| //! List of the unstable feature gates. |
| |
| use std::path::PathBuf; |
| use std::time::{SystemTime, UNIX_EPOCH}; |
| |
| use rustc_data_structures::fx::FxHashSet; |
| use rustc_span::{Span, Symbol, sym}; |
| |
| use super::{Feature, to_nonzero}; |
| |
| #[derive(PartialEq)] |
| enum FeatureStatus { |
| Default, |
| Incomplete, |
| Internal, |
| } |
| |
| macro_rules! status_to_enum { |
| (unstable) => { |
| FeatureStatus::Default |
| }; |
| (incomplete) => { |
| FeatureStatus::Incomplete |
| }; |
| (internal) => { |
| FeatureStatus::Internal |
| }; |
| } |
| |
| /// A set of features to be used by later passes. |
| /// |
| /// There are two ways to check if a language feature `foo` is enabled: |
| /// - Directly with the `foo` method, e.g. `if tcx.features().foo() { ... }`. |
| /// - With the `enabled` method, e.g. `if tcx.features.enabled(sym::foo) { ... }`. |
| /// |
| /// The former is preferred. `enabled` should only be used when the feature symbol is not a |
| /// constant, e.g. a parameter, or when the feature is a library feature. |
| #[derive(Clone, Default, Debug)] |
| pub struct Features { |
| /// `#![feature]` attrs for language features, for error reporting. |
| enabled_lang_features: Vec<EnabledLangFeature>, |
| /// `#![feature]` attrs for non-language (library) features. |
| enabled_lib_features: Vec<EnabledLibFeature>, |
| /// `enabled_lang_features` + `enabled_lib_features`. |
| enabled_features: FxHashSet<Symbol>, |
| } |
| |
| /// Information about an enabled language feature. |
| #[derive(Debug, Copy, Clone)] |
| pub struct EnabledLangFeature { |
| /// Name of the feature gate guarding the language feature. |
| pub gate_name: Symbol, |
| /// Span of the `#[feature(...)]` attribute. |
| pub attr_sp: Span, |
| /// If the lang feature is stable, the version number when it was stabilized. |
| pub stable_since: Option<Symbol>, |
| } |
| |
| /// Information about an enabled library feature. |
| #[derive(Debug, Copy, Clone)] |
| pub struct EnabledLibFeature { |
| pub gate_name: Symbol, |
| pub attr_sp: Span, |
| } |
| |
| impl Features { |
| /// `since` should be set for stable features that are nevertheless enabled with a `#[feature]` |
| /// attribute, indicating since when they are stable. |
| pub fn set_enabled_lang_feature(&mut self, lang_feat: EnabledLangFeature) { |
| self.enabled_lang_features.push(lang_feat); |
| self.enabled_features.insert(lang_feat.gate_name); |
| } |
| |
| pub fn set_enabled_lib_feature(&mut self, lib_feat: EnabledLibFeature) { |
| self.enabled_lib_features.push(lib_feat); |
| self.enabled_features.insert(lib_feat.gate_name); |
| } |
| |
| /// Returns a list of [`EnabledLangFeature`] with info about: |
| /// |
| /// - Feature gate name. |
| /// - The span of the `#[feature]` attribute. |
| /// - For stable language features, version info for when it was stabilized. |
| pub fn enabled_lang_features(&self) -> &Vec<EnabledLangFeature> { |
| &self.enabled_lang_features |
| } |
| |
| pub fn enabled_lib_features(&self) -> &Vec<EnabledLibFeature> { |
| &self.enabled_lib_features |
| } |
| |
| pub fn enabled_features(&self) -> &FxHashSet<Symbol> { |
| &self.enabled_features |
| } |
| |
| /// Is the given feature enabled (via `#[feature(...)]`)? |
| pub fn enabled(&self, feature: Symbol) -> bool { |
| self.enabled_features.contains(&feature) |
| } |
| } |
| |
| macro_rules! declare_features { |
| ($( |
| $(#[doc = $doc:tt])* ($status:ident, $feature:ident, $ver:expr, $issue:expr), |
| )+) => { |
| /// Unstable language features that are being implemented or being |
| /// considered for acceptance (stabilization) or removal. |
| pub static UNSTABLE_LANG_FEATURES: &[Feature] = &[ |
| $(Feature { |
| name: sym::$feature, |
| since: $ver, |
| issue: to_nonzero($issue), |
| }),+ |
| ]; |
| |
| impl Features { |
| $( |
| pub fn $feature(&self) -> bool { |
| self.enabled_features.contains(&sym::$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, |
| )* |
| _ if self.enabled_features.contains(&feature) => { |
| // Accepted/removed features and library features aren't in this file but |
| // are never incomplete. |
| 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, |
| )* |
| _ if self.enabled_features.contains(&feature) => { |
| // This could be accepted/removed, or a libs feature. |
| // Accepted/removed features aren't in this file but are never internal |
| // (a removed feature might have been internal, but that's now irrelevant). |
| // Libs features are internal if they end in `_internal` or `_internals`. |
| // As a special exception we also consider `core_intrinsics` internal; |
| // renaming that age-old feature is just not worth the hassle. |
| // We just always test the name; it's not a big deal if we accidentally hit |
| // an accepted/removed lang feature that way. |
| let name = feature.as_str(); |
| name == "core_intrinsics" || name.ends_with("_internal") || name.ends_with("_internals") |
| } |
| _ => 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 alphabetically 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. |
| (internal, abi_unadjusted, "1.16.0", None), |
| /// Allows using `#![needs_allocator]`, an implementation detail of `#[global_allocator]`. |
| (internal, allocator_internals, "1.20.0", 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), |
| /// 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), |
| /// Allows using anonymous lifetimes in argument-position impl-trait. |
| (unstable, anonymous_lifetime_in_impl_trait, "1.63.0", None), |
| /// Allows access to the emscripten_wasm_eh config, used by panic_unwind and unwind |
| (internal, cfg_emscripten_wasm_eh, "1.86.0", None), |
| /// Allows checking whether or not the backend correctly supports unstable float types. |
| (internal, cfg_target_has_reliable_f16_f128, "1.88.0", None), |
| /// Allows identifying the `compiler_builtins` crate. |
| (internal, compiler_builtins, "1.13.0", None), |
| /// Allows writing custom MIR |
| (internal, custom_mir, "1.65.0", None), |
| /// Outputs useful `assert!` messages |
| (unstable, generic_assert, "1.63.0", None), |
| /// Allows using the #[rustc_intrinsic] attribute. |
| (internal, intrinsics, "1.0.0", None), |
| /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic. |
| (internal, lang_items, "1.0.0", None), |
| /// Allows `#[link(..., cfg(..))]`; perma-unstable per #37406 |
| (internal, link_cfg, "1.14.0", None), |
| /// Allows using `?Trait` trait bounds in more contexts. |
| (internal, more_maybe_bounds, "1.82.0", None), |
| /// Allows the `multiple_supertrait_upcastable` lint. |
| (unstable, multiple_supertrait_upcastable, "1.69.0", None), |
| /// Allow negative trait bounds. This is an internal-only feature for testing the trait solver! |
| (internal, negative_bounds, "1.71.0", None), |
| /// Set the maximum pattern complexity allowed (not limited by default). |
| (internal, pattern_complexity_limit, "1.78.0", None), |
| /// Allows using pattern types. |
| (internal, pattern_types, "1.79.0", Some(123646)), |
| /// Allows using `#[prelude_import]` on glob `use` items. |
| (internal, prelude_import, "1.2.0", None), |
| /// Used to identify crates that contain the profiler runtime. |
| (internal, profiler_runtime, "1.18.0", None), |
| /// Allows using `rustc_*` attributes (RFC 572). |
| (internal, rustc_attrs, "1.0.0", None), |
| /// Introduces a hierarchy of `Sized` traits (RFC 3729). |
| (unstable, sized_hierarchy, "1.89.0", None), |
| /// Allows using the `#[stable]` and `#[unstable]` attributes. |
| (internal, staged_api, "1.0.0", None), |
| /// Added for testing unstable lints; perma-unstable. |
| (internal, test_unstable_lint, "1.60.0", None), |
| /// Helps with formatting for `group_imports = "StdExternalCrate"`. |
| (unstable, unqualified_local_imports, "1.83.0", Some(138299)), |
| /// Use for stable + negative coherence and strict coherence depending on trait's |
| /// rustc_strict_coherence value. |
| (unstable, with_negative_coherence, "1.60.0", 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 using the `vectorcall` ABI. |
| (unstable, abi_vectorcall, "1.7.0", Some(124485)), |
| /// Allows features specific to auto traits. |
| /// Renamed from `optin_builtin_traits`. |
| (unstable, auto_traits, "1.50.0", Some(13231)), |
| /// Allows using `box` in patterns (RFC 469). |
| (unstable, box_patterns, "1.0.0", Some(29641)), |
| /// Allows builtin # foo() syntax |
| (internal, builtin_syntax, "1.71.0", Some(110680)), |
| /// Allows `#[doc(notable_trait)]`. |
| /// Renamed from `doc_spotlight`. |
| (unstable, doc_notable_trait, "1.52.0", Some(45040)), |
| /// Allows using the `may_dangle` attribute (RFC 1327). |
| (unstable, dropck_eyepatch, "1.10.0", Some(34761)), |
| /// Allows using the `#[fundamental]` attribute. |
| (unstable, fundamental, "1.0.0", Some(29635)), |
| /// Allows using `#[link_name="llvm.*"]`. |
| (internal, link_llvm_intrinsics, "1.0.0", Some(29602)), |
| /// Allows using the `#[linkage = ".."]` attribute. |
| (unstable, linkage, "1.0.0", Some(29603)), |
| /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed. |
| (internal, needs_panic_runtime, "1.10.0", Some(32837)), |
| /// Allows using the `#![panic_runtime]` attribute. |
| (internal, panic_runtime, "1.10.0", Some(32837)), |
| /// 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)), |
| /// Allows using compiler's own crates. |
| (unstable, rustc_private, "1.0.0", Some(27812)), |
| /// Allows using internal rustdoc features like `doc(keyword)`. |
| (internal, rustdoc_internals, "1.58.0", Some(90418)), |
| /// Allows using the `rustdoc::missing_doc_code_examples` lint |
| (unstable, rustdoc_missing_doc_code_examples, "1.31.0", Some(101730)), |
| /// 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)), |
| /// Allows using the `rust-call` ABI. |
| (unstable, unboxed_closures, "1.0.0", Some(29625)), |
| // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! |
| // 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_unstable_target_feature, "1.82.0", Some(44839)), |
| (unstable, aarch64_ver_target_feature, "1.27.0", Some(44839)), |
| (unstable, apx_target_feature, "1.88.0", Some(139284)), |
| (unstable, arm_target_feature, "1.27.0", Some(44839)), |
| (unstable, bpf_target_feature, "1.54.0", Some(44839)), |
| (unstable, csky_target_feature, "1.73.0", Some(44839)), |
| (unstable, ermsb_target_feature, "1.49.0", Some(44839)), |
| (unstable, hexagon_target_feature, "1.27.0", Some(44839)), |
| (unstable, lahfsahf_target_feature, "1.78.0", Some(44839)), |
| (unstable, loongarch_target_feature, "1.73.0", Some(44839)), |
| (unstable, m68k_target_feature, "1.85.0", Some(134328)), |
| (unstable, mips_target_feature, "1.27.0", Some(44839)), |
| (unstable, movrs_target_feature, "1.88.0", Some(137976)), |
| (unstable, nvptx_target_feature, "CURRENT_RUSTC_VERSION", Some(44839)), |
| (unstable, powerpc_target_feature, "1.27.0", Some(44839)), |
| (unstable, prfchw_target_feature, "1.78.0", Some(44839)), |
| (unstable, riscv_target_feature, "1.45.0", Some(44839)), |
| (unstable, rtm_target_feature, "1.35.0", Some(44839)), |
| (unstable, s390x_target_feature, "1.82.0", Some(44839)), |
| (unstable, sparc_target_feature, "1.84.0", Some(132783)), |
| (unstable, wasm_target_feature, "1.30.0", Some(44839)), |
| (unstable, x87_target_feature, "1.85.0", Some(44839)), |
| // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! |
| // 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 `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`. |
| (unstable, abi_avr_interrupt, "1.45.0", Some(69664)), |
| /// Allows `extern "cmse-nonsecure-call" fn()`. |
| (unstable, abi_cmse_nonsecure_call, "1.90.0", Some(81391)), |
| /// Allows `extern "custom" fn()`. |
| (unstable, abi_custom, "1.89.0", Some(140829)), |
| /// Allows `extern "gpu-kernel" fn()`. |
| (unstable, abi_gpu_kernel, "1.86.0", Some(135467)), |
| /// Allows `extern "msp430-interrupt" fn()`. |
| (unstable, abi_msp430_interrupt, "1.16.0", Some(38487)), |
| /// Allows `extern "ptx-*" fn()`. |
| (unstable, abi_ptx, "1.15.0", Some(38788)), |
| /// Allows `extern "riscv-interrupt-m" fn()` and `extern "riscv-interrupt-s" fn()`. |
| (unstable, abi_riscv_interrupt, "1.73.0", Some(111889)), |
| /// Allows `extern "x86-interrupt" fn()`. |
| (unstable, abi_x86_interrupt, "1.17.0", Some(40180)), |
| /// Allows additional const parameter types, such as `[u8; 10]` or user defined types |
| (unstable, adt_const_params, "1.56.0", Some(95174)), |
| /// Allows defining an `#[alloc_error_handler]`. |
| (unstable, alloc_error_handler, "1.29.0", Some(51540)), |
| /// Allows inherent and trait methods with arbitrary self types. |
| (unstable, arbitrary_self_types, "1.23.0", Some(44874)), |
| /// Allows inherent and trait methods with arbitrary self types that are raw pointers. |
| (unstable, arbitrary_self_types_pointers, "1.83.0", Some(44874)), |
| /// Allows #[cfg(...)] on inline assembly templates and operands. |
| (unstable, asm_cfg, "1.89.0", Some(140364)), |
| /// Enables experimental inline assembly support for additional architectures. |
| (unstable, asm_experimental_arch, "1.58.0", Some(93335)), |
| /// Enables experimental register support in inline assembly. |
| (unstable, asm_experimental_reg, "1.85.0", Some(133416)), |
| /// Allows using `label` operands in inline assembly together with output operands. |
| (unstable, asm_goto_with_outputs, "1.85.0", Some(119364)), |
| /// Allows the `may_unwind` option in inline assembly. |
| (unstable, asm_unwind, "1.58.0", Some(93334)), |
| /// Allows users to enforce equality of associated constants `TraitImpl<AssocConst=3>`. |
| (unstable, associated_const_equality, "1.58.0", Some(92827)), |
| /// Allows associated type defaults. |
| (unstable, associated_type_defaults, "1.2.0", Some(29661)), |
| /// Allows implementing `AsyncDrop`. |
| (incomplete, async_drop, "1.88.0", Some(126482)), |
| /// Allows async functions to be called from `dyn Trait`. |
| (incomplete, async_fn_in_dyn_trait, "1.85.0", Some(133119)), |
| /// Allows `#[track_caller]` on async functions. |
| (unstable, async_fn_track_caller, "1.73.0", Some(110011)), |
| /// Allows `for await` loops. |
| (unstable, async_for_loop, "1.77.0", Some(118898)), |
| /// Allows `async` trait bound modifier. |
| (unstable, async_trait_bounds, "1.85.0", Some(62290)), |
| /// Allows using Intel AVX10 target features and intrinsics |
| (unstable, avx10_target_feature, "1.88.0", Some(138843)), |
| /// Allows using C-variadics. |
| (unstable, c_variadic, "1.34.0", Some(44930)), |
| /// Allows the use of `#[cfg(contract_checks)` to check if contract checks are enabled. |
| (unstable, cfg_contract_checks, "1.86.0", Some(128044)), |
| /// Allows the use of `#[cfg(overflow_checks)` to check if integer overflow behaviour. |
| (unstable, cfg_overflow_checks, "1.71.0", Some(111466)), |
| /// Provides the relocation model information as cfg entry |
| (unstable, cfg_relocation_model, "1.73.0", Some(114929)), |
| /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used. |
| (unstable, cfg_sanitize, "1.41.0", Some(39699)), |
| /// Allows `cfg(sanitizer_cfi_generalize_pointers)` and `cfg(sanitizer_cfi_normalize_integers)`. |
| (unstable, cfg_sanitizer_cfi, "1.77.0", Some(89653)), |
| /// Allows `cfg(target(abi = "..."))`. |
| (unstable, cfg_target_compact, "1.63.0", Some(96901)), |
| /// Allows `cfg(target_has_atomic_load_store = "...")`. |
| (unstable, cfg_target_has_atomic, "1.60.0", Some(94039)), |
| /// Allows `cfg(target_has_atomic_equal_alignment = "...")`. |
| (unstable, cfg_target_has_atomic_equal_alignment, "1.60.0", Some(93822)), |
| /// Allows `cfg(target_thread_local)`. |
| (unstable, cfg_target_thread_local, "1.7.0", Some(29594)), |
| /// Allows the use of `#[cfg(ub_checks)` to check if UB checks are enabled. |
| (unstable, cfg_ub_checks, "1.79.0", Some(123499)), |
| /// Allow conditional compilation depending on rust version |
| (unstable, cfg_version, "1.45.0", Some(64796)), |
| /// Allows to use the `#[cfi_encoding = ""]` attribute. |
| (unstable, cfi_encoding, "1.71.0", Some(89653)), |
| /// Allows `for<...>` on closures and coroutines. |
| (unstable, closure_lifetime_binder, "1.64.0", Some(97362)), |
| /// Allows `#[track_caller]` on closures and coroutines. |
| (unstable, closure_track_caller, "1.57.0", Some(87417)), |
| /// Allows `extern "cmse-nonsecure-entry" fn()`. |
| (unstable, cmse_nonsecure_entry, "1.48.0", Some(75835)), |
| /// Allows `async {}` expressions in const contexts. |
| (unstable, const_async_blocks, "1.53.0", Some(85368)), |
| /// Allows `const || {}` closures in const contexts. |
| (incomplete, const_closures, "1.68.0", Some(106003)), |
| /// Allows using `[const] Destruct` bounds and calling drop impls in const contexts. |
| (unstable, const_destruct, "1.85.0", Some(133214)), |
| /// Allows `for _ in _` loops in const contexts. |
| (unstable, const_for, "1.56.0", Some(87575)), |
| /// Be more precise when looking for live drops in a const context. |
| (unstable, const_precise_live_drops, "1.46.0", Some(73255)), |
| /// Allows `impl const Trait for T` syntax. |
| (unstable, const_trait_impl, "1.42.0", Some(143874)), |
| /// Allows the `?` operator in const contexts. |
| (unstable, const_try, "1.56.0", Some(74935)), |
| /// Allows use of contracts attributes. |
| (incomplete, contracts, "1.86.0", Some(128044)), |
| /// Allows access to internal machinery used to implement contracts. |
| (internal, contracts_internals, "1.86.0", Some(128044)), |
| /// Allows coroutines to be cloned. |
| (unstable, coroutine_clone, "1.65.0", Some(95360)), |
| /// Allows defining coroutines. |
| (unstable, coroutines, "1.21.0", Some(43122)), |
| /// Allows function attribute `#[coverage(on/off)]`, to control coverage |
| /// instrumentation of that function. |
| (unstable, coverage_attribute, "1.74.0", Some(84605)), |
| /// Allows non-builtin attributes in inner attribute position. |
| (unstable, custom_inner_attributes, "1.30.0", Some(54726)), |
| /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`. |
| (unstable, custom_test_frameworks, "1.30.0", Some(50297)), |
| /// Allows declarative macros 2.0 (`macro`). |
| (unstable, decl_macro, "1.17.0", Some(39412)), |
| /// Allows the use of default values on struct definitions and the construction of struct |
| /// literals with the functional update syntax without a base. |
| (unstable, default_field_values, "1.85.0", Some(132162)), |
| /// Allows using `#[deprecated_safe]` to deprecate the safeness of a function or trait |
| (unstable, deprecated_safe, "1.61.0", Some(94978)), |
| /// Allows having using `suggestion` in the `#[deprecated]` attribute. |
| (unstable, deprecated_suggestion, "1.61.0", Some(94785)), |
| /// Allows deref patterns. |
| (incomplete, deref_patterns, "1.79.0", Some(87121)), |
| /// Allows deriving the From trait on single-field structs. |
| (unstable, derive_from, "CURRENT_RUSTC_VERSION", Some(144889)), |
| /// Tells rustdoc to automatically generate `#[doc(cfg(...))]`. |
| (unstable, doc_auto_cfg, "1.58.0", Some(43781)), |
| /// Allows `#[doc(cfg(...))]`. |
| (unstable, doc_cfg, "1.21.0", Some(43781)), |
| /// Allows `#[doc(cfg_hide(...))]`. |
| (unstable, doc_cfg_hide, "1.57.0", Some(43781)), |
| /// Allows `#[doc(masked)]`. |
| (unstable, doc_masked, "1.21.0", Some(44027)), |
| /// Allows the .use postfix syntax `x.use` and use closures `use |x| { ... }` |
| (incomplete, ergonomic_clones, "1.87.0", Some(132290)), |
| /// Allows exhaustive pattern matching on types that contain uninhabited types. |
| (unstable, exhaustive_patterns, "1.13.0", Some(51085)), |
| /// Disallows `extern` without an explicit ABI. |
| (unstable, explicit_extern_abis, "1.88.0", Some(134986)), |
| /// Allows explicit tail calls via `become` expression. |
| (incomplete, explicit_tail_calls, "1.72.0", Some(112788)), |
| /// Allows using `#[export_stable]` which indicates that an item is exportable. |
| (incomplete, export_stable, "1.88.0", Some(139939)), |
| /// Allows using `aapcs`, `efiapi`, `sysv64` and `win64` as calling conventions |
| /// for functions with varargs. |
| (unstable, extended_varargs_abi_support, "1.65.0", Some(100189)), |
| /// Allows using `system` as a calling convention with varargs. |
| (unstable, extern_system_varargs, "1.86.0", Some(136946)), |
| /// Allows defining `extern type`s. |
| (unstable, extern_types, "1.23.0", Some(43467)), |
| /// Allow using 128-bit (quad precision) floating point numbers. |
| (unstable, f128, "1.78.0", Some(116909)), |
| /// Allow using 16-bit (half precision) floating point numbers. |
| (unstable, f16, "1.78.0", Some(116909)), |
| /// Allows the use of `#[ffi_const]` on foreign functions. |
| (unstable, ffi_const, "1.45.0", Some(58328)), |
| /// Allows the use of `#[ffi_pure]` on foreign functions. |
| (unstable, ffi_pure, "1.45.0", Some(58329)), |
| /// Controlling the behavior of fmt::Debug |
| (unstable, fmt_debug, "1.82.0", Some(129709)), |
| /// Allows using `#[align(...)]` on function items |
| (unstable, fn_align, "1.53.0", Some(82232)), |
| /// Support delegating implementation of functions to other already implemented functions. |
| (incomplete, fn_delegation, "1.76.0", Some(118212)), |
| /// Allows impls for the Freeze trait. |
| (internal, freeze_impls, "1.78.0", Some(121675)), |
| /// Frontmatter `---` blocks for use by external tools. |
| (unstable, frontmatter, "1.88.0", Some(136889)), |
| /// Allows defining gen blocks and `gen fn`. |
| (unstable, gen_blocks, "1.75.0", Some(117078)), |
| /// Allows non-trivial generic constants which have to have wfness manually propagated to callers |
| (incomplete, generic_const_exprs, "1.56.0", Some(76560)), |
| /// Allows generic parameters and where-clauses on free & associated const items. |
| (incomplete, generic_const_items, "1.73.0", Some(113521)), |
| /// Allows the type of const generics to depend on generic parameters |
| (incomplete, generic_const_parameter_types, "1.87.0", Some(137626)), |
| /// Allows any generic constants being used as pattern type range ends |
| (incomplete, generic_pattern_types, "1.86.0", Some(136574)), |
| /// Allows registering static items globally, possibly across crates, to iterate over at runtime. |
| (unstable, global_registration, "1.80.0", Some(125119)), |
| /// Allows using guards in patterns. |
| (incomplete, guard_patterns, "1.85.0", Some(129967)), |
| /// Allows using `..=X` as a patterns in slices. |
| (unstable, half_open_range_patterns_in_slices, "1.66.0", Some(67264)), |
| /// Allows `if let` guard in match arms. |
| (unstable, if_let_guard, "1.47.0", Some(51114)), |
| /// Allows `impl Trait` to be used inside associated types (RFC 2515). |
| (unstable, impl_trait_in_assoc_type, "1.70.0", Some(63063)), |
| /// Allows `impl Trait` in bindings (`let`). |
| (unstable, impl_trait_in_bindings, "1.64.0", Some(63065)), |
| /// 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)), |
| /// Allows `use` associated functions from traits. |
| (unstable, import_trait_associated_functions, "1.86.0", Some(134691)), |
| /// Allows associated types in inherent impls. |
| (incomplete, inherent_associated_types, "1.52.0", Some(8995)), |
| /// Allows using `pointer` and `reference` in intra-doc links |
| (unstable, intra_doc_pointers, "1.51.0", Some(80896)), |
| /// Allows setting the threshold for the `large_assignments` lint. |
| (unstable, large_assignments, "1.52.0", Some(83518)), |
| /// Allow to have type alias types for inter-crate use. |
| (incomplete, lazy_type_alias, "1.72.0", Some(112792)), |
| /// Allows using `#[link(kind = "link-arg", name = "...")]` |
| /// to pass custom arguments to the linker. |
| (unstable, link_arg_attribute, "1.76.0", Some(99427)), |
| /// Allows fused `loop`/`match` for direct intraprocedural jumps. |
| (incomplete, loop_match, "1.90.0", Some(132306)), |
| /// Allow `macro_rules!` attribute rules |
| (unstable, macro_attr, "CURRENT_RUSTC_VERSION", Some(83527)), |
| /// Give access to additional metadata about declarative macro meta-variables. |
| (unstable, macro_metavar_expr, "1.61.0", Some(83527)), |
| /// Provides a way to concatenate identifiers using metavariable expressions. |
| (unstable, macro_metavar_expr_concat, "1.81.0", Some(124225)), |
| /// Allows `#[marker]` on certain traits allowing overlapping implementations. |
| (unstable, marker_trait_attr, "1.30.0", Some(29864)), |
| /// Enables the generic const args MVP (only bare paths, not arbitrary computation). |
| (incomplete, min_generic_const_args, "1.84.0", Some(132980)), |
| /// 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)), |
| /// Allows qualified paths in struct expressions, struct patterns and tuple struct patterns. |
| (unstable, more_qualified_paths, "1.54.0", Some(86935)), |
| /// Allows the `#[must_not_suspend]` attribute. |
| (unstable, must_not_suspend, "1.57.0", Some(83310)), |
| /// Allows `mut ref` and `mut ref mut` identifier patterns. |
| (incomplete, mut_ref, "1.79.0", Some(123076)), |
| /// Allows using `#[naked]` on `extern "Rust"` functions. |
| (unstable, naked_functions_rustic_abi, "1.88.0", Some(138997)), |
| /// Allows using `#[target_feature(enable = "...")]` on `#[naked]` on functions. |
| (unstable, naked_functions_target_feature, "1.86.0", Some(138568)), |
| /// Allows specifying the as-needed link modifier |
| (unstable, native_link_modifiers_as_needed, "1.53.0", Some(81490)), |
| /// Allow negative trait implementations. |
| (unstable, negative_impls, "1.44.0", Some(68318)), |
| /// Allows the `!` pattern. |
| (incomplete, never_patterns, "1.76.0", Some(118155)), |
| /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more. |
| (unstable, never_type, "1.13.0", Some(35121)), |
| /// Allows diverging expressions to fall back to `!` rather than `()`. |
| (unstable, never_type_fallback, "1.41.0", Some(65992)), |
| /// Switch `..` syntax to use the new (`Copy + IntoIterator`) range types. |
| (unstable, new_range, "1.86.0", Some(123741)), |
| /// Allows `#![no_core]`. |
| (unstable, no_core, "1.3.0", Some(29639)), |
| /// Allows the use of `no_sanitize` attribute. |
| (unstable, no_sanitize, "1.42.0", Some(39699)), |
| /// Allows using the `non_exhaustive_omitted_patterns` lint. |
| (unstable, non_exhaustive_omitted_patterns_lint, "1.57.0", Some(89554)), |
| /// Allows `for<T>` binders in where-clauses |
| (incomplete, non_lifetime_binders, "1.69.0", Some(108185)), |
| /// Allows using enums in offset_of! |
| (unstable, offset_of_enum, "1.75.0", Some(120141)), |
| /// Allows using fields with slice type in offset_of! |
| (unstable, offset_of_slice, "1.81.0", Some(126151)), |
| /// Allows using `#[optimize(X)]`. |
| (unstable, optimize_attribute, "1.34.0", Some(54882)), |
| /// Allows specifying nop padding on functions for dynamic patching. |
| (unstable, patchable_function_entry, "1.81.0", Some(123115)), |
| /// Experimental features that make `Pin` more ergonomic. |
| (incomplete, pin_ergonomics, "1.83.0", Some(130494)), |
| /// Allows postfix match `expr.match { ... }` |
| (unstable, postfix_match, "1.79.0", Some(121618)), |
| /// Allows macro attributes on expressions, statements and non-inline modules. |
| (unstable, proc_macro_hygiene, "1.30.0", Some(54727)), |
| /// Allows the use of raw-dylibs on ELF platforms |
| (incomplete, raw_dylib_elf, "1.87.0", Some(135694)), |
| /// Makes `&` and `&mut` patterns eat only one layer of references in Rust 2024. |
| (incomplete, ref_pat_eat_one_layer_2024, "1.79.0", Some(123076)), |
| /// Makes `&` and `&mut` patterns eat only one layer of references in Rust 2024—structural variant |
| (incomplete, ref_pat_eat_one_layer_2024_structural, "1.81.0", Some(123076)), |
| /// Allows using the `#[register_tool]` attribute. |
| (unstable, register_tool, "1.41.0", Some(66079)), |
| /// Allows `repr(simd)` and importing the various simd intrinsics. |
| (unstable, repr_simd, "1.4.0", Some(27731)), |
| /// Allows bounding the return type of AFIT/RPITIT. |
| (unstable, return_type_notation, "1.70.0", Some(109417)), |
| /// Allows `extern "rust-cold"`. |
| (unstable, rust_cold_cc, "1.63.0", Some(97544)), |
| /// Allows the use of SIMD types in functions declared in `extern` blocks. |
| (unstable, simd_ffi, "1.0.0", Some(27731)), |
| /// Allows specialization of implementations (RFC 1210). |
| (incomplete, specialization, "1.7.0", Some(31844)), |
| /// Allows attributes on expressions and non-item statements. |
| (unstable, stmt_expr_attributes, "1.6.0", Some(15701)), |
| /// Allows lints part of the strict provenance effort. |
| (unstable, strict_provenance_lints, "1.61.0", Some(130351)), |
| /// Allows string patterns to dereference values to match them. |
| (unstable, string_deref_patterns, "1.67.0", Some(87121)), |
| /// Allows `super let` statements. |
| (unstable, super_let, "1.88.0", Some(139076)), |
| /// Allows subtrait items to shadow supertrait items. |
| (unstable, supertrait_item_shadowing, "1.86.0", Some(89151)), |
| /// Allows using `#[thread_local]` on `static` items. |
| (unstable, thread_local, "1.0.0", Some(29594)), |
| /// Allows defining `trait X = A + B;` alias items. |
| (unstable, trait_alias, "1.24.0", Some(41517)), |
| /// Allows for transmuting between arrays with sizes that contain generic consts. |
| (unstable, transmute_generic_consts, "1.70.0", Some(109929)), |
| /// Allows #[repr(transparent)] on unions (RFC 2645). |
| (unstable, transparent_unions, "1.37.0", Some(60405)), |
| /// Allows inconsistent bounds in where clauses. |
| (unstable, trivial_bounds, "1.28.0", Some(48214)), |
| /// Allows using `try {...}` expressions. |
| (unstable, try_blocks, "1.29.0", Some(31436)), |
| /// Allows `impl Trait` to be used inside type aliases (RFC 2515). |
| (unstable, type_alias_impl_trait, "1.38.0", Some(63063)), |
| /// 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)), |
| /// Allows using `unsafe<'a> &'a T` unsafe binder types. |
| (incomplete, unsafe_binders, "1.85.0", Some(130516)), |
| /// Allows declaring fields `unsafe`. |
| (incomplete, unsafe_fields, "1.85.0", Some(132922)), |
| /// Allows const generic parameters to be defined with types that |
| /// are not `Sized`, e.g. `fn foo<const N: [u8]>() {`. |
| (incomplete, unsized_const_params, "1.82.0", Some(95174)), |
| /// Allows unsized fn parameters. |
| (internal, unsized_fn_params, "1.49.0", Some(48055)), |
| /// Allows using the `#[used(linker)]` (or `#[used(compiler)]`) attribute. |
| (unstable, used_with_arg, "1.60.0", Some(93798)), |
| /// Allows use of attributes in `where` clauses. |
| (unstable, where_clause_attrs, "1.87.0", Some(115590)), |
| /// Allows use of x86 `AMX` target-feature attributes and intrinsics |
| (unstable, x86_amx_intrinsics, "1.81.0", Some(126622)), |
| /// Allows use of the `xop` target-feature |
| (unstable, xop_target_feature, "1.81.0", Some(127208)), |
| /// Allows `do yeet` expressions |
| (unstable, yeet_expr, "1.62.0", Some(96373)), |
| (unstable, yield_expr, "1.87.0", Some(43122)), |
| // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! |
| // Features are listed in alphabetical order. Tidy will fail if you don't keep it this way. |
| // !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! !!!! |
| |
| // ------------------------------------------------------------------------- |
| // feature-group-end: actual feature gates |
| // ------------------------------------------------------------------------- |
| ); |
| |
| impl Features { |
| pub fn dump_feature_usage_metrics( |
| &self, |
| metrics_path: PathBuf, |
| ) -> Result<(), Box<dyn std::error::Error>> { |
| #[derive(serde::Serialize)] |
| struct LibFeature { |
| timestamp: u128, |
| symbol: String, |
| } |
| |
| #[derive(serde::Serialize)] |
| struct LangFeature { |
| timestamp: u128, |
| symbol: String, |
| since: Option<String>, |
| } |
| |
| #[derive(serde::Serialize)] |
| struct FeatureUsage { |
| lib_features: Vec<LibFeature>, |
| lang_features: Vec<LangFeature>, |
| } |
| |
| let metrics_file = std::fs::File::create(metrics_path)?; |
| let metrics_file = std::io::BufWriter::new(metrics_file); |
| |
| let now = || { |
| SystemTime::now() |
| .duration_since(UNIX_EPOCH) |
| .expect("system time should always be greater than the unix epoch") |
| .as_nanos() |
| }; |
| |
| let lib_features = self |
| .enabled_lib_features |
| .iter() |
| .map(|EnabledLibFeature { gate_name, .. }| LibFeature { |
| symbol: gate_name.to_string(), |
| timestamp: now(), |
| }) |
| .collect(); |
| |
| let lang_features = self |
| .enabled_lang_features |
| .iter() |
| .map(|EnabledLangFeature { gate_name, stable_since, .. }| LangFeature { |
| symbol: gate_name.to_string(), |
| since: stable_since.map(|since| since.to_string()), |
| timestamp: now(), |
| }) |
| .collect(); |
| |
| let feature_usage = FeatureUsage { lib_features, lang_features }; |
| |
| serde_json::to_writer(metrics_file, &feature_usage)?; |
| |
| Ok(()) |
| } |
| } |
| |
| /// Some features are not allowed to be used together at the same time, if |
| /// the two are present, produce an error. |
| pub const INCOMPATIBLE_FEATURES: &[(Symbol, Symbol)] = &[ |
| // Experimental match ergonomics rulesets are incompatible with each other, to simplify the |
| // boolean logic required to tell which typing rules to use. |
| (sym::ref_pat_eat_one_layer_2024, sym::ref_pat_eat_one_layer_2024_structural), |
| ]; |
