diff options
Diffstat (limited to 'compiler/rustc_feature/src')
| -rw-r--r-- | compiler/rustc_feature/src/accepted.rs | 275 | ||||
| -rw-r--r-- | compiler/rustc_feature/src/active.rs | 607 | ||||
| -rw-r--r-- | compiler/rustc_feature/src/builtin_attrs.rs | 602 | ||||
| -rw-r--r-- | compiler/rustc_feature/src/lib.rs | 137 | ||||
| -rw-r--r-- | compiler/rustc_feature/src/removed.rs | 129 |
5 files changed, 1750 insertions, 0 deletions
diff --git a/compiler/rustc_feature/src/accepted.rs b/compiler/rustc_feature/src/accepted.rs new file mode 100644 index 00000000000..d16f023c00a --- /dev/null +++ b/compiler/rustc_feature/src/accepted.rs @@ -0,0 +1,275 @@ +//! List of the accepted feature gates. + +use super::{Feature, State}; +use rustc_span::symbol::sym; + +macro_rules! declare_features { + ($( + $(#[doc = $doc:tt])* (accepted, $feature:ident, $ver:expr, $issue:expr, None), + )+) => { + /// Those language feature has since been Accepted (it was once Active) + pub const ACCEPTED_FEATURES: &[Feature] = &[ + $( + Feature { + state: State::Accepted, + name: sym::$feature, + since: $ver, + issue: $issue, + edition: None, + description: concat!($($doc,)*), + } + ),+ + ]; + } +} + +#[rustfmt::skip] +declare_features! ( + // ------------------------------------------------------------------------- + // feature-group-start: for testing purposes + // ------------------------------------------------------------------------- + + /// A temporary feature gate used to enable parser extensions needed + /// to bootstrap fix for #5723. + (accepted, issue_5723_bootstrap, "1.0.0", None, None), + /// These are used to test this portion of the compiler, + /// they don't actually mean anything. + (accepted, test_accepted_feature, "1.0.0", None, None), + + // ------------------------------------------------------------------------- + // feature-group-end: for testing purposes + // ------------------------------------------------------------------------- + + // ------------------------------------------------------------------------- + // feature-group-start: accepted features + // ------------------------------------------------------------------------- + + /// Allows using associated `type`s in `trait`s. + (accepted, associated_types, "1.0.0", None, None), + /// Allows using assigning a default type to type parameters in algebraic data type definitions. + (accepted, default_type_params, "1.0.0", None, None), + // FIXME: explain `globs`. + (accepted, globs, "1.0.0", None, None), + /// Allows `macro_rules!` items. + (accepted, macro_rules, "1.0.0", None, None), + /// Allows use of `&foo[a..b]` as a slicing syntax. + (accepted, slicing_syntax, "1.0.0", None, None), + /// Allows struct variants `Foo { baz: u8, .. }` in enums (RFC 418). + (accepted, struct_variant, "1.0.0", None, None), + /// Allows indexing tuples. + (accepted, tuple_indexing, "1.0.0", None, None), + /// Allows the use of `if let` expressions. + (accepted, if_let, "1.0.0", None, None), + /// Allows the use of `while let` expressions. + (accepted, while_let, "1.0.0", None, None), + /// Allows using `#![no_std]`. + (accepted, no_std, "1.6.0", None, None), + /// Allows overloading augmented assignment operations like `a += b`. + (accepted, augmented_assignments, "1.8.0", Some(28235), None), + /// Allows empty structs and enum variants with braces. + (accepted, braced_empty_structs, "1.8.0", Some(29720), None), + /// Allows `#[deprecated]` attribute. + (accepted, deprecated, "1.9.0", Some(29935), None), + /// Allows macros to appear in the type position. + (accepted, type_macros, "1.13.0", Some(27245), None), + /// Allows use of the postfix `?` operator in expressions. + (accepted, question_mark, "1.13.0", Some(31436), None), + /// Allows `..` in tuple (struct) patterns. + (accepted, dotdot_in_tuple_patterns, "1.14.0", Some(33627), None), + /// Allows some increased flexibility in the name resolution rules, + /// especially around globs and shadowing (RFC 1560). + (accepted, item_like_imports, "1.15.0", Some(35120), None), + /// Allows using `Self` and associated types in struct expressions and patterns. + (accepted, more_struct_aliases, "1.16.0", Some(37544), None), + /// Allows elision of `'static` lifetimes in `static`s and `const`s. + (accepted, static_in_const, "1.17.0", Some(35897), None), + /// Allows field shorthands (`x` meaning `x: x`) in struct literal expressions. + (accepted, field_init_shorthand, "1.17.0", Some(37340), None), + /// Allows the definition recursive static items. + (accepted, static_recursion, "1.17.0", Some(29719), None), + /// Allows `pub(restricted)` visibilities (RFC 1422). + (accepted, pub_restricted, "1.18.0", Some(32409), None), + /// Allows `#![windows_subsystem]`. + (accepted, windows_subsystem, "1.18.0", Some(37499), None), + /// Allows `break {expr}` with a value inside `loop`s. + (accepted, loop_break_value, "1.19.0", Some(37339), None), + /// Allows numeric fields in struct expressions and patterns. + (accepted, relaxed_adts, "1.19.0", Some(35626), None), + /// Allows coercing non capturing closures to function pointers. + (accepted, closure_to_fn_coercion, "1.19.0", Some(39817), None), + /// Allows attributes on struct literal fields. + (accepted, struct_field_attributes, "1.20.0", Some(38814), None), + /// Allows the definition of associated constants in `trait` or `impl` blocks. + (accepted, associated_consts, "1.20.0", Some(29646), None), + /// Allows usage of the `compile_error!` macro. + (accepted, compile_error, "1.20.0", Some(40872), None), + /// Allows code like `let x: &'static u32 = &42` to work (RFC 1414). + (accepted, rvalue_static_promotion, "1.21.0", Some(38865), None), + /// Allows `Drop` types in constants (RFC 1440). + (accepted, drop_types_in_const, "1.22.0", Some(33156), None), + /// Allows the sysV64 ABI to be specified on all platforms + /// instead of just the platforms on which it is the C ABI. + (accepted, abi_sysv64, "1.24.0", Some(36167), None), + /// Allows `repr(align(16))` struct attribute (RFC 1358). + (accepted, repr_align, "1.25.0", Some(33626), None), + /// Allows '|' at beginning of match arms (RFC 1925). + (accepted, match_beginning_vert, "1.25.0", Some(44101), None), + /// Allows nested groups in `use` items (RFC 2128). + (accepted, use_nested_groups, "1.25.0", Some(44494), None), + /// Allows indexing into constant arrays. + (accepted, const_indexing, "1.26.0", Some(29947), None), + /// Allows using `a..=b` and `..=b` as inclusive range syntaxes. + (accepted, inclusive_range_syntax, "1.26.0", Some(28237), None), + /// Allows `..=` in patterns (RFC 1192). + (accepted, dotdoteq_in_patterns, "1.26.0", Some(28237), None), + /// Allows `fn main()` with return types which implements `Termination` (RFC 1937). + (accepted, termination_trait, "1.26.0", Some(43301), None), + /// Allows implementing `Clone` for closures where possible (RFC 2132). + (accepted, clone_closures, "1.26.0", Some(44490), None), + /// Allows implementing `Copy` for closures where possible (RFC 2132). + (accepted, copy_closures, "1.26.0", Some(44490), None), + /// Allows `impl Trait` in function arguments. + (accepted, universal_impl_trait, "1.26.0", Some(34511), None), + /// Allows `impl Trait` in function return types. + (accepted, conservative_impl_trait, "1.26.0", Some(34511), None), + /// Allows using the `u128` and `i128` types. + (accepted, i128_type, "1.26.0", Some(35118), None), + /// Allows default match binding modes (RFC 2005). + (accepted, match_default_bindings, "1.26.0", Some(42640), None), + /// Allows `'_` placeholder lifetimes. + (accepted, underscore_lifetimes, "1.26.0", Some(44524), None), + /// Allows attributes on lifetime/type formal parameters in generics (RFC 1327). + (accepted, generic_param_attrs, "1.27.0", Some(48848), None), + /// Allows `cfg(target_feature = "...")`. + (accepted, cfg_target_feature, "1.27.0", Some(29717), None), + /// Allows `#[target_feature(...)]`. + (accepted, target_feature, "1.27.0", None, None), + /// Allows using `dyn Trait` as a syntax for trait objects. + (accepted, dyn_trait, "1.27.0", Some(44662), None), + /// Allows `#[must_use]` on functions, and introduces must-use operators (RFC 1940). + (accepted, fn_must_use, "1.27.0", Some(43302), None), + /// Allows use of the `:lifetime` macro fragment specifier. + (accepted, macro_lifetime_matcher, "1.27.0", Some(34303), None), + /// Allows `#[test]` functions where the return type implements `Termination` (RFC 1937). + (accepted, termination_trait_test, "1.27.0", Some(48854), None), + /// Allows the `#[global_allocator]` attribute. + (accepted, global_allocator, "1.28.0", Some(27389), None), + /// Allows `#[repr(transparent)]` attribute on newtype structs. + (accepted, repr_transparent, "1.28.0", Some(43036), None), + /// Allows procedural macros in `proc-macro` crates. + (accepted, proc_macro, "1.29.0", Some(38356), None), + /// Allows `foo.rs` as an alternative to `foo/mod.rs`. + (accepted, non_modrs_mods, "1.30.0", Some(44660), None), + /// Allows use of the `:vis` macro fragment specifier + (accepted, macro_vis_matcher, "1.30.0", Some(41022), None), + /// Allows importing and reexporting macros with `use`, + /// enables macro modularization in general. + (accepted, use_extern_macros, "1.30.0", Some(35896), None), + /// Allows keywords to be escaped for use as identifiers. + (accepted, raw_identifiers, "1.30.0", Some(48589), None), + /// Allows attributes scoped to tools. + (accepted, tool_attributes, "1.30.0", Some(44690), None), + /// Allows multi-segment paths in attributes and derives. + (accepted, proc_macro_path_invoc, "1.30.0", Some(38356), None), + /// Allows all literals in attribute lists and values of key-value pairs. + (accepted, attr_literals, "1.30.0", Some(34981), None), + /// Allows inferring outlives requirements (RFC 2093). + (accepted, infer_outlives_requirements, "1.30.0", Some(44493), None), + /// Allows annotating functions conforming to `fn(&PanicInfo) -> !` with `#[panic_handler]`. + /// This defines the behavior of panics. + (accepted, panic_handler, "1.30.0", Some(44489), None), + /// Allows `#[used]` to preserve symbols (see llvm.used). + (accepted, used, "1.30.0", Some(40289), None), + /// Allows `crate` in paths. + (accepted, crate_in_paths, "1.30.0", Some(45477), None), + /// Allows resolving absolute paths as paths from other crates. + (accepted, extern_absolute_paths, "1.30.0", Some(44660), None), + /// Allows access to crate names passed via `--extern` through prelude. + (accepted, extern_prelude, "1.30.0", Some(44660), None), + /// Allows parentheses in patterns. + (accepted, pattern_parentheses, "1.31.0", Some(51087), None), + /// Allows the definition of `const fn` functions. + (accepted, min_const_fn, "1.31.0", Some(53555), None), + /// Allows scoped lints. + (accepted, tool_lints, "1.31.0", Some(44690), None), + /// Allows lifetime elision in `impl` headers. For example: + /// + `impl<I:Iterator> Iterator for &mut Iterator` + /// + `impl Debug for Foo<'_>` + (accepted, impl_header_lifetime_elision, "1.31.0", Some(15872), None), + /// Allows `extern crate foo as bar;`. This puts `bar` into extern prelude. + (accepted, extern_crate_item_prelude, "1.31.0", Some(55599), None), + /// Allows use of the `:literal` macro fragment specifier (RFC 1576). + (accepted, macro_literal_matcher, "1.32.0", Some(35625), None), + /// Allows use of `?` as the Kleene "at most one" operator in macros. + (accepted, macro_at_most_once_rep, "1.32.0", Some(48075), None), + /// Allows `Self` struct constructor (RFC 2302). + (accepted, self_struct_ctor, "1.32.0", Some(51994), None), + /// Allows `Self` in type definitions (RFC 2300). + (accepted, self_in_typedefs, "1.32.0", Some(49303), None), + /// Allows `use x::y;` to search `x` in the current scope. + (accepted, uniform_paths, "1.32.0", Some(53130), None), + /// Allows integer match exhaustiveness checking (RFC 2591). + (accepted, exhaustive_integer_patterns, "1.33.0", Some(50907), None), + /// Allows `use path as _;` and `extern crate c as _;`. + (accepted, underscore_imports, "1.33.0", Some(48216), None), + /// Allows `#[repr(packed(N))]` attribute on structs. + (accepted, repr_packed, "1.33.0", Some(33158), None), + /// Allows irrefutable patterns in `if let` and `while let` statements (RFC 2086). + (accepted, irrefutable_let_patterns, "1.33.0", Some(44495), None), + /// Allows calling `const unsafe fn` inside `unsafe` blocks in `const fn` functions. + (accepted, min_const_unsafe_fn, "1.33.0", Some(55607), None), + /// Allows let bindings, assignments and destructuring in `const` functions and constants. + /// As long as control flow is not implemented in const eval, `&&` and `||` may not be used + /// at the same time as let bindings. + (accepted, const_let, "1.33.0", Some(48821), None), + /// Allows `#[cfg_attr(predicate, multiple, attributes, here)]`. + (accepted, cfg_attr_multi, "1.33.0", Some(54881), None), + /// Allows top level or-patterns (`p | q`) in `if let` and `while let`. + (accepted, if_while_or_patterns, "1.33.0", Some(48215), None), + /// Allows `cfg(target_vendor = "...")`. + (accepted, cfg_target_vendor, "1.33.0", Some(29718), None), + /// Allows `extern crate self as foo;`. + /// This puts local crate root into extern prelude under name `foo`. + (accepted, extern_crate_self, "1.34.0", Some(56409), None), + /// Allows arbitrary delimited token streams in non-macro attributes. + (accepted, unrestricted_attribute_tokens, "1.34.0", Some(55208), None), + /// Allows paths to enum variants on type aliases including `Self`. + (accepted, type_alias_enum_variants, "1.37.0", Some(49683), None), + /// Allows using `#[repr(align(X))]` on enums with equivalent semantics + /// to wrapping an enum in a wrapper struct with `#[repr(align(X))]`. + (accepted, repr_align_enum, "1.37.0", Some(57996), None), + /// Allows `const _: TYPE = VALUE`. + (accepted, underscore_const_names, "1.37.0", Some(54912), None), + /// Allows free and inherent `async fn`s, `async` blocks, and `<expr>.await` expressions. + (accepted, async_await, "1.39.0", Some(50547), None), + /// Allows mixing bind-by-move in patterns and references to those identifiers in guards. + (accepted, bind_by_move_pattern_guards, "1.39.0", Some(15287), None), + /// Allows attributes in formal function parameters. + (accepted, param_attrs, "1.39.0", Some(60406), None), + /// Allows macro invocations in `extern {}` blocks. + (accepted, macros_in_extern, "1.40.0", Some(49476), None), + /// Allows future-proofing enums/structs with the `#[non_exhaustive]` attribute (RFC 2008). + (accepted, non_exhaustive, "1.40.0", Some(44109), None), + /// Allows calling constructor functions in `const fn`. + (accepted, const_constructor, "1.40.0", Some(61456), None), + /// Allows the use of `#[cfg(doctest)]`, set when rustdoc is collecting doctests. + (accepted, cfg_doctest, "1.40.0", Some(62210), None), + /// Allows relaxing the coherence rules such that + /// `impl<T> ForeignTrait<LocalType> for ForeignType<T>` is permitted. + (accepted, re_rebalance_coherence, "1.41.0", Some(55437), None), + /// Allows #[repr(transparent)] on univariant enums (RFC 2645). + (accepted, transparent_enums, "1.42.0", Some(60405), None), + /// Allows using subslice patterns, `[a, .., b]` and `[a, xs @ .., b]`. + (accepted, slice_patterns, "1.42.0", Some(62254), None), + /// Allows the use of `if` and `match` in constants. + (accepted, const_if_match, "1.46.0", Some(49146), None), + /// Allows the use of `loop` and `while` in constants. + (accepted, const_loop, "1.46.0", Some(52000), None), + /// Allows `#[track_caller]` to be used which provides + /// accurate caller location reporting during panic (RFC 2091). + (accepted, track_caller, "1.46.0", Some(47809), None), + + // ------------------------------------------------------------------------- + // feature-group-end: accepted features + // ------------------------------------------------------------------------- +); diff --git a/compiler/rustc_feature/src/active.rs b/compiler/rustc_feature/src/active.rs new file mode 100644 index 00000000000..e858980738d --- /dev/null +++ b/compiler/rustc_feature/src/active.rs @@ -0,0 +1,607 @@ +//! List of the active feature gates. + +use super::{Feature, State}; + +use rustc_span::edition::Edition; +use rustc_span::symbol::{sym, Symbol}; +use rustc_span::Span; + +macro_rules! set { + ($field: ident) => {{ + fn f(features: &mut Features, _: Span) { + features.$field = true; + } + f as fn(&mut Features, Span) + }}; +} + +macro_rules! declare_features { + ($( + $(#[doc = $doc:tt])* (active, $feature:ident, $ver:expr, $issue:expr, $edition:expr), + )+) => { + /// Represents active features that are currently being implemented or + /// currently being considered for addition/removal. + pub const ACTIVE_FEATURES: + &[Feature] = + &[$( + // (sym::$feature, $ver, $issue, $edition, set!($feature)) + Feature { + state: State::Active { set: set!($feature) }, + name: sym::$feature, + since: $ver, + issue: $issue, + edition: $edition, + description: concat!($($doc,)*), + } + ),+]; + + /// A set of features to be used by later passes. + #[derive(Clone, Default)] + 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)>, + $( + $(#[doc = $doc])* + pub $feature: bool + ),+ + } + + impl Features { + pub fn walk_feature_fields(&self, mut f: impl FnMut(&str, bool)) { + $(f(stringify!($feature), self.$feature);)+ + } + + /// Is the given feature enabled? + /// + /// Panics if the symbol doesn't correspond to a declared feature. + pub fn enabled(&self, feature: Symbol) -> bool { + match feature { + $( sym::$feature => self.$feature, )* + + _ => panic!("`{}` was not listed in `declare_features`", feature), + } + } + } + }; +} + +impl Feature { + /// Sets this feature in `Features`. Panics if called on a non-active feature. + pub fn set(&self, features: &mut Features, span: Span) { + match self.state { + State::Active { set } => set(features, span), + _ => panic!("called `set` on feature `{}` which is not `active`", self.name), + } + } +} + +// If you change this, please modify `src/doc/unstable-book` as well. +// +// Don't ever remove anything from this list; move them to `removed.rs`. +// +// The version numbers here correspond to the version in which the current status +// was set. This is most important for knowing when a particular feature became +// stable (active). +// +// 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-start + + /// Allows using `rustc_*` attributes (RFC 572). + (active, rustc_attrs, "1.0.0", None, None), + + /// Allows using compiler's own crates. + (active, rustc_private, "1.0.0", Some(27812), None), + + /// Allows using the `rust-intrinsic`'s "ABI". + (active, intrinsics, "1.0.0", None, None), + + /// Allows using `#[lang = ".."]` attribute for linking items to special compiler logic. + (active, lang_items, "1.0.0", None, None), + + /// Allows using the `#[stable]` and `#[unstable]` attributes. + (active, staged_api, "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). + (active, allow_internal_unstable, "1.0.0", 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). + (active, allow_internal_unsafe, "1.0.0", None, None), + + /// no-tracking-issue-end + + /// Allows using `#[link_name="llvm.*"]`. + (active, link_llvm_intrinsics, "1.0.0", Some(29602), None), + + /// Allows using the `box $expr` syntax. + (active, box_syntax, "1.0.0", Some(49733), None), + + /// Allows using `#[main]` to replace the entrypoint `#[lang = "start"]` calls. + (active, main, "1.0.0", Some(29634), None), + + /// Allows using `#[start]` on a function indicating that it is the program entrypoint. + (active, start, "1.0.0", Some(29633), None), + + /// Allows using the `#[fundamental]` attribute. + (active, fundamental, "1.0.0", Some(29635), None), + + /// Allows using the `rust-call` ABI. + (active, unboxed_closures, "1.0.0", Some(29625), None), + + /// Allows using the `#[linkage = ".."]` attribute. + (active, linkage, "1.0.0", Some(29603), None), + + /// Allows features specific to OIBIT (auto traits). + (active, optin_builtin_traits, "1.0.0", Some(13231), None), + + /// Allows using `box` in patterns (RFC 469). + (active, box_patterns, "1.0.0", Some(29641), None), + + // no-tracking-issue-start + + /// Allows using `#[prelude_import]` on glob `use` items. + (active, prelude_import, "1.2.0", None, None), + + // no-tracking-issue-end + + // no-tracking-issue-start + + /// Allows using `#[omit_gdb_pretty_printer_section]`. + (active, omit_gdb_pretty_printer_section, "1.5.0", None, None), + + /// Allows using the `vectorcall` ABI. + (active, abi_vectorcall, "1.7.0", None, None), + + // no-tracking-issue-end + + /// 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. + (active, structural_match, "1.8.0", Some(31434), None), + + /// Allows using the `may_dangle` attribute (RFC 1327). + (active, dropck_eyepatch, "1.10.0", Some(34761), None), + + /// Allows using the `#![panic_runtime]` attribute. + (active, panic_runtime, "1.10.0", Some(32837), None), + + /// Allows declaring with `#![needs_panic_runtime]` that a panic runtime is needed. + (active, needs_panic_runtime, "1.10.0", Some(32837), None), + + // no-tracking-issue-start + + /// Allows identifying the `compiler_builtins` crate. + (active, compiler_builtins, "1.13.0", None, None), + + /// Allows using the `unadjusted` ABI; perma-unstable. + (active, abi_unadjusted, "1.16.0", None, None), + + /// Used to identify crates that contain the profiler runtime. + (active, profiler_runtime, "1.18.0", None, None), + + /// Allows using the `thiscall` ABI. + (active, abi_thiscall, "1.19.0", None, None), + + /// Allows using `#![needs_allocator]`, an implementation detail of `#[global_allocator]`. + (active, allocator_internals, "1.20.0", None, None), + + /// Added for testing E0705; perma-unstable. + (active, test_2018_feature, "1.31.0", None, Some(Edition::Edition2018)), + + /// Allows `#[repr(no_niche)]` (an implementation detail of `rustc`, + /// it is not on path for eventual stabilization). + (active, no_niche, "1.42.0", None, None), + + // no-tracking-issue-end + + // ------------------------------------------------------------------------- + // 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. + (active, arm_target_feature, "1.27.0", Some(44839), None), + (active, aarch64_target_feature, "1.27.0", Some(44839), None), + (active, hexagon_target_feature, "1.27.0", Some(44839), None), + (active, powerpc_target_feature, "1.27.0", Some(44839), None), + (active, mips_target_feature, "1.27.0", Some(44839), None), + (active, avx512_target_feature, "1.27.0", Some(44839), None), + (active, mmx_target_feature, "1.27.0", Some(44839), None), + (active, sse4a_target_feature, "1.27.0", Some(44839), None), + (active, tbm_target_feature, "1.27.0", Some(44839), None), + (active, wasm_target_feature, "1.30.0", Some(44839), None), + (active, adx_target_feature, "1.32.0", Some(44839), None), + (active, cmpxchg16b_target_feature, "1.32.0", Some(44839), None), + (active, movbe_target_feature, "1.34.0", Some(44839), None), + (active, rtm_target_feature, "1.35.0", Some(44839), None), + (active, f16c_target_feature, "1.36.0", Some(44839), None), + (active, riscv_target_feature, "1.45.0", Some(44839), None), + + // ------------------------------------------------------------------------- + // feature-group-end: actual feature gates (target features) + // ------------------------------------------------------------------------- + + // ------------------------------------------------------------------------- + // feature-group-start: actual feature gates + // ------------------------------------------------------------------------- + + /// Allows using the `#[link_args]` attribute. + (active, link_args, "1.0.0", Some(29596), None), + + /// Allows defining identifiers beyond ASCII. + (active, non_ascii_idents, "1.0.0", Some(55467), None), + + /// Allows using `#[plugin_registrar]` on functions. + (active, plugin_registrar, "1.0.0", Some(29597), None), + + /// Allows using `#![plugin(myplugin)]`. + (active, plugin, "1.0.0", Some(29597), None), + + /// Allows using `#[thread_local]` on `static` items. + (active, thread_local, "1.0.0", Some(29594), None), + + /// Allows the use of SIMD types in functions declared in `extern` blocks. + (active, simd_ffi, "1.0.0", Some(27731), None), + + /// Allows using non lexical lifetimes (RFC 2094). + (active, nll, "1.0.0", Some(43234), None), + + /// Allows the definition of `const` functions with some advanced features. + (active, const_fn, "1.2.0", Some(57563), None), + + /// Allows associated type defaults. + (active, associated_type_defaults, "1.2.0", Some(29661), None), + + /// Allows `#![no_core]`. + (active, no_core, "1.3.0", Some(29639), None), + + /// Allows default type parameters to influence type inference. + (active, default_type_parameter_fallback, "1.3.0", Some(27336), None), + + /// Allows `repr(simd)` and importing the various simd intrinsics. + (active, repr_simd, "1.4.0", Some(27731), None), + + /// Allows `extern "platform-intrinsic" { ... }`. + (active, platform_intrinsics, "1.4.0", Some(27731), None), + + /// Allows `#[unwind(..)]`. + /// + /// Permits specifying whether a function should permit unwinding or abort on unwind. + (active, unwind_attributes, "1.4.0", Some(58760), None), + + /// Allows attributes on expressions and non-item statements. + (active, stmt_expr_attributes, "1.6.0", Some(15701), None), + + /// Allows the use of type ascription in expressions. + (active, type_ascription, "1.6.0", Some(23416), None), + + /// Allows `cfg(target_thread_local)`. + (active, cfg_target_thread_local, "1.7.0", Some(29594), None), + + /// Allows specialization of implementations (RFC 1210). + (active, specialization, "1.7.0", Some(31844), None), + + /// A minimal, sound subset of specialization intended to be used by the + /// standard library until the soundness issues with specialization + /// are fixed. + (active, min_specialization, "1.7.0", Some(31844), None), + + /// Allows using `#[naked]` on functions. + (active, naked_functions, "1.9.0", Some(32408), None), + + /// Allows `cfg(target_has_atomic = "...")`. + (active, cfg_target_has_atomic, "1.9.0", Some(32976), None), + + /// Allows `X..Y` patterns. + (active, exclusive_range_pattern, "1.11.0", Some(37854), None), + + /// Allows the `!` type. Does not imply 'exhaustive_patterns' (below) any more. + (active, never_type, "1.13.0", Some(35121), None), + + /// Allows exhaustive pattern matching on types that contain uninhabited types. + (active, exhaustive_patterns, "1.13.0", Some(51085), None), + + /// Allows `union`s to implement `Drop`. Moreover, `union`s may now include fields + /// that don't implement `Copy` as long as they don't have any drop glue. + /// This is checked recursively. On encountering type variable where no progress can be made, + /// `T: Copy` is used as a substitute for "no drop glue". + /// + /// NOTE: A limited form of `union U { ... }` was accepted in 1.19.0. + (active, untagged_unions, "1.13.0", Some(55149), None), + + /// Allows `#[link(..., cfg(..))]`. + (active, link_cfg, "1.14.0", Some(37406), None), + + /// Allows `extern "ptx-*" fn()`. + (active, abi_ptx, "1.15.0", Some(38788), None), + + /// Allows the `#[repr(i128)]` attribute for enums. + (active, repr128, "1.16.0", Some(56071), None), + + /// Allows `#[link(kind="static-nobundle"...)]`. + (active, static_nobundle, "1.16.0", Some(37403), None), + + /// Allows `extern "msp430-interrupt" fn()`. + (active, abi_msp430_interrupt, "1.16.0", Some(38487), None), + + /// Allows declarative macros 2.0 (`macro`). + (active, decl_macro, "1.17.0", Some(39412), None), + + /// Allows `extern "x86-interrupt" fn()`. + (active, abi_x86_interrupt, "1.17.0", Some(40180), None), + + /// Allows a test to fail without failing the whole suite. + (active, allow_fail, "1.19.0", Some(46488), None), + + /// Allows unsized tuple coercion. + (active, unsized_tuple_coercion, "1.20.0", Some(42877), None), + + /// Allows defining generators. + (active, generators, "1.21.0", Some(43122), None), + + /// Allows `#[doc(cfg(...))]`. + (active, doc_cfg, "1.21.0", Some(43781), None), + + /// Allows `#[doc(masked)]`. + (active, doc_masked, "1.21.0", Some(44027), None), + + /// Allows `#[doc(spotlight)]`. + (active, doc_spotlight, "1.22.0", Some(45040), None), + + /// Allows `#[doc(include = "some-file")]`. + (active, external_doc, "1.22.0", Some(44732), None), + + /// Allows using `crate` as visibility modifier, synonymous with `pub(crate)`. + (active, crate_visibility_modifier, "1.23.0", Some(53120), None), + + /// Allows defining `extern type`s. + (active, extern_types, "1.23.0", Some(43467), None), + + /// Allows trait methods with arbitrary self types. + (active, arbitrary_self_types, "1.23.0", Some(44874), None), + + /// Allows in-band quantification of lifetime bindings (e.g., `fn foo(x: &'a u8) -> &'a u8`). + (active, in_band_lifetimes, "1.23.0", Some(44524), None), + + /// Allows associated types to be generic, e.g., `type Foo<T>;` (RFC 1598). + (active, generic_associated_types, "1.23.0", Some(44265), None), + + /// Allows defining `trait X = A + B;` alias items. + (active, trait_alias, "1.24.0", Some(41517), None), + + /// Allows inferring `'static` outlives requirements (RFC 2093). + (active, infer_static_outlives_requirements, "1.26.0", Some(54185), None), + + /// Allows accessing fields of unions inside `const` functions. + (active, const_fn_union, "1.27.0", Some(51909), None), + + /// Allows casting raw pointers to `usize` during const eval. + (active, const_raw_ptr_to_usize_cast, "1.27.0", Some(51910), None), + + /// Allows dereferencing raw pointers during const eval. + (active, const_raw_ptr_deref, "1.27.0", Some(51911), None), + + /// Allows `#[doc(alias = "...")]`. + (active, doc_alias, "1.27.0", Some(50146), None), + + /// Allows inconsistent bounds in where clauses. + (active, trivial_bounds, "1.28.0", Some(48214), None), + + /// Allows `'a: { break 'a; }`. + (active, label_break_value, "1.28.0", Some(48594), None), + + /// Allows using `#[doc(keyword = "...")]`. + (active, doc_keyword, "1.28.0", Some(51315), None), + + /// Allows using `try {...}` expressions. + (active, try_blocks, "1.29.0", Some(31436), None), + + /// Allows defining an `#[alloc_error_handler]`. + (active, alloc_error_handler, "1.29.0", Some(51540), None), + + /// Allows using the `amdgpu-kernel` ABI. + (active, abi_amdgpu_kernel, "1.29.0", Some(51575), None), + + /// Allows panicking during const eval (producing compile-time errors). + (active, const_panic, "1.30.0", Some(51999), None), + + /// Allows `#[marker]` on certain traits allowing overlapping implementations. + (active, marker_trait_attr, "1.30.0", Some(29864), None), + + /// Allows macro attributes on expressions, statements and non-inline modules. + (active, proc_macro_hygiene, "1.30.0", Some(54727), None), + + /// Allows unsized rvalues at arguments and parameters. + (active, unsized_locals, "1.30.0", Some(48055), None), + + /// Allows custom test frameworks with `#![test_runner]` and `#[test_case]`. + (active, custom_test_frameworks, "1.30.0", Some(50297), None), + + /// Allows non-builtin attributes in inner attribute position. + (active, custom_inner_attributes, "1.30.0", Some(54726), None), + + /// Allows `impl Trait` in bindings (`let`, `const`, `static`). + (active, impl_trait_in_bindings, "1.30.0", Some(63065), None), + + /// Allows using `reason` in lint attributes and the `#[expect(lint)]` lint check. + (active, lint_reasons, "1.31.0", Some(54503), None), + + /// Allows exhaustive integer pattern matching on `usize` and `isize`. + (active, precise_pointer_size_matching, "1.32.0", Some(56354), None), + + /// Allows using `#[ffi_returns_twice]` on foreign functions. + (active, ffi_returns_twice, "1.34.0", Some(58314), None), + + /// Allows const generic types (e.g. `struct Foo<const N: usize>(...);`). + (active, const_generics, "1.34.0", Some(44580), None), + + /// Allows using `#[optimize(X)]`. + (active, optimize_attribute, "1.34.0", Some(54882), None), + + /// Allows using C-variadics. + (active, c_variadic, "1.34.0", Some(44930), None), + + /// Allows the user of associated type bounds. + (active, associated_type_bounds, "1.34.0", Some(52662), None), + + /// Allows `if/while p && let q = r && ...` chains. + (active, let_chains, "1.37.0", Some(53667), None), + + /// Allows #[repr(transparent)] on unions (RFC 2645). + (active, transparent_unions, "1.37.0", Some(60405), None), + + /// Allows explicit discriminants on non-unit enum variants. + (active, arbitrary_enum_discriminant, "1.37.0", Some(60553), None), + + /// Allows `impl Trait` with multiple unrelated lifetimes. + (active, member_constraints, "1.37.0", Some(61997), None), + + /// Allows `async || body` closures. + (active, async_closure, "1.37.0", Some(62290), None), + + /// Allows `[x; N]` where `x` is a constant (RFC 2203). + (active, const_in_array_repeat_expressions, "1.37.0", Some(49147), None), + + /// Allows `impl Trait` to be used inside type aliases (RFC 2515). + (active, type_alias_impl_trait, "1.38.0", Some(63063), None), + + /// Allows the use of or-patterns (e.g., `0 | 1`). + (active, or_patterns, "1.38.0", Some(54883), None), + + /// Allows the definition of `const extern fn` and `const unsafe extern fn`. + (active, const_extern_fn, "1.40.0", Some(64926), None), + + /// Allows the use of raw-dylibs (RFC 2627). + (active, raw_dylib, "1.40.0", Some(58713), 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. + (active, object_safe_for_dispatch, "1.40.0", Some(43561), None), + + /// Allows using the `efiapi` ABI. + (active, abi_efiapi, "1.40.0", Some(65815), None), + + /// Allows `&raw const $place_expr` and `&raw mut $place_expr` expressions. + (active, raw_ref_op, "1.41.0", Some(64490), None), + + /// Allows diverging expressions to fall back to `!` rather than `()`. + (active, never_type_fallback, "1.41.0", Some(65992), None), + + /// Allows using the `#[register_attr]` attribute. + (active, register_attr, "1.41.0", Some(66080), None), + + /// Allows using the `#[register_tool]` attribute. + (active, register_tool, "1.41.0", Some(66079), None), + + /// Allows the use of `#[cfg(sanitize = "option")]`; set when -Zsanitizer is used. + (active, cfg_sanitize, "1.41.0", Some(39699), None), + + /// Allows using `..X`, `..=X`, `...X`, and `X..` as a pattern. + (active, half_open_range_patterns, "1.41.0", Some(67264), None), + + /// Allows using `&mut` in constant functions. + (active, const_mut_refs, "1.41.0", Some(57349), None), + + /// Allows bindings in the subpattern of a binding pattern. + /// For example, you can write `x @ Some(y)`. + (active, bindings_after_at, "1.41.0", Some(65490), None), + + /// Allows patterns with concurrent by-move and by-ref bindings. + /// For example, you can write `Foo(a, ref b)` where `a` is by-move and `b` is by-ref. + (active, move_ref_pattern, "1.42.0", Some(68354), None), + + /// Allows `impl const Trait for T` syntax. + (active, const_trait_impl, "1.42.0", Some(67792), None), + + /// Allows `T: ?const Trait` syntax in bounds. + (active, const_trait_bound_opt_out, "1.42.0", Some(67794), None), + + /// Allows the use of `no_sanitize` attribute. + (active, no_sanitize, "1.42.0", Some(39699), None), + + // Allows limiting the evaluation steps of const expressions + (active, const_eval_limit, "1.43.0", Some(67217), None), + + /// Allow negative trait implementations. + (active, negative_impls, "1.44.0", Some(68318), None), + + /// Allows the use of `#[target_feature]` on safe functions. + (active, target_feature_11, "1.45.0", Some(69098), None), + + /// Allow conditional compilation depending on rust version + (active, cfg_version, "1.45.0", Some(64796), None), + + /// Allows the use of `#[ffi_pure]` on foreign functions. + (active, ffi_pure, "1.45.0", Some(58329), None), + + /// Allows the use of `#[ffi_const]` on foreign functions. + (active, ffi_const, "1.45.0", Some(58328), None), + + /// No longer treat an unsafe function as an unsafe block. + (active, unsafe_block_in_unsafe_fn, "1.45.0", Some(71668), None), + + /// Allows `extern "avr-interrupt" fn()` and `extern "avr-non-blocking-interrupt" fn()`. + (active, abi_avr_interrupt, "1.45.0", Some(69664), None), + + /// Be more precise when looking for live drops in a const context. + (active, const_precise_live_drops, "1.46.0", Some(73255), None), + + /// Allows capturing variables in scope using format_args! + (active, format_args_capture, "1.46.0", Some(67984), None), + + /// Lazily evaluate constants. This allows constants to depend on type parameters. + (active, lazy_normalization_consts, "1.46.0", Some(72219), None), + + /// Allows calling `transmute` in const fn + (active, const_fn_transmute, "1.46.0", Some(53605), None), + + /// The smallest useful subset of `const_generics`. + (active, min_const_generics, "1.47.0", Some(74878), None), + + /// Allows `if let` guard in match arms. + (active, if_let_guard, "1.47.0", Some(51114), None), + + // ------------------------------------------------------------------------- + // feature-group-end: actual feature gates + // ------------------------------------------------------------------------- +); + +/// 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 const INCOMPLETE_FEATURES: &[Symbol] = &[ + sym::if_let_guard, + sym::impl_trait_in_bindings, + sym::generic_associated_types, + sym::const_generics, + sym::let_chains, + sym::raw_dylib, + sym::const_trait_impl, + sym::const_trait_bound_opt_out, + sym::lazy_normalization_consts, + sym::specialization, +]; diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs new file mode 100644 index 00000000000..879f06f89a7 --- /dev/null +++ b/compiler/rustc_feature/src/builtin_attrs.rs @@ -0,0 +1,602 @@ +//! Built-in attributes and `cfg` flag gating. + +use AttributeGate::*; +use AttributeType::*; + +use crate::{Features, Stability}; + +use lazy_static::lazy_static; +use rustc_data_structures::fx::FxHashMap; +use rustc_span::symbol::{sym, Symbol}; + +type GateFn = fn(&Features) -> bool; + +macro_rules! cfg_fn { + ($field: ident) => { + (|features| features.$field) as GateFn + }; +} + +pub type GatedCfg = (Symbol, Symbol, GateFn); + +/// `cfg(...)`'s that are feature gated. +const GATED_CFGS: &[GatedCfg] = &[ + // (name in cfg, feature, function to check if the feature is enabled) + (sym::target_thread_local, sym::cfg_target_thread_local, cfg_fn!(cfg_target_thread_local)), + (sym::target_has_atomic, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)), + (sym::target_has_atomic_load_store, sym::cfg_target_has_atomic, cfg_fn!(cfg_target_has_atomic)), + (sym::sanitize, sym::cfg_sanitize, cfg_fn!(cfg_sanitize)), + (sym::version, sym::cfg_version, cfg_fn!(cfg_version)), +]; + +/// Find a gated cfg determined by the `pred`icate which is given the cfg's name. +pub fn find_gated_cfg(pred: impl Fn(Symbol) -> bool) -> Option<&'static GatedCfg> { + GATED_CFGS.iter().find(|(cfg_sym, ..)| pred(*cfg_sym)) +} + +// If you change this, please modify `src/doc/unstable-book` as well. You must +// move that documentation into the relevant place in the other docs, and +// remove the chapter on the flag. + +#[derive(Copy, Clone, PartialEq, Debug)] +pub enum AttributeType { + /// Normal, builtin attribute that is consumed + /// by the compiler before the unused_attribute check + Normal, + + /// Builtin attribute that may not be consumed by the compiler + /// before the unused_attribute check. These attributes + /// will be ignored by the unused_attribute lint + AssumedUsed, + + /// Builtin attribute that is only allowed at the crate level + CrateLevel, +} + +#[derive(Clone, Copy)] +pub enum AttributeGate { + /// Is gated by a given feature gate, reason + /// and function to check if enabled + Gated(Stability, Symbol, &'static str, fn(&Features) -> bool), + + /// Ungated attribute, can be used on all release channels + Ungated, +} + +// fn() is not Debug +impl std::fmt::Debug for AttributeGate { + fn fmt(&self, fmt: &mut std::fmt::Formatter<'_>) -> std::fmt::Result { + match *self { + Self::Gated(ref stab, name, expl, _) => { + write!(fmt, "Gated({:?}, {}, {})", stab, name, expl) + } + Self::Ungated => write!(fmt, "Ungated"), + } + } +} + +impl AttributeGate { + fn is_deprecated(&self) -> bool { + match *self { + Self::Gated(Stability::Deprecated(_, _), ..) => true, + _ => false, + } + } +} + +/// A template that the attribute input must match. +/// Only top-level shape (`#[attr]` vs `#[attr(...)]` vs `#[attr = ...]`) is considered now. +#[derive(Clone, Copy, Default)] +pub struct AttributeTemplate { + pub word: bool, + pub list: Option<&'static str>, + pub name_value_str: Option<&'static str>, +} + +/// A convenience macro for constructing attribute templates. +/// E.g., `template!(Word, List: "description")` means that the attribute +/// supports forms `#[attr]` and `#[attr(description)]`. +macro_rules! template { + (Word) => { template!(@ true, None, None) }; + (List: $descr: expr) => { template!(@ false, Some($descr), None) }; + (NameValueStr: $descr: expr) => { template!(@ false, None, Some($descr)) }; + (Word, List: $descr: expr) => { template!(@ true, Some($descr), None) }; + (Word, NameValueStr: $descr: expr) => { template!(@ true, None, Some($descr)) }; + (List: $descr1: expr, NameValueStr: $descr2: expr) => { + template!(@ false, Some($descr1), Some($descr2)) + }; + (Word, List: $descr1: expr, NameValueStr: $descr2: expr) => { + template!(@ true, Some($descr1), Some($descr2)) + }; + (@ $word: expr, $list: expr, $name_value_str: expr) => { AttributeTemplate { + word: $word, list: $list, name_value_str: $name_value_str + } }; +} + +macro_rules! ungated { + ($attr:ident, $typ:expr, $tpl:expr $(,)?) => { + (sym::$attr, $typ, $tpl, Ungated) + }; +} + +macro_rules! gated { + ($attr:ident, $typ:expr, $tpl:expr, $gate:ident, $msg:expr $(,)?) => { + (sym::$attr, $typ, $tpl, Gated(Stability::Unstable, sym::$gate, $msg, cfg_fn!($gate))) + }; + ($attr:ident, $typ:expr, $tpl:expr, $msg:expr $(,)?) => { + (sym::$attr, $typ, $tpl, Gated(Stability::Unstable, sym::$attr, $msg, cfg_fn!($attr))) + }; +} + +macro_rules! rustc_attr { + (TEST, $attr:ident, $typ:expr, $tpl:expr $(,)?) => { + rustc_attr!( + $attr, + $typ, + $tpl, + concat!( + "the `#[", + stringify!($attr), + "]` attribute is just used for rustc unit tests \ + and will never be stable", + ), + ) + }; + ($attr:ident, $typ:expr, $tpl:expr, $msg:expr $(,)?) => { + ( + sym::$attr, + $typ, + $tpl, + Gated(Stability::Unstable, sym::rustc_attrs, $msg, cfg_fn!(rustc_attrs)), + ) + }; +} + +macro_rules! experimental { + ($attr:ident) => { + concat!("the `#[", stringify!($attr), "]` attribute is an experimental feature") + }; +} + +const IMPL_DETAIL: &str = "internal implementation detail"; +const INTERNAL_UNSTABLE: &str = "this is an internal attribute that will never be stable"; + +pub type BuiltinAttribute = (Symbol, AttributeType, AttributeTemplate, AttributeGate); + +/// Attributes that have a special meaning to rustc or rustdoc. +#[rustfmt::skip] +pub const BUILTIN_ATTRIBUTES: &[BuiltinAttribute] = &[ + // ========================================================================== + // Stable attributes: + // ========================================================================== + + // Conditional compilation: + ungated!(cfg, Normal, template!(List: "predicate")), + ungated!(cfg_attr, Normal, template!(List: "predicate, attr1, attr2, ...")), + + // Testing: + ungated!(ignore, Normal, template!(Word, NameValueStr: "reason")), + ungated!( + should_panic, Normal, + template!(Word, List: r#"expected = "reason"#, NameValueStr: "reason"), + ), + // FIXME(Centril): This can be used on stable but shouldn't. + ungated!(reexport_test_harness_main, Normal, template!(NameValueStr: "name")), + + // Macros: + ungated!(derive, Normal, template!(List: "Trait1, Trait2, ...")), + ungated!(automatically_derived, Normal, template!(Word)), + // FIXME(#14407) + ungated!(macro_use, Normal, template!(Word, List: "name1, name2, ...")), + ungated!(macro_escape, Normal, template!(Word)), // Deprecated synonym for `macro_use`. + ungated!(macro_export, Normal, template!(Word, List: "local_inner_macros")), + ungated!(proc_macro, Normal, template!(Word)), + ungated!( + proc_macro_derive, Normal, + template!(List: "TraitName, /*opt*/ attributes(name1, name2, ...)"), + ), + ungated!(proc_macro_attribute, Normal, template!(Word)), + + // Lints: + ungated!(warn, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)), + ungated!(allow, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)), + ungated!(forbid, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)), + ungated!(deny, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#)), + ungated!(must_use, AssumedUsed, template!(Word, NameValueStr: "reason")), + // FIXME(#14407) + ungated!( + deprecated, Normal, + template!( + Word, + List: r#"/*opt*/ since = "version", /*opt*/ note = "reason""#, + NameValueStr: "reason" + ), + ), + + // Crate properties: + ungated!(crate_name, CrateLevel, template!(NameValueStr: "name")), + ungated!(crate_type, CrateLevel, template!(NameValueStr: "bin|lib|...")), + ungated!(crate_id, CrateLevel, template!(NameValueStr: "ignored")), + + // ABI, linking, symbols, and FFI + ungated!( + link, AssumedUsed, + template!(List: r#"name = "...", /*opt*/ kind = "dylib|static|...", /*opt*/ wasm_import_module = "...""#), + ), + ungated!(link_name, AssumedUsed, template!(NameValueStr: "name")), + ungated!(no_link, Normal, template!(Word)), + ungated!(repr, Normal, template!(List: "C")), + ungated!(export_name, AssumedUsed, template!(NameValueStr: "name")), + ungated!(link_section, AssumedUsed, template!(NameValueStr: "name")), + ungated!(no_mangle, AssumedUsed, template!(Word)), + ungated!(used, AssumedUsed, template!(Word)), + + // Limits: + ungated!(recursion_limit, CrateLevel, template!(NameValueStr: "N")), + ungated!(type_length_limit, CrateLevel, template!(NameValueStr: "N")), + gated!( + const_eval_limit, CrateLevel, template!(NameValueStr: "N"), const_eval_limit, + experimental!(const_eval_limit) + ), + + // Entry point: + ungated!(main, Normal, template!(Word)), + ungated!(start, Normal, template!(Word)), + ungated!(no_start, CrateLevel, template!(Word)), + ungated!(no_main, CrateLevel, template!(Word)), + + // Modules, prelude, and resolution: + ungated!(path, Normal, template!(NameValueStr: "file")), + ungated!(no_std, CrateLevel, template!(Word)), + ungated!(no_implicit_prelude, Normal, template!(Word)), + ungated!(non_exhaustive, AssumedUsed, template!(Word)), + + // Runtime + ungated!(windows_subsystem, AssumedUsed, template!(NameValueStr: "windows|console")), + ungated!(panic_handler, Normal, template!(Word)), // RFC 2070 + + // Code generation: + ungated!(inline, AssumedUsed, template!(Word, List: "always|never")), + ungated!(cold, AssumedUsed, template!(Word)), + ungated!(no_builtins, AssumedUsed, template!(Word)), + ungated!(target_feature, AssumedUsed, template!(List: r#"enable = "name""#)), + ungated!(track_caller, AssumedUsed, template!(Word)), + gated!( + no_sanitize, AssumedUsed, + template!(List: "address, memory, thread"), + experimental!(no_sanitize) + ), + + // FIXME: #14408 assume docs are used since rustdoc looks at them. + ungated!(doc, AssumedUsed, template!(List: "hidden|inline|...", NameValueStr: "string")), + + // ========================================================================== + // Unstable attributes: + // ========================================================================== + + // Linking: + gated!(naked, AssumedUsed, template!(Word), naked_functions, experimental!(naked)), + gated!( + link_args, Normal, template!(NameValueStr: "args"), + "the `link_args` attribute is experimental and not portable across platforms, \ + it is recommended to use `#[link(name = \"foo\")] instead", + ), + gated!( + link_ordinal, AssumedUsed, template!(List: "ordinal"), raw_dylib, + experimental!(link_ordinal) + ), + + // Plugins: + ( + sym::plugin_registrar, Normal, template!(Word), + Gated( + Stability::Deprecated( + "https://github.com/rust-lang/rust/pull/64675", + Some("may be removed in a future compiler version"), + ), + sym::plugin_registrar, + "compiler plugins are deprecated", + cfg_fn!(plugin_registrar) + ) + ), + ( + sym::plugin, CrateLevel, template!(List: "name"), + Gated( + Stability::Deprecated( + "https://github.com/rust-lang/rust/pull/64675", + Some("may be removed in a future compiler version"), + ), + sym::plugin, + "compiler plugins are deprecated", + cfg_fn!(plugin) + ) + ), + + // Testing: + gated!(allow_fail, Normal, template!(Word), experimental!(allow_fail)), + gated!( + test_runner, CrateLevel, template!(List: "path"), custom_test_frameworks, + "custom test frameworks are an unstable feature", + ), + // RFC #1268 + gated!(marker, Normal, template!(Word), marker_trait_attr, experimental!(marker)), + gated!( + thread_local, AssumedUsed, template!(Word), + "`#[thread_local]` is an experimental feature, and does not currently handle destructors", + ), + gated!(no_core, CrateLevel, template!(Word), experimental!(no_core)), + // RFC 2412 + gated!( + optimize, AssumedUsed, template!(List: "size|speed"), optimize_attribute, + experimental!(optimize), + ), + + gated!(ffi_returns_twice, AssumedUsed, template!(Word), experimental!(ffi_returns_twice)), + gated!(ffi_pure, AssumedUsed, template!(Word), experimental!(ffi_pure)), + gated!(ffi_const, AssumedUsed, template!(Word), experimental!(ffi_const)), + gated!( + register_attr, CrateLevel, template!(List: "attr1, attr2, ..."), + experimental!(register_attr), + ), + gated!( + register_tool, CrateLevel, template!(List: "tool1, tool2, ..."), + experimental!(register_tool), + ), + + // ========================================================================== + // Internal attributes: Stability, deprecation, and unsafe: + // ========================================================================== + + ungated!(feature, CrateLevel, template!(List: "name1, name1, ...")), + // FIXME(#14407) -- only looked at on-demand so we can't + // guarantee they'll have already been checked. + ungated!( + rustc_deprecated, AssumedUsed, + template!(List: r#"since = "version", reason = "...""#) + ), + // FIXME(#14407) + ungated!(stable, AssumedUsed, template!(List: r#"feature = "name", since = "version""#)), + // FIXME(#14407) + ungated!( + unstable, AssumedUsed, + template!(List: r#"feature = "name", reason = "...", issue = "N""#), + ), + // FIXME(#14407) + ungated!(rustc_const_unstable, AssumedUsed, template!(List: r#"feature = "name""#)), + // FIXME(#14407) + ungated!(rustc_const_stable, AssumedUsed, template!(List: r#"feature = "name""#)), + gated!( + allow_internal_unstable, AssumedUsed, template!(Word, List: "feat1, feat2, ..."), + "allow_internal_unstable side-steps feature gating and stability checks", + ), + gated!( + allow_internal_unsafe, Normal, template!(Word), + "allow_internal_unsafe side-steps the unsafe_code lint", + ), + + // ========================================================================== + // Internal attributes: Type system related: + // ========================================================================== + + gated!(fundamental, AssumedUsed, template!(Word), experimental!(fundamental)), + gated!( + may_dangle, Normal, template!(Word), dropck_eyepatch, + "`may_dangle` has unstable semantics and may be removed in the future", + ), + + // ========================================================================== + // Internal attributes: Runtime related: + // ========================================================================== + + rustc_attr!(rustc_allocator, AssumedUsed, template!(Word), IMPL_DETAIL), + rustc_attr!(rustc_allocator_nounwind, AssumedUsed, template!(Word), IMPL_DETAIL), + gated!(alloc_error_handler, Normal, template!(Word), experimental!(alloc_error_handler)), + gated!( + default_lib_allocator, AssumedUsed, template!(Word), allocator_internals, + experimental!(default_lib_allocator), + ), + gated!( + needs_allocator, Normal, template!(Word), allocator_internals, + experimental!(needs_allocator), + ), + gated!(panic_runtime, AssumedUsed, template!(Word), experimental!(panic_runtime)), + gated!(needs_panic_runtime, AssumedUsed, template!(Word), experimental!(needs_panic_runtime)), + gated!( + unwind, AssumedUsed, template!(List: "allowed|aborts"), unwind_attributes, + experimental!(unwind), + ), + gated!( + compiler_builtins, AssumedUsed, template!(Word), + "the `#[compiler_builtins]` attribute is used to identify the `compiler_builtins` crate \ + which contains compiler-rt intrinsics and will never be stable", + ), + gated!( + profiler_runtime, AssumedUsed, template!(Word), + "the `#[profiler_runtime]` attribute is used to identify the `profiler_builtins` crate \ + which contains the profiler runtime and will never be stable", + ), + + // ========================================================================== + // Internal attributes, Linkage: + // ========================================================================== + + gated!( + linkage, AssumedUsed, template!(NameValueStr: "external|internal|..."), + "the `linkage` attribute is experimental and not portable across platforms", + ), + rustc_attr!(rustc_std_internal_symbol, AssumedUsed, template!(Word), INTERNAL_UNSTABLE), + + // ========================================================================== + // Internal attributes, Macro related: + // ========================================================================== + + rustc_attr!(rustc_builtin_macro, AssumedUsed, template!(Word), IMPL_DETAIL), + rustc_attr!(rustc_proc_macro_decls, Normal, template!(Word), INTERNAL_UNSTABLE), + rustc_attr!( + rustc_macro_transparency, AssumedUsed, + template!(NameValueStr: "transparent|semitransparent|opaque"), + "used internally for testing macro hygiene", + ), + + // ========================================================================== + // Internal attributes, Diagnostics related: + // ========================================================================== + + rustc_attr!( + rustc_on_unimplemented, AssumedUsed, + template!( + List: r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#, + NameValueStr: "message" + ), + INTERNAL_UNSTABLE + ), + // Enumerates "identity-like" conversion methods to suggest on type mismatch. + rustc_attr!(rustc_conversion_suggestion, AssumedUsed, template!(Word), INTERNAL_UNSTABLE), + + // ========================================================================== + // Internal attributes, Const related: + // ========================================================================== + + rustc_attr!(rustc_promotable, AssumedUsed, template!(Word), IMPL_DETAIL), + rustc_attr!(rustc_allow_const_fn_ptr, AssumedUsed, template!(Word), IMPL_DETAIL), + rustc_attr!(rustc_args_required_const, AssumedUsed, template!(List: "N"), INTERNAL_UNSTABLE), + + // ========================================================================== + // Internal attributes, Layout related: + // ========================================================================== + + rustc_attr!( + rustc_layout_scalar_valid_range_start, AssumedUsed, template!(List: "value"), + "the `#[rustc_layout_scalar_valid_range_start]` attribute is just used to enable \ + niche optimizations in libcore and will never be stable", + ), + rustc_attr!( + rustc_layout_scalar_valid_range_end, AssumedUsed, template!(List: "value"), + "the `#[rustc_layout_scalar_valid_range_end]` attribute is just used to enable \ + niche optimizations in libcore and will never be stable", + ), + rustc_attr!( + rustc_nonnull_optimization_guaranteed, AssumedUsed, template!(Word), + "the `#[rustc_nonnull_optimization_guaranteed]` attribute is just used to enable \ + niche optimizations in libcore and will never be stable", + ), + + // ========================================================================== + // Internal attributes, Misc: + // ========================================================================== + gated!( + lang, Normal, template!(NameValueStr: "name"), lang_items, + "language items are subject to change", + ), + ( + sym::rustc_diagnostic_item, + Normal, + template!(NameValueStr: "name"), + Gated( + Stability::Unstable, + sym::rustc_attrs, + "diagnostic items compiler internal support for linting", + cfg_fn!(rustc_attrs), + ), + ), + gated!( + // Used in resolve: + prelude_import, AssumedUsed, template!(Word), + "`#[prelude_import]` is for use by rustc only", + ), + gated!( + rustc_paren_sugar, Normal, template!(Word), unboxed_closures, + "unboxed_closures are still evolving", + ), + rustc_attr!( + rustc_inherit_overflow_checks, AssumedUsed, template!(Word), + "the `#[rustc_inherit_overflow_checks]` attribute is just used to control \ + overflow checking behavior of several libcore functions that are inlined \ + across crates and will never be stable", + ), + rustc_attr!(rustc_reservation_impl, Normal, template!(NameValueStr: "reservation message"), + "the `#[rustc_reservation_impl]` attribute is internally used \ + for reserving for `for<T> From<!> for T` impl" + ), + rustc_attr!( + rustc_test_marker, Normal, template!(Word), + "the `#[rustc_test_marker]` attribute is used internally to track tests", + ), + rustc_attr!( + rustc_unsafe_specialization_marker, Normal, template!(Word), + "the `#[rustc_unsafe_specialization_marker]` attribute is used to check specializations" + ), + rustc_attr!( + rustc_specialization_trait, Normal, template!(Word), + "the `#[rustc_specialization_trait]` attribute is used to check specializations" + ), + + // ========================================================================== + // Internal attributes, Testing: + // ========================================================================== + + rustc_attr!(TEST, rustc_outlives, Normal, template!(Word)), + rustc_attr!(TEST, rustc_variance, Normal, template!(Word)), + rustc_attr!(TEST, rustc_layout, Normal, template!(List: "field1, field2, ...")), + rustc_attr!(TEST, rustc_regions, Normal, template!(Word)), + rustc_attr!( + TEST, rustc_error, AssumedUsed, + template!(Word, List: "delay_span_bug_from_inside_query") + ), + rustc_attr!(TEST, rustc_dump_user_substs, AssumedUsed, template!(Word)), + rustc_attr!(TEST, rustc_if_this_changed, AssumedUsed, template!(Word, List: "DepNode")), + rustc_attr!(TEST, rustc_then_this_would_need, AssumedUsed, template!(List: "DepNode")), + rustc_attr!( + TEST, rustc_dirty, AssumedUsed, + template!(List: r#"cfg = "...", /*opt*/ label = "...", /*opt*/ except = "...""#), + ), + rustc_attr!( + TEST, rustc_clean, AssumedUsed, + template!(List: r#"cfg = "...", /*opt*/ label = "...", /*opt*/ except = "...""#), + ), + rustc_attr!( + TEST, rustc_partition_reused, AssumedUsed, + template!(List: r#"cfg = "...", module = "...""#), + ), + rustc_attr!( + TEST, rustc_partition_codegened, AssumedUsed, + template!(List: r#"cfg = "...", module = "...""#), + ), + rustc_attr!( + TEST, rustc_expected_cgu_reuse, AssumedUsed, + template!(List: r#"cfg = "...", module = "...", kind = "...""#), + ), + rustc_attr!(TEST, rustc_synthetic, AssumedUsed, template!(Word)), + rustc_attr!(TEST, rustc_symbol_name, AssumedUsed, template!(Word)), + rustc_attr!(TEST, rustc_polymorphize_error, AssumedUsed, template!(Word)), + rustc_attr!(TEST, rustc_def_path, AssumedUsed, template!(Word)), + rustc_attr!(TEST, rustc_mir, AssumedUsed, template!(List: "arg1, arg2, ...")), + rustc_attr!(TEST, rustc_dump_program_clauses, AssumedUsed, template!(Word)), + rustc_attr!(TEST, rustc_dump_env_program_clauses, AssumedUsed, template!(Word)), + rustc_attr!(TEST, rustc_object_lifetime_default, AssumedUsed, template!(Word)), + rustc_attr!(TEST, rustc_dummy, Normal, template!(Word /* doesn't matter*/)), + gated!( + omit_gdb_pretty_printer_section, AssumedUsed, template!(Word), + "the `#[omit_gdb_pretty_printer_section]` attribute is just used for the Rust test suite", + ), +]; + +pub fn deprecated_attributes() -> Vec<&'static BuiltinAttribute> { + BUILTIN_ATTRIBUTES.iter().filter(|(.., gate)| gate.is_deprecated()).collect() +} + +pub fn is_builtin_attr_name(name: Symbol) -> bool { + BUILTIN_ATTRIBUTE_MAP.get(&name).is_some() +} + +lazy_static! { + pub static ref BUILTIN_ATTRIBUTE_MAP: FxHashMap<Symbol, &'static BuiltinAttribute> = { + let mut map = FxHashMap::default(); + for attr in BUILTIN_ATTRIBUTES.iter() { + if map.insert(attr.0, attr).is_some() { + panic!("duplicate builtin attribute `{}`", attr.0); + } + } + map + }; +} diff --git a/compiler/rustc_feature/src/lib.rs b/compiler/rustc_feature/src/lib.rs new file mode 100644 index 00000000000..f8bf0315d0c --- /dev/null +++ b/compiler/rustc_feature/src/lib.rs @@ -0,0 +1,137 @@ +//! # Feature gates +//! +//! This crate declares the set of past and present unstable features in the compiler. +//! Feature gate checking itself is done in `librustc_ast_passes/feature_gate.rs` +//! at the moment. +//! +//! Features are enabled in programs via the crate-level attributes of +//! `#![feature(...)]` with a comma-separated list of features. +//! +//! For the purpose of future feature-tracking, once a feature gate is added, +//! even if it is stabilized or removed, *do not remove it*. Instead, move the +//! symbol to the `accepted` or `removed` modules respectively. + +mod accepted; +mod active; +mod builtin_attrs; +mod removed; + +use rustc_span::{edition::Edition, symbol::Symbol, Span}; +use std::fmt; +use std::num::NonZeroU32; + +#[derive(Clone, Copy)] +pub enum State { + Accepted, + Active { set: fn(&mut Features, Span) }, + Removed { reason: Option<&'static str> }, + Stabilized { reason: Option<&'static str> }, +} + +impl fmt::Debug for State { + fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result { + match self { + State::Accepted { .. } => write!(f, "accepted"), + State::Active { .. } => write!(f, "active"), + State::Removed { .. } => write!(f, "removed"), + State::Stabilized { .. } => write!(f, "stabilized"), + } + } +} + +#[derive(Debug, Clone)] +pub struct Feature { + pub state: State, + pub name: Symbol, + pub since: &'static str, + issue: Option<u32>, // FIXME: once #58732 is done make this an Option<NonZeroU32> + pub edition: Option<Edition>, + description: &'static str, +} + +impl Feature { + fn issue(&self) -> Option<NonZeroU32> { + self.issue.and_then(NonZeroU32::new) + } +} + +#[derive(Copy, Clone, Debug)] +pub enum Stability { + Unstable, + // First argument is tracking issue link; second argument is an optional + // help message, which defaults to "remove this attribute". + Deprecated(&'static str, Option<&'static str>), +} + +#[derive(Clone, Copy, Hash)] +pub enum UnstableFeatures { + /// Hard errors for unstable features are active, as on beta/stable channels. + Disallow, + /// Allow features to be activated, as on nightly. + Allow, + /// Errors are bypassed for bootstrapping. This is required any time + /// during the build that feature-related lints are set to warn or above + /// because the build turns on warnings-as-errors and uses lots of unstable + /// features. As a result, this is always required for building Rust itself. + Cheat, +} + +impl UnstableFeatures { + pub fn from_environment() -> UnstableFeatures { + // `true` if this is a feature-staged build, i.e., on the beta or stable channel. + let disable_unstable_features = option_env!("CFG_DISABLE_UNSTABLE_FEATURES").is_some(); + // `true` if we should enable unstable features for bootstrapping. + let bootstrap = std::env::var("RUSTC_BOOTSTRAP").is_ok(); + match (disable_unstable_features, bootstrap) { + (_, true) => UnstableFeatures::Cheat, + (true, _) => UnstableFeatures::Disallow, + (false, _) => UnstableFeatures::Allow, + } + } + + pub fn is_nightly_build(&self) -> bool { + match *self { + UnstableFeatures::Allow | UnstableFeatures::Cheat => true, + UnstableFeatures::Disallow => false, + } + } +} + +fn find_lang_feature_issue(feature: Symbol) -> Option<NonZeroU32> { + if let Some(info) = ACTIVE_FEATURES.iter().find(|t| t.name == feature) { + // FIXME (#28244): enforce that active features have issue numbers + // assert!(info.issue().is_some()) + info.issue() + } else { + // search in Accepted, Removed, or Stable Removed features + let found = ACCEPTED_FEATURES + .iter() + .chain(REMOVED_FEATURES) + .chain(STABLE_REMOVED_FEATURES) + .find(|t| t.name == feature); + match found { + Some(found) => found.issue(), + None => panic!("feature `{}` is not declared anywhere", feature), + } + } +} + +pub enum GateIssue { + Language, + Library(Option<NonZeroU32>), +} + +pub fn find_feature_issue(feature: Symbol, issue: GateIssue) -> Option<NonZeroU32> { + match issue { + GateIssue::Language => find_lang_feature_issue(feature), + GateIssue::Library(lib) => lib, + } +} + +pub use accepted::ACCEPTED_FEATURES; +pub use active::{Features, ACTIVE_FEATURES, INCOMPLETE_FEATURES}; +pub use builtin_attrs::{ + deprecated_attributes, find_gated_cfg, is_builtin_attr_name, AttributeGate, AttributeTemplate, + AttributeType, BuiltinAttribute, GatedCfg, BUILTIN_ATTRIBUTES, BUILTIN_ATTRIBUTE_MAP, +}; +pub use removed::{REMOVED_FEATURES, STABLE_REMOVED_FEATURES}; diff --git a/compiler/rustc_feature/src/removed.rs b/compiler/rustc_feature/src/removed.rs new file mode 100644 index 00000000000..8d410894e8b --- /dev/null +++ b/compiler/rustc_feature/src/removed.rs @@ -0,0 +1,129 @@ +//! List of the removed feature gates. + +use super::{Feature, State}; +use rustc_span::symbol::sym; + +macro_rules! declare_features { + ($( + $(#[doc = $doc:tt])* (removed, $feature:ident, $ver:expr, $issue:expr, None, $reason:expr), + )+) => { + /// Represents unstable features which have since been removed (it was once Active) + pub const REMOVED_FEATURES: &[Feature] = &[ + $( + Feature { + state: State::Removed { reason: $reason }, + name: sym::$feature, + since: $ver, + issue: $issue, + edition: None, + description: concat!($($doc,)*), + } + ),+ + ]; + }; + + ($( + $(#[doc = $doc:tt])* (stable_removed, $feature:ident, $ver:expr, $issue:expr, None), + )+) => { + /// Represents stable features which have since been removed (it was once Accepted) + pub const STABLE_REMOVED_FEATURES: &[Feature] = &[ + $( + Feature { + state: State::Stabilized { reason: None }, + name: sym::$feature, + since: $ver, + issue: $issue, + edition: None, + description: concat!($($doc,)*), + } + ),+ + ]; + }; +} + +#[rustfmt::skip] +declare_features! ( + // ------------------------------------------------------------------------- + // feature-group-start: removed features + // ------------------------------------------------------------------------- + + (removed, import_shadowing, "1.0.0", None, None, None), + (removed, managed_boxes, "1.0.0", None, None, None), + /// Allows use of unary negate on unsigned integers, e.g., -e for e: u8 + (removed, negate_unsigned, "1.0.0", Some(29645), None, None), + (removed, reflect, "1.0.0", Some(27749), None, None), + /// A way to temporarily opt out of opt in copy. This will *never* be accepted. + (removed, opt_out_copy, "1.0.0", None, None, None), + (removed, quad_precision_float, "1.0.0", None, None, None), + (removed, struct_inherit, "1.0.0", None, None, None), + (removed, test_removed_feature, "1.0.0", None, None, None), + (removed, visible_private_types, "1.0.0", None, None, None), + (removed, unsafe_no_drop_flag, "1.0.0", None, None, None), + /// Allows using items which are missing stability attributes + (removed, unmarked_api, "1.0.0", None, None, None), + (removed, allocator, "1.0.0", None, None, None), + (removed, simd, "1.0.0", Some(27731), None, + Some("removed in favor of `#[repr(simd)]`")), + (removed, advanced_slice_patterns, "1.0.0", Some(62254), None, + Some("merged into `#![feature(slice_patterns)]`")), + (removed, macro_reexport, "1.0.0", Some(29638), None, + Some("subsumed by `pub use`")), + /// Allows using custom attributes (RFC 572). + (removed, custom_attribute, "1.0.0", Some(29642), None, + Some("removed in favor of `#![register_tool]` and `#![register_attr]`")), + (removed, pushpop_unsafe, "1.2.0", None, None, None), + (removed, needs_allocator, "1.4.0", Some(27389), None, + Some("subsumed by `#![feature(allocator_internals)]`")), + /// Allows identifying crates that contain sanitizer runtimes. + (removed, sanitizer_runtime, "1.17.0", None, None, None), + (removed, proc_macro_mod, "1.27.0", Some(54727), None, + Some("subsumed by `#![feature(proc_macro_hygiene)]`")), + (removed, proc_macro_expr, "1.27.0", Some(54727), None, + Some("subsumed by `#![feature(proc_macro_hygiene)]`")), + (removed, proc_macro_non_items, "1.27.0", Some(54727), None, + Some("subsumed by `#![feature(proc_macro_hygiene)]`")), + (removed, proc_macro_gen, "1.27.0", Some(54727), None, + Some("subsumed by `#![feature(proc_macro_hygiene)]`")), + (removed, panic_implementation, "1.28.0", Some(44489), None, + Some("subsumed by `#[panic_handler]`")), + /// Allows the use of `#[derive(Anything)]` as sugar for `#[derive_Anything]`. + (removed, custom_derive, "1.32.0", Some(29644), None, + Some("subsumed by `#[proc_macro_derive]`")), + /// Paths of the form: `extern::foo::bar` + (removed, extern_in_paths, "1.33.0", Some(55600), None, + Some("subsumed by `::foo::bar` paths")), + (removed, quote, "1.33.0", Some(29601), None, None), + /// Allows using `#[unsafe_destructor_blind_to_params]` (RFC 1238). + (removed, dropck_parametricity, "1.38.0", Some(28498), None, None), + (removed, await_macro, "1.38.0", Some(50547), None, + Some("subsumed by `.await` syntax")), + /// Allows defining `existential type`s. + (removed, existential_type, "1.38.0", Some(63063), None, + Some("removed in favor of `#![feature(type_alias_impl_trait)]`")), + /// Allows using the macros: + /// + `__diagnostic_used` + /// + `__register_diagnostic` + /// +`__build_diagnostic_array` + (removed, rustc_diagnostic_macros, "1.38.0", None, None, None), + /// Allows using `#[on_unimplemented(..)]` on traits. + /// (Moved to `rustc_attrs`.) + (removed, on_unimplemented, "1.40.0", None, None, None), + /// Allows overlapping impls of marker traits. + (removed, overlapping_marker_traits, "1.42.0", Some(29864), None, + Some("removed in favor of `#![feature(marker_trait_attr)]`")), + /// Allows `#[no_debug]`. + (removed, no_debug, "1.43.0", Some(29721), None, Some("removed due to lack of demand")), + + /// Allows comparing raw pointers during const eval. + (removed, const_compare_raw_pointers, "1.46.0", Some(53020), None, + Some("cannot be allowed in const eval in any meaningful way")), + + // ------------------------------------------------------------------------- + // feature-group-end: removed features + // ------------------------------------------------------------------------- +); + +#[rustfmt::skip] +declare_features! ( + (stable_removed, no_stack_check, "1.0.0", None, None), +); |