| //! Built-in attributes and `cfg` flag gating. |
| |
| use AttributeDuplicates::*; |
| use AttributeGate::*; |
| use AttributeType::*; |
| |
| use crate::{Features, Stability}; |
| |
| use rustc_data_structures::fx::FxHashMap; |
| use rustc_span::symbol::{sym, Symbol}; |
| |
| use std::sync::LazyLock; |
| |
| 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::overflow_checks, sym::cfg_overflow_checks, cfg_fn!(cfg_overflow_checks)), |
| (sym::target_thread_local, sym::cfg_target_thread_local, cfg_fn!(cfg_target_thread_local)), |
| ( |
| sym::target_has_atomic_equal_alignment, |
| sym::cfg_target_has_atomic_equal_alignment, |
| cfg_fn!(cfg_target_has_atomic_equal_alignment), |
| ), |
| (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)), |
| (sym::relocation_model, sym::cfg_relocation_model, cfg_fn!(cfg_relocation_model)), |
| (sym::sanitizer_cfi_generalize_pointers, sym::cfg_sanitizer_cfi, cfg_fn!(cfg_sanitizer_cfi)), |
| (sym::sanitizer_cfi_normalize_integers, sym::cfg_sanitizer_cfi, cfg_fn!(cfg_sanitizer_cfi)), |
| ]; |
| |
| /// 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 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 { |
| matches!(*self, Self::Gated(Stability::Deprecated(_, _), ..)) |
| } |
| } |
| |
| /// 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 { |
| /// If `true`, the attribute is allowed to be a bare word like `#[test]`. |
| pub word: bool, |
| /// If `Some`, the attribute is allowed to take a list of items like `#[allow(..)]`. |
| pub list: Option<&'static str>, |
| /// If `Some`, the attribute is allowed to be a name/value pair where the |
| /// value is a string, like `#[must_use = "reason"]`. |
| pub name_value_str: Option<&'static str>, |
| } |
| |
| /// How to handle multiple duplicate attributes on the same item. |
| #[derive(Clone, Copy, Default)] |
| pub enum AttributeDuplicates { |
| /// Duplicates of this attribute are allowed. |
| /// |
| /// This should only be used with attributes where duplicates have semantic |
| /// meaning, or some kind of "additive" behavior. For example, `#[warn(..)]` |
| /// can be specified multiple times, and it combines all the entries. Or use |
| /// this if there is validation done elsewhere. |
| #[default] |
| DuplicatesOk, |
| /// Duplicates after the first attribute will be an unused_attribute warning. |
| /// |
| /// This is usually used for "word" attributes, where they are used as a |
| /// boolean marker, like `#[used]`. It is not necessarily wrong that there |
| /// are duplicates, but the others should probably be removed. |
| WarnFollowing, |
| /// Same as `WarnFollowing`, but only issues warnings for word-style attributes. |
| /// |
| /// This is only for special cases, for example multiple `#[macro_use]` can |
| /// be warned, but multiple `#[macro_use(...)]` should not because the list |
| /// form has different meaning from the word form. |
| WarnFollowingWordOnly, |
| /// Duplicates after the first attribute will be an error. |
| /// |
| /// This should be used where duplicates would be ignored, but carry extra |
| /// meaning that could cause confusion. For example, `#[stable(since="1.0")] |
| /// #[stable(since="2.0")]`, which version should be used for `stable`? |
| ErrorFollowing, |
| /// Duplicates preceding the last instance of the attribute will be an error. |
| /// |
| /// This is the same as `ErrorFollowing`, except the last attribute is the |
| /// one that is "used". This is typically used in cases like codegen |
| /// attributes which usually only honor the last attribute. |
| ErrorPreceding, |
| /// Duplicates after the first attribute will be an unused_attribute warning |
| /// with a note that this will be an error in the future. |
| /// |
| /// This should be used for attributes that should be `ErrorFollowing`, but |
| /// because older versions of rustc silently accepted (and ignored) the |
| /// attributes, this is used to transition. |
| FutureWarnFollowing, |
| /// Duplicates preceding the last instance of the attribute will be a |
| /// warning, with a note that this will be an error in the future. |
| /// |
| /// This is the same as `FutureWarnFollowing`, except the last attribute is |
| /// the one that is "used". Ideally these can eventually migrate to |
| /// `ErrorPreceding`. |
| FutureWarnPreceding, |
| } |
| |
| /// A convenience macro to deal with `$($expr)?`. |
| macro_rules! or_default { |
| ($default:expr,) => { |
| $default |
| }; |
| ($default:expr, $next:expr) => { |
| $next |
| }; |
| } |
| |
| /// 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, $duplicates:expr $(, @only_local: $only_local:expr)? $(,)?) => { |
| BuiltinAttribute { |
| name: sym::$attr, |
| only_local: or_default!(false, $($only_local)?), |
| type_: $typ, |
| template: $tpl, |
| gate: Ungated, |
| duplicates: $duplicates, |
| } |
| }; |
| } |
| |
| macro_rules! gated { |
| ($attr:ident, $typ:expr, $tpl:expr, $duplicates:expr $(, @only_local: $only_local:expr)?, $gate:ident, $msg:expr $(,)?) => { |
| BuiltinAttribute { |
| name: sym::$attr, |
| only_local: or_default!(false, $($only_local)?), |
| type_: $typ, |
| template: $tpl, |
| duplicates: $duplicates, |
| gate: Gated(Stability::Unstable, sym::$gate, $msg, cfg_fn!($gate)), |
| } |
| }; |
| ($attr:ident, $typ:expr, $tpl:expr, $duplicates:expr $(, @only_local: $only_local:expr)?, $msg:expr $(,)?) => { |
| BuiltinAttribute { |
| name: sym::$attr, |
| only_local: or_default!(false, $($only_local)?), |
| type_: $typ, |
| template: $tpl, |
| duplicates: $duplicates, |
| gate: Gated(Stability::Unstable, sym::$attr, $msg, cfg_fn!($attr)), |
| } |
| }; |
| } |
| |
| macro_rules! rustc_attr { |
| (TEST, $attr:ident, $typ:expr, $tpl:expr, $duplicate:expr $(, @only_local: $only_local:expr)? $(,)?) => { |
| rustc_attr!( |
| $attr, |
| $typ, |
| $tpl, |
| $duplicate, |
| $(@only_local: $only_local,)? |
| concat!( |
| "the `#[", |
| stringify!($attr), |
| "]` attribute is just used for rustc unit tests \ |
| and will never be stable", |
| ), |
| ) |
| }; |
| ($attr:ident, $typ:expr, $tpl:expr, $duplicates:expr $(, @only_local: $only_local:expr)?, $msg:expr $(,)?) => { |
| BuiltinAttribute { |
| name: sym::$attr, |
| only_local: or_default!(false, $($only_local)?), |
| type_: $typ, |
| template: $tpl, |
| duplicates: $duplicates, |
| gate: 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 struct BuiltinAttribute { |
| pub name: Symbol, |
| /// Whether this attribute is only used in the local crate. |
| /// |
| /// If so, it is not encoded in the crate metadata. |
| pub only_local: bool, |
| pub type_: AttributeType, |
| pub template: AttributeTemplate, |
| pub duplicates: AttributeDuplicates, |
| pub gate: 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"), DuplicatesOk), |
| ungated!(cfg_attr, Normal, template!(List: "predicate, attr1, attr2, ..."), DuplicatesOk), |
| |
| // Testing: |
| ungated!( |
| ignore, Normal, template!(Word, NameValueStr: "reason"), WarnFollowing, |
| @only_local: true, |
| ), |
| ungated!( |
| should_panic, Normal, |
| template!(Word, List: r#"expected = "reason""#, NameValueStr: "reason"), FutureWarnFollowing, |
| @only_local: true, |
| ), |
| // FIXME(Centril): This can be used on stable but shouldn't. |
| ungated!( |
| reexport_test_harness_main, CrateLevel, template!(NameValueStr: "name"), ErrorFollowing, |
| @only_local: true, |
| ), |
| |
| // Macros: |
| ungated!(automatically_derived, Normal, template!(Word), WarnFollowing), |
| ungated!( |
| macro_use, Normal, template!(Word, List: "name1, name2, ..."), WarnFollowingWordOnly, |
| @only_local: true, |
| ), |
| ungated!(macro_escape, Normal, template!(Word), WarnFollowing, @only_local: true), // Deprecated synonym for `macro_use`. |
| ungated!(macro_export, Normal, template!(Word, List: "local_inner_macros"), WarnFollowing), |
| ungated!(proc_macro, Normal, template!(Word), ErrorFollowing, @only_local: true), |
| ungated!( |
| proc_macro_derive, Normal, template!(List: "TraitName, /*opt*/ attributes(name1, name2, ...)"), |
| ErrorFollowing, @only_local: true, |
| ), |
| ungated!(proc_macro_attribute, Normal, template!(Word), ErrorFollowing, @only_local: true), |
| |
| // Lints: |
| ungated!( |
| warn, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), |
| DuplicatesOk, @only_local: true, |
| ), |
| ungated!( |
| allow, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), |
| DuplicatesOk, @only_local: true, |
| ), |
| gated!( |
| expect, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), DuplicatesOk, |
| @only_local: true, lint_reasons, experimental!(expect) |
| ), |
| ungated!( |
| forbid, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), |
| DuplicatesOk, @only_local: true, |
| ), |
| ungated!( |
| deny, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), |
| DuplicatesOk, @only_local: true, |
| ), |
| ungated!(must_use, Normal, template!(Word, NameValueStr: "reason"), FutureWarnFollowing), |
| gated!( |
| must_not_suspend, Normal, template!(Word, NameValueStr: "reason"), WarnFollowing, |
| experimental!(must_not_suspend) |
| ), |
| ungated!( |
| deprecated, Normal, |
| template!( |
| Word, |
| List: r#"/*opt*/ since = "version", /*opt*/ note = "reason""#, |
| NameValueStr: "reason" |
| ), |
| ErrorFollowing |
| ), |
| |
| // Crate properties: |
| ungated!( |
| crate_name, CrateLevel, template!(NameValueStr: "name"), FutureWarnFollowing, |
| @only_local: true, |
| ), |
| ungated!( |
| crate_type, CrateLevel, template!(NameValueStr: "bin|lib|..."), DuplicatesOk, |
| @only_local: true, |
| ), |
| // crate_id is deprecated |
| ungated!( |
| crate_id, CrateLevel, template!(NameValueStr: "ignored"), FutureWarnFollowing, |
| @only_local: true, |
| ), |
| |
| // ABI, linking, symbols, and FFI |
| ungated!( |
| link, Normal, |
| template!(List: r#"name = "...", /*opt*/ kind = "dylib|static|...", /*opt*/ wasm_import_module = "...", /*opt*/ import_name_type = "decorated|noprefix|undecorated""#), |
| DuplicatesOk, |
| @only_local: true, |
| ), |
| ungated!(link_name, Normal, template!(NameValueStr: "name"), FutureWarnPreceding), |
| ungated!(no_link, Normal, template!(Word), WarnFollowing, @only_local: true), |
| ungated!(repr, Normal, template!(List: "C"), DuplicatesOk, @only_local: true), |
| ungated!(export_name, Normal, template!(NameValueStr: "name"), FutureWarnPreceding, @only_local: true), |
| ungated!(link_section, Normal, template!(NameValueStr: "name"), FutureWarnPreceding, @only_local: true), |
| ungated!(no_mangle, Normal, template!(Word), WarnFollowing, @only_local: true), |
| ungated!(used, Normal, template!(Word, List: "compiler|linker"), WarnFollowing, @only_local: true), |
| ungated!(link_ordinal, Normal, template!(List: "ordinal"), ErrorPreceding), |
| |
| // Limits: |
| ungated!( |
| recursion_limit, CrateLevel, template!(NameValueStr: "N"), FutureWarnFollowing, |
| @only_local: true |
| ), |
| ungated!( |
| type_length_limit, CrateLevel, template!(NameValueStr: "N"), FutureWarnFollowing, |
| @only_local: true |
| ), |
| gated!( |
| move_size_limit, CrateLevel, template!(NameValueStr: "N"), ErrorFollowing, |
| @only_local: true, large_assignments, experimental!(move_size_limit) |
| ), |
| |
| // Entry point: |
| gated!(unix_sigpipe, Normal, template!(NameValueStr: "inherit|sig_ign|sig_dfl"), ErrorFollowing, experimental!(unix_sigpipe)), |
| ungated!(start, Normal, template!(Word), WarnFollowing, @only_local: true), |
| ungated!(no_start, CrateLevel, template!(Word), WarnFollowing, @only_local: true), |
| ungated!(no_main, CrateLevel, template!(Word), WarnFollowing, @only_local: true), |
| |
| // Modules, prelude, and resolution: |
| ungated!(path, Normal, template!(NameValueStr: "file"), FutureWarnFollowing, @only_local: true), |
| ungated!(no_std, CrateLevel, template!(Word), WarnFollowing, @only_local: true), |
| ungated!(no_implicit_prelude, Normal, template!(Word), WarnFollowing, @only_local: true), |
| ungated!(non_exhaustive, Normal, template!(Word), WarnFollowing), |
| |
| // Runtime |
| ungated!( |
| windows_subsystem, CrateLevel, |
| template!(NameValueStr: "windows|console"), FutureWarnFollowing, |
| @only_local: true |
| ), |
| ungated!(panic_handler, Normal, template!(Word), WarnFollowing), // RFC 2070 |
| |
| // Code generation: |
| ungated!(inline, Normal, template!(Word, List: "always|never"), FutureWarnFollowing, @only_local: true), |
| ungated!(cold, Normal, template!(Word), WarnFollowing, @only_local: true), |
| ungated!(no_builtins, CrateLevel, template!(Word), WarnFollowing), |
| ungated!( |
| target_feature, Normal, template!(List: r#"enable = "name""#), |
| DuplicatesOk, @only_local: true, |
| ), |
| ungated!(track_caller, Normal, template!(Word), WarnFollowing), |
| ungated!(instruction_set, Normal, template!(List: "set"), ErrorPreceding, @only_local: true), |
| gated!( |
| no_sanitize, Normal, |
| template!(List: "address, kcfi, memory, thread"), DuplicatesOk, |
| @only_local: true, experimental!(no_sanitize) |
| ), |
| gated!( |
| coverage, Normal, template!(Word, List: "on|off"), |
| WarnFollowing, @only_local: true, |
| coverage_attribute, experimental!(coverage) |
| ), |
| |
| ungated!( |
| doc, Normal, template!(List: "hidden|inline|...", NameValueStr: "string"), DuplicatesOk |
| ), |
| |
| // Debugging |
| ungated!( |
| debugger_visualizer, Normal, |
| template!(List: r#"natvis_file = "...", gdb_script_file = "...""#), |
| DuplicatesOk, @only_local: true |
| ), |
| |
| // ========================================================================== |
| // Unstable attributes: |
| // ========================================================================== |
| |
| // Linking: |
| gated!( |
| naked, Normal, template!(Word), WarnFollowing, @only_local: true, |
| naked_functions, experimental!(naked) |
| ), |
| |
| // Testing: |
| gated!( |
| test_runner, CrateLevel, template!(List: "path"), ErrorFollowing, custom_test_frameworks, |
| "custom test frameworks are an unstable feature", |
| ), |
| // RFC #1268 |
| gated!( |
| marker, Normal, template!(Word), WarnFollowing, @only_local: true, |
| marker_trait_attr, experimental!(marker) |
| ), |
| gated!( |
| thread_local, Normal, template!(Word), WarnFollowing, @only_local: true, |
| "`#[thread_local]` is an experimental feature, and does not currently handle destructors", |
| ), |
| gated!( |
| no_core, CrateLevel, template!(Word), WarnFollowing, |
| @only_local: true, experimental!(no_core) |
| ), |
| // RFC 2412 |
| gated!( |
| optimize, Normal, template!(List: "size|speed"), ErrorPreceding, |
| @only_local: true, optimize_attribute, experimental!(optimize) |
| ), |
| |
| gated!( |
| ffi_pure, Normal, template!(Word), WarnFollowing, |
| @only_local: true, experimental!(ffi_pure) |
| ), |
| gated!( |
| ffi_const, Normal, template!(Word), WarnFollowing, |
| @only_local: true, experimental!(ffi_const) |
| ), |
| gated!( |
| register_tool, CrateLevel, template!(List: "tool1, tool2, ..."), DuplicatesOk, |
| @only_local: true, experimental!(register_tool), |
| ), |
| |
| gated!( |
| cmse_nonsecure_entry, Normal, template!(Word), WarnFollowing, |
| @only_local: true, experimental!(cmse_nonsecure_entry) |
| ), |
| // RFC 2632 |
| gated!( |
| const_trait, Normal, template!(Word), WarnFollowing, const_trait_impl, |
| "`const_trait` is a temporary placeholder for marking a trait that is suitable for `const` \ |
| `impls` and all default bodies as `const`, which may be removed or renamed in the \ |
| future." |
| ), |
| // lang-team MCP 147 |
| gated!( |
| deprecated_safe, Normal, template!(List: r#"since = "version", note = "...""#), ErrorFollowing, |
| experimental!(deprecated_safe), |
| ), |
| |
| // `#[collapse_debuginfo]` |
| gated!( |
| collapse_debuginfo, Normal, template!(Word, List: "no|external|yes"), ErrorFollowing, |
| @only_local: true, experimental!(collapse_debuginfo) |
| ), |
| |
| // RFC 2397 |
| gated!( |
| do_not_recommend, Normal, template!(Word), WarnFollowing, |
| @only_local: true, experimental!(do_not_recommend) |
| ), |
| |
| // `#[cfi_encoding = ""]` |
| gated!( |
| cfi_encoding, Normal, template!(NameValueStr: "encoding"), ErrorPreceding, |
| experimental!(cfi_encoding) |
| ), |
| |
| // ========================================================================== |
| // Internal attributes: Stability, deprecation, and unsafe: |
| // ========================================================================== |
| |
| ungated!( |
| feature, CrateLevel, |
| template!(List: "name1, name2, ..."), DuplicatesOk, @only_local: true, |
| ), |
| // DuplicatesOk since it has its own validation |
| ungated!( |
| stable, Normal, |
| template!(List: r#"feature = "name", since = "version""#), DuplicatesOk, @only_local: true, |
| ), |
| ungated!( |
| unstable, Normal, |
| template!(List: r#"feature = "name", reason = "...", issue = "N""#), DuplicatesOk, |
| ), |
| ungated!(rustc_const_unstable, Normal, template!(List: r#"feature = "name""#), DuplicatesOk), |
| ungated!( |
| rustc_const_stable, Normal, |
| template!(List: r#"feature = "name""#), DuplicatesOk, @only_local: true, |
| ), |
| ungated!( |
| rustc_default_body_unstable, Normal, |
| template!(List: r#"feature = "name", reason = "...", issue = "N""#), |
| DuplicatesOk, @only_local: true |
| ), |
| gated!( |
| allow_internal_unstable, Normal, template!(Word, List: "feat1, feat2, ..."), DuplicatesOk, |
| "allow_internal_unstable side-steps feature gating and stability checks", |
| ), |
| gated!( |
| rustc_allow_const_fn_unstable, Normal, |
| template!(Word, List: "feat1, feat2, ..."), DuplicatesOk, @only_local: true, |
| "rustc_allow_const_fn_unstable side-steps feature gating and stability checks" |
| ), |
| gated!( |
| allow_internal_unsafe, Normal, template!(Word), WarnFollowing, |
| @only_local: true, "allow_internal_unsafe side-steps the unsafe_code lint", |
| ), |
| rustc_attr!( |
| rustc_allowed_through_unstable_modules, Normal, template!(Word), |
| WarnFollowing, @only_local: true, |
| "rustc_allowed_through_unstable_modules special cases accidental stabilizations of stable items \ |
| through unstable paths" |
| ), |
| |
| // ========================================================================== |
| // Internal attributes: Type system related: |
| // ========================================================================== |
| |
| gated!(fundamental, Normal, template!(Word), WarnFollowing, experimental!(fundamental)), |
| gated!( |
| may_dangle, Normal, template!(Word), WarnFollowing, |
| @only_local: true, dropck_eyepatch, |
| "`may_dangle` has unstable semantics and may be removed in the future", |
| ), |
| |
| rustc_attr!( |
| rustc_never_type_mode, Normal, template!(NameValueStr: "fallback_to_unit|fallback_to_niko|fallback_to_never|no_fallback"), ErrorFollowing, |
| @only_local: true, |
| "`rustc_never_type_fallback` is used to experiment with never type fallback and work on \ |
| never type stabilization, and will never be stable" |
| ), |
| |
| // ========================================================================== |
| // Internal attributes: Runtime related: |
| // ========================================================================== |
| |
| rustc_attr!( |
| rustc_allocator, Normal, template!(Word), WarnFollowing, |
| @only_local: true, IMPL_DETAIL |
| ), |
| rustc_attr!( |
| rustc_nounwind, Normal, template!(Word), WarnFollowing, |
| @only_local: true, IMPL_DETAIL |
| ), |
| rustc_attr!( |
| rustc_reallocator, Normal, template!(Word), WarnFollowing, |
| @only_local: true, IMPL_DETAIL |
| ), |
| rustc_attr!( |
| rustc_deallocator, Normal, template!(Word), WarnFollowing, |
| @only_local: true, IMPL_DETAIL |
| ), |
| rustc_attr!( |
| rustc_allocator_zeroed, Normal, template!(Word), WarnFollowing, |
| @only_local: true, IMPL_DETAIL |
| ), |
| gated!( |
| default_lib_allocator, Normal, template!(Word), WarnFollowing, |
| @only_local: true, allocator_internals, experimental!(default_lib_allocator), |
| ), |
| gated!( |
| needs_allocator, Normal, template!(Word), WarnFollowing, |
| @only_local: true, allocator_internals, experimental!(needs_allocator), |
| ), |
| gated!( |
| panic_runtime, Normal, template!(Word), WarnFollowing, |
| @only_local: true, experimental!(panic_runtime) |
| ), |
| gated!( |
| needs_panic_runtime, Normal, template!(Word), WarnFollowing, |
| @only_local: true, experimental!(needs_panic_runtime) |
| ), |
| gated!( |
| compiler_builtins, Normal, template!(Word), WarnFollowing, |
| @only_local: true, |
| "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, Normal, template!(Word), WarnFollowing, |
| @only_local: true, |
| "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, Normal, template!(NameValueStr: "external|internal|..."), ErrorPreceding, @only_local: true, |
| "the `linkage` attribute is experimental and not portable across platforms", |
| ), |
| rustc_attr!( |
| rustc_std_internal_symbol, Normal, template!(Word), WarnFollowing, @only_local: true, INTERNAL_UNSTABLE |
| ), |
| |
| // ========================================================================== |
| // Internal attributes, Macro related: |
| // ========================================================================== |
| |
| rustc_attr!( |
| rustc_builtin_macro, Normal, |
| template!(Word, List: "name, /*opt*/ attributes(name1, name2, ...)"), ErrorFollowing, |
| IMPL_DETAIL, |
| ), |
| rustc_attr!( |
| rustc_proc_macro_decls, Normal, template!(Word), WarnFollowing, |
| @only_local: true, INTERNAL_UNSTABLE |
| ), |
| rustc_attr!( |
| rustc_macro_transparency, Normal, |
| template!(NameValueStr: "transparent|semitransparent|opaque"), ErrorFollowing, |
| "used internally for testing macro hygiene", |
| ), |
| |
| // ========================================================================== |
| // Internal attributes, Diagnostics related: |
| // ========================================================================== |
| |
| rustc_attr!( |
| rustc_on_unimplemented, Normal, |
| template!( |
| List: r#"/*opt*/ message = "...", /*opt*/ label = "...", /*opt*/ note = "...""#, |
| NameValueStr: "message" |
| ), |
| ErrorFollowing, |
| INTERNAL_UNSTABLE |
| ), |
| rustc_attr!( |
| rustc_confusables, Normal, |
| template!(List: r#""name1", "name2", ..."#), |
| ErrorFollowing, |
| INTERNAL_UNSTABLE, |
| ), |
| // Enumerates "identity-like" conversion methods to suggest on type mismatch. |
| rustc_attr!( |
| rustc_conversion_suggestion, Normal, template!(Word), WarnFollowing, INTERNAL_UNSTABLE |
| ), |
| // Prevents field reads in the marked trait or method to be considered |
| // during dead code analysis. |
| rustc_attr!( |
| rustc_trivial_field_reads, Normal, template!(Word), WarnFollowing, INTERNAL_UNSTABLE |
| ), |
| // Used by the `rustc::potential_query_instability` lint to warn methods which |
| // might not be stable during incremental compilation. |
| rustc_attr!(rustc_lint_query_instability, Normal, template!(Word), WarnFollowing, INTERNAL_UNSTABLE), |
| // Used by the `rustc::diagnostic_outside_of_impl` lints to assist in changes to diagnostic |
| // APIs. Any function with this attribute will be checked by that lint. |
| rustc_attr!(rustc_lint_diagnostics, Normal, template!(Word), WarnFollowing, INTERNAL_UNSTABLE), |
| // Used by the `rustc::bad_opt_access` lint to identify `DebuggingOptions` and `CodegenOptions` |
| // types (as well as any others in future). |
| rustc_attr!(rustc_lint_opt_ty, Normal, template!(Word), WarnFollowing, INTERNAL_UNSTABLE), |
| // Used by the `rustc::bad_opt_access` lint on fields |
| // types (as well as any others in future). |
| rustc_attr!(rustc_lint_opt_deny_field_access, Normal, template!(List: "message"), WarnFollowing, INTERNAL_UNSTABLE), |
| |
| // ========================================================================== |
| // Internal attributes, Const related: |
| // ========================================================================== |
| |
| rustc_attr!( |
| rustc_promotable, Normal, template!(Word), WarnFollowing, |
| @only_local: true, IMPL_DETAIL), |
| rustc_attr!( |
| rustc_legacy_const_generics, Normal, template!(List: "N"), ErrorFollowing, |
| INTERNAL_UNSTABLE |
| ), |
| // Do not const-check this function's body. It will always get replaced during CTFE. |
| rustc_attr!( |
| rustc_do_not_const_check, Normal, template!(Word), WarnFollowing, INTERNAL_UNSTABLE |
| ), |
| // Ensure the argument to this function is &&str during const-check. |
| rustc_attr!( |
| rustc_const_panic_str, Normal, template!(Word), WarnFollowing, INTERNAL_UNSTABLE |
| ), |
| |
| // ========================================================================== |
| // Internal attributes, Layout related: |
| // ========================================================================== |
| |
| rustc_attr!( |
| rustc_layout_scalar_valid_range_start, Normal, template!(List: "value"), ErrorFollowing, |
| "the `#[rustc_layout_scalar_valid_range_start]` attribute is just used to enable \ |
| niche optimizations in libcore and libstd and will never be stable", |
| ), |
| rustc_attr!( |
| rustc_layout_scalar_valid_range_end, Normal, template!(List: "value"), ErrorFollowing, |
| "the `#[rustc_layout_scalar_valid_range_end]` attribute is just used to enable \ |
| niche optimizations in libcore and libstd and will never be stable", |
| ), |
| rustc_attr!( |
| rustc_nonnull_optimization_guaranteed, Normal, template!(Word), WarnFollowing, |
| "the `#[rustc_nonnull_optimization_guaranteed]` attribute is just used to enable \ |
| niche optimizations in libcore and libstd and will never be stable", |
| ), |
| |
| // ========================================================================== |
| // Internal attributes, Misc: |
| // ========================================================================== |
| gated!( |
| lang, Normal, template!(NameValueStr: "name"), DuplicatesOk, @only_local: true, lang_items, |
| "language items are subject to change", |
| ), |
| rustc_attr!( |
| rustc_pass_by_value, Normal, template!(Word), ErrorFollowing, |
| "#[rustc_pass_by_value] is used to mark types that must be passed by value instead of reference." |
| ), |
| rustc_attr!( |
| rustc_never_returns_null_ptr, Normal, template!(Word), ErrorFollowing, |
| "#[rustc_never_returns_null_ptr] is used to mark functions returning non-null pointers." |
| ), |
| rustc_attr!( |
| rustc_coherence_is_core, AttributeType::CrateLevel, template!(Word), ErrorFollowing, @only_local: true, |
| "#![rustc_coherence_is_core] allows inherent methods on builtin types, only intended to be used in `core`." |
| ), |
| rustc_attr!( |
| rustc_coinductive, AttributeType::Normal, template!(Word), WarnFollowing, @only_local: true, |
| "#![rustc_coinductive] changes a trait to be coinductive, allowing cycles in the trait solver." |
| ), |
| rustc_attr!( |
| rustc_allow_incoherent_impl, AttributeType::Normal, template!(Word), ErrorFollowing, @only_local: true, |
| "#[rustc_allow_incoherent_impl] has to be added to all impl items of an incoherent inherent impl." |
| ), |
| rustc_attr!( |
| rustc_deny_explicit_impl, |
| AttributeType::Normal, |
| template!(List: "implement_via_object = (true|false)"), |
| ErrorFollowing, |
| @only_local: true, |
| "#[rustc_deny_explicit_impl] enforces that a trait can have no user-provided impls" |
| ), |
| rustc_attr!( |
| rustc_has_incoherent_inherent_impls, AttributeType::Normal, template!(Word), ErrorFollowing, |
| "#[rustc_has_incoherent_inherent_impls] allows the addition of incoherent inherent impls for \ |
| the given type by annotating all impl items with #[rustc_allow_incoherent_impl]." |
| ), |
| rustc_attr!( |
| rustc_box, AttributeType::Normal, template!(Word), ErrorFollowing, @only_local: true, |
| "#[rustc_box] allows creating boxes \ |
| and it is only intended to be used in `alloc`." |
| ), |
| |
| BuiltinAttribute { |
| name: sym::rustc_diagnostic_item, |
| // FIXME: This can be `true` once we always use `tcx.is_diagnostic_item`. |
| only_local: false, |
| type_: Normal, |
| template: template!(NameValueStr: "name"), |
| duplicates: ErrorFollowing, |
| gate: Gated( |
| Stability::Unstable, |
| sym::rustc_attrs, |
| "diagnostic items compiler internal support for linting", |
| cfg_fn!(rustc_attrs), |
| ), |
| }, |
| gated!( |
| // Used in resolve: |
| prelude_import, Normal, template!(Word), WarnFollowing, |
| @only_local: true, "`#[prelude_import]` is for use by rustc only", |
| ), |
| gated!( |
| rustc_paren_sugar, Normal, template!(Word), WarnFollowing, @only_local: true, |
| unboxed_closures, "unboxed_closures are still evolving", |
| ), |
| rustc_attr!( |
| rustc_inherit_overflow_checks, Normal, template!(Word), WarnFollowing, @only_local: true, |
| "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"), ErrorFollowing, |
| "the `#[rustc_reservation_impl]` attribute is internally used \ |
| for reserving for `for<T> From<!> for T` impl" |
| ), |
| rustc_attr!( |
| rustc_test_marker, Normal, template!(NameValueStr: "name"), WarnFollowing, |
| @only_local: true, "the `#[rustc_test_marker]` attribute is used internally to track tests", |
| ), |
| rustc_attr!( |
| rustc_unsafe_specialization_marker, Normal, template!(Word), |
| WarnFollowing, @only_local: true, |
| "the `#[rustc_unsafe_specialization_marker]` attribute is used to check specializations" |
| ), |
| rustc_attr!( |
| rustc_specialization_trait, Normal, template!(Word), |
| WarnFollowing, @only_local: true, |
| "the `#[rustc_specialization_trait]` attribute is used to check specializations" |
| ), |
| rustc_attr!( |
| rustc_main, Normal, template!(Word), WarnFollowing, @only_local: true, |
| "the `#[rustc_main]` attribute is used internally to specify test entry point function", |
| ), |
| rustc_attr!( |
| rustc_skip_array_during_method_dispatch, Normal, template!(Word), |
| WarnFollowing, @only_local: true, |
| "the `#[rustc_skip_array_during_method_dispatch]` attribute is used to exclude a trait \ |
| from method dispatch when the receiver is an array, for compatibility in editions < 2021." |
| ), |
| rustc_attr!( |
| rustc_must_implement_one_of, Normal, template!(List: "function1, function2, ..."), |
| ErrorFollowing, @only_local: true, |
| "the `#[rustc_must_implement_one_of]` attribute is used to change minimal complete \ |
| definition of a trait, it's currently in experimental form and should be changed before \ |
| being exposed outside of the std" |
| ), |
| rustc_attr!( |
| rustc_doc_primitive, Normal, template!(NameValueStr: "primitive name"), ErrorFollowing, |
| r#"`rustc_doc_primitive` is a rustc internal attribute"#, |
| ), |
| rustc_attr!( |
| rustc_safe_intrinsic, Normal, template!(Word), WarnFollowing, |
| @only_local: true, |
| "the `#[rustc_safe_intrinsic]` attribute is used internally to mark intrinsics as safe" |
| ), |
| rustc_attr!( |
| rustc_intrinsic, Normal, template!(Word), ErrorFollowing, |
| "the `#[rustc_intrinsic]` attribute is used to declare intrinsics with function bodies", |
| ), |
| rustc_attr!( |
| rustc_no_mir_inline, Normal, template!(Word), WarnFollowing, |
| "#[rustc_no_mir_inline] prevents the MIR inliner from inlining a function while not affecting codegen" |
| ), |
| rustc_attr!( |
| rustc_intrinsic_must_be_overridden, Normal, template!(Word), ErrorFollowing, |
| "the `#[rustc_intrinsic_must_be_overridden]` attribute is used to declare intrinsics without real bodies", |
| ), |
| |
| // ========================================================================== |
| // Internal attributes, Testing: |
| // ========================================================================== |
| |
| rustc_attr!(TEST, rustc_effective_visibility, Normal, template!(Word), WarnFollowing), |
| rustc_attr!( |
| TEST, rustc_outlives, Normal, template!(Word), |
| WarnFollowing, @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_capture_analysis, Normal, template!(Word), |
| WarnFollowing, @only_local: true |
| ), |
| rustc_attr!(TEST, rustc_insignificant_dtor, Normal, template!(Word), WarnFollowing), |
| rustc_attr!(TEST, rustc_strict_coherence, Normal, template!(Word), WarnFollowing), |
| rustc_attr!(TEST, rustc_variance, Normal, template!(Word), WarnFollowing, @only_local: true), |
| rustc_attr!( |
| TEST, rustc_variance_of_opaques, Normal, template!(Word), |
| WarnFollowing, @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_hidden_type_of_opaques, Normal, template!(Word), |
| WarnFollowing, @only_local: true), |
| rustc_attr!(TEST, rustc_layout, Normal, template!(List: "field1, field2, ..."), WarnFollowing), |
| rustc_attr!( |
| TEST, rustc_abi, Normal, template!(List: "field1, field2, ..."), |
| WarnFollowing, @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_regions, Normal, template!(Word), |
| WarnFollowing, @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_error, Normal, |
| template!(Word, List: "delayed_bug_from_inside_query"), WarnFollowingWordOnly |
| ), |
| rustc_attr!( |
| TEST, rustc_dump_user_args, Normal, template!(Word), WarnFollowing, |
| @only_local: true |
| ), |
| rustc_attr!(TEST, rustc_evaluate_where_clauses, Normal, template!(Word), WarnFollowing), |
| rustc_attr!( |
| TEST, rustc_if_this_changed, Normal, template!(Word, List: "DepNode"), |
| DuplicatesOk, @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_then_this_would_need, Normal, template!(List: "DepNode"), |
| DuplicatesOk, @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_clean, Normal, |
| template!(List: r#"cfg = "...", /*opt*/ label = "...", /*opt*/ except = "...""#), |
| DuplicatesOk, @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_partition_reused, Normal, |
| template!(List: r#"cfg = "...", module = "...""#), DuplicatesOk, @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_partition_codegened, Normal, |
| template!(List: r#"cfg = "...", module = "...""#), DuplicatesOk, @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_expected_cgu_reuse, Normal, |
| template!(List: r#"cfg = "...", module = "...", kind = "...""#), DuplicatesOk, |
| @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_symbol_name, Normal, template!(Word), WarnFollowing, |
| @only_local: true |
| ), |
| rustc_attr!(TEST, rustc_polymorphize_error, Normal, template!(Word), WarnFollowing), |
| rustc_attr!( |
| TEST, rustc_def_path, Normal, template!(Word), WarnFollowing, |
| @only_local: true |
| ), |
| rustc_attr!(TEST, rustc_mir, Normal, template!(List: "arg1, arg2, ..."), DuplicatesOk), |
| gated!( |
| custom_mir, Normal, template!(List: r#"dialect = "...", phase = "...""#), |
| ErrorFollowing, @only_local: true, |
| "the `#[custom_mir]` attribute is just used for the Rust test suite", |
| ), |
| rustc_attr!( |
| TEST, rustc_dump_program_clauses, Normal, template!(Word), WarnFollowing, |
| @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_dump_env_program_clauses, Normal, template!(Word), WarnFollowing, |
| @only_local: true |
| ), |
| rustc_attr!( |
| TEST, rustc_object_lifetime_default, Normal, template!(Word), WarnFollowing, |
| @only_local: true |
| ), |
| rustc_attr!(TEST, rustc_dump_vtable, Normal, template!(Word), WarnFollowing), |
| rustc_attr!( |
| TEST, rustc_dummy, Normal, template!(Word /* doesn't matter*/), DuplicatesOk, |
| @only_local: true |
| ), |
| gated!( |
| omit_gdb_pretty_printer_section, Normal, template!(Word), WarnFollowing, |
| @only_local: true, |
| "the `#[omit_gdb_pretty_printer_section]` attribute is just used for the Rust test suite", |
| ), |
| rustc_attr!( |
| TEST, pattern_complexity, CrateLevel, template!(NameValueStr: "N"), |
| ErrorFollowing, @only_local: true, |
| ), |
| ]; |
| |
| pub fn deprecated_attributes() -> Vec<&'static BuiltinAttribute> { |
| BUILTIN_ATTRIBUTES.iter().filter(|attr| attr.gate.is_deprecated()).collect() |
| } |
| |
| pub fn is_builtin_attr_name(name: Symbol) -> bool { |
| BUILTIN_ATTRIBUTE_MAP.get(&name).is_some() |
| } |
| |
| /// Whether this builtin attribute is only used in the local crate. |
| /// If so, it is not encoded in the crate metadata. |
| pub fn is_builtin_only_local(name: Symbol) -> bool { |
| BUILTIN_ATTRIBUTE_MAP.get(&name).is_some_and(|attr| attr.only_local) |
| } |
| |
| pub fn is_valid_for_get_attr(name: Symbol) -> bool { |
| BUILTIN_ATTRIBUTE_MAP.get(&name).is_some_and(|attr| match attr.duplicates { |
| WarnFollowing | ErrorFollowing | ErrorPreceding | FutureWarnFollowing |
| | FutureWarnPreceding => true, |
| DuplicatesOk | WarnFollowingWordOnly => false, |
| }) |
| } |
| |
| pub static BUILTIN_ATTRIBUTE_MAP: LazyLock<FxHashMap<Symbol, &BuiltinAttribute>> = |
| LazyLock::new(|| { |
| let mut map = FxHashMap::default(); |
| for attr in BUILTIN_ATTRIBUTES.iter() { |
| if map.insert(attr.name, attr).is_some() { |
| panic!("duplicate builtin attribute `{}`", attr.name); |
| } |
| } |
| map |
| }); |
