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Diffstat (limited to 'compiler/rustc_feature/src/builtin_attrs.rs')
| -rw-r--r-- | compiler/rustc_feature/src/builtin_attrs.rs | 833 |
1 files changed, 833 insertions, 0 deletions
diff --git a/compiler/rustc_feature/src/builtin_attrs.rs b/compiler/rustc_feature/src/builtin_attrs.rs new file mode 100644 index 000000000..0e73d8fd7 --- /dev/null +++ b/compiler/rustc_feature/src/builtin_attrs.rs @@ -0,0 +1,833 @@ +//! 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::target_abi, sym::cfg_target_abi, cfg_fn!(cfg_target_abi)), + (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)), +]; + +/// 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 conveniece 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), + ungated!( + should_panic, Normal, + template!(Word, List: r#"expected = "reason"#, NameValueStr: "reason"), FutureWarnFollowing, + ), + // FIXME(Centril): This can be used on stable but shouldn't. + ungated!(reexport_test_harness_main, CrateLevel, template!(NameValueStr: "name"), ErrorFollowing), + + // Macros: + ungated!(automatically_derived, Normal, template!(Word), WarnFollowing), + ungated!(macro_use, Normal, template!(Word, List: "name1, name2, ..."), WarnFollowingWordOnly), + ungated!(macro_escape, Normal, template!(Word), WarnFollowing), // Deprecated synonym for `macro_use`. + ungated!(macro_export, Normal, template!(Word, List: "local_inner_macros"), WarnFollowing), + ungated!(proc_macro, Normal, template!(Word), ErrorFollowing), + ungated!( + proc_macro_derive, Normal, + template!(List: "TraitName, /*opt*/ attributes(name1, name2, ...)"), ErrorFollowing, + ), + ungated!(proc_macro_attribute, Normal, template!(Word), ErrorFollowing), + + // Lints: + ungated!( + warn, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), DuplicatesOk + ), + ungated!( + allow, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), DuplicatesOk + ), + gated!( + expect, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), DuplicatesOk, + lint_reasons, experimental!(expect) + ), + ungated!( + forbid, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), DuplicatesOk + ), + ungated!( + deny, Normal, template!(List: r#"lint1, lint2, ..., /*opt*/ reason = "...""#), DuplicatesOk + ), + 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), + ungated!(crate_type, CrateLevel, template!(NameValueStr: "bin|lib|..."), DuplicatesOk), + // crate_id is deprecated + ungated!(crate_id, CrateLevel, template!(NameValueStr: "ignored"), FutureWarnFollowing), + + // ABI, linking, symbols, and FFI + ungated!( + link, Normal, + template!(List: r#"name = "...", /*opt*/ kind = "dylib|static|...", /*opt*/ wasm_import_module = "...""#), + DuplicatesOk, + ), + ungated!(link_name, Normal, template!(NameValueStr: "name"), FutureWarnPreceding), + ungated!(no_link, Normal, template!(Word), WarnFollowing), + ungated!(repr, Normal, template!(List: "C"), DuplicatesOk), + ungated!(export_name, Normal, template!(NameValueStr: "name"), FutureWarnPreceding), + ungated!(link_section, Normal, template!(NameValueStr: "name"), FutureWarnPreceding), + ungated!(no_mangle, Normal, template!(Word), WarnFollowing, @only_local: true), + ungated!(used, Normal, template!(Word, List: "compiler|linker"), WarnFollowing, @only_local: true), + + // Limits: + ungated!(recursion_limit, CrateLevel, template!(NameValueStr: "N"), FutureWarnFollowing), + ungated!(type_length_limit, CrateLevel, template!(NameValueStr: "N"), FutureWarnFollowing), + gated!( + const_eval_limit, CrateLevel, template!(NameValueStr: "N"), ErrorFollowing, + const_eval_limit, experimental!(const_eval_limit) + ), + gated!( + move_size_limit, CrateLevel, template!(NameValueStr: "N"), ErrorFollowing, + large_assignments, experimental!(move_size_limit) + ), + + // Entry point: + ungated!(start, Normal, template!(Word), WarnFollowing), + ungated!(no_start, CrateLevel, template!(Word), WarnFollowing), + ungated!(no_main, CrateLevel, template!(Word), WarnFollowing), + + // Modules, prelude, and resolution: + ungated!(path, Normal, template!(NameValueStr: "file"), FutureWarnFollowing), + ungated!(no_std, CrateLevel, template!(Word), WarnFollowing), + ungated!(no_implicit_prelude, Normal, template!(Word), WarnFollowing), + ungated!(non_exhaustive, Normal, template!(Word), WarnFollowing), + + // Runtime + ungated!( + windows_subsystem, CrateLevel, + template!(NameValueStr: "windows|console"), FutureWarnFollowing + ), + 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), + ungated!(track_caller, Normal, template!(Word), WarnFollowing), + gated!( + no_sanitize, Normal, + template!(List: "address, memory, thread"), DuplicatesOk, + experimental!(no_sanitize) + ), + gated!(no_coverage, Normal, template!(Word), WarnFollowing, experimental!(no_coverage)), + + ungated!( + doc, Normal, template!(List: "hidden|inline|...", NameValueStr: "string"), DuplicatesOk + ), + + // ========================================================================== + // Unstable attributes: + // ========================================================================== + + // RFC #3191: #[debugger_visualizer] support + gated!( + debugger_visualizer, Normal, template!(List: r#"natvis_file = "...", gdb_script_file = "...""#), + DuplicatesOk, experimental!(debugger_visualizer) + ), + + // Linking: + gated!(naked, Normal, template!(Word), WarnFollowing, @only_local: true, naked_functions, experimental!(naked)), + gated!( + link_ordinal, Normal, template!(List: "ordinal"), ErrorPreceding, raw_dylib, + experimental!(link_ordinal) + ), + + // Plugins: + BuiltinAttribute { + name: sym::plugin, + only_local: false, + type_: CrateLevel, + template: template!(List: "name"), + duplicates: DuplicatesOk, + gate: 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!( + 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, marker_trait_attr, experimental!(marker) + ), + gated!( + thread_local, Normal, template!(Word), WarnFollowing, + "`#[thread_local]` is an experimental feature, and does not currently handle destructors", + ), + gated!(no_core, CrateLevel, template!(Word), WarnFollowing, experimental!(no_core)), + // RFC 2412 + gated!( + optimize, Normal, template!(List: "size|speed"), ErrorPreceding, optimize_attribute, + experimental!(optimize), + ), + // RFC 2867 + gated!( + instruction_set, Normal, template!(List: "set"), ErrorPreceding, + isa_attribute, experimental!(instruction_set) + ), + + gated!( + ffi_returns_twice, Normal, template!(Word), WarnFollowing, experimental!(ffi_returns_twice) + ), + gated!(ffi_pure, Normal, template!(Word), WarnFollowing, experimental!(ffi_pure)), + gated!(ffi_const, Normal, template!(Word), WarnFollowing, experimental!(ffi_const)), + gated!( + register_attr, CrateLevel, template!(List: "attr1, attr2, ..."), DuplicatesOk, + experimental!(register_attr), + ), + gated!( + register_tool, CrateLevel, template!(List: "tool1, tool2, ..."), DuplicatesOk, + experimental!(register_tool), + ), + + gated!( + cmse_nonsecure_entry, Normal, template!(Word), WarnFollowing, + experimental!(cmse_nonsecure_entry) + ), + // RFC 2632 + gated!( + const_trait, Normal, template!(Word), WarnFollowing, const_trait_impl, + "`const` 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), + ), + + // ========================================================================== + // Internal attributes: Stability, deprecation, and unsafe: + // ========================================================================== + + ungated!(feature, CrateLevel, template!(List: "name1, name2, ..."), DuplicatesOk), + // DuplicatesOk since it has its own validation + ungated!( + stable, Normal, template!(List: r#"feature = "name", since = "version""#), DuplicatesOk, + ), + 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), + 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, + "rustc_allow_const_fn_unstable side-steps feature gating and stability checks" + ), + gated!( + allow_internal_unsafe, Normal, template!(Word), WarnFollowing, + "allow_internal_unsafe side-steps the unsafe_code lint", + ), + rustc_attr!(rustc_allowed_through_unstable_modules, Normal, template!(Word), WarnFollowing, + "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, dropck_eyepatch, + "`may_dangle` has unstable semantics and may be removed in the future", + ), + + // ========================================================================== + // Internal attributes: Runtime related: + // ========================================================================== + + rustc_attr!(rustc_allocator, Normal, template!(Word), WarnFollowing, IMPL_DETAIL), + rustc_attr!(rustc_allocator_nounwind, Normal, template!(Word), WarnFollowing, IMPL_DETAIL), + rustc_attr!(rustc_reallocator, Normal, template!(Word), WarnFollowing, IMPL_DETAIL), + rustc_attr!(rustc_deallocator, Normal, template!(Word), WarnFollowing, IMPL_DETAIL), + rustc_attr!(rustc_allocator_zeroed, Normal, template!(Word), WarnFollowing, IMPL_DETAIL), + gated!( + alloc_error_handler, Normal, template!(Word), WarnFollowing, + experimental!(alloc_error_handler) + ), + gated!( + default_lib_allocator, Normal, template!(Word), WarnFollowing, allocator_internals, + experimental!(default_lib_allocator), + ), + gated!( + needs_allocator, Normal, template!(Word), WarnFollowing, allocator_internals, + experimental!(needs_allocator), + ), + gated!(panic_runtime, Normal, template!(Word), WarnFollowing, experimental!(panic_runtime)), + gated!( + needs_panic_runtime, Normal, template!(Word), WarnFollowing, + experimental!(needs_panic_runtime) + ), + gated!( + compiler_builtins, Normal, template!(Word), WarnFollowing, + "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, + "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, 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 + ), + // 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::untranslatable_diagnostic` and `rustc::diagnostic_outside_of_impl` lints + // to assist in changes to diagnostic APIs. + 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, 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 + ), + + // ========================================================================== + // 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_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_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_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, + "#[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, + "`#[prelude_import]` is for use by rustc only", + ), + gated!( + rustc_paren_sugar, Normal, template!(Word), WarnFollowing, 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!(Word), WarnFollowing, + "the `#[rustc_test_marker]` attribute is used internally to track tests", + ), + rustc_attr!( + rustc_unsafe_specialization_marker, Normal, template!(Word), WarnFollowing, + "the `#[rustc_unsafe_specialization_marker]` attribute is used to check specializations" + ), + rustc_attr!( + rustc_specialization_trait, Normal, template!(Word), WarnFollowing, + "the `#[rustc_specialization_trait]` attribute is used to check specializations" + ), + rustc_attr!( + rustc_main, Normal, template!(Word), WarnFollowing, + "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, + "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, + "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" + ), + + // ========================================================================== + // Internal attributes, Testing: + // ========================================================================== + + rustc_attr!(TEST, rustc_outlives, Normal, template!(Word), WarnFollowing), + rustc_attr!(TEST, rustc_capture_analysis, Normal, template!(Word), WarnFollowing), + 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), + rustc_attr!(TEST, rustc_layout, Normal, template!(List: "field1, field2, ..."), WarnFollowing), + rustc_attr!(TEST, rustc_regions, Normal, template!(Word), WarnFollowing), + rustc_attr!( + TEST, rustc_error, Normal, + template!(Word, List: "delay_span_bug_from_inside_query"), WarnFollowingWordOnly + ), + rustc_attr!(TEST, rustc_dump_user_substs, Normal, template!(Word), WarnFollowing), + rustc_attr!(TEST, rustc_evaluate_where_clauses, Normal, template!(Word), WarnFollowing), + rustc_attr!( + TEST, rustc_if_this_changed, Normal, template!(Word, List: "DepNode"), DuplicatesOk + ), + rustc_attr!( + TEST, rustc_then_this_would_need, Normal, template!(List: "DepNode"), DuplicatesOk + ), + rustc_attr!( + TEST, rustc_clean, Normal, + template!(List: r#"cfg = "...", /*opt*/ label = "...", /*opt*/ except = "...""#), + DuplicatesOk, + ), + rustc_attr!( + TEST, rustc_partition_reused, Normal, + template!(List: r#"cfg = "...", module = "...""#), DuplicatesOk, + ), + rustc_attr!( + TEST, rustc_partition_codegened, Normal, + template!(List: r#"cfg = "...", module = "...""#), DuplicatesOk, + ), + rustc_attr!( + TEST, rustc_expected_cgu_reuse, Normal, + template!(List: r#"cfg = "...", module = "...", kind = "...""#), DuplicatesOk, + ), + rustc_attr!(TEST, rustc_symbol_name, Normal, template!(Word), WarnFollowing), + rustc_attr!(TEST, rustc_polymorphize_error, Normal, template!(Word), WarnFollowing), + rustc_attr!(TEST, rustc_def_path, Normal, template!(Word), WarnFollowing), + rustc_attr!(TEST, rustc_mir, Normal, template!(List: "arg1, arg2, ..."), DuplicatesOk), + rustc_attr!(TEST, rustc_dump_program_clauses, Normal, template!(Word), WarnFollowing), + rustc_attr!(TEST, rustc_dump_env_program_clauses, Normal, template!(Word), WarnFollowing), + rustc_attr!(TEST, rustc_object_lifetime_default, Normal, template!(Word), WarnFollowing), + rustc_attr!(TEST, rustc_dump_vtable, Normal, template!(Word), WarnFollowing), + rustc_attr!(TEST, rustc_dummy, Normal, template!(Word /* doesn't matter*/), DuplicatesOk), + gated!( + omit_gdb_pretty_printer_section, Normal, template!(Word), WarnFollowing, + "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(|attr| attr.gate.is_deprecated()).collect() +} + +pub fn is_builtin_attr_name(name: Symbol) -> bool { + BUILTIN_ATTRIBUTE_MAP.get(&name).is_some() +} + +pub fn is_builtin_only_local(name: Symbol) -> bool { + BUILTIN_ATTRIBUTE_MAP.get(&name).map_or(false, |attr| attr.only_local) +} + +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 + }); |