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Diffstat (limited to 'compiler/rustc_feature/src/unstable.rs')
| -rw-r--r-- | compiler/rustc_feature/src/unstable.rs | 612 |
1 files changed, 612 insertions, 0 deletions
diff --git a/compiler/rustc_feature/src/unstable.rs b/compiler/rustc_feature/src/unstable.rs new file mode 100644 index 00000000000..27cdf1ba831 --- /dev/null +++ b/compiler/rustc_feature/src/unstable.rs @@ -0,0 +1,612 @@ +//! List of the unstable feature gates. + +use super::{to_nonzero, Feature}; + +use rustc_data_structures::fx::FxHashSet; +use rustc_span::edition::Edition; +use rustc_span::symbol::{sym, Symbol}; +use rustc_span::Span; + +pub struct UnstableFeature { + pub feature: Feature, + pub set_enabled: fn(&mut Features), +} + +#[derive(PartialEq)] +enum FeatureStatus { + Default, + Incomplete, + Internal, +} + +macro_rules! status_to_enum { + (unstable) => { + FeatureStatus::Default + }; + (incomplete) => { + FeatureStatus::Incomplete + }; + (internal) => { + FeatureStatus::Internal + }; +} + +macro_rules! declare_features { + ($( + $(#[doc = $doc:tt])* ($status:ident, $feature:ident, $ver:expr, $issue:expr, $edition:expr), + )+) => { + /// Unstable language features that are being implemented or being + /// considered for acceptance (stabilization) or removal. + pub const UNSTABLE_FEATURES: &[UnstableFeature] = &[ + $(UnstableFeature { + feature: Feature { + name: sym::$feature, + since: $ver, + issue: to_nonzero($issue), + edition: $edition, + }, + // Sets this feature's corresponding bool within `features`. + set_enabled: |features| features.$feature = true, + }),+ + ]; + + /// A set of features to be used by later passes. + #[derive(Clone, Default, Debug)] + pub struct Features { + /// `#![feature]` attrs for language features, for error reporting. + pub declared_lang_features: Vec<(Symbol, Span, Option<Symbol>)>, + /// `#![feature]` attrs for non-language (library) features. + pub declared_lib_features: Vec<(Symbol, Span)>, + /// `declared_lang_features` + `declared_lib_features`. + pub declared_features: FxHashSet<Symbol>, + /// Active state of individual features (unstable only). + $( + $(#[doc = $doc])* + pub $feature: bool + ),+ + } + + impl Features { + pub fn set_declared_lang_feature( + &mut self, + symbol: Symbol, + span: Span, + since: Option<Symbol> + ) { + self.declared_lang_features.push((symbol, span, since)); + self.declared_features.insert(symbol); + } + + pub fn set_declared_lib_feature(&mut self, symbol: Symbol, span: Span) { + self.declared_lib_features.push((symbol, span)); + self.declared_features.insert(symbol); + } + + pub fn walk_feature_fields(&self, mut f: impl FnMut(&str, bool)) { + $(f(stringify!($feature), self.$feature);)+ + } + + /// Is the given feature explicitly declared, i.e. named in a + /// `#![feature(...)]` within the code? + pub fn declared(&self, feature: Symbol) -> bool { + self.declared_features.contains(&feature) + } + + /// Is the given feature active, i.e. declared or automatically + /// enabled due to the edition? + /// + /// Panics if the symbol doesn't correspond to a declared feature. + pub fn active(&self, feature: Symbol) -> bool { + match feature { + $( sym::$feature => self.$feature, )* + + _ => panic!("`{}` was not listed in `declare_features`", feature), + } + } + + /// Some features are known to be incomplete and using them is likely to have + /// unanticipated results, such as compiler crashes. We warn the user about these + /// to alert them. + pub fn incomplete(&self, feature: Symbol) -> bool { + match feature { + $( + sym::$feature => status_to_enum!($status) == FeatureStatus::Incomplete, + )* + // Accepted/removed features aren't in this file but are never incomplete. + _ if self.declared_features.contains(&feature) => false, + _ => panic!("`{}` was not listed in `declare_features`", feature), + } + } + + /// Some features are internal to the compiler and standard library and should not + /// be used in normal projects. We warn the user about these to alert them. + pub fn internal(&self, feature: Symbol) -> bool { + match feature { + $( + sym::$feature => status_to_enum!($status) == FeatureStatus::Internal, + )* + // Accepted/removed features aren't in this file but are never internal + // (a removed feature might have been internal, but that's now irrelevant). + _ if self.declared_features.contains(&feature) => false, + _ => panic!("`{}` was not listed in `declare_features`", feature), + } + } + } + }; +} + +// See https://rustc-dev-guide.rust-lang.org/feature-gates.html#feature-gates for more +// documentation about handling feature gates. +// +// If you change this, please modify `src/doc/unstable-book` as well. +// +// Don't ever remove anything from this list; move them to `accepted.rs` if +// accepted or `removed.rs` if removed. +// +// The version numbers here correspond to the version in which the current status +// was set. +// +// Note that the features are grouped into internal/user-facing and then +// sorted by version inside those groups. This is enforced with tidy. +// +// N.B., `tools/tidy/src/features.rs` parses this information directly out of the +// source, so take care when modifying it. + +#[rustfmt::skip] +declare_features! ( + // ------------------------------------------------------------------------- + // feature-group-start: internal feature gates (no tracking issue) + // ------------------------------------------------------------------------- + // no-tracking-issue-start + + /// Allows using the `unadjusted` ABI; perma-unstable. + (unstable, abi_unadjusted, "1.16.0", None, None), + /// Allows using the `vectorcall` ABI. + (unstable, abi_vectorcall, "1.7.0", None, None), + /// Allows using `#![needs_allocator]`, an implementation detail of `#[global_allocator]`. + (internal, allocator_internals, "1.20.0", None, None), + /// Allows using `#[allow_internal_unsafe]`. This is an + /// attribute on `macro_rules!` and can't use the attribute handling + /// below (it has to be checked before expansion possibly makes + /// macros disappear). + (internal, allow_internal_unsafe, "1.0.0", None, None), + /// Allows using `#[allow_internal_unstable]`. This is an + /// attribute on `macro_rules!` and can't use the attribute handling + /// below (it has to be checked before expansion possibly makes + /// macros disappear). + (internal, allow_internal_unstable, "1.0.0", None, None), + /// Allows using anonymous lifetimes in argument-position impl-trait. + (unstable, anonymous_lifetime_in_impl_trait, "1.63.0", None, None), + /// Allows identifying the `compiler_builtins` crate. + (internal, compiler_builtins, "1.13.0", None, None), + /// Allows writing custom MIR + (internal, custom_mir, "1.65.0", None, None), + /// Outputs useful `assert!` messages + (unstable, generic_assert, "1.63.0", None, None), + /// Allows using the `rust-intrinsic`'s "ABI". + (internal, intrinsics, "1.0.0", None, None), + /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic. + (internal, lang_items, "1.0.0", None, None), + /// Allows `#[link(..., cfg(..))]`; perma-unstable per #37406 + (unstable, link_cfg, "1.14.0", None, None), + /// Allows the `multiple_supertrait_upcastable` lint. + (unstable, multiple_supertrait_upcastable, "1.69.0", None, None), + /// Allow negative trait bounds. This is an internal-only feature for testing the trait solver! + (incomplete, negative_bounds, "1.71.0", None, None), + /// Allows using `#[omit_gdb_pretty_printer_section]`. + (internal, omit_gdb_pretty_printer_section, "1.5.0", None, None), + /// Allows using `#[prelude_import]` on glob `use` items. + (internal, prelude_import, "1.2.0", None, None), + /// Used to identify crates that contain the profiler runtime. + (internal, profiler_runtime, "1.18.0", None, None), + /// Allows using `rustc_*` attributes (RFC 572). + (internal, rustc_attrs, "1.0.0", None, None), + /// Allows using the `#[stable]` and `#[unstable]` attributes. + (internal, staged_api, "1.0.0", None, None), + /// Added for testing E0705; perma-unstable. + (internal, test_2018_feature, "1.31.0", None, Some(Edition::Edition2018)), + /// Added for testing unstable lints; perma-unstable. + (internal, test_unstable_lint, "1.60.0", None, None), + /// Allows non-`unsafe` —and thus, unsound— access to `Pin` constructions. + /// Marked `internal` since perma-unstable and unsound. + (internal, unsafe_pin_internals, "1.60.0", None, None), + /// Use for stable + negative coherence and strict coherence depending on trait's + /// rustc_strict_coherence value. + (unstable, with_negative_coherence, "1.60.0", None, None), + // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! + // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. + // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! + + // no-tracking-issue-end + // ------------------------------------------------------------------------- + // feature-group-end: internal feature gates (no tracking issue) + // ------------------------------------------------------------------------- + + // ------------------------------------------------------------------------- + // feature-group-start: internal feature gates + // ------------------------------------------------------------------------- + + /// Allows features specific to auto traits. + /// Renamed from `optin_builtin_traits`. + (unstable, auto_traits, "1.50.0", Some(13231), None), + /// Allows using `box` in patterns (RFC 469). + (unstable, box_patterns, "1.0.0", Some(29641), None), + /// Allows `#[doc(notable_trait)]`. + /// Renamed from `doc_spotlight`. + (unstable, doc_notable_trait, "1.52.0", Some(45040), None), + /// Allows using the `may_dangle` attribute (RFC 1327). + (unstable, dropck_eyepatch, "1.10.0", Some(34761), None), + /// Allows using the `#[fundamental]` attribute. + (unstable, fundamental, "1.0.0", Some(29635), None), + /// Allows using `#[link_name="llvm.*"]`. + (internal, link_llvm_intrinsics, "1.0.0", Some(29602), None), + /// Allows using the `#[linkage = ".."]` attribute. + (unstable, linkage, "1.0.0", Some(29603), None), + /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed. + (internal, needs_panic_runtime, "1.10.0", Some(32837), None), + /// Allows using the `#![panic_runtime]` attribute. + (internal, panic_runtime, "1.10.0", Some(32837), None), + /// Allows `extern "platform-intrinsic" { ... }`. + (internal, platform_intrinsics, "1.4.0", Some(27731), None), + /// Allows using `#[rustc_allow_const_fn_unstable]`. + /// This is an attribute on `const fn` for the same + /// purpose as `#[allow_internal_unstable]`. + (internal, rustc_allow_const_fn_unstable, "1.49.0", Some(69399), None), + /// Allows using compiler's own crates. + (unstable, rustc_private, "1.0.0", Some(27812), None), + /// Allows using internal rustdoc features like `doc(keyword)`. + (internal, rustdoc_internals, "1.58.0", Some(90418), None), + /// Allows using the `rustdoc::missing_doc_code_examples` lint + (unstable, rustdoc_missing_doc_code_examples, "1.31.0", Some(101730), None), + /// Allows using `#[start]` on a function indicating that it is the program entrypoint. + (unstable, start, "1.0.0", Some(29633), None), + /// Allows using `#[structural_match]` which indicates that a type is structurally matchable. + /// FIXME: Subsumed by trait `StructuralPartialEq`, cannot move to removed until a library + /// feature with the same name exists. + (unstable, structural_match, "1.8.0", Some(31434), None), + /// Allows using the `rust-call` ABI. + (unstable, unboxed_closures, "1.0.0", Some(29625), None), + // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! + // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. + // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! + + // ------------------------------------------------------------------------- + // feature-group-end: internal feature gates + // ------------------------------------------------------------------------- + + // ------------------------------------------------------------------------- + // feature-group-start: actual feature gates (target features) + // ------------------------------------------------------------------------- + + // FIXME: Document these and merge with the list below. + + // Unstable `#[target_feature]` directives. + (unstable, aarch64_ver_target_feature, "1.27.0", Some(44839), None), + (unstable, arm_target_feature, "1.27.0", Some(44839), None), + (unstable, avx512_target_feature, "1.27.0", Some(44839), None), + (unstable, bpf_target_feature, "1.54.0", Some(44839), None), + (unstable, csky_target_feature, "1.73.0", Some(44839), None), + (unstable, ermsb_target_feature, "1.49.0", Some(44839), None), + (unstable, hexagon_target_feature, "1.27.0", Some(44839), None), + (unstable, mips_target_feature, "1.27.0", Some(44839), None), + (unstable, powerpc_target_feature, "1.27.0", Some(44839), None), + (unstable, riscv_target_feature, "1.45.0", Some(44839), None), + (unstable, rtm_target_feature, "1.35.0", Some(44839), None), + (unstable, sse4a_target_feature, "1.27.0", Some(44839), None), + (unstable, tbm_target_feature, "1.27.0", Some(44839), None), + (unstable, wasm_target_feature, "1.30.0", Some(44839), None), + // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! + // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. + // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! + + // ------------------------------------------------------------------------- + // feature-group-end: actual feature gates (target features) + // ------------------------------------------------------------------------- + + // ------------------------------------------------------------------------- + // feature-group-start: actual feature gates + // ------------------------------------------------------------------------- + + /// Allows using the `amdgpu-kernel` ABI. + (unstable, abi_amdgpu_kernel, "1.29.0", Some(51575), None), + /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`. + (unstable, abi_avr_interrupt, "1.45.0", Some(69664), None), + /// Allows `extern "C-cmse-nonsecure-call" fn()`. + (unstable, abi_c_cmse_nonsecure_call, "1.51.0", Some(81391), None), + /// Allows `extern "msp430-interrupt" fn()`. + (unstable, abi_msp430_interrupt, "1.16.0", Some(38487), None), + /// Allows `extern "ptx-*" fn()`. + (unstable, abi_ptx, "1.15.0", Some(38788), None), + /// Allows `extern "riscv-interrupt-m" fn()` and `extern "riscv-interrupt-s" fn()`. + (unstable, abi_riscv_interrupt, "1.73.0", Some(111889), None), + /// Allows `extern "x86-interrupt" fn()`. + (unstable, abi_x86_interrupt, "1.17.0", Some(40180), None), + /// Allows additional const parameter types, such as `&'static str` or user defined types + (incomplete, adt_const_params, "1.56.0", Some(95174), None), + /// Allows defining an `#[alloc_error_handler]`. + (unstable, alloc_error_handler, "1.29.0", Some(51540), None), + /// Allows trait methods with arbitrary self types. + (unstable, arbitrary_self_types, "1.23.0", Some(44874), None), + /// Allows using `const` operands in inline assembly. + (unstable, asm_const, "1.58.0", Some(93332), None), + /// Enables experimental inline assembly support for additional architectures. + (unstable, asm_experimental_arch, "1.58.0", Some(93335), None), + /// Allows the `may_unwind` option in inline assembly. + (unstable, asm_unwind, "1.58.0", Some(93334), None), + /// Allows users to enforce equality of associated constants `TraitImpl<AssocConst=3>`. + (unstable, associated_const_equality, "1.58.0", Some(92827), None), + /// Allows the user of associated type bounds. + (unstable, associated_type_bounds, "1.34.0", Some(52662), None), + /// Allows associated type defaults. + (unstable, associated_type_defaults, "1.2.0", Some(29661), None), + /// Allows `async || body` closures. + (unstable, async_closure, "1.37.0", Some(62290), None), + /// Allows `#[track_caller]` on async functions. + (unstable, async_fn_track_caller, "1.73.0", Some(110011), None), + /// Allows builtin # foo() syntax + (unstable, builtin_syntax, "1.71.0", Some(110680), None), + /// Allows `c"foo"` literals. + (unstable, c_str_literals, "1.71.0", Some(105723), None), + /// Treat `extern "C"` function as nounwind. + (unstable, c_unwind, "1.52.0", Some(74990), None), + /// Allows using C-variadics. + (unstable, c_variadic, "1.34.0", Some(44930), None), + /// Allows the use of `#[cfg(overflow_checks)` to check if integer overflow behaviour. + (unstable, cfg_overflow_checks, "1.71.0", Some(111466), None), + /// Provides the relocation model information as cfg entry + (unstable, cfg_relocation_model, "1.73.0", Some(114929), None), + /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used. + (unstable, cfg_sanitize, "1.41.0", Some(39699), None), + /// Allows `cfg(target_abi = "...")`. + (unstable, cfg_target_abi, "1.55.0", Some(80970), None), + /// Allows `cfg(target(abi = "..."))`. + (unstable, cfg_target_compact, "1.63.0", Some(96901), None), + /// Allows `cfg(target_has_atomic_load_store = "...")`. + (unstable, cfg_target_has_atomic, "1.60.0", Some(94039), None), + /// Allows `cfg(target_has_atomic_equal_alignment = "...")`. + (unstable, cfg_target_has_atomic_equal_alignment, "1.60.0", Some(93822), None), + /// Allows `cfg(target_thread_local)`. + (unstable, cfg_target_thread_local, "1.7.0", Some(29594), None), + /// Allow conditional compilation depending on rust version + (unstable, cfg_version, "1.45.0", Some(64796), None), + /// Allows to use the `#[cfi_encoding = ""]` attribute. + (unstable, cfi_encoding, "1.71.0", Some(89653), None), + /// Allows `for<...>` on closures and generators. + (unstable, closure_lifetime_binder, "1.64.0", Some(97362), None), + /// Allows `#[track_caller]` on closures and generators. + (unstable, closure_track_caller, "1.57.0", Some(87417), None), + /// Allows to use the `#[cmse_nonsecure_entry]` attribute. + (unstable, cmse_nonsecure_entry, "1.48.0", Some(75835), None), + /// Allows use of the `#[collapse_debuginfo]` attribute. + (unstable, collapse_debuginfo, "1.65.0", Some(100758), None), + /// Allows `async {}` expressions in const contexts. + (unstable, const_async_blocks, "1.53.0", Some(85368), None), + /// Allows `const || {}` closures in const contexts. + (incomplete, const_closures, "1.68.0", Some(106003), None), + /// Allows the definition of `const extern fn` and `const unsafe extern fn`. + (unstable, const_extern_fn, "1.40.0", Some(64926), None), + /// Allows basic arithmetic on floating point types in a `const fn`. + (unstable, const_fn_floating_point_arithmetic, "1.48.0", Some(57241), None), + /// Allows `for _ in _` loops in const contexts. + (unstable, const_for, "1.56.0", Some(87575), None), + /// Allows using `&mut` in constant functions. + (unstable, const_mut_refs, "1.41.0", Some(57349), None), + /// Be more precise when looking for live drops in a const context. + (unstable, const_precise_live_drops, "1.46.0", Some(73255), None), + /// Allows references to types with interior mutability within constants + (unstable, const_refs_to_cell, "1.51.0", Some(80384), None), + /// Allows `impl const Trait for T` syntax. + (unstable, const_trait_impl, "1.42.0", Some(67792), None), + /// Allows the `?` operator in const contexts. + (unstable, const_try, "1.56.0", Some(74935), None), + /// Allows function attribute `#[coverage(on/off)]`, to control coverage + /// instrumentation of that function. + (unstable, coverage_attribute, "1.74.0", Some(84605), None), + /// Allows users to provide classes for fenced code block using `class:classname`. + (unstable, custom_code_classes_in_docs, "1.74.0", Some(79483), None), + /// Allows non-builtin attributes in inner attribute position. + (unstable, custom_inner_attributes, "1.30.0", Some(54726), None), + /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`. + (unstable, custom_test_frameworks, "1.30.0", Some(50297), None), + /// Allows declarative macros 2.0 (`macro`). + (unstable, decl_macro, "1.17.0", Some(39412), None), + /// Allows default type parameters to influence type inference. + (unstable, default_type_parameter_fallback, "1.3.0", Some(27336), None), + /// Allows using `#[deprecated_safe]` to deprecate the safeness of a function or trait + (unstable, deprecated_safe, "1.61.0", Some(94978), None), + /// Allows having using `suggestion` in the `#[deprecated]` attribute. + (unstable, deprecated_suggestion, "1.61.0", Some(94785), None), + /// Allows using the `#[diagnostic]` attribute tool namespace + (unstable, diagnostic_namespace, "1.73.0", Some(111996), None), + /// Controls errors in trait implementations. + (unstable, do_not_recommend, "1.67.0", Some(51992), None), + /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`. + (unstable, doc_auto_cfg, "1.58.0", Some(43781), None), + /// Allows `#[doc(cfg(...))]`. + (unstable, doc_cfg, "1.21.0", Some(43781), None), + /// Allows `#[doc(cfg_hide(...))]`. + (unstable, doc_cfg_hide, "1.57.0", Some(43781), None), + /// Allows `#[doc(masked)]`. + (unstable, doc_masked, "1.21.0", Some(44027), None), + /// Allows `dyn* Trait` objects. + (incomplete, dyn_star, "1.65.0", Some(102425), None), + // Uses generic effect parameters for ~const bounds + (unstable, effects, "1.72.0", Some(102090), None), + /// Allows `X..Y` patterns. + (unstable, exclusive_range_pattern, "1.11.0", Some(37854), None), + /// Allows exhaustive pattern matching on types that contain uninhabited types. + (unstable, exhaustive_patterns, "1.13.0", Some(51085), None), + /// Allows explicit tail calls via `become` expression. + (incomplete, explicit_tail_calls, "1.72.0", Some(112788), None), + /// Allows using `efiapi`, `sysv64` and `win64` as calling convention + /// for functions with varargs. + (unstable, extended_varargs_abi_support, "1.65.0", Some(100189), None), + /// Allows defining `extern type`s. + (unstable, extern_types, "1.23.0", Some(43467), None), + /// Allows the use of `#[ffi_const]` on foreign functions. + (unstable, ffi_const, "1.45.0", Some(58328), None), + /// Allows the use of `#[ffi_pure]` on foreign functions. + (unstable, ffi_pure, "1.45.0", Some(58329), None), + /// Allows using `#[ffi_returns_twice]` on foreign functions. + (unstable, ffi_returns_twice, "1.34.0", Some(58314), None), + /// Allows using `#[repr(align(...))]` on function items + (unstable, fn_align, "1.53.0", Some(82232), None), + /// Allows generators to be cloned. + (unstable, generator_clone, "1.65.0", Some(95360), None), + /// Allows defining generators. + (unstable, generators, "1.21.0", Some(43122), None), + /// Infer generic args for both consts and types. + (unstable, generic_arg_infer, "1.55.0", Some(85077), None), + /// An extension to the `generic_associated_types` feature, allowing incomplete features. + (incomplete, generic_associated_types_extended, "1.61.0", Some(95451), None), + /// Allows non-trivial generic constants which have to have wfness manually propagated to callers + (incomplete, generic_const_exprs, "1.56.0", Some(76560), None), + /// Allows generic parameters and where-clauses on free & associated const items. + (incomplete, generic_const_items, "1.73.0", Some(113521), None), + /// Allows using `..=X` as a patterns in slices. + (unstable, half_open_range_patterns_in_slices, "1.66.0", Some(67264), None), + /// Allows `if let` guard in match arms. + (unstable, if_let_guard, "1.47.0", Some(51114), None), + /// Allows `impl Trait` to be used inside associated types (RFC 2515). + (unstable, impl_trait_in_assoc_type, "1.70.0", Some(63063), None), + /// Allows `impl Trait` as output type in `Fn` traits in return position of functions. + (unstable, impl_trait_in_fn_trait_return, "1.64.0", Some(99697), None), + /// Allows using imported `main` function + (unstable, imported_main, "1.53.0", Some(28937), None), + /// Allows associated types in inherent impls. + (incomplete, inherent_associated_types, "1.52.0", Some(8995), None), + /// Allow anonymous constants from an inline `const` block + (unstable, inline_const, "1.49.0", Some(76001), None), + /// Allow anonymous constants from an inline `const` block in pattern position + (incomplete, inline_const_pat, "1.58.0", Some(76001), None), + /// Allows using `pointer` and `reference` in intra-doc links + (unstable, intra_doc_pointers, "1.51.0", Some(80896), None), + // Allows setting the threshold for the `large_assignments` lint. + (unstable, large_assignments, "1.52.0", Some(83518), None), + /// Allow to have type alias types for inter-crate use. + (incomplete, lazy_type_alias, "1.72.0", Some(112792), None), + /// Allows `if/while p && let q = r && ...` chains. + (unstable, let_chains, "1.37.0", Some(53667), None), + /// Allows using `reason` in lint attributes and the `#[expect(lint)]` lint check. + (unstable, lint_reasons, "1.31.0", Some(54503), None), + /// Give access to additional metadata about declarative macro meta-variables. + (unstable, macro_metavar_expr, "1.61.0", Some(83527), None), + /// Allows `#[marker]` on certain traits allowing overlapping implementations. + (unstable, marker_trait_attr, "1.30.0", Some(29864), None), + /// A minimal, sound subset of specialization intended to be used by the + /// standard library until the soundness issues with specialization + /// are fixed. + (unstable, min_specialization, "1.7.0", Some(31844), None), + /// Allows qualified paths in struct expressions, struct patterns and tuple struct patterns. + (unstable, more_qualified_paths, "1.54.0", Some(86935), None), + /// Allows the `#[must_not_suspend]` attribute. + (unstable, must_not_suspend, "1.57.0", Some(83310), None), + /// Allows using `#[naked]` on functions. + (unstable, naked_functions, "1.9.0", Some(32408), None), + /// Allows specifying the as-needed link modifier + (unstable, native_link_modifiers_as_needed, "1.53.0", Some(81490), None), + /// Allow negative trait implementations. + (unstable, negative_impls, "1.44.0", Some(68318), None), + /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more. + (unstable, never_type, "1.13.0", Some(35121), None), + /// Allows diverging expressions to fall back to `!` rather than `()`. + (unstable, never_type_fallback, "1.41.0", Some(65992), None), + /// Allows `#![no_core]`. + (unstable, no_core, "1.3.0", Some(29639), None), + /// Allows the use of `no_sanitize` attribute. + (unstable, no_sanitize, "1.42.0", Some(39699), None), + /// Allows using the `non_exhaustive_omitted_patterns` lint. + (unstable, non_exhaustive_omitted_patterns_lint, "1.57.0", Some(89554), None), + /// Allows `for<T>` binders in where-clauses + (incomplete, non_lifetime_binders, "1.69.0", Some(108185), None), + /// Allows making `dyn Trait` well-formed even if `Trait` is not object safe. + /// In that case, `dyn Trait: Trait` does not hold. Moreover, coercions and + /// casts in safe Rust to `dyn Trait` for such a `Trait` is also forbidden. + (unstable, object_safe_for_dispatch, "1.40.0", Some(43561), None), + /// Allows using `#[optimize(X)]`. + (unstable, optimize_attribute, "1.34.0", Some(54882), None), + /// Allows using `#![plugin(myplugin)]`. + (unstable, plugin, "1.0.0", Some(29597), None), + /// Allows exhaustive integer pattern matching on `usize` and `isize`. + (unstable, precise_pointer_size_matching, "1.32.0", Some(56354), None), + /// Allows macro attributes on expressions, statements and non-inline modules. + (unstable, proc_macro_hygiene, "1.30.0", Some(54727), None), + /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions. + (unstable, raw_ref_op, "1.41.0", Some(64490), None), + /// Allows using the `#[register_tool]` attribute. + (unstable, register_tool, "1.41.0", Some(66079), None), + /// Allows the `#[repr(i128)]` attribute for enums. + (incomplete, repr128, "1.16.0", Some(56071), None), + /// Allows `repr(simd)` and importing the various simd intrinsics. + (unstable, repr_simd, "1.4.0", Some(27731), None), + /// Allows bounding the return type of AFIT/RPITIT. + (incomplete, return_type_notation, "1.70.0", Some(109417), None), + /// Allows `extern "rust-cold"`. + (unstable, rust_cold_cc, "1.63.0", Some(97544), None), + /// Allows the use of SIMD types in functions declared in `extern` blocks. + (unstable, simd_ffi, "1.0.0", Some(27731), None), + /// Allows specialization of implementations (RFC 1210). + (incomplete, specialization, "1.7.0", Some(31844), None), + /// Allows attributes on expressions and non-item statements. + (unstable, stmt_expr_attributes, "1.6.0", Some(15701), None), + /// Allows lints part of the strict provenance effort. + (unstable, strict_provenance, "1.61.0", Some(95228), None), + /// Allows string patterns to dereference values to match them. + (unstable, string_deref_patterns, "1.67.0", Some(87121), None), + /// Allows the use of `#[target_feature]` on safe functions. + (unstable, target_feature_11, "1.45.0", Some(69098), None), + /// Allows using `#[thread_local]` on `static` items. + (unstable, thread_local, "1.0.0", Some(29594), None), + /// Allows defining `trait X = A + B;` alias items. + (unstable, trait_alias, "1.24.0", Some(41517), None), + /// Allows dyn upcasting trait objects via supertraits. + /// Dyn upcasting is casting, e.g., `dyn Foo -> dyn Bar` where `Foo: Bar`. + (unstable, trait_upcasting, "1.56.0", Some(65991), None), + /// Allows for transmuting between arrays with sizes that contain generic consts. + (unstable, transmute_generic_consts, "1.70.0", Some(109929), None), + /// Allows #[repr(transparent)] on unions (RFC 2645). + (unstable, transparent_unions, "1.37.0", Some(60405), None), + /// Allows inconsistent bounds in where clauses. + (unstable, trivial_bounds, "1.28.0", Some(48214), None), + /// Allows using `try {...}` expressions. + (unstable, try_blocks, "1.29.0", Some(31436), None), + /// Allows `impl Trait` to be used inside type aliases (RFC 2515). + (unstable, type_alias_impl_trait, "1.38.0", Some(63063), None), + /// Allows the use of type ascription in expressions. + (unstable, type_ascription, "1.6.0", Some(23416), None), + /// Allows creation of instances of a struct by moving fields that have + /// not changed from prior instances of the same struct (RFC #2528) + (unstable, type_changing_struct_update, "1.58.0", Some(86555), None), + /// Allows using type privacy lints (`private_interfaces`, `private_bounds`, `unnameable_types`). + (unstable, type_privacy_lints, "1.72.0", Some(48054), None), + /// Enables rustc to generate code that instructs libstd to NOT ignore SIGPIPE. + (unstable, unix_sigpipe, "1.65.0", Some(97889), None), + /// Allows unnamed fields of struct and union type + (incomplete, unnamed_fields, "1.74.0", Some(49804), None), + /// Allows unsized fn parameters. + (unstable, unsized_fn_params, "1.49.0", Some(48055), None), + /// Allows unsized rvalues at arguments and parameters. + (incomplete, unsized_locals, "1.30.0", Some(48055), None), + /// Allows unsized tuple coercion. + (unstable, unsized_tuple_coercion, "1.20.0", Some(42877), None), + /// Allows using the `#[used(linker)]` (or `#[used(compiler)]`) attribute. + (unstable, used_with_arg, "1.60.0", Some(93798), None), + /// Allows `extern "wasm" fn` + (unstable, wasm_abi, "1.53.0", Some(83788), None), + /// Allows `do yeet` expressions + (unstable, yeet_expr, "1.62.0", Some(96373), None), + // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! + // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. + // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! + + // ------------------------------------------------------------------------- + // feature-group-end: actual feature gates + // ------------------------------------------------------------------------- +); + +/// Some features are not allowed to be used together at the same time, if +/// the two are present, produce an error. +/// +/// Currently empty, but we will probably need this again in the future, +/// so let's keep it in for now. +pub const INCOMPATIBLE_FEATURES: &[(Symbol, Symbol)] = &[]; |