1 //! List of the active feature gates.
3 use super::{State, Feature};
5 use crate::edition::Edition;
6 use crate::symbol::{Symbol, sym};
12 fn f(features: &mut Features, _: Span) {
13 features.$field = true;
15 f as fn(&mut Features, Span)
19 macro_rules! declare_features {
21 $(#[doc = $doc:tt])* (active, $feature:ident, $ver:expr, $issue:expr, $edition:expr),
23 /// Represents active features that are currently being implemented or
24 /// currently being considered for addition/removal.
25 pub const ACTIVE_FEATURES:
28 // (sym::$feature, $ver, $issue, $edition, set!($feature))
30 state: State::Active { set: set!($feature) },
35 description: concat!($($doc,)*),
39 /// A set of features to be used by later passes.
42 /// `#![feature]` attrs for language features, for error reporting.
43 pub declared_lang_features: Vec<(Symbol, Span, Option<Symbol>)>,
44 /// `#![feature]` attrs for non-language (library) features.
45 pub declared_lib_features: Vec<(Symbol, Span)>,
53 pub fn new() -> Features {
55 declared_lang_features: Vec::new(),
56 declared_lib_features: Vec::new(),
61 pub fn walk_feature_fields<F>(&self, mut f: F)
62 where F: FnMut(&str, bool)
64 $(f(stringify!($feature), self.$feature);)+
71 /// Sets this feature in `Features`. Panics if called on a non-active feature.
72 pub fn set(&self, features: &mut Features, span: Span) {
74 State::Active { set } => set(features, span),
75 _ => panic!("called `set` on feature `{}` which is not `active`", self.name)
80 // If you change this, please modify `src/doc/unstable-book` as well.
82 // Don't ever remove anything from this list; move them to `removed.rs`.
84 // The version numbers here correspond to the version in which the current status
85 // was set. This is most important for knowing when a particular feature became
88 // Note that the features are grouped into internal/user-facing and then
89 // sorted by version inside those groups. This is enforced with tidy.
91 // N.B., `tools/tidy/src/features.rs` parses this information directly out of the
92 // source, so take care when modifying it.
95 // -------------------------------------------------------------------------
96 // feature-group-start: internal feature gates
97 // -------------------------------------------------------------------------
99 // no-tracking-issue-start
101 /// Allows using compiler's own crates.
102 (active, rustc_private, "1.0.0", Some(27812), None),
104 /// Allows using the `rust-intrinsic`'s "ABI".
105 (active, intrinsics, "1.0.0", None, None),
107 /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic.
108 (active, lang_items, "1.0.0", None, None),
110 /// Allows using the `#[stable]` and `#[unstable]` attributes.
111 (active, staged_api, "1.0.0", None, None),
113 /// Allows using `#[allow_internal_unstable]`. This is an
114 /// attribute on `macro_rules!` and can't use the attribute handling
115 /// below (it has to be checked before expansion possibly makes
116 /// macros disappear).
117 (active, allow_internal_unstable, "1.0.0", None, None),
119 /// Allows using `#[allow_internal_unsafe]`. This is an
120 /// attribute on `macro_rules!` and can't use the attribute handling
121 /// below (it has to be checked before expansion possibly makes
122 /// macros disappear).
123 (active, allow_internal_unsafe, "1.0.0", None, None),
125 /// Allows using `#[rustc_const_unstable(feature = "foo", ..)]` which
126 /// lets a function to be `const` when opted into with `#![feature(foo)]`.
127 (active, rustc_const_unstable, "1.0.0", None, None),
129 /// no-tracking-issue-end
131 /// Allows using `#[link_name="llvm.*"]`.
132 (active, link_llvm_intrinsics, "1.0.0", Some(29602), None),
134 /// Allows using `rustc_*` attributes (RFC 572).
135 (active, rustc_attrs, "1.0.0", Some(29642), None),
137 /// Allows using `#[on_unimplemented(..)]` on traits.
138 (active, on_unimplemented, "1.0.0", Some(29628), None),
140 /// Allows using the `box $expr` syntax.
141 (active, box_syntax, "1.0.0", Some(49733), None),
143 /// Allows using `#[main]` to replace the entrypoint `#[lang = "start"]` calls.
144 (active, main, "1.0.0", Some(29634), None),
146 /// Allows using `#[start]` on a function indicating that it is the program entrypoint.
147 (active, start, "1.0.0", Some(29633), None),
149 /// Allows using the `#[fundamental]` attribute.
150 (active, fundamental, "1.0.0", Some(29635), None),
152 /// Allows using the `rust-call` ABI.
153 (active, unboxed_closures, "1.0.0", Some(29625), None),
155 /// Allows using the `#[linkage = ".."]` attribute.
156 (active, linkage, "1.0.0", Some(29603), None),
158 /// Allows features specific to OIBIT (auto traits).
159 (active, optin_builtin_traits, "1.0.0", Some(13231), None),
161 /// Allows using `box` in patterns (RFC 469).
162 (active, box_patterns, "1.0.0", Some(29641), None),
164 // no-tracking-issue-start
166 /// Allows using `#[prelude_import]` on glob `use` items.
167 (active, prelude_import, "1.2.0", None, None),
169 // no-tracking-issue-end
171 // no-tracking-issue-start
173 /// Allows using `#[omit_gdb_pretty_printer_section]`.
174 (active, omit_gdb_pretty_printer_section, "1.5.0", None, None),
176 /// Allows using the `vectorcall` ABI.
177 (active, abi_vectorcall, "1.7.0", None, None),
179 // no-tracking-issue-end
181 /// Allows using `#[structural_match]` which indicates that a type is structurally matchable.
182 (active, structural_match, "1.8.0", Some(31434), None),
184 /// Allows using the `may_dangle` attribute (RFC 1327).
185 (active, dropck_eyepatch, "1.10.0", Some(34761), None),
187 /// Allows using the `#![panic_runtime]` attribute.
188 (active, panic_runtime, "1.10.0", Some(32837), None),
190 /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed.
191 (active, needs_panic_runtime, "1.10.0", Some(32837), None),
193 // no-tracking-issue-start
195 /// Allows identifying the `compiler_builtins` crate.
196 (active, compiler_builtins, "1.13.0", None, None),
198 /// Allows using the `unadjusted` ABI; perma-unstable.
199 (active, abi_unadjusted, "1.16.0", None, None),
201 /// Allows identifying crates that contain sanitizer runtimes.
202 (active, sanitizer_runtime, "1.17.0", None, None),
204 /// Used to identify crates that contain the profiler runtime.
205 (active, profiler_runtime, "1.18.0", None, None),
207 /// Allows using the `thiscall` ABI.
208 (active, abi_thiscall, "1.19.0", None, None),
210 /// Allows using `#![needs_allocator]`, an implementation detail of `#[global_allocator]`.
211 (active, allocator_internals, "1.20.0", None, None),
213 // no-tracking-issue-end
215 /// Added for testing E0705; perma-unstable.
216 (active, test_2018_feature, "1.31.0", Some(0), Some(Edition::Edition2018)),
218 // -------------------------------------------------------------------------
219 // feature-group-end: internal feature gates
220 // -------------------------------------------------------------------------
222 // -------------------------------------------------------------------------
223 // feature-group-start: actual feature gates (target features)
224 // -------------------------------------------------------------------------
226 // FIXME: Document these and merge with the list below.
228 // Unstable `#[target_feature]` directives.
229 (active, arm_target_feature, "1.27.0", Some(44839), None),
230 (active, aarch64_target_feature, "1.27.0", Some(44839), None),
231 (active, hexagon_target_feature, "1.27.0", Some(44839), None),
232 (active, powerpc_target_feature, "1.27.0", Some(44839), None),
233 (active, mips_target_feature, "1.27.0", Some(44839), None),
234 (active, avx512_target_feature, "1.27.0", Some(44839), None),
235 (active, mmx_target_feature, "1.27.0", Some(44839), None),
236 (active, sse4a_target_feature, "1.27.0", Some(44839), None),
237 (active, tbm_target_feature, "1.27.0", Some(44839), None),
238 (active, wasm_target_feature, "1.30.0", Some(44839), None),
239 (active, adx_target_feature, "1.32.0", Some(44839), None),
240 (active, cmpxchg16b_target_feature, "1.32.0", Some(44839), None),
241 (active, movbe_target_feature, "1.34.0", Some(44839), None),
242 (active, rtm_target_feature, "1.35.0", Some(44839), None),
243 (active, f16c_target_feature, "1.36.0", Some(44839), None),
245 // -------------------------------------------------------------------------
246 // feature-group-end: actual feature gates (target features)
247 // -------------------------------------------------------------------------
249 // -------------------------------------------------------------------------
250 // feature-group-start: actual feature gates
251 // -------------------------------------------------------------------------
253 /// Allows using the `#[link_args]` attribute.
254 (active, link_args, "1.0.0", Some(29596), None),
256 /// Allows defining identifiers beyond ASCII.
257 (active, non_ascii_idents, "1.0.0", Some(55467), None),
259 /// Allows using `#[plugin_registrar]` on functions.
260 (active, plugin_registrar, "1.0.0", Some(29597), None),
262 /// Allows using `#![plugin(myplugin)]`.
263 (active, plugin, "1.0.0", Some(29597), None),
265 /// Allows using `#[thread_local]` on `static` items.
266 (active, thread_local, "1.0.0", Some(29594), None),
268 /// Allows the use of SIMD types in functions declared in `extern` blocks.
269 (active, simd_ffi, "1.0.0", Some(27731), None),
271 /// Allows using custom attributes (RFC 572).
272 (active, custom_attribute, "1.0.0", Some(29642), None),
274 /// Allows using non lexical lifetimes (RFC 2094).
275 (active, nll, "1.0.0", Some(43234), None),
277 /// Allows using slice patterns.
278 (active, slice_patterns, "1.0.0", Some(62254), None),
280 /// Allows the definition of `const` functions with some advanced features.
281 (active, const_fn, "1.2.0", Some(57563), None),
283 /// Allows associated type defaults.
284 (active, associated_type_defaults, "1.2.0", Some(29661), None),
286 /// Allows `#![no_core]`.
287 (active, no_core, "1.3.0", Some(29639), None),
289 /// Allows default type parameters to influence type inference.
290 (active, default_type_parameter_fallback, "1.3.0", Some(27336), None),
292 /// Allows `repr(simd)` and importing the various simd intrinsics.
293 (active, repr_simd, "1.4.0", Some(27731), None),
295 /// Allows `extern "platform-intrinsic" { ... }`.
296 (active, platform_intrinsics, "1.4.0", Some(27731), None),
298 /// Allows `#[unwind(..)]`.
300 /// Permits specifying whether a function should permit unwinding or abort on unwind.
301 (active, unwind_attributes, "1.4.0", Some(58760), None),
303 /// Allows `#[no_debug]`.
304 (active, no_debug, "1.5.0", Some(29721), None),
306 /// Allows attributes on expressions and non-item statements.
307 (active, stmt_expr_attributes, "1.6.0", Some(15701), None),
309 /// Allows the use of type ascription in expressions.
310 (active, type_ascription, "1.6.0", Some(23416), None),
312 /// Allows `cfg(target_thread_local)`.
313 (active, cfg_target_thread_local, "1.7.0", Some(29594), None),
315 /// Allows specialization of implementations (RFC 1210).
316 (active, specialization, "1.7.0", Some(31844), None),
318 /// Allows using `#[naked]` on functions.
319 (active, naked_functions, "1.9.0", Some(32408), None),
321 /// Allows `cfg(target_has_atomic = "...")`.
322 (active, cfg_target_has_atomic, "1.9.0", Some(32976), None),
324 /// Allows `X..Y` patterns.
325 (active, exclusive_range_pattern, "1.11.0", Some(37854), None),
327 /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more.
328 (active, never_type, "1.13.0", Some(35121), None),
330 /// Allows exhaustive pattern matching on types that contain uninhabited types.
331 (active, exhaustive_patterns, "1.13.0", Some(51085), None),
333 /// Allows untagged unions `union U { ... }`.
334 (active, untagged_unions, "1.13.0", Some(32836), None),
336 /// Allows `#[link(..., cfg(..))]`.
337 (active, link_cfg, "1.14.0", Some(37406), None),
339 /// Allows `extern "ptx-*" fn()`.
340 (active, abi_ptx, "1.15.0", Some(38788), None),
342 /// Allows the `#[repr(i128)]` attribute for enums.
343 (active, repr128, "1.16.0", Some(35118), None),
345 /// Allows `#[link(kind="static-nobundle"...)]`.
346 (active, static_nobundle, "1.16.0", Some(37403), None),
348 /// Allows `extern "msp430-interrupt" fn()`.
349 (active, abi_msp430_interrupt, "1.16.0", Some(38487), None),
351 /// Allows declarative macros 2.0 (`macro`).
352 (active, decl_macro, "1.17.0", Some(39412), None),
354 /// Allows `extern "x86-interrupt" fn()`.
355 (active, abi_x86_interrupt, "1.17.0", Some(40180), None),
357 /// Allows overlapping impls of marker traits.
358 (active, overlapping_marker_traits, "1.18.0", Some(29864), None),
360 /// Allows a test to fail without failing the whole suite.
361 (active, allow_fail, "1.19.0", Some(46488), None),
363 /// Allows unsized tuple coercion.
364 (active, unsized_tuple_coercion, "1.20.0", Some(42877), None),
366 /// Allows defining generators.
367 (active, generators, "1.21.0", Some(43122), None),
369 /// Allows `#[doc(cfg(...))]`.
370 (active, doc_cfg, "1.21.0", Some(43781), None),
372 /// Allows `#[doc(masked)]`.
373 (active, doc_masked, "1.21.0", Some(44027), None),
375 /// Allows `#[doc(spotlight)]`.
376 (active, doc_spotlight, "1.22.0", Some(45040), None),
378 /// Allows `#[doc(include = "some-file")]`.
379 (active, external_doc, "1.22.0", Some(44732), None),
381 /// Allows future-proofing enums/structs with the `#[non_exhaustive]` attribute (RFC 2008).
382 (active, non_exhaustive, "1.22.0", Some(44109), None),
384 /// Allows using `crate` as visibility modifier, synonymous with `pub(crate)`.
385 (active, crate_visibility_modifier, "1.23.0", Some(53120), None),
387 /// Allows defining `extern type`s.
388 (active, extern_types, "1.23.0", Some(43467), None),
390 /// Allows trait methods with arbitrary self types.
391 (active, arbitrary_self_types, "1.23.0", Some(44874), None),
393 /// Allows in-band quantification of lifetime bindings (e.g., `fn foo(x: &'a u8) -> &'a u8`).
394 (active, in_band_lifetimes, "1.23.0", Some(44524), None),
396 /// Allows associated types to be generic, e.g., `type Foo<T>;` (RFC 1598).
397 (active, generic_associated_types, "1.23.0", Some(44265), None),
399 /// Allows defining `trait X = A + B;` alias items.
400 (active, trait_alias, "1.24.0", Some(41517), None),
402 /// Allows infering `'static` outlives requirements (RFC 2093).
403 (active, infer_static_outlives_requirements, "1.26.0", Some(54185), None),
405 /// Allows macro invocations in `extern {}` blocks.
406 (active, macros_in_extern, "1.27.0", Some(49476), None),
408 /// Allows accessing fields of unions inside `const` functions.
409 (active, const_fn_union, "1.27.0", Some(51909), None),
411 /// Allows casting raw pointers to `usize` during const eval.
412 (active, const_raw_ptr_to_usize_cast, "1.27.0", Some(51910), None),
414 /// Allows dereferencing raw pointers during const eval.
415 (active, const_raw_ptr_deref, "1.27.0", Some(51911), None),
417 /// Allows comparing raw pointers during const eval.
418 (active, const_compare_raw_pointers, "1.27.0", Some(53020), None),
420 /// Allows `#[doc(alias = "...")]`.
421 (active, doc_alias, "1.27.0", Some(50146), None),
423 /// Allows inconsistent bounds in where clauses.
424 (active, trivial_bounds, "1.28.0", Some(48214), None),
426 /// Allows `'a: { break 'a; }`.
427 (active, label_break_value, "1.28.0", Some(48594), None),
429 /// Allows using `#[doc(keyword = "...")]`.
430 (active, doc_keyword, "1.28.0", Some(51315), None),
432 /// Allows reinterpretation of the bits of a value of one type as another
433 /// type during const eval.
434 (active, const_transmute, "1.29.0", Some(53605), None),
436 /// Allows using `try {...}` expressions.
437 (active, try_blocks, "1.29.0", Some(31436), None),
439 /// Allows defining an `#[alloc_error_handler]`.
440 (active, alloc_error_handler, "1.29.0", Some(51540), None),
442 /// Allows using the `amdgpu-kernel` ABI.
443 (active, abi_amdgpu_kernel, "1.29.0", Some(51575), None),
445 /// Allows panicking during const eval (producing compile-time errors).
446 (active, const_panic, "1.30.0", Some(51999), None),
448 /// Allows `#[marker]` on certain traits allowing overlapping implementations.
449 (active, marker_trait_attr, "1.30.0", Some(29864), None),
451 /// Allows macro invocations on modules expressions and statements and
452 /// procedural macros to expand to non-items.
453 (active, proc_macro_hygiene, "1.30.0", Some(54727), None),
455 /// Allows unsized rvalues at arguments and parameters.
456 (active, unsized_locals, "1.30.0", Some(48055), None),
458 /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`.
459 (active, custom_test_frameworks, "1.30.0", Some(50297), None),
461 /// Allows non-builtin attributes in inner attribute position.
462 (active, custom_inner_attributes, "1.30.0", Some(54726), None),
464 /// Allows `impl Trait` in bindings (`let`, `const`, `static`).
465 (active, impl_trait_in_bindings, "1.30.0", Some(63065), None),
467 /// Allows using `reason` in lint attributes and the `#[expect(lint)]` lint check.
468 (active, lint_reasons, "1.31.0", Some(54503), None),
470 /// Allows exhaustive integer pattern matching on `usize` and `isize`.
471 (active, precise_pointer_size_matching, "1.32.0", Some(56354), None),
473 /// Allows relaxing the coherence rules such that
474 /// `impl<T> ForeignTrait<LocalType> for ForeignType<T>` is permitted.
475 (active, re_rebalance_coherence, "1.32.0", Some(55437), None),
477 /// Allows using `#[ffi_returns_twice]` on foreign functions.
478 (active, ffi_returns_twice, "1.34.0", Some(58314), None),
480 /// Allows const generic types (e.g. `struct Foo<const N: usize>(...);`).
481 (active, const_generics, "1.34.0", Some(44580), None),
483 /// Allows using `#[optimize(X)]`.
484 (active, optimize_attribute, "1.34.0", Some(54882), None),
486 /// Allows using C-variadics.
487 (active, c_variadic, "1.34.0", Some(44930), None),
489 /// Allows the user of associated type bounds.
490 (active, associated_type_bounds, "1.34.0", Some(52662), None),
492 /// Allows calling constructor functions in `const fn`.
493 (active, const_constructor, "1.37.0", Some(61456), None),
495 /// Allows `if/while p && let q = r && ...` chains.
496 (active, let_chains, "1.37.0", Some(53667), None),
498 /// Allows #[repr(transparent)] on enums (RFC 2645).
499 (active, transparent_enums, "1.37.0", Some(60405), None),
501 /// Allows #[repr(transparent)] on unions (RFC 2645).
502 (active, transparent_unions, "1.37.0", Some(60405), None),
504 /// Allows explicit discriminants on non-unit enum variants.
505 (active, arbitrary_enum_discriminant, "1.37.0", Some(60553), None),
507 /// Allows `impl Trait` with multiple unrelated lifetimes.
508 (active, member_constraints, "1.37.0", Some(61977), None),
510 /// Allows `async || body` closures.
511 (active, async_closure, "1.37.0", Some(62290), None),
513 /// Allows the use of `#[cfg(doctest)]`; set when rustdoc is collecting doctests.
514 (active, cfg_doctest, "1.37.0", Some(62210), None),
516 /// Allows `[x; N]` where `x` is a constant (RFC 2203).
517 (active, const_in_array_repeat_expressions, "1.37.0", Some(49147), None),
519 /// Allows `impl Trait` to be used inside type aliases (RFC 2515).
520 (active, type_alias_impl_trait, "1.38.0", Some(63063), None),
522 /// Allows the use of or-patterns (e.g., `0 | 1`).
523 (active, or_patterns, "1.38.0", Some(54883), None),
525 // -------------------------------------------------------------------------
526 // feature-group-end: actual feature gates
527 // -------------------------------------------------------------------------
530 /// Some features are known to be incomplete and using them is likely to have
531 /// unanticipated results, such as compiler crashes. We warn the user about these
533 pub const INCOMPLETE_FEATURES: &[Symbol] = &[
534 sym::impl_trait_in_bindings,
535 sym::generic_associated_types,