1 //! List of the active feature gates. 2 3 use super::{to_nonzero, Feature, State}; 4 5 use rustc_data_structures::fx::FxHashSet; 6 use rustc_span::edition::Edition; 7 use rustc_span::symbol::{sym, Symbol}; 8 use rustc_span::Span; 9 10 macro_rules! set { 11 ($field: ident) => {{ 12 fn f(features: &mut Features, _: Span) { 13 features.$field = true; 14 } 15 f as fn(&mut Features, Span) 16 }}; 17 } 18 19 macro_rules! declare_features { 20 (__status_to_bool active) => { 21 false 22 }; 23 (__status_to_bool incomplete) => { 24 true 25 }; 26 ($( 27 $(#[doc = $doc:tt])* ($status:ident, $feature:ident, $ver:expr, $issue:expr, $edition:expr), 28 )+) => { 29 /// Represents active features that are currently being implemented or 30 /// currently being considered for addition/removal. 31 pub const ACTIVE_FEATURES: 32 &[Feature] = 33 &[$( 34 // (sym::$feature, $ver, $issue, $edition, set!($feature)) 35 Feature { 36 state: State::Active { set: set!($feature) }, 37 name: sym::$feature, 38 since: $ver, 39 issue: to_nonzero($issue), 40 edition: $edition, 41 } 42 ),+]; 43 44 /// A set of features to be used by later passes. 45 #[derive(Clone, Default, Debug)] 46 pub struct Features { 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>, 53 $( 54 $(#[doc = $doc])* 55 pub $feature: bool 56 ),+ 57 } 58 59 impl Features { 60 pub fn walk_feature_fields(&self, mut f: impl FnMut(&str, bool)) { 61 $(f(stringify!($feature), self.$feature);)+ 62 } 63 64 /// Is the given feature active? 65 pub fn active(&self, feature: Symbol) -> bool { 66 self.active_features.contains(&feature) 67 } 68 69 /// Is the given feature enabled? 70 /// 71 /// Panics if the symbol doesn't correspond to a declared feature. 72 pub fn enabled(&self, feature: Symbol) -> bool { 73 match feature { 74 $( sym::$feature => self.$feature, )* 75 76 _ => panic!("`{}` was not listed in `declare_features`", feature), 77 } 78 } 79 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 82 /// to alert them. 83 pub fn incomplete(&self, feature: Symbol) -> bool { 84 match feature { 85 $( 86 sym::$feature => declare_features!(__status_to_bool $status), 87 )* 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), 92 } 93 } 94 } 95 }; 96 } 97 98 impl Feature { 99 /// Sets this feature in `Features`. Panics if called on a non-active feature. set(&self, features: &mut Features, span: Span)100 pub fn set(&self, features: &mut Features, span: Span) { 101 match self.state { 102 State::Active { set } => set(features, span), 103 _ => panic!("called `set` on feature `{}` which is not `active`", self.name), 104 } 105 } 106 } 107 108 // See https://rustc-dev-guide.rust-lang.org/feature-gates.html#feature-gates for more 109 // documentation about handling feature gates. 110 // 111 // If you change this, please modify `src/doc/unstable-book` as well. 112 // 113 // Don't ever remove anything from this list; move them to `accepted.rs` if 114 // accepted or `removed.rs` if removed. 115 // 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 118 // stable (active). 119 // 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. 122 // 123 // N.B., `tools/tidy/src/features.rs` parses this information directly out of the 124 // source, so take care when modifying it. 125 126 #[rustfmt::skip] 127 declare_features! ( 128 // ------------------------------------------------------------------------- 129 // feature-group-start: internal feature gates (no tracking issue) 130 // ------------------------------------------------------------------------- 131 // no-tracking-issue-start 132 133 /// 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 `#[link(..., cfg(..))]`; perma-unstable per #37406 164 (active, link_cfg, "1.14.0", None, None), 165 /// Allows the `multiple_supertrait_upcastable` lint. 166 (active, multiple_supertrait_upcastable, "1.69.0", None, None), 167 /// Allow negative trait bounds. This is an internal-only feature for testing the trait solver! 168 (incomplete, negative_bounds, "1.71.0", None, None), 169 /// Allows using `#[omit_gdb_pretty_printer_section]`. 170 (active, omit_gdb_pretty_printer_section, "1.5.0", None, None), 171 /// Allows using `#[prelude_import]` on glob `use` items. 172 (active, prelude_import, "1.2.0", None, None), 173 /// Used to identify crates that contain the profiler runtime. 174 (active, profiler_runtime, "1.18.0", None, None), 175 /// Allows using `rustc_*` attributes (RFC 572). 176 (active, rustc_attrs, "1.0.0", None, None), 177 /// Allows using the `#[stable]` and `#[unstable]` attributes. 178 (active, staged_api, "1.0.0", None, None), 179 /// Added for testing E0705; perma-unstable. 180 (active, test_2018_feature, "1.31.0", None, Some(Edition::Edition2018)), 181 /// Added for testing unstable lints; perma-unstable. 182 (active, test_unstable_lint, "1.60.0", None, None), 183 /// Allows non-`unsafe` —and thus, unsound— access to `Pin` constructions. 184 /// Marked `incomplete` since perma-unstable and unsound. 185 (incomplete, unsafe_pin_internals, "1.60.0", None, None), 186 /// Use for stable + negative coherence and strict coherence depending on trait's 187 /// rustc_strict_coherence value. 188 (active, with_negative_coherence, "1.60.0", None, None), 189 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! 190 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. 191 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! 192 193 // no-tracking-issue-end 194 // ------------------------------------------------------------------------- 195 // feature-group-end: internal feature gates (no tracking issue) 196 // ------------------------------------------------------------------------- 197 198 // ------------------------------------------------------------------------- 199 // feature-group-start: internal feature gates 200 // ------------------------------------------------------------------------- 201 202 /// Allows features specific to auto traits. 203 /// Renamed from `optin_builtin_traits`. 204 (active, auto_traits, "1.50.0", Some(13231), None), 205 /// Allows using `box` in patterns (RFC 469). 206 (active, box_patterns, "1.0.0", Some(29641), None), 207 /// Allows `#[doc(notable_trait)]`. 208 /// Renamed from `doc_spotlight`. 209 (active, doc_notable_trait, "1.52.0", Some(45040), None), 210 /// Allows using the `may_dangle` attribute (RFC 1327). 211 (active, dropck_eyepatch, "1.10.0", Some(34761), None), 212 /// Allows using the `#[fundamental]` attribute. 213 (active, fundamental, "1.0.0", Some(29635), None), 214 /// Allows using `#[link_name="llvm.*"]`. 215 (active, link_llvm_intrinsics, "1.0.0", Some(29602), None), 216 /// Allows using the `#[linkage = ".."]` attribute. 217 (active, linkage, "1.0.0", Some(29603), None), 218 /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed. 219 (active, needs_panic_runtime, "1.10.0", Some(32837), None), 220 /// Allows using `+bundled,+whole-archive` native libs. 221 (active, packed_bundled_libs, "1.69.0", Some(108081), None), 222 /// Allows using the `#![panic_runtime]` attribute. 223 (active, panic_runtime, "1.10.0", Some(32837), None), 224 /// Allows using `#[rustc_allow_const_fn_unstable]`. 225 /// This is an attribute on `const fn` for the same 226 /// purpose as `#[allow_internal_unstable]`. 227 (active, rustc_allow_const_fn_unstable, "1.49.0", Some(69399), None), 228 /// Allows using compiler's own crates. 229 (active, rustc_private, "1.0.0", Some(27812), None), 230 /// Allows using internal rustdoc features like `doc(keyword)`. 231 (active, rustdoc_internals, "1.58.0", Some(90418), None), 232 /// Allows using the `rustdoc::missing_doc_code_examples` lint 233 (active, rustdoc_missing_doc_code_examples, "1.31.0", Some(101730), None), 234 /// Allows using `#[start]` on a function indicating that it is the program entrypoint. 235 (active, start, "1.0.0", Some(29633), None), 236 /// Allows using `#[structural_match]` which indicates that a type is structurally matchable. 237 /// FIXME: Subsumed by trait `StructuralPartialEq`, cannot move to removed until a library 238 /// feature with the same name exists. 239 (active, structural_match, "1.8.0", Some(31434), None), 240 /// Allows using the `rust-call` ABI. 241 (active, unboxed_closures, "1.0.0", Some(29625), None), 242 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! 243 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. 244 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! 245 246 // ------------------------------------------------------------------------- 247 // feature-group-end: internal feature gates 248 // ------------------------------------------------------------------------- 249 250 // ------------------------------------------------------------------------- 251 // feature-group-start: actual feature gates (target features) 252 // ------------------------------------------------------------------------- 253 254 // FIXME: Document these and merge with the list below. 255 256 // Unstable `#[target_feature]` directives. 257 (active, aarch64_ver_target_feature, "1.27.0", Some(44839), None), 258 (active, arm_target_feature, "1.27.0", Some(44839), None), 259 (active, avx512_target_feature, "1.27.0", Some(44839), None), 260 (active, bpf_target_feature, "1.54.0", Some(44839), None), 261 (active, ermsb_target_feature, "1.49.0", Some(44839), None), 262 (active, hexagon_target_feature, "1.27.0", Some(44839), None), 263 (active, mips_target_feature, "1.27.0", Some(44839), None), 264 (active, powerpc_target_feature, "1.27.0", Some(44839), None), 265 (active, riscv_target_feature, "1.45.0", Some(44839), None), 266 (active, rtm_target_feature, "1.35.0", Some(44839), None), 267 (active, sse4a_target_feature, "1.27.0", Some(44839), None), 268 (active, tbm_target_feature, "1.27.0", Some(44839), None), 269 (active, wasm_target_feature, "1.30.0", Some(44839), None), 270 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! 271 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. 272 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! 273 274 // ------------------------------------------------------------------------- 275 // feature-group-end: actual feature gates (target features) 276 // ------------------------------------------------------------------------- 277 278 // ------------------------------------------------------------------------- 279 // feature-group-start: actual feature gates 280 // ------------------------------------------------------------------------- 281 282 /// Allows using the `amdgpu-kernel` ABI. 283 (active, abi_amdgpu_kernel, "1.29.0", Some(51575), None), 284 /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`. 285 (active, abi_avr_interrupt, "1.45.0", Some(69664), None), 286 /// Allows `extern "C-cmse-nonsecure-call" fn()`. 287 (active, abi_c_cmse_nonsecure_call, "1.51.0", Some(81391), None), 288 /// Allows `extern "msp430-interrupt" fn()`. 289 (active, abi_msp430_interrupt, "1.16.0", Some(38487), None), 290 /// Allows `extern "ptx-*" fn()`. 291 (active, abi_ptx, "1.15.0", Some(38788), None), 292 /// Allows `extern "x86-interrupt" fn()`. 293 (active, abi_x86_interrupt, "1.17.0", Some(40180), None), 294 /// Allows additional const parameter types, such as `&'static str` or user defined types 295 (incomplete, adt_const_params, "1.56.0", Some(95174), None), 296 /// Allows defining an `#[alloc_error_handler]`. 297 (active, alloc_error_handler, "1.29.0", Some(51540), None), 298 /// Allows trait methods with arbitrary self types. 299 (active, arbitrary_self_types, "1.23.0", Some(44874), None), 300 /// Allows using `const` operands in inline assembly. 301 (active, asm_const, "1.58.0", Some(93332), None), 302 /// Enables experimental inline assembly support for additional architectures. 303 (active, asm_experimental_arch, "1.58.0", Some(93335), None), 304 /// Allows the `may_unwind` option in inline assembly. 305 (active, asm_unwind, "1.58.0", Some(93334), None), 306 /// Allows users to enforce equality of associated constants `TraitImpl<AssocConst=3>`. 307 (active, associated_const_equality, "1.58.0", Some(92827), None), 308 /// Allows the user of associated type bounds. 309 (active, associated_type_bounds, "1.34.0", Some(52662), None), 310 /// Allows associated type defaults. 311 (active, associated_type_defaults, "1.2.0", Some(29661), None), 312 /// Allows `async || body` closures. 313 (active, async_closure, "1.37.0", Some(62290), None), 314 /// Allows async functions to be declared, implemented, and used in traits. 315 (active, async_fn_in_trait, "1.66.0", Some(91611), None), 316 /// Allows builtin # foo() syntax 317 (active, builtin_syntax, "1.71.0", Some(110680), None), 318 /// Allows `c"foo"` literals. 319 (active, c_str_literals, "1.71.0", Some(105723), None), 320 /// Treat `extern "C"` function as nounwind. 321 (active, c_unwind, "1.52.0", Some(74990), None), 322 /// Allows using C-variadics. 323 (active, c_variadic, "1.34.0", Some(44930), None), 324 /// Allows the use of `#[cfg(overflow_checks)` to check if integer overflow behaviour. 325 (active, cfg_overflow_checks, "1.71.0", Some(111466), None), 326 /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used. 327 (active, cfg_sanitize, "1.41.0", Some(39699), None), 328 /// Allows `cfg(target_abi = "...")`. 329 (active, cfg_target_abi, "1.55.0", Some(80970), None), 330 /// Allows `cfg(target(abi = "..."))`. 331 (active, cfg_target_compact, "1.63.0", Some(96901), None), 332 /// Allows `cfg(target_has_atomic_load_store = "...")`. 333 (active, cfg_target_has_atomic, "1.60.0", Some(94039), None), 334 /// Allows `cfg(target_has_atomic_equal_alignment = "...")`. 335 (active, cfg_target_has_atomic_equal_alignment, "1.60.0", Some(93822), None), 336 /// Allows `cfg(target_thread_local)`. 337 (active, cfg_target_thread_local, "1.7.0", Some(29594), None), 338 /// Allow conditional compilation depending on rust version 339 (active, cfg_version, "1.45.0", Some(64796), None), 340 /// Allows to use the `#[cfi_encoding = ""]` attribute. 341 (active, cfi_encoding, "1.71.0", Some(89653), None), 342 /// Allows `for<...>` on closures and generators. 343 (active, closure_lifetime_binder, "1.64.0", Some(97362), None), 344 /// Allows `#[track_caller]` on closures and generators. 345 (active, closure_track_caller, "1.57.0", Some(87417), None), 346 /// Allows to use the `#[cmse_nonsecure_entry]` attribute. 347 (active, cmse_nonsecure_entry, "1.48.0", Some(75835), None), 348 /// Allows use of the `#[collapse_debuginfo]` attribute. 349 (active, collapse_debuginfo, "1.65.0", Some(100758), None), 350 /// Allows `async {}` expressions in const contexts. 351 (active, const_async_blocks, "1.53.0", Some(85368), None), 352 /// Allows `const || {}` closures in const contexts. 353 (incomplete, const_closures, "1.68.0", Some(106003), None), 354 /// Allows the definition of `const extern fn` and `const unsafe extern fn`. 355 (active, const_extern_fn, "1.40.0", Some(64926), None), 356 /// Allows basic arithmetic on floating point types in a `const fn`. 357 (active, const_fn_floating_point_arithmetic, "1.48.0", Some(57241), None), 358 /// Allows `for _ in _` loops in const contexts. 359 (active, const_for, "1.56.0", Some(87575), None), 360 /// Allows using `&mut` in constant functions. 361 (active, const_mut_refs, "1.41.0", Some(57349), None), 362 /// Be more precise when looking for live drops in a const context. 363 (active, const_precise_live_drops, "1.46.0", Some(73255), None), 364 /// Allows references to types with interior mutability within constants 365 (active, const_refs_to_cell, "1.51.0", Some(80384), None), 366 /// Allows `impl const Trait for T` syntax. 367 (active, const_trait_impl, "1.42.0", Some(67792), None), 368 /// Allows the `?` operator in const contexts. 369 (active, const_try, "1.56.0", Some(74935), None), 370 /// Allows non-builtin attributes in inner attribute position. 371 (active, custom_inner_attributes, "1.30.0", Some(54726), None), 372 /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`. 373 (active, custom_test_frameworks, "1.30.0", Some(50297), None), 374 /// Allows declarative macros 2.0 (`macro`). 375 (active, decl_macro, "1.17.0", Some(39412), None), 376 /// Allows default type parameters to influence type inference. 377 (active, default_type_parameter_fallback, "1.3.0", Some(27336), None), 378 /// Allows using `#[deprecated_safe]` to deprecate the safeness of a function or trait 379 (active, deprecated_safe, "1.61.0", Some(94978), None), 380 /// Allows having using `suggestion` in the `#[deprecated]` attribute. 381 (active, deprecated_suggestion, "1.61.0", Some(94785), None), 382 /// Controls errors in trait implementations. 383 (active, do_not_recommend, "1.67.0", Some(51992), None), 384 /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`. 385 (active, doc_auto_cfg, "1.58.0", Some(43781), None), 386 /// Allows `#[doc(cfg(...))]`. 387 (active, doc_cfg, "1.21.0", Some(43781), None), 388 /// Allows `#[doc(cfg_hide(...))]`. 389 (active, doc_cfg_hide, "1.57.0", Some(43781), None), 390 /// Allows `#[doc(masked)]`. 391 (active, doc_masked, "1.21.0", Some(44027), None), 392 /// Allows `dyn* Trait` objects. 393 (incomplete, dyn_star, "1.65.0", Some(102425), None), 394 // Uses generic effect parameters for ~const bounds 395 (active, effects, "1.72.0", Some(102090), None), 396 /// Allows `X..Y` patterns. 397 (active, exclusive_range_pattern, "1.11.0", Some(37854), None), 398 /// Allows exhaustive pattern matching on types that contain uninhabited types. 399 (active, exhaustive_patterns, "1.13.0", Some(51085), None), 400 /// Allows explicit tail calls via `become` expression. 401 (incomplete, explicit_tail_calls, "1.72.0", Some(112788), None), 402 /// Allows using `efiapi`, `sysv64` and `win64` as calling convention 403 /// for functions with varargs. 404 (active, extended_varargs_abi_support, "1.65.0", Some(100189), None), 405 /// Allows defining `extern type`s. 406 (active, extern_types, "1.23.0", Some(43467), None), 407 /// Allows the use of `#[ffi_const]` on foreign functions. 408 (active, ffi_const, "1.45.0", Some(58328), None), 409 /// Allows the use of `#[ffi_pure]` on foreign functions. 410 (active, ffi_pure, "1.45.0", Some(58329), None), 411 /// Allows using `#[ffi_returns_twice]` on foreign functions. 412 (active, ffi_returns_twice, "1.34.0", Some(58314), None), 413 /// Allows using `#[repr(align(...))]` on function items 414 (active, fn_align, "1.53.0", Some(82232), None), 415 /// Allows generators to be cloned. 416 (active, generator_clone, "1.65.0", Some(95360), None), 417 /// Allows defining generators. 418 (active, generators, "1.21.0", Some(43122), None), 419 /// Infer generic args for both consts and types. 420 (active, generic_arg_infer, "1.55.0", Some(85077), None), 421 /// An extension to the `generic_associated_types` feature, allowing incomplete features. 422 (incomplete, generic_associated_types_extended, "1.61.0", Some(95451), None), 423 /// Allows non-trivial generic constants which have to have wfness manually propagated to callers 424 (incomplete, generic_const_exprs, "1.56.0", Some(76560), None), 425 /// Allows using `..=X` as a patterns in slices. 426 (active, half_open_range_patterns_in_slices, "1.66.0", Some(67264), None), 427 /// Allows `if let` guard in match arms. 428 (active, if_let_guard, "1.47.0", Some(51114), None), 429 /// Allows `impl Trait` to be used inside associated types (RFC 2515). 430 (active, impl_trait_in_assoc_type, "1.70.0", Some(63063), None), 431 /// Allows `impl Trait` as output type in `Fn` traits in return position of functions. 432 (active, impl_trait_in_fn_trait_return, "1.64.0", Some(99697), None), 433 /// Allows referencing `Self` and projections in impl-trait. 434 (active, impl_trait_projections, "1.67.0", Some(103532), None), 435 /// Allows using imported `main` function 436 (active, imported_main, "1.53.0", Some(28937), None), 437 /// Allows associated types in inherent impls. 438 (incomplete, inherent_associated_types, "1.52.0", Some(8995), None), 439 /// Allow anonymous constants from an inline `const` block 440 (active, inline_const, "1.49.0", Some(76001), None), 441 /// Allow anonymous constants from an inline `const` block in pattern position 442 (incomplete, inline_const_pat, "1.58.0", Some(76001), None), 443 /// Allows using `pointer` and `reference` in intra-doc links 444 (active, intra_doc_pointers, "1.51.0", Some(80896), None), 445 // Allows setting the threshold for the `large_assignments` lint. 446 (active, large_assignments, "1.52.0", Some(83518), None), 447 /// Allow to have type alias types for inter-crate use. 448 (active, lazy_type_alias, "1.72.0", Some(112792), None), 449 /// Allows `if/while p && let q = r && ...` chains. 450 (active, let_chains, "1.37.0", Some(53667), None), 451 /// Allows using `reason` in lint attributes and the `#[expect(lint)]` lint check. 452 (active, lint_reasons, "1.31.0", Some(54503), None), 453 /// Give access to additional metadata about declarative macro meta-variables. 454 (active, macro_metavar_expr, "1.61.0", Some(83527), None), 455 /// Allows `#[marker]` on certain traits allowing overlapping implementations. 456 (active, marker_trait_attr, "1.30.0", Some(29864), None), 457 /// A minimal, sound subset of specialization intended to be used by the 458 /// standard library until the soundness issues with specialization 459 /// are fixed. 460 (active, min_specialization, "1.7.0", Some(31844), None), 461 /// Allows qualified paths in struct expressions, struct patterns and tuple struct patterns. 462 (active, more_qualified_paths, "1.54.0", Some(86935), None), 463 /// Allows the `#[must_not_suspend]` attribute. 464 (active, must_not_suspend, "1.57.0", Some(83310), None), 465 /// Allows using `#[naked]` on functions. 466 (active, naked_functions, "1.9.0", Some(32408), None), 467 /// Allows specifying the as-needed link modifier 468 (active, native_link_modifiers_as_needed, "1.53.0", Some(81490), None), 469 /// Allow negative trait implementations. 470 (active, negative_impls, "1.44.0", Some(68318), None), 471 /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more. 472 (active, never_type, "1.13.0", Some(35121), None), 473 /// Allows diverging expressions to fall back to `!` rather than `()`. 474 (active, never_type_fallback, "1.41.0", Some(65992), None), 475 /// Allows `#![no_core]`. 476 (active, no_core, "1.3.0", Some(29639), None), 477 /// Allows function attribute `#[no_coverage]`, to bypass coverage 478 /// instrumentation of that function. 479 (active, no_coverage, "1.53.0", Some(84605), None), 480 /// Allows the use of `no_sanitize` attribute. 481 (active, no_sanitize, "1.42.0", Some(39699), None), 482 /// Allows using the `non_exhaustive_omitted_patterns` lint. 483 (active, non_exhaustive_omitted_patterns_lint, "1.57.0", Some(89554), None), 484 /// Allows `for<T>` binders in where-clauses 485 (incomplete, non_lifetime_binders, "1.69.0", Some(108185), None), 486 /// Allows making `dyn Trait` well-formed even if `Trait` is not object safe. 487 /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and 488 /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden. 489 (active, object_safe_for_dispatch, "1.40.0", Some(43561), None), 490 /// Allows using `#[optimize(X)]`. 491 (active, optimize_attribute, "1.34.0", Some(54882), None), 492 /// Allows `extern "platform-intrinsic" { ... }`. 493 (active, platform_intrinsics, "1.4.0", Some(27731), None), 494 /// Allows using `#![plugin(myplugin)]`. 495 (active, plugin, "1.0.0", Some(29597), None), 496 /// Allows exhaustive integer pattern matching on `usize` and `isize`. 497 (active, precise_pointer_size_matching, "1.32.0", Some(56354), None), 498 /// Allows macro attributes on expressions, statements and non-inline modules. 499 (active, proc_macro_hygiene, "1.30.0", Some(54727), None), 500 /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions. 501 (active, raw_ref_op, "1.41.0", Some(64490), None), 502 /// Allows using the `#[register_tool]` attribute. 503 (active, register_tool, "1.41.0", Some(66079), None), 504 /// Allows the `#[repr(i128)]` attribute for enums. 505 (incomplete, repr128, "1.16.0", Some(56071), None), 506 /// Allows `repr(simd)` and importing the various simd intrinsics. 507 (active, repr_simd, "1.4.0", Some(27731), None), 508 /// Allows return-position `impl Trait` in traits. 509 (active, return_position_impl_trait_in_trait, "1.65.0", Some(91611), None), 510 /// Allows bounding the return type of AFIT/RPITIT. 511 (incomplete, return_type_notation, "1.70.0", Some(109417), None), 512 /// Allows `extern "rust-cold"`. 513 (active, rust_cold_cc, "1.63.0", Some(97544), None), 514 /// Allows the use of SIMD types in functions declared in `extern` blocks. 515 (active, simd_ffi, "1.0.0", Some(27731), None), 516 /// Allows specialization of implementations (RFC 1210). 517 (incomplete, specialization, "1.7.0", Some(31844), None), 518 /// Allows attributes on expressions and non-item statements. 519 (active, stmt_expr_attributes, "1.6.0", Some(15701), None), 520 /// Allows lints part of the strict provenance effort. 521 (active, strict_provenance, "1.61.0", Some(95228), None), 522 /// Allows string patterns to dereference values to match them. 523 (active, string_deref_patterns, "1.67.0", Some(87121), None), 524 /// Allows the use of `#[target_feature]` on safe functions. 525 (active, target_feature_11, "1.45.0", Some(69098), None), 526 /// Allows using `#[thread_local]` on `static` items. 527 (active, thread_local, "1.0.0", Some(29594), None), 528 /// Allows defining `trait X = A + B;` alias items. 529 (active, trait_alias, "1.24.0", Some(41517), None), 530 /// Allows dyn upcasting trait objects via supertraits. 531 /// Dyn upcasting is casting, e.g., `dyn Foo -> dyn Bar` where `Foo: Bar`. 532 (active, trait_upcasting, "1.56.0", Some(65991), None), 533 /// Allows for transmuting between arrays with sizes that contain generic consts. 534 (active, transmute_generic_consts, "1.70.0", Some(109929), None), 535 /// Allows #[repr(transparent)] on unions (RFC 2645). 536 (active, transparent_unions, "1.37.0", Some(60405), None), 537 /// Allows inconsistent bounds in where clauses. 538 (active, trivial_bounds, "1.28.0", Some(48214), None), 539 /// Allows using `try {...}` expressions. 540 (active, try_blocks, "1.29.0", Some(31436), None), 541 /// Allows `impl Trait` to be used inside type aliases (RFC 2515). 542 (active, type_alias_impl_trait, "1.38.0", Some(63063), None), 543 /// Allows the use of type ascription in expressions. 544 (active, type_ascription, "1.6.0", Some(23416), None), 545 /// Allows creation of instances of a struct by moving fields that have 546 /// not changed from prior instances of the same struct (RFC #2528) 547 (active, type_changing_struct_update, "1.58.0", Some(86555), None), 548 /// Allows using type privacy lints (`private_interfaces`, `private_bounds`, `unnameable_types`). 549 (active, type_privacy_lints, "1.72.0", Some(48054), None), 550 /// Enables rustc to generate code that instructs libstd to NOT ignore SIGPIPE. 551 (active, unix_sigpipe, "1.65.0", Some(97889), None), 552 /// Allows unsized fn parameters. 553 (active, unsized_fn_params, "1.49.0", Some(48055), None), 554 /// Allows unsized rvalues at arguments and parameters. 555 (incomplete, unsized_locals, "1.30.0", Some(48055), None), 556 /// Allows unsized tuple coercion. 557 (active, unsized_tuple_coercion, "1.20.0", Some(42877), None), 558 /// Allows using the `#[used(linker)]` (or `#[used(compiler)]`) attribute. 559 (active, used_with_arg, "1.60.0", Some(93798), None), 560 /// Allows `extern "wasm" fn` 561 (active, wasm_abi, "1.53.0", Some(83788), None), 562 /// Allows `do yeet` expressions 563 (active, yeet_expr, "1.62.0", Some(96373), None), 564 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! 565 // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. 566 // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! 567 568 // ------------------------------------------------------------------------- 569 // feature-group-end: actual feature gates 570 // ------------------------------------------------------------------------- 571 ); 572 573 /// Some features are not allowed to be used together at the same time, if 574 /// the two are present, produce an error. 575 /// 576 /// Currently empty, but we will probably need this again in the future, 577 /// so let's keep it in for now. 578 pub const INCOMPATIBLE_FEATURES: &[(Symbol, Symbol)] = &[]; 579