cfg_target_compact
, "1.63.0", Some(96901), None
),
327 /// Allows `cfg(target_has_atomic_load_store = "...")`.
328 (active
, cfg_target_has_atomic
, "1.60.0", Some(94039), None
),
329 /// Allows `cfg(target_has_atomic_equal_alignment = "...")`.
330 (active
, cfg_target_has_atomic_equal_alignment
, "1.60.0", Some(93822), None
),
331 /// Allows `cfg(target_thread_local)`.
332 (active
, cfg_target_thread_local
, "1.7.0", Some(29594), None
),
333 /// Allow conditional compilation depending on rust version
334 (active
, cfg_version
, "1.45.0", Some(64796), None
),
335 /// Allows `for<...>` on closures and generators.
336 (active
, closure_lifetime_binder
, "1.64.0", Some(97362), None
),
337 /// Allows `#[track_caller]` on closures and generators.
338 (active
, closure_track_caller
, "1.57.0", Some(87417), None
),
339 /// Allows to use the `#[cmse_nonsecure_entry]` attribute.
340 (active
, cmse_nonsecure_entry
, "1.48.0", Some(75835), None
),
341 /// Allows use of the `#[collapse_debuginfo]` attribute.
342 (active
, collapse_debuginfo
, "1.65.0", Some(100758), None
),
343 /// Allows `async {}` expressions in const contexts.
344 (active
, const_async_blocks
, "1.53.0", Some(85368), None
),
345 // Allows limiting the evaluation steps of const expressions
346 (active
, const_eval_limit
, "1.43.0", Some(67217), None
),
347 /// Allows the definition of `const extern fn` and `const unsafe extern fn`.
348 (active
, const_extern_fn
, "1.40.0", Some(64926), None
),
349 /// Allows basic arithmetic on floating point types in a `const fn`.
350 (active
, const_fn_floating_point_arithmetic
, "1.48.0", Some(57241), None
),
351 /// Allows `for _ in _` loops in const contexts.
352 (active
, const_for
, "1.56.0", Some(87575), None
),
353 /// Allows using `&mut` in constant functions.
354 (active
, const_mut_refs
, "1.41.0", Some(57349), None
),
355 /// Be more precise when looking for live drops in a const context.
356 (active
, const_precise_live_drops
, "1.46.0", Some(73255), None
),
357 /// Allows references to types with interior mutability within constants
358 (active
, const_refs_to_cell
, "1.51.0", Some(80384), None
),
359 /// Allows `impl const Trait for T` syntax.
360 (active
, const_trait_impl
, "1.42.0", Some(67792), None
),
361 /// Allows the `?` operator in const contexts.
362 (active
, const_try
, "1.56.0", Some(74935), None
),
363 /// Allows non-builtin attributes in inner attribute position.
364 (active
, custom_inner_attributes
, "1.30.0", Some(54726), None
),
365 /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`.
366 (active
, custom_test_frameworks
, "1.30.0", Some(50297), None
),
367 /// Allows using `#[debugger_visualizer]`.
368 (active
, debugger_visualizer
, "1.62.0", Some(95939), None
),
369 /// Allows declarative macros 2.0 (`macro`).
370 (active
, decl_macro
, "1.17.0", Some(39412), None
),
371 /// Allows rustc to inject a default alloc_error_handler
372 (active
, default_alloc_error_handler
, "1.48.0", Some(66741), None
),
373 /// Allows default type parameters to influence type inference.
374 (active
, default_type_parameter_fallback
, "1.3.0", Some(27336), None
),
375 /// Allows using `#[deprecated_safe]` to deprecate the safeness of a function or trait
376 (active
, deprecated_safe
, "1.61.0", Some(94978), None
),
377 /// Allows having using `suggestion` in the `#[deprecated]` attribute.
378 (active
, deprecated_suggestion
, "1.61.0", Some(94785), None
),
379 /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`.
380 (active
, doc_auto_cfg
, "1.58.0", Some(43781), None
),
381 /// Allows `#[doc(cfg(...))]`.
382 (active
, doc_cfg
, "1.21.0", Some(43781), None
),
383 /// Allows `#[doc(cfg_hide(...))]`.
384 (active
, doc_cfg_hide
, "1.57.0", Some(43781), None
),
385 /// Allows `#[doc(masked)]`.
386 (active
, doc_masked
, "1.21.0", Some(44027), None
),
387 /// Allows `dyn* Trait` objects.
388 (incomplete
, dyn_star
, "1.65.0", Some(91611), None
),
389 /// Allows `X..Y` patterns.
390 (active
, exclusive_range_pattern
, "1.11.0", Some(37854), None
),
391 /// Allows exhaustive pattern matching on types that contain uninhabited types.
392 (active
, exhaustive_patterns
, "1.13.0", Some(51085), None
),
393 /// Allows using `efiapi`, `sysv64` and `win64` as calling convention
394 /// for functions with varargs.
395 (active
, extended_varargs_abi_support
, "1.65.0", Some(100189), None
),
396 /// Allows defining `extern type`s.
397 (active
, extern_types
, "1.23.0", Some(43467), None
),
398 /// Allows the use of `#[ffi_const]` on foreign functions.
399 (active
, ffi_const
, "1.45.0", Some(58328), None
),
400 /// Allows the use of `#[ffi_pure]` on foreign functions.
401 (active
, ffi_pure
, "1.45.0", Some(58329), None
),
402 /// Allows using `#[ffi_returns_twice]` on foreign functions.
403 (active
, ffi_returns_twice
, "1.34.0", Some(58314), None
),
404 /// Allows using `#[repr(align(...))]` on function items
405 (active
, fn_align
, "1.53.0", Some(82232), None
),
406 /// Allows generators to be cloned.
407 (active
, generator_clone
, "1.65.0", Some(95360), None
),
408 /// Allows defining generators.
409 (active
, generators
, "1.21.0", Some(43122), None
),
410 /// Infer generic args for both consts and types.
411 (active
, generic_arg_infer
, "1.55.0", Some(85077), None
),
412 /// An extension to the `generic_associated_types` feature, allowing incomplete features.
413 (incomplete
, generic_associated_types_extended
, "1.61.0", Some(95451), None
),
414 /// Allows non-trivial generic constants which have to have wfness manually propagated to callers
415 (incomplete
, generic_const_exprs
, "1.56.0", Some(76560), None
),
416 /// Allows using `..=X` as a patterns in slices.
417 (active
, half_open_range_patterns_in_slices
, "1.66.0", Some(67264), None
),
418 /// Allows `if let` guard in match arms.
419 (active
, if_let_guard
, "1.47.0", Some(51114), None
),
420 /// Allows `impl Trait` as output type in `Fn` traits in return position of functions.
421 (active
, impl_trait_in_fn_trait_return
, "1.64.0", Some(99697), None
),
422 /// Allows referencing `Self` and projections in impl-trait.
423 (active
, impl_trait_projections
, "1.67.0", Some(103532), None
),
424 /// Allows using imported `main` function
425 (active
, imported_main
, "1.53.0", Some(28937), None
),
426 /// Allows associated types in inherent impls.
427 (incomplete
, inherent_associated_types
, "1.52.0", Some(8995), None
),
428 /// Allow anonymous constants from an inline `const` block
429 (active
, inline_const
, "1.49.0", Some(76001), None
),
430 /// Allow anonymous constants from an inline `const` block in pattern position
431 (incomplete
, inline_const_pat
, "1.58.0", Some(76001), None
),
432 /// Allows using `pointer` and `reference` in intra-doc links
433 (active
, intra_doc_pointers
, "1.51.0", Some(80896), None
),
434 // Allows setting the threshold for the `large_assignments` lint.
435 (active
, large_assignments
, "1.52.0", Some(83518), None
),
436 /// Allows `if/while p && let q = r && ...` chains.
437 (active
, let_chains
, "1.37.0", Some(53667), None
),
438 /// Allows `#[link(..., cfg(..))]`.
439 (active
, link_cfg
, "1.14.0", Some(37406), None
),
440 /// Allows using `reason` in lint attributes and the `#[expect(lint)]` lint check.
441 (active
, lint_reasons
, "1.31.0", Some(54503), None
),
442 /// Give access to additional metadata about declarative macro meta-variables.
443 (active
, macro_metavar_expr
, "1.61.0", Some(83527), None
),
444 /// Allows `#[marker]` on certain traits allowing overlapping implementations.
445 (active
, marker_trait_attr
, "1.30.0", Some(29864), None
),
446 /// A minimal, sound subset of specialization intended to be used by the
447 /// standard library until the soundness issues with specialization
449 (active
, min_specialization
, "1.7.0", Some(31844), None
),
450 /// Allows qualified paths in struct expressions, struct patterns and tuple struct patterns.
451 (active
, more_qualified_paths
, "1.54.0", Some(86935), None
),
452 /// Allows the `#[must_not_suspend]` attribute.
453 (active
, must_not_suspend
, "1.57.0", Some(83310), None
),
454 /// Allows using `#[naked]` on functions.
455 (active
, naked_functions
, "1.9.0", Some(32408), None
),
456 /// Allows specifying the as-needed link modifier
457 (active
, native_link_modifiers_as_needed
, "1.53.0", Some(81490), None
),
458 /// Allow negative trait implementations.
459 (active
, negative_impls
, "1.44.0", Some(68318), None
),
460 /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more.
461 (active
, never_type
, "1.13.0", Some(35121), None
),
462 /// Allows diverging expressions to fall back to `!` rather than `()`.
463 (active
, never_type_fallback
, "1.41.0", Some(65992), None
),
464 /// Allows `#![no_core]`.
465 (active
, no_core
, "1.3.0", Some(29639), None
),
466 /// Allows function attribute `#[no_coverage]`, to bypass coverage
467 /// instrumentation of that function.
468 (active
, no_coverage
, "1.53.0", Some(84605), None
),
469 /// Allows the use of `no_sanitize` attribute.
470 (active
, no_sanitize
, "1.42.0", Some(39699), None
),
471 /// Allows using the `non_exhaustive_omitted_patterns` lint.
472 (active
, non_exhaustive_omitted_patterns_lint
, "1.57.0", Some(89554), None
),
473 /// Allows making `dyn Trait` well-formed even if `Trait` is not object safe.
474 /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and
475 /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden.
476 (active
, object_safe_for_dispatch
, "1.40.0", Some(43561), None
),
477 /// Allows using `#[optimize(X)]`.
478 (active
, optimize_attribute
, "1.34.0", Some(54882), None
),
479 /// Allows `extern "platform-intrinsic" { ... }`.
480 (active
, platform_intrinsics
, "1.4.0", Some(27731), None
),
481 /// Allows using `#![plugin(myplugin)]`.
482 (active
, plugin
, "1.0.0", Some(29597), None
),
483 /// Allows exhaustive integer pattern matching on `usize` and `isize`.
484 (active
, precise_pointer_size_matching
, "1.32.0", Some(56354), None
),
485 /// Allows macro attributes on expressions, statements and non-inline modules.
486 (active
, proc_macro_hygiene
, "1.30.0", Some(54727), None
),
487 /// Allows the use of raw-dylibs (RFC 2627).
488 (active
, raw_dylib
, "1.65.0", Some(58713), None
),
489 /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions.
490 (active
, raw_ref_op
, "1.41.0", Some(64490), None
),
491 /// Allows using the `#[register_tool]` attribute.
492 (active
, register_tool
, "1.41.0", Some(66079), None
),
493 /// Allows the `#[repr(i128)]` attribute for enums.
494 (incomplete
, repr128
, "1.16.0", Some(56071), None
),
495 /// Allows `repr(simd)` and importing the various simd intrinsics.
496 (active
, repr_simd
, "1.4.0", Some(27731), None
),
497 /// Allows return-position `impl Trait` in traits.
498 (incomplete
, return_position_impl_trait_in_trait
, "1.65.0", Some(91611), None
),
499 /// Allows `extern "rust-cold"`.
500 (active
, rust_cold_cc
, "1.63.0", Some(97544), None
),
501 /// Allows the use of SIMD types in functions declared in `extern` blocks.
502 (active
, simd_ffi
, "1.0.0", Some(27731), None
),
503 /// Allows specialization of implementations (RFC 1210).
504 (incomplete
, specialization
, "1.7.0", Some(31844), None
),
505 /// Allows attributes on expressions and non-item statements.
506 (active
, stmt_expr_attributes
, "1.6.0", Some(15701), None
),
507 /// Allows lints part of the strict provenance effort.
508 (active
, strict_provenance
, "1.61.0", Some(95228), None
),
509 /// Allows string patterns to dereference values to match them.
510 (active
, string_deref_patterns
, "1.67.0", Some(87121), None
),
511 /// Allows the use of `#[target_feature]` on safe functions.
512 (active
, target_feature_11
, "1.45.0", Some(69098), None
),
513 /// Allows using `#[thread_local]` on `static` items.
514 (active
, thread_local
, "1.0.0", Some(29594), None
),
515 /// Allows defining `trait X = A + B;` alias items.
516 (active
, trait_alias
, "1.24.0", Some(41517), None
),
517 /// Allows dyn upcasting trait objects via supertraits.
518 /// Dyn upcasting is casting, e.g., `dyn Foo -> dyn Bar` where `Foo: Bar`.
519 (active
, trait_upcasting
, "1.56.0", Some(65991), None
),
520 /// Allows #[repr(transparent)] on unions (RFC 2645).
521 (active
, transparent_unions
, "1.37.0", Some(60405), None
),
522 /// Allows inconsistent bounds in where clauses.
523 (active
, trivial_bounds
, "1.28.0", Some(48214), None
),
524 /// Allows using `try {...}` expressions.
525 (active
, try_blocks
, "1.29.0", Some(31436), None
),
526 /// Allows `impl Trait` to be used inside type aliases (RFC 2515).
527 (active
, type_alias_impl_trait
, "1.38.0", Some(63063), None
),
528 /// Allows the use of type ascription in expressions.
529 (active
, type_ascription
, "1.6.0", Some(23416), None
),
530 /// Allows creation of instances of a struct by moving fields that have
531 /// not changed from prior instances of the same struct (RFC #2528)
532 (active
, type_changing_struct_update
, "1.58.0", Some(86555), None
),
533 /// Enables rustc to generate code that instructs libstd to NOT ignore SIGPIPE.
534 (active
, unix_sigpipe
, "1.65.0", Some(97889), None
),
535 /// Allows unsized fn parameters.
536 (active
, unsized_fn_params
, "1.49.0", Some(48055), None
),
537 /// Allows unsized rvalues at arguments and parameters.
538 (incomplete
, unsized_locals
, "1.30.0", Some(48055), None
),
539 /// Allows unsized tuple coercion.
540 (active
, unsized_tuple_coercion
, "1.20.0", Some(42877), None
),
541 /// Allows using the `#[used(linker)]` (or `#[used(compiler)]`) attribute.
542 (active
, used_with_arg
, "1.60.0", Some(93798), None
),
543 /// Allows `extern "wasm" fn`
544 (active
, wasm_abi
, "1.53.0", Some(83788), None
),
545 /// Allows `do yeet` expressions
546 (active
, yeet_expr
, "1.62.0", Some(96373), 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
)] = &[];